VIEW ARTICLE

Electron Microscopy of Cucumber Mosaic Virus-Infected Tobacco Leaves Showing Mosaic Symptoms. Y. Honda, Plant Pathology Laboratory, Faculty of Agriculture, Nagoya University, Nagoya 464, Japan; C. Matsui, Plant Pathology Laboratory, Faculty of Agriculture, Nagoya University, Nagoya 464, Japan. Phytopathology 64:534-539. Accepted for publication 31 October 1973. DOI: 10.1094/Phyto-64-534.

Thin-sectioning, and a method which allowed easy detection of virus particles, were used to compare the intracellular virus distribution and fine structure of green and yellow tissues of cucumber mosaic virus-infected tobacco (Nicotiana tabacum 'Bright Yellow') leaves showing clear mosaic symptoms. Intracellular profiles of green tissues were similar to those of healthy ones, and no abnormalities were found in them. About half the cells of these tissues contained a few virus particles which were distributed randomly throughout the cytoplasm, although they were difficult to differentiate from the ribosomes. The cells of yellow tissues, however, were smaller than those of green tissues, and the cell arrangement was disordered. Intracellular profiles were different from those of green tissues. Degeneration of grana and lamellae and the occurrence of myelin-like structures was prominent in the chloroplasts. The virus particles were numerous in the ground cytoplasm of most cells and they were less frequently aggregated. A considerable number of the nuclei contained virus particles in the nucleoplasm. No virus particles were found in the chloroplasts or mitochondria.