Changes in cell wall constituents during the cell cycle in a synchronous culture of Catharanthus roseus

Changes in cell wall constituents during the cell cycle were investigated using a synchronous culture of Catharanthus roseus (L.) G. Don which was obtained by the double phosphate starvation method (S. Amino et al. 1983. Physiol. Plant. 59: 393–396). Cell walls isolated from the cells in each phase of the cell cycle were fractionated into EDTA-soluble (pectin), 5 and 24% KOH-soluble (hemicellulose) and 24% KOH-insoluble (cellulose) fractions. Their sugar compositions were investigated by gas chromatography and methylation analysis. The following changes were observed: (1) a significant increase in total cell walls in the G1 phase after cell division, (2) a temporary increase in the relative amount of the EDTA-soluble fraction during cytokinesis, (3) an increase in the relative amount of galactose, probably 4-linked galactose, in the EDTA-soluble fraction prior to cytokinesis, (4) a temporary increase in the relative amount of 3-linked glucose during cytokinesis, (5) little change in the composition of polysaccharides throughout the cell cycle in the 24% KOH-soluble fraction, which consisted mainly of xyloglucan. The changes observed are discussed in relation to the progression and physiological significance of each phase of the cell cycle.