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1.
J Agric Food Chem ; 70(45): 14352-14366, 2022 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-36326728

RESUMO

Diuron [DU; 3-(3,4-dichlorophenyl)-1,1-dimethylurea], a widely used herbicide for weed control, arouses ecological and health risks due to its environment persistence. Our findings revealed that DU at 0.125-2.0 mg L-1 caused oxidative damage to rice. RNA-sequencing profiles disclosed a globally genetic expression landscape of rice under DU treatment. DU mediated downregulated gene encoding photosynthesis and biosynthesis of protein, fatty acid, and carbohydrate. Conversely, it induced the upregulation of numerous genes involved in xenobiotic metabolism, detoxification, and anti-oxidation. Furthermore, 15 DU metabolites produced by metabolic genes were identified, 7 of which include two Phase I-based and 5 Phase II-based derivatives, were reported for the first time. The changes of resistance-related phytohormones, like JA, ABA, and SA, in terms of their contents and molecular-regulated signaling pathways positively responded to DU stress. Our work provides a molecular-scale perspective on the response of rice to DU toxicity and clarifies the biotransformation and degradation fate of DU in rice crops.


Assuntos
Herbicidas , Oryza , Diurona/metabolismo , Oryza/genética , Oryza/metabolismo , Herbicidas/farmacologia , Herbicidas/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Reguladores de Crescimento de Plantas/metabolismo , Estresse Oxidativo , Produtos Agrícolas/genética , Produtos Agrícolas/metabolismo , Regulação da Expressão Gênica de Plantas
2.
J Mol Model ; 28(11): 360, 2022 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-36227347

RESUMO

The vibrational, mechanical, electronic, and optical properties of the ε-O8 phase in the pressure range of 11.4-70 GPa were studied by the first-principle calculation method. The phonon dispersion curves have a tiny virtual frequency at 60 GPa, which indicates that ε-O8 is dynamically unstable at 60 GPa. However, the 3-BM EOS demonstrates that the unit cell is stable up to 70 GPa. It has been shown that ε-O8 remains ductile within the whole applied pressure range. Concurrently, we calculated the variation of the band gap of ε-O8 in the pressure range of 11.4-70 GPa. The results show that the band gap of ε-O8 decreases with increasing pressure. Notably, the band gap disappears within the range of 50-60 GPa, which reveals that the metallic phase transition occurs within this pressure range.

3.
Transl Oncol ; 18: 101304, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35144091

RESUMO

BACKGROUND: Radiotherapy resistance is one of the major causes of rectal cancer treatment failure. LncRNA DLGAP1-AS2 participates in the progression of several cancers. We explored the role and potential mechanism of DLGAP1-AS2 in the radioresistance of rectal cancer stem cells. METHODS: HR8348-R cells, radioresistant cells from HR8348 after irradiation, were isolated into CD133 negative (CD133-) and positive (CD133+) cells. Cell proliferation, apoptosis, migration and tumorsphere formation were determined by CCK-8, flow cytometry, wound healing assay and tumorsphere formation assay, respectively. CD133, tumor stem cell drug resistance gene (MDR1 and BCRP1), DNA repair marker (γ-H2AX) and AKT/mTOR/cyclinD1 signaling were measured by Western blot. The relationship between DLGAP1-AS2 and E2F1 was verified using RIP. The interaction between E2F1 and CD151 promoter was confirmed using dual-luciferase reporter gene assay and ChIP. AKT inhibitor API-2 was employed for validating the effect of AKT/mTOR/cyclinD1 signaling in the radioresistance of rectal cancer cells. RESULTS: The DLGAP1-AS2 level was increased in CD133+ cells after irradiation. DLGAP1-AS2 knockdown inhibited the proliferation, migration and tumorsphere formation while stimulating apoptosis in CD133+ cells. DLGAP1-AS2 inhibition downregulated the expression of CD133, MDR1, BCRP1 and γ-H2AX and suppressed AKT/mTOR/cyclinD1 activation. DLGAP1-AS2 upregulated the expression of CD151 by interacting with E2F1. API-2 neutralized the promotive effects of overexpressed CD151 on radioresistance. CONCLUSION: DLGAP1-AS2 accelerates the radioresistance of rectal cancer cells through interactions with E2F1 to upregulate CD151 expression via the activation of the AKT/mTOR/cyclinD1 pathway.

4.
World J Gastroenterol ; 27(43): 7530-7545, 2021 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-34887647

RESUMO

BACKGROUND: Severe acute pancreatitis (SAP) is a deadly inflammatory disease with complex pathogenesis and lack of effective therapeutic options. N6-methyladenosine (m6A) modification of circRNAs plays important roles in physiological and pathological processes. However, the roles of m6A circRNA in the pathological process of SAP remains unknown. AIM: To identify transcriptome-wide map of m6A circRNAs and to determine their biological significance and potential mechanisms in SAP. METHODS: The SAP in C57BL/6 mice was induced using 4% sodium taurocholate salt. The transcriptome-wide map of m6A circRNAs was identified by m6A-modified RNA immunoprecipitation sequencing. The biological significance of circRNAs with differentially expressed m6A peaks was evaluated through gene ontology and Kyoto Encyclopedia of Genes and Genomes analysis. The underlying mechanism of m6A circRNAs in SAP was analyzed by constructing of m6A circRNA-microRNA networks. The expression of demethylases was determined by quantitative polymerase chain reaction and western blot to deduce the possible mechanism of reversible m6A process in SAP. RESULTS: Fifty-seven circRNAs with differentially expressed m6A peaks were identified by m6A-modified RNA immunoprecipitation sequencing, of which 32 were upregulated and 25 downregulated. Functional analysis of these m6A circRNAs in SAP found some important pathways involved in the pathogenesis of SAP, such as regulation of autophagy and protein digestion. In m6A circRNA-miRNA networks, several important miRNAs participated in the occurrence and progression of SAP were found to bind to these m6A circRNAs, such as miR-24-3p, miR-26a, miR-92b, miR-216b, miR-324-5p and miR-762. Notably, the total m6A level of circRNAs was reduced, while the demethylase alkylation repair homolog 5 was upregulated in SAP. CONCLUSION: m6A modification of circRNAs may be involved in the pathogenesis of SAP. Our findings may provide novel insights to explore the possible pathogenetic mechanism of SAP and seek new potential therapeutic targets for SAP.


Assuntos
MicroRNAs , Pancreatite , Doença Aguda , Adenosina/análogos & derivados , Animais , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/genética , Pancreatite/induzido quimicamente , Pancreatite/genética , RNA Circular
5.
Anal Bioanal Chem ; 413(2): 389-401, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33145646

RESUMO

Because of its widespread distribution in the environment, bisphenol A (BPA) has become a global concern as an endocrine disruptor and a threat to human health through the food chain. Thus an efficient determination method is urgently needed for monitoring the levels of BPA. Herein, a novel electrochemical technique for the detection of BPA was performed by synchronous extraction and pre-concentration of BPA onto magnetic molecularly imprinted polymer (BMMIP), with subsequent readout on a magneto-actuated glassy carbon electrode (MGCE) by differential pulse voltammetry. Compared to the current methods of BPA determination, this BMMIP-based electrochemical sensor (BMMIPs@MGCE) not only simplifies the sample handling procedures substantially, without filtration, centrifugation, or other complex operations, but also can be easily renewed by a controllable magnetic field. As a sensor component, the core-shell BMMIPs exhibited excellent binding capacity (Qe = 82.5 mg g-1), short adsorption equilibrium time (30 s), and outstanding selectivity (k' = 7.239) towards BPA, as well as stability and recyclability. Importantly, the BMMIPs@MGCE sensor was successfully applied for the on-site monitoring and rapid detection of BPA in complicated real-world specimens, with good recoveries (81.31-119.77%) and a low limit of detection (0.133 µmol L-1). Therefore, the stable and low-cost BMMIPs@MGCE sensor provides a new approach for the rapid determination of BPA in the field of environmental control and food safety. Graphical abstract.

6.
Sensors (Basel) ; 20(22)2020 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-33228249

RESUMO

A surface acoustic wave (SAW) sensor was investigated for its application in C-reactive protein (CRP) detection. Piezoelectric lithium niobate (LiNbO3) substrates were used to study their frequency response characteristics in a SAW sensor with a CRP sensing area. After the fabrication of the SAW sensor, the immobilization process was performed for CRP/anti-CRP interaction. The CRP/anti-CRP interaction can be detected as mass variations in the sensing area. These mass variations may produce changes in the amplitude of sensor response. It was clearly observed that a CRP concentration of 0.1 µg/mL can be detected in the proposed SAW sensor. A good fitting linear relationship between the detected insertion loss (amplitude) and the concentrations of CRP from 0.1 µg/mL to 1 mg/mL was obtained. The detected shifts in the amplitude of insertion loss in SAW sensors for different CRP concentrations may be useful in the diagnosis of risk of cardiovascular diseases.


Assuntos
Proteína C-Reativa , Doenças Cardiovasculares , Som , Proteína C-Reativa/análise , Doenças Cardiovasculares/diagnóstico
7.
Nanoscale ; 12(6): 4061-4068, 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32022049

RESUMO

Bright and fast-response CH3NH3PbBr3 perovskite light-emitting diodes (PeLEDs) are realized by using ICBA:modified C60 (MC60) nanocomposites as the hole blocking layer (HBL) and electron transport layer (ETL). The photoluminescence spectrum shows that the use of hydrophilic MC60 in the ETL helps the surface passivation of the perovskite layer. In addition, the photoelectron spectra and water-droplet contact angle images show that the use of the ICBA:MC60 nanocomposite ETL can simultaneously confine the electrons and holes in the perovskite layer, which boosts the injected electron-hole radiative recombination efficiency and thereby increases the electroluminescence from 1 cd m-2 to 2080 cd m-2 at 6 V when the ICBA:3,5OEC60 nanocomposite ETL is used. In addition, the operational frequency of the optimal PeLED is up to 1.5 MHz.

8.
Environ Sci Pollut Res Int ; 27(10): 11246-11259, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31960244

RESUMO

Triclosan (TCS) is a broad-spectrum antimicrobial agent that is broadly used in personal care products. It has been shown to cause the contamination of a variety of aquatic environments. Since algae has been the primary producers of aquatic ecosystems, understanding the toxicological mechanisms and the metabolic fate of TCS is vital for assessing its risk in an aquatic environment. In our study, 0.5-4 mg L-1 TCS treatments for 72 h in a culture of Chlamydomonas reinhardtii (C. reinhardtii) showed progressive inhibition of cell growth and reduced the chlorophyll content. The EC50 value of C. reinhardtii after 72 h was 1.637 mg L-1, which showed its higher level of resistance to TCS in comparison with other algal species. The exposure to TCS led to oxidative injuries of algae in relation to the increment of malonaldehyde content, cell membrane permeability, and H2O2 levels. Furthermore, the oxidative stress from TCS stimulated a series of antioxidant enzyme activities and their gene expressions. Simultaneously, the accumulated TCS in C. reinhardtii arouses the detoxification/degradation-related enzymes and related gene transcriptions. In the medium, approximately 82% of TCS was removed by C. reinhardtii. Importantly, eight TCS metabolites were identified by ultra-performance liquid chromatography-high-resolution mass spectrometry and their relative abundances were measured in a time-course experiment. Six of these metabolites are reported here for the first time. The metabolic pathways of triclosan via C. reinhardtii including reductive dechlorination, hydroxylation, sulfhydrylation, and binding with thiol/cysteine/GSH/glycosyl were manifested to broaden our understanding of the environmental fate of TCS. Graphical Abstract.


Assuntos
Chlamydomonas reinhardtii , Triclosan/análise , Poluentes Químicos da Água/análise , Bioacumulação , Ecossistema , Peróxido de Hidrogênio
9.
Chemosphere ; 238: 124640, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31524609

RESUMO

Triclosan (TCS) is a kind of chronic toxicity to aquatic organisms. Due to its highly effective antimicrobial, TCS has been widely applied in personal-care products, which naturally poses a potential risk to the ecological system and human health since its release into water-ecological environment. Therefore, it urgently demands a selective, easily separated, recyclable, and low-cost adsorbent to remove the residues of TCS from aquatic environments. In this study, a novel magnetic molecularly imprinted nano-polymers (TMIPs) were prepared for selective adsorption and convenient collection of TCS in aquatic samples, based on a core-shell technique using TCS as template molecule and SiO2-coated Fe3O4 nanoparticles as the support substrate. The functional groups, particle size, morphology and magnetic property of TMIPs were characterized by Fourier-transform infrared spectroscopy, scanning electron microscope, transmission electron microscopy and vibrating sample magnetometer, respectively. The obtained TMIPs possessed excellent adsorption capacity (Qe = 53.12 mg g-1), speedy adsorption equilibrium time (2 min) and high selectivity (k' = 6.321) for TCS. Moreover, the pH-tolerance and stability tests manifested that the adsorption capacity of TMIPs for TCS was acid-resistance and could retain 94.2% of the maximum Qe after 5 times removal-regeneration cycles. The feature of magnetically susceptibility can simplify the procedures of sample handling in TCS determination, because the TMIPs of TCS are easy to be recycled from aquatic samples. As an application demonstration, the toxicity test in microalgae confirmed that a tiny amount of TMIPs could significantly eliminate the toxic effect of TCS on Chlamydomonas reinhardtii via the efficient binding with TCS.


Assuntos
Magnetismo/métodos , Impressão Molecular , Nanopartículas/química , Triclosan/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Antibacterianos/isolamento & purificação , Antibacterianos/toxicidade , Cosméticos/química , Cosméticos/toxicidade , Impressão Molecular/métodos , Tamanho da Partícula , Polímeros/química , Dióxido de Silício/química , Triclosan/toxicidade
10.
Ecotoxicol Environ Saf ; 177: 66-76, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-30974245

RESUMO

A novel magnetic MIPs (DUMIPs) was prepared by surface molecular imprinting method using superparamagnetic core-shell nanoparticle (Fe3O4@SiO2) as the sacrificial support matrix, herbicide diuron as template, α-methacrylic acid as the functional monomer, trimethylolpropane trimethacrylate as the crosslinker, azobisisobutyronitrile as the initiator, and acetonitrile as the porogen. Highly cross-linked porous surface and excellent magnetic property were characterized by Fourier-transform infrared spectroscopy, transmission electron microscopy, and vibrating sample magnetometer, respectively. The adsorption capacity of DUMIPs was 8.1 mg g-1, 2.6-fold over its corresponding non-imprinted polymers (DUNIPs). The adsorption in DUMIPs was considered as multilayer adsorption and posed high affinity to diuron, due to the better fitting to Freundilich isotherm. Competitive recognition study demonstrated DUMIPs had highly selective binding diuron. DUMIPs, as an influential sorbent has been used for selective extraction of diuron from environmental samples (paddy field water, paddy soil and grain seedlings) and the elution was determined by high efficiency liquid chromatography (HPLC). In this analytical method, various factors affecting the extraction efficiency such as pH, sorbent dosage, utilization efficiency and volumes of eluent were simultaneously investigated. Under the optimal conditions, the linearity of the method obtained is in the range of 0.02-10.0 mg L-1. The limit of detection is 0.012 mg L-1. In four spiked levels (0.04, 0.2, 1.0, and 4.0 mg kg-1), the recoveries of diuron in real samples are in the range of 83.56%-116.10% with relative standard deviations in the range of 1.21-6.81%. Importantly, compared to C18-SPE column, the MMIPs exhibited convenient separation by external magnetic field, strong clean-up capacity, and selective enrichment for diuron. Thus, the DUMIPs-based method is great potential for efficient sample preparation in the determination of trace amounts of diuron residues in complex matrices.


Assuntos
Diurona/análise , Herbicidas/análise , Impressão Molecular/métodos , Adsorção , Cromatografia Líquida de Alta Pressão/métodos , Diurona/química , Herbicidas/química , Magnetismo , Metacrilatos/química , Nanopartículas/química , Polímeros/química , Porosidade , Dióxido de Silício/química , Água/química
11.
Nanotechnology ; 29(27): 275704, 2018 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-29664736

RESUMO

Photocurrent extraction and electron injection in CH3NH3PbBr3 (MAPbBr3) perovskite-based optoelectronic devices are both significantly increased by improving the contact at the PCBM/MAPbBr3 interface with an extended solvent annealing (ESA) process. Photoluminescence quenching and x-ray diffraction experiments show that the ESA not only improves the contact at the PCBM/MAPbBr3 interface but also increases the crystallinity of the MAPbBr3 thin films. The optimized dual-functional PCBM-MAPbBr3 heterojunction based optoelectronic device has a high power conversion efficiency of 4.08% and a bright visible luminescence of 1509 cd m-2. In addition, the modulation speed of the MAPbBr3 based light-emitting diodes is larger than 14 MHz, which indicates that the defect density in the MAPbBr3 thin film can be effectively reduced by using the ESA process.

12.
Front Hum Neurosci ; 12: 27, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29545745

RESUMO

A reward or punishment can modulate motivation and emotions, which in turn affect cognitive processing. The present simultaneous functional magnetic resonance imaging-electroencephalography study examines neural mechanisms of response inhibition under the influence of a monetary reward or punishment by implementing a modified stop-signal task in a virtual battlefield scenario. The participants were instructed to play as snipers who open fire at a terrorist target but withhold shooting in the presence of a hostage. The participants performed the task under three different feedback conditions in counterbalanced order: a reward condition where each successfully withheld response added a bonus (i.e., positive feedback) to the startup credit, a punishment condition where each failure in stopping deduced a penalty (i.e., negative feedback), and a no-feedback condition where response outcome had no consequences and served as a control setting. Behaviorally both reward and punishment conditions led to significantly down-regulated inhibitory function in terms of the critical stop-signal delay. As for the neuroimaging results, increased activities were found for the no-feedback condition in regions previously reported to be associated with response inhibition, including the right inferior frontal gyrus and the pre-supplementary motor area. Moreover, higher activation of the lingual gyrus, posterior cingulate gyrus (PCG) and inferior parietal lobule were found in the reward condition, while stronger activation of the precuneus gyrus was found in the punishment condition. The positive feedback was also associated with stronger changes of delta, theta, and alpha synchronization in the PCG than were the negative or no-feedback conditions. These findings depicted the intertwining relationship between response inhibition and motivation networks.

13.
Hu Li Za Zhi ; 64(6): 19-25, 2017 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-29164543

RESUMO

The development of science and technology has fundamentally changed people's lives and the way that medical systems function. Increasingly, mobile technologies are being introduced and integrated into classroom teaching and clinical applications, resulting in healthcare providers introducing innovative applications into health education. These applications enhance the clinical, education, and research expertise of medical staffs and nurses, while improving quality of care and providing new experiences for patients. In order to understand the current situation and trends in nursing education, the present study adopted literature analysis to explore the influence and effect of mobile technologies that have been introduced into nursing education from the school and clinical environments. The results found that students hold positive attitudes toward introducing these technologies into their curricula. Although these technologies may increase the work efficiency of nurses in the workplace, questions remain user perceptions and professional expression. Therefore, securing patient agreement and healthcare system approval were major turning points in the introduction of mobile technologies into nursing education. In the future, adapting mobile technologies for use in teaching materials and courses may be further developed. Moreover, empirical studies may be used in future research in order to facilitate the increasingly successful integration of relevant technologies into nursing education.


Assuntos
Instrução por Computador , Educação à Distância , Educação em Enfermagem , Humanos
14.
Environ Sci Technol ; 51(19): 11258-11268, 2017 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-28872855

RESUMO

Atrazine (ATZ) residue in farmland is one of the environmental contaminants seriously affecting crop production and food safety. Understanding the regulatory mechanism for ATZ metabolism and degradation in plants is important to help reduce ATZ potential toxicity to both plants and human health. Here, we report our newly developed engineered rice overexpressing a novel Phase II metabolic enzyme glycosyltransfearse1 (ARGT1) responsible for transformation of ATZ residues in rice. Our results showed that transformed lines, when exposed to environmentally realistic ATZ concentration (0.2-0.8 mg/L), displayed significantly high tolerance, with 8-27% biomass and 36-56% chlorophyll content higher, but 37-69% plasma membrane injury lower than untransformed lines. Such results were well confirmed by ARGT1 expression in Arabidopsis. ARGT1-transformed rice took up 1.6-2.7 fold ATZ from its growth medium compared to its wild type (WT) and accumulated ATZ 10%-43% less than that of WT. A long-term study also showed that ATZ in the grains of ARGT1-transformed rice was reduced by 30-40% compared to WT. The ATZ-degraded products were characterized by UPLC/Q-TOF-MS/MS. More ATZ metabolites and conjugates accumulated in ARGT1-transformed rice than in WT. Eight ATZ metabolites for Phase I reaction and 10 conjugates for Phase II reaction in rice were identified, with three ATZ-glycosylated conjugates that have never been reported before. These results indicate that ARGT1 expression can facilitate uptake of ATZ from environment and metabolism in rice plants.


Assuntos
Atrazina , Oryza , Resíduos de Praguicidas , Clorofila , Inativação Metabólica , Espectrometria de Massas em Tandem
15.
Ecotoxicol Environ Saf ; 145: 398-407, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28763756

RESUMO

Propazine is a s-triazine herbicide widely used for controlling weeds for crop production. Its persistence and contamination in environment nagatively affect crop growth and food safety. Elimination of propazine residues in the environment is critical for safe crop production. This study identified a microbial community able to degrade propazine in a farmland soil. About 94% of the applied propazine was degraded within 11 days of incubation when soil was treated with 10mgkg-1 propazine as the initial concentration. The process was accompanied by increased microbial biomass and activities of soil enzymes. Denaturing gradient gel electrophoresis (DGGE) revealed multiple bacterial strains in the community as well as dynamic change of the composition of microbial community with a reduced microbial diversity (H' from 3.325 to 2.78). Tracking the transcript level of degradative genes AtzB, AtzC and TrzN showed that these genes were induced by propazine and played important roles in the degradation process. The activities of catalase, dehydrogenase and phenol oxidase were stimulated by propazine exposure. Five degradation products (hydroxyl-, methylated-, dimeric-propazine, ammeline and ammelide) were characterized by UPLC-MS2, revealing a biodegradation of propazine in soil. Several novel methylated and dimeric products of propazine were characterized in thepropazine-exposed soil. These data help understand the pathway, detailed mechanism and efficiency of propazine biodegradation in soil under realistic field condition.


Assuntos
Consórcios Microbianos , Microbiologia do Solo , Poluentes do Solo/análise , Solo/química , Triazinas/análise , Biodegradação Ambiental , Biomassa , Eletroforese em Gel de Gradiente Desnaturante , Genes Bacterianos , Consórcios Microbianos/genética , Poluentes do Solo/metabolismo , Triazinas/metabolismo
16.
Ecotoxicol Environ Saf ; 140: 264-270, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28279883

RESUMO

Ametryn is a selective herbicide belonging to the triazine family and widely used for killing annual grasses or weeds in China and other parts of the world. However, reports on its environmental risk assessment with regard to soil and crop contamination are limited. In this study, accumulation of ametryn in wheat, maize, ryegrass and alfalfa crops along with ametryn residues in the soil planted with the plants were comparatively investigated. Soil enzyme activities and low molecular weight organic acids (LMWOAs), as well as antioxidant and degradation enzyme activities in plant tissues were measured. The maximum accumulation of ametryn was found in shoots and roots of wheat and alfalfa. Ryegrass had the maximum ametryn translocation factor (TF) from roots to shoots, with more than three times over the other crops. The ametryn residue in ryegrass-planted soil was much lower than that in soil planted with others. The residual content of ametryn in crop-planted soils was ordered as rhizosphere soil

Assuntos
Herbicidas/metabolismo , Lolium/metabolismo , Medicago sativa/metabolismo , Triazinas/metabolismo , Triticum/metabolismo , Zea mays/metabolismo , Biodegradação Ambiental , China , Glutationa Transferase/metabolismo , Raízes de Plantas/metabolismo , Rizosfera , Solo/química , Microbiologia do Solo , Poluentes do Solo/análise
17.
Chemosphere ; 165: 487-496, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27677124

RESUMO

Atrazine (ATR) as a toxic herbicide has become one of the seriously environmental contaminants worldwide due to its long-term intensive use in crop production. This study identified novel methyltransferases (MTs) involved in detoxification and degradation of ATR residues in rice plants. From a subset of MTs differentially expressed in ATR-exposed rice, forty-four O-methyltransferase genes were investigated. Total activities were significantly enhanced by ATR in rice tissues. To prove detoxifying capacity of the MTs in rice plants, two rice O-MTs (LOC_Os04g09604 and LOC_Os11g15040) were selected and transformed into yeast cells (Pichia pastoris X-33). The positive transformants accumulated less ATR and showed less toxicity. Using UPLC-TOF-MS/MS, ATR-degraded products in rice and yeast cells were characterized. A novel O-methylated-modified metabolite (atraton) and six other ATR-derivatives were detected. The topological interaction between LOC_Os04g09604 enzyme and its substrate was specially analyzed by homology modeling programs, which was well confirmed by the molecular docking analysis. The significance of the study is to provide a better understanding of mechanisms for the specific detoxification and degradation of ATR residues in rice growing in environmentally relevant ATR-contaminated soils and may hold a potential engineering perspective for generating ATR-resistant rice that helps to minimize ATR residues in crops.


Assuntos
Atrazina/metabolismo , Herbicidas/metabolismo , Metiltransferases/metabolismo , Oryza/enzimologia , Poluentes do Solo/metabolismo , Inativação Metabólica , Metiltransferases/genética , Simulação de Acoplamento Molecular , Oryza/genética , Pichia/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Espectrometria de Massas em Tandem
18.
J Agric Food Chem ; 64(33): 6397-406, 2016 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-27499219

RESUMO

Atrazine (ATR) and isoproturon (IPU) as herbicides have become serious environmental contaminants due to their overuse in crop production. Although ATR and IPU in soils are easily absorbed by many crops, the mechanisms for their degradation or detoxification in plants are poorly understood. This study identified a group of novel genes encoding laccases (EC 1.10.3.2) that are possibly involved in catabolism or detoxification of ATR and IPU residues in rice. Transcriptome profiling shows at least 22 differentially expressed laccase genes in ATR/IPU-exposed rice. Some of the laccase genes were validated by RT-PCR analysis. The biochemical properties of the laccases were analyzed, and their activities in rice were induced under ATR/IPU exposure. To investigate the roles of laccases in degrading or detoxifying ATR/IPU in rice, transgenic yeast cells (Pichia pastoris X-33) expressing two rice laccase genes (LOC_Os01g63180 and LOC_Os12g15680) were generated. Both transformants were found to accumulate less ATR/IPU compared to the control. The ATR/IPU-degraded products in the transformed yeast cells using UPLC-TOF-MS/MS were further characterized. Two metabolites, hydroxy-dehydrogenated atrazine (HDHA) and 2-OH-isopropyl-IPU, catalyzed by laccases were detected in the eukaryotic cells. These results indicate that the laccase-coding genes identified here could confer degradation or detoxification of the herbicides and suggest that the laccases could be one of the important enzymatic pathways responsible for ATR/IPU degradation/detoxification in rice.


Assuntos
Atrazina/metabolismo , Herbicidas/metabolismo , Lacase/metabolismo , Oryza/enzimologia , Compostos de Fenilureia/metabolismo , Proteínas de Plantas/metabolismo , Cromatografia Líquida de Alta Pressão , Perfilação da Expressão Gênica , Inativação Metabólica , Lacase/genética , Pichia/genética , Pichia/metabolismo , Proteínas de Plantas/genética , Poluentes do Solo/metabolismo , Espectrometria de Massas em Tandem , Transformação Genética
19.
Ecotoxicol Environ Saf ; 130: 103-12, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27092973

RESUMO

Plants are constantly exposed to a variety of toxic compounds (or xenobiotics) such as pesticides (or herbicides). Atrazine (ATZ) as herbicide has become one of the environmental contaminants due to its intensive use during crop production. Plants have evolved strategies to cope with the adverse impact of ATZ. However, the mechanism for ATZ degradation and detoxification in plants is largely unknown. Here we employed a global RNA-sequencing (RNA-Seq) strategy to dissect transcriptome variation in alfalfa (Medicago sativa) exposed to ATZ. Four libraries were constructed including Root-ATZ (root control, ATZ-free), Shoot-ATZ, Root+ATZ (root treated with ATZ) and Shoot+ATZ. Hierarchical clustering was performed to display the expression patterns for all differentially expressed genes (DEGs) under ATZ exposure. Transcripts involved in ATZ detoxification, stress responses (e.g. oxidation and reduction, conjugation and hydrolytic reactions), and regulations of cysteine biosynthesis were identified. Several genes encoding glycosyltransferases, glutathione S-transferases or ABC transporters were up-regulated notably. Also, many other genes involved in oxidation-reduction, conjugation, and hydrolysis for herbicide degradation were differentially expressed. These results suggest that ATZ in alfalfa can be detoxified or degraded through different pathways. The expression patterns of some DEGs by high-throughput sequencing were well confirmed by qRT-PCR. Our results not only highlight the transcriptional complexity in alfalfa exposed to ATZ but represent a major improvement for analyzing transcriptional changes on a large scale as well.


Assuntos
Atrazina/toxicidade , Herbicidas/toxicidade , Medicago sativa/efeitos dos fármacos , Transcriptoma/efeitos dos fármacos , Atrazina/farmacocinética , Poluição Ambiental , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Herbicidas/farmacocinética , Inativação Metabólica , Medicago sativa/metabolismo , Raízes de Plantas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de RNA
20.
Sci Rep ; 6: 18985, 2016 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-26739616

RESUMO

Atrazine (ATR) is a pesticide widely used for controlling weeds for crop production. Crop contamination with ATR negatively affects crop growth and development. This study presents the first genome-wide single-base-resolution maps of DNA methylation in ATR-exposed rice. Widespread differences were identified in CG and non-CG methylation marks between the ATR-exposed and ATR-free (control) rice. Most of DNA methyltransferases, histone methyltransferases and DNA demethylase were differentially regulated by ATR. We found more genes hypermethylated than those hypomethylated in the regions of upstream, genebody and downstream under ATR exposure. A stringent group of 674 genes (p < 0.05, two-fold change) with a strong preference of differential expression in ATR-exposed rice was identified. Some of the genes were identified in a subset of loss of function mutants defective in DNA methylation/demethylation. Provision of 5-azacytidine (AZA, inhibitor of DNA methylation) promoted the rice growth and reduced ATR content. By UPLC/Q-TOF-MS/MS, 8 degraded products and 9 conjugates of ATR in AZA-treated rice were characterized. Two of them has been newly identified in this study. Our data show that ATR-induced changes in DNA methylation marks are possibly involved in an epigenetic mechanism associated with activation of specific genes responsible for ATR degradation and detoxification.


Assuntos
Atrazina/farmacologia , Metilação de DNA , Oryza/genética , Praguicidas/farmacologia , DNA de Plantas/genética , DNA de Plantas/metabolismo , Epigênese Genética , Perfilação da Expressão Gênica , Ontologia Genética , Genoma de Planta , Oryza/efeitos dos fármacos , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas , Análise de Sequência de DNA , Transcriptoma/efeitos dos fármacos
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