Infection of Turnip Protoplasts with Radish Mosaic Virus and Its RNA

Abstract

Conditions for infection of turnip protoplasts with radish mosaic virus (RaMV) and its RNA were investigated. Up to 90% of protoplasts were infected with RaMV in the absence of poly-L-ornithine (PLO) when protoplasts were inoculated with 10μg/ml RaMV in 50mM K-citrate-phosphate buffer, pH5.0. About 35% of protoplasts were infected with 0.5μg/ml RaMV RNA together with 1μg/ml PLO in 25mM phosphate buffer, pH5.8. Few protoplasts, however, were infected with RaMV RNA in the absence of PLO, and the efficiency of infection was greatly enhanced by the addition of PLO. RaMV antigen was detectable 16hr after inoculation and the percentage of fluorescing protoplasts continued to increase up to 36hr. The number of virus particles was estimated to be 1.5×10⁵ per infected protoplast at 48hr after inoculation.