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

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 Ca ²⁺ signal that is essential to evoke an immune response. By confocal imaging and proteomic analysis of the rice PM, we found that the Ca ²⁺ 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 Ca ²⁺ 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 Ca ²⁺ signal-induced nanodomain assembly leading to protein reorganisation in the PM to prepare the plant for an imminent pathogen invasion.