Investigation of biochemical diversity in a soybean lineage representing 35 years of breeding.

This paper reports an assessment of seed biochemical and metabolite variability and diversity in a series of nine soybean varieties; all lines share the same genetic lineage but represent ∼35 years of breeding (launch years 1972-2008) and differing yield potentials. These varieties, including six conventional and three glyphosate-tolerant lines, were grown concurrently at two replicated field sites in the United States during the 2011 growing season, and seeds were harvested at maturity. A compositional assessment included measurement of proximates, amino acids, fatty acids, tocopherols, isoflavones, saccharides, organic acids, and selected phytohormones. Statistical analysis included application of principal variance component analysis (PVCA) to investigate the interrelationships among compositional components from these soybean varieties and the impacts of location (environment) and pedigree on variability of these components. Results demonstrated that (i) some biochemical analytes showed trends (either increased or decreased) with launch year and/or yield, (ii) some analytes varied according to variety but showed no trend with launch year and/or yield, and (iii) almost all analytes showed extensive variation within and across sites. In summary, varietal development of high-yielding soybean, as represented in this study, has been accompanied by compositional changes but these are typically modest relative to environmental factors.

Bayesian statistical approaches to compositional analyses of transgenic crops 2. Application and validation of informative prior distributions.

Bayesian approaches to evaluation of crop composition data allow simpler interpretations than traditional statistical significance tests. An important advantage of Bayesian approaches is that they allow formal incorporation of previously generated data through prior distributions in the analysis steps. This manuscript describes key steps to ensure meaningful and transparent selection and application of informative prior distributions. These include (i) review of previous data in the scientific literature to form the prior distributions, (ii) proper statistical model specification and documentation, (iii) graphical analyses to evaluate the fit of the statistical model to new study data, and (iv) sensitivity analyses to evaluate the robustness of results to the choice of prior distribution. The validity of the prior distribution for any crop component is critical to acceptance of Bayesian approaches to compositional analyses and would be essential for studies conducted in a regulatory setting. Selection and validation of prior distributions for three soybean isoflavones (daidzein, genistein, and glycitein) and two oligosaccharides (raffinose and stachyose) are illustrated in a comparative assessment of data obtained on GM and non-GM soybean seed harvested from replicated field sites at multiple locations in the US during the 2009 growing season.

Compositional equivalence of insect-protected glyphosate-tolerant soybean MON 87701 × MON 89788 to conventional soybean extends across different world regions and multiple growing seasons.

The soybean product MON 87701 × MON 89788 expresses both the cry1Ac gene derived from Bacillus thuringiensis and the cp4 epsps (5-enolpyruvylshikimate-3-phosphate synthase) gene derived from Agrobacterium sp. strain CP4. Each biotechnology-derived trait confers specific benefits of insect resistance and glyphosate tolerance, respectively. The purpose of this study was to compare the composition of seed and forage from this combined-trait product to those of conventional soybean grown in geographically and climatically distinct regions. Field trials were conducted in the United States during the 2007 growing season, in Argentina during the 2007-2008 growing season, and in the northern and southern soybean regions of Brazil during the 2007-2008 and 2008-2009 growing seasons. Results demonstrated that the compositional equivalence of MON 87701 × MON 89788 to the conventional soybean extended across all regions and growing seasons. Further evaluation of the data showed that natural variation (region and growing season) contributed more to compositional variability in soybean, particularly for such components as isoflavones, fatty acids, and vitamin E, than transgene insertion.

Compositional variability in conventional and glyphosate-tolerant soybean (Glycine max L.) varieties grown in different regions in Brazil.

The compositions of a diverse range of commercially available conventional and genetically modified (GM; glyphosate-tolerant) soybean varieties from maturity groups 8 and 5, respectively, grown in the northern and southern soybean regions of Brazil during the 2007-2008 and 2008-2009 growing seasons were compared. Compositional analyses included measurement of essential macro- and micronutrients, antinutrients, and selected secondary metabolites in harvested seed as well as measurement of proximates in both forage and harvested seed. Statistical comparisons utilized a mixed analysis of variance model to evaluate the relative contributions of growing season, soybean growing region, production site, phenotype (GM or conventional), and variety. The study highlighted extensive variability in the overall data set particularly for components such as fatty acids, vitamin E, and isoflavones. There were few differences between the GM and non-GM populations, and most of the variability in the data set could be attributed to regional and variety differences. Overall, the results were consistent with the expanding literature on the lack of any meaningful impact of transgene insertion on crop composition.

Stability in the composition equivalence of grain from insect-protected maize and seed from glyphosate-tolerant soybean to conventional counterparts over multiple seasons, locations, and breeding germplasms.

Insect-protected maize MON 810 and Roundup Ready soybean 40-3-2 represent major milestones in the adoption of genetically modified (GM) crops to enhance agricultural productivity. This study provides an assessment of the compositional stability of these products over multiple seasons, multiple germplasms, and diverse geographies encompassing North, Central, and South America and Europe. The compositional assessment evaluated levels of proximates in MON 810 and proximates, antinutrients, and isoflavones in 40-3-2. The means and range values for component levels in the GM crops and their conventional comparators were consistently similar to each other within each corresponding year from 2000 to 2009. To our knowledge, this study represents the first meta-analysis of comparative composition assessments of GM products. This approach, combined with graphical approaches, provided an effective summary of the overall data set and confirmed the continued compositional equivalence of these important crops to their conventional counterparts over time.

Compositions of forage and seed from second-generation glyphosate-tolerant soybean MON 89788 and insect-protected soybean MON 87701 from Brazil are equivalent to those of conventional soybean (Glycine max).

Brazil has become one of the largest soybean producers. Two Monsanto Co. biotechnology-derived soybean products are designed to offer benefits in weed and pest management. These are second-generation glyphosate-tolerant soybean, MON 89788, and insect-protected soybean, MON 87701. The second-generation glyphosate-tolerant soybean product, MON 89788, contains the 5-enolpyruvylshikimate-3-phosphate synthase gene derived from Agrobacterium sp. strain CP4 (cp4 epsps). MON 87701 contains the cry1Ac gene and expression of the Cry1Ac protein providing protection from feeding damage caused by certain lepidopteran insect pests. The purpose of this assessment was to determine whether the compositions of seed and forage of MON 89788 and MON 87701 are comparable to those of conventional soybean grown in two geographically and climatically distinct regions in multiple replicated sites in Brazil during the 2007-2008 growing season. Overall, results demonstrated that the seed and forage of MON 89788 and MON 87701 are compositionally equivalent to those of conventional soybean. Strikingly, the results also showed that differences in mean component values of forage and seed from the two controls grown in the different geographical regions were generally greater than that observed in test and control comparisons. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) of compositional data generated on MON 89788, MON 87701, and their respective region-specific controls provide a graphical illustration of how natural variation contributes more than biotechnology-driven genetic modification to compositional variability in soybean. Levels of isoflavones and fatty acids were particularly variable.

Compositions of seed, forage, and processed fractions from insect-protected soybean MON 87701 are equivalent to those of conventional soybean.

Monsanto Co. has developed biotechnology-derived, insect-protected soybean MON 87701 that produces the Cry1Ac insecticidal crystal (delta-endotoxin) protein derived from Bacillus thuringiensis (Bt) subsp. kurstaki. Cry1Ac provides protection from feeding damage caused by certain targeted lepidopteran pests. The purpose of this work was to assess whether the compositions of seed, forage, and processed fractions (meal, oil, protein isolate, and lecithin) of MON 87701 are comparable to those of conventional soybean. Compositional analyses were conducted on seed and forage tissues harvested from MON 87701 and conventional soybean grown in multiple replicated sites in the United States during the 2007 growing season and in Argentina during the 2007-2008 growing season. Seed, forage, and processed fractions from conventional soybean varieties currently in the marketplace were included in the analyses to establish a range of natural variability for each compositional component; the range of variability was defined by a 99% tolerance interval. Additional seed was collected from soybean grown in a separate U.S. production during the 2007 season. This seed and processed fractions (meal, oil, protein isolate, and crude lecithin) derived from it were also subjected to compositional analyses. Forage samples were analyzed for levels of proximates (ash, fat, moisture, and protein), carbohydrates by calculation, and fiber. Seed samples were analyzed for proximates, carbohydrates by calculation, fiber, amino acids, fatty acids, antinutrients, and vitamin E. Toasted, defatted (TD) meal was analyzed for proximates, fiber, amino acids, and antinutrients. Refined, bleached, and deodorized (RBD) oil was analyzed for fatty acids and vitamin E. Protein isolate was analyzed for amino acids and moisture. Crude lecithin was analyzed for phosphatides. Overall, results demonstrated that the seed, forage, and processed fractions of MON 87701 are compositionally equivalent to those of conventional soybean.