Glycyrrhiza inflata Batalin is a medicinal licorice species that has been widely used by humans for centuries. Licochalcone A (LCA) is a characteristic flavonoid that accumulates in G. inflata roots with high economical value. However, the biosynthetic pathway and regulatory network of its accumulation remain largely unknown. Here we found that a histone deacetylase (HDAC) inhibitor nicotinamide (NIC) could enhance the accumulation of LCA and total flavonoids in G. inflata seedlings. GiSRT2, a NIC-targeted HDAC was functionally analyzed and its RNAi transgenic hairy roots accumulated much more LCA and total flavonoids than its OE lines and the controls, indicating a negative regulatory role of GiSRT2 in the accumulation of LCA and total flavonoids. Co-analysis of transcriptome and metabolome of RNAi-GiSRT2 lines revealed potential mechanisms in this process. An O-methyltransferase gene, GiLMT1 was up-regulated in RNAi-GiSRT2 lines and the encoded enzyme catalyzed an intermediate step in LCA biosynthesis pathway. Transgenic hairy roots of GiLMT1 proved that GiLMT1 is required for LCA accumulation. Together, this work highlights the critical role of GiSRT2 in the regulation of flavonoid biosynthesis and identifies GiLMT1 as a candidate gene for the biosynthesis of LCA with synthetic biology approaches.

Flammulina velutipes is a renowned edible and medicinal fungus. Commercially cultivated F. velutipes occurs in two distinct phenotypes: white and yellow. However, the underlying mechanism contributing to the yellow phenotype and high nutritional value remain uncertain. We reconfirmed that the browning process in F. velutipes is attributable to melanin accumulation, although the initial yellow cap seemed unrelated to melanin. A transcriptomic and metabolomic joint analysis revealed that 477 chemical compounds categorized into 11 classes, among which 191 exhibited significantly different levels of accumulation between different phenotypes. Specifically, 12 compounds were unique to the yellow F. velutipes, including ferulic acid, and 3-Aminosalicylic acid. Free fatty acids and xanthine were identified as the primary compounds correlating with the yellow and oily cap. A total of 44,087 genes were identified, which were more homologous to Pleurotus ostreatus PC15. Structural genes such as PAL (phenylalanine ammonialyase), C4H (cinnamate 4-hydroxylase), C3H (Coumarin-3-hydroxylase), AoMT (caffeoyl coenzyme A-O-methyltransferase), and 4CL (4-coumarate: CoA ligase) were up-regulated, thereby activating the lignin biosynthesis and metabolism pathway. Additionally, FvbHLH1 can lead to the consumption of a huge amount of phenylalanine while generating flavonoids and organic acid compounds. Meanwhile, ferulic acid biosynthesis was activated. Therefore, this study clarifies the chemical and molecular bases for the yellow phenotype and nutritional value of F. velutipes.

Pleurotus citrinopileatus is a low-cholesterol, protein-rich, and high-nutrient food. The molecular mechanisms of the compounds and coloration have not been reported. Metabolome and transcriptome were used to clarify the molecular mechanisms of key compounds biosynthesis. K-means analysis identified 19 compounds in P. citrinopileatus, mainly lipids and alkaloids in class 8. In addition, 84 lipids were higher and that the different compounds were mainly enriched in linoleic acid metabolism. A total of 14 compounds detected in the linoleic acid metabolism pathway were significantly up-regulated, while 3 sterol regulatory element binding protein (SREBP) transcription factors were screened. Tryptophan metabolism and riboflavin biosynthesis pathway analysis indicated that 3 Unigenes had tryptophan decarboxylase similar elements, which belonged to tyrosine decarboxylase 1. Moreover, CL15618.Contig5_All had high homology with MFS. In conclusion, the expression of 3 SREBP, the synthesis of isobavachalcone D, and the regulation of riboflavin transport by MCH5 were the reasons for fatty acid accumulation and yellow cap formation in the P. citrinopileatus.

Knee osteoarthritis (KOA) remains a leading cause of global disability, yet no disease-modifying osteoarthritis drug (DMOAD) has been approved. This exploratory computational study aimed to elucidate the potential bioactive basis and mechanism of action of a clinically used licorice extract against KOA. UPLC-Q-TOF-MS/MS profiling identified 1,071 metabolites, among which prenylated chalcones—including glabrene, 4′-O-methylglabridin, butein and echinatin—were selected as candidate chemotypes for further investigation based on their known pharmacological activities and relative abundance. Network pharmacology revealed 309 overlapping targets between these constituents and KOA-related genes; topological analysis identified TNF, AKT1, GAPDH and HIF1A as highly connected nodes. Functional enrichment indicated that PI3K-Akt, MAPK and HIF-1α pathways are among the principal predicted intervention axes. Molecular docking showed favorable predicted binding energies (≤−8.4 kcal mol ^-1 ) of the key chalcones for the hub proteins, and 100-ns GROMACS simulations confirmed structurally stable binding sustained by persistent hydrogen bonds and low residue flexibility (RMSF <4 Å). Collectively, these computational findings suggest that licorice prenylated chalcones may exert multi-target, multi-pathway effects potentially relevant to suppressing inflammation, apoptosis and extracellular-matrix degradation in joint tissues. These findings provide a hypothesis-generating framework for developing prenyl-chalcone-based DMOADs and demonstrate the utility of integrating untargeted metabolomics with network pharmacology for botanical drug discovery hypothesis generation.