抗虫棉品系L22依赖抗坏血酸H2O2清除酶系统活性的降低

以早衰型转 Bt基因抗虫棉 L2 2为主要试材 ,研究了其体内活性氧代谢和一些抗氧化酶活性与对照常规棉 JM1 1、抗虫棉 33B的差异。结果表明 ,抗虫棉 L 2 2在生长中期时叶片中 H2 O2 含量和膜脂过氧化产物丙二醛 ( MDA)显著增高 ,在依赖抗坏血酸 ( As A)的 H2 O2 清除酶系统中 ,抗坏血酸过氧化物酶 ( As A- POD)、脱氢抗坏血酸还原酶 ( DR)、谷胱甘肽还原酶 ( GR)等酶活性极显著低于常规棉 JM1 1和 33B,叶片中 As A含量也以 L2 2为最低 ,而 DAs A/As A是最高的 ,分别是JM1 1和 33B的 3.75倍和 4.31倍。初步认为 L2 2出现早衰现象与其体内活性氧代谢失调和依赖As A的 H2 O2 清除酶系统活性显著降低有关 ,并分析了可能的原因

The Decrease of AsA Dependent H2O2-Scavenging System Activities in Transgenic Bt Cotton Line L22

This paper studied the mechanism of earlier senescence in transgenic Bt cotton line L22, which was based on the difference of metabolism of active oxygen and the activities of some scavenging enzymes in the leaves of L22 and common cotton JM11 and another insect resistant cotton 33B. The results showed that the content of SOD, MDA in L22 leaves were higher than JM11 and 33B, however the activities of AsA POD, DR and GR in AsA dependent H 2O 2_scavenging system were prominently lower. Among these cotton varieties, the content of AsA in L22 leaves was the lowest and the ratio of DAsA/AsA was the highest. This paper promilarily concluded that there were correlations between the accumulation of active oxygen, the decrease of AsA dependent H 2O 2_scavenging system activities with the earlier senescence of transgenic Bt cotton line L22, and also analyzed the possible reasons.