Tanshinone and salvianolic acid biosynthesis are regulated by SmMYB98 in Salvia miltiorrhiza hairy roots

• Published in: Journal of advanced research 2020-05, Vol.23, p.1-12
• Main Authors: Hao, Xiaolong, Pu, Zhongqiang, Cao, Gang, You, Dawei, Zhou, Yang, Deng, Changping, Shi, Min, Nile, Shivraj Hariram, Wang, Yao, Zhou, Wei, Kai, Guoyin
• Format: Article
• Language: English
• Subjects: Metabolic engineering; Plant secondary metabolism; R2R3-MYB transcription factor; Traditional Chinese Medicine; Transcriptional regulation
• ISSN: 2090-1232; 2090-1224
• DOI: 10.1016/j.jare.2020.01.012

[Display omitted] •SmMYB98 was predominantly expressed in the lateral roots of Salvia miltiorrhiza.•Tanshinones and salvianolic acids were improved in the SmMYB98-OE hairy roots.•Tanshinone and salvianolic acid contents in SmMYB98-KO lines were reduced.•SmMYB98 regulates the expression of tanshinones and salvianolic acids biosynthetic genes.•SmMYB98 negatively regulates the biosynthesis of gibberellins in S. miltiorrhiza. Salvia miltiorrhiza 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), SmMYB98, which was predominantly expressed in S. miltiorrhiza lateral roots. The accumulation of major bioactive metabolites, tanshinones, and salvianolic acids, was improved in SmMYB98 overexpression (OE) hairy root lines, but reduced in SmMYB98 knockout (KO) lines. The qRT-PCR analysis revealed that the transcriptional expression levels of tanshinone and salvianolic acid biosynthesis genes were upregulated by SmMYB98-OE and downregulated by SmMYB98-KO. Dual-Luciferase (Dual-LUC) assays demonstrated that SmMYB98 significantly activated the transcription of SmGGPPS1, SmPAL1, and SmRAS1. These results suggest that SmMYB98-OE 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 S. miltiorrhiza.