ESIS · Energy signaling in the stress response

Plants are constantly confronted by multiple types of nutritional, abiotic and biotic stress. Often associated with stress is a reduction in photosynthesis and/or respiration, which in turn results in energy deprivation and ultimately in growth arrest. Despite their distinct origin and mode of perception, different stresses trigger similar downstream responses that include largely overlapping patterns of gene expression. Our work has shown that this general stress transcriptome is partly regulated by the evolutionarily conserved energy sensor protein kinases, SNF1 (sucrose non-fermenting1) in yeast, AMPK (AMP-activated protein kinase) in mammals and SnRK1 (Snf1-related kinase1) in plants. Upon sensing the energy deficit associated with stress, SnRK1 triggers extensive transcriptional changes that contribute to restoring metabolic and energy homeostasis, promoting cell survival and allowing the elaboration of longer-term responses for adaptation, growth and development. Despite the importance of the uncovered energy signaling pathway, virtually nothing is known regarding its mode of operation. Using a combination of cell-based assays, functional genomics, bioinformatics, mutant screens and genetics, this proposal seeks to gain insight on the regulatory mechanisms that govern SnRK1 action and to further dissect this signaling pathway through the identification of novel components. Elucidation of these mechanisms will contribute to understanding how stress resistance is established and how plant growth and development are finely orchestrated by the environment.