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用天然毒素蛋白杀灭害虫是农林病虫害防治的一个重要发展方向。利用家蚕核型多角体病毒(BmNPV)多角体蛋白基因的部分序列与蝎毒素蛋白基因(BmK ITa1)融合表达,SDS-PAGE分析通过融合表达策略构建的含有蝎毒素蛋白基因的重组病毒具有较高的蝎毒素蛋白表达水平,重组病毒vBmBac(polh-)PH5B/35B-BmK ITa1.6His,在家蚕BmN细胞内的BmKITa1蛋白表达水平分别为0.4、0.2 mg/mL。以家蚕和棉铃虫为供试昆虫,探讨融合蝎毒素蛋白的杀虫效果,结果表明:经口添食含融合蝎毒素蛋白的BmN细胞液对不同龄期家蚕幼虫均具有毒性,尤其对低龄幼虫的毒性较强,蚁蚕添食后的死亡率达80%;给1龄期的家蚕和棉铃虫幼虫经口添食含有不同剂量融合蝎毒素蛋白的BmN细胞破碎液,当添食剂量在2.8μg/头时,家蚕的死亡率即达100%,棉铃虫的死亡率达74%。研究结果提示:BmNPV多角体蛋白编码基因的部分序列与蝎毒素蛋白基因融合表达,可提高蝎毒素蛋白的表达水平,且重组病毒表达的蝎毒素蛋白具有较好的杀虫活性,在较低剂量下即可对低龄昆虫产生良好的杀灭效果。
Natural toxin protein to kill pests is an important development direction of pest control in agriculture and forestry. The partial sequence of polyhedrin gene of Bombyx mori nucleopolyhedrovirus (BmNPV) was expressed by fusion with the scorpion toxin protein gene (BmK ITa1), and the recombinant virus containing the scorpion toxin protein gene was constructed by fusion expression strategy The level of BmKITa1 protein in silkworm BmN cells was 0.4 and 0.2 mg / mL, respectively, for the recombinant protein vBmBac (polh-) PH5B / 35B-BmK ITa1.6His. Bombyx mori and Helicoverpa armigera were used as test insects to explore the insecticidal effect of the fusion scorpion toxin protein. The results showed that oral administration of BmN cytosol containing scorpion toxin protein fusion was toxic to silkworm larvae at different instars, especially to young larvae The mortality of silkworm after feeding was 80%. The silkworm and cotton bollworm larvae at the first instar stage were orally fed with the BmN cell disruption solution containing different doses of the scorpion toxin protein, μg / head, the mortality rate of silkworm reached 100%, and the mortality rate of cotton bollworm reached 74%. The results suggest that the partial sequence of BmNPV polyhedrin encoding fusion protein with scorpion toxin protein can increase the expression level of scorpion toxin protein and the scorpion toxin protein expressed by recombinant virus has good insecticidal activity. Under the age of the insect can have a good killing effect.