Rhizosphere analysis of field-grown Panax ginseng with different degrees of red skin provides the basis for preventing red skin syndrome.

BACKGROUND: Ginseng red skin root syndrome (GRS) is one of the most common ginseng (Panax ginseng Meyer) diseases. It leads to a severe decline in P. ginseng quality and seriously affects the P. ginseng industry in China. However, as a root disease, the characteristics of the GRS rhizosphere microbiome are still unclear. METHODS: The amplicon bacterial 16 S rRNA genes and fungal ITS (Internal Transcribed Spacer) regions Illumina sequencing technology, combined with microbial diversity and composition analysis based on R software, was used to explore the relationship between soil ecological environment and GRS. RESULTS: There were significant differences in the diversity and richness of soil microorganisms between the rhizosphere with different degrees of disease, especially between healthy P. ginseng (HG) and heavily diseased groups. The variation characteristics of microbial abundance in different taxa levels were analyzed. The interaction network of rhizosphere microorganisms of P. ginseng under GRS background was established. We also found that different P. ginseng rhizosphere microbial communities have multiple changes in stability and complexity through the established interaction network. Microbes closely related to potential pathogenic fungi were also identified according to the interaction network, which provided clues for looking for biological control agents. Finally, the Distance-based redundancy analysis (dbRDA) results indicated that total phosphorus (TP), available potassium (AK), available phosphorus (AP), catalase (CAT), invertase (INV) are the key factors that influence the microbial communities. Moreover, the content of these key factors in the rhizosphere was negatively correlated with disease degrees. CONCLUSIONS: In this study, we comprehensively analyzed the rhizosphere characteristics of P. ginseng with different levels of disease, and explored the interaction relationship among microorganisms. These results provide a basis for soil improvement and biological control of field-grown in the future.

Metabolome and transcriptome analysis reveals the molecular profiles underlying the ginseng response to rusty root symptoms.

BACKGROUND: Ginseng rusty root symptoms (GRS) is one of the primary diseases of ginseng. This disease leads to a severe decline in the quality of ginseng. It has been shown that the occurrence of GRS is associated with soil environmental degradation, which may involve changes in soil microbiology and physicochemical properties. RESULTS: In this study, GRS and healthy ginseng (HG) samples were used as experimental materials for comparative analysis of transcriptome and metabolome. Compared with those in HG samples, 949 metabolites and 9451 genes were significantly changed at the metabolic and transcriptional levels in diseased samples. The diseased tissues' metabolic patterns changed, and the accumulation of various organic acids, alkaloids, alcohols and phenols in diseased tissues increased significantly. There were significant differences in the expression of genes involved in plant hormone signal transduction, phenylpropanoid biosynthesis, the peroxidase pathway, and the plant-pathogen interaction pathway. CONCLUSION: The current study involved a comparative metabolome and transcriptome analysis of GRS and HG samples. Based on the findings at the transcriptional and metabolic levels, a mechanism model of the ginseng response to GRS was established. Our results provide new insights into ginseng's response to GRS, which will reveal the potential molecular mechanisms of this disease in ginseng.

Regulatory role of non-coding RNA in ginseng rusty root symptom tissue.

Ginseng rusty root symptom (GRS) is one of the primary diseases of ginseng. It leads to a severe decline in the quality of ginseng and significantly affects the ginseng industry. The regulatory mechanism of non-coding RNA (ncRNA) remains unclear in the course of disease. This study explored the long ncRNAs (lncRNAs), circular RNAs (circRNAs), and microRNAs (miRNAs) in GRS tissues and healthy ginseng (HG) tissues and performed functional enrichment analysis of the screened differentially expressed ncRNAs. Considering the predictive and regulatory effects of ncRNAs on mRNAs, we integrated ncRNA and mRNA data to analyze and construct relevant regulatory networks. A total of 17,645 lncRNAs, 245 circRNAs, and 299 miRNAs were obtained from HG and GRS samples, and the obtained ncRNAs were characterized, including the classification of lncRNAs, length and distribution of circRNA, and the length and family affiliations of miRNAs. In the analysis of differentially expressed ncRNA target genes, we found that lncRNAs may be involved in the homeostatic process of ginseng tissues and that lncRNAs, circRNAs, and miRNAs are involved in fatty acid-related regulation, suggesting that alterations in fatty acid-related pathways may play a key role in GRS. Besides, differentially expressed ncRNAs play an essential role in regulating transcriptional translation processes, primary metabolism such as starch and sucrose, and secondary metabolism such as alkaloids in ginseng tissues. Finally, we integrated the correlations between ncRNAs and mRNAs, constructed corresponding interaction networks, and identified ncRNAs that may play critical roles in GRS. These results provide a basis for revealing GRS's molecular mechanism and enrich our understanding of ncRNAs in ginseng.