(A) Percent maximal phosphorylation of the MPK3/6 TEY motif in Col-0 and the adf4 mutant, +/− AvrPphB, followed by 1 µM flg22 treatment. (B) Percent maximal phosphorylation of the MPK3/6 TEY motif in Col-0 and the rps5-1 mutant, +/− AvrPphB, followed by 1 µM flg22 treatment. AvrPphB expression was induced at 48 h pre-treatment with 100 µM estradiol in Col-0, adf4 and rps5-1 mutant plants containing an estradiol-inducible AvrPphB transgene (pER8:AvrPphB). Statistical significance was determined using two-way ANOVA as compared to Col-0 untreated, with Bonferroni post test, where *p<0.05, **p<0.005, n = 3. (C) Western blot analysis of MPK3/6 TEY phosphorylation.