Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 121
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Small ; : e2400662, 2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38534137

RESUMEN

Developing high-performance electrocatalysts for alkaline hydrogen evolution reaction (HER) is crucial for producing green hydrogen, yet it remains challenging due to the sluggish kinetics in alkaline environments. Pt is located near the peak of HER volcano plot, owing to its exceptional performance in hydrogen adsorption and desorption, and Rh plays an important role in H2O dissociation. Lanthanides (Ln) are commonly used to modulate the electronic structure of materials and further influence the adsorption/desorption of reactants, intermediates, and products, and noble metal-Ln alloys are recognized as effective platforms where Ln elements regulate the catalytic properties of noble metals. Here Pt1.5Rh1.5Tm alloy is synthesized using the sodium vapor reduction method. This alloy demonstrates superior catalytic activity, being 4.4 and 6.6 times more effective than Pt/C and Rh/C, respectively. Density Functional Theory (DFT) calculations reveal that the upshift of d-band center and the charge transfer induced by alloying promote adsorption and dissociation of H2O, making Pt1.5Rh1.5Tm alloy more favorable for the alkaline HER reaction, both kinetically and thermodynamically.

2.
Cell Mol Biol Lett ; 29(1): 2, 2024 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-38172726

RESUMEN

Neointimal hyperplasia is a pathological vascular remodeling caused by abnormal proliferation and migration of subintimal vascular smooth muscle cells (VSMCs) following intimal injury. There is increasing evidence that tRNA-derived small RNA (tsRNA) plays an important role in vascular remodeling. The purpose of this study is to search for tsRNAs signature of neointima formation and to explore their potential functions. The balloon injury model of rat common carotid artery was replicated to induce intimal hyperplasia, and the differentially expressed tsRNAs (DE-tsRNAs) in arteries with intimal hyperplasia were screened by small RNA sequencing and tsRNA library. A total of 24 DE-tsRNAs were found in the vessels with intimal hyperplasia by small RNA sequencing. In vitro, tRF-Glu-CTC inhibited the expression of fibromodulin (FMOD) in VSMCs, which is a negative modulator of TGF-ß1 activity. tRF-Glu-CTC also increased VSMC proliferation and migration. In vivo experiments showed that inhibition of tRF-Glu-CTC expression after balloon injury of rat carotid artery can reduce the neointimal area. In conclusion, tRF-Glu-CTC expression is increased after vascular injury and inhibits FMOD expression in VSMCs, which influences neointima formation. On the other hand, reducing the expression of tRF-Glu-CTC after vascular injury may be a potential approach to prevent vascular stenosis.


Asunto(s)
Traumatismos de las Arterias Carótidas , Lesiones del Sistema Vascular , Animales , Ratas , Traumatismos de las Arterias Carótidas/genética , Traumatismos de las Arterias Carótidas/metabolismo , Movimiento Celular , Proliferación Celular , Células Cultivadas , Modelos Animales de Enfermedad , Fibromodulina/metabolismo , Hiperplasia/complicaciones , Hiperplasia/metabolismo , Hiperplasia/patología , Miocitos del Músculo Liso/metabolismo , Neointima/metabolismo , Neointima/patología , Neointima/prevención & control , Ratas Sprague-Dawley , ARN/metabolismo , ARN de Transferencia/metabolismo , Remodelación Vascular , Lesiones del Sistema Vascular/metabolismo
3.
Biosci Biotechnol Biochem ; 88(5): 517-521, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38337185

RESUMEN

A new lipopeptide, N-desmethylmajusculamide B (1), was isolated from the Okinawan cyanobacterium Okeania hirsuta along with 2 known compounds majusculamide A (2) and majusculamide B (3). The planar structure of (1) was elucidated by a detailed analysis of mass spectrometry and nuclear magnetic resonance spectra. The absolute configurations of the amino acid residues were determined using Marfey's analysis. The configuration of C-16 in the α-methyl-ß-keto-decanoyl moiety was determined unambiguously to be S by conducting a semisynthesis of N-desmethylmajusculamide B from 3. The cytotoxicity against mouse L1210 leukemia cells was evaluated for majusculamides (1-3).


Asunto(s)
Cianobacterias , Lipopéptidos , Cianobacterias/química , Ratones , Animales , Lipopéptidos/química , Lipopéptidos/aislamiento & purificación , Lipopéptidos/farmacología , Línea Celular Tumoral , Antineoplásicos/química , Antineoplásicos/farmacología , Antineoplásicos/aislamiento & purificación , Espectroscopía de Resonancia Magnética
4.
J Am Chem Soc ; 145(48): 26133-26143, 2023 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-37977134

RESUMEN

The copper-based (Cu-based) electrocatalytic materials effectively carry out the electrocatalytic carbon dioxide reduction reaction (CO2RR) toward C2+ products, yet the superiority and stability of the oxidation state of Cu are still worth studying. Herein, we designed and prepared three Cu-based electrocatalysts with different oxidation states to study the valence state-activity relationship. Among these Cu-based electrocatalysts, the Cu2O nanosheets with thickness of only 0.9 nm show an extremely high C2+ Faraday efficiency (FEC2+) of ∼81%, and the FEC2+ has an increase of 37% compared with the traditional CuOx phase. The ultrathin two-dimensional (2D) nanosheet structure with abundant oxygen vacancies can stabilize the oxidation state of Cu to improve the selectivity for C2+ products in CO2RR. In situ Raman spectroscopy and density functional theory calculations demonstrate that the rich Cu+ in the ultrathin 2D Cu2O nanosheets is the most suitable oxidation state for *CO adsorption and coverage on the catalyst surface, which promotes the C-C coupling reaction in CO2RR. This work provides an excellent catalyst for CO2RR toward C2+ products.

5.
J Environ Manage ; 348: 119386, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37879175

RESUMEN

Various activated persulfate (PS) technologies have been investigated and implemented to eliminate antibiotic contaminants from water. The investigation and evaluation of different activation systems are essential for the application of PS techniques. The degradation of amoxicillin (AMX) by heat, light, or heterogeneous catalyst of Fe-AC composite activated PS was investigated, and the kinetics, mechanisms and toxicities were compared in this work. The apparent activation energy of the Fe-AC system was lower than that of the heat system. Hydroxyl and sulfate radicals were demonstrated by electron paramagnetic resonance (EPR) spectroscopy and quenching tests. There were 22, 21 and 13 types of degradation intermediates detected in heat, light and Fe-AC system, respectively. Six pathways of AMX degradation were proposed and compared in the three activated PS systems. The toxicity prediction of degradation intermediates under different treatment processes was estimated by ecological structure-activity relationship model and toxicity estimation software tool. The genotoxicity of the AMX degradation solution was tested by Acinetobacter baylyi ADP1_recA, which indicated that the AMX solution after treatment in the Fe-AC system had almost no genotoxicity. The Fe-AC/PS system shows apparent advantages over the heat or light activated PS system in most cases, demonstrating that the Fe-AC/PS system is suitable for AMX-contaminated remediation in aqueous solution.


Asunto(s)
Amoxicilina , Contaminantes Químicos del Agua , Calor , Oxidación-Reducción , Contaminantes Químicos del Agua/química , Antibacterianos , Agua
6.
Small ; 18(40): e2202981, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36058646

RESUMEN

The next generation of high-energy-density storage devices is expected to be rechargeable lithium metal batteries. However, unstable metal-electrolyte interfaces, dendrite growth, and volume expansion will compromise lithium metal batteries (LMB) safety and life. A simple drop-casting method is used to create a double-layer functional interface composed of inorganic mesoporous TiO2 and F-rich organics PFDMA. For high-quality lithium deposition, TiO2 can provide uniform mechanical pressure, abundant mesoporous channels, and increased ionic conductivity, while PFDMA provides enough F to form LiF in the first cycle and improves Li-electrolyte compatibility. Experiments and simulations are combined to investigate the optimized mechanism of the LiF-rich solid electrolyte interface (SEI). The high binding energy of organic matter and Li demonstrates that Li+ preferentially binds with the F atom in organic matter. As a result, the tightly bound double-layer structure can inhibit lithium dendrite growth and slow electrolyte decomposition. Consequently, the symmetric Li||Li cell has a high stability performance of over 800 h. The assembled LiFePO4 ||Li cell can sustain 300 cycles at a 1 C rate and has a reversible capacity of 136.7 mAh g-1 .

7.
J Transl Med ; 20(1): 462, 2022 10 08.
Artículo en Inglés | MEDLINE | ID: mdl-36209225

RESUMEN

BACKGROUND: Single-cell transcription data provided unprecedented molecular information, enabling us to directly encode the ecosystem of colorectal cancer (CRC). Characterization of the diversity of epithelial cells and how they cooperate with tumor microenvironment cells (TME) to endow CRC with aggressive characteristics at single-cell resolution is critical for the understanding of tumor progression mechanism. METHODS: In this study, we comprehensively analyzed the single-cell transcription data, bulk-RNA sequencing data and pathological tissue data. In detail, cellular heterogeneity of TME and epithelial cells were analyzed by unsupervised classification and consensus nonnegative matrix factorization analysis, respectively. Functional status of epithelial clusters was annotated by CancerSEA and its crosstalk with TME cells was investigated using CellPhoneDB and correlation analysis. Findings from single-cell transcription data were further validated in bulk-RNA sequencing data and pathological tissue data. RESULTS: A distinct cellular composition was observed between tumor and normal tissues, and tumors exhibited immunosuppressive phenotypes. Regarding epithelial cells, we identified one highly invasiveQuery cluster, C4, that correlated closely with tumor-associated macrophages (TAMs) and cancer-associated fibroblasts (CAFs). Further analysis emphasized the TAMs subclass TAM1 and CAFs subclass S5 are closely related with C4. CONCLUSIONS: In summary, our study elaborates on the cellular heterogeneity of CRC, revealing that TAMs and CAFs were critical for crosstalk network epithelial cells and TME cells. This in-depth understanding of cancer cell-TME network provided theoretical basis for the development of new drugs targeting this sophisticated network in CRC.


Asunto(s)
Fibroblastos Asociados al Cáncer , Neoplasias Colorrectales , Fibroblastos Asociados al Cáncer/patología , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Ecosistema , Humanos , Microambiente Tumoral , Macrófagos Asociados a Tumores
8.
Bioorg Med Chem ; 74: 117053, 2022 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-36270112

RESUMEN

Cathepsin K (Cat K), mainly expressed by osteoclasts, plays an important role in bone resorption. Covalent Cat K inhibitors will show great potential in the future treatment of osteoporosis. It has been reported that the selectivity of covalent cathepsin K inhibitors was related to the drug's safety. The type of warhead has a crucial influence on the enzyme bioactivity and selectivity of covalent inhibitors. In order to develop novel covalent inhibitors with the selective new warhead, quantum chemical calculations were performed to estimate the reactivity of the nitrile warheads. Moreover, binding mode analysis between ligands and high homology Cat K, S and B revealed differences in non-covalent interactions. Novel covalent Cat K inhibitors containing 4-cyanopyrimidine warhead (11) were determined for the first time. Among them, compound 34 significantly inhibited Cat K (IC50 = 61.9 nM) with excellent selectivity compared to Cat S (>810-fold) and Cat B (>1620-fold), respectively. Binding mode analysis of Cat K-34 complex provided the basis for further optimization. Compound 34 could be a valuable lead compound for further research on safe and effective Cat K inhibitors.


Asunto(s)
Resorción Ósea , Humanos , Catepsina K , Resorción Ósea/metabolismo , Osteoclastos , Nitrilos/química , Ligandos , Catepsinas
9.
Sensors (Basel) ; 22(17)2022 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-36081173

RESUMEN

To improve the motion distortion caused by LiDAR data at low and medium frame rates when moving, this paper proposes an improved algorithm for scanning matching of estimated velocity that combines an IMU and odometer. First, the information of the IMU and the odometer is fused, and the pose of the LiDAR is obtained using the linear interpolation method. The ICP method is used to scan and match the LiDAR data. The data fused by the IMU and the odometer provide the optimal initial value for the ICP. The estimated speed of the LiDAR is introduced as the termination condition of the ICP method iteration to realize the compensation of the LiDAR data. The experimental comparative analysis shows that the algorithm is better than the ICP algorithm and the VICP algorithm in matching accuracy.

10.
Entropy (Basel) ; 24(5)2022 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-35626455

RESUMEN

To comprehensively control the corner separation and mid-span boundary layer (BL) separation, this study proposed and evaluated two new flow control configurations. One is a slotted configuration composed of blade-end and whole-span slots, and the other is a combined configuration with end-wall BL suction and whole-span slot. Additionally, the adaptability of the combined configuration to the lower blade solidity (c/t) condition was verified. The results indicate that both the slotted configuration and combined configuration can eliminate the mid-span BL separation, but a better reduction in the corner separation can be observed in the combined configuration. The two configurations can remove the concentrated shedding vortex and reduce the passage vortex (PV) for the datum cascade, but the wall vortex (WV) will be generated. By contrast, the combined configuration has weaker WV and PV than the slotted configuration, which contributes to further reducing the corner separation. In the combined configuration with a c/t of 1.66 and 1.36, the total pressure loss is reduced by 38.4% and 42.1%, respectively, on average, while the averaged static pressure rise coefficient is increased by 16.2% and 17.6%, respectively. This is advantageous for enhancing the working stability and pressure diffusion capacity for compressors. Besides this, the combined configuration with lower c/t can achieve a stronger pressure diffusion capacity and smaller loss than the higher c/t datum cascade. Therefore, the combined configuration is advantageous to the improvement of the aero-engine thrust-to-weight ratio through decreasing the compressor single-stage blade number.

11.
J Environ Sci (China) ; 105: 100-115, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34130827

RESUMEN

Sodium percarbonate (SPC) and peroxymonocarbonate (PMC) have been widely used in modified Fenton reactions because of their multiple superior features, such as a wide pH range and environmental friendliness. This broad review is intended to provide the fundamental information, status and progress of SPC and PMC based decontamination technologies according to the peer-reviewed papers in the last two decades. Both SPC and PMC can directly decompose various pollutants. The degradation efficiency will be enhanced and the target contaminants will be expanded after the activation of SPC and PMC. The most commonly used catalysts for SPC activation are iron compounds while cobalt compositions are applied to activate PMC in homogenous and heterogeneous catalytical systems. The generation and participation of hydroxyl, superoxide and/or carbonate radicals are involved in the activated SPC and PMC system. The reductive radicals, such as carbon dioxide and hydroxyethyl radicals, can be generated when formic acid or methanol is added in the Fe(II)/SPC system, which can reduce target contaminants. SPC can also be activated by energy, tetraacetylethylenediamine, ozone and buffered alkaline to generate different reactive radicals for pollutant decomposition. The SPC and activated SPC have been assessed for application in-situ chemical oxidation and sludge dewatering treatment. The challenges and prospects of SPC and PMC based decontamination technologies are also addressed in the last section.


Asunto(s)
Contaminantes Químicos del Agua , Carbonatos , Descontaminación , Peróxido de Hidrógeno , Oxidación-Reducción , Contaminantes Químicos del Agua/análisis
12.
Planta ; 251(4): 77, 2020 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-32152790

RESUMEN

MAIN CONCLUSION: Dysfunctional mutation of OsNDPK4 resulted in severe defects in root development of rice. However, the resistance of Osndpk4 against bacterial blight was significantly enhanced. Nucleoside diphosphate kinases (NDPKs) are an evolutionarily conserved family of important enzymes balancing the energy currency nucleoside triphosphates by catalyzing the transfer of their phosphate groups. The aim of this study was to elucidate the function of OsNDPK4 in rice. A dysfunctional rice mutant was employed to characterize the function of OsNDPK4. Its expression and subcellular localization were examined. The transcriptomic change in roots of Osndpk4 was analyzed by RNA-seq. The rice mutant Osndpk4 showed severe defects in root development from the early seedling stage. Further analysis revealed that meristematic activity and cell elongation were significantly inhibited in primary roots of Osndpk4, together with reduced accumulation of reactive oxygen species (ROS). Map-based cloning identified that the mutation occurred in the OsNDPK4 gene. OsNDPK4 was found to be expressed in a variety of tissues throughout the plant and OsNDPK4 was located in the cytosol. Osndpk4 showed enhanced resistance to the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo) and up-regulation of pathogenesis-related marker genes. In addition, transcriptomic analysis showed that OsNDPK4 was significantly associated with a number of biological processes, including translation, protein modification, metabolism, biotic stress response, etc. Detailed analysis revealed that the dysfunction of OsNDPK4 might reorchestrate energy homeostasis and hormone metabolism and signalling, resulting in repression of translation, DNA replication and cell cycle progression, and priming of biotic stress defense. Our results demonstrate that OsNDPK4 plays important roles in energy homeostasis, development process, and defense responses in rice.


Asunto(s)
Nucleósido-Difosfato Quinasa/genética , Oryza/genética , Proteínas de Plantas/genética , Raíces de Plantas/genética , Secuencia de Aminoácidos , Clonación Molecular , Resistencia a la Enfermedad/genética , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Nucleósido-Difosfato Quinasa/metabolismo , Oryza/metabolismo , Oryza/microbiología , Desarrollo de la Planta/genética , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/metabolismo , Raíces de Plantas/metabolismo , Raíces de Plantas/microbiología , Especies Reactivas de Oxígeno/metabolismo , Análisis de Secuencia de ARN , Estrés Fisiológico , Transcriptoma , Secuenciación Completa del Genoma , Xanthomonas/metabolismo
13.
Luminescence ; 35(2): 274-283, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31736184

RESUMEN

Based on the chemiluminescence (CL) phenomenon of peroxymonosulfate (PMS) and Tb(III) enhanced by its ligand in a micelle microenvironment, a fast and sensitive flow injection CL method for PMS detection was proposed and applied to the analysis of different samples and PMS decomposition. Under the optimized conditions, a linear range was obtained from 4.0 × 10-6  mol L-1 to 2.0 × 10-4  mol L-1 with a high correlation coefficient (r = 0.9997), detection limit of 5.0 × 10-7  mol L-1 (S/N = 3) and relative standard deviation of 2.4% for 1.0 × 10-5  mol L-1 PMS (n = 9). This was successfully applied to the determination of PMS in Virkon powder, tap water, and swimming pool water samples with satisfactory recoveries from 94.8% to 104.8%. In particular, the analytical frequency could be as fast as five samples per minute because there was no reaction step before analysis and the CL phenomenon was instantaneous. Therefore, this CL method has also been successfully applied to investigate the PMS decomposition profiles in carbon material (carbon nanotubes, carbon nanofibres, activated carbon and graphene oxide) catalysis systems, which followed pseudo-first-order kinetics with good correlation coefficients (r > 0.9305). Quenching experiments and electron spin resonance spectra verified that the CL phenomenon was due to the formation of singlet oxygen, and that hydroxyl and sulfate radicals might be important in the generation of singlet oxygen. Tb(III) is the luminescent emitter according to the characteristics emission bands of the fluorescence and CL spectra in different media.


Asunto(s)
Análisis de Inyección de Flujo , Colorantes Fluorescentes/química , Luminiscencia , Mediciones Luminiscentes , Peróxidos/análisis , Terbio/química , Análisis de Inyección de Flujo/instrumentación , Ligandos , Mediciones Luminiscentes/instrumentación , Micelas
14.
Molecules ; 25(3)2020 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-31978978

RESUMEN

A new aplysiatoxin derivative, neo-aplysiatoxin A (1), along with seven known compounds, neo-debromoaplysiatoxin A (2), dolastatin 3 (3), lyngbic acid (4), malyngamide M (5), hermitamide A (6), (-)-loliolide (7), and (+)-epiloliolide (8), was isolated from the Okinawan cyanobacterium Moorea producens. Their structures were elucidated on the basis of spectroscopic data, including high-resolution mass spectrometry and nuclear magnetic resonance. The compounds were evaluated for cytotoxic and diatom growth inhibition activities.


Asunto(s)
Cianobacterias/metabolismo , Toxinas de Lyngbya/metabolismo , Depsipéptidos/metabolismo , Ácidos Grasos Monoinsaturados/metabolismo , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Estructura Molecular
15.
Water Sci Technol ; 82(4): 773-786, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32970628

RESUMEN

Petrochemical wastewater is difficult to process because of various types of pollutants with high toxicity. With the improvement in the national discharge standard, traditional biochemical treatment methods may not meet the standards and further advanced treatment techniques would be required. In this study, electrochemical oxidation with boron doped diamond (BDD) anode as post-treatment was carried out for the treatment of real biotreated petrochemical wastewater. The effects of current density, pH value, agitation rate, and anode materials on chemical oxygen demand (COD) removal and current efficiency were studied. The results revealed the appropriate conditions to be a current density of 10 mA·cm-2, a pH value of 3, and an agitation rate of 400 rpm. Moreover, as compared with the graphite electrode, the BDD electrode had a higher oxidation efficiency and COD removal efficiency. Furthermore, GC-MS was used to analyze the final degradation products, in which ammonium chloride, formic acid, acetic acid, and malonic acid were detected. Finally, the energy consumption was estimated to be 6.24 kWh·m-3 with a final COD of 30.2 mg·L-1 at a current density of 10 mA·cm-2 without the addition of extra substances. This study provides an alternative for the upgrading of petrochemical wastewater treatment plants.


Asunto(s)
Diamante , Contaminantes Químicos del Agua , Boro , Electrodos , Cinética , Oxidación-Reducción , Aguas Residuales/análisis
16.
Entropy (Basel) ; 22(2)2020 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-33285904

RESUMEN

To investigate the influence of the change of tip clearance size on the control effect of the endwall suction, the effects of endwall suction on the aerodynamic performance of the axial compressor cascade were studied numerically. Three tip clearance sizes of 0.5% h, 1.0% h, and 2.0% h (h is the blade height) were mainly considered. The results show that the endwall suction scheme whose coverage range was 8-33% axial chord can reduce the leakage flow and improve the aerodynamic performance by directly influencing the structure of tip leakage vortex. The overall total pressure loss coefficients of the three clearance size schemes at 0° angle of incidence with 0.4 inlet Mach number are reduced by about 10.3%, 10.8%, and 6.0%, respectively, at the suction flow rate of 0.7%. Under the same suction flow rate, the onset position of the tip leakage vortex of the cascade with small clearance is shifted from the 15% of the axial chord length of original to the 48% of the axial chord length, which with large clearance is nearly no changed. The leakage flow rate and the distance from the leakage vortex to the suction slot are the main reasons for the different control effect of the endwall suction under different tip clearance sizes. The difference of the spanwise distribution of flow field parameters may also cause the difference of flow control effect.

17.
Plant Physiol ; 173(3): 1824-1843, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-28167700

RESUMEN

Plants sense and integrate a variety of signals from the environment through different interacting signal transduction pathways that involve hormones and signaling molecules. Using ALTERNATIVE OXIDASE1a (AOX1a) gene expression as a model system of retrograde or stress signaling between mitochondria and the nucleus, MYB DOMAIN PROTEIN29 (MYB29) was identified as a negative regulator (regulator of alternative oxidase1a 7 [rao7] mutant) in a genetic screen of Arabidopsis (Arabidopsis thaliana). rao7/myb29 mutants have increased levels of AOX1a transcript and protein compared to wild type after induction with antimycin A. A variety of genes previously associated with the mitochondrial stress response also display enhanced transcript abundance, indicating that RAO7/MYB29 negatively regulates mitochondrial stress responses in general. Meta-analysis of hormone-responsive marker genes and identification of downstream transcription factor networks revealed that MYB29 functions in the complex interplay of ethylene, jasmonic acid, salicylic acid, and reactive oxygen species signaling by regulating the expression of various ETHYLENE RESPONSE FACTOR and WRKY transcription factors. Despite an enhanced induction of mitochondrial stress response genes, rao7/myb29 mutants displayed an increased sensitivity to combined moderate light and drought stress. These results uncover interactions between mitochondrial retrograde signaling and the regulation of glucosinolate biosynthesis, both regulated by RAO7/MYB29. This common regulator can explain why perturbation of the mitochondrial function leads to transcriptomic responses overlapping with responses to biotic stress.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Regulación de la Expresión Génica de las Plantas/genética , Proteínas Mitocondriales/genética , Oxidorreductasas/genética , Proteínas de Plantas/genética , Factores de Transcripción/genética , Antimicina A/farmacología , Arabidopsis/enzimología , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Núcleo Celular/genética , Núcleo Celular/metabolismo , Perfilación de la Expresión Génica/métodos , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Ontología de Genes , Redes Reguladoras de Genes , Immunoblotting , Mitocondrias/genética , Mitocondrias/metabolismo , Proteínas Mitocondriales/metabolismo , Mutación , Oxidorreductasas/metabolismo , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente , Regiones Promotoras Genéticas/genética , Unión Proteica , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal/genética , Factores de Transcripción/metabolismo
18.
Ann Bot ; 122(3): 359-371, 2018 08 27.
Artículo en Inglés | MEDLINE | ID: mdl-29771278

RESUMEN

Background and Aims: Pelota (Pelo) are evolutionarily conserved genes reported to be involved in ribosome rescue, cell cycle control and meiotic cell division. However, there is little known about their function in plants. The aim of this study was to elucidate the function of an ethylmethane sulphonate (EMS)-derived mutation of a Pelo-like gene in rice (named Ospelo). Methods: A dysfunctional mutant was used to characterize the function of OsPelo. Analyses of its expression and sub-cellular localization were performed. The whole-genome transcriptomic change in leaves of Ospelo was also investigated by RNA sequencing. Key Results: The Ospelo mutant showed defects in root system development and spotted leaves at early seedling stages. Map-based cloning revealed that the mutation occurred in the putative Pelo gene. OsPelo was found to be expressed in various tissues throughout the plant, and the protein was located in mitochondria. Defence responses were induced in the Ospelo mutant, as shown by enhanced resistance to the bacterial pathogen Xanthomonas oryzae pv. oryzae, coupled with upregulation of three pathogenesis-related marker genes. In addition, whole-genome transcriptome analysis showed that OsPelo was significantly associated with a number of biological processes, including translation, metabolism and biotic stress response. Detailed analysis showed that activation of a number of innate immunity-related genes might be responsible for the enhanced disease resistance in the Ospelo mutant. Conclusions: These results demonstrate that OsPelo positively regulates root development while its loss of function enhances pathogen resistance by pre-activation of defence responses in rice.


Asunto(s)
Resistencia a la Enfermedad , Regulación de la Expresión Génica de las Plantas , Oryza/genética , Enfermedades de las Plantas/inmunología , Transcriptoma , Xanthomonas/fisiología , Perfilación de la Expresión Génica , Mutación , Oryza/crecimiento & desarrollo , Oryza/inmunología , Oryza/microbiología , Enfermedades de las Plantas/microbiología , Hojas de la Planta/genética , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/inmunología , Hojas de la Planta/microbiología , Raíces de Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/inmunología , Raíces de Plantas/microbiología
19.
J Nanosci Nanotechnol ; 17(1): 720-24, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29633810

RESUMEN

Herein we report the facile fabrication and electrocatalytic activity of nanostructured bimetallic iron molybdenum nitride (Fe3Mo3N), which was prepared by an ammonolysis process directly towards the solid state mixture of Mo precursor and Fe precursor. The prepared nanostructured Fe3Mo3N presented remarkable electrocatalytic activities towards both oxygen reduction reaction and oxygen evolution reaction in nonaqueous phase, due to the modulation of electronic configuration of catalyst by Fe element and porous structure. Then, lithium-O2 batteries with nanostructured Fe3Mo3N as cathode catalysts were assembled, which show alleviated polarization and enhanced cyclability.

20.
Proc Natl Acad Sci U S A ; 111(12): 4632-7, 2014 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-24550464

RESUMEN

The CRISPR (clustered regularly interspaced short palindromic repeat)/Cas (CRISPR-associated) system has emerged as a powerful tool for targeted gene editing in many organisms, including plants. However, all of the reported studies in plants focused on either transient systems or the first generation after the CRISPR/Cas system was stably transformed into plants. In this study we examined several plant generations with seven genes at 12 different target sites to determine the patterns, efficiency, specificity, and heritability of CRISPR/Cas-induced gene mutations or corrections in Arabidopsis. The proportion of plants bearing any mutations (chimeric, heterozygous, biallelic, or homozygous) was 71.2% at T1, 58.3% at T2, and 79.4% at T3 generations. CRISPR/Cas-induced mutations were predominantly 1 bp insertion and short deletions. Gene modifications detected in T1 plants occurred mostly in somatic cells, and consequently there were no T1 plants that were homozygous for a gene modification event. In contrast, ∼22% of T2 plants were found to be homozygous for a modified gene. All homozygotes were stable to the next generation, without any new modifications at the target sites. There was no indication of any off-target mutations by examining the target sites and sequences highly homologous to the target sites and by in-depth whole-genome sequencing. Together our results show that the CRISPR/Cas system is a useful tool for generating versatile and heritable modifications specifically at target genes in plants.


Asunto(s)
Arabidopsis/genética , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas/genética , Genes de Plantas , Secuencia de Bases , Recombinación Homóloga , Mutación , Polimorfismo de Nucleótido Simple
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA