苏云金芽孢杆菌无质粒突变株BMB171的转化和表达性能

TRANSFORMATION AND EXPRESSION PROPERTIES OF A BACILLUS THURINGIENSIS PLASMID FREE DERIVATIVE STRAIN BMB171

研究了苏云金芽孢杆菌无质粒突变株ＢＭＢ１７１的转化性能和表达ｃｒｙ１Ａｃ和ｃｒｙ１Ｃａ基因的性能．用ｐＨＴ３１０１、ｐＢＭＢ３０５、ｐＢＭＢ１７３６、ｐＢＭＢ６７１、ｐＢＴＬ１和ｐＨＶ１２４９等６种外源质粒电转化无质粒突变株ＢＭＢ１７１，其转化频率分别是Ｂｔ４Ｑ７、Ｂｔ４Ｄ１０和Ｂｔｉ．ＩＰＳ．７８／１１等３种常用受体菌相应最高转化频率的１０００、６．７、１２．５、６６．７、３５００和２倍，其每μｇＤＮＡ的最高转化子数达１０７．导入ＢＭＢ１７１的外源质粒的稳定性与其复制子类型和质粒大小有关．无质粒突变株ＢＭＢ１７１表达ｃｒｙ１Ａｃ基因的表达量高于对照受体菌Ｂｔ４Ｑ７，略低于Ｂｔ４Ｄ１０和Ｂｔｉ．ＩＰＳ．７８／１１，而ＢＭＢ１７１表达ｃｒｙ１Ｃａ基因的表达量高于这３种受体菌；对小菜蛾３龄幼虫和甜菜夜蛾初孵幼虫的毒力测定结果表明，ＢＭＢ１７１表达ｃｒｙ１Ａｃ基因的杀虫毒力高于Ｂｔ４Ｑ７和Ｂｔ４Ｄ１０，略低于Ｂｔｉ．ＩＰＳ．７８／１；

The transformation and expression properties of a Bacillus thuringiensis plasmid free derivative strain BMB171 was reported. High transformation efficiencies in BMB171 were found as 1000 , 6.7 , 12.5 , 66.7 , 3500 , and were 2 folds as high as the highest values of 3 recipients Bt 4Q7, Bt 4D10 and Bti.IPS.78/11, respectively using 6 exogenous plasmids (pHT3101,pBMB3305,etc.) as the donor DNAs. The highest transformants could reach 10 7 per μ g DNA in BMB171. The stability of exogenous plasmids introduced in BMB171 was correlated with the patterns of replicons and sizes of plasmids. The properties of expressing cry 1Ac and cry 1Ca in BMB171 were also studied by quantifying the expression level and determinating the toxicity of the relevant transformants against two Lepidopteran larvae.It showed that the expression level of cry 1Ac gene in BMB171 was higher than that in Bt 4Q7, and less than those in Bt 4D10 and Bti.IPS.78/11 , but the expression level of cry 1Ca in BMB171 was higher than each of the three recipients; and the toxicity against Plutella xylostella produced by BMB171 transformants was higher than those by Bt 4Q7 and Bt 4D10, but less than that by Bti.IPS.78/11, whereas the toxicity against Spodoptera exigua larvae was higher than those produced by the three recipients.