Search Results (29)

Electrospun nanofiber membranes based on cellulose acetate (CA) have gained increasing attention for wastewater treatment due to their high surface area, tuneable structure, and ease of functionalization. In this study, the performance of CA membranes was enhanced by incorporating aluminum oxide (Al₂O₃) nanoparticles (NPs) at varying concentrations (0–2 wt.%). The structural, morphological, and thermal properties of the resulting CA/Al₂O₃ nanocomposite membranes were investigated through FTIR, XRD, SEM, water contact angle (WCA), pore size measurements, and DSC analyses. FTIR and XRD confirmed strong interactions and the uniform dispersion of the Al₂O₃ NPs within the CA matrix. The incorporation of Al₂O₃ improved membrane hydrophilicity, reducing the WCA from 107° to 35°, and increased the average pore size from 0.62 µm to 0.86 µm. These modifications led to enhanced filtration performance, with the membrane containing 2 wt.% Al₂O₃ achieving a 99% removal efficiency for Indigo Carmine (IC) dye, a maximum adsorption capacity of 45.59 mg/g, and a high permeate flux of 175.47 L·m⁻² h⁻¹ bar⁻¹. Additionally, phytotoxicity tests using Lactuca sativa seeds showed a significant increase in germination index from 20% (untreated) to 88% (treated), confirming the safety of the permeate for potential reuse in agricultural irrigation. These results highlight the effectiveness of Al₂O₃-modified CA electrospun membranes for sustainable wastewater treatment and water reuse. Full article

The disposal of olive mill wastewater (OMWW) poses significant environmental challenges due to its high content of phytotoxic and pollutant compounds. This study aims to explore the chemical composition of OMWW derived from various olive varieties (Buža, Buža puntoža, Istarska bjelica, Leccino, and Rosinjola) and assess its antifungal potential against phytopathogenic fungi from the Botryosphaeriaceae family. OMWW samples were analyzed for their physicochemical properties, phenolic composition via LC-MS/MS, and antifungal activity against Botryosphaeria dothidea (Moug. ex Fr.) Ces. & De Not., Diplodia mutila (Fr.) Fr., D. seriata De Not., Dothiorella iberica A.J.L. Phillips, J. Luque & A. Alves, Do. sarmentorum (Fr.) A.J.L. Phillips, Alves & Luque, and Neofusicoccum parvum (Pennycook & Samuels) Crous, Slippers & A.J.L. Phillips. Antifungal efficacy was tested at varying concentrations, alongside the phenolic compounds hydroxytyrosol and vanillic acid. Antifungal activity varied across fungal species and OMWW concentrations. Lower OMWW concentrations inhibited mycelial growth in some pathogens, while higher concentrations often had a stimulatory effect. Among the OMWW treatments, Leccino and Buža showed the most significant antifungal activity against species from the Botryosphaeriaceae family. The results demonstrated significant variability in OMWW composition, with Istarska bjelica exhibiting the highest concentrations of phenolic compounds, sugars, dry matter, and carbon and nitrogen content. The results also highlight the impact of acidification on the phenolic profile of OMWW. Treatment with HCl significantly altered the concentration of individual phenolic compounds, either enhancing their release or contributing to their degradation. Among the two compounds, vanillic acid showed greater efficacy than hydroxytyrosol. In addition, microorganisms isolated from OMWW, including Bacillus velezensis Ruiz-Garcia et al., Rhodotorula mucilaginosa (A. Jörg.) F.C. Harrison, Nakazawaea molendiniolei (N. Cadez, B. Turchetti & G. Peter) C. P. Kurtzman & C. J. Robnett, and Penicillium crustosum Thom, demonstrated antagonistic potential against fungal pathogens, with B. velezensis showing the strongest inhibitory effect. The greatest antagonistic effect against fungi was observed with the species Do. Iberica. The findings highlight the potential of OMWW as a sustainable alternative to chemical fungicides, simultaneously contributing to the management of waste and protection of plants through circular economy principles. Full article

The phytotoxicity of aluminum (Al) to plants is well known. Auxin accumulation and reactive oxygen species (ROS) burst induced by Al toxicity are the key factors in root growth inhibition. Yucasin, an auxin synthesis inhibitor, effectively ameliorates Al phytotoxicity in tomato seedlings. However, the physiological mechanisms by which yucasin alleviates Al phytotoxicity in tomatoes remain elusive. Here, we examined the regulatory mechanisms of yucasin involved in tomato seedling growth under Al conditions through phenotypic, plant physiology analysis, and cellular experiments. Exogenous indole-3-acetic acid (IAA) application increased Al accumulation in tomato seedling roots, while yucasin decreased Al accumulation. Yucasin application reduced Al-induced ROS accumulation, lipid peroxidation, and cell death, enhanced root viability, and promoted tomato seedling root growth. Further, yucasin enhanced the antioxidant enzyme activities of superoxide dismutase, catalase, and peroxidase in plants under Al conditions. The results suggest that yucasin improves the scavenging capacity of ROS by maintaining the activities of antioxidative enzymes. This study elucidates the physiological mechanism by which yucasin alleviates Al phytotoxicity, highlighting its potential to enhance plant tolerance under acidic Al conditions. Full article

Real textile wastewater (RTWW) poses significant environmental challenges. RTWW typically contains high levels of organic compounds, such as dyes, as well as inorganic substances like salts. These contaminants can harm aquatic life when released into water bodies without appropriate treatment. RTWW was subjected to a series of sequential treatments: exchange resins for removing ions, advanced oxidation with bicarbonate-activated peroxide to degrade organic matter, and a biological treatment based on the Zahn–Wellens test to remove remaining chemical oxygen demand (COD) The advanced oxidation process based on the activation of H₂O₂ with NaHCO₃ (catalyzed with cobalt impregnated on a pillared clay, Co/Al–PILC)) was optimized using central composite design (CCD) and response surface methodology (RSM). After the process integration, reductions in ion concentrations, chemical oxygen demand (COD), and total organic carbon content (TOC) were achieved. Reduced hardness (99.94%) and ions (SO₄²⁻ and acid black 194 dye of 99.88 and 99.46%, respectively), COD (96.64%), and TOC (96.89%), guaranteeing complete treatment of RTWW, were achieved. Additionally, the biodegradability index of RTWW increased from 0.28 ± 0.01 to 0.90 ± 0.01, and phytotoxicity was reduced, going from a phytotoxic that inhibited the germination of lettuce seeds to a phytostimulant after biological treatment with activated sludge. Full article

Metsulfuron-methyl, a widely used herbicide, could cause damage to the sensitive plants in crop-rotation systems at extremely low levels in the soil. The potential of plant growth-promoting bacteria (PGPB) for enhancing the resistance of plants against herbicide stress has been discovered recently. Therefore, it is poorly understood how physiological processes occur in plants, while PGPB reduce the phytotoxicity of herbicides for agricultural crops. In greenhouse studies, the effect of strains Pseudomonas protegens DA1.2 and Pseudomonas chlororaphis 4CH on oxidative damage, acetolactate synthase (ALS), enzymatic and non-enzymatic antioxidants in canola (Brassica napus L.), and wheat (Triticum aestivum L.) were investigated under two levels (0.05 and 0.25 mg∙kg⁻¹) of metsulfuron-methyl using spectrophotometric assays. The inoculation of herbicide-exposed wheat with bacteria significantly increased the shoots fresh weight (24–28%), amount of glutathione GSH (60–73%), and flavonoids (5–14%), as well as activity of ascorbate peroxidase (129–140%), superoxide dismutase SOD (35–49%), and ALS (50–57%). Bacterial treatment stimulated the activity of SOD (37–94%), ALS (65–73%), glutathione reductase (19–20%), and the accumulation of GSH (61–261%), flavonoids (17–22%), and shoots weight (27–33%) in herbicide-exposed canola. Simultaneous inoculation prevented lipid peroxidation induced by metsulfuron-methyl in sensitive plants. Based on the findings, it is possible that the protective role of bacterial strains against metsulfuron-metil is linked to antioxidant system activation. Full article

This article presents the results of research on the influence of polymetallic-dust aerial emissions on the pollution levels in the soil and plants by heavy metals, which have been under the impact of the “Severonickel” smelter complex on the Kola peninsula (Russia) for more than 40 years. Research using soil and plant indicators was carried out at monitoring plots in the years 1980–1999 (with high aerotechnogenic emissions) and 2000–2019 (with low aerotechnogenic emissions). The organic horizon (forest litter) of the Al-Fe-humus podzol, assimilation organs of Vaccinium myrtillus L., V. vitis-idaea L., V. uliginosum L., Empetrum hermaphroditum Hagerup, and Pinus sylvestris L. as well as tree rings of Scots pine were used for bioindication research. The content of heavy metals was determined using the AAS method. During these time periods, the emissions of polymetallic dust decreased 3.5 fold, while the level of forest litter contamination with heavy metals in the buffer and impact zones increased by 2–5 times, resulting in increased phytotoxicity of the soil and reduced habitat quality for forest plants. At present, the content of Ni and Cu in the leaves (needles) of the plant indicators in the impact zone has decreased by 3–8 times compared with 1980–1999 but their elevated levels pose a potential health risk. The decrease in atmospheric emissions of pollutants led to a 1.5-fold increase in the width of the annual rings of pine trunks in the impact zone, which may indicate the beginning of the recovery of pine-trunk-wood productivity. Full article

Background and Aims: In acidic soils, aluminum (Al) toxicity remains a critical crop limitation that can be ameliorated by organic amendments through Al complexation with high-molecular-weight carbon compounds, particularly fulvic and humic acids (FA and HA) However, no research discriminates between the direct effects of FA and HA on plant growth and the indirect effect that occurs through ameliorating Al toxicity. This study delineates the direct and indirect effects of FA and HA on plant growth. Methods: Eucalyptus and Hay FA and HA, and Al effects on maize (Zea mays) root growth were investigated using dilute nutrient solution. Five Al concentrations (0–270 µM) were combined with four organic acid (OA) treatments, including Nil-OA, FA40, and HA40 (each at 40 mg C L⁻¹) and a combined treatment FA40HA40 (80 mg C L⁻¹). Results: Eucalyptus FA and HA stimulated root growth by ~20% compared with root growth in the Nil-OA (17.4 cm). In the absence of Al, Hay FA and HA inhibited root growth (by ~20%) compared with the Nil-OA but the addition of Al resulted in stimulation of root growth. In the presence of FA and HA, root growth was not inhibited by nominally toxic monomeric Al (Al³⁺) concentrations (~20 µM Al). However, when expressed on a relative basis to remove the direct effect of the ligand, the response was consistent with Al toxicity. Conclusions: The effects of FA and HA were either inhibitory or stimulatory depending on the source while both sources of FA and HA mitigated Al toxicity through complexation. The study provides mechanistic data that highlights limitations of soil bioassays where the direct effects of organic ligands on root growth are confounded with the indirect effect of their reduction of Al toxicity. These two independent processes must be considered in evaluating the amelioration of Al by organic amendments. Full article

Chaetomium cupreum, a root endophyte in Miscanthus sinensis, enhances Al tolerance in M. sinensis by changing aluminum (Al) localization and the production of a siderophore, oosporein, which chelates Al for detoxification. Oosporein has various functions, including insecticidal activity, phytotoxicity, antifungal activity, and a siderophore. In our study, we focused on the detoxification effect of oosporein as a siderophore and on the growth of M. sinensis under Al exposure. In addition, the phytotoxicity of oosporein to M. sinensis was confirmed to compare with those in Lactuca sativa and Oryza sativa as control plants. Under Al stress, oosporein promoted plant growth in M. sinensis seedlings at 10 ppm, which was the same concentration as that detected in M. sinensis roots infected with C. cupreum in our previous study. Oosporein also showed low phytotoxicity to M. sinensis compared with L. sativa at even high concentrations of oosporein. These results suggest that the concentration of oosporein in M. sinensis roots would be maintained at the appropriate concentration to detoxify Al and would promote M. sinensis growth under Al stress, although oosporein would show low phytotoxicity to the natural host plant, M. sinensis, compared with the non-host plant, L. sativa. Full article

Bispyribac-sodium (BS) is an herbicide often used to control weeds in rice fields. Hydrogen-rich water (HRW) has recently been recommended for alleviating adverse effects, but whether and how HRW alleviates the injury to rice from exposure to BS is still largely unknown. In this study, a greenhouse hydroponic experiment showed that BS alone could substantially inhibit the plant height and fresh weight of both indica and japonica rice seedlings. For indica rice, its pretreatment with HRW at 75% saturation could markedly alleviate the impact on its size but not so with either 50% or 100% HRW. For japonica rice, all the concentrations of HRW used in this study (50%, 75%, and 100% HRW) were capable of reversing the plant size reductions. Further results revealed that the HRW supplement could increase the activity of antioxidative enzymes, including that of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD), which assist in the effective removal of ROS (reactive oxygen species). Subsequent results demonstrated a weaker inhibition of the acetolactate synthase (ALS) enzyme within five days by BS in rice seedlings pretreated with HRW than those receiving the BS treatment alone, and that the HRW pretreatment can hasten the rate at which BS is degraded in rice. Taken together, these findings strongly suggest that pretreatment with HRW may offer a promising and effective strategy to improve the ability of rice to tolerate BS. Full article

The bacteria Pseudomonas savastanoi pv. glycinea (Coerper, 1919; Gardan et al., 1992) (Psg) and Curtobacterium flaccumfaciens pv. flaccumfaciens (Hedges 1922) (Cff) are harmful pathogens of soybean (Glycine max). Presently, there are several strategies to control these bacteria, and the usage of environmentally friendly approaches is encouraged. In this work, purified essential oils (EOs) from 19 plant species and total aqueous and ethanolic plant extracts (PEs) from 19 plant species were tested in vitro to observe their antimicrobial activity against Psg and Cff (by agar diffusion and broth microdilution method). Tested EOs and PEs produced significant bacterial growth inhibition with technologically acceptable MIC and MBC values. Non-phytotoxic concentrations for Chinese cinnamon and Oregano essential oils and leather bergenia ethanolic extract, which previously showed the lowest MBC values, were determined. Testing of these substances with artificial infection of soybean plants has shown that the essential oils of Chinese cinnamon and oregano have the maximum efficiency against Psg and Cff. Treatment of leaves and seeds previously infected with phytopathogens with these essential oils showed that the biological effectiveness of leaf treatments was 80.6–77.5% and 86.9–54.6%, respectively, for Psg and Cff. GC-MS and GC-FID analyzes showed that the major compounds were 5-Methyl-3-methylenedihydro-2(3H)-furanone (20.32%) in leather bergenia ethanolic extract, cinnamaldehyde (84.25%) in Chinese cinnamon essential oil and carvacrol (62.32%) in oregano essential oil. Full article

The current research aims to study the impacts of adding corncob biochar to a sandy soil irrigated with drainage water on wheat productivity, heavy metals fate, and some soil properties that reflect healthy soil conditions. This research consists of two separate experiments under field (lysimeters) and pot incubation conditions conducted on sandy soil irrigated with drainage water and treated with corncob biochar at the rate of 0.0, 1, 2, and 3% as mixing or mulching. Results specified that drainage water electrical conductivity value (5.89 dS m⁻¹) lies under the degree of restriction on use of “Severe”, indicating that nonstop irrigation with such drainage water may cause a severe salinity problem in soil in the long run. A comparison of heavy metal concentrations of biochar-treated soils with the control showed that total heavy metals had accumulated significantly in the topsoil layer. Most of the available heavy metal concentrations in all soil leachate fractions were below the method detection limits. Mean concentrations of Ni, Cd, and Pb in wheat crops were far below the concentrations considered phytotoxic to wheat plants. More than 90% of the Ni, Cd, and Pb contained in the drainage water of the Al-Moheet drain were significantly present (p ≤ 0.05) and adsorbed by biochar in the top 20 cm of soil lysimeters, indicating the high biochar adsorptive capacity of heavy metals. Total counts of bacteria and fungi gradually and significantly increased over the soil incubation time despite irrigation with contaminated drainage water. Soil resistance index (SRI) values for microbial biomass were positive throughout the experiment and increased significantly as the application rate of corncob biochar increased. These results indicated the high feasibility of using corncob biochar at a rate of 3% to temporarily improve the health of sandy soil despite irrigation with drainage water. Full article

Herbicides, commonly used in agriculture to control weeds, often cause negative effects on crops. Safeners are applied to reduce the damage to crops without affecting the effectiveness of herbicides against weeds. Plant biostimulants have the potential to increase tolerance to a series of abiotic stresses, but very limited information exists about their effects on herbicide-stressed plants. This study aims to verify whether the application of a potential safener such as Terra-Sorb^®, an L-α-amino acid-based biostimulant, reduces the phytotoxicity of an Imazamox-based herbicide and to elucidate which tolerance mechanisms are induced. Sunflower plants were treated with Pulsar^® 40 (4% Imazamox) both alone and in combination with Terra-Sorb^®. Plants treated with the herbicide in combination with Terra-Sorb^® showed higher growth, increased acetolactate synthase (ALS) activity, and amino acid concentration with respect to the plants treated with Imazamox alone. Moreover, the biostimulant protected photosynthetic activity and reduced oxidative stress. This protective effect could be due to the glutathione S-transferase (GST) induction and antioxidant systems dependent on glutathione (GSH). However, no effect of the biostimulant application was observed regarding phenolic compound phenylalanine ammonium-lyase (PAL) activity. Therefore, this study opens the perspective of using Terra-Sorb^® in protecting sunflower plants against an imazamox-based herbicide effect. Full article

Hydrangea macrophylla exhibiting blue sepals (versus purple or pink) have improved marketability; however, little research has been conducted to evaluate aluminum (Al), the element responsible for bluing, on crop growth, effectiveness of bluing sepals, and characteristics of flower clusters in an outdoor nursery. This study compared substrate Al availability, crop growth, flower color, number, and size over a 56-week period in two locations. A polymer coated (90-day release) or ground aluminum sulfate [Al₂(SO₄)₃; water soluble] was either incorporated into a non-limed pine bark substrate, applied to the surface of the substrate as a top dress, or as a routinely applied Al₂(SO₄)₃ drench (low concn.) or applied once (high concn.). In general, application of Al increased plant foliar Al concentration, but also decreased substrate pore-water pH and increased electrical conductivity (EC) with varying effects based on the applied product’s solubility and subsequent longevity. Aluminum sulfate increased the potential of Al phytotoxicity negatively affecting root morphology and creating an undesirable rhizosphere electrochemistry due to the pH being continually acidic, <4, and the EC being temporarily increased to >1.5 mS·cm⁻¹. These suboptimal rhizosphere conditions resulted in a lower quality or smaller plant. No plants exhibited clear, deep blue flower cluster sought by consumers. Neither the effect of pore water pH or EC could, alone or in combination, account for the lack of plant vigor or blue flower clusters when substrate and foliar Al concentrations were adequate in flowering H. macrophylla. More research is needed to investigate the effect of pore-water electrochemical properties, possible mineral nutrient co-factors that provide Al synergisms or toxicity protections, and holistic plant health on ensuring blue coloration of a vigorous H. macrophylla. Full article