Premium
Broadening the insecticidal spectrum of Lepidoptera‐specific Bacillus thuringiensis strains by chromosomal integration of cry3A
Author(s) -
Yue Chaoyin,
Sun Ming,
Yu Ziniu
Publication year - 2005
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.20493
Subject(s) - bacillus thuringiensis , biology , lepidoptera genitalia , plutella , recombinant dna , strain (injury) , helicoverpa armigera , instar , gene , bioassay , microbiology and biotechnology , botany , larva , genetics , bacteria , anatomy
A TnpI‐TnpIA‐mediated and thermosensitive recombination system was developed to construct genetically modified Bacillus thuringiensis strains encoding a crystal protein particularly active against Coleopteran species. Based on B. thuringiensis transposon Tn4430, an integrative vector, pBMB‐R14E, was constructed, by which the cry3A δ‐endotoxin gene highly toxic to Lepidoptera was delivered into a wildtype B. thuringiensis subsp. kurstaki strain YBT1520. The cry3A gene was integrated into the chromosome of the host strain. Then the integrative vector was eliminated by moving recombinant cultures to 46°C. Two recombinant B. thuringiensis strains, BMB1520‐S and BMB1520‐T, were obtained. In recombinant strains, the cry3A gene was stably expressed in measurable amounts and did not reduce the expression of endogenous crystal protein genes. Bioassay results showed that BMB1520‐S and BMB1520‐T, in addition to the activity against lepidopteran Plutella xylostella third‐instar larvae present in the parental strains, exhibited a high level of activity against coleopteran Rhyllodecta vulgatissima third‐instar larvae, absent from the parental strains. © 2005 Wiley Periodicals, Inc.