Exploring the role of elicitors in enhancing medicinal values of plants under in vitro condition

Plants have been scrutinized as the great repository of various natural compounds referred to as secondary metabolites. Secondary metabolites possess diverse organic effects that uplift the usage of medicinal herbs by humans. In vitro culture system, being a promising and efficient platform for the production of plant bioactive products has been gaining prominence throughout the world. However, it's difficult to produce a large quantity of secondary metabolites from differentiated or undifferentiated cultures of plants. To avoid such obstructions, a promising biotechnological tool, ‘elicitation’ has been in use for the last four decades. There has been successful employment of various types of abiotic and biotic elicitors in culture media to elicit pharmacologically important plant secondary metabolites and their release to the culture medium. These in vitro established plants of high medicinal value have sustained many changes at distinct levels of morpho-physiology, biochemistry and gene expression, responding to elicitors' application. This review aims at understanding the mechanism of improving the medicinal attributes of in vitro plants through the elicitation strategy. Besides, this also highlights the contribution of some elicitors in relation to significant morphological, biochemical and metabolic variations in culture medium and stress tolerance under aseptically controlled conditions.