新型转录因子CpcR调控的非芽胞杀虫蛋白表达系统的建立及应用

苏云金芽胞杆菌作为一种对人畜安全无毒、不污染环境且高效的微生物杀虫剂，在我国生物防治领域占有极其重要地位。针对苏云金芽胞杆菌制剂在田间应用易失活的问题，构建杀虫晶体蛋白高效表达的工程菌和延长持效期的工程菌是非常有效的遗传改良途径。本项目从苏云金芽胞杆菌制剂应用面临的实际问题出发，以具有独特分化表型的Bt LM1212菌株为切入点，明确其转录因子CpcR调控基因表达的模式，构建无芽胞杀虫蛋白表达新体系，为苏云金芽胞杆菌制剂的遗传改良提供新途径。2019年草地贪夜蛾入侵我国并完成了定殖过程，2020年将进入暴发危害阶段。为了遏制草地贪夜蛾对农业生产造成的严重危害，以无芽胞杀虫蛋白表达新体系为基础，进一步构建防治草地贪夜蛾的高毒力Bt菌株，为草地贪夜蛾的绿色与可持续治理奠定基础。

Bacillus thuringiensis, as a kind of safe, non-toxic, non-polluting and efficient microbial insecticide, plays an important role in the field of biological control in China. To solve the problem of inactivation of B. thuringiensis preparations in field application, the construction of engineered bacteria with high expression of insecticidal crystal proteins and prolonged duration of the engineered bacteria is a very effective way of genetic improvement. Starting from the practical problems faced by the application of B. thuringiensis preparations, this project took Bt LM1212 strain with unique differentiation phenotype as the entry point, clarified the expression mode of its transcription factor CpcR, constructed a new system for the insecticidal crystal proteins expression in the non-sporulating cells, and provided a new way for the genetic improvement of B. thuringiensis preparations. In 2019, Spodoptera frugiperda invaded China and completed the colonization process. In 2020, it will enter the outbreak hazard stage. In order to control the serious harm caused to agricultural production by Spodoptera frugiperda, a Bt strain with high virulence was further constructed to prevent and control S. frugiperda on the basis of the new system of non-sporulating insecticidal protein expression, so as to lay a foundation for the green and sustainable management of S. frugiperda.