Antigenic Analysis of the Coat Protein of Alfalfa Mosaic Virus and Its Involvement in Aphid Transmission.

Two strains -425 and y87/47- 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 425. these antibodies were of isotypes igg1 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 30-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 30-kda structural coat protein of amv by immunoblot analysis and in pta-elisa for the y87/47 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-2 was effective in blocking (inhibiting) transmission. this result suggests that the epitope which was localised by mab-2 plays a role in the aphid transmission of amv.