title: Improved oxidative tolerance in suspension-cultured cells of C4-pepctransgenic rice by H2O2 and Ca(2+) under PEG-6000.
abstract: To understand the molecular responses of PC (Overexpressing the maize C4-pepc gene, which encodes phosphoenolpyruvate carboxylase (PEPC)), to drought stress at cell level, we analyzed changes in the levels of signaling molecules (hydrogen peroxide (H2O2), calcium ion (Ca(2+)), and nitric oxide (NO)) in suspension-cultured PC and wild-type (WT) rice (Oryza sativa L.) cell under drought stress induced by 20% polyethylene glycol 6000 (PEG-6000). Results demonstrated that PC improved drought tolerance by enhancing antioxidant defense, retaining higher relative water content, survival percentages, and dry weight of cells. In addition, PEPC activity in PC under PEG treatment was strengthened by addition of H2O2 inhibitor, dimethylthiourea (DMTU) and NO synthesis inhibitor, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO), respectively, while that in PC was weakened by addition of free calcium chelator, ethylene glycol-bis(b-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) + calcium channel outflow inhibitor, ruthenium red (RR) + plasma membrane channel blocker La(NO3)3, but EGTA + RR did not. Results also showed that NO and Ca(2+) was lying downstream of H2O2 in drought-induced signaling. Calcium ion was also involved in the expression of C4-pepc in PC. These results suggested that PC could improve oxidative tolerance in suspension-cultured cells and the acquisition of this tolerance required downregulation of H2O2 and the entry of extracellular Ca(2+) into cells across the plasma membrane for regulation of PEPC activity and C4-pepc expression.
authors.affiliation: Institute of Food Crops, Jiangsu Academy of Agricultural Sciences, Jiangsu High Quality Rice Research and Development Center, Nanjing Branch, China National Center for Rice Improvement, Nanjing, 210014, China.|College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.|Provincial Key Laboratory of Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China.
authors.forename: Baoyun
authors.initials: B
authors.lastname: Qian
authors.affiliation: Institute of Food Crops, Jiangsu Academy of Agricultural Sciences, Jiangsu High Quality Rice Research and Development Center, Nanjing Branch, China National Center for Rice Improvement, Nanjing, 210014, China.|Provincial Key Laboratory of Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.affiliation: Institute of Food Crops, Jiangsu Academy of Agricultural Sciences, Jiangsu High Quality Rice Research and Development Center, Nanjing Branch, China National Center for Rice Improvement, Nanjing, 210014, China.|College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.|Provincial Key Laboratory of Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China.
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Liu
authors.affiliation: Institute of Food Crops, Jiangsu Academy of Agricultural Sciences, Jiangsu High Quality Rice Research and Development Center, Nanjing Branch, China National Center for Rice Improvement, Nanjing, 210014, China.|Provincial Key Laboratory of Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China.
authors.forename: Man
authors.initials: M
authors.lastname: Wang
mesh_terms: D060387:Ascorbate Peroxidases / Q000378:metabolism; D001565:Benzoates / Q000494:pharmacology; D018533:Biomass; D002118:Calcium / Q000494:pharmacology*; D020013:Calcium Signaling / Q000187:drug effects; D002374:Catalase / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D055864:Droughts; D004533:Egtazic Acid / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007093:Imidazoles / Q000494:pharmacology; D008315:Malondialdehyde / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D012275:Oryza / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000502:physiology*; D018384:Oxidative Stress / Q000187:drug effects*; D010730:Phosphoenolpyruvate Carboxylase / Q000235:genetics*; D030821:Plants, Genetically Modified; D011092:Polyethylene Glycols / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D013535:Suspensions; D013890:Thiourea / Q000031:analogs & derivatives / Q000494:pharmacology; D014170:Transformation, Genetic / Q000187:drug effects
chemical_list: D001565:Benzoates; D007093:Imidazoles; D012333:RNA, Messenger; D013535:Suspensions; C079393:1,3-dihydroxy-4,4,5,5-tetramethyl-2-(4-carboxyphenyl)tetrahydroimidazole; C000595215:Polyethylene Glycol 6000; D009569:Nitric Oxide; D011092:Polyethylene Glycols; D008315:Malondialdehyde; D004533:Egtazic Acid; C038983:1,3-dimethylthiourea; D006861:Hydrogen Peroxide; D060387:Ascorbate Peroxidases; D002374:Catalase; D013482:Superoxide Dismutase; D010730:Phosphoenolpyruvate Carboxylase; D013890:Thiourea; D002118:Calcium
keywords: Calcium; drought; hydrogen peroxide; phosphoenolpyruvate carboxylase; rice (Oryza sativa L.)