Phytophthora effector exploits host susceptibility factor NRL1 (PNAS)

Some pathogen effectors disarm a plant’s immunity directly, for example through targeting resistance genes, whereas others work indirectly, through the plants own susceptibility (S) factors. He et al. provide an example of the latter. Previously, the authors showed that the Phytophthora infestans effector Pi02860 interacts with NRL1, a host S factor that is required for host susceptibility. NRL1 is a substrate adaptor component of a CULLIN3-associated ubiquitin E3 ligase. In this new work, they show that the presence of the effector enhances the interaction between NRL1 and SWAP70, a positive regulator of immunity, leading to SWAP70s degradation. As the authors observe, their research shows that “preventing the degradation of SWAP70 … provides a strategy to combat potato late blight.” (Summary by Mary Williams) Proc. Natl. Acad. Sci. USA 10.1073/pnas.1808585115