Figure 2.

Characterization of MEKK KO Lines.

(A) Toluidine blue staining of untreated and 48 h chitin-treated wild type, Δcerk1-1, and single KOs of two MEKK homologs (Δmekk1a and b) and their double KO (Δmekk1a/b). Bar = 5 mm.

(B) Quantitation of stainings in (A).

(C) MAP kinase phosphorylation in the same moss lines treated with 100 µg/mL chitin and assayed by immunoblotting with anti-phospho-p44/42 MPK antibody (α-pTEpY). Loading control is Ponceau staining of total protein.

(D) Quantitative RT-PCR of PAL4 and CHS transcript levels in the wild type and Δmekk1a-1, Δmekk1b-1, and Δmekk1a/b as fold change relative to the wild type untreated at times specified after 100 µg/mL chitin treatment. Data points represent an average of three independent experiments, each with three technical replicates. Error bars represent se of the means.