National Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China.
Grain Crops Research Institute, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, China.
Mol Genet Genomics. 2021 Nov;296(6):1203-1219. doi: 10.1007/s00438-021-01820-y. Epub 2021 Oct 3.
Drought severely affects the growth and development of maize, but there is a certain degree of compensation effect after rewatering. This study intends to elaborate the response mechanism of maize at the physiological and molecular level as well as excavating potential genes with strong drought resistance and recovery ability. Physiological indexes analysis demonstrated that stomata conductance, transpiration rate, photosynthesis rate, antioxidant enzymes, and proline levels in maize were significantly altered in response to drought for 60 and 96 h and rewatering for 3 days. At 60 h, 96 h, and R3d, we detected 3095, 1941, and 5966 differentially expressed genes (DEGs) and 221, 226, and 215 differentially expressed miRNAs. Weighted correlation network analysis (WGCNA) showed that DEGs responded to maize drought and rewatering through participating in photosynthesis, proline metabolism, ABA signaling, and oxidative stress. Joint analysis of DEGs, miRNA, and target genes showed that zma-miR529, miR5072, zma-miR167e, zma-miR167f, zma-miR167j, miR397, and miR6214 were involved to regulate SBPs, MYBs, ARFs, laccases, and antioxidant enzymes, respectively. Hundreds of differentially expressed DNA methylation-related 24-nt siRNA clusters overlap with DEGs, indicating that DNA methylation is involved in responses under drought stress. These results provide new insights into the molecular mechanisms of drought tolerance, and may identify new targets for breeding drought-tolerant maize lines.
干旱严重影响玉米的生长和发育，但再浇水后会有一定程度的补偿效应。本研究旨在阐述玉米在生理和分子水平上的响应机制，并挖掘具有较强抗旱性和恢复能力的潜在基因。生理指标分析表明，玉米的气孔导度、蒸腾速率、光合速率、抗氧化酶和脯氨酸水平在干旱 60 和 96 h 以及再浇水 3 天后均发生了显著变化。在 60 h、96 h 和 R3d 时，我们检测到 3095、1941 和 5966 个差异表达基因（DEGs）和 221、226 和 215 个差异表达 miRNA。加权相关网络分析（WGCNA）表明，DEGs 通过参与光合作用、脯氨酸代谢、ABA 信号和氧化应激来响应玉米干旱和再浇水。DEGs、miRNA 和靶基因的联合分析表明，zma-miR529、miR5072、zma-miR167e、zma-miR167f、zma-miR167j、miR397 和 miR6214 分别参与调节 SBP、MYB、ARF、漆酶和抗氧化酶。数百个差异表达的 24-nt siRNA 簇与 DEGs 重叠，表明 DNA 甲基化参与了干旱胁迫下的反应。这些结果为耐旱性的分子机制提供了新的见解，并可能为培育耐旱玉米品系鉴定新的靶标。
