A comprehensive investigation of the effect of thyme oil‐loaded chitosan nanoparticles on aphid‐mediated transmission of potato virus Y

BACKGROUND: Sustainable nanotechnology, particularly chitosan (CS)-based biodegradable nanoparticles (NPs), offers an eco-friendly delivery system compared to conventional techniques. Potato virus Y (PVY) causes severe potato yield losses and reduces tuber quality. Its control is challenging owing to nonpersistent aphid transmission, especially by Myzus persicae, the most efficient vector. Chemical insecticides lead to environmental pollution, health risks, and resistance, highlighting the need for alternatives. This study assessed pure CS, thyme essential oil (TEO)-loaded CS, CS-lecithin (LH) encapsulated TEO, and TEO alone for their ability to block PVY transmission by M. persicae. To the best of our knowledge, no prior studies have examined the CS + LH + TEO formulation's effect on aphid-mediated PVY transmission. RESULTS: The results clearly indicate that all NP formulations significantly reduced aphid vectored transmission of PVY to healthy plants and inhibited virus acquisition from infected sources. The CS + LH + TEO and pure TEO treatments were the most effective, with CS + LH + TEO reducing transmission by 50.0% and pure TEO suppressing acquisition by 57.5%. Moreover, these formulations, especially CS + LH + TEO, substantially enhanced antioxidant enzyme activities, increased proline levels, and upregulated expression of the defense genes PAL-1and PR-2. As a result, accumulation of post-PVY infection oxidative stress markers H₂O₂ and MDA was considerably lower in NP-treated plants, emphasizing their protective effect against membrane damage. CONCLUSION: In this study, TEO was successfully encapsulated using CS and LH. Although previous research has primarily focused on the individual effects of CS and TEO on aphids, the inhibitory effect of CS + LH + TEO NPs on PVY transmission and acquisition by aphids offers a promising avenue for developing novel integrated pest management strategies. © 2026 Society of Chemical Industry.