Fig 7. Arabidopsis parp mutants are compromised in basal resistance.
(A) Bacterial population sizes of Pst within leaves. Pst DC3000 strains with or without avrRpt2 were syringe infiltrated into leaf mesophyll at 1×105 cfu/ml and bacterial populations were measured 3 d post-inoculation. Mean ± standard error of mean for one experiment shown. Experiments were performed three times with similar results; * indicates significant difference from Col-0 across the three experiments (ANOVA, Tukey pairwise comparisons, P < 0.05). (B) Flg22-induced callose deposition. Seedlings exposed to 1 μM flg22 for 24 h were fixed and stained with aniline blue to highlight callose deposition. Left panel: representative images of the four genotypes; right panel: data summary for all tested leaves (n = 24 per genotype). * indicates significant difference from Col-0 across the three experiments (ANOVA, Tukey pairwise comparisons, P < 0.05). (C) Seedling growth inhibition due to chronic flg22-induced defense activation. Ratio is weight of individual seedlings grown for 14 d in liquid MS media + 1 μM flg22, divided by mean of seedlings of same genotype grown without flg22 within same experiment (mean ± standard error of mean). * indicates significant difference from Col-0 across the three experiments (ANOVA, Tukey pairwise comparisons, P < 0.05). (D) Flg22-triggered oxidative burst. Reactive oxygen species from leaf discs of the indicated genotype were measured for 30 min after treatment with 1 μM flg22. RLU: relative luminescence units. (E) Pst-induced γ-H2AX accumulation. Arabidopsis plants of the indicated genotype were vacuum-infiltrated with the indicated Pst strain at 1×107 cfu/ml. The level of γ-H2AX in leaf samples from the indicated time points after inoculation was assessed by immunoblot using anti-γ-H2AX antibody. Equivalent loading of lanes was verified using Ponceau S stain. Upper and lower blots are from separate experiments. Similar results obtained in two separate experiments.