• International Journal of Industrial Entomology and Biomaterials
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• v.14 no.1
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• pp.33-36
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• 2007

To improve insecticidal activity of B. thuringiensis 2385-1 (Bt 2385-1), a recombinant plasmid, pHT1K-1Ac, was introduced into lepidopteran toxic Bt 2385-1 by electroporation. The presence of the recombinant plasmid in Bt 2385-1 after electroporation was confirmed by PCR. Bt 2385-1 transformant was named as Bt pHT1K-1Ac/2385-1 (1K-1Ac/2385-1). The 1K-1Ac/2385-1 transformant produced bipyramidal-shaped parasporal inclusion as like the wild-type strain, Bt 2385-1, and showed an 130 kDa band of Cry1Ac protein. The insecticidal activity of 1K-lAc/2385-1 against S. exigua was similar to that of Bt 2385-1 but the $LC_{50}$ value of transformant against P. xylostella was 1.8 times lower. Through these bioassay results, it was confirmed that toxicity of Bt 2385-1 transformant showed synergistic effect by introducing Cry1Ac. These results suggested that the multiple expressions of Cry proteins in a promising Bt strain may interact synergistically in insect midgut, resulting in increase of toxicity and expansion of host spectrum.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2003.10a
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• pp.114-115
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• 2003

A Bacillus thuringiensis isolate, Bt 2385-1, which showed toxicity to lepidopteran, was isolated from Korean soil sample and characterized. PCR-RFLP showed that this isolate contains two novel cryl-type crystal protein genes. In this study, we designed cryl-type specific primer set (ATG1-F and N400-R) to clone the toxic domain of the all cryl-type genes. The two novel rlyl-type toxin genes in addition to crylJal gene were cloned and sequenced. (omitted)