PDF(Pubmed)
Abstract：
Wheat is an important cereal crop constrained by several biotic and abiotic stresses including drought stress. Understating the effect of drought stress and the genetic basis of stress tolerance is important to develop drought resilient, high-yielding wheat cultivars. In this study, we investigated the effects of drought stress on seedling characteristics in an association panel consisting of 198 germplasm lines. Our findings revealed that drought stress had a detrimental effect on all the seedling characteristics under investigation with a maximum effect on shoot length (50.94% reduction) and the minimum effect on germination percentage (7.9% reduction). To gain a deeper understanding, we conducted a genome-wide association analysis using 12,511 single nucleotide polymorphisms (SNPs), which led to the identification of 39 marker-trait associations (MTAs). Of these 39 MTAs, 13 were particularly noteworthy as they accounted for >10% of the phenotypic variance with a LOD score >5. These high-confidence MTAs were further utilized to extract 216 candidate gene (CGs) models within 1 Mb regions. Gene annotation and functional characterization identified 83 CGs with functional relevance to drought stress. These genes encoded the WD40 repeat domain, Myb/SANT-like domain, WSD1-like domain, BTB/POZ domain, Protein kinase domain, Cytochrome P450, Leucine-rich repeat domain superfamily, BURP domain, Calmodulin-binding protein60, Ubiquitin-like domain, etc. Findings from this study hold significant promise for wheat breeders as they provide direct assistance in selecting lines harboring favorable alleles for improved drought stress tolerance. Additionally, the identified SNPs and CGs will enable marker-assisted selection of potential genomic regions associated with enhanced drought stress tolerance in wheat.
摘要：
小麦是受多种生物和非生物胁迫(包括干旱胁迫)约束的重要谷类作物。了解干旱胁迫的影响和胁迫耐受性的遗传基础对于发展抗旱性，高产小麦品种。在这项研究中,我们在由198个种质系组成的关联小组中研究了干旱胁迫对幼苗特性的影响。我们的发现表明，干旱胁迫对所研究的所有幼苗特性都有不利影响，对芽长度的影响最大（减少50.94％），对发芽率的影响最小（减少7.9％）。为了获得更深入的理解，我们使用12,511个单核苷酸多态性（SNP）进行了全基因组关联分析，这导致了39个标记-性状关联(MTA)的鉴定。在这39个MTA中，13是特别值得注意的,因为它们占表型变异的>10%,LOD评分>5。这些高置信度MTA进一步用于提取1Mb区域内的216个候选基因(CG)模型。基因注释和功能表征鉴定了83个与干旱胁迫功能相关的CGs。这些基因编码WD40重复结构域,Myb/SANT类域名，类似WSD1的域，BTB/POZ域，蛋白激酶结构域，细胞色素P450，富含亮氨酸的重复结构域超家族，BURP域,钙调蛋白结合蛋白60，泛素样结构域，等。这项研究的结果对小麦育种者具有重要意义，因为它们为选择具有有利等位基因的品系提供了直接帮助，以改善干旱胁迫耐受性。此外,鉴定的SNP和CGs将能够标记辅助选择与小麦干旱胁迫耐受性增强相关的潜在基因组区域。
