Research

Academic Abstract “Nitrate Signaling in Fungi” Ecologically, nitrate (NO3-) plays a central role in the global nitrogen cycle and it is the main nitrogenous nutrient for plants. Also archaea, bacteria and fungi utilize nitrate for growth but for fungi it is not known, how the genetic network is activated, that leads to the production of the necessary enzymes. Nitrate is not only an essential nutrient for saprophytic, but also for pathogenic fungi. Based on our previous work with NirA and on a collaboration with an experienced structural biology group we will try to crystallize NirA domains or the whole protein in absence and presence of the inducers, to better understand structure-function relationships. Finally, we plan to perform an unbiased forward genetic screen to identify the enzyme that reduces a crucial regulatory methionine sulfoxide (Metox169) during induction. The mechanism by which nitrate-specific transcription factors are activated is not known for any fungal species. Thus, the results of this project will certainly have impact on our understanding how this ecologically important pathway is regulated.

Due to decommissioning of the building due to relocation to another site, there is currently the very rare opportunity of measurement in a decommissioned AUVA office/laboratory building. In fact, such premises offer the opportunity to be able to determine the proportion of deposited mold cells in rooms, which only enter the breathing air during heavy use or when ventilating, by applying controlled ventilation. Since not only viable but also dead mold cells can cause discomfort (allergies, irritation of mucous membranes and respiratory tract), different methods of detection suitable for this issue are used.

As human populations increase while arable land area decreases limited food resources will become a global challenge in the near future. This issue becomes even more clear and urgent in times, in which climate change and geopolitical crises endanger the global food supply. Plant diseases caused by fungi represent the most important threat to the global food supply, yet finding sustainable ways to limit diseases and food spoilage caused by mycotoxins remains a key challenge. To date there is no existing cropping strategy that is fully effective in limiting mycotoxin contaminations and guarantees compliance with official limits (set by EC regulation number 1881/2006). On top of that, published fungal genomes illustrate the enormous genetic capacity to produce hitherto unknown, potentially toxic compounds (so-called secondary metabolites, SMs) not even considered yet1. This is further underlined by the fact that fungal communities are rapidly adapting to changing environmental conditions e.g. mycotoxin occurrence is affected by weather fluctuations and climate change. Next to this, fungi are also known to produce highly effective antibiotics (e.g. penicillin). As antibiotic resistance is one of the biggest threats to global health, food security, and development of our time, discovery of new antibiotics is urgently needed. Without immediate action, we are heading for a post-antibiotic era, in which common infections and minor injuries can once again become life threatening. In both regards, knowledge on the determinants that govern fungal SM biosynthesis is a key challenge in this field of study. Limitations to exploit the full genetic potential of SM-producing fungi arise from the fact that only a fraction of these compounds is produced under standard laboratory conditions. Over the past years, chromatin structure, as determined by changes in histone marks, emerged as a key player in regulating SM gene expression. A breakthrough was the finding that a large proportion of SM genes is silenced by facultative heterochromatin in the genus Fusarium, one of the most economically important fungal genera in the world. Using strains deficient in facultative heterochromatin will be key to fully exploit the chemical potential of filamentous fungi.