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Modifying Baculovirus Expression Vectors to Produce Secreted Plant Proteins in Insect Cells
Published on: August 20, 2018
Characterization of chimeric Bacillus thuringiensis Vip3 toxins
Jun Fang1, Xiaoli Xu, Ping Wang
1Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029, China.
Applied and Environmental Microbiology
|November 24, 2006
Summary
New Bacillus thuringiensis vegetative insecticidal proteins (Vip) show promise for insect control. Researchers engineered a chimeric Vip3A toxin with enhanced activity and no cross-resistance to existing endotoxins, offering a new generation of pest-resistant crops.
Area of Science:
- Agricultural Science
- Molecular Biology
- Entomology
Background:
- Bacillus thuringiensis (Bt) vegetative insecticidal proteins (Vips) are alternatives to Bt endotoxins in transgenic crops.
- Current Bt endotoxins face insect resistance challenges.
Purpose of the Study:
- To clone and characterize novel Vip3A toxins.
- To engineer Vip3A toxins for altered host specificity and enhanced insecticidal activity.
- To investigate cross-resistance between Vip3A toxins and Bt Cry1A proteins.
Main Methods:
- Screening of B. thuringiensis isolates for Vip genes.
- Cloning and expression of vip3Ac1 and vip3Aa1 genes.
- Construction and testing of chimeric vip3AcAa gene.
- Insecticidal activity assays against Spodoptera frugiperda, Helicoverpa zea, Bombyx mori, Ostrinia nubilalis, and Trichoplusia ni.
Main Results:
- Vip3Ac1 exhibited high toxicity to fall armyworm and cotton bollworm, but low toxicity to silkworm.
- Chimeric Vip3AcAa showed insecticidal activity against European corn borer and increased toxicity to fall armyworm.
- Vip3Ac1 and Vip3AcAa were highly toxic to a Cry1Ac-resistant cabbage looper strain, demonstrating no cross-resistance.
Conclusions:
- The vip3Ac1 gene and its chimeric variants are promising candidates for developing next-generation insect-resistant transgenic plants.
- Vip3A toxins offer a valuable tool for managing insect pests, including those resistant to Bt endotoxins.
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