English: Activation of PR-1a::GUS in Arabidopsis tga mutant lines. Leaf protoplasts were cotransfected with PR-1a::GUS constructs together with expression plasmids containing 35S::NtWRKY12 (W12), 35S::TGA2.2 (TGA2.2), a combination, or with empty expression vector, as indicated by the plus and minus signs in (A,B). Protoplasts in (C) were transfected with a 35S::GUS construct. Protoplasts were isolated from a TGA triple mutant (tga256), a TGA quadruple mutant (tga2356), or WT Col-0 (WT) as indicated below the panels. The bars represent the percentage of GUS activity from triplicate experiments relative to that of the protoplasts cotransfected with the corresponding promoter::GUS construct and empty vector control incubated overnight in W5 medium. Error bars represent the SEM.