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1.
Plant Cell ; 34(12): 4778-4794, 2022 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-35976113

RESUMO

Glycosylphosphatidylinositol (GPI) anchoring is a common protein modification that targets proteins to the plasma membrane (PM). Knowledge about the GPI lipid tail, which guides the secretion of GPI-anchored proteins (GPI-APs), is limited in plants. Here, we report that rice (Oryza sativa) BRITTLE CULM16 (BC16), a membrane-bound O-acyltransferase (MBOAT) remodels GPI lipid tails and governs cell wall biomechanics. The bc16 mutant exhibits fragile internodes, resulting from reduced cell wall thickness and cellulose content. BC16 is the only MBOAT in rice and is located in the endoplasmic reticulum and Golgi apparatus. Yeast gup1Δ mutant restoring assay and GPI lipid composition analysis demonstrated BC16 as a GPI lipid remodelase. Loss of BC16 alters GPI lipid structure and disturbs the targeting of BC1, a GPI-AP for cellulose biosynthesis, to the PM lipid nanodomains. Atomic force microscopy revealed compromised deposition of cellulosic nanofibers in bc16, leading to an increased Young's modulus and abnormal mechanical properties. Therefore, BC16-mediated lipid remodeling directs the GPI-APs, such as BC1, to the cell surface to fulfill multiple functions, including cellulose organization. Our work unravels a mechanism by which GPI lipids are remodeled in plants and provides insights into the control of cell wall biomechanics, offering a tool for breeding elite crops with improved support strength.


Assuntos
Glicosilfosfatidilinositóis , Complexo de Golgi , Glicosilfosfatidilinositóis/metabolismo , Complexo de Golgi/metabolismo , Membrana Celular/metabolismo , Saccharomyces cerevisiae/metabolismo , Aciltransferases/metabolismo , Parede Celular/metabolismo , Celulose/metabolismo
2.
Plant Physiol ; 193(2): 1091-1108, 2023 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-37418568

RESUMO

FUSCA 3 (FUS3), a seed master regulator, plays critical role in seed dormancy and oil accumulation. However, its downstream regulation mechanisms remain poorly understood. Here, we explored the roles of AINTEGUMENTA-like 6 (AIL6), a seed transcription factor, in these processes. The activation of AIL6 by FUS3 was demonstrated by dual-LUC assay. Seeds of ail6 mutants showed alterations in fatty acid compositions, and both AtAIL6 (AIL6 from Arabidopsis thaliana) and BnaAIL6 (AIL6 from Brassica napus) rescued the phenotype. Over-expression (OE) of AIL6s reversed changes in seed fatty acid composition. Notably, OE lines showed low seed germination rates down to 12% compared to 100% of wild-type Col-0. Transcriptome analysis of the mutant and an OE line indicated widespread expression changes of genes involved in lipid metabolism and phytohormone pathways. In OE mature seeds, GA4 content decreased more than 15-fold, while abscisic acid and indole-3-acetic acid (IAA) contents clearly increased. Exogenous GA3 treatments did not effectively rescue the low germination rate. Nicking seed coats increased germination rates from 25% to nearly 80% while the wild-type rdr6-11 is 100% and 98% respectively, and elongation of storage time also improved seed germination. Furthermore, dormancy imposed by AIL6 was fully released in the della quintuple mutant. Together, our results indicate AIL6 acts as a manager downstream of FUS3 in seed dormancy and lipid metabolism.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Dormência de Plantas/genética , Proteínas de Arabidopsis/metabolismo , Giberelinas/metabolismo , Metabolismo dos Lipídeos/genética , Regulação da Expressão Gênica de Plantas , Arabidopsis/genética , Arabidopsis/metabolismo , Germinação/fisiologia , Ácido Abscísico/farmacologia , Ácido Abscísico/metabolismo , Sementes/metabolismo , Fatores de Transcrição/metabolismo
3.
Nature ; 556(7700): 255-258, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29618817

RESUMO

Cross-species transmission of viruses from wildlife animal reservoirs poses a marked threat to human and animal health 1 . Bats have been recognized as one of the most important reservoirs for emerging viruses and the transmission of a coronavirus that originated in bats to humans via intermediate hosts was responsible for the high-impact emerging zoonosis, severe acute respiratory syndrome (SARS) 2-10 . Here we provide virological, epidemiological, evolutionary and experimental evidence that a novel HKU2-related bat coronavirus, swine acute diarrhoea syndrome coronavirus (SADS-CoV), is the aetiological agent that was responsible for a large-scale outbreak of fatal disease in pigs in China that has caused the death of 24,693 piglets across four farms. Notably, the outbreak began in Guangdong province in the vicinity of the origin of the SARS pandemic. Furthermore, we identified SADS-related CoVs with 96-98% sequence identity in 9.8% (58 out of 591) of anal swabs collected from bats in Guangdong province during 2013-2016, predominantly in horseshoe bats (Rhinolophus spp.) that are known reservoirs of SARS-related CoVs. We found that there were striking similarities between the SADS and SARS outbreaks in geographical, temporal, ecological and aetiological settings. This study highlights the importance of identifying coronavirus diversity and distribution in bats to mitigate future outbreaks that could threaten livestock, public health and economic growth.


Assuntos
Alphacoronavirus/isolamento & purificação , Alphacoronavirus/patogenicidade , Doenças dos Animais/epidemiologia , Doenças dos Animais/virologia , Quirópteros/virologia , Infecções por Coronavirus/veterinária , Diarreia/veterinária , Suínos/virologia , Alphacoronavirus/classificação , Alphacoronavirus/genética , Doenças dos Animais/transmissão , Animais , Biodiversidade , China/epidemiologia , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/transmissão , Diarreia/patologia , Diarreia/virologia , Reservatórios de Doenças/veterinária , Reservatórios de Doenças/virologia , Genoma Viral/genética , Humanos , Jejuno/patologia , Jejuno/virologia , Filogenia , Síndrome Respiratória Aguda Grave/epidemiologia , Síndrome Respiratória Aguda Grave/veterinária , Síndrome Respiratória Aguda Grave/virologia , Análise Espaço-Temporal , Zoonoses/epidemiologia , Zoonoses/transmissão , Zoonoses/virologia
4.
J Environ Manage ; 351: 119617, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38039590

RESUMO

Various studies have suggested decoupling material stock from economic output as an important measure for promoting sustainable development. Here, we develop three theoretical hypotheses to describe the evolution features and economic effects of material stock intensity, and predict in theory that (1) Countries with higher material stock intensity are more likely to decouple economic growth from material stock. (2) Material stock intensity follows convergence trends. (3) Higher material stock intensity leads to higher long-run economic growth rates. To examine the adaptability of these hypotheses, we choose steel in-use stock as the proxy for the material capital stock and use panel data in 85 countries from 1950 to 2018 to conduct empirical analysis. Our empirical results in most countries support the theoretical predictions of the hypotheses. In particular, a 0.1t/k$ increase in steel stock intensity leads to a 2.12% increase in the probability of decoupling between steel stock and economic output next year and a 0.34% increase in the long-run GDP per capita growth rate annually. Moreover, steel stock intensity converges to approximately 0.25t/k$ to 0.35t/k$ at mature development stages. We predict that, except China, which is expected to follow decoupling trends, other large developing economies will couple economic output with steel stock. However, the shape of intensity curves is still uncertain for highly developed countries in the future.


Assuntos
Desenvolvimento Econômico , Eficiência , China , Aço , Desenvolvimento Sustentável , Dióxido de Carbono/análise
5.
J Exp Bot ; 73(7): 2077-2092, 2022 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-34849730

RESUMO

ABA-INSENSITIVE 3 (ABI3) has long been known for activation of storage protein accumulation. A role of ABI3 on oil accumulation was previously suggested based on a decrease of oil content in seeds of abi3 mutant. However, this conclusion could not exclude possibilities of indirect or pleiotropic effects, such as through mutual regulatory interactions with FUSCA3 (FUS3), an activator of oil accumulation. To identify that ABI3 functions independent of the effects of related seed transcription factors, we expressed ABI3 under the control of an inducible promoter in tobacco BY2 cells and Arabidopsis rosette leaves. Inducible expression of ABI3 activated oil accumulation in these non-seed cells, demonstrating a general role of ABI3 in regulation of oil biosynthesis. Further expressing ABI3 in rosette leaves of fus3 knockout mutant still caused up to 3-fold greater triacylglycerol accumulation, indicating ABI3 can activate lipid accumulation independently of FUS3. Transcriptome analysis revealed that LIPID DROPLET PROTEIN (LDP) genes, including OLEOSINs and CALEOSINs, were up-regulated up to 1000-fold by ABI3 in the absence of FUS3, while the expression of WRINKLED1 was doubled. Taken together, our results provide genetic evidence that ABI3 activates oil accumulation with or without FUS3, most likely through up-regulating LDPs and WRINKLED1.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis , Fatores de Transcrição/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Proteínas Associadas a Gotículas Lipídicas/genética , Proteínas Associadas a Gotículas Lipídicas/metabolismo , Sementes/metabolismo , Fatores de Transcrição/genética
6.
J Exp Bot ; 73(12): 3946-3962, 2022 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-35419601

RESUMO

Caleosins are lipid droplet- and endoplasmic reticulum-associated proteins. To investigate their functions in oil accumulation, expression levels of caleosins in developing seeds of Arabidopsis thaliana were examined and four seed-expressed caleosins (CLO1, CLO2, CLO4, and CLO6) were identified. The four single mutants showed similar minor changes of fatty acid composition in seeds. Two double mutants (clo1 clo2 and clo1×clo2) demonstrated distinct changes of fatty acid composition, a 16-23% decrease of oil content, and a 10-13% decrease of seed weight. Moreover, a 40% decrease of oil content, further fatty acid changes, and misshapen membranes of smaller lipid droplets were found in seeds of quadruple CLO RNAi lines. Notably, ~40% of quadruple CLO RNAi T1 seeds failed to germinate, and deformed embryos and seedlings were also observed. Complementation experiments showed that CLO1 rescued the phenotype of clo1 clo2. Overexpression of CLO1 in seedlings and BY2 cells increased triacylglycerol content up to 73.6%. Transcriptome analysis of clo1 clo2 developing seeds showed that expression levels of some genes related to lipid, embryo development, calcium signaling, and stress responses were affected. Together, these results suggest that the major seed-expressed caleosins have overlapping functions in oil accumulation and show pleiotropic effects on embryo development.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Ligação ao Cálcio , Desenvolvimento Embrionário , Ácidos Graxos/metabolismo , Regulação da Expressão Gênica de Plantas , Óleos de Plantas/metabolismo , Proteínas de Plantas/metabolismo , Plântula/metabolismo , Sementes
7.
Plant Cell ; 31(5): 1113-1126, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30886126

RESUMO

Acetylation, a prevalent modification of cell-wall polymers, is a tightly controlled regulatory process that orchestrates plant growth and environmental adaptation. However, due to limited characterization of the enzymes involved, it is unclear how plants establish and dynamically regulate the acetylation pattern in response to growth requirements. In this study, we identified a rice (Oryza sativa) GDSL esterase that deacetylates the side chain of the major rice hemicellulose, arabinoxylan. Acetyl esterases involved in arabinoxylan modification were screened using enzymatic assays combined with mass spectrometry analysis. One candidate, DEACETYLASE ON ARABINOSYL SIDECHAIN OF XYLAN1 (DARX1), is specific for arabinosyl residues. Disruption of DARX1 via Tos17 insertion and CRISPR/Cas9 approaches resulted in the accumulation of acetates on the xylan arabinosyl side chains. Recombinant DARX1 abolished the excess acetyl groups on arabinoxylan-derived oligosaccharides of the darx1 mutants in vitro. Moreover, DARX1 is localized to the Golgi apparatus. Two-dimensional 13C-13C correlation spectroscopy and atomic force microscopy further revealed that the abnormal acetylation pattern observed in darx1 interrupts arabinoxylan conformation and cellulose microfibril orientation, resulting in compromised secondary wall patterning and reduced mechanical strength. This study provides insight into the mechanism controlling the acetylation pattern on arabinoxylan side chains and suggests a strategy to breed robust elite crops.


Assuntos
Oryza/enzimologia , Proteínas de Plantas/metabolismo , Xilanos/metabolismo , Acetilação , Parede Celular/metabolismo , Parede Celular/ultraestrutura , Celulose/metabolismo , Produtos Agrícolas , Esterases/genética , Esterases/metabolismo , Complexo de Golgi/metabolismo , Complexo de Golgi/ultraestrutura , Mutação , Oligossacarídeos/metabolismo , Oryza/genética , Oryza/ultraestrutura , Melhoramento Vegetal , Proteínas de Plantas/genética
8.
Ecotoxicol Environ Saf ; 226: 112877, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34634738

RESUMO

Bisphenol A (BPA), an important chemical raw material, is now a ubiquitous environmental contaminant. As an endocrine disruptor similar to estrogen, BPA increases the risk of various metabolic and chronic diseases. BPA has immunotoxicity to humans and animals. 1,8-cineole (CIN) is a plant-derived monoterpene with antioxidant and antiapoptosis actions. However, there are no reports about whether CIN could antagonize the BPA-induced apoptosis and necroptosis in bursa of Fabricius (BF) of chicken. This study was to elucidate the ameliorative mechanism of CIN on the apoptosis and necroptosis in BF induced by BPA. 120 broilers (1-day-old) were randomly divided into four groups: control group, CIN group, CIN and BPA co-treatment group, and BPA group. TUNEL analysis results, histopathological variations, and the overexpression of proapoptosis biomakers (Caspase 3, Bax, Cyt-c, and p53) and necroptosis pathway-related factors (RIPK1, RIPK3, MLKL, and FADD) indicated that BPA exposure induced the apoptosis and necroptosis in chicken BF. Moreover, BPA treatment elevated the levels of oxidative stress indexes (MDA, iNOS, and NO) and weaken antioxidases activity (SOD, GPx, and CAT) and total antioxidant capacity in chicken BF. BPA administration also lessened the expression of PI3K and AKT and promoted HSPs (HSP27, HSP40, HSP60, and HSP70) activation. whereas CIN supplementation prominently mitigated BPA-caused these changes and the apoptosis and necroptosis damages. In brief, this study illuminated that CIN could protect the chicken BF against BPA-induced apoptosis and necroptosis through restraining oxidative stress and activating PI3K/AKT pathway.


Assuntos
Bolsa de Fabricius , Necroptose , Animais , Apoptose , Compostos Benzidrílicos , Bolsa de Fabricius/metabolismo , Galinhas/metabolismo , Eucaliptol/metabolismo , Estresse Oxidativo , Fenóis , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo
9.
Plant Physiol ; 181(2): 669-682, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31358682

RESUMO

During growth, plant cells must coordinate cell expansion and cell wall reinforcement by integrating distinct regulatory pathways in concert with intrinsic and external cues. However, the mechanism underpinning this integration is unclear, as few of the regulators that orchestrate cell expansion and wall strengthening have been identified. Here, we report a rice (Oryza sativa) Class II KNOX-like homeobox protein, KNOTTED ARABIDOPSIS THALIANA7 (KNAT7), that interacts with different partners to govern cell expansion and wall thickening. A loss-of-function mutation in KNAT7 enhanced wall mechanical strength and cell expansion, resulting in improved lodging resistance and grain size. Overexpression of KNAT7 gave rise to the opposite phenotypes, with plants having weaker cell walls and smaller grains. Biochemical and gene expression analyses revealed that rice KNAT7 interacts with a secondary wall key regulator, NAC31, and a cell growth master regulator, Growth-Regulating Factor 4 (GRF4). The KNAT7-NAC31 and KNAT7-GRF4 modules suppressed regulatory pathways of cell expansion and wall reinforcement, as we show in internode and panicle development. These modules function in sclerenchyma fiber cells and modulate fiber cell length and wall thickness. Hence, our study uncovers a mechanism for the combined control of cell size and wall strengthening, providing a tool to improve lodging resistance and yield in rice production.


Assuntos
Parede Celular/fisiologia , Proteínas de Homeodomínio/fisiologia , Oryza/fisiologia , Proteínas de Arabidopsis , Proteínas Repressoras , Sementes/crescimento & desenvolvimento
10.
Plant Physiol ; 173(1): 470-481, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27864442

RESUMO

Acetylation is a ubiquitous modification on cell wall polymers, which play a structural role in plant growth and stress defenses. However, the mechanisms for how crop plants accomplish cell wall polymer O-acetylation are largely unknown. Here, we report on the isolation and characterization of two trichome birefringence-like (tbl) mutants in rice (Oryza sativa), which are affected in xylan O-acetylation. ostbl1 and ostbl2 single mutant and the tbl1 tbl2 double mutant displayed a stunted growth phenotype with varied degree of dwarfism. As shown by chemical assays, the wall acetylation level is affected in the mutants and the knock-down and overexpression transgenic plants. Furthermore, NMR spectroscopy analyses showed that all those mutants have varied decreases in xylan monoacetylation. The divergent expression levels of OsTBL1 and OsTBL2 explained the chemotype difference and indicated that OsTBL1 is a functionally dominant gene. OsTBL1 was found to be Golgi-localized. The recombinant OsTBL1 protein incorporates acetyl groups onto xylan. By using xylopentaose, a preferred acceptor substrate, OsTBL1 can transfer up to four acetyl residues onto xylopentaose, and this activity showed saturable kinetics. 2D-NMR spectroscopy showed that OsTBL1 transfers acetate to both 2-O and 3-O sites of xylosyl residues. In addition, ostbl1 and tbl1 tbl2 displayed susceptibility to rice blight disease, indicating that this xylan modification is required for pathogen resistance. This study identifies the major genes responsible for xylan acetylation in rice plants.


Assuntos
Oryza/metabolismo , Oryza/microbiologia , Proteínas de Plantas/metabolismo , Xilanos/metabolismo , Acetilação , Acetiltransferases/genética , Acetiltransferases/metabolismo , Birrefringência , Regulação da Expressão Gênica de Plantas , Complexo de Golgi/metabolismo , Mutação , Oryza/genética , Filogenia , Doenças das Plantas/microbiologia , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Tricomas/metabolismo , Xilanos/genética
11.
Plant Cell ; 27(6): 1681-96, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26002868

RESUMO

Cellulose, which can be converted into numerous industrial products, has important impacts on the global economy. It has long been known that cellulose synthesis in plants is tightly regulated by various phytohormones. However, the underlying mechanism of cellulose synthesis regulation remains elusive. Here, we show that in rice (Oryza sativa), gibberellin (GA) signals promote cellulose synthesis by relieving the interaction between SLENDER RICE1 (SLR1), a DELLA repressor of GA signaling, and NACs, the top-layer transcription factors for secondary wall formation. Mutations in GA-related genes and physiological treatments altered the transcription of CELLULOSE SYNTHASE genes (CESAs) and the cellulose level. Multiple experiments demonstrated that transcription factors NAC29/31 and MYB61 are CESA regulators in rice; NAC29/31 directly regulates MYB61, which in turn activates CESA expression. This hierarchical regulation pathway is blocked by SLR1-NAC29/31 interactions. Based on the results of anatomical analysis and GA content examination in developing rice internodes, this signaling cascade was found to be modulated by varied endogenous GA levels and to be required for internode development. Genetic and gene expression analyses were further performed in Arabidopsis thaliana GA-related mutants. Altogether, our findings reveal a conserved mechanism by which GA regulates secondary wall cellulose synthesis in land plants and provide a strategy for manipulating cellulose production and plant growth.


Assuntos
Celulose/biossíntese , Genes de Plantas/fisiologia , Giberelinas/fisiologia , Oryza/fisiologia , Reguladores de Crescimento de Plantas/fisiologia , Transdução de Sinais/fisiologia , Regulação da Expressão Gênica de Plantas/fisiologia , Glucosiltransferases/genética , Glucosiltransferases/fisiologia , Oryza/metabolismo , Proteínas de Plantas/fisiologia
12.
Sensors (Basel) ; 17(12)2017 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-29168735

RESUMO

Due to its highly autonomy, the strapdown inertial navigation system (SINS) is widely used in unmanned underwater vehicles (UUV) navigation. Initial alignment is crucial because the initial alignment results will be used as the initial SINS value, which might affect the subsequent SINS results. Due to the rapid convergence of Earth meridians, there is a calculation overflow in conventional initial alignment algorithms, making conventional initial algorithms are invalid for polar UUV navigation. To overcome these problems, a polar initial alignment algorithm for UUV is proposed in this paper, which consists of coarse and fine alignment algorithms. Based on the principle of the conical slow drift of gravity, the coarse alignment algorithm is derived under the grid frame. By choosing the velocity and attitude as the measurement, the fine alignment with the Kalman filter (KF) is derived under the grid frame. Simulation and experiment are realized among polar, conventional and transversal initial alignment algorithms for polar UUV navigation. Results demonstrate that the proposed polar initial alignment algorithm can complete the initial alignment of UUV in the polar region rapidly and accurately.

13.
PLoS Genet ; 9(8): e1003704, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23990797

RESUMO

Cellulose represents the most abundant biopolymer in nature and has great economic importance. Cellulose chains pack laterally into crystalline forms, stacking into a complicated crystallographic structure. However, the mechanism of cellulose crystallization is poorly understood. Here, via functional characterization, we report that Brittle Culm1 (BC1), a COBRA-like protein in rice, modifies cellulose crystallinity. BC1 was demonstrated to be a glycosylphosphatidylinositol (GPI) anchored protein and can be released into cell walls by removal of the GPI anchor. BC1 possesses a carbohydrate-binding module (CBM) at its N-terminus. In vitro binding assays showed that this CBM interacts specifically with crystalline cellulose, and several aromatic residues in this domain are essential for binding. It was further demonstrated that cell wall-localized BC1 via the CBM and GPI anchor is one functional form of BC1. X-ray diffraction (XRD) assays revealed that mutations in BC1 and knockdown of BC1 expression decrease the crystallite width of cellulose; overexpression of BC1 and the CBM-mutated BC1s caused varied crystallinity with results that were consistent with the in vitro binding assay. Moreover, interaction between the CBM and cellulose microfibrils was largely repressed when the cell wall residues were pre-stained with two cellulose dyes. Treating wild-type and bc1 seedlings with the dyes resulted in insensitive root growth responses in bc1 plants. Combined with the evidence that BC1 and three secondary wall cellulose synthases (CESAs) function in different steps of cellulose production as revealed by genetic analysis, we conclude that BC1 modulates cellulose assembly by interacting with cellulose and affecting microfibril crystallinity.


Assuntos
Celulose/química , Glicosilfosfatidilinositóis/química , Microfibrilas/química , Oryza/química , Sequência de Aminoácidos , Parede Celular/genética , Parede Celular/metabolismo , Celulose/genética , Clonagem Molecular , Cristalização , Cristalografia por Raios X , Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Glicosilfosfatidilinositóis/genética , Glicosilfosfatidilinositóis/metabolismo , Espectroscopia de Ressonância Magnética , Microfibrilas/genética , Mutação , Oryza/genética , Oryza/metabolismo
14.
J Exp Bot ; 65(12): 3055-69, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24723395

RESUMO

The ribosome is the basic machinery for translation, and biogenesis of ribosomes involves many coordinated events. However, knowledge about ribosomal dynamics in higher plants is very limited. This study chose a highly conserved trans-factor, the 60S ribosomal subunit nuclear export adaptor NMD3, to characterize the mechanism of ribosome biogenesis in the monocot plant Oryza sativa (rice). O. sativa NMD3 (OsNMD3) shares all the common motifs and shuttles between the nucleus and cytoplasm via CRM1/XPO1. A dominant negative form of OsNMD3 with a truncated nuclear localization sequence (OsNMD3(ΔNLS)) was retained in the cytoplasm, consequently interfering with the release of OsNMD3 from pre-60S particles and disturbing the assembly of ribosome subunits. Analyses of the transactivation activity and cellulose biosynthesis level revealed low protein synthesis efficiency in the transgenic plants compared with the wild-type plants. Pharmaceutical treatments demonstrated structural alterations in ribosomes in the transgenic plants. Moreover, global expression profiles of the wild-type and transgenic plants were investigated using the Illumina RNA sequencing approach. These expression profiles suggested that overexpression of OsNMD3(ΔNLS) affected ribosome biogenesis and certain basic pathways, leading to pleiotropic abnormalities in plant growth. Taken together, these results strongly suggest that OsNMD3 is important for ribosome assembly and the maintenance of normal protein synthesis efficiency.


Assuntos
Regulação da Expressão Gênica de Plantas , Oryza/genética , Proteínas de Plantas/genética , Proteínas de Ligação a RNA/genética , Sequência de Aminoácidos , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Dados de Sequência Molecular , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Fenótipo , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/química , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/metabolismo , Reação em Cadeia da Polimerase em Tempo Real
15.
Proc Natl Acad Sci U S A ; 108(12): 5110-5, 2011 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-21383162

RESUMO

Golgi-localized nucleotide sugar transporters (NSTs) are considered essential for the biosynthesis of wall polysaccharides and glycoproteins based on their characteristic transport of a large number of nucleotide sugars to the Golgi lumen. The lack of NST mutants in plants has prevented evaluation of this hypothesis in plants. A previously undescribed Golgi NST mutant, brittle culm14 (bc14), displays reduced mechanical strength caused by decreased cellulose content and altered wall structure, and exhibits abnormalities in plant development. Map-based cloning revealed that all of the observed mutant phenotypes result from a missense mutation in a putative NST gene, Oryza sativa Nucleotide Sugar Transporter1 (OsNST1). OsNST1 was identified as a Golgi-localized transporter by analysis of a fluorescence-tagged OsNST1 expressed in rice protoplast cells and demonstration of UDP-glucose transport activity via uptake assays in yeast. Compositional sugar analyses in total and fractionated wall residues of wild-type and bc14 culms showed a deficiency in the synthesis of glucoconjugated polysaccharides in bc14, indicating that OsNST1 supplies the glucosyl substrate for the formation of matrix polysaccharides, and thereby modulates cellulose biosynthesis. OsNST1 is ubiquitously expressed, with high expression in mechanical tissues. The inferior mechanical strength and abnormal development of bc14 plants suggest that OsNST1 has pleiotropic effects on cell wall biosynthesis and plant growth. Identification of OsNST1 has improved our understanding of how cell wall polysaccharide synthesis is regulated by Golgi NSTs in plants.


Assuntos
Parede Celular/metabolismo , Complexo de Golgi/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Oryza/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Polissacarídeos/biossíntese , Transporte Biológico/fisiologia , Parede Celular/genética , Clonagem Molecular , Complexo de Golgi/genética , Proteínas de Membrana Transportadoras/genética , Mutação de Sentido Incorreto , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Polissacarídeos/genética
16.
ACS Appl Mater Interfaces ; 16(6): 7415-7429, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38303129

RESUMO

The synthesis of materials with a multicomponent hierarchical structure is an essential strategy for achieving high-performance electromagnetic wave (EMW) absorption. However, conventional design strategies face challenges in terms of the rational construction of specific architecture. In this study, we employ a combined space-restricted and hierarchical construction strategy to surface-plant MoS2 nanosheets on yolk-shell structural carbon-modified Co-based composites, leading to the development of high-performance Co/NC@void@C@MoS2 absorbers with advanced architecture. The surface-planted MoS2 nanosheets, the Co/NC magnetic yolk, and the dielectric carbon shell work together to enhance the impedance matching characteristics and synergistic loss capabilities in the composites. Experimental results indicate that Co/NC@void@C-700@MoS2 exhibited the best absorption performance with an effective absorption bandwidth of 7.54 GHz (at 2.05 mm) and a minimum reflection loss of -60.88 dB (at 1.85 mm). Furthermore, radar cross-section simulation results demonstrate that Co/NC@void@C-700@MoS2 effectively suppresses the scattering and transmission of EMWs on perfect electric conductor substrates, implying its superior practical application value. This study provides inspiration and experimental basis for designing and optimizing EMW absorption materials with hierarchical yolk-shell architecture.

17.
J Colloid Interface Sci ; 659: 945-958, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38219313

RESUMO

The rational and effective combination of multicomponent materials and the design of subtle microstructure for efficient microwave absorption are still challenging. In this study, carbon-coated CoFe with heterogeneous interfaces was space-restricted in the void space of hollow mesoporous carbon spheres through a facile approach involving electrostatic adsorption and annealing, and a high-performance microwave absorber (MAs) (denoted as Co0.7Fe0.3@C@void@C) was successfully prepared. The heterostructure, three-dimensional lightweight porous morphology, and electromagnetic synergy strategy enabled the Co0.7Fe0.3@C@void@C material with yolk-shell structure to exhibit surprising microwave absorption properties. When the annealing temperature and filler loading were 550° C and 15 wt%, respectively, the composites exhibited an effective absorption bandwidth (EAB) of 7.16 GHz at 2.48 mm and a minimum reflection loss of -24.1 dB at 2.11 mm. A maximum EAB of 7.21 GHz at 2.37 mm could be achieved for the composite prepared with an annealing temperature of 650° C. In addition, radar cross-section experiments demonstrated, the potential practical applicability of Co0.7Fe0.3@C@void@C. This work expands a new avenue to develop high-performance and lightweight MAs with ingenious microstructure.

18.
Quant Imaging Med Surg ; 13(5): 2871-2880, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-37179919

RESUMO

Background: For lung cancer screening in patients with previous malignant tumors, Lung Imaging Reporting and Data System (Lung-RADS) and other lung cancer screening tools are controversial in terms of requirements for the previous cancer history. This study investigated the effect of the length and type of malignancy history on the diagnostic efficacy of Lung Imaging Reporting and Data System (Lung-RADS) 2022 in pulmonary nodules (PNs). Methods: Chest computed tomography and clinical data of PNs in patients with a history of cancer who underwent surgical resection in The First Affiliated Hospital of Chongqing Medical University from January 1, 2018, to November 30, 2021, were retrospectively collected and evaluated based on Lung-RADS. All PNs were divided into 2 groups: the prior lung cancer (PLC) and the prior extrapulmonary cancer (PEPC) groups. Each group was divided into the ≥5 years and <5 years groups based on the duration of cancer history. The diagnostic agreement of Lung-RADS was evaluated based on the pathological diagnosis of nodules after operation. The diagnostic agreement rate (AR) of Lung-RADS and the composition ratios of different types between different groups were calculated and compared. Results: A total of 451 patients with 565 PNs were included in this study. These patients were divided into the PLC group (<5 years: 135 cases, 175 PNs; ≥5 years: 9 cases, 12 PNs) and the PEPC group (<5 years: 219 cases, 278 PNs; ≥5 years: 88 cases, 100 PNs). The diagnostic AR of partial solid nodules (93.0%; 95% CI: 88.7-97.2%) and solid nodules (88.1%; 95% CI: 84.1-92.1%) was close (P=0.13), while both were higher than that of the pure ground-glass nodules (24.0%; 95% CI: 17.5-30.4%; all P values <0.001). Within 5 years, the composition ratio of PNs and the diagnostic AR (PLC: 58.9%, 95% CI: 51.5-66.2%; PEPC: 76.6%, 95% CI: 71.6-81.6%) between the PLC and PEPC groups were all different (all P values <0.001), and the others [composition ratio of PNs & the diagnostic AR: PLC (≥5 years) vs. PEPC (≥5 years); PLC (<5 years) vs. PLC (≥5 years); PEPC (<5 years) vs. PEPC (≥5 years)] were similar (all P values >0.05; range: 0.10-0.93). Conclusions: The length of prior cancer history may affect the diagnostic agreement of Lung-RADS, especially for patients with prior lung cancer within 5 years.

19.
Sci Total Environ ; 898: 165551, 2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-37454844

RESUMO

In China, wide variations exist not only among different provinces, but also inside provinces. Therefore, intensive policy adjustments are essential for promoting carbon neutral in China, which calls for a clear understanding of carbon emission disparities in each individual province. Based on panel data of 2001 county-level administrative areas from 2004 to 2017, we use Theil index and spatial regression models to measure contributions and distributions of intra-provincial carbon inequality, as well as effects of intra-provincial economic inequality on intra-provincial carbon inequality, in order to design provincial specific strategies considering carbon differentiations inside each province. Our main contributions are studying China's carbon inequality from intra- instead of inter-provincial perspectives and exploring spatial connections of carbon inequality, which has not been fully discussed in previous studies. The empirical results indicate that intra- rather than inter- provincial carbon inequality contributes the majority of China's overall carbon inequality. Intra-provincial inequality shows high levels of regional clustering and decrease from west to east, although their differences are smaller in 2017 than 2004, mainly because carbon inequality levels experience large declines in some central and western provinces. Low carbon inequality levels in eastern provinces are mainly attributed to very negative correlation between development levels and carbon intensity. Intra-provincial economic development inequality plays nonnegligible roles in intra-provincial carbon inequality in all provinces, although they are not the major driving factors in some provinces. There also exist positive spatial spillover effects of intra-provincial economic inequality on intra-provincial carbon inequality. We provide specific policy suggestions on key areas of carbon emission reductions and demand degree of economic transitions for each individual province and also evaluate effects of "common prosperity" measures, which have been frequently discussed recently, on intra-provincial carbon distributions.

20.
Diagnostics (Basel) ; 13(13)2023 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-37443604

RESUMO

BACKGROUND: In addition to the diameters of pulmonary nodules, the number and morphology of blood vessels in pure ground-glass nodules (pGGNs) were closely related to the occurrence of lung cancer. Moreover, the benign and malignant signs of nodules were also valuable for the identification of nodules. Based on these two points, we tried to revise Lung-RADS 2022 and proposed our Modified Lung-RADS. The aim of the study was to verify the diagnostic performance of Modified Lung-RADS for pulmonary solid nodules (SNs) and pure ground-glass nodules (pGGNs) in patients with previous malignancies. METHODS: The chest CT and clinical data of patients with prior cancer who underwent pulmonary nodulectomies from 1 January 2018 to 30 November 2021 were enrolled according to inclusion and exclusion criteria. A total of 240 patients with 293 pulmonary nodules were included in this study. In contrast with the original version, the risk classification of pGGNs based on the GGN-vascular relationships (GVRs), and the SNs without burrs and with benign signs, could be downgraded to category 2. The sensitivity, specificity, and agreement rate of the original Lung-RADS 2022 and Modified Lung-RADS for pGGNs and SNs were calculated and compared. RESULTS: Compared with the original version, the sensitivity and agreement rate of the Modified version for pGGNs increased from 0 and 23.33% to 97.10% and 92.22%, respectively, while the specificity decreased from 100% to 76.19%. As regards SNs, the specificity and agreement rate of the Modified version increased from 44.44% to 75.00% (p < 0.05) and 88.67% to 94.09% (p = 0.052), respectively, while the sensitivity was unchanged (98.20%). CONCLUSIONS: In general, the diagnostic efficiency of Modified Lung-RADS was superior to that of the original version, and Modified Lung-RADS could be a preliminary attempt to improve Lung-RADS 2022.

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