Figure 1. Expression of MPK3, 4, 6 and 11 upon elicitation with PAMPs. (A, B) Arabidopsis thaliana Col-0 seedlings were grown in liquid MS medium in 24-well microtiter plates (10 seeds per well) as described.¹⁶ Seedlings were either mock-treated with an equivalent volume of medium (white bars) or elicited with 1 µM elf18 (A) and ch8 (B) (black bars). Samples were taken at the indicated time post elicitation. Total RNA isolation, cDNA synthesis and quantitative real-time PCR were performed as described.¹⁷ Expression levels are depicted as fold changes with respect to the basal expression level at time point zero. Statistical significance of expression compared with the basal levels are indicated (*p < 0.05, **p < 0.01, ***p < 0.001). The inserts in the first panels depict the MPK11 microarray signal intensities of corresponding experiments from microarray depositories (Array Express E-MEXP-547 for elf26 treatment and GEO GSM48125 for treatment with chitin prepared from crab-shells or N-acetylchitooctaose, ch8).