Many signals that modify plant cell growth and development initiate changes in cytoplasmic Ca
2+
. The subsequent movement of Ca
2+
in the cytoplasm is thought to take place via waves of free Ca
2+
. These waves may be initiated at defined regions of the cell and movement requires release from a reticulated endoplasmic reticulum and the vacuole. The mechanism of wave propagation is outlined and the possible basis of repetitive reticulum wave formation, Ca
2+
oscillations and capacitative Ca
2+
signalling is discussed. Evidence for the presence of Ca
2+
waves in plant cells is outlined, and from studies on raphides it is suggested that the capabilities for capacitative Ca
2+
signalling are also present. The paper finishes with an outline of the possible interrelation between Ca
2+
waves and organelles and describes the intercellular movement of Ca
2+
waves and the relevance of such information communication to plant development.
Carbenoxolone and 18β‐Glycyrrhetinic Acid Inhibit IP
3
‐Mediated Endothelial Cell Calcium Signalling and Depolarise Mitochondria