ABSTRACT
Food is the utmost necessity of every human being and this demand is increasing with the increase in population. But increasing food production at a sustained rate is getting difficult due to the interference of abiotic stresses. Among several abiotic stresses, heavy metal stress is known to affect productivity severely. The sources of heavy metal stress are natural as well as anthropogenic. Natural sources include weathering of rocks, volcanic eruptions, forest fires, etc., while anthropogenic sources are industrial waste release, domestic effluents and smelting. The increased heavy metal stress affects plant growth and developmental processes by inhibiting important growth regulating processes, i.e. photosynthesis and nitrogen metabolism. This effect is mediated from cellular to whole plant level, thereby affecting the growth. In order to overcome the losses due to heavy metal toxicity, several strategies are being employed like the application of phytohormones, mineral nutrients, metabolites, antioxidants, etc. In this chapter, we have discussed heavy metal toxicity with special emphasis on the sources and its mechanism of inducing toxicity in plants. In later sections, we have provided an overview of some mitigants like phytohormones, mineral nutrients and metabolites that are involved in mitigating heavy metal stress. This chapter reviews the toxicity of heavy metals and the mitigation strategies of plants through the application of nutrients, hormones and metabolites.
