Abstract: This study utilized oat （Avena sativa） as the material to systematically analyze its physiological and transcriptomic responses under simulated drought stress. The physiological results indicated that drought stress caused a significant decrease in leaf relative water content （RWC） and an increase in relative electrical conductivity （REC）， and induced dynamic changes in the activities of antioxidant enzymes such as superoxide dismutase （SOD）， peroxidase （POD）， and catalase （CAT）. Transcriptome sequencing （RNA-Seq） revealed that the expression of numerous genes were changed dynamically， of which 369 were common differentially expressed genes （DEGs） across all stress time points. These common DEGs were primarily enriched in plant hormone signal transduction， the mitogen-activated protein kinase （MAPK） signaling pathway， and starch and sucrose metabolism. Furthermore， weighted gene co-expression network analysis （WGCNA） identified one core module that was positively correlated with phenotypic traits， from which nine hub genes were identified. These genes are mainly involved in processes such as cell wall reinforcement， osmotic protection and metabolic regulation， playing a pivotal role in the response of oat to drought stress. This research provides a theoretical basis for an in-depth understanding of the molecular mechanisms underlying drought resistance in oats.

Key words: Oat, Drought stress, Transcriptome, WGCNA

摘要： 本研究以燕麦（Avena sativa）为材料，通过模拟干旱胁迫，系统分析了其生理响应与转录组变化。生理结果表明，干旱胁迫导致叶片相对含水量（Relative water content，RWC）显著降低，相对电导率（Relative electrical conductivity，REC）上升，并诱导了超氧化物歧化酶（Superoxide dismutase，SOD）、过氧化物酶（Peroxidase，POD）和过氧化氢酶（Catalase，CAT）等抗氧化酶活性的动态变化。转录组测序（RNA-Seq）揭示了大量基因的表达变化，其中369个为各胁迫时间点共有差异表达基因（Differentially expressed genes，DEGs），主要富集于植物激素信号转导、丝裂原活化蛋白激酶（Mitogen-activated protein kinase，MAPK）信号通路和淀粉蔗糖代谢途径。进一步通过加权基因共表达网络分析（Weighted gene co-expression network analysis，WGCNA），筛选出1个与表型性状正相关的核心模块，并从中识别出9个枢纽基因。这些基因主要参与细胞壁强化、渗透保护和代谢调节等过程，在燕麦应对干旱胁迫中发挥核心作用，为深入理解燕麦抗旱分子机制提供了理论基础。

关键词: 燕麦, 干旱胁迫, 转录组, WGCNA