Genome organization of Beet necrotic yellow vein virus and function of viral gene products. All RNAs are polyadenylated at the 3_ end and capped at the 5_ terminal. The boxes represent the open reading frames existing in the viral genome and colours indicate their corresponding functions. RdRp: RNA dependent RNA polymerase, TGB: triple gene block movement proteins, RT: read through protein. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of the article.)