Production of Non-Genetically Modified Food-Use Soybeans with High Functional Properties Using Soy bean-and Wild Soybean-Natural Variants with Different Composition of Seed Saponin Components

摘要

Soybean saponins are divided into two groups: Group A saponins which are the primary cause of undesirable tastes, and DDMP saponins which possess healthbeneficial characteristics. The degree of the taste characteristics and functionalproperties of saponin components depend on their chemical structures and density in the seeds. Genetic improvement of the saponin composition and density of fooduse soybeans is expected to spread rapidly worldwide;however, the relationship between genetic modification of saponin composition and accompanying changes in saponin contents is not yet clearly understood. Therefore, in this study, some mutants discovered in G. max collections and wild G. soja accessions in Japan which carry different saponin compositions were used to prepare hybrid F1seeds, progeny F2 and F3 Seeds, and recombinant inbred lines (RILs). Saponincompositions and contents having diffrent combinations of genes controlling thesugar chain sequences at the C-3 and C-22 positions of soyasapogenol glycosideswere determined by LC/PDA/MS/MS analysis and were evaluated by statistical analysis. Different combinations of the genes (phenotypes) did not change seed saponin contents even though their saponin composition was changed according tothe combinations of the genes. These results suggest that the supply of common precursors(soyasapogenols A and B)in saponin biosynthesis is not changed by the combination of these genes, and that saponin precursors (soyasapogenol glycosiaes)are competitively used as the substrates of some glycosyltransferases according to the recombination of the genes. Production of expected, specific, or sole saponin component in soybean seeds by using soybean-and wild soybean-natural variants would be possible.