Identification and development of a functional marker of TaGW2 associated with grain weight in bread wheat (Triticum aestivum L.)
Identification and development of a functional marker of TaGW2 associated with grain weight in bread wheat (Triticum aestivum L.)
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与面包小麦 (Triticum aestivum L.) 粒重相关的 TaGW2 功能标记的鉴定和开发
DOI：
10.1007/s00122-010-1437-z
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发表时间：
2011-01-01
影响因子：
5.4
通讯作者：
Zhang, Xueyong
中科院分区：
文献类型：
--
作者：
Su, Zhenqi;Hao, Chenyang;Zhang, Xueyong
OsGW2 基因参与水稻籽粒发育，影响籽粒宽度和重量。它在小麦中的直系同源物TaGW2被认为是与谷物发育相关的候选基因。我们发现 TaGW2 是组成型表达的，三个直系同源物同时表达。 TaGW2的编码序列（CDS）为1,275 bp，编码424个氨基酸的蛋白质，并具有与OsGW2共享的功能域。在 10 个品种的同一位点的 CDS 序列中未检测到差异。根据3个直系同源基因启动子区序列差异设计基因组特异性引物，通过CS nulli-tetrasomic (NT)将TaGW2定位于同源6组染色体。在TaGW2-6A的启动子区检测到两个SNP，形成两种单倍型：Hap-6A-A（-593A和-739G）和Hap-6A-G（-593G和-769A）。基于-593 A-G 多态性开发了切割扩增多态性序列（CAPS）标记，以区分 TaGW2-6A 中的两种单倍型。该基因被精细定位在重组自交系 (RIL) 群体中着丝粒附近距标记 cfd80.2 0.6 cM 处。对 265 个中国小麦品种进行了基因分型，关联分析显示 Hap-6A-A 与两个作物季节的宽粒和千粒重 (TGW) 显着相关。 qRT-PCR 显示 TaGW2 表达水平与粒宽之间呈负相关。 Hap-6A-A在不同时期发布的中国品种中的频率表明其在选育过程中受到了强烈的正向选择。地方品种中，Hap-6A-A主要分布在中国南方麦区。关联分析还表明，Hap-6A-A不仅使TGW增加了3 g以上，而且抽穗和成熟也较早。与中国品种相比，Hap-6A-G 是欧洲品种的主要单倍型； Hap-6A-A主要存在于前南斯拉夫、意大利、保加利亚、匈牙利和葡萄牙发布的品种中。
The OsGW2 gene is involved in rice grain development, influencing grain width and weight. Its ortholog in wheat, TaGW2, was considered as a candidate gene related to grain development. We found that TaGW2 is constitutively expressed, with three orthologs expressing simultaneously. The coding sequence (CDS) of TaGW2 is 1,275 bp encoding a protein with 424 amino acids, and has a functional domain shared with OsGW2. No divergence was detected within the CDS sequences in the same locus in ten varieties. Genome-specific primers were designed based on the sequence divergence of the promoter regions in the three orthologous genes, and TaGW2 was located in homologous group 6 chromosomes through CS nulli-tetrasomic (NT). Two SNPs were detected in the promoter region of TaGW2-6A, forming two haplotypes: Hap-6A-A (-593A and -739G) and Hap-6A-G (-593G and -769A). A cleaved amplified polymorphic sequence (CAPS) marker was developed based on the -593 A-G polymorphism to distinguish the two haplotypes in TaGW2-6A. This gene was fine mapped 0.6 cM from marker cfd80.2 near the centromere in a recombinant inbred line (RIL) population. Two hundred sixty-five Chinese wheat varieties were genotyped and association analysis revealed that Hap-6A-A was significantly associated with wider grains and higher one-thousand grain weight (TGW) in two crop seasons. qRT-PCR revealed a negative relationship between TaGW2 expression level and grain width. The Hap-6A-A frequencies in Chinese varieties released at different periods showed that it had been strongly positively selected in breeding. In landraces, Hap-6A-A is mainly distributed in southern Chinese wheat regions. Association analysis also indicated that Hap-6A-A not only increased TGW by more than 3 g, but also had earlier heading and maturity. In contrast to Chinese varieties, Hap-6A-G was the predominant haplotype in European varieties; Hap-6A-A was mainly present in varieties released in the former Yugoslavia, Italy, Bulgaria, Hungary and Portugal.