RESUMEN
An expanding trend for genetically engineered (GE) crops is to cultivate varieties in which two or more single trait products have been combined using conventional breeding to produce a stacked trait product that provides a useful grouping of traits. Here, we report results from compositional analysis of several GE stacked trait products from maize and soybean. The results demonstrate that these products are each compositionally equivalent to a relevant non-GE comparator variety, except for predictable shifts in the fatty acid profile in the case of stacked trait products that contain a trait, MON 87705, that confers a high-oleic-acid phenotype in soybean. In each case, the conclusion on compositional equivalence for the stacked trait product reflects the conclusions obtained for the single trait products. These results provide strong support for conducting a reassessment of those regulatory guidelines that mandate explicit characterization of stacked trait products produced through conventional breeding.
Asunto(s)
Glycine max/química , Plantas Modificadas Genéticamente/química , Zea mays/química , Aminoácidos/química , Cruzamiento , Ácidos Grasos/química , Alimentos Modificados Genéticamente , Ingeniería Genética , Proteínas de Plantas/química , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Glycine max/genética , Glycine max/metabolismo , Zea mays/genética , Zea mays/metabolismoRESUMEN
Currently, traditional immunochemistry technologies such as enzyme-linked immunosorbent assays (ELISA) are the predominant analytical tool used to measure levels of recombinant proteins expressed in genetically engineered (GE) plants. Recent advances in agricultural biotechnology have created a need to develop methods capable of selectively detecting and quantifying multiple proteins in complex matrices because of increasing numbers of transgenic proteins being coexpressed or "stacked" to achieve tolerance to multiple herbicides or to provide multiple modes of action for insect control. A multiplexing analytical method utilizing liquid chromatography with tandem mass spectrometry (LC-MS/MS) has been developed and validated to quantify three herbicide-tolerant proteins in soybean tissues: aryloxyalkanoate dioxygenase (AAD-12), 5-enol-pyruvylshikimate-3-phosphate synthase (2mEPSPS), and phosphinothricin acetyltransferase (PAT). Results from the validation showed high recovery and precision over multiple analysts and laboratories. Results from this method were comparable to those obtained with ELISA with respect to protein quantitation, and the described method was demonstrated to be suitable for multiplex quantitation of transgenic proteins in GE crops.