Ultrastructural investigation of various membrane configurations in Nicotiana tabacum

Abstract

Lamellar and tubular inclusion bodies in the cell vacuole became more numerous as the severity of plant stunting was increased. In normal-appearing greenhouse plants, only a few of these inclusions were seen. In vacuoles of the severely stunted plants, much larger quantities of inclusion bodies were observed. In severely stunted plants, lamellar inclusions occurred that contained osmiophilic globules along the lamellar strands. These types of lamellar inclusions were also seen accumulating in the starch cavities of chloroplasts. From these observations, we postulated that a cell, with a given capacity to produce membrane material, produces membranous material in anticipation of growth. When the cell does not grow, owing to stunting, this excess of membrane material forms the large number of inclusion bodies seen in the vacuoles of stunted cells.

Comparative Ultrastructural Observations of Plasmalemmasomes in PSTVd‐Infected Healthy and Artificially Stunted Tomato Leaves

“…The presented evidence suggests that stunting is caused by the infection and that this, in turn, will result in the assemblage of variously shaped plasmalemmasomes. In their report on stunted Nicotiana tabacum L. plants GiLLESPiE and HAMILTON (1977) support this point of view but concluded that the plasmalemmasomes provide a reservoir of membranes for the future growth of cells. As leaves have a terminal growth period it seems unlikely that these membranes will be used as kind of a storage product for the newly developing and perhaps larger leaves.…”

“…Some appeared to be detached lying free in the vacuole (Figs 3, 8). Plasmalemmasomes have been tentatively classified into three morphological types (GiLLESPiE and HAMILTON 1977) which were all observed in the examined material: the tubular type (Fig. 3), the lamellar type which combines from the spirally arranged (Figs 2, 10) and stacked membrane type (Fig.…”