Salicylic acid (SA)-mediated defenses in wild type (WT) Col-0 and the tir1 afb1 afb4 afb5 auxin receptor mutant. A, SA levels in WT Col-0 and tir1 afb1 afb4 afb5 mutant plants, 24 h after mock treatment (10 mM MgCl2) or inoculation with PtoDC3000. Values are expressed as a percent SA accumulation in WT Col-0 24 h after inoculation with PtoDC3000, and represent an average ± standard error of the mean (SEM) for data compiled from two independent experiments, with six biological replicates per plant genotype per treatment. Results were analyzed using analysis of variation, followed by a Tukey’s post hoc test, and different letters indicate significant difference between samples with P < 0.05. B, Expression of PATHOGENESIS RELATED 1 (PR1) 24 h after mock treatment (10 mM MgCl2) or inoculation with PtoDC3000. Expression data were normalized using PP2AA3 and UBQ10 to give the relative gene expression. Values are an average ± SEM for data compiled from two independent experiments with six biological replicates in total.