The ERF-VII transcription factor SmERF73 coordinately regulates tanshinone biosynthesis in response to stress elicitors in Salvia miltiorrhiza.

Here, we investigated the role of SmERF73, a group VII ETHYLENE RESPONSE FACTOR stress response transcription factor, in the regulation of post-modification of the skeleton precursors of diterpene tanshinones in Salvia miltiorrhiza. Most genes found to be involved in tanshinone biosynthesis are located on chromosome 6, and five of which comprise a large gene cluster in S. miltiorrhiza. We found that SmERF73 overexpression in S. miltiorrhiza coordinately up-regulated transcription of seven tanshinone biosynthetic genes, four of which were located in the tanshinone gene cluster, consequently increasing tanshinone accumulation, while SmERF73 silencing reduced corresponding gene transcription and tanshinones accumulation. SmERF73 recognizes GCC-box promoter elements of four tanshinone-associated genes (DXR1, CPS1, KSL1, and CYP76AH3) and activate their expression. Moreover, SmERF73 and its targets were up-regulated by stress elicitors; SmERF73 appears to be at least partly mediated by JA signaling pathway via interaction with SmJAZ3. SmERF73 coordinately regulates tanshinone biosynthetic gene expression, suggesting a potential link between tanshinone production and plant stress response.