Ermolaev Aleksey, Bespalova Ludmila, Korobkova Varvara, Yanovsky Aleksey, Nazarova Lubov, Kroupina Aleksandra, Chernook Anastasia, Mudrova Aleksandra, Voronezhskaya Viktoria, Kroupin Pavel, Karlov Gennady, Divashuk Mikhail
All-Russian Research Institute of Agricultural Biotechnology, Moscow, Russia.
P.P. Lukyanenko National Grain Center, Krasnodar, Russia.
Front Plant Sci. 2025 Aug 12;16:1632673. doi: 10.3389/fpls.2025.1632673. eCollection 2025.
Grain protein content (GPC) is a critical determinant of durum wheat quality, with cysteine playing a pivotal role in gluten strength. This study aimed to develop genetic markers associated with GPC through a genome-wide association study (GWAS) and validate their utility for breeding programs. A panel of 190 durum wheat accessions was phenotyped for GPC across multiple environments and genotyped using 4927 high-quality SNPs. GWAS identified a significant SNP on chromosome 4B, located in an intergenic region. Through the analysis of linkage disequilibrium decay rate, and functional gene ontology annotation, the gene involved in cysteine biosynthesis was identified as a candidate gene for GPC. A missense mutation (Gly325Ser) in the ninth exon of was associated with a 1.33% GPC increase in spring durum wheat recombinant inbred lines. Structural analysis indicated that the Gly325Ser mutation alters the SAT2 protein's C-terminal -helix, potentially influencing enzyme activity. Additionally, an intronic SNP showed association with multi-year average GPC increase of 0.92% in spring durum wheat. Despite the intronic SNP's lack of direct amino acid impact, its high phenotypic variance explained (40.23% in spring wheat) suggests regulatory roles in gene expression. Expression profiling of homologous from bread wheat revealed peak transcription during grain filling stages, aligning with grain protein accumulation dynamics. The developed KASP markers demonstrated robust allelic discrimination, offering practical tools for marker-assisted selection. This study provides actionable genetic resources for breeding high-protein spring durum wheat genotypes.
籽粒蛋白质含量（GPC）是硬粒小麦品质的关键决定因素，其中半胱氨酸在面筋强度中起关键作用。本研究旨在通过全基因组关联研究（GWAS）开发与GPC相关的遗传标记，并验证其在育种计划中的实用性。对190份硬粒小麦材料在多个环境中进行了GPC表型分析，并使用4927个高质量单核苷酸多态性（SNP）进行了基因分型。GWAS在4B染色体上的一个基因间区域鉴定出一个显著的SNP。通过连锁不平衡衰减率分析和功能基因本体注释，确定参与半胱氨酸生物合成的基因是GPC的候选基因。在硬粒小麦重组自交系中，该基因第九外显子中的一个错义突变（Gly325Ser）与GPC增加1.33%相关。结构分析表明，Gly325Ser突变改变了SAT2蛋白的C端α螺旋，可能影响酶活性。此外，一个内含子SNP与硬粒小麦多年平均GPC增加0.92%相关。尽管该内含子SNP对氨基酸没有直接影响，但其高表型变异解释率（春小麦中为40.23%）表明其在基因表达中具有调控作用。对面包小麦同源基因的表达谱分析显示，在籽粒灌浆阶段转录达到峰值，与籽粒蛋白质积累动态一致。开发的竞争性等位基因特异性PCR（KASP）标记表现出强大的等位基因区分能力，为标记辅助选择提供了实用工具。本研究为培育高蛋白硬粒小麦基因型提供了可操作的遗传资源。
