A LIGHT AND ELECTRON MICROSCOPE STUDY OF INTERLAMELLAR POLYGLUCOSIDE BODIES IN OSCILLATORIA CHALYBIA

Acid and basic buffer solutions were applied on slides under cover glasses to thin, hand sections of leaf tissue from normal tobacco plants and equivalent plants infected with tobacco mosaic virus (TMV). The effects on living cells were observed and photographed through phase optics. First, reversible changes and, later, irreversible changes were produced in the cells. Movement of the cytoplasm in a cell could be stopped completely and started again by replacing the unfavorable buffer solution with a favorable medium. Of the organelles, plastids became static first, then mitochondria, and lastly spherosomes. Spherosomes often moved actively when all other organelles werestill. Translucent virus monolayers, consisting of particles aggregated side by side, provided markers in the parietal cytoplasm of recently infected cells. Mitochondria generally moved across their surface on the side adjacent to the tonoplast, spherosomes across the surface facing the cell wall. Alkaline buffer solution caused little change of texture in nucleus and cytoplasm or change of form in mitochondria. Clear areas appeared in some plastids. The acid buffer emphasized a cytoplasmic network representing flow lines and eliminated many cytoplasmic vesicles; mitochondria became shorter or spherical in outline, grana of chloroplasts more obvious. Virus inclusions, even the fragile monolayers, were not greatly altered until irreversible changes began. In pH 11-treated cells, the final changes included violent bubbling of cytoplasm, and in pH 2.2-treated cells, snapping of flow lines and coagulation of the cytoplasm. In either case, disintegration of cell structure and virus inclusions was rapid. TESTS were made on the action of buffer solutions on the state of living tobacco cells, healthy and infected with tobacco mosaic virus (TMV), strain U1 (Siegel and Wildman, 1954). At the beginning of this work the buffer solutions were used to stop cytoplasmic streaming without visibly affecting structure, so that the cell contents could be observed more easily under the phase microscope and photographed more accurately. The pathological effect that sometimes followed and the death of the treated cells gave information on structure and on changes in the cytoplasm 1 Received for publication August 15, 1963. similar to those caused by some fixatives. The actions of buffer solutions on TMV-infected cells were studied to see whether they caused changes in virus inclusions and aggregates. A useful consequence of infection was the presence in the parietal cytoplasm of fragile and translucent virus aggregates, of thickness determined by the length of a single virus particle (Bald and Solberg, 1961; Solberg and Bald, 1962). These were earlier called "grey plates," but are here called virus monolayers. They served as markers, showing the relative position of other structures within the depth of the parietal cytoplasm. They were present in the cytoplasm during the earlier stages This content downloaded from 207.46.13.45 on Sun, 27 Mar 2016 06:44:02 UTC All use subject to http://about.jstor.org/terms