Molecular dissection of mitochondrial responses to environmental stress

Plants have extensive cellular defense systems to cope with environmental stress. Mitochondria, which perform key metabolic functions such as respiration, form a crucial part of plant stress responses.

This project aims to obtain mechanistic insight into the molecular processes that allow communication between mitochondria and the nucleus, termed retrograde signaling.

Retrograde signalling underpins efficient stress responses and survival, for instance during drought, flooding and pathogen attack.

A transcription factor crucial for retrograde signaling was identified recently, but the molecular mechanisms of how mitochondrial stress leads to its activation are unknown.This project proposes complementary approaches to identify key components of plant retrograde signaling.

These include identification of the second messengers such as Ca2+, H2O2 and ATP that initiate retrograde responses, and screening for proteins that accumulate differentially or undergo redox changes upon mitochondrial inhibition.

Also protein-protein interactions and the ER membrane topology of the transcription factor will be revealed, giving important insights into its recruitment.

Finally, the project will investigate if autophagy plays an important role in retrograde signaling and stress response, using novel detection tools.The ability of plants to respond to environmental stress is of great importance for agriculture. This project will also provide valuable leads for future application in crop species.