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【目的】开发高毒力的重组斜纹夜蛾核型多角体病毒(Spodoptera litura multicapsid nucleopolyhedroviruse,SpltMNPV)杀虫剂。【方法】构建编码蜕皮激素UDP-葡萄糖基转移酶(ecdysterioid UDP-glucosyl transferase gene,egt)基因缺失并插入东亚钳蝎神经毒素(B.martensi Karsch,BmK ITa1)基因的重组转移载体,重组转移载体与SpltMNPVⅡ基因组DNA共转染斜纹夜蛾细胞,通过荧光斑法与有限稀释法相结合筛选重组病毒。【结果】成功筛选出缺失egt基因的、早期启动子(ie-1)启动的、表达BmK ITa1成熟肽的重组病毒SpltMNPV-Δegt-Pph-egfp-ie-1-BmK ITa1。生物测定结果显示,重组病毒的杀虫速度(LT50)较野生病毒提前0.7-0.8 d。【结论】通过在SpltMNPV病毒基因组中插入外源毒素基因可明显增强病毒的杀虫效果,结果说明开发高毒力SpltMNPV生物杀虫剂具有可行性。
【Objective】 To develop a highly virulent Spodoptera litura multicapsid nucleopolyhedroviruse (SpltMNPV) insecticide. 【Method】 The recombinant transfer vector encoding for deletion of the ecdysterioid UDP-glucosyl transferase gene (egt) gene was inserted into the B. martensi Karsch (BmK ITa1) gene and the recombinant transfer vector Cotransfected with SpltMNPVII genomic DNA to S. litura, and the recombinant virus was screened by fluorescence spot method and limiting dilution method. 【Result】 The recombinant virus SpltMNPV-Δegt-Pph-egfp-ie-1-BmK ITa1 which was deleted from the egt gene and started by the early promoter (ie-1) and expressed mature BmK ITa1 peptide was successfully screened. Bioassay results showed that the recombinant virus had an insecticidal rate (LT50) 0.7-0.8 d earlier than that of wild-type virus. 【Conclusion】 Through the insertion of exotoxin gene into the genome of SpltMNPV virus, the insecticidal effect of the virus can be obviously enhanced. The result shows that it is feasible to develop a highly toxic SpltMNPV biocide.