The PtrWRKY73 gene was previously reported to be induced by Methyl Jasmonate (MeJA), salicylic acid (SA) and canker (Dothiorella greariasacc Sacc.) in Populus trichocarpa., which enhanced the resistance of transgenic Arabidopsis to biotrophic pathogens, but increased its sensitivity to the necrotrophic pathogenic fungi by positively regulating SA pathways.