不同耐盐性水稻材料对盐胁迫的生理响应及分子机制

Physiological Response and Molecular Mechanism of Rice to Salt-stress

【目的】研究不同耐盐性水稻材料应答高盐胁迫的生理及分子机理,对筛选和培育耐盐水稻新品种具有重要的参考价值。【方法】分别以耐盐水稻品系X1、X2、X3和盐敏感水稻品系X20、X30为试验材料,分析其在高盐胁迫(200 mmol·L^(−1) NaCl的1/2KB溶液)条件下的生理代谢及耐盐相关功能基因表达差异。【结果】在高盐胁迫条件下,耐盐水稻材料体内脯氨酸及可溶性糖含量、超氧化物歧化酶及过氧化氢酶的活性,以及耐盐相关功能基因OsP5CS1、OsProt、OsCu/Zn-SOD、OsAPX2、OsNCED3及OsNCED5的表达水平明显高于盐敏感型,而丙二醛和过氧化氢含量明显低于盐敏感型。【结论】耐盐性水稻材料主要通过提高渗透调节能力、活性氧清除能力及耐盐相关功能基因的表达来提高其耐盐性。

【Objective】Physiological response and molecular mechanism of different salt-tolerant rice lines in dealing with high salt stress were studied to facilitate screening and breeding resistant varieties.【Methods】Salt-tolerant rice X1,X2,and X3 as well as salt-sensitive X20 and X30 were treated by a high salt condition of 1/2KB solution with 200 mmol·L^(−1) NaCl.The physiological metabolism and expression of functional genes of the two contrasting groups of rice were compared.【Results】Under the stress,the proline and soluble sugar contents,superoxide dismutase and catalase activities,and expressions of OsP5CS1,OsProt,OsCu/Zn-SOD,OsAPX2,OsNCED3,and OsNCED5 of the salt-tolerant rice were significantly higher,whereas the malondialdehyde and hydrogen peroxide contents significantly lower,than those of the saltsensitive counterparts.【Conclusion】The salt-tolerant rice lines resisted the high salt exposure mainly by increasing osmotic regulation,activating oxygen scavenging,and accentuating functional gene expression of the plants.