Role of Heavy Metal ATPases in Transport of Cadmium and Zinc in Plants

Abstract

AbstractAnthropogenic causes have led to a constant increase in heavy metal concentration in soil. Cadmium (Cd), copper (Cu), zinc (Zn), nickel (Ni), cobalt (Co), chromium (Cr), lead (Pb), and arsenic (As) toxicity is recorded in agricultural soils throughout the world. Some of these heavy metal ions are essential micronutrients for plant metabolism but when present in excess are extremely toxic. Heavy metal toxicity in soil not only affects crop yield but may also lead to biomagnification of metals as they enter the food chain, thereby exerting detrimental effect both on human health and the environment. Plants experience oxidative stress upon exposure to heavy metals as they produce ROS (reactive oxygen species) that leads to cellular damage. Plants also accumulate metal ions that disturb cellular ionic homeostasis and several physiological processes which ultimately manifest in reduction of growth and yield. To overcome these, stress plants are equipped with different transporters which transport, sequester, and ultimately detoxify nonessential or excess heavy metals. Heavy metal ATPases need special mention in this respect. They play a significant role in the trafficking and sequestration of hazardous metals across the membrane in plants, thereby minimizing their toxic effect. The chapter aims to highlight the role of heavy metal ATPases in cadmium and zinc transportation and stress-related toxicity in plants.KeywordsHMACadmiumZincToxicityTranslocationTransportTonoplastROS