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1.
Hortic Res ; 11(7): uhae133, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38974190

RESUMO

Seed development and yield depend on the transport and supply of sugar. However, an insufficient supply of nutrients from maternal tissues to embryos results in seed abortion and yield reduction in Camellia oleifera. In this study, we systematically examined the route and regulatory mechanisms of sugar import into developing C. oleifera seeds using a combination of histological observations, transcriptome profiling, and functional analysis. Labelling with the tracer carboxyfluorescein revealed a symplasmic route in the integument and an apoplasmic route for postphloem transport at the maternal-filial interface. Enzymatic activity and histological observation showed that at early stages [180-220 days after pollination (DAP)] of embryo differentiation, the high hexose/sucrose ratio was primarily mediated by acid invertases, and the micropylar endosperm/suspensor provides a channel for sugar import. Through Camellia genomic profiling, we identified three plasma membrane-localized proteins including CoSWEET1b, CoSWEET15, and CoSUT2 and one tonoplast-localized protein CoSWEET2a in seeds and verified their ability to transport various sugars via transformation in yeast mutants and calli. In situ hybridization and profiling of glycometabolism-related enzymes further demonstrated that CoSWEET15 functions as a micropylar endosperm-specific gene, together with the cell wall acid invertase CoCWIN9, to support early embryo development, while CoSWEET1b, CoSWEET2a, and CoSUT2 function at transfer cells and chalazal nucellus coupled with CoCWIN9 and CoCWIN11 responsible for sugar entry in bulk into the filial tissue. Collectively, our findings provide the first comprehensive evidence of the molecular regulation of sugar import into and within C. oleifera seeds and provide a new target for manipulating seed development.

2.
Int J Mol Sci ; 25(4)2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38396714

RESUMO

The NAC family of transcription factors (TFs) regulate plant development and abiotic stress. However, the specific function and response mechanism of NAC TFs that increase drought resistance in Picea wilsonii remain largely unknown. In this study, we functionally characterized a member of the PwNAC family known as PwNAC31. PwNAC31 is a nuclear-localized protein with transcriptional activation activity and contains an NAC domain that shows extensive homology with ANAC072 in Arabidopsis. The expression level of PwNAC31 is significantly upregulated under drought and ABA treatments. The heterologous expression of PwNAC31 in atnac072 Arabidopsis mutants enhances the seed vigor and germination rates and restores the hypersensitive phenotype of atnac072 under drought stress, accompanied by the up-regulated expression of drought-responsive genes such as DREB2A (DEHYDRATION-RESPONSIVE ELEMENT BINDING PROTEIN 2A) and ERD1 (EARLY RESPONSIVE TO DEHYDRATION STRESS 1). Yeast two-hybrid and bimolecular fluorescence complementation assays confirmed that PwNAC31 interacts with DREB2A and ABF3 (ABSCISIC ACID-RESPONSIVE ELEMENT-BINDING FACTOR 3). Yeast one-hybrid and dual-luciferase assays showed that PwNAC31, together with its interaction protein DREB2A, directly regulated the expression of ERD1 by binding to the DRE element of the ERD1 promoter. Collectively, our study provides evidence that PwNAC31 activates ERD1 by interacting with DREB2A to enhance drought tolerance in transgenic Arabidopsis.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Resistência à Seca , Picea , Ácido Abscísico/farmacologia , Ácido Abscísico/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Desidratação/genética , Resistência à Seca/genética , Secas , Regulação da Expressão Gênica de Plantas , Picea/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Saccharomyces cerevisiae/metabolismo , Estresse Fisiológico/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo
3.
Autism Res ; 17(3): 482-496, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38031655

RESUMO

Difficulties in auditory language comprehension are common among children and adolescents with autism spectrum disorder. However, findings regarding the underlying neural mechanisms remain mixed, and few studies have systematically explored the overall patterns of these findings. Therefore, this study aims to systematically review and meta-analyze the functional magnetic resonance imaging evidence of neural activation patterns while engaging in auditory language comprehension tasks among children and adolescents with autism. Using activation likelihood estimation, we conducted a series of meta-analyses to investigate neural activation patterns during auditory language comprehension tasks compared to baseline conditions in autism and non-autism groups and compared the activation patterns of the groups, respectively. Eight studies were included in the within-group analyses, and seven were included in the between-group analysis. The within-group analyses revealed that the bilateral superior temporal gyrus was activated during auditory language comprehension tasks in both groups, whereas the left superior frontal gyrus and dorsal medial prefrontal cortex were activated only in the non-autism group. Furthermore, the between-group analysis showed that children and adolescents with autism, compared to those without autism, showed reduced activation in the right superior temporal gyrus, left middle temporal gyrus, and insula, whereas the autism group did not show increased activation in any of the regions relative to the non-autism group. Overall, these findings contribute to our understanding of the potential neural mechanisms underlying difficulties in auditory language comprehension in children and adolescents with autism and provide practical implications for early screening and language-related interventions for children and adolescents with autism.


Assuntos
Transtorno do Espectro Autista , Criança , Humanos , Adolescente , Transtorno do Espectro Autista/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Compreensão/fisiologia , Mapeamento Encefálico/métodos , Idioma , Encéfalo
4.
Environ Pollut ; 343: 123239, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38154782

RESUMO

A total of 84 PM2.5 (fine particulate matter) aerosol samples were collected between October 2020 and August 2021 within an urban site in Hangzhou, an East China megacity. Chemical species, such as organic carbon (OC), elemental carbon (EC), as well as char, soot, and n-alkanes, were analyzed to determine their pollution characteristics and source contributions. The mean yearly concentrations of OC, EC, char, soot, and total n-alkanes (∑n-alkane) were 8.76 ± 3.61 µg/m3, 1.44 ± 0.76 µg/m3, 1.21 ± 0.69 µg/m3, 0.3 ± 0.1 µg/m3, and 24.2 ± 10.6 ng/m3. The OC, EC, and ∑n-alkanes were found in the highest levels during winter and lowest during summer. There were strong correlations between OC and EC in both winter and spring, suggesting similar potential sources for these carbonaceous components in both seasons. There were poor correlations among the target pollutants due to summertime secondary organic carbon formation. Potential source contribution functions analysis showed that local pollution levels in winter and autumn were likely influenced by long-range transportation from the Plain of North China. Source index and positive matrix factorization models provided insights into the complex sources of n-alkanes in Hangzhou. Their major contributors were identified as terrestrial plant releases (32.7%), traffic emissions (28.8%), coal combustion (27.3%), and microbial activity (11.2%). Thus, controlling vehicular emissions and coal burning could be key measures to alleviate n-alkane concentrations in the atmosphere of Hangzhou, as well as other Chinese urban centers.


Assuntos
Poluentes Atmosféricos , Poluentes Atmosféricos/análise , Fuligem/análise , Monitoramento Ambiental , Material Particulado/análise , Emissões de Veículos/análise , China , Carvão Mineral/análise , Alcanos/análise , Aerossóis/análise , Carbono/análise , Estações do Ano
5.
Mar Pollut Bull ; 199: 115920, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38113801

RESUMO

To investigate the distribution, sources, influencing factors, and ecological risk of polycyclic aromatic hydrocarbons (PAHs) in East China Marginal Seas (ECMSs) sediments, we measured the concentrations of 16 PAHs in 104 surface sediment samples collected from the ECMSs in 2014 and 2016. Total PAH concentration (∑PAHs) ranged from 4.49 to 163.66 ng/g dry weight (dry w), with 65.98 ± 33.00 (mean ± SD) ng/g dry w. The highest PAH concentrations and total organic carbon were observed in areas with fine-grained sediments in the Bohai Sea (BS), Yellow Sea (YS), and coastal East China Sea (ECS), indicating the prominent influence of regional hydrodynamics and sediment properties. The dominant PAH congener in BS and YS was BbF, whereas coastal ECS was Phe. The heterogeneity of PAH sources implies that terrestrial PAH input and shelf mud deposition have crucial roles in the source-sink processes of PAHs in a strongly human-influenced marginal sea.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Humanos , Hidrocarbonetos Policíclicos Aromáticos/análise , Sedimentos Geológicos , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Oceanos e Mares , China
6.
Plant Physiol ; 194(1): 511-529, 2023 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-37757893

RESUMO

Soil salinity is a major environmental factor constraining growth and productivity of highbush blueberry (Vaccinium corymbosum). Leaf Na+ content is associated with variation in salt tolerance among blueberry cultivars; however, the determinants and mechanisms conferring leaf Na+ exclusion are unknown. Here, we observed that the blueberry cultivar 'Duke' was more tolerant than 'Sweetheart' and accumulated less Na+ in leaves under salt stress conditions. Through transcript profiling, we identified a member of the high-affinity K+ transporter (HKT) family in blueberry, VcHKT1;1, as a candidate gene involved in leaf Na+ exclusion and salt tolerance. VcHKT1;1 encodes a Na+-preferential transporter localized to the plasma membrane and is preferentially expressed in the root stele. Heterologous expression of VcHKT1;1 in Arabidopsis (Arabidopsis thaliana) rescued the salt hypersensitivity phenotype of the athkt1 mutant. Decreased VcHKT1;1 transcript levels in blueberry plants expressing antisense-VcHKT1;1 led to increased Na+ concentrations in xylem sap and higher leaf Na+ contents compared with wild-type plants, indicating that VcHKT1;1 promotes leaf Na+ exclusion by retrieving Na+ from xylem sap. A naturally occurring 8-bp insertion in the promoter increased the transcription level of VcHKT1;1, thus promoting leaf Na+ exclusion and blueberry salt tolerance. Collectively, we provide evidence that VcHKT1;1 promotes leaf Na+ exclusion and propose natural variation in VcHKT1;1 will be valuable for breeding Na+-tolerant blueberry cultivars in the future.


Assuntos
Arabidopsis , Mirtilos Azuis (Planta) , Tolerância ao Sal/genética , Mirtilos Azuis (Planta)/genética , Mirtilos Azuis (Planta)/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Melhoramento Vegetal , Proteínas de Membrana Transportadoras/metabolismo , Arabidopsis/metabolismo
7.
Plants (Basel) ; 12(16)2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37631118

RESUMO

The Agrobacterium tumefaciens-mediated transformation for blueberries remains less efficient than is desirable. A new leaf callus regeneration and genetic transformation system was investigated in blueberries in this study. The leaf explants of cv. 'Legacy' and 'Northland' were used to establish the stable callus induction system when placed on the woody plant medium (WPM) supplemented with 1.0 mg·L-1 2, 4-D, 0.4 mg·L-1 6-BA for 30 d; then, the callus was sub-cultured in the proliferation medium supplemented with 1.5 mg·L-1 2, 4-D, 0.4 mg·L-1 6-BA in the darkness at 25 °C every 30 days. The co-cultivation of callus with A. tumefaciens was operated on WPM plus 100 µM acetosyringone for 4 days; then, the transferred callus was grown in WPM supplemented with 1.5 mg·L-1 2,4-D, 0.4 mg·L-1 6-BA, 50 mg·L-1 hygromycin, and 200 mg·L-1 cefotaxime. The VcCHS transgenic blueberry callus with both GFP signal and Hyg resistance was obtained from the transformed callus of cv. 'Northland'. The rate of GFP signal detected in the transformed callus was as high as 49.02%, which was consistent with the PCR assay. Collectively, this study provides a highly efficient genetic transformation system in blueberry callus and a powerful approach for the molecular breeding of blueberries.

8.
Plants (Basel) ; 12(15)2023 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-37570971

RESUMO

Sugar transport from the source leaf to the sink organ is critical for seed development and crop yield, as well as for responding to abiotic stress. SWEETs (sugar will eventually be exported transporters) mediate sugar efflux into the reproductive sink and are therefore considered key candidate proteins for sugar unloading during seed development. However, the specific mechanism underlying the sugar unloading to seeds in Camellia oleifera remains elusive. Here, we identified a SWEET gene named CoSWEET10, which belongs to Clade III and has high expression levels in the seeds of C. oleifera. CoSWEET10 is a plasma membrane-localized protein. The complementation assay of CoSWEET10 in SUSY7/ura3 and EBY.VW4000 yeast strains showed that CoSWEET10 has the ability to transport sucrose, glucose, and fructose. Through the C. oleifera seeds in vitro culture, we found that the expression of CoSWEET10 can be induced by hexose and sucrose, and especially glucose. By generating the restoration lines of CoSWEET10 in Arabidopsis atsweet10, we found that CoSWEET10 restored the seed defect phenotype of the mutant by regulating soluble sugar accumulation and increased plant drought tolerance. Collectively, our study demonstrates that CoSWEET10 plays a dual role in promoting seed development and enhancing plant drought resistance as a sucrose and hexose transporter.

9.
Mol Plant ; 16(10): 1496-1517, 2023 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-37464740

RESUMO

Global climate change exacerbates the effects of environmental stressors, such as drought, flooding, extreme temperatures, salinity, and alkalinity, on crop growth and grain yield, threatening the sustainability of the food supply. Maize (Zea mays) is one of the most widely cultivated crops and the most abundant grain crop in production worldwide. However, the stability of maize yield is highly dependent on environmental conditions. Recently, great progress has been made in understanding the molecular mechanisms underlying maize responses to environmental stresses and in developing stress-resilient varieties due to advances in high-throughput sequencing technologies, multi-omics analysis platforms, and automated phenotyping facilities. In this review, we summarize recent advances in dissecting the genetic factors and networks that contribute to maize abiotic stress tolerance through diverse strategies. We also discuss future challenges and opportunities for the development of climate-resilient maize varieties.


Assuntos
Grão Comestível , Zea mays , Produtos Agrícolas/genética , Agricultura , Estresse Fisiológico/genética
10.
Int J Colorectal Dis ; 38(1): 89, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37004572

RESUMO

PURPOSE: The standard of care for locally advanced rectal cancer (LARC) has changed from a single radical surgical treatment to the current multimodality treatment (standard chemoradiotherapy (CRT) and total neoadjuvant therapy (TNT)). The efficacy and safety of both TNT and standard CRT are evaluated in randomized controlled trials (RCTs). METHODS: RCTs were comprehensively searched in Chinese and English electronic databases. The experimental and control groups were TNT and the standard CRT, respectively, included in this meta-analysis. The outcomes were assessed through a fixed-effect or random-effect model of pooled odds (OR) or hazard ratios (HR). RESULTS: Eleven RCTs, involving 3,101 patients were included in the final analysis. TNT showed increase in the pathological complete response (pCR) (OR = 1.95, 95% confidence interval (CI): 1.57-2.41; P < 0.05) and the R0 resection (OR = 1.19, 95% CI: 0.99-1.43; P = 0.062). There was no significant difference in local recurrence-free survival (LRFS) (HR = 0.97, P = 0.803), but TNT had better 3-year disease-free survival (DFS) (HR = 0.82, 95% CI: 0.72-0.93, P < 0.05), overall survival (OS) (HR = 0.87, 95% CI: 0.74-1.02, P = 0.08) and distant metastasis-free survival (DMFS) (HR = 0.79, 95% CI: 0.67-0.93, P < 0.05) than standard CRT. CONCLUSIONS: TNT was safe and feasible as it improved pCR and survival outcomes, and reduced the risk of distant metastasis compared with standard CRT. TNT may be a superior strategy for LARC, but more RCTs are needed to prove it. REGISTRATION AND PROTOCOL: PROSPERO CRD42022327697. We added the Chinese database after registration because of the inclusion of fewer RCTs www.crd.york.ac.uk/PROSPERO/ .


Assuntos
Neoplasias Retais , Humanos , Neoplasias Retais/patologia , Terapia Neoadjuvante/efeitos adversos , Reto/patologia , Intervalo Livre de Doença , Quimiorradioterapia/efeitos adversos , Resultado do Tratamento , Estadiamento de Neoplasias
11.
Comput Netw ; 224: 109595, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36741551

RESUMO

Epidemics, such as Corona Virus Disease 2019 (COVID-19), have serious consequences globally, of which the most effective way to control the infection is contact tracing. Nowadays, research related to privacy-preserving epidemic infection control has been conducted, nevertheless, current researchers do not regard the authenticity of records and infection facts as well as poor traceability. Moreover, with the emergence of quantum computing, there is a bottleneck in upholding privacy, security and efficiency. Our paper proposes a privacy-preserving epidemic infection control scheme through lattice-based linkable ring signature in blockchain, called AQRS. Firstly, our scheme adopts a blockchain with three ledgers to store information in a distributed manner, which offers transparency and immunity from the Single Point of Failure (SPoF) and Denial of Service (DoS) attacks. Moreover, we design a lattice-based linkable ring signature scheme to secure privacy-preserving of epidemic infection control. Significantly, we are the first to introduce the lattice-based linkable ring signature into privacy preserving in epidemic control scenario. Security analysis indicates that our scheme ensures unconditional users anonymity, record unforgeability, signature linkability, link non-slanderability and contact traceability. Finally, the comprehensive performance evaluation demonstrates that our scheme has an efficient time-consuming, storage consumption and system communication overhead and is practical for epidemic and future pandemic privacy-preserving.

12.
Sci Total Environ ; 869: 161792, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-36702280

RESUMO

Ninety-six fine particulate matter (PM2.5) samples covering four seasons from October 2020 to August 2021 were collected at a 'super' site in Hangzhou, a megacity in eastern China. These samples were analyzed to determine the sources and potential cancer risks to humans of 16 United States Environmental Protection Agency priority polycyclic aromatic hydrocarbons (PAHs). The average concentrations of the PAHs in PM2.5 in autumn, winter, spring, and summer were 8.35 ± 4.90, 27.9 ± 13.6, 8.3 ± 5.97, and 1.05 ± 0.50 ng/m3, respectively, and with an annual average of 11.9 ± 13.2 ng/m3. The source apportionment by positive matrix factorization analysis indicated that, based on the yearly average, the major sources of PAHs were traffic emissions (38.2 %), coal combustion (28.9 %), coke (21.7 %), and volatilization (11.1 %). Strong correlations between high concentrations of carbonaceous aerosols and high-molecular-weight PAHs in winter could be attributed to incomplete combustion. Long-range transport of air from the sea to the southeast resulted in low concentrations of carbonaceous aerosols and low-molecular-weight PAHs in summer. Trajectory clustering and the potential source contribution function both indicated that the Yangtze River Delta was the main source region of PAHs for PM2.5 in Hangzhou in spring and summer. In autumn and winter, it was dominated by long-range transport from northern China. Lifetime lung cancer risk assessment revealed that the PAHs in PM2.5 impose moderate human health risks in Hangzhou due to traffic emissions. The results of this study provide important information for policymakers to establish abatement strategies to reduce PAH emissions in Hangzhou, and perhaps other urban centers across China.


Assuntos
Poluentes Atmosféricos , Neoplasias , Hidrocarbonetos Policíclicos Aromáticos , Humanos , Poluentes Atmosféricos/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Monitoramento Ambiental/métodos , Material Particulado/análise , Estações do Ano , China , Neoplasias/induzido quimicamente , Neoplasias/epidemiologia , Medição de Risco , Emissões de Veículos/análise
13.
Int J Mol Sci ; 23(24)2022 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-36555693

RESUMO

Saline-alkali stress is a widespread adversity that severely affects plant growth and productivity. Saline-alkaline soils are characterized by high salt content and high pH values, which simultaneously cause combined damage from osmotic stress, ionic toxicity, high pH and HCO3-/CO32- stress. In recent years, many determinants of salt tolerance have been identified and their regulatory mechanisms are fairly well understood. However, the mechanism by which plants respond to comprehensive saline-alkali stress remains largely unknown. This review summarizes recent advances in the physiological, biochemical and molecular mechanisms of plants tolerance to salinity or salt- alkali stress. Focused on the progress made in elucidating the regulation mechanisms adopted by plants in response to saline-alkali stress and present some new views on the understanding of plants in the face of comprehensive stress. Plants generally promote saline-alkali tolerance by maintaining pH and Na+ homeostasis, while the plants responding to HCO3-/CO32- stress are not exactly the same as high pH stress. We proposed that pH-tolerant or sensitive plants have evolved distinct mechanisms to adapt to saline-alkaline stress. Finally, we highlight the areas that require further research to reveal the new components of saline-alkali tolerance in plants and present the current and potential application of key determinants in breed improvement and molecular breeding.


Assuntos
Álcalis , Tolerância ao Sal , Melhoramento Vegetal , Plantas , Estresse Salino , Solução Salina
14.
Dev Cell ; 57(17): 2081-2094.e7, 2022 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-36007523

RESUMO

Excessive Na+ in soils inhibits plant growth. Here, we report that Na+ stress triggers primary calcium signals specifically in a cell group within the root differentiation zone, thus forming a "sodium-sensing niche" in Arabidopsis. The amplitude of this primary calcium signal and the speed of the resulting Ca2+ wave dose-dependently increase with rising Na+ concentrations, thus providing quantitative information about the stress intensity encountered. We also delineate a Ca2+-sensing mechanism that measures the stress intensity in order to mount appropriate salt detoxification responses. This is mediated by a Ca2+-sensor-switch mechanism, in which the sensors SOS3/CBL4 and CBL8 are activated by distinct Ca2+-signal amplitudes. Although the SOS3/CBL4-SOS2/CIPK24-SOS1 axis confers basal salt tolerance, the CBL8-SOS2/CIPK24-SOS1 module becomes additionally activated only in response to severe salt stress. Thus, Ca2+-mediated translation of Na+ stress intensity into SOS1 Na+/H+ antiporter activity facilitates fine tuning of the sodium extrusion capacity for optimized salt-stress tolerance.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Cálcio/metabolismo , Estresse Salino , Sódio/metabolismo , Trocadores de Sódio-Hidrogênio/genética
15.
Inorg Chem ; 61(27): 10548-10556, 2022 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-35763374

RESUMO

We have designed and synthesized a new family of neutral phosphorescent iridium(III) complexes (Ir1-Ir6) featuring three differently charged (0, -1, and -2) ligands, in which biphenyl (bp) is used as a dianionic (-2) ligand, 4,6-difluorophenylpyridine (dfppy) or 1-phenylisoquinoline (piq) is used as a monoanionic (-1) ligand, and 2,2'-bipyridyl (bpy), 1,10-phenanthroline (phen), 1,2-bis(diphenylphosphanyl)benzene (dppb), or 1,2-bis(diphenylphosphanyl)ethane (dppe) is used as a neutral (0) ligand. The X-ray structures confirm that three coordination carbon atoms of all complexes assume a facial geometry, which can be beneficial to the stability of the structure. More importantly, the emitting color of the complexes can be tuned from deep red/near-infrared (NIR) (680-710 nm) to blue-green (466-496 nm) with different monoanionic (-1) ligands and neutral (0) ligands. Interestingly, the complex Ir5 shows a significant aggregation-induced phosphorescent emission effect, while Ir6 with a similar structure shows an opposite aggregation-caused quenching effect, mainly due to slight differences in the neutral (0) ligand structure. Notably, all deep red/NIR-emitting complexes (Ir1-Ir4) exhibit a distinct charge transfer (CT) excited state from the dianionic (-2) ligand to the neutral (0) ligand according to density functional theory calculations, whereas the excited state of blue-green-emitting complexes (Ir5-Ir6) displays the CT from the dianionic (-2) ligand to the monoanionic (-1) ligand. Considering better stability and optical performance, the deep red-emitting complexes (Ir2 and Ir4) with a simple structure are used as emitting layers of organic light-emitting diode devices and achieved good maximum external quantum efficiency (4.9 and 5.8%) peaking at 676 and 655 nm, respectively, with a very low turn-on voltage (2.5 V). This research provides a good strategy for the design of phosphorescent iridium complexes based on three differently charged (0, -1, and -2) ligands and their optoelectric applications.

16.
Int J Mol Sci ; 23(9)2022 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-35562980

RESUMO

Sucrose phloem unloading plays a vital role in photoassimilate distribution and storage in sink organs such as fruits and seeds. In most plants, the phloem unloading route was reported to shift between an apoplasmic and a symplasmic pattern with fruit development. However, the molecular transition mechanisms of the phloem unloading pathway still remain largely unknown. In this study, we applied RNA sequencing to profile the specific gene expression patterns for sucrose unloading in C. oleifera fruits in the apo- and symplasmic pathways that were discerned by CF fluoresce labelling. Several key structural genes were identified that participate in phloem unloading, such as PDBG11, PDBG14, SUT8, CWIN4, and CALS10. In particular, the key genes controlling the process were involved in callose metabolism, which was confirmed by callose staining. Based on the co-expression network analysis with key structural genes, a number of transcription factors belonging to the MYB, C2C2, NAC, WRKY, and AP2/ERF families were identified to be candidate regulators for the operation and transition of phloem unloading. KEGG enrichment analysis showed that some important metabolism pathways such as plant hormone metabolism, starch, and sucrose metabolism altered with the change of the sugar unloading pattern. Our study provides innovative insights into the different mechanisms responsible for apo- and symplasmic phloem unloading in oil tea fruit and represents an important step towards the omics delineation of sucrose phloem unloading transition in crops.


Assuntos
Camellia , Floema , Camellia/genética , Camellia/metabolismo , Frutas/metabolismo , Humanos , Floema/genética , Floema/metabolismo , Plantas/metabolismo , Sacarose/metabolismo , Açúcares/metabolismo , Transcriptoma
17.
Nat Commun ; 13(1): 2222, 2022 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-35468878

RESUMO

Plant salt-stress response involves complex physiological processes. Previous studies have shown that some factors promote salt tolerance only under high transpiring condition, thus mediating transpiration-dependent salt tolerance (TDST). However, the mechanism underlying crop TDST remains largely unknown. Here, we report that ZmSTL1 (Salt-Tolerant Locus 1) confers natural variation of TDST in maize. ZmSTL1 encodes a dirigent protein (termed ZmESBL) localized to the Casparian strip (CS) domain. Mutants lacking ZmESBL display impaired lignin deposition at endodermal CS domain which leads to a defective CS barrier. Under salt condition, mutation of ZmESBL increases the apoplastic transport of Na+ across the endodermis, and then increases the root-to-shoot delivery of Na+ via transpiration flow, thereby leading to a transpiration-dependent salt hypersensitivity. Moreover, we show that the ortholog of ZmESBL also mediates CS development and TDST in Arabidopsis. Our study suggests that modification of CS barrier may provide an approach for developing salt-tolerant crops.


Assuntos
Arabidopsis , Tolerância ao Sal , Arabidopsis/genética , Arabidopsis/metabolismo , Parede Celular/metabolismo , Raízes de Plantas/metabolismo , Tolerância ao Sal/genética , Zea mays/metabolismo
18.
Front Nutr ; 8: 765809, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34938760

RESUMO

The aim of this meta-analysis was to evaluate the clinical significance of glutamine in the management of patients with colorectal cancer (CRC) after radical operation. Electronic databases, including PubMed, EMBASE, MEDLINE, Cochrane Library, Chinese Biomedical Database (CBM), China National Knowledge Infrastructure (CNKI), VIP medicine information system (VIP), and Wanfang electronic databases were comprehensively searched from inception to 30, July 2021. Prospective randomized trials with glutamine vs. routine nutrition or blank therapy were selected. The immune function related indicators (including IgA, IgG, IgM, CD4+, CD8+, and the ratio of CD4+/CD8+), post-operative complications [including surgical site infection (SSI), anastomotic leakage, and length of hospital stay (LOS)], and corresponding 95% confidence intervals (CIs) were assessed in the pooled analysis. Subsequently, the heterogeneity between studies, sensitivity, publication bias, and meta-regression analysis were performed. Consequently, 31 studies which contained 2,201 patients (1,108 in the glutamine group and 1,093 in the control group) were included. Results of pooled analysis indicated that glutamine significantly improved the humoral immune function indicators [including IgA (SMD = 1.15, 95% CI: 0.72-1.58), IgM (SMD = 0.68, 95% CI: 0.48-0.89), and IgG (SMD = 1.10, 95% CI: 0.70-1.50)], and the T cell immune function indicators [including CD4+ (SMD = 0.76, 95% CI: 0.53-0.99) and the ratio of CD4+/CD8+ (SMD = 0.92, 95% CI: 0.57-1.28)]. Meanwhile, the content of CD8+ was decreased significantly (SMD = -0.50, 95% CI: -0.91 to -0.10) followed by glutamine intervention. Pooled analysis of SSI (RR = 0.48, 95% CI: 0.30-0.75), anastomotic leakage (RR = 0.23, 95% CI: 0.09-0.61), and LOS (SMD = -1.13, 95% CI: -1.68 to -0.58) were decreased significantly in glutamine group compared with control group. Metaregression analysis revealed that the covariate of small-sample effects influenced the robustness and reliability of IgG outcome potentially. Findings of the present work demonstrated that glutamine ought to be applied as an effective immunenutrition therapy in the treatment of patients with CRC after radical surgery. The present meta-analysis has been registered in PROSPERO (no. CRD42021243327). Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO, Identifier: CRD42021243327.

19.
Plant Sci ; 313: 111089, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34763874

RESUMO

The process of phloem unloading and post-unloading transport of photoassimilate is critical to crop output. Xanthoceras sorbifolia is a woody oil species with great biomass energy prospects in China; however, underproduction of seeds seriously restricts its development. Here, our cytological studies by ultrastructural observation revealed that the sieve element-companion cell complex in carpellary bundle was symplasmically interconnected with surrounding parenchyma cells at the early and late fruit developmental stages, whereas it was symplasmically isolated at middle stage. Consistently, real-time imaging showed that fluorescent tracer 6(5)carboxyfluorescein was confined to phloem strands at middle stage but released into surrounding parenchymal cells at early and late stages. Enzymatic assay showed that sucrose synthase act as the key enzyme catalyzing the progress of Suc degradation post-unloading pathway whether in pericarp or in seed, while vacuolar acid invertase and neutral invertase play compensation roles in sucrose decomposition. Sugar transporter XsSWEET10 had a high expression profile in fruit, especially at middle stage. XsSWEET10 is a plasma membrane-localized protein and heterologous expression in SUC2-deficient yeast strain SUSY7/ura3 confirmed its ability to uptake sucrose. These findings approved the transition from symplasmic to apoplasmic phloem unloading in Xanthoceras sorbifolia fruit and XsSWEET10 as a key candidate in sugar transport.


Assuntos
Transporte Biológico/fisiologia , Frutas/crescimento & desenvolvimento , Floema/citologia , Floema/metabolismo , Sapindaceae/anatomia & histologia , Sapindaceae/crescimento & desenvolvimento , Sapindaceae/metabolismo , Sacarose/metabolismo , China
20.
Front Pharmacol ; 12: 604811, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34276353

RESUMO

Ischemic stroke is a leading cause of death and disability worldwide. Currently, only a limited number of drugs are available for treating ischemic stroke. Hence, studies aiming to explore and develop other potential strategies and agents for preventing and treating ischemic stroke are urgently needed. Ginseng Rb1 (GRb1), a saponin from natural active ingredients derived from traditional Chinese medicine (TCM), exerts neuroprotective effects on the central nervous system (CNS). We conducted this review to explore and summarize the protective effects and mechanisms of GRb1 on cerebral ischemic injury, providing a valuable reference and insights for developing new agents to treat ischemic stroke. Our summarized results indicate that GRb1 exerts significant neuroprotective effects on cerebral ischemic injury both in vivo and in vitro, and these network actions and underlying mechanisms are mediated by antioxidant, anti-inflammatory, and antiapoptotic activities and involve the inhibition of excitotoxicity and Ca2+ influx, preservation of blood-brain barrier (BBB) integrity, and maintenance of energy metabolism. These findings indicate the potential of GRb1 as a candidate drug for treating ischemic stroke. Further studies, in particular clinical trials, will be important to confirm its therapeutic value in a clinical setting.

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