The Effects of Extracellular Calmodulin on Cell Wall Regeneration of Protoplasts and Cell Division

The effects of anti-calmodulin (CaM) serum, CaM antagonist W7-agarose and exogenous pure CaM on cell wall regeneration of protoplasts and cell division for Angelica dahurica and other plants were studied. Anti-CaM serum inhibited cell wall regeneration of protoplasts and the first cell division in dose-dependent manner, while the same amount of preimmune serum had a much less inhibitory effect than anti-CaM serum. The first cell division was also inhibited by CaM antagonist W7-agarose. The addition of exogenous pure CaM enhanced cell wall regeneration of protoplasts and the cell division for several species of plants, while the same amount of bovine serum albumin had no obvious effect. CaM was detected in the normal culture medium by means of enzyme-linked immunosorbent assay. Its content increased with the culture time. The results suggest that extracellular CaM plays an important role in promoting cell wall regeneration of protoplasts and cell division. The possible mechanisms by which extracellular CaM achieves its effects are discussed.