Study On The Accumulation Dynamics Of Saponins In Soybean Seed

Soybean is one of the important food crops in China.Soybean saponin is one of the important secondary metabolites in soybean seeds.More and more studies show that daidzein has a variety of beneficial functions for human body,so people pay more attention to soybean saponins.In order to elucidate the mechanism of soybean saponin accumulation during seed development and germination,the contents of soaponin a,soapanol b and total soaponin in sprouts and cotyledons during germination at different temperatures were determined by hplc method using Jinda 53 as raw material;the contents of soybean saponins in embryo,cotyledon and pod bark during the development of soybean seeds were determined by HPLC-ESI-MS/MS method.;The spatial distribution of soybean root and stem soybean saponins was studied by hand-cut method.The main findings are as follows:(1)Soapol in bud and cotyledon showed different accumulation mechanism during germination.The contents of soapol A,soapol B and total soapol in bud decreased gradually,while the contents of soapol A,soapol B and total soapol in cotyledon decreased gradually.Under different temperature,the order of soapol content in bud was 18?>20?>25?>30?,while in cotyledon,it was 30 ?>25 ?>20 ?>18 ? in cotyledon.(2)The embryo weight,cotyledon weight,grain length,grain width and pod dry weight increased firstly and then tended to steady during the development of soybean kernel,and the development of embryo was earlier than that of cotyledon(3)Total saponins?A saponins?B saponins?DDMP saponins and E saponins in the embryo showed a trend of first rising and then decreasing during the grain development.The content of saponins in embryos reached the highest about 50 days after flowering.The contents of total saponins?A saponins?B saponins?DDMP saponins and E saponins in cotyledons were not significantly changed during grain development.The change range of 6.24mg/g to 22.19 mg/g.The total saponins?A saponins?B saponins?DDMP saponins and E saponins in pods showed a general decreasing trend during grain development.The contents of saponins in pods of Jinda 53,Jinyi 30 and Wuhei were lower than those in embryo and cotyledon.(4)The saponins in soybean root were mainly distributed in epidermis,cortical thick horn and primary phloem,and in soybean stem were mainly distributed in epidermis,cortical thick horn and primary phloem.