两类苏云金芽胞杆菌Cry1Ac蛋白杀玉米螟活性的比较  

Comparing the Activity of Killing Corn Borer between Two Cry1Acs from Different Bacillus thuringiensis

作　　者：田宇曦[1,2] 刘晓艳[1,2] 张志刚[1,2] 杨自文[1,2] 

机构地区：[1]湖北省农业科学院 [2]湖北省生物农药工程研究中心,武汉430064

出　　处：《湖北农业科学》2014年第23期5742-5744,5747,共4页Hubei Agricultural Sciences

基　　金：国家863科技计划(2011AA10A201);湖北省农业科学院青年基金(2012NKYJJ21)

摘　　要：通过PCR技术将2种不同来源的苏云金芽胞杆菌(Bacillus thuringiensis,简称Bt)cry1Ac蛋白基因克隆到大肠杆菌p GEX-6P-1表达载体,并转化到宿主菌BL21,采用IPTG进行诱导表达,并用亲和层析法进行融合蛋白的纯化,纯化后的蛋白质进行玉米螟的室内生物测定试验。结果表明,来自Bt菌株NBIN-866的Cry1Ac蛋白杀玉米螟的LC50为65.39μg/m L,来自Bt菌株NBIC-380的Cry1Ac蛋白杀玉米螟的LC50为15.07μg/m L,后者具有更高的杀虫活性。氨基酸序列比对发现来自菌株NBIC-380的Cry1Ac氨基酸序列的71位和393位都为丝氨酸S,而NBIN-866的都为脯氨酸P,推测这两个位点的氨基酸的变化可能是影响毒性大小的重要因素。The cry1Ac genes from two different Bacillus thuringiensis strains were cloned to Escherichia coli expression vector pGEX-6P-1 by PCR technology and transformed the recombinant plasmid into strain BL21. With IPTG the recombinant strains were induced expression. The expressed fusion proteins were purified with affinity chromatography. The insecticidal activity of the purified proteins were tested with corn borers indoor. Results showed that LCso value of CrylAc fusion protein from strain NBIN-866 was 65.39 μg/mL. LC50 value of CrylAc fusion protein from strain NBIN-380 was 15.07 μg/mL, having a high insecticidal activity against corn borer. The results of blasting two amino acid sequences of CrylAc proteins showed that the 71st and 393rd amino acid was Proline in strain NBIN-866. 71st and 393rd amino acid were replaced by Serine in strain NBIN-380. It is indicated that the amino acids changes of the two sites might be the key factors affecting the toxic effect against corn borers.

关 键 词：苏云金芽胞杆菌(Bacillus thuringiensis) CRY1AC 融合蛋白 玉米螟 活性比较 

分 类 号：S476[农业科学—农业昆虫与害虫防治]