Journal or Publishing Institution: Applied and Environmental Microbiology
Study: http://aem.asm.org/content/early/2014/12/02/AEM.03382-14.short
Author(s): Kain, W., Song, X., Janmaat, A.F., Zhao, J.Z., Myers, J., Shelton, A.M. and Wang, P.
Article Type: Peer Reviewed Study
Record ID: 1191
Abstract: Two populations of Trichoplusia ni that had developed resistance to Bacillus thuringiensis (Bt) sprays in commercial greenhouse vegetable production were tested for their resistance to the pyramided Bt cotton (BollGard II) plants expressing Cry1Ac and Cry2Ab. The T. ni colonies resistant to Bt var. kurstaki (Btk) formulations were not only resistant to the Bt toxin Cry1Ac as previously reported, but also had a high frequency of Cry2Ab resistant alleles, exhibiting ca. 20% of survival on BollGard II foliage. BollGard II-resistant T. ni strains were established by selection with BollGard II foliage to further remove Cry2Ab sensitive alleles in the T. ni populations. The BollGard II-resistant strains showed incomplete resistance to BollGard II with an adjusted survival from 0.50 to 0.78 after 7 days. The resistance to the dual toxin cotton plants was conferred by two genetically independent resistance mechanisms – one to Cry1Ac and one to Cry2Ab. The resistance ratio to Cry2Ab was at least 1,467 fold, compared to the susceptible T. ni. The resistance to Cry2Ab in the resistant T. ni was an autosomally inherited incompletely recessive monogenic trait. Results from this study indicate that insect populations under selection of Bt sprays in agriculture can be resistant to multiple Bt toxins and may potentially confer resistance to multi-toxin Bt crops.
Keywords: Trichoplusia ni, Bacillus thuringiensis, Bt cotton, BollGard, Cry1Ac, Cry2Ab, Genetically modified, GMO, GM, Transgenic, Genetically engineered
Citation: Kain, W., Song, X., Janmaat, A.F., Zhao, J.Z., Myers, J., Shelton, A.M. and Wang, P., 2014. Resistance of Trichoplusia ni populations selected by Bacillus thuringiensis sprays to pyramided Bt cotton plants expressing Cry1Ac and Cry2Ab. Applied and Environmental Microbiology, pp.AEM-03382.
