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1.
Small ; 20(15): e2307288, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37997215

RESUMO

Ocean energy is a kind of clean and renewable energy source, but it cannot be efficiently harvested by traditional electromagnetic generators, due to its low-frequency characteristic. The emergence of triboelectric nanogenerators provides a more promising technology for collecting ocean energy. In this work, a durable roller-based swing-structured triboelectric nanogenerator (RS-TENG) is designed and fabricated for low-frequency water wave energy harvesting. The rolling structure reduces the wear between triboelectric materials and improves the device's durability. After a continuous operation of 1 260 000 cycles, the attenuation of the electrical outputs of the RS-TENG is below 1.6%, exhibiting excellent durability. At the same time, the output current can arrive at 53.2 µA. Under the triggering of water waves, the RS-TENG can generate an output power of 4.27 mW, corresponding to a power density of 1.16 W m-3. After the arraying, the output performance can be doubled, so that the TENG can successfully power an environmental monitoring sensor and ensure long-term stable operation of the sensor. This work provides an effective strategy for improving the device durability, which benefits the practical applications of the TENGs in large-scale blue energy harvesting.

2.
Small ; : e2402661, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38813727

RESUMO

Traffic lights play vital roles in urban traffic management systems, providing clear directional guidance for vehicles and pedestrians while ensuring traffic safety. However, the vast quantity of traffic lights widely distributed in the transportation system aggravates energy consumption. Here, a self-powered traffic light system is proposed through wind energy harvesting based on a high-performance fur-brush dish triboelectric nanogenerator (FD-TENG). The FD-TENG harvests wind energy to power the traffic light system continuously without needing an external power supply. Natural rabbit furs are applied to dish structures, due to their outstanding characteristics of shallow wear, high performance, and resistance to humidity. Also, the grid pattern of the dish structure significantly impacts the TENG outputs. Additionally, the internal electric field and the influences of mechanical and structural parameters on the outputs are analyzed by finite element simulations. After optimization, the FD-TENG can achieve a peak power density of 3.275 W m-3. The portable and miniature features of FD-TENG make it suitable for other natural environment systems such as forests, oceans, and mountains, besides the traffic light systems. This study presents a viable strategy for self-powered traffic lights, establishing a basis for efficient environmental energy harvesting toward big data and Internet of Things applications.

3.
Plant Physiol ; 192(3): 2554-2568, 2023 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-36988071

RESUMO

Mycorrhizae are ubiquitous symbioses established between fungi and plant roots. Orchids, in particular, require compatible mycorrhizal fungi for seed germination and protocorm development. Unlike arbuscular mycorrhizal fungi, which have wide host ranges, orchid mycorrhizal fungi are often highly specific to their host orchids. However, the molecular mechanism of orchid mycorrhizal symbiosis is largely unknown compared to that of arbuscular mycorrhizal and rhizobial symbiosis. Here, we report that an endophytic Sebacinales fungus, Serendipita indica, promotes seed germination and the development of protocorms into plantlets in several epiphytic Epidendroideae orchid species (6 species in 2 genera), including Dendrobium catenatum, a critically endangered orchid with high medicinal value. Although plant-pathogen interaction and high meristematic activity can induce the hypoxic response in plants, it has been unclear whether interactions with beneficial fungi, especially mycorrhizal ones, also involve the hypoxic response. By studying the symbiotic relationship between D. catenatum and S. indica, we determined that hypoxia-responsive genes, such as those encoding alcohol dehydrogenase (ADH), are highly induced in symbiotic D. catenatum protocorms. In situ hybridization assay indicated that the ADH gene is predominantly expressed in the basal mycorrhizal region of symbiotic protocorms. Additionally, the ADH inhibitors puerarin and 4-methylpyrazole both decreased S. indica colonization in D. catenatum protocorms. Thus, our study reveals that S. indica is widely compatible with orchids and that ADH and its related hypoxia-responsive pathway are involved in establishing successful symbiotic relationships in germinating orchids.


Assuntos
Basidiomycota , Dendrobium , Micorrizas , Orchidaceae , Simbiose , Dendrobium/genética , Sementes , Micorrizas/fisiologia , Basidiomycota/fisiologia , Orchidaceae/genética , Filogenia
4.
Proc Natl Acad Sci U S A ; 118(27)2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34187897

RESUMO

Immunoglobulin A (IgA)-producing plasma cells derived from conventional B cells in the gut play an important role in maintaining the homeostasis of gut flora. Both T cell-dependent and T cell-independent IgA class switching occurs in the lymphoid structures in the gut, whose formation depends on lymphoid tissue inducers (LTis), a subset of innate lymphoid cells (ILCs). However, our knowledge on the functions of non-LTi helper-like ILCs, the innate counter parts of CD4 T helper cells, in promoting IgA production is still limited. By cell adoptive transfer and utilizing a unique mouse strain, we demonstrated that the generation of IgA-producing plasma cells from B cells in the gut occurred efficiently in the absence of both T cells and helper-like ILCs and without engaging TGF-ß signaling. Nevertheless, B cell recruitment and/or retention in the gut required functional NKp46-CCR6+ LTis. Therefore, while CCR6+ LTis contribute to the accumulation of B cells in the gut through inducing lymphoid structure formation, helper-like ILCs are not essential for the T cell-independent generation of IgA-producing plasma cells.


Assuntos
Linfócitos B/imunologia , Trato Gastrointestinal/imunologia , Imunidade Inata , Imunoglobulina A/imunologia , Switching de Imunoglobulina , Linfócitos/imunologia , Linfócitos T/imunologia , Animais , Fator de Transcrição GATA3/metabolismo , Switching de Imunoglobulina/imunologia , Integrases/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta/metabolismo
5.
Angew Chem Int Ed Engl ; : e202400477, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38712648

RESUMO

Polyethylene oxide (PEO)-based solid-state batteries hold great promise as the next-generation batteries with high energy density and high safety. However, PEO-based electrolytes encounter certain limitations, including inferior ionic conductivity, low Li+ transference number, and poor mechanical strength. Herein, we aim to simultaneously address these issues by utilizing one-dimensional zwitterionic cellulose nanofiber (ZCNF) as fillers for PEO-based electrolytes using a simple aqueous solution casting method. Multiple characterizations and theoretical calculations demonstrate that the unique zwitterionic structure imparts ZCNF with various functions, such as disrupting PEO crystallization, dissociating lithium salts, anchoring anions through cationic groups, accelerating Li+ migration by anionic groups, as well as its inherent reinforcement effect. As a result, the prepared PL-ZCNF electrolyte exhibits remarkable ionic conductivity (5.37×10-4 S cm-1) and Li+ transference number (0.62) at 60 °C without sacrificing mechanical strength (9.2 MPa), together with high critical current density of 1.1 mA cm-2. Attributed to these merits of PL-ZCNF, the LiFePO4|PL-ZCNF|Li solid-state full-cell delivers exceptional rate capability and cycling performance (900 cycles at 5 C). Notably, the assembled pouch-cell can maintain steady operation over 1000 cycles with an impressive 93.7 % capacity retention at 0.5 C and 60 °C, highlighting the great potential of PL-ZCNF for practical applications.

6.
Angew Chem Int Ed Engl ; 63(11): e202320183, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38265307

RESUMO

Alloying-type antimony (Sb) with high theoretical capacity is a promising anode candidate for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). Given the larger radius of Na+ (1.02 Å) than Li+ (0.76 Å), it was generally believed that the Sb anode would experience even worse capacity degradation in SIBs due to more substantial volumetric variations during cycling when compared to LIBs. However, the Sb anode in SIBs unexpectedly exhibited both better electrochemical and structural stability than in LIBs, and the mechanistic reasons that underlie this performance discrepancy remain undiscovered. Here, using substantial in situ transmission electron microscopy, X-ray diffraction, and Raman techniques complemented by theoretical simulations, we explicitly reveal that compared to the lithiation/delithiation process, sodiation/desodiation process of Sb anode displays a previously unexplored two-stage alloying/dealloying mechanism with polycrystalline and amorphous phases as the intermediates featuring improved resilience to mechanical damage, contributing to superior cycling stability in SIBs. Additionally, the better mechanical properties and weaker atomic interaction of Na-Sb alloys than Li-Sb alloys favor enabling mitigated mechanical stress, accounting for enhanced structural stability as unveiled by theoretical simulations. Our finding delineates the mechanistic origins of enhanced cycling stability of Sb anode in SIBs with potential implications for other large-volume-change electrode materials.

7.
J Am Chem Soc ; 145(50): 27757-27766, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-38059839

RESUMO

H2O2 photosynthesis has attracted great interest in harvesting and converting solar energy to chemical energy. Nevertheless, the high-efficiency process of H2O2 photosynthesis is driven by the low H2O2 productivity due to the recombination of photogenerated electron-hole pairs, especially in the absence of a sacrificial agent. In this work, we demonstrate that ultrathin ZnIn2S4 nanosheets with S vacancies (Sv-ZIS) can serve as highly efficient catalysts for H2O2 photosynthesis via O2/H2O redox. Mechanism studies confirm that Sv in ZIS can extend the lifetimes of photogenerated carriers and suppress their recombination, which triggers the O2 reduction and H2O oxidation to H2O2 through radical initiation. Theoretical calculations suggest that the formation of Sv can strongly change the coordination structure of ZIS, modulating the adsorption abilities to intermediates and avoiding the overoxidation of H2O to O2 during O2/H2O redox, synergistically promoting 2e- O2 reduction and 2e- H2O oxidation for ultrahigh H2O2 productivity. The optimal catalyst displays a H2O2 productivity of 1706.4 µmol g-1 h-1 under visible-light irradiation without a sacrificial agent, which is ∼29 times higher than that of pristine ZIS (59.4 µmol g-1 h-1) and even much higher than those of reported photocatalysts. Impressively, the apparent quantum efficiency is up to 9.9% at 420 nm, and the solar-to-chemical conversion efficiency reaches ∼0.81%, significantly higher than the value for natural synthetic plants (∼0.10%). This work provides a facile strategy to separate the photogenerated electron-hole pairs of ZIS for H2O2 photosynthesis, which may promote fundamental research on solar energy harvest and conversion.

8.
Opt Express ; 31(23): 38744-38760, 2023 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-38017971

RESUMO

Low-dimensional CsPbBr3 perovskite materials have gained widespread attention, derived from their remarkable properties and potential for numerous optoelectronic applications. Herein, the sample of CsPbBr3 microwires were prepared horizontally onto n-type InGaN film substrate using an in-plane solution growth method. The resulting CsPbBr3 microwire/InGaN heterojunction allows for the achievement of a highly sensitive and broadband photodetector. Particularly for the implementation in a self-supplying manner, the best-performing photodetector can achieve a superior On/Off ratio of 4.6×105, the largest responsivity ∼ 800.0 mA/W, a maximum detectivity surpassing 4.6× 1012 Jones, and a high external quantum efficiency approaching 86.5% upon 405 nm light illumination. A rapid response time (∼ 4.48 ms/7.68 ms) was also achieved. The as-designed CsPbBr3 microwire/InGaN heterojunction device without any encapsulation exhibits superior comprehensive stability. Besides, the device featuring as a single pixel imaging unit can readily detect simple images under broadband light illumination with a high spatial resolution, acknowledging its outstanding imaging capability. The robust photodetection properties could be derived from the intense absorption of CsPbBr3 MWs and high-efficiency charge carriers transporting toward the in-situ formed CsPbBr3/InGaN heterointerface. The results may offer an available strategy for the in-situ construction of best-performing low-dimensional perovskite heterojunction optoelectronic devices.

9.
Liver Int ; 43(2): 329-339, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36453086

RESUMO

BACKGROUND AND AIMS: Myeloid-derived suppressor cells (MDSCs) and CD4+ regulatory T cells (Tregs) expand during chronic hepatitis B virus (HBV) infection and inhibit antiviral immunity. However, the relationship between antiviral effect and the frequencies of those immune suppressive cells after pegylated interferon α-2a (PegIFNα-2a) therapy is not clearly understood. This study aimed to investigate the contribution of monocytic MDSCs (mMDSCs) and CD4+ Tregs to functional cure (HBsAg seroclearance) after PegIFNα-2a therapy and evaluate the effect of PegIFNα-2a therapy on these cells. METHODS: Flow cytometry analysis was performed along with longitudinal immune monitoring of 97 hepatitis B e antigen (HBeAg) negative chronic hepatitis B (CHB) patients receiving PegIFNα-2a weekly for 48 weeks. RESULTS: The frequencies of mMDSCs and CD4+ Tregs increased in all HBV patients, and they were higher in the HBsAg persistence group than in the HBsAg seroclearance group. A significant decline in the frequency of mMDSCs was found in patients who realized functional cure after PegIFNα-2a treatment. In contrast, the frequency of CD4+ Tregs in both the HBsAg seroclearance and persistence groups significantly increased. Multivariate analyses indicated that the baseline serum HBsAg levels (p < .001) and mMDSCs frequency (p = .027) were independently associated with the HBsAg clearance, and the combined marker (HBsAg plus mMDSCs) displayed the highest specificity (93.1%) than any other markers in predicting HBsAg seroclearance. CONCLUSIONS: These results suggest that a poor response to PegIFNα-2a treatment in CHB patients may be related to the frequencies of immune suppressive cells, while the therapeutic targeting of these cells might be effective in boosting anti-HBV immunity.


Assuntos
Hepatite B Crônica , Células Supressoras Mieloides , Humanos , Antígenos de Superfície da Hepatite B , Antivirais , Antígenos E da Hepatite B , Polietilenoglicóis/uso terapêutico , Proteínas Recombinantes/uso terapêutico , Vírus da Hepatite B/genética , DNA Viral
10.
Nano Lett ; 22(14): 5874-5882, 2022 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-35763376

RESUMO

Constructing 3D skeletons modified with lithiophilic seeds has proven effective in achieving dendrite-free lithium metal anodes. However, these lithiophilic seeds are mostly alloy- or conversion-type materials, and they tend to aggregate and redistribute during cycling, resulting in the failure of regulating Li deposition. Herein, we address this crucial but long-neglected issue by using intercalation-type lithiophilic seeds, which enable antiaggregation owing to their negligible volume expansion and high electrochemical stability against Li. To exemplify this, a 3D carbon-based host is built, in which ultrafine TiO2 seeds are uniformly embedded in nitrogen-doped hollow porous carbon spheres (N-HPCSs). The TiO2@N-HPCSs electrode exhibits superior Coulombic efficiency, high-rate capability, and long-term stability when evaluated as compertitive anodes for Li metal batteries. Furthermore, the superiority of intercalation-type seeds is comprehensively revealed through controlled experiments by various in situ/ex situ electron and optical microscopies, which highlights the excellent structural stability and lithiophilicity of TiO2 nanoseeds upon repeated cycling.


Assuntos
Lítio , Sementes , Carbono , Eletrodos
11.
Plant J ; 105(5): 1326-1338, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33278042

RESUMO

Plants have short-term stress memory that enables them to maintain the expression state of a substantial subset of heat-inducible genes during stress recovery after heat stress. Little is known about the molecular mechanisms controlling stress-responsive gene expression at the recovery stage in plants, however. In this article, we demonstrate that histone H3K4 methyltransferases SDG25 and ATX1 are required for heat-stress tolerance in Arabidopsis. SDG25 and ATX1 are not only important for stress-responsive gene expression during heat stress, but also for maintaining stress-responsive gene expression during stress recovery. A combination of whole-genome bisulfite sequencing, RNA-sequencing and ChIP-qPCR demonstrated that mutations of SDG25 and ATX1 decrease histone H3K4me3 levels, increase DNA cytosine methylation and inhibit the expression of a subset of heat stress-responsive genes during stress recovery in Arabidopsis. ChIP-qPCR results confirm that ATX1 binds to chromatins associated with these target genes. Our results reveal that histone H3K4me3 affects DNA methylation at regions in the loci associated with heat stress-responsive gene expression during stress recovery, providing insights into heat-stress transcriptional memory in plants.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Arabidopsis/metabolismo , Histona Metiltransferases/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Metilação de DNA , Regulação da Expressão Gênica de Plantas , Histona Metiltransferases/genética
12.
Opt Express ; 30(17): 29969-29978, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-36242109

RESUMO

Due to geometric overlap factor, the backscattering lidar is not suitable to detect atmospheric characteristics near the ground. A new sidescattering lidar system consisting of three CCD cameras and one CW laser is developed for the first time to measure the profiles of the backscattering coefficient of atmospheric aerosols across the whole troposphere, which has no detection blind zone near the ground. The aerosol relative phase function was detected by its horizontal CCD channel. The vertical distribution of aerosol backscattering coefficient across the whole troposphere was observed by the other two CCD cameras of vertical channel. The reasons for choosing three CCD cameras and their respective functions are analyzed in detail. Comparative experiments and continuous observations indicate that the new sidescattering lidar system including three CCD cameras is simple in structure and reliable in performance with low cost as well.

13.
Nano Lett ; 21(13): 5633-5640, 2021 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-34137617

RESUMO

Harvesting distributed and low-quality mechanical energies by triboelectric nanogenerators to power electrochemical reactions is beneficial to electric energy saving and certain applications. However, the conventional self-powered electrochemical process is awkward about the reaction rate, energy conversion efficiency, high-operation frequency, and mismatched impedance. Here we demonstrate an advanced self-powered electrochemical system. In comparison with the conventional system that is inert in activity, the superior power management and electrochemical reaction regulation in tandem make the novel system outstanding for hydrogen peroxide production. In addition to the visible product, an internal current efficiency of 24.6% in the system was achieved. The developed system provides an optimization strategy toward electric energy saving for electrochemical reactions as well as enabling their applications in remote areas by converting environmental mechanical vibrational energy for ecological improvement or recyclable chemical fuel generation.


Assuntos
Fontes de Energia Elétrica , Nanotecnologia , Eletricidade
14.
Int J Mol Sci ; 23(24)2022 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-36555789

RESUMO

Proteasome is a large proteolytic complex that consists of a 20S core particle (20SP) and 19S regulatory particle (19SP) in eukaryotes. The proteasome degrades most cellular proteins, thereby controlling many key processes, including gene expression and protein quality control. Proteasome dysfunction in plants leads to abnormal development and reduced adaptability to environmental stresses. Previous studies have shown that proteasome dysfunction upregulates the gene expression of proteasome subunits, which is known as the proteasome bounce-back response. However, the proteasome bounce-back response cannot explain the damaging effect of proteasome dysfunction on plant growth and stress adaptation. To address this question, we focused on downregulated genes caused by proteasome dysfunction. We first confirmed that the 20SP subunit PBE is an essential proteasome subunit in Arabidopsis and that PBE1 mutation impaired the function of the proteasome. Transcriptome analyses showed that hypoxia-responsive genes were greatly enriched in the downregulated genes in pbe1 mutants. Furthermore, we found that the pbe1 mutant is hypersensitive to waterlogging stress, a typical hypoxic condition, and hypoxia-related developments are impaired in the pbe1 mutant. Meanwhile, the 19SP subunit rpn1a mutant seedlings are also hypersensitive to waterlogging stress. In summary, our results suggested that proteasome dysfunction downregulated the hypoxia-responsive pathway and impaired plant growth and adaptability to hypoxia stress.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Citoplasma/metabolismo , Regulação da Expressão Gênica de Plantas , Hipóxia , Complexo de Endopeptidases do Proteassoma/genética , Complexo de Endopeptidases do Proteassoma/metabolismo
15.
Molecules ; 27(23)2022 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-36500675

RESUMO

Dengue fever is the most common mosquito-borne viral disease and is caused by the dengue virus (DENV). There is still a lack of efficient drugs against DENV infection, so it is urgent to develop new inhibitors for future clinical use. Our previous research indicated the role of VEGFR2/AMPK in regulating cellular metabolism during DENV infection, while acetyl-CoA carboxylase (ACC) is located downstream of AMPK and plays a crucial role in mediating cellular lipid synthesis; therefore, we speculated that an ACC inhibitor could serve as an antiviral agent against DENV. Luckily, we found that CP640186, a reported noncompetitive ACC inhibitor, significantly inhibited DENV proliferation, and CP640186 clearly reduced DENV2 proliferation at an early stage with an EC50 of 0.50 µM. A mechanism study indicated that CP640186 inhibited ACC activation and destroyed the cellular lipid environment for viral proliferation. In the DENV2 infection mice model, oral CP640186 administration (10 mg/kg/day) significantly improved the mice survival rate after DENV2 infection. In summary, our research suggests that lipid synthesis plays an important role during DENV2 proliferation and indicates that CP640186 is a promising drug candidate against DNEV2 in the future.


Assuntos
Vírus da Dengue , Dengue , Camundongos , Animais , Dengue/tratamento farmacológico , Acetil-CoA Carboxilase , Replicação Viral , Linhagem Celular , Antivirais/farmacologia , Antivirais/uso terapêutico , Lipídeos/farmacologia
16.
Molecules ; 27(15)2022 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-35956950

RESUMO

HBx plays a significant role in the cccDNA epigenetic modification regulating the hepatitis B virus (HBV) life cycle and in hepatocyte proliferation and carcinogenesis. By using the sleeping-beauty transposon system, we constructed a tetracycline-induced HBx-expressing stable cell line, SBHX21. HBx with a HiBiT tag can be quickly detected utilizing a NanoLuc-based HiBiT detection system. By screening a drug library using SBHX21 cells, we identified estradiol benzoate as a novel anti-HBx agent. Estradiol benzoate also markedly reduced the production of HBeAg, HBsAg, HBV pgRNA, and HBV DNA in a dose-dependent manner, suggesting that estradiol benzoate could be an anti-HBV agent. Docking model results revealed that estradiol benzoate binds to HBx at TRP87 and TRP107. Collectively, our results suggest that estradiol benzoate inhibits the HBx protein and HBV transcription and replication, which may serve as a novel anti-HBV molecular compound for investigating new treatment strategies for HBV infection.


Assuntos
Vírus da Hepatite B , Transativadores , Estradiol/análogos & derivados , Células Hep G2 , Vírus da Hepatite B/metabolismo , Humanos , Luciferases , Transativadores/genética , Transativadores/metabolismo , Proteínas Virais Reguladoras e Acessórias/metabolismo , Replicação Viral
17.
J Integr Plant Biol ; 64(7): 1297-1302, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35524486

RESUMO

During recovery from heat stress, plants clear away the heat-stress-induced misfolded proteins through the ubiquitin-proteasome system (UPS). In the UPS, the recognition of substrate proteins by E3 ligase can be regulated by the N-terminal acetyltransferase A (NatA) complex. Here, we determined that Arabidopsis STRESS-RELATED UBIQUITIN-ASSOCIATED-DOMAIN PROTEIN FACTOR 1 (SUF1) interacts with the NatA complex core subunit NAA15 and positively regulates NAA15. The suf1 and naa15 mutants are sensitive to heat stress; the NatA substrate N SNC1 is stabilized in suf1 mutant plants during heat stress recovery. Therefore, SUF1 and its interactor NAA15 play important roles in basal thermotolerance in Arabidopsis.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Termotolerância , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Acetiltransferase N-Terminal A/química , Acetiltransferase N-Terminal A/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Termotolerância/genética , Ubiquitinas/metabolismo
18.
J Integr Plant Biol ; 63(3): 438-450, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33421288

RESUMO

Environmental stress from climate change and agricultural activity threatens global plant biodiversity as well as crop yield and quality. As sessile organisms, plants must maintain the integrity of their genomes and adjust gene expression to adapt to various environmental changes. In eukaryotes, nucleosomes are the basic unit of chromatin around which genomic DNA is packaged by condensation. To enable dynamic access to packaged DNA, eukaryotes have evolved Snf2 (sucrose nonfermenting 2) family proteins as chromatin remodeling factors (CHRs) that modulate the position of nucleosomes on chromatin. During plant stress responses, CHRs are recruited to specific genomic loci, where they regulate the distribution or composition of nucleosomes, which in turn alters the accessibility of these loci to general transcription or DNA damage repair machinery. Moreover, CHRs interplay with other epigenetic mechanisms, including DNA methylation, histone modifications, and deposition of histone variants. CHRs are also involved in RNA processing at the post-transcriptional level. In this review, we discuss major advances in our understanding of the mechanisms by which CHRs function during plants' response to environmental stress.


Assuntos
Montagem e Desmontagem da Cromatina , Meio Ambiente , Plantas/metabolismo , Estresse Fisiológico , Montagem e Desmontagem da Cromatina/genética , Dano ao DNA/genética , Regulação da Expressão Gênica de Plantas , Plantas/genética , Estresse Fisiológico/genética
19.
J Mol Recognit ; 33(3): e2820, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31835276

RESUMO

Co-Co3 O4 /carbon nanotube/carbon foam (Co-Co3 O4 /CNT/CF) nanocomposites were prepared by soaking melamine foam into a solution of Co(NO3 )2 ·6H2 O, followed by calcination in N2 and air in sequence. The obtained Co-Co3 O4 /CNT/CF nanocomposites were characterized with scanning electron microscopy and cyclic voltammetry. It was found that Co3 O4 nanoparticles were grown on the external of CF successfully, while CNTs were grown on the surfaces of CF in a large amount, which further improved the electrical conductivity of the. The prepared Co-Co3 O4 /CNT/CF nanocomposites were then used to construct nonenzymatic sensor to detect glucose in alkaline solution. The sensor showed detection range from 1.2 µM to 2.29 mM with a detection limit of 0.4 µM (S/N =3) and a high sensitivity of 637.5 µA-1 cm-2 . The developed sensor also showed an instant response, favorable reproducibility, and high selectivity. The results attest that Co-Co3 O4 /CNT/CF composites have great potential in the development of nonenzymatic sensors for glucose.


Assuntos
Técnicas Biossensoriais , Glucose/isolamento & purificação , Nanotubos de Carbono/química , Eletrodos , Microscopia Eletrônica de Varredura , Nanocompostos/química , Nanopartículas/química , Níquel/química
20.
New Phytol ; 221(3): 1359-1368, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30346042

RESUMO

The ubiquitin 26S proteasome (26SP) system efficiently degrades many key regulators of plant development. 26SP consists of two subcomplexes: the catalytic 20S core particle (CP) and the 19S regulatory particle (RP). Previous studies have focused on 19S RP; whether there is a specific subunit in 20S CP that has a stress-related biological function in plants is unclear. PBE1, one of the ß5 subunits of Arabidopsis proteasome CP, is essential for the assembly and proteolytic activity of 26SP in salt-stressed seedlings. The expression of PBE1 is stress-induced. During the transition from seed germination to autotrophic growth in salt-stressed seedlings, loss of PBE1 function results specifically in arrest in developmental transition but not in germination and post-germination growth. PBE1 is also important for other types of proteasome stress and Endoplasmic Reticulum (ER) stress. PBE1 modulates the protein level of the transcription factor ABI5 and thereby down-regulates the expression of several genes downstream of this key regulator which are known to be essential for plant growth under stress. Collectively, our results showed PBE1-mediated intact proteasome assembly that is essential for successful autotrophic growth, and revealed how PBE1 mediated stress proteasome functions to control both proteasome activity and abscisic acid (ABA)-mediated stress signaling in plants.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/fisiologia , Processos Autotróficos , Complexo de Endopeptidases do Proteassoma/metabolismo , Estresse Salino , Ácido Abscísico/farmacologia , Sequência de Aminoácidos , Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Processos Autotróficos/efeitos dos fármacos , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Mutação com Perda de Função/genética , Complexo de Endopeptidases do Proteassoma/genética , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Estresse Salino/efeitos dos fármacos , Plântula/efeitos dos fármacos , Plântula/metabolismo , Cloreto de Sódio/farmacologia
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