Publication from the IPBT COVID-19 activity

"Generation of enzymatically competent SARS‐CoV‐2 decoy receptor ACE2‐Fc in glycoengineered Nicotiana benthamiana"

Human angiotensin‐converting enzyme 2 (ACE2) is the primary host cell receptor for Severe Acute Respiratory Syndrome Coronavirus‐2 (SARS‐CoV‐2) binding and cell entry. Administration of high concentrations of soluble ACE2 can be utilized as a decoy to block the interaction of the virus with cellular ACE2 receptors and potentially be used as a strategy for treatment or prevention of coronavirus disease 2019 (COVID‐19). Human ACE2 is heavily glycosylated and its glycans impact on binding to the SARS‐CoV‐2 spike protein and virus infectivity. Here, we describe the production of a recombinant soluble ACE2‐Fc variant in glycoengineered Nicotiana benthamiana. Our data reveal that the produced dimeric ACE2‐Fc variant is glycosylated with mainly complex human‐type N‐glycans and functional with regard to enzyme activity, affinity to the SARS‐CoV‐2 receptor‐binding domain (RBD) and wild‐type virus neutralization.

» https://doi.org/10.1002/biot.202000566

» Institute of Plant Biotechnology and Cell Biology (IPBT)

Review on cell wall signaling from Georg Seifert

"The FLA4-FEI Pathway: A Unique and Mysterious Signaling Module Related to Cell Wall Structure and Stress Signaling"

Cell wall integrity control in plants involves multiple signaling modules that are mostly defined by genetic interactions. The putative co-receptors FEI1 and FEI2 and the extracellular glycoprotein FLA4 present the core components of a signaling pathway that acts in response to environmental conditions and insults to cell wall structure to modulate the balance of various growth regulators and, ultimately, to regulate the performance of the primary cell wall. Although the previously established genetic interactions are presently not matched by intermolecular binding studies, numerous receptor-like molecules that were identified in genome-wide interaction studies potentially contribute to the signaling machinery around the FLA4-FEI core. Apart from its function throughout the model plant Arabidopsis thaliana for the homeostasis of growth and stress responses, the FLA4-FEI pathway might support important agronomic traits in crop plants.

» https://doi.org/10.3390/genes12020145

» Seifert Lab

Publication from Mach Lab

"Naphthylphthalamic acid associates with and inhibits PIN auxin transporters"

The plant hormone auxin regulates many aspects of plant life and has the unique ability to flow throughout the plant in defined directions, as observed by Darwin over a century ago. The chemical NPA inhibits this directional flow, thereby severely affecting plant growth. In studying the specific effects of NPA, researchers have also uncovered general principles underlying plant development. Exactly how NPA inhibits directional auxin flow is unclear. NPA interacts with proteins that can transport auxin, such as ABCB transporters, and we show here that NPA also associates with and inhibits the major transporters that specialize in directional auxin flow—PINs. This explanation of NPA action will guide future research and may help reveal how PINs perform auxin transport.

» https://doi.org/10.1073/pnas.2020857118

» Mach Lab

Doris Lucyshyn auf Ö1 über die Folgen der UG-Novelle

Doris Lucyshyn und Christoph Reinprecht vom Institut für Soziologie (Universität Wien) haben in der Punkt eins Folge vom 20.01.2021 über die Folgen dier UG-Novelle für Studierende, Forschende und die Hochschulen selbst diskutiert.

Studierende müssen künftig jedes Jahr eine Mindestleistung erbringen, ansonsten erlischt ihre Zulassung; die Senate der Universitäten verlieren Mitbestimmungsrechte; die maximale Dauer befristeter Arbeitsverhältnisse wird auf acht Jahre gesetzt. Diese Neuerungen und einige andere Vorhaben, die sich in der Novelle des Universitätsgesetzes finden, sorgen bei vielen für Unmut und Kritik, bei anderen für Zustimmung.

» https://oe1.orf.at/player/20210120/625113/1611144002200

» Lucyshyn Lab

Schimmelpilz auf dem Weg zum Lebensretter

Immer mehr Bakterien werden gegen die bekannten Antibiotika resistent und damit nicht mehr behandelbar. Das BIMM-Team in Tulln forscht mit Robotertechnik an Schimmelpilzen, die das ändern sollen. Sie könnten die Antibiotika der Zukunft werden – unter anderem.

» https://noe.orf.at/stories/3084889/

» ORF TVthek


BiMM cooperation paper with Italian Fusarium group on the mycotoxin repressing function of thymol

"Naturally Occurring Phenols Modulate Vegetative Growth and Deoxynivalenol Biosynthesis in Fusarium graminearum"

This paper reports a couple of natural substances from plants that repress the production of the main Fusarium mycotoxin DON but does not inhibit growth of the fungus. Application perspectives are open and we also will try to understand the underlying mechanisms.

To assess the in vitro activity of five naturally occurring phenolic compounds (ferulic acid, apocynin, magnolol, honokiol, and thymol) on mycelial growth and type B trichothecene mycotoxin accumulation by Fusarium graminearum, three complementary approaches were adopted. First, a high-throughput photometric continuous reading array allowed a parallel quantification of F. graminearum hyphal growth and reporter TRI5 gene expression directly on solid medium. Second, RT-qPCR confirmed the regulation of TRI5 expression by the tested compounds. Third, liquid chromatography–tandem mass spectrometry analysis allowed quantification of deoxynivalenol (DON) and its acetylated forms released upon treatment with the phenolic compounds. Altogether, the results confirmed the activity of thymol and an equimolar mixture of thymol–magnolol at 0.5 mM, respectively, in inhibiting DON production without affecting vegetative growth. The medium pH buffering capacity after 72–96 h of incubation is proposed as a further element to highlight compounds displaying trichothecene inhibitory capacity with no significant fungicidal effect.

» https://doi.org/10.1021/acsomega.0c04260

» https://www.bimm-research.at/

Revealing a complex interplay between alternative splicing, RNAi, mRNA isoform compartmentalization and nonsense-mediated mRNA decay - Paper by Maria Kalyna

"Targeting alternative splicing by RNAi: from the differential impact on splice variants to triggering artificial pre-mRNA splicing"

Alternative splicing generates multiple transcript and protein isoforms from a single gene and controls transcript intracellular localization and stability by coupling to mRNA export and nonsense-mediated mRNA decay (NMD). RNA interference (RNAi) is a potent mechanism to modulate gene expression. However, its interactions with alternative splicing are poorly understood. We used artificial microRNAs (amiRNAs, also termed shRNAmiR) to knockdown all splice variants of selected target genes in Arabidopsis thaliana. We found that splice variants, which vary by their protein-coding capacity, subcellular localization and sensitivity to NMD, are affected differentially by an amiRNA, although all of them contain the target site. Particular transcript isoforms escape amiRNA-mediated degradation due to their nuclear localization. The nuclear and NMD-sensitive isoforms mask RNAi action in alternatively spliced genes. Interestingly, Arabidopsis SPL genes, which undergo alternative splicing and are targets of miR156, are regulated in the same manner. Moreover, similar results were obtained in mammalian cells using siRNAs, indicating cross-kingdom conservation of these interactions among RNAi and splicing isoforms. Furthermore, we report that amiRNA can trigger artificial alternative splicing, thus expanding the RNAi functional repertoire. Our findings unveil novel interactions between different post-transcriptional processes in defining transcript fates and regulating gene expression.

» https://doi.org/10.1093/nar/gkaa1260

» Kalyna Lab

Hertha Firnberg fellowship for Lena Studt (Strauss Lab)

EpiVit: Role, function and crosstalk of Kmt6 in Fusarium spp.

Phytopathogenic fusaria produce a plethora of natural compounds, referred to as secondary metabolites (SMs), including harmful mycotoxins that frequently contaminate food and feed. A crucial step to combat mycotoxin contaminations is to understand the regulatory network that orchestrates their biosynthesis. Here, morphological changes in chromatin structure in general and Kmt6-mediated histone 3 lysine 27 methylation in particular play a key role in fungal SM gene regulation. Within a recently FWF-funded Hertha-Firnberg-Stipend to Lena Studt, we will explore Kmt6-mediated gene silencing and study in depth SM gene expression at the level of chromatin in the genus Fusarium, to unravel regulatory circuits that orchestrate SM biosynthesis. Results from this study will thus provide foundational knowledge to advance the understanding of epigenetic mechanisms ruling fungal life traits, but also for novel drug-discovery strategies.

» FWF Hertha Firnberg Project

» Strauss Lab

Publication on the role of nucleosome positioning in regulation of alternative splicing in response to cold in Arabidopsis with contribution from Maria Kalyna

"Differential nucleosome occupancy modulates alternative splicing in Arabidopsis thaliana"


  • Alternative splicing (AS) is a major gene regulatory mechanism in plants. Recent evidence supports co‐transcriptional splicing in plants, hence the chromatin state can impact AS. However, how dynamic changes in the chromatin state such as nucleosome occupancy influence the cold‐induced AS remains poorly understood.
  • Here, we generated transcriptome (RNA‐Seq) and nucleosome positioning (MNase‐Seq) data for Arabidopsis thaliana to understand how nucleosome positioning modulates cold‐induced AS.
  • Our results show that characteristic nucleosome occupancy levels are strongly associated with the type and abundance of various AS events under normal and cold temperature conditions in Arabidopsis. Intriguingly, exitrons, alternatively spliced internal regions of protein‐coding exons, exhibit distinctive nucleosome positioning pattern compared to other alternatively spliced regions. Likewise, nucleosome patterns differ between exitrons and retained introns pointing to their distinct regulation.
  • Collectively, our data show that characteristic changes in nucleosome positioning modulate AS in plants in response to cold.

»  https://doi.org/10.1111/nph.17062

» Kalyna Lab

Novel genetic link between histone variant H2A.Z and chromatin remodelling found in Fusarium wheat pathogen

The collaborative paper with the Pont group from INRA-Bordeaux published in the October issue of PLOS-Genetics describes the H2A.Z histone variant in Fusarium graminearum, one of the most relevant fungal wheat pathogens worldwide (https://journals.plos.org/plosgenetics/article/authors?id=10.1371/journal.pgen.1009125). 

H2A.Z is essential there, but it was possible to select strains that survive despite having a H2A.Z deletion. 
WGS of several revertants revealed a number of possible compensatory mutations, all of them affected in components of the chromatin remodelling machinery. Hence, a new molecular link between H2A.Z and chromatin remodeller function is popping up. 

» Strauss Lab

Publication with Contribution from Gergely Molnár (Strauss Lab)

"Receptor kinase module targets PIN-dependent auxin transport during canalization"

Spontaneously arising channels that transport the phytohormone auxin provide positional cues for selforganizing aspects of plant development such as flexible vasculature regeneration or its patterning during leaf venation. The auxin canalization hypothesis proposes a feedback between auxin signaling and transport as the underlying mechanism, but molecular players await discovery. We identified part of the machinery that routes auxin transport. The auxin-regulated receptor CAMEL (Canalization-related Auxin-regulated Malectin-type RLK) together with CANAR (Canalization-related Receptor-like kinase) interact with and phosphorylate PIN auxin transporters. camel and canar mutants are impaired in PIN1 subcellular trafficking and auxin-mediated PIN polarization, which macroscopically manifests as defects in leaf venation and vasculature regeneration after wounding. The CAMEL-CANAR receptor complex is part of the auxin feedback that coordinates polarization of individual cells during auxin canalization.

» https://science.sciencemag.org/content/370/6516/550.full 

» Strauss Lab

Publication from Hauser Lab

"Beyond the visible and below the peel: how UV-B radiation influences the phenolic profile in the pulp of peach fruit. A biochemical and molecular study"

In the last decades, UV-B radiation has attracted attention due to its potential to increase nutraceutical values of fruit and vegetables, especially by inducing the accumulation of phenolics in a structure-dependent way. However, most current studies have investigated the UV-B-driven changes only in the peel or focusing on individual phenolic classes. Adopting an “-omics” approach, this work aimed to deepen the knowledge about the effects of UV-B radiation on the phenolic profile in the pulp of peach fruit. Based on these considerations, melting flesh yellow peaches (Prunus persica L., cv. Fairtime) were subjected to either a 10- or 60-min UV-B treatment (1.39 and 8.33 kJ m–2, respectively), and sampled at different time points from the exposure. A UHPLC-ESI/QTOF-MS analysis coupled with a phenolics-specific database for the annotation of compounds and a multivariate discriminant analysis revealed a marked effect of UV-B radiation on the phenolic profiles of peach pulp. Particularly, a general, transient increase was observed after 24 h from the irradiation, especially for flavanols, flavonols, and flavones. Such behavior diverges from what was observed in the peel, where an overall increase of phenolics was observed after 36 h from the irradiation. Concerning the flavonols in the pulp, UV-B exposure stimulated a specific accumulation of isorhamnetin and kaempferol derivatives, with variations imposed by the different sugar moiety bound. Anthocyanins, which were the second most abundant flavonoid group after flavonols, displayed a general decrease after 36 h that was not attributable to specific molecules. The UV-B treatments also increased the glycoside/aglycone ratio of flavonols and anthocyanins after 24 h, by increasing the glycoside concentration of both, flavonols and anthocyanins, and decreasing the aglycone concentration of anthocyanins. In support of the biochemical results, targeted gene expression analysis by RT-qPCR revealed an UV-B-induced activation of many genes involved in the flavonoid pathway, e.g., CHS, F3H, F3′H, DFR, as well as some MYB transcription factors and few genes involved in the UV-B perception. Generally, all the flavonoid-related and MYB genes showed a transient UV-B dose-dependent activation after 6 h from the irradiation, similarly to what was observed in the peel.

We kindly acknowledge the technical support of Julia Richter and Nataliia Konstantinova for help with the sampling. Marco Santin was further supported by an Erasmus+ traineeship.

» https://doi.org/10.3389/fpls.2020.579063

» Hauser Lab

The Internet of Fungi - communication and memory within a fungal network

Our contribution to this year´s "Lange Nacht der Forschung": the simplified 3D animation movie of the inner life of a fungal cell. It was created in the course of the "Sparkling Science" project "The Internet of Fungi - communication and memory within a fungal network". 
The tour is of course most enjoyable with a real VR equipment, however, also on your 2D screen, it is a nice cell biology travel experience.

» 3D-Reise ins Innere einer Pilzzelle (Virtual Reality) (YouTube)

» PiNet - The Internet of fungi

» Strauss Lab

FWF Project for Barbara Kobei

"Differential function of TOL homologs"

project number: P 33989
lead: Barbara KORBEI
decision board: 2020/09/28
keywords: Arabidopsis thaliana, Ubiquitin receptor, Endocytosis, ESCRT, Plasma Membrane Protein Degradation

»  FWF Project details

» Korbei Lab

Publication from Strauss Lab

"A novel fungal gene regulation system based on inducible VPR-dCas9 and nucleosome map-guided sgRNA positioning"

Programmable transcriptional regulation is a powerful tool to study gene functions. Current methods to selectively regulate target genes are mainly based on promoter exchange or on overexpressing transcriptional activators. To expand the discovery toolbox, we designed a dCas9-based RNA-guided synthetic transcription activation system for Aspergillus nidulans that uses enzymatically disabled “dead” Cas9 fused to three consecutive activation domains (VPR-dCas9). The dCas9-encoding gene is under the control of an estrogen-responsive promoter to allow induction timing and to avoid possible negative effects by strong constitutive expression of the highly active VPR domains. Especially in silent genomic regions, facultative heterochromatin and strictly positioned nucleosomes can constitute a relevant obstacle to the transcriptional machinery. To avoid this negative impact and to facilitate optimal positioning of RNA-guided VPR-dCas9 to targeted promoters, we have created a genome-wide nucleosome map from actively growing cells and stationary cultures to identify the cognate nucleosome-free regions (NFRs). Based on these maps, different single-guide RNAs (sgRNAs) were designed and tested for their targeting and activation potential. Our results demonstrate that the system can be used to regulate several genes in parallel and, depending on the VPR-dCas9 positioning, expression can be pushed to very high levels. We have used the system to turn on individual genes within two different biosynthetic gene clusters (BGCs) which are silent under normal growth conditions. This method also opens opportunities to stepwise activate individual genes in a cluster to decipher the correlated biosynthetic pathway.

» https://doi.org/10.1007/s00253-020-10900-9

» Strauss Lab

Publication from Hauser Lab

"A trimeric CrRLK1L-LLG1 complex genetically modulates SUMM2-mediated autoimmunity"

Cell death is intrinsically linked with immunity. Disruption of an immune-activated MAPK cascade, consisting of MEKK1, MKK1/2, and MPK4, triggers cell death and autoimmunity through the nucleotide-binding leucine-rich repeat (NLR) protein SUMM2 and the MAPK kinase kinase MEKK2. In this study, we identify a Catharanthus roseus receptor-like kinase 1-like (CrRLK1L), named LETUM2/MEDOS1 (LET2/MDS1), and the glycosylphosphatidylinositol (GPI)-anchored protein LLG1 as regulators of mekk1-mkk1/2-mpk4 cell death. LET2/MDS1 functions additively with LET1, another CrRLK1L, and acts genetically downstream of MEKK2 in regulating SUMM2 activation. LET2/MDS1 complexes with LET1 and promotes LET1 phosphorylation, revealing an intertwined regulation between different CrRLK1Ls. LLG1 interacts with the ectodomain of LET1/2 and mediates LET1/2 transport to the plasma membrane, corroborating its function as a co-receptor of LET1/2 in the mekk1-mkk1/2-mpk4 cell death pathway. Thus, our data suggest that a trimeric complex consisting of two CrRLK1Ls LET1, LET2/MDS1, and a GPI-anchored protein LLG1 that regulates the activation of NLR SUMM2 for initiating cell death and autoimmunity.

» https://doi.org/10.1038/s41467-020-18600-8

» Hauser Lab

Publication from Lucyshyn Lab

"Arabidopsis O-fucosyltransferase SPINDLY regulates root hair patterning independently of gibberellin signaling"

Root hairs are able to sense soil composition and play an important role for water and nutrient uptake. In Arabidopsis thaliana, root hairs are distributed in the epidermis in a specific pattern, regularly alternating with non-root hair cells in continuous cell files. This patterning is regulated by internal factors such as a number of hormones, as well as external factors like nutrient availability. Thus, root hair patterning is an excellent model for studying the plasticity of cell fate determination in response to environmental changes. Here, we report that loss-of-function mutants in the Protein O-fucosyltransferase, SPINDLY (SPY) show defects in root hair patterning. Using transcriptional reporters, we show that patterning in spy-22 is affected upstream of the GLABRA2 (GL2) and WEREWOLF (WER). O-fucosylation of nuclear and cytosolic proteins is an important post-translational modification that is still not very well understood. So far, SPY is best characterized for its role in gibberellin signaling via fucosylation of the growth-repressing DELLA protein REPRESSOR OF ga1-3 (RGA). Our data suggests that the epidermal patterning defects in spy-22 are independent of RGA and gibberellin signaling.

» http://dev.biologists.org/lookup/doi/10.1242/dev.192039

» Lucyshyn Lab

Publication with Contribution from Luschnig Lab

"Strigolactones inhibit auxin feedback on PIN-dependent auxin transport canalization"

Directional transport of the phytohormone auxin is a versatile, plant-specific mechanism regulating many aspects of plant development. The recently identified plant hormones, strigolactones (SLs), are implicated in many plant traits; among others, they modify the phenotypic output of PIN-FORMED (PIN) auxin transporters for fine-tuning of growth and developmental responses. Here, we show in pea and Arabidopsis that SLs target processes dependent on the canalization of auxin flow, which involves auxin feedback on PIN subcellular distribution. D14 receptor- and MAX2 F-box-mediated SL signaling inhibits the formation of auxin-conducting channels after wounding or from artificial auxin sources, during vasculature de novo formation and regeneration. At the cellular level, SLs interfere with auxin effects on PIN polar targeting, constitutive PIN trafficking as well as clathrin-mediated endocytosis. Our results identify a non-transcriptional mechanism of SL action, uncoupling auxin feedback on PIN polarity and trafficking, thereby regulating vascular tissue formation and regeneration.

» https://doi.org/10.1038/s41467-020-17252-y

» Luschnig Lab

Publication with Contribution from Barbara Korbei

"Establishment of Proximity-dependent Biotinylation Approaches in Different Plant Model Systems"

Proximity labeling is a powerful approach for detecting protein-protein interactions. Most proximity labeling techniques use a promiscuous biotin ligase (PBL) or a peroxidase fused to a protein of interest, enabling the covalent biotin labelling of proteins and subsequent capture and identification of interacting and neighbouring proteins without the need for the protein complex to remain intact. To date, only few papers report on the use of proximity labeling in plants. Here, we present the results of a systematic study applying a variety of biotin-based proximity labeling approaches in several plant systems using various conditions and bait proteins. We show that TurboID is the most promiscuous variant in several plant model systems and establish protocols which combine Mass Spectrometry-based analysis with harsh extraction and washing conditions. We demonstrate the applicability of TurboID in capturing membrane-associated protein interactomes using Lotus japonicus symbiotically active receptor kinases as test-case. We further benchmark the efficiency of various PBLs in comparison with one-step affinity purification approaches. We identified both known as well as novel interactors of the endocytic TPLATE complex. We furthermore present a straightforward strategy to identify both non-biotinylated as well as biotinylated peptides in a single experimental setup. Finally, we provide initial evidence that our approach has the potential to infer structural information of protein complexes.

» https://doi.org/10.1105/tpc.20.00235

» Korbei Lab

Publication from Seifert Lab

"On the Potential Function of Type II Arabinogalactan O-Glycosylation in Regulating the Fate of Plant Secretory Proteins"

In a plant-specific mode of protein glycosylation, various sugars and glycans are attached to hydroxyproline giving rise to a variety of diverse O-glycoproteins. The sub-family of arabinogalactan proteins is implicated in a multitude of biological functions, however, the mechanistic role of O-glycosylation on AGPs by type II arabinogalactans is largely elusive. Some models suggest roles of the O-glycans such as in ligand-receptor interactions and as localized calcium ion store. Structurally different but possibly analogous types of protein O-glycosylation exist in animal and yeast models and roles for O-glycans were suggested in determining the fate of O-glycoproteins by affecting intracellular sorting or proteolytic activation and degradation. At present, only few examples exist that describe how the fate of artificial and endogenous arabinogalactan proteins is affected by O-glycosylation with type II arabinogalactans. In addition to other roles, these glycans might act as a molecular determinant for cellular localization and protein lifetime of many endogenous proteins.

» https://doi.org/10.3389/fpls.2020.563735

» Seifert Lab

e-book from Kalyna Lab

"Alternative Splicing Regulation in Plants"

Topic Editors:
Ezequiel Petrillo, CONICET Institute of Physiology, Molecular Biology and Neurosciences (IFIBYNE), Argentina
Maria Kalyna, University of Natural Resources and Life Sciences Vienna, Austria
Craig G. Simpson, The James Hutton Institute, United Kingdom
Shih-Long Tu, Institute of Plant and Microbial Biology, Academia Sinica, Taiwan
Kranthi Kiran Mandadi, Texas A&M University, United States

» doi: 10.3389/978-2-88963-974-8

» Kalyna Lab

Publication from Korbei Lab

"The Beginning of the End: Initial Steps in the Degradation of Plasma Membrane Proteins"

The plasma membrane (PM), as border between the inside and the outside of a cell, is densely packed with proteins involved in the sensing and transmission of internal and external stimuli, as well as transport processes and is therefore vital for plant development as well as quick and accurate responses to the environment. It is consequently not surprising that several regulatory pathways participate in the tight regulation of the spatiotemporal control of PM proteins. Ubiquitination of PM proteins plays a key role in directing their entry into the endo-lysosomal system, serving as a signal for triggering endocytosis and further sorting for degradation. Nevertheless, a uniting picture of the different roles of the respective types of ubiquitination in the consecutive steps of down-regulation of membrane proteins is still missing. The trans-Golgi network (TGN), which acts as an early endosome (EE) in plants receives the endocytosed cargo, and here the decision is made to either recycled back to the PM or further delivered to the vacuole for degradation. A multi-complex machinery, the endosomal sorting complex required for transport (ESCRT), concentrates ubiquitinated proteins and ushers them into the intraluminal vesicles of multi-vesicular bodies (MVBs). Several ESCRTs have ubiquitin binding subunits, which anchor and guide the cargos through the endocytic degradation route. Basic enzymes and the mode of action in the early degradation steps of PM proteins are conserved in eukaryotes, yet many plant unique components exist, which are often essential in this pathway. Thus, deciphering the initial steps in the degradation of ubiquitinated PM proteins, which is the major focus of this review, will greatly contribute to the larger question of how plants mange to fine-tune their responses to their environment.

» https://doi.org/10.3389/fpls.2020.00680

» Korbei Lab

Publication from Hauser Lab

"The outer influences the inner: postharvest UV-B irradiation modulates peach flesh metabolome although shielded by the skin"

• Peach flesh metabolome is strongly influenced by UV-B exposure
• Phenolics, terpenoids and phytoalexins highly responded to UV-B
• Decreased levels of most metabolic classes were detected after 24 h
• Accumulation of most metabolic classes was observed after 36 h
• UV-B radiation does not penetrate peach skin.

UV-B-driven modulation of secondary metabolism in peach fruit by enhancing the biosynthesis of specific phenolic subclasses, is attracting interest among consumers. However, current literature explored the UV-B-induced metabolic changes only in peach skin subjected to direct UV-B irradiation. Accordingly, this study aimed to understand whether UV-B radiation penetrates the fruit skin and is able to induce metabolic changes also within the inner flesh. Peaches were UV-B-irradiated either 10 or 60 min, and the flesh was sampled after 24 and 36 h. Non-targeted metabolomics revealed that UV-B has a strong impact on peach flesh metabolome, determining an initial decrease after 24 h, followed by an overall increase after 36 h, particularly for terpenoids, phenylpropanoids, phytoalexins and fatty acids in the 60 min UV-B-treated samples (+150.02, +99.14, +43.79 and +25.44 log2FC, respectively). Transmittance analysis indicated that UV-B radiation does not penetrate below the skin, suggesting a possible signalling pathway between tissues.

» https://doi.org/10.1016/j.foodchem.2020.127782

» Hauser Lab

SFB paper with contribution of AG Adam

"Suppression of Trichothecene-Mediated Immune Response by the Fusarium Secondary Metabolite Butenolide in Human Colon Epithelial Cells"

Butenolide (BUT, 4-acetamido-4-hydroxy-2-butenoic acid gamma-lactone) is a secondary metabolite produced by several Fusarium species and is co-produced with the major trichothecene mycotoxin deoxynivalenol (DON) on cereal grains throughout the world. BUT has low acute toxicity and only very limited occurrence and exposure data are available. The intestinal epithelium represents the first physiological barrier against food contaminants. We aimed to elucidate the intestinal inflammatory response of the human, non-cancer epithelial HCEC-1CT cells to BUT and to characterize potential combinatory interactions with co-occurring trichothecenes, such as DON and NX-3. Using a reporter gene approach, BUT (≥5 μM, 20 h) was found to decrease lipopolysaccharide (LPS; 10 ng/mL) induced nuclear factor kappa B (NF-κB) activation in a dose-dependent manner, and in combinatory treatments BUT represses trichothecene-induced enhancement of this important inflammatory pathway. Analysis of transcription and secretion levels of NF-κB-dependent, pro-inflammatory cytokines, revealed a significant down-regulation of IL-1β, IL-6, and TNF-α in IL-1β-stimulated (25 ng/mL) HCEC-1CT cells after BUT exposure (10 μM). Trichothecene-induced expression of pro-inflammatory cytokines by the presence of 1 μM DON or NX-3 was substantially suppressed in the presence of 10 μM BUT. The emerging mycotoxin BUT has the ability to suppress NF-κB-induced intestinal inflammatory response mechanisms and to modulate substantially the immune responsiveness of HCEC-1CT cells after trichothecene treatment. Our results suggest that BUT, present in naturally occurring mixtures of Fusarium fungal metabolites, should be increasingly monitored, and the mechanism of inhibition of NF-κB that might affect the pathogenesis or progression of intestinal inflammatory disorders, should be further investigated.

» https://doi.org/10.3389/fnut.2020.00127

» Adam Lab

Publication from Maria Kalyna

Editorial on the Research Topic: Alternative Splicing Regulation in Plants

Research on alternative splicing (AS) in plants has bloomed during the past decade, largely fueled by the advance of high-throughput sequencing (HTS) technologies and pioneering papers demonstrating an unexpectedly high frequency of AS in plants (Filichkin et al., 2010; Lu et al., 2010; Marquez et al., 2012; Syed et al., 2012). The formation and regulation of alternative transcripts from individual transcribed genes by alternative splice site selection pervades all aspects of a eukaryote's development and adaptive response to its changing environment. This is particularly relevant to sessile plant species that must be able to rapidly respond to abiotic, biotic, diurnal, and seasonal fluctuations. The mechanism of pre-mRNA splicing and the process of splice site selection has existed since its divergence from metazoans (Fedorov et al., 2002) and is regulated by splicing factors that are components of the assembling spliceosome. Many knowledge gaps remain to be addressed, not only to define the AS prevalence in different plant species and its impact on various biological processes, but also to understand its mechanistic basis with the aim of manipulating crops for important traits required for food security. Here, we share with the plant biology community a Research Topic that aims to showcase current findings, emerging questions, and technical advances, in the field of AS in plants.

» https://doi.org/10.3389/fpls.2020.00913

» Kalyna Lab

Publication from Jürgen Kleine-Vehn

On the discovery of an endomembrane compartment in plants

To maintain homeostasis and to react to external stimuli, eukaryotic cells have evolved a complex internal membrane system. Among them, lytic compartments are hallmarks of eukaryotic cells: Animals possess lysosomes, whereas fungi and plants build up vacuoles. Although largely molecularly conserved, the plant endomembrane system displays unique features, among them the presence of large vacuoles. The central vacuole can occupy up to 90% of the cellular volume in mature vegetative tissues and is involved in numerous essential functions. These include degradation of cellular waste, storage of ions and proteins, plant growth, defense against pathogens, and intracellular pH homeostasis. Given the importance of vacuoles for plants, it is not surprising that trafficking to this compartment has been intensively studied. Despite significant progress toward the identification of different trafficking routes, the underlying molecular machinery is far from being understood and is, in part, controversially discussed in the field. In PNAS, Delgadillo et al. (1) elegantly identify and characterize a set of mutants impaired in vacuolar transport. Most identified mutant alleles were known trafficking factors, but subsequent localization analysis proposes the identification of a previously unknown plant compartment.

»  https://doi.org/10.1073/pnas.2006766117

» Kleine-Vehn Lab

Publication from Gergely Molnar (Strauss Lab)

The lipid code-dependent phosphoswitch PDK1–D6PK activates PIN-mediated auxin efflux in Arabidopsis

Directional intercellular transport of the phytohormone auxin mediated by PIN-FORMED (PIN) efflux carriers has essential roles in both coordinating patterning processes and integrating multiple external cues by rapidly redirecting auxin fluxes. PIN activity is therefore regulated by multiple internal and external cues, for which the underlying molecular mechanisms are not fully elucidated. Here, we demonstrate that 3′-PHOSPHOINOSITIDE-DEPENDENT PROTEIN KINASE1 (PDK1), which is conserved in plants and mammals, functions as a molecular hub that perceives upstream lipid signalling and modulates downstream substrate activity through phosphorylation. Using genetic analysis, we show that the loss-of-function Arabidopsis pdk1.1 pdk1.2 mutant exhibits a plethora of abnormalities in organogenesis and growth due to defective polar auxin transport. Further cellular and biochemical analyses reveal that PDK1 phosphorylates D6 protein kinase, a well-known upstream activator of PIN proteins. We uncover a lipid-dependent phosphorylation cascade that connects membrane-composition-based cellular signalling with plant growth and patterning by regulating morphogenetic auxin fluxes.

» https://doi.org/10.1038/s41477-020-0648-9

» Strauss Lab

Öffentliches Habilitationskolloquium

Mag. Dr. Barbara Korbei
BOKU-Institut für Molekulare Pflanzenbiologie
für das wissenschaftliche Fach Molekulare Zellbiologie 

mit dem Lehrvortrag: 
Mechanismus der Endozytose in Pflanzen

und dem Fachvortrag: 
Ubiquitin receptors in the early steps of plasma membrane protein degradation in plants

Donnerstag, 14. Mai 2020, 13:15 Uhr
Per Zoom-Meeting:
Die Vorsitzende der Habilitationskommission
Univ.-Prof. Mag. Dr. Eva Stöger
Department für Angewandte Genetik und Zellbiologie

» Korbei Lab

Publication from Sascha Waidmann (Kleine-Vehn Lab)

"Asymmetric cytokinin signaling opposes gravitropism in roots"

Plants depend on gravity to provide the constant landmark for downward root growth and upward shoot growth. The phytohormone auxin and its cell‐to‐cell transport machinery are central determinants ensuring gravitropic growth. Statolith sedimentation toward gravity is sensed in specialized cells. This positional cue is translated into the polar distribution of PIN auxin efflux carriers at the plasma membrane, leading to asymmetric auxin distribution and consequently, differential growth and organ bending. While we have started to understand the general principles of how primary organs execute gravitropism, we currently lack basic understanding of how lateral plant organs can defy gravitropic responses. Here we briefly review the establishment of the oblique gravitropic set point angle in lateral roots and particularly discuss the emerging role of asymmetric cytokinin signaling as a central anti‐gravitropic signal. Differential cytokinin signaling is co‐opted in gravitropic lateral and hydrotropic primary roots to counterbalance gravitropic root growth.

» https://doi.org/10.1111/jipb.12929

» Kleine-Vehn Lab

Publication from Lin Sun (Kleine-Vehn Lab)

"PIN-LIKES Coordinate Brassinosteroid Signaling with Nuclear Auxin Input in Arabidopsis thaliana"

• Impaired BR perception enhances PILS5 overexpression phenotypes
• BR signaling increases PILS protein turnover
• BR signaling defines PILS-dependent nuclear abundance and signaling of auxin
• PILS-dependent BR-auxin crosstalk affects organ growth

Auxin and brassinosteroids (BR) are crucial growth regulators and display overlapping functions during plant development. Here, we reveal an alternative phytohormone crosstalk mechanism, revealing that BR signaling controls PIN-LIKES (PILS)-dependent nuclear abundance of auxin. We performed a forward genetic screen for imperial pils (imp) mutants that enhance the overexpression phenotypes of PILS5 putative intracellular auxin transport facilitator. Here, we report that the imp1 mutant is defective in the BR-receptor BRASSINOSTEROID INSENSITIVE 1 (BRI1). Our set of data reveals that BR signaling transcriptionally and post-translationally represses the accumulation of PILS proteins at the endoplasmic reticulum, thereby increasing nuclear abundance and signaling of auxin. We demonstrate that this alternative phytohormonal crosstalk mechanism integrates BR signaling into auxin-dependent organ growth rates and likely has widespread importance for plant development.

» https://doi.org/10.1016/j.cub.2020.02.002

» Kleine-Vehn Lab

Publication from BiMM

"High Throughput Screening for New Fungal Polyester Hydrolyzing Enzymes"

here is a strong need for novel and more efficient polyester hydrolyzing enzymes in order to enable the development of more environmentally friendly plastics recycling processes allowing the closure of the carbon cycle. In this work, a high throughput system on microplate scale was used to screen a high number of fungi for their ability to produce polyester-hydrolyzing enzymes. For induction of responsible enzymes, the fungi were cultivated in presence of aliphatic and aromatic polyesters [poly(1,4-butylene adipate co terephthalate) (PBAT), poly(lactic acid) (PLA) and poly(1,4-butylene succinate) (PBS)], and the esterase activity in the culture supernatants was compared to the culture supernatants of fungi grown without polymers. The results indicate that the esterase activity of the culture supernatants was induced in about 10% of the tested fungi when grown with polyesters in the medium, as indicated by increased activity (to >50 mU/mL) toward the small model substrate para-nitrophenylbutyrate (pNPB). Incubation of these 50 active culture supernatants with different polyesters (PBAT, PLA, PBS) led to hydrolysis of at least one of the polymers according to liquid chromatography-based quantification of the hydrolysis products terephthalic acid, lactic acid and succinic acid, respectively. Interestingly, the specificities for the investigated polyesters varied among the supernatants of the different fungi.

» https://doi.org/10.3389/fmicb.2020.00554

» https://www.bimm-research.at/

Publication from AG Strasser

"Efficient N-Glycosylation of the Heavy Chain Tailpiece Promotes the Formation of Plant-Produced Dimeric IgA"

Production of monomeric IgA in mammalian cells and plant expression systems such as Nicotiana benthamiana is well-established and can be achieved by co-expression of the corresponding light and heavy chains. In contrast, the assembly of dimeric IgA requires the additional expression of the joining chain and remains challenging especially in plant-based systems. Here, we examined factors affecting the assembly and expression of HER2 binding dimeric IgA1 and IgA2m(2) variants transiently produced in N. benthamiana. While co-expression of the joining chain resulted in efficient formation of dimeric IgAs in HEK293F cells, a mixture of monomeric, dimeric and tetrameric variants was detected in plants. Mass-spectrometric analysis of site-specific glycosylation revealed that the N-glycan profile differed between monomeric and dimeric IgAs in the plant expression system. Co-expression of a single-subunit oligosaccharyltransferase from the protozoan Leishmania major in N. benthamiana increased the N-glycosylation occupancy at the C-terminal heavy chain tailpiece and changed the ratio of monomeric to dimeric IgAs. Our data demonstrate that N-glycosylation engineering is a suitable strategy to promote the formation of dimeric IgA variants in plants.

» https://doi.org/10.3389/fchem.2020.00346

» Strasser Lab

Joint Publication from AG Steinkellner & AG Mach

"Plant-based production of highly potent anti-HIV antibodies with engineered posttranslational modifications"

Broadly neutralising antibodies (bNAbs) against human immunodeficiency virus type 1 (HIV-1), such as CAP256-VRC26 are being developed for HIV prevention and treatment. These Abs carry a unique but crucial post-translational modification (PTM), namely O-sulfated tyrosine in the heavy chain complementarity determining region (CDR) H3 loop. Several studies have demonstrated that plants are suitable hosts for the generation of highly active anti-HIV-1 antibodies with the potential to engineer PTMs. Here we report the expression and characterisation of CAP256-VRC26 bNAbs with posttranslational modifications (PTM). Two variants, CAP256-VRC26 (08 and 09) were expressed in glycoengineered Nicotiana benthamiana plants. By in planta co-expression of tyrosyl protein sulfotransferase 1, we installed O-sulfated tyrosine in CDR H3 of both bNAbs. These exhibited similar structural folding to the mammalian cell produced bNAbs, but non-sulfated versions showed loss of neutralisation breadth and potency. In contrast, tyrosine sulfated versions displayed equivalent neutralising activity to mammalian produced antibodies retaining exceptional potency against some subtype C viruses. Together, the data demonstrate the enormous potential of plant-based systems for multiple posttranslational engineering and production of fully active bNAbs for application in passive immunisation or as an alternative for current HIV/AIDS antiretroviral therapy regimens.

» https://doi.org/10.1038/s41598-020-63052-1

» Steinkellner Lab

» Mach Lab

Joint Publication from AG Steinkellner & AG Mach

"Steric Accessibility of the Cleavage Sites Dictates the Proteolytic Vulnerability of the Anti‐HIV‐1 Antibodies 2F5, 2G12, and PG9 in Plants"

Broadly neutralizing antibodies (bNAbs) to human immunodeficiency virus type 1 (HIV‐1) hold great promise for immunoprophylaxis and the suppression of viremia in HIV‐positive individuals. Several studies have demonstrated that plants as Nicotiana benthamiana are suitable hosts for the generation of protective anti‐HIV‐1 antibodies. However, the production of the anti‐HIV‐1 bNAbs 2F5 and PG9 in N. benthamiana is associated with their processing by apoplastic proteases in the complementarity‐determining‐region (CDR) H3 loops of the heavy chains. Here, it is shown that apoplastic proteases can also cleave the CDR H3 loop of the bNAb 2G12 when the unusual domain exchange between its heavy chains is prevented by the replacement of Ile19 with Arg. It is demonstrated that CDR H3 proteolysis leads to a strong reduction of the antigen‐binding potencies of 2F5, PG9, and 2G12‐I19R. Inhibitor profiling experiments indicate that different subtilisin‐like serine proteases account for bNAb fragmentation in the apoplast. Differential scanning calorimetry experiments corroborate that the antigen‐binding domains of wild‐type 2G12 and 4E10 are more compact than those of proteolysis‐sensitive antibodies, thus shielding their CDR H3 regions from proteolytic attack. This suggests that the extent of proteolytic inactivation of bNAbs in plants is primarily dictated by the steric accessibility of their CDR H3 loops.

» https://doi.org/10.1002/biot.201900308

» Steinkellner Lab

» Mach Lab

SFB paper with contribution of AG Adam

"Pro-Inflammatory Effects of NX-3 Toxin Are Comparable to Deoxynivalenol and not Modulated by the Co-Occurring Pro-Oxidant Aurofusarin"

The type A trichothecene NX-3, produced by certain Fusarium graminearum strains, is similar to the mycotoxin deoxynivalenol (DON), with the exception that it lacks the carbonyl moiety at the C-8 position. NX-3 inhibits protein biosynthesis and induces cytotoxicity to a similar extent as DON, but so far, immunomodulatory effects have not been assessed. In the present study, we investigated the impact of NX-3 on the activity of the nuclear factor kappa B (NF-κB) signaling pathway in direct comparison to DON. Under pro-inflammatory conditions (IL-1β treatment), the impact on cytokine mRNA levels of NF-κB downstream genes was studied in human colon cell lines, comparing noncancer (HCEC-1CT) and cancer cells (HT-29). In addition, potential combinatory effects with the co-occurring Fusarium secondary metabolite aurofusarin (AURO), a dimeric naphthoquinone known to induce oxidative stress, were investigated. NX-3 and DON (1 μM, 20 h) significantly activated a NF-κB regulated reporter gene to a similar extent. Both trichothecenes also enhanced transcript levels of the known NF-κB-dependent pro-inflammatory cytokines IL-8, IL-6, TNF-α and IL-1β. Comparing the colon cancer HT-29 and noncancer HCEC-1CT cells, significant differences in cytokine signaling were identified. In contrast, AURO did not affect NF-κB pathway activity and respective cytokine expression levels at the tested concentration. Despite its pro-oxidant potency, the combination with AURO did not significantly affect the immunomodulatory effects of the tested trichothecenes. Taken together, the present study reveals comparable potency of DON and NX-3 with respect to immunomodulatory and pro-inflammatory potential. Consequently, not only DON but also NX-3 should be considered as factors contributing to intestinal inflammatory processes.

» https://doi.org/10.3390/microorganisms8040603

» Adam Lab

Publication with contribution from Kalyna Lab

"Current Challenges in Studying Alternative Splicing in Plants: The Case of Physcomitrella patens SR Proteins"

To colonize different terrestrial habitats, early land plants had to overcome the challenge of coping with harsh new environments. Alternative splicing – an RNA processing mechanism through which splice sites are differentially recognized, originating multiple transcripts and potentially different proteins from the same gene – can be key for plant stress tolerance. Serine/arginine-rich (SR) proteins constitute an evolutionarily conserved family of major alternative splicing regulators that in plants subdivides into six subfamilies. Despite being well studied in animals and a few plant species, such as the model angiosperm Arabidopsis thaliana and the crop Oryza sativa, little is known of these splicing factors in early land plants. Establishing the whole complement of SR proteins in different species is essential to understand the functional and evolutionary significance of alternative splicing. An in silico search for SR proteins in the extant moss Physcomitrella patens revealed inconsistencies both in the published data and available databases, likely arising from automatic annotation lacking adequate manual curation. These misannotations interfere with the description not only of the number and subfamily classification of Physcomitrella SR proteins but also of their domain architecture, potentially hindering the elucidation of their molecular functions. We therefore advise caution when looking into P. patens genomic resources. Our systematic survey nonetheless confidently identified 16 P. patens SR proteins that fall into the six described subfamilies and represent counterparts of well-established members in Arabidopsis and rice. Intensified research efforts should disclose whether SR proteins were already determining alternative splicing modulation and stress tolerance in early land plants.

» https://doi.org/10.3389/fpls.2020.00286

» Kalyna Lab

Publication from Melina Velasquez & Georg Seifert

"A cell surface arabinogalactan‐peptide influences root hair cell fate"


  • Root hairs (RHs) develop from specialized epidermal trichoblast cells, whereas epidermal cells that lack RHs are known as atrichoblasts. The mechanism controlling RH cell fate is only partially understood.
  • RH cell fate is regulated by a transcription factor complex that promotes the expression of the homeodomain protein GLABRA 2 (GL2), which blocks RH development by inhibiting ROOT HAIR DEFECTIVE 6 (RHD6). Suppression of GL2 expression activates RHD6, a series of downstream TFs including ROOT HAIR DEFECTIVE 6 LIKE‐4 (RSL4) and their target genes, and causes epidermal cells to develop into RHs. Brassinosteroids (BRs) influence RH cell fate. In the absence of BRs, phosphorylated BIN2 (a Type‐II GSK3‐like kinase) inhibits a protein complex that regulates GL2 expression.
  • Perturbation of the arabinogalactan peptide (AGP21) in Arabidopsis thaliana triggers aberrant RH development, similar to that observed in plants with defective BR signaling. We reveal that an O‐glycosylated AGP21 peptide, which is positively regulated by BZR1, a transcription factor activated by BR signaling, affects RH cell fate by altering GL2 expression in a BIN2‐dependent manner.
  • Changes in cell surface AGP disrupts BR responses and inhibits the downstream effect of BIN2 on the RH repressor GL2 in root epidermis.

» https://doi.org/10.1111/nph.16487

» Kleine-Vehn Lab

» Seifert Lab

FWF Project for Sascha Waidmann (Kleine-Vehn Lab)

"Blue light-dependent phosphorylation of PILS proteins"

project number: P 33497
lead: Sascha WAIDMANN
decision board: 2020/03/09
keywords: plant cell biology, phytohormones, auxin, phosphorylation, PILS, auxin homeostasis

» FWF Project details

» Kleine-Vehn Lab

SFB paper with contribution of AG Adam

"Stable isotope-assisted metabolomics for deciphering xenobiotic metabolism in mammalian cell culture"

Xenobiotics are ubiquitous in the environment and modified in the human body by phase I and II metabolism. Liquid chromatography coupled to high resolution mass spectrometry is a powerful tool to investigate these biotransformation products. We present a workflow based on stable isotope-assisted metabolomics and the bioinformatics tool MetExtract II for deciphering xenobiotic metabolites produced by human cells. Its potential was demonstrated by the investigation of the metabolism of deoxynivalenol (DON), an abundant food contaminant, in a liver carcinoma cell line (HepG2) and a model for colon carcinoma (HT29). Detected known metabolites included DON-3-sulfate, DON-10-sulfonate, and DON-10-glutathione as well as DON-cysteine. Conjugation with amino acids and antibiotics was confirmed for the first time. The approach allows the untargeted elucidation of human xenobiotic products in tissue culture. It may be applied to other fields of research including drug metabolism, personalized medicine and systems biology to better understand the relevance of in vitro experiments.

» https://doi.org/10.1021/acschembio.9b01016

» Adam Lab

Publication from Kleine-Vehn Lab

"PIN-LIKES Coordinate Brassinosteroid Signaling with Nuclear Auxin Input in Arabidopsis thaliana"

Auxin and brassinosteroids (BR) are crucial growth regulators and display overlapping functions during plant development. Here, we reveal an alternative phytohormone crosstalk mechanism, revealing that BR signaling controls PIN-LIKES (PILS)-dependent nuclear abundance of auxin. We performed a forward genetic screen for imperial pils (imp) mutants that enhance the overexpression phenotypes of PILS5 putative intracellular auxin transport facilitator. Here, we report that the imp1 mutant is defective in the BR-receptor BRASSINOSTEROID INSENSITIVE 1 (BRI1). 
Our set of data reveals that BR signaling transcriptionally and post-translationally represses the accumulation of PILS proteins at the endoplasmic reticulum, thereby increasing nuclear abundance and signaling of auxin. We demonstrate that this alternative phytohormonal crosstalkmechanism integrates BR signaling into auxin-dependent organ growth rates and likely has widespread importance for plant development.

» https://doi.org/10.1016/j.cub.2020.02.002

» Kleine-Vehn Lab

Publication from Kalyna Lab

"Alternative Splicing and DNA Damage Response in Plants"

Plants are exposed to a variety of abiotic and biotic stresses that may result in DNA damage. Endogenous processes - such as DNA replication, DNA recombination, respiration, or photosynthesis - are also a threat to DNA integrity. It is therefore essential to understand the strategies plants have developed for DNA damage detection, signaling, and repair. Alternative splicing (AS) is a key post-transcriptional process with a role in regulation of gene expression. Recent studies demonstrate that the majority of intron-containing genes in plants are alternatively spliced, highlighting the importance of AS in plant development and stress response. Not only does AS ensure a versatile proteome and influence the abundance and availability of proteins greatly, it has also emerged as an important player in the DNA damage response (DDR) in animals. Despite extensive studies of DDR carried out in plants, its regulation at the level of AS has not been comprehensively addressed. Here, we provide some insights into the interplay between AS and DDR in plants.

» https://doi.org/10.3389/fpls.2020.00091

» Kalyna Lab

Publication from Korbei Lab

"TOLs function as ubiquitin receptors in the early steps of the ESCRT pathway in higher plants"

Protein abundance and localization at the plasma membrane (PM) shapes plant development and mediates adaptation to changing environmental conditions. It is regulated by ubiquitination, a post-translational modification crucial for the proper sorting of endocytosed PM proteins to the vacuole for subsequent degradation. To understand the significance and the variety of roles played by this reversible modification, the function of ubiquitin receptors, which translate the ubiquitin signature into a cellular response, needs to be elucidated. In this study, we show that TOL (TOM1-like) proteins function in plants as multivalent ubiquitin receptors, governing ubiquitinated cargo delivery to the vacuole via the conserved Endosomal Sorting Complex Required for Transport (ESCRT) pathway. TOL2 and TOL6 interact with components of the ESCRT machinery and bind to K63-linked ubiquitin, via two tandemly arranged conserved ubiquitin binding domains. Mutation of these domains results not only in a loss of ubiquitin binding, but also altered localization, abolishing TOL6 ubiquitin receptor activity. Function and localization of TOL6 is itself regulated by ubiquitination, whereby TOL6 ubiquitination potentially modulates degradation of PM-localized cargos, assisting in the fine-tuning of the delicate interplay between protein recycling and downregulation. Our findings demonstrate the function and regulation of a ubiquitin receptor, mediating vacuolar degradation of PM proteins in higher plants.

» https://doi.org/10.1016/j.molp.2020.02.012

» Korbei Lab


"The hydrolytic battlefield at the plant-pathogen interface"

Renier van der Hoorn
Department of Plant Sciences of the University of Oxford

Tuesday 18th February , 10:00 am
DAGZ Seminar room (MUG2 04/54)
Muthgasse 18, 4th floor

» Castilho Lab

VIBT/DAGZ Impromptu Seminar

"Phospholipid Signalling in Plant Stress & Development"

Teun Munnik 
Plant Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam

Monday, 17 February 2020, 2 pm
DAGZ, Seminar room
Host: Marie-Theres Hauser

» Hauser Lab

Publication from Strauss Lab

"Nitric oxide homeostasis is required for light-dependent regulation of conidiation in Aspergillus"

Nitric oxide (NO) can be biologically synthesized from nitrite or from arginine. Although NO is involved as a signal in many biological processes in bacteria, plants, and mammals, still little is known about the role of NO in fungi. Here we show that NO levels are regulated by light as an environmental signal in Aspergillus nidulans. The flavohaemoglobin-encoding fhbB gene involved in NO oxidation to nitrate, and the arginine-regulated arginase encoded by agaA, which controls the intracellular concentration of arginine, are both up-regulated by light. The phytochrome fphA is required for the light-dependent induction of fhbB and agaA, while the white-collar gene lreA acts as a repressor when arginine is present in the media. The intracellular arginine pools increase upon induction of both developmental programs (conidiation and sexual development), and the increase is higher under conditions promoting sexual development. The presence of low concentrations of arginine does not affect the light-dependent regulation of conidiation, but high concentrations of arginine overrun the light signal. Deletion of fhbB results in the partial loss of the light regulation of conidiation on arginine and on nitrate media, while deletion of fhbA only affects the light regulation of conidiation on nitrate media. Our working model considers a cross-talk between environmental cues and intracellular signals to regulate fungal reproduction.

» https://doi.org/10.1016/j.fgb.2020.103337

» Strauss Lab

Publication from Gergely Molnar (Strauss Lab) and Lindy Abas (Mach Lab)

"Salicylic Acid Targets Protein Phosphatase 2A to Attenuate Growth in Plants"

Plants, like other multicellular organisms, survive through a delicate balance between growth and defense against pathogens. Salicylic acid (SA) is a major defense signal in plants, and the perception mechanism as well as downstream signaling activating the immune response are known. Here, we identify a parallel SA signaling that mediates growth attenuation. SA directly binds to A subunits of protein phosphatase 2A (PP2A), inhibiting activity of this complex. Among PP2A targets, the PIN2 auxin transporter is hyperphosphorylated in response to SA, leading to changed activity of this important growth regulator. Accordingly, auxin transport and auxin-mediated root development, including growth, gravitropic response, and lateral root organogenesis, are inhibited. This study reveals how SA, besides activating immunity, concomitantly attenuates growth through crosstalk with the auxin distribution network. Further analysis of this dual role of SA and characterization of additional SA-regulated PP2A targets will provide further insights into mechanisms maintaining a balance between growth and defense.

» https://doi.org/10.1016/j.cub.2019.11.058

» Strauss Lab

» Mach Lab

Publication from Sascha Waidmann (Kleine-Vehn Lab)

"Same same, but different: growth responses of primary and lateral roots"

The root system architecture describes the shape and spatial arrangement of roots within the soil. Its spatial distribution depends on growth and branching rates as well as directional organ growth. The embryonic primary root gives rise to lateral (secondary) roots, and the ratio of both root types changes over the life span of a plant. Most studies have focused on the growth of primary roots and lateral root primordia development. Comparably less is known about the growth regulation of secondary root organs. Here, we review similarities and differences between primary and lateral root organ growth and particularly emphasize on how external stimuli and internal signals differentially integrate root system growth.

» https://doi.org/10.1093/jxb/eraa027

» Kleine-Vehn Lab

Neues aus dem Internet der Pilze

Wenn ein Pilzgeflecht eine Nahrungsquelle gegen Bakterien verteidigt oder auf sonstige Art mit seiner Umwelt interagiert, dann sehen Forscherinnen und Forscher der Plattform BiMM (Bioactive Microbial Metabolites) in Tulln ganz genau hin. Das Wissen um die molekularen Prozesse und die "Links" im "Internet der Pilze" könnte sich sogar als Waffe gegen Krebs oder multiresistente Keime erweisen...

zum Artikel

» Strauss Lab

Publication from Castilho Lab

"BGAL1 depletion boosts the level of β‐galactosylation of N‐ and O‐glycans in N. benthamiana"

Glyco‐design of proteins is a powerful tool in fundamental studies of structure‐function relationship and in obtaining profiles optimized for efficacy of therapeutic glycoproteins. Plants and particularly Nicotiana benthamiana, are attractive hosts to produce recombinant glycoproteins and recent advances in glyco‐engineering facilitate customized N‐glycosylation of plant‐derived glycoproteins. However, with exception of monoclonal antibodies, homogenous human‐like β1,4‐galactosylation is very hard to achieve in recombinant glycoproteins. Despite significant efforts to optimize the expression of β1,4‐galactosyltransferase, many plant‐derived glycoproteins still exhibit incomplete processed N‐glycans with heterogeneous terminal galactosylation. The most obvious suspects to be involved in trimming terminal galactose residues are β‐galactosidases (BGALs) from the glycosyl‐hydrolase family GH35.

To elucidate the so far uncharacterized mechanisms leading to the trimming of terminal galactose residues from glycans of secreted proteins, we studied a N. benthamiana BGAL known to be active in the apoplast (NbBGAL1). Here we determined the NbBGAL1 subcellular localization, substrate specificity and in planta biological activity. We show that NbBGAL1 can remove β1,4‐ and β1,3‐galactose residues on both N‐ and O‐glycans. Transient BGAL1 downregulation by RNA interference (RNAi) and BGAL1 depletion by genome editing drastically reduce β‐galactosidase activity in N. benthamiana and increase the amounts of fully galactosylated complex N‐glycans on several plant‐produced glycoproteins. Altogether, our data demonstrate that NbBGAL1 acts on galactosylated complex N‐glycans of plant‐produced glycoproteins.

» https://doi.org/10.1111/pbi.13316

» Castilho Lab

BiRT Seminar Series

Dr. Ines Swoboda & Sandra Pfeiffer 

FH Campus Wien 
Section of Molecular Biotechnology

"Identification and characterisation of respiratory + food allergens"

Thursday, December 12th 2019
10:00 am
Campus Tulln, UFT - Seminar Room 14

Hosts: Joseph Strauss & Marcus Gorfer

» Strauss Lab

Publication from Luschnig Lab

"Brassinosteroid signaling delimits root gravitropism via sorting of the Arabidopsis PIN2 auxin transporter"

Arabidopsis PIN2 protein directs transport of the phytohormone auxin from the root tip into the root elongation zone. Variation in hormone transport, which depends on a delicate interplay between PIN2 sorting to and from polar plasma membrane domains, determines root growth. By employing a constitutively degraded version of PIN2, we identify brassinolides as antagonists of PIN2 endocytosis. This response does not require de novo protein synthesis, but involves early events in canonical brassinolide signaling. Brassinolide-controlled adjustments in PIN2 sorting and intracellular distribution governs formation of a lateral PIN2 gradient in gravistimulated roots, coinciding with adjustments in auxin signaling and directional root growth. Strikingly, simulations indicate that PIN2 gradient formation is no prerequisite for root bending but rather dampens asymmetric auxin flow and signaling. Crosstalk between brassinolide signaling and endocytic PIN2 sorting, thus, appears essential for determining the rate of gravity-induced root curvature via attenuation of differential cell elongation.

» https://doi.org/10.1038/s41467-019-13543-1

» Luschnig Lab

FWF Project for Jürgen Kleine-Vehn

"Mechanisms of Feronia-dependent growth control"

Project number: P 33044

Decision board: 2019/11/25

» Kleine-Vehn Lab

Publication from Hauser Lab

"Involvement of the eIF2α Kinase GCN2 in UV-B Responses"

GCN2 (general control nonrepressed 2) is a serine/threonine-protein kinase that regulates translation in response to stressors such as amino acid and purin deprivation, cold shock, wounding, cadmium, and UV-C exposure. Activated GCN2 phosphorylates the α-subunit of the eukaryotic initiation factor 2 (eIF2) leading to a drastic inhibition of protein synthesis and shifting translation to specific mRNAs. To investigate the role of GCN2 in responses to UV-B radiation its activity was analyzed through eIF2α phosphorylation assays in mutants of the specific UV-B and stress signaling pathways of Arabidopsis thaliana. EIF2α phosphorylation was detectable 30 min after UV-B exposure, independent of the UV-B photoreceptor UV RESISTANCE LOCUS8 and its downstream signaling components. GCN2 dependent phosphorylation of eIF2α was also detectable in mutants of the stress related MAP kinases, MPK3 and MPK6 and their negative regulator map kinase phosphatase1 (MKP1). Transcription of downstream components of the UV-B signaling pathway, the Chalcone synthase (CHS) was constitutively higher in gcn2-1 compared to wildtype and further increased upon UV-B while GLUTATHIONE PEROXIDASE7 (GPX7) behaved similarly to wildtype. The UVR8 independent FAD-LINKED OXIDOREDUCTASE (FADox) had a lower basal expression in gcn2-1 which was increased upon UV-B. Since high fluence rates of UV-B induce DNA damage the expression of the RAS ASSOCIATED WITH DIABETES PROTEIN51 (RAD51) was quantified before and after UV-B. While the basal expression was similar to wildtype it was significantly less induced upon UV-B in the gcn2-1 mutant. This expression pattern correlates with the finding that gcn2 mutants develop less cyclobutane pyrimidine dimers after UV-B exposure. Quantification of translation with the puromycination assay revealed that gcn2 mutants have an increased rate of translation which was also higher upon UV-B. Growth of gcn2 mutants to chronic UV-B exposure supports GCN2’s role as a negative regulator of UV-B responses. The elevated resistance of gcn2 mutants towards repeated UV-B exposure points to a critical role of GCN2 in the regulation of translation upon UV-B.

» https://doi.org/10.3389/fpls.2019.01492

» Hauser Lab

Bodenkinotag - UNO-Welttag des Bodens

FILMPREMIERE 5. Dezember 2019 um 19 Uhr

Die Österreichische Bodenkundliche Gesellschaft und die Universität für Bodenkultur Wien laden zur Filmpremiere „Galápagos beneath the surface“

Eintritt frei!

Peter-Jordan-Straße 76
1190 Wien


BiRT Seminar Series „Die Welt der biologischen Interaktionen“

Dr. Sabine Fillinger
INRA-Institute National de la Rechérche Agronomique, AgroParisTech, Paris-Saclay, France

"Target & Non target-site resistance mechanisms against agricultural fungicides, the tip of the iceberg?"

Freitag 22. November 2019
10:00 Uhr
Campus Tulln / UFT – Seminarraum 16

Host: Joseph Strauss

PhD Defensio of Lin Sun

“Novel molecular players of PILS-dependent cellular auxin homeostasis”

Friday 15th of Nov. 2019, 2:00 pm
Muthgasse 18, 1190 Vienna
Seminarraum, 4th floor

» Kleine-Vehn Lab

SFB publication with contribution of Adam Lab

"Stable Isotope–Assisted Plant Metabolomics: Combination of Global and Tracer-Based Labeling for Enhanced Untargeted Profiling and Compound Annotation"

Untargeted approaches and thus biological interpretation of metabolomics results are still hampered by the reliable assignment of the global metabolome as well as classification and (putative) identification of metabolites. In this work we present an liquid chromatography-mass spectrometry (LC-MS)–based stable isotope assisted approach that combines global metabolome and tracer based isotope labeling for improved characterization of (unknown) metabolites and their classification into tracer derived submetabolomes. To this end, wheat plants were cultivated in a customized growth chamber, which was kept at 400 ± 50 ppm 13CO2 to produce highly enriched uniformly 13C-labeled sample material. Additionally, native plants were grown in the greenhouse and treated with either 13C9-labeled phenylalanine (Phe) or 13C11-labeled tryptophan (Trp) to study their metabolism and biochemical pathways. After sample preparation, liquid chromatography-high resolution mass spectrometry (LC-HRMS) analysis and automated data evaluation, the results of the global metabolome- and tracer-labeling approaches were combined. A total of 1,729 plant metabolites were detected out of which 122 respective 58 metabolites account for the Phe- and Trp-derived submetabolomes. Besides m/z and retention time, also the total number of carbon atoms as well as those of the incorporated tracer moieties were obtained for the detected metabolite ions. With this information at hand characterization of unknown compounds was improved as the additional knowledge from the tracer approaches considerably reduced the number of plausible sum formulas and structures of the detected metabolites. Finally, the number of putative structure formulas was further reduced by isotope-assisted annotation tandem mass spectrometry (MS/MS) derived product ion spectra of the detected metabolites. A major innovation of this paper is the classification of the metabolites into submetabolomes which turned out to be valuable information for effective filtering of database hits based on characteristic structural subparts. This allows the generation of a final list of true plant metabolites, which can be characterized at different levels of specificity.

» https://doi.org/10.3389/fpls.2019.01366

» SFB F37: Fusarium metabolites and detoxification reactions

» Adam Lab

SFB publication with contribution of Adam Lab

"Stable Isotope-Assisted Plant Metabolomics: Investigation of Phenylalanine-Related Metabolic Response in Wheat Upon Treatment With the Fusarium Virulence Factor Deoxynivalenol"

The major Fusarium mycotoxin deoxynivalenol (DON) is a virulence factor in wheat and has also been shown to induce defense responses in host plant tissue. In this study, global and tracer labeling with 13C were combined to annotate the overall metabolome of wheat spikes and to evaluate the response of phenylalanine-related pathways upon treatment with DON. At anthesis, spikes of resistant and susceptible cultivars as well as two related near isogenic wheat lines (NILs) differing in the presence/absence of the major resistance QTL Fhb1 were treated with 1 mg DON or water (control), and samples were collected at 0, 12, 24, 48, and 96 h after treatment (hat). A total of 172 Phe-derived wheat constituents were detected with our untargeted approach employing 13C-labeled phenylalanine and subsequently annotated as flavonoids, lignans, coumarins, benzoic acid derivatives, hydroxycinnamic acid amides (HCAAs), as well as peptides. Ninety-six hours after the DON treatment, up to 30% of the metabolites biosynthesized from Phe showed significantly increased levels compared to the control samples. Major metabolic changes included the formation of precursors of compounds implicated in cell wall reinforcement and presumed antifungal compounds. In addition, also dipeptides, which presumably are products of proteolytic degradation of truncated proteins generated in the presence of the toxin, were significantly more abundant upon DON treatment. An in-depth comparison of the two NILs with correlation clustering of time course profiles revealed some 70 DON-responsive Phe derivatives. While several flavonoids had constitutively different abundance levels between the two NILs differing in resistance, other Phe-derived metabolites such as HCAAs and hydroxycinnamoyl quinates were affected differently in the two NILs after treatment with DON. Our results suggest a strong activation of the general phenylpropanoid pathway and that coumaroyl-CoA is mainly diverted towards HCAAs in the presence of Fhb1, whereas the metabolic route to monolignol(-conjugates), lignans, and lignin seems to be favored in the absence of the Fhb1 resistance quantitative trait loci.

» https://doi.org/10.3389/fpls.2019.01137

» SFB F37: Fusarium metabolites and detoxification reactions

» Adam Lab

BOKU Erfinderin 2019

Die Auszeichnung BOKU Erfinderin 2019 ging dieses Jahr ex aequo an Prof.in Hertha Steinkellner, Prof.in Grabherr und Prof.in Gasser. Ihr Einsatz und ihre Vorbildwirkung wird neben einem Geldpreis mit einem persönlichen Video, das beim Tullner Herbstfest vorgestellt wurde, belohnt ⇒ zur BOKU Top Story

» Video Prof.in Steinkellner

» Steinkellner Lab

Publication from Hauser and Adam Lab

"Zearalenone and ß-Zearalenol But Not Their Glucosides Inhibit Heat Shock Protein 90 ATPase Activity"

The mycotoxin zearalenone (ZEN) is produced by many plant pathogenic Fusarium species. It is well known for its estrogenic activity in humans and animals, but whether ZEN has a role in plant–pathogen interaction and which process it is targeting in planta was so far unclear. We found that treatment of Arabidopsis thaliana seedlings with ZEN induced transcription of the AtHSP90.1 gene. This heat shock protein (HSP) plays an important role in plant–pathogen interaction, assisting in stability and functionality of various disease resistance gene products. Inhibition of HSP90 ATPase activity impairs functionality. Because HSP90 inhibitors are known to induce HSP90 gene expression and due to the structural similarity with the known HSP90 inhibitor radicicol (RAD), we tested whether ZEN and its phase I metabolites α- and ß-zearalenol are also HSP90 ATPase inhibitors. Indeed, AtHSP90.1 and wheat TaHSP90-2 were inhibited by ZEN and ß-zearalenol, while α-zearalenol was almost inactive. Plants can efficiently glycosylate ZEN and α/ß-zearalenol. We therefore tested whether glucosylation has an effect on the inhibitory activity of these metabolites. Expression of the A. thaliana glucosyltransferase UGT73C6 conferred RAD resistance to a sensitive yeast strain. Glucosylation of RAD, ZEN, and α/ß-zearalenol abolished the in vitro inhibitory activity with recombinant HSP90 purified from Escherichia coli. In conclusion, the mycotoxin ZEN has a very prominent target in plants, HSP90, but it can be inactivated by glycosylation. This may explain why there is little evidence for a virulence function of ZEN in host plants.

» https://doi.org/10.3389/fphar.2019.01160

» Hauser Lab

» Adam Lab

Preprint from Kleine-Vehn Lab

"Auxin-dependent xyloglucan remodelling defines differential tissue expansion in Arabidopsis thaliana"

Size control is a fundamental question in biology, showing incremental complexity in case of cell wall surrounded plant cells. Here we show that auxin signalling restricts the complexity of extracellular xyloglucans, which defines cell wall properties and tissue expansion. Our work uncovers an alternative mechanism of how the phytohormone auxin modulates the cell wall for steering differential growth control in gravitropic hypocotyls.

» https://doi.org/10.1101/808964

» Kleine-Vehn Lab

MSc Defence of Ricarda Kriechbaum


Thursday 24th October 2019 
10:00 am DAGZ-Seminar room (MUG2-04/54)
Muthgasse 18, 4th floor

» Castilho Lab

PhD Defensio of Laura Montero Morales

"Immunoglobulin E and glycosylation"

October 23, 2019, 11:00 a.m.
Seminar-room DAGZ (04/54, 4th floor)
Muthgasse 18, 1190

» Steinkellner Lab

FWF Project for Joseph Strauss

"Chromatin composition at fungal gene clusters"

Project number: P 32790

Decision board: 2019/09/30

Keywords: filamentous fungi, chromatin, secondary metabolism, gene cluster regulation, Aspergillus

» Strauss Lab

Publication from Steinkellner Lab

"In Planta Glycan Engineering and Functional Activities of IgE Antibodies"

Human immunoglobulin E (IgE) is the most extensively glycosylated antibody isotype so glycans attached to the seven N-glycosites (NGS) in its Fab and Fc domains may modulate its functions. However, targeted modification of glycans in multiply glycosylated proteins remains a challenge. Here, we applied an in vivo approach that allows the manipulation of IgE N-glycans, using a trastuzumab equivalent IgE (HER2-IgE) as a model. Taking advantage of plant inherent features, i.e., synthesis of largely homogeneous complex N-glycans and susceptibility to glycan engineering, we generated targeted glycoforms of HER2-IgE largely resembling those found in serum IgE. Plant-derived HER2-IgE exhibited N-glycans terminating with GlcNAc, galactose or sialic acid, lacking, or carrying core fucose and xylose. We were able to not only modulate the five NGSs naturally decorated with complex N-glycans, but to also induce targeted glycosylation at the usually unoccupied NGS6, thus increasing the overall glycosylation content of HER2-IgE. Recombinant human cell-derived HER2-IgE exhibited large N-glycan heterogeneity. All HER2-IgE variants demonstrated glycosylation-independent binding to the target antigen and the high affinity receptor FcεRI, and subsequent similar capacity to trigger mast cell degranulation. In contrast, binding to the low affinity receptor CD23 (FcεRII) was modulated by the glycan profile, with increased binding to IgE variants with glycans terminating with GlcNAc residues. Here we offer an efficient in planta approach to generate defined glycoforms on multiply glycosylated IgE, allowing the precise exploration of glycosylation-dependent activities.

» https://doi.org/10.3389/fbioe.2019.00242

» Steinkellner Lab

Congrats Jonathan!

Jonathan Ferreira Da Silva Santos obtained a prestigious DOC Fellowship of the Austrian Academy of Sciences.

» Kleine-Vehn Lab

» ÖAW - Austrian Academy of Sciences

Publication from Kleine-Vehn Lab

"NET4 Modulates the Compactness of Vacuoles in Arabidopsis thaliana"

The dimension of the plants largest organelle—the vacuole—plays a major role in defining cellular elongation rates. The morphology of the vacuole is controlled by the actin cytoskeleton, but molecular players remain largely unknown. Recently, the Networked (NET) family of membrane-associated, actin-binding proteins has been identified. Here, we show that NET4A localizes to highly constricted regions of the vacuolar membrane and contributes to vacuolar morphology. Using genetic interference, we found that deregulation of NET4 abundance increases vacuolar occupancy, and that overexpression of NET4 abundance decreases vacuolar occupancy. Our data reveal that NET4A induces more compact vacuoles, correlating with reduced cellular and organ growth in Arabidopsis thaliana.

» https://doi.org/10.3390/ijms20194752

» Kleine-Vehn Lab

DAGZ Seminar

Aaron Rashotte (Auburn University, USA) will talk about:

"Cytokinin Response Factors and their expanding roles in stress response."

Tuesday, 8th October 2019, 09:00 am
Muthgasse 18, 1190 Vienna
DAGZ Seminar room 4th floor
Host: Sascha Waidmann

» Kleine-Vehn Lab

Publication from Kai Dünser (Kleine-Vehn Lab)

"Leucine-Rich Repeat Extensin Proteins and Their Role in Cell Wall Sensing"

Plant cells are surrounded by a cell wall that provides shape and physically limits cell expansion. To sense the environment and status of cell wall structures, plants have evolved cell wall integrity-sensing mechanisms that involve a number of receptors at the plasma membrane. These receptors can bind cell wall components and/or hormones to coordinate processes in the cell wall and the cytoplasm. This review focuses on the role of leucine-rich repeat extensins (LRXs) during cell wall development. LRXs are chimeric proteins that insolubilize in the cell wall and form protein–protein interaction platforms. LRXs bind RALF peptide hormones that modify cell wall expansion and also directly interact with the transmembrane receptor FERONIA, which is involved in cell growth regulation. LRX proteins, therefore, also represent a link between the cell wall and plasma membrane, perceiving extracellular signals and indirectly relaying this information to the cytoplasm.

» https://doi.org/10.1016/j.cub.2019.07.039

» Kleine-Vehn Lab

Publication from Adam Lab

"Biochemical Characterization of the Fusarium graminearum Candidate ACC-Deaminases and Virulence Testing of Knockout Mutant Strains"

​​​​​​Fusarium graminearum is a plant pathogenic fungus which is able to infect wheat and other economically important cereal crop species. The role of ethylene in the interaction with host plants is unclear and controversial. We have analyzed the inventory of genes with a putative function in ethylene production or degradation of the ethylene precursor 1-aminocyclopropane carboxylic acid (ACC). F. graminearum, in contrast to other species, does not contain a candidate gene encoding ethylene-forming enzyme. Three genes with similarity to ACC synthases exist; heterologous expression of these did not reveal enzymatic activity. The F. graminearum genome contains in addition two ACC deaminase candidate genes. We have expressed both genes in E. coli and characterized the enzymatic properties of the affinity-purified products. One of the proteins had indeed ACC deaminase activity, with kinetic properties similar to ethylene-stress reducing enzymes of plant growth promoting bacteria. The other candidate was inactive with ACC but turned out to be a D-cysteine desulfhydrase. Since it had been reported that ethylene insensitivity in transgenic wheat increased Fusarium resistance and reduced the content of the mycotoxin deoxynivalenol (DON) in infected wheat, we generated single and double knockout mutants of both genes in the F. graminearum strain PH-1. No statistically significant effect of the gene disruptions on fungal spread or mycotoxin content was detected, indicating that the ability of the fungus to manipulate the production of the gaseous plant hormones ethylene and H2S is dispensable for full virulence.

» https://doi.org/10.3389/fpls.2019.01072

» Adam Lab

Publication with Contribution from Adam Lab

"Biotransformation of the Mycotoxin Zearalenone to its Metabolites Hydrolyzed Zearalenone (HZEN) and Decarboxylated Hydrolyzed Zearalenone (DHZEN) Diminishes its Estrogenicity In Vitro and In Vivo"

Zearalenone (ZEN)-degrading enzymes are a promising strategy to counteract the negative effects of this mycotoxin in livestock. The reaction products of such enzymes need to be thoroughly characterized before technological application as a feed additive can be envisaged. Here, we evaluated the estrogenic activity of the metabolites hydrolyzed zearalenone (HZEN) and decarboxylated hydrolyzed zearalenone (DHZEN) formed by hydrolysis of ZEN by the zearalenone-lactonase Zhd101p. ZEN, HZEN, and DHZEN were tested in two in vitro models, the MCF-7 cell proliferation assay (0.01–500 nM) and an estrogen-sensitive yeast bioassay (1–10,000 nM). In addition, we compared the impact of dietary ZEN (4.58 mg/kg) and equimolar dietary concentrations of HZEN and DHZEN on reproductive tract morphology as well as uterine mRNA and microRNA expression in female piglets (n = 6, four weeks exposure). While ZEN increased cell proliferation and reporter gene transcription, neither HZEN nor DHZEN elicited an estrogenic response, suggesting that these metabolites are at least 50–10,000 times less estrogenic than ZEN in vitro. In piglets, HZEN and DHZEN did not increase vulva size or uterus weight. Moreover, RNA transcripts altered upon ZEN treatment (EBAG9, miR-135a-5p, miR-187-3p and miR-204-5p) were unaffected by HZEN and DHZEN. Our study shows that both metabolites exhibit markedly reduced estrogenicity in vitro and in vivo, and thus provides an important basis for further evaluation of ZEN-degrading enzymes.

» https://doi.org/10.3390/toxins11080481

» Adam Lab


Congratulations to Anna Atanasoff-Kardjalieff who successfully defended her Master Thesis on Fusarium heterochromatin and epigenetics.

Very well done and welcome to our group as PhD student!

» Strauss Lab

Publication from Jennifer Schoberer & Strasser Lab

"A signal motif retains Arabidopsis ER-α-mannosidase I in the cis-Golgi and prevents enhanced glycoprotein ERAD"

The Arabidopsis ER-α-mannosidase I (MNS3) generates an oligomannosidic N-glycan structure that is characteristically found on ER-resident glycoproteins. The enzyme itself has so far not been detected in the ER. Here, we provide evidence that in plants MNS3 exclusively resides in the Golgi apparatus at steady-state. Notably, MNS3 remains on dispersed punctate structures when subjected to different approaches that commonly result in the relocation of Golgi enzymes to the ER. Responsible for this rare behavior is an amino acid signal motif (LPYS) within the cytoplasmic tail of MNS3 that acts as a specific Golgi retention signal. This retention is a means to spatially separate MNS3 from ER-localized mannose trimming steps that generate the glycan signal required for flagging terminally misfolded glycoproteins for ERAD. The physiological importance of the very specific MNS3 localization is demonstrated here by means of a structurally impaired variant of the brassinosteroid receptor BRASSINOSTEROID INSENSITIVE 1.

» https://doi.org/10.1038/s41467-019-11686-9

» Jennifer Schoberer

» Strasser Lab

Publication from Strauss/Studt Lab

"Evidence of a Demethylase-Independent Role for the H3K4-Specific Histone Demethylases in Aspergillus nidulans and Fusarium graminearum Secondary Metabolism"

Fungi produce a plethora of secondary metabolites (SMs) involved in cellular protection, defense, and signaling. Like other metabolic processes, transcription of SM biosynthesis genes is tightly regulated to prevent an unnecessary use of resources. Genes involved in SM biosynthesis are usually physically linked, arranged in secondary metabolite gene clusters (SMGCs). Research over the last decades has shown that chromatin structure and posttranslational modifications (PTMs) of histones represent important layers of SMGC regulation. For instance, trimethylation of histone H3 lysine 4 (H3K4me3) is a PTM typically associated with promoter regions of actively transcribed genes. Previously, we have shown that the H3K4me3-specific, JmjC domain-containing histone demethylase KdmB functions not only in repression but also in activation of secondary metabolism in Aspergillus nidulans, suggesting that KdmB has additional functions apart from histone demethylation. In this study, we identified demethylase-independent functions of KdmB in transcriptional regulation of SM gene clusters. Furthermore, we show that this activating and demethylase-independent role of the H3K4 demethylase is also conserved in the phytopathogenic fungus Fusarium graminearum. Lack of FgKdm5 resulted in significant downregulation of five of seven analyzed SMs, whereby only one SMGC depends on a functional JmjC-domain. In A. nidulans strains deficient in H3K4 methylation, i.e., cclA∆, largely phenocopied kdmB∆, while this is not the case for most of the SMs analyzed in Fusarium spp. Notably, KdmB could not rescue the demethylase function in ∆fgkdm5 but restored all demethylase-independent phenotypes.

» https://doi.org/10.3389/fmicb.2019.01759

» Strauss Lab

» Lena Studt

Publication from Sascha Waidmann (Kleine-Vehn Lab)

"Cytokinin functions as an asymmetric and anti-gravitropic signal in lateral roots"

Directional organ growth allows the plant root system to strategically cover its surroundings. Intercellular auxin transport is aligned with the gravity vector in the primary root tips, facilitating downward organ bending at the lower root flank. Here we show that cytokinin signaling functions as a lateral root specific anti-gravitropic component, promoting the radial distribution of the root system. We performed a genome-wide association study and reveal that signal peptide processing of Cytokinin Oxidase 2 (CKX2) affects its enzymatic activity and, thereby, determines the degradation of cytokinins in natural Arabidopsis thaliana accessions. Cytokinin signaling interferes with growth at the upper lateral root flank and thereby prevents downward bending. Our interdisciplinary approach proposes that two phytohormonal cues at opposite organ flanks counterbalance each other’s negative impact on growth, suppressing organ growth towards gravity and allow for radial expansion of the root system.

» https://doi.org/10.1038/s41467-019-11483-4

» BOKU Top Story

» Kleine-Vehn Lab

Publication from Strasser Lab

"Distinct Fc alpha receptor N-glycans modulate the binding affinity to immunoglobulin A (IgA) antibodies"

Human immunoglobulin A (IgA) is the most prevalent antibody class at mucosal sites with an important role in mucosal defense. Little is known about the impact of N-glycan modifications of IgA1 and IgA2 on binding to the Fc alpha receptor (FcαRI) which is also heavily glycosylated at its extracellular domain. Here, we transiently expressed human epidermal growth factor receptor 2 (HER2)-binding monomeric IgA1, IgA2m(1) and IgA2m(2) variants in Nicotiana benthamiana ΔXT/FT plants lacking the enzymes responsible for generating non-human N-glycan structures. By co-infiltrating IgA with the respective glycan modifying enzymes, we generated IgA carrying distinct homogenous N-glycans. We demonstrate that distinctly different N-glycan profiles do not influence antigen binding or the overall structure and integrity of the IgA antibodies, but did affect their thermal stability. Using size-exclusion chromatography, differential scanning and isothermal titration calorimetry, surface plasmon resonance spectroscopy, and molecular modeling, we probed distinct IgA1 and IgA2 glycoforms for binding to four different FcαRI glycoforms and investigated the thermodynamics and kinetics of complex formation. Our results suggest that different N-glycans on the receptor significantly contribute to binding affinities for its cognate ligand. We also noted that full-length IgA and FcαRI form a mix of 1:1 and 1:2 complexes tending toward a 1:1 stoichiometry due to different IgA tailpiece conformations that make it less likely that both binding sites are simultaneously occupied. In conclusion, N-glycans of human IgA do not affect its structure and integrity, but its thermal stability, and FcαRI N-glycans significantly modulate binding affinity to IgA.

» http://www.jbc.org/content/early/2019/07/30/jbc.RA119.009954

» Strasser Lab

Publication from Kleine-Vehn Lab

"PIN-FORMED and PIN-LIKES auxin transport facilitators"

The phytohormone auxin influences virtually all aspects of plant growth and development. Auxin transport across membranes is facilitated by, among other proteins, members of the PIN-FORMED (PIN) and the structurally similar PIN-LIKES (PILS) families, which together govern directional cell-to-cell transport and intracellular accumulation of auxin. Canonical PIN proteins, which exhibit a polar localization in the plasma membrane, determine many patterning and directional growth responses. Conversely, the less-studied non-canonical PINs and PILS proteins, which mostly localize to the endoplasmic reticulum, attenuate cellular auxin responses. Here, and in the accompanying poster, we provide a brief summary of current knowledge of the structure, evolution, function and regulation of these auxin transport facilitators.

» https://dev.biologists.org/content/146/15/dev168088

» Kleine-Vehn Lab

Publication from Strasser & Mach Lab

"Genome and transcriptome characterization of the glycoengineered Nicotiana benthamiana line ΔXT/FT"

Based on an existing draft assembly of the N. benthamiana genome we predict 50,516 protein –encoding genes (62,216 transcripts) supported by expression data derived from 2.35 billion mRNA-seq reads. Using singlecopy core genes we show high completeness of the predicted gene set. We functionally annotate more than two thirds of the gene set through sequence homology to genes from other Nicotiana species. We demonstrate that the expression profiles from leaf tissue of ΔXT/FT and its wild type progenitor only show minimal differences. We identify the transgene insertion sites in ΔXT/FT and show that one of the transgenes was inserted inside another predicted gene that most likely lost its function upon insertion. Based on publicly available mRNA-seq data, we confirm that the N. benthamiana accessions used by different research institutions most likely derive from a single source.

» https://doi.org/10.1186/s12864-019-5960-2

» Strasser Lab
» Mach Lab

Preprint from Kleine-Vehn

"NET4 modulates the compactness of vacuoles in Arabidopsis thaliana"

The dimension of the plants largest organelle – the vacuole, plays a major role in defining cellular elongation rates. The morphology of the vacuole is controlled by the actin cytoskeleton but the mechanistic connection between them remains largely elusive. Recently, the NETWORKED (NET) family of membrane-associated, actin-binding proteins has been identified and represent potential candidates to impact on vacuolar morphology. Here, we show that NET4A localizes to highly constricted regions in the vacuolar membrane and contributes to the compactness of the vacuole. Using genetic interference, we found that deregulation of NET4 abundance impacts on vacuole morphogenesis and overexpression leads to more compact vacuoles. We moreover show that the NET4A-induced changes in vacuolar shape correlates with reduced cellular and organ growth in Arabidopsis thaliana. Our results demonstrate that NET4 modulates the compactness of vacuoles and reveal higher complexity in the regulation of actin-reliant vacuolar morphology.

» https://doi.org/10.1101/714774

» Kleine-Vehn Lab

Kinderuni am DAGZ

Am Montag und Dienstag (17./18.06.2019) waren je eine Klasse der Volksschule Familienschule Leopoldstadt bei uns zu Gast, jeweils für den ganzen Vormittag.
Die Kinder waren zwischen 8 und 10 Jahre alt (3. und 4. Klasse), es waren einmal 20 und einmal 21 Kinder, und wir hatten ein Programm mit Experimenten zum Thema Pflanzen und Pilze, und generell zur Arbeit in einem Biologie-Labor.

Die Mitwirkenden waren: Jeanette Moulinier-Anzola, Barbara Korbei, Elena Feraru, Sabine Strauss-Goller, Max Schwihla, Kai Dünser und Doris Lucyshyn.

» Korbei Lab
» Lucyshyn Lab
» Kleine-Vehn Lab
» Strauss Lab

Wissenschaftskommunikation "extended" - Wie beeinflussen Bakterien die Genexpression in assoziierten Pilzen?

Die eLIFE Publikation über Bakterien-Pilz Interaktion der Arbeitsgruppe Strauss, wurde als Highlight in der Märzausgabe der Zeitschrift Biospektrum vorgestellt.

» https://doi.org/10.1007/s12268-019-1048-4 (Biospektrum)

» https://www.ncbi.nlm.nih.gov/pubmed/30311911 (eLIFE)

» Strauss Lab

Preprint from Kleine-Vehn Lab

"Brassinosteroid signaling controls PILS-dependent nuclear auxin input in Arabidopsis thaliana"

Auxin and brassinosteroids (BR) are crucial growth regulators and display overlapping functions during plant development. Here, we reveal an alternative phytohormone crosstalk mechanism, revealing that brassinosteroid signaling controls nuclear abundance of auxin. We performed a forward genetic screen for imperial pils (imp) mutants that enhance the overexpression phenotypes of PIN-LIKES (PILS) putative intracellular auxin transport facilitator. Here we report that the imp1 mutant is defective in the brassinosteroid-receptor BRI1. BR signaling transcriptionally and posttranslationally represses accumulation of PILS proteins at the endoplasmic reticulum, thereby increasing nuclear abundance and signaling of auxin. We demonstrate that this alternative phytohormonal crosstalk mechanism integrates BR signaling into auxin-dependent organ growth rates and likely has widespread importance for plant development.

» https://doi.org/10.1101/646489

» Kleine-Vehn Lab


Qiang Chen
The Biodesign Institute and School of Life Sciences

"Improving effector functions of antibodies against flavi-and alphaviruses"

Host: Herta Steinkellner

Muthgasse18, 1190 Vienna
Seminar-room DAGZ (4thfloor)
June 6th2019, 11:30 h

Publication from Strauss Lab

"Fusaoctaxin A, an Example of a Two-Step Mechanism for Non-Ribosomal Peptide Assembly and Maturation in Fungi"

Fungal non-ribosomal peptide synthetase (NRPS) clusters are spread across the chromosomes, where several modifying enzyme-encoding genes typically flank one NRPS. However, a recent study showed that the octapeptide fusaoctaxin A is tandemly synthesized by two NRPSs in Fusarium graminearum. Here, we illuminate parts of the biosynthetic route of fusaoctaxin A, which is cleaved into the tripeptide fusatrixin A and the pentapeptide fusapentaxin A during transport by a cluster-specific ABC transporter with peptidase activity. Further, we deleted the histone H3K27 methyltransferase kmt6, which induced the production of fusaoctaxin A.

» https://doi.org/10.3390/toxins11050277

» Strauss Lab

Publication with Contribution from Adam Lab

"Simple validated method for simultaneous determination of deoxynivalenol, nivalenol, and their 3-β-D-glucosides in baby formula and Korean rice wine via HPLC-UV with immunoaffinity cleanup"

A simple and reliable method for the simultaneous determination of major type B trichothecene mycotoxins, deoxynivalenol (DON) and nivalenol (NIV), along with their 3-β-d-glucosides (DON-3-glucoside (DON3G) and NIV-3-glucoside (NIV3G)) in baby formula and Korean rice wine was validated in the present study. The method was based on immunoaffinity cleanup followed by analysis using an HPLC-UV technique. The method was validated in-house for two matrices as follows: linearity (R2 > 0.99) was established in the range of 20-1000 μg kg-1; accuracy (expressed as recovery) ranged from 78.7 to 106.5% for all the analytes; good intermediate precision (relative standard deviation < 12%), and adequate detection and quantitation limits (< 4.4 and < 13.3 μg kg-1, respectively) were achieved. Furthermore, the estimated measurement expanded uncertainty was determined to be 4-24%. The validated method was successfully applied to the analysis of 31 baby formulas and Korean rice wines marketed in Korea.

» DOI: 10.1080/19440049.2019.1606454

» Adam Lab

Publication from Adam Lab

"The Fusarium metabolite culmorin suppresses the in vitro glucuronidation of deoxynivalenol"

Glucuronidation is a major phase II conjugation pathway in mammals, playing an important role in the detoxification and biotransformation of xenobiotics including mycotoxins such as deoxynivalenol (DON). Culmorin (CUL), a potentially co-occurring Fusarium metabolite, was recently found to inhibit the corresponding detoxification reaction in plants, namely DON-glucoside formation, raising the question whether CUL might affect also the mammalian counterpart. Using cell-free conditions, CUL when present equimolar (67 µM) or in fivefold excess, suppressed DON glucuronidation by human liver microsomes, reducing the formation of DON-15-glucuronide by 15 and 50%, and DON-3-glucuronide by 30 and 50%, respectively. Substantial inhibitory effects on DON glucuronidation up to 100% were found using the human recombinant uridine 5'-diphospho-glucuronosyltransferases (UGT) 2B4 and 2B7, applying a tenfold excess of CUL (100 µM). In addition, we observed the formation of a novel metabolite of CUL, CUL-11-glucuronide, identified for the first time in vitro as well as in vivo in piglet and human urine samples. Despite the observed potency of CUL to inhibit glucuronidation, no significant synergistic toxicity on cell viability was observed in combinations of CUL (0.1-100 µM) and DON (0.01-10 µM) in HT-29 and HepG2 cells, presumably reflecting the limited capacity of the tested cell lines for DON glucuronidation. However, in humans, glucuronidation is known to represent the main detoxification pathway for DON. The present results, including the identification of CUL-11-glucuronide in urine samples of piglets and humans, underline the necessity of further studies on the relevance of CUL as a potentially co-occurring modulator of DON toxicokinetics in vivo.itro glucuronidation of deoxynivalenol.

» DOI: 10.1007/s00204-019-02459-w

» Adam Lab

Publication from Mach Lab

"Comparative Antigenicity of Thiourea and Adipic Amide Linked Neoglycoconjugates Containing Modified Oligomannose Epitopes for the Carbohydrate-Specific anti-HIV Antibody 2G12"

Novel neoglycoproteins containing oligomannosidic penta- and heptasaccharides as structural variants of oligomannose-type N-glycans found on human immunodeficiency virus type 1 gp120 have been prepared using different conjugation methods. Two series of synthetic ligands equipped with 3-aminopropyl spacer moieties and differing in the anomeric configuration of the reducing mannose residue were activated either as isothiocyanates or as adipic acid succinimidoyl esters and coupled to bovine serum albumin. Coupling efficiency for adipic acid connected neoglycoconjugates was better than for the thiourea-linked derivatives; the latter constructs, however, exhibited higher reactivity toward antibody 2G12, an HIV-neutralizing antibody with exquisite specificity for oligomannose-type glycans. 2G12 binding avidities for the conjugates, as determined by Bio-Layer Interferometry, were mostly higher for the β-linked ligands and, as expected, increased with the numbers of covalently linked glycans, leading to approximate KD values of 10 to 34 nM for optimized ligand-to-BSA ratios. A similar correlation was observed by enzyme-linked immunosorbent assays. In addition, dendrimer-type ligands presenting trimeric oligomannose epitopes were generated by conversion of the amino-spacer group into a terminal azide, followed by triazole formation using “click chemistry”. The severe steric bulk of the ligands, however, led to poor efficiency in the coupling step and no increased antibody binding by the resulting neoglycoconjugates, indicating that the low degree of substitution and the spatial orientation of the oligomannose epitopes within these trimeric ligands are not conducive to multivalent 2G12 binding

» https://dx.doi.org/10.1021%2Facs.bioconjchem.8b00731

» Mach Lab

Publication from Jennifer Schoberer & Strasser Lab

"Golgi localization of GnTI requires a polar amino acid residue within its transmembrane domain"

The Golgi apparatus consists of stacked cisternae filled with enzymes to facilitate the sequential and highly controlled modification of glycans from proteins that transit through the organelle. Although the glycan processing pathways have been extensively studied, the underlying mechanisms that concentrate Golgi resident glycosyltransferases and glycosidases in distinct Golgi compartments are unclear. The single-pass transmembrane domain of N-acetylglucosaminyltransferase I (GnTI) accounts for its steady-state distribution in the cis/medial-Golgi. Here, we investigated the contribution of individual amino acid residues from the GnTI transmembrane domain for Golgi localization and N-glycan processing. Conserved sequence motifs within the transmembrane domain were replaced with those from the well-known trans-Golgi enzyme alpha2,6-sialyltransferase (ST) and site-directed mutagenesis was used to exchange individual amino acid residues. Subcellular localization of fluorescent fusion proteins and N-glycan profiling revealed that a conserved glutamine residue in the GnTI transmembrane domain is essential for its cis/medial-Golgi localization. Replacing the crucial glutamine residue with other amino acids results in mislocalization to the vacuole and impaired N-glycan processing in vivo. Our results suggest that sequence-specific features in the transmembrane domain of GnTI are required for interaction with a Golgi-resident adaptor protein or specific lipid environment that likely promotes COPI-mediated retrograde transport to maintain the steady-state distribution of GnTI in the cis/medial-Golgi.

» https://doi.org/10.1104/pp.19.00310

» https://twitter.com/PlantPhys/status/1116737558472482820

» Strasser Lab

DAGZ Impromptu seminar

Vivien Rolland
CSIRO, Australia

“I see the light! Cell wall engineering, pH and fluorescence”

Wednesday 24.04.2019, 09:00 am
DAGZ Seminar room, 4th floor (MUG2‐04/54)
Muthgasse 18, 1190 Wien
Hosts: Elke Barbez, Sascha Waidmann

» Kleine-Vehn Lab

BiRT Seminar Series

Prof. Dr. Gerhard H. Braus

Georg-August-University Göttingen,
Institute of Microbiology and Genetics
"Aspergillus as model for coordinated development and secondary metabolism"
Donnerstag: 04. April 2019, 09:30 
Campus Tulln / UFT – Seminarraum 14

» Strauss Lab

Publication with contribution from Hauser Lab

"UV-B exposure reduces the activity of several cell wall-dismantling enzymes and affects the expression of their biosynthetic genes in peach fruit (Prunus persica L., cv. Fairtime, melting phenotype)"

Softening processes after ripening are a major factor contributing to the perishability of fleshy fruits and, together with mechanical damage, represents the onset of physiological decay. Softening involves multiple co-ordinated events leading to modifications of the cell wall architecture. Several studies described that UV-B radiation positively affects both the nutraceutical and aesthetical qualities of fruits. However, very few studies investigated the effect of UV-B irradiation on the activity of cell wall-related enzymes. This research aimed to study how different UV-B treatments (10 min and 60 min) affect the activity of cell wall-modifying enzymes (pectin methylesterase, polygalacturonase and β-galactosidase) together with the expression of some of their isoforms up to 36 h after UV-B treatment of peach (cv. Fairtime, melting phenotype) fruits. Results revealed that UV-B radiation did not affect the soluble solid content and the titratable acidity, two important parameters influencing consumers choice and taste. On the contrary, UV-B was effective in reducing the loss of firmness 24 h after the 60 min irradiation. Generally, a lower activity of the hydrolytic enzymes compared to untreated fruits was observed, regardless of the UV-B dose. However, gene expression did not reflect the corresponding enzymatic activity. Based on these results, UV-B irradiation might be a successful tool in reducing the loss of firmness of peach fruit in post-harvest, thus improving their quality and shelf-life.

» https://doi.org/10.1039/C8PP00505B

» Hauser Lab

FWF Projekt für Jennifer Schoberer

"Untersuchung des ER-Golgi Interface mittels Arabidopsis MNS3"

Projektnummer: P 31921 Einzelprojekte  Kuratoriumssitzung: 11.03.2019 » Strasser Lab

FWF Projekt für Georg Seifert

"Protein O-Glycosylierungskontrolle"

Projektnummer: P 32332 Einzelprojekte Kuratoriumssitzung: 11.03.2019 » Seifert Lab

Preprint from Kleine-Vehn Lab

"Cytokinin functions as an asymmetric and anti-gravitropic signal in lateral roots" Abstract
Directional organ growth allows the plant root system to strategically cover its surroundings. Intercellular auxin transport is aligned with the gravity vector in the primary root tips, facilitating downward organ bending at the lower root flank. Here we show that cytokinin signaling functions as a lateral root specific anti-gravitropic component, promoting the radial distribution of the root system. We performed a genome-wide association study and revealed that signal peptide processing of Cytokinin Oxidase 2 (CKX2) affects its enzymatic activity and, thereby, determines the degradation of cytokinins in natural Arabidopsis thaliana accessions. Cytokinin signaling interferes with growth at the upper lateral root flank and thereby prevents downward bending. Our interdisciplinary approach revealed that two phytohormonal cues at opposite organ flanks counterbalance each others negative impact on growth, suppressing organ growth towards gravity and allow for radial expansion of the root system. » https://doi.org/10.1101/572941 » Kleine-Vehn Lab

Publication from Kleine-Vehn Lab

"Extracellular matrix sensing by FERONIA and Leucine‐Rich Repeat Extensins controls vacuolar expansion during cellular elongation in Arabidopsis thaliana" Abstract
Cellular elongation requires the defined coordination of intra‐ and extracellular processes, but the underlying mechanisms are largely unknown. The vacuole is the biggest plant organelle, and its dimensions play a role in defining plant cell expansion rates. Here, we show that the increase in vacuolar occupancy enables cellular elongation with relatively little enlargement of the cytosol in Arabidopsis thaliana. We demonstrate that cell wall properties are sensed and impact on the intracellular expansion of the vacuole. Using vacuolar morphology as a quantitative read‐out for intracellular growth processes, we reveal that the underlying cell wall sensing mechanism requires interaction of extracellular leucine‐rich repeat extensins (LRXs) with the receptor‐like kinase FERONIA (FER). Our data suggest that LRXs link plasma membrane‐localised FER with the cell wall, allowing this module to jointly sense and convey extracellular signals to the cell. This mechanism coordinates the onset of cell wall acidification and loosening with the increase in vacuolar size. » https://doi.org/10.15252/embj.2018100353 » Kleine-Vehn Lab

Umwelt.Wissen Tage für Kids

Die Umwelt.Wissen Tage für Kids geben Kindern und Jugendlichen die Möglichkeit, auf spannende Art Umwelt-, Klima- und Energie-Themen  zu erforschen und Organisationen kennen zu lernen, die in diesen Themenfeldern aktiv sind.  „Liquid handling“ oder Was tun die im Labor den ganzen Tag?
Kannst Du mit kleinen Mengen Substanz umgehen? In unserer Forschung analysieren wir Pilze, Bakterien sowie Proben aller Art. Wir verwenden oft kleine Mengen Flüssigkeit und beobachten Reaktionen. An der Station wird anhand eines Pipettierschemas der Umgang mit Pipetten geübt.
Wir verwenden Farblösungen und kreieren eine bunte Platte mit bis zu 96 Positionen. So kann ein Eindruck der wesentlichsten Arbeitsschritte in der molekularen und mikrobiologischen Forschung gewonnen werden. Die BiMM hat mit 120 Kindern pipettieren geübt. Jetzt wissen die was wir im Labor so machen. » http://www.umweltwissenkids.at/ » Videoclip der Umwelt.Wissen Tage » https://www.bimm-research.at/

Publication from Kalyna Lab

"Does co-transcriptional regulation of alternative splicing mediate plant stress responses?" Abstract
Plants display exquisite control over gene expression to elicit appropriate responses under normal and stress conditions. Alternative splicing (AS) of pre-mRNAs, a process that generates two or more transcripts from multi-exon genes, adds another layer of regulation to fine-tune condition-specific gene expression in animals and plants. However, exactly how plants control splice isoform ratios and the timing of this regulation in response to environmental signals remains elusive. In mammals, recent evidence indicate that epigenetic and epitranscriptome changes, such as DNA methylation, chromatin modifications and RNA methylation, regulate RNA polymerase II processivity, co-transcriptional splicing, and stability and translation efficiency of splice isoforms. In plants, the role of epigenetic modifications in regulating transcription rate and mRNA abundance under stress is beginning to emerge. However, the mechanisms by which epigenetic and epitranscriptomic modifications regulate AS and translation efficiency require further research. Dynamic changes in the chromatin landscape in response to stress may provide a scaffold around which gene expression, AS and translation are orchestrated. Finally, we discuss CRISPR/Cas-based strategies for engineering chromatin architecture to manipulate AS patterns (or splice isoforms levels) to obtain insight into the epigenetic regulation of AS. » https://doi.org/10.1093/nar/gkz121 » Kalyna Lab

DAGZ Tulln Seminar

"Key findings on how different nitrogen sources affect root development in Arabidopsis thaliana" Great insights how different forms of nitrogen nutrition influence plant root development in the yeasterday DAGZ Tulln seminar given by IST researcher Krisztina Ötvös.  » https://www.researchgate.net/profile/Krisztina_Oetvoes » Strauss Lab

Publication with contribution of Strauss Lab (Simone Bachleitner & Lena Studt)

"Regulation of a novel Fusarium cytokinin in Fusarium pseudograminearum" Abstract
Fusarium pseudograminearum is an agronomically important fungus, which infects many crop plants, including wheat, where it causes Fusarium crown rot. Like many other fungi, the Fusarium genus produces a wide range of secondary metabolites of which only few have been characterized. Recently a novel gene cluster was discovered in F. pseudograminearum, which encodes production of cytokinin-like metabolites collectively named Fusarium cytokinins. They are structurally similar to plant cytokinins and can activate cytokinin signalling in vitro and in planta. Here, the regulation of Fusarium cytokinin production was analysed in vitro. This revealed that, similar to deoxynivalenol (DON) production in Fusarium graminearum, cytokinin production can be induced in vitro by specific nitrogen sources in a pH-dependent manner. DON production was also induced in both F. graminearum and F. pseudograminearum in cytokinin-inducing conditions. In addition, microscopic analyses of wheat seedlings infected with a F. pseudograminearum cytokinin reporter strain showed that the fungus specifically induces its cytokinin production in hyphae, which are in close association with the plant, suggestive of a function of Fusarium cytokinins during infection. » https://doi.org/10.1016/j.funbio.2018.12.009 » Strauss Lab

Publication with contribution of Adam Lab

"Metabolism of nivalenol and nivalenol-3-glucoside in rats" Highlights

  • Characterization of 7 novel nivalenol (NIV)- and NIV-3-glucoside (NIV3 G) metabolites in rats.
  • Development of LC-MS/MS based methods for analysis of NIV(3 G) metabolites in rat excrements.
  • Similar metabolization of NIV and deoxynivalenol in rats, but with different metabolite patterns.
  • NIV3 G is largely hydrolyzed in the GI tract of rats, but also extensively further metabolized.
  • The systemic exposure to NIV is roughly 30 times lower after NIV3 G consumption than after NIV dosage.

» https://doi.org/10.1016/j.toxlet.2019.02.006 » Adam Lab

Publication from Kleine-Vehn Lab

"PILS6 is a temperature-sensitive regulator of nuclear auxin input and organ growth in Arabidopsis thaliana" Significance
High temperature (HT) strongly modulates plant growth and eventually threatens yield stability. HT induces biosynthesis of the phytohormone auxin, which in turn increases cellular auxin levels and growth rates in shoots. This mechanism does not control HT-induced root growth and, hence, the role of auxin in this process is currently controversial. Here we show that the putative auxin carrier PIN-LIKES 6 (PILS6) localizes to the endoplasmic reticulum, where it gates nuclear auxin accumulation and perception. HT decreases the abundance of PILS6 proteins, consequently increasing nuclear auxin signaling and root growth. Our data dismantle current controversy, revealing an alternative subcellular mechanism in roots, which links PILS6-dependent control of cellular auxin sensitivity with HT-induced organ growth. » https://doi.org/10.1073/pnas.1814015116 » Presseaussendung » Kleine-Vehn Lab

Publication from Kleine-Vehn Lab

"Identification of novel inhibitors of auxin-induced Ca2+ signaling via a plant-based chemical screen" Abstract
Many signal perception mechanisms are connected to Ca2+-based second messenger signaling to modulate specific cellular responses. The well-characterized plant hormone auxin elicits a very rapid Ca2+ signal. However, the cellular targets of auxin-induced Ca2+ are largely unknown. Here, we screened a biologically annotated chemical library for inhibitors of auxin-induced Ca2+ entry in plant cell suspensions to better understand the molecular mechanism of auxin-induced Ca2+ and to explore the physiological relevance of Ca2+ in auxin signal transduction. Using this approach, we defined a set of diverse, small molecules that interfere with auxin-induced Ca2+ entry. Based on annotated biological activities of the hit molecules, we found that auxin-induced Ca2+ signaling is, among others, highly sensitive to disruption of membrane proton gradients and the mammalian Ca2+ channel inhibitor bepridil. Whereas protonophores nonselectively inhibited auxin-induced and osmotic-stress-induced Ca2+ signals, bepridil specifically inhibited auxin-induced Ca2+. We found evidence that bepridil severely alters vacuolar morphology and antagonized auxin-induced vacuolar remodeling. Further exploration of this plant-tailored collection of inhibitors will lead to a better understanding of auxin-induced Ca2+ entry and its relevance for auxin responses. » https://doi.org/10.1104/pp.18.01393 » Kleine-Vehn Lab

Publication from Kalyna Lab

"VARIFI-Web-Based Automatic Variant Identification, Filtering and Annotation of Amplicon Sequencing Data" Abstract
Fast and affordable benchtop sequencers are becoming more important in improving personalized medical treatment. Still, distinguishing genetic variants between healthy and diseased individuals from sequencing errors remains a challenge. Here we present VARIFI, a pipeline for finding reliable genetic variants (single nucleotide polymorphisms (SNPs) and insertions and deletions (indels)). We optimized parameters in VARIFI by analyzing more than 170 amplicon-sequenced cancer samples produced on the Personal Genome Machine (PGM). In contrast to existing pipelines, VARIFI combines different analysis methods and, based on their concordance, assigns a confidence score to each identified variant. Furthermore, VARIFI applies variant filters for biases associated with the sequencing technologies (e.g., incorrectly identified homopolymer-associated indels with Ion Torrent). VARIFI automatically extracts variant information from publicly available databases and incorporates methods for variant effect prediction. VARIFI requires little computational experience and no in-house compute power since the analyses are conducted on our server. VARIFI is a web-based tool available at varifi.cibiv.univie.ac.at. » https://doi.org/10.3390/jpm9010010 » Kalyna Lab

Welcome Felipe dos Santos Maraschin!

The Kleine-Vehn lab is currently hosting Prof. Felipe dos Santos Maraschin from the Federal University of Rio Grande do Sul (Porto Alegre, Brazil). In the frame of an ERC project, the labs are collaborating on light signalling in roots. » https://www.researchgate.net/profile/Felipe_Maraschin » Kleine-Veh Lab

Impromptu seminar by Toshiki Kameyama

"Cancer-specific aberrant mRNA re-splicing and its repressors: What are the splicing termination mechanisms destroyed in cancer cells?"
(Fujita Health University, Japan) Talk synopsis:
"We have recently discovered the cancer-specific aberrant splicing that occurs through re-splicing in the mature spliced mRNAs.  In normal cells, spliced mRNA must export to the cytoplasm to serve as a template for the protein biosynthesis. However, such mature mRNA is spliced again and generates aberrant truncated mRNA in cancer cells.  This finding implicates the control mechanism to prevent deleterious extra mRNA splicing that must operate in normal cells.  We are currently identifying repressor candidates of mRNA re-splicing."  About speaker:
Toshiki Kameyama is an Assistant Professor at the Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Japan. His research focuses on aberrant splicing in cancer and transcriptional and post-transcriptional regulation of gene expression in the nervous system development and in neurological diseases. 27. February 2019, 11:00 am
Seminarraum Angewandte Genetik (MUG2-04/54)
Muthgasse 18, 1190 Wien

Publication from Strauss Lab

"A novel laminar-flow-based bioaerosol test system to determine biological sampling efficiencies of bioaerosol samplers" Abstract
In this work, we describe a novel type of bioaerosol test system based on a laminar airflow chamber that provides a homogenous aerosol of microbial cells with known concentrations and defined culturability to bioaerosol samplers positioned in the chamber. In the system, three control and monitoring points (CMPs) are implemented in which the number and culturability of microbes can be determined by combining optical particle counting with microscopic and culture-based microbiological analyses...  » https://doi.org/10.1080/02786826.2018.1562151  » Strauss Lab

Paper from BiMM and Schüller Lab with AKH

"Antifungal susceptibility of yeast blood stream isolates collected during a 10 year period in Austria" Background
Candida‐associated infections put a significant burden on western health care systems. Development of (multi‐) resistant fungi can become untreatable and threaten especially vulnerable target groups, such as the immunocompromised. Objectives
We assessed antifungal susceptibility and explored possible influence factors of clinical Candida isolates collected from Austrian hospitals between 2007 and 2016 » https://doi.org/10.1111/myc.12892 » BiMM Bioactive Microbial Metabolites » Schüller Lab

Publication with contribution from Hauser Lab

"Comparative “phenol-omics” and gene expression analyses in peach (Prunus persica) skin in response to different postharvest UV-B treatments" Highlights

  • UV-B exposure increased expression of flavonoid and UVR8 genes
  • Accumulation of most phenolics occurred 36 h after UV-B irradiation
  • 60 min-UVB-exposure determined a greater phenolic accumulation than 10 min-UVB
  • Flavonoids, particularly anthocyanins, were the most UV-B-affected phenolics
  • UV-B treatment determined a higher complexity level of anthocyanins after 36 h

» https://doi.org/10.1016/j.plaphy.2018.11.009 » Hauser Lab

Publication with contribution from Adam Lab

"The role of roughage provision on the absorption and disposition of the mycotoxin deoxynivalenol and its acetylated derivatives in calves: from field observations to toxicokinetics." Abstract
A clinical case in Belgium demonstrated that feeding a feed concentrate containing considerable levels of deoxynivalenol (DON, 1.13 mg/kg feed) induced severe liver failure in 2- to 3-month-old beef calves. Symptoms disappeared by replacing the highly contaminated corn and by stimulating ruminal development via roughage administration. A multi-mycotoxin contamination was demonstrated in feed samples collected at 15 different veal farms in Belgium... » https://doi.org/10.1007/s00204-018-2368-8 » Adam Lab

Publication with contribution from Adam Lab

"Untargeted LC–MS based 13C labelling provides a full mass balance of deoxynivalenol and its degradation products formed during baking of crackers, biscuits and bread" Highlights

  • Deoxynivalenol (DON) is mostly stable during the baking process.
  • isoDON, norDON B and norDON C were identified as DON degradation products.
  • The major thermal degradation product of DON is isoDON.
  • isoDON is far less toxic to ribosomes than DON.

» https://doi.org/10.1016/j.foodchem.2018.11.150 » Adam Lab

Publication from Adam Lab

"Cross-reactivity of commercial and non-commercial deoxynivalenol-antibodies to emerging trichothecenes and common deoxynivalenol-derivatives" Abstract
Immunoassay based techniques are an important and fast option for the detection and quantification of mycotoxins. They are frequently used as on-site screening tools in grain elevators, storage and production facilities. However, accurate quantification may be hampered by the co-recognition of structurally related metabolites by the used antibodies. Therefore, it is crucial to assess their cross-reactivity to avoid misinterpretation of the results... » https://www.wageningenacademic.com/doi/pdf/10.3920/WMJ2018.2363 » Adam Lab

International PhD Programme “Biomolecular Technology of Proteins (BioToP)”

at the Vienna Institute of BioTechnology of BOKU
University of Natural Resources and Life Sciences, Vienna, Austria » fully-funded PhD student positions for three years BioToP offers an inter- and multi-disciplinary research-based doctoral education at the interface of basic and applied science in the field of protein biotechnology.
BioToP offers a challenging scientific environment with state-of-the-art facilities and provides comprehensive and thorough up-to-date research training in the fields of:

  • structure-function analysis, engineering and design of proteins
  • protein synthesis, targeting and post-translational modifications
  • expression systems and cell factories
  • bioinformatics and molecular modelling

The BioToP-specific educational programme comprises lectures, seminars and instructional courses that complement the research work in the participating groups. Highly qualified and motivated students of any nationality are invited to apply for the 3-year studentships. Funding will be according to the salary scheme of the Austrian Science Fund.
Additionally students will receive funding for research stays abroad and for the participation at international conferences. Further information on research projects as well as application guidelines and forms are available at:  http://biotop.boku.ac.at Application deadline: February 13th, 2019

Publication from Lena Studt (Strauss Lab)

"The putative H3K36 demethylase BcKDM1 affects virulence, stress responses and photomorphogenesis in Botrytis cinerea" Highlights:

  • T-DNA insertion in the virulence-attenuated mutant PA2810 disrupts bckdm1.
  • Bckdm1 encodes a putative histone 3 lysine 36-specific demethylase. 
  • Bckdm1 is required for virulence, stress responses and photomorphogenesis.
  • Orthologs from other Ascomycetes cannot replace BcKDM1.

» https://doi.org/10.1016/j.fgb.2018.11.003 » Strauss Lab

Impromptu Seminar of Dr. Surinder Chopra

"Maize and Sorghum Flavonoid Pigments: From Genetic and Epigenetic Markers to Plant Health Applications"
(Penn State University, Department of Plant Sciences) The goal of Dr. Surinder Chopra’s research is to develop a better understanding of metabolic coordination and role of secondary metabolites in plant developmental process as well as plant resistance to biotic and abiotic stresses. His group uses a flavonoid biosynthetic pathway in maize and sorghum as a model system. The research has led to the identification of a genetic factor that is involved in the biosynthesis of a class of plant flavonoid compounds, which act as anti-fungal agents in sorghum. These antifungal metabolites are also known as phytoalexins and in sorghum these compounds belong to the 3-deoxyanthocyanidin category. The group is now generating sorghum and maize mutants and introgression lines/over expression breeding lines to understand the regulation of defense compounds. In addition to the biotic stress, they are screening and developing new sorghum accessions that are tolerant to colder climatic regions. 19. December 2018, 11:00-11:45
Seminarraum Angewandte Genetik (MUG2-04/54)
Muthgasse 18, 1190 Wien

Guest Professor at the DAGZ

David Cánovas research interests are focused on the signals that control fungal development and reproduction using Aspergillus nidulans and Neurospora crassa as model organisms. 941001 VU Genetics of fungal development (in Eng.)  BOKU online
06.12.2018 - 14.12.2018, UFT Tulln, 3 ECTS

  • 06.12.2018: 09:00 14:00 (Lab E2.4.170)
  • 07.12.2018: 09:00 14:00 (Lab E2.4.170)
  • 10.12.2018: 09:00 15:00 (Lab E2.4.170)
  • 11.12.2018: 09:00 15:00 (Lab E2.4.170)
  • 12.12.2018: 09:00 14:00 (Lab E2.4.170)
  • 13.12.2018: 09:00 14:00 (Lab E2.4.170)
  • 14.12.2018: 09:00 14:00 (Lab E2.4.170)

David Cánovas studied Pharmacology at the University of Sevilla and received his Ph.D. degree in Pharmacology with a focus on Molecular and Cellular Biology in 1999. He received further training as a postdoc, first in environmental microbiology and then in fungal genetics, in the National Center for Biotechnology – CSIC (Madrid, Spain) and the University of Melbourne (Australia). He was appointed as a tenure track (within the competitive national “Ramon y Cajal” program) in the Department of Genetics – University of Sevilla in 2008. He was appointed Associate Professor in 2012. Currently he is associate editor of several international journals.  He was recently the recipient of a Lise Meitner project from the FWF to study the role of nitric oxide in fungal reproduction at the DAGZ, which finished in 2017 and has already resulted in several publications.

Preprint from Kalyna Lab

"Remote control of alternative splicing in roots through TOR kinase" Abstract
For plants, light is the source of energy and the most relevant regulator of growth and adaptations to the environment by inducing changes in gene expression at various levels, including alternative splicing. Chloroplasts trigger retrograde signals that control alternative splicing in leaves and roots in response to light.  https://doi.org/10.1101/472126 Kalyna Lab

Publication From Strauss Lab

"Chromatin mapping identifies BasR, a key regulator of bacteria-triggered production of fungal secondary metabolites" The eukaryotic epigenetic machinery can be modified by bacteria to reprogram the response of eukaryotes during their interaction with microorganisms. We discovered that the bacterium Streptomyces rapamycinicus triggered increased chromatin acetylation and thus activation of the silent secondary metabolism ors gene cluster in the fungus Aspergillus nidulanshttps://www.ncbi.nlm.nih.gov/pubmed/30311911 Strauss Lab

DAGZ Seminar 11.12.2018

Alexander Jones
Sainsbury Laboratory "The makings of a gradient: visualising plant hormones in vivo"" Tuesday 11.12.2018
09:00 am
DAGZ seminar room (4th floor, Muthgasse 18, 1190 Wien) 
Host: Sascha Waidmann Kleine-Vehn Lab

BiRT Lecture Series

Dr. Jan-Peter George
BFW Bundesforschungszentrum für Wald
Institut für Waldgenetik "Molecular genetics reveal putative adaptive variation in resistance against Chrysomyxa rhododendri in Norway spruce" Thursday November 22nd, 2018
Time: 10:00
Campus Tulln / UFT – Seminar Room 14
Host: Joseph Strauss & Markus Gorfer Strauss Lab

VIBT Seminar

Kris Vissenberg
IMPRES (Integrated Molecular Plant physiology Research)
Biology Department, University of Antwerp, Belgium "Control of root hair development in Arabidopsis thaliana" Friday 09.11.2018, 13:00
DAGZ seminar room (MUG2-04/54)
Host: Marie-Theres Hauser Hauser Lab

BiRT Seminar Series „die Welt der biologischen Interaktionen“

Friedrich Kragler Univ. Doz. Dr.
Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm Germany "Lost in translation: messenger RNA moving to distant tissues" Wann: 14. November 2018, 10:00
Wo: Campus Tulln / UFT – Seminarraum 17'
Host: Christoph Schüller Schüller Lab

Die BiMM und das Internet der Pilze

Auf der Suche nach Links im Internet der Pilze 
Können Schimmelpilze Informationen über die Abwehr von Bakterien an das gesamte Pilznetzwerk weitergeben und speichern?
Die Antwort auf diese Frage könnte bei der Entwicklung neuer Antibiotika und Krebstherapien helfen » zum Artikel Strauss Lab BiMM Bioactive Microbial Metabolites

Publication from Kalyna Lab

"PRP4KA, a Putative Spliceosomal Protein Kinase, Is Important for Alternative Splicing and Development in Arabidopsis thaliana" Splicing of pre-mRNAs is an essential step in the expression of most eukaryotic genes. Both constitutive splicing and alternative splicing, which produces multiple mRNA isoforms from a single primary transcript, are modulated by reversible protein phosphorylation. Although the plant splicing machinery is known to be a target for phosphorylation, the protein kinases involved remain to be fully defined... The article has been chosen as a highlight for the December issue of GENETICS. http://www.genetics.org/content/210/4/NP https://doi.org/10.1534/genetics.118.301515 Kalyna Lab

Publication from Schüller Lab

"A constitutive active allele of the transcription factor Msn2 mimicking low PKA activity dictates metabolic remodeling in yeast" In yeast, protein kinase A (PKA) adjusts transcriptional profiles, metabolic rates and cell growth in concordance with carbon source availability. PKA affects gene expression mostly via the transcription factors Msn2 and Msn4, two key regulators of the environmental stress response. Here we analyzed the role of the PKA-Msn2 signaling module by using an Msn2 allele that harbors serine to alanine substitutions at six functionally important PKA motifs (Msn2A6)... https://doi.org/10.1091/mbc.E18-06-0389 Schüller Lab

FWF Einzelprojekt für Richard Strasser

"Der Oligosaccharyltransferase-Komplex von Pflanzen"

Projektnummer: P 31920 Einzelprojekte ProjektleiterIn: Richard STRASSER Kuratoriumssitzung: 01.10.2018 Strasser Lab

“Endoplasmic reticulum-associated degradation of glycoproteins”

Richard Strasser talks about “Endoplasmic reticulum-associated degradation of glycoproteins” at the GMI seminar. Friday, 19 October 2018, 11:30am @ GMI, Orange Seminar Room. Gregor Mendel Institute of Molecular Plant Biology GmbH
Dr. Bohr-Gasse 3, 1030 Vienna Strasser Lab

BiRT Seminar Series „die Welt der biologischen Interaktionen“

Prof. Ivo Frébort
Palacký University Olomouc, Czech Republic "Plants as a tool for sustainable global development - Genetic improvement of barley and molecular farming" Wann: 18. Oktober 2018, 9:30
Wo: Campus Tulln / UFT – Seminarraum 14

Publication from Strauss Lab

Fungus found floating in the Danube river - now identified and described by BiMM team as new fungal species: 
"Metapochonia lutea, a new species isolated from the Danube river in Austria" A new species Metapochonia lutea (Ascomycota, Hypocreales) is described and illustrated. This fungus differs from the other taxa in the genus Metapochonia by its production of intensive yellow pigment in culture, conidiophores with relatively complex verticillate branching, bean-shaped conidia, and by delayed development of one-celled and prominent thick-walled submerged chlamydospores usually in chains or irregular clusters of 3–5 cells...  https://www.schweizerbart.de/journals/nova_hedwigia Strauss Lab

Publication from Adam Lab

"Impact of glutathione modulation on the toxicity of the Fusarium mycotoxins deoxynivalenol (DON), NX-3 and butenolide in human liver cells." DON, NX-3 and butenolide (BUT) are secondary metabolites formed by Fusarium graminearum. Evidence for formation of DON-glutathione adducts exists in plants, and also in human liver (HepG2) cells mass spectrometric evidence for GSH-adduct formation was reported. NX-3 is a DON derivative lacking structural features for Thiol-Michael addition, while BUT has the structural requirements (conjugated double bond and keto group)... https://www.ncbi.nlm.nih.gov/pubmed/30244016 Adam Lab

Publication from Adam Lab

"New Plasmids for Fusarium Transformation Allowing Positive-Negative Selection and Efficient Cre-loxP Mediated Marker Recycling" In filamentous fungi such as Fusarium graminearum, disruption of multiple genes of interest in the same strain (e.g., to test for redundant gene function) is a difficult task due to the limited availability of reliable selection markers. We have created a series of transformation vectors that allow antibiotic-based selection of transformants and subsequent negative selection for marker removal using thymidine kinase fusions combined with the Cre-loxP system...  https://doi.org/10.3389/fmicb.2018.01954 Adam Lab

Hands-on Exhibition for children "Earth & Soil"

Our department is a cooperation partner for an upcoming exhibition of the Zoom museum.
This hands on exhibition on "Earth and Soil" is for children ages 6-12.
Running time: 27. September 2018 - 24. February 2019 Zoom Kindermuseum Kleine-Vehn Lab

Congratulations Verena!

Congratulation to Verena Unterwurzacher to finalzing her PhD Thesis with an excellent defense!
Thesis was done over the last years in collaboration with the AIT group of Markus Gorfer.
Topic: "Development of a multiplex qPCR detection systems for fungal indoor contamination" Strauss Lab


At the 10th ÖGMBT meeting Somanath Kallolimath was awarded with the ÖGMBT Life Science PhD Award 2018 (sponsored by THP medical products). Steinkellner Lab

WKO Preis 2018 für Andreas Schüller (Strauss Lab)

Andreas Schüller stellt sein Projekt vor, welches mit dem Wirtschaftskammerpreis 2018 an der BOKU ausgezeichnet wurde. Es geht um die Etablierung eines neuen Systems zur gezielten Aktivierung und Entdeckung von bioaktiven Stoffen in filamentösen Pilzen. https://www.youtube.com/watch?v=3BCayifmbxo Strauss Lab

"Development of the Next Generation Influenza Vaccine"

Seminar of Marc-André D’Aoust Vice-President, Research and Innovation Medicago, inc, CAN

Thurs, 4th Oct 2018, 2 pm
Seminar room Department of Applied Genetics and Cell Biology (Muthgasse 18, 4th floor)

Host: Herta Steinkellner, Richard Strasser, Alexandra Castilho


The BOKU (Jürgen Kleine-Vehn), GMI (Yasin Dagdas) and the University of Vienna (Verena Ibl) have organized (4th-7th September 2018) together the 21st Meeting of the European Network of Plant Endomembrane Research (ENPER)  #ENPER 2018
150 plant cell biologists attended the meeting. » Kleine-Vehn Lab
» Dagdas Lab
» Ibl Lab

FWF Project for Lena Studt 

"Role of the histone variant H2A.Z in phytopathogenic fusaria" project number:  I 3911 Internationale Projekte decision board: 25.06.2018 » Lena Studt

Publication from Seifert Lab

"A speculation on the tandem fasciclin 1 repeat of FLA4 proteins in angiosperms" Abstract
The Arabidopsis thaliana Fasciclin like arabinogalactan protein 4 (FLA4) locus is required for normal root growth in a linear genetic pathway with the FEI1 and FEI2 loci coding for receptor-like kinases. The two Fas1 domains of FLA4 are onserved among angiosperms but only the C-terminal Fas1 domain is required for genetic function... » https://doi.org/10.1080/15592324.2018.1507403 » Seifert Lab

»Just cut it - an easy way to turn a negative regulator to positive mode-of-action« Publication from Strauss Lab

"Truncation of the transcriptional repressor protein Cre1 in Trichoderma reesei Rut-C30 turns it into an activator" Background
The filamentous fungus Trichoderma reesei is a natural producer of cellulolytic and xylanolytic enzymes and is therefore industrially used. Many industries require high amounts of enzymes, in particular cellulases. Strain improvement strategies by random mutagenesis yielded the industrial ancestor strain Rut-C30...  » https://doi.org/10.1186/s40694-018-0059-0 » Strauss Lab

Publication from Schüller Lab

"Competition of Candida glabrata against Lactobacillus is Hog1 dependent" Abstract
Candida glabrata is a common human fungal commensal and opportunistic pathogen. This fungus shows remarkable resilience as it can form recalcitrant biofilms on indwelling catheters, has intrinsic resistance against azole antifungals and is causing vulvo‐vaginal candidiasis. As a nosocomial pathogen, it can cause life‐threatening bloodstream infections in immune‐compromised patients...  » https://doi.org/10.1111/cmi.12943 » Schüller Lab

Publication from Hauser Lab

"Multiplex mutagenesis of four clustered CrRLK1L with CRISPR/Cas9 exposes their growth regulatory roles in response to metal ions" Abstract
Resolving functions of closely linked genes is challenging or nearly impossible with classical genetic tools. Four members of the Catharanthus roseus receptor-like kinase 1-like (CrRLK1L) family are clustered on Arabidopsis chromosome five. To resolve the potentially redundant functions of this subclass of CrRLK1Ls named MEDOS1 to 4 (MDS1 to 4), we generated a single CRISPR/Cas9 transformation vector using a Golden Gate based cloning system to target all four genes simultaneously...  » https://doi.org/10.1038/s41598-018-30711-3 » Hauser Lab

Publication from Lena Studt (Strauss Lab)

"Set1 and Kdm5 are antagonists for H3K4 methylation and regulators of the major conidiation‐specific transcription factor gene ABA1 in Fusarium fujikuroi" Summary
Here we present the identification and characterisation of the H3K4‐specific histone methyltransferase Set1 and its counterpart, the Jumonji C demethylase Kdm5, in the rice pathogen Fusarium fujikuroi. While Set1 is responsible for all detectable H3K4me2/me3 in this fungus, Kdm5 antagonises the H3K4me3 mark. Notably, deletion of both SET1 and KDM5 mainly resulted in the upregulation of genome‐wide transcription, also affecting a large set of secondary metabolite (SM) key genes...  » https://doi.org/10.1111/1462-2920.14339 » Strauss Lab

Preprint from Korbei Lab

"TOL proteins mediate vacuolar sorting of the borate transporter BOR1 in Arabidopsis thaliana" Abstract
Boron (B) is an essential micronutrient for plants, however, it shows cytotoxicity at high concentrations. A borate transporter BOR1 is required for efficient transport of boron (B) toward the root stele in Arabidopsis thaliana. BOR1 shows polar localization in the plasma membrane of various root cells toward the stele-side under B limitation.  » https://doi.org/10.1101/342345 » Korbei Lab

Josef Glössl zum Urteil des Europäischen Gerichtshofs über den Einsatz neuer Mutagenese Methoden:

"Ich bin von diesem Urteil sehr enttäuscht, weil ich es in den wesentlichen Punkten nicht für sachlich begründet und nachvollziehbar halte" ⇒ zum Artikel   ⇒ zum Urteil im Wortlaut

Gesichter der BOKU - David Cánovas

Interview mit David Cánovas Mitarbeiter Fungal Genomics Unit - Universitäts- und Forschungszentrum Tulln https://youtu.be/iSoieigVGv0  » Strauss Lab

Publication from Adam Lab

"Response of intestinal HT-29 cells to the trichothecene mycotoxin deoxynivalenol and its sulfated conjugates" The sulfated forms of the Fusarium toxin deoxynivalenol (DON), deoxynivalenol-3-sulfate (DON-3-Sulf) and deoxynivalenol-15-sulfate (DON-15-Sulf) were recently described, however little is known about their mechanism of action in mammalian cells...  » https://doi.org/10.1016/j.toxlet.2018.07.007 » Adam Lab

PhD Defense of Julia Richter  - passed with distinction!

"The role of cell wall integrity receptors in responses to heavy metals" Zeit: Mittwoch, 11.07.2018, 10:00
Ort: Seminarraum Angewandte Genetik (MUG2-04/54)
Muthgasse 18, 4. Stock Supervisor: Marie-Theres Hauser

Publication from Mach Lab

"The two cathepsin B-like proteases of Arabidopsis thaliana are closely related enzymes with discrete endopeptidase and carboxydipeptidase activities" The genome of the model plant Arabidopsis thaliana encodes three paralogues of the papain-like cysteine proteinase cathepsin B (AtCathB1, AtCathB2 and AtCathB3), whose individual functions are still largely unknown. » https://doi.org/10.1515/hsz-2018-0186 » Mach Lab

FWF Elise-Richter Programm for Elena Feraru

Auxin homeostasis in plant organ responses to high temperature project number: V 690 Richter-Programm decision board: 25.06.2018 » Elena Feraru

FWF Elise-Richter Programm for Doris Lucyshyn

O-GlcNAc and O-fucose binding plant lectins project number: V 658 Richter-Programm decision board: 25.06.2018 » Lucyshyn Lab

FWF Stand-Alone Project for Christian Luschnig

Ubiquitin E3 Ligases and Cell Polarity in Arabidopsis project number: P 31493 Einzelprojekte decision board: 25.06.2018 » Luschnig Lab

Agrargenetik und Biodiversität - Exkursion 20.06.2018

Das war auch heuer wieder ein spannender Exkursionstag im Zoo Schönbrunn mit Vorträgen und Backstage-Führungen für unsere Studierenden des Bachelorstudiums Agrarwissenschaften.
Die Themen: Warum ist Biodiversität nur mit genetischer Diversität denkbar, warum ist Artenschutz essentiell und was sind die Gründe für die „Kernschmelze der Agrar-Biodiversität“ in den letzten Jahrzehnten? 

Diese und viele weitere Fragen wurden von den Studierenden mit den Veranstaltern diskutiert. Ein Angebot des DAGZ im Zuge der Lehrveranstaltung "941091 Agrargenetik und Biodiversität - Exkursion". 

Publication from Steinkellner Lab

"Advanced Plant-Based Glycan Engineering" With respect to biomanufacturing, glycosylation is one of the most addressed post-translational modifications, since it is well-known that the attachment of sugar residues efficiently affects protein homogeneity and functionality. Much effort has been taken into engineering various expression systems to control glycosylation and to generate molecules with targeted sugar profiles.  » https://doi.org/10.3389/fbioe.2018.00081 » Steinkellner Lab

Vortrag zum Thema "Der EU-Sortenschutz, gewerblicher Rechtsschutz für Pflanzensorten"

Der dazu eingeladene Experte, Dirk Theobal kommt vom Gemeinschaftlichen Sortenamt (CPVO) und wird über die Funktionsweise des gemeinschaftlichen Systems zum Schutz von Pflanzensorten, die technischen Schutzanforderungen an Sorten und die rechtlichen Verfahren berichten (die Agenda finden Sie im Anhang) Donnerstag, 14.06.2018, von 09:00 bis 12:00 Uhr   Department für Angewandte Genetik und Zellbiologie (DAGZ): Muthgasse 18, (MUG2-04/54)

Publication from Seifert Lab

"Fascinating Fasciclins: A Surprisingly Widespread Family of Proteins that Mediate Interactions between the Cell Exterior and the Cell Surface" The Fas1 proteins act as mediators between the cell and its environment and function in similar fashion in processes as diverse as human brain cancer and pollen formation in plants.This review for the first time compares the biology of Fas1 proteins from all kingdoms of life. » https://doi.org/10.3390/ijms19061628 » Seifert Lab

Josef Glössl zum stellvertretenden Vorsitzenden des Universitätsrats der Medizinischen Universität Innsbruck gewählt   Professor Josef Glössl, gerade eben aus dem Rektorat der BOKU (Vizerektor für Forschung und Internationale Beziehungen) an das DAGZ zurückgekehrt, wurde vor Kurzem zum stellvertretenden Vorsitzenden des Universitätsrats der Medizinischen Universität Innsbruck gewählt.  Herzliche Gratulation! » Universitätsrat der Medizinischen Universität Innsbruck 

Visit from the Wake Forest University

Elizabeth Sarkel, a junior biochemistry and molecular biology major from Columbus, Ohio is joining the Kleine-Vehn Lab again this summer. Elizabeth received a Fulbright Program fellowship and will work on gravitropic set point angle of lateral roots.
______________ Twitter: • The Fulbright Program @FulbrightPrgrm
• Wake Forest University @WakeForest
• Kleine-Vehn Lab  @KleineVehnLab 

FWF-Project for Herta Steinkellner

IgG Subclass Glycosylation

Project lead: Herta Steinkellner

I 3721 Internationale Projekte
Start: 01.06.2018

Publication from Seifert Lab

"Mad moves of the building blocks – nucleotide sugars find unexpected paths into cell walls"  This short review tracks the unexpectedly yet purposefully complex, intracellular journey of an activated sugar before it safely reaches its destination in plant fibre polysaccharides. » https://doi.org/10.1093/jxb/ery026 » Seifert Lab

Publication from Kleine-Vehn Lab

"The Road to Auxin-Dependent Growth Repression and Promotion in Apical Hooks" The phytohormone auxin controls growth rates within plant tissues, but the underlying mechanisms are still largely enigmatic. The apical hook is a superb model to understand differential growth, because it displays both auxin-dependent growth repression and promotion. In this special issue on membranes, we illustrate how the distinct utilization of vesicle trafficking contributes to the spatial control of polar auxin transport, thereby pinpointing the site of growth repression in apical hooks. » https://doi.org/10.1016/j.cub.2018.01.069 » Kleine-Vehn Lab

Publication from Kleine-Vehn Lab

"PIN7 Auxin Carrier Has a Preferential Role in Terminating Radial Root Expansion in Arabidopsis thaliana" Directional growth of lateral roots is critical for radial expansion and soil coverage. Despite its importance, almost nothing is known about its molecular determinants. Initially, young lateral roots (LRs) grow away from the parental root, maintaining the angle acquired shortly after emergence. A second downwards bending response to gravity terminates the so-called plateau phase and thereby limits radial root expansion  » doi:10.3390/ijms19041238 » Kleine-Vehn Lab

Publication from Hauser Lab

"Arabidopsis ILITHYIA protein is necessary for proper chloroplast biogenesis and root development independent of eIF2α phosphorylation"  One of the main mechanisms blocking translation after stress situations is mediated by phosphorylation of the α-subunit of the eukaryotic initiation factor 2 (eIF2), performed in Arabidopsis by the protein kinase GCN2 which interacts and is activated by ILITHYIA(ILA). ILA is involved in plant immunity and its mutant lines present phenotypes not shared by the gcn2 mutants » doi.org/10.1016/j.jplph.2018.04.003 » Hauser Lab

Faszination Pflanze: Warum die Karotte orange ist

Jürgen Kleine-Vehn im Blog der Junge Akademie der ÖAW über die Faszination Pflanze. Hier geht es zum »Blog  
• Jürgen Kleine-Vehn  @KleineVehnLab 
• Junge Akademie der ÖAW  @ya_OeAW

Book on Root Development edited by Elke Barbez (Kleine-Vehn Lab)

This detailed volume provides diverse elegant methods, complemented with existing protocols, which are optimized for the current needs in plant root biology as well as for use in plant species other than Arabidopsis thaliana. The collection covers methods ranging from genetic screens, phenotypic analysis, and cell biology methods to systems biology tools and genome-wide approaches. The collection contains a range of complexity from fundamental methods for quantification of different root developmental processes to complex methods that require sophisticated equipment  » Methods in Molecular Biology, vol 1761

Publication from Korbei Lab and Kleine-Vehn Lab

Immunoprecipitation of Membrane Proteins from Arabidopsis thaliana Root Tissue Abstract
Here, we present different methods for immunoprecipitating membrane proteins of Arabidopsis thaliana root material. We describe two extraction methods for the precipitation either for an integral membrane protein of the endoplasmic reticulum (ER) or a peripheral membrane protein partially localized at the plasma membrane, where we precipitate the protein out of the total membrane as well as total cytosolic fractions  » doi.org/10.1007/978-1-4939-7747-5_16

Publication from Kleine-Vehn Lab

Growth Rate Normalization Method to Assess Gravitropic Root Growth Abstract
Time-lapse imaging of roots is highly suitable for depicting gravitropic growth behaviors. However, roots may show faster or slower bending kinetics when compared to control as a result of differences in overall root growth. Accordingly, conditions that cause differential organ growth require growth rate normalization to compare gravitropic curvature  » doi.org/10.1007/978-1-4939-7747-5_15

Publication from Kleine-Vehn Lab

Cortical Cell Length Analysis During Gravitropic Root Growth

The typical parameter used to evaluate the root growth response to gravity is the degree of root bending in time. This employs the quantification of the root tip angle toward gravity and, hence, does not directly assess the actual differential growth process. Here, we describe the cortical cell length as a parameter to quantify cell elongation during the gravitropic response, using median longitudinal confocal sections  » doi.org/10.1007/978-1-4939-7747-5_14

Congratulations Alexandra!

New FWF Stand-Alone Project: 

N. benthamiana ß-galactosidases acting on glycoproteins

Project lead: Alexandra Castilho

Publication from Adam Lab

UDP-Glucosyltransferases from Rice, Brachypodium, and Barley: Substrate Specificities and Synthesis of Type A and B Trichothecene-3-O-β-D-glucosides Abstract
Trichothecene toxins are confirmed or suspected virulence factors of various plant-pathogenic Fusarium species. Plants can detoxify these to a variable extent by glucosylation, a reaction catalyzed by UDP-glucosyltransferases (UGTs). Due to the unavailability of analytical standards for many trichothecene-glucoconjugates, information on such compounds is limited  » full text

PhD Defense of Somanath Kallolimath

Production of recombinant proteins with polysialylated N-glycans in Nicotiana benthamiana 23.02.2018 - 14:00
DAGZ-Seminarroom (MUG2-04/54)
Muthgasse 18, 4th floor Supervisor: Herta Steinkellner

PhD Defense of Chloé Béziat

Characterization of PILS putative intracellular auxin carrier family during developmental processes in Arabidopsis 22.02.2018 - 14:30
DAGZ-Seminarroom (MUG2-04/54)
Muthgasse 18, 4th floor Supervisor: Jürgen Kleine-Vehn

Publication from Steinkellner/Strasser Lab

An oligosaccharyltransferase from Leishmania major increases the N-glycan occupancy on recombinantglycoproteins produced in Nicotiana benthamiana. Summary
N-glycosylation is critical for recombinant glycoprotein production as it influences the heterogeneity of products and affects their biological function. In most eukaryotes, the oligosaccharyltransferase is the central protein-complex facilitating the N-glycosylation of proteins in the lumen of the endoplasmic reticulum (ER)  » doi.org/10.1111/pbi.12906

Publication from Adam Lab:

Chemical synthesis of culmorin metabolites and their biologic role in culmorin and acetyl-culmorin treated wheat cells The Fusarium metabolite culmorin (1) is receiving increased attention as an “emerging mycotoxin”. It cooccurs with trichothecene mycotoxins and potentially influences their toxicity. Its ecological role and fate in plants is unknown. We synthesized sulfated and glucosylated culmorin conjugates as potential metabolites, which are expected to be formed in planta, and used them as reference compounds. An efficient procedure for the synthesis of culmorin sulfates was developed  » DOI: 10.1039/c7ob02460f

Publication from Strasser Lab

The glycan-dependent ERAD machinery degrades topologically diverse misfolded proteins. Summary
A great number of soluble and integral membrane proteins fold in the endoplasmic reticulum (ER) with the help of chaperones and folding factors. Despite these efforts, protein folding is intrinsically error prone and amino acid changes, alterations in posttranslational modifications or cellular stress can cause protein misfolding. Folding-defective non-native proteins are cleared from the ER and typically undergo ER-associated degradation (ERAD)  » doi.org/10.1111/tpj.13851

Publication from Hauser Lab:

Root hair abundance impacts cadmium accumulation in Arabidopsis thaliana shoots Background and Aims
Root hairs increase the contact area of roots with soil and thereby enhance the capacity for solute uptake. The strict hair/non-hair pattern of Arabidopsis thaliana can change with nutrient deficiency or exposure to toxic elements, which modify root hair density. The effects of root hair density on cadmium (Cd) accumulation in shoots of arabidopsis genotypes with altered root hair development and patterning were studied  » doi.org/10.1093/aob/mcx220

Pre-print from Elena Feraru (Kleine-Vehn Lab):

PILS6 is a temperature-sensitive regulator of nuclear auxin input and organ growth in Arabidopsis thaliana Abstract
Global warming is threatening plant productivity, because plant growth is highly sensitive to elevated temperatures. High temperature (HT) triggers the auxin biosynthesis-dependent growth in aerial tissues. On the other hand, the contribution of auxin to HT-induced root growth is currently under debate. Here we show that the putative intracellular auxin carrier PIN-LIKES 6 (PILS6) is a negative regulator of organ growth and that its abundance is highly sensitive to HT  » get the pre-print