Production and role of plants secondary metabolites under various environmental pollution

Plants synthesize an enormous number of secondary metabolites through several metabolic pathways from primary metabolites. Plant secondary metabolites include terpenoids, carotenoids, flavonoids, phenolics, alkaloids, etc. which exhibit a wide range of biological activities. These secondary metabolites are produced only at very low concentrations in plant cells and the production depends greatly on the physiological and developmental stage of the plant. Though they do not play much of a significant role in the primary life of plants, plant secondary metabolites are important for the defense, and adaptation to challenging and changing environment. Environmental pollution is a major concern worldwide. Rapid industrialization and other anthropogenic activities lead to the accumulation of a variety of pollutants in the environment. Several environmental pollutants can influence the primary metabolism which in turn affects the synthesis of an array of secondary metabolites. In his book, we have discussed the effects of various pollutants such as elevated CO2, ozone, heavy metals, toxic gases, and particulate matter on the production of plant secondary metabolites. Additionally, we have also briefly discussed the role of these PSMs on the plant-herbivore or plant-microbe interactions.