Elicitor-induced cellular and molecular events are responsible for productivity enhancement in hairy root cultures:...

A wide range of external stress stimuli triggers a plant cell to undergo a complex network of reactions that ultimately lead to the synthesis and accumulation of secondary metabolites. These secondary metabolites help the plant to survive under stress challenge. The potential of biotic and abiotic elicitors for the induction and enhancement of secondary metabolite production in various culture systems including hairy root (HR) cultures is well-known. The elicitor-induced defense responses involves signal perception of elicitor by a cell surface receptor followed by its transduction involving some major cellular and molecular events including activation of major secondary message signaling pathways. This result in induction of gene expressions escorting to the synthesis of various proteins mainly associated with plant defense responses and secondary metabolite synthesis and accumulation. The review discusses the elicitor-induced various cellular and molecular events and correlates them with enhanced secondary metabolite synthesis in HR systems. Further, this review also concludes that combining elicitation with in-silico approaches enhances the usefulness of this practice in better understanding and identifying the rate-limiting steps of biosynthetic pathways existing in HRs which in turn can contribute towards better productivity by utilizing metabolic engineering aspects.