Sui Meinan, Jing Yan, Li Haiyan, Zhan Yuhang, Luo Jian, Teng Weili, Qiu Lijuan, Zheng Hongkun, Li Wenbin, Zhao Xue, Han Yingpeng
Key Laboratory of Soybean Biology in Chinese Ministry of Education (Key Laboratory of Soybean Biology and Breeding/Genetics of Chinese Agriculture Ministry), Northeast Agricultural University, Harbin, China.
Institute of Crop Science, National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI) Chinese Academy of Agricultural Sciences, Beijing, China.
Front Plant Sci. 2020 Sep 9;11:539460. doi: 10.3389/fpls.2020.539460. eCollection 2020.
Tocopherol (Toc) occurs in soybean seeds and is extracted together with the soybean oil. Toc is utilized as an antioxidant in food and an additive in animal feed. A total of 180 representative accessions and 144 recombinant inbred lines (RILs) from the cross of 'Hefeng 25' and 'OAC Bayfield' were selected to evaluate individuals and total Toc concentrations in soybean seeds. The 180 soybean samples were sequenced by the approach of Specific Locus Amplified Fragment Sequencing (SLAF-seq). A total of 22,611 single nucleotide polymorphisms (SNPs) were developed. Nineteen quantitative trait nucleotides (QTNs) were identified associated with individual or total-Toc based on genome-wide association analysis (GWAS). Among them, three QTNs located near known QTLs, and 16 were novel. Eighteen QTLs and nine eQTLs were also detected by linkage mapping. The QTN rs9337368 on Chr.02 was colocalized according to the linkage mapping of the RILs and genome-wide association analysis and regarded as a stable locus for mining the candidate genes in association with Toc. A total of 42 candidate genes near the 200 kbp flanking region of this identified locus were found. Upon a gene-based association, 11 SNPs from five genes out of the 42 candidates were detected. Expression level analysis of five candidate genes revealed that two genes were significantly related to Toc content. The identified loci, along with the candidate genes, might be valuable for increasing the Toc concentration in soybean seeds and improving the nutritional value of soybean oil.
生育酚（Toc）存在于大豆种子中，并与大豆油一起被提取出来。Toc被用作食品中的抗氧化剂和动物饲料中的添加剂。选取了180份代表性种质以及来自‘合丰25’与‘OAC Bayfield’杂交后代的144个重组自交系（RIL），以评估大豆种子中个体和总Toc浓度。通过特异位点扩增片段测序（SLAF-seq）方法对180份大豆样品进行测序。共开发出22611个单核苷酸多态性（SNP）。基于全基因组关联分析（GWAS），鉴定出19个与个体或总Toc相关的数量性状核苷酸（QTN）。其中，3个QTN位于已知QTL附近，16个为新发现的。通过连锁图谱分析还检测到18个QTL和9个eQTL。根据RIL的连锁图谱和全基因组关联分析，Chr.02上的QTN rs9337368共定位，被视为挖掘与Toc相关候选基因的稳定位点。在该鉴定位点侧翼200 kbp区域附近共发现42个候选基因。基于基因关联分析，在42个候选基因中的5个基因上检测到11个SNP。对5个候选基因的表达水平分析表明，有2个基因与Toc含量显著相关。所鉴定的位点以及候选基因，对于提高大豆种子中的Toc浓度和改善大豆油的营养价值可能具有重要价值。
