Pandey Poonam, Srivastava Rajneesh Kumar, Dubey R S
Department of Biochemistry, Faculty of Science, Banaras Hindu University, Varanasi, 221005, India.
Protoplasma. 2014 Jan;251(1):147-60. doi: 10.1007/s00709-013-0533-8. Epub 2013 Aug 31.
Plant growth and productivity are greatly affected due to changes in the environmental conditions. In the present investigation, the interactive effects of two important abiotic stresses, i.e., water deficit and Al toxicity, were examined in the seedlings of two rice (Oryza sativa L.) cvs. Malviya-36 (water deficit/Al sensitive) and Vandana (water deficit/Al tolerant). When 15 days grown seedlings were exposed to water deficit (created with 15 % polyethylene glycol 6000) or Al (1 mM AlCl3) treatment or both the treatments together for 48 h, the lengths of root/shoot, relative water content, and chlorophyll greatly declined in the seedlings of the sensitive cultivar, whereas in the tolerant seedlings, either little or insignificant decline in these parameters was observed due to the treatments. Seedlings subjected to water deficit or Al treatment alone or in combination showed increased intensity of the isoenzyme activity bands of superoxide dismutase (SOD), guaiacol peroxidase (GPX), and ascorbate peroxidase (APX) in in-gel activity staining studies. Water deficit caused decrease in intensity of catalase (CAT) activity bands; however, when seedlings were exposed to AlCl3 alone or in combination with water deficit, the intensity of the CAT isoforms increased in both the rice cultivars. The level of expression of the activity bands of SOD, CAT, GPX, and APX was always higher in the seedlings of tolerant cv. Vandana compared to the sensitive cv. Malviya-36 under both controls as well as stress treatments. Higher intensity of isozymes representing higher activity levels of antioxidative enzymes in the rice seedlings and their further increase under water deficit, Al exposure, or in combination of both the stresses appears to serve as useful marker for specifying a combination of water deficit and Al tolerance in rice.
植物生长和生产力会因环境条件的变化而受到极大影响。在本研究中，对两个水稻（Oryza sativa L.）品种Malviya - 36（对水分亏缺/铝毒敏感）和Vandana（对水分亏缺/铝毒耐受）的幼苗，研究了两种重要非生物胁迫即水分亏缺和铝毒的交互作用。当生长15天的幼苗分别暴露于水分亏缺（用15%聚乙二醇6000造成）、铝（1 mM AlCl3）处理或两种处理共同作用48小时后，敏感品种幼苗的根/茎长度、相对含水量和叶绿素含量大幅下降，而在耐受品种的幼苗中，这些参数因处理仅出现轻微或不显著的下降。在凝胶活性染色研究中，单独或联合进行水分亏缺或铝处理的幼苗，超氧化物歧化酶（SOD）、愈创木酚过氧化物酶（GPX）和抗坏血酸过氧化物酶（APX）的同工酶活性带强度增加。水分亏缺导致过氧化氢酶（CAT）活性带强度降低；然而，当幼苗单独暴露于AlCl3或与水分亏缺联合处理时，两个水稻品种中CAT同工型的强度均增加。在对照和胁迫处理下，耐受品种Vandana幼苗中SOD、CAT、GPX和APX活性带的表达水平始终高于敏感品种Malviya - 36。代表水稻幼苗抗氧化酶较高活性水平的同工酶强度更高，且在水分亏缺、铝暴露或两种胁迫联合作用下进一步增加，这似乎是确定水稻对水分亏缺和铝耐受性组合的有用指标。
