Effect of Ca2+ channel blockers on glycerol levels in Dunaliella tertiolecta under hypoosmotic stress

The role of Ca2+ in glycerol dissimilation under hypoosmotic stress in the halotolerant alga Dunaliella tertiolecta was investigated using a pharmacol ogical approach. A stretch-activated Ca2+ channel blocker, CdCl3, inhibited glycerol dissimilation under hypoosmotic stress. However, addition of volt age-dependent Ca2+ channel blockers and inhibitors of mitochondrial and end oplasmic reticulum Ca2+ channels did not affect the glycerol dissimilation under hypoosmotic stress. The results of the present study suggest that the influx of Ca2+ from the extracellular space via the stretch-activated Ca2 channels localized in the plasma membrane is required for the transduction of osmotic signal of D. tertiolecta. (C) 1999 Elsevier Science B.V. All ri ghts reserved.