Compositional assessment of event DAS-59122-7 maize using substantial equivalence

Event DAS-59122-7 (Herculex™ RW) maize (Zea mays L.) plants were transformed to express the Cry34Ab1 and Cry35Ab1 binary insecticidal crystal proteins originally isolated from Bacillus thuringiensis Berliner (Bt) strain PS149B1. These proteins protect maize roots from attack by corn rootworms, Diabrotica spp. DAS-59122-7 maize also contains the pat gene, originally isolated from Streptomyces viridochromogenes, which confers tolerance to glufosinate–ammonium herbicides (e.g. Liberty™). We assessed the composition of these transgenic plants (with and without Liberty herbicide treatment), grown at a total of eight fields sites over 2 years, by applying the principle of substantial equivalence. Forage and grain samples were analyzed for proximates, fiber and minerals, and grain was further analyzed for amino acids, fatty acids, vitamins, secondary metabolites and anti-nutrients. Data plots were prepared that allow for efficient investigation of equivalency between event DAS-59122-7 maize and a non-transgenic near-isogenic maize line grown contemporaneously. Results demonstrated that DAS-59122-7 maize is equivalent to non-transgenic maize with respect to these important constituents.