The R-rich motif of Beet black scorch virus P7a movement protein is important for the nuclear localization, nucleolar targeting and viral infectivity

► The movement protein P7a of Beet black scorch virus can localize in the nuclear and nucleolar. ► The protein P7a interacts with importin α and nucleolar protein fibrillarin during its nuclear import. ► Mutations on the R-rich motif of the protein P7a influenced subcellular localization, viral replication and virus infection.