Synthesis of plant secondary metabolites under the influence of elicitors, application in stress management and in vitro techniques to enhance their production

A wide range of secondary metabolites are produced by plants, which aid in their ability to adapt to environmental stressors and interaction with microorganisms. The primary functions of these bioactive compounds, which comprise flavonoids, terpenoids, alkaloids, and phenolics, include ecological communication, defense, and development in plants. Various metabolic pathways, such as the methylerythritol phosphate (MEP), shikimate, and mevalonate (MVA) pathways are involved in their production. They are frequently triggered by biotic and abiotic stressors. The use of elicitors, which are chemical or biological agents that mimic stress signals, is one of the key strategies to boost the synthesis of these metabolites. Elicitors set off certain signal transduction cascades that lead to transcriptional control of the key biosynthetic genes, including the production of reactive oxygen species (ROS), calcium influx, and MAPK activation. The taxonomy and biosynthesis of secondary metabolites, their role in stress adaptation, and recent advances in elicitor-based techniques for upregulating their production are highlighted in this review. The effects of elicitors on metabolite biosynthesis, their integration into plant defense signaling, and their application in sustainable agriculture and the pharmaceutical industry are highlighted.