Ca 2+ -driven nanodomain enrichment and plasma membrane proteome remodelling enable bacterial outer membrane vesicle perception in rice

Summary Xanthomonas oryzae pv. oryzae (Xoo) releases OMVs; however, the role of Xoo-OMVs in Xoo-rice interaction has not yet been studied. We investigated the early signalling events underlying Xoo-OMV perception by rice to gain insight into early plant-pathogen interactions. We observed that Xoo-OMVs are perceived by rice through a rapid and unique Ca2+ signal that is essential to evoke an immune response. By confocal imaging and proteomic analysis of the rice PM, we found that the Ca2+ signal is required for Xoo-OMV-induced nanodomain enrichment and for the aggregation of defence response-associated proteins in rice PM. The differential assembly of proteins in the PM helps the plant defend itself against Xoo. In the absence of the early Ca2+ signal, Xoo-OMVs are not perceived by the plant, resulting in a compromised immune response. Collectively, our study shows that Xoo-OMVs are recognised by rice via Ca2+ signal-induced nanodomain assembly leading to protein reorganisation in the PM to prepare the plant for an imminent pathogen invasion. Competing Interest Statement The authors have declared no competing interest. Footnotes Results updated with additional experimental data, including figures and tables, to further strengthen the hypothesis