Bakrudeen Ali Ahmed¹*_, R. Arun Kumar², Muneeb M. Musthafa³, Davindran Rajandram³,

Faiz M.M.T. Marikar⁴

¹Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam

²Center for Research and Development, Ponnaiyah Ramajayam Institute of Science and Technology,

PRIST Deemed University, Vallam, Thanjavur, Tamil Nadu, India

³Faculty of Science, Institute of Biological Sciences, University of Malaya, Kuala Lumpur-50603, Malaysia

⁴General Sir, John Kotelawala, Defence University, Kandawala Estate, Ratmalana, Sri Lanka

(Manuscript received 10 January 2020; accepted for publication 27 April 2020)

Abstract. Plant metabolic engineering is a modern discipline that promises to create opportunities in pharmaceutical industries to produce and biomedicine. Over the long period natural and synthetic plant hormones have had tremendous implications in callus/cell culture /suspension/ for secondary metabolites production (SMs). Generally, SMs plays a vital fundamental role in protecting the plant from biotic and abiotic attacks to which it may be subjected. This review article focused on the relationship between various factors related to the drug production. In medicinal plants, in vitro studies, based on biotic factors such as fungal/endo-phytic fungal elicitors/microbe-derived exogenous elicitor yeast extract (YE) were cross checked  with the abiotic six factor groups, including auxins and cytokinins, gamma radiation, lights, temperature, carbon sources, photoperiods, precursor chemicals and plant metabolic enzymes. Moreover, key enzymes and gene networks can serve as a resource to selected potential targets for specific SMs production. This is the first review to describe the light factors needed for the SM production, which has favorable role for SMs. We envisage that the researcher can design how to modulate the stress factors in terms of drug improvement from medicinal plants.