Tissue and Cell Culture of Tea (Camellia sp.)

Tea(Camellia sp.) is a non-alcoholic drink consumed across the globe. Upon consumption, it provides refreshment and enormous health benefits. Tea possesses antioxidant compounds which prevent human health from several diseases and disorders as well. Micropropagation and somatic embryogenesis are two distinct cell and tissue culture methods which have been utilized for a long time for the production of secondary metabolites having economical and industrial values. Micropropagation is a clonal propagation method accomplished by selection of explants and establishment of culture in basal media followed by shoot multiplication, development of callus, rhizogenesis, hardening and acclimatization by transferring plantlets from the laboratory to an open environment in the greenhouse or in the field. Somatic embryogenesis is the development of embryos from somatic cells, not from the zygotic cells. It consists of induction, multiplication, development and maturation of the embryo. Globular, heart and torpedo, these three distinguishable developmental stages are visible in somatic embryogenesis. Numerous genes associated with cell division, organ formation and specific cellular processes related to somatic embryogenesis have been identified. Tea possesses several secondary metabolites which have versatile functions. Caffeine, theobromine and theophylline are typical secondary metabolites which impart characteristic taste and flavour to tea. In addition, polyphenols, catechins, proanthocyanin and flavonoids act as antioxidant compounds and possess several health benefits. Various cell and tissue culture methods have been adopted for the biosynthesis of secondary metabolites on laboratory and industrial scales. These methods can be adopted on a larger scale, from experimental laboratory investigation to the industrial setup for the discovery of novel metabolic compounds for their potential applications as medicines and in commercial sectors.

Keywords: Antioxidants, Callus, Micropropagation, Somatic embryogenesis, Secondary metabolites, Tea.