外源一氧化氮对氯化钠处理下秋茄幼苗抗氧化系统的调节效应

Regulation effect of exogenous nitric oxide on anti-oxidation system of Kandelia candel seedlings treated with NaCl

研究了外源一氧化氮(NO)供体硝普钠(SNP)对NaCl处理下红树植物秋茄(Kan-deliacandel)幼苗叶片中抗氧化酶活性、抗氧化物质及脯氨酸含量的影响。结果表明:NaCl处理下,秋茄幼苗叶片中超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)等4种活性氧清除酶的活性均受到明显抑制(P<0.05),SNP可以不同程度地恢复SOD、POD、CAT的活性,但对APX活性影响不大;SNP提高谷胱甘肽(GSH)及类胡萝卜素(Car)的含量,促进脯氨酸含量的上升,显著降低叶片中过氧化氢(H2O2)和丙二醛(MDA)的累积。表明外源NO可以缓解NaCl处理诱导的秋茄幼苗叶片氧化损伤,降低膜脂过氧化水平,有利于秋茄适应盐生环境。

By using sodium nitroprusside （SNP） as the donor of exogenous nitric oxide, this paper studied its effects on the antioxidant enzyme activities, anti-oxidation substances, and proline content in the leaves of Kandelia candel seedlings treated with NaCl. The results showed that after treated with NaCl, the activities of superoxide dismutase （SOD）, peroxidase （POD）, catalase （CAT） and ascorbate peroxidase （APX） in K. candel seedling leaves were depressed significantly （P 〈 0. 05） , while SNP could recover the activities of SOD, POD and CAT to different degrees but showed little effect on APX. SNP increased the contents of glutathione （GSH） and carotenoid （Car）, promoted the production of proline, and decreased the accumulation,of H2O2 and malondialdehyde （MDA） significantly. It was indicated that SNP could relieve the oxidation damages induced by NaCl via decreasing the level of membrane lipid peroxidation in K. candel leaves, and facilitate K. candel to adapt to saline environment.