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Ginseng (Panax ginseng C.A. Meyer) is the most famous edible Chinese herbal medicine. In the present study, soluble dietary fiber of ginseng (ginseng‐SDF, 8.98% content) was extracted from ginseng residue, and its physicochemical characterization, structure, and biological activities were studied. Ginseng‐SDF was an acidic heteropolysaccharide (uronic acid, 4.42% content) rich in protein, amino acids, and mineral elements. Glucose was its main monosaccharide composition (58.03%). Ginseng‐SDF had a porous microstructure, a typical cellulose I structure and a large number of hydroxyl functional groups. These chemical composition and structural characteristics gave ginseng‐SDF a good water solubility (98.56%), oil‐holding capacity (OHC) (3.01 g/g), and biological activities, as the antioxidant activity (13.35 μM TE/g, 105.17 μM TE/g, 54.20 μM TE/g for DPPH, ABTs, and FRAP assays, respectively), glucose diffusion retardation index (GDRI, 33.33%–7.43%), and α‐amylase/α‐glucosidase inhibitory activities (IC50, 6.70 mg/ml, and 4.89 mg/ml, respectively). The results suggested that ginseng residue is a valuable source of functional dietary fiber, and the ginseng‐SDF has a potential use in antioxidant and hypoglycemic foods. Practical applications: Ginseng has long been popular as a health food in Asia, North America, and Europe. Ginseng residue is rich in polysaccharides, dietary fiber, proteins, and other components, which is also of great research value. However, there are few studies focus on the soluble dietary fiber of ginseng at present. The research shows that ginseng residue is a valuable source of functional dietary fiber. The chemical components and structural characteristics give ginseng‐SDF a noteworthy antioxidant activity and enzyme inhibitory activity in vitro. These properties and biological activities indicate that ginseng‐SDF has application value in antioxidant and hypoglycemic foods. [ABSTRACT FROM AUTHOR]

BACKGROUND: Fresh ginseng was buried in three types of sand with different moisture contents and three types of soil and then stored at 2 °C to determine the effects of these storage substrates on fresh ginseng. RESULTS: At a storage time of 200 days, ginseng stored in underforest soil softened the most slowly and had a significantly greater firmness compared to the other samples (P < 0.05). The amount of most ginsenosides changed after storage for most of the substrates. Samples stored in ginseng soil and biological fertilizer had the highest concentration of total saponin and ginseng polysaccharides, respectively. Fresh ginseng stored in medium‐water content sand had a significantly lower polyphenol oxidase activity (P < 0.05). A significant difference was observed in the total concentration of nucleosides and nucleobases between the ginseng samples stored with and without substrates (P < 0.05). CONCLUSION: The data obtained in the present study suggest that the use of storage substrates is an optimal method for extending the shelf life of fresh ginseng without detrimental effects on its components. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Mountain-cultivated ginseng ( MCG) can be considered a mimic of wild ginseng, whose seeds are sowed artificially, cultivated in the natural environment, and returned to the wild state before being used clinically. Cultivated ginseng ( CG) and MCG are mainly used as the commercial material for clinical applications. However, MCG is much more expensive but effective than CG. The aim of this study is to explore the differences in the pharmacokinetics and brain concentration of Rg1, Re, Rb1, and Rd after oral administration of MCG, CG, and pure ginsenosides. An ultra-performance liquid chromatography-tandem mass spectrometry method was developed and validated to determine the concentration of the four ginsenosides in rat plasma and brain tissue. Compared with the pure group, the area under the curve ( AUC) of all the four ginsenosides for CG and MCG increased. The mean brain concentrations of the four ginsenosides were found to be 10- to 15-fold lower than the corresponding contents in the plasma, and the poor permeability of ginsenosides into blood-brain barrier was indicated by the low concentrations of the four ginsenosides. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ginseng-SDF was associated with the growth performance improvement in rats. • Ginseng-SDF affected the serum antioxidant status and immune factor levels. • Ginseng-SDF had positive effects on the SCFA levels and cecal microflora. • Some microfloras were correlated with physiological indexes such as SCFA levels. As an important component of ginseng, the in vivo benefits of ginseng water-soluble dietary fiber (ginseng-SDF) have not been fully revealed. To explore these benefits, healthy rats were given ginseng-SDF (200, 400, and 800 mg/kg body weight/day) by gavage for 15 days. The results showed that ginseng-SDF significantly improved the rats' growth performance and serum antioxidant status. Insulin-like growth factor (IGF-1 and IGF-2) and immunoglobulin (IgA, IgM, and IgG) levels in the ginseng-SDF groups were increased. High-dose ginseng-SDF significantly increased the cecal butyric acid proportion compared with the K group. Ginseng-SDF increased the abundance of Firmicutes and promoted the proliferation of probiotics such as Lactobacillus , and cellulose decomposers such as Ruminococcus and Clostridium in cecal microflora. These altered microflora were correlated with growth performance, antioxidant status and immunoglobulin indexes. The above results suggested that ginseng-SDF might have positive effects on growth, oxidative-immune levels and cecal health in rats. [ABSTRACT FROM AUTHOR]

Panax ginseng and Panax quinquefolius can survive for long periods of time in iron toxicity-stressed environments, which cause rusty roots and reduced productivity. To reveal the proteomic changes in these two Panax species in response to iron toxicity stress, plants of these two species were divided into a control group and an iron toxicity-stress group. An isobaric tags for relative and absolute quantitation (iTRAQ) proteomics approach was used to explore the changes in protein accumulation and the potential mechanisms underlying the response to iron toxicity stress in the two Panax species. Proteomic analyses revealed approximately 725 differentially expressed proteins (DEPs) in the iron toxicity-stress and control groups, including 233 and 492 proteins whose expression was upregulated and downregulated, respectively. The expression of DEPs related to photosynthesis was significantly downregulated, and DEPs whose expression was significantly upregulated were associated with redox reactions. Many upregulated DEPs were also involved in pathways such as those involving phenylpropanoid, flavonoid, isoflavone and ginsenoside synthesis. The abundance of some ginsenoside monomers (Rg 1 and Rb 3) also significantly increased in P. ginseng and P. quinquefolius. Moreover, P. quinquefolius contained 455 DEPs whose expression was higher than that in P. ginseng , including many proteins related to the regulation of ion homeostasis, indicating that P. quinquefolius is more resistant to iron toxicity stress than P. ginseng is. • Iron can promote the synthesis of ginsenosides and other secondary metabolites. • C4H, CAD and PAL etc. are related to the regulation of ion homeostasis. • Panax quinquefolius is more resistant to iron stress than P. ginseng. [ABSTRACT FROM AUTHOR]

Background: This study analyzed the effect of silicon (Si) application on the occurrence of ginseng black spot caused by Alternaria panax. We explored the differences in soil physical and chemical factors and microbial community structure following Si application as well as the key factors that affected the occurrence of ginseng black spot in soil. Potted Panax ginseng plants were used to assess the effect of Si treatment on ginseng black spot. Soil physical and chemical properties were comprehensively analyzed. Bacterial communities were analyzed using Illumina HiSeq sequencing targeting the 16S rRNA gene. Results: After inoculation with A. panax, the morbidity (and morbidity index) of ginseng with and without Si was 52% (46) and 83% (77), respectively. Soil physical and chemical analysis showed that under the ginseng black spot inoculation, bacterial communities were mainly affected by pH and available potassium, followed by ammonium nitrogen and available Si. NMDS and PLS-DA analyses and the heat maps of relative abundance revealed that Si application elevated the resistance of ginseng black spot as regulated by the abundance and diversity of bacterial flora in rhizosphere soils. Heatmap analysis at the genus level revealed that A. panax + Si inoculations significantly increased the soil community abundance of Sandaracinus, Polycyclovorans, Hirschia, Haliangium, Nitrospira, Saccharothrix, Aeromicrobium, Luteimonas, and Rubellimicrobium and led to a bacterial community structure with relative abundances that were significantly similar to that of untreated soil. Conclusions: Short-term Si application also significantly regulated the structural impact on soil microorganisms caused by ginseng black spot. Our findings indicated that Si applications may possibly be used in the prevention and treatment of ginseng black spot. [ABSTRACT FROM AUTHOR]

• Ascomycota and Basidiomycota are the dominant phyla in Panax ginseng -growing soil. • Changes induced by all treatments on soil fungal communities are evaluated. • Adding different leaf litter alters the composition of fungal community. • Basidiomycota were negatively affected by total nitrogen. • Some active biomarkers may be involved in the decomposition of different leaf litters. Soil fungi communities play a vital role in the plant-soil ecosystem and affect plant growth and health, but the underlying mechanism controlling soil fungi communities in understory wild ginseng soil is still unknown. To study that mechanism, a pot culture experiment adding different leaf litters based on a completely randomized design was carried out. The results indicated that 1990 operational taxonomic units were obtained from eighteen samples. Ascomycota and Basidiomycota, the two dominant phyla, accounted for 84.57% of the total valid reads at the phylum level. The observed species and Chao 1 index in treatment E were significantly lower than those in the other treatments, although no significant differences were found among the Shannon index of all treatments (p > 0.05). Different types of leaf litter significantly changed the fungal community composition; specifically, Ascomycota was higher in broad leaf litter treatments (A, C, D and E) than in the coniferous leaf litter treatment (B), but Basidiomycota showed the opposite trend, indicating that Ascomycota and Basidiomycota could be used to identify the species of coniferous and broad leaves. The active biomarker fungal (Bmf), 36 different phylotypes, were identified by a linear discriminant analysis effect size algorithm in all treatments, and some Bmf may participate in the decomposition of different tree litters. Additionally, the changes in fungal community diversity and composition were closely related to the changes in soil microbial biomass carbon, total nitrogen and available phosphorus in all treatment soils. Overall, our study indicated that leaf litter changed the soil fungal community structure, and some Bmf were directly involved in leaf litter decomposition. Bmf is more indicative and helpful for distinguishing leaf species. [ABSTRACT FROM AUTHOR]

Abstract Rusty root is a widespread problem in ginseng production, which can reduce ginseng quality and root price. The formation of rusty root is a complex process caused by multiple factors, primarily soil physicochemical factors and microorganisms. However, the precise roles played by these factors in the development of this disease remain unclear, especially the role of microorganisms. Deciphering the structure of the rhizosphere microbial communities will provide a more comprehensive and deeper understanding of rusty root disease. Rhizosphere microbial communities from five ginseng fields with different rusty root grades and indices were characterized by MiSeq sequencing. The pattern of beta diversity indicated that rusty root disease might be positively correlated with bacterial community structure, but not with fungal community structure. Rusty root may be caused by excessive Fe (II) oxidation and Fe (III) deposition accompanied by aluminum (Al) and manganese (Mn), in which nitrate-dependent Fe (II)-oxidizing bacteria, including Acidobacteria, Chloroflexi, and Nitrospirae, play a driving role. Moreover, the accumulation of iron (Fe), Al, and Mn could enhance growth and weak invasion of some fungi, thus exacerbating the rust symptoms. However, no correlation was found between the relative abundance of the genus Ilyonectria and rusty root grade or index (P > 0.05); suggesting that Ilyonectria species may not be essential for rusty root disease. Thus, the oxidation and deposition of rhizosphere Fe, Al, and Mn facilitated by nitrate-dependent Fe (II)-oxidizing bacteria might be key factors contributing to rusty root disease. Further studies on the inhibition of Fe, Al, and Mn transformation and accumulation, and application of iron/nitrogen-cycling related bacteria in ginseng soil might elucidate effective methods for preventing rusty root. Highlights • Rusty root could be a physiological disorder but not an infectious disease. • Rusty root may be caused by Fe (II) oxidation and deposition. • Nitrate-dependent Fe(II) oxidizing bacteria play a driving role in rusty root. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ascomycota and Basidiomycota had the same change trend in ginseng soils of all ages. • Soil harmful microbes predominate as culture time increased in ginseng. • Enhanced synergy of pathogenic bacteria with the extension of cultivation time. • Decreased amino acid synthesis and physiological metabolism in aged ginseng soils. • Soil pH was a driver of microbial community structure in cultivated ginseng soil. Changes in the microbial community are considered important factors affecting the yield and quality of ginseng cultivated in farmland, while the characteristics of the change in the microbial community of the soil before and after cultivation of ginseng in farmland are not well understood. Here, we aimed to fill this research gap by comparing the differences in soil nutrients and microbial communities between continuously cultivated ginseng soils for 1-, 2-, 3- and 5-year-old ginseng soils and corresponding uncultivated ginseng soils. The soil properties (pH, total soil organic carbon (TOC) content and total nitrogen (TN) content) of aged ginseng soil (3- and 5-year-old) were significantly reduced compared with those of the control soil after ginseng was cultivated in farmland. With the exception of 2-year-old ginseng, soil bacterial richness and diversity were higher in different ages of cultivated ginseng soils than in the control soil, while fungal diversity decreased in aged ginseng soil and increased in young ginseng soil (1- and 2-year-old). Ascomycota and Basidiomycota showed a consistent increasing/decreasing trend in cultivated ginseng soils of all ages compared to the control. In addition, ginseng cultivation resulted in a substantial decrease in the complexity of soil bacterial networks but a slight decrease in the complexity of fungal networks. The results from the linear discriminant size effect (LEfSe) analysis showed that beneficial microorganisms were biomarkers of the young ginseng soil, including Nitrosospira , Cephalotrichum and Humicola , while harmful microorganisms were biomarkers of aged ginseng, such as Plectosphaerella , Cladosporium and Alternaria. PICRUSt2 analysis revealed that the increase in the incidence of ginseng disease with continuous cultivation time may be related to the decreases in amino acid synthesis and physiological metabolism and the increase in fungal saprophytes. Soil pH was the most common and best predictor of bacterial and fungal community structure, followed by TOC and ammonium nitrogen (NH 4 +-N) contents. Meanwhile, the decreased of soil pH, TOC and AK may be the driving factors for the growth of ginseng soil pathogens. Overall, this study revealed the changing ginseng rhizosphere soil microbial community at different continuous cultivation times, provided a theoretical basis for ginseng cultivation, and promoted the development of medicinal plants such as ginseng. [ABSTRACT FROM AUTHOR]

Potassium fulvic acid (BSFA) and potassium humate (KHM), as organic fertilizers, can improve soil structure, increase soil nutrient levels and prevent plant diseases. However, knowledge is limited regarding how BSFA and KHM influence soil microbial communities and the interrelationships between community members associated with Panax ginseng. Soil pH and nutrient content increased significantly as a result of the addition of BSFA and KHM. The pH, NH 4 +-N, NO 3 −-N, AP and AK increased by 1.72 %–5.55 %, 70.09 %–108.39 %, 35.38 %–216.20 %, 1.21 %–14.19 % and 3.40 %–5.94 %, respectively, in the BSFA and KHM treatments. The soil nutrient increase may be related to Micrococcaceae and arbuscular mycorrhizal fungi (AMF). The structure of the microbial community also changed radically from that of the control group, and Chloroflexi (2.69 %–3.15 %), Actinobacteria (4.33 %–7.53 %) and Acidobacteria (9.44 %–11.62 %) were the dominant microorganisms at the phylum level in bacteria. In contrast, the dominant fungi at the phylum level were Ascomycota (77.39 %–78.08 %), Glomeromycota (0.36 %–2.68), Olpidiomycota (0.02 %–3.78 %) and Basidiomycota (0.80 %–1.17 %). Fusarium oxysporum and Ascomycota were biomarkers for BSFA and KHM, which may be related to pathogenic bacteria. Network analysis revealed that the association among members of the soil microbial community was more positive than negative following application of KHM, and more positive (62.5 %) than negative (37.5 %) correlations were observed between bacteria, whereas the fungal community exhibited more positive (97.3 %) than negative (2.7 %) correlations. PICRUST predicted the microbial function of adding KHM and BSFA to the soil, and these pathways mainly belong to the degradation and metabolism of organic matter, saprophytic organisms and plant pathogens. In summary, our study demonstrated that the addition of BSFA and KHM increased the nutrients in the ginseng soil and reshaped the microbial function in soils, providing a theoretical foundation for soil improvement and biological control of ginseng diseases. However, due to the limitations of greenhouse cultivation, additional long-term experiments on farmland with different climate changes are recommended. [ABSTRACT FROM AUTHOR]