Gudi Santosh, Halladakeri Priyanka, Singh Gurjeet, Kumar Pradeep, Singh Satinder, Alwutayd Khairiah Mubarak, Abd El-Moneim Diaa, Sharma Achla
Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana, Punjab, India.
Department of Genetics and Plant Breeding, Anand Agricultural University, Anand, India.
Front Plant Sci. 2024 Mar 4;15:1351075. doi: 10.3389/fpls.2024.1351075. eCollection 2024.
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.
小麦是一种重要的谷类作物，受到包括干旱胁迫在内的多种生物和非生物胁迫的制约。了解干旱胁迫的影响以及胁迫耐受性的遗传基础对于培育耐旱、高产的小麦品种至关重要。在本研究中，我们调查了干旱胁迫对由198个种质系组成的关联群体中幼苗特性的影响。我们的研究结果表明，干旱胁迫对所有被研究的幼苗特性都有不利影响，对苗长的影响最大（降低了50.94%），对发芽率的影响最小（降低了7.9%）。为了更深入地了解，我们使用12511个单核苷酸多态性（SNP）进行了全基因组关联分析，从而鉴定出39个标记-性状关联（MTA）。在这39个MTA中，有13个特别值得注意，因为它们解释了>10%的表型变异，且LOD得分>5。这些高可信度的MTA被进一步用于在1 Mb区域内提取216个候选基因（CG）模型。基因注释和功能表征鉴定出83个与干旱胁迫功能相关的CG。这些基因编码WD40重复结构域、Myb/SANT样结构域、WSD1样结构域、BTB/POZ结构域、蛋白激酶结构域、细胞色素P450、富含亮氨酸重复结构域超家族、BURP结构域、钙调蛋白结合蛋白60、泛素样结构域等。本研究的结果为小麦育种者带来了重大希望，因为它们为选择携带有利等位基因以提高干旱胁迫耐受性的品系提供了直接帮助。此外，鉴定出的SNP和CG将有助于在小麦中进行与增强干旱胁迫耐受性相关的潜在基因组区域的标记辅助选择。
