Abstract
The main constituents of the cell wall of the unicellular green alge Acetabularia mediterranea are mannose, glucose, galactose and rhamnose. There are, however, striking differences in the composition of the cell wall of the stalk and the cap. The glucose and galactose content of the cap wall is much higher than that of the stalk wall. Rhamnose is found in the cap wall only. The different composition of stalk and cap wall is also manifest in cells which were enucleated prior to cap formation. Therefore, regulation of the enzymatic processes which are responsible for the different composition of stalk and cap wall take place in enucleated cells also.