Stress-Induced Metabolite Production Utilizing Plant Hairy Roots

Abstract

Plant secondary metabolites comprise a diverse variety of organic compounds that facilitates defense response against various biotic and abiotic factors present in the environment. Many of these secondary metabolites are used in pharmaceutical, food, confectionary, cosmetics, insecticide, rubber, and agrochemical industries. In the last two decades, various attempts have therefore been undertaken to increase the production and accumulation of valuable secondary metabolites utilizing several approaches in cell, tissue, and organ culture systems. Cell and tissue culture systems, being undifferentiated, have limited potential to increase the production of secondary metabolites. Among different organ culture systems, hairy root has gained considerable interest due to its high rate of growth in minimal media, genetic and biochemical stability, non-dependence on phytohormones, and higher accumulation of secondary metabolites in short time period. Manipulations with hairy root culture medium and concentrations of carbon and nitrogen source have resulted in limited success. However, as plant secondary metabolites are produced under stress conditions, use of elicitors (elicitation) is one of the most promising strategies to increase secondary metabolite production. The present chapter briefly discusses the various extrinsic factors and their role in valuable secondary metabolite production in hairy root culture system.