cry1ac gene
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Author(s):  
Åshild Kristin Andreassen ◽  
Nana Yaa Ohene Asare ◽  
Anne Marie Bakke ◽  
Knut Kelkås Dahl ◽  
Knut Thomas Dalen ◽  
...  

Soybean MON 87701 expresses the cry1Ac gene from Bacillus thuringiensis. The encoded Cry1Ac protein confers resistance against specific lepidopteran pests. Updated bioinformatics analyses of the inserted DNA and flanking sequences in soybean MON 87701 have not indicated a potential production of harmful toxins and allergens or polypeptides caused by the genetic modification. Genomic stability of the functional insert and consistent expression of the cry1Ac gene, have been shown over several generations of soybean MON 87701. Data from several field trials performed in USA, Canada, Chile and Argentina during 2005-2006 show that soybean MON 87701 is compositionally, morphologically and agronomically equivalent to its conventional counterpart and other commercial soybean cultivars. Subchronic feeding studies with rats as well as nutritional assessment with broilers have not revealed relevant adverse effects of MON 87701. These studies indicate that MON 87701 is nutritionally equivalent to and as safe as conventional soybean cultivars. The Cry1Ac protein produced in soybean MON 87701 do not show sequence resemblance to known toxins or IgE-dependent allergens, nor has the whole GM plant been reported to cause changes in IgE-mediated allergic reactions in patients reactive to soybean or in non-ectopic control individuals. Soybean is not cultivated in Norway, and there are no cross-compatible wild or weedy relatives of soybean in Europe.  Based on current knowledge and considering the intended uses, which exclude cultivation, the VKM GMO Panel concludes that soybean MON 87701 with the Cry1Ac protein:    -   Is compositionally, morphologically and agronomically equivalent to its conventional counterpart and other commercial soybean cultivars  -   Is unlikely to introduce a toxic or allergenic potential in food or feed compared to conventional soybean cultivars  -   Is nutritionally equivalent to and as safe as its conventional counterpart and other conventional soybean cultivars  -    Does not represent an environmental risk in Norway.


2020 ◽  
Author(s):  
Larbouga Bourgou ◽  
Ester Kargougou ◽  
Mahamadou Sawadogo ◽  
Michel Fok

Abstract BackgroundSince the commercial release of Bt cotton in Burkina Faso in 2009, the issue of seed purity in producers' fields has rarely been addressed in an unbiased and objective manner. The potential for contamination of conventional seed varieties with Bt traits and the consequent threat to the continuation of organic cotton production has been documented. However, studies are rare on the varietal purity of Bt cotton seeds, despite the implications for the effectiveness and sustainability of their use.This paper compensates for the lack of research on the varietal purity of cotton seeds in Burkina Faso by reporting the results of Enzyme linked immunosorbent assay tests collected in 2015 on samples of both conventional and Bt varieties from 646 fields.ResultsAccording to the conservative criteria used to declare the presence of a Bt gene in a given variety (more than 10% of seeds of conventional variety exhibit Bt traits, and at least 90% of seeds of Bt variety exhibit Bt traits), seed purity was very questionable for both types of variety. For the supposedly conventional variety, the Cry1Ac gene was observed in 63.6% of samples, the Cry2Ab gene was observed in 59.3% of samples, and both genes were detected in 52.2% of the seed samples. Only 29.3% of the seeds that were supposed to be of conventional type contained no Bt genes. Conversely, for the labeled Bt variety, the Cry1Ac gene was found in only 59.6% of samples, the Cry2Ab gene was found in 53.6% of the samples, and both genes were found in 40.4% of the samples. Finally, for the seeds that were supposed to contain both genes (Bollguard 2), both Cry1Ac and Cry2Ab genes were found in only 40.4% of the samples, only one of the genes was found in 32.4% of the samples, and 27.2% of the seeds in the samples contained neither.Two factors are responsible for the severe lack of seed purity. First, conventional varieties are being contaminated with Bt traits because of a failure to revise the seed production scheme in Burkina Faso to prevent cross-pollination. Second, the original Bt seeds provided to Burkina Faso lacked varietal purity.The organic sector plays a very minor role in the cotton sector of Burkina Faso (production of organic cotton totaled 453 tonnes in 2018/2019, out of national cotton production of 183 000 tonnes). Nevertheless, the lack of purity in conventional seed varieties is a threat to efforts to expand certified organic cotton production. The poor presence of Bt proteins in supposedly Bt varieties undermines their effectiveness in controlling pests and increases the likelihood of the development of resistance among pest populations.ConclusionOur results show the extent of purity loss when inadequate attention is paid to the preservation of seed purity. Pure conventional seeds could vanish in Burkina Faso, while Bt seeds do not carry the combination of the expected Bt traits. Any country wishing to embark on the use of Bt cotton, or to resume its use, as in the case of Burkina Faso, must first adjust its national seed production scheme to ensure that procedures to preserve varietal purity are enforced. The preservation of varietal purity is necessary to enable the launch or the continuation of identity-cotton production. In addition, the preservation of varietal purity is necessary to ensure the sustainable effectiveness of Bt cotton. In order to ensure that procedures to preserve varietal purity are observed, seed purity must be tested regularly, and test results must be published.


2020 ◽  
Author(s):  
Larbouga Bourgou ◽  
Ester Kargougou ◽  
Mahamadou Sawadogo ◽  
Michel Fok

Abstract [Background] Since the commercial release of Bt cotton in Burkina Faso in 2009, the issue of seed purity in producers' fields has rarely been addressed in an unbiased and objective manner. The potential for contamination of conventional seed varieties with Bt traits, and the consequent threat to the continuation of organic cotton production has been documented. However, studies are rare on the varietal purity of Bt cotton seeds, despite the implications for the effectiveness and sustainability of their use. This paper compensates for the lack of research on the varietal purity of cotton seeds in Burkina Faso by reporting the results of ELISA tests collected in 2015 on samples of both conventional and Bt varieties from 646 fields. [Results] According to the conservative criteria used to declare the presence of a Bt gene in a given variety (more than 10% of seeds of conventional variety exhibit Bt traits, and at least 90% of seeds of Bt variety exhibit Bt traits) seed purity was very questionable for both types of variety. For the supposedly conventional variety, the Cry1Ac gene was observed in 63.6% of samples, the Cry2Ab gene was observed in 59.3% of samples, and both genes were detected in 52.2% of the seed samples. Only 29.3% of the seeds that were supposed to be conventional contained no Bt genes. Conversely, for the labeled Bt variety, the Cry1Ac gene was found in only 59.6% of samples, the Cry2Ab gene was found in 53.6% of the samples, and both genes were found in 40.4% of the samples. Finally, for the seeds that were supposed to contain both genes (Bollguard 2), both Cry1Ac and Cry2Ab genes were found in only 40.4% of the samples, only one of the genes was found in 32.4% of the samples, and 27.2% of the seeds in the samples contained neither gene. Two factors are responsible for the severe lack of seed purity. First, conventional varieties are being contaminated with Bt traits because of a failure to revise the seed production scheme in Burkina Faso to prevent cross fertilization. Second, the original Bt seeds provided to Burkina Faso lacked varietal purity. The organic sector plays a very minor role in the cotton sector of Burkina Faso (production of organic cotton totaled 453 tonnes in 2018/19, out of national cotton production of 183,000 tonnes). Nevertheless, the lack of purity in conventional seed varieties is a threat to efforts to expand certified organic cotton production. The poor expression of Bt traits in supposedly Bt varieties undermines their effectiveness in controlling pests and increases the likelihood of the development of resistance among pest populations. [Conclusion] Our results show the extent of purity loss when inadequate attention is paid to the preservation of seed purity. Pure conventional seeds could totally vanish in Burkina Faso, while Bt seeds do not carry the combination of the expected Bt traits. Any country wishing to embark on the use of Bt cotton, or to resume its use, as in the case of Burkina Faso, must first adjust its national seed production scheme to ensure that procedures to preserve varietal purity are enforced. The preservation of varietal purity is necessary to enable the launch or the continuation of identity-cotton production. In addition, the preservation of varietal purity is necessary to ensure the sustainable effectiveness of Bt cotton. In order to ensure that procedures to preserve varietal purity are observed, seed purity must be tested regularly, and test results must be published.


2020 ◽  
Vol 12 (1) ◽  
pp. 47-56
Author(s):  
Eldessoky S. Dessoky ◽  
Roba M. Ismail ◽  
Nagwa I. Elarabi ◽  
Abdelhadi A. Abdelhadi ◽  
Naglaa A. Abdallah

Author(s):  
Nayana Hazarika ◽  
Rashmi Rekha Boruah ◽  
Pratap Jyoti Handique ◽  
Sumita Acharjee ◽  
Bidyut Kumar Sarmah

Availability of a suitable plant transformation binary vector is necessary for the generation of transgenic crops with an adequate expression of transgenic proteins. Therefore, three binary vectors were constructed viz., pBK204, pBK205, and pBK206 harboring either a truncated or a full-length version of a Cry1Ac gene for the generation of Helicoverpa protected crops. Two different promoters viz., Arabidopsis Rubisco small subunit (AtSSU) gene promoter or CaMV35S promoters were used to regulate the various versions of Cry1Ac gene. The binary vectors were reconstructed either by the Gibson assembly method and others by ligating the restriction enzyme digested fragments. The reconstructed binary vectors were mobilized into Agrobacterium strain AGL1 and validated by Agrobacterium infiltration assays of Nicotiana benthamiana. The amount of Cry1Ac protein accumulated in the Agroinfiltrated tobacco leaves was quantified using the quantitative ELISA assay. The expression of the Cry1Ac protein in the tobacco leaves ranged from 0.25 to 0.26 µg /g fresh weight (FW) when transformed with these three constructs. Thus, the vectors constructed in this study appeared to be suitable for generation of Helicoverpa resistant transgenic crops by Agrobacterium-mediated genetic transformation method.


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