A self‐amplifying NO‐H2S loop mediates melatonin‐induced CBF‐responsive pathway and cold tolerance in watermelon

• DOI: 10.1111/tpj.70025
• Publication Date: 2025-02-26T19:17:14Z
• Authors: Yanliang Guo; Jiayue Li; Lingling Liu; Jiahe Liu; Wanbang Yang; Yi Chen; Chao Li; Li Yuan; Chunhua Wei; Jianxiang Ma; Yong Zhang; Jianqiang Yang; Feishi Luan; Xian Zhang; Hao Li
• Keywords: Sodium nitroprusside

Melatonin is a pivotal bioactive molecule that enhances plant cold stress tolerance, but the precise mechanisms remain enigmatic. Here, we have discovered overexpressing melatonin biosynthetic gene ClCOMT1 or applying exogenous activates C-repeat binding factor (CBF)-responsive pathway and watermelon tolerance. This enhancement accompanied by elevated levels of nitric oxide (NO) hydrogen sulfide (H2S), along with upregulation nitrate reductase 1 (ClNR1) L-cysteine desulfhydrase (ClLCD) genes involved in NO H2S generation respectively. Conversely, knockout exhibits contrasting effects compared to its overexpression. Furthermore, application sodium nitroprusside (SNP, donor) NaHS (a promotes accumulation NO, respectively, activating CBF enhancing However, ClNR1 ClLCD abolished melatonin-induced production respectively abrogated supplementation SNP restored diminished response caused deletion. Additionally, deletion either eliminated NaHS- SNP-induced response, Overall, these findings suggest reciprocal positive-regulatory loop between ClNR1-mediated ClLCD-mediated H2S, which plays crucial role mediating