title: Low pH-induced changes of antioxidant enzyme and ATPase activities in the roots of rice (Oryza sativa L.) seedlings.
abstract: Soil acidification is the main problem in the current rice production. Here, the effects of low pH on the root growth, reactive oxygen species metabolism, plasma membrane functions, and the transcript levels of the related genes were investigated in rice seedlings (Oryza sativa L.) in a hydroponic system at pH 3.5, 4.5, and 5.5. There were two hybrid rice cultivars in this trial, including Yongyou 12 (YY12, a japonica hybrid) and Zhongzheyou 1 (ZZY1, an indica hybrid). Higher H+ activity markedly decreased root length, the proportion of fine roots, and dry matter production, but induced a significant accumulation of hydrogen peroxide (H2O2), and led to serious lipid peroxidation in the roots of the two varieties. The transcript levels of copper/zinc superoxide dismutase 1 (Cu/Zn SOD1), copper/zinc superoxide dismutase 2 (Cu/Zn SOD2), catalase A (CATA) and catalase B (CATB) genes in YY12 and ZZY1 roots were significantly down-regulated after low pH exposure for two weeks. Meanwhile, a significant decrease was observed in the expression of the P-type Ca2+-ATPases in roots at pH 3.5. The activities of antioxidant enzymes (SOD, CAT) and plasma membrane (PM) Ca2+-ATPase in the two varieties were dramatically inhibited by strong rhizosphere acidification. However, the expression levels of ascorbate peroxidase 1 (APX1) and PM H+-ATPase isoform 7 were up-regulated under H+ stress compared with the control. Significantly higher activities of APX and PM H+-ATPase could contribute to the adaptation of rice roots to low pH.
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, Zhejiang, 310006, P. R. China.
authors.forename: Yi-Kai
authors.initials: YK
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, Zhejiang, 310006, P. R. China.
authors.forename: De-Feng
authors.initials: DF
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, Zhejiang, 310006, P. R. China.
authors.forename: Yu-Ping
authors.initials: YP
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, Zhejiang, 310006, P. R. China.
authors.forename: Hui-Zhe
authors.initials: HZ
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, Zhejiang, 310006, P. R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Xiang
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, Zhejiang, 310006, P. R. China.
authors.forename: Xian-Qing
authors.initials: XQ
authors.lastname: Lin
mesh_terms: D060387:Ascorbate Peroxidases / Q000235:genetics / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000235:genetics / Q000378:metabolism*; D002374:Catalase / Q000235:genetics / Q000378:metabolism*; D002678:Chimera / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D012275:Oryza / Q000201:enzymology* / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000201:enzymology; D006180:Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D058441:Rhizosphere; D036226:Seedlings / Q000201:enzymology; D012987:Soil / Q000737:chemistry; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D012333:RNA, Messenger; D012987:Soil; D060387:Ascorbate Peroxidases; D002374:Catalase; D013482:Superoxide Dismutase; D006180:Proton-Translocating ATPases; D000252:Calcium-Transporting ATPases