The increasing demand for sustainable agriculture has accelerated research into eco-friendly plant health management, particularly through natural substances rich in bioactive compounds.
In this study, various substances, including essential oils, extracts from Aloe vera, artichoke and ornamental plants, by-products from beer and coffee processing, and selected commercial formulations including biostimulants and a plant strengthener, were evaluated for their antimicrobial properties and ability to trigger plant defenses. Notably, Agapanthus spp. exhibited strong antifungal activity against the fungus Botrytis cinerea (Bc), while thyme, tea tree, and lavender essential oils were effective against both Bc and the bacterium Pseudomonas syringae pv. tomato (Pst). Greenhouse trials on tomato plants demonstrated the protective effects of A. vera gel and ornamental plant extracts against Bc and Potato virus Y (PVY), while coffee and artichoke extracts were effective against Pst. An alginate-based formulation containing thyme oil showed enhanced in planta efficacy against the three pathogens. Gene expression analyses revealed early upregulation of PR-1 and PR-4, especially with alginate treatments and A. vera gel at 12 h post-treatment (hpt) while coffee extract triggered the strongest late response at 72 hpt.
These findings highlight the potential of plant-derived substances in promoting sustainable plant disease management through both direct antimicrobial action and immune system activation.
Bilen, C.; Laera, S.; Rotondo, P.R.; Dimaglie, M.; Vaccaro, L.; Marashi, M.; Mascia, T.; Lopedota, A.A.; Spanò, R.; Pollastro, S.; et al. Antimicrobial Activity and Activation of Defense Genes in Plants by Natural Extracts: Toward Sustainable Plant Health Management. Agronomy 2025, 15, 2342. https://doi.org/10.3390/agronomy15102342
Source: MDPI
