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Bacillus thuringiensis metalloproteinase Bmp1 functions as a nematicidal virulence factor
Xiaoxia Luo1, Ling Chen, Qiong Huang
1State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China.
Applied and Environmental Microbiology
|November 6, 2012
Summary
Bacillus thuringiensis metalloproteinase Bmp1 shows toxicity to nematodes. When combined with Cry5Ba protein, Bmp1 exhibits significantly enhanced nematicidal activity, degrading intestinal tissues.
Area of Science:
- Microbiology
- Molecular Biology
- Nematology
Background:
- Bacillus thuringiensis (Bt) strains exhibit nematicidal activity against nematodes.
- Nematicidal toxins are often crystal (Cry) proteins, including Cry5, Cry6, and Cry55 families.
- Bt strain YBT-1518 possesses multiple virulence factors, including three highly nematicidal cry genes.
Purpose of the Study:
- To investigate the pathogenic potential of the metalloproteinase Bmp1 from Bt strain YBT-1518.
- To determine the nematicidal activity of purified Bmp1 protein.
- To evaluate the synergistic effect of Bmp1 and Cry5Ba on nematode toxicity.
Main Methods:
- Purification and characterization of Bmp1 metalloproteinase.
- Toxicity assays against Caenorhabditis elegans (C. elegans).
- Confocal microscopy to observe Bmp1 localization and tissue damage in C. elegans.
Main Results:
- Purified Bmp1 demonstrated metalloproteinase activity and toxicity against C. elegans (LC50 = 610 ± 9.37 μg/ml).
- Co-administration of Bmp1 and Cry5Ba enhanced toxicity 7.9-fold compared to individual toxicities.
- Bmp1 localized to the C. elegans intestine and caused tissue degradation, while Cry5Ba induced intestinal shrinkage.
Conclusions:
- Bmp1 is a nematicidal virulence factor produced by Bacillus thuringiensis.
- Bmp1 exhibits synergistic toxicity with Cry5Ba, enhancing its nematicidal potential.
- These findings provide new insights into Bt-nematode interactions and potential biocontrol strategies.
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