中文摘要：

利用PCR技术扩增了粉纹夜蛾（Trichoplusia ni）颗粒体病毒增效基因全长片段，扩增产物用EcoRⅠ／HindⅢ双酶消化，经0．7％低熔点琼脂糖凝胶电泳纯化后插入pRSET-B中，得重组表达质粒pRSET／enhancin；但重组子生长异常，在IPTG诱导下未能明显表达目标蛋白．用PstⅠ／HindⅢ双酶消化pRSET／enhancin，电泳回收2．7kb片段后插入pQE-30中，得重组表达载体pQE／enhancin；在IPTG诱导下于35℃成功表达出分子量（Mr）约为108×10^3的融合蛋白并命名为P108．初步纯化的P108显示了极显著的增效活性，对棉铃虫核型多角体病毒感染棉铃虫3龄幼虫的7d致死率提高34．03％，LT50缩短1．4d；对苏云金杆菌杀棉铃虫3龄幼虫的72h致死率提高65．96％．

英文摘要：

A span enhancin gene of Trichoplusia ni granulovirus was amplified by PCR and cloned into pRSET - B vector successfully. The recombinant vector pRSET/enhancin, however, failed to express foreign protein in Escherichia coli BL21 （ DE3 ）. The 2.7 kb target gene was then retrieved by 0.7% low melt point temperature agarose from pRSET/enhancin digested by Pst Ⅰ and Hind Ⅲ, and inserted into pQE -30 vector and expressed successfully in M15 （pREP4 ）. The synergy of the expression product （P108） on Helicoverpa armigera nuclear polyhedrosis virus （HaNPV） and Bacillus thuringiensis （Bt） against the 3^rd instar larvae of cotton bollworm, H. armigera, was studied. The results indicated that the accumulated mortality of the larvae was increased by 34.03% on the 7^th day post-infection and the median lethal time decreased by 1.4 days in HaNPV ＋ P108 treated compared with that in HaNPV treated, and the mortality in 72 h increased by 65.96% in Bt ＋ P108 treated compared with that in Bt treated.