Hyperaccumulator

Hyperaccumulator is a term used in the field of phytoremediation to describe plants that have the ability to accumulate high levels of toxic metals in their tissues. These plants are of significant interest due to their potential use in the remediation of contaminated soils.

Definition

A hyperaccumulator is a plant that can grow in soils with high concentrations of metals, and accumulate these metals in their tissues at concentrations much higher than normal. The exact definition of a hyperaccumulator varies, but a commonly used definition is a plant that can accumulate more than 1000 mg/kg of a metal in its above-ground tissues.

Mechanism of Hyperaccumulation

The mechanism by which hyperaccumulators accumulate high levels of metals is not fully understood. However, it is believed that these plants have evolved mechanisms to tolerate high levels of metals in their environment, and these mechanisms also allow them to accumulate these metals in their tissues. These mechanisms may include enhanced uptake of metals by the roots, efficient transport of metals from the roots to the shoots, and sequestration of metals in the leaves.

Examples of Hyperaccumulators

There are many examples of hyperaccumulators, including plants that can accumulate nickel, cadmium, zinc, copper, lead, arsenic, and mercury. Some examples of hyperaccumulators include Thlaspi caerulescens, which can accumulate high levels of zinc and cadmium, and Alyssum bertolonii, which can accumulate high levels of nickel.

Use in Phytoremediation

Hyperaccumulators are of significant interest in the field of phytoremediation, which is the use of plants to remove, stabilize, or degrade contaminants in the environment. Hyperaccumulators can be used to remove metals from contaminated soils, a process known as phytoextraction. The plants are grown on the contaminated soil, and as they grow, they take up the metals from the soil and accumulate them in their tissues. The plants can then be harvested and disposed of safely, removing the metals from the site.

See Also

• Phytoremediation
• Phytoextraction
• Toxic metals

References

• File:Gelbes Galmeiveilchen (viola lutea ssp. calaminaria).jpg