title: Decreased glutathione reductase2 leads to early leaf senescence in Arabidopsis.
abstract: Glutathione reductase (GR) catalyzes the reduction of glutathione disulfide (GSSG) to reduced glutathione (GSH) and participates in the ascorbate-glutathione cycle, which scavenges H2 O2 . Here, we report that chloroplastic/mitochondrial GR2 is an important regulator of leaf senescence. Seed development of the homozygous gr2 knockout mutant was blocked at the globular stage. Therefore, to investigate the function of GR2 in leaf senescence, we generated transgenic Arabidopsis plants with decreased GR2 using RNAi. The GR2 RNAi plants displayed early onset of age-dependent and dark- and H2 O2 -induced leaf senescence, which was accompanied by the induction of the senescence-related marker genes SAG12 and SAG13. Furthermore, transcriptome analysis revealed that genes related to leaf senescence, oxidative stress, and phytohormone pathways were upregulated directly before senescence in RNAi plants. In addition, H2 O2 accumulated to higher levels in RNAi plants than in wild-type plants and the levels of H2 O2 peaked in RNAi plants directly before the early onset of leaf senescence. RNAi plants showed a greater decrease in GSH/GSSG levels than wild-type plants during leaf development. Our results suggest that GR2 plays an important role in leaf senescence by modulating H2 O2 and glutathione signaling in Arabidopsis.
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
authors.forename: Shunhua
authors.initials: S
authors.lastname: Ding
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Wang
authors.forename: Zhipan
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
authors.forename: Qingtao
authors.initials: Q
authors.lastname: Lu
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Wen
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
authors.forename: Congming
authors.initials: C
authors.lastname: Lu
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000196:embryology / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D003624:Darkness; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005978:Glutathione / Q000378:metabolism; D005980:Glutathione Reductase / Q000235:genetics / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D007700:Kinetics; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects / Q000235:genetics; D010641:Phenotype; D010937:Plant Growth Regulators / Q000494:pharmacology; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D030821:Plants, Genetically Modified; D034622:RNA Interference / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D010937:Plant Growth Regulators; D012333:RNA, Messenger; D006861:Hydrogen Peroxide; D005980:Glutathione Reductase; C000609479:glutathione reductase 2, Arabidopsis; D005978:Glutathione
keywords: Arabidopsis thaliana; ascorbate-glutathione cycle; glutathione reductase2; hydrogen peroxide; leaf senescence