麻鹏达、董娟娥等《Horticulture Research》2023年

论文题目：The SmNPR4-SmTGA5 module regulates SA-mediated phenolic acid biosynthesis in Salvia miltiorrhiza hairy roots

论文作者：Meiling Ding, Bin Zhang, Shuo Zhang, RongRong Hao, Yu Xia, Pengda Ma＊, Juane Dong1＊

论文摘要：

Phenolic acids are the main bioactive compounds in Salvia miltiorrhiza, which can be increased by salicylic acid (SA) elicitation. However, the specific molecular mechanism remains unclear. The nonexpresser of PR genes 1 (NPR1) and its family members are essential components of the SA signaling pathway. Here, we report an NPR protein, SmNPR4, showed strongly expression in hairy root after SA treatment, acting as a negative moderator of SA-induced phenolic acid biosynthesis in Salvia miltiorrhiza (S. miltiorrhiza). Moreover, a basic leucine zipper family transcription factor SmTGA5 was identified and was found to interact with SmNPR4. SmTGA5 activates the expression of phenolic acid biosynthesis gene SmTAT1 through binding to the as-1 element. Finally, a series of biochemical assays and dual gene overexpression analysis demonstrated that the SmNPR4 significantly inhibited the function of SmTGA5, and SA can alleviate the inhibitory effect of SmNPR4 on SmTGA5. Overall, our results reveal the molecular mechanism of salicylic acid regulating phenolic acid biosynthesis in S. miltiorrhiza and provides new insights for SA signaling to regulate secondary metabolic biosynthesis.

酚酸类化合物是丹参中主要的生物活性物质，水杨酸（SA）诱导可以提高酚酸类化合物的含量。然而，具体的分子机制尚不清楚。病程相关基因1（NPR1）及其家族成员是SA信号通路的重要组成部分。在此，我们报道了一种NPR蛋白SmNPR4，在SA处理后的毛状根中表现出强烈的表达，作为SA诱导的丹参（S. miltiorrhiza）酚酸生物合成的负调节因子。此外，还鉴定了一个基本亮氨酸拉链家族转录因子SmTGA5，并发现其与SmNPR4相互作用。SmTGA5通过与as-1元件结合，激活酚酸生物合成基因SmTAT1的表达。最后，一系列生化实验和双基因过表达分析表明，SmNPR4显著抑制SmTGA5的功能，SA可以减轻SmNPR4对SmTGA5的抑制作用。总之，我们的研究结果揭示了水杨酸调控丹参酚酸生物合成的分子机制，为SA信号调控次生代谢生物合成提供了新的思路。

论文链接：https://doi.org/10.1093/hr/uhad066