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1.
Nat Commun ; 9(1): 4680, 2018 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-30409967

RESUMO

Drought represents a major threat to food security. Mechanistic data describing plant responses to drought have been studied extensively and genes conferring drought resistance have been introduced into crop plants. However, plants with enhanced drought resistance usually display lower growth, highlighting the need for strategies to uncouple drought resistance from growth. Here, we show that overexpression of BRL3, a vascular-enriched member of the brassinosteroid receptor family, can confer drought stress tolerance in Arabidopsis. Whereas loss-of-function mutations in the ubiquitously expressed BRI1 receptor leads to drought resistance at the expense of growth, overexpression of BRL3 receptor confers drought tolerance without penalizing overall growth. Systematic analyses reveal that upon drought stress, increased BRL3 triggers the accumulation of osmoprotectant metabolites including proline and sugars. Transcriptomic analysis suggests that this results from differential expression of genes in the vascular tissues. Altogether, this data suggests that manipulating BRL3 expression could be used to engineer drought tolerant crops.


Assuntos
Arabidopsis/fisiologia , Secas , Desenvolvimento Vegetal , Feixe Vascular de Plantas/metabolismo , Receptores de Superfície Celular/metabolismo , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Metaboloma , Mutação/genética , Pressão Osmótica , Desenvolvimento Vegetal/genética , Raízes de Plantas/genética , Raízes de Plantas/fisiologia , Plantas Geneticamente Modificadas , Estresse Fisiológico/genética , Transcrição Genética , Tropismo
2.
J Exp Bot ; 67(6): 1639-48, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26956505

RESUMO

Shoot apical meristem activity is controlled by complex regulatory networks in which components such as transcription factors, miRNAs, small peptides, hormones, enzymes and epigenetic marks all participate. Many key genes that determine the inherent characteristics of the shoot apical meristem have been identified through genetic approaches. Recent advances in genome-wide studies generating extensive transcriptomic and DNA-binding datasets have increased our understanding of the interactions within the regulatory networks that control the activity of the meristem, identifying new regulators and uncovering connections between previously unlinked network components. In this review, we focus on recent studies that illustrate the contribution of whole genome analyses to understand meristem function.


Assuntos
Redes Reguladoras de Genes , Genoma de Planta , Meristema/genética , Genes de Plantas , Folhas de Planta/embriologia , Folhas de Planta/genética , Células-Tronco/citologia , Células-Tronco/metabolismo
4.
BMC Genomics ; 15: 1083, 2014 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-25491154

RESUMO

BACKGROUND: Small RNAs (sRNAs), including small interfering RNAs (siRNAs) and microRNAs (miRNAs), have emerged as important regulators of eukaryotic gene expression. In plants, miRNAs play critical roles in development, nutrient homeostasis and abiotic stress responses. Accumulating evidence also reveals that sRNAs are involved in plant immunity. Most studies on pathogen-regulated sRNAs have been conducted in Arabidopsis plants infected with the bacterial pathogen Pseudomonas syringae, or treated with the flagelin-derived elicitor peptide flg22 from P. syringae. This work investigates sRNAs that are regulated by elicitors from the fungus Fusarium oxysporum in Arabidopsis. RESULTS: Microarray analysis revealed alterations on the accumulation of a set of sRNAs in response to elicitor treatment, including miRNAs and small RNA sequences derived from massively parallel signature sequencing. Among the elicitor-regulated miRNAs was miR168 which regulates ARGONAUTE1, the core component of the RNA-induced silencing complex involved in miRNA functioning. Promoter analysis in transgenic Arabidopsis plants revealed transcriptional activation of MIR168 by fungal elicitors. Furthermore, transgenic plants expressing a GFP-miR168 sensor gene confirmed that the elicitor-induced miR168 is active. MiR823, targeting Chromomethylase3 (CMT3) involved in RNA-directed DNA methylation (RdDM) was also found to be regulated by fungal elicitors. In addition to known miRNAs, microarray analysis allowed the identification of an elicitor-inducible small RNA that was incorrectly annotated as a miRNA. Studies on Arabidopsis mutants impaired in small RNA biogenesis demonstrated that this sRNA, is a heterochromatic-siRNA (hc-siRNA) named as siRNA415. Hc-siRNAs are known to be involved in RNA-directed DNA methylation (RdDM). SiRNA415 is detected in several plant species. CONCLUSION: Results here presented support a transcriptional regulatory mechanism underlying MIR168 expression. This finding highlights the importance of miRNA functioning in adaptive processes of Arabidopsis plants to fungal infection. The results of this study also lay a foundation for the involvement of RdDM processes through the activity of siRNA415 and miR823 in mediating regulation of immune responses in Arabidopsis plants.


Assuntos
Arabidopsis/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , MicroRNAs/genética , Doenças das Plantas/genética , RNA Interferente Pequeno/genética , Arabidopsis/microbiologia , Fungos , Fenótipo , Doenças das Plantas/microbiologia , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas , Precursores de RNA , Ativação Transcricional
5.
Genome Biol ; 15(3): R41, 2014 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-24581456

RESUMO

BACKGROUND: Development of eukaryotic organisms is controlled by transcription factors that trigger specific and global changes in gene expression programs. In plants, MADS-domain transcription factors act as master regulators of developmental switches and organ specification. However, the mechanisms by which these factors dynamically regulate the expression of their target genes at different developmental stages are still poorly understood. RESULTS: We characterized the relationship of chromatin accessibility, gene expression, and DNA binding of two MADS-domain proteins at different stages of Arabidopsis flower development. Dynamic changes in APETALA1 and SEPALLATA3 DNA binding correlated with changes in gene expression, and many of the target genes could be associated with the developmental stage in which they are transcriptionally controlled. We also observe dynamic changes in chromatin accessibility during flower development. Remarkably, DNA binding of APETALA1 and SEPALLATA3 is largely independent of the accessibility status of their binding regions and it can precede increases in DNA accessibility. These results suggest that APETALA1 and SEPALLATA3 may modulate chromatin accessibility, thereby facilitating access of other transcriptional regulators to their target genes. CONCLUSIONS: Our findings indicate that different homeotic factors regulate partly overlapping, yet also distinctive sets of target genes in a partly stage-specific fashion. By combining the information from DNA-binding and gene expression data, we are able to propose models of stage-specific regulatory interactions, thereby addressing dynamics of regulatory networks throughout flower development. Furthermore, MADS-domain TFs may regulate gene expression by alternative strategies, one of which is modulation of chromatin accessibility.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Montagem e Desmontagem da Cromatina , Cromatina/metabolismo , Flores/crescimento & desenvolvimento , Proteínas de Homeodomínio/metabolismo , Proteínas de Domínio MADS/metabolismo , Fatores de Transcrição/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Cromatina/genética , Flores/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/genética , Proteínas de Domínio MADS/genética , Ligação Proteica , Fatores de Transcrição/genética
6.
Methods Mol Biol ; 1110: 103-24, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24395254

RESUMO

Almost three decades of genetic and molecular analyses have resulted in detailed insights into many of the processes that take place during flower development and in the identification of a large number of key regulatory genes that control these processes. Despite this impressive progress, many questions about how flower development is controlled in different angiosperm species remain unanswered. In this chapter, we discuss some of these open questions and the experimental strategies with which they could be addressed. Specifically, we focus on the areas of floral meristem development and patterning, floral organ specification and differentiation, as well as on the molecular mechanisms underlying the evolutionary changes that have led to the astounding variations in flower size and architecture among extant and extinct angiosperms.


Assuntos
Flores/crescimento & desenvolvimento , Evolução Molecular , Flores/anatomia & histologia , Flores/genética , Meristema/anatomia & histologia , Meristema/genética , Meristema/crescimento & desenvolvimento , Modelos Biológicos
7.
Methods Mol Biol ; 1110: 347-62, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24395269

RESUMO

Determining gene function through reverse genetics has been an important experimental approach in the field of flower development. The method largely relies on the availability of knockout lines for the gene of interest. Insertional mutagenesis can be performed using either T-DNA or transposable elements, but the former has been more frequently employed in Arabidopsis. A primary concern for working with insertional mutant lines is whether the respective insertion results in a complete or rather a partial loss of gene function. The effect of the insertion largely depends on its position with respect to the structure of the gene. In order to quickly identify and obtain knockout lines for genes of interest in Arabidopsis, more than 325,000 mapped insertion lines have been catalogued on indexed libraries and made publicly available to researchers. Online accessible databases provide information regarding the site of insertion, whether a mutant line is available in a homozygous or hemizygous state, and outline technical aspects for plant identification, such as primer design tools used for genotyping. In this chapter, we describe the procedure for isolating knockout lines for genes of interest in Arabidopsis.


Assuntos
Arabidopsis/genética , Técnicas de Inativação de Genes/métodos , Genes de Plantas/genética , Marcadores Genéticos/genética , Técnicas de Genotipagem , Homozigoto , Mutagênese Insercional , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Plântula/genética , Sementes/genética
8.
Methods Mol Biol ; 1110: 363-82, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24395270

RESUMO

Real-time, or quantitative, reverse transcription polymerase chain reaction (qRT-PCR), is a powerful method for rapid and reliable quantification of mRNA abundance. Although it has not featured prominently in flower development research in the past, the availability of novel techniques for the synchronized induction of flower development, or for the isolation of cell-specific mRNA populations, suggests that detailed quantitative analyses of gene expression over time and in specific tissues and cell types by qRT-PCR will become more widely used. In this chapter, we discuss specific considerations for studying gene expression by using qRT-PCR, such as the identification of suitable reference genes for the experimental setup used. In addition, we provide protocols for performing qRT-PCR experiments in a multiwell plate format (with the LightCycler(®) 480 system, Roche) and with nanofluidic arrays (BioMark™ system, Fluidigm), which allow the automatic combination of sets of samples with sets of assays, and significantly reduce reaction volume and the number of liquid-handling steps performed during the experiment.


Assuntos
Perfilação da Expressão Gênica/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Flores/genética , RNA de Plantas/genética , RNA de Plantas/isolamento & purificação , Transcrição Reversa
9.
J Exp Bot ; 65(1): 1-9, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24277279

RESUMO

Floral organs are specified by the activities of a small group of transcriptional regulators, the floral organ identity factors. Extensive genetic and molecular analyses have shown that these proteins act as master regulators of flower development, and function not only in organ identity determination but also during organ morphogenesis. Although it is now well established that these transcription factors act in higher order protein complexes in the regulation of transcription, the gene expression programmes controlled by them have remained largely elusive. Only recently, detailed insights into their functions have been obtained through the combination of a wide range of experimental methods, including transcriptomic and proteomic approaches. Here, we review the progress that has been made in the characterization of the floral organ identity factors from the main model plant Arabidopsis thaliana, and we discuss what is known about the processes acting downstream of these regulators. We further outline open questions, which we believe need to be addressed to obtain a more complete view of the molecular processes that govern floral organ development and specification.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Flores/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Flores/genética , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Mutação , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
10.
Methods Mol Biol ; 876: 207-16, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22576098

RESUMO

Gene transcripts are under extensive posttranscriptional regulation, including the regulation of their stability. A major route for mRNA degradation produces uncapped mRNAs, which can be generated by decapping enzymes, endonucleases, and small RNAs. Profiling uncapped mRNA molecules is important for the understanding of the transcriptome, whose composition is determined by a balance between mRNA synthesis and degradation. In this chapter, we describe a method to profile these uncapped mRNAs at the genome scale.


Assuntos
Perfilação da Expressão Gênica/métodos , RNA Mensageiro/genética , Transcriptoma/genética , Estabilidade de RNA/genética
11.
Methods Mol Biol ; 815: 147-59, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22130990

RESUMO

We present a quantification method for affinity-based DNA microarrays which is based on the real-time measurements of hybridization kinetics. This method, i.e., real-time DNA microarrays, enhances the detection dynamic range of conventional systems by being impervious to probe saturation, washing artifacts, microarray spot-to-spot variations, and other intensity-affecting impediments. We demonstrate in both theory and practice that the time-constant of target capturing is inversely proportional to the concentration of the target analyte, which we take advantage of as the fundamental parameter to estimate the concentration of the analytes. Furthermore, to experimentally validate the capabilities of this method in practical applications, we present a FRET-based assay which enables the real-time detection in gene expression DNA microarrays.


Assuntos
Transferência Ressonante de Energia de Fluorescência , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Algoritmos , Animais , Calibragem , Sondas de DNA/síntese química , Perfilação da Expressão Gênica/métodos , Cinética , Camundongos , Análise de Sequência com Séries de Oligonucleotídeos/normas , Padrões de Referência
12.
Curr Opin Biotechnol ; 22(2): 260-70, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21167706

RESUMO

Arabidopsis genomic and network analyses have facilitated crop research towards the understanding of many biological processes of fundamental importance for agriculture. Genes that were identified through genomic analyses in Arabidopsis have been used to manipulate crop traits such as pathogen resistance, yield, water-use efficiency, and drought tolerance, with the effects being tested in field conditions. The integration of diverse Arabidopsis genome-wide datasets in probabilistic functional networks has been demonstrated as a feasible strategy to associate novel genes with traits of interest, and novel genomic methods continue to be developed. The combination of genome-wide location studies, using ChIP-Seq, with gene expression profiling data is affording a genome-wide view of regulatory networks previously delineated through genetic and molecular analyses, leading to the identification of novel components and of new connections within these networks.


Assuntos
Arabidopsis/metabolismo , Produtos Agrícolas/metabolismo , Regulação da Expressão Gênica de Plantas/fisiologia , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Produtos Agrícolas/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/genética , Redes Reguladoras de Genes
13.
Science ; 328(5974): 85-9, 2010 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-20360106

RESUMO

The MADS-domain transcription factor APETALA1 (AP1) is a key regulator of Arabidopsis flower development. To understand the molecular mechanisms underlying AP1 function, we identified its target genes during floral initiation using a combination of gene expression profiling and genome-wide binding studies. Many of its targets encode transcriptional regulators, including known floral repressors. The latter genes are down-regulated by AP1, suggesting that it initiates floral development by abrogating the inhibitory effects of these genes. Although AP1 acts predominantly as a transcriptional repressor during the earliest stages of flower development, at more advanced stages it also activates regulatory genes required for floral organ formation, indicating a dynamic mode of action. Our results further imply that AP1 orchestrates floral initiation by integrating growth, patterning, and hormonal pathways.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/genética , Flores/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Proteínas de Domínio MADS/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Sítios de Ligação , Imunoprecipitação da Cromatina , Regulação para Baixo , Perfilação da Expressão Gênica , Genes de Plantas , Genoma de Planta , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Proteínas de Domínio MADS/genética , Análise de Sequência com Séries de Oligonucleotídeos , Fatores de Transcrição/genética , Sítio de Iniciação de Transcrição , Ativação Transcricional
14.
Nucleic Acids Res ; 37(20): e132, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19723688

RESUMO

We present a quantification method for affinity-based DNA microarrays which is based on the real-time measurements of hybridization kinetics. This method, i.e. real-time DNA microarrays, enhances the detection dynamic range of conventional systems by being impervious to probe saturation in the capturing spots, washing artifacts, microarray spot-to-spot variations, and other signal amplitude-affecting non-idealities. We demonstrate in both theory and practice that the time-constant of target capturing in microarrays, similar to all affinity-based biosensors, is inversely proportional to the concentration of the target analyte, which we subsequently use as the fundamental parameter to estimate the concentration of the analytes. Furthermore, to empirically validate the capabilities of this method in practical applications, we present a FRET-based assay which enables the real-time detection in gene expression DNA microarrays.


Assuntos
Perfilação da Expressão Gênica/métodos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Transferência Ressonante de Energia de Fluorescência , Cinética , Modelos Teóricos
15.
Plant Cell ; 20(10): 2571-85, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18952771

RESUMO

The composition of the transcriptome is determined by a balance between mRNA synthesis and degradation. An important route for mRNA degradation produces uncapped mRNAs, and this decay process can be initiated by decapping enzymes, endonucleases, and small RNAs. Although uncapped mRNAs are an important intermediate for mRNA decay, their identity and abundance have never been studied on a large scale until recently. Here, we present an experimental method for transcriptome-wide profiling of uncapped mRNAs that can be used in any eukaryotic system. We applied the method to study the prevalence of uncapped transcripts during the early stages of Arabidopsis thaliana flower development. Uncapped transcripts were identified for the majority of expressed genes, although at different levels. By comparing uncapped RNA levels with steady state overall transcript levels, our study provides evidence for widespread mRNA degradation control in numerous biological processes involving genes of varied molecular functions, implying that uncapped mRNA levels are dynamically regulated. Sequence analyses identified structural features of transcripts and cis-elements that were associated with different levels of uncapping. These transcriptome-wide profiles of uncapped mRNAs will aid in illuminating new regulatory mechanisms of eukaryotic transcriptional networks.


Assuntos
Arabidopsis/genética , Perfilação da Expressão Gênica/métodos , Estabilidade de RNA , RNA Mensageiro/metabolismo , RNA de Plantas/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Flores/genética , Flores/crescimento & desenvolvimento , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas , MicroRNAs/metabolismo , RNA Mensageiro/química , RNA de Plantas/química , Análise de Sequência de RNA , Regiões não Traduzidas/química
16.
Plant Physiol ; 145(3): 747-62, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17905860

RESUMO

To obtain detailed information about gene expression during stamen development in Arabidopsis (Arabidopsis thaliana), we compared, by microarray analysis, the gene expression profile of wild-type inflorescences to those of the floral mutants apetala3, sporocyteless/nozzle, and male sterile1 (ms1), in which different aspects of stamen formation are disrupted. These experiments led to the identification of groups of genes with predicted expression at early, intermediate, and late stages of stamen development. Validation experiments using in situ hybridization confirmed the predicted expression patterns. Additional experiments aimed at characterizing gene expression specifically during microspore formation. To this end, we compared the gene expression profiles of wild-type flowers of distinct developmental stages to those of the ms1 mutant. Computational analysis of the datasets derived from this experiment led to the identification of genes that are likely involved in the control of key developmental processes during microsporogenesis. We also identified a large number of genes whose expression is prolonged in ms1 mutant flowers compared to the wild type. This result suggests that MS1, which encodes a putative transcriptional regulator, is involved in the stage-specific repression of these genes. Lastly, we applied reverse genetics to characterize several of the genes identified in the microarray experiments and uncovered novel regulators of microsporogenesis, including the transcription factor MYB99 and a putative phosphatidylinositol 4-kinase.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Arabidopsis/genética , Flores/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Flores/genética , Genoma de Planta , Mutação , Análise de Sequência com Séries de Oligonucleotídeos , Reprodutibilidade dos Testes
17.
Plant Cell ; 19(4): 1278-94, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17449808

RESUMO

The composition and permeability of the cuticle has a large influence on its ability to protect the plant against various forms of biotic and abiotic stress. WAX INDUCER1 (WIN1) and related transcription factors have recently been shown to trigger wax production, enhance drought tolerance, and modulate cuticular permeability when overexpressed in Arabidopsis thaliana. We found that WIN1 influences the composition of cutin, a polyester that forms the backbone of the cuticle. WIN1 overexpression induces compositional changes and an overall increase in cutin production in vegetative and reproductive organs, while its downregulation has the opposite effect. Changes in cutin composition are preceded by the rapid and coordinated induction of several genes known or likely to be involved in cutin biosynthesis. This transcriptional response is followed after a delay by the induction of genes associated with wax biosynthesis, suggesting that the regulation of cutin and wax production by WIN1 is a two-step process. We demonstrate that at least one of the cutin pathway genes, which encodes long-chain acyl-CoA synthetase LACS2, is likely to be directly targeted by WIN1. Overall, our results suggest that WIN1 modulates cuticle permeability in Arabidopsis by regulating genes encoding cutin pathway enzymes.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Lipídeos de Membrana/biossíntese , Transativadores/genética , Fatores de Transcrição/genética , Proteínas de Arabidopsis/genética , Coenzima A Ligases/genética , Inativação Gênica , Lipídeos/fisiologia , Análise de Sequência com Séries de Oligonucleotídeos , Ceras/metabolismo
18.
Development ; 134(6): 1051-60, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17287247

RESUMO

In plants, members of microRNA (miRNA) families are often predicted to target the same or overlapping sets of genes. It has thus been hypothesized that these miRNAs may act in a functionally redundant manner. This hypothesis is tested here by studying the effects of elimination of all three members of the MIR164 family from Arabidopsis. It was found that a loss of miR164 activity leads to a severe disruption of shoot development, in contrast to the effect of mutation in any single MIR164 gene. This indicates that these miRNAs are indeed functionally redundant. Differences in the expression patterns of the individual MIR164 genes imply, however, that redundancy among them is not complete, and that these miRNAs show functional specialization. Furthermore, the results of molecular and genetic analyses of miR164-mediated target regulation indicate that miR164 miRNAs function to control the transcript levels, as well as the expression patterns, of their targets, suggesting that they might contribute to developmental robustness. For two of the miR164 targets, namely CUP-SHAPED COTYLEDON1 (CUC1) and CUC2, we provide evidence for their involvement in the regulation of growth and show that their derepression in miR164 loss-of-function mutants is likely to account for most of the mutant phenotype.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , MicroRNAs/fisiologia , Morfogênese/genética , Arabidopsis/anatomia & histologia , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/fisiologia , MicroRNAs/genética , Folhas de Planta/anatomia & histologia , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Brotos de Planta/anatomia & histologia , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento
19.
PLoS Genet ; 2(7): e117, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16789830

RESUMO

Detailed information about stage-specific changes in gene expression is crucial for the understanding of the gene regulatory networks underlying development. Here, we describe the global gene expression dynamics during early flower development, a key process in the life cycle of a plant, during which floral patterning and the specification of floral organs is established. We used a novel floral induction system in Arabidopsis, which allows the isolation of a large number of synchronized floral buds, in conjunction with whole-genome microarray analysis to identify genes with differential expression at distinct stages of flower development. We found that the onset of flower formation is characterized by a massive downregulation of genes in incipient floral primordia, which is followed by a predominance of gene activation during the differentiation of floral organs. Among the genes we identified as differentially expressed in the experiment, we detected a significant enrichment of closely related members of gene families. The expression profiles of these related genes were often highly correlated, indicating similar temporal expression patterns. Moreover, we found that the majority of these genes is specifically up-regulated during certain developmental stages. Because co-expressed members of gene families in Arabidopsis frequently act in a redundant manner, these results suggest a high degree of functional redundancy during early flower development, but also that its extent may vary in a stage-specific manner.


Assuntos
Arabidopsis/genética , Flores , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Arabidopsis/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Genes de Plantas , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas de Plantas/genética , Fatores de Tempo , Transcrição Genética , Ativação Transcricional
20.
Int J Dev Biol ; 49(5-6): 745-59, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16096979

RESUMO

The analysis of the gene regulatory networks underlying development is of central importance for a better understanding of the mechanisms that control the formation of the different cell-types, tissues or organs of an organism. The recent invention of genomic technologies has opened the possibility of studying these networks at a global level. In this paper, we summarize some of the recent advances that have been made in the understanding of plant development by the application of genomic technologies. We focus on a few specific processes, namely flower and root development and the control of the cell cycle, but we also highlight landmark studies in other areas that opened new avenues of experimentation or analysis. We describe the methods and the strategies that are currently used for the analysis of plant development by genomic technologies, as well as some of the problems and limitations that hamper their application. Since many genomic technologies and concepts were first developed and tested in organisms other than plants, we make reference to work in non-plant species and compare the current state of network analysis in plants to that in other multicellular organisms.


Assuntos
Desenvolvimento Vegetal , Plantas/genética , Ciclo Celular , Flores/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Genômica/métodos , Morfogênese , Células Vegetais , Raízes de Plantas/crescimento & desenvolvimento , Transcrição Genética
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