大豆皂苷Aa、Ab的含量影响大豆制品口感,旨在了解大豆籽粒中皂苷Aa和Ab的组成及含量,进而研究其合成代谢机制。采用HPLC-ESI-MS/MS技术测定大豆材料中Aa、Ab皂苷的含量,利用q RT-PCR技术研究籽粒发育过程中GmSg-1基因的相对表达量。结果显示,68个山西大豆材料种子中Aa型大豆材料胚和子叶中Aa皂苷含量的变异范围分别为0.41-33.79 mg/g,0.21-8.39 mg/g;Ab型大豆胚和子叶中Ab皂苷的变异范围分别为0.85-44.96 mg/g,0.26-11.09 mg/g。GmSg-1基因序列有19个SNP多态性位点,其中10个SNP引起氨基酸变异。Aa、Ab大豆皂苷含量在籽粒发育过程中呈现先增后减的趋势,在开花后40-50 d皂苷含量达到最大值,而GmSg-1基因的相对表达量在前期呈现与含量基本相同的趋势。
The contents of soysaponin Aa and Ab determine the taste of soybean products,this study aims to understand the compositionand content of Aa and Ab soysaponin in soybean seeds,and then to study the mechanism of anabolism and synthesis. HPLC-ESI-MS/MS wasemployed to measure the contents of Aa and Ab saponins in soybean,and q RT-PCR technique to study the relative expression of GmSg-1 genein grain accumulation. Results showed among 68 Shanxi soybean seeds,the range of Aa saponin variation were 0.41-33.79 mg/g and 0.21-8.39 mg/g in hypocotyls and cotyledons respectively for Aa type soybean materials;and the range of Ab saponin variation were 0.85-44.96 mg/g and 0.26-11.09 mg/g for Ab type soybean materials. There were 19 SNP variants in GmSg-1 gene,and 10 of them resulting in amino acidsubstitutions were detected. The contents of Aa and Ab soysaponin increased at first and then decreased in the process of accumulation,and thecontents of soysaponin were the highest after blossoming 40-50 d,while the relative expression of GmSg-1 gene was basically in the same trendas the content of soysaponin.