With the deployment of transgenic crops expressing δ -endotoxins from Bacillus thuringiensis (Bt) for pest management, there is a need to generate information on the interaction of crop pests with their natural enemies that are important for regulation of pest populations. Therefore, we studied the effects of the Bt δ -endotoxins Cry1Ab and Cry1Ac on the survival and development of the parasito...

Expression of the transgene with a desirable character in crop plant is the ultimate goal of transgenic research. Transformation of two Bt genes namely Cry1Ac and Cry2A cloned as separate cassette under 35S promoter in pKHG4 plant expression vector was done by using shoot apex cut method of Agrobacterium. Molecular confirmation of putative transgenic cotton plants for Cry1Ac, Cry2A and GT gene ...

Two experiments were conducted to evaluate dry matter intake (DMI), milk yield, and milk composition from feeding rations that contained different sources of genetically modified whole cottonseed to Argentinean Holstein dairy cows. Twenty-four lactating multiparous Argentinean Holstein dairy cows were used in 2 experiments with a replicated 4 x 4 Latin square design, with cows averaging 565 kg ...

Genetically modified (GM) soybeans expressing Cry1A.105/Cry2Ab2/Cry1Ac (event MON 87701 × 89788 87751 87708) and Cry1Ac 89788) from Bacillus thuringiensis Berliner (Bt) are valuable technologies for managing key lepidopteran pests of soybean in South America, but do not provide stand-alone protection against Spodoptera species. Here, we evaluated the use these Bt their integration with insectic...

High-temperature stress reduces the endotoxin expression of insecticidal gene (Cry1Ac) in transgenic Bacillus thuringiensis (Bt) cotton and affects nitrogen metabolism. However, its effects on Cry1Ac after high-temperature termination remain unclear. In order to investigate effect proteins Bt squares, conventional Sikang-1 cultivar hybrid Sikang-3 were used as experimental materials. The potted...

1. Changes in the frequency of Cry1Ac resistance genes and shifts in tolerance of cotton bollworm, Helicoverpa armigera , to the Cry1Ac toxin were assessed using bioassays of F 1 and F 2 offspring of isofemale lines from Anci County of Hebei Province (a multiple-crop system including corn, soybean, peanut, and Bt cotton) and Xiajin County of Shandong Province (an intensive Bt cotton planting ar...

Transgenic insect-resistant cotton (Bt cotton) has been extensively planted in China, but its effects on non-targeted insect species such as the economically important honey bee (Apis mellifera) and silkworm (Bombyx mori) currently are unknown. In this study, pollen from two Bt cotton cultivars, one expressing Cry1Ac/EPSPS and the other expressing Cry1Ac/Cry2Ab, were used to evaluate the effect...

Toxins from the bacterium Bacillus thuringiensis (Bt) are used widely for insect control in sprays and transgenic plants, but their efficacy is reduced when pests evolve resistance. Previous work showed that mutations in a gene encoding the transporter protein ABCC2 are linked with resistance to Bt toxins Cry1Ab, Cry1Ac or both in four species of Lepidoptera. Here we compared the ABCC2 gene of ...

A field population (SERD3) of Plutella xylostella L. collected in December 1994, and resistant to various insecticides, including Bacillus thuringiensis subsp. kurstaki (Btk) and B.t. subsp. aizawai (Bta), was selected with Btk (Btk-Sel) and Bta (Bta-Sel). Little evidence of cross-resistance was observed. Binding to midgut brush border membrane vesicles was examined for insecticidal crystal pro...

We investigated whether development of resistance to a Bt crop in the presence of a natural enemy would be slower than without the natural enemy and whether biological control, in conjunction with a Bt crop, could effectively suppress the pest population. Additionally, we investigated whether insecticide-sprayed refuges of non-Bt crops would delay or accelerate resistance to the Bt crop. We use...