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1.
Theor Appl Genet ; 135(5): 1685-1703, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35312799

RESUMO

KEY MESSAGE: Low-lodging high-yielding wheat germplasm and SNP-tagged novel alleles for lodging were identified in a process that involved selecting donors through functional phenotyping for underlying traits with a designed phenotypic screen, and a crossing strategy involving multiple-donor × elite populations. Lodging is a barrier to achieving high yield in wheat. As part of a study investigating the potential to breed low-lodging high-yielding wheat, populations were developed crossing four low-lodging high-yielding donors selected based on lodging related traits, with three cultivars. Lodging was evaluated in single rows in an early generation and subsequently in plots in 2 years with contrasting lodging environment. A large number of lines lodged less than their recurrent parents, and some were also higher yielding. Heritability for lodging was high, but the genetic correlation between contrasting environments was intermediate-low. Lodging genotypic rankings in single rows did not correlate well with plots. Populations from the highest lodging background were genotyped (90 K iSelect BeadChip array). Fourteen markers on nine chromosomes were associated with lodging, differing under high- versus low-lodging conditions. Of the fourteen markers, ten were found to co-locate with previously identified QTL for lodging-related traits or at homoeologous locations for previously identified lodging-related QTL, while the remaining four markers (in chromosomes 2D, 4D, 7B and 7D) appear to map to novel QTL for lodging. Lines with more favourable markers lodged less, suggesting value in these markers as a selection tool. This study demonstrates that the combination of donor functional phenotyping, screen design and crossing strategy can help identify novel alleles in germplasm without requiring extensive bi-parental populations.


Assuntos
Locos de Características Quantitativas , Triticum , Mapeamento Cromossômico , Fenótipo , Melhoramento Vegetal , Triticum/genética
2.
BMC Nephrol ; 21(1): 15, 2020 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-31937266

RESUMO

BACKGROUND: Patients with chronic kidney disease are at higher risk of developing cardiovascular disease. Chronic exposure to intermittent hemodialysis may be a source of added stress to the cardiovascular system; intradialytic hypotension is a common complication of hemodialysis, and repeated events may lead to hemodynamic stress and ischemic injuries. Administration of non-pneumatic compression stockings to the lower limbs has demonstrated hemodynamic stabilizing effects in other settings and may provide similar benefits in the kidney disease population. Therefore, we conducted this pilot study assessing the feasibility and tolerability of the application of non-pneumatic compression stockings to patients with kidney disease. We also assessed the changes in hemodynamic measurements following the application of the compression stockings to explore the biological feasibility of this being an effective intervention for intradialytic hypotension. METHODS: Fifteen individuals were enrolled in the study (5 healthy, 5 chronic kidney disease patients, and 5 dialysis patients). Outcomes including hemodynamic parameters such as cardiac output, peripheral vascular resistance, and blood pressure were measured using continuous pulse wave analysis. Changes in global longitudinal strain were measured via echocardiography. These outcome measurements were made before and after the application of compression stockings. RESULTS: All study participants tolerated the compression garments well and without complication. Hemodynamic response to lower body compression caused varying effects on cardiac output, mean arterial pressure and global longitudinal strain. Some individuals saw large improvements in hemodynamic parameters while in others the opposite effect was observed. No consistent response was elicited. CONCLUSIONS: Application of compression stockings to patients with renal dysfunction is well-tolerated. However, significant variations in hemodynamic outcomes exist, and may be a barrier for larger scale trials without prior identification of specific patient characteristics indicating likely benefit from the application of external compression. TRIAL REGISTRATION: ClinicalTrials.gov, Identifier: NCT02915627, Registration Date: Sept 27, 2016.


Assuntos
Hemodinâmica , Insuficiência Renal Crônica/fisiopatologia , Meias de Compressão , Adulto , Idoso , Pressão Sanguínea/fisiologia , Débito Cardíaco/fisiologia , Ecocardiografia , Estudos de Viabilidade , Humanos , Pessoa de Meia-Idade , Projetos Piloto , Estudos Prospectivos , Diálise Renal/efeitos adversos , Insuficiência Renal Crônica/terapia , Choque
3.
Ecotoxicology ; 29(8): 1221-1228, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31531800

RESUMO

Passerines appear to have a greater sensitivity to mercury than other avian orders, and little data exists for mercury exposure in songbirds breeding at high latitudes. In this preliminary study, we examined mercury exposure in 12 migratory songbird species breeding in Denali National Park & Preserve, in subarctic interior Alaska. Overall, we analyzed 343 feather samples collected in 2015-2017 for their total mercury content. Mercury levels found in feathers indicates exposure during the period of feather growth, which we assume largely took place on the breeding ground. In this limited sample of songbird feathers, mercury concentrations ranged from near zero to 6.34 µg/g. Most species sampled showed relatively low mercury, but some individuals had high enough concentrations to be subject to adverse physiological and behavioral effects. There was an indication that mercury concentrations of breeding songbirds may vary by diet composition, with non-invertivorous species possibly tending towards lower mercury concentrations. Overall, however, the degree of mercury exposure observed was low for songbirds breeding in the subarctic. Further examination would prove useful in clarifying mercury exposure and ecological relationships in this under-studied region.


Assuntos
Monitoramento Ambiental , Poluentes Ambientais/análise , Plumas/química , Mercúrio/análise , Aves Canoras , Alaska , Migração Animal , Animais
4.
Mol Psychiatry ; 23(4): 843-849, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28397839

RESUMO

Target identification and contact selection are known contributors to variability in efficacy across different clinical indications of deep brain stimulation surgery. A retrospective analysis of responders to subcallosal cingulate deep brain stimulation (SCC DBS) for depression demonstrated the common impact of the electrical stimulation on a stereotypic connectome of converging white matter bundles (forceps minor, uncinate fasciculus, cingulum and fronto-striatal fibers). To test the utility of a prospective connectomic approach for SCC DBS surgery, this pilot study used the four-bundle tractography 'connectome blueprint' to plan surgical targeting in 11 participants with treatment-resistant depression. Before surgery, targets were selected individually using deterministic tractography. Selection of contacts for chronic stimulation was made by matching the post-operative probabilistic tractography map to the pre-surgical deterministic tractography map for each subject. Intraoperative behavioral responses were used as a secondary verification of location. A probabilistic tract map of all participants demonstrated inclusion of the four bundles as intended, matching the connectome blueprint previously defined. Eight of 11 patients (72.7%) were responders and 5 were remitters after 6 months of open-label stimulation. At one year, 9 of 11 patients (81.8%) were responders, with 6 of them in remission. These results support the utility of a group probabilistic tractography map as a connectome blueprint for individualized, patient-specific, deterministic tractography targeting, confirming retrospective findings previously published. This new method represents a connectomic approach to guide future SCC DBS studies.


Assuntos
Estimulação Encefálica Profunda/métodos , Transtorno Depressivo Resistente a Tratamento/terapia , Córtex Pré-Frontal/fisiologia , Adulto , Conectoma/métodos , Depressão/terapia , Transtorno Depressivo Maior/terapia , Transtorno Depressivo Resistente a Tratamento/fisiopatologia , Imagem de Tensor de Difusão , Feminino , Giro do Cíngulo/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Rede Nervosa , Projetos Piloto , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/cirurgia , Estudos Prospectivos , Estudos Retrospectivos , Substância Branca/fisiologia
5.
Plant Cell Rep ; 37(2): 225-237, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29079898

RESUMO

KEY MESSAGE: TaRNAC1 is a constitutively and predominantly root-expressed NAC transcription factor. TaRNAC1 overexpression in wheat roots confers increased root length, biomass and drought tolerance and improved grain yield under water limitation. A large and deep root system is an important trait for yield sustainability of dryland cereal crops in drought-prone environments. This study investigated the role of a predominantly root-expressed NAC transcription factor from wheat (TaRNAC1) in the root growth. Expression analysis showed that TaRNAC1 was a constitutively expressed gene with high level expression in the roots and was not drought-upregulated. Overexpression of TaRNAC1 in wheat using a predominantly root-expressed promoter resulted in increased root length and biomass observed at the early growth stage and a marked increase in the maturity root biomass with dry root weight of > 70% higher than that of the wild type plants. Analysis of some root growth-related genes revealed that the expression level of GA3-ox2, which encodes GIBBERELLIN 3-OXIDASE catalysing the conversion of inactive gibberellin (GA) to active GA, was elevated in the roots of transgenic wheat. TaRNAC1 overexpressing transgenic wheat showed more dehydration tolerance under polyethylene glycol (PEG) treatment and produced more aboveground biomass and grain under water-limited conditions than the wild type plants. These data suggest that TaRNAC1 may play a role in root growth and be used as a molecular tool for potential enlargement of root system in wheat.


Assuntos
Biomassa , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Raízes de Plantas/genética , Fatores de Transcrição/genética , Triticum/genética , Adaptação Fisiológica/genética , Secas , Giberelinas/metabolismo , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas , Fatores de Transcrição/metabolismo , Triticum/crescimento & desenvolvimento , Triticum/metabolismo
6.
Artigo em Inglês | MEDLINE | ID: mdl-28597947

RESUMO

The purpose of this study was to investigate the feasibility and preliminary efficacy of a pragmatic distance-based intervention designed to increase physical activity (PA) participation in lung cancer survivors. Fourteen lung cancer survivors were recruited via invitation from the State Cancer Registry to join a 12-week PA intervention of print materials paired with brief telephone follow-up. Outcome measures of feasibility, PA participation and quality of life (QoL) were assessed at baseline, post-intervention and follow-up via telephone interview. Eligibility, recruitment and attrition rates were 16%, 58% and 29% respectively. No adverse events were reported; however, pain scores worsened following the intervention (median change -3.6, IQR -8.0, 0.0). Average intervention adherence was 91% with low median ratings of participation burden (i.e., all items 1/7) and high trial evaluation (i.e., all items 7/7). Post-intervention, median change in self-reported moderate and vigorous PA was 84 min (IQR -22, 188), and several domains of QoL improved. However, for both of these outcomes, improvements were not maintained at follow-up. Our findings suggest that this pragmatic distance-based intervention was safe, had good adherence rates, and indicate potential for improving short-term PA and QoL in lung cancer survivors. Additional strategies are needed to improve other indicators of feasibility, particularly recruitment, retention and long-term maintenance of improvements. Australian New Zealand Clinical Trials Registration: ACTRN12612000085875.


Assuntos
Sobreviventes de Câncer , Exercício Físico , Neoplasias Pulmonares/reabilitação , Cooperação do Paciente , Qualidade de Vida , Telefone , Adulto , Idoso , Idoso de 80 Anos ou mais , Dispneia , Fadiga , Estudos de Viabilidade , Feminino , Humanos , Neoplasias Pulmonares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Dor , Medidas de Resultados Relatados pelo Paciente , Seleção de Pacientes , Projetos Piloto , Austrália Ocidental
7.
Phys Rev Lett ; 118(4): 044102, 2017 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-28186807

RESUMO

A stable nonlinear wave packet, self-localized in all three dimensions, is an intriguing and much sought after object in nonlinear science in general and in nonlinear photonics in particular. We report on the experimental observation of mode-locked spatial laser solitons in a vertical-cavity surface-emitting laser with frequency-selective feedback from an external cavity. These spontaneously emerging and long-term stable spatiotemporal structures have a pulse length shorter than the cavity round-trip time and may pave the way to completely independent cavity light bullets.

8.
Genome ; 60(1): 26-45, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27996306

RESUMO

Wheat crops frequently experience a combination of abiotic stresses in the field, but most quantitative trait loci (QTL) studies have focused on the identification of QTLs for traits under single stress field conditions. A recombinant inbred line (RIL) population derived from SeriM82 × Babax was used to map QTLs under well-irrigated, heat, drought, and a combination of heat and drought stress conditions in two years. A total of 477 DNA markers were used to construct linkage groups that covered 1619.6 cM of the genome, with an average distance of 3.39 cM between adjacent markers. Moderate to relatively high heritability estimates (0.60-0.70) were observed for plant height (PHE), grain yield (YLD), and grain per square meter (GM2). The most important QTLs for days to heading (DHE), thousand grain weight (TGW), and YLD were detected on chromosomes 1B, 1D-a, and 7D-b. The prominent QTLs related to canopy temperature were on 3B. Results showed that common QTLs for DHE, YLD, and TGW on 7D-b were validated in heat and drought trials. Three QTLs for chlorophyll content in SPAD unit (on 1A/6B), leaf rolling (ROL) (on 3B/4A), and GM2 (on 1B/7D-b) showed significant epistasis × environment interaction. Six heat- or drought-specific QTLs (linked to 7D-acc/cat-10, 1B-agc/cta-9, 1A-aag/cta-8, 4A-acg/cta-3, 1B-aca/caa-3, and 1B-agc/cta-9 for day to maturity (DMA), SPAD, spikelet compactness (SCOM), TGW, GM2, and GM2, respectively) were stable and validated over two years. The major DHE QTL linked to 7D-acc/cat-10, with no QTL × environment (QE) interaction increased TGW and YLD. This QTL (5.68 ≤ LOD ≤ 10.5) explained up to 19.6% variation in YLD in drought, heat, and combined stress trials. This marker as a candidate could be used for verification in other populations and identifying superior allelic variations in wheat cultivars or its wild progenitors to increase the efficiency of selection of high yielding lines adapted to end-season heat and drought stress conditions.


Assuntos
Mapeamento Cromossômico , Secas , Temperatura Alta , Locos de Características Quantitativas , Característica Quantitativa Herdável , Estresse Fisiológico/genética , Triticum/genética , Meio Ambiente , Epistasia Genética , Interação Gene-Ambiente , Estudos de Associação Genética , Ligação Genética , Marcadores Genéticos , Genética Populacional , Genótipo , Fenótipo
9.
Plant Cell Physiol ; 57(10): 2076-2090, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27440550

RESUMO

A well-known physiological adaptation process of plants encountering drying soil is to achieve water balance by reducing shoot growth and maintaining or promoting root elongation, but little is known about the molecular basis of this process. This study investigated the role of a drought-up-regulated Triticum aestivum NAC69-1 (TaNAC69-1) in the modulation of root growth in wheat. TaNAC69-1 was predominantly expressed in wheat roots at the early vegetative stage. Overexpression of TaNAC69-1 in wheat roots using OsRSP3 (essentially root-specific) and OsPIP2;3 (root-predominant) promoters resulted in enhanced primary seminal root length and a marked increase in maturity root biomass. Competitive growth analysis under water-limited conditions showed that OsRSP3 promoter-driven TaNAC69-1 transgenic lines produced 32% and 35% more above-ground biomass and grains than wild-type plants, respectively. TaNAC69-1 overexpression in the roots down-regulated the expression of TaSHY2 and TaIAA7, which are from the auxin/IAA (Aux/IAA) transcriptional repressor gene family and are the homologs of negative root growth regulators SHY2/IAA3 and IAA7 in Arabidopsis. The expression of TaSHY2 and TaIAA7 in roots was down-regulated by drought stress and up-regulated by cytokinin treatment, which inhibited root growth. DNA binding and transient expression analyses revealed that TaNAC69-1 bound to the promoters of TaSHY2 and TaIAA7, acted as a transcriptional repressor and repressed the expression of reporter genes driven by the TaSHY2 or TaIAA7 promoter. These data suggest that TaNAC69-1 is a transcriptional repressor of TaSHY2 and TaIAA7 homologous to Arabidopsis negative root growth regulators and is likely to be involved in promoting root elongation in drying soil.


Assuntos
Biomassa , Secas , Proteínas de Plantas/metabolismo , Raízes de Plantas/anatomia & histologia , Transcrição Gênica , Triticum/genética , Triticum/fisiologia , Regulação para Cima/genética , Biotinilação , Núcleo Celular/metabolismo , Citocininas/farmacologia , DNA de Plantas/metabolismo , Regulação para Baixo/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Proteínas de Fluorescência Verde/metabolismo , Proteínas de Plantas/genética , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas/genética , Proteínas Repressoras/metabolismo , Estresse Fisiológico/genética , Transcrição Gênica/efeitos dos fármacos , Triticum/anatomia & histologia , Triticum/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
10.
Phys Rev Lett ; 116(15): 157401, 2016 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-27127985

RESUMO

In modulation doped quantum wells, the excitons are formed as a result of the interactions of the charged holes with the electrons at the Fermi edge in the conduction band, leading to the so-called "Mahan excitons." The binding energy of Mahan excitons is expected to be greatly reduced and any quantum coherence destroyed as a result of the screening and electron-electron interactions. Surprisingly, we observe strong quantum coherence between the heavy hole and light hole excitons. Such correlations are revealed by the dominating cross-diagonal peaks in both one-quantum and two-quantum two-dimensional Fourier transform spectra. Theoretical simulations based on the optical Bloch equations where many-body effects are included phenomenologically reproduce well the experimental spectra. Time-dependent density functional theory calculations provide insight into the underlying physics and attribute the observed strong quantum coherence to a significantly reduced screening length and collective excitations of the many-electron system.

11.
Plant Cell Rep ; 35(2): 469-81, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26563345

RESUMO

KEY MESSAGE: A strong, stable and root-specific expression system was developed from a rice root-specific GLYCINE - RICH PROTEIN 7 promoter for use as an enabling technology for genetic manipulation of wheat root traits. Root systems play an important role in wheat productivity. Genetic manipulation of wheat root traits often requires a root-specific or root-predominant expression system as an essential enabling technology. In this study, we investigated promoters from rice root-specific or root-predominant expressed genes for development of a root expression system in bread wheat. Transient expression analysis using a GREEN FLUORESCENT PROTEIN (GFP) reporter gene driven by rice promoters identified six promoters that were strongly expressed in wheat roots. Extensive organ specificity analysis of three rice promoters in transgenic wheat revealed that the promoter of rice GLYCINE-RICH PROTEIN 7 (OsGRP7) gene conferred a root-specific expression pattern in wheat. Strong GFP fluorescence in the seminal and branch roots of wheat expressing GFP reporter driven by the OsGRP7 promoter was detected in epidermal, cortical and endodermal cells in mature parts of the root. The GFP reporter driven by the promoter of rice METALLOTHIONEIN-LIKE PROTEIN 1 (OsMTL1) gene was mainly expressed in the roots with essentially no expression in the leaf, stem or seed. However, it was also expressed in floral organs including glume, lemma, palea and awn. In contrast, strong expression of rice RCg2 promoter-driven GFP was found in many tissues. The GFP expression driven by these three rice promoters was stable in transgenic wheat plants through three generations (T1-T3) examined. These data suggest that the OsGRP7 promoter can provide a strong, stable and root-specific expression system for use as an enabling technology for genetic manipulation of wheat root traits.


Assuntos
Expressão Gênica , Técnicas Genéticas , Raízes de Plantas/genética , Transgenes/genética , Triticum/genética , Raízes de Plantas/metabolismo , Triticum/metabolismo
12.
J Exp Bot ; 66(3): 1025-39, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25428996

RESUMO

Heat stress is a significant environmental factor adversely affecting crop yield. Crop adaptation to high-temperature environments requires transcriptional reprogramming of a suite of genes involved in heat stress protection. This study investigated the role of TaHsfA6f, a member of the A6 subclass of heat shock transcription factors, in the regulation of heat stress protection genes in Triticum aestivum (bread wheat), a poorly understood phenomenon in this crop species. Expression analysis showed that TaHsfA6f was expressed constitutively in green organs but was markedly up-regulated during heat stress. Overexpression of TaHsfA6f in transgenic wheat using a drought-inducible promoter resulted in up-regulation of heat shock proteins (HSPs) and a number of other heat stress protection genes that included some previously unknown Hsf target genes such as Golgi anti-apoptotic protein (GAAP) and the large isoform of Rubisco activase. Transgenic wheat plants overexpressing TaHsfA6f showed improved thermotolerance. Transactivation assays showed that TaHsfA6f activated the expression of reporter genes driven by the promoters of several HSP genes (TaHSP16.8, TaHSP17, TaHSP17.3, and TaHSP90.1-A1) as well as TaGAAP and TaRof1 (a co-chaperone) under non-stress conditions. DNA binding analysis revealed the presence of high-affinity TaHsfA6f-binding heat shock element-like motifs in the promoters of these six genes. Promoter truncation and mutagenesis analyses identified TaHsfA6f-binding elements that were responsible for transactivation of TaHSP90.1-A1 and TaGAAP by TaHsfA6f. These data suggest that TaHsfA6f is a transcriptional activator that directly regulates TaHSP, TaGAAP, and TaRof1 genes in wheat and its gene regulatory network has a positive impact on thermotolerance.


Assuntos
Regulação da Expressão Gênica de Plantas , Genes de Plantas , Proteínas de Choque Térmico/genética , Proteínas de Plantas/genética , Triticum/genética , Sequência de Aminoácidos , Sequência de Bases , Genes Reporter , Proteínas de Choque Térmico/química , Proteínas de Choque Térmico/metabolismo , Dados de Sequência Molecular , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/química , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Regiões Promotoras Genéticas , Alinhamento de Sequência , Triticum/química , Triticum/metabolismo
13.
Ann Bot ; 115(5): 717-31, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25808446

RESUMO

BACKGROUND: Cereal diseases cause tens of billions of dollars of losses annually and have devastating humanitarian consequences in the developing world. Increased understanding of the molecular basis of cereal host-pathogen interactions should facilitate development of novel resistance strategies. However, achieving this in most cereals can be challenging due to large and complex genomes, long generation times and large plant size, as well as quarantine and intellectual property issues that may constrain the development and use of community resources. Brachypodium distachyon (brachypodium) with its small, diploid and sequenced genome, short generation time, high transformability and rapidly expanding community resources is emerging as a tractable cereal model. SCOPE: Recent research reviewed here has demonstrated that brachypodium is either susceptible or partially susceptible to many of the major cereal pathogens. Thus, the study of brachypodium-pathogen interactions appears to hold great potential to improve understanding of cereal disease resistance, and to guide approaches to enhance this resistance. This paper reviews brachypodium experimental pathosystems for the study of fungal, bacterial and viral cereal pathogens; the current status of the use of brachypodium for functional analysis of cereal disease resistance; and comparative genomic approaches undertaken using brachypodium to assist characterization of cereal resistance genes. Additionally, it explores future prospects for brachypodium as a model to study cereal-pathogen interactions. CONCLUSIONS: The study of brachypodium-pathogen interactions appears to be a productive strategy for understanding mechanisms of disease resistance in cereal species. Knowledge obtained from this model interaction has strong potential to be exploited for crop improvement.


Assuntos
Brachypodium/genética , Resistência à Doença , Genoma de Planta/genética , Interações Hospedeiro-Patógeno , Doenças das Plantas/microbiologia , Brachypodium/imunologia , Brachypodium/microbiologia , Produtos Agrícolas , Grão Comestível , Genômica , Doenças das Plantas/imunologia
14.
J Exp Bot ; 65(2): 539-57, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24323502

RESUMO

Heat shock factors (Hsfs) play a central regulatory role in acquired thermotolerance. To understand the role of the major molecular players in wheat adaptation to heat stress, the Hsf family was investigated in Triticum aestivum. Bioinformatic and phylogenetic analyses identified 56 TaHsf members, which are classified into A, B, and C classes. Many TaHsfs were constitutively expressed. Subclass A6 members were predominantly expressed in the endosperm under non-stress conditions. Upon heat stress, the transcript levels of A2 and A6 members became the dominant Hsfs, suggesting an important regulatory role during heat stress. Many TaHsfA members as well as B1, C1, and C2 members were also up-regulated during drought and salt stresses. The heat-induced expression profiles of many heat shock protein (Hsp) genes were paralleled by those of A2 and A6 members. Transactivation analysis revealed that in addition to TaHsfA members (A2b and A4e), overexpression of TaHsfC2a activated expression of TaHsp promoter-driven reporter genes under non-stress conditions, while TaHsfB1b and TaHsfC1b did not. Functional heat shock elements (HSEs) interacting with TaHsfA2b were identified in four TaHsp promoters. Promoter mutagenesis analysis demonstrated that an atypical HSE (GAACATTTTGGAA) in the TaHsp17 promoter is functional for heat-inducible expression and transactivation by Hsf proteins. The transactivation of Hsp promoter-driven reporter genes by TaHsfC2a also relied on the presence of HSE. An activation motif in the C-terminal domain of TaHsfC2a was identified by amino residue substitution analysis. These data demonstrate the role of HsfA and HsfC2 in regulation of Hsp genes in wheat.


Assuntos
Regulação da Expressão Gênica de Plantas , Proteínas de Choque Térmico/genética , Resposta ao Choque Térmico/genética , Família Multigênica , Estresse Fisiológico/genética , Triticum/genética , Triticum/fisiologia , Motivos de Aminoácidos , Sequência de Aminoácidos , Sequência de Bases , Secas , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Genes Reporter , Proteínas de Choque Térmico/química , Proteínas de Choque Térmico/classificação , Proteínas de Choque Térmico/metabolismo , Resposta ao Choque Térmico/efeitos dos fármacos , Dados de Sequência Molecular , Especificidade de Órgãos/efeitos dos fármacos , Especificidade de Órgãos/genética , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/classificação , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas/genética , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Transativadores/metabolismo , Triticum/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética
15.
Plant Mol Biol ; 81(1-2): 71-92, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23114999

RESUMO

Fructans represent the major component of water soluble carbohydrates (WSCs) in the maturing stem of temperate cereals and are an important temporary carbon reserve for grain filling. To investigate the importance of source carbon availability in fructan accumulation and its molecular basis, we performed comparative analyses of WSC components and the expression profiles of genes involved in major carbohydrate metabolism and photosynthesis in the flag leaves of recombinant inbred lines from wheat cultivars Seri M82 and Babax (SB lines). High sucrose levels in the mature flag leaf (source organ) were found to be positively associated with WSC and fructan concentrations in both the leaf and stem of SB lines in several field trials. Analysis of Affymetrix expression array data revealed that high leaf sucrose lines grown in abiotic-stress-prone environments had high expression levels of a number of genes in the leaf involved in the sucrose synthetic pathway and photosynthesis, such as Calvin cycle genes, antioxidant genes involved in chloroplast H(2)O(2) removal and genes involved in energy dissipation. The expression of the majority of genes involved in fructan and starch synthetic pathways were positively correlated with sucrose levels in the leaves of SB lines. The high level of leaf fructans in high leaf sucrose lines is likely attributed to the elevated expression levels of fructan synthetic enzymes, as the mRNA levels of three fructosyltransferase families were consistently correlated with leaf sucrose levels among SB lines. These data suggest that high source strength is one of the important genetic factors determining high levels of WSC in wheat.


Assuntos
Frutanos/metabolismo , Triticum/genética , Triticum/metabolismo , Trifosfato de Adenosina/biossíntese , Antioxidantes/metabolismo , Metabolismo dos Carboidratos , Cloroplastos/metabolismo , Genes de Plantas , Variação Genética , Genótipo , Peróxido de Hidrogênio/metabolismo , Redes e Vias Metabólicas , Modelos Biológicos , Fotossíntese/genética , Folhas de Planta/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA de Plantas/genética , RNA de Plantas/metabolismo , Solubilidade , Amido/biossíntese , Sacarose/metabolismo , Transcriptoma
16.
Am J Transplant ; 13(1): 31-5, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23279680

RESUMO

The transplant surgeon's decision to accept and utilize an organ typically is made within a constrained time window, explicitly cognizant of numerous health-related risks and under the potential influence of considerable regulatory and institutional pressures. This decision affects the health of two distinct populations, those patients receiving organ transplants and those waiting to receive a transplant; it also influences the physician's life and their institute's productivity. The numerous, at times nonaligned, incentives established by the complex clinical and regulatory environment, have been derived specifically to influence physicians' behaviors, and though well intended, may lead to responses that are nonoptimal when considering the myriad stakeholders being influenced. This may compromise the quality of care provided to the population at risk, and has potential to influence the physician-patient relationship. A synergistic collaboration between transplant physicians and economists that is focused on this decision environment may help to alleviate these strains. This viewpoint discusses behavioral economic principles and how they might be applied to transplantation. Specifically, the previous medical decision-making literature on transplantation will be reviewed and a discussion on how a behavioral model of physician decision making can be utilized will be explored. To date this approach has not been integrated into transplantation decision making.


Assuntos
Atenção à Saúde , Economia , Transplante , Tomada de Decisões , Humanos , Relações Médico-Paciente , Padrões de Prática Médica
17.
J Exp Bot ; 64(12): 3681-96, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23873993

RESUMO

Fructans are the major component of temporary carbon reserve in the stem of temperate cereals, which is used for grain filling. Three families of fructosyltransferases are directly involved in fructan synthesis in the vacuole of Triticum aestivum. The regulatory network of the fructan synthetic pathway is largely unknown. Recently, a sucrose-upregulated wheat MYB transcription factor (TaMYB13-1) was shown to be capable of activating the promoter activities of sucrose:sucrose 1-fructosyltransferase (1-SST) and sucrose:fructan 6-fructosyltransferase (6-SFT) in transient transactivation assays. This work investigated TaMYB13-1 target genes and their influence on fructan synthesis in transgenic wheat. TaMYB13-1 overexpression resulted in upregulation of all three families of fructosyltransferases including fructan:fructan 1-fructosyltransferase (1-FFT). A γ-vacuolar processing enzyme (γ-VPE1), potentially involved in processing the maturation of fructosyltransferases in the vacuole, was also upregulated by TaMYB13-1 overexpression. Multiple TaMYB13 DNA-binding motifs were identified in the Ta1-FFT1 and Taγ-VPE1 promoters and were bound strongly by TaMYB13-1. The expression profiles of these target genes and TaMYB13-1 were highly correlated in recombinant inbred lines and during stem development as well as the transgenic and non-transgenic wheat dataset, further supporting a direct regulation of these genes by TaMYB13-1. TaMYB13-1 overexpression in wheat led to enhanced fructan accumulation in the leaves and stems and also increased spike weight and grain weight per spike in transgenic plants under water-limited conditions. These data suggest that TaMYB13-1 plays an important role in coordinated upregulation of genes necessary for fructan synthesis and can be used as a molecular tool to improve the high fructan trait.


Assuntos
Frutanos/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Triticum/genética , Frutanos/metabolismo , Estudo de Associação Genômica Ampla , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/metabolismo , Transcriptoma , Triticum/enzimologia , Regulação para Cima
18.
Theor Appl Genet ; 126(10): 2511-20, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23824201

RESUMO

Fusarium crown rot (FCR) is a serious cereal disease in semi-arid regions worldwide. In assisting the effort of breeding cultivars with enhanced resistance, we identified several barley genotypes with high levels of FCR resistance. One of these genotypes, AWCS079 which is a barley landrace originating from Japan, was investigated by developing and assessing three populations of recombinant inbred lines. Two QTL, one located on the long arm of chromosome 1H (designated as Qcrs.cpi-1H) and the other on 3HL (designated as Qcrs.cpi-3H), were found to be responsible for the FCR resistance of this genotype. Qcrs.cpi-1H is novel as no other FCR loci have been reported on this chromosome arm. Qcrs.cpi-3H co-located with a reduced height (Rht) locus and the effectiveness of the former was significantly affected by the latter. The total phenotypic variance explained by these two QTL was over 60 %. Significant effects were detected for each of the QTL in each of the three populations assessed. The existence of these loci with major effects should not only facilitate breeding and exploitation of FCR-resistant barley cultivars but also their further characterization based on fine mapping and map-based gene cloning.


Assuntos
Resistência à Doença/genética , Fusarium/fisiologia , Hordeum/genética , Hordeum/microbiologia , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Locos de Características Quantitativas/genética , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Resistência à Doença/imunologia , Hordeum/anatomia & histologia , Hordeum/imunologia , Escore Lod , Doenças das Plantas/microbiologia , Reprodutibilidade dos Testes
19.
Theor Appl Genet ; 126(4): 971-84, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23269228

RESUMO

Heat and drought adaptive quantitative trait loci (QTL) in a spring bread wheat population resulting from the Seri/Babax cross designed to minimize confounding agronomic traits have been identified previously in trials conducted in Mexico. The same population was grown across a wide range of environments where heat and drought stress are naturally experienced including environments in Mexico, West Asia, North Africa (WANA), and South Asia regions. A molecular genetic linkage map including 475 marker loci associated to 29 linkage groups was used for QTL analysis of yield, days to heading (DH) and to maturity (DM), grain number (GM2), thousand kernel weight (TKW), plant height (PH), canopy temperature at the vegetative and grain filling stages (CTvg and CTgf), and early ground cover. A QTL for yield on chromosome 4A was confirmed across several environments, in subsets of lines with uniform allelic expression of a major phenology QTL, but not independently from PH. With terminal stress, TKW QTL was linked or pleiotropic to DH and DM. The link between phenology and TKW suggested that early maturity would favor the post-anthesis grain growth periods resulting in increased grain size and yields under terminal stress. GM2 and TKW were partially associated with markers at different positions suggesting different genetic regulation and room for improvement of both traits. Prediction accuracy of yield was improved by 5 % when using marker scores of component traits (GM2 and DH) together with yield in multiple regression. This procedure may provide accumulation of more favorable alleles during selection.


Assuntos
Adaptação Biológica/genética , Clima , Hibridização Genética , Fenótipo , Locos de Características Quantitativas/genética , Triticum/crescimento & desenvolvimento , Triticum/genética , África do Norte , Ásia , Mapeamento Cromossômico , Marcadores Genéticos/genética , México , Análise de Regressão
20.
Nephron Clin Pract ; 123(1-2): 36-40, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23752138

RESUMO

Diabetes is commonly complicated by the development of chronic kidney disease (CKD). Equally prevalent is the development of diabetic foot disease and it is now recognised that there is a higher risk of the development of foot disease and major amputation in those patients with CKD. This is particularly marked in those patients with end-stage kidney disease receiving renal replacement therapy for which there are many possible mechanisms, including the effect of dialysis on tissue hypoxia. What has been recognised recently is that the risk of the development of foot disease appears to start prior to the onset of renal replacement therapy. Whilst this may be due to the fact that the emphasis of care shifts towards the requirements of the patients' renal disease, here we discuss the possibility that the presence of a foot ulcer itself may contribute to the development or progression of CKD through repeated episodes of sepsis or chronic inflammation, or both.


Assuntos
Pé Diabético/epidemiologia , Pé Diabético/imunologia , Inflamação/epidemiologia , Inflamação/imunologia , Modelos Imunológicos , Insuficiência Renal Crônica/epidemiologia , Insuficiência Renal Crônica/imunologia , Causalidade , Comorbidade , Humanos , Prevalência , Medição de Risco , Fatores de Risco
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