Capsid protein of cucumber mosaic virus accumulates in the nuclei and at the periphery of the nucleoli in infected cells.

Tobacco leaves infected with two strains and their reciprocal RNA 3 pseudorecombinants of cucumber mosaic virus (CMV) were examined by immunoelectron microscopy. In addition to the regular detection of CMV in the cytoplasm and vacuoles, immunogold-labelled viral proteins occurred commonly in the nuclei and at the periphery of impacted nucleoli in all four samples examined. However, viral protein was present only in the euchromatin region and rare in the heterochromatin region.