利用结构域交换和密码子优化方法对苏云金芽孢杆菌(Bt)杀虫晶体蛋白Cry1Ab进行合理化设计改造,获得新型Bt蛋白编码基因cryFLIa。利用农杆菌介导法将该基因转入玉米HiII中,对转基因后代开展分子鉴定和抗性评价等相关工作。结果表明,cryFLIa 基因已整合进玉米基因组中,连续3代自交材料检测显示,转基因玉米目标基因正常表达并稳定遗传;蛋白在植株叶片中发育各时期的表达各异,在灌浆期蛋白表达量较高(471.883 ng/g)。室内生测和田间人工接虫试验表明,转cryFLIa 基因玉米具有抗亚洲玉米螟的能力。

Cry1 proteins were mutated from Bacillus thuringiensis by protein rational design, a mutant CryFLIa was gained that contains the selected domains from different Cry1s. The maize gene codon-optimized cryFLIa was induced into maize with the agrobacterium-mediated transformation. PCR and RT-PCR assessment were performed to 3 self-generations, exhibiting that the cryFLIa was integrated into the maize genome with stable expression. The cryFLIa expressed in various parts of the transgenic maize throughout life cycle leaves with the highest occurring during grain filling stage. Insect resistance assessment in both laboratory and the field showed that the cryFLIa trans-genic maize resisted to the Asian corn borer Ostrinia furnacalis. The results suggested that rational protein engineer-ing produced Cry protein of expected functionality, and the mutant cryFLIa possesses potential in insect-resistant maize biotech breeding.

黑龙江省自然基金项目“转MAD1 基因球孢白僵菌工程菌株防治玉米螟配套技术研究”(C201307)