Printed in Great Britain © Company of Biologists Limited ig8o WALL REGENERATION BY PLASMOLYSED CELLS FROM TISSUE SUSPENSION CULTURES OF SPHAEROCARPOS DONNELLII

De novo synthesis of wall material by cells of Sphaerocarpos donnellii was followed using radioactive tracer techniques. Uniform uptake of [uC]glucose by plasmolysed suspension cultures was demonstrated autoradiographically. Liquid scintillation counts of acid- or alkali-soluble wall carbohydrates indicate that hemicellulose and cellulose make up the major wall fractions in control and plasmolysed tissues. The amount of label in walls of plasmolysed cells was significantly lower than in those of controls. Higher relative radioactivity in pectin and hemicellulose, and lower radioactivity in cellulose were found in plasmolysed tissue. These compositional changes may enhance wall stability by providing numerous sites for cross-linkage between cellulose microfibrils of regenerated walls