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Risk Assessment
Record information and status
Record ID
Date of creation
2013-01-14 17:22 UTC (gutemberg.sousa@mctic.gov.br)
Date of publication
2013-01-15 13:23 UTC (davi.bonavides@itamaraty.gov.br)

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General Information
  • Brazil
Title of risk assessment
Risk Assessment of insect resistant and ammonium glyphosate herbicide tolerant genetically modified cotton T304-40 x GHB119, styled TwinLink cotton
Date of the risk assessment
Competent National Authority(ies) responsible for the risk assessment
National Technical Biosafety Commission
Setor Policial Sul -SPO Área 5 Quadra 3 Bloco B - Térreo Salas 10 à 14
Brasília, DF
Brazil, CEP - 70610-200
Phone:(5561) 3411-5516
Fax:(5561) 3317-7475
Url:National Technical Biosafety Comission
Contact details of the main responsible risk assessor
Dr Edilson Paiva
President of National Biosafety Commitie
Ministry Of Science and Technology (MCT)
SPO - Área 05 - Quadra 03 Bloco B - Térreo - Salas  08 a 10
Brasília , DF - CEP: 70610-200
Fones: (55)(61) 3411 5151 - FAX: (55)(61) 3317 7475
Brasilia, Brasília
Brazil, 70610-200
Risk assessment details
Living modified organism
BCS-GHØØ4-7 x BCS-GHØØ5-8 - TwinLink™ Cotton
Bayer S.A Resistance to diseases and pests - Insects - Lepidoptera (butterflies and moths) - Cotton bollworm (Helicoverpa spp.), armyworm (Spodoptera frugiperda) Resistance to herbicides - Glufosinate
Show detection method(s)
Scope of the risk assessment
  • LMOs for Contained use
  • LMOs for direct use as feed
  • LMOs for direct use as food
  • LMOs for Introduction into the environment
    • Commercial production
    • Field trial
  • LMOs for processing
Risk assessment report / Summary
Methodology and points to consider
Potential adverse effects identified in the risk assessment
Event T304-40 x GHB119 results from crossing,  through classic genetic improvement, of genetically modified T304-40 and GHB119 cotton parents. Parental events were obtained through transformation mediated by A. tumefasciens and molecular characterization by Southern Blot confirmed both presence and structure of the inserts. Genotypic stability was confirmed for parental events and the stacked event through analysis of multiple generations, different germoplasms and cultivation locations. Stacked event T304-40 x GHB119  inherited from its parental T304-40 genes cry1Ab and bar and from its parental GHB119, genes cry2Ae and bar. Genes cry1Ab and cry2Ae are derived from Bacillus thuringiensis  and codify proteins Cry1Ab and Cry2Ae, respectively, responsible for granting resistance to insects. It is known that the action mechanism of Cry proteins is mediated by  specific receptors located at the middle intestine of susceptible insects. Association of Cry proteins to these receptors leads to the formation of pores that cause the insect death. Gene bar is derived from Streptomyces hygroscopicus and codes the PAT protein (phosphinothricin-N-acetyltransferase), responsible for granting tolerance to the herbicide ammonium glyphosate . Tolerance to the herbicide is granted by "acetylation", catalyzed by PAT, of synthetic phosphinothricin  (styled ammonium gluphosinate) producing the inactive compound N acetyl phosphinothricin, which is later metabolized in plant cells. Expression levels of proteins Cry1Ab, Cry2Ae and PAT in leaves, flower-buds and kernels of TwinLink cotton and its byproducts, such as husk, cakes and oil. Besides, the identity confirmation of target proteins was conducted by mass spectrometry (MS). The results were compared with the adequate controls and all results obtained point towards stability of constructs and adequate expression of the target-proteins and, in some byproducts, the amount of proteins is below detection level (oil and cotton cake). Results of studies of centesimal composition, mineral contents, E vitamin, antinutrients, gossypol, amino acids and fat acids, were used to compare the genetically transformed event TwinLink with conventional cotton. The majority of the components examined did not show differences between the genotypes and, in cases where the change took place, it remained between the range described in the literature and therefore does not represent impact of nutritional relevance. There was no performance difference between birds treated with cakes of genetically modified cotton (coming from event T304-40, GHB119 and T304-40 x GHB119) and cakes of conventional corn. No adverse effect was recorded in acute toxicity studies by oral ingestion of proteins Cry1Ab and Cry2Ae in mice. Essays in simulated gastric and intestinal fluids showed that proteins Cry1Ab and Cry2Ae are completely degraded, so that no cumulative effects, or persistence of such proteins in the organism, are expected. In silico analysis showed that there is no homology between heterolog proteins Cry1Ab and Cry2Ae with allergens and know toxic proteins. The studies indicate that Events T304-40 and GHB119, as well as their combination in TwinLink cotton, are substantially equivalent to other cotton varieties, and also indicate that the DNA inserted and the expressed proteins Cry1Ab, Cry2Ae and PAT fail to pose significant risk to human/animal health comparatively with the use of conventional cotton and  its byproducts in food. Environment security aspects were analyzed in a series of studies conducted both in Brazil and abroad. Experiments conducted in regions featuring favorable edaphoclimatic conditions, which are representative for the culture of cotton in Brazil, assessed reproduction, survival, and agronomic aspects comparing lineages of genetically modified cotton and the conventional variety. The results recorded a regular occurrence of phenologic phases along the cycle and similarity of growth, development and phenotypic characters between genetically modified lineages and the isogenic non-modified cultivar, and therefore no additional characteristic was recorded that could regulate the survival of genetically modified cotton in the environment, discarding the possibility of occurrence of epistatic and pleiotropic effects of the genes introduced. Analyses of development and vegetative growth and reproduction during the cycle showed that the genetically modified genotypes T304-40, GHB119 and T304-40 x GHB119 are as sensitive as conventional corn when submitted to biotic stresses, that is to say, no competitive advantage of such genetically modified genotypes is observed when they are exposed to environmentally adverse conditions.  Furthermore, TwinLink cotton  displayed the same resprouting behavior, so that the data taken together demonstrate that there are no evidences relating the expression of genes bar, cry1Ab and cry2Ae with appearance of characteristics that may lead TwinLink cotton  to be more invasive or display higher ability to survive as against conventional genotypes.
Likelihood that the potential adverse effects will be realized
Studies submitted by Applicant showed that there were no significant differences between genetically modified cotton and its conventional isoline regarding agronomic characteristics, reproduction, dissemination and survival ability. All evidence submitted in the process and bibliographic references verify the transgenic variety level of risk as equivalent to non-transgenic varieties vis-à-vis the soil microbiota,  as well as other plants and human and animal health. Therefore, cultivation and consumption of TwinLink cotton are not potential causes of significant degradation to the environment or risk  to human and animal life. For the foregoing, there are not restrictions to the use of this cotton and its byproducts, except in locations mentioned by Law nº 11,460, of March 21, 2007 and in the Annex to the Ministry of Agriculture - MAPA Directive nº 21, of 01.16.2006.
After 17 years of use in different countries, no problem has been  detected for human and animal health or to the environment that could be ascribed to transgenic  cotton. It shall be stressed that lack of negative effects resulting from farming of transgenic cotton plants does not mean that such results may not occur in  the future. Zero risk and absolute safety do not exist in the biologic world, although there is a host of reliable scientific information and a safe use history of transgenic varieties in agriculture.
VII. Considerations on particulars of different regions of the country (subsidies to monitoring agencies)
Possible consequences:
Considering that the cotton (Gossypium hirsutum) variety TwinLink, event T304-40 x GHB119 belongs to the most well-characterized species with a solid safety history for human consumption and that genes cry1Ab, cry2Ae and bar introduced in this variety code proteins that are ubiquitous in nature.
Considering that the construct of this genotype occurred through classical genetic improvement that resulting in the insertion of a stable and functional copy of genes cry1Ab, cry2Ae and bar that granted the plant tolerance to the herbicide ammonium gluphosinate and  resistance to insects.
Considering that centesimal composition data failed to point out significant differences between genetically modified varieties and conventional varieties, suggesting  nutritional equivalence between them.
1. Event T304-40 x GHB119 was very well characterized at the molecular level and verified the integrity of genic constructs inherited from the respective parental during the process of classical genetic improvement;
2. Proteins Cry1Ab and Cry2Ae belong to the family of Cry proteins derived from Bacillus thuringiensis, an organism that is being commercially used for over forty years in producing microbial formulations for controlling insects;
3. PAT protein, granting tolerance to the herbicide ammonium gluphosinate is expressed in several events of different agricultural cultures already approved for commercial use in different countries around the world;
4. During agronomic assessments conducted with cotton T304-40 x GHB119  there was no record of any other characteristics, but the expected ones, being expressed, discarding the possibility of pleiotropic and epistatic effects from the genes introduced.
5. Birds treated with cotton cake containing the TwinLink event, or its parental varieties separately, failed to show any variation in sanitary and growth characteristics when compared to the conventional cake.
6. The rapid degradation of proteins in gastric and intestinal system simulations demonstrated its safety for use in human and animal food;
7. Essays of oral acute toxicity showed no abnormality or significant clinical signs in mice after administration of proteins Cry1Ab and Cry2Ae;
8. In silico analyzes showed no similarity between Cry proteins and allergens or known toxins;
9. Agronomic assessments revealed that there are no changes in parameters growth, development, reproducing ability and phenotypic characters between plants of genetically modified cotton and the conventional cultivar;
10. Genetically modified plants showed to be equally sensitive to biotic stress and therefore there is no evidence of change in their survival invading ability;
11. No direct effect was recorded on non-target pests and natural enemies derived from cultivation of genetically modified cotton events;
12. No toxicity was recorded of Cry proteins on non-target species selected after incorporation of the purified proteins to the diet;
13. Degradability analyzes of Cry proteins showed that both  reach undetectable values, though in different times, posing no risk to the soil microbiological and biochemical processes;
14. Several parameters related to soil microbiota, such as population of protozoa, mycorrhizal fungi, carbon and nitrogen biomass and soil respiration were not affected by the presence of plant tissues from genetically modified TwinLink cotton;
15.  Biodegradability of roots and aerial parts of TwinLink cotton was the same when compared to the traditional lineage. Leaves of TwinLink cotton displayed higher degradability, which fails to represent change in its safety to the soil biota;
16. Internationally accepted criteria in analyzing risk of genetically modified raw materials(53)
One may conclude that TwinLink cotton is as safe as its conventional equivalent.
Under Article 14 of Law nº 11,105/2005, CTNBio considered that the request meets the applicable rules and legislation in effect aiming at securing environment, agriculture, human and animal health biosafety, and concluded that TwinLink cotton is substantially equivalent to conventional cotton and that is consumption is safe for human and animal health. Regarding the environment, CTNBio concluded that TwinLink cotton is not a potential cause to significant degradation of the environment, keeping with the biota a relation identical to that of conventional cotton.
Estimation of the overall risk
Therefore, cultivation and consumption of TwinLink cotton are not potential causes of significant degradation to the environment or risk  to human and animal life. For the foregoing, there are not restrictions to the use of this cotton and its byproducts, except in locations mentioned by Law nº 11,460, of March 21, 2007 and in the Annex to the Ministry of Agriculture - MAPA Directive nº 21, of 01.16.2006.
not applicable
Need(s) for further information on specific issues of concern
not applicable
Receiving environment(s) considered
The results showed that none of the parameters assessed, such as population of protozoa, mychorrizal fungi, soil respiration rate and carbon and nitrogen biomass were negatively impacted by the presence of plant tissues containing proteins Cry. Biodegradability of TwinLink cotton plants was also assessed against the conventional lineage. To this end, a greenhouse experiment was conducted where plants were maintained in vases containing soil coming from the traditional cotton-growing region (Santo Antonio do Leste/MT). The plants were cultivated to the first flowering bud, then removed from the vases, separated into leaves, branches and foots. One gram of each plant part was weighted to pack them in nylon mesh bags and buried into the soil. Each treatment had five repetitions for each part of the plant. After thirty days maintained  under greenhouse conditions, the bags were removed and weighted and again buried. After sixty days buried into the soil, the bags were again removed and the non-degraded biomass was weighted, dried and the dry matter remaining in the two assessments was estimated.  Results obtained showed that root biodegradability, as well as that of the aerial part, were equal when the GM variety was compared to the conventional isoline. The GM plant leaves displayed greater degradability when contrasted to the isogenic non-Bt, which does not represent change in the product safety to the environment or, specifically, to the soil biota.
Available data indicate that plants derived from TwinLink cotton do not show characteristics  that could grant undesired selective advantage to the genetically modified cotton or atypic behavior to the species. Assessments on non-target orbanisms and natural enemies showed that the events so tested are safe and act specifically on the lepidopteran target pests. During the post-harvest monitoring, conducted in experimental areas, presence of residual (spontaneous) cotton plants from seeds and new sprouting was assessed  and showed to be equally and easily eliminated by usual practices, indicating that the GMO does not remain in the agricultural environment without human intervention, in a different form, nor displays characteristics that could make it more aggressive or invader of the ecosystem than its conventional parental
LMO detection and identification methods proposed
traditional molecular methods
Additional Information
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