Cross-resistance and interactions between Bt toxins Cry1Ac and Cry2Ab against the cotton bollworm

To delay evolution of pest resistance to transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt), the "pyramid" strategy uses plants that produce two or more toxins that kill the same pest. We conducted laboratory diet experiments with the cotton bollworm, Helicov...

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Main Authors:	Wei, Jizhen, Guo, Yuyuan, Liang, Gemei, Wu, Kongming, Zhang, Jie, Tabashnik, Bruce E., Li, Xianchun
Format:	Online
Language:	English
Published:	Nature Publishing Group 2015
Online Access:	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4293620/

id	pubmed-4293620
recordtype	oai_dc
spelling	pubmed-42936202015-01-27 Cross-resistance and interactions between Bt toxins Cry1Ac and Cry2Ab against the cotton bollworm Wei, Jizhen Guo, Yuyuan Liang, Gemei Wu, Kongming Zhang, Jie Tabashnik, Bruce E. Li, Xianchun Article To delay evolution of pest resistance to transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt), the "pyramid" strategy uses plants that produce two or more toxins that kill the same pest. We conducted laboratory diet experiments with the cotton bollworm, Helicoverpa armigera, to evaluate cross-resistance and interactions between two toxins in pyramided Bt cotton (Cry1Ac and Cry2Ab). Selection with Cry1Ac for 125 generations produced 1000-fold resistance to Cry1Ac and 6.8-fold cross-resistance to Cry2Ab. Selection with Cry2Ab for 29 generations caused 5.6-fold resistance to Cry2Ab and 61-fold cross-resistance to Cry1Ac. Without exposure to Bt toxins, resistance to both toxins decreased. For each of the four resistant strains examined, 67 to 100% of the combinations of Cry1Ac and Cry2Ab tested yielded higher than expected mortality, reflecting synergism between these two toxins. Results showing minor cross-resistance to Cry2Ab caused by selection with Cry1Ac and synergism between these two toxins against resistant insects suggest that plants producing both toxins could prolong the efficacy of Bt cotton against this pest in China. Including toxins against which no cross-resistance occurs and integrating Bt cotton with other control tactics could also increase the sustainability of management strategies. Nature Publishing Group 2015-01-14 /pmc/articles/PMC4293620/ /pubmed/25586723 http://dx.doi.org/10.1038/srep07714 Text en Copyright © 2015, Macmillan Publishers Limited. All rights reserved http://creativecommons.org/licenses/by-nc-nd/4.0/ This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder in order to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-nd/4.0/
repository_type	Open Access Journal
institution_category	Foreign Institution
institution	US National Center for Biotechnology Information
building	NCBI PubMed
collection	Online Access
language	English
format	Online
author	Wei, Jizhen Guo, Yuyuan Liang, Gemei Wu, Kongming Zhang, Jie Tabashnik, Bruce E. Li, Xianchun
spellingShingle	Wei, Jizhen Guo, Yuyuan Liang, Gemei Wu, Kongming Zhang, Jie Tabashnik, Bruce E. Li, Xianchun Cross-resistance and interactions between Bt toxins Cry1Ac and Cry2Ab against the cotton bollworm
author_facet	Wei, Jizhen Guo, Yuyuan Liang, Gemei Wu, Kongming Zhang, Jie Tabashnik, Bruce E. Li, Xianchun
author_sort	Wei, Jizhen
title	Cross-resistance and interactions between Bt toxins Cry1Ac and Cry2Ab against the cotton bollworm
title_short	Cross-resistance and interactions between Bt toxins Cry1Ac and Cry2Ab against the cotton bollworm
title_full	Cross-resistance and interactions between Bt toxins Cry1Ac and Cry2Ab against the cotton bollworm
title_fullStr	Cross-resistance and interactions between Bt toxins Cry1Ac and Cry2Ab against the cotton bollworm
title_full_unstemmed	Cross-resistance and interactions between Bt toxins Cry1Ac and Cry2Ab against the cotton bollworm
title_sort	cross-resistance and interactions between bt toxins cry1ac and cry2ab against the cotton bollworm
description	To delay evolution of pest resistance to transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt), the "pyramid" strategy uses plants that produce two or more toxins that kill the same pest. We conducted laboratory diet experiments with the cotton bollworm, Helicoverpa armigera, to evaluate cross-resistance and interactions between two toxins in pyramided Bt cotton (Cry1Ac and Cry2Ab). Selection with Cry1Ac for 125 generations produced 1000-fold resistance to Cry1Ac and 6.8-fold cross-resistance to Cry2Ab. Selection with Cry2Ab for 29 generations caused 5.6-fold resistance to Cry2Ab and 61-fold cross-resistance to Cry1Ac. Without exposure to Bt toxins, resistance to both toxins decreased. For each of the four resistant strains examined, 67 to 100% of the combinations of Cry1Ac and Cry2Ab tested yielded higher than expected mortality, reflecting synergism between these two toxins. Results showing minor cross-resistance to Cry2Ab caused by selection with Cry1Ac and synergism between these two toxins against resistant insects suggest that plants producing both toxins could prolong the efficacy of Bt cotton against this pest in China. Including toxins against which no cross-resistance occurs and integrating Bt cotton with other control tactics could also increase the sustainability of management strategies.
publisher	Nature Publishing Group
publishDate	2015
url	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4293620/
_version_	1613176442238009344

Cross-resistance and interactions between Bt toxins Cry1Ac and Cry2Ab against the cotton bollworm

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