title: Genetic and chemical analysis of a key biosynthetic step for soyasapogenol A, an aglycone of group A saponins that influence soymilk flavor.
abstract: Although certain saponins in soybean seeds have been reported to have health benefits, group A acetyl saponins cause undesirable bitter and astringent tastes in soy products. Therefore, reduction or elimination of group A saponins is an important target for soybean breeders. A wide survey of cultivated and wild soybean germplasm identified a mutant line that lacked group A saponins. The absence of soyasapogenol A, a group A saponin aglycone, is controlled by a single recessive allele, sg-5 that mapped genetically near the SSR marker, Satt117, on soybean chromosome 15 (linkage group E). The locus is epistatic to Sg-1, which controls the terminal sugar variation on the C-22 sugar chain of soyasapogenol A, and allelic differences at this locus lead to changes in the amount of DDMP saponins and their derivatives group B and E products. These findings provide a new insight into the biosynthetic pathway of soybean saponins, and identify a genetic approach that can be applied to improve the quality of foods produced from soybean.
authors.affiliation: National Agricultural Research Organization (NARO) Western Region Agricultural Research Center, 1-3-1 Senyu, Zentsuji, Kagawa, 765-8508, Japan.
authors.forename: Yoshitake
authors.initials: Y
authors.lastname: Takada
authors.forename: Hiroko
authors.initials: H
authors.lastname: Sasama
authors.forename: Takashi
authors.initials: T
authors.lastname: Sayama
authors.forename: Akio
authors.initials: A
authors.lastname: Kikuchi
authors.forename: Shin
authors.initials: S
authors.lastname: Kato
authors.forename: Masao
authors.initials: M
authors.lastname: Ishimoto
authors.forename: Chigen
authors.initials: C
authors.lastname: Tsukamoto
mesh_terms: D000483:Alleles; D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics; D017353:Gene Deletion; D005808:Genes, Recessive; D056426:Genetic Loci; D018895:Microsatellite Repeats; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D012503:Saponins / Q000737:chemistry* / Q000235:genetics*; D041942:Soy Milk / Q000737:chemistry*; D013025:Glycine max / Q000737:chemistry; D013649:Taste / Q000502:physiology*
chemical_list: D012503:Saponins; C116604:soyasapogenol A; D009828:Oleanolic Acid