Objective The total flavonoid content, antioxidant capacity and key differentially expressed proteins associated with flavonoid accumulation of the roots of different leaf-lobed types of Ficus hirta were studied.

Method Taking the roots of three-year-old five-lobed (FF), seven-lobed (SF), and nine-lobed (NF) Ficus hirta Vahl. as research subjects, proteomic technology was employed to compare and analyze the differential expression of flavonoid biosynthesis-related proteins among different leaf-lobed types.

Result The total flavonoid content and antioxidant capacity of the nine-lobed type were significantly higher than those of the five-lobed and seven-lobed types. KEGG enrichment analysis showed that differentially expressed proteins were significantly enriched in phenylpropanoid biosynthesis and flavonoid biosynthesis pathways. A total of 32 key enzymes closely related to flavonoid synthesis were identified, including phenylalanine ammonia-lyase (PAL), 4-coumarate-CoA ligase (4CL), chalcone synthase (CHS), chalcone isomerase (CHI), and caffeic acid O-methyltransferase (COMT), and most of these enzymes were upregulated in the nine-lobed type. Protein-protein interaction network analysis revealed extensive synergistic interactions among these enzymes, jointly regulating flavonoid biosynthesis.

Conclusion The differentially expressed proteins associated with flavonoid biosynthesis in different leaf-lobed types of Ficus hirta Vahl. were identified from the protein level. It revealed the molecular mechanism by which the nine-lobed type drives efficient flavonoid accumulation through synergistic up-regulation of key enzymes in the phenylpropanoid pathway and the flavonoid branch pathway. This provides a proteomic basis for its quality evaluation and elite germplasm of Ficus hirta.