Cold stress inhibits growth, reduces productivity and deteriorates fruit quality in tomato (Solanum lycopersicum). It is thus of critical importance to elucidate the mechanisms by which tomato plants respond to cold stress. Jasmonates (JAs) are a group of phytohormones crucial for plant growth, development and stress responses. However, the role of JA and the mode of actions in the cold response in tomato plants remain largely unknown. Here, we report a JA-responsive glutathione S-transferase gene SlGSTU24 that functions to alleviate cold stress in tomato. We found that SlGSTU24 was ubiquitously expressed in all examined tissues and was responsive to both JA and cold stress. Knockdown of SlGSTU24 via an approach of VIGS (virus-induced gene silencing) aggravated cold-induced damages, as evidenced by enhanced ROS (Reactive Oxygen Species) accumulation, MDA (malondialdehyde) content and electrolyte leakage. Application of MeJA prominently increased the expression of SlGSTU24, with concomitant decreases in MDA content as well as electrolyte leakage in tomato leaves under cold conditions. In contrast, blocking JA biosynthesis using DIECA dramatically suppressed the expression of SlGSTU24 and elevated MDA content and electrolyte leakage. Furthermore, JA-regulated SlGSTU24 expression was dependent on SlMYC2, a crucial regulator of JA signaling pathway. Knockdown of SlMYC2 profoundly decreased the expression of SlGSTU24, accompanied by enhanced MDA content and electrolyte leakage under cold conditions. Dual-luciferase assay showed that SlMYC2 activates the expression of SlGSTU24 in tobacco leaves. Collectively, these results support that JA-upregulated SlGSTU24 attenuates cold-induced oxidative stress in tomato. This study uncovers a crucial module MYC2-SlGSTU24 that maintains ROS homeostasis in tomato under cold conditions.

冷胁迫抑制番茄（番茄）的生长、降低生产力并降低果实品质。因此，阐明番茄植物对冷胁迫的反应机制至关重要。茉莉酸 (JAs) 是一组对植物生长、发育和应激反应至关重要的植物激素。然而，JA 在番茄植物冷反应中的作用和作用方式在很大程度上仍然未知。在这里，我们报告了一种 JA 响应型谷胱甘肽S-转移酶基因SlGSTU24，其作用是缓解番茄的冷应激。我们发现SlGSTU24在所有检查的组织中普遍表达，并且对 JA 和冷应激都有反应。击倒SlGSTU24通过 VIGS（病毒诱导的基因沉默）方法加重了寒冷引起的损伤，这可以通过增强 ROS（活性氧）积累、MDA（丙二醛）含量和电解质泄漏来证明。MeJA的应用显着增加了SlGSTU24的表达，伴随着MDA含量的降低以及低温条件下番茄叶片中的电解质渗漏。相比之下，使用 DIECA 阻断 JA 生物合成可显着抑制 SlGSTU24 的表达，并提高 MDA 含量和电解质泄漏。此外，JA 调节的SlGSTU24表达依赖于 SlMYC2，它是 JA 信号通路的关键调节因子。SlMYC2的敲低显着降低了SlGSTU24的表达，伴随着在寒冷条件下增加的MDA含量和电解质泄漏。双荧光素酶测定表明，SlMYC2 激活了烟叶中SlGSTU24的表达。总的来说，这些结果支持 JA 上调的SlGSTU24减弱了番茄中冷诱导的氧化应激。这项研究揭示了一个关键模块 MYC2 -SlGSTU24，它在寒冷条件下维持番茄中的 ROS 稳态。