Figure 5. The conserved domain is required for function of Pit2 and virulence of U. maydis.

(A) Disease rating of maize seedlings 12 days after infection with U. maydis. SG200: virulent U. maydis strain showing wild type disease symptoms. Δpit2: strain SG200Δpit2, a pit2 deletion mutant derived from strain SG200 [27]. Δpit2_pit2^mut49–53: Strain SG200Δpit2 complemented with pit2^mut49–53 (see Figure 4A, Table 1). Δpit2_pit2^Δ49–53: Strain SG200Δpit2 complemented with pit2^Δ49–53 (see Figure 4A, Table 1). Δpit2_pit2: Δpit2 mutant complemented with wild-type pit2 [27]. (B) Disease symptoms on maize leaves 12 days after infection with the U. maydis strains shown in (A). (C) Confocal images of intracellular U. maydis hyphae showing secretion of mCherry-tagged wild type Pit2 (lower panel) as well as the mutated Pit2 versions Pit2^Δ44–57 (upper panel) and Pit2^mut49–53 (middle panel). Red: mCherry fluorescence. Grey: UV-laser induced autofluorescence of maize cell walls. Bars: 10 µm.