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Cyt1Aa protein of Bacillus thuringiensis is toxic to the Cottonwood Leaf Beetle, Chrysomela scripta, and suppresses high levels of resistance to Cry3Aa
Author(s): Brian A. Federici; Leah S. Bauer
Date: 1998
Source: Applied and Environmental Microbiology. 64(11): 4368-4371.
Publication Series: Scientific Journal (JRNL)
Station: North Central Research Station
PDF: Download Publication (342.1 KB)Description
The insecticidal activity of Bacillus thuringiensis is due primarily to Cry and Cyt proteins. Cry proteins are typically toxic to lepidopterous, coleopterous, or dipterous insects, whereas the known toxicity of Cyt proteins is limited to dipterans. We report here that a Cyt protein, Cyt1Aa, is also highly toxic to the cottonwood leaf beetle, Chrysomela scripta, with a median lethal concentration of 2.5 ng/mm2 of leaf surface for second-instar larvae. Additionally, we show that Cyt1Aa suppresses resistance to Cry3Aa greater than 5,000-fold in C. scripta, a level only partially overcome by Cry1Ba due to cross-resistance. Studies of the histopathology of C. scripta larvae treated with Cyt1Aa revealed disruption and sloughing of midgut epithelial cells, indicating that its mechanism of action against C. scripta is similar to that observed in mosquito and blackfly larvae. These novel properties suggest that Cyt proteins may have an even broader spectrum of activity against insects and, owing to their different mechanism of action in comparison to Cry proteins, might be useful in managing resistance to Cry3 and possibly other Cry toxins used in microbial insecticides and transgenic plants.Publication Notes
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Citation
Federici, Brian A.; Bauer, Leah S. 1998. Cyt1Aa protein of Bacillus thuringiensis is toxic to the Cottonwood Leaf Beetle, Chrysomela scripta, and suppresses high levels of resistance to Cry3Aa. Applied and Environmental Microbiology. 64(11): 4368-4371.Related Search
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- Bacillus thuringiensis pore-forming toxins trigger massive shedding of GPI-anchored aminopeptidase N from gypsy moth midgut epithelial cells
- Localization of Bacillus thuringiensis Cry1A toxin-binding molecules in gypsy moth larval gut sections using fluorescence microscopy
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