Untargeted metabolomics based on ultra-high-performance liquid chromatography-high-resolution mass spectrometry merged with chemometrics: A new predictable tool for an early detection of mycotoxins

•Mycotoxins, Fusarium spp. and metabolic pathways were jointly investigated.•SLE-UHPLC-HRMS untargeted metabolomics revealed cross-talk plant pathogen.•Strong infection was associated with oxylipin and phosphatidic acid pathways.•Low infection showed up higher levels of alkylresorcinols and phosphatidic acid.

In order to explore the early detection of mycotoxins in wheat three standardized approaches (Fusarium disease severity, PCR assays for Fusarium spp. identification and mycotoxin quantification) and a novel untargeted metabolomics strategy were jointly assessed. In the first phase of this research, standardized approaches were able to quantify mycotoxins and identify Fusarium spp. Then, an UHPLC-QTOF metabolic fingerprinting method was developed to investigate plant-pathogen cross-talk. At the same time, chemometrics analysis demonstrated to be a powerful tool in order to distinguish low and strong infection levels. Combining these results, the cross-talk plant pathogen related to the early detection of mycotoxins was discovered. As a rapid response to fungal infection an overexpression of phosphatidic acids was discovered. By contrast, when the infection became stronger an increase of oxylipins and diacylglycerols was revealed.