Localization of hyphal growth associated with mycotoxin production during the malting of Fusarium head blight infected grains

The objectives of this study were to image fungal hyphae within FHB infected small grains and their malts, and then to determine if there was any association between fungal localization and the amount of mycotoxin production observed during malting. Barley, wheat, rye, and triticale grains were all examined because of differences in flowering, and our previous observations on DON production during malting. CLSM examination combined with WGA-Alexa Fluor 488 fungal staining was adapted from the original method of Solanki et al. (2019). Modifications in the sample preparation were required to overcome challenges for application to grain and malt tissues. SEM was used as a supplementary technique to localize hyphae, in consideration of the fact that the extensive washing steps during pre-staining for CLSM might have removed some nonadherent hyphae from host tissues. Metagenomic analysis was utilized to identify the primary fungal microorganisms within these grains and malts.