Genetic analysis of variation in sugar chain composition at the C-22 position of group A saponins in soybean, Glycine max (L.) Merrill

• DOI: 10.1270/jsbbs.60.3
• Publication Date: 2010-03-19T06:04:40Z
• Authors: Yoshitake Takada; Takashi Sayama; Akio Kikuchi; Shin Kato; Nana Tatsuzaki; Yumi Nakamoto; Ayako Suzuki; Chigen Tsukamoto; Masao Ishimoto
• Keywords: 2. Zero hunger; 0303 health sciences; 03 medical and health sciences

Saponins are a diverse group of secondary metabolites widely distributed in plants. Some saponins in soybean seeds have medicinal properties, but the terminal acetylated sugar at the C-22 position of group A saponins in seed hypocotyls causes a bitter and astringent taste. We used cultivated and wild soybean accessions classified into four different group A saponin phenotypes, including non-acetylated A0-αg and deacetyl-Af, as parents to obtain four F2 populations and a population of recombinant inbred lines to test their genetic relationship. The gene controlling the phenotype of the group A saponins in each line was mapped near the simple sequence repeat marker Satt336 on soybean chromosome 7 (linkage group M). An allelism test of the A0-αg and deacetyl-Af variants revealed no segregation of Aa and Ab phenotypes in the progeny, although the genes controlling the two phenotypes have been assigned to two different loci, Sg-1 and Sg-2. These results suggest that the four group A saponin phenotypes are controlled by multiple alleles at the single locus Sg-1.