title: Knockdown of GDCH gene reveals reactive oxygen species-induced leaf senescence in rice.
abstract: Glycine decarboxylase complex (GDC) is a multi-protein complex, comprising P-, H-, T- and L-protein subunits, which plays a major role in photorespiration in plants. While structural analysis has demonstrated that the H subunit of GDC (GDCH) plays a pivotal role in GDC, research on the role of GDCH in biological processes in plants is seldom reported. Here, the function of GDCH, stresses resulting from GDCH-knockdown and the interactions of these stresses with other cellular processes were studied in rice plants. Under high CO(2), the OsGDCH RNA interference (OsGDCH-RNAi) plants grew normally, but under ambient CO(2), severely suppressed OsGDCH-RNAi plants (SSPs) were non-viable, which displayed a photorespiration-deficient phenotype. Under ambient CO(2), chlorophyll loss, protein degradation, lipid peroxidation and photosynthesis decline occurred in SSPs. Electron microscopy studies showed that chloroplast breakdown and autophagy took place in these plants. Reactive oxygen species (ROS), including O2(-) and H(2)O(2), accumulated and the antioxidant enzyme activities decreased in the leaves of SSPs under ambient CO(2). The expression of transcription factors and senescence-associated genes (SAGs), which was up-regulated in SSPs after transfer to ambient CO(2), was enhanced in wild-type plants treated with H(2)O(2). Evidences demonstrate ROS induce senescence in SSPs, and transcription factors OsWRKY72 may mediate the ROS-induced senescence.
authors: State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China.
authors: Qiying
authors: Q
authors: Zhou
authors: Qian
authors: Q
authors: Yu
authors: Zhanqi
authors: Z
authors: Wang
authors: Yufang
authors: Y
authors: Pan
authors: Wentang
authors: W
authors: Lv
authors: Lili
authors: L
authors: Zhu
authors: Rongzhi
authors: R
authors: Chen
authors: Guangcun
authors: G
authors: He
mesh_terms: D002245:Carbon Dioxide / Q000494:pharmacology; D019069:Cell Respiration; D016922:Cellular Senescence; D002734:Chlorophyll / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D050959:Glycine Decarboxylase Complex; D050961:Glycine Decarboxylase Complex H-Protein / Q000235:genetics / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D015227:Lipid Peroxidation; D009928:Organ Specificity; D012275:Oryza / Q000187:drug effects / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D018384:Oxidative Stress; D010641:Phenotype; D010788:Photosynthesis; D018515:Plant Leaves / Q000187:drug effects / Q000235:genetics / Q000502:physiology / Q000648:ultrastructure; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018526:Plant Transpiration; D030821:Plants, Genetically Modified; D034622:RNA Interference; D017382:Reactive Oxygen Species / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D050961:Glycine Decarboxylase Complex H-Protein; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D014157:Transcription Factors; D002734:Chlorophyll; D002245:Carbon Dioxide; D006861:Hydrogen Peroxide; D050959:Glycine Decarboxylase Complex
keywords: Oryza sativa; antioxidant enzyme; autophagy; glycine decarboxylase; photorespiration; senescence-associated genes (SAGs)