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.