The Experts below are selected from a list of 141 Experts worldwide ranked by ideXlab platform
Paula Elomaa - One of the best experts on this subject based on the ideXlab platform.
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TCP and MADS-box transcription factor networks regulate heteromorphic flower type identity in Gerbera hybrida
Plant physiology, 2020Co-Authors: Yafei Zhao, Anneke S Rijpkema, Teemu H Teeri, Victor A. Albert, Suvi K. Broholm, Feng Wang, Tianying Lan, Paula ElomaaAbstract:The large sunflower family, Asteraceae, is characterized by compressed, flower-like inflorescences that may bear phenotypically distinct flower types. The CYCLOIDEA (CYC)/TEOSINTE BRANCHED1-like transcription factors (TFs) belonging to the TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) protein family are known to regulate bilateral symmetry in single flowers. In Asteraceae, they function at the inflorescence level, and were recruited to define differential flower type identities. Here, we identified upstream regulators of GhCYC3, a gene that specifies Ray flower identity at the flower head margin in the model plant Gerbera hybrida We discovered a previously unidentified expression domain and functional role for the paralogous CINCINNATA-like TCP proteins. They function upstream of GhCYC3 and affect the developmental delay of Marginal Ray primordia during their early ontogeny. At the level of single flowers, the Asteraceae CYC genes show a unique function in regulating the elongation of showy ventral ligules that play a major role in pollinator attraction. We discovered that during ligule development, the E class MADS-box TF GRCD5 activates GhCYC3 expression. We propose that the C class MADS-box TF GAGA1 contributes to stamen development upstream of GhCYC3 Our data demonstrate how interactions among and between the conserved floral regulators, TCP and MADS-box TFs, contribute to the evolution of the elaborate inflorescence architecture of Asteraceae.
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evolution and diversification of the cyc tb1 gene family in asteraceae a comparative study in gerbera mutisieae and sunflower heliantheae
Molecular Biology and Evolution, 2012Co-Authors: Sari Tahtiharju, Anneke S Rijpkema, Teemu H Teeri, Adrien Vetterli, Victor A. Albert, Paula ElomaaAbstract:Plant-specific TCP domain transcription factors have been shown to regulate morphological novelties during plant evolution, including the complex architecture of the Asteraceae inflorescence that involves different types of flowers. We conducted comparative analysis of the CYCLOIDEA/TEOSINTE BRANCHED1 (CYC/TB1) gene family in Gerbera hybrida (gerbera) and Helianthus annuus (sunflower), two species that represent distant tribes within Asteraceae. Our data confirm that the CYC/TB1 gene family has expanded in Asteraceae, a condition that appears to be connected with the increased developmental complexity and evolutionary success of this large plant family. Phylogenetic analysis of the CYC/TB1 gene family revealed both shared and lineage-specific duplications in gerbera and sunflower, corresponding to the three gene lineages previously identified as specific to core eudicots: CYC1, CYC2, and CYC3. Expression analyses of early stages of flower primordia development indicated that especially within the CYC2 clade, with the greatest number of secondary gene duplications, gene expression patterns are conserved between the species and associated with flower and inflorescence development. All sunflower and gerbera CYC2 clade genes showed differential expression between developing flower types, being upregulated in Marginal Ray (and trans) flowers. One gene in gerbera (GhCYC3) and two in sunflower (HaCYC2d and HaCYC2c) were indicated to be strong candidates as regulators of Ray flower identity, a function that is specific for Asteraceae. Our data further showed that other CYC2 clade genes are likely to have more specialized functions at the level of single flowers, including the late functions in floral reproductive organs that may be more conserved across plant families. The expression patterns of CYC1 and CYC3 clade genes showed more differences between the two species but still pointed to possible conserved functions during vegetative plant development. Pairwise protein– protein interaction assays gave the first molecular evidence that CYC/TB1-like proteins function in complexes. Compared with sunflower, the gerbera proteins showed higher capacity for dimerization, between as well as within CYC clades. Our data from two distant species within the Asteraceae suggest that the expansion and the apparent conservation of especially the CYC2 clade CYC/TB1-like genes are associated with the evolution of the increased complexity of the Asteraceae inflorescence architecture.
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Evolution and Diversification of the CYC/TB1 Gene Family in Asteraceae—A Comparative Study in Gerbera (Mutisieae) and Sunflower (Heliantheae)
Molecular biology and evolution, 2011Co-Authors: Sari Tahtiharju, Anneke S Rijpkema, Teemu H Teeri, Adrien Vetterli, Victor A. Albert, Paula ElomaaAbstract:Plant-specific TCP domain transcription factors have been shown to regulate morphological novelties during plant evolution, including the complex architecture of the Asteraceae inflorescence that involves different types of flowers. We conducted comparative analysis of the CYCLOIDEA/TEOSINTE BRANCHED1 (CYC/TB1) gene family in Gerbera hybrida (gerbera) and Helianthus annuus (sunflower), two species that represent distant tribes within Asteraceae. Our data confirm that the CYC/TB1 gene family has expanded in Asteraceae, a condition that appears to be connected with the increased developmental complexity and evolutionary success of this large plant family. Phylogenetic analysis of the CYC/TB1 gene family revealed both shared and lineage-specific duplications in gerbera and sunflower, corresponding to the three gene lineages previously identified as specific to core eudicots: CYC1, CYC2, and CYC3. Expression analyses of early stages of flower primordia development indicated that especially within the CYC2 clade, with the greatest number of secondary gene duplications, gene expression patterns are conserved between the species and associated with flower and inflorescence development. All sunflower and gerbera CYC2 clade genes showed differential expression between developing flower types, being upregulated in Marginal Ray (and trans) flowers. One gene in gerbera (GhCYC3) and two in sunflower (HaCYC2d and HaCYC2c) were indicated to be strong candidates as regulators of Ray flower identity, a function that is specific for Asteraceae. Our data further showed that other CYC2 clade genes are likely to have more specialized functions at the level of single flowers, including the late functions in floral reproductive organs that may be more conserved across plant families. The expression patterns of CYC1 and CYC3 clade genes showed more differences between the two species but still pointed to possible conserved functions during vegetative plant development. Pairwise protein– protein interaction assays gave the first molecular evidence that CYC/TB1-like proteins function in complexes. Compared with sunflower, the gerbera proteins showed higher capacity for dimerization, between as well as within CYC clades. Our data from two distant species within the Asteraceae suggest that the expansion and the apparent conservation of especially the CYC2 clade CYC/TB1-like genes are associated with the evolution of the increased complexity of the Asteraceae inflorescence architecture.
Alfredo Dubra - One of the best experts on this subject based on the ideXlab platform.
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Design of two spherical mirror unobscured relay telescopes using nodal aberration theory.
Optics express, 2019Co-Authors: Samuel Steven, Julie L. Bentley, Alfredo DubraAbstract:Nodal aberration theory is used to calculate the third-order aberrations that result in image blur for an unobscured modified 4f relay (2f1 + 2f2) formed by two tilted spherical mirrors for objects at infinity (infinite conjugate) and near the front focal plane of the first mirror (finite conjugate). The field-averaged wavefront variance containing only non-rotationally symmetric aberration coefficients is then proposed as an optimization metric. Analytical and Ray tracing optimization are demonstrated through sample designs. The particular cases of in-plane and orthogonal folding of the optical axis Ray are discussed, followed by an analysis of a modified 2f1 + 2f2 relay in which the distance of the first mirror to the object or pupil is allowed to vary for aberration correction. The sensitivity of the infinite conjugate 2f1 + 2f2 relay to the input Marginal Ray angle is also examined. Finally, the optimization of multiple conjugate systems through a weighted combination of wavefront variances is proposed.
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first order design of off axis reflective ophthalmic adaptive optics systems using afocal telescopes
Optics Express, 2009Co-Authors: Armando Gomezvieyra, Alfredo Dubra, Daniel Malacarahernandez, David R WilliamsAbstract:Expressions for minimal astigmatism in image and pupil planes in off-axis afocal reflective telescopes formed by pairs of spherical mirrors are presented. These formulae which are derived from the Marginal Ray fan equation can be used for designing laser cavities, spectrographs and adaptive optics retinal imaging systems. The use, range and validity of these formulae are limited by spherical aberration and coma for small and large angles respectively. This is discussed using examples from adaptive optics retinal imaging systems. The performance of the resulting optical designs are evaluated and compared against the configurations with minimal wavefront RMS, using the defocus-corrected wavefront RMS as a metric.
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First-order design of off-axis reflective ophthalmic adaptive optics systems using afocal telescopes
Seventh Symposium Optics in Industry, 2009Co-Authors: Armando Gómez-vieyra, Alfredo Dubra, David R Williams, Daniel Malacara-hernándezAbstract:Scanning laser ophthalmoscopes (SLOs) and optical coherence tomographs are the state-of-the-art retinal imaging instruments, and are essential for early and reliable diagnosis of eye disease. Recently, with the incorporation of adaptive optics (AO), these instruments have started to deliver near diffraction-limited performance in both humans and animal models, enabling the resolution of the retinal ganglion cell bodies, their processes, the cone photoreceptor and the retinal pigment epithelial cells mosaics. Unfortunately, these novel instruments have not delivered consistent performance across human subjects and animal models. One of the limitations of current instruments is the astigmatism in the pupil and imaging planes, which degrades image quality, by preventing the wavefront sensor from measuring aberrations with high spatial content. This astigmatism is introduced by the sequence of off-axis reflective elements, typically spherical mirrors, used for relaying pupil and imaging planes. Expressions for minimal astigmatism on the image and pupil planes in off-axis reflective afocal telescopes formed by pairs of spherical mirrors are presented. The formulas, derived from the Marginal Ray fans equation, are valid for small angles of incidence (≤15°), and can be used to design laser cavities, spectrographs and vision adaptive optics systems. An example related to this last application is discussed.
Sari Tahtiharju - One of the best experts on this subject based on the ideXlab platform.
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evolution and diversification of the cyc tb1 gene family in asteraceae a comparative study in gerbera mutisieae and sunflower heliantheae
Molecular Biology and Evolution, 2012Co-Authors: Sari Tahtiharju, Anneke S Rijpkema, Teemu H Teeri, Adrien Vetterli, Victor A. Albert, Paula ElomaaAbstract:Plant-specific TCP domain transcription factors have been shown to regulate morphological novelties during plant evolution, including the complex architecture of the Asteraceae inflorescence that involves different types of flowers. We conducted comparative analysis of the CYCLOIDEA/TEOSINTE BRANCHED1 (CYC/TB1) gene family in Gerbera hybrida (gerbera) and Helianthus annuus (sunflower), two species that represent distant tribes within Asteraceae. Our data confirm that the CYC/TB1 gene family has expanded in Asteraceae, a condition that appears to be connected with the increased developmental complexity and evolutionary success of this large plant family. Phylogenetic analysis of the CYC/TB1 gene family revealed both shared and lineage-specific duplications in gerbera and sunflower, corresponding to the three gene lineages previously identified as specific to core eudicots: CYC1, CYC2, and CYC3. Expression analyses of early stages of flower primordia development indicated that especially within the CYC2 clade, with the greatest number of secondary gene duplications, gene expression patterns are conserved between the species and associated with flower and inflorescence development. All sunflower and gerbera CYC2 clade genes showed differential expression between developing flower types, being upregulated in Marginal Ray (and trans) flowers. One gene in gerbera (GhCYC3) and two in sunflower (HaCYC2d and HaCYC2c) were indicated to be strong candidates as regulators of Ray flower identity, a function that is specific for Asteraceae. Our data further showed that other CYC2 clade genes are likely to have more specialized functions at the level of single flowers, including the late functions in floral reproductive organs that may be more conserved across plant families. The expression patterns of CYC1 and CYC3 clade genes showed more differences between the two species but still pointed to possible conserved functions during vegetative plant development. Pairwise protein– protein interaction assays gave the first molecular evidence that CYC/TB1-like proteins function in complexes. Compared with sunflower, the gerbera proteins showed higher capacity for dimerization, between as well as within CYC clades. Our data from two distant species within the Asteraceae suggest that the expansion and the apparent conservation of especially the CYC2 clade CYC/TB1-like genes are associated with the evolution of the increased complexity of the Asteraceae inflorescence architecture.
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Evolution and Diversification of the CYC/TB1 Gene Family in Asteraceae—A Comparative Study in Gerbera (Mutisieae) and Sunflower (Heliantheae)
Molecular biology and evolution, 2011Co-Authors: Sari Tahtiharju, Anneke S Rijpkema, Teemu H Teeri, Adrien Vetterli, Victor A. Albert, Paula ElomaaAbstract:Plant-specific TCP domain transcription factors have been shown to regulate morphological novelties during plant evolution, including the complex architecture of the Asteraceae inflorescence that involves different types of flowers. We conducted comparative analysis of the CYCLOIDEA/TEOSINTE BRANCHED1 (CYC/TB1) gene family in Gerbera hybrida (gerbera) and Helianthus annuus (sunflower), two species that represent distant tribes within Asteraceae. Our data confirm that the CYC/TB1 gene family has expanded in Asteraceae, a condition that appears to be connected with the increased developmental complexity and evolutionary success of this large plant family. Phylogenetic analysis of the CYC/TB1 gene family revealed both shared and lineage-specific duplications in gerbera and sunflower, corresponding to the three gene lineages previously identified as specific to core eudicots: CYC1, CYC2, and CYC3. Expression analyses of early stages of flower primordia development indicated that especially within the CYC2 clade, with the greatest number of secondary gene duplications, gene expression patterns are conserved between the species and associated with flower and inflorescence development. All sunflower and gerbera CYC2 clade genes showed differential expression between developing flower types, being upregulated in Marginal Ray (and trans) flowers. One gene in gerbera (GhCYC3) and two in sunflower (HaCYC2d and HaCYC2c) were indicated to be strong candidates as regulators of Ray flower identity, a function that is specific for Asteraceae. Our data further showed that other CYC2 clade genes are likely to have more specialized functions at the level of single flowers, including the late functions in floral reproductive organs that may be more conserved across plant families. The expression patterns of CYC1 and CYC3 clade genes showed more differences between the two species but still pointed to possible conserved functions during vegetative plant development. Pairwise protein– protein interaction assays gave the first molecular evidence that CYC/TB1-like proteins function in complexes. Compared with sunflower, the gerbera proteins showed higher capacity for dimerization, between as well as within CYC clades. Our data from two distant species within the Asteraceae suggest that the expansion and the apparent conservation of especially the CYC2 clade CYC/TB1-like genes are associated with the evolution of the increased complexity of the Asteraceae inflorescence architecture.
Anneke S Rijpkema - One of the best experts on this subject based on the ideXlab platform.
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TCP and MADS-box transcription factor networks regulate heteromorphic flower type identity in Gerbera hybrida
Plant physiology, 2020Co-Authors: Yafei Zhao, Anneke S Rijpkema, Teemu H Teeri, Victor A. Albert, Suvi K. Broholm, Feng Wang, Tianying Lan, Paula ElomaaAbstract:The large sunflower family, Asteraceae, is characterized by compressed, flower-like inflorescences that may bear phenotypically distinct flower types. The CYCLOIDEA (CYC)/TEOSINTE BRANCHED1-like transcription factors (TFs) belonging to the TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) protein family are known to regulate bilateral symmetry in single flowers. In Asteraceae, they function at the inflorescence level, and were recruited to define differential flower type identities. Here, we identified upstream regulators of GhCYC3, a gene that specifies Ray flower identity at the flower head margin in the model plant Gerbera hybrida We discovered a previously unidentified expression domain and functional role for the paralogous CINCINNATA-like TCP proteins. They function upstream of GhCYC3 and affect the developmental delay of Marginal Ray primordia during their early ontogeny. At the level of single flowers, the Asteraceae CYC genes show a unique function in regulating the elongation of showy ventral ligules that play a major role in pollinator attraction. We discovered that during ligule development, the E class MADS-box TF GRCD5 activates GhCYC3 expression. We propose that the C class MADS-box TF GAGA1 contributes to stamen development upstream of GhCYC3 Our data demonstrate how interactions among and between the conserved floral regulators, TCP and MADS-box TFs, contribute to the evolution of the elaborate inflorescence architecture of Asteraceae.
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evolution and diversification of the cyc tb1 gene family in asteraceae a comparative study in gerbera mutisieae and sunflower heliantheae
Molecular Biology and Evolution, 2012Co-Authors: Sari Tahtiharju, Anneke S Rijpkema, Teemu H Teeri, Adrien Vetterli, Victor A. Albert, Paula ElomaaAbstract:Plant-specific TCP domain transcription factors have been shown to regulate morphological novelties during plant evolution, including the complex architecture of the Asteraceae inflorescence that involves different types of flowers. We conducted comparative analysis of the CYCLOIDEA/TEOSINTE BRANCHED1 (CYC/TB1) gene family in Gerbera hybrida (gerbera) and Helianthus annuus (sunflower), two species that represent distant tribes within Asteraceae. Our data confirm that the CYC/TB1 gene family has expanded in Asteraceae, a condition that appears to be connected with the increased developmental complexity and evolutionary success of this large plant family. Phylogenetic analysis of the CYC/TB1 gene family revealed both shared and lineage-specific duplications in gerbera and sunflower, corresponding to the three gene lineages previously identified as specific to core eudicots: CYC1, CYC2, and CYC3. Expression analyses of early stages of flower primordia development indicated that especially within the CYC2 clade, with the greatest number of secondary gene duplications, gene expression patterns are conserved between the species and associated with flower and inflorescence development. All sunflower and gerbera CYC2 clade genes showed differential expression between developing flower types, being upregulated in Marginal Ray (and trans) flowers. One gene in gerbera (GhCYC3) and two in sunflower (HaCYC2d and HaCYC2c) were indicated to be strong candidates as regulators of Ray flower identity, a function that is specific for Asteraceae. Our data further showed that other CYC2 clade genes are likely to have more specialized functions at the level of single flowers, including the late functions in floral reproductive organs that may be more conserved across plant families. The expression patterns of CYC1 and CYC3 clade genes showed more differences between the two species but still pointed to possible conserved functions during vegetative plant development. Pairwise protein– protein interaction assays gave the first molecular evidence that CYC/TB1-like proteins function in complexes. Compared with sunflower, the gerbera proteins showed higher capacity for dimerization, between as well as within CYC clades. Our data from two distant species within the Asteraceae suggest that the expansion and the apparent conservation of especially the CYC2 clade CYC/TB1-like genes are associated with the evolution of the increased complexity of the Asteraceae inflorescence architecture.
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Evolution and Diversification of the CYC/TB1 Gene Family in Asteraceae—A Comparative Study in Gerbera (Mutisieae) and Sunflower (Heliantheae)
Molecular biology and evolution, 2011Co-Authors: Sari Tahtiharju, Anneke S Rijpkema, Teemu H Teeri, Adrien Vetterli, Victor A. Albert, Paula ElomaaAbstract:Plant-specific TCP domain transcription factors have been shown to regulate morphological novelties during plant evolution, including the complex architecture of the Asteraceae inflorescence that involves different types of flowers. We conducted comparative analysis of the CYCLOIDEA/TEOSINTE BRANCHED1 (CYC/TB1) gene family in Gerbera hybrida (gerbera) and Helianthus annuus (sunflower), two species that represent distant tribes within Asteraceae. Our data confirm that the CYC/TB1 gene family has expanded in Asteraceae, a condition that appears to be connected with the increased developmental complexity and evolutionary success of this large plant family. Phylogenetic analysis of the CYC/TB1 gene family revealed both shared and lineage-specific duplications in gerbera and sunflower, corresponding to the three gene lineages previously identified as specific to core eudicots: CYC1, CYC2, and CYC3. Expression analyses of early stages of flower primordia development indicated that especially within the CYC2 clade, with the greatest number of secondary gene duplications, gene expression patterns are conserved between the species and associated with flower and inflorescence development. All sunflower and gerbera CYC2 clade genes showed differential expression between developing flower types, being upregulated in Marginal Ray (and trans) flowers. One gene in gerbera (GhCYC3) and two in sunflower (HaCYC2d and HaCYC2c) were indicated to be strong candidates as regulators of Ray flower identity, a function that is specific for Asteraceae. Our data further showed that other CYC2 clade genes are likely to have more specialized functions at the level of single flowers, including the late functions in floral reproductive organs that may be more conserved across plant families. The expression patterns of CYC1 and CYC3 clade genes showed more differences between the two species but still pointed to possible conserved functions during vegetative plant development. Pairwise protein– protein interaction assays gave the first molecular evidence that CYC/TB1-like proteins function in complexes. Compared with sunflower, the gerbera proteins showed higher capacity for dimerization, between as well as within CYC clades. Our data from two distant species within the Asteraceae suggest that the expansion and the apparent conservation of especially the CYC2 clade CYC/TB1-like genes are associated with the evolution of the increased complexity of the Asteraceae inflorescence architecture.
Teemu H Teeri - One of the best experts on this subject based on the ideXlab platform.
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TCP and MADS-box transcription factor networks regulate heteromorphic flower type identity in Gerbera hybrida
Plant physiology, 2020Co-Authors: Yafei Zhao, Anneke S Rijpkema, Teemu H Teeri, Victor A. Albert, Suvi K. Broholm, Feng Wang, Tianying Lan, Paula ElomaaAbstract:The large sunflower family, Asteraceae, is characterized by compressed, flower-like inflorescences that may bear phenotypically distinct flower types. The CYCLOIDEA (CYC)/TEOSINTE BRANCHED1-like transcription factors (TFs) belonging to the TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) protein family are known to regulate bilateral symmetry in single flowers. In Asteraceae, they function at the inflorescence level, and were recruited to define differential flower type identities. Here, we identified upstream regulators of GhCYC3, a gene that specifies Ray flower identity at the flower head margin in the model plant Gerbera hybrida We discovered a previously unidentified expression domain and functional role for the paralogous CINCINNATA-like TCP proteins. They function upstream of GhCYC3 and affect the developmental delay of Marginal Ray primordia during their early ontogeny. At the level of single flowers, the Asteraceae CYC genes show a unique function in regulating the elongation of showy ventral ligules that play a major role in pollinator attraction. We discovered that during ligule development, the E class MADS-box TF GRCD5 activates GhCYC3 expression. We propose that the C class MADS-box TF GAGA1 contributes to stamen development upstream of GhCYC3 Our data demonstrate how interactions among and between the conserved floral regulators, TCP and MADS-box TFs, contribute to the evolution of the elaborate inflorescence architecture of Asteraceae.
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evolution and diversification of the cyc tb1 gene family in asteraceae a comparative study in gerbera mutisieae and sunflower heliantheae
Molecular Biology and Evolution, 2012Co-Authors: Sari Tahtiharju, Anneke S Rijpkema, Teemu H Teeri, Adrien Vetterli, Victor A. Albert, Paula ElomaaAbstract:Plant-specific TCP domain transcription factors have been shown to regulate morphological novelties during plant evolution, including the complex architecture of the Asteraceae inflorescence that involves different types of flowers. We conducted comparative analysis of the CYCLOIDEA/TEOSINTE BRANCHED1 (CYC/TB1) gene family in Gerbera hybrida (gerbera) and Helianthus annuus (sunflower), two species that represent distant tribes within Asteraceae. Our data confirm that the CYC/TB1 gene family has expanded in Asteraceae, a condition that appears to be connected with the increased developmental complexity and evolutionary success of this large plant family. Phylogenetic analysis of the CYC/TB1 gene family revealed both shared and lineage-specific duplications in gerbera and sunflower, corresponding to the three gene lineages previously identified as specific to core eudicots: CYC1, CYC2, and CYC3. Expression analyses of early stages of flower primordia development indicated that especially within the CYC2 clade, with the greatest number of secondary gene duplications, gene expression patterns are conserved between the species and associated with flower and inflorescence development. All sunflower and gerbera CYC2 clade genes showed differential expression between developing flower types, being upregulated in Marginal Ray (and trans) flowers. One gene in gerbera (GhCYC3) and two in sunflower (HaCYC2d and HaCYC2c) were indicated to be strong candidates as regulators of Ray flower identity, a function that is specific for Asteraceae. Our data further showed that other CYC2 clade genes are likely to have more specialized functions at the level of single flowers, including the late functions in floral reproductive organs that may be more conserved across plant families. The expression patterns of CYC1 and CYC3 clade genes showed more differences between the two species but still pointed to possible conserved functions during vegetative plant development. Pairwise protein– protein interaction assays gave the first molecular evidence that CYC/TB1-like proteins function in complexes. Compared with sunflower, the gerbera proteins showed higher capacity for dimerization, between as well as within CYC clades. Our data from two distant species within the Asteraceae suggest that the expansion and the apparent conservation of especially the CYC2 clade CYC/TB1-like genes are associated with the evolution of the increased complexity of the Asteraceae inflorescence architecture.
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Evolution and Diversification of the CYC/TB1 Gene Family in Asteraceae—A Comparative Study in Gerbera (Mutisieae) and Sunflower (Heliantheae)
Molecular biology and evolution, 2011Co-Authors: Sari Tahtiharju, Anneke S Rijpkema, Teemu H Teeri, Adrien Vetterli, Victor A. Albert, Paula ElomaaAbstract:Plant-specific TCP domain transcription factors have been shown to regulate morphological novelties during plant evolution, including the complex architecture of the Asteraceae inflorescence that involves different types of flowers. We conducted comparative analysis of the CYCLOIDEA/TEOSINTE BRANCHED1 (CYC/TB1) gene family in Gerbera hybrida (gerbera) and Helianthus annuus (sunflower), two species that represent distant tribes within Asteraceae. Our data confirm that the CYC/TB1 gene family has expanded in Asteraceae, a condition that appears to be connected with the increased developmental complexity and evolutionary success of this large plant family. Phylogenetic analysis of the CYC/TB1 gene family revealed both shared and lineage-specific duplications in gerbera and sunflower, corresponding to the three gene lineages previously identified as specific to core eudicots: CYC1, CYC2, and CYC3. Expression analyses of early stages of flower primordia development indicated that especially within the CYC2 clade, with the greatest number of secondary gene duplications, gene expression patterns are conserved between the species and associated with flower and inflorescence development. All sunflower and gerbera CYC2 clade genes showed differential expression between developing flower types, being upregulated in Marginal Ray (and trans) flowers. One gene in gerbera (GhCYC3) and two in sunflower (HaCYC2d and HaCYC2c) were indicated to be strong candidates as regulators of Ray flower identity, a function that is specific for Asteraceae. Our data further showed that other CYC2 clade genes are likely to have more specialized functions at the level of single flowers, including the late functions in floral reproductive organs that may be more conserved across plant families. The expression patterns of CYC1 and CYC3 clade genes showed more differences between the two species but still pointed to possible conserved functions during vegetative plant development. Pairwise protein– protein interaction assays gave the first molecular evidence that CYC/TB1-like proteins function in complexes. Compared with sunflower, the gerbera proteins showed higher capacity for dimerization, between as well as within CYC clades. Our data from two distant species within the Asteraceae suggest that the expansion and the apparent conservation of especially the CYC2 clade CYC/TB1-like genes are associated with the evolution of the increased complexity of the Asteraceae inflorescence architecture.