Olive cultivation in newly reclaimed semi-arid lands is constrained by poor soil fertility and environmental stress, limiting productivity and oil quality. Sustainable biostimulant-based strategies are therefore required to enhance olive performance under such conditions. Here, we evaluated the individual and combined effects of chitosan nanoparticles (CHNPs) and N-acetylthiazolidine-4-carboxylic acid (N-ATCA) on growth, yield, fruit characteristics, and oil quality of Olea europaea L. cv. Arbosana. Using 16 foliar treatments comprising CHNPs (0, 500, 1000 and 1500 ppm), N-ATCA (0, 50, 100 and 150 ppm), and their combinations CHNPs + N-ATCA at concentrations (500 + 50 ppm, 500 + 100 ppm, 500 + 100 ppm, 500 + 150 ppm, 1000 + 50 ppm, 1000 + 100 ppm, 1000 + 150 ppm, 1500 + 50 ppm, 1500 + 100 ppm and 1500 + 150 ppm).Vegetative growth traits, leaf mineral status, fruit yield and quality, and olive oil fatty acid composition and oxidative stability were assessed. The combined application of CHNPs and N-ATCA consistently outperformed single treatments, demonstrating a clear synergistic effect. The highest vegetative growth and leaf nitrogen, phosphorus, and potassium accumulation were recorded with 1500 ppm CHNPs + 150 ppm N-ATCA, while the greatest fruit and oil yields approximately 30% higher than the control were achieved with 1500 ppm CHNPs + 100 ppm N-ATCA. Combined treatments promoted optimal fruit ripening, characterized by enhanced skin coloration without excessive softening. Importantly, all extracted oils met extra virgin olive oil standards, with oleic acid remaining the dominant fatty acid. Moreover, the combined treatments preserved or improved oxidative stability, mitigating the higher oxidation indices observed under individual N-ATCA applications. These findings demonstrate that foliar co-application of chitosan nanoparticles and N-acetylthiazolidine-4-carboxylic acid enhance olive tree performance, yield, and oil quality in newly reclaimed semi-arid environments. This approach offers practical implications for improving olive productivity while maintaining high oil quality under challenging cultivation conditions.

Research on nanoparticles (NPs) is gaining increasing popularity as a way to enhance abiotic stress tolerance and improve crop productivity. This study assessed the effects of foliar spray of selenium NPs (Se NPs) and selenium/copper oxide nanoparticles (Se/CuO NPs) at 50 and 100 ppm on the growth and biochemical characteristics of Zea mays L. plants grown under saline stress conditions (100 mM). Se NPs and Se/CuO NPs were analyzed by energy dispersive X-ray, transmission electron microscopy, and Fourier transform infrared spectroscopy analyses. The Se NPs and Se/CuO NPs were found to have an average particle size of 135.2 and 75.1 nm using the ImageJ tool. Shoot and root lengths, chlorophyll levels, protein, phenols, and flavonoids were all investigated in this study. Plant growth and chlorophyll concentration dropped under salt stress but were improved with the application of Se and Se/CuO NPs. The enzymes catalase, superoxide dismutase, and glutathione reductase exhibited the highest values at 100 ppm of Se/CuO NPs, of 74.4, 132.1, and 43.2 mmol/g, respectively. Se and Se/CuO NPs reduced stress and increased chlorophyll. ZnO-NPs improved maize plants’ resistance to the unfavorable effects of saline soils. Finally, plant metabolism and abiotic stress tolerance were improved by Se and Se/CuO NPs.

The cytotoxic, antioxidant, anticancer, and antibacterial properties of ethanolic extracts from Phragmanthera austroarabica is of interest. Plants of P. austroarabica were gathered from the southern Saudi Arabian region of Albaha. P. austroarabica extract was assessed using DPPH (2, 2-diphenyl-1-picrylhydrazyl). The German Collection of Microorganisms and Cell Cultures (DSMZ) cancer cell lines used in this investigation. The cytotoxic activity of P. austroarabica extract was explored against MCF-7 breast and A549 lung cancer cell lines, along with doxorubicin as a positive control. In both treated cells, P. austroarabica showed a remarkable activity via suppressing the cell’s survival. In terms of IC50 (concentration equivalent to a survival rate of 50%), MCF-7 breast cancer cells were more sensitive to P. austroarabica extract.) DPPH colorimetric assay was employed to assess the antioxidant properties of P. austroarabica extract, the antioxidant activity was increased along with increment of extract concentrations. The leaves aqueous extract of P. austroarabica inhibited the growth of S. aureus by 6.3±0.12 mm and 24±0.43 mm and 15±0.56 mm respectively for seed, leaf and stem at concentrations 50 μl. However, the same concentrations inhibited the growth of E. coli by 25±0.75, 0.00 mm and 24±0.18 mm, following the same order. Different superscript letters indicate means that are significantly different at level (p˂0.05). Minimal inhibitory concentrations (MIC) of P. austroarabica ethanolic extracts against the tested microorganisms were 1.5, 1.6 and 1.5, respectively for seed, leaf and stem against Staph. Aureus and were 1.2, 0.00 and 1.2, respectively for seed, leaf and stem against E. coli.