Beyond pathways: genetic dissection of tocopherol content in maize kernels by combining linkage and association analyses

作者：Hong Wang, Shutu Xu, Yaming Fan, Nannan Liu, Wei Zhan, Haijun Liu, Yingjie Xiao, Kun Li, Qingchun Pan, Wenqiang Li, Min Deng, Jie Liu, Min Jin, Xiaohong Yang, Jiansheng Li, Qing Li, Jianbing Yan · 发表于：Plant Biotechnology Journal · 年份：2018 · DOI：10.1111/pbi.12889 · 被引用次数：72 · 研究领域：Genetic Mapping and Diversity in Plants and Animals、Lipid metabolism and biosynthesis、Antioxidant Activity and Oxidative Stress

Although tocopherols play an important role in plants and animals, the genetic architecture of tocopherol content in maize kernels has remained largely unknown. In this study, linkage and association analyses were conducted to examine the genetic architecture of tocopherol content in maize kernels. Forty-one unique quantitative trait loci (QTLs) were identified by linkage mapping in six populations of recombinant inbred lines (RILs). In addition, 32 significant loci were detected via genome-wide association study (GWAS), 18 of which colocalized with the QTLs identified by linkage mapping. Fine mapping of a major QTL validated the accuracy of GWAS and QTL mapping results and suggested a role for nontocopherol pathway genes in the modulation of natural tocopherol variation. We provided genome-wide evidence that genes involved in fatty acid metabolism, chlorophyll metabolism and chloroplast function may affect natural variation in tocopherols. These findings were confirmed through mutant analysis of a particular gene from the fatty acid pathway. In addition, the favourable alleles for many of the significant SNPs/QTLs represented rare alleles in natural populations. Together, our results revealed many novel genes that are potentially involved in the variation of tocopherol content in maize kernels. Pyramiding of the favourable alleles of the newly elucidated genes and the well-known tocopherol pathway genes would greatly improve tocopherol content in maize.