Fig. 2.

Ethylene signaling is required for flg22-induced responses. (A) Total ROS production triggered by 100 nM flg22 in Col-0, fin3, and ein2-5 mutants. Values are expressed as percentage of ROS obtained with Col-0 for 40 min and are mean ± SE (n = 20). (B) Callose deposition triggered in leaves 24 h after infiltration with water or 1 μM flg22 in Col-0, fin3, and ein2-5 plants. Results showing quantification of callose deposits (foci/mm⁻²) are mean ± SE (n = 4). For ein2-5, the same letter indicates statistically nonsignificant (one-way ANOVA; P > 0.05) differences between samples. (C) Activation profile of the MAP kinases MPK3 and MPK6 in response to treatment with water or 100 nM flg22 in Col-0, fin3, and ein2-5 mutants. Arrowheads indicate phosphorylated MPK6 and MPK3. Blots stained with colloidal Coomassie Blue (CCB) are presented to show equal loading. (D) Growth inhibition of Col-0, fin3, and ein2-5 seedlings treated with different concentrations of flg22 for 12 d. Values are mean ± SE (n = 12). (E) Growth of Pto DC3000 on Col-0, fls2, and ein2-5 plants pretreated with water or 1 μM flg22 for 24 h and then syringe-infiltrated with 10⁵ cfu/mL⁻¹ of bacteria. Bacterial growth was determined 2 d postinoculation. Values are mean ± SE (n = 8). Statistical significance by comparison with Col-0 was assessed using one-way ANOVA followed by Dunnett's test. *P < 0.05; **P < 0.01; ***P < 0.001. Similar results were observed in at least three independent experiments.