Improved production of insecticidal proteins in Bacillus thuringiensis strains carrying an additional cry1C gene in its chromosome.
A cryIC gene, whose product is active against Spodoptera exigua, was introduced into wildtype Bacillus thuringiensis kurstaki strain YBT1520 using an integrative and thermosensitive vector, pBMB-FLCE, which was developed based on B. thuringiensis transposon Tn4430 harboring a tnpI-tnpA gene. With the mediation of TnpI-TnpA, the cry1C gene was integrated into the chromosome of the host strain. To prevent secondary integration, the integrative vector was eliminated by moving recombinant cultures to 46 degrees C for generations. Two integrative recombinant B. thuringiensis strains BMB1520-E and BMB1520-F were obtained. In recombinant BMB1520-F, the cry1C gene was expressed stably at a significant level and did not reduce the expression of endogenous crystal protein genes. Bioassay results indicated that BMB1520-E and BMB1520-F showed a higher level of activity against S. exigua third-instar larvae than did their parent strains, in addition to the high toxicity to Plutella xylostella third-instar later larvae.
Yue
Chaoyin
C
Biotechnology Research Center, China Three Gorges University, Yichang, 443002 Hubei, People's Republic of China.
Sun
Ming
M
Yu
Ziniu
Z
D000818:Animals; D001413:Bacillus thuringiensis / Q000378:metabolism*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics*; D001427:Bacterial Toxins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics*; D001681:Biological Assay; D001709:Biotechnology / Q000379:methods*; D015139:Blotting, Southern; D002874:Chromosome Mapping; D004247:DNA / Q000737:chemistry; D004251:DNA Transposable Elements; D004731:Endotoxins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics*; D004926:Escherichia coli / Q000378:metabolism; D005786:Gene Expression Regulation; D005818:Genetic Engineering; D005822:Genetic Vectors; D006460:Hemolysin Proteins; D008854:Microscopy, Electron; D046529:Microscopy, Electron, Transmission; D008957:Models, Genetic; D009036:Moths; D009693:Nucleic Acid Hybridization; D010957:Plasmids / Q000378:metabolism; D011995:Recombination, Genetic
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004251:DNA Transposable Elements; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D004247:DNA