Bioactivity of vip3A Protein from Bacillus thuringiensis Isolates and Cloning of Vip3A-LS1 Gene from Bt LS1

Vegetative insecticidal protein (VIP),which was highly toxic to Lepidoptera and Coleoptera,was found from some Bt strains in recent years. Bioassay of the VIPs from 31 isolates,with vip3A genes detected by PCR,was carried out. The results showed that the strain of Bt LS1 had higher toxicity to Spodoptera exigua and Helicoverpa armigera.The morality rates against S.exigua and H.armigera (1st instar) were 9.7% and 22.1% respectively,and the inhibiting rates of larval weight against S.exigua and H.armigera (2nd instar) were 90.7%±6.6% and 78.7%±6.6% respectively.VIP was mostly soluble in cell of Bt LS1.The vip3A gene amplified from Bt LS1 was cloned into pBluescript SK(+) and Vip3A-LS1 gene was obtained. The GenBank accession number was DQ016968. 8 AAs in Vip3A-LS1 were different from other deduced vip3A proteins.