Methionine (Met) sulfoxide reductase (Msr) is a protein that converts free or protein-bound Met sulfoxide (MetSO) to Met in horticultural crops, thereby facilitating protein repair. In our previous study, we identified as a significant up-regulated gene in response to methyl jasmonate (MeJA) treatment. Many studies have shown that MeJA not only induces ethylene production and promotes ripening but also improves the postharvest quality of horticultural crops. However, the specific function and mechanisms of SlMsrB5 in MeJA-regulated postharvest fruit ripening and quality remain unclear. In this work, we analyzed the effect of -s on the ripening and physiological quality of postharvest tomato fruit ( L.cv Jiaxina) treated with 0.05 mmol L MeJA, which resulted in decreased fruit quality, and inhibited ethylene synthesis pathway. Through yeast two-hybrid (Y2H) screening and subsequent validation assays, we identified an interaction between SlMsrB5 and a member of the GRAS transcription factor family, namely SlGRAS4. Furthermore, oxidative treatment with 1 mmol L hydrogen peroxide was shown to damage the protein structure of SlGRAS4 and its capacity to bind DNA, as demonstrated by protein migration tests and gel shift assays. However, the interaction between SlMsrB5 and SlGRAS4 partially restored the structure of SlGRAS4 and its ability to bind to DNA. SlGRAS4 is recognized to play a critical role in the ethylene biosynthesis regulation and stress responses in tomato fruit. Thus, current findings demonstrate the participation of SlMsrB5 in modulating postharvest tomato fruit ripening and quality by regulating the oxidation-reduction status of SlGRAS4. These findings shed light on the function and potential mechanisms of SlMsrB5 in the MeJA-mediated regulation of postharvest tomato fruit ripening and quality, contributing to our understanding of the underlying mechanisms that govern impact of MeJA on postharvest fruit quality.

中文翻译：

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SlMsrB5-SlGRAS4 参与茉莉酸甲酯介导的番茄采后果实成熟和品质

蛋氨酸 (Met) 亚砜还原酶 (Msr) 是一种蛋白质，可将园艺作物中游离或蛋白质结合的蛋氨酸亚砜 (MetSO) 转化为蛋氨酸，从而促进蛋白质修复。在我们之前的研究中，我们发现了一个响应茉莉酸甲酯 (MeJA) 治疗而显着上调的基因。许多研究表明，MeJA不仅能诱导乙烯产生、促进成熟，还能改善园艺作物的采后品质。然而，SlMsrB5 在 MeJA 调控采后果实成熟和品质中的具体功能和机制仍不清楚。本研究分析了0.05 mmol·L MeJA处理后-s对采后番茄果实(L.cv Jiaxina)成熟和生理品质的影响，导致果实品质下降，并抑制乙烯合成途径。通过酵母双杂交 (Y2H) 筛选和随后的验证测定，我们确定了 SlMsrB5 与 GRAS 转录因子家族成员 SlGRAS4 之间的相互作用。此外，蛋白质迁移测试和凝胶迁移试验证明，1 mmol·L 过氧化氢的氧化处理会破坏 SlGRAS4 的蛋白质结构及其结合 DNA 的能力。然而，SlMsrB5 和 SlGRAS4 之间的相互作用部分恢复了 SlGRAS4 的结构及其与 DNA 结合的能力。 SlGRAS4 被认为在番茄果实的乙烯生物合成调节和应激反应中发挥着关键作用。因此，目前的研究结果表明，SlMsrB5 通过调节 SlGRAS4 的氧化还原状态参与调节采后番茄果实成熟和品质。这些发现揭示了 SlMsrB5 在 MeJA 介导的采后番茄果实成熟和品质调节中的功能和潜在机制，有助于我们了解 MeJA 对采后果实品质影响的潜在机制。