Figure 4

Infection structures of a trichothecene deficient Δ TRI5-GFP mutant of F. graminearum on wheat cv Nandu. A-C White light and fluorescence micrographs of an infected glume at 13 dpi done with MZFLIII microscope, scale bars = 200 μm. A White light image of infection cushions formed by the ΔTRI5-GFP mutant. B GFP fluorescence of the mycelium due to constitutive GFP expression. C Brownish necroses around infection cushions visible by white light microscopy after critical point drying. D-F Scanning electron micrographs show different infection structures of a ΔTRI5-GFP mutant on glume at 8 dpi. D Infection cushions, E lobate appressoria, F foot structures and infection hyphae, scale bars: D and E = 4 μm, F = 1 μm. Abbreviations: FS Foot structure, IC infection cushion, IH infection hypha, LA lobate appressorium, RH runner hypha.