Nano-Elicitation Approaches for Boosting Secondary Metabolites in Medicinal Plant Cell Cultures

Medicinal plants are a rich source of diverse secondary metabolites (SMs) with significant industrial and medicinal applications. However, the natural content of these compounds is often low and influenced by various environmental and biological factors, making large-scale extraction from conventionally cultivated plants challenging. This review comprehensively examines the efficacy and benefits of plant in vitro culture techniques, specifically, callus, cell suspension, and hairy root cultures, for enhanced SMs production. A primary focus is placed on the elicitation effects of various nanomaterials and their mechanisms of action in boosting SMs synthesis. We present successful case studies utilizing different classes of nanomaterials, including metal oxides, non-metal oxides, carbon-based materials, polysaccharides, and quantum dots, as nano-elicitors. Furthermore, the review discusses the advantages and current challenges of nanomaterial-based elicitation, as well as its future applications and prospects. The insights consolidated in this review underscore the potential of nanoparticle-mediated elicitation as a robust strategy for the efficient production of valuable SMs in plant cell cultures. Finally, we emphasize the broad utility of diverse nanomaterials and highlight critical areas requiring further investigation in this field.