Cellular mechanisms for heavy metal detoxification and tolerance

J Exp Bot. 2002 Jan;53(366):1-11.


Heavy metals such as Cu and Zn are essential for normal plant growth, although elevated concentrations of both essential and non-essential metals can result in growth inhibition and toxicity symptoms. Plants possess a range of potential cellular mechanisms that may be involved in the detoxification of heavy metals and thus tolerance to metal stress. These include roles for the following: for mycorrhiza and for binding to cell wall and extracellular exudates; for reduced uptake or efflux pumping of metals at the plasma membrane; for chelation of metals in the cytosol by peptides such as phytochelatins; for the repair of stress-damaged proteins; and for the compartmentation of metals in the vacuole by tonoplast-located transporters. This review provides a broad overview of the evidence for an involvement of each mechanism in heavy metal detoxification and tolerance.

Publication types

  • Review

MeSH terms

  • Adaptation, Physiological*
  • Cell Wall / metabolism
  • Chelating Agents / metabolism*
  • Glutathione
  • Heat-Shock Proteins / metabolism
  • Inactivation, Metabolic
  • Metalloproteins / metabolism*
  • Metallothionein / metabolism
  • Metals, Heavy / metabolism*
  • Metals, Heavy / pharmacokinetics
  • Phytochelatins
  • Plant Roots / metabolism
  • Vacuoles / metabolism


  • Chelating Agents
  • Heat-Shock Proteins
  • Metalloproteins
  • Metals, Heavy
  • Metallothionein
  • Phytochelatins
  • Glutathione