Yang Yongping, Wu Kongfen, Yu Diqiu, Han Xiao, Jiang Yanjuan
CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, China.
University of Chinese Academy of Sciences, Beijing, China.
Plant Cell Environ. 2025 Aug;48(8):6140-6152. doi: 10.1111/pce.15593. Epub 2025 May 4.
Leaf senescence is triggered by various endogenous signals and exogenous cues. The plant hormone salicylic acid (SA) is a key signaling molecule that induces leaf senescence, but the underlying mechanism has not been fully clarified. Here, we found that INDUCER OF CBF EXPRESSION1 (ICE1) negatively regulates SA-induced leaf senescence in Arabidopsis. Upon treatment with SA, the ice1-2 mutant displayed an accelerated-leaf senescence phenotype compared with that of the wild type (Col-0), including severe leaf yellowing, lower chlorophyll content, and higher expression levels of senescence-associated genes, whereas ICE1-overexpressing plants exhibited delayed leaf senescence. ICE1 interacts with WRKY46, a positive regulator of SA-induced leaf senescence, to suppress its ability to activate WRKY6 expression. Phenotypic assays indicated that the accelerated-leaf senescence of ice1-2 was largely recovered by wrky46, indicating that ICE1 functions genetically upstream of WRKY46 during SA-induced leaf senescence. Further analyses suggested that the accelerated-leaf senescence phenotype of ice1-2 is dependent on WRKY6. Collectively, our results demonstrate the negative regulatory role of ICE1 in SA-induced leaf senescence. Given the importance of SA in leaf senescence, the discovery of the role of ICE1 reveals new details of how the onset of senescence is regulated.
叶片衰老由多种内源信号和外源信号触发。植物激素水杨酸（SA）是诱导叶片衰老的关键信号分子，但其潜在机制尚未完全阐明。在此，我们发现CBF表达诱导因子1（ICE1）在拟南芥中负调控SA诱导的叶片衰老。用SA处理后，与野生型（Col-0）相比，ice1-2突变体表现出加速叶片衰老的表型，包括严重的叶片黄化、较低的叶绿素含量以及衰老相关基因的较高表达水平，而ICE1过表达植株则表现出叶片衰老延迟。ICE1与SA诱导叶片衰老的正调控因子WRKY46相互作用，以抑制其激活WRKY6表达的能力。表型分析表明，wrky46在很大程度上恢复了ice1-2的加速叶片衰老，这表明在SA诱导的叶片衰老过程中，ICE1在WRKY46的遗传上游发挥作用。进一步分析表明，ice1-2的加速叶片衰老表型依赖于WRKY6。总的来说，我们的结果证明了ICE1在SA诱导的叶片衰老中的负调控作用。鉴于SA在叶片衰老中的重要性，ICE1作用的发现揭示了衰老起始调控方式的新细节。
