title: Vip3A is responsible for the potency of Bacillus thuringiensis 9816C culture supernatant against Helicoverpa armigera and Spodoptera exigua.
abstract: Culture supernatant of Bacillus thuringiensis 9816C had high toxicity against Helicoverpa armigera and Spodoptera exigua. However, it lost insecticidal activities after being bathed in boiling water for 5 min. Acrystalliferous mutants of Bt9816C (Bt9816C-NP1 and Bt9816C-NP2) cured of its endogenous plasmids no longer possessed vip3A gene and toxicity. The 89 kD protein which existed in Bt9816C supernatant disappeared in the two mutants' supernatant; nevertheless, the two mutants still exhibited hemolytic and phospholipase C activity as Bt9816C did. The vip3A gene of Bt9816C, vip3Aa18, was cloned and expressed in Escherichia coli BL21. Bioassay demonstrated that the recombinant E. coli had high toxicity against S. exigua. Taken together, it suggested that Vip3A protein was responsible for the toxicity of Bt9816C culture supernatants.
authors.affiliation: Tianjin Key Laboratory of Microbial Functional Genomics, Department of Microbiology, College of Life Sciences, Nankai University, China. caijun@nankai.edu.cn
authors.forename: Jun
authors.initials: J
authors.lastname: Cai
authors.forename: Liang
authors.initials: L
authors.lastname: Xiao
authors.forename: Bing
authors.initials: B
authors.lastname: Yan
authors.forename: Guan
authors.initials: G
authors.lastname: Bin
authors.forename: Yuehua
authors.initials: Y
authors.lastname: Chen
authors.forename: Gaixin
authors.initials: G
authors.lastname: Ren
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D007313:Insecta / Q000382:microbiology*; D018411:Spodoptera / Q000382:microbiology
chemical_list: D001426:Bacterial Proteins; C447139:Vip3A protein, Bacillus thuringiensis