Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Yangzhou University, 225009, Yangzhou, China.
Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, 225009, Yangzhou, China.
Nat Commun. 2019 Apr 26;10(1):1949. doi: 10.1038/s41467-019-09919-y.
Grain protein content (GPC) affects rice nutrition quality. Here, we identify two stable quantitative trait loci (QTLs), qGPC-1 and qGPC-10, controlling GPC in a mapping population derived from indica and japonica cultivars crossing. Map-based cloning reveals that OsGluA2, encoding a glutelin type-A2 precursor, is the candidate gene underlying qGPC-10. It functions as a positive regulator of GPC and has a pleiotropic effect on rice grain quality. One SNP located in OsGluA2 promoter region is associated with its transcript expression level and GPC diversity. Polymorphisms of this nucleotide can divide all haplotypes into low (OsGluA2) and high (OsGluA2) expression types. Population genetic and evolutionary analyses reveal that OsGluA2, mainly present in japonica accessions, originates from wild rice. However, OsGluA2, the dominant type in indica, is acquired through mutation of OsGluA2. Our results shed light on the understanding of natural variations of GPC between indica and japonica subspecies.
谷物蛋白质含量（GPC）影响稻米的营养品质。在这里，我们在一个由籼稻和粳稻品种杂交衍生的作图群体中鉴定到两个控制 GPC 的稳定数量性状位点（QTL），qGPC-1 和 qGPC-10。基于图谱的克隆表明，编码谷蛋白 A2 前体的 OsGluA2 是 qGPC-10 的候选基因。它作为 GPC 的正调控因子，对水稻籽粒品质具有多效性。位于 OsGluA2 启动子区域的一个 SNP 与其转录表达水平和 GPC 多样性相关。该核苷酸的多态性可以将所有单倍型分为低（OsGluA2）和高（OsGluA2）表达类型。群体遗传和进化分析表明，主要存在于粳稻品种中的 OsGluA2 来源于野生稻。然而，在籼稻中占优势的 OsGluA2 是通过 OsGluA2 的突变获得的。我们的研究结果为理解籼稻和粳稻亚种间 GPC 的自然变异提供了线索。
