Multi-omics study reveals a light-dependent regulatory network of flavonoid biosynthesis in lettuce (Lactuca sativa L.).

Although lettuce (Lactuca sativa L.) is known for its high flavonoid content, the regulatory mechanisms of flavonoid biosynthesis are yet to be fully investigated. A metabolic network profile was constructed based on metabolomic and transcriptomic datasets derived from five lettuce growth stages. From this analysis, we identified 201 metabolites and 15,775 co-expressed genes, which were subsequently organized into six distinct expression modules. A novel flavonoid biosynthesis regulatory network emerged, comprising the transcription factors LsBBX20, LsMYB114, and LsMYB114-like. Each of these three factors was found to individually regulate the expression of flavonoid biosynthesis genes. LsBBX20 further regulates the expression of LsMYB114 and LsMYB114-like in a light-dependent manner. The results of this study include not only a novel regulatory network of flavonoid biosynthesis but also a valuable dataset for the systematic investigation of metabolic regulation in lettuce.