Effects of Fusarium solani and F. oxysporum Infection on the Metabolism of Ginsenosides in American Ginseng Roots

Abstract

American ginseng (Panax quinquefolius L.) is a highly valuable herb widely used for medicinal treatments. Its pharmacologically important compounds are the ginsenosides, which are secondary metabolites in American ginseng root. The concentrations of ginsenoside in roots can be changed by fungal infection, but it is unclear what specific root tissues are impacted and whether the change is systemic. In this study, American ginseng roots were inoculated with two fungal pathogens (Fusarium solani or F. oxysporum) and the levels of six ginsenosides (Rb1, Rb2, Rc, Rd, Re, and Rg1) were then measured in the phloem and xylem around the discolored lesions and adjacent healthy areas of the root. Results indicated that the growth of Fusarium spp. was strictly limited to phloem, and correspondingly the ginsenoside concentration was only altered in this infected phloem. The concentration of Rg1, Rd, and Rc significantly changed in phloem tissues where F. solani was inoculated, while only Rg1 and Rd changed significantly after F. oxysporum inoculation. However, no changes of any ginsenoside occurred in either xylem or phloem tissue adjacent to the inoculation point. In addition, when two Fusarium spp. were grown on ginsenoside-amended Czapek medium, the majority of ginsenosides were depleted. Therefore, pathogenic Fusarium spp. may reduce ginsenoside levels by consuming them.

Microbial Community Changes in the Rhizosphere Soil of Healthy and Rusty Panax ginseng and Discovery of Pivotal Fungal Genera Associated with Rusty Roots

“…Interestingly, three of these five genera (Cylindrocarpon, Alternaria, and Fusarium) have been widely reported to be closely related to the occurrence of root diseases in medicinal plants of the genus Panax, such as P. ginseng, P. notoginseng, and P. quinquefolius. Root rot diseases of P. notoginseng and P. quinquefolius are due primarily to two species of Fusarium, F. solani, and F. oxysporum [62,63]; moreover, a soilborne pathogenic fungus of the genus Cylindrocarpon, C. destructans, can cause primary root rot or rusty root symptoms in ginseng (P. ginseng and P. notoginseng) [55,64]. A pathogenic species of the genus Alternaria, A. panax Whetz, causes Alternaria panax disease, one of the most commonly occurring and harmful diseases in ginseng (P. ginseng and P. quinquefolius) [13,56].…”

Comprehensive Genome Analysis on the Novel Species Sphingomonas panacis DCY99T Reveals Insights into Iron Tolerance of Ginseng

“…The compatibility of Fusarium solani with P. ginseng was assessed by investigating morphological alterations in fungal infection. F. solani is known to cause root rot or rusty root disease in ginseng [81]. No disease symptoms were observed in seedling with F. solani.…”

Association between dipsacus saponin VI level and diversity of endophytic fungi in roots of Dipsacus asperoides

“…D. asperoides in the wild has diminished as a result of exploitation (Zhang et al 1997; Chen et al 2014; Wang et al 2016), and the cultivated plant contains lower levels of dipsacus saponin VI than the plant in the wild. Therefore, rapid, efficient and environmentally sustainable methods are needed to obtain this and other saponins from D. asperoides (Cira et al 2008; Jiao et al 2015).…”

“…It may be possible to obtain saponins from the endophytic fungi that colonize D. asperoides (Jiao et al 2015). Such fungi colonize the flowers, seeds, taproots, stems and leaves of many plant species, without causing visible disease symptoms (Aly et al 2011).…”