Different strategies, biological and abiological, have been developed for the biomass production and accumulation of the plant secondary metabolites, such as micropropagation and organogenesis, cell cloning and repeated selection of high-yielding strains, metabolic engineering, biotransformation, elicitation, using precursors, optimization of medium and culture environments, permeabilization, immobilization, biotransformation methods, and bioreactor cultures. Moreover, in vitro cell and organ cultures have a higher rate of metabolism than whole plants. Elicitation of in vitro cultured cells is one of the most efficient strategies that leads to the enhancement of the production of various plant secondary metabolites.

Callus derived from Cynara cardunculus leaf explants grown on NAA-BAP (3:1 mg/L) enhanced rutin, cynarin, cynaropicrin, and pinoresinol accumulation. Elicitation of this callus with 50 μM of MeJA elevated luteolin, quercetin, and chlorogenic acid levels. The phytohormone combination, NAA-BAP (3:1 mg/L) with 0.5 mg/L TDZ, strongly enhanced total phenolic content.