Table 1.

The concentration of Ca²⁺ in plant organelles.

Organelle	[Ca2+]T (mM)	[Ca2+]F (nM)	References
Vacuole	80	200~5000	[14,15]
Chloroplast	15	~150	[14]
Apoplast	~1.0	330~500	[20,21]
Endoplasmic reticulum	-	-	[14,15]
Mitochondria	-	~200	[22]
Nucleus	-	~100	[23,24]
Cytoplasm	-	~100	[14]

[Ca²⁺]_T: total Ca²⁺ concentration; [Ca²⁺]_F: free Ca²⁺ concentration; -: Not determined.