Hu Yanru, Jiang Yanjuan, Han Xiao, Wang Houping, Pan Jinjing, Yu Diqiu
Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, China.
J Exp Bot. 2017 Mar 1;68(6):1361-1369. doi: 10.1093/jxb/erx004.
Plants are challenged with numerous abiotic stresses, such as drought, cold, heat, and salt stress. These environmental stresses are major causes of crop failure and reduced yields worldwide. Phytohormones play essential roles in regulating various plant physiological processes and alleviating stressful perturbations. Jasmonate (JA), a group of oxylipin compounds ubiquitous in the plant kingdom, acts as a crucial signal to modulate multiple plant processes. Recent studies have shown evidence supporting the involvement of JA in leaf senescence and tolerance to cold stress. Concentrations of JA are much higher in senescent leaves compared with those in non-senescent ones. Treatment with exogenous JA induces leaf senescence and expression of senescence-associated genes. In response to cold stress, exogenous application of JA enhances Arabidopsis freezing tolerance with or without cold acclimation. Consistently, biosynthesis of endogenous JA is activated in response to cold exposure. JA positively regulates the CBF (C-REPEAT BINDING FACTOR) transcriptional pathway to up-regulate downstream cold-responsive genes and ultimately improve cold tolerance. JA interacts with other hormone signaling pathways (such as auxin, ethylene, and gibberellin) to regulate leaf senescence and tolerance to cold stress. In this review, we summarize recent studies that have provided insights into JA-mediated leaf senescence and cold-stress tolerance.
植物面临着众多非生物胁迫，如干旱、寒冷、高温和盐胁迫。这些环境胁迫是全球范围内作物歉收和产量降低的主要原因。植物激素在调节各种植物生理过程和缓解胁迫干扰方面发挥着重要作用。茉莉酸（JA）是一类在植物界普遍存在的氧脂类化合物，作为一种关键信号调节多种植物过程。最近的研究表明有证据支持JA参与叶片衰老和对冷胁迫的耐受性。与未衰老叶片相比，衰老叶片中JA的浓度要高得多。外源施用JA可诱导叶片衰老和衰老相关基因的表达。在冷胁迫下，无论是否经过冷驯化，外源施用JA均可提高拟南芥的抗冻性。同样，内源JA的生物合成在冷暴露时被激活。JA正向调节CBF（C-重复结合因子）转录途径，以上调下游冷响应基因并最终提高耐寒性。JA与其他激素信号通路（如生长素、乙烯和赤霉素）相互作用，以调节叶片衰老和对冷胁迫的耐受性。在本综述中，我们总结了最近的研究，这些研究为JA介导的叶片衰老和冷胁迫耐受性提供了见解。
