Fig. 3. Effects of A. brassicicola inoculation on the cellular defense responses in Arabidopsis wild type Col-0 , dnd1-1, and acd2-2. Arabidopsis was sprayed with a conidial suspension of A. brassicicola in 250 μg ml^-1 T ween 2 0 or Tween 20 (mock) only. (A) Microscopic observation and quantification of hydrogen peroxide and callose deposition were performed at 12 h post inoculation (hpi). Cell death was analyzed on leaves harvested at 16 hpi. The brown color indicates hydrogen peroxide production. The presence of green fluorescence indicates callose deposition. Cell death was determined by the presence (dead) or absence (live) of red luminescence. Asterisks indicate cell death, callose deposition, and hydrogen peroxide accumulation. Bars = 50 μm. (B) Effects of A. brassicicola inoculation on cell death examined by staining with Evans blue. (C) Effects of A. brassicicola inoculation on callose deposition. (D) Effects of A. brassicicola inoculation on hydrogen peroxide accumulation. Data presented in (B, D) were taken in experiments performed more than three times. Bars with different letters indicate that the corresponding data are significantly different (Duncan’s multiple range test; P < 0.05).