Fig. 1. Rice suspension-cultured cells exhibit cell death upon treatment with recombinant PBZ1 protein. Degree of cell death-induced by the PBZ1 protein was determined by staining them with Evans blue for 24 h, followed by spectrophotometric quantification at A₅₉₅. (A) Morphology of cell death. Dark brown color serves as an indication of cell death. (B) Effect of increasing concentration of PBZ1 protein (1, 2.5, 5 and 10 μM) on cell death. BSA (100 μg/ml) represents appropriate control. (C) Effect of prolonged incubation (0, 6, 12, 18 and 24 h) of cultured cells with PBZ1 protein (100 μg/ml) on cell death. (D) Cell death blocking assay. Effect of increasing amount of PBZ1 antibody (0, 5, 10, 50 and 100 μl) on cell deathinduced by PBZ1 protein (100 μg/ml) was monitored. Each bar represents S.E. of three independent experiments.