Polysaccharide localization in the sporophyte cell wall of Adenocystis utricularis (Ectocarpales s.l., Phaeophyceae)

Abstract

The chemical composition of the sporophyte cell wall of Adenocystis utricularis was examined by using a number of histochemical techniques for the localization of polysaccharides, including labeling with a fluorescent alginate probe. Histochemical staining allowed confirmation of a low alginate/fucoidan ratio in the cell wall indicated by exhaustive extraction of polysaccharides from the algal thalli. Alginate was located in the inner portion of cell walls. “Egg-box” structure of alginate in inner cortical cells may be related to the mechanism of algal growth. Abundance of fucoidan was confirmed by extraction on semithin sections and staining. Weak staining on nonextracted material was in agreement with previously proposed blockage of sulfate groups in these polysaccharides.