Regulation of Metabolites by Nutrients in Plants

Abstract

Mineral nutrition plays a vital role in plant growth and metabolism. To date, 17 essential nutrients have been identified that are direly needed for plant growth. Nitrogen (N), phosphorus (P), and potassium (K) are among the most important macronutrients, whereas micronutrients include chloride (Cl), copper (Cu), manganese (Mn), iron (Fe), zinc (Zn), cobalt (Co), molybdenum (Mo), and nickel (Ni). Each mineral carries equal importance, and a deficiency of any of them can affect growth and disrupt the plant life cycle. Plants are treasure troves of bioactive metabolites that essentially regulate nearly all fundamental processes like growth, reproduction, and environmental responses. These plant metabolites are divided into two major categories, i.e. primary metabolites (PMs) and secondary metabolites (SMs) according to their functions. There is a strong linkage between plant metabolites and mineral nutrients. Biosynthesis of metabolites involves various metabolic pathways such as absorption, carbon assimilation, photosynthesis, protoplast formation, respiration, transpiration, translocation, and storage. These pathways are regulated by mineral nutrients available in different forms in the soil solution. N is necessary for the biosynthesis of various PMs (i.e. amino acids, chlorophyll, nucleic acids, lipids, proteins, and enzymes) and SMs (i.e. flavonoids and phenolic compounds). P is important for sugar phosphates, phospholipids, DNA, RNA, and nucleotide synthesis as well as actively involved in energy metabolism. K mediates the synthesis of sugars, amino acids, organic acids, and antioxidants and also plays many regulatory roles. Similarly, micronutrients (S, Ca, Mg, Fe, Cu, Mn, B, and Cl) also regulate the synthesis of wide array of PMs and SMs such as proteins, amino acids, sugars, flavonoids, phytohormones, organic acids, vitamins, antioxidants, glucosinolates, and various cofactors that have crucial role in plant growth and development. Availability and composition of mineral nutrients have a profound effect on the type and amount of PMs and SMs produced. So there lies an increased interest in unraveling the regulatory roles of mineral nutrients in the biosynthesis of plant metabolites. Therefore, this chapter specifically aims to improve our understanding regarding the regulatory roles of mineral nutrients in the biosynthesis of plant metabolites.