Effect of EBR treatment on heat induced-oxidative damage and hsp90 accumulation in WT and mutant seedlings. (A) Percent TBARS was measured for untreated (C) and EBR-treated (E) WT and mutant seedlings exposed to 43°C for 3 h and allowed to recover at 22°C for 2 days. Data shown are average of three replicates. Error bars represent SE of mean for three replicates. The differences between the (C) and (E) values for npr1-1 and cpr5-2 were not significant, but for all other genotypes the differences were significant to p < 0.02. (B) Total protein was isolated from WT (Ler) and aba1-1 seedlings grown in the absence (C) or presence (E) of EBR at 22°C and either maintained at 22°C or exposed to 43°C for 3 h and 4 h (HS). Samples were analyzed by Western blotting using an anti-hsp90 antibody. Coomassie blue staining of ribulose-1, 5-biphosphate carboxylase/oxygenease (rubisco) was used as loading control.