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1.
Methods Mol Biol ; 2686: 163-198, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37540358

RESUMO

The shoot apical and floral meristems (SAM and FM, respectively) of Arabidopsis thaliana contain reservoirs of self-renewing stem cells that function as sources of progenitor cells for organ formation during development. The primary SAM produces all the aerial structures of the adult plant, while the FMs generate the four types of floral organs. Consequently, aberrant SAM and FM activity can profoundly affect vegetative and reproductive plant morphology. The embedded location and small size of Arabidopsis meristems make accessing these structures difficult, so specialized techniques have been developed to facilitate their analysis. Microscopic, histological, and molecular techniques provide both qualitative and quantitative data on meristem organization and function, which are crucial for the normal growth and development of the entire plant.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Meristema , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Plantas/metabolismo , Crescimento e Desenvolvimento , Regulação da Expressão Gênica de Plantas
2.
Plant Direct ; 7(5): e496, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37168319

RESUMO

Plants generate their reproductive organs, the stamens and the carpels, de novo within the flowers that form when the plant reaches maturity. The carpels comprise the female reproductive organ, the gynoecium, a complex organ that develops along several axes of polarity and is crucial for plant reproduction, fruit formation, and seed dispersal. The epigenetic trithorax group (trxG) protein ULTRAPETALA1 (ULT1) and the GARP domain transcription factor KANADI1 (KAN1) act cooperatively to regulate Arabidopsis thaliana gynoecium patterning along the apical-basal polarity axis; however, the molecular pathways through which this patterning activity is achieved remain to be explored. In this study, we used transcriptomics to identify genome-wide ULT1 and KAN1 target genes during reproductive development. We discovered 278 genes in developing flowers that are regulated by ULT1, KAN1, or both factors together. Genes involved in developmental and reproductive processes are overrepresented among ULT1 and/or KAN1 target genes, along with genes involved in biotic or abiotic stress responses. Consistent with their function in regulating gynoecium patterning, a number of the downstream target genes are expressed in the developing gynoecium, including a unique subset restricted to the stigmatic tissue. Further, we also uncovered a number of KAN1- and ULT1-induced genes that are transcribed predominantly or exclusively in developing stamens. These findings reveal a potential cooperative role for ULT1 and KAN1 in male as well as female reproductive development that can be investigated with future genetic and molecular experiments.

3.
Plant Signal Behav ; 9(12): e977723, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25531183

RESUMO

Trithorax group (trxG) and Polycomb group (PcG) proteins are epigenetic modifiers that play key roles in eukaryotic development by promoting active or repressive gene expression states, respectively. Although PcG proteins have well-defined roles in controlling developmental transitions, cell fate decisions and cellular differentiation in plants, relatively little is known about the functions of plant trxG factors. We recently determined the biological roles for the ULT1 and ULT2 trxG genes during Arabidopsis vegetative and reproductive development. Our study revealed that ULT1 and ULT2 genes have overlapping activities in regulating Arabidopsis shoot and floral stem cell activity, and that they have a redundant function in establishing the apical-basal polarity axis of the gynoecium. Here we present data that ult1 and ult1 ult2 siliques contain a significant proportion of aborted ovules, supporting an additional role for ULT1 in Arabidopsis fertility. Our results add to the number of plant developmental processes that are regulated by trxG activity.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Fertilização/fisiologia , Fatores de Transcrição/metabolismo , Mutação/genética , Óvulo Vegetal/metabolismo , Sementes/crescimento & desenvolvimento
4.
Plant Cell ; 26(11): 4345-61, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25381352

RESUMO

Organ formation relies upon precise patterns of gene expression that are under tight spatial and temporal regulation. Transcription patterns are specified by several cellular processes during development, including chromatin remodeling, but little is known about how chromatin-remodeling factors contribute to plant organogenesis. We demonstrate that the trithorax group (trxG) gene ULTRAPETALA1 (ULT1) and the GARP transcription factor gene KANADI1 (KAN1) organize the Arabidopsis thaliana gynoecium along two distinct polarity axes. We show that ULT1 activity is required for the kan1 adaxialized polarity defect, indicating that ULT1 and KAN1 act oppositely to regulate the adaxial-abaxial axis. Conversely, ULT1 and KAN1 together establish apical-basal polarity by promoting basal cell fate in the gynoecium, restricting the expression domain of the basic helix-loop-helix transcription factor gene SPATULA. Finally, we show that ult alleles display dose-dependent genetic interactions with kan alleles and that ULT and KAN proteins can associate physically. Our findings identify a dual role for plant trxG factors in organ patterning, with ULT1 and KAN1 acting antagonistically to pattern the adaxial-abaxial polarity axis but jointly to pattern the apical-basal axis. Our data indicate that the ULT proteins function to link chromatin-remodeling factors with DNA binding transcription factors to regulate target gene expression.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Flores/genética , Regulação da Expressão Gênica de Plantas , Fatores de Transcrição/metabolismo , Arabidopsis/citologia , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Flores/citologia , Flores/crescimento & desenvolvimento , Flores/metabolismo , Hibridização In Situ , Modelos Biológicos , Fenótipo , Folhas de Planta/citologia , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Ligação Proteica , Análise de Sequência de DNA , Fatores de Transcrição/genética , Técnicas do Sistema de Duplo-Híbrido
5.
Methods Mol Biol ; 1110: 157-89, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24395256

RESUMO

The shoot apical and floral meristems (SAM and FM, respectively) of Arabidopsis thaliana contain reservoirs of self-renewing stem cells that function as sources of progenitor cells for organ formation during development. The primary SAM produces all of the aerial structures of the adult plant, whereas the FMs generate the four types of floral organs. Consequently, aberrant SAM and FM activity can profoundly affect vegetative and reproductive plant morphology. The embedded location and small size of Arabidopsis meristems make accessing these structures difficult, so specialized techniques have been developed to facilitate their analysis. Microscopic, histological, and molecular techniques provide both qualitative and quantitative data on meristem organization and function, which are crucial for the normal growth and development of the entire plant.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Arabidopsis/genética , Flores/crescimento & desenvolvimento , Flores/genética , Meristema/crescimento & desenvolvimento , Meristema/genética , Fenótipo , Arabidopsis/anatomia & histologia , Arabidopsis/citologia , Flores/anatomia & histologia , Flores/citologia , Meristema/anatomia & histologia , Meristema/citologia , Microscopia Confocal , Tamanho do Órgão , Inclusão em Parafina , Coloração e Rotulagem , Fixação de Tecidos
6.
Mol Plant ; 6(5): 1564-79, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23446032

RESUMO

The epigenetic regulation of gene expression is critical for ensuring the proper deployment and stability of defined genome transcription programs at specific developmental stages. The cellular memory of stable gene expression states during animal and plant development is mediated by the opposing activities of Polycomb group (PcG) factors and trithorax group (trxG) factors. Yet, despite their importance, only a few trxG factors have been characterized in plants and their roles in regulating plant development are poorly defined. In this work, we report that the closely related Arabidopsis trxG genes ULTRAPETALA1 (ULT1) and ULT2 have overlapping functions in regulating shoot and floral stem cell accumulation, with ULT1 playing a major role but ULT2 also making a minor contribution. The two genes also have a novel, redundant activity in establishing the apical­basal polarity axis of the gynoecium, indicating that they function in differentiating tissues. Like ULT1 proteins, ULT2 proteins have a dual nuclear and cytoplasmic localization, and the two proteins physically associate in planta. Finally, we demonstrate that ULT1 and ULT2 have very similar overexpression phenotypes and regulate a common set of key development target genes, including floral MADS-box genes and class I KNOX genes. Our results reveal that chromatin remodeling mediated by the ULT1 and ULT2 proteins is necessary to control the development of meristems and reproductive organs. They also suggest that, like their animal counterparts, plant trxG proteins may function in multi-protein complexes to up-regulate the expression of key stage- and tissue-specific developmental regulatory genes.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/genética , Proteínas Cromossômicas não Histona/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Desenvolvimento Vegetal/genética , Fatores de Transcrição/genética , Arabidopsis/anatomia & histologia , Arabidopsis/ultraestrutura , Proteínas de Arabidopsis/metabolismo , Polaridade Celular/genética , Proteínas Cromossômicas não Histona/metabolismo , Inflorescência/anatomia & histologia , Inflorescência/genética , Inflorescência/ultraestrutura , Meristema/anatomia & histologia , Meristema/genética , Meristema/ultraestrutura , Mutação/genética , Tamanho do Órgão/genética , Fenótipo , Plantas Geneticamente Modificadas , Ligação Proteica/genética , Transporte Proteico , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Frações Subcelulares/metabolismo , Fatores de Transcrição/metabolismo
7.
Plant J ; 66(6): 1020-31, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21435046

RESUMO

The BASIC PENTACYSTEINE (BPC) proteins are a plant-specific transcription factor family that is present throughout land plants. The Arabidopsis BPC proteins have been categorized into three classes based on sequence similarity, and we demonstrate that there is functional overlap between classes. Single gene mutations produce no visible phenotypic effects, and severe morphological phenotypes occur only in higher order mutants between members of classes I and II, with the most severe phenotype observed in bpc1-1 bpc2 bpc4 bpc6 plants. These quadruple mutants are dwarfed and display small curled leaves, aberrant ovules, altered epidermal cells and reduced numbers of lateral roots. Affected processes include coordinated growth of cell layers, cell shape determination and timing of senescence. Disruption of BPC3 function rescues some aspects of the bpc1-1 bpc2 bpc4 bpc6 phenotype, indicating that BPC3 function may be antagonistic to other members of the family. Ethylene response is diminished in bpc1-1 bpc2 bpc4 bpc6 plants, although not all aspects of the phenotype can be explained by reduced ethylene sensitivity. Our data indicate that the BPC transcription factor family is integral for a wide range of processes that support normal growth and development.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Família Multigênica , Fatores de Transcrição/metabolismo , Alelos , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/ultraestrutura , Proteínas de Arabidopsis/genética , Clonagem Molecular , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Pleiotropia Genética , Hipocótilo/crescimento & desenvolvimento , Inflorescência/crescimento & desenvolvimento , Mutagênese Insercional , Óvulo Vegetal/crescimento & desenvolvimento , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/ultraestrutura , Raízes de Plantas/crescimento & desenvolvimento , Mutação Puntual , Regiões Promotoras Genéticas , Pseudogenes , Fatores de Transcrição/genética
8.
Plant J ; 37(3): 426-38, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14731261

RESUMO

INNER NO OUTER (INO) expression is limited to the abaxial cell layer of the incipient and developing outer integument in Arabidopsis ovules. Using deletion analysis of the previously defined INO promoter (P-INO), at least three distinct regions that contribute to the endogenous INO expression pattern were identified. One such positive element, designated POS9, which comprises at least three distinct subelements, was found to include sufficient information to duplicate the INO expression pattern when four or more copies were used in conjunction with a heterologous minimal promoter. While known regulators of INO, including INO, SUPERMAN, BELL1, and AINTEGUMENTA, did not detectably interact with POS9 in yeast one-hybrid assays, two groups of proteins that interact specifically with POS9 were identified in one-hybrid library screens. Members of one group include C2H2 zinc finger motifs. Members of the second group contain a novel, conserved DNA-binding region and were designated the BASIC PENTACYSTEINE (BPC) proteins on the basis of conserved features of this region. The BPC proteins are nuclear localized and specifically bind in vitro to GA dinucleotide repeats located within POS9. The widespread expression patterns of the BPCs and the large number of GA repeat potential target sequences in the Arabidopsis genome indicate that BPC proteins may affect expression of genes involved in a variety of plant processes.


Assuntos
Arabidopsis/genética , Sequências Reguladoras de Ácido Nucleico , Sequência de Aminoácidos , Sequência de Bases , DNA de Plantas , Ensaio de Desvio de Mobilidade Eletroforética , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Homologia de Sequência de Aminoácidos
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