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1.
Int J Mol Sci ; 20(7)2019 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-30974727

RESUMO

Brachypodium distachyon is an established model for drought tolerance. We previously identified accessions exhibiting high tolerance, susceptibility and intermediate tolerance to drought; respectively, ABR8, KOZ1 and ABR4. Transcriptomics and metabolomic approaches were used to define tolerance mechanisms. Transcriptional analyses suggested relatively few drought responsive genes in ABR8 compared to KOZ1. Linking these to gene ontology (GO) terms indicated enrichment for "regulated stress response", "plant cell wall" and "oxidative stress" associated genes. Further, tolerance correlated with pre-existing differences in cell wall-associated gene expression including glycoside hydrolases, pectin methylesterases, expansins and a pectin acetylesterase. Metabolomic assessments of the same samples also indicated few significant changes in ABR8 with drought. Instead, pre-existing differences in the cell wall-associated metabolites correlated with drought tolerance. Although other features, e.g., jasmonate signaling were suggested in our study, cell wall-focused events appeared to be predominant. Our data suggests two different modes through which the cell wall could confer drought tolerance: (i) An active response mode linked to stress induced changes in cell wall features, and (ii) an intrinsic mode where innate differences in cell wall composition and architecture are important. Both modes seem to contribute to ABR8 drought tolerance. Identification of the exact mechanisms through which the cell wall confers drought tolerance will be important in order to inform development of drought tolerant crops.


Assuntos
Brachypodium/metabolismo , Parede Celular/metabolismo , Regulação da Expressão Gênica de Plantas , Estresse Oxidativo , Proteínas de Plantas/biossíntese , Estresse Fisiológico , Brachypodium/genética , Parede Celular/genética , Desidratação/genética , Desidratação/metabolismo , Proteínas de Plantas/genética
2.
J Exp Bot ; 67(8): 2207-17, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26873977

RESUMO

The Fertilization Independent Endosperm (FIE) gene is required to restrict endosperm development without fertilization, and it represses flowering during embryo and seedling development in Arabidopsis thaliana However, the regulatory mechanism of the FIE gene in postembryonic shoot development is not well understood. Silencing of Nicotiana benthamiana homologues of the FIE gene, NbFIE1 and NbFIE2, resulted in the enhanced outgrowth of axillary buds and the impairment of secondary xylem differentiation. RNA sequencing analysis found that one of the auxin-responsive GRETCHEN HAGEN 3(GH3) family genes, NbGH3.6, was upregulated and maintained a high expression during the time course of silencing NbFIE genes. Chromatin immunoprecipiation (ChIP)-PCR results showed a lack of H3K27me3 marks on NbGH3.6 chromatin in NbFIE-silenced plants compared with negative control plants, indicating that NbGH3.6 was a direct target of NbFIE genes during postembryonic shoot development. Moreover, the free IAA content was reduced significantly in NbFIE-silenced plants, which might cause the enhanced outgrowth of axillary buds as well as impaired secondary xylem differentiation. These results clearly indicated that NbGH3.6 was a primary target of NbFIE genes during postembryonic shoot development, and NbFIE genes regulated axillary bud growth and secondary xylem formation through tuning endogenous auxin homeostasis, possibly by regulating the expression of the NbGH3.6 gene.


Assuntos
Endosperma/genética , Fertilização , Genes de Plantas , Ácidos Indolacéticos/metabolismo , Nicotiana/genética , Proteínas de Plantas/metabolismo , Brotos de Planta/crescimento & desenvolvimento , Sequência de Bases , Clonagem Molecular , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Fenótipo , Proteínas de Plantas/genética , Brotos de Planta/genética , Vírus de Plantas/metabolismo , Análise de Sequência de RNA , Homologia de Sequência do Ácido Nucleico , Nicotiana/embriologia , Xilema/anatomia & histologia , Xilema/genética
3.
J Exp Bot ; 67(21): 6111-6123, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27811080

RESUMO

Polycomb group (PcG) proteins are evolutionarily conserved chromatin modifiers that regulate developmental pathways in plants. PcGs form nuclear multi-subunit Polycomb Repressive Complexes (PRCs). The PRC2 complex mediates gene repression via methylation of lysine 27 on histone H3, which consequently leads to chromatin condensation. In Arabidopsis thaliana, several PRC2 complexes with different compositions were identified, each controlling a particular developmental program.The core subunit FIE is crucial for PRC2 function throughout the plant life cycle, yet accurate information on its spatial and temporal localization was absent. This study focused on identifying FIE accumulation patterns, using microscopy and biochemical approaches. Analysing endogenous FIE and transgenic gFIE-green fluorescent protein fusion protein (gFIE-GFP) showed that FIE accumulates in the nuclei of every cell type examined. Interestingly, gFIE-GFP, as well as the endogenous FIE, also localized to the cytoplasm in all examined tissues. In both vegetative and reproductive organs, FIE formed cytoplasmic high-molecular-mass complexes, in parallel to the nuclear PRC2 complexes. Moreover, size-exclusion chromatography and bimolecular fluorescence complementation assays indicated that in inflorescences FIE formed a cytoplasmic complex with MEA, a PRC2 histone methyltransferase subunit. In contrast, CLF and SWN histone methyltransferases were strictly nuclear. Presence of PRC2 subunits in cytoplasmic complexes has not been previously described in plants. Our findings are in agreement with accumulating evidence demonstrating cytoplasmic localization and function of PcGs in metazoa. The cytosolic accumulation of PRC2 components in plants supports the model that PcGs have alternative non-nuclear functions that go beyond chromatin methylation.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Citoplasma/metabolismo , Proteínas Repressoras/metabolismo , Cromatina/metabolismo , Cromatografia em Gel , Imunoprecipitação , Microscopia Confocal , Plantas Geneticamente Modificadas , Complexo Repressor Polycomb 2
4.
Trends Ecol Evol ; 39(2): 131-140, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37743188

RESUMO

Fishing-induced evolution (FIE) threatens the ecology, resilience, and economic value of fish populations. Traits under selection, and mechanisms of selection, can be influenced by abiotic and biotic perturbations, yet this has been overlooked. Here, we present the fishery selection continuum, where selection ranges from rigid fisheries selection to flexible fisheries selection. We provide examples on how FIE may function along this continuum, and identify selective processes that should be considered less or more flexible. We also introduce fishery reaction norms, which serve to conceptualise how selection from fishing may function in a dynamic context. Ultimately, we suggest an integrative approach to studying FIE that considers the environmental conditions in which it functions.


Assuntos
Ecologia , Pesqueiros , Animais , Fenótipo , Peixes , Conservação dos Recursos Naturais
5.
Plant Physiol Biochem ; 213: 108841, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38879987

RESUMO

Epigenetic modifications, such as histone alterations, play crucial roles in regulating the flowering process in Arabidopsis, a typical long-day model plant. Histone modifications are notably involved in the intricate regulation of FLC, a key inhibitor of flowering. Although sirtuin-like protein and NAD+-dependent deacetylases play an important role in regulating energy metabolism, plant stress responses, and hormonal signal transduction, the mechanisms underlying their developmental transitions remain unclear. Thus, this study aimed to reveal how Arabidopsis NAD + -dependent deacetylase AtSRT1 affects flowering by regulating the expression of flowering integrators. Genetic and molecular evidence demonstrated that AtSRT1 mediates histone deacetylation by directly binding near the transcriptional start sites (TSS) of the flowering integrator genes FT and SOC1 and negatively regulating their expression by modulating the expression of the downstream gene LFY to inhibit flowering. Additionally, AtSRT1 directly down-regulates the expression of TOR, a glucose-driven central hub of energy signaling, which controls cell metabolism and growth in response to nutritional and environmental factors. This down-regulation occurs through binding near the TSS of TOR, facilitating the addition of H3K27me3 marks on FLC via the TOR-FIE-PRC2 pathway, further repressing flowering. These results uncover a multi-pathway regulatory network involving deacetylase AtSRT1 during the flowering process, highlighting its interaction with TOR as a hub for the coordinated regulation of energy metabolism and flowering initiation. These findings significantly enhance understanding of the complexity of histone modifications in the regulation of flowering.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Flores , Regulação da Expressão Gênica de Plantas , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/fisiologia , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Metabolismo Energético/genética , Flores/genética , Flores/crescimento & desenvolvimento , Histona Desacetilases/metabolismo , Histona Desacetilases/genética , Histonas/metabolismo , Proteínas de Domínio MADS/metabolismo , Proteínas de Domínio MADS/genética , Transdução de Sinais
6.
JMIR Res Protoc ; 13: e57031, 2024 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-39240685

RESUMO

BACKGROUND: Schizophrenia is a disorder associated with neurocognitive deficits that adversely affect daily functioning and impose an economic burden. Cognitive rehabilitation interventions, particularly during the early phases of illness, have been shown to improve cognition, functionality, and quality of life. The Feuerstein Instrumental Enrichment (FIE) program, based on the Mediated Learning Experience and the Structural Cognitive Modifiability theory, has been applied in various disorders, but its applicability in schizophrenia has not yet been clarified. OBJECTIVE: This study aims to investigate the effects of the FIE program on the functionality of patients with first-episode schizophrenia. METHODS: In total, 17 patients will be recruited for an open-label intervention consisting of twice-weekly sessions for 10 weeks. The primary outcome measure will be changes in the Goal Achievement Scale score. Maze task performance from the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) battery will serve as a secondary outcome measure. At the same time, changes in Positive and Negative Syndrome Scale scores and other MATRICS domains will be analyzed as exploratory outcomes. Assessments will be administered before and after the intervention, with a follow-up period of 6 months. RESULTS: This trial was preregistered in The Brazilian Registry of Clinical Trials (RBR-4gzhy4s). By February 2024, 11 participants were enrolled in the training. Recruitment is expected to be completed by May 2024. Data analysis will be conducted between May and September 2024. The results are expected to be published in January 2025. CONCLUSIONS: This study may establish a protocol for the FIE program that uses mediation techniques for individuals in the early stages of schizophrenia. The results will add to the knowledge about strategies to promote cognitive skills and functional impairment in daily life. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/57031.


Assuntos
Transtornos Psicóticos , Esquizofrenia , Humanos , Esquizofrenia/reabilitação , Esquizofrenia/complicações , Transtornos Psicóticos/terapia , Adulto , Masculino , Feminino , Adulto Jovem , Brasil , Adolescente
7.
Ecol Evol ; 12(2): e8596, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35169454

RESUMO

Commercial fishery harvest can influence the evolution of wild fish populations. Our knowledge of selection on morphology is however limited, with most previous studies focusing on body size, age, and maturation. Within species, variation in morphology can influence locomotor ability, possibly making some individuals more vulnerable to capture by fishing gears. Additionally, selection on morphology has the potential to influence other foraging, behavioral, and life-history related traits. Here we carried out simulated fishing using two types of gears: a trawl (an active gear) and a trap (a passive gear), to assess morphological trait-based selection in relation to capture vulnerability. Using geometric morphometrics, we assessed differences in shape between high and low vulnerability fish, showing that high vulnerability individuals display shallower body shapes regardless of gear type. For trawling, low vulnerability fish displayed morphological characteristics that may be associated with higher burst-swimming, including a larger caudal region and narrower head, similar to evolutionary responses seen in fish populations responding to natural predation. Taken together, these results suggest that divergent selection can lead to phenotypic differences in harvested fish populations.

8.
G3 (Bethesda) ; 12(10)2022 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-36018241

RESUMO

Traffic lines are transgenic stocks of Arabidopsis thaliana that contain a pair of linked seed-specific eGFP and DsRed markers. These stocks were originally developed for the purpose of studying recombination, but can also be used to follow the inheritance of unmarked chromosomes placed in trans to the marked chromosome. They are particularly useful for this latter purpose if the distance between markers is short, making double recombination within this interval relatively rare. We generated 163 traffic lines that cover the Arabidopsis genome in overlapping intervals of approximately 1.2 Mb (6.9 cM). These stocks make it possible to predict the genotype of a plant based on its seed fluorescence (or lack thereof) and facilitate many experiments in genetic analysis that are difficult, tedious, or expensive to perform using current techniques. Here, we show how these lines enable a phenotypic analysis of alleles with weak or variable phenotypes, genetic mapping of novel mutations, introducing transgenes into a lethal or sterile genetic background, and separating closely linked mutations.


Assuntos
Arabidopsis , Arabidopsis/genética , Mapeamento Cromossômico , Cromossomos , Testes Genéticos , Transgenes
9.
Dement Geriatr Cogn Dis Extra ; 10(3): 135-142, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33442390

RESUMO

BACKGROUND: The rate of elderly individuals with mild cognitive impairment (MCI) has increased over recent decades. The Feuerstein Instrumental Enrichment (FIE) program for the elderly has been shown to be effective in various age groups but is has never been tested as a treatment for MCI in elderly patients. The aim of this study was to assess the effect of the FIE on the cognitive and functional state of elderly patients with MCI. METHODS: This was an interventional pilot study in community-dwelling patients aged ≥65 years diagnosed with MCI in the previous year. The protocol included 30 twice-weekly 90-min sessions with a full neurocognitive evaluation prior to the intervention (v1), at its conclusion (v2), and half a year later (v3). RESULTS: Nine of the 15 recruited participants completed the study. The mean age was 76.2 years. Compared to v1 and v2, the only significant improvements found at v3 were in the "visual perception" subtest of the NeuroTrax test and the total score of the MOCA test (p = 0.048 and 0.028, respectively). The effect size was >0.7 (r = 0.7), indicating a moderate-to-high clinical significance. The results of the qualitative questionnaire were consistent with the positive effect of the group on the fostering of social ties, the motivation to learn, the cognitive contribution, and the development of a sense of self-efficacy. CONCLUSION: The study findings support the conclusion that an intervention with a focus on cognitive exercising can promote a feeling of self-efficacy and preserve some cognitive skills.

10.
Plant Sci ; 234: 86-96, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25804812

RESUMO

FERTILIZATION INDEPENDENT ENDOSPERM (FIE) is a core component of PcG complexes and functions in plant phase transition and seed generation. However, understanding in its function of apomictic monocot plants remains blank. Here an FIE homology EbFIE, has been isolated from apomictic Graminae species Eulaliopsis binata. EbFIE shares higher homology to OsFIE2 than OsFIE1, and has been classified into the monocot FIE2 clade. In addition, the broad expression pattern of EbFIE is also similar to OsFIE2. While, ectopic expression of EbFIE in rice resulted in pleiotropic phenotypes similar to that of OsFIE1 over-expressing plants. Meanwhile, EbFIE could bind OsCLF in vitro as OsFIE1 but different with OsFIE2. Molecular models comparison indicated that both EbFIE and OsFIE1 had a smaller E(z) protein binding groove than OsFIE2. Further site-directed mutagenesis analysis revealed that single amino acid substitution of I194F in OsFIE2 could improve its OsCLF binding capacity. Taken together, our results suggested that EbFIE was a conserved FIE homolog belonging to monocot FIE2 clade, but due to the similarity in protein conformation with FIE1, EbFIE might play a broad role in vegetative and reproductive development regulation by interaction with CLF homolog.


Assuntos
Regulação da Expressão Gênica de Plantas , Oryza/genética , Proteínas de Plantas/metabolismo , Poaceae/genética , Sequência de Aminoácidos , Substituição de Aminoácidos , Expressão Ectópica do Gene , Endosperma/citologia , Endosperma/genética , Endosperma/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Modelos Moleculares , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Oryza/citologia , Oryza/metabolismo , Fenótipo , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Ligação Proteica , Reprodução , Sementes/citologia , Sementes/genética , Sementes/metabolismo , Alinhamento de Sequência
11.
Anal Chim Acta ; 801: 22-33, 2013 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-24139571

RESUMO

Real-world applications will inevitably entail divergence between samples on which chemometric classifiers are trained and the unknowns requiring classification. This has long been recognized, but there is a shortage of empirical studies on which classifiers perform best in 'external validation' (EV), where the unknown samples are subject to sources of variation relative to the population used to train the classifier. Survey of 286 classification studies in analytical chemistry found only 6.6% that stated elements of variance between training and test samples. Instead, most tested classifiers using hold-outs or resampling (usually cross-validation) from the same population used in training. The present study evaluated a wide range of classifiers on NMR and mass spectra of plant and food materials, from four projects with different data properties (e.g., different numbers and prevalence of classes) and classification objectives. Use of cross-validation was found to be optimistic relative to EV on samples of different provenance to the training set (e.g., different genotypes, different growth conditions, different seasons of crop harvest). For classifier evaluations across the diverse tasks, we used ranks-based non-parametric comparisons, and permutation-based significance tests. Although latent variable methods (e.g., PLSDA) were used in 64% of the surveyed papers, they were among the less successful classifiers in EV, and orthogonal signal correction was counterproductive. Instead, the best EV performances were obtained with machine learning schemes that coped with the high dimensionality (914-1898 features). Random forests confirmed their resilience to high dimensionality, as best overall performers on the full data, despite being used in only 4.5% of the surveyed papers. Most other machine learning classifiers were improved by a feature selection filter (ReliefF), but still did not out-perform random forests.


Assuntos
Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Algoritmos , Arabidopsis/química , Arabidopsis/classificação , Arabidopsis/genética , Arabidopsis/metabolismo , Biomassa , Cacau/química , Cacau/classificação , Cacau/genética , Cacau/metabolismo , Análise Discriminante , Metabolômica , Reprodutibilidade dos Testes , Ácido Salicílico/metabolismo
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