Background Bt technology has played significant role in controlling bollworms and increasing cotton yield in earlier days of its introduction,a subsequent decline in yield became apparent over time.This decline may be...Background Bt technology has played significant role in controlling bollworms and increasing cotton yield in earlier days of its introduction,a subsequent decline in yield became apparent over time.This decline may be attributed to various environmental factors,pest dynamics,or combination of both.Therefore,the present biophysical survey and questionnaire were designed to evaluate the impact of Bt cotton on bollworms management and its effect on reducing spray costs,targeting farmers with varied landholdings and educational backgrounds.Additionally,data on farmers'cultivated varieties and the prevalence of bollworms and sucking insects in their fields were recorded.Subsequently,about eleven thousand cotton samples from farmer fields were tested for Cry1Ac,Cry2Ab and Vip3A genes by strip test.Results In this analysis,83% of the farmers planting approved varieties believe that Bt technology control bollworms,while 17% hold contradictory views.Similarly,among farmers cultivating unapproved varieties,77% agree on effectiveness of Bt technology against bollworms,while 23% disagree.On the other hand,67% of farmers planting approved varieties believe that Bt technology does not reduce spray costs,while 33% agree with the effectiveness.Similarly,78% of farmers cultivating unapproved varieties express doubt regarding its role to reduce spray costs,while 22% are in favour of this notion.Differences in opinions on the effectiveness of Bt cotton in controlling bollworms and reducing spray cost between farmers planting unapproved and approved varieties may stem from several factors.One major cause is the heavy infestation of sucking insects,which is probably due to the narrow genetic variation of the cultivated varieties.Additionally,the widespread cultivation of unapproved varieties(21.67%)is also an important factor to cause different opinions on the effectiveness of Bt cotton.Conclusion Based on our findings,we propose that the ineffective control of pests on cotton crop may be attributed to large scale cultivation of unap展开更多
为明确棉铃虫Helicoverpa armigera ATP结合盒转运蛋白家族A蛋白亚家族2(ATP binding cassette transporter subfamily A member 2,ABCA2)在Cry2Ab杀虫机制中的作用,利用酵母双杂交技术研究棉铃虫ABCA2与Cry2Ab的结合特性,并利用RNA干涉...为明确棉铃虫Helicoverpa armigera ATP结合盒转运蛋白家族A蛋白亚家族2(ATP binding cassette transporter subfamily A member 2,ABCA2)在Cry2Ab杀虫机制中的作用,利用酵母双杂交技术研究棉铃虫ABCA2与Cry2Ab的结合特性,并利用RNA干涉(dsRNA和siRNA)降低ABCA2在细胞和幼虫中的表达,结合细胞毒理学试验分析ABCA2的功能。结果表明,棉铃虫ABCA2能与Cry2Ab特异性结合;棉铃虫的ABCA2序列与美洲棉铃虫H.zea相关序列的相似度为92.86%,利用dsRNA干涉美洲棉铃虫中肠细胞ABCA2的表达能显著降低Cry2Ab对中肠细胞的毒力;利用siRNA干涉技术降低ABCA2在棉铃虫幼虫活体中的表达也显著降低了Cry2Ab对幼虫的毒力。表明棉铃虫ABCA2不仅是Cry2Ab的特异性结合蛋白,而且参与Cry2Ab的杀虫过程,是Cry2Ab的一个重要功能受体。展开更多
Since 1996, transgenic Bacillus thuringiensis(Bt) cotton has been commercially grown in numerous countries in an effort to stem the losses caused by key lepidopteran pests. However, the development of pest resistance ...Since 1996, transgenic Bacillus thuringiensis(Bt) cotton has been commercially grown in numerous countries in an effort to stem the losses caused by key lepidopteran pests. However, the development of pest resistance to Bt toxins has jeopardized the continued utilization of Bt cotton. As a strategy designed to circumvent the development of resistance, Bt cotton varieties expressing two or more toxins targeting the same pest have been introduced. Nevertheless, from the perspective of long-term planting of Bt cotton, the potential risk of cross-resistance to these Bt toxins is a threat that cannot be ignored. In this paper, we review current research(including that based on the analysis of protein binding sites and resistance genes) on the resistance of cotton bollworm(Helicoverpa armigera) to the Bt toxins Cry1 Ac and Cry2 Ab and the interrelationship between these toxins. On the basis of existing evidence, we assume that the actions of Cry1 Ac and Cry2 Ab against cotton bollworm are not completely independent, and then propose the "resistance-associated gene mutation potential hypothesis". Although the mechanisms underlying the resistance of pests to Bt toxins are yet to be comprehensively elucidated, this hypothesis could undoubtedly have important implications for adopting "pyramid" strategy in the future. Further research is recommended to devise strategies to retard the development of H. armigera resistance to Bt cotton, either using different Bt toxins or their various combinations.展开更多
[Objective] This study aimed to predict the structural characteristics of Bt Cry2Ab protein in transgenic crops with bioinformatic analysis to provide the theoretical clues for design of antibody Cry2Ab. [Method] The ...[Objective] This study aimed to predict the structural characteristics of Bt Cry2Ab protein in transgenic crops with bioinformatic analysis to provide the theoretical clues for design of antibody Cry2Ab. [Method] The amino acid sequence of Cry2Ab protein was searched from NCBI database. The B cell epitopes were predicted with DNAStar. The binding affinity between Cry2Ab protein and MHC-II molecules was analyzed with NetMHCII 2.2 Server to predict the T cell epitopes. [Result] Prediction result suggested the potential B cell epitope of Cry2Ab locating in the region of 208-215. Analysis of the binding affinity between Cry2Ab and MHC-II molecules suggested the regions of 177-185, 299-307 and 255-263 were the potential T cell epitopes. Human with HLA-DRB10101 alleles and HLA-DRB10701 alleles were more sensitive to Cry2Ab protein. [Conclusion] This study facilitates to understand the structural characteristics of Cry2Ab protein and provides a new clue to improve the assessment method for potential allergenicity of genetically modified food.展开更多
基金supported by Punjab Agriculture Research Board,Grant numbers PARB No.890received research support from Punjab Agriculture Board。
文摘Background Bt technology has played significant role in controlling bollworms and increasing cotton yield in earlier days of its introduction,a subsequent decline in yield became apparent over time.This decline may be attributed to various environmental factors,pest dynamics,or combination of both.Therefore,the present biophysical survey and questionnaire were designed to evaluate the impact of Bt cotton on bollworms management and its effect on reducing spray costs,targeting farmers with varied landholdings and educational backgrounds.Additionally,data on farmers'cultivated varieties and the prevalence of bollworms and sucking insects in their fields were recorded.Subsequently,about eleven thousand cotton samples from farmer fields were tested for Cry1Ac,Cry2Ab and Vip3A genes by strip test.Results In this analysis,83% of the farmers planting approved varieties believe that Bt technology control bollworms,while 17% hold contradictory views.Similarly,among farmers cultivating unapproved varieties,77% agree on effectiveness of Bt technology against bollworms,while 23% disagree.On the other hand,67% of farmers planting approved varieties believe that Bt technology does not reduce spray costs,while 33% agree with the effectiveness.Similarly,78% of farmers cultivating unapproved varieties express doubt regarding its role to reduce spray costs,while 22% are in favour of this notion.Differences in opinions on the effectiveness of Bt cotton in controlling bollworms and reducing spray cost between farmers planting unapproved and approved varieties may stem from several factors.One major cause is the heavy infestation of sucking insects,which is probably due to the narrow genetic variation of the cultivated varieties.Additionally,the widespread cultivation of unapproved varieties(21.67%)is also an important factor to cause different opinions on the effectiveness of Bt cotton.Conclusion Based on our findings,we propose that the ineffective control of pests on cotton crop may be attributed to large scale cultivation of unap
文摘为明确棉铃虫Helicoverpa armigera ATP结合盒转运蛋白家族A蛋白亚家族2(ATP binding cassette transporter subfamily A member 2,ABCA2)在Cry2Ab杀虫机制中的作用,利用酵母双杂交技术研究棉铃虫ABCA2与Cry2Ab的结合特性,并利用RNA干涉(dsRNA和siRNA)降低ABCA2在细胞和幼虫中的表达,结合细胞毒理学试验分析ABCA2的功能。结果表明,棉铃虫ABCA2能与Cry2Ab特异性结合;棉铃虫的ABCA2序列与美洲棉铃虫H.zea相关序列的相似度为92.86%,利用dsRNA干涉美洲棉铃虫中肠细胞ABCA2的表达能显著降低Cry2Ab对中肠细胞的毒力;利用siRNA干涉技术降低ABCA2在棉铃虫幼虫活体中的表达也显著降低了Cry2Ab对幼虫的毒力。表明棉铃虫ABCA2不仅是Cry2Ab的特异性结合蛋白,而且参与Cry2Ab的杀虫过程,是Cry2Ab的一个重要功能受体。
基金This study was supported by the National Natural Science Foundation of China(U1803233).The authors thank Prof.Kathreen RUCKSTUHL and Dr.WANG Muyang for their helpful suggestions on this manuscript.
文摘Since 1996, transgenic Bacillus thuringiensis(Bt) cotton has been commercially grown in numerous countries in an effort to stem the losses caused by key lepidopteran pests. However, the development of pest resistance to Bt toxins has jeopardized the continued utilization of Bt cotton. As a strategy designed to circumvent the development of resistance, Bt cotton varieties expressing two or more toxins targeting the same pest have been introduced. Nevertheless, from the perspective of long-term planting of Bt cotton, the potential risk of cross-resistance to these Bt toxins is a threat that cannot be ignored. In this paper, we review current research(including that based on the analysis of protein binding sites and resistance genes) on the resistance of cotton bollworm(Helicoverpa armigera) to the Bt toxins Cry1 Ac and Cry2 Ab and the interrelationship between these toxins. On the basis of existing evidence, we assume that the actions of Cry1 Ac and Cry2 Ab against cotton bollworm are not completely independent, and then propose the "resistance-associated gene mutation potential hypothesis". Although the mechanisms underlying the resistance of pests to Bt toxins are yet to be comprehensively elucidated, this hypothesis could undoubtedly have important implications for adopting "pyramid" strategy in the future. Further research is recommended to devise strategies to retard the development of H. armigera resistance to Bt cotton, either using different Bt toxins or their various combinations.
文摘[Objective] This study aimed to predict the structural characteristics of Bt Cry2Ab protein in transgenic crops with bioinformatic analysis to provide the theoretical clues for design of antibody Cry2Ab. [Method] The amino acid sequence of Cry2Ab protein was searched from NCBI database. The B cell epitopes were predicted with DNAStar. The binding affinity between Cry2Ab protein and MHC-II molecules was analyzed with NetMHCII 2.2 Server to predict the T cell epitopes. [Result] Prediction result suggested the potential B cell epitope of Cry2Ab locating in the region of 208-215. Analysis of the binding affinity between Cry2Ab and MHC-II molecules suggested the regions of 177-185, 299-307 and 255-263 were the potential T cell epitopes. Human with HLA-DRB10101 alleles and HLA-DRB10701 alleles were more sensitive to Cry2Ab protein. [Conclusion] This study facilitates to understand the structural characteristics of Cry2Ab protein and provides a new clue to improve the assessment method for potential allergenicity of genetically modified food.
