Analysis of hypersensitive response (HR) cell death in Arabidopsis using seedling flood-inoculation assay. A. HR of Arabidopsis seedlings flood-inoculated with Pseudomonas syringae pv. tabaci wild-type (Psta), Psta flagellin-defective mutant (Psta ΔfliC) and Psta type III secretion defective mutant (Psta ΔhrcC) at a concentration of 5 × 107 CFU/ml. Photographs were taken at 1 dpi. B. Ion leakage from Arabidopsis seedlings flooded with water (mock) or Psta (WT) or Psta ΔfliC or Psta ΔhrcC at 1 dpi. Bars show the percentage of total ions.