1
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Wang W, Malka R, Lindemeier M, Cyprys P, Tiedemann S, Sun K, Zhang X, Xiong H, Sprunck S, Sun MX. EGG CELL 1 contributes to egg-cell-dependent preferential fertilization in Arabidopsis. Nat Plants 2024; 10:268-282. [PMID: 38287093 DOI: 10.1038/s41477-023-01616-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 12/20/2023] [Indexed: 01/31/2024]
Abstract
During double fertilization in angiosperms, the pollen tube delivers two sperm cells into an embryo sac; one sperm cell fuses with an egg cell, and the other sperm cell fuses with the central cell. It has long been proposed that the preference for fusion with one or another female gamete cell depends on the sperm cells and occurs during gamete recognition. However, up to now, sperm-dependent preferential fertilization has not been demonstrated, and results on preferred fusion with either female gamete have remained conflicting. To investigate this topic, we generated Arabidopsis thaliana mutants that produce single sperm-like cells or whose egg cells are eliminated; we found that although the three different types of sperm-like cell are functionally equivalent in their ability to fertilize the egg and the central cell, each type of sperm-like cell fuses predominantly with the egg cell. This indicates that it is the egg cell that controls its preferential fertilization. We also found that sperm-activating small secreted EGG CELL 1 proteins are involved in the regulation of egg-cell-dependent preferential fertilization, revealing another important role for this protein family during double fertilization.
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Affiliation(s)
- Wei Wang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Raphael Malka
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Maria Lindemeier
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Philipp Cyprys
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Sophie Tiedemann
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Kaiting Sun
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Xuecheng Zhang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Hanxian Xiong
- School of Life Science and Technology, Wuhan Polytechnic University, Wuhan, China.
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany.
| | - Meng-Xiang Sun
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China.
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2
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Liu L, Trendel J, Jiang G, Liu Y, Bruckmann A, Küster B, Sprunck S, Dresselhaus T, Bleckmann A. RBPome identification in egg-cell like callus of Arabidopsis. Biol Chem 2023; 404:1137-1149. [PMID: 37768858 DOI: 10.1515/hsz-2023-0195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Accepted: 09/11/2023] [Indexed: 09/30/2023]
Abstract
RNA binding proteins (RBPs) have multiple and essential roles in transcriptional and posttranscriptional regulation of gene expression in all living organisms. Their biochemical identification in the proteome of a given cell or tissue requires significant protein amounts, which limits studies in rare and highly specialized cells. As a consequence, we know almost nothing about the role(s) of RBPs in reproductive processes such as egg cell development, fertilization and early embryogenesis in flowering plants. To systematically identify the RBPome of egg cells in the model plant Arabidopsis, we performed RNA interactome capture (RIC) experiments using the egg cell-like RKD2-callus and were able to identify 728 proteins associated with poly(A+)-RNA. Transcripts for 97 % of identified proteins could be verified in the egg cell transcriptome. 46 % of identified proteins can be associated with the RNA life cycle. Proteins involved in mRNA binding, RNA processing and metabolism are highly enriched. Compared with the few available RBPome datasets of vegetative plant tissues, we identified 475 egg cell-enriched RBPs, which will now serve as a resource to study RBP function(s) during egg cell development, fertilization and early embryogenesis. First candidates were already identified showing an egg cell-specific expression pattern in ovules.
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Affiliation(s)
- Liping Liu
- Cell Biology and Plant Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
| | - Jakob Trendel
- Chair of Proteomics and Bioanalytics, Technical University of Munich (TUM), D-85354 Freising, Germany
| | - Guojing Jiang
- Cell Biology and Plant Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
| | - Yanhui Liu
- College of Life Science, Longyan University, Longyan 364012, China
| | - Astrid Bruckmann
- Biochemistry I, University of Regensburg, D-93053 Regensburg, Germany
| | - Bernhard Küster
- Chair of Proteomics and Bioanalytics, Technical University of Munich (TUM), D-85354 Freising, Germany
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
| | - Andrea Bleckmann
- Cell Biology and Plant Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
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3
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Sprunck S, Schwechheimer C, Morita MT. Editorial overview: Cell biology and cell signalling. Curr Opin Plant Biol 2022; 70:102312. [PMID: 36400664 DOI: 10.1016/j.pbi.2022.102312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Affiliation(s)
- Stefanie Sprunck
- Institute of Plant Science, Department of Cell Biology and Plant Biochemistry, University of Regensburg, Universitaetsstrasse 31, 93053, Regensburg, Germany.
| | - Claus Schwechheimer
- Plant Systems Biology, School of Life Sciences, Technical University of Munich, Emil-Ramann-Strasse 8, 85354, Freising, Germany
| | - Miyo T Morita
- Division of Plant Environmental Responses, National Institute for Basic Biology, National Institutes of Natural Sciences, Nishigonaka 38, Myodaiji-cho, Okazaki-shi, Aichi, 444-8585, Japan
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4
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Julca I, Ferrari C, Flores-Tornero M, Proost S, Lindner AC, Hackenberg D, Steinbachová L, Michaelidis C, Gomes Pereira S, Misra CS, Kawashima T, Borg M, Berger F, Goldberg J, Johnson M, Honys D, Twell D, Sprunck S, Dresselhaus T, Becker JD, Mutwil M. Comparative transcriptomic analysis reveals conserved programmes underpinning organogenesis and reproduction in land plants. Nat Plants 2021; 7:1143-1159. [PMID: 34253868 DOI: 10.1101/2020.10.29.361501] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 06/02/2021] [Indexed: 05/19/2023]
Abstract
The appearance of plant organs mediated the explosive radiation of land plants, which shaped the biosphere and allowed the establishment of terrestrial animal life. The evolution of organs and immobile gametes required the coordinated acquisition of novel gene functions, the co-option of existing genes and the development of novel regulatory programmes. However, no large-scale analyses of genomic and transcriptomic data have been performed for land plants. To remedy this, we generated gene expression atlases for various organs and gametes of ten plant species comprising bryophytes, vascular plants, gymnosperms and flowering plants. A comparative analysis of the atlases identified hundreds of organ- and gamete-specific orthogroups and revealed that most of the specific transcriptomes are significantly conserved. Interestingly, our results suggest that co-option of existing genes is the main mechanism for evolving new organs. In contrast to female gametes, male gametes showed a high number and conservation of specific genes, which indicates that male reproduction is highly specialized. The expression atlas capturing pollen development revealed numerous transcription factors and kinases essential for pollen biogenesis and function.
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Affiliation(s)
- Irene Julca
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Camilla Ferrari
- Max Planck Institute for Molecular Plant Physiology, Potsdam-Golm, Germany
| | - María Flores-Tornero
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Sebastian Proost
- Max Planck Institute for Molecular Plant Physiology, Potsdam-Golm, Germany
- Laboratory of Molecular Bacteriology, Department of Microbiology and Immunology, Rega Institute, KU Leuven, Leuven, Belgium
- VIB, Center for Microbiology, Leuven, Belgium
| | | | - Dieter Hackenberg
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
- School of Life Sciences, Gibbet Hill Campus, The University of Warwick, Coventry, UK
| | - Lenka Steinbachová
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - Christos Michaelidis
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | | | - Chandra Shekhar Misra
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Tomokazu Kawashima
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna, BioCenter (VBC), Vienna, Austria
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY, USA
| | - Michael Borg
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna, BioCenter (VBC), Vienna, Austria
| | - Frédéric Berger
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna, BioCenter (VBC), Vienna, Austria
| | - Jacob Goldberg
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, USA
| | - Mark Johnson
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, USA
| | - David Honys
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - David Twell
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Jörg D Becker
- Instituto Gulbenkian de Ciência, Oeiras, Portugal.
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal.
| | - Marek Mutwil
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
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5
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Julca I, Ferrari C, Flores-Tornero M, Proost S, Lindner AC, Hackenberg D, Steinbachová L, Michaelidis C, Gomes Pereira S, Misra CS, Kawashima T, Borg M, Berger F, Goldberg J, Johnson M, Honys D, Twell D, Sprunck S, Dresselhaus T, Becker JD, Mutwil M. Comparative transcriptomic analysis reveals conserved programmes underpinning organogenesis and reproduction in land plants. Nat Plants 2021; 7:1143-1159. [PMID: 34253868 DOI: 10.1038/s41477-021-00958-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 06/02/2021] [Indexed: 05/22/2023]
Abstract
The appearance of plant organs mediated the explosive radiation of land plants, which shaped the biosphere and allowed the establishment of terrestrial animal life. The evolution of organs and immobile gametes required the coordinated acquisition of novel gene functions, the co-option of existing genes and the development of novel regulatory programmes. However, no large-scale analyses of genomic and transcriptomic data have been performed for land plants. To remedy this, we generated gene expression atlases for various organs and gametes of ten plant species comprising bryophytes, vascular plants, gymnosperms and flowering plants. A comparative analysis of the atlases identified hundreds of organ- and gamete-specific orthogroups and revealed that most of the specific transcriptomes are significantly conserved. Interestingly, our results suggest that co-option of existing genes is the main mechanism for evolving new organs. In contrast to female gametes, male gametes showed a high number and conservation of specific genes, which indicates that male reproduction is highly specialized. The expression atlas capturing pollen development revealed numerous transcription factors and kinases essential for pollen biogenesis and function.
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Affiliation(s)
- Irene Julca
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Camilla Ferrari
- Max Planck Institute for Molecular Plant Physiology, Potsdam-Golm, Germany
| | - María Flores-Tornero
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Sebastian Proost
- Max Planck Institute for Molecular Plant Physiology, Potsdam-Golm, Germany
- Laboratory of Molecular Bacteriology, Department of Microbiology and Immunology, Rega Institute, KU Leuven, Leuven, Belgium
- VIB, Center for Microbiology, Leuven, Belgium
| | | | - Dieter Hackenberg
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
- School of Life Sciences, Gibbet Hill Campus, The University of Warwick, Coventry, UK
| | - Lenka Steinbachová
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - Christos Michaelidis
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | | | - Chandra Shekhar Misra
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Tomokazu Kawashima
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna, BioCenter (VBC), Vienna, Austria
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY, USA
| | - Michael Borg
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna, BioCenter (VBC), Vienna, Austria
| | - Frédéric Berger
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna, BioCenter (VBC), Vienna, Austria
| | - Jacob Goldberg
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, USA
| | - Mark Johnson
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, USA
| | - David Honys
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - David Twell
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Jörg D Becker
- Instituto Gulbenkian de Ciência, Oeiras, Portugal.
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal.
| | - Marek Mutwil
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
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6
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Flores-Tornero M, Wang L, Potěšil D, Hafidh S, Vogler F, Zdráhal Z, Honys D, Sprunck S, Dresselhaus T. Comparative analyses of angiosperm secretomes identify apoplastic pollen tube functions and novel secreted peptides. Plant Reprod 2021; 34:47-60. [PMID: 33258014 PMCID: PMC7902602 DOI: 10.1007/s00497-020-00399-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 11/10/2020] [Indexed: 05/14/2023]
Abstract
KEY MESSAGE Analyses of secretomes of in vitro grown pollen tubes from Amborella, maize and tobacco identified many components of processes associated with the cell wall, signaling and metabolism as well as novel small secreted peptides. Flowering plants (angiosperms) generate pollen grains that germinate on the stigma and produce tubes to transport their sperm cells cargo deep into the maternal reproductive tissues toward the ovules for a double fertilization process. During their journey, pollen tubes secrete many proteins (secreted proteome or secretome) required, for example, for communication with the maternal reproductive tissues, to build a solid own cell wall that withstands their high turgor pressure while softening simultaneously maternal cell wall tissue. The composition and species specificity or family specificity of the pollen tube secretome is poorly understood. Here, we provide a suitable method to obtain the pollen tube secretome from in vitro grown pollen tubes of the basal angiosperm Amborella trichopoda (Amborella) and the Poaceae model maize. The previously published secretome of tobacco pollen tubes was used as an example of eudicotyledonous plants in this comparative study. The secretome of the three species is each strongly different compared to the respective protein composition of pollen grains and tubes. In Amborella and maize, about 40% proteins are secreted by the conventional "classic" pathway and 30% by unconventional pathways. The latter pathway is expanded in tobacco. Proteins enriched in the secretome are especially involved in functions associated with the cell wall, cell surface, energy and lipid metabolism, proteolysis and redox processes. Expansins, pectin methylesterase inhibitors and RALFs are enriched in maize, while tobacco secretes many proteins involved, for example, in proteolysis and signaling. While the majority of proteins detected in the secretome occur also in pollen grains and pollen tubes, and correlate in the number of mapped peptides with relative gene expression levels, some novel secreted small proteins were identified. Moreover, the identification of secreted proteins containing pro-peptides indicates that these are processed in the apoplast. In conclusion, we provide a proteome resource from three distinct angiosperm clades that can be utilized among others to study the localization, abundance and processing of known secreted proteins and help to identify novel pollen tube secreted proteins for functional studies.
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Affiliation(s)
- María Flores-Tornero
- Cell Biology and Plant Biochemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Lele Wang
- Cell Biology and Plant Biochemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - David Potěšil
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
| | - Said Hafidh
- Laboratory of Pollen Biology, Institute of Experimental Botany ASCR, Rozvojová 263, 165 02, Prague 6, Czech Republic
| | - Frank Vogler
- Cell Biology and Plant Biochemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Zbyněk Zdráhal
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
| | - David Honys
- Laboratory of Pollen Biology, Institute of Experimental Botany ASCR, Rozvojová 263, 165 02, Prague 6, Czech Republic
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany.
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7
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Kulich I, Vogler F, Bleckmann A, Cyprys P, Lindemeier M, Fuchs I, Krassini L, Schubert T, Steinbrenner J, Beynon J, Falter-Braun P, Längst G, Dresselhaus T, Sprunck S. Author Correction: ARMADILLO REPEAT ONLY proteins confine Rho GTPase signalling to polar growth sites. Nat Plants 2021; 7:234. [PMID: 33408348 DOI: 10.1038/s41477-020-00841-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Affiliation(s)
- Ivan Kulich
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Frank Vogler
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Andrea Bleckmann
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Philipp Cyprys
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Maria Lindemeier
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Ingrid Fuchs
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Laura Krassini
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | | | - Jens Steinbrenner
- School of Life Sciences, Warwick University, Coventry, UK
- Institute for Phytopathology and Applied Zoology, University of Giessen, Giessen, Germany
| | - Jim Beynon
- School of Life Sciences, Warwick University, Coventry, UK
| | - Pascal Falter-Braun
- Department of Plant Systems Biology, Center of Life and Food Sciences Weihenstephan, Technische Universität München, Freising, Germany
- Institute of Network Biology (INET), Helmholtz Zentrum München, Neuherberg, Germany
- Microbe-Host Interactions, Faculty of Biology, Ludwig-Maximilians-Universität (LMU) München, Munich, Germany
| | - Gernot Längst
- Biochemistry III, Biochemistry Centre Regensburg, University of Regensburg, Regensburg, Germany
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany.
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8
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Flores-Tornero M, Vogler F, Mutwil M, Potěšil D, Ihnatová I, Zdráhal Z, Sprunck S, Dresselhaus T. Transcriptomic and Proteomic Insights into Amborella trichopoda Male Gametophyte Functions. Plant Physiol 2020; 184:1640-1657. [PMID: 32989009 PMCID: PMC7723084 DOI: 10.1104/pp.20.00837] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 09/16/2020] [Indexed: 05/27/2023]
Abstract
Flowering plants (angiosperms) are characterized by pollen tubes (PTs; male gametophytes) carrying two immobile sperm cells that grow over long distances through the carpel toward the ovules, where double fertilization is executed. It is not understood how these reproductive structures evolved, which genes occur de novo in male gametophytes of angiosperms, and to which extent PT functions are conserved among angiosperms. To contribute to a deeper understanding of the evolution of gametophyte functions, we generated RNA sequencing data from seven reproductive and two vegetative control tissues of the basal angiosperm Amborella trichopoda and complemented these with proteomic data of pollen grains (PGs) and PTs. The eudicot model plant Arabidopsis (Arabidopsis thaliana) served as a reference organism for data analysis, as more than 200 genes have been associated with male gametophyte functions in this species. We describe methods to collect bicellular A. trichopoda PGs, to induce their germination in vitro, and to monitor PT growth and germ cell division. Transcriptomic and proteomic analyses indicate that A. trichopoda PGs are prepared for germination requiring lipids, energy, but likely also reactive oxygen species, while PTs are especially characterized by catabolic/biosynthetic and transport processes including cell wall biosynthesis and gene regulation. Notably, a number of pollen-specific genes were lacking in Arabidopsis, and the number of genes involved in pollen signaling is significantly reduced in A. trichopoda In conclusion, we provide insight into male gametophyte functions of the most basal angiosperm and establish a valuable resource for future studies on the evolution of flowering plants.
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Affiliation(s)
- María Flores-Tornero
- Cell Biology and Plant Biochemistry, University of Regensburg, 93053 Regensburg, Germany
| | - Frank Vogler
- Cell Biology and Plant Biochemistry, University of Regensburg, 93053 Regensburg, Germany
| | - Marek Mutwil
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - David Potěšil
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, CZ-62500 Brno, Czech Republic
| | - Ivana Ihnatová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, CZ-62500 Brno, Czech Republic
- RECETOX, Faculty of Science, Masaryk University, CZ-62500 Brno, Czech Republic
| | - Zbyněk Zdráhal
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, CZ-62500 Brno, Czech Republic
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, University of Regensburg, 93053 Regensburg, Germany
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, University of Regensburg, 93053 Regensburg, Germany
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9
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Kulich I, Vogler F, Bleckmann A, Cyprys P, Lindemeier M, Fuchs I, Krassini L, Schubert T, Steinbrenner J, Beynon J, Falter-Braun P, Längst G, Dresselhaus T, Sprunck S. ARMADILLO REPEAT ONLY proteins confine Rho GTPase signalling to polar growth sites. Nat Plants 2020; 6:1275-1288. [PMID: 33020609 DOI: 10.1038/s41477-020-00781-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 09/03/2020] [Indexed: 06/11/2023]
Abstract
Polar growth requires the precise tuning of Rho GTPase signalling at distinct plasma membrane domains. The activity of Rho of plant (ROP) GTPases is regulated by the opposing action of guanine nucleotide-exchange factors (GEFs) and GTPase-activating proteins (GAPs). Whereas plant-specific ROPGEFs have been shown to be embedded in higher-level regulatory mechanisms involving membrane-bound receptor-like kinases, the regulation of GAPs has remained enigmatic. Here, we show that three Arabidopsis ARMADILLO REPEAT ONLY (ARO) proteins are essential for the stabilization of growth sites in root hair cells and trichomes. AROs interact with ROP1 enhancer GAPs (RENGAPs) and bind to the plasma membrane via a conserved polybasic region at the ARO amino terminus. The ectopic spreading of ROP2 in aro2/3/4 mutant root hair cells and the preferential interaction of AROs with active ROPs and anionic phospholipids suggests that AROs recruit RENGAPs into complexes with ROPs to confine ROP signalling to distinct membrane regions.
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Affiliation(s)
- Ivan Kulich
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Frank Vogler
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Andrea Bleckmann
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Philipp Cyprys
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Maria Lindemeier
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Ingrid Fuchs
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Laura Krassini
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | | | - Jens Steinbrenner
- School of Life Sciences, Warwick University, Coventry, UK
- Institute for Phytopathology and Applied Zoology, University of Giessen, Giessen, Germany
| | - Jim Beynon
- School of Life Sciences, Warwick University, Coventry, UK
| | - Pascal Falter-Braun
- Department of Plant Systems Biology, Center of Life and Food Sciences Weihenstephan, Technische Universität München, Freising, Germany
- Institute of Network Biology (INET), Helmholtz Zentrum München, Neuherberg, Germany
- Microbe-Host Interactions, Faculty of Biology, Ludwig-Maximilians-Universität (LMU) München, Munich, Germany
| | - Gernot Längst
- Biochemistry III, Biochemistry Centre Regensburg, University of Regensburg, Regensburg, Germany
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany.
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10
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Sprunck S. Twice the fun, double the trouble: gamete interactions in flowering plants. Curr Opin Plant Biol 2020; 53:106-116. [PMID: 31841779 DOI: 10.1016/j.pbi.2019.11.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 11/14/2019] [Accepted: 11/17/2019] [Indexed: 05/13/2023]
Abstract
During sexual reproduction two gametes of opposite sex unite to produce a zygote. Gamete fusion is a highly controlled process and it has become evident that, across species, common concepts apply to this ancient and fundamental event. Sexual reproduction in flowering plants is even more complex in that two sperm cells fertilize two female reproductive cells (egg and central cell) in a process called double fertilization. Due to the coordinated developmental progression and mutual dependency of the two fertilization products (embryo and endosperm), the success and timing of the two fusion events substantially affects seed set. So far, four proteins are known to act on the surfaces of Arabidopsis gametes to accomplish double fertilization. The molecular and evolutionary characteristics of these players prove that flowering plants integrate plant-specific and widely conserved mechanisms to accomplish the timely fusion of each sperm cell with one female reproductive cell.
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Affiliation(s)
- Stefanie Sprunck
- Cell Biology and Plant Biochemistry, University of Regensburg, Universitätsstr. 31, 93053 Regensburg, Germany.
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11
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Flores-Tornero M, Proost S, Mutwil M, Scutt CP, Dresselhaus T, Sprunck S. Correction to: Transcriptomics of manually isolated Amborella trichopoda egg apparatus cells. Plant Reprod 2019; 32:229. [PMID: 30805714 PMCID: PMC6500505 DOI: 10.1007/s00497-019-00367-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The article Transcriptomics of manually isolated Amborella trichopoda egg apparatus cells, written by María Flores-Tornero, Sebastian Proost, Marek Mutwil, Charles P. Scutt, Thomas Dresselhaus, Stefanie Sprunck, was originally published electronically on the publisher's internet portal (currently SpringerLink) on 1 February 2019 without open access.
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Affiliation(s)
- María Flores-Tornero
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Universitätsstrasse 31, 93053, Regensburg, Germany
| | - Sebastian Proost
- Max-Planck Institute for Molecular Plant Physiology, Am Muehlenberg 1, 14476, Potsdam, Germany
- Laboratory of Molecular Bacteriology (Rega Institute), KU Leuven, Louvain, Belgium
| | - Marek Mutwil
- Max-Planck Institute for Molecular Plant Physiology, Am Muehlenberg 1, 14476, Potsdam, Germany
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore
| | - Charles P Scutt
- Laboratoire Reproduction et Développement des Plantes, École Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, CNRS, INRA, Université de Lyon, Lyon, France
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Universitätsstrasse 31, 93053, Regensburg, Germany
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Universitätsstrasse 31, 93053, Regensburg, Germany.
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12
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Ehrnsberger HF, Pfaff C, Hachani I, Flores-Tornero M, Sørensen BB, Längst G, Sprunck S, Grasser M, Grasser KD. The UAP56-Interacting Export Factors UIEF1 and UIEF2 Function in mRNA Export. Plant Physiol 2019; 179:1525-1536. [PMID: 30700540 PMCID: PMC6446781 DOI: 10.1104/pp.18.01476] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 01/18/2019] [Indexed: 06/01/2023]
Abstract
In eukaryotes, the regulated transport of mRNAs from the nucleus to the cytosol through nuclear pore complexes represents an important step in the expression of protein-coding genes. In plants, the mechanism of nucleocytosolic mRNA transport and the factors involved are poorly understood. The Arabidopsis (Arabidopsis thaliana) genome encodes two likely orthologs of UAP56-interacting factor, which acts as mRNA export factor in mammalian cells. In yeast and plant cells, both proteins interact directly with the mRNA export-related RNA helicase UAP56 and the interaction was mediated by an N-terminal UAP56-binding motif. Accordingly, the two proteins were termed UAP56-INTERACTING EXPORT FACTOR1 and 2 (UIEF1/2). Despite lacking a known RNA-binding motif, recombinant UIEF1 interacted with RNA, and the C-terminal part of UIEF1 mainly contributed to the RNA interaction. Mutation of UIEF1, UIEF2, or both in the double-mutant 2xuief caused modest growth defects. A cross between the 2xuief and 4xaly (defective in the four ALY1-4 mRNA export factors) mutants produced the sextuple mutant 4xaly 2xuief, which displayed more severe growth impairment than the 4xaly plants. Developmental defects including delayed bolting and reduced seed set were observed in the 4xaly but not the 2xuief plants. Analysis of the cellular distribution of polyadenylated mRNAs revealed more pronounced nuclear mRNA accumulation in 4xaly 2xuief than in 2xuief and 4xaly cells. In conclusion, the results indicate that UIEF1 and UIEF2 act as mRNA export factors in plants and that they cooperate with ALY1-ALY4 to mediate efficient nucleocytosolic mRNA transport.
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Affiliation(s)
- Hans F Ehrnsberger
- Department of Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, D-93053 Regensburg, Germany
| | - Christina Pfaff
- Department of Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, D-93053 Regensburg, Germany
| | - Ines Hachani
- Department of Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, D-93053 Regensburg, Germany
| | - María Flores-Tornero
- Department of Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, D-93053 Regensburg, Germany
| | - Brian B Sørensen
- Department of Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, D-93053 Regensburg, Germany
| | - Gernot Längst
- Department of Biochemistry III, Biochemistry Centre, University of Regensburg, D-93053 Regensburg, Germany
| | - Stefanie Sprunck
- Department of Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, D-93053 Regensburg, Germany
| | - Marion Grasser
- Department of Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, D-93053 Regensburg, Germany
| | - Klaus D Grasser
- Department of Cell Biology & Plant Biochemistry, Biochemistry Centre, University of Regensburg, D-93053 Regensburg, Germany
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13
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Cyprys P, Lindemeier M, Sprunck S. Gamete fusion is facilitated by two sperm cell-expressed DUF679 membrane proteins. Nat Plants 2019; 5:253-257. [PMID: 30850817 DOI: 10.1038/s41477-019-0382-3] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 02/06/2019] [Indexed: 05/02/2023]
Abstract
Successful double fertilization in flowering plants relies on two coordinated gamete fusion events, but the underlying molecular processes are not well understood. We show that two sperm-specific DOMAIN OF UNKNOWN FUNCTION 679 membrane proteins (DMP8 and DMP9) facilitate gamete fusion, with a greater effect on sperm-egg fusion than on sperm-central cell fusion. We also show that sperm adhesion and sperm cell separation depend on egg cell-secreted EGG CELL 1 proteins.
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Affiliation(s)
- Philipp Cyprys
- Cell Biology and Plant Biochemistry, Biochemistry Centre Regensburg, University of Regensburg, Regensburg, Germany
| | - Maria Lindemeier
- Cell Biology and Plant Biochemistry, Biochemistry Centre Regensburg, University of Regensburg, Regensburg, Germany
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, Biochemistry Centre Regensburg, University of Regensburg, Regensburg, Germany.
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14
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Flores-Tornero M, Proost S, Mutwil M, Scutt CP, Dresselhaus T, Sprunck S. Transcriptomics of manually isolated Amborella trichopoda egg apparatus cells. Plant Reprod 2019; 32:15-27. [PMID: 30707279 DOI: 10.1007/s00497-019-00361-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 01/09/2019] [Indexed: 05/27/2023]
Abstract
A protocol for the isolation of egg apparatus cells from the basal angiosperm Amborella trichopoda to generate RNA-seq data for evolutionary studies of fertilization-associated genes. Sexual reproduction is particularly complex in flowering plants (angiosperms). Studies in eudicot and monocot model species have significantly contributed to our knowledge on cell fate specification of gametophytic cells and on the numerous cellular communication events necessary to deliver the two sperm cells into the embryo sac and to accomplish double fertilization. However, for a deeper understanding of the evolution of these processes, morphological, genomic and gene expression studies in extant basal angiosperms are inevitable. The basal angiosperm Amborella trichopoda is of special importance for evolutionary studies, as it is likely sister to all other living angiosperms. Here, we report about a method to isolate Amborella egg apparatus cells and on genome-wide gene expression profiles in these cells. Our transcriptomics data revealed Amborella-specific genes and genes conserved in eudicots and monocots. Gene products include secreted proteins, such as small cysteine-rich proteins previously reported to act as extracellular signaling molecules with important roles during double fertilization. The detection of transcripts encoding EGG CELL 1 (EC1) and related prolamin-like family proteins in Amborella egg cells demonstrates the potential of the generated data set to study conserved molecular mechanisms and the evolution of fertilization-related genes and their encoded proteins.
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Affiliation(s)
- María Flores-Tornero
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Universitätsstrasse 31, 93053, Regensburg, Germany
| | - Sebastian Proost
- Max-Planck Institute for Molecular Plant Physiology, Am Muehlenberg 1, 14476, Potsdam, Germany
- Laboratory of Molecular Bacteriology (Rega Institute), KU Leuven, Louvain, Belgium
| | - Marek Mutwil
- Max-Planck Institute for Molecular Plant Physiology, Am Muehlenberg 1, 14476, Potsdam, Germany
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore
| | - Charles P Scutt
- Laboratoire Reproduction et Développement des Plantes, École Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, CNRS, INRA, Université de Lyon, Lyon, France
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Universitätsstrasse 31, 93053, Regensburg, Germany
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Universitätsstrasse 31, 93053, Regensburg, Germany.
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15
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Bauer N, Škiljaica A, Malenica N, Razdorov G, Klasić M, Juranić M, Močibob M, Sprunck S, Dresselhaus T, Leljak Levanić D. The MATH-BTB Protein TaMAB2 Accumulates in Ubiquitin-Containing Foci and Interacts With the Translation Initiation Machinery in Arabidopsis. Front Plant Sci 2019; 10:1469. [PMID: 31824527 PMCID: PMC6883508 DOI: 10.3389/fpls.2019.01469] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 10/22/2019] [Indexed: 05/20/2023]
Abstract
MATH-BTB proteins are known to act as substrate-specific adaptors of CUL3-based E3 ligases in the ubiquitin proteasome pathway. Their BTB domain binds to CUL3 scaffold proteins and the less conserved MATH domain targets a highly diverse collection of substrate proteins to promote their ubiquitination and subsequent degradation. In plants, a significant expansion of the MATH-BTB family occurred in the grasses. Here, we report analysis of TaMAB2, a MATH-BTB protein transiently expressed at the onset of embryogenesis in wheat. Due to difficulties in studying its role in zygotes and early embryos, we have overexpressed TaMAB2 in Arabidopsis to generate gain-of-function mutants and to elucidate interaction partners and substrates. Overexpression plants showed severe growth defects as well as disorganization of microtubule bundles indicating that TaMAB2 interacts with substrates in Arabidopsis. In tobacco BY-2 cells, TaMAB2 showed a microtubule and ubiquitin-associated cytoplasmic localization pattern in form of foci. Its direct interaction with CUL3 suggests functions in targeting specific substrates for ubiquitin-dependent degradation. Although direct interactions with tubulin could not be confimed, tandem affinity purification of TaMAB2 interactors point towards cytoskeletal proteins including tubulin and actin as well as the translation initiation machinery. The idenification of various subunits of eucaryotic translation initiation factors eIF3 and eIF4 as TaMAB2 interactors indicate regulation of translation initiation as a major function during onset of embryogenesis in plants.
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Affiliation(s)
- Nataša Bauer
- Division of Molecular Biology, Department of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | - Andreja Škiljaica
- Division of Molecular Biology, Department of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | - Nenad Malenica
- Division of Molecular Biology, Department of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | | | - Marija Klasić
- Division of Molecular Biology, Department of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | - Martina Juranić
- Division of Molecular Biology, Department of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | - Marko Močibob
- Division of Biochemistry, Department of Chemistry, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Dunja Leljak Levanić
- Division of Molecular Biology, Department of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia
- *Correspondence: Dunja Leljak Levanić,
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16
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Kirioukhova O, Shah JN, Larsen DS, Tayyab M, Mueller NE, Govind G, Baroux C, Federer M, Gheyselinck J, Barrell PJ, Ma H, Sprunck S, Huettel B, Wallace H, Grossniklaus U, Johnston AJ. Aberrant imprinting may underlie evolution of parthenogenesis. Sci Rep 2018; 8:10626. [PMID: 30006526 PMCID: PMC6045609 DOI: 10.1038/s41598-018-27863-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 05/11/2018] [Indexed: 01/10/2023] Open
Abstract
Genomic imprinting confers parent-of-origin-specific gene expression, thus non-equivalent and complementary function of parental genomes. As a consequence, genomic imprinting poses an epigenetic barrier to parthenogenesis in sexual organisms. We report aberrant imprinting in Boechera, a genus in which apomicts evolved from sexuals multiple times. Maternal activation of a MADS-box gene, a homolog of which is imprinted and paternally expressed in the sexual relative Arabidopsis, is accompanied by locus-specific DNA methylation changes in apomicts where parental imprinting seems to be relaxed.
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Affiliation(s)
- Olga Kirioukhova
- University of Heidelberg, Centre for Organismal Studies, Laboratory of Germline Genetics & Evo-Devo, Heidelberg, Germany.,Jacobs University, Life Sciences & Chemistry, Laboratory of Germline Genetics & Evo-Devo, Bremen, Germany
| | - Jubin N Shah
- University of Heidelberg, Centre for Organismal Studies, Laboratory of Germline Genetics & Evo-Devo, Heidelberg, Germany
| | - Danaé S Larsen
- University of Heidelberg, Centre for Organismal Studies, Laboratory of Germline Genetics & Evo-Devo, Heidelberg, Germany
| | - Muhammad Tayyab
- University of Heidelberg, Centre for Organismal Studies, Laboratory of Germline Genetics & Evo-Devo, Heidelberg, Germany
| | - Nora E Mueller
- University of Heidelberg, Centre for Organismal Studies, Laboratory of Germline Genetics & Evo-Devo, Heidelberg, Germany
| | - Geetha Govind
- University of Heidelberg, Centre for Organismal Studies, Laboratory of Germline Genetics & Evo-Devo, Heidelberg, Germany.,University of Agricultural Sciences, College of Agriculture Sciences, Department of crop physiology, Hassan, India
| | - Célia Baroux
- University of Zurich, Department of Plant and Microbial Biology and Zurich-Basel Plant Science Center, Zurich, Switzerland
| | - Michael Federer
- University of Zurich, Department of Plant and Microbial Biology and Zurich-Basel Plant Science Center, Zurich, Switzerland
| | - Jacqueline Gheyselinck
- University of Zurich, Department of Plant and Microbial Biology and Zurich-Basel Plant Science Center, Zurich, Switzerland
| | - Philippa J Barrell
- University of Zurich, Department of Plant and Microbial Biology and Zurich-Basel Plant Science Center, Zurich, Switzerland.,New Zealand Institute for Plant and Food Research, Christchurch, New Zealand
| | - Hong Ma
- University of Zurich, Department of Plant and Microbial Biology and Zurich-Basel Plant Science Center, Zurich, Switzerland.,The Pennsylvania State University, the Huck Institute of Life Sciences, Department of Biology, The University Park, Pennsylvania, USA.,Fudan University, State Key Laboratory of Genetic Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, China
| | - Stefanie Sprunck
- University of Regensburg, Cell Biology and Plant Biochemistry, Regensburg, Germany
| | - Bruno Huettel
- Max-Planck-Institute for Plant Breeding, Cologne, Germany
| | - Helen Wallace
- University of the Sunshine Coast, Faculty of Science, Health, Education and Engineering, Genecology Research Centre, Maroochydore, Australia
| | - Ueli Grossniklaus
- University of Zurich, Department of Plant and Microbial Biology and Zurich-Basel Plant Science Center, Zurich, Switzerland.
| | - Amal J Johnston
- University of Heidelberg, Centre for Organismal Studies, Laboratory of Germline Genetics & Evo-Devo, Heidelberg, Germany. .,Jacobs University, Life Sciences & Chemistry, Laboratory of Germline Genetics & Evo-Devo, Bremen, Germany. .,University of Zurich, Department of Plant and Microbial Biology and Zurich-Basel Plant Science Center, Zurich, Switzerland. .,ETH Zurich, Department of Biology and Zurich-Basel Plant Science Center, Zurich, Switzerland.
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17
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Kirioukhova O, Shah JN, Larsen DS, Tayyab M, Mueller NE, Govind G, Baroux C, Federer M, Gheyselinck J, Barrell PJ, Ma H, Sprunck S, Huettel B, Wallace H, Grossniklaus U, Johnston AJ. Aberrant imprinting may underlie evolution of parthenogenesis. Sci Rep 2018. [PMID: 30006526 DOI: 10.1038/s41598-018-27863-27867] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023] Open
Abstract
Genomic imprinting confers parent-of-origin-specific gene expression, thus non-equivalent and complementary function of parental genomes. As a consequence, genomic imprinting poses an epigenetic barrier to parthenogenesis in sexual organisms. We report aberrant imprinting in Boechera, a genus in which apomicts evolved from sexuals multiple times. Maternal activation of a MADS-box gene, a homolog of which is imprinted and paternally expressed in the sexual relative Arabidopsis, is accompanied by locus-specific DNA methylation changes in apomicts where parental imprinting seems to be relaxed.
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Affiliation(s)
- Olga Kirioukhova
- University of Heidelberg, Centre for Organismal Studies, Laboratory of Germline Genetics & Evo-Devo, Heidelberg, Germany
- Jacobs University, Life Sciences & Chemistry, Laboratory of Germline Genetics & Evo-Devo, Bremen, Germany
| | - Jubin N Shah
- University of Heidelberg, Centre for Organismal Studies, Laboratory of Germline Genetics & Evo-Devo, Heidelberg, Germany
| | - Danaé S Larsen
- University of Heidelberg, Centre for Organismal Studies, Laboratory of Germline Genetics & Evo-Devo, Heidelberg, Germany
| | - Muhammad Tayyab
- University of Heidelberg, Centre for Organismal Studies, Laboratory of Germline Genetics & Evo-Devo, Heidelberg, Germany
| | - Nora E Mueller
- University of Heidelberg, Centre for Organismal Studies, Laboratory of Germline Genetics & Evo-Devo, Heidelberg, Germany
| | - Geetha Govind
- University of Heidelberg, Centre for Organismal Studies, Laboratory of Germline Genetics & Evo-Devo, Heidelberg, Germany
- University of Agricultural Sciences, College of Agriculture Sciences, Department of crop physiology, Hassan, India
| | - Célia Baroux
- University of Zurich, Department of Plant and Microbial Biology and Zurich-Basel Plant Science Center, Zurich, Switzerland
| | - Michael Federer
- University of Zurich, Department of Plant and Microbial Biology and Zurich-Basel Plant Science Center, Zurich, Switzerland
| | - Jacqueline Gheyselinck
- University of Zurich, Department of Plant and Microbial Biology and Zurich-Basel Plant Science Center, Zurich, Switzerland
| | - Philippa J Barrell
- University of Zurich, Department of Plant and Microbial Biology and Zurich-Basel Plant Science Center, Zurich, Switzerland
- New Zealand Institute for Plant and Food Research, Christchurch, New Zealand
| | - Hong Ma
- University of Zurich, Department of Plant and Microbial Biology and Zurich-Basel Plant Science Center, Zurich, Switzerland
- The Pennsylvania State University, the Huck Institute of Life Sciences, Department of Biology, The University Park, Pennsylvania, USA
- Fudan University, State Key Laboratory of Genetic Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, China
| | - Stefanie Sprunck
- University of Regensburg, Cell Biology and Plant Biochemistry, Regensburg, Germany
| | - Bruno Huettel
- Max-Planck-Institute for Plant Breeding, Cologne, Germany
| | - Helen Wallace
- University of the Sunshine Coast, Faculty of Science, Health, Education and Engineering, Genecology Research Centre, Maroochydore, Australia
| | - Ueli Grossniklaus
- University of Zurich, Department of Plant and Microbial Biology and Zurich-Basel Plant Science Center, Zurich, Switzerland.
| | - Amal J Johnston
- University of Heidelberg, Centre for Organismal Studies, Laboratory of Germline Genetics & Evo-Devo, Heidelberg, Germany.
- Jacobs University, Life Sciences & Chemistry, Laboratory of Germline Genetics & Evo-Devo, Bremen, Germany.
- University of Zurich, Department of Plant and Microbial Biology and Zurich-Basel Plant Science Center, Zurich, Switzerland.
- ETH Zurich, Department of Biology and Zurich-Basel Plant Science Center, Zurich, Switzerland.
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18
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Pfaff C, Ehrnsberger HF, Flores-Tornero M, Sørensen BB, Schubert T, Längst G, Griesenbeck J, Sprunck S, Grasser M, Grasser KD. ALY RNA-Binding Proteins Are Required for Nucleocytosolic mRNA Transport and Modulate Plant Growth and Development. Plant Physiol 2018; 177:226-240. [PMID: 29540591 PMCID: PMC5933122 DOI: 10.1104/pp.18.00173] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 03/07/2018] [Indexed: 05/19/2023]
Abstract
The regulated transport of mRNAs from the cell nucleus to the cytosol is a critical step linking transcript synthesis and processing with translation. However, in plants, only a few of the factors that act in the mRNA export pathway have been functionally characterized. Flowering plant genomes encode several members of the ALY protein family, which function as mRNA export factors in other organisms. Arabidopsis (Arabidopsis thaliana) ALY1 to ALY4 are commonly detected in root and leaf cells, but they are differentially expressed in reproductive tissue. Moreover, the subnuclear distribution of ALY1/2 differs from that of ALY3/4. ALY1 binds with higher affinity to single-stranded RNA than double-stranded RNA and single-stranded DNA and interacts preferentially with 5-methylcytosine-modified single-stranded RNA. Compared with the full-length protein, the individual RNA recognition motif of ALY1 binds RNA only weakly. ALY proteins interact with the RNA helicase UAP56, indicating a link to the mRNA export machinery. Consistently, ALY1 complements the lethal phenotype of yeast cells lacking the ALY1 ortholog Yra1. Whereas individual aly mutants have a wild-type appearance, disruption of ALY1 to ALY4 in 4xaly plants causes vegetative and reproductive defects, including strongly reduced growth, altered flower morphology, as well as abnormal ovules and female gametophytes, causing reduced seed production. Moreover, polyadenylated mRNAs accumulate in the nuclei of 4xaly cells. Our results highlight the requirement of efficient mRNA nucleocytosolic transport for proper plant growth and development and indicate that ALY1 to ALY4 act partly redundantly in this process; however, differences in expression and subnuclear localization suggest distinct functions.
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Affiliation(s)
- Christina Pfaff
- Department of Cell Biology and Plant Biochemistry, Biochemistry Centre, University of Regensburg, D-93053 Regensburg, Germany
| | - Hans F Ehrnsberger
- Department of Cell Biology and Plant Biochemistry, Biochemistry Centre, University of Regensburg, D-93053 Regensburg, Germany
| | - María Flores-Tornero
- Department of Cell Biology and Plant Biochemistry, Biochemistry Centre, University of Regensburg, D-93053 Regensburg, Germany
| | - Brian B Sørensen
- Department of Cell Biology and Plant Biochemistry, Biochemistry Centre, University of Regensburg, D-93053 Regensburg, Germany
| | - Thomas Schubert
- Department for Biochemistry III, Biochemistry Centre, University of Regensburg, D-93053 Regensburg, Germany
| | - Gernot Längst
- Department for Biochemistry III, Biochemistry Centre, University of Regensburg, D-93053 Regensburg, Germany
| | - Joachim Griesenbeck
- Department for Biochemistry III, Biochemistry Centre, University of Regensburg, D-93053 Regensburg, Germany
| | - Stefanie Sprunck
- Department of Cell Biology and Plant Biochemistry, Biochemistry Centre, University of Regensburg, D-93053 Regensburg, Germany
| | - Marion Grasser
- Department of Cell Biology and Plant Biochemistry, Biochemistry Centre, University of Regensburg, D-93053 Regensburg, Germany
| | - Klaus D Grasser
- Department of Cell Biology and Plant Biochemistry, Biochemistry Centre, University of Regensburg, D-93053 Regensburg, Germany
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19
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Chen J, Strieder N, Krohn NG, Cyprys P, Sprunck S, Engelmann JC, Dresselhaus T. Zygotic Genome Activation Occurs Shortly after Fertilization in Maize. Plant Cell 2017; 29:2106-2125. [PMID: 28814645 PMCID: PMC5635985 DOI: 10.1105/tpc.17.00099] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 07/19/2017] [Accepted: 08/15/2017] [Indexed: 05/18/2023]
Abstract
The formation of a zygote via the fusion of an egg and sperm cell and its subsequent asymmetric division herald the start of the plant's life cycle. Zygotic genome activation (ZGA) is thought to occur gradually, with the initial steps of zygote and embryo development being primarily maternally controlled, and subsequent steps being governed by the zygotic genome. Here, using maize (Zea mays) as a model plant system, we determined the timing of zygote development and generated RNA-seq transcriptome profiles of gametes, zygotes, and apical and basal daughter cells. ZGA occurs shortly after fertilization and involves ∼10% of the genome being activated in a highly dynamic pattern. In particular, genes encoding transcriptional regulators of various families are activated shortly after fertilization. Further analyses suggested that chromatin assembly is strongly modified after fertilization, that the egg cell is primed to activate the translational machinery, and that hormones likely play a minor role in the initial steps of early embryo development in maize. Our findings provide important insights into gamete and zygote activity in plants, and our RNA-seq transcriptome profiles represent a comprehensive, unique RNA-seq data set that can be used by the research community.
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Affiliation(s)
- Junyi Chen
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93053 Regensburg, Germany
| | - Nicholas Strieder
- Institute of Functional Genomics, University of Regensburg, 93053 Regensburg, Germany
| | - Nadia G Krohn
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93053 Regensburg, Germany
| | - Philipp Cyprys
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93053 Regensburg, Germany
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93053 Regensburg, Germany
| | - Julia C Engelmann
- Institute of Functional Genomics, University of Regensburg, 93053 Regensburg, Germany
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93053 Regensburg, Germany
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20
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Resentini F, Cyprys P, Steffen JG, Alter S, Morandini P, Mizzotti C, Lloyd A, Drews GN, Dresselhaus T, Colombo L, Sprunck S, Masiero S. SUPPRESSOR OF FRIGIDA (SUF4) Supports Gamete Fusion via Regulating Arabidopsis EC1 Gene Expression. Plant Physiol 2017; 173:155-166. [PMID: 27920160 PMCID: PMC5210714 DOI: 10.1104/pp.16.01024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Accepted: 12/05/2016] [Indexed: 05/03/2023]
Abstract
The EGG CELL1 (EC1) gene family of Arabidopsis (Arabidopsis thaliana) comprises five members that are specifically expressed in the egg cell and redundantly control gamete fusion during double fertilization. We investigated the activity of all five EC1 promoters in promoter-deletion studies and identified SUF4 (SUPPRESSOR OF FRIGIDA4), a C2H2 transcription factor, as a direct regulator of the EC1 gene expression. In particular, we demonstrated that SUF4 binds to all five Arabidopsis EC1 promoters, thus regulating their expression. The down-regulation of SUF4 in homozygous suf4-1 ovules results in reduced EC1 expression and delayed sperm fusion, which can be rescued by expressing SUF4-β-glucuronidase under the control of the SUF4 promoter. To identify more gene products able to regulate EC1 expression together with SUF4, we performed coexpression studies that led to the identification of MOM1 (MORPHEUS' MOLECULE1), a component of a silencing mechanism that is independent of DNA methylation marks. In mom1-3 ovules, both SUF4 and EC1 genes are down-regulated, and EC1 genes show higher levels of histone 3 lysine-9 acetylation, suggesting that MOM1 contributes to the regulation of SUF4 and EC1 gene expression.
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Affiliation(s)
- Francesca Resentini
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133 Milan, Italy (F.R., P.M., C.M., L.C., S.M.)
- Lehrstuhl Zellbiologie und Pflanzenbiochemie, Biochemie-Zentrum Regensburg, Universität Regensburg, D-93053 Regensburg, Germany (P.C., S.A., T.D., S.S.)
- Department of Biology, University of Utah, Salt Lake City, Utah 84112 (J.G.S., A.L., G.N.D.); and
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Università di Milano, 20133 Milan, Italy (P.M., L.C.)
| | - Philipp Cyprys
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133 Milan, Italy (F.R., P.M., C.M., L.C., S.M.)
- Lehrstuhl Zellbiologie und Pflanzenbiochemie, Biochemie-Zentrum Regensburg, Universität Regensburg, D-93053 Regensburg, Germany (P.C., S.A., T.D., S.S.)
- Department of Biology, University of Utah, Salt Lake City, Utah 84112 (J.G.S., A.L., G.N.D.); and
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Università di Milano, 20133 Milan, Italy (P.M., L.C.)
| | - Joshua G Steffen
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133 Milan, Italy (F.R., P.M., C.M., L.C., S.M.)
- Lehrstuhl Zellbiologie und Pflanzenbiochemie, Biochemie-Zentrum Regensburg, Universität Regensburg, D-93053 Regensburg, Germany (P.C., S.A., T.D., S.S.)
- Department of Biology, University of Utah, Salt Lake City, Utah 84112 (J.G.S., A.L., G.N.D.); and
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Università di Milano, 20133 Milan, Italy (P.M., L.C.)
| | - Svenja Alter
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133 Milan, Italy (F.R., P.M., C.M., L.C., S.M.)
- Lehrstuhl Zellbiologie und Pflanzenbiochemie, Biochemie-Zentrum Regensburg, Universität Regensburg, D-93053 Regensburg, Germany (P.C., S.A., T.D., S.S.)
- Department of Biology, University of Utah, Salt Lake City, Utah 84112 (J.G.S., A.L., G.N.D.); and
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Università di Milano, 20133 Milan, Italy (P.M., L.C.)
| | - Piero Morandini
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133 Milan, Italy (F.R., P.M., C.M., L.C., S.M.)
- Lehrstuhl Zellbiologie und Pflanzenbiochemie, Biochemie-Zentrum Regensburg, Universität Regensburg, D-93053 Regensburg, Germany (P.C., S.A., T.D., S.S.)
- Department of Biology, University of Utah, Salt Lake City, Utah 84112 (J.G.S., A.L., G.N.D.); and
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Università di Milano, 20133 Milan, Italy (P.M., L.C.)
| | - Chiara Mizzotti
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133 Milan, Italy (F.R., P.M., C.M., L.C., S.M.)
- Lehrstuhl Zellbiologie und Pflanzenbiochemie, Biochemie-Zentrum Regensburg, Universität Regensburg, D-93053 Regensburg, Germany (P.C., S.A., T.D., S.S.)
- Department of Biology, University of Utah, Salt Lake City, Utah 84112 (J.G.S., A.L., G.N.D.); and
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Università di Milano, 20133 Milan, Italy (P.M., L.C.)
| | - Alan Lloyd
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133 Milan, Italy (F.R., P.M., C.M., L.C., S.M.)
- Lehrstuhl Zellbiologie und Pflanzenbiochemie, Biochemie-Zentrum Regensburg, Universität Regensburg, D-93053 Regensburg, Germany (P.C., S.A., T.D., S.S.)
- Department of Biology, University of Utah, Salt Lake City, Utah 84112 (J.G.S., A.L., G.N.D.); and
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Università di Milano, 20133 Milan, Italy (P.M., L.C.)
| | - Gary N Drews
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133 Milan, Italy (F.R., P.M., C.M., L.C., S.M.)
- Lehrstuhl Zellbiologie und Pflanzenbiochemie, Biochemie-Zentrum Regensburg, Universität Regensburg, D-93053 Regensburg, Germany (P.C., S.A., T.D., S.S.)
- Department of Biology, University of Utah, Salt Lake City, Utah 84112 (J.G.S., A.L., G.N.D.); and
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Università di Milano, 20133 Milan, Italy (P.M., L.C.)
| | - Thomas Dresselhaus
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133 Milan, Italy (F.R., P.M., C.M., L.C., S.M.)
- Lehrstuhl Zellbiologie und Pflanzenbiochemie, Biochemie-Zentrum Regensburg, Universität Regensburg, D-93053 Regensburg, Germany (P.C., S.A., T.D., S.S.)
- Department of Biology, University of Utah, Salt Lake City, Utah 84112 (J.G.S., A.L., G.N.D.); and
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Università di Milano, 20133 Milan, Italy (P.M., L.C.)
| | - Lucia Colombo
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133 Milan, Italy (F.R., P.M., C.M., L.C., S.M.)
- Lehrstuhl Zellbiologie und Pflanzenbiochemie, Biochemie-Zentrum Regensburg, Universität Regensburg, D-93053 Regensburg, Germany (P.C., S.A., T.D., S.S.)
- Department of Biology, University of Utah, Salt Lake City, Utah 84112 (J.G.S., A.L., G.N.D.); and
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Università di Milano, 20133 Milan, Italy (P.M., L.C.)
| | - Stefanie Sprunck
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133 Milan, Italy (F.R., P.M., C.M., L.C., S.M.);
- Lehrstuhl Zellbiologie und Pflanzenbiochemie, Biochemie-Zentrum Regensburg, Universität Regensburg, D-93053 Regensburg, Germany (P.C., S.A., T.D., S.S.);
- Department of Biology, University of Utah, Salt Lake City, Utah 84112 (J.G.S., A.L., G.N.D.); and
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Università di Milano, 20133 Milan, Italy (P.M., L.C.)
| | - Simona Masiero
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133 Milan, Italy (F.R., P.M., C.M., L.C., S.M.);
- Lehrstuhl Zellbiologie und Pflanzenbiochemie, Biochemie-Zentrum Regensburg, Universität Regensburg, D-93053 Regensburg, Germany (P.C., S.A., T.D., S.S.);
- Department of Biology, University of Utah, Salt Lake City, Utah 84112 (J.G.S., A.L., G.N.D.); and
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Università di Milano, 20133 Milan, Italy (P.M., L.C.)
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21
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Abstract
The few-celled female gametophyte, or embryo sac, of flowering plants is not easily accessible as it is buried within the sporophytic tissues of the ovule. Nevertheless, it has become an attractive model system to study the molecular mechanisms underlying patterning and cell type specification, as well as fertilization of the two female gametes, the egg and the central cell. While female gametes, zygotes, and early embryos can be manually isolated from the embryo sacs in maize, wheat, tobacco, and rice by micromanipulation, this approach had been considered impossible for the much smaller embryo sac of the model plant Arabidopsis thaliana. Here, we describe a method to isolate living cells from the Arabidopsis female gametophyte by micromanipulation. The manual isolation of egg cells, central cells, and synergid cells is a technique that enables a number of important studies such as cell-type-specific transcriptional profiling or the analysis of DNA methylation profiles. It also offers the possibility to use isolated female gametes for in vitro fertilization studies.
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Affiliation(s)
- Maria Englhart
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Universitaetsstrasse 31, 93053, Regensburg, Germany
| | - Lucija Šoljić
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Universitaetsstrasse 31, 93053, Regensburg, Germany
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Universitaetsstrasse 31, 93053, Regensburg, Germany.
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22
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Abstract
Compared with the animal kingdom, fertilization is particularly complex in flowering plants (angiosperms). Sperm cells of angiosperms have lost their motility and require transportation as a passive cargo by the pollen tube cell to the egg apparatus (egg cell and accessory synergid cells). Sperm cell release from the pollen tube occurs after intensive communication between the pollen tube cell and the receptive synergid, culminating in the lysis of both interaction partners. Following release of the two sperm cells, they interact and fuse with two dimorphic female gametes (the egg and the central cell) forming the major seed components embryo and endosperm, respectively. This process is known as double fertilization. Here, we review the current understanding of the processes of sperm cell reception, gamete interaction, their pre-fertilization activation and fusion, as well as the mechanisms plants use to prevent the fusion of egg cells with multiple sperm cells. The role of Ca(2+) is highlighted in these various processes and comparisons are drawn between fertilization mechanisms in flowering plants and other eukaryotes, including mammals.
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Affiliation(s)
- Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93040 Regensburg, Germany.
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93040 Regensburg, Germany
| | - Gary M Wessel
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island 02912, USA
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23
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Abstract
Fertilization of both egg and central cell is a major distinguishing feature of flowering plants. Now, Maruyama et al. report a third cell fusion event between the persistent synergid and the fertilized central cell shortly after double fertilization in Arabidopsis. This causes rapid dilution of pollen tube attractant(s), preventing polytubey.
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Affiliation(s)
- Stefanie Sprunck
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93053 Regensburg, Germany
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93053 Regensburg, Germany.
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24
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Vogler F, Konrad SSA, Sprunck S. Knockin' on pollen's door: live cell imaging of early polarization events in germinating Arabidopsis pollen. Front Plant Sci 2015; 6:246. [PMID: 25954283 PMCID: PMC4404733 DOI: 10.3389/fpls.2015.00246] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 03/27/2015] [Indexed: 05/20/2023]
Abstract
Pollen tubes are an excellent system for studying the cellular dynamics and complex signaling pathways that coordinate polarized tip growth. Although several signaling mechanisms acting in the tip-growing pollen tube have been described, our knowledge on the subcellular and molecular events during pollen germination and growth site selection at the pollen plasma membrane is rather scarce. To simultaneously track germinating pollen from up to 12 genetically different plants we developed an inexpensive and easy mounting technique, suitable for every standard microscope setup. We performed high magnification live-cell imaging during Arabidopsis pollen activation, germination, and the establishment of pollen tube tip growth by using fluorescent marker lines labeling either the pollen cytoplasm, vesicles, the actin cytoskeleton or the sperm cell nuclei and membranes. Our studies revealed distinctive vesicle and F-actin polarization during pollen activation and characteristic growth kinetics during pollen germination and pollen tube formation. Initially, the germinating Arabidopsis pollen tube grows slowly and forms a uniform roundish bulge, followed by a transition phase with vesicles heavily accumulating at the growth site before switching to rapid tip growth. Furthermore, we found the two sperm cells to be transported into the pollen tube after the phase of rapid tip growth has been initiated. The method presented here is suitable to quantitatively study subcellular events during Arabidopsis pollen germination and growth, and for the detailed analysis of pollen mutants with respect to pollen polarization, bulging, or growth site selection at the pollen plasma membrane.
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Affiliation(s)
- Frank Vogler
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum RegensburgUniversity of Regensburg, Regensburg Germany
| | - Sebastian S. A. Konrad
- Faculty of Biology, Institute of Genetics, Ludwig-Maximilians-University of MunichMartinsried, Germany
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum RegensburgUniversity of Regensburg, Regensburg Germany
- *Correspondence: Stefanie Sprunck, Department of Cell Biology and Plant Biochemistry, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany
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25
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Vogler F, Sprunck S. F-actin forms mobile and unwinding ring-shaped structures in germinating Arabidopsis pollen expressing Lifeact. Plant Signal Behav 2015; 10:e1075684. [PMID: 26337326 PMCID: PMC4883927 DOI: 10.1080/15592324.2015.1075684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The flowering plant pollen tube is the fastest elongating plant cell and transports the sperm cells for double fertilization. The highly dynamic formation and reorganization of the actin cytoskeleton is essential for pollen germination and pollen tube growth. To drive pollen-specific expression of fluorescent marker proteins, commonly the strong Lat52 promoter is used. Here we show by quantitative fluorescent analysis that the gametophyte-specific ARO1 promoter from Arabidopsis drives an about 3.5 times weaker transgene expression than the Lat52 promoter. In one third of the pollen of F-actin-labeled ARO1p:tagRFP-T-Lifeact transgenic lines we observed mobile ring-shaped actin structures in pollen grains and pollen tubes. Pollen tube growth, transgene transmission and seed production were not affected by tagRFP-T-Lifeact expression. F-actin rings were able to integrate into emerging actin filaments and they may reflect a particular physiological state of the pollen or a readily available storage form provided for rapid actin network remodeling.
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Affiliation(s)
- Frank Vogler
- Cell Biology and Plant Biochemistry; Biochemie-Zentrum Regensburg; University of Regensburg; Regensburg, Germany
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry; Biochemie-Zentrum Regensburg; University of Regensburg; Regensburg, Germany
- Correspondence to: Stefanie Sprunck;
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26
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Pereira AM, Masiero S, Nobre MS, Costa ML, Solís MT, Testillano PS, Sprunck S, Coimbra S. Differential expression patterns of arabinogalactan proteins in Arabidopsis thaliana reproductive tissues. J Exp Bot 2014; 65:5459-71. [PMID: 25053647 PMCID: PMC4400541 DOI: 10.1093/jxb/eru300] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 06/12/2014] [Accepted: 06/15/2014] [Indexed: 05/05/2023]
Abstract
Arabinogalactan proteins (AGPs) are heavily glycosylated proteins existing in all members of the plant kingdom and are differentially distributed through distinctive developmental stages. Here, we showed the individual distributions of specific Arabidopsis AGPs: AGP1, AGP9, AGP12, AGP15, and AGP23, throughout reproductive tissues and indicated their possible roles in several reproductive processes. AGP genes specifically expressed in female tissues were identified using available microarray data. This selection was confirmed by promoter analysis using multiple green fluorescent protein fusions to a nuclear localization signal, β-glucuronidase fusions, and in situ hybridization as approaches to confirm the expression patterns of the AGPs. Promoter analysis allowed the detection of a specific and differential presence of these proteins along the pathway followed by the pollen tube during its journey to reach the egg and the central cell inside the embryo sac. AGP1 was expressed in the stigma, style, transmitting tract, and the chalazal and funiculus tissues of the ovules. AGP9 was present along the vasculature of the reproductive tissues and AGP12 was expressed in the stigmatic cells, chalazal and funiculus cells of the ovules, and in the septum. AGP15 was expressed in all pistil tissues, except in the transmitting tract, while AGP23 was specific to the pollen grain and pollen tube. The expression pattern of these AGPs provides new evidence for the detection of a subset of specific AGPs involved in plant reproductive processes, being of significance for this field of study. AGPs are prominent candidates for male-female communication during reproduction.
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Affiliation(s)
- Ana Marta Pereira
- Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal Center for Biodiversity, Functional & Integrative Genomics (BioFIG), Porto, Portugal Dipartimento di BioScienze, Università degli Studi di Milano, 20133 Milan, Italy
| | - Simona Masiero
- Dipartimento di BioScienze, Università degli Studi di Milano, 20133 Milan, Italy
| | - Margarida Sofia Nobre
- Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
| | - Mário Luís Costa
- Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal Center for Biodiversity, Functional & Integrative Genomics (BioFIG), Porto, Portugal
| | - María-Teresa Solís
- Pollen Biotechnology of Crop Plants Group, Centro de Investigaciones Biológicas (CIB) CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Pilar S Testillano
- Pollen Biotechnology of Crop Plants Group, Centro de Investigaciones Biológicas (CIB) CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Sílvia Coimbra
- Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal Center for Biodiversity, Functional & Integrative Genomics (BioFIG), Porto, Portugal
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27
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Vogler F, Schmalzl C, Englhart M, Bircheneder M, Sprunck S. Brassinosteroids promote Arabidopsis pollen germination and growth. Plant Reprod 2014; 27:153-67. [PMID: 25077683 DOI: 10.1007/s00497-014-0247-x] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 07/07/2014] [Indexed: 05/08/2023]
Abstract
Pollen tubes are among the fastest tip-growing plant cells and represent an excellent experimental system for studying the dynamics and spatiotemporal control of polarized cell growth. However, investigating pollen tube tip growth in the model plant Arabidopsis remains difficult because in vitro pollen germination and pollen tube growth rates are highly variable and largely different from those observed in pistils, most likely due to growth-promoting properties of the female reproductive tract. We found that in vitro grown Arabidopsis pollen respond to brassinosteroid (BR) in a dose-dependent manner. Pollen germination and pollen tube growth increased nine- and fivefold, respectively, when media were supplemented with 10 µM epibrassinolide (epiBL), resulting in growth kinetics more similar to growth in vivo. Expression analyses show that the promoter of one of the key enzymes in BR biosynthesis, CYP90A1/CPD, is highly active in the cells of the reproductive tract that form the pathway for pollen tubes from the stigma to the ovules. Pollen tubes grew significantly shorter through the reproductive tract of a cyp90a1 mutant compared to the wild type, or to a BR perception mutant. Our results show that epiBL promotes pollen germination and tube growth in vitro and suggest that the cells of the reproductive tract provide BR compounds to stimulate pollen tube growth.
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Affiliation(s)
- Frank Vogler
- Cell Biology and Plant Biochemistry, Biochemistry Center Regensburg, University of Regensburg, Universitaetsstrasse 31, 93053, Regensburg, Germany
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28
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Rademacher S, Sprunck S. Downregulation of egg cell-secreted EC1 is accompanied with delayed gamete fusion and polytubey. Plant Signal Behav 2013; 8:e27377. [PMID: 24384993 DOI: 10.4161/psb.2737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
One major player known to be essential for successful gamete interactions during double fertilization in Arabidopsis thaliana is the recently identified family of egg cell-secreted EC1 proteins. Both gamete fusion events are affected in EC1-deficient female gametophytes. Here, we show that the number of ovules with unfused sperm cells is considerably higher than the number of undeveloped seeds in the same ec1-RNAi knockdown lines. We found that some sperm cells are able to fuse with the female gametes even 2 to 3 days after pollination, as reflected by delayed embryo and endosperm development, and by polytubey. We propose that the egg cell secretes EC1 proteins upon sperm arrival to promote rapid sperm activation, thereby accelerating gamete fusion and preventing polytubey.
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Affiliation(s)
- Svenja Rademacher
- Cell Biology and Plant Biochemistry; University of Regensburg; Regensburg, Germany
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry; University of Regensburg; Regensburg, Germany
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29
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Leljak-Levanić D, Juranić M, Sprunck S. De novo zygotic transcription in wheat (Triticum aestivum L.) includes genes encoding small putative secreted peptides and a protein involved in proteasomal degradation. Plant Reprod 2013; 26:267-85. [PMID: 23912470 DOI: 10.1007/s00497-013-0229-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 07/10/2013] [Indexed: 05/12/2023]
Abstract
Wheat is one of the world's most important crops, and increasing grain yield is a major challenge for the future. Still, our knowledge about the molecular machineries responsible for early post-fertilization events such as zygotic reprogramming, the initial cell-specification events during embryogenesis, and the intercellular communication between the early embryo and the developing endosperm is very limited. Here, we describe the identification of de novo transcribed genes in the wheat zygote. We used wheat ovaries of defined post-fertilization stages to isolate zygotes and early embryos, and identified genes that are specifically induced in these particular stages. Importantly, we observed that some of the zygotic-induced genes encode proteins with similarity to secreted signaling peptides such as TAPETUM DETERMINANT 1 and EGG APPARATUS 1, and to MATH-BTB proteins which are known substrate-binding adaptors for the Cullin3-based ubiquitin E3 ligase. This suggests that both cell-cell signaling and targeted proteasomal degradation may be important molecular events during zygote formation and the progression of early embryogenesis.
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Affiliation(s)
- Dunja Leljak-Levanić
- Department of Molecular Biology, Faculty of Science and Mathematics, University of Zagreb, Horvatovac 102a, 10000, Zagreb, Croatia
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30
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Rademacher S, Sprunck S. Downregulation of egg cell-secreted EC1 is accompanied with delayed gamete fusion and polytubey. Plant Signal Behav 2013; 8:e27377. [PMID: 24384993 PMCID: PMC4091341 DOI: 10.4161/psb.27377] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 11/27/2013] [Accepted: 11/28/2013] [Indexed: 05/18/2023]
Abstract
One major player known to be essential for successful gamete interactions during double fertilization in Arabidopsis thaliana is the recently identified family of egg cell-secreted EC1 proteins. Both gamete fusion events are affected in EC1-deficient female gametophytes. Here, we show that the number of ovules with unfused sperm cells is considerably higher than the number of undeveloped seeds in the same ec1-RNAi knockdown lines. We found that some sperm cells are able to fuse with the female gametes even 2 to 3 days after pollination, as reflected by delayed embryo and endosperm development, and by polytubey. We propose that the egg cell secretes EC1 proteins upon sperm arrival to promote rapid sperm activation, thereby accelerating gamete fusion and preventing polytubey.
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Sprunck S, Rademacher S, Vogler F, Gheyselinck J, Grossniklaus U, Dresselhaus T. Egg cell-secreted EC1 triggers sperm cell activation during double fertilization. Science 2012. [PMID: 23180860 DOI: 10.1126/science.1223944] [Citation(s) in RCA: 223] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Double fertilization is the defining characteristic of flowering plants. However, the molecular mechanisms regulating the fusion of one sperm with the egg and the second sperm with the central cell are largely unknown. We show that gamete interactions in Arabidopsis depend on small cysteine-rich EC1 (EGG CELL 1) proteins accumulating in storage vesicles of the egg cell. Upon sperm arrival, EC1-containing vesicles are exocytosed. The sperm endomembrane system responds to exogenously applied EC1 peptides by redistributing the potential gamete fusogen HAP2/GCS1 (HAPLESS 2/GENERATIVE CELL SPECIFIC 1) to the cell surface. Furthermore, fertilization studies with ec1 quintuple mutants show that successful male-female gamete interactions are necessary to prevent multiple-sperm cell delivery. Our findings provide evidence that mutual gamete activation, regulated exocytosis, and sperm plasma membrane modifications govern flowering plant gamete interactions.
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Affiliation(s)
- Stefanie Sprunck
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany.
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Juranić M, Srilunchang KO, Krohn NG, Leljak-Levanić D, Sprunck S, Dresselhaus T. Germline-specific MATH-BTB substrate adaptor MAB1 regulates spindle length and nuclei identity in maize. Plant Cell 2012; 24:4974-91. [PMID: 23250449 PMCID: PMC3556970 DOI: 10.1105/tpc.112.107169] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Germline and early embryo development constitute ideal model systems to study the establishment of polarity, cell identity, and asymmetric cell divisions (ACDs) in plants. We describe here the function of the MATH-BTB domain protein MAB1 that is exclusively expressed in the germ lineages and the zygote of maize (Zea mays). mab1 (RNA interference [RNAi]) mutant plants display chromosome segregation defects and short spindles during meiosis that cause insufficient separation and migration of nuclei. After the meiosis-to-mitosis transition, two attached nuclei of similar identity are formed in mab1 (RNAi) mutants leading to an arrest of further germline development. Transient expression studies of MAB1 in tobacco (Nicotiana tabacum) Bright Yellow-2 cells revealed a cell cycle-dependent nuclear localization pattern but no direct colocalization with the spindle apparatus. MAB1 is able to form homodimers and interacts with the E3 ubiquitin ligase component Cullin 3a (CUL3a) in the cytoplasm, likely as a substrate-specific adapter protein. The microtubule-severing subunit p60 of katanin was identified as a candidate substrate for MAB1, suggesting that MAB1 resembles the animal key ACD regulator Maternal Effect Lethal 26 (MEL-26). In summary, our findings provide further evidence for the importance of posttranslational regulation for asymmetric divisions and germline progression in plants and identified an unstable key protein that seems to be involved in regulating the stability of a spindle apparatus regulator(s).
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Affiliation(s)
- Martina Juranić
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93053 Regensburg, Germany
- Department of Molecular Biology, Faculty of Science and Mathematics, University of Zagreb, 10000 Zagreb, Croatia
| | | | - Nádia Graciele Krohn
- Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirao Preto 14040-903, Brazil
| | - Dunja Leljak-Levanić
- Department of Molecular Biology, Faculty of Science and Mathematics, University of Zagreb, 10000 Zagreb, Croatia
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93053 Regensburg, Germany
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93053 Regensburg, Germany
- Address correspondence to
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Zhao X, Harashima H, Dissmeyer N, Pusch S, Weimer AK, Bramsiepe J, Bouyer D, Rademacher S, Nowack MK, Novak B, Sprunck S, Schnittger A. A general G1/S-phase cell-cycle control module in the flowering plant Arabidopsis thaliana. PLoS Genet 2012; 8:e1002847. [PMID: 22879821 PMCID: PMC3410867 DOI: 10.1371/journal.pgen.1002847] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Accepted: 06/05/2012] [Indexed: 01/12/2023] Open
Abstract
The decision to replicate its DNA is of crucial importance for every cell and, in many organisms, is decisive for the progression through the entire cell cycle. A comparison of animals versus yeast has shown that, although most of the involved cell-cycle regulators are divergent in both clades, they fulfill a similar role and the overall network topology of G1/S regulation is highly conserved. Using germline development as a model system, we identified a regulatory cascade controlling entry into S phase in the flowering plant Arabidopsis thaliana, which, as a member of the Plantae supergroup, is phylogenetically only distantly related to Opisthokonts such as yeast and animals. This module comprises the Arabidopsis homologs of the animal transcription factor E2F, the plant homolog of the animal transcriptional repressor Retinoblastoma (Rb)-related 1 (RBR1), the plant-specific F-box protein F-BOX-LIKE 17 (FBL17), the plant specific cyclin-dependent kinase (CDK) inhibitors KRPs, as well as CDKA;1, the plant homolog of the yeast and animal Cdc2⁺/Cdk1 kinases. Our data show that the principle of a double negative wiring of Rb proteins is highly conserved, likely representing a universal mechanism in eukaryotic cell-cycle control. However, this negative feedback of Rb proteins is differently implemented in plants as it is brought about through a quadruple negative regulation centered around the F-box protein FBL17 that mediates the degradation of CDK inhibitors but is itself directly repressed by Rb. Biomathematical simulations and subsequent experimental confirmation of computational predictions revealed that this regulatory circuit can give rise to hysteresis highlighting the here identified dosage sensitivity of CDK inhibitors in this network.
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Affiliation(s)
- Xin'Ai Zhao
- Department of Molecular Mechanisms of Phenotypic Plasticity, Institut de Biologie Mole´culaire des Plantes, Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
| | - Hirofumi Harashima
- Department of Molecular Mechanisms of Phenotypic Plasticity, Institut de Biologie Mole´culaire des Plantes, Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
- Trinationales Institut für Pflanzenforschung, Strasbourg, France
| | - Nico Dissmeyer
- Department of Molecular Mechanisms of Phenotypic Plasticity, Institut de Biologie Mole´culaire des Plantes, Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
| | - Stefan Pusch
- Unigruppe am Max-Planck-Institut für Pflanzenzü chtungsforschung, Lehrstuhl für Botanik III, Universität zu Köln, Köln, Germany
| | - Annika K. Weimer
- Department of Molecular Mechanisms of Phenotypic Plasticity, Institut de Biologie Mole´culaire des Plantes, Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
| | - Jonathan Bramsiepe
- Department of Molecular Mechanisms of Phenotypic Plasticity, Institut de Biologie Mole´culaire des Plantes, Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
| | - Daniel Bouyer
- Department of Molecular Mechanisms of Phenotypic Plasticity, Institut de Biologie Mole´culaire des Plantes, Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
| | - Svenja Rademacher
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Moritz K. Nowack
- Department of Plant Systems Biology, VIB, Gent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Gent, Belgium
| | - Bela Novak
- Oxford Centre for Integrative Systems Biology, Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Arp Schnittger
- Department of Molecular Mechanisms of Phenotypic Plasticity, Institut de Biologie Mole´culaire des Plantes, Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
- Trinationales Institut für Pflanzenforschung, Strasbourg, France
- Unigruppe am Max-Planck-Institut für Pflanzenzü chtungsforschung, Lehrstuhl für Botanik III, Universität zu Köln, Köln, Germany
- * E-mail:
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Völz R, von Lyncker L, Baumann N, Dresselhaus T, Sprunck S, Groß-Hardt R. LACHESIS-dependent egg-cell signaling regulates the development of female gametophytic cells. Development 2012; 139:498-502. [DOI: 10.1242/dev.075234] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In contrast to animals, plant germ cells are formed along with accessory cells in specialized haploid generations, termed gametophytes. The female gametophyte of flowering plants consists of four different cell types, which exert distinct functions in the reproductive process. For successful fertilization, the development of the four cell types has to be tightly coordinated; however, the underlying mechanisms are not yet understood. We have previously isolated the lachesis (lis) mutant, which forms supernumerary gametes at the expense of adjacent accessory cells. LIS codes for the Arabidopsis homolog of the pre-mRNA splicing factor PRP4 and shows a dynamic expression pattern in the maturing female gametophyte. Here, we used LIS as a molecular tool to study cell-cell communication in the female gametophyte. We show that reducing LIS transcript amounts specifically in the egg cell, affects the development of all female gametophytic cells, indicating that cell differentiation in the female gametophyte is orchestrated by the egg cell. Among the defects observed is the failure of homotypic nuclei fusion in the central cell and, as a consequence, a block in endosperm formation. LIS-mediated egg cell signaling, thus, provides a safeguard mechanism that prevents the formation of nurturing tissue in the absence of a functional egg cell.
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Affiliation(s)
- Ronny Völz
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany
| | - Ludwig von Lyncker
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany
| | - Nadine Baumann
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Rita Groß-Hardt
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany
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Ingouff M, Sakata T, Li J, Sprunck S, Dresselhaus T, Berger F. The two male gametes share equal ability to fertilize the egg cell in Arabidopsis thaliana. Curr Biol 2009; 19:R19-20. [PMID: 19138583 DOI: 10.1016/j.cub.2008.11.025] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Gebert M, Dresselhaus T, Sprunck S. F-actin organization and pollen tube tip growth in Arabidopsis are dependent on the gametophyte-specific Armadillo repeat protein ARO1. Plant Cell 2008; 20:2798-814. [PMID: 18931021 PMCID: PMC2590741 DOI: 10.1105/tpc.108.061028] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The signal-mediated and spatially controlled assembly and dynamics of actin are crucial for maintaining shape, motility, and tip growth of eukaryotic cells. We report that a novel Armadillo repeat protein in Arabidopsis thaliana, ARMADILLO REPEAT ONLY1 (ARO1), is of fundamental importance for polar growth and F-actin organization in tip-growing pollen tubes. ARO1 is specifically expressed in the vegetative cell of pollen as well as in the egg cell. ARO1-GFP (for green fluorescent protein) fusion proteins accumulate most notably in pollen tube tips and partially colocalize with F-actin in the shank of pollen tubes. ARO1 knockout results in a highly disorganized actin cytoskeleton, growth depolarization, and ultimately tube growth arrest. Tip-localized ARO1-GFP is spatially shifted toward the future site of tip growth, indicating a role of ARO1 in the signaling network controlling tip growth and regulating actin organization. After the pollen tube discharges its contents into the receptive synergid, ARO1-GFP colocalizes with emerging F-actin structures near the site of sperm cell fusion, suggesting additional participation in the mechanism of sperm cell tracking toward the female gametes. The variable localization of ARO1 in the cytoplasm, the nucleus, and at the plasma membrane, however, indicates a multifunctional role like that of beta-catenin/Armadillo and the p120 catenins.
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Affiliation(s)
- Marina Gebert
- Cell Biology and Plant Physiology, University of Regensburg, 93053 Regensburg, Germany
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Sprunck S, Baumann U, Edwards K, Langridge P, Dresselhaus T. The transcript composition of egg cells changes significantly following fertilization in wheat (Triticum aestivum L.). Plant J 2005; 41:660-72. [PMID: 15703054 DOI: 10.1111/j.1365-313x.2005.02332.x] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Here, we report the transcript profile of wheat egg cells and proembryos, just after the first cell division. Microdissected female gametophytes of wheat were used to isolate eggs and two-celled proembryos to construct cell type-specific cDNA libraries. In total, 1197 expressed sequence tags (ESTs) were generated. Analysis of these ESTs revealed numerous novel transcripts. In egg cells, 17.6% of the clustered ESTs represented novel transcripts, while 11.4% novel clusters were identified in the two-celled proembryo. Functional classification of sequences with similarity to previously characterized proteins indicates that the unfertilized egg cell has a higher metabolic activity and protein turnover than previously thought. Transcript composition of two-celled proembryos was significantly distinct from egg cells, reflecting DNA replication as well as high transcriptional and translational activity. Several novel transcripts of the egg cell are specific for this cell. In contrast, some fertilization induced novel mRNAs are abundant also in sporophytic tissues indicating a more general role in plant growth and development. The potential functions of genes based on similarity to known genes involved in developmental processes are discussed. Our analysis has identified numerous genes with potential roles in embryo sac function such as signaling, fertilization or induction of embryogenesis.
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Affiliation(s)
- Stefanie Sprunck
- Developmental Biology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg, Ohnhorststrasse 18, D-22609 Hamburg, Germany
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Kluth A, Sprunck S, Becker D, Lörz H, Lütticke S. 5' deletion of a gbss1 promoter region from wheat leads to changes in tissue and developmental specificities. Plant Mol Biol 2002; 49:669-682. [PMID: 12081374 DOI: 10.1023/a:1015576930688] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Expression of granule-bound starch synthase 1 (GBSS1) in wheat is restricted to the grain filling process. In order to identify promoter regions which are involved in transcriptional control of the observed expression pattern, we isolated about 8 kb of a wheat gbss1-upstream region. Within this sequence several putative cis-acting elements were identified. In addition, an untranslated leader region is located in the 5' region of the gbss1 gene. To investigate promoter activity of the isolated region, the proximal 4.0 kb and progressively 5'-deleted fragments were transcriptionally fused to a beta-glucuronidase reporter gene. The function of the promoter constructs was tested by transient expression assays in various wheat tissues and in transgenic wheat plants, which were selected for low number and integrity of transgene copies. Analysis of stable transformants revealed that the -4.0 kb promoter region mediates reporter gene expression that is in accordance with the endogenous gbss1 expression. Promoter deletion to -1.9 kb or to -1.0 kb did not change the expression profile with regard to grain and pollen specificity. However, the profile of beta-glucuronidase expression during the grain filling process is altered in such a way that the level of beta-glucuronidase activity declines due to the decreasing promoter length. It is proposed that enhancer elements and cis-acting elements, which are involved in gbss1 transcription during the grain filling process, are located -1.9 kb upstream of the promoter. In addition, participation of the untranslated leader region in tissue-specific gene expression is discussed.
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Affiliation(s)
- Antje Kluth
- Centre for Applied Plant Molecular Biology (AMP II), University of Hamburg, Germany
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