中文摘要：

用转Cry1Ab/Cry1Ac基因水稻的叶片饲喂稻纵卷叶螟Cnaphalocrocis medinalis（Guene）幼虫,采用酶活力测定方法研究了转基因水稻对稻纵卷叶螟幼虫体内3种保护酶（SOD,CAT和POD）活性的影响。结果表明：取食转基因水稻叶片4h后,幼虫体内SOD酶活性比对照提高了91.5%,与对照有显著差异;36h后活性达到最大值,但与对照差异不显著。取食转基因水稻叶片24h后,幼虫体内CAT酶活性达到最大值且高于对照,但与对照差异不显著;48h后酶活性受到显著抑制,与对照差异显著。取食转基因水稻叶片12h后,幼虫体内POD酶活性达到最大值,与对照差异不显著;48h后酶活性逐渐下降达到最小值,比对照下降68.05%。实验同时测定了幼虫体内及其粪便中Bt毒蛋白含量的变化,结果表明取食转基因水稻叶片12h后,随着大量取食进入体内的毒蛋白随粪便排出,幼虫体内的毒蛋白含量一直低于粪便中的含量,且在24h时两者差异达到最大。由于Bt毒蛋白在幼虫体内的积累,扰乱了稻纵卷叶螟幼虫体内SOD,CAT和POD3种保护酶的动态平衡,使虫体内自由基的清除遇到障碍,从而对其产生毒害作用。

英文摘要：

The effects of transgenic rice on the activities of SOD, CAT and POD in Cnaphalocrocis medinalis larvae were studied by assaying enzyme activities after the 3rd instar larvae had been fed with leaves of transgenic and non-tarnsgenic rice （control） for different time. The results showed its SOD activity was significantly higher （91.5%） than that of control after the larvae fed on transgenic rice for 4 h and reached the maximum with a little difference from that of control after the larvae fed for 36 h. The CAT activity of larvae fed with leaves of transgenic rice reached the maximum and was a little higher than that of control after feeding for 24 h, but significantly lower than that of control after the larvae fed for 48 h. The POD activity of larvae fed with leaves of transgenic rice reached the maximum with a little difference from that of control after feeding for 12 h, but decreased by 68.05% after feeding for 48 h. Meanwhile we also assayed the variation of the Bt protein in the larval body and dejecta. By voidance of dejecta, the level of Bt protein in the larval body was always lower than that in dejecta after feeding for 12 h, and the difference between both reached the highest at 24 h after feeding. It was so inferred that the gradual accumulation of Bt protein in the larval body disturbed the dynamic balance of SOD, CAT and POD, baffled the clearance of free radicals and produced toxic effects on C. medinalis larvae.