Cell-cycle arrest of plant suspension cultures by tunicamycin

摘要

The effect of tunicamycin, an inhibitor of N-glycosylation of proteins, on growth and on synthesis of DNA and protein was studied in suspension cultures fromNicotiana tabacumandCatharanthus rosea. In the presence of 0.1–1 μg · ml-1tunicamycin, cell division and DNA synthesis stopped in cells which had been proliferating logarithmically, but protein formation continued. Cytophotometric determination of the nuclear DNA content inCatharanthuscells showed that a cell-cycle arrest had occurred in G1 phase. Metabolic labelling of cells with the glycoprotein precursors glucosamine or mannose was inhibited, too. The results indicate that one or more glycoproteins are needed for the cell to pass through the G1 phase, as was recently postulated for animal and yeast ce