GpRpb-1 from Globodera pallida manipulates plant post-translational modification in host cells to promote nematode infection

In persistent nematode infections plant cell morphology and physiology are manipulated by the nematodes to establish sophisticated feeding structures. Modifications to plant cells are largely attributed to the activity of nematode secreted effectors. SPRYSECs are a remarkably expanded family of effectors identified initially in potato cyst nematodes. While SPRYSECs have been implicated in suppression of plant immunity, their intrinsic role in nematode virulence remains unexplored. GpRpb-1 is a ‘type’ SPRYSEC from Globodera pallida with virulent and avirulent variants present in field populations of the nematode. Y2H screening of a nematode-infected susceptible potato library yielded interacting candidates for a virulent GpRpb-1 that are involved in post-translational modification in the plant. We have independently confirmed that two ligases involved in post-translational modification can interact with virulent and avirulent variants of GpRbp-1 in yeast. A localization study also shows that the candidate interactors localize to the nucleus, which allows interaction with GpRpb-1. Furthermore, upon silencing of the corresponding ligase genes in A. thaliana, we observed significant differences in the amount of developing females present in the roots of nematode-infected plants. These candidate interactors of GpRbp-1 suggest that the intrinsic role of the effector is carried out through manipulation of the plant post-translational modification machinery. Our findings suggest that nematodes are able to use this family of effectors to control different aspects of the plant cell to establish a feeding site. Therefore, our results may provide further insight into the basis of virulence of nematodes in plants.