Zhang Siqi, Sun Lei, Ma Chunhong, Xu Dajin, Jiao Bo, Wang Jiao, Dong Fushuang, Yang Fan, Zhou Shuo, Yang Qing, Zhao Pu
Institute of Biotechnology and Food Science, Hebei Academy of Agriculture and Forestry Science/Hebei Key Laboratory of Plant Genetic Engineering, Shijiazhuang 050051, China.
College of Agronomy and Biotechnology, Hebei Key Laboratory of Crop Stress Biology, Hebei Normal University of Science and Technology, Qinhuangdao 066600, China.
Genes (Basel). 2025 Apr 24;16(5):480. doi: 10.3390/genes16050480.
High temperatures during the early generative stage significantly threaten maize productivity, yet the molecular basis of heat tolerance remains unclear.
To elucidate the molecular mechanisms of heat tolerance in maize, two hybrids-ZD309 (heat-tolerant) and XY335 (heat-sensitive)-were selected for integrated transcriptomic and physiological analyses. The plants were subjected to high-temperature treatments (3-5 °C above ambient field temperature) for 0, 1, 3, 5, and 7 days, with controls grown under natural conditions. Physiological indices, including Superoxide dismutase (SOD) activity, and proline (PRO), malondialdehyde (MDA), soluble sugar, and protein content, were measured.
Transcriptome analysis identified 1595 differentially expressed genes (DEGs) in XY335 (509 up- and 1086 down-regulated) and 1526 DEGs in ZD309 (863 up- and 663 down-regulated), with the most pronounced changes occurring on day 5. Key DEGs in XY335 were enriched in galactose metabolism and carbohydrate catabolism, whereas ZD309 exhibited rapid activation of oxidative stress and cell wall integrity pathways. Mfuzz time-series analysis categorized DEGs from XY335 and ZD309 into six clusters each. Weighted gene co-expression network analysis (WGCNA) identified 10 hub genes involved in ubiquitin thioesterase activity and RNA modification, suggesting protein-level regulatory roles.
This study reveals distinct transcriptional dynamics between heat-tolerant and heat-sensitive varieties, providing candidate genes for breeding thermotolerant maize and advancing our understanding of heat stress responses during critical reproductive stages.
生殖早期的高温严重威胁玉米产量，然而耐热性的分子基础仍不清楚。
为阐明玉米耐热性的分子机制，选择两个杂交种——ZD309（耐热）和XY335（热敏）——进行转录组和生理综合分析。将植株在高于田间环境温度3 - 5°C的高温处理下分别处理0、1、3、5和7天，对照组在自然条件下生长。测定了包括超氧化物歧化酶（SOD）活性、脯氨酸（PRO）、丙二醛（MDA）、可溶性糖和蛋白质含量在内的生理指标。
转录组分析在XY335中鉴定出1595个差异表达基因（DEGs）（509个上调和1086个下调），在ZD309中鉴定出1526个DEGs（863个上调和663个下调），最显著的变化发生在第5天。XY335中的关键DEGs富集在半乳糖代谢和碳水化合物分解代谢中，而ZD309表现出氧化应激和细胞壁完整性途径的快速激活。Mfuzz时间序列分析将XY335和ZD309的DEGs分别分为六个簇。加权基因共表达网络分析（WGCNA）鉴定出10个参与泛素硫酯酶活性和RNA修饰的枢纽基因，表明其在蛋白质水平上的调控作用。
本研究揭示了耐热和热敏品种之间不同的转录动态，为培育耐热玉米提供了候选基因，并增进了我们对关键生殖阶段热应激反应的理解。
