Plants are an immense source of phytochemicals with therapeutic effects and
are widely used as life-saving drugs, and other products of varied applications. Plant
tissue culture is a unique technique employed under aseptic conditions from different
plant parts called explants (leaves, stems, roots, meristems, etc.) for in vitro
regeneration and multiplication of plants and synthesis of secondary metabolites (SMs).
Selection of elite germplasm, high-producing cell lines, strain enhancements, and
optimization of media and plant growth regulators may lead to increased in vitro
biosynthesis of SMs. Interventions in plant biotechnology, like the synthesis of natural
and recombinant bioactive molecules of commercial importance, have attracted
attention over the past few decades; and the rate of SMs biosynthesis has increased
manifold than the supply of intact plants, leading to a quick acceleration in its
production through novel plant cultures. Over the years, the production of SMs in vitro
has been enhanced by standardising cultural conditions, selection of high-yielding
varieties, application of transformation methods, precursor feeding, and various
immobilization techniques; however, most often, SM production is the result of abiotic
or biotic stresses, triggered by elicitor molecules like natural polysaccharides (pectin
and chitosan) that are used to immobilize and cause permeabilization of plant cells. In
vitro synthesis of SMs is especially promising in plant species with poor root systems,
difficulty in harvesting, unavailability of elite quality planting material, poor seed set
and germination, and difficult to propagate species. Thus, the present article reviews
various biotechnological interventions to enhance commercially precious SMs
production in vitro.
Keywords: Biotecnology, Callus secondary metabolites, Phytomolecules, Plant tissue culture, Suspension cultures.
