The specificity of the interactions between ARF5 and the three WRKYs was confirmed by co-expressing ARF3 (AT2G33860)-cYFP, which naturally lacks domain III and IV, and WRKY53-cYFP, expressed early after infection with A. tumefaciens strain C58 (3 hpi; S2 Table) [20,53]. Here, ARF3 is linked to infection.