Introduction: This study investigates the In Vitro antifungal activity of silicon dioxide nanoparticles (SiO₂ NPs) against mycotoxigenic Fusarium brachygibbosum species, a fungus posing a significant threat to olive trees in Tunisia.Methods: Two different doses of SiO₂ 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 SiO₂ 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 SiO₂ NPs, including hyphal disorganization after the adherence of nanoparticles. Furthermore, SiO₂ 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 SiO₂, while an increasing level of neosolaniol and diacetoxyscirpenol was observed. Pathogenicity tests on olive and sorghum leaves revealed a reduction of disease severity in SiO₂ treated samples compared to untreated controls, showcasing the potential of SiO₂ NPs as a sustainable alternative for managing Fusarium infections. These findings underline the potential use of SiO₂ 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.

In this study, the response to salt stress was evaluated in ex vitro acclimated date palm plants, regenerated from in vitro culture multiplication. The plants, eighteen-month-old, were irrigated with 0 (control), 150, 300 or 450 mM NaCl solutions (high to very high-water salinity). Photosynthesis parameters and antioxidant compounds were determined at the end of the experiment in leaves. At 150 mM NaCl, net CO2 assimilation rate and internal CO2 concentration were not impaired; while transpiration and stomatal conductance decreased by 60 and 70%, respectively. By increasing salt concentrations, all gas exchanges parameters were decreased. Measurement of chlorophyll fluorescence and P700 redox state showed that PSII and PSI machineries were significantly enhanced under 150 mM NaCl, conditions. With the 300 mM NaCl, the PSI parameters remained unchanged compared to control, while some of the PSII parameters, such as NPQ and Y (NPQ), were increased. At 450 mM NaCl, photosystems functionality was light intensity (PAR) dependent. Only at low PAR, a significant increase of some PSI and PSII parameters was observed. At the contrary, with high PAR, most of the energy conversion functions were significantly reduced, especially those related to PSI, indicating that PSI was more susceptible for damage by salinity than PSII. To overcome high salinity stress, ex vitro date palm plants mobilized a cascade of physio-biochemical pathways including the antioxidant activity and proline biosynthesis. Overall, the salinity of irrigation water, and up to 150 mM, improves the physiological performance of ex vitro date palm plants, which manage to tolerate very high levels of this stress.

The effects of arbuscular mycorrhizal fungi (AMF) inoculation on the chemical composition of the fruits and cladodes of two Opuntia ficus-indica cultivars, characterized by their red and yellow fruit color, were investigated under field conditions. AMF treatment was found to significantly influence the concentration of phytonutrients in the fruits. The concentrations of betacyanin and betaxanthin increased by 1.2- and 1.9-fold in red and yellow fruits, respectively. The polyphenol content increased by 50%, with piscidic acid being the most abundant polyphenol in the red fruits. A similar increase in ascorbic acid was observed in the yellow fruits. Regarding the cladodes, AMF treatment was found to significantly affect macronutrient levels, with glucose and fructose contents being 90% and 34% higher, respectively. Additionally, cladodes from plants grown with AMF inoculation showed a 20% increase in ascorbic acid and phosphorus. These results demonstrate cultivar- and part-of-plant-dependent effects of AMF inoculation and confirm the nutritional and sustainable potential of Opuntia ficus-indica, particularly when coupled with mycorrhizal biofertilization practices.

Oat (Avena sativa L.) is increasingly recognized as a functional food due to its unique profile of antioxidant and health-promoting compounds. Beyond its traditional role, our study reveals that Mediterranean landraces and related species harbour exceptional variability in both their nutritional and bioactive traits, offering untapped potential for functional food development. We analysed 126 genotypes, including landraces and cultivars, from 18 Mediterranean and European countries, quantifying the β-glucans, arabinoxylans, phenolic acids (soluble and cell wall bound), avenanthramides (AVAs: A, B, and C), carbon (C), nitrogen (N), C:N ratio, and protein content. The protein levels ranged from 9.5% to 18.5%, with several genotypes exceeding 17%, far above typical oat averages. The β-glucans reached clinically relevant thresholds (>5%) in multiple accessions, while the arabinoxylans surpassed 2% in selected genotypes. The phenolic acids and avenanthramides showed striking diversity, with some landraces accumulating more than 2000 µg/g of total AVAs. The species and phenology strongly influenced the grain composition. Thus, A. strigosa exhibited the highest β-glucan and avenanthramide contents, while early-heading genotypes had doubled avenanthramide levels compared to late-heading ones. A correlation analysis revealed synergistic patterns among the β-glucans, avenanthramides, and proteins, suggesting multi-component interactions that could enhance antioxidant functionality. These findings underscore the strategic value of Mediterranean oat germplasm for breeding programs targeting high-protein, fibre-rich, and antioxidant-enhanced cultivars. By exploiting this diversity, oats could play a pivotal role in preventing chronic diseases and advancing sustainable, health-oriented food systems.