An overview of heavy metal challenge in plants: from roots to shoots

Heavy metals are often present naturally in soils, but many human activities (e.g. mining, agriculture,sewage processing, the metal industry and automobiles) increase their prevalence in the environmentresulting in concentrations that are toxic to animals and plants. Excess heavy metals affect plantphysiology by inducing stress symptoms, but many plants have adapted to avoid the damaging effectsof metal toxicity, using strategies such as metal chelation, transport and compartmentalization.Understanding the molecular basis of heavy metal tolerance in plants will facilitate the development ofnew strategies to create metal-tolerant crops, biofortified foods and plants suitable for thephytoremediation of contaminated sites.