SA-mediated suppression of the JA-responsive marker gene
PDF1.2 in Arabidopsis. a Northern-blot analysis of transcript levels
of the SA-responsive PR-1 gene and the JA-responsive PDF1.2 gene
in 5-week-old Arabidopsis Col-0 plants that were treated with
0.1 mM MeJA and 24 h later with either water (control) or 1 mM SA.
Leaves were harvested at the indicated time points. b PR-1 and
PDF1.2 transcript levels in 5-week-old Arabidopsis plants that were
first inoculated with the SA-inducing biotroph H. arabidopsidis and
72 h later with the JA-inducing necrotroph Alternaria brassicicola.
Leaves were harvested 24 h after Alternaria brassicicola inoculation.
c PR-1 and PDF1.2 transcript levels in 5-week-old Arabidopsis plants
24 h after treatment with 0.1 mM of MeJA, LA, OPDA, JA or JA-Ile,
and either water or 1 mM SA. Equal loading of RNA samples was
checked using a probe for 18S rRNA or by ethidium bromide staining
of the RNA gel