Engineering Modified Bt Toxins to Counter Insect Resistance
November 9, 2007| |
Evolution of insect resistance threatens the effectiveness of Bacillus thuringiensis (Bt) toxins that are widely used in sprays and transgenic crops. Previous researches showed that resistance of some insects to Bt proteins is caused by mutations that disrupt a toxin-binding cadherin (proteins necessary for cell to cell adhesion). Bt toxins bind to cadherin in a lock and key fashion. Upon binding, an enzyme removes portions of the bound toxins. The trimmed toxin molecules clump and form pores in the gut membrane cells, causing entry and exit of substances within the cell and ultimately cell death.
Using RNA interference, scientists from the University of Arizona and Universidad Nacional Autónoma de México confirmed the cadherin’s role in Bt toxicity. Tobacco hornworm larvae with silenced cadherin gene showed reduced susceptibility to the Bt toxin Cry1A. The scientists then changed the structure of the Cry1A toxin by deleting one alpha chain from the protein. The modified Cry1A killed cadherin-silenced tobacco hornworms as well as the Bt resistant pink bollworm. The modified Bt toxins may be useful against pests resistant to standard Bt toxins.
The paper published by Science is available to subcribers at http://www.sciencemag.org/cgi/rapidpdf/1146453.pdf. Non subscribers can read the abstract at http://www.sciencemag.org/cgi/content/abstract/1146453
| |
Biotech Updates is a weekly newsletter of ISAAA, a not-for-profit organization. It is distributed for free to over 22,000 subscribers worldwide to inform them about the key developments in biosciences, especially in biotechnology. Your support will help us in our mission to feed the world with knowledge. You can help by donating as little as $10.
-
See more articles:
-
News from Around the World
- 162 Million People Still Live Under US 50 Cents
- Priorities for Sweet Potato Research in Developing Countries
- Building Capacity in the Life Sciences
- Egypt Harvests Bt Maize Field Trials
- Jordan Open to Biotech Initiatives
- Kenya Government Committed to Biosafety Bill 2007
- Program to Improve Quality Compliance of GE Products
- UC to Research on Improved Cowpeas for Africa
- Researchers Identify Cause of Watermelon Vine Decline
- Test-Tube Bananas Give New Hope to Philippine Farmers
- A Low-Cost Method Increases Farm Yield in Kazakhstan
- Extra income for Aussie Farmers from GM canola
- DRR and ISAAA Hold Seminar on Outlook of Biotech/GM Crops
- Filipina Bt Maize Farmer Gets International Award
- Dupont Supports Indonesia's Rice and Corn Industry
- Genes Identified to Protect Brassicas from TuMV
- Chlorophyll Breakdown Products are Active Antioxidants
- New Findings May Help Fight Blackleg and Softrot Potato Disease
- Cellectis Launches Program with Bayer CropScience
-
Research Highlights
- Engineering Modified Bt Toxins to Counter Insect Resistance
- RNAi to Control Coleopteran Pests
- Cotton Bollworm With Impaired Tolerance to Gossypol
-
Announcements
- Conference on Legume Genomics and Genetics
- International Conference on Biofuels
- International Symposium on Induced Mutations in Plants
-
Read the latest: - Biotech Updates (April 30, 2025)
- Gene Editing Supplement (April 30, 2025)
- Gene Drive Supplement (February 22, 2023)
-
Subscribe to BU: - Share
- Tweet