Combining metabolomics and transcriptomics to reveal the effect of β-glucosidase on scopolin in Angelica dahurica var. formosana

Angelica dahurica var. formosana (ADF), a diversified variety that integrates medicine, food, and cosmetics, possessing abundant coumarin compounds. One of the pharmacologically active and aromatic components found in it is coumarins. However, the biosynthetic mechanism of coumarins in ADF is still unclear. We found that β-glucosidase plays an important role in the simple coumarin biosynthesis pathway and has also been confirmed to promote the release of potential aroma components in other plants. Therefore, we selected BGLU genes from ADF to investigate their biological functions. Here, we performed transcriptomic and untargeted metabolomic analyses to explore the metabolic characteristics of different tissues and their associated gene regulation. A total of 108 coumarins were identified from ADF untargeted metabolomic analysis using UPLC-MS/MS, with 87, 75, and 95 coumarins detected in roots, stems, and leaves, respectively Transcriptomic analysis identified 17 BGLU genes, 9 of which were positively correlated with the synthesis of coumarin and scopoletin. Based on the molecular docking results, AdBGLU1 and AdBGLU7 with the lowest binding energies were selected for functional validation. The results from heterologous expression demonstrated the enzyme's ability to facilitate theconversion of scopolin to scopoletin. Notably, AdBGLU7 exhibited a higher conversion rate, consistent with its elevated protein expression levels observed in Western blot analysis. This study provides a comprehensive metabolic and transcriptomic profile analysis, enhancing our understanding of coumarin biosynthesis in ADF.