Chapter 13 - Nanotechnology for Phytoremediation of Heavy Metals: Mechanisms of Nanomaterial-Mediated Alleviation of Toxic Metals

Abstract

Application of nanoparticles aims at sustainable crop production as these have been attributed to manipulate the key plant life events and have been employed in agriculture to serve diverse purposes, such as to minimize nutrient losses, alleviate different types of environmental stresses, including heavy metal stress, and enhance the yield of crops. Several types of contaminants released either accidentally or deliberately, pose negative impacts on the environment. These contaminants need to be remediated to prevent entry into different terrestrial, aquatic, and atmospheric environments. Several plants have been observed, characterized, and engineered to remediate various types of contaminants, including the heavy metals and this capacity of these plants has been improved by employing different types of agents, such as phytohormones, nanoparticles, biochars etc. In fact, some of the plants which usually do not aid in remediation have been capacitated to remediate various contaminants by manipulating their physiology and biochemistry by the exogenous application of such chemicals. Nevertheless, nanoparticles are noteworthy in this regard as their capacity to remediate various types of heavy metal stresses in plants are owed to their role in the protection of plants against induced oxidative stress and they mimic the role of enzymes involved in oxidative metabolism, such as catalase, peroxidase, and superoxide dismutase. This chapter comprehensively dissects the role of nanoparticles-mediated alleviation of heavy metal stress in plants and the mechanism involved in such alleviation.