著者

塚本 知玄 龍崎 菜々 田山 一平

出版者

(財)不二たん白質研究振興財団

雑誌

大豆たん白質研究 (ISSN:13444050)

巻号頁・発行日

vol.13, no.31, pp.43-50, 2010-12

被引用文献数

1

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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.大豆種子サポニン糖鎖組成の遺伝的多型に関与する遺伝子座に座乗する共優性・優勢・劣勢遺伝子の組合わせを遺伝育種的手法で変化させた場合,遺伝子の組み合わせに依存したサポニン合成基質分子の奪い合いが起こり,その結果として,個々のサポニン成分は品種特異的かつ種子の部位特異的に変化する(サポニン組成多型性を示す)が,アグリコン合成量は影響を受けないため種子総サポニン量(モル数)は変化しないと考えられる.単一の有用サポニン成分のみを合成・蓄積するような大豆育種は十分に可能であることが示唆された.