Jose Julian

Our lab investigates how plant cells maintain vacuolar integrity during stress. We discovered a conserved Vacuolar Quality Control (VQC) pathway that protects plant cells when the cell wall is damaged. This mechanism depends on ATG8ylation of the tonoplast, a process that remodels the vacuolar membrane and helps plants sustain growth under stress conditions.

By combining molecular genetics, live-cell imaging, and quantitative electron microscopy, we aim to understand how mechanical cues, turgor pressure, and ion balance are sensed and translated into protective responses at the vacuole. Our goal is to uncover how these processes contribute to plant adaptation and mechanical homeostasis (mechanostasis).

The plant vacuole is not only a storage compartment but also a central hub for signaling and stress response. When plants experience environmental stress—such as cell wall damage from pathogens or changes in soil pH—the vacuole must quickly adapt its structure and function.

Our recent findings reveal that the vacuolar membrane (tonoplast) can undergo selective remodeling through a process analogous to CASM (Conjugation of ATG8 to Single Membranes) known in animal systems. This tonoplast ATG8ylation marks the first described vacuolar quality control mechanism in plants.

We are now investigating how ATG8, ATG16 and the V-ATPase cooperate in this process, and what other intermediate elements are responsible from the sensing of the stress to the vacuolar remodeling process. 

ESPRIT 580 – FWF (01-2024/12-2026): Cell wall damage leads to non-canonical autophagy.

ATG8ylation of vacuolar membrane protects plants against cell wall damage (2025)
Jose Julian, Peng Gao, Alessia del Chiaro, Juan Carlos de la Concepción, Laia Armengot, Marc Somssich, Heloise Duverge, Marion Clavel, Nenad Grujic, Roksolana Kobylinska, Ingo Polivka, Maarten Besten, Tonni Grube Andersen, Christian Dank, Barbara Korbei, Andreas Bachmair, Nuria S. Coll, Elena A. Minina, Joris Sprakel & Yasin Dagdas
Nature Plants | Volume 11 | February 2025 | 321–339 View publication

Vacuolar signaling, biogenesis, and quality control in plants (2025)
Jose Julian & Yasin Dagdas
Current Opinion in Plant Biology 2025, 86:102756 View publication