Herein, CuO-NPs were fabricated by harnessing metabolites of Aspergillus niger strain (G3-1) and characterized using UV–vis spectroscopy, XRD, TEM, SEM-EDX, FT-IR, and XPS. Spherical, crystallographic CuO-NPs were synthesized in sizes ranging from 14.0 to 47.4 nm, as indicated by TEM and XRD. EDX and XPS confirmed the presence of Cu and O with weight percentages of 62.96% and 22.93%, respectively, at varied bending energies. FT-IR spectra identified functional groups of metabolites that could act as reducing, capping, and stabilizing agents to the CuO-NPs. The insecticidal activity of CuO-NPs against wheat grain insects Sitophilus granarius and Rhyzopertha dominica was dose- and time-dependent. The mortality percentages due to NP treatment were 55–94.4% (S. granarius) and 70–90% (R. dominica). A botanical experiment was done in a randomized block design. Low CuO-NP concentration (50 ppm) caused significant increases in growth characteristics (shoot and root length, fresh and dry weight of shoot and root, and leaves number), photosynthetic pigments (total chlorophylls and carotenoids), and antioxidant enzymes of wheat plants. There was no significant change in carbohydrate or protein content. The use of CuO-NPs is a promising tool to control grain insects and enhance wheat growth performance.

A pot experiment was designed and performed in a completely randomized block design (CRBD) to determine the main effect of two plant growth-promoting rhizobacteria (PGPR) and their co-inoculation on growth criteria and physio-biochemical attributes of canola plants (Brassica napus L.) plant grown in saline soil. The results showed that inoculation with two PGPR (Azotobacter chroococcum and/or Alcaligenes faecalis) energized the growth parameters and photosynthetic pigments of stressed plants. Moreover, soluble sugars’ and proteins’ contents were boosted due to the treatments mentioned above. Proline, malondialdehyde (MDA), and hydrogen peroxide (H₂O₂) contents were markedly declined. At the same time, antioxidant enzymes, viz. superoxide dismutase (SOD), ascorbate peroxidase (APX), and peroxidase (POD), were augmented due to the inoculation with Azotobacter chroococcum and/or Alcaligenes faecalis. Regarding minerals’ uptake, there was a decline in sodium (Na) and an increase in nitrogen (N), potassium (K), calcium (Ca), and magnesium (Mg) uptake due to the application of either individual or co-inoculation with the mentioned bacterial isolates. This study showed that co-inoculation with Azotobacter chroococcum and Alcaligenes faecalis was the most effective treatment and could be considered a premium tool used in facing environmental problems, especially saline soils.

Symbiotic plant-fungi interaction is a promising approach to alleviate salt stress in plants. Moreover, endophytic fungi are well known to promote the growth of various crop plants. Herein, seven fungal endophytes were screened for salt tolerance; the results revealed that Aspergillus ochraceus showed a great potentiality in terms of salt tolerance, up to 200 g L⁻¹. The indole acetic acid (IAA) production antioxidant capacity and antifungal activity of A. ochraceus were evaluated, in vitro, under two levels of seawater stress, 15 and 30% (v/v; seawater/distilled water). The results illustrated that A. ochraceus could produce about 146 and 176 µg mL⁻¹ IAA in 15 and 30% seawater, respectively. The yield of IAA by A. ochraceus at 30% seawater was significantly higher at all tryptophan concentrations, as compared with that at 15% seawater. Moreover, the antioxidant activity of ethyl acetate extract of A. ochraceus (1000 µg mL⁻¹) at 15 and 30% seawater was 95.83 ± 1.25 and 98.33 ± 0.57%, respectively. Crude extracts of A. ochraceus obtained at 15 and 30% seawater exhibited significant antifungal activity against F. oxysporum, compared to distilled water. The irrigation of barley plants with seawater (15 and 30%) caused notable declines in most morphological indices, pigments, sugars, proteins, and yield characteristics, while increasing the contents of proline, malondialdehyde, and hydrogen peroxide and the activities of antioxidant enzymes. On the other hand, the application of A. ochraceus mitigated the harmful effects of seawater on the growth and physiology of barley plants. Therefore, this study suggests that the endophytic fungus A. ochraceus MT089958 could be applied as a strategy for mitigating the stress imposed by seawater irrigation in barley plants and, therefore, improving crop growth and productivity.

Drought is the main limiting abiotic environmental stress worldwide. Water scarcity restricts the growth, development, and productivity of crops. Wheat (Triticum aestivum L.) is a fundamentally cultivated cereal crop. This study aimed to evaluate the effect of grain-priming with arginine (0.25, 0.5, and 1 mM) on growth performance and some physiological aspects of wheat plants under normal or drought-stressed conditions. Morphological growth parameters, photosynthetic pigments, soluble sugars, free amino acids, proline, total phenols, flavonoids, and proteins profiles were determined. Drought stress lowered plant growth parameters and chlorophyll a and b contents while increasing carotenoids, soluble sugars, free amino acids, proline, total phenols, and flavonoids. Soaking wheat grains with arginine (0.25, 0.5, and 1 mM) improves plant growth and mitigates the harmful effects of drought stress. The most effective treatment to alleviate the effects of drought stress on wheat plants was (1 mM) arginine, that increased root length (48.3%), leaves number (136%), shoot fresh weight (110.5%), root fresh weight (110.8%), root dry weight (107.7%), chlorophyll a (11.4%), chlorophyll b (38.7%), and carotenoids content (41.9%) compared to the corresponding control values. Arginine enhanced the synthesis of soluble sugars, proline, free amino acids, phenols, and flavonoids in wheat plants under normal or stressed conditions. Furthermore, the protein profile varies in response to drought stress and arginine pretreatments. Ultimately, pretreatment with arginine had a powerful potential to face the impacts of drought stress on wheat plants by promoting physiological and metabolic aspects.

The application of green nanotechnology in agriculture has been receiving substantial attention, especially in the development of new nano-fertilizers and nano-insecticides. Herein, the metabolites secreted by the fungal strain Penicillium chrysogenum are used as a reducing agent for selenium ions to form selenium nanoparticles (Se-NPs). The synthesized Se-NPs were characterized using color change, UV-Vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), and dynamic light scattering (DLS). The biomass filtrate of the fungal strain changed from colorless to a ruby red color after mixing with sodium selenite with a maximum surface plasmon resonance at 262 nm. Data exhibits the successful formation of spherical, amorphous Se-NPs with sizes ranging between 3–15 nm and a weight percentage of 38.52%. The efficacy of Se-NPs on the growth performance of sunflower (Helianthus annuus L.) and inhibition of cutworm Agrotis ipsilon was investigated. The field experiment revealed the potentiality of Se-NPs to enhance the growth parameters and carotenoid content in sunflower, especially at 20 ppm. The chlorophylls, carbohydrates, proteins, phenolic compounds, and free proline contents were markedly promoted in response to Se-NPs concentrations. The antioxidant enzymes (peroxidase, catalase, superoxide dismutase, and polyphenol oxidase) were significantly decreased compared with the control. Data analysis showed that the highest mortality for the 1st, 2nd, 3rd, 4th, and 5th instar larvae of Agrotis ipsilon was achieved at 25 ppm with percentages of 89.7 ± 0.3, 78.3 ± 0.3, 72.3 ± 0.6, 63.7 ± 0.3, and 68.7 ± 0.3 respectively after 72 h.