Submitted to: Journal of Insect Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/17/2009
Publication Date: 1/15/2010
Publication URL: http://hdl.handle.net/10113/48767
Citation: Liu, C., Gao, Y., Ning, C., Wu, K., Oppert, B.S., Guo, Y. 2010. Antisera-mediated in vivo reduction of Cry 1Ac toxicity against Helicoverpa armigera. Journal of Insect Physiology. 56(7):18-24. doi: http://dx.doi.org/10.1016/j.jinsphys.2009.12.012. Interpretive Summary: The microbial toxins of Bacillus thuringiensis (Bt), a bacterium that kills insects, are effective in controlling damaging larvae of moths, but resistance to Bt may develop. To understand and prevent resistance development, we identified Bt toxin receptors in the guts of cotton bollworms and suggest how toxin binding can lead to insect mortality. Understanding the mode of action of Bt toxins will lead to better strategies to prevent resistance development.
Technical Abstract: A functional assessment of Bacillus thuringiensis (Bt) toxin receptors in the midgut of lepidopteran insects will facilitate understanding of the toxin mode of action and provide effective strategies to counter the development of resistance. In this study, we produced anti-aminopeptidase (APN) and anti-cadherin sera with purified Cry1Ac toxin-binding APN or cadherin fragments from H. armigera. Antisera were evaluated for their effects on Cry1Ac toxicity through bioassays. Our results indicated that both the anti-APN and anti-cadherin sera reduced Cry1Ac toxicity in vivo, although cadherin receptor antiserum reduced toxicity more than APN antiserum. These results suggest that both APN and cadherin are involved in Cry1Ac intoxication of H. armigera and indicate that both pore-formation and signaling pathways may promote Cry1Ac toxicity in vivo.