EXTRACELLULAR CALMODULIN ACCELERATES THE PROLIFERATION OF SUSPENSION-CULTURED CELLS OF ANGELICA-DAHURICA

Calmodulin (CaM) was detected in culture medium containing the cells of Angelica dahurica by the methods of enzyme-linked immunosorbent assay (ELISA) and nicotinamide adenine dinucleotide (NAD) kinase enzymatic assay. The level of CaM showed a close relationship to the cell growth cycle. CaM antagonists strongly inhibited cell proliferation and the addition of purified CaM could reverse this inhibitory effect. Anti-CaM serum also inhibited cell proliferation significantly. Exogenously applied CaM in the culture medium could accelerate the cell proliferation rate, and the lower the density of the initial cell culture, the more obvious was the acceleration effect. Addition of the same amount of bovine serum albumin (BSA) as that of CaM had no effect on cell proliferation, indicating that the effect of CaM was not due to a nutritional effect of protein. These results suggest that extracellular CaM can have an effect on plant cell proliferation.