Role of Plant Growth Regulators for Augmenting Secondary Metabolites Production in Medicinal Plants

Plants are an important source of natural products for health care throughout the globe. Recent trends show an abrupt increase in the demand for medicinal plants due to their cost-efficiency, safety, and potency. The medicinal properties of the plants are attributable to the presence of secondary metabolites, which accumulate as the natural defense against herbivory and other interspecies defenses. Along with their medicinal uses, secondary metabolites are also used in flavorings, agrochemicals, fragrances, bio-pesticides, and food additives. The demand for secondary metabolites is mainly expedited through the collection of medicinal plants from the wild. This has provided an impetus for overharvesting medicinal plants from the wild, and many of them are threatened. The accumulation of secondary metabolites in medicinal plants is limited, and therefore diverse strategies for improving the production of secondary metabolites are a priority. Biotechnological applications, especially plant tissue culture techniques, offer a viable alternative for obtaining secondary metabolites. Along with the optimization of growth media and culture conditions, the role of plant growth regulators is vital in enhancing biomass and secondary metabolite accumulation in the culture medium. The present chapter demonstrates the types and uses of plant growth regulators with a focus on the application of plant growth regulators for the production of secondary metabolites from medicinal plants.