SGT1 interacts with the Prf resistance protein and is required for Prf accumulation and Prf-mediated defense signaling

► We find the co-chaperone SGT1 is required for the accumulation of Prf resistance protein. ► We determine the interaction of Prf and SGT1 in plant cells. ► We find SGT1 is required for the Prf-mediated resistance to Pseudomonas bacterium in tomato.