Combined transcriptome and metabolome analysis highlights a central role of AmMYB30 in MeJA induced flavonoid accumulation in Astragalus membranaceus

Flavonoids are rich active components in plants, widely used in pharmaceuticals and nutritional supplements. Flavonoids are the important active healthcare components in Astragalus membranaceus. Methyl jasmonate (MeJA) is an important growth regulator that promotes the accumulation of flavonoids in a variety of plants. However, the molecular regulatory mechanism of the flavonoid synthesis in A. membranaceus after MeJA treatment is unclear. We conducted metabolomic and transcriptomic analyses of A. membranaceus subjected to MeJA treatment were conducted. A group of 118 differentially accumulated metabolites (DAMs) identified were primarily associated with the biosynthesis pathways of flavones. Flavonoid biosynthesis was one of the most enriched pathways in differentially expressed genes (DEGs). Multiple-omics analysis revealed an association between gene expression levels and the metabolic flux within the flavonoid pathway. Weighted gene co-expression network analysis (WGCNA) identified five co-expression modules and nineteen hub genes involved in flavonoid biosynthesis. AmMYB30 interacted with the promoters of AmCHS, AmFLS, and AmF3H, thereby regulating the flavonoid signaling pathway in A. membranaceus. Elevated expression of AmMYB30 in hairy roots resulted in heightened levels of AmCHS, AmFLS, and AmF3H expression, along with an increase in total flavonoid content, indicated AmMYB30 induced flavonoid accumulation after MeJA treatment. In summary, this study identified key regulators for flavonoid biosynthesis and offered valuable insights for understanding the regulation of flavonoid biosynthesis in A. membranaceus.