Antigenic Analysis of the Coat Protein of Alfalfa mosaic virus and its Involvement in Aphid Transmission

Two strains -۴۲۵ and Y۸۷/۴۷- of Alfalfa mosaic virus (AMV) were propagated in and purified from Nicotiana tabacum cv. Samsun NN. Thirty-three AMV specific monoclonal antibodies (MAbs) from two fusions were raised against strain ۴۲۵. These antibodies were of isotypes IgG۱ and IgM. MAbs recognised three types of epitope. Group I did not react with the virus particle surface or viral coat protein of two strains in PTA-ELISA, but they reacted with a ۳۰-kDa structural coat protein of AMV by immunoblot analysis only and were able to recognise cryptotopes. Group II reacted with metatopes of both strains in PTA-ELISA. Group III reacted with a ۳۰-kDa structural coat protein of AMV by immunoblot analysis and in PTA-ELISA for the Y۸۷/۴۷ strain only. Immunoblocking experiments in which suspensions of purified AMV and MAb were offered between parafilm membranes for acquisition by Myzus persicae revealed that MAb-۲ was effective in blocking (inhibiting) transmission. This result suggests that the epitope which was localised by MAb-۲ plays a role in the aphid transmission of AMV.

Keywords:

ELISA , Immunoblot , Immunoblocking , monoclonal antibody , Transmission