Ginseng (Panax ginseng C.A. Meyer) is a perennial herb belonging to the family Araliaceae and has been used for thousands of years in East Asia as an essential traditional medicine with a wide range of pharmacological activities of its main active ingredient, ginsenosides. The AP2/ERF gene family, widely present in plants, is a class of transcription factors capable of responding to ethylene regulation that has an influential role in regulating the synthesis of major active ingredients in medicinal plants and in response to biotic and abiotic stresses, which have not been reported in Panax ginseng. In this study, the AP2/ERF gene was localized on the ginseng chromosome, and an AP2/ERF gene duplication event was also discovered in Panax ginseng. The expression of seven ERF genes and three key enzyme genes related to saponin synthesis was measured by fluorescence quantitative PCR using ethylene treatment of ginseng hairy roots, and it was observed that ethylene promoted the expression of genes related to the synthesis of ginsenosides, among which the PgERF120 gene was the most sensitive to ethylene. We analyzed the sequence features and expression patterns of the PgERF120 gene and found that the expression of the PgERF120 gene was specific in time and space. The PgERF120 gene was subsequently cloned, and plant overexpression and RNA interference vectors were constructed. Ginseng adventitious roots were transformed using the Agrobacterium tumefaciens-mediated method to obtain transgenic ginseng hairy roots, and the gene expression, ginsenoside content and malondialdehyde content in overexpression-positive hairy roots were also analyzed. This study preliminarily verified that the PgERF120 gene can be involved in the regulation of ginsenoside synthesis, which provides a theoretical basis for the study of functional genes in ginseng and a genetic resource for the subsequent use of synthetic biology methods to improve the yield of ginsenosides.

Ginseng (Panax ginseng C. A. Mey.) is an important and valuable medicinal plant species used in traditional Chinese medicine, and its metabolite ginsenoside is the primary active ingredient. The FAR1/FHY3 gene family members play critical roles in plant growth and development as well as participate in a variety of physiological processes, including plant development and signaling of hormones. Studies have indicated that methyl jasmonate treatment of ginseng adventitious roots resulted in a significant increase in the content of protopanaxadiol ginsenosides. Therefore, it is highly significant to screen the FAR1/FHY3 gene family members in ginseng and preliminarily investigate their expression patterns in response to methyl jasmonic acid signaling. In this study, we screened and identified the FAR1/FHY3 family genes in the ginseng transcriptome databases. And then, we analyzed their gene structure and phylogeny, chromosomal localization and expression patterns, and promoter cis-acting elements, and made GO functional annotations on the members of this family. After that, we treated the ginseng adventitious roots with 200 mM methyl jasmonate and investigated the trend of the expression of four genes containing the largest number of methyl jasmonate cis-acting elements at different treatment times. All four genes were able to respond to methyl jasmonate, the most significant change was in the PgFAR40 gene. This study provides data support for subsequent studies of this family member in ginseng and provides experimental reference for subsequent validation of the function of this family member under methyl jasmonic acid signaling.

Ginseng (Panax ginseng C.A. Meyer) is a perennial herb of the Araliaceae family, a traditional and valuable Chinese herb in China. The main active component of ginseng is ginsenoside. The NAC transcription factors belong to a large family of plant-specific transcription factors, which are involved in growth and development, stress response and secondary metabolism. In this study, we mapped the NAC gene family on 24 pairs of ginseng chromosomes and found numerous gene replications in the genome. The NAC gene PgNAC41-2, found to be highly related to ginsenoside synthesis, was specifically screened. The phylogeny and expression pattern of the PgNAC41-2 gene were analyzed, along with the derived protein sequence, and a structure model was generated. Furthermore, the PgNAC41-2 gene was cloned and overexpressed by a Rhizobium rhizogenes mediated method, using ginseng petioles as receptor material. The saponin content of the transformed material was analyzed to verify the function of the NAC transcription factor in ginseng. Our results indicate that the PgNAC41-2 gene positively regulates the biosynthesis of saponins.

Ginseng, an important medicinal plant, is characterized by its main active component, ginsenosides. Among more than 40 ginsenosides, Rg1 is one of the ginsenosides used for measuring the quality of ginseng. Therefore, the identification and characterization of genes for Rg1 biosynthesis are important to elucidate the molecular basis of Rg1 biosynthesis. In this study, we utilized 39,327 SNPs and the corresponding Rg1 content from 344 core ginseng cultivars from Jilin Province. We conducted a genome-wide association study (GWAS) combining weighted gene co-expression network analysis (WGCNA), SNP-Rg1 content association analysis, and gene co-expression network analysis; three candidate Rg1 genes (PgRg1-1, PgRg1-2, and PgRg1-3) and one crucial candidate gene (PgRg1-3) were identified. Functional validation of PgRg1-3 was performed using methyl jasmonate (MeJA) regulation and RNAi, confirming that this gene regulates Rg1 biosynthesis. The spatial–temporal expression patterns of the PgRg1-3 gene and known key enzyme genes involved in ginsenoside biosynthesis differ. Furthermore, variations in their networks have a significant impact on Rg1 biosynthesis. This study established an accurate and efficient method for identifying candidate genes, cloned a novel gene controlling Rg1 biosynthesis, and identified 73 SNPs significantly associated with Rg1 content. This provides genetic resources and effective tools for further exploring the molecular mechanisms of Rg1 biosynthesis and molecular breeding.

Ginseng (Panax ginseng C. A. Meyer) is a perennial herb from the genus Panax in the family Araliaceae. It is famous in China and abroad. The biosynthesis of ginsenosides is controlled by structural genes and regulated by transcription factors. GRAS transcription factors are widely found in plants. They can be used as tools to modify plant metabolic pathways by interacting with promoters or regulatory elements of target genes to regulate the expression of target genes, thereby activating the synergistic interaction of multiple genes in metabolic pathways and effectively improving the accumulation of secondary metabolites. However, there are no reports on the involvement of the GRAS gene family in ginsenoside biosynthesis. In this study, the GRAS gene family was located on chromosome 24 pairs in ginseng. Tandem replication and fragment replication also played a key role in the expansion of the GRAS gene family. The PgGRAS68-01 gene closely related to ginsenoside biosynthesis was screened out, and the sequence and expression pattern of the gene were analyzed. The results showed that the expression of PgGRAS68-01 gene was spatio-temporal specific. The full-length sequence of PgGRAS68-01 gene was cloned, and the overexpression vector pBI121-PgGRAS68-01 was constructed. The ginseng seedlings were transformed by Agrobacterium rhifaciens-mediated method. The saponin content in the single root of positive hair root was detected, and the inhibitory role of PgGRAS68-01 in ginsenoside synthesis is reported.

WRKY transcription factors are some of the most important transcription factors in planta, and they are involved in biological and abiotic stresses, growth and development, and biochemical processes. The WRKY gene family has been found in many higher plants, while little is known about WRKY-encoding genes in ginseng. As a traditional and important economic medicinal herb and health food, ginseng has been a model species for other related medicinal plants. Here, we analyze the WRKY transcript factor gene family in ginseng from a genetics and genomics perspective in the hope that this study can create a new avenue for understanding the role of PgWRKYs. By identifying and analyzing all candidate WRKY transcription factor family members based on the transcriptome of ginseng, a total of 118 PgWRKY genes was obtained following gene classification, the phylogenetic relationship, conserved domain structure, functional differentiation, and an expression activity analysis. A phylogenetic analysis revealed that the PgWRKYs were clustered into three groups: I, II, and III transcription factors. Members in group Ⅱ were further divided into five sub-groups: Ⅱa to Ⅱe. An expression analysis showed a trend of co-expression among most PgWRKY genes, forming an interaction network. The coding sequences were WRKYGQK; only two genes were WRKYGKK, and only one gene was WSKYGQK. Moreover, a salt stress treatment analysis of the response of PgWRKY39-01, PgWRKY062, and PgWRKY064 genes was investigated using RT-qPCR. After salt stress treatment, the expression of three PgWRKY genes was increased, indicating that PgWRKYs can participate in regulating the response to salt stresses in ginseng. These comprehensive data provide a reference for elucidating the functions of this transcription factor family in the growth, development, and salt stress response of ginseng.