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1.
Nat Genet ; 56(5): 1018-1031, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38693345

RESUMO

Zygnematophyceae are the algal sisters of land plants. Here we sequenced four genomes of filamentous Zygnematophyceae, including chromosome-scale assemblies for three strains of Zygnema circumcarinatum. We inferred traits in the ancestor of Zygnematophyceae and land plants that might have ushered in the conquest of land by plants: expanded genes for signaling cascades, environmental response, and multicellular growth. Zygnematophyceae and land plants share all the major enzymes for cell wall synthesis and remodifications, and gene gains shaped this toolkit. Co-expression network analyses uncover gene cohorts that unite environmental signaling with multicellular developmental programs. Our data shed light on a molecular chassis that balances environmental response and growth modulation across more than 600 million years of streptophyte evolution.


Assuntos
Embriófitas , Evolução Molecular , Filogenia , Transdução de Sinais , Transdução de Sinais/genética , Embriófitas/genética , Redes Reguladoras de Genes , Genoma/genética , Genoma de Planta
2.
Data Brief ; 50: 109456, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37600597

RESUMO

The Alexander micro-estuary, located at the eastern edge of the Mediterranean Sea, is a typical example of small water bodies that suffer from a combination of urban and agricultural pollution, and overuse of its natural water sources. It is∼6.5 km long, with maximum depth of 3 m and maximum width of 45 m. To evaluate the anthropogenic stress on the system and its ability to mitigate pollution, water samples were collected within the framework of Ruppin's Estuarine and Coastal Observatory [1]. Water samples were collected from the estuary head, which drains about 510 km2, and at a point 300 m upstream from the estuary mouth before water flows into the Mediterranean Sea. A total of 236 stormwater and 44 base-flow water samples between December 2016 and December 2018. Stormwater samples were collected every 0.25 - 4 h along the entire course of the flow events using an automated samplers (Sigma 900, Hach Company, Loveland CO, USA; and ISCO 3700 Full-Size Portable Sampler, Teledyne, Lincoln, NE, USA). Base-flow samples were taken once a month using a horizontal grab sampler (5 L, model 110B, OceanTest Equipment, Fort Lauderdale, FL, USA). All samples were filtered using 90mmGF/F filters (nominal pore size of 0.7 µm, MGF, Sartorius, Göttingen, Germany) and immediately frozen (-20°C) before chemical analysis. Chemical analysis was performed using liquid chromatography with high-resolution mass spectrometry (LC-HRMS) analysis using a QExactive Plus hybrid FT mass spectrometer coupled with a Dionex Ultimate 3000 RS UPLC (Thermo Fisher Scientific, Waltham, MA, USA). The targeted analysis, which included 15 fungicides, 25 herbicides, 18 Insecticides, and 19 pharmaceuticals, concluded with a total of 21,142 entries. All entries are organized in a worksheet, along with location, date, flood section duration, discharge rate, and the total water volume discharged during the relevant period. The provided data offers an opportunity to explore the sources, transport, and impact of a large mixture of organic pollutants in a confined aquatic system located in an urbanized coastal environment.

3.
Animals (Basel) ; 13(13)2023 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-37443995

RESUMO

Wheat and corn silages are widely used as ruminant feed in Israel due to their availability and cost-effectiveness. To ensure long-term preservation without compromising nutritional quality, effective methods must be employed. The inclusion of additives during harvest and ensiling can enhance efficiency and address preservation challenges. In the current study, the effects of microbial inoculum (MI) and urea on the chemical composition, amino acid profiles, aerobic stability, and in vitro digestibility of wheat and corn silages were investigated. Samples of wheat and corn were subjected to four treatments: control, MI, urea and a combination of MI + urea. The treatments were ensiled in anaerobic conditions and opened after 1, 7, 14 or 28 days. The results showed that additives improved the quality parameters of wheat and corn silages. The inclusion of MI produced the most aerobically stable silages. The inclusion of urea in silages decreased aerobic stability. Additives improved in vitro cell wall carbohydrates' digestibility in both silages and was the best when MI was combined with urea. These results imply that additives could be incorporated in silages to enhance their nutritional value, aerobic stability and digestibility. Nonetheless, increased CP content with additives was not accompanied with a parallel increase in amino acids' content in corn silage.

4.
Proc Natl Acad Sci U S A ; 118(14)2021 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-33795512

RESUMO

Bacteria have evolved a diverse array of signaling pathways that enable them to quickly respond to environmental changes. Understanding how these pathways reflect environmental conditions and produce an orchestrated response is an ongoing challenge. Herein, we present a role for collective modifications of environmental pH carried out by microbial colonies living on a surface. We show that by collectively adjusting the local pH value, Paenibacillus spp., specifically, regulate their swarming motility. Moreover, we show that such pH-dependent regulation can converge with the carbon repression pathway to down-regulate flagellin expression and inhibit swarming in the presence of glucose. Interestingly, our results demonstrate that the observed glucose-dependent swarming repression is not mediated by the glucose molecule per se, as commonly thought to occur in carbon repression pathways, but rather is governed by a decrease in pH due to glucose metabolism. In fact, modification of the environmental pH by neighboring bacterial species could override this glucose-dependent repression and induce swarming of Paenibacillus spp. away from a glucose-rich area. Our results suggest that bacteria can use local pH modulations to reflect nutrient availability and link individual bacterial physiology to macroscale collective behavior.


Assuntos
Fenômenos Fisiológicos Bacterianos , Interações Microbianas , Paenibacillus/fisiologia , Flagelina/metabolismo , Concentração de Íons de Hidrogênio , Proteus mirabilis/fisiologia , Xanthomonas/fisiologia
5.
Environ Pollut ; 265(Pt B): 114941, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32806444

RESUMO

Pesticides are potentially toxic to aquatic systems, even at low concentration, depending on their individual ecotoxicological properties and their mixture composition. Thus, to evaluate possible ecological stress due to pesticide load, a thorough assessment of the potential toxicity of pesticide mixtures is required. Here we report water discharge and quality data of an eastern Mediterranean micro-estuary (Alexander stream), targeting the temporal distribution of a pesticide mixture. Over 150 water samples were collected during 2 hydrological years representing base-flow and flood conditions. On average, each water sample contained 34 and 45 different pesticides with peak concentrations of 1.4 µg L-1 of Imidacloprid and 55 µg L-1 of Diuron during base-flow and flood events, respectively. Pesticide mixtures were potentially toxic to benthic invertebrates and algae during flood events, surpassing the toxicity benchmark with medians of 110% and 155%, respectively. The herbicide Diuron and the insecticide Imidacloprid were the main pesticides responsible for the high potential toxicity during flood events. The falling limb of the flood hydrographs was found to inflict the highest stress on the estuarine environment due to elevated toxicity combined with prolonged residence time of the water. Examination of the potential chronic toxicity of single compounds showed continuous stress for plants, algae, amphibians, crustaceans, insects and fish from nine pesticides. Our data show that the ecosystem of the Alexander micro-estuary is under a continuous chronic stress with acute peaks in potential toxicity during flood events and the period that follows them. We propose that analyzing a small set of flood-tail samples is needed for the evaluation of small estuarine ecosystems risk during the rainy season. From a management perspective, we suggest better control of application practices for Diuron in the watershed to minimize the stress to the estuarine ecosystem.


Assuntos
Praguicidas/análise , Poluentes Químicos da Água/análise , Animais , Ecossistema , Estuários , Rios
6.
Food Addit Contam Part B Surveill ; 13(4): 233-243, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32406338

RESUMO

Throughout the world, more than six billion people consume milk and milk products yearly. The safety and quality of dairy milk are regularly monitored in most countries worldwide. The Israeli monitoring program of chemical residues in milk has not changed in the last decades, focusing only on major veterinary drugs and few selected environmental contaminants such as heavy metals and persistent organic pollutants. Consequently, a knowledge gap exists regarding the potential occurrence of other chemicals such as human pharmaceuticals and non-monitored pesticides in milk. In this survey, 51 commercial bovine and goat milk samples were analysed by LC-MS/MS and pharmaceutical and pesticide residues are reported in the range of 0.1-93 µg/L. Israeli milk samples revealed at least one and up to five chemical residues simultaneously. The pesticides found in milk were below the European maximum residue limit values. The risk assessment performed, indicated negligible risk.


Assuntos
Dieta , Resíduos de Drogas/análise , Contaminação de Alimentos/análise , Leite/química , Resíduos de Praguicidas/análise , Animais , Bovinos , Cromatografia Líquida de Alta Pressão , Poluentes Ambientais/análise , Cabras , Humanos , Israel , Concentração Máxima Permitida , Reprodutibilidade dos Testes , Medição de Risco , Espectrometria de Massas em Tandem , Drogas Veterinárias/análise
7.
Front Plant Sci ; 10: 1561, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31827486

RESUMO

Floral pigmentation is of major importance to the ornamental industry, which is constantly searching for cultivars with novel colors. Goldenrod (Solidago canadensis) has monochromatic yellow carotenoid-containing flowers that cannot be modified using classical breeding approaches due to a limited gene pool. To generate Solidago with novel colors through metabolic engineering, we first developed a procedure for its regeneration and transformation. Applicability of different cytokinins for adventitious regeneration was examined in the commercial cv. Tara, with zeatin yielding higher efficiency than 6-benzylaminopurine or thidiazuron. A comparison of regeneration of commercial cvs. Tara, Golden Glory and Ivory Glory revealed Tara to be the most potent, with an efficiency of 86% (number of shoots per 100 leaf explants). Agrobacterium-based transformation efficiency was highest for cv. Golden Glory (5 independent transgenic shoots per 100 explants) based on kanamycin selection and the GUS reporter gene. In an attempt to promote anthocyanin biosynthesis, we generated transgenic Solidago expressing snapdragon (Antirrhinum majus) Rosea1 and Delila, as well as Arabidopsis thaliana PRODUCTION OF ANTHOCYANIN PIGMENT 1 (PAP1) transcription factors. Transgenic cv. Golden Glory expressing cauliflower mosaic virus 35S-driven PAP1 generated red flowers that accumulated delphinidin and its methylated derivatives, as compared to control yellow flowers in the GUS-expressing plants. The protocol described here allows efficient engineering of Solidago for novel coloration and improved agricultural traits.

8.
Environ Pollut ; 250: 546-553, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31026702

RESUMO

One of the most persistent pharmaceutical compounds commonly found in treated wastewater is lamotrigine (LTG). It has also been detected in soils and crops irrigated with treated wastewater. Here we focused on the ability of the white-rot edible mushroom Pleurotus ostreatus to remove and transform LTG in liquid cultures. At concentrations of environmental relevance (1 and 10 µg L-1) LTG was almost completely removed from the culture medium within 20 days. To elucidate the mechanism of LTG removal and transformation, we applied a physiological-based approach using inhibitors and a competing agent. These experiments were conducted at a higher concentration for metabolites detection. Based on identification of sulfur-containing metabolites and LTG N2-oxide and the effect of specific inhibitors, cytochrome P450 oxidation is suggested as one of the reaction mechanisms leading to LTG transformation. The variety and number of transformation products (i.e., conjugates) found in the current study were larger than reported in mammals. Moreover, known conjugates with glucuronide, glutathione, or cysteine/glycine, were not found in our system. Since the majority of the identified transformation products were conjugates of LTG, this study highlights the persistence of LTG as an organic pollutant in ecosystems exposed to wastewater.


Assuntos
Biodegradação Ambiental , Lamotrigina/metabolismo , Pleurotus/metabolismo , Poluentes Químicos da Água/metabolismo , Águas Residuárias/química , Águas Residuárias/microbiologia
9.
Curr Genet ; 65(5): 1199-1215, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31011791

RESUMO

When glucose is available, Saccharomyces cerevisiae prefers fermentation to respiration. In fact, it can live without respiration at all. Here, we study the role of respiration in stress tolerance in yeast. We found that colony growth of respiratory-deficient yeast (petite) is greatly inhibited by canavanine, the toxic analog of arginine that causes proteotoxic stress. We found lower amounts of the amino acids involved in arginine biosynthesis in petites compared with WT. This finding may be explained by the fact that petite cells exposed to canavanine show reduction in the efficiency of targeting of proteins required for arginine biosynthesis. The retrograde (RTG) pathway signals mitochondrial stress. It positively controls production of arginine precursors. We show that canavanine abrogates RTG signaling especially in petite cells, and mutants in the RTG pathway are extremely sensitive to canavanine. We suggest that petite cells are naturally ineffective in production of some amino acids; combination of this fact with the effect of canavanine on the RTG pathway is the simplest explanation why petite cells are inhibited by canavanine. Surprisingly, we found that canavanine greatly inhibits colony formation when WT cells are forced to respire. Our research proposes a novel connection between respiration and proteotoxic stress.


Assuntos
Canavanina/metabolismo , Respiração Celular , Mitocôndrias/metabolismo , Saccharomyces cerevisiae/fisiologia , Aminoácidos/metabolismo , Glutamatos/metabolismo , Ácido Glutâmico/metabolismo , Potencial da Membrana Mitocondrial , Mitocôndrias/genética , Mutação , Nitrogênio/metabolismo
10.
Plant J ; 98(5): 928-941, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30735592

RESUMO

Abscisic acid (ABA) receptors belong to the START domain superfamily, which encompasses ligand-binding proteins present in all kingdoms of life. START domain proteins contain a central binding pocket that, depending on the protein, can couple ligand binding to catalytic, transport or signaling functions. In Arabidopsis, the best characterized START domain proteins are the 14 PYR/PYL/RCAR ABA receptors, while the other members of the superfamily do not have assigned ligands. To address this, we used affinity purification of biotinylated proteins expressed transiently in Nicotiana benthamiana coupled to untargeted LC-MS to identify candidate binding ligands. We optimized this method using ABA-PYL interactions and show that ABA co-purifies with wild-type PYL5 but not a binding site mutant. The Kd of PYL5 for ABA is 1.1 µm, which suggests that the method has sufficient sensitivity for many ligand-protein interactions. Using this method, we surveyed a set of 37 START domain-related proteins, which resulted in the identification of ligands that co-purified with MLBP1 (At4G01883) or MLP165 (At1G35260). Metabolite identification and the use of authentic standards revealed that MLBP1 binds to monolinolenin, which we confirmed using recombinant MLBP1. Monolinolenin also co-purified with MLBP1 purified from transgenic Arabidopsis, demonstrating that the interaction occurs in a native context. Thus, deployment of this relatively simple method allowed us to define a protein-metabolite interaction and better understand protein-ligand interactions in plants.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas de Ligação a Ácido Graxo/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Ligação a Ácido Graxo/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Ligantes , Ácidos Linolênicos/química , Ácidos Linolênicos/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Plantas Geneticamente Modificadas , Ligação Proteica , Transdução de Sinais
11.
Environ Pollut ; 213: 308-313, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26925753

RESUMO

Pharmaceutically active compounds are taken up and accumulate in crops irrigated with treated wastewater. This raises the concern of chronic human exposure to pharmaceuticals via food consumption. Thus, there is a need to develop a reliable technique to detect and quantify pharmaceuticals at environmentally relevant concentrations in human biological matrices, particularly urine. In this study, we focus on carbamazepine, an antiepileptic drug and recalcitrant compound that is taken up by crops-making it an excellent model compound for this study. This paper presents a new analytical technique enabling quantification of trace concentrations of carbamazepine and its metabolites in the urine of individuals who have been environmentally exposed. Sample preparation included extraction with acetonitrile followed by clean-up through mixed-mode ion-exchange cartridges and analysis using LC/MS/MS. This technique, which was validated for a wide range of concentrations (5-2000 ng L(-1)), exhibits low limits of quantification (3.0-7.2 ng L(-1)), acceptable recovery levels (70-120%), and low relative standard deviation (<20%). Unlike currently available methods for the analysis of water or treated wastewater that require large volumes (up to 1 L), the new method uses only 10 mL of urine. Moreover, relative to available methods for carbamazepine detection in the urine of individuals who are chronically treated with this drug, the limit of quantification values with our method are six orders of magnitude lower. The newly developed method has been successfully applied for the quantification of carbamazepine and its metabolites in the urine of healthy people exposed to this pharmaceutical through their diet. Our analytical protocol can provide the scientific community and stakeholders with real data for risk assessments and the design of policies ensuring safe use of wastewater for crop irrigation.


Assuntos
Carbamazepina/urina , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/urina , Cromatografia Líquida , Exposição Ambiental , Humanos , Espectrometria de Massas em Tandem , Águas Residuárias
12.
NPJ Biofilms Microbiomes ; 2: 15027, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28721238

RESUMO

Bacillus subtilis biofilms have a fundamental role in shaping the soil ecosystem. During this process, they unavoidably interact with neighbour bacterial species. We studied the interspecies interactions between biofilms of the soil-residing bacteria B. subtilis and related Bacillus species. We found that proximity between the biofilms triggered recruitment of motile B. subtilis cells, which engulfed the competing Bacillus simplex colony. Upon interaction, B. subtilis secreted surfactin and cannibalism toxins, at concentrations that were inert to B. subtilis itself, which eliminated the B. simplex colony, as well as colonies of Bacillus toyonensis. Surfactin toxicity was correlated with the presence of short carbon-tail length isomers, and synergistic with the cannibalism toxins. Importantly, during biofilm development and interspecies interactions a subpopulation in B. subtilis biofilm lost its native plasmid, leading to increased virulence against the competing Bacillus species. Overall, these findings indicate that genetic programs and traits that have little effect on biofilm development when each species is grown in isolation have a dramatic impact when different bacterial species interact.

13.
PLoS One ; 10(7): e0130896, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26154164

RESUMO

We examined acute exposure of Holstein cows to di(2-ethylhexyl) phthalate (DEHP) and its carryover effects on ovarian function and oocyte developmental competence. Synchronized cows were tube-fed with water or 100 mg/kg DEHP per day for 3 days. Blood, urine and milk samples were collected before, during and after DEHP exposure to examine its clearance pattern. Ovarian follicular dynamics was monitored through an entire estrous cycle by ultrasonographic scanning. Follicular fluids were aspirated from the preovulatory follicles on days 0 and 29 of the experiment and analyzed for phthalate metabolites and estradiol concentration. The aspirated follicular fluid was used as maturation medium for in-vitro embryo production. Findings revealed that DEHP impairs the pattern of follicular development, with a prominent effect on dominant follicles. The diameter and growth rate of the first- and second-wave dominant follicles were lower (P < 0.05) in the DEHP-treated group. Estradiol concentration in the follicular fluid was lower in the DEHP-treated group than in controls, and associated with a higher number of follicular pathologies (follicle diameter >25 mm). The pattern of growth and regression of the corpus luteum differed between groups, with a lower volume in the DEHP-treated group (P < 0.05). The follicular fluid aspirated from the DEHP-treated group, but not the controls, contained 23 nM mono(2-ethylhexyl) phthalate. Culturing of cumulus oocyte complexes in the follicular fluid aspirated from DEHP-treated cows reduced the proportion of oocytes progressing to the MII stage, and the proportions of 2- to 4-cell-stage embryos (P < 0.04) and 7-day blastocysts (P < 0.06). The results describe the risk associated with acute exposure to DEHP and its deleterious carryover effects on ovarian function, nuclear maturation and oocyte developmental competence.


Assuntos
Dietilexilftalato/química , Oócitos/citologia , Folículo Ovariano/efeitos dos fármacos , Ovário/efeitos dos fármacos , Animais , Bovinos , Núcleo Celular/metabolismo , Corpo Lúteo/efeitos dos fármacos , Corpo Lúteo/metabolismo , Células do Cúmulo/citologia , Células do Cúmulo/efeitos dos fármacos , Citoplasma/metabolismo , Dietilexilftalato/sangue , Dietilexilftalato/urina , Estradiol/metabolismo , Ciclo Estral , Feminino , Líquido Folicular , Lactação , Meiose , Leite/química , Oócitos/efeitos dos fármacos , Folículo Ovariano/diagnóstico por imagem , Ácidos Ftálicos/química , Análise de Regressão , Espectrometria de Massas em Tandem , Ultrassonografia
14.
Appl Microbiol Biotechnol ; 98(15): 6795-804, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24737058

RESUMO

The manganese peroxidase gene family (mnps) is a part of the ligninolytic system of Pleurotus ostreatus. This gene family is comprised of nine members, mnp1-9, encoding short manganese peroxidases (short-MnPs) or versatile peroxidases (VPs). We show that unlike in Mn(2+)-amended glucose-peptone (GP) medium, where redundancy among mnps was reported, in Mn(2+)-deficient GP medium mnp4 [encoding versatile peroxidase isoenzyme 4 (VP4)] has a key and nonredundant function. The abundance of mnps transcripts at time points corresponding to the tropophase (active growth), early idiophase, and idiophase indicates that mnp4 is the predominantly expressed mnp gene and that its relative predominance is dependent on the age of the culture. In this medium, azo dye, Orange II (OII) decolorization occurs only during the idiophase and a Δmnp4 strain showed a drastic reduction in this decolorization. Three degradation metabolites were identified by liquid chromatography-mass spectroscopy (LC-MS), indicating both asymmetric and symmetric enzymatic cleavage of the azo-bond. In addition, the culture filtrate of Δmnp4 showed negligible values of oxidation capability of four typical VP substrates: Mn(2+), 2,6-dimethoxyphenol, phenol red, and Reactive Black 5 (RB5), compared to the wild-type strain PC9. We concluded that under Mn(2+)-deficient GP culture, VP4 (encoded by mnp4) is the main active ligninolytic enzyme able to oxidize Mn(2+) as well as high and low redox potential aromatic substrate, including dyes. Furthermore, other VPs/MnPs do not compensate for the lack of VP4 activity.


Assuntos
Proteínas Fúngicas/metabolismo , Manganês/deficiência , Peroxidase/metabolismo , Pleurotus/enzimologia , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Isoenzimas/genética , Isoenzimas/metabolismo , Oxirredução , Peroxidase/química , Peroxidase/genética , Pleurotus/genética , Pleurotus/metabolismo , Especificidade por Substrato
15.
Environ Sci Technol ; 48(10): 5876-82, 2014 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-24730613

RESUMO

The enhancement of the degradation of polycyclic aromatic hydrocarbons (PAHs), exemplified by pyrene and phenanthrene, using mild grinding in the presence of common minerals was investigated. Magnetite, birnessite, and Na- and Cu-montmorillonite samples were loaded with pyrene or phenanthrene and ground manually or in a ball mill for short periods of time. The ground samples were analyzed for PAHs and for their metabolites, using high-performance liquid chromatography and liquid chromatography-mass spectrometry. No degradation of pyrene occurred when it was in contact with Na-montmorillonite or birnessite. Sorption of pyrene on Cu-montmorillonite enhanced its degradation, but grinding of the loaded clay actually inhibited pyrene's degradation. Phenanthrene hardly degraded on Cu-montmorillonite. Grinding magnetite loaded with either PAH resulted in a significant degradation of both (∼50% after grinding for 5 min), while in the nonground samples, negligible degradation was detected. The extent of degradation increased with the duration of grinding. The degradation of either PAH loaded on magnetite yielded oxidized products. In soil samples contaminated with PAHs and mixed with magnetite, a similar grinding-induced degradation pattern was observed, but with a lower rate. A liquid phase was required to initiate degradation in the soil. The liquid phase apparently served as the medium through which the pollutants reached the surface of the degradation-enhancing mineral.


Assuntos
Óxido Ferroso-Férrico/química , Fenômenos Mecânicos , Fenantrenos/química , Pirenos/química , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Hidrocarbonetos Policíclicos Aromáticos/química , Solo/química , Poluentes do Solo/química
16.
J Plant Physiol ; 169(10): 965-70, 2012 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-22575056

RESUMO

Ultrastructural and molecular studies have provided experimental evidence for the classification of cucurbits as symplastic loaders, mainly translocating the raffinose family oligosaccharides (RFOs) raffinose and stachyose. Earlier studies established that cucumber mosaic virus (CMV) infection causes a significant increase in the sucrose-to-RFO ratio in the phloem sap of melon plants. The alteration in phloem sap sugar composition was associated with upregulation of CmSUT1 transcript within the vascular bundles. The current research aimed to explore the effect of CMV infection on the enzymes involved in symplastic phloem loading and RFO biosynthesis. Viral infection did not affect the activity of either raffinose or stachyose synthases in source leaves, but caused upregulation of the respective transcripts. Interestingly, activity of galactinol synthase was higher in CMV-infected leaves, associated with upregulation of CmGAS2. A significant increase in CmGAS2 expression in source leaves of melon plants exposed to high temperatures indicated that this response is common for both biotic and abiotic stresses. However, the effect of CMV or heat stress on phloem sap sugar composition is not due to alteration in RFO biosynthesis.


Assuntos
Vias Biossintéticas , Cucumovirus/fisiologia , Cucurbitaceae/enzimologia , Cucurbitaceae/virologia , Temperatura Alta , Doenças das Plantas/virologia , Rafinose/biossíntese , Vias Biossintéticas/genética , Cromatografia Líquida , Cucurbitaceae/genética , Galactosiltransferases/genética , Galactosiltransferases/metabolismo , Regulação da Expressão Gênica de Plantas , Espectrometria de Massas , Oligossacarídeos/metabolismo , Doenças das Plantas/genética , Folhas de Planta/enzimologia , Folhas de Planta/genética , Reação em Cadeia da Polimerase em Tempo Real , Estresse Fisiológico/genética , Sacarose/metabolismo , Regulação para Cima/genética
17.
J Lipid Res ; 53(6): 1056-70, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22357704

RESUMO

Postnatal intestinal ontogenesis in an animal model of diabesity may recapitulate morphological and transduction features of diabesity-induced intestinal dysplasia and its amelioration by endogenous (n-3) polyunsaturated fatty acids (PUFA). Proliferation, differentiation, and transduction aspects of intestinal ontogenesis have been studied here in obese, insulin-resistant db/db mice, in fat-1 transgene coding for desaturation of (n-6) PUFA into (n-3) PUFA, in db/db crossed with fat-1 mice, and in control mice. Diabesity resulted in increased colonic proliferation and dedifferentiation of epithelial colonocytes and goblet cells, with increased colonic ß-catenin and hepatocyte nuclear factor (HNF)-4α transcriptional activities accompanied by enrichment in HNF-4α-bound (n-6) PUFA. In contrast, in fat-1 mice, colonic proliferation was restrained, accompanied by differentiation of crypt stem cells into epithelial colonocytes and goblet cells and by decrease in colonic ß-catenin and HNF-4α transcriptional activities, with concomitant enrichment in HNF-4α-bound (n-3) PUFA at the expense of (n-6) PUFA. Colonic proliferation and differentiation, the profile of ß-catenin and HNF-4α-responsive genes, and the composition of HNF-4α-bound PUFA of db/db mice reverted to wild-type by introducing the fat-1 gene into the db/db context. Suppression of intestinal HNF-4α activity by (n-3) PUFA may ameliorate diabesity-induced intestinal ontogenesis and offer an effective preventive modality for colorectal cancer.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Ácidos Graxos Ômega-3/metabolismo , Mucosa Intestinal/metabolismo , Intestinos/patologia , Animais , Diferenciação Celular , Proliferação de Células , Colo/metabolismo , Colo/patologia , Camundongos , Fenótipo , Transdução de Sinais , Especificidade da Espécie
19.
Environ Sci Technol ; 45(16): 6800-5, 2011 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-21744850

RESUMO

Carbamazepine (CBZ) is an environmentally recalcitrant compound highly stable in soil and during wastewater treatment. In this study, we examined the mechanisms by which the white-rot fungus Pleurotus ostreatus metabolizes CBZ in liquid culture using a physiological approach. P. ostreatus PC9 was grown in media known to support different levels of a multiplicity of enzyme systems such as cytochrome P450 (CYP450) and manganese peroxidase (MnP). When both CYP450 and MnP systems were active, 99% of the added CBZ was eliminated from the solution and transformed to 10,11-epoxycarbamazepine. High removal of CBZ was also obtained when either MnP or CYP450 was active. When both CYP450 and MnP were inactivated, only 10 to 30% of the added CBZ was removed. In this latter system, removal of CBZ might be partially attributed to the activity of versatile peroxidase. P. ostreatus was able to eliminate CBZ in liquid culture even when CBZ was added at an environmentally relevant concentration (1 µg L(-1)). On the basis of our study, we suggest that two families of enzymes are involved in the oxidation of CBZ in liquid culture: MnP in a Mn(2+)-dependent or independent manner and CYP450. Our study also highlights the potential of using P. ostreatus for bioremediation systems.


Assuntos
Carbamazepina/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Peroxidases/metabolismo , Preparações Farmacêuticas/metabolismo , Pleurotus/enzimologia , Biodegradação Ambiental/efeitos dos fármacos , Biotransformação/efeitos dos fármacos , Carbamazepina/isolamento & purificação , Meios de Cultura/farmacologia , Preparações Farmacêuticas/isolamento & purificação , Pleurotus/efeitos dos fármacos , Pleurotus/metabolismo
20.
Chemosphere ; 82(6): 905-10, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21071061

RESUMO

Reclaimed wastewater is an important source of irrigation in semiarid and arid zones. Here we report data on carbamazepine (CBZ) uptake by cucumber plants in hydroponic culture and greenhouse experiments using different soil types irrigated with fresh water or reclaimed wastewater. Data obtained from the hydroponic culture experiments suggest that CBZ is mainly translocated by water mass flow, and thus it is concentrated and accumulated to the largest extent in the mature/older leaves. Carbamazepine concentration in cucumber fruits and leaves was negatively correlated with soil organic matter content. The concentrations of CBZ in the roots and stems were relatively low, and most CBZ in the plant (76-84% of total uptake) was detected in the leaves. A greenhouse experiment using fresh water and reclaimed wastewater spiked, or not, with CBZ at 1 µg L(-1) (typical concentration in effluents) revealed that CBZ can be taken up and bioaccumulated from its background concentration in reclaimed wastewater. Bioaccumulation factor (calculated as the ratio of CBZ concentration in the plant to that in the soil solution) for the fruits (0.8-1) was significantly lower than the value calculated for the leaves (17-20). This study emphasizes the potential uptake of active pharmaceutical compounds by crops in organic-matter-poor soils irrigated with reclaimed wastewater and highlights the potential risks associated with this agricultural practice.


Assuntos
Irrigação Agrícola , Anticonvulsivantes/metabolismo , Cucumis sativus/metabolismo , Dietilcarbamazina/metabolismo , Poluentes do Solo/metabolismo , Poluentes Químicos da Água/metabolismo , Anticonvulsivantes/análise , Anticonvulsivantes/toxicidade , Cucumis sativus/efeitos dos fármacos , Dietilcarbamazina/análise , Dietilcarbamazina/toxicidade , Hidroponia , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
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