大豆油分/蛋白含量是受人工选择的重要品质性状，两者呈显著负相关，但其遗传选择与调控机制知之甚少。大豆油分/蛋白主效QTL“cqPro/Oil-15”在多个环境/群体中均具有较高的表型贡献率，克隆和分析该QTL基因将具有重要理论意义和应用价值。申请人前期利用图位克隆将该QTL定位在280Kb内，该区间重要候选基因GmSWEET10a在启动子与CDS多个位点具有显著多态性。该基因及同源基因GmSWEET10b的基因编辑突变体中，大豆油分含量显著降低而蛋白含量升高。本项目拟在此基础上，对GmSWEET10a/10b开展表达模式分析、不同单倍型CDS过表达、定点基因编辑转换单倍型等研究。项目旨在解析GmSWEET10a启动子与CDS序列多样性的遗传效应与调控机制，明确GmSWEET10a/10b的功能及遗传效应异同。研究将为大豆油分/蛋白的遗传调控机制提供线索，为相关育种提供理论依据。

Soybean seed oil content and protein content are important domestication-related traits, and there is a strong negative correlation between them, but little is known about their genetic selection and regulation mechanism. A major QTL (cqPro/Oil-15) for soybean seed oil/protein content has high explained phenotypic variation in several different environments/populations. Cloning and functional analysis of this QTL gene will have great theoretical significance and application value. In our previous study, cqPro/Oil-15 was fine-mapped into a 280 Kb region and a candidate gene, named GmSWEET10a, was identified within this region. Multiple significant polymorphism sites were found in the promoter and CDS region of GmSWEET10a. Furthermore, knockout of GmSWEET10a and/or its homologous gene GmSWEET10b using CRISPR/Cas9 system in the soybean, caused decreased seed oil content and increased seed protein content. In this project, we are planning to analyze the genetic effects and regulatory mechanisms of GmSWEET10a promoter and CDS sequence diversity on seed protein and oil content, and to clarify the similarities and differences of the functions and genetic effects of GmSWEET10a and its homologous gene GmSWEET10b, through the analysis of gene expression profiling, phenotype and metabonome of GmSWEET10a/10b overexpression and site-directed gene editing stably transformed soybean. The research results of this project are expected to provide valuable information for better understanding the genetic regulation mechanism of soybean seed oil/protein content and provide theoretical basis for related breeding.