Potential Transference of CP4 EPSPS to Weed Species from Genetically Modified Gossypium hirsutum in Northern Mexico

The family of enzymes 5-enolpiruvil shikimato-3-phosphate synthase (EPSPS) is found in plants and microorganisms. The substrates of this enzyme are phosphoenolpyruvate (PEP) and 3-phospho-shikimate and their products are phosphate and 5-enolpyruvylshikimate-3-phosphate that is the biological target of the herbicide glyphosate, which is used in genetically modified crops. The interaction between cultivated genetically modified plants (GMP) and wild plant species could be a transference source of transgenes. Presence of transgenes could be cause and adverse environmental impact on non-target organisms. Gossypium hirsutum genotype Bollgard II® is a GMP with tolerance to herbicide glyphosate and it has been cultivated during 20 years in Mexico and the possibility to gene flow primary in congeners of the Malvaceae family is possible. The objective of this study was to quantify and identify weed species associated to genetically modified cotton fields and to detect the present of glyphosate-insensitive EPSP synthases (CP4 EPSPS) in these species. The results showed that plants of the families Amaranthaceae, Asteraceae, Boraginaceae, Chenopodiaceae, Convolvulaceae, Fabaceae, Malvaceae, Poaceae, Portulacaceae, Solanaceae and Zygophyllaceae are present in the study site. Twenty-five weed species belonging to these botanical families were collected and identified in the site. From these, two species of the Malvaceae family with potential risk of gene flow plants, Anoda cristata and Sida hederacea were identified in the site; however, the CP4 EPSPS protein was not detected in none of the collected weed species and only the GM genotype Bollgard II® was positive to the CP4 EPSPS protein in the study site.