Background Ginsenoside, as the main active substance in ginseng, has the function of treating various diseases. However, the ginsenosides content of cultivated ginseng is obviously affected by the growth years, but the molecular mechanism is not clear. In addition, there are significant differences in morphology and physiology between wild ginseng and cultivated ginseng, and the effect of growth years on ginsenoside synthesis not yet understood in wild ginseng. Results Transcriptome sequencing on the roots, stems and leaves of cultivated ginseng and wild ginseng with different growth years was performed in this study, exploring the effect of growth years on gene expression in ginseng. The number of differentially expressed genes (DEGs) from comparison groups in cultivated ginseng was higher than that in wild ginseng. The result of weighted gene co-expression network analysis (WGCNA) showed that growth years significantly affected the gene expression of Mitogen-activated protein kinases (MAPK) signaling pathway and terpenoid backbone biosynthesis pathway in cultivated ginseng, but had no effects in wild ginseng. Furthermore, the growth years had significant effects on the genes related to ginsenoside synthesis in cultivated ginseng, and the effects were different in the roots, stems and leaves. However, it had little influence on the expression of genes related to ginsenoside synthesis in wild ginseng. Growth years might affect the expression of genes for ginsenoside synthesis by influencing the expression of these transcription factors (TFs), like my elob lastosis (MYB), NAM, ATAF1 and 2, and CUC2 (NAC), APETALA2/ethylene-responsive factor (AP2/ERF), basic helix-loop-helix (bHLH) and WRKY, etc., thereby affecting the content of ginsenosides. Conclusions This study complemented the gaps in the genetic information of wild ginseng in different growth periods and helped to clarify the potential mechanisms of the effect of growth years on the physiological state in wild ginseng and cultivated ginseng, which also provided a new insight into the mechanism of ginsenoside regulation.

Background Ginseng polysaccharides, have been used to treat various diseases as an important active ingredient. Nevertheless, the biosynthesis of ginseng polysaccharides is poorly understood. To elucidate the biosynthesis mechanism of ginseng polysaccharides, combined the transcriptome analysis and polysaccharides content determination were performed on the roots, stems, and leaves collected from four cultivars of ginseng. Results The results indicated that the total contents of nine monosaccharides were highest in the roots. Moreover, the total content of nine monosaccharides in the roots of the four cultivars were different but similar in stems and leaves. Glucose (Glc) was the most component of all monosaccharides. In total, 19 potential enzymes synthesizing of ginseng polysaccharides were identified, and 17 enzymes were significantly associated with polysaccharides content. Among these genes, the expression of phosphoglucomutase (PGM), glucose-6-phosphate isomerase (GPI), UTP–glucose-1-phosphate uridylyltransferase (UGP2), fructokinase (scrK), mannose-1-phosphate guanylyltransferase (GMPP), phosphomannomutase (PMM), UDP-glucose 4-epimerase (GALE), beta-fructofuranosidase (sacA), and sucrose synthase (SUS) were correlated with that of MYB, AP2/ERF, bZIP, and NAC transcription factors (TFs). These TFs may regulate the expression of genes involved in ginseng polysaccharides synthesis. Conclusion Our findings could provide insight into a better understanding of the regulatory mechanism of polysaccharides biosynthesis, and would drive progress in genetic improvement and plantation development of ginseng.

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.

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Background: As a famous Chinese medicine, ginseng has been used in the world for nearly 5,000 years. Wild ginseng is endangered due to environmental damage. Thus, cultivated ginseng is developed to replace wild ginseng. The morphological and physiological characteristics of both wild ginseng and cultivated ginseng change during growth, and the mechanism of this change is not yet understood. Results: This study performed transcriptome sequencing on the roots, stems and leaves of cultivated ginseng and wild ginseng with different growth years, exploring the effect of growth years on gene expression in ginseng. The number of DEGs in cultivated ginseng is more than that in wild ginseng. Based on the weighted gene co-expression network analysis, we found that the growth years significantly affected the gene expression of MAPK signaling pathway - plant and terpenoid backbone biosynthesis pathway in cultivated ginseng, but had no effects in wild ginseng. Furthermore, the growth years had significant effects on the genes related to ginsenoside synthesis in cultivated ginseng, and the effects were different in the roots, stems and leaves. However, it had little influence on the expression of genes related to ginsenoside synthesis in wild ginseng and no effect on leaves. These results showed wild ginseng was less affected by growth years than cultivated ginseng. Furthermore, HMGR, SS, DXS, DS, IspF, AACT, CYP450 and UGTs were related with MYB, NAC, AP2/ERF, bHLH and WRKY transcription factors. Growth years may regulate genes for ginsenoside synthesis by influencing these transcription factors, thereby affecting the content of ginsenosides. Conclusions: This study complemented the gaps in the genetic information of wild ginseng in different growth periods and different tissues and provided a new insight into the mechanism of ginsenoside regulation.