Figure 5.

SCFE1-Mediated Immune Responses Require BAK1.

(A) SCFE1-induced ethylene accumulation in bak1-3, bak1-4, and bak1-5 mutants. Leaves were treated with 0.25 µg/mL of the SCFE1-containing fraction or 500 nM flg22. Bars represent average values ± sd (n = 2). The experiment was repeated three times with similar results.

(B) Immunoblotting of activated MAPK with anti-phospho p44/p42 antibody in Arabidopsis seedling extracts. Seedlings were collected 0, 10, or 20 min after treatment with 1 µg/mL of the SCFE1-containing fraction (top panels) or 100 nM flg22 (bottom panels). Ponceau S staining served as a loading control. The identity of individual MAPKs as determined by size is indicated by arrowheads.

(C) Transcriptional profiling of the defense-related genes FRK1 and CYP71A13 by qRT-PCR. Arabidopsis seedlings were treated with 100 nM flg22 or 1 µg/mL of the SCFE1-containing fraction and collected 6 h after treatment. Gene expression was normalized to the levels of EF-1α transcript and is presented as fold induction compared with the respective control as described in Figure 1E. Error bars indicate sd (n = 3).