Hairy Root Culture Through Agrobacterium rhizogenes for Enhancement of Secondary Metabolites Production in Medicinal Plants: A Review

Abstract

Plants are a tremendous source for the discovery of new products with medicinal importance in drug development. Several distinct chemicals derived from plants are used in various important ways. Secondary metabolites are economically important as drugs, flavor, dye, pesticides, and food additives. Plants produce the diversity of secondary metabolites which not only plays an important role in adaption according to the environment but also represents an important source of active pharmaceuticals. The possibility of altering the production of bioactive plant metabolites through tissue culture technology is one of the emerging fields of biotechnology to investigate and enhance the production of secondary metabolites. This enhancement through field cultivation has many defects such as slow growth and low and variable yield due to the environmental and biotic factors. Therefore, hairy root culture has been developed as a more efficient alternative biotechnological tool for secondary metabolite synthesis, regardless of environmental, seasonal, and climatic variations. In vitro hairy roots formed by genetic transformation have been efficiently utilized for the synthesis of higher levels of flavonoids due to their biochemical and genetic stability as well as their fast growth in media without phytohormones. The focus of the present review is a detailed assessment of research on rhizogenesis in different plants using Agrobacterium rhizogenes for the last twelve years particularly for the enhancement of secondary metabolites. The study reveals different techniques involved for rhizogenesis in different plants, compatibility trends of the desired gene, and modifications in the techniques during these years. The rationale of the study Plant secondary metabolites are unique sources for pharmaceuticals, food additives, flavors, and industrially important biochemicals. Accumulation of such metabolites often occurs in plants subjected to stresses including various elicitors or signal molecules. Secondary metabolites play a major role in the adaptation of plants to the environment and in overcoming stress conditions. Environmental factors viz. temperature, humidity , light intensity, the supply of water, minerals, and CO 2 influence the growth of a plant and secondary metabolite production. The principle advantage of recent technology is that it may provide a continuous and reliable source of plant pharmaceuticals and could be used for the large-scale culture of plant cells from which these metabolites can be extracted. Plant cell and tissue cultures hold great promise for controlled production of useful secondary metabo-lites on demand. The current yield and productivity cannot fulfill the commercial goal of plant JAM 4(1) 2020 pp 45-58 45