Tanshinone and salvianolic acid biosynthesis are regulated by in hairy roots.

Bunge is an herb rich in bioactive tanshinone and salvianolic acid compounds. It is primarily used as an effective medicine for treating cardiovascular and cerebrovascular diseases. Liposoluble tanshinones and water-soluble phenolic acids are a series of terpenoids and phenolic compounds, respectively. However, the regulation mechanism for the simultaneous promotion of tanshinone and salvianolic acid biosynthesis remains unclear. This study identified a R2R3-MYB subgroup 20 transcription factor (TF), , which was predominantly expressed in lateral roots. The accumulation of major bioactive metabolites, tanshinones, and salvianolic acids, was improved in overexpression (OE) hairy root lines, but reduced in knockout (KO) lines. The qRT-PCR analysis revealed that the transcriptional expression levels of tanshinone and salvianolic acid biosynthesis genes were upregulated by and downregulated by . Dual-Luciferase (Dual-LUC) assays demonstrated that significantly activated the transcription of , , and . These results suggest that can promote tanshinone and salvianolic acid production. The present findings illustrate the exploitation of R2R3-MYB in terpenoid and phenolic biosynthesis, as well as provide a feasible strategy for improving tanshinone and salvianolic acid contents by MYB proteins in .