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期 刊 ：植物保护学报 2009年

关键词：小地老虎；Cry2Ab杀虫蛋白；中肠蛋白酶；

Keywords:Agrotis ypsilon, Cry2Ab insecticidal proteins, midgut protease,

摘 要 ：为治理小地老虎的危害,研究了Bt杀虫蛋白对小地老虎幼虫的控制作用。室内生物测定结果表明,Cry2Ab杀虫蛋白对小地老虎初孵幼虫的致死效果高于Cry1Ac杀虫蛋白。取食含有Cry2Ab杀虫蛋白人工饲料的小地老虎幼虫体内的中肠总蛋白酶和类胰凝乳蛋白酶活性高于对照,当人工饲料中Cry2Ab杀虫蛋白含量达到12μg/g时,小地老虎幼虫中肠氨肽酶活性显著升高;而取食含有Cry1Ac杀虫蛋白人工饲料的小地老虎幼虫中肠蛋白酶活性无显著变化。此外,小地老虎幼虫取食含有Cry2Ab杀虫蛋白的人工饲料后,体内谷胱甘肽-S-转移酶活性显著升高,而取食含有Cry1Ac杀虫蛋白的人工饲料后其变化不明显。

Abstract:Researching on insecticidal activity of Bt proteins to larvae of Agrotis ypsilon is able to provide a scientific basis for controlling this insect. Thus, the insecticidal activity of Cry2Ab proteins to newly hatched larvae of A.ypsilon and the protease activity changes in 4^th instar larvae fed on Cry2Ab-containing artificial diet were investigated in the laboratory. The results showed that Cry2Ab proteins have a significantly higher insecticidal activity to newly hatched A.ypsilon larvae than those of Cry1Ac protein. Activities of total midgut protease and chymotrypsin-like enzyme increased notably in the 4^th instar A.ypsilon larvae fed on the Cry2Ab toxin intoxicated artificial diet. When the Cry2Ab concentration in diet reached 12μg/g, the aminopeptidase activity in midgut of 4^th instar larvae was significantly higher than that in conventional diet. However, the activity of midgut protease changed little in the 4^th instar larvae fed on Cry1Ac-protein intoxicated artificial diet. This shows that the midgut protease is related to the difference of susceptibility of A.ypsilon larvae to Cry2Ab and Cry1Ac proteins. Moreover, the activity of glutathione S-transferase in the 4^th instar A.ypsilon larvae fed on artificial diet containing Cry2Ab proteins were increased, which was much higher than that in 4^th instar larvae of A.ypsilon fed on artificial diet containing Cry1Ac. It demonstrates that the changes of glutathione S-transferase activities in A.ypsilon larvae were related to insecticidal activity of Cry2Ab proteins to A.ypsilon larvae.

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