CALLOSE DEPOSITION IN THE PRIMARY WALL OF SUSPENSION CELLS AND REGENERATING PROTOPLASTS, AND ITS RELATIONSHIP TO PATTERNED CELLULOSE SYNTHESIS

Monitoring cell-wall formation in vivo with Fluorescent Brightener 28, by fluorescence microscopy, revealed that tobacco protoplasts regener ation started within 30 min indicated by cellulose microfibril formati on at distinct sites on the protoplast surface. Oriented cellulose mic rofibril deposition was apparent before elongation and indicated the e arly polarization of protoplasts. The sequence of cellulose microfibri l deposition correlates with an helicoidal-like texture. Within 6 h, a texture was completed. Tobacco suspension cells, stained by decolouri zed aniline blue, showed radiant granular callose fluorescence in cell plates and transverse walls. During the culture cycle of suspension c ells, transverse fibrillar deposits of callose gradually appeared in t he lateral walls during the log-phase, and subsequently disappeared in the early stationary phase of the cell culture. Similar callose trans itions were observed in regenerated elongating protoplasts. Culture ce lls of Morinda citrifolia L. only showed transient granular deposition s in the lateral walls. The callose formations did not result from art ificial wounding. The transient appearance of callose might be related to cellulose microfibril deposition.