Toxic effects of essential metals on plants: From damage to adaptation responses

Through the arrival of human culture and their participation in multiple activities, and applications, viz., plant species in food, cosmetics, pharmaceutical, and nutritional values have increased in the past 50 years. Interestingly, all anthropogenic activities in the shade of agricultural and industrial involvement negatively interfere with normal plant functions, their growth, and development as well as the health of biotic communities. Polluted water can significantly wash the essential metals and nutrient ions including nitrogen, phosphorus, potassium, magnesium, calcium, etc. Without its deficiency or hyperaccumulation, both create more susceptibility of the plant toward abiotic and biotic constraints. Furthermore, as per the Intergovernmental Panel on Climate Change reports, the whole scenario becomes more frightening over the next three decades. In this alarming scenario, water pollution has emerged as one of the major environmental stresses that affect crop health. Water pollution negatively alters the biosynthesis of metabolites (primary and secondary), antioxidants, and chelating agents, as well as impacting the homeostasis of physiological pathways, nutrient efficiency, and defense responses. In past decades, the reports on the various effect of toxic but essentials metals on plant species show various acclimation and adaptation responses to maintain their growth phase to complete their life cycle. So, this chapter highlighted the response of toxic/essential metals on plants, damage detection, repair strategies, and adaptation responses.