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Michiel Vandenbussche - One of the best experts on this subject based on the ideXlab platform.
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Divergent Functional Diversification Patterns in the SEP/AGL6/AP1 MADS-box Transcription Factor Superclade
The Plant cell, 2019Co-Authors: Patrice Morel, Pierre Chambrier, Véronique Boltz, Sophy Chamot, Frédérique Rozier, Suzanne Rodrigues Bento, Christophe Trehin, Marie Monniaux, Jan Zethof, Michiel VandenbusscheAbstract:Members of SEPALLATA (SEP) and APETALA1 (AP1)/SQUAMOSA (SQUA) MADS-box transcription factor subfamilies play key roles in Floral organ identity determination and Floral meristem determinacy in the Rosid species Arabidopsis. Here, we present a functional characterization of the seven SEP/AGL6 and four AP1/SQUA genes in the distant Asterid species Petunia x hybrida petunia. Based on the analysis of single and higher order mutants, we report that the petunia SEP1/SEP2/SEP3 orthologs together with AGL6 encode classical SEP Floral organ identity and Floral termination functions, with a master role for the petunia SEP3 ortholog Floral BINDING PROTEIN 2 (FBP2). By contrast, the FBP9 subclade members FBP9 and FBP23, for which no clear ortholog is present in Arabidopsis, play a major role in determining Floral meristem identity together with FBP4, while contributing only moderately to Floral organ identity. In turn, the four members of the petunia AP1/SQUA subfamily redundantly are required for inflorescence meristem identity, and act as B-function repressors in the first Floral Whorl, together with BEN/ROB genes. Overall, these data together with studies in other species suggest major differences in the functional diversification of the SEP/AGL6 and AP1/SQUA MADS-box subfamilies during angiosperm evolution.
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Divergence of the Floral A-Function between an Asterid and a Rosid Species.
The Plant cell, 2017Co-Authors: Patrice Morel, Pierre Chambrier, Sophy Chamot, Frédérique Rozier, Christophe Trehin, Jan Zethof, Klaas Heijmans, Suzanne Rodrigues Bento, Aurélie C. M. Vialette-guiraud, Michiel VandenbusscheAbstract:The ABC model is widely used as a genetic framework for understanding Floral development and evolution. In this model, the A-function is required for the development of sepals and petals and to antagonize the C-function in the outer Floral Whorls. In the rosid species Arabidopsis thaliana, the AP2-type AP2 transcription factor represents a major A-function protein, but how the A-function is encoded in other species is not well understood. Here, we show that in the asterid species petunia (Petunia hybrida), AP2B/BLIND ENHANCER (BEN) confines the C-function to the inner petunia Floral Whorls, in parallel with the microRNA BLIND. BEN belongs to the TOE-type AP2 gene family, members of which control flowering time in Arabidopsis. In turn, we demonstrate that the petunia AP2-type REPRESSOR OF B-FUNCTION (ROB) genes repress the B-function (but not the C-function) in the first Floral Whorl, together with BEN. We propose a combinatorial model for patterning the B- and C-functions, leading to the homeotic conversion of sepals into petals, carpels, or stamens, depending on the genetic context. Combined with earlier results, our findings suggest that the molecular mechanisms controlling the spatial restriction of the Floral organ identity genes are more diverse than the well-conserved B and C Floral organ identity functions.
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toward the analysis of the petunia mads box gene family by reverse and forward transposon insertion mutagenesis approaches b c and d Floral organ identity functions require sepallata like mads box genes in petunia
The Plant Cell, 2003Co-Authors: Michiel Vandenbussche, Silvia Ferrario, Gerco C. Angenent, Johannes Zethof, Erik Souer, Ronald Koes, Giovanni Battista Tornielli, Mario Pezzotti, Tom GeratsAbstract:We have initiated a systematic functional analysis of the MADS box, intervening region, K domain, C domain-type MADS box gene family in petunia. The starting point for this has been a reverse-genetics approach, aiming to select for transposon insertions into any MADS box gene. We have developed and applied a family signature insertion screening protocol that is highly suited for this purpose, resulting in the isolation of 32 insertion mutants in 20 different MADS box genes. In addition, we identified three more MADS box gene insertion mutants using a candidate-gene approach. The defined insertion lines provide a sound foundation for a systematic functional analysis of the MADS box gene family in petunia. Here, we focus on the analysis of Floral Binding Protein2 (FBP2) and FBP5 genes that encode the E-function, which in Arabidopsis has been shown to be required for B and C Floral organ identity functions. fbp2 mutants display sepaloid petals and ectopic inflorescences originating from the third Floral Whorl, whereas fbp5 mutants appear as wild type. In fbp2 fbp5 double mutants, reversion of Floral organs to leaf-like organs is increased further. Strikingly, ovules are replaced by leaf-like structures in the carpel, indicating that in addition to the B- and C-functions, the D-function, which specifies ovule development, requires E-function activity. Finally, we compare our data with results obtained using cosuppression approaches and conclude that the latter might be less suited for assigning functions to individual members of the MADS box gene family.
Elliot M Meyerowitz - One of the best experts on this subject based on the ideXlab platform.
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role of superman in maintaining arabidopsis Floral Whorl boundaries
Nature, 1995Co-Authors: Hajime Sakai, Leonard Medrano, Elliot M MeyerowitzAbstract:The Arabidopsis gene SUPERMAN (SUP) is necessary for the proper spatial development of reproductive Floral tissues1–3. Recessive mutations cause extra stamens to form interior to the normal third Whorl stamens, at the expense of fourth Whorl carpel development. The mutant phenotype is associated with the ectopic expression of the B function genes, AP3 and PI, in the altered Floral region, closer to the centre of the flower than in the wild type, and ap3 sup and pi sup double mutants exhibit a phenotype similar to ap3 and pi single mutants. These findings led to SUP being interpreted as an upstream negative regulator of the B function organ-identity genes, acting in the fourth Whorl, to establish a boundary between stamen and carpel Whorls. Here we show, using molecular cloning and analysis, that it is expressed in the third Whorl and acts to maintain this boundary in developing flowers. The putative SUPERMAN protein contains one zinc-finger and a region resembling a basic leucine zipper motif, suggesting a function in transcriptional regulation.
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Expression of the Arabidopsis Floral homeotic gene AGAMOUS is restricted to specific cell types late in flower development.
The Plant cell, 1991Co-Authors: John L. Bowman, Gary N. Drews, Elliot M MeyerowitzAbstract:Mutations in the AGAMOUS (AG) gene cause transformations in two adjacent Whorls of the Arabidopsis flower. Petals develop in the third Floral Whorl rather than the normal stamens, and the cells that would normally develop into the fourth Whorl gynoecium behave as if they constituted an ag flower primordium. Early in flower development, AG RNA is evenly distributed throughout third and fourth Whorl organ primordia but is not present in the organ primordia of Whorls one and two. In contrast to the early expression pattern, later in flower development, AG RNA is restricted to specific cell types within the stamens and carpels as cellular differentiation occurs in those organs. Ectopic AG expression patterns in flowers mutant for the Floral homeotic gene APETELA2 (AP2), which regulates early AG expression, suggest that the late AG expression is not directly dependent on AP2 activity.
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negative regulation of the arabidopsis homeotic gene agamous by the apetala2 product
Cell, 1991Co-Authors: Gary N. Drews, John L. Bowman, Elliot M MeyerowitzAbstract:We characterized the distribution of AGAMOUS (AG) RNA during early flower development in Arabidopsis. Mutations in this homeotic gene cause the transformation of stamens to petals in Floral Whorl 3 and of carpels to another ag flower in Floral Whorl 4. We found that AG RNA is present in the stamen and carpel primordia but is undetectable in sepal and petal primordia throughout early wild-type flower development, consistent with the mutant phenotype. We also analyzed the distribution of AG RNA in apetela2 (ap2) mutant flowers. AP2 is a Floral homeotic gene that is necessary for the normal development of sepals and petals in Floral Whorls 1 and 2. In ap2 mutant flowers, AG RNA is present in the organ primordia of all Floral Whorls. These observations show that the expression patterns of the Arabidopsis Floral homeotic genes are in part established by regulatory interactions between these genes.
Patrice Morel - One of the best experts on this subject based on the ideXlab platform.
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Divergent Functional Diversification Patterns in the SEP/AGL6/AP1 MADS-box Transcription Factor Superclade
The Plant cell, 2019Co-Authors: Patrice Morel, Pierre Chambrier, Véronique Boltz, Sophy Chamot, Frédérique Rozier, Suzanne Rodrigues Bento, Christophe Trehin, Marie Monniaux, Jan Zethof, Michiel VandenbusscheAbstract:Members of SEPALLATA (SEP) and APETALA1 (AP1)/SQUAMOSA (SQUA) MADS-box transcription factor subfamilies play key roles in Floral organ identity determination and Floral meristem determinacy in the Rosid species Arabidopsis. Here, we present a functional characterization of the seven SEP/AGL6 and four AP1/SQUA genes in the distant Asterid species Petunia x hybrida petunia. Based on the analysis of single and higher order mutants, we report that the petunia SEP1/SEP2/SEP3 orthologs together with AGL6 encode classical SEP Floral organ identity and Floral termination functions, with a master role for the petunia SEP3 ortholog Floral BINDING PROTEIN 2 (FBP2). By contrast, the FBP9 subclade members FBP9 and FBP23, for which no clear ortholog is present in Arabidopsis, play a major role in determining Floral meristem identity together with FBP4, while contributing only moderately to Floral organ identity. In turn, the four members of the petunia AP1/SQUA subfamily redundantly are required for inflorescence meristem identity, and act as B-function repressors in the first Floral Whorl, together with BEN/ROB genes. Overall, these data together with studies in other species suggest major differences in the functional diversification of the SEP/AGL6 and AP1/SQUA MADS-box subfamilies during angiosperm evolution.
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Divergence of the Floral A-Function between an Asterid and a Rosid Species.
The Plant cell, 2017Co-Authors: Patrice Morel, Pierre Chambrier, Sophy Chamot, Frédérique Rozier, Christophe Trehin, Jan Zethof, Klaas Heijmans, Suzanne Rodrigues Bento, Aurélie C. M. Vialette-guiraud, Michiel VandenbusscheAbstract:The ABC model is widely used as a genetic framework for understanding Floral development and evolution. In this model, the A-function is required for the development of sepals and petals and to antagonize the C-function in the outer Floral Whorls. In the rosid species Arabidopsis thaliana, the AP2-type AP2 transcription factor represents a major A-function protein, but how the A-function is encoded in other species is not well understood. Here, we show that in the asterid species petunia (Petunia hybrida), AP2B/BLIND ENHANCER (BEN) confines the C-function to the inner petunia Floral Whorls, in parallel with the microRNA BLIND. BEN belongs to the TOE-type AP2 gene family, members of which control flowering time in Arabidopsis. In turn, we demonstrate that the petunia AP2-type REPRESSOR OF B-FUNCTION (ROB) genes repress the B-function (but not the C-function) in the first Floral Whorl, together with BEN. We propose a combinatorial model for patterning the B- and C-functions, leading to the homeotic conversion of sepals into petals, carpels, or stamens, depending on the genetic context. Combined with earlier results, our findings suggest that the molecular mechanisms controlling the spatial restriction of the Floral organ identity genes are more diverse than the well-conserved B and C Floral organ identity functions.
Pierre Chambrier - One of the best experts on this subject based on the ideXlab platform.
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Divergent Functional Diversification Patterns in the SEP/AGL6/AP1 MADS-box Transcription Factor Superclade
The Plant cell, 2019Co-Authors: Patrice Morel, Pierre Chambrier, Véronique Boltz, Sophy Chamot, Frédérique Rozier, Suzanne Rodrigues Bento, Christophe Trehin, Marie Monniaux, Jan Zethof, Michiel VandenbusscheAbstract:Members of SEPALLATA (SEP) and APETALA1 (AP1)/SQUAMOSA (SQUA) MADS-box transcription factor subfamilies play key roles in Floral organ identity determination and Floral meristem determinacy in the Rosid species Arabidopsis. Here, we present a functional characterization of the seven SEP/AGL6 and four AP1/SQUA genes in the distant Asterid species Petunia x hybrida petunia. Based on the analysis of single and higher order mutants, we report that the petunia SEP1/SEP2/SEP3 orthologs together with AGL6 encode classical SEP Floral organ identity and Floral termination functions, with a master role for the petunia SEP3 ortholog Floral BINDING PROTEIN 2 (FBP2). By contrast, the FBP9 subclade members FBP9 and FBP23, for which no clear ortholog is present in Arabidopsis, play a major role in determining Floral meristem identity together with FBP4, while contributing only moderately to Floral organ identity. In turn, the four members of the petunia AP1/SQUA subfamily redundantly are required for inflorescence meristem identity, and act as B-function repressors in the first Floral Whorl, together with BEN/ROB genes. Overall, these data together with studies in other species suggest major differences in the functional diversification of the SEP/AGL6 and AP1/SQUA MADS-box subfamilies during angiosperm evolution.
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Divergence of the Floral A-Function between an Asterid and a Rosid Species.
The Plant cell, 2017Co-Authors: Patrice Morel, Pierre Chambrier, Sophy Chamot, Frédérique Rozier, Christophe Trehin, Jan Zethof, Klaas Heijmans, Suzanne Rodrigues Bento, Aurélie C. M. Vialette-guiraud, Michiel VandenbusscheAbstract:The ABC model is widely used as a genetic framework for understanding Floral development and evolution. In this model, the A-function is required for the development of sepals and petals and to antagonize the C-function in the outer Floral Whorls. In the rosid species Arabidopsis thaliana, the AP2-type AP2 transcription factor represents a major A-function protein, but how the A-function is encoded in other species is not well understood. Here, we show that in the asterid species petunia (Petunia hybrida), AP2B/BLIND ENHANCER (BEN) confines the C-function to the inner petunia Floral Whorls, in parallel with the microRNA BLIND. BEN belongs to the TOE-type AP2 gene family, members of which control flowering time in Arabidopsis. In turn, we demonstrate that the petunia AP2-type REPRESSOR OF B-FUNCTION (ROB) genes repress the B-function (but not the C-function) in the first Floral Whorl, together with BEN. We propose a combinatorial model for patterning the B- and C-functions, leading to the homeotic conversion of sepals into petals, carpels, or stamens, depending on the genetic context. Combined with earlier results, our findings suggest that the molecular mechanisms controlling the spatial restriction of the Floral organ identity genes are more diverse than the well-conserved B and C Floral organ identity functions.
Jan Zethof - One of the best experts on this subject based on the ideXlab platform.
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Divergent Functional Diversification Patterns in the SEP/AGL6/AP1 MADS-box Transcription Factor Superclade
The Plant cell, 2019Co-Authors: Patrice Morel, Pierre Chambrier, Véronique Boltz, Sophy Chamot, Frédérique Rozier, Suzanne Rodrigues Bento, Christophe Trehin, Marie Monniaux, Jan Zethof, Michiel VandenbusscheAbstract:Members of SEPALLATA (SEP) and APETALA1 (AP1)/SQUAMOSA (SQUA) MADS-box transcription factor subfamilies play key roles in Floral organ identity determination and Floral meristem determinacy in the Rosid species Arabidopsis. Here, we present a functional characterization of the seven SEP/AGL6 and four AP1/SQUA genes in the distant Asterid species Petunia x hybrida petunia. Based on the analysis of single and higher order mutants, we report that the petunia SEP1/SEP2/SEP3 orthologs together with AGL6 encode classical SEP Floral organ identity and Floral termination functions, with a master role for the petunia SEP3 ortholog Floral BINDING PROTEIN 2 (FBP2). By contrast, the FBP9 subclade members FBP9 and FBP23, for which no clear ortholog is present in Arabidopsis, play a major role in determining Floral meristem identity together with FBP4, while contributing only moderately to Floral organ identity. In turn, the four members of the petunia AP1/SQUA subfamily redundantly are required for inflorescence meristem identity, and act as B-function repressors in the first Floral Whorl, together with BEN/ROB genes. Overall, these data together with studies in other species suggest major differences in the functional diversification of the SEP/AGL6 and AP1/SQUA MADS-box subfamilies during angiosperm evolution.
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Divergence of the Floral A-Function between an Asterid and a Rosid Species.
The Plant cell, 2017Co-Authors: Patrice Morel, Pierre Chambrier, Sophy Chamot, Frédérique Rozier, Christophe Trehin, Jan Zethof, Klaas Heijmans, Suzanne Rodrigues Bento, Aurélie C. M. Vialette-guiraud, Michiel VandenbusscheAbstract:The ABC model is widely used as a genetic framework for understanding Floral development and evolution. In this model, the A-function is required for the development of sepals and petals and to antagonize the C-function in the outer Floral Whorls. In the rosid species Arabidopsis thaliana, the AP2-type AP2 transcription factor represents a major A-function protein, but how the A-function is encoded in other species is not well understood. Here, we show that in the asterid species petunia (Petunia hybrida), AP2B/BLIND ENHANCER (BEN) confines the C-function to the inner petunia Floral Whorls, in parallel with the microRNA BLIND. BEN belongs to the TOE-type AP2 gene family, members of which control flowering time in Arabidopsis. In turn, we demonstrate that the petunia AP2-type REPRESSOR OF B-FUNCTION (ROB) genes repress the B-function (but not the C-function) in the first Floral Whorl, together with BEN. We propose a combinatorial model for patterning the B- and C-functions, leading to the homeotic conversion of sepals into petals, carpels, or stamens, depending on the genetic context. Combined with earlier results, our findings suggest that the molecular mechanisms controlling the spatial restriction of the Floral organ identity genes are more diverse than the well-conserved B and C Floral organ identity functions.