title: Restraining Erwinia virulence by expression of N-acyl homoserine lactonase gene pro3A-aiiA in Bacillus thuringiensis subsp leesis.
abstract: To widen the biological control function of a genetically modified Bacillus thuringiensis subsp leesis strain BMB-005, an acyl homoserine lactonase (AHL lactonase) gene aiiA transcribed by the promoter of insecticidal crystal protein coding gene cry3A, was transformed into strain BMB-005. The amount of AHL lactonase protein produced by transformant BMB821A was 2.4-fold more than that produced by BMB-005. AHL-degradation assay showed that transformant BMB821A could degrade more AHLs molecules than the original strain BMB-005. The result of Erwinia carotovora pathogenicity test showed that the parental strain BMB-005 had no restraint of Erwinia infection, but the transformants exhibited strong restraint of E. carotovora infection on potato slices and cactus stems. Insecticidal bioassay against lepidopteran Spodoptera exigua showed that both strain BMB-005 and transformant BMB821A were toxic to S. exigua. The toxicity of transformant BMB821A (LC(50) was 3.8) was a little attenuated comparing with the toxicity of the original strain BMB-005 (LC(50) was 2.9). The B. thuringiensis strain BMB-005 has high toxicity against Helicoverpa armigera, Plutella xylostella, and S. exigua. This work provided new strategy for developing genetically engineered multi-functional B. thuringiensis strain that possesses insecticidal activity together with restraint of bacterial pathogenicity.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Chenguang
authors.initials: C
authors.lastname: Zhu
authors.forename: Ziniu
authors.initials: Z
authors.lastname: Yu
authors.forename: Ming
authors.initials: M
authors.lastname: Sun
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis / Q000201:enzymology* / Q000235:genetics; D029421:Cactaceae / Q000382:microbiology; D002265:Carboxylic Ester Hydrolases / Q000235:genetics* / Q000378:metabolism; D005822:Genetic Vectors; D007300:Insect Control / Q000379:methods*; D007915:Lepidoptera; D030781:Organisms, Genetically Modified; D016973:Pectobacterium carotovorum / Q000472:pathogenicity*; D010572:Pest Control, Biological / Q000379:methods*; D011198:Solanum tuberosum / Q000382:microbiology; D014774:Virulence / Q000502:physiology
chemical_list: D002265:Carboxylic Ester Hydrolases; C432003:N-acyl homoserine lactonase