Latent Pathogenic Fungi in the Medicinal Plant Thunb. Are Modulated by Secondary Metabolites and Colonizing Microbiota Originating from Soil.

Latent pathogenic fungi (LPFs) affect plant growth, but some of them may stably colonize plants. LPFs were isolated from healthy rhizomes to reveal this mechanism and identified as , an unidentified fungal sp., and . Sterile seedlings were cultivated in sterile or non-sterile soils and inoculated with the LPFs, followed by the plants' analysis. The antifungal activity of rhizome crude extracts on LPF were determined. The effect of inoculation of sterile seedlings by LPFs on the concentrations of rhizome phenolics was evaluated. The rates of growth inhibition amongst LPFs were determined. The LPFs had a strong negative effect on in sterile soil; microbiota in non-sterile soil eliminated such influence. There was an interactive inhibition among LPFs; the secondary metabolites also regulated their colonization in rhizomes. LPFs changed the accumulation of phenolics in . The results provide that colonization of LPFs in rhizomes was regulated by the colonizing microbiota of , the secondary metabolites in the rhizomes, and the mutual inhibition and competition between the different latent pathogens.