Phytochelatin

They are found in plants, fungi, nematodes and all groups of algae including cyanobacteria.

Phytochelatins act as chelators, and are important for heavy metal detoxification.

A mutant Arabidopsis thaliana lacking phytochelatin synthase is very sensitive to cadmium, but it grows just as well as the wild-type plant at normal concentrations of zinc and copper, two essential metal ions, indicating that phytochelatin is only involved in resistance to metal poisoning.

[4] Because phytochelatin synthase uses glutathione with a blocked thiol group in the synthesis of phytochelatin, the presence of heavy metal ions that bind to glutathione causes the enzyme to work faster.

[6] Phytochelatin seems to be transported into the vacuole of plants, so that the metal ions it carries are stored safely away from the proteins of the cytosol.