Bt玉米秸秆杀虫蛋白对赤子爱胜蚓酶活性的影响

Effects of Bt corn straw insecticidal proteins on enzyme activities of Eisenia fetida

Bt玉米分泌的Bt蛋白可通过秸秆还田、根系分泌、花粉飘落等途径进入土壤.本文模拟秸秆还田,在土壤中添加5%或7.5%的Bt玉米及其同源常规玉米秸秆饲养赤子爱胜蚓,分别于7、14d后检测蚯蚓总蛋白含量、乙酰胆碱酯酶(AchE)、谷胱甘肽过氧化物酶(GSH-PX)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)的活性.结果表明:同一玉米品种,同一秸秆添加量处理下,与培养7d相比,培养14d的蚯蚓总蛋白含量下降,AchE、CAT和SOD酶活性提高,GSH-PX酶活性降低.同一培养时间、同一秸秆添加量处理下,与常规相比,Bt玉米培养的蚯蚓SOD活性提高,AchE和GSH-PX活性下降,总蛋白含量和CAT活性无显著变化.表明Bt玉米秸秆处理对蚯蚓总蛋白没有抑制作用,能降低AchE和GSH-PX活性,对CAT没有诱导作用,但在短时间内能诱导蚯蚓SOD酶活性.

Bacillus thuringiensis（Bt） proteins released from Bt corn can enter soil ecosystem via returning straw into field,root exudation,and pollen fluttering-down.In this study,the straws of Bt corn and its near-isogenic non-Bt line were added into soil with an application rate of 5% and 7.5% to breed Eisenia fetida,and the total protein content and the activities of acetylcholine esterase（AchE）,glutathione peroxidase（GSH-PX）,catalase（CAT）,and superoxide dismutase（SOD） in E.fetida were determined after 7 and 14 days.Under the same application rate of the straws,the total protein content and GSH-PX activity of E.fetida decreased while the AchE,CAT,and SOD activities increased on the 14th day,compared with those on the 7th day.The Bt corn straw increased the SOD activity and decreased the AchE and GSH-PX activities,but had less effects on the total protein content and CAT activity,compared with non-Bt corn straw.All the results suggested that Bt corn straw had no inhibitory effect on E.fetida total protein but could inhibit the AchE and GSH-PX activities,and could not induce CAT activity but induce SOD activity within a short time.