Water deficits are a major constraint on maize growth and yield, and deep roots are one of the major mechanisms of drought tolerance. In this study, four root and shoot traits were evaluated within an association panel consisting of 209 diverse maize accessions under well-watered (WW) and water-stressed (WS) conditions. A significant positive correlation was observed between seminal root length (SRL) under WS treatment and the drought tolerance index (DI) of maize seedlings. The transcriptome profiles of maize seminal roots were compared between four drought-tolerant lines and four drought-sensitive lines under both water conditions to identify genes associated with the drought stress response. After drought stress, 343 and 177 common differentially expressed genes (DEGs) were identified in the drought-tolerant group and drought-sensitive group, respectively. In parallel, a coexpression network underlying SRL was constructed on the basis of transcriptome data, and 10 hub genes involved in two significant associated modules were identified. Additionally, a genome-wide association study (GWAS) of the SRL revealed 62 loci for the two water treatments. By integrating the results of the GWAS, the common DEGs and the coexpression network analysis, 7 promising candidate genes were prioritized for further research. Together, our results provide a foundation for the enhanced understanding of seminal root changes in response to drought stress in maize.

中文翻译：

---

转录组和 GWAS 分析揭示干旱胁迫下玉米幼苗精根长度的候选基因

缺水是玉米生长和产量的主要制约因素，深根是耐旱的主要机制之一。在这项研究中，在一个由 209 种不同玉米种质组成的关联小组中评估了四种根和芽性状，该小组在充分浇水 (WW) 和缺水 (WS) 条件下。WS处理下的精根长度（SRL）与玉米幼苗的耐旱指数（DI）呈显着正相关。比较四种耐旱品系和四种干旱敏感品系在两种水条件下玉米精根的转录组谱，以确定与干旱胁迫反应相关的基因。干旱胁迫后，耐旱组和干旱敏感组共鉴定出343个和177个常见差异表达基因（DEGs），分别。同时，基于转录组数据构建了基于 SRL 的共表达网络，并确定了涉及两个重要关联模块的 10 个中枢基因。此外，SRL 的全基因组关联研究 (GWAS) 揭示了两种水处理的 62 个位点。通过整合GWAS、常见DEGs和共表达网络分析的结果，7个有前景的候选基因被优先用于进一步研究。总之，我们的结果为加深理解玉米干旱胁迫响应的精根变化奠定了基础。SRL 的全基因组关联研究 (GWAS) 揭示了两种水处理的 62 个位点。通过整合GWAS、常见DEGs和共表达网络分析的结果，7个有前景的候选基因被优先用于进一步研究。总之，我们的结果为加深理解玉米干旱胁迫响应的精根变化奠定了基础。SRL 的全基因组关联研究 (GWAS) 揭示了两种水处理的 62 个位点。通过整合GWAS、常见DEGs和共表达网络分析的结果，7个有前景的候选基因被优先用于进一步研究。总之，我们的结果为加深理解玉米干旱胁迫响应的精根变化奠定了基础。