对黏虫具有杀虫活性的Bt蛋白筛选及分析

Screening and analysis of insecticidal activity of protein from Bacillus thuringiensis against Mythimna separata

为筛选对黏虫[Mythimna separata(Walker)]具有毒杀作用的苏云金芽胞杆菌杀虫蛋白,本研究提取Cry1类、Cry2类、Cry9类及Vip3A类等11种蛋白,通过人工饲料喂毒方法对黏虫进行生物活性测定。结果表明,Cry1Ac、Cry1Ab、Cry2Ab、Cry1Be及Cry1Bb蛋白对黏虫具有杀虫活性,其致死中浓度依次为5.09、17.71、26.75、27.42及43.93μg/g;Cry9Aa、Cry9Eb、Cry9Ee蛋白对黏虫生长具有抑制作用,其浓度为10μg/g时的体重抑制率分别为78.4%、79.0%、86.9%,浓度为100μg/g时的体重抑制率分别为92.8%、95.7%、96.7%;Cry1Ba、Cry1Ca和Vip3Aa蛋白对黏虫无显著活性。本研究为黏虫的生物防治奠定了基础,并为抗虫转基因作物的研究提供优良的候选基因。

In order to investigate the insecticidal activity of some Bacillus thuringiensis proteins against Mythimna separata（Walker）,11 proteins of Cry1,Cry2,Cry9 and Vip3A were extracted and used for bioassay against M.separata by feeding artificial diet.The bioassay results showed that Cry1Ac,Cry1Ab,Cry2Ab,Cry1Be and Cry1Bb had insecticidal activity against M.separata larvae,with a LC50 value of 5.09 μg/g,17.71 μg/g,26.75μg/g,27.42μg/g and43.93μg/g,respectively.Cry9Aa,Cry9Eb and Cry9Ee only inhibited growth of M.separata,with a growth inhibition rate of 78.4%,79.0% and 86.9% at the concentration of 10μg/g,and with an inhibition rate of 92.8%,95.7% and 96.7%,respectively,at the concentration of 100μg/g.However,Cry1Ba,Cry1Ca and Vip3Aa showed no apparent toxicity to M.separatalarvae.It lays the foundation for biological control of M.separata,and may provide some excellent candidate genes for insect-resistant genetically modified crops.