外源NO供体硝普钠(SNP)对盐胁迫下水稻幼苗中叶绿素和游离脯氨酸含量以及抗氧化酶的影响

在100 mmol L^-1 NaCl胁迫下, 研究了不同浓度一氧化氮供体硝普钠(sodium nitroprusside, SNP)处理对水稻叶片叶绿素、游离脯氨酸含量, 叶片及幼根中愈创木酚过氧化酶(guaiacol peroxidase, GPX)、超氧化物歧化酶(superoxide dis-mutase, SOD)、过氧化氢酶(catalase, CAT)活性以及超氧阴离子产生速率等生理指标的影响。结果表明, 适当低浓度SNP处理可以显著提高盐胁迫下水稻叶片中叶绿素和脯氨酸含量, 并明显缓解盐胁迫下叶片和幼根受到的氧化性损伤; 但在水稻幼苗不同器官, SNP调节的主要靶酶有所不同, 在叶片中促进SOD和CAT活性, 而在幼根中除SOD和CAT活性外, 还提高GPX活性。

Effects of Exogenous Nitric Oxide Donor SNP on Contents of Chlorophyll and Free Proline,Activity of Antioxidative Enzyme in Rice Seedlings under NaCl Stress

In this study, the contents of chlorophyll, free proline and the activities of GPX, SOD, CAT, and the producing rate of superoxide radicals in rice seedlings treated with a varying concentration of SNP under 100 mmol L^-1 NaCl stress were investigated. The results showed that the contents of chlorophyll and free proline increased by treatment with low SNP concentration under salt stress. SNP alleviated significantly the oxidative damage caused by salt stress in leaf and root of rice seedlings. Different enzyme activities were regulated by SNP between leaf and root in rice seedlings under salt stress, SNP alleviated significantly the oxida-tive damage via promoting SOD and CAT activities in rice leaf, whereas, via regulating GPX activity mainly besides promoting SOD and CAT activities in root.