Co-ordinate regulation of sugar, ethylene and hypoxia responses at the levels of transcription and metabolism by the SnRK1 kinase in Arabidopsis
Zell- und Entwicklungsbiologie der Pflanzen
Zusammenfassung der Projektergebnisse
The Arabidopsis Snf1-related kinase 1 (SnRK1) plays a central role in the regulation of cellular responses to changes of energy homeostasis. In this project, we performed pathway specific identification of genes that show altered transcription by silencing of SnRK1 and analyzed the underlying changes in the production of critical metabolites. We found that SnRK1 silencing leads to coordinate induction of genes involved in salicylic acid (SA) biosynthesis, uncoupling of mitochondrial respiration, endoplasmic reticulum stress, innate and effector triggered immunity, SA and EIN3-dependent ethylene signaling, trehalose production and programmed cell death, while repressing functions in the maintenance of chloroplast photosystem, cyclin electron transport and photorespiratory activities, blue light, auxin, cytokinin, gibberellin and brassinosteroid signaling. Our data also indicate that SnRK1 is associated with the SCFEBF1/2 ubiquitin ligase and involved in post-translational control of EIN3-dependent ethylene signaling. Metabolite analyses show that silencing of SnRK1 leads to increased levels of SA and other immune-regulatory metabolites, which was accompanied by an inhibition of respiration and impaired photosynthetic performance. Moreover, SnRK1 was found to be important to regulate fermentation by promoting the transcription of hypoxic marker genes under anoxia, being indispensable to optimize anoxic resistance of Arabidopsis plants.
