Pathogen-induced PR1 expression and SA accumulation. A. RNA blot analysis of PR1 expression in wild type (Col-0), F3 progeny of transgenic 35S:WRKY25 plants (line 12) and wrky25 mutants following inoculation with PsmES4326 (OD600 = 0.0001). Total RNA was isolated from inoculated leaves harvested at indicated times after inoculation and probed with a PR1 probe. Ethidium bromide-stained rRNA was used as a loading control. The experiment was repeated two additional times with similar results. B. Determination of free and SA glucoside (SAG) levels in wild type (Col-0), transgenic 35S:WRKY25 plants (line 12) and the wrky25 mutants after inoculation with PsmES4326 (OD600 = 0.0001). Inoculated leaves were harvested at indicated times for SA and SA glucoside (SAG) determination. The means and standard errors were calculated from 2–3 replicate samples. FW, fresh weight.