摘要
苏云金芽孢杆菌BtC008对棉铃虫、小菜蛾和甜菜夜蛾等鳞翅目害虫具有高毒力。本文分析了其杀虫基因类型包括cry1Ab、cry1Ca、cry1Ia、cry2Ab和一种新的cry1类基因,SDS-PAGE分析其至少2种cry1类基因获得了表达,在分子水平说明了该菌株高毒力的原因。在此基础上克隆了1种cry1Ab类杀虫晶体蛋白(insecticidalcrystalproteins,ICPs)基因,并被Bt杀虫晶体蛋白基因命名委员会命名为cry1Ab20。序列分析显示该基因所编码蛋白与已知的Cry1Ab13有1个氨基酸不同。将cry1Ab基因毒性片段(1.95kb)插入表达载体pET-21b,转化EscherichiacoliRosetta(DE3)菌株,表达的包涵体蛋白对小菜蛾和棉铃虫幼虫具有杀虫活性,LC50分别为100.74μg/mL和29.87μg/mL,进一步明确了Cry1Ab20蛋白的杀虫活性区。
Bacillus thuringiensis isolate BtC008 was highly toxic to Helicoverpa armigera, Plutella xylostella and Spodoptera exigua. The cry1Ab, cry1Ca, cry1Ia, cry2Ab and a novel cry1 gene were found by use of PCR-RFLP method, and two cry1-type genes were expressed at least in isolate BtC008. One cry1Ab-type gene of BtC008 was cloned and designated as cry1Ab20 by Bt Insecticidal Crystal Proteins Nomenclature Committee. The sequence analysis showed that there was only one amino acid residue different between Cry1Ab20 and Cry1Ab13 protein. The active region of crylAb20 gene at 5＇-terminal was inserted into a pET-21b vector and transformed into Escherichia coli Rosetta （DE3） strain, and the truncated CrylAb20 protein expressed in Rosetta （DE3） was active against two lepidopteran insect larvae of P. xylostella and H. armigera, with LC50 as 100. 74 mg/mL and 29.87 mg/mL, respectively.
出处
《植物保护》
CAS
CSCD
北大核心
2006年第6期22-26,共5页
Plant Protection
基金
国家"973"计划项目(2003CB114201
2001CB109005)
