Jasmonic acid signaling and glutathione coordinate plant recovery from high light stress
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ABSTRACT: High light (HL)-induced chloroplast retrograde signaling originates from the photosynthetic apparatus and regulates nuclear gene expression to enhance photoprotection and coordinate cell metabolism. Here, we analyzed the transcript profiles and accumulation of reactive oxygen species (ROS), stress hormones and small molecule antioxidants to investigate the signaling mechanisms operating under HL stress, and in particular during plant recovery (R) from stress under growth conditions. Exposure to HL for 15 min induced a number of singlet oxygen (1O2) and hydrogen peroxide (H2O2)-responsive genes and accumulation of an oxidative form of glutathione (GSSG) and ascorbate (DHA), the hallmarks of oxidative stress in cells. Prolonged exposure to HL resulted in accumulation of transcripts encoding oxylipin biosynthesis enzymes, leading to accumulation of 12-oxo-phytodienoic acid (OPDA) and jasmonic acid (JA). However, the expression of several JA-responsive genes, already induced by HL, peaked during the R-phase (R-sustained) together with accumulation of JA, reduced glutathione (GSH) and ascorbate (AsA), highlighting the critical role of JA signaling in restoring chloroplast redox balance following HL stress. The involvement of JA signaling in R-sustained gene expression was further confirmed by conducting experiments with JA receptor mutants (coi1). HL exposure of only 2 min was sufficient to induce some R-sustained genes, indicating rapid response of plants to changing light conditions. We propose that ROS production at HL induces the signaling cascade for early oxylipin biosynthesis and OPDA accumulation, while increased accumulation of JA in R-phase activates the genes that fully restore the glutathione metabolism, and ultimately allow recovery from short-term HL stress.
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE277977 | GEO | 2024/10/15
REPOSITORIES: GEO
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