Mass-Spectrometry-Based Approach for Visualizing Deoxynivalenol in Fusarium-Infected Wheat Grains

In this study, we used desorption electrospray ionization–mass spectrometry imaging (DESI-MSI) to delineate the distribution of deoxynivalenol (DON), which is a common mycotoxin produced by Fusarium, in wheat grains. Initially, we identified grains with high levels of DON contamination by splitting them into two parts and quantifying DON in one part using liquid chromatography–mass spectrometry. Subsequently, we visualized the distribution of DON in the other part of the grains using the optimized DESI-tandem MSI (MS/MSI). DON was primarily localized in the bran, endosperm side of the germ, and crease, whereas it was less prevalent in the endosperm. This distribution suggests that the cuticular layer or the plant's dynamic defense mechanisms─such as enzymatic glycation─may impede the invasion and expansion of Fusarium into the endosperm. This spatial information, coupled with the DESI-MS/MSI analysis, may facilitate the production of flour with lower DON contamination during the milling process.