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1.
Ecotoxicol Environ Saf ; 214: 112119, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33714137

RESUMO

Rice cultivation under cadmium (Cd) contaminated soil often results in reduced growth with excess grain Cd concentrations. A pot experiment was conducted to assess the potential of ultrasonic seed treatment to alleviate Cd stress in rice. Seeds of two aromatic rice cultivars i.e., Xiangyaxiangzhan and Meixiangzhan 2 and two non-aromatic rice cultivars i.e., Huahang 31 and Guangyan 1 were exposed to ultrasonic waves for 1.5 min in 20-40 KHz mixing frequency. The experimental treatments were comprised of untreated seeds (U0) and ultrasonic treated seeds (U1) transplanted in un-contaminated soil (H0) and Cd-contaminated soil (H1). Results revealed that Cd contents and Cd accumulation in grain in U1 were 33.33-42.31% and 12.86-57.58% lower than U0 for fragrant rice cultivars under H1. Meanwhile, biomass production was higher in U1 than U0 under H0 and better yield was assessed in U1 for all cultivars under H1. The activity of peroxidase (POD) in flag leaves was increased by 8.28-115.65% for all cultivars while malondialdehyde (MDA) contents were significantly decreased in U1 compared with U0 under H0. Conclusively, ultrasonic treatment modulated Cd distribution and accumulation in different parts while improved physiological performance as well as yield and grain quality of rice under Cd contaminated conditions.


Assuntos
Cádmio/metabolismo , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Poluentes do Solo/metabolismo , Ondas Ultrassônicas , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/metabolismo , Malondialdeído/metabolismo , Peroxidases/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Sementes/crescimento & desenvolvimento
2.
Int J Mol Sci ; 22(3)2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33513755

RESUMO

High bicarbonate concentrations of calcareous soils with high pH can affect crop performance due to different constraints. Among these, Fe deficiency has mostly been studied. The ability to mobilize sparingly soluble Fe is a key factor for tolerance. Here, a comparative transcriptomic analysis was performed with two naturally selected Arabidopsis thaliana demes, the carbonate-tolerant A1(c+) and the sensitive T6(c-). Analyses of plants exposed to either pH stress alone (pH 5.9 vs. pH 8.3) or to alkalinity caused by 10 mM NaHCO3 (pH 8.3) confirmed better growth and nutrient homeostasis of A1(c+) under alkaline conditions. RNA-sequencing (RNA-seq) revealed that bicarbonate quickly (3 h) induced Fe deficiency-related genes in T6(c-) leaves. Contrastingly, in A1(c+), initial changes concerned receptor-like proteins (RLP), jasmonate (JA) and salicylate (SA) pathways, methionine-derived glucosinolates (GS), sulfur starvation, starch degradation, and cell cycle. Our results suggest that leaves of carbonate-tolerant plants do not sense iron deficiency as fast as sensitive ones. This is in line with a more efficient Fe translocation to aerial parts. In A1(c+) leaves, the activation of other genes related to stress perception, signal transduction, GS, sulfur acquisition, and cell cycle precedes the induction of iron homeostasis mechanisms yielding an efficient response to bicarbonate stress.


Assuntos
Arabidopsis/metabolismo , Bicarbonatos/toxicidade , Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Brotos de Planta/efeitos dos fármacos , Salicilatos/metabolismo , Estresse Fisiológico/genética , Transcriptoma/genética , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/fisiologia , Bicarbonatos/farmacologia , Calmodulina/metabolismo , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/genética , Ontologia Genética , Glucosinolatos/metabolismo , Glutationa/metabolismo , Homeostase , Concentração de Íons de Hidrogênio , Ferro/metabolismo , Peroxidases/metabolismo , Brotos de Planta/genética , Brotos de Planta/metabolismo , Brotos de Planta/fisiologia , Mapas de Interação de Proteínas , RNA-Seq , Transdução de Sinais/efeitos dos fármacos , Amido/metabolismo , Enxofre/metabolismo , Fatores de Transcrição
3.
Ecotoxicol Environ Saf ; 208: 111703, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396034

RESUMO

Polychlorinated biphenyls (PCBs) are widespread persistent pollutants deleterious for environment and very dangerous for human kind. As the bioremediation of PCB polluted sites by model white-rot fungi is still unsatisfactory, the use of efficient native strains which have the natural capacity to develop on polluted sites may constitute a relevant alternative strategy. In this study, we isolated 12 fungal strains from PCB contaminated soil and sediment, improved the screening method to obtain the most efficient ones in biodegradation and detoxification of PCBs and characterized potential underlying enzymatic activities. Four strains Penicillium chrysogenum, P. citreosulfuratum, P. canescens and Aspergillus jensenii, showed remarkable biodegradation capacities, greater than 70%. The remaining PCB-toxicity of their culture, including that of Trametes versicolor and Acremonium sclerotigenum, which present interesting ecological and metabolic properties, was studied. Only P. canescens was able to significantly reduce the toxicity related to PCBs and their metabolites. The enzymatic activities induced by PCBs were different according to the strains, namely laccases in T. versicolor and peroxidases in Ac. sclerotigenum. Our promising results show that the use of native fungal strains can constitute an effective strategy in the depollution of PCB polluted sites.


Assuntos
Fungos/isolamento & purificação , Fungos/metabolismo , Bifenilos Policlorados/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Biodegradação Ambiental , Proteínas Fúngicas/metabolismo , Fungos/classificação , Humanos , Lacase/metabolismo , Peroxidases/metabolismo
4.
Ecotoxicol Environ Saf ; 208: 111619, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396139

RESUMO

Fluorene, a low molecular weight polycyclic aromatic hydrocarbon (PAH), is of immense environmental interest because of its carcinogenicity, teratogenicity, mutagenicity, toxicity and persistence to microbial degradation. Existentially, there is paucity of information on PAH degradation by fungi isolated from marine environment. Therefore, this study investigated fluorene degradation efficiency of marine derived filamentous fungus, Mucor irregularis strain bpo1 (GenBank Accession Number: MK373020). Response Surface Methodology (RSM) using Box-Behnken Design (BBD) was successfully deployed in the optimization of process parameters (pH-7, temperature-32.5 °C, substrate concentration-100 mg L-1 and dry weight-2 g) resulting in 81.50% fluorene degradation on 5th day. The design and regression model were found to be statistically significant, adequate and appropriate with p < 0.0001, F value= 202.39, and predicted coefficient of determination (R2 =0.9991). Optimization of the vital constituents of the mineral salt medium (MSM) used for the study using RSM-Central Composite Design (CCD) resulted in 79.80% fluorene degradation rate. Enhanced fluorene degradation efficiency (82.50%) was recorded when the optimized process variables were subjected to growth-linked validation experiments. The enzyme activities revealed 87%, 59% and 31% induction of laccase, manganese peroxidase and lignin peroxidase respectively. Four metabolites; 9H-fluoren-9-one, benzene-1,2-dicarboxylic acid, 2-hydroxybenzoic acid and phenol obtained after the experiment were characterized and confirmed with GC-MS analysis. The findings revealed the promising potentials of M. irregularis in PAH degradation and by extension green remediation technology.


Assuntos
Fluorenos/metabolismo , Modelos Teóricos , Mucor/metabolismo , Biodegradação Ambiental , Biomassa , Fluorenos/análise , Lacase/metabolismo , Mucor/crescimento & desenvolvimento , Mucor/isolamento & purificação , Peroxidases/metabolismo , Água do Mar/microbiologia
5.
Life Sci ; 267: 118941, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33359748

RESUMO

AIMS: Acute lung injury (ALI) / acute respiratory distress syndrome (ARDS) is a critical clinical syndrome with complex pathology and pathogenesis. Since there is no specific treatment for ALI, it is important to study the mechanism of how ALI develop. Sestrin2 (Sesn2) plays a critical role in the regulation of cellular stress response and oxidant defense. However, the potential function of Sesn2 in ALI/ARDS and the associated mechanism remains unclear. MAIN METHODS: Lipopolysaccharide (LPS) induced ALI model was performed in the wild-type and Sesn2 knockout (Sesn2-/-) mice. The nod-like receptor protein 3 (NLRP3) inflammasome, cell pyroptosis and mitophagy were detected by western blots, immunofluorescent staining, flow cytometry. Lung injury were measured by histopathology and electron microscopy. KEY FINDINGS: Knockout of Sesn2 enhanced LPS-induced ALI. As detailed in Sesn2-/- mice, NLRP3 inflammasome and cell pyroptosis were increased in lungs; IL-1ß and IL-18 in serum and bronchoalveolar lavage fluid (BALF) were further promoted; In the isolated alveolar macrophages from Sesn2-/- mice, mitophagy induced by LPS was markedly inhibited, while reactive oxygen species (ROS), mitochondrial damage and cell pyroptosis were enhanced. Knocking down or overexpressing Sensn2 in J774.A1 cells demonstrated Sesn2 promoted Sequestosome1 (SQSTM1) expression and mitophagy by PTEN-induced putative kinase 1 (Pink1)/Parkin pathway. SIGNIFICANCE: Sesn2 protected ALI by promoting mitophagy that exerts protection of AMs pyroptosis and negative regulation of NLRP3 inflammasomes. These data indicated Sesn2 might be a potential target for ALI treatment.


Assuntos
Lesão Pulmonar Aguda/prevenção & controle , Macrófagos Alveolares/efeitos dos fármacos , Mitofagia/efeitos dos fármacos , Peroxidases/metabolismo , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/metabolismo , Animais , Líquido da Lavagem Broncoalveolar , Modelos Animais de Doenças , Inflamassomos/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Macrófagos Alveolares/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Piroptose/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
6.
Biochim Biophys Acta Proteins Proteom ; 1869(1): 140536, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32891739

RESUMO

There is a high functional diversity within the structural superfamily of porphyrin-binding dimeric α + ß barrel proteins. In this review we aim to analyze structural constraints of chlorite dismutases, dye-decolorizing peroxidases and coproheme decarboxylases in detail. We identify regions of structural variations within the highly conserved fold, which are most likely crucial for functional specificities. The loop linking the two ferredoxin-like domains within one subunit can be of different sequence lengths and can adopt various structural conformations, consequently defining the shape of the substrate channels and the respective active site architectures. The redox cofactor, heme b or coproheme, is oriented differently in either of the analyzed enzymes. By thoroughly dissecting available structures and discussing all available results in the context of the respective functional mechanisms of each of these redox-active enzymes, we highlight unsolved mechanistic questions in order to spark future research in this field.


Assuntos
Bactérias/enzimologia , Proteínas de Bactérias/química , Carboxiliases/química , Ferredoxinas/química , Oxirredutases/química , Peroxidases/química , Porfirinas/química , Bactérias/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Carboxiliases/genética , Carboxiliases/metabolismo , Domínio Catalítico , Sequência Conservada , Ferredoxinas/genética , Ferredoxinas/metabolismo , Heme/química , Heme/metabolismo , Modelos Moleculares , Oxirredução , Oxirredutases/genética , Oxirredutases/metabolismo , Peroxidases/genética , Peroxidases/metabolismo , Porfirinas/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Multimerização Proteica , Descoloração da Água/métodos
7.
Food Chem ; 339: 127981, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32916399

RESUMO

The objective of the present study was to explore the effect of folic acid on the postharvest physiology of broccoli placed in storage. Broccoli heads were immersed in 5 mg L-1 folic acid for 10 min, then stored at 20 ± 1 °C for 4 days. Results indicated that the postharvest treatment of broccoli with folic acid decreased the rate of flower opening and yellowing, inhibited weight loss, reduced the level of respiration, as well as ethylene generation. Folic acid-treated broccoli maintained their level of chlorophyll, total soluble solids, vitamin C, total phenolics, flavonoids, glucosinolate, and folic acid. Treated broccoli also exhibited reduced accumulation of malondialdehyde (MDA) and reactive oxygen species (ROS). Concomitantly, antioxidant enzyme activity and corresponding gene expression were also enhanced. In contrast, chlorophyll-degrading enzyme gene expression was suppressed. These results indicated that folic acid treatment of broccoli could be used to prolong shelf-life.


Assuntos
Brassica/efeitos dos fármacos , Ácido Fólico/farmacologia , Armazenamento de Alimentos/métodos , Antioxidantes/metabolismo , Ácido Ascórbico/análise , Brassica/fisiologia , Catalase/genética , Catalase/metabolismo , Etilenos/metabolismo , Flavonoides/análise , Ácido Fólico/química , Expressão Gênica/efeitos dos fármacos , Malondialdeído/metabolismo , Peroxidases/genética , Peroxidases/metabolismo , Fenóis/análise , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Temperatura
8.
Food Chem ; 340: 127935, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32891895

RESUMO

This study aimed at evaluating mitigation of nivalenol (NIV) in alcoholic fermentation with magnetic field application (MF). Mitigation was related to both the glutathione (GSH) redox molecule and the enzyme peroxidase (PO), which were synthesized by Saccharomyces cerevisiae US-05. Conditions under evaluation were NIV (0.2 µg mL-1), MF application (35 mT) and simultaneous use of mycotoxin and MF. The GSH content and the PO activity were increased when the culture contained NIV and the alcohol profile was altered after 48 h of fermentation. At the end of the alcoholic fermentation, NIV was mitigated by 56.5%. Therefore, this process is a promising method to reduce contamination by NIV, although the mycotoxin affects the chemical characteristics of the final product.


Assuntos
Bebidas Alcoólicas , Microbiologia de Alimentos/métodos , Tricotecenos/metabolismo , Etanol/análise , Fermentação , Glutationa/metabolismo , Campos Magnéticos , Micotoxinas/química , Peroxidases/metabolismo , Saccharomyces cerevisiae/metabolismo
9.
Food Chem ; 340: 128147, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33032148

RESUMO

Alfalfa sprouts are well known for their nutritive values. Although there are several studies reported the positive impact of elevated CO2 (eCO2) on plants, there are no in-depth, comprehensive studies on how eCO2 could improve the sprouting of plant seeds. Herein, the production of health-promoting metabolites was determined in eCO2 (620 ppm)-treated Alfalfa sprout cultivars (Giza 1, Nubaria and Ismailia 1). eCO2 increased the photosynthetic process and pigment contents, which consequently induced carbohydrates, proteins, fats and fiber accumulation. eCO2 also boosted the levels of vitamins, phenolics, flavonoids and mineral individuals and enhanced the antioxidant capacity of alfalfa sprouts. Interestingly, eCO2 reduced the antinutritional factor l-canavanine content in Ismailia 1 cultivar and improved the anti-inflammatory activities through inhibiting cyclooxygenase-2 and lipoxygenase activity. Therefore, eCO2 is a promising approach to improve the health-promoting prospective of alfalfa sprouts to be a valuable source of nutritious and bioactive compounds in our daily diet.


Assuntos
Dióxido de Carbono/metabolismo , Medicago sativa/metabolismo , Nutrientes/análise , Antioxidantes/química , Catalase/metabolismo , Cromatografia Líquida de Alta Pressão , Análise por Conglomerados , Flavonoides/análise , Cromatografia Gasosa-Espectrometria de Massas , Genótipo , Medicago sativa/genética , Peroxidases/metabolismo , Fenóis/análise , Fotossíntese , Proteínas de Plantas/metabolismo , Sementes/química , Sementes/crescimento & desenvolvimento , Sementes/metabolismo
10.
J Chem Phys ; 153(22): 225102, 2020 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-33317287

RESUMO

This work explores the possibility of simulating an electron transfer process between a donor and an acceptor in real time using time-dependent density functional theory electron dynamics. To achieve this objective, a central issue to resolve is the definition of the initial state. This must be a non-equilibrium electronic state able to trigger the charge transfer dynamics; here, two schemes are proposed to prepare such states. One is based on the combination of the density matrices of the donor and acceptor converged separately with appropriate charges (for example, -1 for the donor and +1 for the acceptor). The second approach relied on constrained DFT to localize the charge on each fragment. With these schemes, electron transfer processes are simulated in different model systems of increasing complexity: an atomic hydrogen dimer, a polyacetylene chain, and the active site of the T. cruzi hybrid type A heme peroxidase, for which two possible electron transfer paths have been postulated. For the latter system, the present methodology applied in a hybrid Quantum Mechanics - Molecular Mechanics framework allows us to establish the relative probabilities of each path and provides insight into the inhibition of the electron transfer provoked by the substitution of tryptophan by phenylalanine in the W233F mutant.


Assuntos
Heme/química , Modelos Químicos , Peroxidases/química , Fenilalanina/química , Triptofano/química , Transporte de Elétrons , Heme/metabolismo , Simulação de Dinâmica Molecular , Peroxidases/metabolismo , Fenilalanina/metabolismo , Teoria Quântica , Trypanosoma cruzi/enzimologia , Trypanosoma cruzi/metabolismo , Triptofano/metabolismo
11.
Proc Natl Acad Sci U S A ; 117(35): 21420-21431, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32817494

RESUMO

One of the emerging hallmarks of cancer illustrates the importance of metabolic reprogramming, necessary to synthesize the building blocks required to fulfill the high demands of rapidly proliferating cells. However, the proliferation-independent instructive role of metabolic enzymes in tumor plasticity is still unclear. Here, we provide evidence that glutathione peroxidase 8 (GPX8), a poorly characterized enzyme that resides in the endoplasmic reticulum, is an essential regulator of tumor aggressiveness. We found that GPX8 expression was induced by the epithelial-mesenchymal transition (EMT) program. Moreover, in breast cancer patients, GPX8 expression significantly correlated with known mesenchymal markers and poor prognosis. Strikingly, GPX8 knockout in mesenchymal-like cells (MDA-MB-231) resulted in an epithelial-like morphology, down-regulation of EMT characteristics, and loss of cancer stemness features. In addition, GPX8 knockout significantly delayed tumor initiation and decreased its growth rate in mice. We found that these GPX8 loss-dependent phenotypes were accompanied by the repression of crucial autocrine factors, in particular, interleukin-6 (IL-6). In these cells, IL-6 bound to the soluble receptor (sIL6R), stimulating the JAK/STAT3 signaling pathway by IL-6 trans-signaling mechanisms, so promoting cancer aggressiveness. We observed that in GPX8 knockout cells, this signaling mechanism was impaired as sIL6R failed to activate the JAK/STAT3 signaling pathway. Altogether, we present the GPX8/IL-6/STAT3 axis as a metabolic-inflammatory pathway that acts as a robust regulator of cancer cell aggressiveness.


Assuntos
Neoplasias da Mama/enzimologia , Interleucina-6/metabolismo , Janus Quinases/metabolismo , Peroxidases/metabolismo , Fator de Transcrição STAT3/metabolismo , Animais , Neoplasias da Mama/mortalidade , Linhagem Celular Tumoral , Transição Epitelial-Mesenquimal , Feminino , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Fenótipo , Transdução de Sinais
12.
Food Chem ; 331: 127352, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32652343

RESUMO

The influence of some additives, including metal ions, antioxidants, enzyme inhibitors and organic solvents, on the storage stability of four organophosphorus pesticides in cucumber samples were investigated. It was found that metal ions, including Al3+, Fe3+, and Co2+, increased the stability of dichlorvos, malathion, and chlorpyrifos. Conversely, Al3+, Fe3+, Fe2+, and Co2+ caused catalytic degradation of diazinon. With the addition of organic solvents (CH2Cl2, CHCl3, CCl4, CH3OH and CH3COCH3), remaining of diazinon residues was higher (16-54%) after storage for seven days. CCl4 was associated with the highest retention of malathion, diazinon, and chlorpyrifos (33%, 48% and 44%, respectively) in samples. SDS also stabilized the pesticides since residues were, again, higher (13-38%) after seven days storage. Furthermore, addition of Al3+ and Fe3+ decreased peroxidase (POD) activity and inhibited degradation of dichlorvos and malathion. After 14 days, lyophilization increased the pesticide residues remaining by 36%, 29%, and 58% for diazinon, malathion and chlorpyrifos, respectively. Overall, the stability of these pesticides during storage is impacted by water content and addition of exogenous substances. This could ensure higher quality of pesticide residue data in samples.


Assuntos
Cucumis sativus/química , Contaminação de Alimentos/análise , Armazenamento de Alimentos , Inseticidas/química , Compostos Organofosforados/química , Alumínio/química , Clorpirifos/análise , Clorpirifos/química , Diazinon/análise , Diazinon/química , Diclorvós/análise , Diclorvós/química , Aditivos Alimentares/química , Liofilização , Inseticidas/análise , Malation/análise , Malation/química , Compostos Organofosforados/análise , Oxirredutases/química , Peroxidases/química , Peroxidases/metabolismo , Resíduos de Praguicidas/análise , Resíduos de Praguicidas/química , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Dodecilsulfato de Sódio/química , Água/química
13.
Aquat Toxicol ; 226: 105559, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32652412

RESUMO

High nitrate (NO3--N) concentration is a growing aquatic risk concern worldwide. However, adverse effects of high NO3--N concentration on submerged macrophytes-epiphytic biofilms are unclear. In this study, the alterations in physiological changes, biofilms formation and chemical compositions were investigated on leaves of Vallisneria asiatica exposed to different NO3--N concentrations. The findings showed that 10 mg L-1NO3--N resulted in low photosynthetic efficiency by inhibiting chlorophyll content 26.2 % and decreased intrinsic efficiency of photosystem II significantly at 14th day post treatment. Malondialdehyde, several antioxidant enzyme activities (i.e., superoxide dismutase, peroxidase and catalase), and secondary metabolites (i.e., phenolic compounds and anthocyanin) were all significantly up-regulated with 10 mg L-1NO3--N, implied oxidative stress were stimulated. However, no significant alterations in these indicators were observed with 5 mg L-1NO3--N. Compared to control, 10 mg L-1NO3--N concentration significantly stimulated microbes growth in biofilm and reduced the roughness of leaf-biofilms surface, but it had little effect on the biofilms distribution (from single clone to blocks) as revealed by scanning electron microscope and multifractal analysis. Results from X-ray photoelectron spectroscopy analysis showed that the percentage of P, Cl, K and the ratio of O1 (-O-) /O2 (C = O) were higher in leaves of control than treatments with 10 mg L-1NO3--N, indicating that 10 mg L-1NO3--N concentration exhibited significant inhibition of chemical activity and nutrient uptake of the leaf surfaces. Overall, these results demonstrated that high NO3--N does stimulate the biofilm growth and can cause negative impacts on submerged macrophytes growth.


Assuntos
Biofilmes/crescimento & desenvolvimento , Hydrocharitaceae/efeitos dos fármacos , Nitratos/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Biofilmes/efeitos dos fármacos , Catalase/metabolismo , Clorofila/metabolismo , Hydrocharitaceae/crescimento & desenvolvimento , Hydrocharitaceae/metabolismo , Hydrocharitaceae/microbiologia , Malondialdeído/metabolismo , Peroxidases/metabolismo , Fotossíntese/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Superóxido Dismutase/metabolismo
14.
Ecotoxicol Environ Saf ; 202: 110895, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32615496

RESUMO

Halogenated phenols, such as 2,4-dichlorophenol (2,4-DCP) and 4-bromophenol (4-BP) are pollutants generated by a various industrial sectors like chemical, dye, paper bleaching, pharmaceuticals or in an agriculture as pesticides. The use of Horseradish peroxidase (HRP) in the halogenated phenols treatment has already been mentioned, but it is not well understood how the different phenolic substrates can bind in the peroxidase active site nor how these specific interactions can influence in the bioremediation potential. In this work, different removal efficiencies were obtained for phenolic compounds investigated using HRP as catalyst (93.87 and 59.19% to 4BP and 2,4 DCP, respectively). Thus, to rationalize this result based on the interactions of phenols with active center of HRP, we combine computational and experimental methodologies. The theoretical approaches utilized include density functional theory (DFT) calculations, docking simulation and quantum mechanics/molecular mechanics (QM/MM) technique. Michaelis Menten constant (Km) obtained through experimental methodologies were 2.3 and 0.95 mM to 2,4-DCP and 4-BP, respectively, while the specificity constant (Kcat/Km) found was 1.44 mM-1 s-1 and 0.62 mM-1 s-1 for 4-BP and 2,4-DCP, respectively. The experimental parameters appointed to the highest affinity of HRP to 4-BP. According to the molecular docking calculations, both ligands have shown stabilizing intermolecular interaction energies within the HRP active site, however, the 4-BP showed more stabilizing interaction energy (-53.00 kcal mol-1) than 2,4-dichlorophenol (-49.23 kcal mol-1). Besides that, oxidative mechanism of 4-BP and 2,4-DCP was investigated by the hybrid QM/MM approach. This study showed that the lowest activation energy values for transition states investigated were obtained for 4-BP. Therefore, by theoretical approach, the compound 4-BP showed the more stabilizing interaction and activation energy values related to the interaction within the enzyme and the oxidative reaction mechanism, respectively, which corroborates with experimental parameters obtained. The combination between experimental and theoretical approaches was essential to understand how the degradation potential of the HRP enzyme depends on the interactions between substrate and the active center cavity of the enzyme.


Assuntos
Biodegradação Ambiental , Peroxidases/metabolismo , Fenóis/metabolismo , Catálise , Poluentes Ambientais , Peroxidase do Rábano Silvestre/química , Cinética , Simulação de Acoplamento Molecular , Oxirredução
15.
Chemosphere ; 255: 127041, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32679635

RESUMO

Microplastics pollution in farmlands has become a major concern. However, few studies have assessed the effects of microplastics on higher plants. In this study, we investigated the influence of polystyrene nanoplastics (PSNPs, 50 mg L-1), with four different particle sizes (100, 300, 500, and 700 nm), on the physiological and biochemical indexes of cucumber leaves. The biomass of cucumber plants significantly decreased after exposure to 300 nm PSNPs. Similarly, the chlorophyll a, chlorophyll b, soluble sugar, carotenoid, and proline content, as well as the fluorescence of cucumber leaves were significantly reduced by 100 nm PSNPs. Malondialdehyde, proline, peroxidase gene expression and enzyme activity, and hydrogen peroxide content significantly increased in cucumber leaves exposed to 700 nm PSNPs. In addition, increasing PSNPs particle size led to decreased relative expression levels and activities of the major antioxidant enzymes superoxide dismutase and catalase, while vitamin C and soluble protein content significantly increased. Overall, our results indicated that PSNPs affect the photosynthetic, antioxidant, and sugar metabolism systems of cucumber leaves, with the latter clearly affecting the total biomass of cucumber plants. The benzene ring resulting from the degradation of PSNPs in cucumber leaves may be the main factor affecting chlorophyll metabolism and sugar metabolism. Our findings provide a scientific basis for the risk assessment of PSNPs exposure in soil-plant systems.


Assuntos
Cucumis sativus/fisiologia , Poliestirenos/toxicidade , Poluentes do Solo/toxicidade , Antioxidantes/metabolismo , Carotenoides/metabolismo , Catalase/metabolismo , Clorofila , Clorofila A , Cucumis sativus/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Malondialdeído/metabolismo , Peroxidases/metabolismo , Fotossíntese/efeitos dos fármacos , Folhas de Planta/metabolismo , Plásticos/metabolismo , Poliestirenos/metabolismo , Superóxido Dismutase/metabolismo
16.
PLoS One ; 15(6): e0220598, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32579545

RESUMO

Roof greening is an important national policy for maintaining the hydrological balance in China; however, plant growth is limited by drought stress. This study aims to identify strong drought resistant plant species for roof greening from ten common species: Paeonia lactiflora, Hemerocallis dumortieri, Meehania urticifolia, Iris lactea var. chinensis, Hylotelephium erythrostictum, Sedum lineare, Iris germanica, Cosmos bipinnata, Hosta plantaginea, and Dianthus barbatus. By controlling the soil relative water content (RWC), we designed three treatments: moderate drought stress (40±2% < RWC < 45±2%), severe drought stress (RWC < 30±2%) and well-watered control (RWC > 75±2%). After the seedlings were provided different levels of water, their membrane permeability (MP), chlorophyll concentration (Chl), and superoxide dismutase (SOD), peroxidase (POD) and ascorbate peroxidase (APX) activity were measured. Finally, the membership function method was used to assess the drought resistance of these species. The results showed that C. bipinnata and M. urticifolia were not suitable for moderate or severe drought stress and did not survive. The other species presented variations in physiological and biochemical parameters. The MP of He. dumortieri, I. lactea and Ho. plantaginea showed minor changes between the well-watered control and drought stress. Most of the species showed reduced SOD activity under moderate drought stress but increased activity under severe stress. All of the plant species showed decreases in the protective enzymes POD and APX with increasing drought stress. The membership function method was applied to calculate the plant species' drought resistance, and the following order of priority of the roof-greening plant species was suggested: He. dumortieri > I. germanica > I. lactea > D. barbatus > Hy. erythrostictum > S. lineare > Ho. plantaginea > P. lactiflora.


Assuntos
Secas , Fenômenos Fisiológicos Vegetais , Plântula/fisiologia , Estresse Fisiológico , Ascorbato Peroxidases/metabolismo , Permeabilidade da Membrana Celular , Clorofila/metabolismo , Peroxidases/metabolismo , Plântula/metabolismo , Solo/química , Superóxido Dismutase/metabolismo , Análise de Sobrevida , Água/análise
17.
Chemosphere ; 259: 127258, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32585458

RESUMO

This is the first study to investigate the reduction mechanism of Tl (III) to Tl(I) in the presence of plants, especially rice. Smaller plant density could effectively reduce the content of organic acids in the hydroponic system to keep the stability of Tl(III). As the plant density was reduced from 40 seedlings to 10 seedlings in 100 mL Tl(III) solution, the content of oxalate was declined to one-third of the original, and the ratio of Tl(III)/total Tl was increased from 39.6% to 81.0% in the first 2 h treatment. Then the differences in antioxidant capacity of rice exposed to the two Tl species were studied. The contents of malondialdehyde (MDA), hydrogen peroxide (H2O2) and superoxide anion (O2˙-) of rice roots exposed to Tl(III) were all higher than those to Tl(I). Meanwhile, the catalase (CAT) activity was significantly depressed and peroxidase (POD) was increased by Tl(III), whereas superoxide dismutase (SOD) showed a rise in both Tl(I) and Tl(III) with no significant difference between them. The expression of metallothionein gene OsMT1a to Tl(I) was upregulated to 255.5 times of Tl(III) though OsMT2c was downregulated to 0.39 times of Tl(III). Overall, the different responses in metallothionein gene expression and antioxidative enzyme activation might result in more ROS accumulation to rice roots by Tl(III) treatment than those by Tl(I).


Assuntos
Metalotioneína/genética , Oryza/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Tálio/toxicidade , Antioxidantes/metabolismo , Catalase/metabolismo , Peróxido de Hidrogênio/metabolismo , Hidroponia , Malondialdeído/metabolismo , Metalotioneína/metabolismo , Oryza/genética , Oryza/metabolismo , Peroxidase/metabolismo , Peroxidases/metabolismo , Raízes de Plantas/metabolismo , Plântula/metabolismo , Superóxido Dismutase/metabolismo , Superóxidos/metabolismo
18.
Arch Biochem Biophys ; 689: 108443, 2020 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-32485152

RESUMO

Human peroxidasin 1 (PXDN) is a homotrimeric multidomain heme peroxidase and essential for tissue development and architecture. It has a biosynthetic function and catalyses the hypobromous acid-mediated formation of specific covalent sulfilimine (SN) bonds, which cross-link type IV collagen chains in basement membranes. Currently, it is unknown whether and which domain(s) [i.e. leucine-rich repeat domain (LRR), immunoglobulin domains, peroxidase domain, von Willebrand factor type C domain] of PXDN interact with the polymeric networks of the extracellular matrix (ECM), and how these interactions integrate and regulate the enzyme's cross-linking activity, without imparting oxidative damage to the ECM. In this study, we probed the interactions of four PXDN constructs with different domain compositions with components of a basement membrane extract by immunoprecipitation. Strong binding of the LRR-containing construct was detected with the major ECM protein laminin. Analysis of these interactions by surface plasmon resonance spectroscopy revealed similar kinetics and affinities of binding of the LRR-containing construct to human and murine laminin-111, with calculated dissociation constants of 1.0 and 1.5 µM, respectively. The findings are discussed with respect to the recently published in-solution structures of the PXDN constructs and the proposed biological role of this peroxidase.


Assuntos
Membrana Basal/metabolismo , Laminina/metabolismo , Peroxidases/metabolismo , Animais , Células HEK293 , Humanos , Leucina/química , Leucina/metabolismo , Camundongos , Peroxidases/química , Ligação Proteica , Domínios Proteicos , Isoformas de Proteínas/metabolismo
19.
Proc Natl Acad Sci U S A ; 117(22): 12017-12028, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32434917

RESUMO

Synthetic chemical elicitors, so called plant strengtheners, can protect plants from pests and pathogens. Most plant strengtheners act by modifying defense signaling pathways, and little is known about other mechanisms by which they may increase plant resistance. Moreover, whether plant strengtheners that enhance insect resistance actually enhance crop yields is often unclear. Here, we uncover how a mechanism by which 4-fluorophenoxyacetic acid (4-FPA) protects cereals from piercing-sucking insects and thereby increases rice yield in the field. Four-FPA does not stimulate hormonal signaling, but modulates the production of peroxidases, H2O2, and flavonoids and directly triggers the formation of flavonoid polymers. The increased deposition of phenolic polymers in rice parenchyma cells of 4-FPA-treated plants is associated with a decreased capacity of the white-backed planthopper (WBPH) Sogatella furcifera to reach the plant phloem. We demonstrate that application of 4-PFA in the field enhances rice yield by reducing the abundance of, and damage caused by, insect pests. We demonstrate that 4-FPA also increases the resistance of other major cereals such as wheat and barley to piercing-sucking insect pests. This study unravels a mode of action by which plant strengtheners can suppress herbivores and increase crop yield. We postulate that this represents a conserved defense mechanism of plants against piercing-sucking insect pests, at least in cereals.


Assuntos
Acetatos/farmacologia , Comportamento Alimentar/efeitos dos fármacos , Flavonoides , Hemípteros , Imunidade Vegetal/efeitos dos fármacos , Animais , Bioensaio , Produtos Agrícolas/efeitos dos fármacos , Flavonoides/análise , Flavonoides/metabolismo , Herbivoria , Hordeum/efeitos dos fármacos , Peróxido de Hidrogênio/análise , Peróxido de Hidrogênio/metabolismo , Oryza/efeitos dos fármacos , Peroxidases/análise , Peroxidases/metabolismo , Controle de Pragas/métodos , Folhas de Planta/química , Triticum/efeitos dos fármacos
20.
Mikrochim Acta ; 187(5): 286, 2020 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-32328802

RESUMO

Rosette-shaped graphitic carbon nitride (rosette-GCN) is described as a promising alternative to natural peroxidase for its application to fluorescence-based glucose assays. Rosette-GCN was synthesized via a rapid reaction between melamine and cyanuric acid for 10 min at 35 °C, followed by thermal calcination for 4 h. Importantly, rosette-GCN possesses a peroxidase-like activity, producing intense fluorescence from the oxidation of Amplex UltraRed in the presence of H2O2 over a broad pH-range of, including neutral pH; the peroxidase activity of rosette-GCN was ~ 10-fold higher than that of conventional bulk-GCN. This enhancement of peroxidase activity is presumed to occur because rosette-GCN has a significantly larger surface area and higher porosity while preserving its unique graphitic structure. Based on the high peroxidase activity of rosette-GCN along with the catalytic action of glucose oxidase (GOx), glucose was reliably determined down to 1.2 µM with a dynamic linear concentration range of 5.0 to 275.0 µM under neutral pH conditions. Practical utility of this strategy was also successfully demonstrated by determining the glucose levels in serum samples. This work highlights the advantages of GCNs synthesized via rapid methods but with unique structures for the preparation of enzyme-mimicking catalysts, thus extending their applications to the diagnostics field and other biotechnological fields. Graphical abstract.


Assuntos
Fluorescência , Glucose Oxidase/química , Glucose/análise , Grafite/química , Peróxido de Hidrogênio/química , Compostos de Nitrogênio/química , Peroxidases/química , Biocatálise , Glucose/metabolismo , Glucose Oxidase/metabolismo , Grafite/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Concentração de Íons de Hidrogênio , Estrutura Molecular , Compostos de Nitrogênio/metabolismo , Tamanho da Partícula , Peroxidases/metabolismo , Porosidade , Propriedades de Superfície
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