A tobacco powdery mildew was identified as Golovinomyces cichoracearum SICAU1.
Gc SICAU1 was a poorly-to-well adapted pathogen of Arabidopsis.
Post-invasion defense hinders the growth of Gc SICAU1 on Arabidopsis.
EDS1- and SA-signaling constitute the post-invasion defense against Gc SICAU1.