Abstract：
Chitinase plays a vital role in the virulence of entomopathogenic fungi (EPF) when it infects host insects. We used gene recombination technology to express chitinase of three strains of Lecanicillium lecanii: Vl6063, V3450, and Vp28. The ORF of ChitVl6063, ChitV3450 and ChitVp28 were inserted into the fungal expression vector pBARGPE-1, which contained strong promoter and terminator, respectively, to construct a chitinase overpressing plasmid, then transformed the wild-type strain with blastospore transformation method. The virulence of the three recombinant strains against Toxoptera aurantii was improved by overproduction of ChitVl6063, ChitV3450, and ChitVp28, as demonstrated by significantly lower 3.43 %, 1.72 %, and 1.23 % fatal doses, respectively, according to an insect bioassay. Similarly, lethal times of recombinants (ChitVl6063, ChitV3450 and ChitVp28) were also decreased up to 29.51 %, 30.46 % and 33.90 %, respectively, compared to the wild-type strains. Improving the expression of chitinase is considered as an effective method for the enhancement of the EPF value. The efficacy could be enhanced using recombinant technology, which provides a prospecting view for future insecticidal applications.
摘要：
当几丁质酶感染宿主昆虫时，它在昆虫病原真菌（EPF）的毒力中起着至关重要的作用。我们使用基因重组技术表达了三株Lecanicilliumlecanii的几丁质酶：Vl6063，V3450和Vp28。将ChitVl6063、ChitV3450和ChitVp28的ORF插入到含有强启动子和终止子的真菌表达载体pBARGPE-1中,分别,构建几丁质酶过表达质粒，然后用芽孢子转化法转化野生型菌株。通过ChitVl6063，ChitV3450和ChitVp28的过量生产，三个重组菌株对弓形虫的毒力得到了改善，显着降低了3.43％，1.72%，和1.23%的致命剂量，分别,根据昆虫生物测定法。同样，重组体（ChitVl6063，ChitV3450和ChitVp28）的致死时间也减少了29.51％，30.46%和33.90%，分别,与野生型菌株相比。提高几丁质酶的表达被认为是提高EPF值的有效方法。使用重组技术可以提高疗效，这为未来的杀虫应用提供了展望。
