MEMBRANE-BOUND INCLUSIONS IN EPIDERMAL PLASTIDS OF DEVELOPING SESAME LEAVES AND COTYLEDONS

Epidermal plastids of young sesame leaves and cotyledons contain amorphous membrane bound inclusions similar to those found in the mesophyll. However, unlike the mesophyll inclusions which disappear during chloroplast development, those in epidermal plastids persist, even in fully mature leaves where a limited grana fretwork system develops. The limiting membrane of the inclusion is apparently continuous with both the tubular complex of light grown tissues and the prolamellar body of etiolated tissues as well as with the granal and integranal membranes. These associations, as well as a decrease in staining density of the inclusion with maturation, are interpreted as indications of a precursor‐product relationship of the inclusion and a grana fretwork. The coexistence of both grana and the (presumably) proteinaceous inclusion manifest the multifunctional capacity of plastids. Copyright © 1979, Wiley Blackwell. All rights reserved