董娟娥/麻鹏达等《The Plant Journal》2024年

论文题目：The SmMYC2–SmMYB36 complex is involved in methyl jasmonate-mediated tanshinones biosynthesis in Salvia miltiorrhiza

论文作者：Ruizhi Cao(曹瑞致)†, Bingbing Lv(吕兵兵)†, Shuai Shao(邵帅)†, Ying Zhao(赵英), Mengdan Yang(杨梦丹), Anqi Zuo(左安琪), Jia Wei(魏嘉), Juane Dong (董娟娥)*, and Pengda Ma (麻鹏达)*

论文摘要：

The jasmonic acid (JA) signaling pathway plays an important role in promoting the biosynthesis of tanshinones. While individual transcription factors have been extensively studied in the context of tanshinones biosynthesis regulation, the influence of methyl jasmonate (MeJA)-induced transcriptional complexes remains unexplored. This study elucidates the positive regulatory role of the basic helix-loop-helix protein SmMYC2 in tanshinones biosynthesis in Salvia miltiorrhiza. SmMYC2 not only binds to SmGGPPS1 promoters, activating their transcription, but also interacts with SmMYB36. This interaction enhances the transcriptional activity of SmMYC2 on SmGGPPS1, thereby promoting tanshinones biosynthesis. Furthermore, we identified three JA signaling repressors, SmJAZ3, SmJAZ4, and SmJAZ8, which interact with SmMYC2. These repressors hindered the transcriptional activity of SmMYC2 on SmGGPPS1 and disrupted the interaction between SmMYC2 and SmMYB36. MeJA treatment triggered the degradation of SmJAZ3 and SmJAZ4, allowing the SmMYC2-SmMYB36 complex to subsequently activate the expression of SmGGPPS1, whereas SmJAZ8 inhibited MeJA-mediated degradation due to the absence of the LPIARR motif. These results demonstrate that the SmJAZ-SmMYC2-SmMYB36 module dynamically regulates the JA-mediated accumulation of tanshinones. Our results reveal a new regulatory network for the biosynthesis of tanshinones. This study provides valuable insight for future research on MeJA-mediated modulation of tanshinones biosynthesis.

研究表明，茉莉酸（Jasmonic acid, JA）信号通路在促进丹参酮的生物合成中起着重要作用。虽然单一转录因子调控丹参酮生物合成已被广泛研究，然而茉莉酸甲酯（MeJA）介导的转录复合体参与调控丹参酮的生物合成则未见报道。本研究首先阐明了碱性螺旋-环-螺旋蛋白SmMYC2在丹参酮生物合成中的正调控作用，并在此基础上发现SmMYC2能够结合SmGGPPS1的启动子并激活其表达。进一步研究发现，SmMYC2还能够与SmMYB36形成转录复合体，并通过增强靶基因SmGGPPS1的转录活性协同促进丹参酮的生物合成。此外，本研究还发现JA信号抑制因子SmJAZ3、SmJAZ4和SmJAZ8通过与SmMYC2的相互作用，阻碍了靶基因SmGGPPS1的转录活性以及SmMYC2-SmMYB36复合体的形成。外源MeJA处理在触发SmJAZ3和SmJAZ4降解的同时，释放了SmMYC2-SmMYB36复合体从而激活了靶基因SmGGPPS1的表达。而SmJAZ8由于缺乏LPIARR结构域抑制了MeJA介导的降解。综上所述，SmJAZ-SmMYC2-SmMYB36模块在动态调节JA介导的丹参酮生物合成中具有重要的作用。本研究发现了丹参酮生物合成新的调控网络，同时也为进一步研究MeJA介导的丹参酮生物合成机制提供了有价值的见解。

文章链接：https://onlinelibrary.wiley.com/doi/epdf/10.1111/tpj.16793