PRODUCTION OF FULL LENGTH COPIES OF THE GENOMIC RNAS OF PRUNUS NECROTIC RINGSPOT VIRUS

Co-infection of peach with Prunus necrotic ringspot virus (PNRSV) and Prune dwarf virus (PDV) results in the synergistic peach stunt disease. Studies of this interaction at the molecular level require the production and purification of quantities of the 3 genomic and 1 subgenomic RNAs of each virus. Standard viral purification procedures and procedures used to extract RNA frequently yield less than the needed amount of material thus making some areas of experimentation difficult to complete. As a preliminary to examining the roles of these 4 RNAs in the disease at the molecular level, we have inserted full-length cDNA copies of each RNA molecule of PNRSV, together with an upstream T7 promoter, into the plasmid pUC 19. Transcription of plasmids linearized with SmaI yields full length RNA copies of the 3 genomic and 1 subgenomic RNAs. Results of initial studies on the infectivity of these copies plus additional information concerning attempts to create infectious cDNA clones of the virus are presented.