论文题目：Rosmarinic Acid Synthase 1 phosphorylation by SmMAPK3 is required for salicylic acid-induced salvianolic acid accumulation in Salvia miltiorrhiza hairy roots
论文作者: Xuecui Yin, Shuang Liu, Yuhang Zhang, Wenjing Yang, Junwen Bu, Bin Zhang, Juane Dong
论文摘要：
Salvianolic acid is the main active component of Salvia miltiorrhiza and holds significant value in the clinical treatment of myocardial ischemia and hypoxia. Previous studies have shown that salicylic acid (SA) can significantly promote the accumulation of salvianolic acid, but its molecular mechanism remains incompletely understood. To reveal the molecular mechanism by which SA regulates salvianolic acid, this study treated transgenic hairy roots overexpressing mitogen-activated protein kinase 3 (SmMAPK3) with SA and demonstrated that SmMAPK3 is essential for SA-induced salvianolic acid biosynthesis, with this function relying on the kinase activity of SmMAPK3. Through yeast two-hybrid screening, Rosmarinic Acid Synthase 1 (SmRAS1) was identified as a direct interacting protein of SmMAPK3. In vitro kinase assays showed that SmMAPK3 can catalyse phosphorylation of SmRAS1 at the Ser178 site, a process critical for salvianolic acid biosynthesis. Further studies confirmed that SA promotes the interaction between SmMAPK3 and SmRAS1, activates the kinase activity of SmMAPK3, and enhances the phosphorylation level and protein stability of SmRAS1. Additionally, SA treatment significantly promoted salvianolic acid accumulation in transgenic hairy roots coexpressing SmRAS1 and SmMAPK3. This study elucidates the mechanism by which the SA-SmMAPK3-SmRAS1 signalling module regulates salvianolic acid biosynthesis through post-translational modification, providing new theoretical targets for metabolic engineering and yield improvement of S. miltiorrhiza.
丹酚酸是丹参（Salvia miltiorrhiza）的主要活性成分，在心肌缺血和缺氧的临床治疗中具有重要价值。前期研究表明，水杨酸（SA）可显著促进丹酚酸的积累，但其分子机制尚未完全阐明。为揭示SA调控丹酚酸生物合成的分子机制，本研究以过表达丝裂原活化蛋白激酶3（SmMAPK3）的丹参转基因毛状根为材料进行SA处理，证实SmMAPK3是SA诱导丹酚酸生物合成的关键因子，且其功能依赖于激酶活性。通过酵母双杂交筛选，发现迷迭香酸合酶1（SmRAS1）是SmMAPK3的直接互作蛋白。体外激酶活性分析表明，SmMAPK3可催化SmRAS1的Ser178位点发生磷酸化，该过程对丹酚酸生物合成至关重要。进一步研究表明，SA能促进SmMAPK3与SmRAS1的互作、激活SmMAPK3的激酶活性，并增强SmRAS1的磷酸化水平和蛋白稳定性。共表达SmRAS1和SmMAPK3的转基因毛状根在SA处理下丹酚酸积累显著增加。本研究阐明了SA-SmMAPK3-SmRAS1信号模块通过翻译后修饰水平调控丹酚酸生物合成的机制，为丹参代谢工程提供了新的理论靶点，对推动中医药资源可持续利用和产业高质量发展具有重要指导意义和应用价值。
论文链接：https://doi.org/10.1111/pbi.70370