Figure 2.
elf18-triggered defenses are compromised in the cys6 mutant. A) Three-wk-old WT, cys6, and efr mutants were preinoculated with 10 mM MgSO4 (CK) or 1 µM elf18 (elf18) for 1 d before infiltration with Pm ES4326 (OD600 nm = 0.001). Bacterial titer was determined at 3 dpi. Significant differences were detected by 2-way ANOVA. Data are shown as means ± Sd (n = 8). B) Twelve-d-old seedlings were treated with 1 µM elf18 for the indicated times, and samples were collected for immunoblots to detect the activation of MPK3 and MPK6 using a phospho-p44/42 MAPK antibody. The large subunit of Rubisco (RBCL) was stained with Ponceau S stain to serve as a loading control. C) and D) Leaf discs from 3-wk-old plants were immersed in elicitation solution containing 1 µM elf18, and ROS production was measured using a luminometer at the indicated time points C). ROS production at 6 min after elf18 treatment; a significant difference was detected by Student’s t test D). Data are shown as means ± Sem (n = 8). RLU, relative light units. E) Expression levels of PTI marker genes in 12-d-old WT and cys6 at the indicated time points after 1 µM elf18 treatment. Significant differences were detected by Student’s t test. Data are shown as means ± Sd (n = 3). **P < 0.01; ***P < 0.001; ns, no significant difference.