VPg Northern-immunoblots as a means for detection of viral RNAs in protoplasts or plants infected with grapevine fanleaf nepovirus.

Anti-genome-linked viral protein (anti-VPg) antibodies were produced from a synthetic peptide corresponding to the integral VPg sequence of grapevine fanleaf nepovirus-F13. These antibodies allowed detection of viral VPg-linked proteins which occur during the processing of viral polyproteins and of viral RNAs in total RNA extracts from infected protoplasts or plants after Northern blotting. These highly specific antibodies recognised RNAs from two grapevine fanleaf virus strains but not from arabis mosaic virus.