Cadmium: Uptake, Toxicity, and Tolerance in Crop Plants and Management of Cd-Contaminated Soil
摘要
The contamination of agricultural systems with cadmium (Cd) is an emerging threat that has adverse effects on plant health, food security, and environmental sustainability. Cadmium (Cd) is a non-essential toxic heavy metal that has no known biological function; nevertheless, it occurs in agricultural soils and represents a serious risk for plant health, food safety, and environmental quality. The current manuscript has been prepared in a way to provide thorough knowledge of the accumulation of Cd in plants, its tolerance mechanisms and strategies that can help in cleaning-up contaminated soil. The chapter reviews Cd absorption, translocation, and toxicity mechanisms in crops; deep insights into plant strategies to overcome the negative effect of Cd stress are also provided which includes shuttling of toxic metal to vacuoles, production of peptides having ability to bind with heavy metals such as phytochelatins and metallothioneins and activation of antioxidant defense systems against excess reactive oxygen species (ROS). It also discusses both classical and modern remediation methodologies, including soil amendments, phytoremediation along with the utilization of low-Cd fertilizers favorable for effective soil upkeep. Among the available options, phytoremediation is an eco-friendly and highly socially acceptable technology that utilizes plants to remediate Cd-contaminated soils through a combination of processes such as phytovolatilization, phytoextraction, phytostabilization, rhizofiltration, and phytostimulation. All techniques that could be applied for remediation are also evaluated in terms of its effectiveness, cost, and environmental impact.