Isolation and characterization of strain of Bacillus thuringiensis subsp. kenyae containing two novel cry1-type toxin genes.
To identify novel crystal proteins, Bacillus thuringiensis 2385-1 was isolated from Korean soil samples and characterized. The H-serotype of 2385-1 was identical to that of subsp. kenyae (H4a4c), and its crystal toxin was bipyramidal-shaped. However, 2385-1 showed a much higher toxicity towards Plutella xylostella and Spodoptera exigua larvae than subsp. kenyae. In addition, the crystal protein profile and plasmid DNA pattern of 2385-1 differed from those of subsp. kenyae. To verify the crystal protein gene types of 2385-1, a PCR-RFLP analysis was performed, and the results revealed that 2385-1 contained two novel cry1-type crystal protein genes, cry1-5 and cry1-12, in addition to the cry1Ja1 gene. The deduced amino acid sequences of cry1-5 and cry1-12 showed a 97.9% and 75.7% sequence similarity with the CrylAb and Cry1Ja crystal proteins, respectively. Among the novel crystal proteins, Cry1-5 showed a high toxicity towards P. xylostella and S. exigua larvae. In conclusion, B. thuringiensis 2385-1 is a new isolate in terms of its gene types, and should be a promising source for an insecticide to control lepidopteran larvae.
Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-742, Korea.
Jae Young
JY
Choi
Ming Shun
MS
Li
Hee Jin
HJ
Shim
Jong Yul
JY
Roh
Soo-Dong
SD
Woo
Byung Rae
BR
Jin
Kyung Saeng
KS
Boo
Yeon Ho
YH
Je
D000818:Animals; D001413:Bacillus thuringiensis / Q000737:chemistry* / Q000235:genetics*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics* / Q000633:toxicity*; D001427:Bacterial Toxins / Q000235:genetics* / Q000633:toxicity*; D004731:Endotoxins / Q000235:genetics* / Q000494:pharmacology / Q000633:toxicity; D005798:Genes, Bacterial; D006460:Hemolysin Proteins / Q000235:genetics* / Q000633:toxicity*; D007306:Insecticides / Q000633:toxicity; D007915:Lepidoptera / Q000187:drug effects / Q000382:microbiology; D018411:Spodoptera / Q000187:drug effects / Q000382:microbiology
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D007306:Insecticides; C030956:insecticidal crystal protein, Bacillus Thuringiensis