The Mechanisms of Heavy Metal Uptake and Accumulation in Plants

Phytoremediation is a technology that involves the use of plants to remove heavy metals from contaminated soil. This approach is based on the ability of plants to absorb contaminants from the soil and translocate them to their shoots. Plant uptake of a metal depends primarily on the free metal ion activity. However, some synthetic chelates have been shown to induce the uptake of metals by plants. Vacuolar compartmentalization appears to be the source of tolerance of metal_accumulating plants. In cells, proteins such as metallothioneins and phytochelatins, organic acids and amino acids also play an important role in metal ion storage and detoxification. Physiological and molecular aspects of heavy metal transport in plants are also discussed in this paper.