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1.
Plant Physiol ; 191(3): 1751-1770, 2023 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-36617225

RESUMO

Plant cuticles are composed of hydrophobic cuticular waxes and cutin. Very long-chain fatty acids (VLCFAs) are components of epidermal waxes and the plasma membrane and are involved in organ morphogenesis. By screening a barrelclover (Medicago truncatula) mutant population tagged by the transposable element of tobacco (Nicotiana tabacum) cell type1 (Tnt1), we identified two types of mutants with unopened flower phenotypes, named unopened flower1 (uof1) and uof2. Both UOF1 and UOF2 encode enzymes that are involved in the biosynthesis of VLCFAs and cuticular wax. Comparative analysis of the mutants indicated that the mutation in UOF1, but not UOF2, leads to the increased number of leaflets in M. truncatula. UOF1 was specifically expressed in the outermost cell layer (L1) of the shoot apical meristem (SAM) and leaf primordia. The uof1 mutants displayed defects in VLCFA-mediated plasma membrane integrity, resulting in the disordered localization of the PIN-FORMED1 (PIN1) ortholog SMOOTH LEAF MARGIN1 (SLM1) in M. truncatula. Our work demonstrates that the UOF1-mediated biosynthesis of VLCFAs in L1 is critical for compound leaf patterning, which is associated with the polarization of the auxin efflux carrier in M. truncatula.


Assuntos
Medicago truncatula , Proteínas de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Medicago truncatula/genética , Medicago truncatula/metabolismo , Flores/genética , Flores/metabolismo , Ácidos Graxos/metabolismo , Ceras/metabolismo , Regulação da Expressão Gênica de Plantas , Folhas de Planta/genética , Folhas de Planta/metabolismo , Mutação/genética
2.
Sensors (Basel) ; 24(11)2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38894279

RESUMO

The aim of this paper was to explore the application of multi-channel synchronized dynamic strain gauges in monitoring the neutral axis (N.A.) position of prestressed concrete box girders. The N.A. position has recently been proposed as an indicator for monitoring the health of bridge structures. Laboratory experiments were conducted on a prestressed T-beam under different prestress level conditions to investigate the correlation between the prestress magnitude and the N.A. position. In the development of the multi-channel synchronized dynamic strain gauges, edge computing was employed to significantly reduce the amount of data transmitted from the sensor nodes on-site. In edge computing, only the dynamic strain response caused by the maximum vehicle load in each minute is transmitted. This approach greatly enhances the monitoring efficiency and enables the realization of on-site non-computer-based monitoring systems. The laboratory test results of the prestressed T-beam showed that the N.A. position tends to move slightly downward as the prestress force increases. In other words, when the prestress force decreases due to loss, the N.A. position exhibits a slight upward movement. This study selected a newly constructed prestressed box girder as the subject for on-site measurement of the N.A. position using multi-channel synchronized dynamic strain gauges shortly after the prestress was applied. The on-site monitoring data indeed revealed a gradual upward movement of the N.A. position. This phenomenon confirmed that soon after the completion of prestressed concrete bridges, there is a gradual loss of prestress due to the significant shrinkage and creep effects of the early-age concrete. The on-site monitoring result aligned with the findings from the laboratory experiments, where the N.A. position was observed to move upward as the prestress decreased.

3.
Neuroimmunomodulation ; 30(1): 28-41, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36599309

RESUMO

INTRODUCTION: Inflammation in early life is a risk factor for the development of neuropsychiatric diseases later in adolescence and adulthood, yet the underlying mechanism remains elusive. In the present study, we performed an integrated proteomic and phosphoproteomic analysis of the hippocampus to identify potential molecular mechanisms of early life inflammation-induced cognitive impairment. METHODS: Both female and male mice received a single intraperitoneal injection of 100 µg/kg lipopolysaccharide (LPS) on postnatal day 10 (P10). Behavioral tests, including open field, elevated plus-maze, and Y-maze tests, were performed on P39, P40, and P41, respectively. After behavioral tests, male mice were sacrificed. The whole brain tissues and the hippocampi were harvested on P42 for proteomic, phosphoproteomic, Western blot, and Golgi staining. RESULTS: Early life LPS exposure induced cognitive impairment in male mice but not in female mice, as assessed by the Y-maze test. Therefore, following biochemical tests were conducted on male mice. By proteomic analysis, 13 proteins in LPS group exhibited differential expression. Among these, 9 proteins were upregulated and 4 proteins were downregulated. For phosphoproteomic analysis, a total of 518 phosphopeptides were identified, of which 316 phosphopeptides were upregulated and 202 phosphopeptides were downregulated in the LPS group compared with the control group. Furthermore, KEGG analysis indicated that early life LPS exposure affected the glutamatergic synapse and neuroactive ligand-receptor interaction, which were associated with synaptic function and energy metabolism. Increased level of brain protein i3 (Bri3), decreased levels of PSD-95 and mGLUR5, and dendritic spine loss after early life LPS exposure further confirmed the findings of proteomic and phosphoproteomic analysis. CONCLUSIONS: Our findings demonstrated that neuroinflammation and impaired synapse may be involved in early life inflammation-induced cognitive impairment. Future studies are required to confirm our preliminary results.


Assuntos
Lipopolissacarídeos , Fosfopeptídeos , Animais , Masculino , Feminino , Camundongos , Lipopolissacarídeos/toxicidade , Fosfopeptídeos/efeitos adversos , Fosfopeptídeos/metabolismo , Proteômica , Inflamação/metabolismo , Modelos Animais de Doenças , Hipocampo/metabolismo
4.
Physiol Plant ; 175(2): e13886, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36862032

RESUMO

Metabolic profiles in xylem sap are considered a fundamental mechanism for Cadmium (Cd) detoxification in plants. However, the metabolic mechanism of Brassica juncea xylem sap in response to Cd is still unclear. Here, we investigated the effects on the metabolomics of B. juncea xylem sap treated with Cd at different times by utilizing a nontargeted liquid chromatography-mass spectrometry (LC-MS)-based metabolomics method for further elucidating the response mechanism of Cd exposure. The findings indicated that 48 h and 7 days Cd exposure caused significant differences in metabolic profiles of the B. juncea xylem sap. Those differential metabolites are primarily involved in amino acids, organic acids, lipids, and carbohydrates, and most of them were downregulated, which played essential roles in response to Cd stress. Furthermore, B. juncea xylem sap resisted 48-h Cd exposure via regulation of glycerophospholipid metabolism, carbon metabolism, aminoacyl-tRNA biosynthesis, glyoxylate and dicarboxylate metabolism, linoleic acid metabolism, C5-branched dibasic acid metabolism, alpha-linolenic acid metabolism, cyanoamino acid metabolism, ABC transporters, biosynthesis of amino acids, and pyrimidine metabolism; whereas alpha-linolenic acid metabolism, glycerophospholipid metabolism, photosynthesis, and oxidative phosphorylation were regulated for resisting 7-day Cd exposure.


Assuntos
Cádmio , Mostardeira , Mostardeira/metabolismo , Ácido alfa-Linolênico/análise , Ácido alfa-Linolênico/metabolismo , Metaboloma , Aminoácidos/metabolismo , Xilema/metabolismo , Glicerofosfolipídeos/análise , Glicerofosfolipídeos/metabolismo
5.
Proc Natl Acad Sci U S A ; 117(12): 6910-6917, 2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32152121

RESUMO

Auxin is a class of plant hormone that plays a crucial role in the life cycle of plants, particularly in the growth response of plants to ever-changing environments. Since the auxin responses are concentration-dependent and higher auxin concentrations might often be inhibitory, the optimal endogenous auxin level must be closely controlled. However, the underlying mechanism governing auxin homeostasis remains largely unknown. In this study, a UDP-glycosyltransferase (UGT76F1) was identified from Arabidopsis thaliana, which participates in the regulation of auxin homeostasis by glucosylation of indole-3-pyruvic acid (IPyA), a major precursor of the auxin indole-3-acetic acid (IAA) biosynthesis, in the formation of IPyA glucose conjugates (IPyA-Glc). In addition, UGT76F1 was found to mediate hypocotyl growth by modulating active auxin levels in a light- and temperature-dependent manner. Moreover, the transcription of UGT76F1 was demonstrated to be directly and negatively regulated by PIF4, which is a key integrator of both light and temperature signaling pathways. This study sheds a light on the trade-off between IAA biosynthesis and IPyA-Glc formation in controlling auxin levels and reveals a regulatory mechanism for plant growth adaptation to environmental changes through glucosylation of IPyA.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Glucose/metabolismo , Hipocótilo/crescimento & desenvolvimento , Ácidos Indolacéticos/farmacologia , Indóis/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/metabolismo , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/genética , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/metabolismo , Glucosiltransferases/metabolismo , Glicosilação , Hipocótilo/efeitos dos fármacos , Hipocótilo/metabolismo , Hipocótilo/efeitos da radiação , Indóis/química , Luz , Reguladores de Crescimento de Plantas/farmacologia , Plântula , Temperatura
6.
J Am Ceram Soc ; 106(1): 186-200, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36589901

RESUMO

One-pot synthesized twin perovskite oxide composite of BaCe0.5Fe0.5O3- δ (BCF), comprising cubic and orthorhombic perovskite phases, shows triple-conducting properties for promising solid oxide electrochemical cells. Phase composition evolution of BCF under various conditions was systematically investigated, revealing that the cubic perovskite phase could be fully/partially reduced into the orthorhombic phase under certain conditions. The reduction happened between the two phases at the interface, leading to the microstructure change. As a result, the corresponding apparent conducting properties also changed due to the difference between predominant conduction properties for each phase. Based on the revealed phase composition, microstructure, and electrochemical properties changes, a deep understanding of BCF's application in different conditions (oxidizing atmospheres, reducing/oxidizing gradients, cathodic conditions, and anodic conditions) was achieved. Triple-conducting property (H+/O2-/e-), fast open-circuit voltage response (∼16-∼470 mV) for gradients change, and improved single-cell performance (∼31% lower polarization resistance at 600°C) were comprehensively demonstrated. Besides, the performance was analyzed under anodic conditions, which showed that the microstructure and phase change significantly affected the anodic behavior.

7.
Small ; 18(24): e2201952, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35567327

RESUMO

Electrically accelerated self-healable poly(ionic liquids) copolymers that exhibit resistor-capacitor (RC) circuit properties are developed. At low alternating current (AC) frequencies these materials behave as a resistor (R), whereas at higher frequencies as a capacitor (C). These properties are attributed to a combination of dipolar and electrostatic interactions in (1-[(2-methacryloyloxy)ethyl]-3-butylimidazolium bis(trifluoromethyl-sulfonyl)imide) copolymerized with methyl methacrylate (MMA) monomers to form p(MEBIm-TSFI/MMA)] copolymers. When the monomer molar ratio (MEBIm-TSFI:MMA) is 40/60, these copolymers are capable of undergoing multiple damage-repair cycles and self-healing is accelerated by the application of alternating 1.0-4.0 V electric field (EF). Self-healing in the absence of EFs is facilitated by van der Waals (vdW) interactions, but the application of AC EF induces back and forth movement of charges against the opposing force that result in dithering of electrostatic dipoles giving rise to interchain physical crosslinks. Electrostatic inter- and intrachain interactions facilitated by copolymerization of ionic liquid monomers with typically dielectric acrylic-based monomers result in enhanced cohesive energy densities that accelerate the recovery of vdW forces facilitating self-healing. Incorporating ionic liquids into commodity polymers offers promising uses as green conducting solid polyelectrolytes in self-healable energy storage, energy-harvesting devices, and many other applications.


Assuntos
Líquidos Iônicos , Íons , Polimerização , Polímeros , Eletricidade Estática
8.
Small ; 18(50): e2204784, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36300911

RESUMO

A significant issue that bedeviled the commercialization of renewable energy technologies, ranging from low-temperature water electrolyzers to high-temperature solid oxide cells, is the lack of high-performance catalysts. Among various candidates that could tackle such a challenge, perovskite oxides are rising-star materials because of their unique structural and compositional flexibility. However, single-phase perovskite oxides are challenging to satisfy all the requirements of electrocatalysts concurrently for practical applications, such as high catalytic activity, excellent stability, good ionic and electronic conductivities, and superior chemical/thermo-mechanical robustness. Impressively, perovskite oxides with coupled nanocomposites are emerging as a novel form offering multifunctionality due to their intrinsic features, including infinite interfaces with solid interaction, tunable compositions, flexible configurations, and maximum synergistic effects between assorted components. Considering this new configuration has attracted great attention owing to its promising performances in various energy-related applications, this review timely summarizes the leading-edge development of perovskite oxide-based coupled nanocomposites. Their state-of-art synthetic strategies are surveyed and highlighted, their unique structural advantages are highlighted and illustrated through the typical oxygen reduction reaction and oxygen evolution reactions in both high and low-temperature applications. Opinions on the current critical scientific issues and opportunities in this burgeoning research field are all provided.

9.
Plant Cell ; 31(9): 2107-2130, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31227558

RESUMO

Abscisic acid (ABA) and reactive oxygen species (ROS) act as key signaling molecules in the plant response to salt stress; however, how these signals are transduced and amplified remains unclear. Here, a soybean (Glycine max) salinity-induced NAM/ATAF1/2/CUC2 (NAC) transcription factor encoded by SALT INDUCED NAC1 (GmSIN1) was shown to be a key component of this process. Overexpression of GmSIN1 in soybean promoted root growth and salt tolerance and increased yield under salt stress; RNA interference-mediated knockdown of GmSIN1 had the opposite effect. The rapid induction of GmSIN1 in response to salinity required ABA and ROS, and the effect of GmSIN1 on root elongation and salt tolerance was achieved by boosting cellular ABA and ROS contents. GmSIN1 upregulated 9-cis-epoxycarotenoid dioxygenase coding genes in soybean (GmNCED3s, associated with ABA synthesis) and Respiratory burst oxidase homolog B genes in soybean (GmRbohBs, associated with ROS generation) by binding to their promoters at a site that has not been described to date. Together, GmSIN1, GmNCED3s, and GmRbohBs constitute a positive feed-forward system that enables the rapid accumulation of ABA and ROS, effectively amplifying the initial salt stress signal. These findings suggest that the combined modulation of ABA and ROS contents enhances soybean salt tolerance.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Dioxigenases/metabolismo , Glycine max/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Ribonuclease III/metabolismo , Estresse Salino/fisiologia , Ácido Abscísico/metabolismo , Proteínas de Arabidopsis , Proteínas de Ciclo Celular/genética , Dioxigenases/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Proteínas de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas , Espécies Reativas de Oxigênio/metabolismo , Ribonuclease III/genética , Salinidade , Estresse Salino/genética , Tolerância ao Sal/genética , Tolerância ao Sal/fisiologia , Glycine max/genética , Estresse Fisiológico
10.
BMC Geriatr ; 22(1): 685, 2022 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-35982410

RESUMO

BACKGROUND: Postoperative delirium (POD), one of the most common complications following major surgery, imposes a heavy burden on patients and society. The objective of this exploratory study was to conduct a secondary analysis to identify whether there exist novel and reliable serum biomarkers for the prediction of POD. METHODS: A total of 131 adult patients (≥ 65 years) undergoing lower extremity orthopedic surgery with were enrolled in this study. Cognitive function was assessed preoperatively with Mini-Mental State Examination (MMSE). Delirium was diagnosed according to the Confusion Assessment Method (CAM) criteria on preoperative day and postoperative days 1-3. The preoperative serum levels of a panel of 16 biochemical parameters were measured by ELISA. RESULTS: Thirty-five patients developed POD, with an incidence of 26.7%. Patients in POD group were older (P = 0.001) and had lower preoperative MMSE scores (P = 0.001). Preoperative serum levels of prostaglandin E2 (PGE2, P < 0.001), S100ß (P < 0.001), glial fibrillary acidic protein (P < 0.001) and neurofilament light (P = 0.002) in POD group were significantly increased. Logistic regression analysis showed that advanced age (OR = 1.144, 95%CI: 1.008 ~ 1.298, P = 0.037), higher serum neurofilament light (OR = 1.003, 95%CI: 1.000 ~ 1.005, P = 0.036) and PGE2 (OR = 1.031, 95%CI: 1.018 ~ 1.044, P < 0.001) levels were associated with the development of POD. In addition, serum level of PGE2 yielded an area under the ROC curve (AUC) of 0.897 to predict POD (P < 0.001), with a sensitivity of 80% and a specificity of 83.3%. CONCLUSIONS: Our study showed that higher preoperative serum PGE2 level might be a biomarker to predict the occurrence of POD in elderly patients undergoing elective orthopedic surgery. TRIAL REGISTRATION: NCT03792373 www. CLINICALTRIALS: gov .


Assuntos
Delírio , Procedimentos Ortopédicos , Idoso , Biomarcadores , Delírio/diagnóstico , Delírio/epidemiologia , Delírio/etiologia , Dinoprostona , Humanos , Procedimentos Ortopédicos/efeitos adversos , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Estudos Prospectivos , Fatores de Risco
11.
Sensors (Basel) ; 22(22)2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36433306

RESUMO

This study proposes an innovative method for structural health monitoring of simply supported PCI girder bridges based on dynamic strain and edge computing. Field static and dynamic load tests were conducted on a bridge consisting of a span with newly replaced PCI girders and numerous spans with old PCI girders. Both the static and dynamic test results showed that the flexural rigidity of the old PCI girders decreased significantly due to deterioration. To improve the efficiency of on-site monitoring data transmission and data analysis, this study developed a smart dynamic strain gauge node with the function of edge computing. Continuous data with a sampling frequency of 100 Hz were computed at the sensor node. Among the computed results, only the maximum dynamic strain data caused by the passage of the heaviest vehicle within 1 min were transmitted. The on-site monitoring results indicated that under routine traffic conditions, the dynamic strain response of the new PCI girder was smaller than that of the deteriorated PCI girder. When the monitored dynamic strain response has a tendency to magnify, attention should be paid to the potential prestress loss or other deterioration behaviors of the bridge.


Assuntos
Algoritmos , Computação Matemática
12.
Plant J ; 101(2): 310-323, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31536657

RESUMO

Seed is vital to the conservation of germplasm and plant biodiversity. Seed dormancy is an adaptive trait in numerous seed-plant species, enabling plants to survive under stressful conditions. Seed dormancy is mainly controlled by abscisic acid (ABA) and gibberellin (GA) and can be classified as primary and secondary seed dormancy. The primary seed dormancy is induced by maternal ABA. Here we found that AtPER1, a seed-specific peroxiredoxin, is involved in enhancing primary seed dormancy. Two loss-of-function atper1 mutants, atper1-1 and atper1-2, displayed suppressed primary seed dormancy accompanied with reduced ABA and increased GA contents in seeds. Furthermore, atper1 mutant seeds were insensitive to abiotic stresses during seed germination. The expression of several ABA catabolism genes (CYP707A1, CYP707A2, and CYP707A3) and GA biosynthesis genes (GA20ox1, GA20ox3, and KAO3) in atper1 mutant seeds was increased compared to wild-type seeds. The suppressed primary seed dormancy of atper1-1 was completely reduced by deletion of CYP707A genes. Furthermore, loss-of-function of AtPER1 cannot enhance the seed germination ratio of aba2-1 or ga1-t, suggesting that AtPER1-enhanced primary seed dormancy is dependent on ABA and GA. Additionally, the level of reactive oxygen species (ROS) in atper1 mutant seeds was significantly higher than that in wild-type seeds. Taken together, our results demonstrate that AtPER1 eliminates ROS to suppress ABA catabolism and GA biosynthesis, and thus improves the primary seed dormancy and make the seeds less sensitive to adverse environmental conditions.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Germinação/fisiologia , Giberelinas/metabolismo , Dormência de Plantas/fisiologia , Sementes/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Regulação da Expressão Gênica de Plantas , Germinação/genética , Mutação , Fenótipo , Dormência de Plantas/genética , Reguladores de Crescimento de Plantas/genética , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas , Espécies Reativas de Oxigênio/metabolismo , Plântula/genética , Plântula/metabolismo , Sementes/genética , Transcriptoma
13.
BMC Plant Biol ; 21(1): 308, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193032

RESUMO

BACKGROUND: Rice (Oryza sativa L.) Chalkiness, the opaque part in the kernel endosperm formed by loosely piled starch and protein bodies. Chalkiness is a complex quantitative trait regulated by multiple genes and various environmental factors. Phytohormones play important roles in the regulation of chalkiness formation but the underlying molecular mechanism is still unclear at present. RESULTS: In this research, Xiangzaoxian24 (X24, pure line of indica rice with high-chalkiness) and its origin parents Xiangzaoxian11 (X11, female parent, pure line of indica rice with high-chalkiness) and Xiangzaoxian7 (X7, male parent, pure line of indica rice with low-chalkiness) were used as materials. The phenotype, physiological and biochemical traits combined with transcriptome analysis were conducted to illustrate the dynamic process and transcriptional regulation of rice chalkiness formation. Impressively, phytohormonal contents and multiple phytohormonal signals were significantly different in chalky caryopsis, suggesting the involvement of phytohormones, particularly ABA and auxin, in the regulation of rice chalkiness formation, through the interaction of multiple transcription factors and their downstream regulators. CONCLUSION: These results indicated that chalkiness formation is a dynamic process associated with multiple genes, forming a complex regulatory network in which phytohormones play important roles. These results provided informative clues for illustrating the regulatory mechanisms of chalkiness formation in rice.


Assuntos
Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Oryza/genética , Oryza/fisiologia , Reguladores de Crescimento de Plantas/farmacologia , Transcrição Gênica/efeitos dos fármacos , Endosperma/efeitos dos fármacos , Endosperma/metabolismo , Endosperma/ultraestrutura , Perfilação da Expressão Gênica , Ontologia Genética , Oryza/efeitos dos fármacos , Fenótipo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Reprodutibilidade dos Testes , Amido/metabolismo , Amido/ultraestrutura , Sacarose/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
14.
Plant Physiol ; 184(4): 1969-1978, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33037128

RESUMO

Seed dormancy is an adaptive trait that is crucial to plant survival. Abscisic acid (ABA) is the primary phytohormone that induces seed dormancy. However, little is known about how the level of ABA in seeds is determined. Here we show that the Arabidopsis (Arabidopsis thaliana) H3K27me3 demethylase RELATIVE OF EARLY FLOWERING6 (REF6) suppresses seed dormancy by inducing ABA catabolism in seeds. Seeds of the ref6 loss-of-function mutants displayed enhanced dormancy that was associated with increased endogenous ABA content. We further show that the transcripts of two genes key to ABA catabolism, CYP707A1 and CYP707A3, but not genes involved in ABA biosynthesis, were significantly reduced in ref6 mutants during seed development and germination. In developing siliques, REF6 bound directly to CYP707A1 and CYP707A3, and was responsible for reducing their H3K27me3 levels. Genetic analysis demonstrated that the enhanced seed dormancy and ABA concentration in ref6 depended mainly on the reduced expression of CYP707A1 and CYP707A3 Conversely, overexpression of CYP707A1 could offset the enhanced seed dormancy of ref6 Taken together, our results revealed an epigenetic regulation mechanism that is involved in the regulation of ABA content in seeds.


Assuntos
Ácido Abscísico/metabolismo , Arabidopsis/genética , Arabidopsis/fisiologia , Epigênese Genética , Germinação/genética , Dormência de Plantas/genética , Dormência de Plantas/fisiologia , Regulação da Expressão Gênica de Plantas , Genes de Plantas
15.
Plant Cell ; 30(2): 324-346, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29371438

RESUMO

Successful floral meristem (FM) determinacy is critical for subsequent reproductive development and the plant life cycle. Although the phytohormones cytokinin and auxin interact to coregulate many aspects of plant development, whether and how cytokinin and auxin function in FM determinacy remain unclear. Here, we show that in Arabidopsis thaliana, cytokinin homeostasis is critical for FM determinacy. In this developmental context, auxin promotes the expression of AUXIN RESPONSE FACTOR3 (ARF3) to repress cytokinin activity. ARF3 directly represses the expression of ISOPENTENYLTRANSFERASE (IPT) family genes and indirectly represses LONELY GUY (LOG) family genes, both of which encode enzymes required for cytokinin biosynthesis. ARF3 also directly inhibits the expression of ARABIDOPSIS HISTIDINE KINASE4, a cytokinin receptor gene, resulting in reduced cytokinin activity. Consequently, ARF3 controls cell division by regulating cell cycle gene expression through cytokinin. In flowers, we show that AGAMOUS (AG) dynamically regulates the expression of ARF3 and IPTs, resulting in coordinated regulation of FM maintenance and termination through cell division. Moreover, genome-wide transcriptional profiling revealed both repressive and active roles for ARF3 in early flower development. Our findings establish a molecular link between AG and auxin/cytokinin and shed light on the mechanisms of stem cell maintenance and termination in the FM.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas Nucleares/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Transdução de Sinais , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Divisão Celular , Citocininas/metabolismo , Proteínas de Ligação a DNA/genética , Flores/genética , Flores/crescimento & desenvolvimento , Flores/fisiologia , Homeostase , Ácidos Indolacéticos/metabolismo , Meristema/genética , Meristema/crescimento & desenvolvimento , Meristema/fisiologia , Proteínas Nucleares/genética
16.
Plant J ; 100(3): 562-571, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31350797

RESUMO

Leaves are derived from the shoot apical meristem with three distinct axes: dorsoventral, proximodistal and mediolateral. Different regulators are involved in the establishment of leaf polarity. Members of the class III homeodomain-leucine zipper (HD-ZIPIII) gene family are critical players in the determination of leaf adaxial identity mediated by microRNA165/166. However, their roles in compound leaf development are still unclear. By screening of a retrotransposon-tagged mutant population of the model legume plant Medicago truncatula, a mutant line with altered leaflet numbers was isolated and characterized. Mutant leaves partially lost their adaxial identity. Leaflet numbers in the mutant were increased along the proximodistal axis, showing pinnate pentafoliate leaves in most cases, in contrast to the trifoliate leaves of the wild type. Detailed characterization revealed that a lesion in a HD-ZIPIII gene, REVOLUTA (MtREV1), resulted in the defects of the mutant. Overexpression of MtMIR166-insensitive MtREV1 led to adaxialized leaves and ectopic leaflets along the dorsoventral axis. Accompanying the abnormal leaf patterning, the free auxin content was affected. Our results demonstrate that MtREV1 plays a key role in determination of leaf adaxial-abaxial polarity and compound leaf patterning, which is associated with proper auxin homeostasis.


Assuntos
Padronização Corporal/genética , Ácidos Indolacéticos/metabolismo , Medicago truncatula/genética , MicroRNAs/genética , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Homeostase , Zíper de Leucina , Medicago truncatula/citologia , Medicago truncatula/fisiologia , Filogenia , Folhas de Planta/citologia , Folhas de Planta/genética , Folhas de Planta/fisiologia , Proteínas de Plantas/genética , RNA de Plantas/genética
17.
J Am Chem Soc ; 142(16): 7655-7667, 2020 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-32248688

RESUMO

Recently, there have been renewed interests in exploring new catalysts for ammonia synthesis under mild conditions. Electride-based catalysts are among the emerging ones. Ruthenium particles supported on an electride composed of a mixture of calcium and aluminum oxides (C12A7) have attracted great attention for ammonia synthesis due to their facile ability in activating N2 under ambient pressure. However, the exact nature of the reactive hydrogen species and the role of electride support still remain elusive for this catalytic system. In this work, we report for the first time that the surface-adsorbed hydrogen, rather than the hydride encaged in the C12A7 electride, plays a major role in ammonia synthesis over the Ru/C12A7 electride catalyst with the aid of in situ neutron scattering techniques. Combining in situ neutron diffraction, inelastic neutron spectroscopy, density functional theory (DFT) calculation, and temperature-programmed reactions, the results provide direct evidence for not only the presence of encaged hydrides during ammonia synthesis but also the strong thermal and chemical stability of the hydride species in the Ru/C12A7 electride. Steady state isotopic transient kinetic analysis (SSITKA) of ammonia synthesis showed that the coverage of reactive intermediates increased significantly when the Ru particles were promoted by the electride form (coverage up to 84%) of the C12A7 support rather than the oxide form (coverage up to 15%). Such a drastic change in the intermediate coverage on the Ru surface is attributed to the positive role of electride support where the H2 poisoning effect is absent during ammonia synthesis over Ru. The finding of this work has significant implications for understanding catalysis by electride-based materials for ammonia synthesis and hydrogenation reactions in general.

18.
Brain Behav Immun ; 89: 133-144, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32505714

RESUMO

Neuroinflammation plays a key role in the progression of many neurodegenerative diseases, yet the underlying mechanism remains largely unexplored. Using an animal model of neuroinflammation induced by repeated lipopolysaccharide (LPS) injections, we found selectively reduced expression of parvalbumin (PV) but not somatostatin (SST) in the medial prefrontal cortex (mPFC). The reduced PV expression resulted in decreased intensities of vesicular GABA transporter and PV buttons, suggesting disinhibition in the mPFC. These further induced abnormal mPFC neural activities and consequently contributed to cognitive impairments. In addition, gamma oscillations supported by PV interneuron function were positively associated with time spent with the novel object in the novel object recognition test. Notably, down-regulation of neuroinflammation by microglia inhibitor minocycline or boosting gamma oscillations by dopamine 4 receptor agonist RO-10-5824 improved cognitive performance. In conclusion, our study proposes neural network disturbance as a likely mechanistic linker between neuroinflammation and cognitive impairments in neurodegeneration and possibly other psychiatric disorders.


Assuntos
Disfunção Cognitiva , Parvalbuminas , Animais , Disfunção Cognitiva/induzido quimicamente , Interneurônios/metabolismo , Redes Neurais de Computação , Parvalbuminas/metabolismo , Córtex Pré-Frontal/metabolismo
19.
Cancer Control ; 27(1): 1073274820968900, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33115287

RESUMO

OBJECTIVE: The aim is to explore the prediction effect of 5 machine learning algorithms on peritoneal metastasis of gastric cancer. METHODS: 1080 patients with postoperative gastric cancer were divided into a training group and test group according to the ratio of 7:3. The model of peritoneal metastasis was established by using 5 machine learning (gbm(Light Gradient Boosting Machine), GradientBoosting, forest, Logistic and DecisionTree). Python pair was used to analyze the machine learning algorithm. Gbm algorithm is used to show the weight proportion of each variable to the result. RESULT: Correlation analysis showed that tumor size and depth of invasion were positively correlated with the recurrence of patients after gastric cancer surgery. The results of the gbm algorithm showed that the top 5 important factors were albumin, platelet count, depth of infiltration, preoperative hemoglobin and weight, respectively. In training group: Among the 5 algorithm models, the accuracy of GradientBoosting and gbm was the highest (0.909); the AUC values of the 5 algorithms are gbm (0.938), GradientBoosting (0.861), forest (0.796), Logistic(0.741) and DecisionTree(0.712) from high to low. In the test group: among the 5 algorithm models, the accuracy of forest, DecisionTree and gbm was the highest (0.907); AUC values ranged from high to low to gbm (0.745), GradientBoosting (0.725), forest (0.696), Logistic (0.680) and DecisionTree (0.657). CONCLUSION: Machine learning can predict the peritoneal metastasis in patients with gastric cancer.


Assuntos
Aprendizado de Máquina , Recidiva Local de Neoplasia/epidemiologia , Neoplasias Peritoneais/epidemiologia , Neoplasias Gástricas/patologia , Idoso , Feminino , Gastrectomia , Humanos , Incidência , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/prevenção & controle , Neoplasias Peritoneais/secundário , Curva ROC , Estudos Retrospectivos , Medição de Risco/métodos , Estômago/patologia , Estômago/cirurgia , Neoplasias Gástricas/cirurgia , Resultado do Tratamento
20.
Exp Cell Res ; 382(1): 111441, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31125555

RESUMO

IκBα protein plays an important role in NFκB signaling pathway regulation. The dysfunction of IκBα is tightly related to various diseases, including cancers. However, the molecular mechanisms by which IκBα loses its normal functions are diverse and complex. Here, we reported a novel cleavage of IκBα protein occurred in AML cells. Compared with the full-length IκBα protein, the truncated IκBα fragment exhibited a dramatically weak binding ability to NFκB complex and showed a significant decreased inhibition on NFκB transactivation. Knockdown of PR3, a serine protease mainly expressed in myeloid cells, could inhibit such IκBα cleavage and enhance the sensitivities of AML cells to the differentiation inducers. In addition, we showed that the level of PR3 mRNA was relatively higher in newly diagnosed AML patients than in those patients with complete remission, suggesting that PR3 expression and its involvement in IκBα cleavage might be closely associated with AML. Our studies revealed for the first time a PR3-involved IκBα cleavage in AML cells, providing some new evidences for further understanding the mechanisms underlying the deregulation of NFκB pathway in AML. Finally, we also suggested a potential clinical application value of PR3 protein in the treatment and prognosis surveillance for leukemia.


Assuntos
Leucemia Mieloide Aguda/metabolismo , Mieloblastina/metabolismo , Inibidor de NF-kappaB alfa/metabolismo , Proteínas de Neoplasias/metabolismo , Processamento de Proteína Pós-Traducional , Linhagem Celular Tumoral , Regulação Leucêmica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Leucemia Mieloide Aguda/genética , Mieloblastina/antagonistas & inibidores , Mieloblastina/genética , NF-kappa B/metabolismo , Inibidores de Proteases/farmacologia , Interferência de RNA , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , RNA Neoplásico/biossíntese , RNA Neoplásico/genética , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/farmacologia , Proteínas Recombinantes/metabolismo
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