The role of silicon in mitigating the incidence and damage of yellow stem borer in rice crops is well proven. However, the underlying mechanisms offered by silicon amendment in rice crops against yellow stem borer were not explored or poorly understood. Here, we have shown that silicon supplement to rice plants at 200 mg/kg of soil, improved silicification in stem tissues by increased length, width (18.1-32.5%), and area (6.6-14.2%) of silica cells and silicon content given over scanning electron microscopy and electron-dispersive spectrophotometric analysis. The increased activities of antioxidant and defense enzymes such as catalase (106-215%), superoxide dismutase (74.5%), peroxidase (52.1%), phenylalanine ammonia lyase (74%), and polyphenol oxidase (47.3%) in rice plants supplemented with silicon and infested with yellow stem borer at different durations were shown. The enhanced concentrations of total sugars (23.6%) and total phenols (18.4%) were also observed due to silicon supplement to rice plants. However, the defense enzyme activities were less in rice plants without silicon supplementation and yellow stem borer infestation. The outcome of the study highlighted the impact of silicon in activating the defense responses in rice plants infested with yellow stem borer. Silicon supplementation should be considered as one of the alternative and sustainable measures for integrated management of yellow stem borer in rice across ecosystems.
Organophosphate pesticides, widely used in agriculture, are effective in pest control but pose environmental and health risks through soil, water, and air contamination. Exposure to these chemicals is linked to adverse human health effects, underscoring the need for environmentally sustainable practices. This study aimed to assess urinary organophosphate metabolites and examine the relationship between GSTM1 and GSTT1 gene polymorphisms with biomarkers of oxidative stress among farmers in Himachal Pradesh exposed to pesticides. We collected urine samples (50 mL) from the exposed group to detect organophosphate metabolites using GC-MS. Blood samples (5 mL) were also obtained for GSTM1 and GSTT1 genotyping and assessment of antioxidant enzyme activities. The results showed decreased enzymatic activity of SOD (2.92 +/- 1.07) and catalase (12.60 +/- 3.15) in the exposed group, with increased MDA levels (4.14 +/- 1.36), compared with the unexposed group (SOD: 7.04 +/- 1.34, catalase: 25.75 +/- 2.20, MDA: 1.15 +/- 0.18). No significant associations (p > .05) were found between GSTM1 or GSTT1 genotypes and SOD, catalase, or MDA activities. The study concluded that prolonged pesticide exposure induces oxidative stress linked to specific genetic variations, suggesting directions for further research into the toxicogenetics of pesticide exposure and its health implications.
Heavy metal pollution reduces the community of soil microorganisms, including fungi from the genus Trichoderma, which are plant growth promotors and biological control agents. Because of potential effects on crop productivity, the toxic effects of heavy metals (HMs) in Trichoderma are of interest. However, there have been few studies on the biochemical and molecular response to oxidation caused by exposure to copper (Cu), chromium (Cr), and lead (Pb) and whether this antioxidant response is species-specific. In this study, we compared the tolerance of Trichoderma asperellum and Trichoderma longibrachiatum to Cu, Pb, and Cr and evaluated the expression of genes related to the antioxidant response, including glutathione peroxidase (GPX), catalase (CAT), and cysteine synthase (CYS) as well as the activity of peroxidase and catalase. The isolates of Trichoderma were selected because we previously reported them as promotors of plant growth and agents of biological control. Our results revealed that, with exposure to the three HMs, the Trichoderma cultures formed aggregates and the culture color changed according to the metal and the Trichoderma species. The tolerance index (TI) indicated that the two Trichoderma species were tolerant of HMs (Cu > Cr > Pb). However, the TI and conidia production revealed that T. longibrachiatum was more tolerant of HMs than T. asperellum. The three HMs caused oxidative damage in both Trichoderma species, but the enzyme activity and gene expression were differentially regulated based on exposure time (72 and 144 h) to the HMs and Trichoderma species. The main changes occurred in T. asperellum; the maximum expression of the GPX gene occurred at 144 h in response to all three HMs, whereas the CAT gene was upregulated at 72 h in response to Cu but downregulated at 144 h in response to all three HMs. The CYS gene was upregulated in response to the three metals. The peroxidase activity increased with all three HMs, but the catalase activity increased with Cu and Pb at 72 h and decreased at 144 h with Pb and Cr. In T. longibrachiatum, the GPX gene was upregulated with all three HMs at 72 h, the CAT gene was upregulated only with Pb at 72 h and was downregulated at 144 h with HMs. Cr and Cu upregulated CYS gene expression, but expression did not change with Pb. The peroxidase activity increased with Cu at 144 h and with Cr at 72 h, whereas Pb decreased the enzyme activity. In contrast, catalase activity increased with the three metals at 144 h. In conclusion, T. longibrachiatum was more tolerant of Cu, Cr, and Pb than was T. asperellum, but exposure to all three HMs caused oxidative damage to both Trichoderma species. Peroxidases and catalases were activated, and the expression of the genes GPX and CYS was upregulated, whereas the CAT gene was downregulated. These findings indicate that the antioxidant response to HMs was genetically modulated in each Trichoderma species.
PurposeAcanthamoeba species are eucaryotic protozoa found predominantly in soil and water. They cause ulceration and vision loss in the cornea (Acanthamoeba keratitis) and central nervous system (CNS) infection involving the lungs (granulomatous amoebic encephalitis). Antiparasitic drugs currently used in the treatment of infections caused by Acanthamoeba species are not effective at the desired level in some anatomical regions such as the eye and CNS. The existence of an agent effective against both cysts and trophozoites has not yet been proven. Drugs used for treatment of Acanthamoeba infrections are still limited.MethodThe present study investigates amoebicidal activites of various concentrations of ethanolic fruit extract of E. umbellata (EU) (40, 20, 10, 5, 2.5, 1.25, 0.625 mM/mL), silver nanoparticles (AgNP) that are synthesized from EU and confirmed with characterization tests (20, 10, 5, 1, 0.5 mM/mL), and lauric acid (LA) in EU detected with gas chromatography-mass spectrometry (GC-MS) against A. castellanii trophozoites. In addition, DNA-preserving activities of EU, AgNP and LA were studied on pBR322 plasmid DNA, following damage induced with hydroxyl radical (-OH). Cytotoxicity of EU over HeLa cells was examined with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Furthermore, the effects over the expression of SOD and CAT genes, which are coding oxidative stress enzymes in trophozoites, and expression of genes responsible for pseudocyst and cyst formation (CSII and CSP21, respectively) were investigated following methanol-induced stress, with reverse-transcriptase quantitative polymerase chain reaction (RT-qPCR).ResultsAt highest concentrations, EU, AgNP and LA showed lethal effects against majority of trophozites at 24 th h and against all trophozoites at 48th hour. EU at 5 mg/mL concentration and LA at 1, 0.8, 0.6, 0.4 mM/mL concentrations prevented DNA damage. A dose-dependent decrease in cell viability was observed, EU was found to be non-cytotoxic for 53.82% of HeLa cells at 72 nd h even at 40 mg/mL concentration. Greatest inhibitory effects were found with EU, AgNP and LA on CSII, EU on CAT, LA on CSP21, and hydrogen peroxide (H2O2) on SOD genes.ConclusionThe findings of this study show that EU, LA and AgNPs can be used in a controlled manner to combat A. castellanii infections by reducing or blocking the activity of the parasite's antioxidant enzymes (SOD and CAT), without giving the parasite a chance to initiate the process of pseudocyst or proper cyst formation.
Per- and polyfluoroalkyl substances (PFAS) are a class of persistent organic pollutants that pose a growing threat to environmental and human health. Soil acts as a long-term reservoir for PFAS, potentially impacting soil biodiversity and ecosystem function. Earthworms, as keystone species in soil ecosystems, are particularly vulnerable to PFAS exposure. In this study, we investigated the sublethal effects of three short-chain (C4-C6) next-generation perfluoropropylene oxide acids (PFPOAs) on the earthworm Eisenia fetida, using a legacy perfluoroalkyl carboxylic acid (PFCA), perfluorooctanoic acid (PFOA), as a reference. We assessed a suite of biochemical endpoints, including markers for oxidative stress (catalase and superoxide dismutase activity), immunity (phenol oxidase activity), neurotoxicity (acetylcholinesterase activity), and behavioural endpoints (escape test). Results indicate that all tested PFAS, even at sub-micromolar concentrations, elicited significant effects across multiple physiological domains. Interestingly, HFPO-DA demonstrated the most substantial impact across all endpoints tested, indicating broad and significant biochemical and neurotoxic effects. Our findings underscore the potential risks of both legacy and emerging PFAS to soil ecosystems, emphasising the need for further research to understand the long-term consequences of PFAS contamination.
Antioxidant complex enzymes have a significant role in cellular homeostasis control in plants, and they inhibit the toxic action of reactive oxygen species when they are in excess. There are many antioxidant enzymes executing this role; among these, superoxide dismutase, catalase, and ascorbate peroxidase are reported as the most studied in this process, as they prevent free radicals from becoming more reactive and toxic to cells. Thus, this research was conducted to evaluate antioxidant enzyme expression in response to hydric stress at the reproductive stage in upland rice genotypes. Three genotypes from the upland rice breeding program on agreement between UFLA, EPAMIG, and EMBRAPA, CMG2093, CMG2172, and BRSMG Relampago, were used as controls. Genotypes were grown under field conditions with supplementary irrigation during the whole crop cycle, and hydric stress was induced in the reproductive phase before panicle emission. Seedlings were used in enzyme analyses from the emergence test and IVE on substrate (soil+sand at a 2:1 rate) at 70% and 10% field capacity. Significant differences were observed among genotypes for vigor tests. In biochemical tests, the CMG2093 genotype had lower damage on hydric deficit, with the best performance under hydric restriction conditions, being considered tolerant for this stress type.
Microplastics (MP) are now present in all ecosystems and undergo weathering processes, including physical or chemical degradation. Although most studies have been carried out on MP toxicity in the marine ecosystem, interest is growing for the terrestrial and entire aquatic compartments. However, the interface between both environments, also known as the soil/water continuum, is given little consideration in MP toxicity studies. Only a few studies considered the toxicity of artificially aged or soil field-collected MP on species living at this interface. The present study evaluates the impact of artificial and field aging polyethylene (PE) MP on the bivalve Scrobicularia plana, a key organism of the estuarine compartment, living at the soil/water interface. Clams were exposed for 21 days to environmental concentrations (0.008, 10 and 100 mu g L-1) of unaged as well as artificially and field aged PE MP. Toxicity was assessed from individual to molecular levels including condition index, clearance rate, burrowing behavior, energy reserves, enzyme activities and DNA damage. Results showed differential effects at all biological levels depending on the type and the concentration of the MP tested. Indeed, a decrease in burrowing behavior was observed in S. plana exposed to aged and field PE at low concentration (0.008 mu g L-1). In the gills of clams, exposures to aged PE (0.008 and 100 mu g L-1), virgin PE (10 mu g L-1) and field PE (all tested concentrations) decreased CAT activity while DNA damage increased after exposure to virgin PE (0.008 mu g L-1 and 10 mu g L-1) and field PE (0.008 mu g L-1). Our findings suggest that aging modifies the toxicity profile of PE polymer on S. plana and considering plastic from field at environmental concentrations is important when performing ecotoxicological studies.
Zinc (Zn) deficiency and salt stress are well-known soil problems and often happen parallelly in cultivated soils. In this study, Zn-amino acid complexes (Zn-AAc) were used as a source of Zn to determine their effects on salt-induced damage in wheat plants. The bread wheat (Triticum aestivum L. cvs. Kavir) was supplied with Zn-glycine (Zn-Gly), Zn-alanine (Zn-Ala), and ZnSO4 as Zn sources at three salinity levels (EC 2, 4 and 6 dS m(-)). Salinity caused a significant decrease in shoot dry matter and grain yield of wheat, but this negative effect was significantly improved by the application of Zn-AAc. Salt stress decreased shoot and grain Zn concentration, but this reduction was lower in plants supplied by Zn-AAc. Calcium (Ca) and potassium (K) concentrations were increased in a shoot by salinity stress while decreased in grain. Sodium (Na) concentration decreased in shoot and grain by using Zn-AAc. At all of the salinity levels, wheat supplied with Zn-AAc had lower lipid peroxidation compared to those grown under the ZnSO4 source. Application of Zn-AAc increased the activities of catalase (CAT) and superoxide dismutase (SOD) in the roots of wheat plants in saline conditions. Based on the results, the adverse effects of salinity stress on wheat plants can moderately improve with Zn-AAc application.
Plastic has become indispensable in various industries, including agriculture, due to its affordability and versatility. Overutilizing plastic in agriculture produces microplastics, which pose significant environmental damage and cause several health implications. Hence, biodegradable mulch films were produced as an alternative to plastic by integrating atrazine (PXA) into the Poly (Vinyl Alcohol)/Xanthan gum polymer blend by solvent casting method. The PXA mulch films exhibited a compact structure and a slight reduction in crystallinity due to the crosslinking caused by the atrazine herbicide. The PXA mulch films excelled over the current biodegradable mulches, demonstrating a tensile strength of 42.73 +/- 0.51 MPa and an elongation at a break of 60.58 +/- 1.21 %. The addition of atrazine improved the ability of the PXA mulch films to block ultraviolet (UV) radiation, suppress the water vapour transmission rate (WVTR), and enhance the hydrophobic properties. The PXA mulch films, buried in soil for 15d, exhibited a degradation rate of 7.50 +/- 0.64 %, confirming their biodegradability. Herbicidal test was conducted with PXA mulch using Johnson grass as a weed. PXA mulch effectively retarded weed with enhancement of atrazine concentration. Kinetics investigations have verified that the release of the herbicide is governed by Fickian diffusion and exhibits a dependence on its concentration. For the impending harvest, soil fertility is also a crucial factor. PXA mulch films break down into organic matter to stimulate microbial development. Urease activity due to atrazine creates mulch soil rich in nitrogen content, and elevation in catalase activity ensures significant microbial development. These results of biodegradable PXA mulch films address the loss of soil fertility caused by applying PE mulching, which is the underlying cause of microplastic formation. These research findings suggest that PXA biodegradable mulch film could be an alternative to hazardous PE mulch in agriculture.
The aim of the study was to assess the impact of plant extracts from hemp inflorescences (H10-10% and H20-20%), as well as a mixture of extracts from hemp inflorescences, sage, and tansy leaves (M10-10% and M20-20%) on phytotoxicity and selected physiological and biometric parameters of wheat seedlings, as well as the biological activity of soil in a growth chamber experiment. In all experimental combinations, a low phytotoxicity of the extracts was observed in the form of leaf tip yellowing, classified as first-degree damage or its complete absence. The plant extracts and their mixtures, except for the H20 extract, had an inhibitory effect on the development of fungal pathogens, especially Fusarium spp. The H20 extract increased the fresh and dry weight of root seedlings. The tested extracts also had a positive effect on the chlorophyll content in seedlings. The highest chlorophyll concentrations were recorded for the seedlings sprayed with the M20 extract mixture. The applied plant extracts influenced the activity of soil enzymes. The highest activity of catalase and dehydrogenases was observed after spraying seedlings with M20, while the lowest was recorded after applying H10. Of all the tested groups of soil environment compounds included in the Biolog EcoPlates test, carbohydrates and carboxylic acids were most actively utilized. Conversely, amines and amides constituted the group of compounds utilized the least frequently. The present study demonstrated the high effectiveness of plant extracts on wheat seedlings due to their biocidal action against phytopathogenic fungi and increased biological activity of the soil. This research serves as an initial phase of work, which will aim to verify the results obtained under field conditions, as well as assess the biological stability of the extracts.