Saponins, the Unexplored Secondary Metabolites in Plant Defense: Opportunities in Integrated Pest Management

Author: mycolabadmin
3/10/2025
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Summary

Plants naturally produce compounds called saponins that protect them from insects, fungi, bacteria, parasitic worms, and viruses. This review explains how saponins work as natural pest managers and discusses how plants rich in saponins, such as licorice and soapbark trees, could be used to develop environmentally friendly crop protection products instead of synthetic pesticides.

Background

Plants have evolved diverse defense mechanisms against biotic stressors including fungi, bacteria, nematodes, insects and viruses through the production of secondary metabolites. Saponins, terpenoid secondary metabolites, have demonstrated significant potential in suppressing a wide range of plant pathogens but remain underexplored compared to other secondary metabolite classes like alkaloids and flavonoids.

Objective

This review aims to identify and acknowledge the significance of saponins as being on par with other classes of secondary metabolites in plant defense systems. It provides a holistic review on the role of saponins with known mechanisms against all major plant pathogens and pests, and discusses the potential of saponin-rich crops in providing eco-friendly pest management products for integrated pest management.

Results

Saponins demonstrated significant inhibitory activities against herbivorous insects through antifeedant and toxicity mechanisms, plant-parasitic nematodes through membrane disruption, fungal pathogens through cell membrane integrity disruption, pathogenic bacteria through immune response activation, and plant viruses through replication inhibition. Saponin-rich crops include Glycyrrhiza glabra (22.2-32.3%), Yucca schidigera (10%), and Quillaja saponaria (9-10%), with commercial products like QL Agri 35 and SaponAID® available.

Conclusion

Saponins have demonstrated significant potential for managing major crop pests and pathogens comparable to other secondary metabolites. The review identifies research gaps and recommends gene editing, breeding techniques, and mechanistic investigations to harness saponins for sustainable and eco-friendly integrated pest management strategies.

Published in:Plants (Basel),
Study Type:Review,
Source: 10.3390/plants14060861, PMID: 40265787