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Sharma B, Kramer EM. Aquilegia B gene homologs promote petaloidy of the sepals and maintenance of the C domain boundary. EvoDevo 2017; 8:22. [PMID: 29209492 PMCID: PMC5704387 DOI: 10.1186/s13227-017-0085-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Accepted: 11/09/2017] [Indexed: 11/12/2022] Open
Abstract
The model Aquilegia coerulea x “Origami” possesses several interesting floral features, including petaloid sepals that are morphologically distinct from the true petals and a broad domain containing many whorls of stamens. We undertook the current study in an effort to understand the former trait, but additionally uncovered data that inform on the latter. The Aquilegia B gene homolog AqPI is shown to contribute to the production of anthocyanin in the first whorl sepals, although it has no major role in their morphology. Surprisingly, knockdown of AqPI in Aquilegia coerulea x “Origami” also reveals a role for the B class genes in maintaining the expression of the C gene homolog AqAG1 in the outer whorls of stamens. These findings suggest that the transference of pollinator function to the first whorl sepals included a non-homeotic recruitment of the B class genes to promote aspects of petaloidy. They also confirm results in several other Ranunculales that have revealed an unexpected regulatory connection between the B and C class genes.
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Affiliation(s)
- Bharti Sharma
- Department of Biological Sciences, California Polytechnic State University Pomona, 3801 West Temple Avenue, Pomona, CA 91768 USA
| | - Elena M Kramer
- Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Ave., Cambridge, MA 02138 USA
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Rocha de Almeida AM, Yockteng R, Specht CD. Evolution of petaloidy in the zingiberales: An assessment of the relationship between ultrastructure and gene expression patterns. Dev Dyn 2015; 244:1121-1132. [DOI: 10.1002/dvdy.24280] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 03/23/2015] [Accepted: 03/23/2015] [Indexed: 01/26/2023] Open
Affiliation(s)
- Ana Maria Rocha de Almeida
- Programa de Pós-Graduação em Genética e Biodiversidade, Universidade Federal da Bahia; Campus Ondina Salvador/BA Brazil
- Departments of Plant and Microbial Biology and Integrative Biology and the University and Jepson Herbaria; University of California; Berkeley California
| | - Roxana Yockteng
- Departments of Plant and Microbial Biology and Integrative Biology and the University and Jepson Herbaria; University of California; Berkeley California
- Corporación Colombiana de Investigación (CORPOICA); Bogotá Colombia
| | - Chelsea D. Specht
- Departments of Plant and Microbial Biology and Integrative Biology and the University and Jepson Herbaria; University of California; Berkeley California
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Landis JB, Ventura KL, Soltis DE, Soltis PS, Oppenheimer DG. Optical sectioning and 3D reconstructions as an alternative to scanning electron microscopy for analysis of cell shape. APPLICATIONS IN PLANT SCIENCES 2015; 3:apps1400112. [PMID: 25909040 PMCID: PMC4406833 DOI: 10.3732/apps.1400112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Accepted: 02/21/2015] [Indexed: 05/08/2023]
Abstract
PREMISE OF THE STUDY Visualizing flower epidermal cells is often desirable for investigating the interaction between flowers and their pollinators, in addition to the broader range of ecological interactions in which flowers are involved. We developed a protocol for visualizing petal epidermal cells without the limitations of the commonly used method of scanning electron microscopy (SEM). METHODS Flower material was collected and fixed in glutaraldehyde, followed by dehydration in an ethanol series. Flowers were dissected to collect petals, and subjected to a Histo-Clear series to remove the cuticle. Material was then stained with aniline blue, mounted on microscope slides, and imaged using a compound fluorescence microscope to obtain optical sections that were reconstructed into a 3D image. RESULTS This optical sectioning method yielded high-quality images of the petal epidermal cells with virtually no damage to cells. Flowers were processed in larger batches than are possible using common SEM methods. Also, flower size was not a limiting factor as often observed in SEM studies. Flowers up to 5 cm in length were processed and mounted for visualization. CONCLUSIONS This method requires no special equipment for sample preparation prior to imaging and should be seen as an alternative method to SEM.
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Affiliation(s)
- Jacob B. Landis
- Department of Biology, University of Florida, 876 Newell Drive, Gainesville, Florida 32611 USA
- Florida Museum of Natural History, University of Florida, 1659 Museum Road, Gainesville, Florida 32611 USA
- Author for correspondence:
| | - Kayla L. Ventura
- Florida Museum of Natural History, University of Florida, 1659 Museum Road, Gainesville, Florida 32611 USA
| | - Douglas E. Soltis
- Department of Biology, University of Florida, 876 Newell Drive, Gainesville, Florida 32611 USA
- Florida Museum of Natural History, University of Florida, 1659 Museum Road, Gainesville, Florida 32611 USA
| | - Pamela S. Soltis
- Florida Museum of Natural History, University of Florida, 1659 Museum Road, Gainesville, Florida 32611 USA
| | - David G. Oppenheimer
- Department of Biology, University of Florida, 876 Newell Drive, Gainesville, Florida 32611 USA
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Pabón-Mora N, Suárez-Baron H, Ambrose BA, González F. Flower Development and Perianth Identity Candidate Genes in the Basal Angiosperm Aristolochia fimbriata (Piperales: Aristolochiaceae). FRONTIERS IN PLANT SCIENCE 2015; 6:1095. [PMID: 26697047 PMCID: PMC4675851 DOI: 10.3389/fpls.2015.01095] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 11/22/2015] [Indexed: 05/21/2023]
Abstract
Aristolochia fimbriata (Aristolochiaceae: Piperales) exhibits highly synorganized flowers with a single convoluted structure forming a petaloid perianth that surrounds the gynostemium, putatively formed by the congenital fusion between stamens and the upper portion of the carpels. Here we present the flower development and morphology of A. fimbriata, together with the expression of the key regulatory genes that participate in flower development, particularly those likely controlling perianth identity. A. fimbriata is a member of the magnoliids, and thus gene expression detected for all ABCE MADS-box genes in this taxon, can also help to elucidate patterns of gene expression prior the independent duplications of these genes in eudicots and monocots. Using both floral development and anatomy in combination with the isolation of MADS-box gene homologs, gene phylogenetic analyses and expression studies (both by reverse transcription PCR and in situ hybridization), we present hypotheses on floral organ identity genes involved in the formation of this bizarre flower. We found that most MADS-box genes were expressed in vegetative and reproductive tissues with the exception of AfimSEP2, AfimAGL6, and AfimSTK transcripts that are only found in flowers and capsules but are not detected in leaves. Two genes show ubiquitous expression; AfimFUL that is found in all floral organs at all developmental stages as well as in leaves and capsules, and AfimAG that has low expression in leaves and is found in all floral organs at all stages with a considerable reduction of expression in the limb of anthetic flowers. Our results indicate that expression of AfimFUL is indicative of pleiotropic roles and not of a perianth identity specific function. On the other hand, expression of B-class genes, AfimAP3 and AfimPI, suggests their conserved role in stamen identity and corroborates that the perianth is sepal and not petal-derived. Our data also postulates an AGL6 ortholog as a candidate gene for sepal identity in the Aristolochiaceae and provides testable hypothesis for a modified ABCE model in synorganized magnoliid flowers.
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Affiliation(s)
- Natalia Pabón-Mora
- Instituto de Biología, Universidad de AntioquiaMedellín, Colombia
- The New York Botanical Garden, BronxNY, USA
- *Correspondence: Natalia Pabón-Mora,
| | | | | | - Favio González
- Instituto de Ciencias Naturales, Facultad de Ciencias, Universidad Nacional de ColombiaBogotá, Colombia
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LaRue NC, Sullivan AM, Di Stilio VS. Functional recapitulation of transitions in sexual systems by homeosis during the evolution of dioecy in Thalictrum. FRONTIERS IN PLANT SCIENCE 2013; 4:487. [PMID: 24348491 PMCID: PMC3842162 DOI: 10.3389/fpls.2013.00487] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 11/11/2013] [Indexed: 05/09/2023]
Abstract
Sexual systems are highly variable in flowering plants and an important contributor to floral diversity. The ranunculid genus Thalictrum is especially well-suited to study evolutionary transitions in sexual systems. Homeotic transformation of sexual organs (stamens and carpels) is a plausible mechanism for the transition from hermaphroditic to unisexual flowers in this lineage because flowers of dioecious species develop unisexually from inception. The single-copy gene PISTILLATA (PI) constitutes a likely candidate for rapid switches between stamen and carpel identity. Here, we first characterized the expression pattern of all B class genes in the dioecious species T. dioicum. As expected, all B class orthologs are expressed in stamens from the earliest stages. Certain AP3 lineages were also expressed late in sepal development. We then tested whether orthologs of PI could potentially control sexual system transitions in Thalictrum, by knocking-down their expression in T. dioicum and the hermaphroditic species T. thalictroides. In T. dioicum, we found that ThdPI-1/2 silencing caused stamen primordia to develop into carpels, resulting in male to female flower conversions. In T. thalictroides, we found that ThtPI silencing caused stamen primordia to develop into supernumerary carpels, resulting in hermaphroditic to female flower conversions. These phenotypes illustrate the ability for homeotic mutations to bring about sudden and potentially adaptive changes by altering the function of a single gene. We propose a two-step evolutionary model where transitions from hermaphroditic to unisexual plants in Thalictrum result from two independent mutations at a B class gene locus. Our PI knockdown experiments in T. thalictroides recapitulate the second step in this model: the evolution of female plants as a result of a loss-of-function mutation in a B class gene.
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Affiliation(s)
| | | | - Verónica S. Di Stilio
- *Correspondence: Verónica S. Di Stilio, Department of Biology, University of Washington, BOX 351800, Kincaid 24, Seattle, WA 98195-1800, USA e-mail:
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Brockington SF, Alvarez-Fernandez R, Landis JB, Alcorn K, Walker RH, Thomas MM, Hileman LC, Glover BJ. Evolutionary analysis of the MIXTA gene family highlights potential targets for the study of cellular differentiation. Mol Biol Evol 2012. [PMID: 23188591 DOI: 10.1093/molbev/mss260] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Differentiated epidermal cells such as trichomes and conical cells perform numerous essential functions in plant biology and are important for our understanding of developmental patterning and cell shape regulation. Many are also commercially significant, such as cotton fibers and trichomes that secrete pharmaceutically useful or herbivore-deterring compounds. Here, we focus on the phylogeny and evolution of the subgroup 9 R2R3 MYB gene transcription factors, which include the MIXTA gene, and that are important for the specification and regulation of plant cellular differentiation. We have sequenced 49 subgroup 9 R2R3 MYB genes from key experimental taxa and combined these sequences with those identified by an exhaustive bioinformatic search, to compile a data set of 223 subgroup 9 R2R3 MYB genes. Our phylogenetic analyses demonstrate, for the first time, the complex evolutionary history of the subgroup 9 R2R3 MYB genes. A duplication event is inferred before the origin of seed plants giving rise to two major gene lineages, here termed SBG9-A and SBG9-B. The evolutionary conservation of the SBG9-B gene lineage has not been previously recognized and its role in cellular differentiation is unknown, thus an entire clade of potential candidate genes for epidermal cell regulation remains to be explored. Using a heterologous transformation bioassay, we provide functional data that implicate members of the SBG9-B lineage in the specification of epidermal projections. Furthermore, we reveal numerous putative duplication events in both SBG9-A and SBG9-B lineages, resolving uncertainty about orthology and paralogy among the subgroup 9 R2R3 MYB genes. Finally, we provide a robust framework over which to interpret existing functional data and to direct ongoing comparative genetic research into the evolution of plant cellular diversity.
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Affiliation(s)
- Samuel F Brockington
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom.
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Hofer KA, Ruonala R, Albert VA. The double-corolla phenotype in the Hawaiian lobelioid genus Clermontia involves ectopic expression of PISTILLATA B-function MADS box gene homologs. EvoDevo 2012; 3:26. [PMID: 23116179 PMCID: PMC3564722 DOI: 10.1186/2041-9139-3-26] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 09/05/2012] [Indexed: 11/16/2022] Open
Abstract
Abstract Trial registration Clinical Trials.gov- NCT01710735 Significance and Innovations The present investigation is one of the first to examine the hypothesis of gross
muscle contractile inhibition due to the presence of diagnostically relevant MFTrPs.
Individuals suffering from clinically relevant levels of self-reported pain are able to tolerate maximum voluntary contraction testing, but delayed onset muscle soreness (DOMS) is a likely side-effect irrespective of symptom status. As a consequence, its confounding effect during subsequent testing must be taken into account.
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Affiliation(s)
- Katherine A Hofer
- Department of Biological Sciences, University at Buffalo, Buffalo, NY, 14260, USA.
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Smaczniak C, Immink RGH, Angenent GC, Kaufmann K. Developmental and evolutionary diversity of plant MADS-domain factors: insights from recent studies. Development 2012; 139:3081-98. [PMID: 22872082 DOI: 10.1242/dev.074674] [Citation(s) in RCA: 338] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Members of the MADS-box transcription factor family play essential roles in almost every developmental process in plants. Many MADS-box genes have conserved functions across the flowering plants, but some have acquired novel functions in specific species during evolution. The analyses of MADS-domain protein interactions and target genes have provided new insights into their molecular functions. Here, we review recent findings on MADS-box gene functions in Arabidopsis and discuss the evolutionary history and functional diversification of this gene family in plants. We also discuss possible mechanisms of action of MADS-domain proteins based on their interactions with chromatin-associated factors and other transcriptional regulators.
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Affiliation(s)
- Cezary Smaczniak
- Laboratory of Molecular Biology, Wageningen University, 6708PB Wageningen, The Netherlands
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Feng CM, Liu X, Yu Y, Xie D, Franks RG, Xiang QYJ. Evolution of bract development and B-class MADS box gene expression in petaloid bracts of Cornus s. l. (Cornaceae). THE NEW PHYTOLOGIST 2012; 196:631-643. [PMID: 22897242 DOI: 10.1111/j.1469-8137.2012.04255.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Despite increasing interest in the molecular mechanisms of floral diversity, few studies have investigated the developmental and genetic bases of petaloid bracts. This study examined morphological patterns of bract initiation and expression patterns of B-class MADS-box genes in bracts of several Cornus species. We suggest that petaloid bracts in this genus may not share a single evolutionary origin. Developmental pathways of bracts and spatiotemporal expression of B-class genes in bracts and flowers were examined for four closely related dogwood species. Divergent morphological progressions and gene expression patterns were found in the two sister lineages with petaloid bracts, represented by Cornus florida and Cornus canadensis. Phylogeny-based analysis identified developmental and gene expression changes that are correlated with the evolution of petaloid bracts in C. florida and C. canadensis. Our data support the existence of independent evolutionary origins of petaloid bracts in C. canadensis and C. florida. Additionally, we suggest that functional transference within B-class gene families may have contributed to the origin of bract petaloidy in C. florida. However, the underlying mechanisms of petaloid bract development likely differ between C. florida and C. canadensis. In the future this hypothesis can be tested by functional analyses of Cornus B-class genes.
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Affiliation(s)
- Chun-Miao Feng
- Department of Plant Biology, North Carolina State University, Raleigh, NC 27695, USADepartment of Genetics, North Carolina State University, Raleigh, NC 27695, USA
| | - Xiang Liu
- Department of Plant Biology, North Carolina State University, Raleigh, NC 27695, USADepartment of Genetics, North Carolina State University, Raleigh, NC 27695, USA
| | - Yi Yu
- Department of Plant Biology, North Carolina State University, Raleigh, NC 27695, USADepartment of Genetics, North Carolina State University, Raleigh, NC 27695, USA
| | - Deyu Xie
- Department of Plant Biology, North Carolina State University, Raleigh, NC 27695, USADepartment of Genetics, North Carolina State University, Raleigh, NC 27695, USA
| | - Robert G Franks
- Department of Plant Biology, North Carolina State University, Raleigh, NC 27695, USADepartment of Genetics, North Carolina State University, Raleigh, NC 27695, USA
| | - Qiu-Yun Jenny Xiang
- Department of Plant Biology, North Carolina State University, Raleigh, NC 27695, USADepartment of Genetics, North Carolina State University, Raleigh, NC 27695, USA
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Davies KM, Albert NW, Schwinn KE. From landing lights to mimicry: the molecular regulation of flower colouration and mechanisms for pigmentation patterning. FUNCTIONAL PLANT BIOLOGY : FPB 2012; 39:619-638. [PMID: 32480814 DOI: 10.1071/fp12195] [Citation(s) in RCA: 169] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 07/03/2012] [Indexed: 05/22/2023]
Abstract
Flower colour is a key component for plant signaling to pollinators and a staggering variety of colour variations are found in nature. Patterning of flower colour, such as pigment spots or stripes, is common and is important in promoting pollination success. Developmentally programmed pigmentation patterns are of interest with respect to the evolution of specialised plant-pollinator associations and as models for dissecting regulatory signaling in plants. This article reviews the occurrence and function of flower colour patterns, as well as the molecular genetics of anthocyanin pigmentation regulation. The transcription factors controlling anthocyanin biosynthesis have been characterised for many species and an 'MBW' regulatory complex of R2R3MYB, bHLH and WD-Repeat proteins is of central importance. In particular, R2R3MYBs are key determinants of pigmentation intensity and patterning in plants. Progress is now being made on how environmental or developmental signal pathways may in turn control the production of the MBW components. Furthermore, additional regulatory proteins that interact with the MBW activation complex are being identified, including a range of proteins that repress complex formation or action, either directly or indirectly. This review discusses some of the recent data on the regulatory factors and presents models of how patterns may be determined.
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Affiliation(s)
- Kevin M Davies
- The New Zealand Institute for Plant and Food Research Ltd, Private Bag 11600, Palmerston North, New Zealand
| | - Nick W Albert
- The New Zealand Institute for Plant and Food Research Ltd, Private Bag 11600, Palmerston North, New Zealand
| | - Kathy E Schwinn
- The New Zealand Institute for Plant and Food Research Ltd, Private Bag 11600, Palmerston North, New Zealand
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