Specific activity of a Bacillus thuringiensis strain against Locusta migratoria manilensis |
| |
Authors: | Song Lingli Gao Meiying Dai Shunying Wu Yan Yi Dan Li Rongsen |
| |
Affiliation: | Wuhan Institute of Virology, Chinese Academy of Sciences, Xiaohongshan 44#, Wuhan City, Hubei Province 430071, PR China |
| |
Abstract: | Bacillus thuringiensis (Bt) has played an important role in biocontrol of pests. However, insecticidal activity of B. thuringiensis against locusts has been rarely reported. Bt strain BTH-13 exhibiting specific activity to locusts was isolated from a soil sample in China and characterized. Its bipyramidal parasporal crystal is mainly composed of a protein of 129 kDa, and produces a mature toxin of 64 kDa after activation. The pattern of total DNA from BTH-13 showed a large and three small plasmid bands. Known δ-endotoxin genes, cry1Aa, cry1Ab, cry1Ac, cry1C, cry3, cry4 and cry7Aa were not found from strain BTH-13 by PCR amplification. The sequence analysis of a DNA fragment produced by PCR amplification with degenerate cry-selective primers revealed that the fragment encoded a δ-endotoxin segment, which exhibited some similarity to several Cry proteins (41% of the highest similarity to Cry7Ba1). Toxicity tests were performed against Locusta migratoria manilensis, and the results demonstrated that trypsin-treated sporulated cultures and crystal proteins had high toxicity to larval and adult locusts. Cry toxin of BTH-13 was detected on the midguts of treated locusts using immunofluorescent technology, which confirmed the site of action of the crystal proteins in their toxicity for locusts. |
| |
Keywords: | Bacillus thuringiensis Locusta migratoria manilensis Locust δ-Endotoxin |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|