Influence of Elicitors and Eustressors on the Production of Plant Secondary Metabolites

Abstract

Plants are the main source of secondary metabolites, which can be used in different sectors such as pharmaceutics, food, cosmetics, agriculture, etc. turning them into an attractive source of income. Primary metabolites (carbohydrates, lipids, and proteins) have been linked to vital processes such as growth, development, and fruiting, while the secondary metabolites (phenols, flavonoids, and carotenoids, to name a few) are the result of adaptation and evolution of the plants with respect to changes in the environment. Therefore, it can be said that the secondary metabolites are secreted when the plant is under biotic and abiotic stresses. These secondary metabolites possess several bio-active functions and, hence, are well recognized for industrial applications. Due to difficulties for extracting these natural plant bio-active compounds, they are usually produced alternatively through plant cell/tissue culture methods. Further, several approaches, such as the use of plant and tissue cell cultures, the application of metabolism-inducing factors or elicitation, control of biological factors, such as intensity of light, induction by sound waves, and application of nanoparticles are used to alter/enhance in vitro production of these bio-active metabolites. Overall, these approaches interact with the biochemical routes of the plant either in positive or negative ways to produce secondary metabolites in high quantities. Although there is information on this aspect, the effect of these strategies cannot be generalized, since it has been observed that the metabolism of the plant response depends on the study model, the concentration and time of use of the stimulus, as well as its nature. Considering the above facts, this chapter discusses on the most current strategies for the production of secondary metabolites in plants in a continuous and reliable manner.