Cadmium toxicity in plants and its remediation management: A review

Abstract

Cadmium is a non - essential heavy metal that is universal in the environment. Man-made activities like disposition of urban waste, smelting, mining, metal processing and utilisation of phosphate-based fertilizers increase the Cd levels within the environment that are detrimental to human health. The pollution of soil and water by Cd is extensively reviewed and has attracted enormous researchers due to its deleterious effects in aquatic and terrestrial ecosystem. The growth and development of plant is severely impaired by Cd toxicity. The toxicity of Cd causes a number of changes ranging from germination to reduction in yield. The physiological processes of a plant like photosynthesis, respiration, water relations, enzyme activities and mineral uptake are all negatively affected by the Cd toxicity which ultimately result in reduced plant biomass and therefore the yield of plant as well. The plants show various metabolic alterations due to Cd toxicity directly by impact on enzyme activity or by the accumulation of various metabolites or either as ability for the generation of Reactive Oxygen Species, resulting in oxidative stress or burst .The capability of plants to survive with the Cd toxicity by tolerance and avoidance mechanism through accumulation or stabilize compounds of Cd either by the action of phytochelatins and metallothiones and by vacoular sequestration or compartmentalisation has gained attention for the amendment of Cd contaminated soils. To protect the environment from the Cd toxicity, various remediation strategies are employed either by physiochemical methods, and organic amendments.Currently various molecular approaches like recognization of QTL’s, CRISPR Cas, and operational genomics are implemented to strengthen the tolerance of Cd toxicity in plants could be absolutely friendly.