Temperature stresses (TS), including cold and heat stress, adversely affect the growth, development, and yield of maize (Zea mays L.). To clarify the molecular mechanisms of the tolerance of maize seedling leaves to TS, we applied transcriptomic sequencing of an inbred maize line, B73, with seedlings exposed to various temperature conditions, including normal temperature (NT, 25 °C), cold (4, 10, and 16 °C), and heat (37, 42, and 48 °C) stresses. Differentially expressed genes (DEGs) were detected in different comparison between the NT sample and each temperature-stressed sample, with 5358, 5485, 5312, 1095, 2006, and 4760 DEGs responding to TS of 4, 10, 16, 37, 42, and 48 °C, respectively. For cold and heat stresses, 189 DEGs enriched in the hydrogen peroxidase metabolic process, cellular modified amino acid metabolic process, and sulfur compound metabolic process were common. The DEGs encoding calcium signaling and reactive oxygen species scavenging enzymes demonstrated similar expression characterizations, whereas the DEGs encoding transcription factors, such as ERF, ARF, and HSF, hormone signaling, and heat shock proteins, displayed divergent expression models, implying both common and divergent responses to cold and heat stresses in maize seedling leaves. Co-expression network analysis showed that functional DEGs associated with the core regulators in response to cold and heat stresses were significantly correlated with TS, indicating their vital roles in cold and heat adaptation, respectively. Our investigation focused on the response to gradient TS, and the results presented a relatively comprehensive category of genes involved in differential TS responses. These will contribute a better understanding of the molecular mechanisms of maize seedling leaf responses to TS and provide valuable genetic resources for breeding TS tolerant varieties of maize.

中文翻译：

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转录组学分析揭示了玉米幼苗叶片对冷热应激的共同和不同的反应

温度胁迫 (TS)，包括冷和热胁迫，会对玉米 (Zea mays L.) 的生长、发育和产量产生不利影响。为了阐明玉米幼苗叶片对 TS 耐受性的分子机制，我们应用了自交玉米系 B73 的转录组测序，将幼苗暴露在各种温度条件下，包括常温 (NT, 25 °C)、寒冷 (4, 10 和 16 °C）和热（37、42 和 48 °C）应力。在NT样品和每个温度应激样品之间的不同比较中检测到差异表达基因（DEGs），5358、5485、5312、1095、2006和4760个DEGs响应4、10、16、37、42的TS，和 48 °C，分别。对于冷热应激，189 DEGs 富含过氧化氢酶代谢过程、细胞修饰的氨基酸代谢过程、和硫化合物代谢过程是常见的。编码钙信号和活性氧清除酶的 DEG 表现出相似的表达特征，而编码转录因子（如 ERF、ARF 和 HSF、激素信号和热休克蛋白）的 DEG 表现出不同的表达模型，这意味着共同和不同玉米幼苗叶片对冷热胁迫的响应。共表达网络分析表明，与响应冷热应激的核心调节因子相关的功能性 DEG 与 TS 显着相关，分别表明它们在冷和热适应中的重要作用。我们的研究集中在对梯度 TS 的响应上，结果显示了一个相对全面的基因类别，涉及差异 TS 响应。