Changes in Cell Walls Associated with Cell Separation in Suspension Cultures of Paul's Scarlet Rose

Abstract

Studies of the formation and separation of cellular aggregates in Paul's Scarlet rose suspension cultures have been conducted in an attempt to resolve the basis for intercellular adherence. During the typical growth cycle, cellular aggregates begin to fragment spontaneously at about day 12 in culture. This fragmentation is accompanied by a sharp decrease in the galactose content of wall polysaccharides. At approximately this same time, there is an increase in β-glucosidase and β-galactosidase activity associated with the cell surface. The presence of a β-glucosidase inhibitor, nojirimycin, inhibits the surface β-glycosidase activity, reduces the extent to which cell wall galactose is decreased, and prevents the separation of cells. No other cell wall component examined changes in a manner consistent with cell separation. The results suggest that a galactose-containing wall polysaccharide may be involved in the maintenance of intercellular coherency and that partial removal of this component may be causally related to the spontaneous separation of cells in culture.