Subcellular localisation of cherry leaf roll virus coat protein and genomic RNAs in tobacco leaves

The in vivo subcellular location of the coat protein and RNAs of cherry leaf roll nepovirus (CLRV) was studied in infected tobacco plants by two different approaches and it was correlated with the cytopathic structures induced by the virus. Subcellular fractions were obtained by differential centrifugation, visualised by electron microscopy and analysed for their viral RNA and coat protein content by Northern blot and Western blot analysis, respectively. Results indicate that viral RNAs accumulated preferentially at the microsomal fraction. Immunocytochemical studies revealed a clear association of the coat protein of CLRV with the virus-induced cytopathological structures. In situ hybridisation studies confirmed the cytoplasmic location of the virus and allowed one to elucidate the distribution of the CLRV genomic RNAs in the different cell types of infected tissue.