RAPID DIFFERENTIATION OF SOYBEAN MOSAIC-VIRUS ISOLATES BY ANTIGENIC SIGNATURE ANALYSIS

Antigenic differences among 14 soybean mosaic virus (SMV) isolates wer e shown by signature analysis employing a panel of nine well-character ized monoclonal antibodies. Sets of binding curves were generated by r eacting aliquots of serial dilutions of leaf extracts from soybean pla nts infected with each strain of SMV simultaneously with each antibody in the panel. An iterative alignment procedure allowed comparison of binding profiles from different assays in which the starting concentra tions of SMV antigen were unknown. Desiccation of infected soybean lea f tissue altered antigenic signatures by inducing changes in reactivit y of epitopes recognized by certain antibodies. The method was useful for the elucidation of subtle antigenic differences among SMV strains. The procedure requires a minimum amount of tissue processing, the ana lysis is rapid and sensitive, and it requires neither purification nor knowledge of concentration of virus in ground leaf tissue from infect ed plants.