Spatholobus suberectus is a traditional edible, ornamental, and medicinal vine with an abundant flavonoid content in its dried stems. An integrated metabolomic and transcriptomic analysis was conducted on its vegetative organs to identify flavonoid biosynthesis pathways. The results showed that: (1) a total of 268 flavonoids could be identified among all the vegetative organs, and stems accumulated most of them; (2) a total of 449,569,220 clean reads were retained from all the vegetative organs (many genes related to key enzymes of flavonoid biosynthesis and transcription factors were found in all the compared groups between different organs; among them, 77 genes showed high correlations with key flavonoids in different pathways); and (3) PAL (encoding phenylalanine ammonia-lyase), 4CL (encoding 4-coumarate: CoA ligase), C4H (encoding cinnamate-4-hydroxylase), CHS (encoding chalcone synthase), DFR (encoding dihydroflavonol 4-reductase) and others showed positive correlations with L-phenylalanine and various flavonoids, while FLS (encoding flavonol synthase) showed negative correlations with many flavonols and flavonoids, as revealed through integrated analysis. This study reveals the flavonoid biosynthesis characteristics in S. suberectus and provides new insights into the utilization of its biological resources.
Ma et al. (Sat,) studied this question.