ABSTRACT
Nickel (Ni) is generally considered as a toxic element for plant growth; however, its essentiality in numerous physiological processes emphasizes how much Ni is important for plant growth. Ni is an important part of numerous enzymes and improves N metabolism and nodule formation in legumes. On the other hand Ni at a high concentration significantly reduces plant growth by reducing biomass accumulation, root to shoot length, grain formation, root development, and development of vascular bundles. Reduction in photosynthesis due to Ni-induced stomatal and non-stomatal limitations also explains the negative effects of Ni on plant growth. Ni interacts with NADPH and produces ROS, which subsequently causes oxidative damage to the plasma membrane. In short, Ni at low concentration is beneficial for plant growth, while Ni at high concentration is detrimental for plant growth. In this chapter, the essential and toxic nature of Ni has been discussed.
