LINKING STRESS SIGNALING AND METABOLISM IN PLANTS

Plants face a variety of environmental stresses. As sessile organisms, plants have evolved integrated signal transduction systems to mediate the perception of different environmental cues and to delicately coordinate physiological responses. While progressive global changes call for a better understanding of adaptation processes, our knowledge of how signal transduction coordinates the regulation of metabolic and transcriptional adjustment to stress conditions is scarce. GSK-3/shaggy-like kinases (GSKs) have emerged as novel regulators in plant stress signal transduction. We have provided evidence that MsK4, a GSK from Medicago sativa, links high salinity stress signaling to adjustment of carbohydrate metabolism. Our recent studies on Arabidopsis thaliana GSKs (ASKs) suggest a role for ASKalfa, gamma and epsilon in tolerance to different abiotic stresses as well as in metabolic regulation. The proposed project will characterize ASK-based signaling and analyse its impact on metabolism and gene expression under abiotic stress conditions in a comprehensive approach. To unravel crucial processes in stress signal transduction and adaptation, we aim to address the following questions: (i) How are ASKalfa, gamma and epsilon regulated at the molecular level in response to stress? and (ii) How do ASKalfa-, gamma- and epsilon-based signaling govern stress tolerance, and the temporal dynamics of metabolism and gene expression in response to unfavorable environmental conditions? We will apply an integrative, systems-oriented approach using plants with enhanced ASK activity and mutant lines disrupted in a specific ASK. We seek to correlate physiological phenotypes of ASK-activity mutants with metabolite profiles, obtained by gas chromatography-mass spectrometry (GC-MS), activity levels of metabolic enzymes and gene expression data, and expect to unravel basic mechanisms of ASK-based stress signaling and adaptation processes.

Plants face a variety of environmental stresses. As sessile organisms, plants have evolved integrated signal transduction systems to mediate the perception of different environmental cues and to delicately coordinate physiological responses. While progressive global changes call for a better understanding of adaptation processes, our knowledge of how signal transduction coordinates the regulation of metabolic and transcriptional adjustment to stress conditions is scarce. GSK-3/shaggy-like kinases (GSKs) have emerged as novel regulators in plant stress signal transduction. We have provided evidence that MsK4, a GSK from Medicago sativa, links high salinity stress signaling to adjustment of carbohydrate metabolism. Our recent studies on Arabidopsis thaliana GSKs (ASKs) suggest a role for ASKalfa, gamma and epsilon in tolerance to different abiotic stresses as well as in metabolic regulation. The proposed project will characterize ASK-based signaling and analyse its impact on metabolism and gene expression under abiotic stress conditions in a comprehensive approach. To unravel crucial processes in stress signal transduction and adaptation, we aim to address the following questions: (i) How are ASKalfa, gamma and epsilon regulated at the molecular level in response to stress? and (ii) How do ASKalfa-, gamma- and epsilon-based signaling govern stress tolerance, and the temporal dynamics of metabolism and gene expression in response to unfavorable environmental conditions? We will apply an integrative, systems-oriented approach using plants with enhanced ASK activity and mutant lines disrupted in a specific ASK. We seek to correlate physiological phenotypes of ASK-activity mutants with metabolite profiles, obtained by gas chromatography-mass spectrometry (GC-MS), activity levels of metabolic enzymes and gene expression data, and expect to unravel basic mechanisms of ASK-based stress signaling and adaptation processes.