Korean ginseng (Panax ginseng C.A. Meyer) has been widely used for medicinal purposes and contains potent plant secondary metabolites, including ginsenosides. To obtain transcriptomic data that offers a more comprehensive view of functional genomics in P. ginseng, we generated genome-wide transcriptome data from four different P. ginseng tissues using PacBio isoform sequencing (Iso-Seq) technology. A total of 135,317 assembled transcripts were generated with an average length of 3.2 kb and high assembly completeness. Of those unigenes, 67.5% were predicted to be complete full-length (FL) open reading frames (ORFs) and exhibited a high gene annotation rate. Furthermore, we successfully identified unique full-length genes involved in triterpenoid saponin synthesis and plant hormonal signaling pathways, including auxin and cytokinin. Studies on the functional genomics of P. ginseng seedlings have confirmed the rapid upregulation of negative feed-back loops by auxin and cytokinin signaling cues. The conserved evolutionary mechanisms in the auxin and cytokinin canonical signaling pathways of P. ginseng are more complex than those in Arabidopsis thaliana. Our analysis also revealed a more detailed view of transcriptome-wide alternative isoforms for 88 genes. Finally, transposable elements (TEs) were also identified, suggesting transcriptional activity of TEs in P. ginseng. In conclusion, our results suggest that long-read, full-length or partial-unigene data with high-quality assemblies are invaluable resources as transcriptomic references in P. ginseng and can be used for comparative analyses in closely related medicinal plants.

The present study examined the volatile profiles of Panax ginseng (Korean ginseng) and Panax quinquefolium (American ginseng) grown for different cultivation years by using HS-SPME/GC-MS and determined the key discriminant volatile compounds by chemometric analysis including principal component analysis (PCA), hierarchical cluster analysis (HCA), and partial least squares-discrimination analysis (PLS-DA). Fifty-six compounds, including forty terpenes, eight alcohols, one alkane, one ketone, and one furan, were identified in the ginseng roots. The chemometric results identified two major clusters of American ginseng and Korean ginseng cultivars with distinct volatile compositions. The volatile compounds in fresh white ginseng roots were affected by the species, but the influence of different cultivation ages was ambiguous. The major volatile components of ginseng roots are terpenes, including monoterpenes and sesquiterpenes. In particular, panaginsene, ginsinsene, α-isocomene, and caryophyllene were predominant in Korean ginseng cultivars, whereas β-farnesene levels were higher in American ginseng. The difference in volatile patterns between Panax ginseng and Panax quinquefolium could be attributed to the composition of sesquiterpenes such as β-panaginsene, ginsinsene, caryophyllene, and β-farnesene.

Panax ginseng C. A. Mey., a perennial herb belonging to the family Araliaceae, is a valuable medicinal plant with distinctive biological characteristics. However, comprehensive analyses of the mitochondrial genome (mitogenome) are lacking. In this study, we sequenced the complete mitogenome of ginseng based on long-read data from the Nanopore sequencing platform. The mitogenome was assembled into a “master circle” form of 464,705 bp and contained 72 unique genes. The genome had three large repeat regions, and 10.42% of the sequences were mitogenome sequences of plastid origin (MTPTs). In total, 278 variants (213 SNPs and 65 InDels) were discovered, most of which were identified in intergenic regions. The MTPT regions were mutational hotspots, harboring 74.5% of the variants. The ginseng mitogenome showed a higher mutation rate than that of the chloroplast genome, and this pattern is uncommon in plants. In addition, 10 Kompetitive allele-specific PCR (KASP) markers were developed from 10 SNPs, excluding those in MTPT regions. These markers accurately identified the genotypes of 59 Korean ginseng accessions and elucidated mitogenome diversity. These results provide insight into organellar genomes and genetic diversity in ginseng. Moreover, the complete mitogenome sequence and 10 KASP markers will be useful for ginseng research and breeding.

Panax ginseng Meyer is a valuable medicinal crop. However, the species’ propagation is limited by its long reproductive cycle and low seed yield. The present study focused on P. ginseng plant regeneration via somatic embryogenesis and evaluated the genetic stability of regenerated plantlets. We assessed the effects of carbon source type and concentration on somatic embryo induction, maturation, and germination. Somatic embryogenesis was optimal in Murashige and Skoog (MS) medium supplemented with 5% sucrose; however, maturation peaked in 1/2 MS containing low concentrations of sucrose ranging from 1 to 2%. Germination and plant regeneration were optimal in germination medium supplemented with 2% sucrose based on high germination rates, efficient plantlet production, and balanced growth characteristics. Molecular marker analysis suggested that the genetic fidelity of the regenerated plants was comparable with that of the control. High-performance liquid chromatography (HPLC) analysis showed that in vitro-grown roots (IGRs) accumulated more ginsenoside than those of the control, but the ginsenoside content of 2 year old IGRs was similar to that of the controls after acclimatization. Our study provides valuable insights into the optimization of genetically stable micropropagation and could promote the distribution of superior P. ginseng cultivars with high product yields and quality.

Panax ginseng Meyer is an important medicinal crop; however, most ginseng farmers cultivate native species that are not genetically fixed. Although several cultivars have been developed in Korea, distribution to farmers remains insufficient given their low propagation characteristics. This study compared the efficiency of seed production and micropropagation via somatic embryogenesis. Seeds were collected from cultivars, and zygotic embryo-derived explants were inoculated and cultured in a series of media for micropropagation. Seed production and characteristics of commercial cultivars were evaluated. The number of seeds from a 4-year-old individual cultivar was 23.1–58.8, and seed characteristics varied with cultivars. The genotype had a notable effect on somatic embryogenesis and plant regeneration. The number of somatic embryos and shoots obtained from a single seed of cultivars was 71.3–100.2 and 50.7–61.3, respectively. The number of in vitro grown roots (IGRs) per a single seed was 37.1–41.1 in one year. IGRs were successfully acclimatized and sprouted normally in the field. Flow cytometry analysis suggested that micropropagated plants had no ploidy variations. The results demonstrated the utility of somatic embryogenesis in the in vitro micropropagation of P. ginseng cultivars. Our findings can enhance the distribution of cultivars among farmers in the future.

Panax ginseng Meyer grows in east Russia and Asia. There is a high demand for this crop due to its medicinal properties. However, its low reproductive efficiency has been a hindrance to the crop’s widespread use. This study aims to establish an efficient regeneration and acclimatization system for the crop. The type of basal media and strength were evaluated for their effects on somatic embryogenesis, germination, and regeneration. The highest rate of somatic embryogenesis was achieved for the basal media MS, N6, and GD, with the optimal nitrogen content (≥35 mM) and NH₄⁺/NO₃⁻ ratio (1:2 or 1:4). The full-strength MS medium was the best one for somatic embryo induction. However, the diluted MS medium had a more positive effect on embryo maturation. Additionally, the basal media affected shooting, rooting, and plantlet formation. The germination medium containing 1/2 MS facilitated good shoot development; however, the medium with 1/2 SH yielded outstanding root development. In vitro-grown roots were successfully transferred to soil, and they exhibited a high survival rate (86.3%). Finally, the ISSR marker analysis demonstrated that the regenerated plants were not different from the control. The obtained results provide valuable information for a more efficient micropropagation of various P. ginseng cultivars.