PR000936 (Project)

Description:Alternaria spp. occur as plant pathogens worldwide under field and storage conditions. They lead to food spoilage and also produce several classes of secondary metabolites that contaminate the food production chain. From a food safety perspective, the major challenge with assessing the risk of Alternaria contamination is the lack of a clear consensus on their species-level taxonomy. Furthermore, there are currently no reliable DNA sequencing methods to allow for differentiation of the toxigenic potential of these fungi. To address these issues, we performed metabolomic profiling using liquid chromatography high resolution mass spectrometry (LC-HRMS) on 131 Canadian strains of Alternaria to determine their chemotaxonomy. The Alternaria strains were analyzed using principal component analysis (PCA) and unbiased k-means clustering to identify metabolites with significant differences (P < 0.001) between groups. Four populations or ‘chemotypes’ were identified within the strains studied and several known secondary metabolites of Alternaria were identified as distinguishing metabolites.