Abstract:Protein p8 is encoded by the genome segment S8 of Rice black-streaked dwarf virus (RBSDV). Based on the sequence of S8 (AJ297431), a pair of S8-specific primers were designed and used to amplify a fragment encoding the N-part of p8 protein. The expected product was subcloned into the expression vector pET-32a+, transformed into E.coli BL21plysS and expressed at high level. Antiserum specifically against p8 protein was prepared using the purified protein to immunize mouse. Western blotting revealed that the p8 protein was abundant and easily detected in the infected plants and that the p8 protein was involved in the particles, indicating that p8 is a structural protein of RBSDV. ELISA tests showed that the antiserum against p8 protein could react strongly with the saps of infected rice, maize and wheat from different sources, indicating that the antiserum should be used to rapidly diagnose the RBSDV infection in fields.