title: Light-induced acclimation of the Arabidopsis chlorina1 mutant to singlet oxygen.
abstract: Singlet oxygen (¹O₂) is a reactive oxygen species that can function as a stress signal in plant leaves leading to programmed cell death. In microalgae, ¹O₂-induced transcriptomic changes result in acclimation to ¹O₂. Here, using a chlorophyll b-less Arabidopsis thaliana mutant (chlorina1 [ch1]), we show that this phenomenon can also occur in vascular plants. The ch1 mutant is highly photosensitive due to a selective increase in the release of ¹O₂ by photosystem II. Under photooxidative stress conditions, the gene expression profile of ch1 mutant leaves very much resembled the gene responses to ¹O₂ reported in the Arabidopsis mutant flu. Preexposure of ch1 plants to moderately elevated light intensities eliminated photooxidative damage without suppressing ¹O₂ formation, indicating acclimation to ¹O₂. Substantial differences in gene expression were observed between acclimation and high-light stress: A number of transcription factors were selectively induced by acclimation, and contrasting effects were observed for the jasmonate pathway. Jasmonate biosynthesis was strongly induced in ch1 mutant plants under high-light stress and was noticeably repressed under acclimation conditions, suggesting the involvement of this hormone in ¹O₂-induced cell death. This was confirmed by the decreased tolerance to photooxidative damage of jasmonate-treated ch1 plants and by the increased tolerance of the jasmonate-deficient mutant delayed-dehiscence2.
authors.affiliation: Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environementale et de Biotechnologies, Laboratoire d'Ecophysiologie Moléculaire des Plantes, F-13108 Saint-Paul-lez-Durance, France.
authors.forename: Fanny
authors.initials: F
authors.lastname: Ramel
authors.forename: Brigitte
authors.initials: B
authors.lastname: Ksas
authors.forename: Elsy
authors.initials: E
authors.lastname: Akkari
authors.forename: Alexis S
authors.initials: AS
authors.lastname: Mialoundama
authors.forename: Fabien
authors.initials: F
authors.lastname: Monnet
authors.forename: Anja
authors.initials: A
authors.lastname: Krieger-Liszkay
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Ravanat
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Mueller
authors.forename: Florence
authors.initials: F
authors.lastname: Bouvier
authors.forename: Michel
authors.initials: M
authors.lastname: Havaux
mesh_terms: D000064:Acclimatization / Q000235:genetics / Q000528:radiation effects*; D000085:Acetates / Q000494:pharmacology; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D053898:Biosynthetic Pathways / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D002734:Chlorophyll / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000528:radiation effects; D008027:Light; D015227:Lipid Peroxidation / Q000528:radiation effects; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D010084:Oxidation-Reduction / Q000528:radiation effects; D010105:Oxygenases / Q000235:genetics* / Q000378:metabolism; D054883:Oxylipins / Q000378:metabolism / Q000494:pharmacology; D045332:Photosystem II Protein Complex / Q000235:genetics / Q000378:metabolism; D010937:Plant Growth Regulators / Q000494:pharmacology; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D026082:Singlet Oxygen / Q000378:metabolism*; D059467:Transcriptome / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects
chemical_list: D000085:Acetates; D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D054883:Oxylipins; D045332:Photosystem II Protein Complex; D010937:Plant Growth Regulators; D017382:Reactive Oxygen Species; D002734:Chlorophyll; D026082:Singlet Oxygen; C011006:jasmonic acid; C072239:methyl jasmonate; D010105:Oxygenases; C115272:chlorophyll a oxygenase