Abstract
Background: Protein phosphorylation is a pivotal post-translational modification that regulates diverse biological processes, including signal transduction, growth and development, stress response, and metabolic regulation. Although it is known that the PeVYV P4 protein can co-attract vector and non-vector insects by fine-tuning the volatilization (VOL) of host metabolites, thereby facilitating viral infection and transmission [1], the functional consequences of P4-induced phosphorylation of these host proteins and their potential role in modulating host-PeVYV interaction remain unexplored. In this study, we present the first comprehensive phosphoproteomic analysis of Nicotiana tabacum induced by PeVYV P4 protein, revealing key phosphorylation events that may underlie P4-mediated viral pathogenesis. Results: Comparative phosphoproteomic analysis between PeVYV P4-overexpressing transgenic and wild-type lines identified 1,412 phosphorylated proteins and 3,954 phosphopeptides, with 225 showing significant phosphorylation level differences. Gene ontology (GO) analysis revealed that the differentially phosphorylated proteins were primarily enriched in oxidative phosphorylation, photosynthesis, and metabolic pathways. Notably, we identified phosphorylation at serine 360 (Ser360) of S-acyltransferase (SATF) as a critical determinant for PeVYV infection. Furthermore, we demonstrated that PeVYV infection suppresses the MAPK signaling pathway to promote viral proliferation, suggesting a global interplay between PeVYV and host protein phosphorylation networks. Conclusion: Our findings demonstrate that PeVYV P4-mediated phosphorylation modifications in N. tabacum are crucial for viral infection. This discovery of viral manipulation of host phosphorylation networks provides novel insights into the molecular mechanisms underlying PeVYV pathogenesis, and potential targets for developing PeVYV-resistant cultivars through molecular breeding approaches. These results significantly advance our understanding of the evolutionary arms race between plants and PeVYV at the post-translational modification level.