Iridescent bodies of Cystoseira stricta Sauvageau (Phaeophyta, Fucales): their fine structure, development and nature in vegetative cells

Abstract

Ultrastructural and developmental aspects of the iridescent bodies present in the vegetative cells of Cystoseira stricta are described with the aid of different fixation procedures. Cytochemical experiments have allowed a better understanding of some of these aspects. The chemical nature of iridescent bodies has been investigated by electron microscope cyto-chemistry using enzymatic extractions and staining methods performed on ultrathin sections.Mature iridescent bodies are vesicles which include numerous dense globules. These globules must be proteinaceous but enclose polysaccharides with α-1,4 linkages and some ester linkages. They are scattered throughout a clear or variously fibrillar matrix containing polysaccharides.The present study demonstrates the participation of the Golgi apparatus in the biogenesis of iridescent bodies which are shown to be equivalent to specialized vacuoles.