Abstract:

genetic site-directed mutagenesis is an important way in studying the relation of proteinic formation and function. Mutants have the characters of improved toxicity and expanded specificity, and can be used to develop new biological insecticide and transgenic plants. In addition, Chimeric mutants can be expressed in plants and stave the resistance. Thirdly, the sites of regulons about the δ-endotoxins can be mutated in order to improve their expression in the plant system.

Key words: Bacillus thuringiensis , site-directed mutagenesis , Bt insecticide , transgenic plants

摘要：

综述了苏云金芽孢杆菌（Bacillus thuringiensis）杀虫晶体蛋白的定点突变研究与细菌杀虫剂和转基因植物开发的关系。定点突变作为研究蛋白质结构与功能的重要手段之一，可以改变毒蛋白的特性，产生的突变蛋白比未突变的蛋白毒力更高，杀虫谱更广，为细菌杀虫剂和转基因植物的开发提供充足的后备资源；定点突变可以使细菌的晶体蛋白基因在植物中更好地表达；定点突变可以产生嵌合基因，转入植物体或微生物后，能有效地预防和延缓害虫的抗药性产生。

关键词: 苏云金芽孢杆菌 定点突变 Bt杀虫剂 转基因植物