Table_3_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.）是全球主要的粮食作物之一。尽管在提升小麦品质方面已做出诸多努力，但其微量元素水平仍然低于人类营养的优化标准。特别是在以谷物为主食的国家，锌（Zn）的缺乏是一个普遍的营养问题；因此，提高谷物中锌的积累成为一项迫切需求。本研究旨在探究小麦籽粒中锌浓度遗传结构的组成。我们对369个欧洲小麦基因型进行了全基因组关联研究（GWAS），利用三年田间数据分析了籽粒锌浓度。完整的 wheat panel 通过高密度单核苷酸多态性（SNP）标记芯片（90k iSELECT Infinium 和 35k Affymetrix 芯片）进行基因分型，产生了15,523个多态性标记。此外，183个基因型的亚群体使用新型的135k Affymetrix标记芯片进行了分析，产生了28,710个多态性SNP，以实现潜在基因组区域的精确映射。不同年份中基因型的平均籽粒锌浓度范围在25.05至52.67 μg g-1 干重之间，遗传力值适中。值得注意的是，在完整的品种面板中，在2A、3A、3B、4A、4D、5A、5B、5D、6D、7A、7B和7D染色体上检测到了40个标记-性状关联（MTA）。在亚群体中，MTA的数量增加至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），具有主要影响。这些基因组区域包括新发现的候选基因，这些基因与锌的吸收和转运相关，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。