HISTOCHEMICAL-LOCALIZATION OF AGAR AND CELLULOSE IN THE TISSUE OF GELIDIUM-PACIFICUM (GELIDIACEAE, RHODOPHYTA)

Gelidium pacificum Okamura was histochemically investigated before and after the extraction of agar. The intercellular matrix and outer layer of the wall of parenchyma cells in both the medullary and cortical regions showed metachromatic reddish purple and blue with toluidine blue 0 and alcian blue, respectively. The cell wall of rhizoidal filaments and the inner layer of the cell wall in both the medullary and cortical regions gave a blue reaction with ZnCl2-Iodine. From these stainings it is concluded that the sulfated polysaccharide, agar, of the alga is the main constituent of the intercellular matrix and the outer layer of the walls of parenchyma cells in both the cortical and medullary regions. Cellulose is judged reasonably to constitute a great part of the cell wall material of rhizoidal filaments and the inner layer of walls of both the cortical and the medullary cells. © 2009 Walter de Gruyter