National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China.
BMC Plant Biol. 2024 May 21;24(1):430. doi: 10.1186/s12870-024-05116-2.
As the greenhouse effect intensifies, global temperatures are steadily increasing, posing a challenge to bread wheat (Triticum aestivum L.) production. It is imperative to comprehend the mechanism of high temperature tolerance in wheat and implement breeding programs to identify and develop heat-tolerant wheat germplasm and cultivars.
To identify quantitative trait loci (QTL) related to heat stress tolerance (HST) at seedling stage in wheat, a panel of 253 wheat accessions which were re-sequenced used to conduct genome-wide association studies (GWAS) using the factored spectrally transformed linear mixed models (FaST-LMM). For most accessions, the growth of seedlings was found to be inhibited under heat stress. Analysis of the phenotypic data revealed that under heat stress conditions, the main root length, total root length, and shoot length of seedlings decreased by 47.46%, 49.29%, and 15.19%, respectively, compared to those in normal conditions. However, 17 varieties were identified as heat stress tolerant germplasm. Through GWAS analysis, a total of 115 QTLs were detected under both heat stress and normal conditions. Furthermore, 15 stable QTL-clusters associated with heat response were identified. By combining gene expression, haplotype analysis, and gene annotation information within the physical intervals of the 15 QTL-clusters, two novel candidate genes, TraesCS4B03G0152700/TaWRKY74-B and TraesCS4B03G0501400/TaSnRK3.15-B, were responsive to temperature and identified as potential regulators of HST in wheat at the seedling stage.
This study conducted a detailed genetic analysis and successfully identified two genes potentially associated with HST in wheat at the seedling stage, laying a foundation to further dissect the regulatory mechanism underlying HST in wheat under high temperature conditions. Our finding could serve as genomic landmarks for wheat breeding aimed at improving adaptation to heat stress in the face of climate change.
随着温室效应的加剧，全球气温稳步上升，对小麦（Triticum aestivum L.）生产构成挑战。了解小麦耐高温的机制并实施育种计划，以鉴定和开发耐高温小麦种质和品种势在必行。
为了鉴定小麦幼苗期耐热相关的数量性状位点（QTL），使用 253 个已重测序的小麦品系进行了全基因组关联研究（GWAS），使用因子光谱变换线性混合模型（FaST-LMM）。对于大多数品系，在热胁迫下发现幼苗生长受到抑制。表型数据分析表明，在热胁迫条件下，与正常条件相比，幼苗的主根长、总根长和苗高分别下降了 47.46%、49.29%和 15.19%。然而，有 17 个品种被鉴定为耐热种质。通过 GWAS 分析，在热胁迫和正常条件下共检测到 115 个 QTL。此外，还鉴定出 15 个与热响应相关的稳定 QTL 簇。通过结合 15 个 QTL 簇的物理区间内的基因表达、单倍型分析和基因注释信息，发现两个新的候选基因 TraesCS4B03G0152700/TaWRKY74-B 和 TraesCS4B03G0501400/TaSnRK3.15-B 对温度有反应，并被鉴定为小麦幼苗期高温下耐热的潜在调控因子。
本研究进行了详细的遗传分析，成功鉴定出两个与小麦幼苗期耐热相关的基因，为进一步解析小麦在高温条件下耐热的调控机制奠定了基础。我们的发现可为小麦耐热性育种提供基因组标记，以应对气候变化下的耐热性挑战。
