Genome Wide Association Mapping for Arabinoxylan Content in a Collection of Tetraploid Wheats.
Genome Wide Association Mapping for Arabinoxylan Content in a Collection of Tetraploid Wheats.
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DOI：
10.1371/journal.pone.0132787
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Gadaleta A
中科院分区：
文献类型：
--
作者：
Marcotuli I;Houston K;Waugh R;Fincher GB;Burton RA;Blanco A;Gadaleta A
阿拉伯木聚糖 (AX) 是面包小麦植物细胞壁的主要成分，在面包制作和淀粉提取中发挥着重要作用。此外，阿拉伯木聚糖是可溶性膳食纤维的成分，对人类营养具有潜在的健康促进作用。尽管对人类健康具有很高的价值，但对硬粒小麦中 AX 含量的遗传学研究却很少。在一组 104 个四倍体小麦基因型中研究了 AX 含量的遗传变异性，并通过全基因组关联研究 (GWAS) 鉴定了可归因于 AX 含量的区域。阿拉伯木聚糖的含量以占籽粒干重的百分比 (w/w) 表示，范围为 1.8% 至 5.5%，平均值为 4.0%。 GWAS 总共揭示了 37 个显着的标记性状关联 (MTA)，确定了 19 个与 AX 含量相关的数量性状基因座 (QTL)。在 5A 染色体（七条）上鉴定出数量最多的 MTA，其中三个 QTL 区域与 AX 含量相关，而在 2B 和 4B 染色体上检测到的 MTA 数量最少，其中只有一个 MTA 鉴定出单个基因座。在短柄草、水稻和二色高粱中，SNP 标记序列与注释基因和蛋白质之间的同线性保守性使得能够鉴定出与候选基因一致的 9 个 QTL。其中包括编码 Gal7 的糖基水解酶 GH35 和 1A 染色体上的葡萄糖基转移酶 GT31； 2B 染色体上的 GT1 基因簇，包括 TaUGT1 和 cisZog1；编码 3A 号染色体上的 CelC 基因的糖基水解酶； 5A 染色体上的 Ugt12887 和 TaUGT1 基因； 7A 号染色体上有 (1,3)-β-D-葡聚糖合酶（Gsl12 基因）和葡糖基水解酶（Cel8 基因）。本研究鉴定了四倍体小麦基因型籽粒中 AX 含量的显着 MTA。我们建议这些可用于可溶性纤维含量较高的硬粒小麦品种的分子育种。
Arabinoxylans (AXs) are major components of plant cell walls in bread wheat and are important in bread-making and starch extraction. Furthermore, arabinoxylans are components of soluble dietary fibre that has potential health-promoting effects in human nutrition. Despite their high value for human health, few studies have been carried out on the genetics of AX content in durum wheat. The genetic variability of AX content was investigated in a set of 104 tetraploid wheat genotypes and regions attributable to AX content were identified through a genome wide association study (GWAS). The amount of arabinoxylan, expressed as percentage (w/w) of the dry weight of the kernel, ranged from 1.8% to 5.5% with a mean value of 4.0%. The GWAS revealed a total of 37 significant marker-trait associations (MTA), identifying 19 quantitative trait loci (QTL) associated with AX content. The highest number of MTAs was identified on chromosome 5A (seven), where three QTL regions were associated with AX content, while the lowest number of MTAs was detected on chromosomes 2B and 4B, where only one MTA identified a single locus. Conservation of synteny between SNP marker sequences and the annotated genes and proteins in Brachypodium distachyon, Oryza sativa and Sorghum bicolor allowed the identification of nine QTL coincident with candidate genes. These included a glycosyl hydrolase GH35, which encodes Gal7 and a glucosyltransferase GT31 on chromosome 1A; a cluster of GT1 genes on chromosome 2B that includes TaUGT1 and cisZog1; a glycosyl hydrolase that encodes a CelC gene on chromosome 3A; Ugt12887 and TaUGT1genes on chromosome 5A; a (1,3)-β-D-glucan synthase (Gsl12 gene) and a glucosyl hydrolase (Cel8 gene) on chromosome 7A. This study identifies significant MTAs for the AX content in the grain of tetraploid wheat genotypes. We propose that these may be used for molecular breeding of durum wheat varieties with higher soluble fibre content.