HPSE and infection: The aim of our work was to determine how RxL21 is manipulating Arabidopsis to promote infection by Hpa. We demonstrate that RxL21 interacts in planta with the Arabidopsis corepressors TPL and TPR1 via an EAR motif and that this interaction is essential for RxL21 virulence activity against both Hpa and a necrotrophic plant pathogen.