摘要
为检测苏云金杆菌晶体蛋白Cyt1A对Vip3A表达和杀虫活性的影响,将p20和cyt1A基因与vip3A基因连接构建了重组质粒pHVC20,然后电激转化至苏云金杆菌无晶体突变株CryB中进行了共表达,以单独表达Vip3A蛋白的CryB(pHPT3)作为对照菌株。Westernblot结果显示,Vip3A蛋白在CryB(pHVC20)菌株中的最大表达量约为在CryB(pHPT3)菌株的2倍,这可能是由于前者中的辅助蛋白P20增加了Vip3A表达量的缘故,晶体蛋白Cyt1A的存在对Vip3A的正常表达没有影响。生物测定结果表明,CryB(pHVC20)和CryB(pHPT3)菌株对斜纹夜蛾初孵幼虫的LC50值分别为10.62!g/ml和78!g/ml,前者的毒力比后者提高了6倍,这表明Cyt1A蛋白和Vip3A蛋白对目标昆虫的毒力可能存在着协同增效作用。
To investigate the influence of crystal protein Cyt1A on Vip3A expression and its insecticidal activity, the recombinant plasmid pHVC20 containing cyt1A and vip3A genes were constructed and transformed into the Bacillus thuringiensis acrystalliferous strain CryB, with CryB （pHPT3） strain only expressing Vip3A protein as control. Western blot showed that the maximum yield of Vip3A in CryB （pHVC20） was about 2 fold to that in CryB （pHPT3）. It was deduced that the p20 gene in plasmid pHVC20 could not only be required for efficient production of Cyt1A protein but also promote Vip3A yields. Bioassay showed that LC50B of CryB（pHVC20） and CryB（pHPT3） against the first instar larvae of Spodoptera litura were 10.62 μg/ml and 78.00 μg/ml respectively, with the former performing enhanced insecticidal activity. This result suggested that Cyt1Aa might synergize the activity of Vip3A toxin towards S. liturca.
出处
《科技导报》
CAS
CSCD
2006年第4期18-21,共4页
Science & Technology Review
基金
国家"973计划"项目(G2000016209)
广东省自然科学基金研究团队项目
