Transcription Factor SmMYB53 Drives Enhanced Tanshinone Synthesis in Salvia Miltiorrhiza

Salvia miltiorrhiza has long been used in traditional medicine, with tanshinones being its main active compounds. However, producing sufficient quantities of these compounds is challenging due to the plant's low yield and long growth cycle. The biosynthetic pathway of tanshinones is complex, and understanding its regulation has been a key focus for enhancing production. Despite the identification of various enzymes in the pathway, the transcription factors controlling these processes remain unclear. Based on these challenges, there is a pressing need for further research to uncover the transcriptional regulators that control tanshinone biosynthesis.

A recent study, published (DOI: 10.1093/hr/uhaf058) in Horticulture Research in February 2025, uncovers the pivotal role of the transcription factor SmMYB53 in regulating tanshinone biosynthesis in S. miltiorrhiza. The research, led by Zhejiang Chinese Medical University, identifies SmMYB53 as a key player in activating the expression of SmCYP71D375, a crucial gene in the tanshinone biosynthetic pathway. This study not only provides insights into the molecular mechanisms of tanshinone production but also lays the foundation for future genetic strategies to enhance medicinal substance synthesis in S. miltiorrhiza.

Through a series of genetic experiments, including yeast one-hybrid and dual-luciferase assays, the team identified SmMYB53 as a transcription factor that binds to the SmCYP71D375 promoter, thereby activating its expression. Overexpressing SmMYB53 in S. miltiorrhiza hairy roots led to a significant increase in tanshinone accumulation, confirming its role in enhancing the production of these valuable compounds. Conversely, silencing SmMYB53 through RNA interference resulted in reduced tanshinone levels, further supporting its regulatory function.

Additionally, the researchers discovered that SmMYB53 interacts with another transcription factor, SmbZIP51, which negatively regulates the activation of SmCYP71D375. This interaction suggests a complex regulatory network where SmMYB53 promotes tanshinone biosynthesis, while SmbZIP51 acts as a parallel regulator that dampens its effect. This finding highlights the intricate balance of transcriptional regulation involved in plant secondary metabolism and offers new opportunities for genetic manipulation aimed at boosting the medicinal content of S. miltiorrhiza.

This research is a significant step forward in understanding how transcription factors like SmMYB53 regulate the biosynthesis of valuable secondary metabolites in plants. The discovery of its interaction with SmbZIP51 provides a deeper understanding of the molecular mechanisms that govern tanshinone production, which could lead to more efficient ways of increasing the yield of these bioactive compounds for medicinal use."

Professor Guoyin Kai, co-author of the study, Zhejiang Chinese Medical University

The identification of SmMYB53 as a key regulator of tanshinone biosynthesis opens new avenues for enhancing the production of this important medicinal compound in S. miltiorrhiza. By leveraging genetic engineering techniques to overexpress SmMYB53 or inhibit the interaction with SmbZIP51, it may be possible to significantly increase tanshinone yields in S. miltiorrhiza plants. These findings not only benefit the production of tanshinones for pharmaceutical use but also contribute to the broader field of metabolic engineering in plants, offering a model for improving the production of other bioactive compounds.