Secondary Metabolite Production in Medicinal Plants Using Tissue Cultures

Abstract

Plants are an incredible treasure of lifesaving drugs and other products of diverse applications. Plant tissue cultures can be established routinely under sterile conditions from explants like plant leaves, stems, roots, meristems, etc. for both ways for multiplication and extraction of secondary metabolites. Strain improvement, methods for the selection of high-producing cell lines, and medium optimizations can lead to an enhancement in secondary metabolite production. Production of natural as well as recombinant bioactive products of commercial importance through the exploitation of plant cells has attracted substantial attention over the past few decades. Swift acceleration in the production of explicit secondary metabolism compounds at a rate similar or superior to the intact plants has been discovered through innovative plant cell cultures in the last few years. In view of obtaining optimum yields suitable for commercial exploitation, isolation of the biosynthetic activities of cultured cells has been focused upon, which is being achieved by the optimization of the cultural conditions, selection of high-yielding strains, and employment of transformation methods, precursor feeding, and immobilization techniques. Production of secondary metabolites through hairy root system is based on Agrobacterium rhizogenes inoculation and has grabbed substantial attention during the past few decades as an efficient method of secondary metabolite production in the plant roots. Due to certain reasons like very slow growth of root systems of higher plants and very difficult harvesting, alternative methods of bioactive compound production have been utilized and promising results have been obtained. Root cultures constitute a promising option for the production of medicinally important bioactive compounds. Organ cultures and in vitro biomass production often have sites of synthesis and storage of secondary metabolites in separate compartments. Elicitors, compounds triggering the formation of secondary metabolites, can be abiotic or biotic. Natural elicitors include polysaccharides such as pectin and chitosan, which are also used in the immobilization and permeabilization of plant cells. The present chapter reviews the secondary metabolite production through hairy root cultures, organ cultures, elicitation, and economically valuable secondary metabolites produced through tissue culture.