Heavy metals polluting the environment influence adsorption, uptake and translocation of iron in plants. Toxic metals are usually retained in the roots and there is little accumulation in the shoot, and plants suffer from different levels of stress due in many occasions to insufficient iron supply. However, there are certain plant species or varieties that can accumulate over a thousand times higher concentrations of heavy metals in their shoots as compared to those found in other plant species. These plants have been suggested to be a cheap tool for decontamination of soils, in what is called phytoremediation. Non-Accumulator plants may also be used for phytoextraction of heavy metals, by applying chelating agents directly to the soil. Although interactions of heavy metals with iron have been reported in many cases, the specific physiological processes associated with iron deficiency have remained unexplored until the last decade. Since substantial progress has been made in the investigation of iron uptake and translocation using molecular biological techniques, a new horizon has opened in the area of stress physiology. In the present paper, new findings in iron nutrition research are presented in connection with heavy metal uptake and especially hyperaccumulation. Competitive chelation in the rhizosphere, cytoplasm and xylem sap as well as the effect of heavy metals on iron reduction are discussed, while a brief introductory overview on phytoremediation is also provided.
- heavy metals
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)