Schizosaccharomyces pombe as a model for metal homeostasis in plant cells: the phytochelatin-dependent pathway is the main cadmium detoxification mechanism.

Sequestration of metal ions by phytochelatins is an important metal tolerance mechanism in a wide range of organisms including plants and certain fungi. Substantial progress in understanding phytochelatin formation at the molecular level has been made in Schizosaccharomyces pombe. The genome of S. pombe has been completely sequenced and all the necessary tools of functional genomics are available. Since most other proteins implicated in plant metal tolerance and homeostasis are also present in this yeast, it represents a very powerful system to elucidate basic mechanisms of metal buffering, sequestration, and toxicity in cells that form phytochelatins. Here, we summarize the work on phytochelatin formation and metal homeostasis in S. pombe. We describe examples of molecular insights obtained from experiments with S. pombe that will be useful in guiding studies with plants. We also provide evidence for the dominance of the phytochelatin pathway in Cd detoxification in S. pombe.