Effect of Ca 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 pharmacological approach. A stretch-activated Ca²⁺ channel blocker, GdCl₃, inhibited glycerol dissimilation under hypoosmotic stress. However, addition of voltage-dependent Ca²⁺ channel blockers and inhibitors of mitochondrial and endoplasmic 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.