Wang Xiao-Qiang, Yoon Min-Young, He Qiang, Kim Tae-Sung, Tong Wei, Choi Bu-Woong, Lee Young-Sang, Park Yong-Jin
Department of Plant Resources, College of Industrial Sciences, Kongju National University, Yesan, 340-702, Republic of Korea.
Department of Medical Biotechnology, Soonchunhyang University, Asan, 336-745, Republic of Korea.
Mol Genet Genomics. 2015 Dec;290(6):2121-35. doi: 10.1007/s00438-015-1059-x. Epub 2015 May 20.
Tocopherols and tocotrienols, collectively known as tocochromanols, are lipid-soluble molecules that belong to the group of vitamin E compounds. Among them, α-tocopherol (αΤ) is one of the antioxidants with diverse functions and benefits for humans and animals. Thus, understanding the genetic basis of these traits would be valuable to improve nutritional quality by breeding in rice. Genome-wide association study (GWAS) has emerged as a powerful strategy for identifying genes or quantitative trait loci (QTL) underlying complex traits in plants. To discover the genes or QTLs underlying the naturally occurring variations of αΤ content in rice, we performed GWAS using 1.44 million high-quality single-nucleotide polymorphisms acquired from re-sequencing of 137 accessions from a diverse rice core collection. Thirteen candidate genes were found across 2-year phenotypic data, among which gamma-tocopherol methyltransferase (OsγTMT) was identified as the major factor responsible for the αΤ content among rice accessions. Nucleotide variations in the coding region of OsγTMT were significantly associated with the αΤ content variations, while nucleotide polymorphisms in the promoter region of OsγTMT also could partly demonstrate the correlation with αΤ content variations, according to our RNA expression analyses. This study provides useful information for genetic factors underlying αΤ content variations in rice, which will significantly contribute the research on αΤ biosynthesis mechanisms and αΤ improvement of rice.
生育酚和生育三烯酚统称为生育色满醇，是属于维生素E化合物组的脂溶性分子。其中，α-生育酚（αΤ）是对人类和动物具有多种功能和益处的抗氧化剂之一。因此，了解这些性状的遗传基础对于通过水稻育种提高营养品质具有重要价值。全基因组关联研究（GWAS）已成为鉴定植物复杂性状潜在基因或数量性状位点（QTL）的有力策略。为了发现水稻中αΤ含量自然变异的潜在基因或QTL，我们使用从137份不同水稻核心种质重测序中获得的144万个高质量单核苷酸多态性进行了GWAS。通过两年的表型数据发现了13个候选基因，其中γ-生育酚甲基转移酶（OsγTMT）被确定为水稻种质中αΤ含量的主要影响因素。根据我们的RNA表达分析，OsγTMT编码区的核苷酸变异与αΤ含量变异显著相关，而OsγTMT启动子区的核苷酸多态性也能部分证明与αΤ含量变异的相关性。本研究为水稻中αΤ含量变异的遗传因素提供了有用信息，将对水稻αΤ生物合成机制和αΤ改良研究做出重要贡献。
