Silicon dioxide (SiO2) nanoparticles affect the morphology, sporulation, mycotoxin production, and pathogenicity of Fusarium brachygibbosum infecting olive trees

Abstract

Introduction This study investigates the In Vitro antifungal activity of silicon dioxide nanoparticles (SiO 2 NPs) against mycotoxigenic Fusarium brachygibbosum species, a fungus posing a significant threat to olive trees in Tunisia. Methods Two different doses of SiO 2 NPs (100 and 200 mg kg -1 ) were used to evaluate its effect on fungal growth, mycotoxin production, and virulence capability of tested F. brachygibbosum strain. Results and Discussion While mycelial growth was not influenced by SiO 2 NPs, a notable increase in macroconidia sporulation was observed at the highest dose tested. Scanning electron microscopy revealed structural alterations in fungal hyphae treated with SiO 2 NPs, including hyphal disorganization after the adherence of nanoparticles. Furthermore, SiO 2 NPs influenced oxidative stress in Fusarium , with varying effects on hydrogen peroxide levels, total antioxidant activity, and total phenolic compounds, modulating the capability of the fungus to produce mycotoxins. Indeed, fusaric acid and 15-acetyldeoxynivalenol amounts decreased in presence of SiO 2 , while an increasing level of neosolaniol and diacetoxyscirpenol was observed. Pathogenicity tests on olive and sorghum leaves revealed a reduction of disease severity in SiO 2 treated samples compared to untreated controls, showcasing the potential of SiO 2 NPs as a sustainable alternative for managing Fusarium infections. These findings underline the potential use of SiO 2 NPs as environmentally friendly and effective tool in integrated pest management strategies against F. brachygibbosum as well as other Fusarium species occurring on olive trees. Further research is warranted to optimize their application and understand their interactions with both the pathogen and the host plant.

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