Toxicity of Chromium and Cadmium in Plants and Their Remediation: A Comprehensive Review

Abstract

Minerals in threshold amounts are indispensable for plants. Some of them are non-essential and have heavier atomic masses known as ‘Heavy metals’ due to high reactivity, they can retard plant growth, the process of aging and the process of energy generation hence retardation in plant growth is the main symptom of heavy metal toxicity. Heavy metal toxicity stimulates the production of reactive oxygen species (ROS), which are generated by diverse environmental distresses like elevated light intensity, temperature, water scarcity, salt stress, nutrient scarcity and attack of disease-causing agents. Plants are usually adapted to contrive against the toxicity of the various heavy metals by activating different concentrations of some enzymatic and non-enzymatic antioxidative compounds. Different traditional methods of palliation include pyrolysis of soil, in situ substantiation, landfill, soil washing off and soil solidification. Toxicity from the soil can be reduced by using some plants and microbes by the process of phytoremediation. Among the various heavy metals, the two metals (Cadmium and Chromium) need high concern because a very low amount of these metals are highly toxic for all living beings.