Comparison of saponin composition and content in wild soybean (Glycine soja Sieb. and Zucc.) before and after germination

Abstract

Eight wild soybean accessions with different saponin phenotypes were used to examine saponin composition and relative saponin quantity in various tissues of mature seeds and two-week-old seedlings by LC–PDA/MS/MS. Saponin composition and content were varied according to tissues and accessions. The average total saponin concentration in 1 g mature dry seeds of wild soybean was 16.08 ± 3.13 μmol. In two-week-old seedlings, produced from 1 g mature seeds, it was 27.94 ± 6.52 μmol. Group A saponins were highly concentrated in seed hypocotyl (4.04 ± 0.71 μmol). High concentration of DDMP saponins (7.37 ± 5.22 μmol) and Sg-6 saponins (2.19 ± 0.59 μmol) was found in cotyledonary leaf. In seedlings, the amounts of group A and Sg-6 saponins reduced 2.3- and 1.3-folds, respectively, while DDMP + B + E saponins increased 2.5-fold than those of mature seeds. Our findings show that the group A and Sg-6 saponins in mature seeds were degraded and/or translocated by germination whereas DDMP saponins were newly synthesized.

Genetic characterization of group A acetylsaponin‐deficient mutants from wild soybean (Glycine soja Sieb. and Zucc.)

“…, Krishnamurthy et al. ,c). Based on aglycone structure, soyasaponins have been classified into group A, DDMP (2,3‐dihydro‐2,5‐dihydroxy‐6‐methyl‐4 H ‐pyran‐4‐one), group B, group E and Sg‐6 saponins.…”

“…In both cultivated and wild soybeans, only a trace amount of group A acetylsaponins (Aa and Ab series saponins) are present in adult plants that are often undetectable by the current analytical techniques (Krishnamurthy et al. ). Concurrently, the seed hypocotyl of these two species contains >90% of total group A acetylsaponins while the seed cotyledon contains <10% of it (Shimoyamada et al.…”

Identification of oxidosqualene cyclases from the medicinal legume tree Bauhinia forficata: a step toward discovering preponderant α‐amyrin‐producing activity

“…S2), which were unlike the triterpenoid profile of model legumes. Model legumes such as Medicago truncatula (barrel medic) and Glycine max (soybean) tend to accumulate oxidized triterpenoids derived from the β‐amyrin scaffold such as soyasapogenol B (a β‐amyrin derivative with hydroxyl groups at C‐22 and C‐24), erythrodiol (hydroxyl group at C‐28), and oleanolic acid (carboxyl group at C‐28) (Pollier et al ., ; Krishnamurthy et al ., ). Lupeol and its derivatives, such as betulin (a lupeol derivative with a hydroxyl group at C‐28) and betulinic acid (carboxyl group at C‐28), accumulate in the economically important legume Glycyrrhiza uralensis (licorice; Hayashi et al ., ; Tamura et al ., ).…”

“…In the Leguminosae phylogenetic tree, B. forficata is in the same clade as the Cercidoideae subfamily, which is the farthest clade from the model legumes (Papilionoideae subfamily; LPWG, ). All of the model and economically important legumes such as barrel medic, licorice, and soybean are in the Papilionoideae subfamily, in which soyasapogenol B is a common metabolite (Dixon & Sumner, ; Pollier et al ., ; Krishnamurthy et al ., ). By contrast, we did not detect soyasapogenol B in B. forficata extracts but noted accumulation of germanicol and morolic acid (Figs , S2; Table S3).…”

Identification of environmentally stable QTLs controlling Saponin content in <i>Glycine max</i>

“…A mutant line, which lacked group A saponins, was caused by sg-5 , which is located on chromosome 15 (Takada et al 2013). Sg-6 controls monodesmosides with one sugar chain at the C-3 hydroxyl position of their respective soyasapogenols (Krishnamurthy et al 2014). …”