Figure 1.

Quantification and Visualization of H. arabidopsidis Growth on the dmr1 Mutants (BC₂).

The dmr1 mutants confer nearly complete resistance to the downy mildew pathogen H. arabidopsidis.

(A) Conidiophore formation 5 d after inoculation on 10-d-old Arabidopsis seedlings. The average number (with standard deviation, n = 40) of conidiophores/seedling is displayed.

(B) Macroscopy images of conidiophores on Arabidopsis seedlings 8 d after inoculation with H. arabidopsidis.

(C) Microscopy examination of trypan blue–stained hyphae and haustoria in leaves of Arabidopsis seedlings 5 d after inoculation with H. arabidopsidis. The arrest of H. arabidopsidis growth and appearance of papillae (indicated by the arrows) in the dmr1 mutants was observed in multiple independent experiments.