Response to Heavy Metal Stress
Several heavy metals emanating from industrial mining and sewage disposal operations contaminate the environment. Cadmium is a common contaminant of this class. It affects human health adversely. It usually retards plant metabolic rates. Yet plants can be selected for their ability to grow on normally toxic concentrations of this metal ion. Low molecular weight proteins capable of binding with metal ions have been found in several plant species. Synthesis of these proteins is induced in response to heavy metal-ions present in the environment. These proteins probably help the plants in accumulating the metals and keeping them away from the sensitive cellular sites.