Immunodetection of grapevine fanleaf virus satellite RNA-encoded protein in infected Chenopodium quinoa

An antiserum was raised against a fusion protein containing the C-terminal half of the protein (P3) encoded by the satellite RNA of grapevine fanleaf virus (GFLV; F13 isolate) and the N-terminal portion of the CI repressor of phage lambda. This antiserum specifically recognized P3 synthesized in the in vitro wheatgerm translation system and also in infected Chenopodium quinoa plants. In these plants, the amount of virus increased for 10 days, then remained constant for up to 21 days, whereas P3 was detected transiently, reaching its maximum on day 10.