Some Observations on the Shape and Localization of Different Viruses in Experimentally Infected Plants, and on the Fine Structure of the Host Cells III: Turnip Yellow Mosaic Virus inBrassica ChinensisL.

Abstract

An electron microscopy study has been made on ultrathin sections of leaves from Brassica chinensis experimentally infected with TYMV showing the typical symptoms of the desease. The most prominent alterations have been found in the cells of the whitish leaf areas, where the chloroplasts, shorter and thicker than normal, appear deeply lobated. Portions of these chloroplasts often detach themselves from the chloroplasts and become free in the cytoplasm. The chloroplast membrane invaginates and forms a number of small vesicles all around the chloroplasts. The lamellar system is markedly reduced. A great number of virus-like particles is visible in the cytoplasm. These particles are similar in size and shape to the virus particles isolated from infected plants, and are thought to be TYMV particles.