Figure 6.

Δpmt4 Mutants Are Unable to Penetrate into the Plant.

Maize seedlings were infected with a mixture of compatible FB1 and FB2, FB1 Δgas1 and FB2 Δgas1, and FB1 Δpmt4 and FB2 Δpmt4 strains. Two days after infection, leaf samples were stained with Chlorazole Black E and analyzed by light microscopy. The z axis image projections show the site of penetration (marked with an asterisk) and the hyphae invading into plant cells (narrow point of the clamp-like cells). Δgas1 mutant (identified by stronger staining of the septum closest the hyphae tip) and wild-type strains, but not Δpmt4 mutants, penetrate into the plant. Distance from hyphal tip to the closest visible septum is indicated by double-headed arrows. Bar = 15 μm.