MAPK3-MYB36-ARF1 module regulates the tanshinone formation in <i>Salvia miltiorrhiza</i>

<i>Salvia miltiorrhiza</i>, known as Danshen, is a traditional Chinese medicinal plant with significant cardiovascular benefits, attributed to its secondary metabolites, particularly tanshinones. Despite their medicinal value, tanshinones occur in low natural abundance, necessitating research to increase their content. This study explores the role of the ARF transcription factor (SmARF1) in tanshinone accumulation in Danshen. Overexpressing <i>SmARF1</i> in hairy roots significantly increased tanshinone levels. EMSA and Dual-LUC assays revealed that SmMYB36, a transcription factor interacting with SmMAPK3, binds to and regulates the <i>SmARF1</i> promoter. SmMYB36 alone inhibited the expression of <i>SmARF1</i> gene, while its interaction with SmMAPK3 enhanced <i>SmARF1</i> promoter activity. This MAPK3-MYB36-ARF1 module elucidates a complex regulatory mechanism for tanshinone biosynthesis, offering insights for targeted enhancement of tanshinone content through advanced biotechnological approaches.