Role of Micronutrients in Secondary Metabolism of Plants

Plants require an enormous number of organic and inorganic substances from outside sources called nutrition. Inorganic plant requirements are obtained directly or indirectly from the soil. The important trace elements necessary in very small quantity by plants for their survival are called micronutrients. These micronutrients are involved in various functions like cell protection, gene regulation, signal transduction, intracellular trafficking, as well as primary and secondary metabolite production. Deficiency of these micronutrients strongly affects the secondary metabolite production and also depends upon the plant species. The heritable changes in the primary metabolite pathways of plants result in the formation of secondary metabolites. They are selected by the natural selection and do not have direct role in plant life processes. They have internal roles in plants and are involved against herbivory and microorganisms, to attract pollinators and reduce plant-plant competition and biological symbiotic nitrogen fixation. However, application of micronutrients could increase or decrease the secondary metabolite production. Therefore, in this chapter we discuss about the basic and general overview of the role of micronutrients in plant growth and development with special reference to their role in different aspects of plant secondary metabolism and stress mitigation.