Table_4_Identifying Candidate Genes for Enhancing Grain Zn Concentration in Wheat.XLSX

Wheat (Triticum aestivum L.) is one of the major staple food crops worldwide. Despite efforts in improving wheat quality, micronutrient levels are still below the optimal range for human nutrition. In particular, zinc (Zn) deficiency is a widespread problem in human nutrition in countries relying mainly on a cereal diet; hence improving Zn accumulation in grains is an imperative need. This study was designed to understand the genetic architecture of Zn grain concentrations in wheat grains. We performed a genome-wide association study (GWAS) for grain Zn concentrations in 369 European wheat genotypes, using field data from 3 years. The complete wheat panel was genotyped by high-density arrays of single nucleotide polymorphic (SNP) markers (90k iSELECT Infinium and 35k Affymetrix arrays) resulting in 15,523 polymorphic markers. Additionally, a subpanel of 183 genotypes was analyzed with a novel 135k Affymetrix marker array resulting in 28,710 polymorphic SNPs for high-resolution mapping of the potential genomic regions. The mean grain Zn concentration of the genotypes ranged from 25.05–52.67 μg g-1 dry weight across years with a moderate heritability value. Notably, 40 marker-trait associations (MTAs) were detected in the complete panel of varieties on chromosomes 2A, 3A, 3B, 4A, 4D, 5A, 5B, 5D, 6D, 7A, 7B, and 7D. The number of MTAs in the subpanel was increased to 161 MTAs whereas the most significant and consistent associations were located on chromosomes 3B (723,504,241–723,611,488 bp) and 5A (462,763,758–466,582,184 bp) having major effects. These genomic regions include newly identified putative candidate genes, which are related to Zn uptake and transport or represent bZIP and mitogen-activated protein kinase genes. These findings provide the basis for understanding the genetic background of Zn concentration in wheat grains that in turn may help breeders to select high Zn-containing genotypes to improve human health and grain quality.

小麦（Triticum aestivum L.）乃全球主要的主食作物之一。尽管在提升小麦品质方面已作出诸多努力，但微营养素水平依然低于人类营养所需的理想范围。特别是，锌（Zn）缺乏在依赖谷物饮食的国家的人类营养中普遍存在；因此，提高谷物中锌的积累成为一项迫切需求。本研究旨在阐明小麦籽粒中锌浓度遗传结构。我们针对369个欧洲小麦基因型进行了全基因组关联分析（GWAS），利用三年田间数据进行籽粒锌浓度的分析。完整的 wheat 面板通过高密度单核苷酸多态性（SNP）标记数组（90k iSELECT Infinium 和 35k Affymetrix 数组）进行基因分型，结果产生15,523个多态性标记。此外，对183个基因型的子面板进行了分析，采用新型的135k Affymetrix 标记数组，结果产生了28,710个多态性SNP，以实现潜在基因组区域的高分辨率映射。各基因型籽粒平均锌浓度在多年间波动于25.05–52.67 μg g-1 干重，具有中等的遗传力值。值得注意的是，在品种完整面板中检测到40个标记-性状关联（MTA），位于2A、3A、3B、4A、4D、5A、5B、5D、6D、7A、7B 和 7D 染色体上。子面板中MTA的数量增加到161个，其中最显著且一致的关联位于3B染色体（723,504,241–723,611,488 bp）和5A染色体（462,763,758–466,582,184 bp），具有主要效应。这些基因组区域包括新发现的潜在候选基因，它们与锌的吸收和运输相关，或代表bZIP和丝裂原活化蛋白激酶基因。这些发现为理解小麦籽粒中锌浓度的遗传背景提供了基础，进而可能帮助育种者选择富含锌的基因型，以提升人类健康和谷物品质。