Zhengzhou Research Base, State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, 450001, Henan, China.
State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, Henan, China.
Plant Physiol Biochem. 2024 Dec;217:109297. doi: 10.1016/j.plaphy.2024.109297. Epub 2024 Nov 15.
Cold stress is one of the major abiotic stressor that profoundly impacts plant growth. Cotton, a widely cultivated variety, is particularly susceptible to cold stress. Unraveling the responses to cold stress is critical for cotton demand. In this investigation, we conducted comparative physiological and transcriptomic analyses of the cold-tolerant variety XLZ16 and cold-sensitive variety XLZ84 at seedling emergence stage under cold stress. Following exposure to cold stress, XLZ16 exhibited a markedly higher growth phenotype and increased activity of antioxidant enzymes, while simultaneously showing reduced cellular oxidative damage and apoptosis. Furthermore, the levels of auxin (IAA), cytokinin (CTK), and salicylic acid (SA) significantly increased during cold stress, whereas the contents of catendorsterol (TY), brassinosterone (CS), and jasmonic acid (JA) significantly decreased. Integrated with stoichiometric analysis, these findings definitively demonstrated significant differences in antioxidant capacity and hormone content between the two varieties during their response to cold stress. A total of 6207 potential cold-responsive differentially expressed genes (DEGs) were identified through transcriptome sequencing analysis. Enrichment analyses of these DEGs revealed that pathways related to "hormones biosynthesis and signaling" as well as "circadian rhythm" were associated with cold response. Notably, the hub gene Gh_D12G2567 (GhJAZ3), encoding jasmonate ZIM-domain (JAZ) proteins, was found to influence the JA signal transduction pathway and regulate cotton growth under cold stress within the MEred module network. Furthermore, suppressing the expression level of GhJAZ3 by virus-induced gene silencing led to the reduction of cold resistance, implying GhJAZ3 as a positive regulator of cold tolerance. This study provides valuable insights into the response mechanisms of cotton under cold stress. It also serves as a reference and foundation for further enhancing cold tolerance of new cotton varieties.
冷胁迫是影响植物生长的主要非生物胁迫因素之一。棉花是一种广泛种植的品种，对冷胁迫特别敏感。解析棉花对冷胁迫的响应机制对于棉花需求至关重要。在这项研究中，我们对耐冷品种 XLZ16 和冷敏感品种 XLZ84 在幼苗期进行了比较生理和转录组分析，以研究它们在冷胁迫下的响应。在冷胁迫下，XLZ16 表现出明显更高的生长表型和抗氧化酶活性的增加，同时表现出细胞氧化损伤和凋亡的减少。此外，在冷胁迫下，生长素（IAA）、细胞分裂素（CTK）和水杨酸（SA）的水平显著增加，而蜕皮甾酮（TY）、油菜素内酯（CS）和茉莉酸（JA）的含量显著降低。结合化学计量分析，这些发现明确证明了这两个品种在应对冷胁迫时抗氧化能力和激素含量存在显著差异。通过转录组测序分析，共鉴定出 6207 个潜在的冷响应差异表达基因（DEGs）。这些 DEGs 的富集分析表明，与“激素生物合成和信号转导”以及“昼夜节律”相关的途径与冷响应有关。值得注意的是，Gh_D12G2567（GhJAZ3）基因编码茉莉酸 ZIM 结构域（JAZ）蛋白，它影响 JA 信号转导途径，并在 MEred 模块网络中调节棉花在冷胁迫下的生长。此外，通过病毒诱导的基因沉默抑制 GhJAZ3 的表达水平会导致冷抗性降低，这表明 GhJAZ3 是冷耐性的正调控因子。这项研究为棉花在冷胁迫下的响应机制提供了有价值的见解。它也为进一步提高新棉花品种的冷耐性提供了参考和基础。
