Potyvirus is one of the largest genera of plant viruses responsible for serious diseases in vegetable and fruit crops worldwide. The potyviral species Turnip mosaic virus (TuMV) represents one of the rare examples of plant viruses that utilize the host endomembrane system to produce membranous vesicles mobile between cells. The 6K2 protein of TuMV, a small transmembrane protein, induces the formation of those endoplasmic reticulum (ER)-derived viral vesicles, important for replication and movement.In Arabidopsis thaliana, AtHVA22a (Hordeum vulgare abscisic acid responsive gene 22) belongs to a multigenic family of transmembrane proteins, homologous of reticulons and DP1/Yop1 family proteins, which are responsible for the constriction of ER tubules. Reticulons play a role in positive strand RNA virus replication in animals and plants. Moreover, semi-quantitative proteomics analysis of plasmodesmata (PD) fractions purified from A. thaliana suspension cells showed that AtHVA22c and AtHVA22a are highly enriched in PD proteome.In our study, we showed that TuMV-6K2 interacts with AtHVA22a by split-ubiquitin yeast two hybrid assay (SuY2H) in yeast and further confirmed this interaction in planta by Bimolecular Fluorescence Complementation (BiFC). Overexpression of AtHVA22a increases TuMV propagation in Nicotiana benthamiana. Furthermore, AtHVA22a is partially re-localized at the level of the viral replication complex (VRC) during TuMV infection and the 6K2-induced vesicles at the PD. The interaction between AtHAV22a and 6K2 observed in BiFC is also localized at the VRC during viral infection.Altogether, our results indicate that HVA22a is a candidate protein potentially involved in replication and cell to cell movement of TuMV.< Réduire