Li Wenxin, Wen Yongshuai, Quan Jiajia, Gao Meng, Shang Chunyu, Liu Xiaoyan, Liu Guoying, Hu Xiaohui, Li Jianming
College of Horticulture, Northwest A&F University, Yangling, Shaanxi, China.
Zhanjiang Key Laboratory of Tropical Crop Genetic Improvement, South Subtropical Crops Research Institute, China Academy of Tropical Agricultural Sciences, Zhanjiang, Guangdong, China.
Plant Biotechnol J. 2025 Jun 30. doi: 10.1111/pbi.70201.
Cold stress significantly affects the growth and productivity of tomatoes. Despite the known involvement of jasmonate (JA) in cold stress responses, the underlying mechanism remains to be elucidated. Here, we observed that JA peaked 24 h after cold treatment. The expression of the SlLOXD gene, a key player in JA biosynthesis, also peaked at 24 h of cold exposure, and mutation in SlLOXD reduced JA content and cold tolerance. Downstream of JA signalling, the transcription factor SlMYC2 was implicated in enhancing cold resistance by directly binding to the SlCBF1/2 promoters. Furthermore, the SlMYC2-silenced plants and mutants exhibited increased sensitivity to cold damage. Additionally, SlMYB15 directly bound to the SlLOXD and SlMYC2 promoters. Within 6 h of cold stress, SlMYB15 activated SlLOXD expression while repressing SlMYC2 expression. Between 6 and 24 h, the expression level of SlMYB15 decreased, thereby alleviating the repression of SlMYC2 expression. SlMYC2 further enhanced JA signalling through the transcriptional activation of SlLOXD, thus improving cold tolerance in tomato plants. These findings provide valuable insights into the dynamic regulation of the SlLOXD-SlMYC2 -CBF1/2 module by SlMYB15 and its critical role in tomato cold stress responses.
冷胁迫显著影响番茄的生长和产量。尽管已知茉莉酸（JA）参与冷胁迫反应，但其潜在机制仍有待阐明。在此，我们观察到冷处理24小时后JA达到峰值。JA生物合成中的关键因子SlLOXD基因的表达在冷暴露24小时时也达到峰值，并且SlLOXD突变降低了JA含量和耐寒性。在JA信号传导的下游，转录因子SlMYC2通过直接结合SlCBF1/2启动子参与增强抗寒性。此外，SlMYC2沉默的植株和突变体对冷害表现出更高的敏感性。另外，SlMYB15直接结合到SlLOXD和SlMYC2启动子上。在冷胁迫6小时内，SlMYB15激活SlLOXD表达，同时抑制SlMYC2表达。在6至24小时之间，SlMYB15的表达水平下降，从而减轻对SlMYC2表达的抑制。SlMYC2通过转录激活SlLOXD进一步增强JA信号传导，从而提高番茄植株的耐寒性。这些发现为SlMYB15对SlLOXD-SlMYC2 -CBF1/2模块的动态调控及其在番茄冷胁迫反应中的关键作用提供了有价值的见解。
