Cinnamomum camphora methanolic extract was tested for antifungal activity against three common, isolated, widespread phytopathogens: Alternaria alternata, Fusarium solani, and Fusarium oxysporum, which were molecularly identified and assigned accession numbers ON795987, ON795988, and ON795989, respectively. At 4000 µg/mL, the highest concentration of C. camphora methanolic extract inhibits the fungal mycelia weight of F. oxysporum, A. alternata, and F. solani by 60, 49, and 24%, respectively. The presence of several bioactive metabolites in the C. camphora extract could explain its antifungal activity. The presence of numerous phenolic and flavonoid compounds in the extract was revealed by HPLC analysis, including catechin and gallic acid, which had the highest concentrations of 6.21 and 6.98 µg/mL, respectively. Furthermore, osmoprotectants, total amino acids, and glycine betaine were abundant. Furthermore, total antioxidant activities, as measured by PMA and DPPH, were significant. The most abundant compound in the extract, according to GC-MS analysis, was mono(2-ethylhexyl) ester of 1,2-benzene dicarboxylic acid. Based on its in vitro efficacy in inhibiting mycelial growth weight, the tested extract could be recommended as a safe fungicide instead of a chemical treatment.

Selenium (Se) is a nutritional component necessary for animal and plant development and reproduction. Selenium nanoparticles (SeNPs) have a high absorption rate during routine supplementation. In the current study, a cell-free extract of Aspergillus terreus was used as a reducing and stabilizing agent in the synthesis of SeNPs using a green and eco-friendly method. The mycosynthesized SeNPs were characterized by UV-visible spectrophotometry, Fourier transform infrared spectroscopy, X-ray diffraction spectroscopy, dynamic light scattering, transmission electron microscopy, and scanning electron microscopy. The results of the characterization process showed that the mycosynthesized SeNPs had spherical shapes and sizes less than 100 nm. Results showed that mycosynthesized SeNPs exhibited promising antibacterial activity against both Gram-positive and Gram-negative bacteria where inhibition zones were 14, 20, 16, and 13 mm toward S. haemolyticus, S. aureus, E. coli, and K. pneumoniae, respectively. However, it had weak antifungal activity against C. albicans, where the inhibition zone was 12 mm. The efficacy of mycosynthesized SeNPs for the decolorization of malachite green dye was investigated. Results illustrated that SeNPs exhibited rapid biodegradation of malachite green dye, reaching up to 89% after 240 min. In conclusion, SeNPs were successfully biosynthesized using A. terreus and demonstrated both antimicrobial and photocatalytic activities.

The increasing usage of chemical control agents, as well as fungicides to manage plant diseases, causes human and environmental health problems. Macroalgae represent a reservoir for a tremendous variety of secondary metabolites that display a wide range of biological activities. However, their anti-phytopathogenic properties are still being studied. The current study was conducted to investigate whether or not the macroalgae Ulva fasciata extract exhibits antifungal and antiviral activities. In this regard, the organic extracts of U. fasciata were tested for their capabilities against tobacco mosaic virus (TMV) and three molecularly identified fungal isolates, Fusarium verticillioides, Alternaria tenuissima, and Botrytis cinerea with accession numbers OP363619, OP363620, and OP363621, respectively. Among the three tested extract concentrations, 100 µg/mL had the best biological activity against B. cinerea and TMV, with 69.26%and 81.25% inhibition rates, respectively. The HPLC analysis of chemical profiling of the extract showed the presence of a number of phenolic and flavonoid compounds widely known to display many biological activities. In this line, the 4-Hydroxybenzoic acid was the highest phenolic compound (12.3 µg/mL) present in the extract, followed by ferulic acid (9.05 µg/mL). The 7-hydroxyflavone (12.45 µg/mL) was the highest flavonoid in the organic extract of U. faciata followed by rutin, which recorded a concentration of 7.62 µg/ mL. The results of this study show that the U. fasciata extract has antiviral and antifungal properties, which makes it a possible source of natural antimicrobial agents.

Root rot is one of the most significant soil and seed-borne fungal diseases, limiting the cultivation of fenugreek plants. Endophytic bacteria and their natural bioproducts have emerged as growth promoters and disease suppressors in the current era. Despite limited research, seeds are a good funder of endophytic microbiomes, which are transmitted from them to other seedling parts, thereby providing a shield against biotic and abiotic anxiety and promoting the growth at early germination and later stages. The current study evaluated the hypothesis that seed endophytic bacteria and their lytic enzymes, growth promotors, and antifungal molecules can induce growth, and inhibit root rot disease development at the same time. The isolation trial from fenugreek seeds revealed a lytic Achromobacter sp., which produces indole acetic acid, has antifungal compounds (e.g., 2-Butanol, 3,3’-oxybis-), and reduces the growth of Rhizoctonia solani by 43.75%. Under the greenhouse and natural field conditions, bacterial cells and/or supernatant improved the growth, physiology, and yield performance of fenugreek plants, and effectively suppressed the progress of root rot disease; this is the first extensive study that uses a new seed-borne endophytic bacterium as a plant-growth-promoting, and biocontrol tool against the sclerotia-forming; R. solani; the causative of fenugreek root rot.

Potato virus Y (PVY) is one of the most harmful phytopathogens. It causes big problems for potatoes and other important crops around the world. Nanoclays have been extensively studied for various biomedical applications. However, reports on their interactions with phytopathogens, particularly viral infections, are still limited. In this study, the protective activity of Egyptian nanoclay (CE) and standard nanoclay (CS) against PVY was evaluated on potato (Solanum tuberosum L.) plants. Their physicochemical and morphological properties were examined with scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and energy dispersive spectrometer (EDS). SEM and TEM analyses revealed that CE has a spherical and hexagonal structure ranging from 20 to 80 nm in size, while CS has boulder-like and tubular structures of about 320 nm in size. FTIR and EDS showed that both nanoclay types have different functional groups and contain many vital plant nutrients that are necessary for every stage and process of the plant, including development, productivity, and metabolism. Under greenhouse conditions, a 1% nanoclay foliar application enhanced potato growth, reduced disease symptoms, and reduced PVY accumulation levels compared with non-treated plants. Significant increases in levels of antioxidant enzymes (PPO and POX) and considerable decreases in oxidative stress markers (MDA and H₂O₂) were also reported. Moreover, a significant increase in the transcriptional levels of defense-related genes (PAL-1, PR-5, and CHI-2) was observed. All experiment and analysis results indicate that the CE type is more effective than the CS type against PVY infection. Based on these results, the foliar applications of nanoclay could be used to manage plant viral infections in a way that is both effective and environmentally friendly. To our knowledge, this is the first report of the antiviral activity of the foliar application of nanoclay against PVY infection.

In the current study, four organic solvents, including ethanol, methanol, acetone, and diethyl ether, were used to extract turmeric, wheat bran, and taro peel. The efficiency of three different concentrations of each solvent was assessed for their antifungal and anti-mycotoxin production against Aspergillus flavus. The results indicated that 75% ethanolic and 25% methanolic extracts of taro peels and turmeric were active against fungus growth, which showed the smallest fungal dry weight ratios of 1.61 and 2.82, respectively. Furthermore, the 25% ethanolic extract of turmeric showed the best result (90.78%) in inhibiting aflatoxin B₁ production. After 30 days of grain storage, aflatoxin B₁ (AFB₁) production was effectively inhibited, and the average inhibition ratio ranged between 4.46% and 69.01%. Simultaneously, the Topsin fungicide resulted in an inhibition ratio of 143.92%. Taro extract (25% acetone) produced the highest total phenolic content (61.28 mg GAE/g dry extract wt.) and showed an antioxidant capacity of 7.45 μg/mL, followed by turmeric 25% ethanol (49.82 mg GAE/g), which revealed the highest antioxidant capacity (74.16 μg/mL). RT-qPCR analysis indicated that the expression of aflD, aflP, and aflQ (structural genes) and aflR and aflS (regulatory genes) was down-regulated significantly compared to both untreated and Topsin-treated maize grains. Finally, the results showed that all three plant extracts could be used as promising source materials for potential products to control aflatoxin formation, thus creating a safer method for grain storage in the environment than the currently used protective method.