Ultrastructural Changes in Differentiated Leaf Cells Infected with Cherry Leaf Roll Virus

Tubular structures containing virus-like particles were found by Walkey & Webb (1968) in squashes of meristems of Nicotiana rustica L. systemically infected with cherry leaf roll virus (CLRV), a nepovirus. These tubules occurred in the cytoplasm of undifferentiated meristematic cells of N. rustica, but were not found in differentiated leaf or stem cells (Walkey & Webb, 1970). We have examined differentiated leaf cells of Nicotiana clevelandii Gray infected with four strains of CLRV and here report that tubules occur often in the cell walls of these cells, but rarely in their cytoplasm. We also describe ultrastructural changes induced by CLRV that resemble those produced by bean pod mottle and cowpea mosaic viruses. N. clevelandii leaves systemically infected with CLRV were used.