Metabolomic profiling of fungal pathogens responsible for root rot in American ginseng
Citation
Des Rochers, N., Walsh, J.P., Renaud, J.B., Seifert, K.A., Yeung, K.K.C., Sumarah, M.W. (2020). Metabolomic profiling of fungal pathogens responsible for root rot in American ginseng. Metabolites, [online] 10(1), http://dx.doi.org/10.3390/metabo10010035
Plain language summary
Ginseng production in Canada is a major source of agricultural income for farmers, with 95 % exported to Asia. Its production is under threat from fungal pathogens that cause the root to rot and lose its value in addition to preventing growth of ginseng in gardens where it was previously grown. In this study we compared the chemistry of the ginseng fungal pathogens and determined why some are able to infect the root while others are not. This information is critical for farmers to understand the problem and for the development of tools to manage it.
Abstract
Ginseng root is an economically valuable crop in Canada at high risk of yield loss caused by the pathogenic fungus Ilyonectria mors-panacis, formerly known as Cylindrocarpon destructans. While this pathogen has been well-characterized from morphological and genetic perspectives, little is known about the secondary metabolites it produces and their role in pathogenicity. We used an untargeted tandem liquid chromatography-mass spectrometry (LC-MS)-based approach paired with global natural products social molecular networking (GNPS) to compare the metabolite profiles of virulent and avirulent Ilyonectria strains. The ethyl acetate extracts of 22 I. mors-panacis strains and closely related species were analyzed by LC-MS/MS. Principal component analysis of LC-MS features resulted in two distinct groups, which corresponded to virulent and avirulent Ilyonectria strains. Virulent strains produced more types of compounds than the avirulent strains. The previously reported I. mors-panacis antifungal compound radicicol was present. Additionally, a number of related resorcyclic acid lactones (RALs) were putatively identified, namely pochonins and several additional derivatives of radicicol. Pochonins have not been previously reported in Ilyonectria spp. and have documented antimicrobial activity. This research contributes to our understanding of I. mors-panacis natural products and its pathogenic relationship with ginseng.