杂交稻及其三系叶片衰老过程中SOD、CAT活性和MDA含量的变化

对杂交水稻及其三系主茎第11叶叶片自然衰老过程中超氧物歧化酶(SOD)、过氧化氢酶(CAT)和丙二醛(MDA)含量的变化进行了研究,结果表明:叶片衰老过程中,SOD和CAT活性下降,MDA的含量增加,可作为衰老特征的叶绿素和可溶性蛋白质含量明显下降;SOD的活性和MDA的含量变化相对应;CAT活性大幅度下降与SOD之间的不平衡,致使O_2~-代谢中间产物累积而引起膜的损伤。不育系的衰老进程比杂交水稻、恢复系和保持系慢,其SOD和CAT活性明显高于其它三者,可能是不育系不易早衰的原因之一。

Changes of SOD and CAT activities and MDA content during senescence of hybrid rice and three lines leaves

Superoxide dismutase (SOD) ,Catalase (CAT) activities and malondialdehyde (MDA) ,chloro-phyll,soluble protein contents were investigated during senescence of hybrid rice and three lines. The re-sults indicated that leaf senescence was associated with the decreases of SOD and CAT activities. A marked increase of MDA content,a product of lipid peroxidation was observed during leaf senescence. The decrease of chlorophyll and soluble protein content could be used as a criterion of senescence. CAT activity de-creased more rapidly than that of SOD during senescence of leaves. The disparity between SOD activity and CAT activity during leaf senescence might result in the formation of Oi intermediates which cause the damage of the membrane. Male sterile line senesced later than hybrid rice, restorer line, maintainer line. The relative high activities of SOD and CAT of leaves might be one of the cause of late aging of male sterile line leaves.