利用蝎毒基因改良杆状病毒杀虫剂

杆状病毒(Baculovirus)是昆虫及某些甲壳类动物的专性病原体,昆虫杆状病毒杀虫剂是公认的一类无公害的生物农药,联合国世界卫生组织(WHO)和粮农组织(FAO)早已推荐用于农作物害虫生物防治。但是,杆状病毒都有一个共同的缺点,就是杀死害虫时间太长(一般室内需要5—7天,田间需要时间更长)。由于这一缺点,使杆状病毒杀虫剂的商品生产和推广应用受到很大限制,甚至停滞不前。 本研究通过人工合成一种对昆虫专性的蝎子Androctonus anstralis神经毒素AaIT的编

IMPROVEMENT OF BACULOVIRUS AS INSECTICIDE BY USING A SCORPION TOXIN GENE

A recombinant baculovirus vTN -AaIT3 expressing the insect-specific neurotoxin AaIT of the scorpion Androctonus anstralia was constructed by employing insertion of a synthetic DNA frag-ment containing the toxin coding sequence (210pb) and a synthetic secretion signal sequence (123bp) of the enveloe protein gp67 of the bacolovtrus Autographa californica multinucleocapsid nu-clear polyhedrosis virus (AcMNPV). The DNA fragment was inserted into a transfer vector of Tri-choplusia ni nuclear polyhedrosis virus (TnNPV), pSXIVVI+X3, under control of the synthetic late promoter. The resulting recombinant plasmid and the DNA of phenotype occ- TnNPV were cotransfected intc Spodoptera frugiperda ' cells (Sf-21 cell line). The recombinant virus was puri-fied by passing insect larvae and plaque selection, which contains AaIT3 gene and forms occlu-sion bodies. The expression of toxin protein was determined by SDS?PAGE, showing a 12KD protein band (corresponding to the size of AalT plus gp64 signal peptide) in the sample of the re-combinant virus -infected cells. Bloassay results showed that the engineered baculovirus can infect the larvae of Trichopluaia ni, Argyrogramma agnata, Spodoptera exigus and Heliothis armigera by feeding polyhedron, and cause the larvae paralysis in 2-3 days post -infection, stop feeding and then death at final. Comparison with the wild type TnNPV, the recombinant virus was more effective in controling the pest and protection of the plant leef.