Heavy Metal Toxicity and Tolerance in Plants with Special Reference to Cadmium: A Review

By : Alfiya Bohra, Dheera Sanadhya, Rajani Chauhan

Page No: 51-74

Abstract
Heavy metal (HM) toxicity is one of the major abiotic stresses leading to hazardous effects in plants; many of them are toxic even at very low concentration. Pollution of the biosphere with heavy metal has accelerated dramatically since the industrial revolution. A common consequence of HM toxicity is the excessive accumulation of Reactive Oxygen Species (ROS), which can cause peroxidation of lipids, oxidation of protein, inactivation of enzymes, DNA damage and/or interact with other vital constituents of the plant cells. Plants respond to avoid detrimental effects of HM in a variety of different ways such as restriction of uptake and transport of metals, plasma membrane exclusion, chelation and sequestration of heavy metals by ligands such as phytochelatins and metallothioneins, induction of heat shock proteins, biosynthesis of polyamines, and production of antioxidants (Enzymatic and non enzymatic). This review focuses on sources of HM and its toxicity with special reference to Cadmium, tolerance mechanism in plants and molecular approaches to overcome its deleterious effects on plants.

Authors :
Alfiya Bohra : Ph.D Scholar, School of Life Sciences, Jaipur National University, Jaipur
Dheera Sanadhya and Rajani Chauhan : Associate Professor School of Life Sciences, Jaipur National University, Jaipur-302025, Rajasthan, India.