title: Regulation of basal and oxidative stress-triggered jasmonic acid-related gene expression by glutathione.
abstract: Glutathione is a determinant of cellular redox state with roles in defence and detoxification. Emerging concepts suggest that this compound also has functions in cellular signalling. Here, we report evidence that glutathione plays potentially important roles in setting signalling strength through the jasmonic acid (JA) pathway. Firstly, we show that basal expression of JA-related genes is correlated with leaf glutathione content when the latter is manipulated either genetically or pharmacologically. Secondly, analyses of an oxidative stress signalling mutant, cat2, reveal that up-regulation of the JA pathway triggered by intracellular oxidation requires accompanying glutathione accumulation. Genetically blocking this accumulation in a cat2 cad2 line largely annuls H2 O2 -induced expression of JA-linked genes, and this effect can be rescued by exogenously supplying glutathione. While most attention on glutathione functions in biotic stress responses has been focused on the thiol-regulated protein NPR1, a comparison of JA-linked gene expression in cat2 cad2 and cat2 npr1 double mutants provides evidence that glutathione acts through other components to regulate the response of this pathway to oxidative stress. Our study provides new information implicating glutathione as a factor determining basal JA gene expression and suggests novel glutathione-dependent control points that regulate JA signalling in response to intracellular oxidation.
authors.affiliation: Institut de Biologie des Plantes, UMR CNRS 8618, Université de Paris Sud 11, 91405, Orsay Cedex, France.
authors.forename: Yi
authors.initials: Y
authors.lastname: Han
authors.forename: Amna
authors.initials: A
authors.lastname: Mhamdi
authors.forename: Sejir
authors.initials: S
authors.lastname: Chaouch
authors.forename: Graham
authors.initials: G
authors.lastname: Noctor
mesh_terms: D017360:Arabidopsis; D029681:Arabidopsis Proteins / Q000378:metabolism*; D003517:Cyclopentanes / Q000378:metabolism*; D003545:Cysteine / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D005978:Glutathione / Q000378:metabolism*; D018384:Oxidative Stress; D054883:Oxylipins / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D003517:Cyclopentanes; C105496:NPR1 protein, Arabidopsis; D054883:Oxylipins; C011006:jasmonic acid; C490276:CAT2 protein, Arabidopsis; D005978:Glutathione; D003545:Cysteine