title: Specific activity of a Bacillus thuringiensis strain against Locusta migratoria manilensis.
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 129kDa, and produces a mature toxin of 64kDa after activation. The pattern of total DNA from BTH-13 showed a large and three small plasmid bands. Known delta-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 delta-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.
authors: Wuhan Institute of Virology, Chinese Academy of Sciences, Xiaohongshan 44, Wuhan City, Hubei Province 430071, PR China.
authors: Lingli
authors: L
authors: Song
authors: Meiying
authors: M
authors: Gao
authors: Shunying
authors: S
authors: Dai
authors: Yan
authors: Y
authors: Wu
authors: Dan
authors: D
authors: Yi
authors: Rongsen
authors: R
authors: Li
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis / Q000145:classification / Q000502:physiology*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D017931:DNA Primers; D004269:DNA, Bacterial; D004591:Electrophoresis, Polyacrylamide Gel; D004731:Endotoxins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D005455:Fluorescent Antibody Technique; D006460:Hemolysin Proteins / Q000737:chemistry / Q000235:genetics; D048188:Locusta migratoria / Q000382:microbiology*; D010572:Pest Control, Biological; D016133:Polymerase Chain Reaction; D012988:Soil Microbiology
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis