Background: Ginsenoside is a vital component of ginseng, which has value in many important medical areas. However, the metabolic kinetics and underlying regulatory networks that regulate ginsenoside synthesis remain largely unknown.
Results: In this study, ginsenoside-associated metabolism and transcriptome data from the roots, stems, and leaves of ginseng with different growth years (1-year-old, 3-year-old, 5-year-old, and 6-year-old) were used to explore the regulatory mechanism of ginsenoside synthesis. We found thatthe content of ginsenosides increased with growth years in root tissues and decreased in stems and leaves, and the content in leaves was always much higher than the contentin roots and stems. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated that differentially expressed genes (DEGs) in all groups were enriched primarily in the mitogen-activated protein kinase (MAPK) signaling pathway-plant, adenosine triphosphate (ATP)-binding cassette (ABC) transporters, and sesquiterpenoid and triterpenoid biosynthesis pathways. Moreover, some genes involved in ginsenoside synthesis were identified as differential alternative splicing genes (DASGs) in differentginseng growth years. In addition, weighted gene coexpression network analysis (WGCNA) was used to generate a coexpression network map that included a number of transcription factors (TFs) (such as WRKY, MYB, and ERF) and enzymes (such as UDP-glycosyltransferases (UGTs), hydroxymethylglutaryl-coenzyme A (CoA) reductase (HMGCR), and squalene epoxidase (SQE)) in the ginsenoside metabolism pathway.
Conclusions: These findings articulate the regulatory network of ginsenoside biosynthesis from the perspectives of the metabolome and transcriptome andlay a foundation for the improved control of gene expression related to ginsenoside synthesis and the content of ginsenosides in ginseng.