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A Silent Exonic Mutation in a Rice Integrin-α FG-GAP Repeat-Containing Gene Causes Male-Sterility by Affecting mRNA Splicing. Int J Mol Sci 2020; 21:ijms21062018. [PMID: 32188023 PMCID: PMC7139555 DOI: 10.3390/ijms21062018] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 03/12/2020] [Accepted: 03/14/2020] [Indexed: 12/11/2022] Open
Abstract
Pollen development plays crucial roles in the life cycle of higher plants. Here we characterized a rice mutant with complete male-sterile phenotype, pollen-less 1 (pl1). pl1 exhibited smaller anthers with arrested pollen development, absent Ubisch bodies, necrosis-like tapetal hypertrophy, and smooth anther cuticular surface. Molecular mapping revealed a synonymous mutation in the fourth exon of PL1 co-segregated with the mutant phenotype. This mutation disrupts the exon-intron splice junction in PL1, generating aberrant mRNA species and truncated proteins. PL1 is highly expressed in the tapetal cells of developing anther, and its protein is co-localized with plasma membrane (PM) and endoplasmic reticulum (ER) signal. PL1 encodes an integrin-α FG-GAP repeat-containing protein, which has seven β-sheets and putative Ca2+-binding motifs and is broadly conserved in terrestrial plants. Our findings therefore provide insights into both the role of integrin-α FG-GAP repeat-containing protein in rice male fertility and the influence of exonic mutation on intronic splice donor site selection.
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Oh SA, Hoai TNT, Park HJ, Zhao M, Twell D, Honys D, Park SK. MYB81, a microspore-specific GAMYB transcription factor, promotes pollen mitosis I and cell lineage formation in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 101:590-603. [PMID: 31610057 DOI: 10.1111/tpj.14564] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/10/2019] [Accepted: 09/20/2019] [Indexed: 06/10/2023]
Abstract
Sexual reproduction in flowering plants relies on the production of haploid gametophytes that consist of germline and supporting cells. During male gametophyte development, the asymmetric mitotic division of an undetermined unicellular microspore segregates these two cell lineages. To explore genetic regulation underlying this process, we screened for pollen cell patterning mutants and isolated the heterozygous myb81-1 mutant that sheds ~50% abnormal pollen. Typically, myb81-1 microspores fail to undergo pollen mitosis I (PMI) and arrest at polarized stage with a single central vacuole. Although most myb81-1 microspores degenerate without division, a small fraction divides at later stages and fails to acquire correct cell fates. The myb81-1 allele is transmitted normally through the female, but rarely through pollen. We show that myb81-1 phenotypes result from impaired function of the GAMYB transcription factor MYB81. The MYB81 promoter shows microspore-specific activity and a MYB81-RFP fusion protein is only expressed in a narrow window prior to PMI. Ectopic expression of MYB81 driven by various promoters can severely impair vegetative or reproductive development, reflecting the strict microspore-specific control of MYB81. Our data demonstrate that MYB81 has a key role in the developmental progression of microspores, enabling formation of the two male cell lineages that are essential for sexual reproduction in Arabidopsis.
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Affiliation(s)
- Sung-Aeong Oh
- School of Applied Biosciences, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Thuong Nguyen Thi Hoai
- School of Applied Biosciences, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Hyo-Jin Park
- School of Applied Biosciences, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Mingmin Zhao
- Department of Genetics and Genome Biology, University of Leicester, University Road, Leicester, LE1 7RH, UK
| | - David Twell
- Department of Genetics and Genome Biology, University of Leicester, University Road, Leicester, LE1 7RH, UK
| | - David Honys
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, v.v.i., Prague, Czech Republic
| | - Soon-Ki Park
- School of Applied Biosciences, Kyungpook National University, Daegu, 41566, Republic of Korea
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53
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Zhong S, Wang Z, Qu LJ. Obtaining Mutant Pollen for Phenotypic Analysis and Pollen Tube Dual Staining. Methods Mol Biol 2020; 2160:181-190. [PMID: 32529436 DOI: 10.1007/978-1-0716-0672-8_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Mutant phenotype observation is the most useful and important method to study which biological process a gene-of-interest is involved in. In flowering plants, excessive pollen grains land and germinate on the stigma, then pollen tubes grow through the transmitting tract to reach the ovules, eventually enter the micropyle to complete double fertilization. First, for mutants whose homozygotes could not be obtained due to pollen tube defects, it is difficult to observe the defect phenotype since the pollen grains of different genotypes are mixed together. Here, we provide a detailed protocol to pick out mutant pollen grains from the heterozygous mutant plants in Arabidopsis thaliana. By using this method, we could obtain sufficient mutant pollen grains for phenotypic analysis. Second, it is difficult to compare the pollen/pollen tube behavior of two different genotypes/species in vivo in a same pistil. Here, we develop a new dual staining method which combines GUS staining with aniline blue staining. By using this method, we can analyze the competence of the two different pollen tubes in the same pistil.
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Affiliation(s)
- Sheng Zhong
- State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing, People's Republic of China
| | - Zhijuan Wang
- State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing, People's Republic of China
| | - Li-Jia Qu
- State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing, People's Republic of China. .,National Plant Gene Research Center, Peking University, Beijing, People's Republic of China.
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54
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Norizuki T, Minamino N, Ueda T. Role of Autophagy in Male Reproductive Processes in Land Plants. FRONTIERS IN PLANT SCIENCE 2020; 11:756. [PMID: 32625219 PMCID: PMC7311755 DOI: 10.3389/fpls.2020.00756] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 05/12/2020] [Indexed: 05/02/2023]
Abstract
Autophagy is a highly conserved system for degrading and recycling cytoplasmic components. The identification of autophagy-related (ATG) genes, required for autophagosome formation, has led to numerous studies using atg mutants. These studies have revealed the physiological significance of autophagy in various functions of diverse organisms. In land plants, autophagy is required for higher-order functions such as stress responses and development. Although defective autophagy does not result in any marked defect in the reproductive processes of Arabidopsis thaliana under laboratory conditions, several studies have shown that autophagy plays a pivotal role in male reproduction in several land plants. In this review, we aim to summarize information on the role of autophagy in male reproductive processes in land plants.
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Affiliation(s)
- Takuya Norizuki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
- Division of Cellular Dynamics, National Institute for Basic Biology, Okazaki, Japan
| | - Naoki Minamino
- Division of Cellular Dynamics, National Institute for Basic Biology, Okazaki, Japan
| | - Takashi Ueda
- Division of Cellular Dynamics, National Institute for Basic Biology, Okazaki, Japan
- The Department of Basic Biology, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan
- *Correspondence: Takashi Ueda,
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55
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Hisanaga T, Yamaoka S, Kawashima T, Higo A, Nakajima K, Araki T, Kohchi T, Berger F. Building new insights in plant gametogenesis from an evolutionary perspective. NATURE PLANTS 2019; 5:663-669. [PMID: 31285561 DOI: 10.1038/s41477-019-0466-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 05/29/2019] [Indexed: 05/18/2023]
Abstract
Extant bryophytes are thought to preserve characteristics of ancestral land plants, with a life cycle dominated by the haploid gametophyte. The gametophyte produces gametes in specialized organs that differentiate after an extensive phase of vegetative development. During land plant evolution, these organs became extremely reduced. As a result, in flowers of angiosperms the haploid phase of the life cycle is reduced to few-celled gametophytes, namely the embryo sac (female) and pollen (male). Although many factors contributing to gametogenesis have been identified in flowering plants, the extreme reduction of the gametophytes has prevented a clear molecular dissection of key processes of gametogenesis. Recent studies in the model bryophyte Marchantia polymorpha have identified conserved transcription factors regulating the equivalent steps in the sexual reproduction of land plants. These include FEMALE GAMETOPHYTE MYB for female gametophyte development, BONOBO for gamete progenitor cell specification, DUO POLLEN1 for sperm differentiation and members of the RWP-RK domain family for female gamete formation. These studies demonstrate that M. polymorpha is a powerful model to untangle the core processes of gametogenesis in land plants. We anticipate that a deeper understanding of gametogenesis in bryophytes will circumscribe the origin of plant germ cells and define the differentiation programmes of sperm and eggs.
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Affiliation(s)
- Tetsuya Hisanaga
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
- Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
| | - Shohei Yamaoka
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Tomokazu Kawashima
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY, USA
| | - Asuka Higo
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- Kihara Institute for Biological Research, Yokohama City University, Yokohama, Japan
| | - Keiji Nakajima
- Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
| | - Takashi Araki
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Takayuki Kohchi
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Frédéric Berger
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria.
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56
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He S, Vickers M, Zhang J, Feng X. Natural depletion of histone H1 in sex cells causes DNA demethylation, heterochromatin decondensation and transposon activation. eLife 2019; 8:42530. [PMID: 31135340 PMCID: PMC6594752 DOI: 10.7554/elife.42530] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 05/26/2019] [Indexed: 01/09/2023] Open
Abstract
Transposable elements (TEs), the movement of which can damage the genome, are epigenetically silenced in eukaryotes. Intriguingly, TEs are activated in the sperm companion cell - vegetative cell (VC) - of the flowering plant Arabidopsis thaliana. However, the extent and mechanism of this activation are unknown. Here we show that about 100 heterochromatic TEs are activated in VCs, mostly by DEMETER-catalyzed DNA demethylation. We further demonstrate that DEMETER access to some of these TEs is permitted by the natural depletion of linker histone H1 in VCs. Ectopically expressed H1 suppresses TEs in VCs by reducing DNA demethylation and via a methylation-independent mechanism. We demonstrate that H1 is required for heterochromatin condensation in plant cells and show that H1 overexpression creates heterochromatic foci in the VC progenitor cell. Taken together, our results demonstrate that the natural depletion of H1 during male gametogenesis facilitates DEMETER-directed DNA demethylation, heterochromatin relaxation, and TE activation.
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Affiliation(s)
- Shengbo He
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
| | - Martin Vickers
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
| | - Jingyi Zhang
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
| | - Xiaoqi Feng
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
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57
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Misra CS, Santos MR, Rafael-Fernandes M, Martins NP, Monteiro M, Becker JD. Transcriptomics of Arabidopsis sperm cells at single-cell resolution. PLANT REPRODUCTION 2019; 32:29-38. [PMID: 30675644 DOI: 10.1007/s00497-018-00355-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 12/12/2018] [Indexed: 05/22/2023]
Abstract
We present a detailed protocol for isolation of single sperm cells and transcriptome analysis to study variation in gene expression between sperm cells. Male gametophyte development in flowering plants begins with a microspore mother cell, which upon two consecutive cell divisions forms a mature pollen grain containing a vegetative nucleus and two sperm cells. Pollen development is a highly dynamic process, involving changes at both the transcriptome and epigenome levels of vegetative nuclei and the pair of sperm cells that have their own cytoplasm and nucleus. While the overall transcriptome of Arabidopsis pollen development is well documented, studies at single-cell level, in particular of sperm cells, are still lacking. Such studies would be essential to understand whether and how the two sperm cells are transcriptionally different, in particular once the pollen tube grows through the transmitting tissue of the pistil. Here we describe a detailed protocol for isolation of single sperm cells from growing pollen tubes and analysis of their transcriptome.
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Affiliation(s)
- Chandra Shekhar Misra
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156, Oeiras, Portugal
- Instituto de Tecnologia Química e Biológica, Avenida da República, 2780-157, Oeiras, Portugal
| | - Mário R Santos
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156, Oeiras, Portugal
| | | | - Nuno P Martins
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156, Oeiras, Portugal
| | - Marta Monteiro
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156, Oeiras, Portugal
| | - Jörg D Becker
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156, Oeiras, Portugal.
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58
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Caselli F, Beretta VM, Mantegazza O, Petrella R, Leo G, Guazzotti A, Herrera-Ubaldo H, de Folter S, Mendes MA, Kater MM, Gregis V. REM34 and REM35 Control Female and Male Gametophyte Development in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2019; 10:1351. [PMID: 31708954 PMCID: PMC6821719 DOI: 10.3389/fpls.2019.01351] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 10/01/2019] [Indexed: 05/13/2023]
Abstract
The REproductive Meristem (REM) gene family encodes for transcription factors belonging to the B3 DNA binding domain superfamily. In Arabidopsis thaliana, the REM gene family is composed of 45 members, preferentially expressed during flower, ovule, and seed developments. Only a few members of this family have been functionally characterized: VERNALIZATION1 (VRN1) and, most recently, TARGET OF FLC AND SVP1 (TFS1) regulate flowering time and VERDANDI (VDD), together with VALKYRIE (VAL) that control the death of the receptive synergid cell in the female gametophyte. We investigated the role of REM34, REM35, and REM36, three closely related and linked genes similarly expressed in both female and male gametophytes. Simultaneous silencing by RNA interference (RNAi) caused about 50% of the ovules to remain unfertilized. Careful evaluation of both ovule and pollen developments showed that this partial sterility of the transgenic RNAi lines was due to a postmeiotic block in both female and male gametophytes. Furthermore, protein interaction assays revealed that REM34 and REM35 interact, which suggests that they work together during the first stages of gametogenesis.
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Affiliation(s)
- Francesca Caselli
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | | | - Otho Mantegazza
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - Rosanna Petrella
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - Giulia Leo
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - Andrea Guazzotti
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - Humberto Herrera-Ubaldo
- Laboratorio Nacional de Genómica para la Biodiversidad, Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Mexico
| | - Stefan de Folter
- Laboratorio Nacional de Genómica para la Biodiversidad, Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Mexico
| | | | - Martin M. Kater
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - Veronica Gregis
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
- *Correspondence: Veronica Gregis,
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59
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Garavello M, Cuenca J, Dreissig S, Fuchs J, Houben A, Aleza P. Assessing Ploidy Level Analysis and Single Pollen Genotyping of Diploid and Euploid Citrus Genotypes by Fluorescence-Activated Cell Sorting and Whole-Genome Amplification. FRONTIERS IN PLANT SCIENCE 2019; 10:1174. [PMID: 31611896 PMCID: PMC6769063 DOI: 10.3389/fpls.2019.01174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 08/27/2019] [Indexed: 05/06/2023]
Abstract
Flow cytometry is widely used to determine genome size and ploidy level in plants. This technique, when coupled with fluorescence-activated cell sorting (FACS), whole genome amplification and genotyping (WGA), opens up new opportunities for genetic studies of individualized nuclei. This strategy was used to analyze the genetic composition of single pollen nuclei of different citrus species. The flow cytometry and microscope observations allowed us to differentiate the populations of pollen nuclei present in the diploid and euploid genotypes analyzed, showing that citrus has binuclear pollen. We have identified in the "CSO" tangor an additional nuclei population composed by the vegetative plus generative nuclei. Genotyping of this nuclei population revealed that vegetative and generative nuclei show the same genetic configuration. In addition, we have demonstrated the presence of unreduced gametes in the diploid genotype "Mexican lime." Genomic amplification is a robust method for haploid nuclei genotyping with several molecular markers, whereas in diploid nuclei using heterozygous markers showed a bias towards one of the two alleles, limiting the use of this tool in this type of nuclei. We further discuss the importance and applications of single pollen genotyping in citrus genetic studies.
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Affiliation(s)
- Miguel Garavello
- Centro de Citricultura y Producción Vegetal, Instituto Valenciano de Investigaciones Agrarias (IVIA), Moncada, Valencia, Spain
- INTA, Concordia Agricultural Experiment Station, Concordia, Argentina
| | - José Cuenca
- Centro de Citricultura y Producción Vegetal, Instituto Valenciano de Investigaciones Agrarias (IVIA), Moncada, Valencia, Spain
| | - Steven Dreissig
- Department of Breeding Research, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Seeland, Germany
| | - Jörg Fuchs
- Department of Breeding Research, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Seeland, Germany
| | - Andreas Houben
- Department of Breeding Research, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Seeland, Germany
| | - Pablo Aleza
- Centro de Citricultura y Producción Vegetal, Instituto Valenciano de Investigaciones Agrarias (IVIA), Moncada, Valencia, Spain
- *Correspondence: Pablo Aleza,
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Abstract
The reproductive adaptations of land plants have played a key role in their terrestrial colonization and radiation. This encompasses mechanisms used for the production, dispersal and union of gametes to support sexual reproduction. The production of small motile male gametes and larger immotile female gametes (oogamy) in specialized multicellular gametangia evolved in the charophyte algae, the closest extant relatives of land plants. Reliance on water and motile male gametes for sexual reproduction was retained by bryophytes and basal vascular plants, but was overcome in seed plants by the dispersal of pollen and the guided delivery of non-motile sperm to the female gametes. Here we discuss the evolutionary history of male gametogenesis in streptophytes (green plants) and the underlying developmental biology, including recent advances in bryophyte and angiosperm models. We conclude with a perspective on research trends that promise to deliver a deeper understanding of the evolutionary and developmental mechanisms of male gametogenesis in plants.
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Affiliation(s)
- Dieter Hackenberg
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom.
| | - David Twell
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom.
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61
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Liu L, Lu Y, Wei L, Yu H, Cao Y, Li Y, Yang N, Song Y, Liang C, Wang T. Transcriptomics analyses reveal the molecular roadmap and long non-coding RNA landscape of sperm cell lineage development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 96:421-437. [PMID: 30047180 DOI: 10.1111/tpj.14041] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 07/19/2018] [Indexed: 06/08/2023]
Abstract
Sperm cell (SC) lineage development from the haploid microspore to SCs represents a unique biological process in which the microspore generates a larger vegetative cell (VC) and a smaller generative cell (GC) enclosed in the VC, then the GC further develops to functionally specified SCs in the VC for double fertilization. Understanding the mechanisms of SC lineage development remains a critical goal in plant biology. We isolated individual cells of the three cell types, and characterized the genome-wide atlas of long non-coding (lnc) RNAs and mRNAs of haploid SC lineage cells. Sperm cell lineage development involves global repression of genes for pluripotency, somatic development and metabolism following asymmetric microspore division and coordinated upregulation of GC/SC preferential genes. This process is accompanied by progressive loss of the active marks H3K4me3 and H3K9ac, and accumulation of the repressive methylation mark H3K9. The SC lineage has a higher ratio of lncRNAs to mRNAs and preferentially expresses a larger percentage of lncRNAs than does the non-SC lineage. A co-expression network showed that the largest set of lncRNAs in these nodes, with more than 100 links, are GC-preferential, and a small proportion of lncRNAs co-express with their neighboring genes. Single molecular fluorescence in situ hybridization showed that several candidate genes may be markers distinguishing the three cell types of the SC lineage. Our findings reveal the molecular programming and potential roles of lncRNAs in SC lineage development.
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Affiliation(s)
- Lingtong Liu
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Yunlong Lu
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Liqin Wei
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Hua Yu
- College of Life Science, University of Chinese Academy of Sciences, Beijing, 100049, China
- Research Center for Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yinghao Cao
- Research Center for Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yan Li
- Research Center for Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Ning Yang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Yunyun Song
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chengzhi Liang
- Research Center for Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Tai Wang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, 100049, China
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62
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Yao X, Tian L, Yang J, Zhao YN, Zhu YX, Dai X, Zhao Y, Yang ZN. Auxin production in diploid microsporocytes is necessary and sufficient for early stages of pollen development. PLoS Genet 2018; 14:e1007397. [PMID: 29813066 PMCID: PMC5993292 DOI: 10.1371/journal.pgen.1007397] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 06/08/2018] [Accepted: 05/07/2018] [Indexed: 12/26/2022] Open
Abstract
Gametophytic development in Arabidopsis depends on nutrients and cell wall materials from sporophytic cells. However, it is not clear whether hormones and signaling molecules from sporophytic tissues are also required for gametophytic development. Herein, we show that auxin produced by the flavin monooxygenases YUC2 and YUC6 in the sporophytic microsporocytes is essential for early stages of pollen development. The first asymmetric mitotic division (PMI) of haploid microspores is the earliest event in male gametophyte development. Microspore development in yuc2yuc6 double mutants arrests before PMI and consequently yuc2yuc6 fail to produce viable pollens. Our genetic analyses reveal that YUC2 and YUC6 act as sporophytic genes for pollen formation. We further show that ectopic production of auxin in tapetum, which provides nutrients for pollen development, fails to rescue the sterile phenotypes of yuc2yuc6. In contrast, production of auxin in either microsporocytes or microspores rescued the defects of pollen development in yuc2yuc6 double mutants. Our results demonstrate that local auxin biosynthesis in sporophytic microsporocytic cells and microspore controls male gametophyte development during the generation transition from sporophyte to male gametophyte. Plant life cycle alternates between the diploid sporophyte generation and the haploid gametophyte generation. Understanding the molecular mechanisms governing the generation alternation impacts fundamental plant biology and plant breeding. It is known that the development of haploid generation in vascular plants requires the diploid tapetum cells to supply nutrients. Here we show that the male gametophyte (haploid) development in Arabidopsis requires auxin produced in the diploid microsporocytic cells. Moreover, we show that auxin produced in microsporocytic cells and microspore is also sufficient to support normal development of the haploid microspores. This work demonstrates that Arabidopsis uses two different diploid cell types to supply growth hormone and nutrients for the growth of the haploid generation.
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Affiliation(s)
- Xiaozhen Yao
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai, China
| | - Lei Tian
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai, China
| | - Jun Yang
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai, China
- Sciences Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Yan-Na Zhao
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai, China
| | - Ying-Xiu Zhu
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai, China
| | - Xinhua Dai
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California, United States of America
| | - Yunde Zhao
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California, United States of America
- * E-mail: (YZ); (ZNY)
| | - Zhong-Nan Yang
- College of Life and Environment Sciences, Shanghai Normal University, Shanghai, China
- Sciences Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- * E-mail: (YZ); (ZNY)
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Zamora-Zaragoza J, Scheres B. Tuning Division and Differentiation in Stomata: How to Silence a MUTE. Dev Cell 2018; 45:282-283. [PMID: 29738706 DOI: 10.1016/j.devcel.2018.04.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Precise coordination of cell differentiation and division within a tissue context is critical for plant development. In this issue of Developmental Cell, Han et al. (2018) report a transcriptional switch that ensures proper patterning, the final cell division, and terminal differentiation of stomata.
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Affiliation(s)
| | - Ben Scheres
- Wageningen University and Research, Wageningen, the Netherlands; Rijk Zwaan Department of Biotechnology, Fijnaart, the Netherlands.
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Abstract
For the last 100 years, it has been uncontroversial to state that the plant germline is set aside late in development, but there is surprisingly little evidence to support this view. In contrast, much evolutionary theory and several recent empirical studies seem to suggest the opposite-that the germlines of some and perhaps most plants may be set aside early in development. But is this really the case? How much does it matter? How can we reconcile the new evidence with existing knowledge of plant development? And is there a way to reliably establish the timing of germline segregation in both model and nonmodel plants? Answering these questions is vital to understanding one of the most fundamental aspects of plant development and evolution.
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Affiliation(s)
- Robert Lanfear
- Ecology and Evolution, Research School of Biology, Australian National University, Canberra, Australia
- Biological Sciences, Macquarie University, Sydney, Australia
- * E-mail:
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65
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Lei R, Ma Z, Yu D. WRKY2/34-VQ20 Modules in Arabidopsis thaliana Negatively Regulate Expression of a Trio of Related MYB Transcription Factors During Pollen Development. FRONTIERS IN PLANT SCIENCE 2018; 9:331. [PMID: 29616054 PMCID: PMC5867338 DOI: 10.3389/fpls.2018.00331] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 02/28/2018] [Indexed: 05/25/2023]
Abstract
Male gametogenesis in plants is tightly controlled and involves the complex and precise regulation of transcriptional reprogramming. Interactions between WRKY proteins and VQ motif-containing proteins are required to control these complicated transcriptional networks. However, our understanding of the mechanisms by which these complexes affect downstream gene expression is quite limited. In this study, we found that WRKY2 and WKRY34 repress MYB97, MYB101, and MYB120 expression during male gametogenesis. MYB expression was up-regulated in the wrky2-1 wrky34-1 vq20-1 triple mutant during male gametogenesis. The expression levels of six potential targets of the three MYBs increased the most in the wrky2-1 wrky34-1 vq20-1 triple mutant, followed by the wrky2-1 wrky34-1 double mutant, compared with in wild-type. Yeast one-hybrid and dual luciferase reporter assays indicated that WRKY2 and WRKY34 recognized the MYB97 promoter by binding to its W-boxes. MYB97 overexpression caused defects in pollen germination and pollen tube length, which impacted male fertility. Thus, WRKY2/34-VQ20 complexes appear to negatively regulate the expression of certain MYBs during plant male gametogenesis.
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Affiliation(s)
- Rihua Lei
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Zhenbing Ma
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, China
| | - Diqiu Yu
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, China
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66
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Nakajima K. Be my baby: patterning toward plant germ cells. CURRENT OPINION IN PLANT BIOLOGY 2018; 41:110-115. [PMID: 29223127 DOI: 10.1016/j.pbi.2017.11.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 11/27/2017] [Accepted: 11/27/2017] [Indexed: 05/28/2023]
Abstract
In flowering plants, germ cells are formed via tightly coordinated patterning processes that facilitate specification of spore mother cells and meiosis during sporogenesis, as well as functional differentiation of germ cells in gametogenesis. Studies using the conventional Arabidopsis system and the newly emerged bryophyte system have revealed novel interactions between regulatory factors that restrict the number of spore mother cells, and evolutionarily conserved factors that promote germ cell differentiation. This short review summarizes recent advances in our understanding of the cellular events that lead to the formation of germ cells in plants, and highlights questions that remain to be addressed in the field.
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Affiliation(s)
- Keiji Nakajima
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.
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67
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Wallau GL, Vieira C, Loreto ÉLS. Genetic exchange in eukaryotes through horizontal transfer: connected by the mobilome. Mob DNA 2018; 9:6. [PMID: 29422954 PMCID: PMC5791352 DOI: 10.1186/s13100-018-0112-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 01/24/2018] [Indexed: 12/11/2022] Open
Abstract
Background All living species contain genetic information that was once shared by their common ancestor. DNA is being inherited through generations by vertical transmission (VT) from parents to offspring and from ancestor to descendant species. This process was considered the sole pathway by which biological entities exchange inheritable information. However, Horizontal Transfer (HT), the exchange of genetic information by other means than parents to offspring, was discovered in prokaryotes along with strong evidence showing that it is a very important process by which prokaryotes acquire new genes. Main body For some time now, it has been a scientific consensus that HT events were rare and non-relevant for evolution of eukaryotic species, but there is growing evidence supporting that HT is an important and frequent phenomenon in eukaryotes as well. Conclusion Here, we will discuss the latest findings regarding HT among eukaryotes, mainly HT of transposons (HTT), establishing HTT once and for all as an important phenomenon that should be taken into consideration to fully understand eukaryotes genome evolution. In addition, we will discuss the latest development methods to detect such events in a broader scale and highlight the new approaches which should be pursued by researchers to fill the knowledge gaps regarding HTT among eukaryotes.
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Affiliation(s)
- Gabriel Luz Wallau
- 1Entomology Department, Aggeu Magalhães Institute, Oswaldo Cruz Foundation, Recife, PE Brazil
| | - Cristina Vieira
- 2Université de Lyon, Université Lyon 1, CNRS, Laboratoire de Biométrie et Biologie Evolutive, UMR5558, F-69622 Villeurbanne, France
| | - Élgion Lúcio Silva Loreto
- 3Department of Biochemistry and Molecular Biology, Federal University of Santa Maria, Santa Maria, RS Brazil
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68
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Yamaoka S, Nishihama R, Yoshitake Y, Ishida S, Inoue K, Saito M, Okahashi K, Bao H, Nishida H, Yamaguchi K, Shigenobu S, Ishizaki K, Yamato KT, Kohchi T. Generative Cell Specification Requires Transcription Factors Evolutionarily Conserved in Land Plants. Curr Biol 2018; 28:479-486.e5. [PMID: 29395928 DOI: 10.1016/j.cub.2017.12.053] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 11/11/2017] [Accepted: 12/22/2017] [Indexed: 12/23/2022]
Abstract
Land plants differentiate germ cells in the haploid gametophyte. In flowering plants, a generative cell is specified as a precursor that subsequently divides into two sperm cells in the developing male gametophyte, pollen. Generative cell specification requires cell-cycle control and microtubule-dependent nuclear relocation (reviewed in [1-3]). However, the generative cell fate determinant and its evolutionary origin are still unknown. In bryophytes, gametophytes produce eggs and sperm in multicellular reproductive organs called archegonia and antheridia, respectively, or collectively called gametangia. Given the monophyletic origin of land plants [4-6], evolutionarily conserved mechanisms may play key roles in these diverse reproductive processes. Here, we showed that a single member of the subfamily VIIIa of basic helix-loop-helix (bHLH) transcription factors in the liverwort Marchantia polymorpha primarily accumulated in the initial cells and controlled their development into gametangia. We then demonstrated that an Arabidopsis thaliana VIIIa bHLH transiently accumulated in the smaller daughter cell after an asymmetric division of the meiosis-derived microspore and was required for generative cell specification redundantly with its paralog. Furthermore, these A. thaliana VIIIa bHLHs were functionally replaceable by the M. polymorpha VIIIa bHLH. These findings suggest the VIIIa bHLH proteins as core regulators for reproductive development, including germ cell differentiation, since an early stage of land plant evolution.
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Affiliation(s)
- Shohei Yamaoka
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Ryuichi Nishihama
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | | | - Sakiko Ishida
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Keisuke Inoue
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Misaki Saito
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Keitaro Okahashi
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Haonan Bao
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Hiroyuki Nishida
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Katsushi Yamaguchi
- Functional Genomics Facility, National Institute for Basic Biology (NIBB), Okazaki, Aichi 444-8585, Japan
| | - Shuji Shigenobu
- Functional Genomics Facility, National Institute for Basic Biology (NIBB), Okazaki, Aichi 444-8585, Japan
| | | | - Katsuyuki T Yamato
- Faculty of Biology-Oriented Science and Technology, Kindai University, Kinokawa, Wakayama 649-6493, Japan
| | - Takayuki Kohchi
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan.
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69
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Yao X, Yang H, Zhu Y, Xue J, Wang T, Song T, Yang Z, Wang S. The Canonical E2Fs Are Required for Germline Development in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2018; 9:638. [PMID: 29868091 PMCID: PMC5962754 DOI: 10.3389/fpls.2018.00638] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 04/25/2018] [Indexed: 05/03/2023]
Abstract
A number of cell fate determinations, including cell division, cell differentiation, and programmed cell death, intensely occur during plant germline development. How these cell fate determinations are regulated remains largely unclear. The transcription factor E2F is a core cell cycle regulator. Here we show that the Arabidopsis canonical E2Fs, including E2Fa, E2Fb, and E2Fc, play a redundant role in plant germline development. The e2fa e2fb e2fc (e2fabc) triple mutant is sterile, although its vegetative development appears normal. On the one hand, the e2fabc microspores undergo cell death during pollen mitosis. Microspores start to die at the bicellular stage. By the tricellular stage, the majority of the e2fabc microspores are degenerated. On the other hand, a wild type ovule often has one megaspore mother cell (MMC), whereas the majority of e2fabc ovules have two to three MMCs. The subsequent female gametogenesis of e2fabc mutant is aborted and the vacuole is severely impaired in the embryo sac. Analysis of transmission efficiency showed that the canonical E2Fs from both male and female gametophyte are essential for plant gametogenesis. Our study reveals that the canonical E2Fs are required for plant germline development, especially the pollen mitosis and the archesporial cell (AC)-MMC transition.
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70
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Reichard M. Evolutionary perspectives on ageing. Semin Cell Dev Biol 2017; 70:99-107. [DOI: 10.1016/j.semcdb.2017.05.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 05/19/2017] [Accepted: 05/23/2017] [Indexed: 02/07/2023]
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71
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Rotsch AH, Kopka J, Feussner I, Ischebeck T. Central metabolite and sterol profiling divides tobacco male gametophyte development and pollen tube growth into eight metabolic phases. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 92:129-146. [PMID: 28685881 DOI: 10.1111/tpj.13633] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Revised: 06/23/2017] [Accepted: 06/26/2017] [Indexed: 05/23/2023]
Abstract
While changes in the transcriptome and proteome of developing pollen have been investigated in tobacco and other species, the metabolic consequences remain rather unclear. Here, a broad range of metabolites was investigated in close succession of developmental stages. Thirteen stages of tobacco male gametophyte development were collected, ranging from tetrads to pollen tubes. Subsequently, the central metabolome and sterol composition were analyzed by GC-mass spectrometry (MS), monitoring 77 metabolites and 29 non-identified analytes. The overall results showed that development and tube growth could be divided into eight metabolic phases with the phase including mitosis I being most distinct. During maturation, compounds such as sucrose and proline accumulated. These were degraded after rehydration, while γ-aminobutyrate transiently increased, possibly deriving from proline breakdown. Sterol analysis revealed that tetrads harbor similar sterols as leaves, but throughout maturation unusual sterols increased. Lastly, two further sterols exclusively accumulated in pollen tubes. This study allows a deeper look into metabolic changes during the development of a quasi-single cell type. Metabolites accumulating during maturation might accelerate pollen germination and tube growth, protect from desiccation, and feed pollinators. Future studies of the underlying processes orchestrating the changes in metabolite levels might give valuable insights into cellular regulation of plant metabolism.
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Affiliation(s)
- Alexander H Rotsch
- Department of Plant Biochemistry, University of Goettingen, Albrecht-von-Haller-Institute for Plant Sciences, Justus-von-Liebig-Weg 11, 37077, Goettingen, Germany
| | - Joachim Kopka
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Ivo Feussner
- Department of Plant Biochemistry, University of Goettingen, Albrecht-von-Haller-Institute for Plant Sciences, Justus-von-Liebig-Weg 11, 37077, Goettingen, Germany
- Department of Plant Biochemistry, University of Goettingen, Goettingen Center for Molecular Biosciences (GZMB), Justus-von-Liebig-Weg 11, 37077, Goettingen, Germany
| | - Till Ischebeck
- Department of Plant Biochemistry, University of Goettingen, Albrecht-von-Haller-Institute for Plant Sciences, Justus-von-Liebig-Weg 11, 37077, Goettingen, Germany
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72
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Kravets EA, Yemets AI, Blume YB. Cytoskeleton and nucleoskeleton involvement in processes of cytomixis in plants. Cell Biol Int 2017; 43:999-1009. [DOI: 10.1002/cbin.10842] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 08/12/2017] [Indexed: 12/13/2022]
Affiliation(s)
| | - Alla Ivanovna Yemets
- Institute of Food Biotechnology and GenomicsNatl. Academy of Sciences of UkraineKyiv Ukraine
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73
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Lei R, Li X, Ma Z, Lv Y, Hu Y, Yu D. Arabidopsis WRKY2 and WRKY34 transcription factors interact with VQ20 protein to modulate pollen development and function. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 91:962-976. [PMID: 28635025 DOI: 10.1111/tpj.13619] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 05/13/2017] [Accepted: 06/02/2017] [Indexed: 05/20/2023]
Abstract
Plant male gametogenesis is tightly regulated, and involves complex and precise regulations of transcriptional reprogramming. WRKY transcription factors have been demonstrated to play critical roles in plant development and stress responses. Several members of this family physically interact with VQ motif-containing proteins (VQ proteins) to mediate a plethora of programs in Arabidopsis; however, the involvement of WRKY-VQ complexes in plant male gametogenesis remains largely unknown. In this study, we found that WRKY2 and WKRY34 interact with VQ20 both in vitro and in vivo. Further experiments displayed that the conserved VQ motif of VQ20 is responsible for their physical interactions. The VQ20 protein localizes in the nucleus and specifically expresses in pollens. Phenotypic analysis showed that WRKY2, WRKY34 and VQ20 are crucial for pollen development and function. Mutations of WRKY2, WRKY34 and VQ20 simultaneously resulted in male sterility, with defects in pollen development, germination and tube growth. Further investigation revealed that VQ20 affects the transcriptional functions of its interacting WRKY partners. Complementation evidence supported that the VQ motif of VQ20 is essential for pollen development, as a mutant form of VQ20 in which LVQK residues in the VQ motif were replaced by EDLE did not rescue the phenotype of the w2-1 w34-1 vq20-1 triple-mutant plants. Further expression analysis indicated that WRKY2, WRKY34 and VQ20 co-modulate multiple genes involved in pollen development, germination and tube growth. Taken together, our study provides evidence that VQ20 acts as a key partner of WRKY2 and WKRY34 in plant male gametogenesis.
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Affiliation(s)
- Rihua Lei
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaoli Li
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
| | - Zhenbing Ma
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
| | - Yan Lv
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
| | - Yanru Hu
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
| | - Diqiu Yu
- Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
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74
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Bai SN. Two types of germ cells, the sexual reproduction cycle, and the double-ring mode of plant developmental program. PLANT SIGNALING & BEHAVIOR 2017; 12:e1320632. [PMID: 28463050 PMCID: PMC5586392 DOI: 10.1080/15592324.2017.1320632] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 04/12/2017] [Accepted: 04/12/2017] [Indexed: 05/30/2023]
Abstract
In this viewpoint, the usages of terms for progenitor cells to meiosis and gametogenesis are discussed. Terms for 2 types of germ cells, i.e. "diploid germ cells" and "haploid germ cells" were suggested to replace "archesporial cells" and "generative cells," respectively, in plant developmental research. This suggestion was based on 2 newly proposed concepts, the "sexual reproduction cycle" for eukaryotes, and a "double-ring mode" of plant developmental program.
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Affiliation(s)
- Shu-Nong Bai
- State Key Laboratory of Protein and Plant Gene Research, College of Life Science, Quantitative Biology Center, Peking University, Beijing, China
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75
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Zhang J, Huang Q, Zhong S, Bleckmann A, Huang J, Guo X, Lin Q, Gu H, Dong J, Dresselhaus T, Qu LJ. Sperm cells are passive cargo of the pollen tube in plant fertilization. NATURE PLANTS 2017; 3:17079. [PMID: 28585562 PMCID: PMC5960590 DOI: 10.1038/nplants.2017.79] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Accepted: 05/03/2017] [Indexed: 05/05/2023]
Abstract
Sperm cells of seed plants have lost their motility and are transported by the vegetative pollen tube cell for fertilization, but the extent to which they regulate their own transportation is a long-standing debate. Here we show that Arabidopsis lacking two bHLH transcription factors produces pollen without sperm cells. This abnormal pollen mostly behaves like the wild type and demonstrates that sperm cells are dispensable for normal pollen tube development.
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Affiliation(s)
- Jun Zhang
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
| | - Qingpei Huang
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
| | - Sheng Zhong
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
| | - Andrea Bleckmann
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93053 Regensburg, Germany
| | - Jiaying Huang
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
| | - Xinyang Guo
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
| | - Qing Lin
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
| | - Hongya Gu
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
- The National Plant Gene Research Center (Beijing), Beijing 100101, China
| | - Juan Dong
- The Waksman Institute of Microbiology, Rutgers the State University of New Jersey, Piscataway, New Jersey 08854, USA
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93053 Regensburg, Germany
| | - Li-Jia Qu
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
- The National Plant Gene Research Center (Beijing), Beijing 100101, China
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76
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Vergara Z, Gutierrez C. Emerging roles of chromatin in the maintenance of genome organization and function in plants. Genome Biol 2017; 18:96. [PMID: 28535770 PMCID: PMC5440935 DOI: 10.1186/s13059-017-1236-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Chromatin is not a uniform macromolecular entity; it contains different domains characterized by complex signatures of DNA and histone modifications. Such domains are organized both at a linear scale along the genome and spatially within the nucleus. We discuss recent discoveries regarding mechanisms that establish boundaries between chromatin states and nuclear territories. Chromatin organization is crucial for genome replication, transcriptional silencing, and DNA repair and recombination. The replication machinery is relevant for the maintenance of chromatin states, influencing DNA replication origin specification and accessibility. Current studies reinforce the idea of intimate crosstalk between chromatin features and processes involving DNA transactions.
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Affiliation(s)
- Zaida Vergara
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Nicolas Cabrera 1, Cantoblanco, 28049, Madrid, Spain
| | - Crisanto Gutierrez
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Nicolas Cabrera 1, Cantoblanco, 28049, Madrid, Spain.
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77
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Martinez G, Köhler C. Role of small RNAs in epigenetic reprogramming during plant sexual reproduction. CURRENT OPINION IN PLANT BIOLOGY 2017; 36:22-28. [PMID: 28088028 DOI: 10.1016/j.pbi.2016.12.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 12/29/2016] [Indexed: 05/07/2023]
Abstract
Sexual reproduction, the formation of a new individual from specialized reproductive cells after fertilization, involves the precise orchestration of different developmental and genomic processes. These processes are to a large extent governed by small RNAs (sRNAs) that either belong to the class of micro RNAs (miRNAs) or small-interfering RNAs (siRNAs). The latter are derived from transposable elements (TEs) and involved in genome defense and transgenerational inheritance of heterochromatin identity, ensuring genome stability. Remarkably, male and female gametophytes employ sRNAs to ensure reproductive success, but the underlying processes of their formation and action differ. Here, we review current advances in the field concerning the roles of sRNAs during flowering plant (angiosperm) reproduction and pinpoint where further research is required to solve open questions.
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Affiliation(s)
- German Martinez
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala, Sweden
| | - Claudia Köhler
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala, Sweden.
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78
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Jurečková JF, Sýkorová E, Hafidh S, Honys D, Fajkus J, Fojtová M. Tissue-specific expression of telomerase reverse transcriptase gene variants in Nicotiana tabacum. PLANTA 2017; 245:549-561. [PMID: 27900472 DOI: 10.1007/s00425-016-2624-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 11/23/2016] [Indexed: 06/06/2023]
Abstract
MAIN CONCLUSION In tobacco, three sequence variants of the TERT gene have been described. We revealed unbalanced levels of TERT variant transcripts in vegetative tobacco tissues and enhanced TERT transcription and telomerase activity in reproductive tissues. Telomerase is a ribonucleoprotein complex responsible for the maintenance of telomeres, structures delimiting ends of linear eukaryotic chromosomes. In the Nicotiana tabacum (tobacco) allotetraploid plant, three sequence variants (paralogs) of the gene coding for the telomerase reverse transcriptase subunit (TERT) have been described, two of them derived from the maternal N. sylvestris genome (TERT_Cs, TERT_D) and one originated from the N. tomentosiformis paternal genome (TERT_Ct). In this work, we analyzed the transcription of TERT variants in correlation with telomerase activity in tobacco tissues. High and approximately comparable levels of TERT_Ct and TERT_Cs transcripts were detected in seedlings, roots, flower buds and leaves, while the transcript of the TERT_D variant was markedly underrepresented. Similarly, in N. sylvestris tissues, TERT_Cs transcript significantly predominated. A specific pattern of TERT transcripts was found in samples of tobacco pollen with the TERT_Cs variant clearly dominating particularly at the early stage of pollen development. Detailed analysis of TERT_C variants representation in functionally distinct fractions of pollen transcriptome revealed their prevalence in large ribonucleoprotein particles encompassing translationally silent mRNA; only a minority of TERT_Ct and TERT_Cs transcripts were localized in actively translated polysomes. Histones of the TERT_C chromatin were decorated predominantly with the euchromatin-specific epigenetic modification in both telomerase-positive and telomerase-negative tobacco tissues. We conclude that the existence and transcription pattern of tobacco TERT paralogs represents an interesting phenomenon and our results indicate its functional significance. Nicotiana species have again proved to be appropriate and useful model plants in telomere biology studies.
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Affiliation(s)
- Jana Fišerová Jurečková
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC) and Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Eva Sýkorová
- Institute of Biophysics, Academy of Sciences of the Czech Republic v.v.i., Královopolská 135, 612 65, Brno, Czech Republic
| | - Said Hafidh
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic v.v.i., Rozvojová 263, 165 02, Prague, Czech Republic
| | - David Honys
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic v.v.i., Rozvojová 263, 165 02, Prague, Czech Republic
| | - Jiří Fajkus
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC) and Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic v.v.i., Královopolská 135, 612 65, Brno, Czech Republic
| | - Miloslava Fojtová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC) and Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.
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Abstract
In the last decade, the accumulation and roles of small RNAs have been slowly uncovered. Recently, the RNA silencing pathways active in the male gametophyte of plants have started to be analyzed in depth. Although several studies have shed light on the small RNA populations present in the pollen, we still lack a clear picture of their regulatory activity. This chapter outlines an extraction method of mature pollen grains and its different downstream applications for the purification and detection of small RNAs.
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Affiliation(s)
- German Martinez
- Department of Plant Biology, Swedish University of Agricultural Sciences and Linnean Center of Plant Biology, 750 07, Uppsala, Sweden.
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80
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Peters B, Aidley J, Cadzow M, Twell D, Brownfield L. Identification of Cis-Regulatory Modules that Function in the Male Germline of Flowering Plants. Methods Mol Biol 2017; 1669:275-293. [PMID: 28936666 DOI: 10.1007/978-1-4939-7286-9_22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The male germline of flowering plants develops within the vegetative cell of the male gametophyte and displays a distinct transcriptional profile. Key to understanding the development of this unique cell lineage is determining how gene expression is regulated within germline cells. This knowledge impacts upon our understanding of cell specification, differentiation, and plant fertility. Here, we describe methods to identify cis-regulatory modules (CRMs) that act as key regulatory regions in the promoters of germline-expressed genes. We detail the complimentary techniques of phylogenetic footprinting and the use of fluorescent reporters in pollen for the identification and verification of CRMs.
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Affiliation(s)
- Benjamin Peters
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Jack Aidley
- Department of Genetics, University of Leicester, Leicester, UK
| | - Murray Cadzow
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - David Twell
- Department of Genetics, University of Leicester, Leicester, UK
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81
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Abstract
Visualization of the intact embryo sac within the ovular/gynoecial tissues and clear identification of cell types can be logistically difficult and subject to interpretation. Cellular marker technologies have been available for the embryo sac, but have typically labeled only one cell type in a particular line. Here, we describe techniques for simultaneous labeling each cell type in the embryo sac and visualization methods for such in Arabidopsis, soybean, maize, and sorghum.
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82
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Heidmann I, Schade-Kampmann G, Lambalk J, Ottiger M, Di Berardino M. Impedance Flow Cytometry: A Novel Technique in Pollen Analysis. PLoS One 2016; 11:e0165531. [PMID: 27832091 PMCID: PMC5104384 DOI: 10.1371/journal.pone.0165531] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 10/13/2016] [Indexed: 11/29/2022] Open
Abstract
INTRODUCTION An efficient and reliable method to estimate plant cell viability, especially of pollen, is important for plant breeding research and plant production processes. Pollen quality is determined by classical methods, like staining techniques or in vitro pollen germination, each having disadvantages with respect to reliability, analysis speed, and species dependency. Analysing single cells based on their dielectric properties by impedance flow cytometry (IFC) has developed into a common method for cellular characterisation in microbiology and medicine during the last decade. The aim of this study is to demonstrate the potential of IFC in plant cell analysis with the focus on pollen. METHOD Developing and mature pollen grains were analysed during their passage through a microfluidic chip to which radio frequencies of 0.5 to 12 MHz were applied. The acquired data provided information about the developmental stage, viability, and germination capacity. The biological relevance of the acquired IFC data was confirmed by classical staining methods, inactivation controls, as well as pollen germination assays. RESULTS Different stages of developing pollen, dead, viable and germinating pollen populations could be detected and quantified by IFC. Pollen viability analysis by classical FDA staining showed a high correlation with IFC data. In parallel, pollen with active germination potential could be discriminated from the dead and the viable but non-germinating population. CONCLUSION The presented data demonstrate that IFC is an efficient, label-free, reliable and non-destructive technique to analyse pollen quality in a species-independent manner.
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Affiliation(s)
- Iris Heidmann
- Enza Zaden, Research and Development B.V. P.O. Box 7, 1600AA Enkhuizen, The Netherlands
| | | | - Joep Lambalk
- Enza Zaden, Research and Development B.V. P.O. Box 7, 1600AA Enkhuizen, The Netherlands
| | - Marcel Ottiger
- Amphasys AG, Technopark Lucerne, 6039 Root D4, Switzerland
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83
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Kim M, Kim MJ, Pandey S, Kim J. Expression and Protein Interaction Analyses Reveal Combinatorial Interactions of LBD Transcription Factors During Arabidopsis Pollen Development. PLANT & CELL PHYSIOLOGY 2016; 57:2291-2299. [PMID: 27519310 DOI: 10.1093/pcp/pcw145] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 08/09/2016] [Indexed: 06/06/2023]
Abstract
LATERAL ORGAN BOUNDARIES DOMAIN (LBD) transcription factor gene family members play key roles in diverse aspects of plant development. LBD10 and LBD27 have been shown to be essential for pollen development in Arabidopsis thaliana. From the previous RNA sequencing (RNA-Seq) data set of Arabidopsis pollen, we identified the mRNAs of LBD22, LBD25 and LBD36 in addition to LBD10 and LBD27 in Arabidopsis pollen. Here we conducted expression and cellular analysis using GFP:GUS (green fluorescent protein:β-glucuronidase) reporter gene and subcellular localization assays using LBD:GFP fusion proteins expressed under the control of their own promoters in Arabidopsis. We found that these LBD proteins display spatially and temporally distinct and overlapping expression patterns during pollen development. Bimolecular fluorescence complementation and GST (glutathione S-transferase) pull-down assays demonstrated that protein-protein interactions occur among the LBDs exhibiting overlapping expression during pollen development. We further showed that LBD10, LBD22, LBD25, LBD27 and LBD36 interact with each other to form heterodimers, which are localized to the nucleus in Arabidopsis protoplasts. Taken together, these results suggest that combinatorial interactions among LBD proteins may be important for their function in pollen development in Arabidopsis.
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Affiliation(s)
- Mirim Kim
- Department of Bioenergy Science and Technology and Kumho Life Science Laboratory, Chonnam National University, Gwangju 500-757, Korea
| | - Min-Jung Kim
- Department of Bioenergy Science and Technology and Kumho Life Science Laboratory, Chonnam National University, Gwangju 500-757, Korea
| | - Shashank Pandey
- Department of Bioenergy Science and Technology and Kumho Life Science Laboratory, Chonnam National University, Gwangju 500-757, Korea
| | - Jungmook Kim
- Department of Bioenergy Science and Technology and Kumho Life Science Laboratory, Chonnam National University, Gwangju 500-757, Korea
- Kumho Life Science Laboratory, Chonnam National University, Buk-Gu, Gwangju 500-757, Korea
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84
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Oh SA, Jeon J, Park HJ, Grini PE, Twell D, Park SK. Analysis of gemini pollen 3 mutant suggests a broad function of AUGMIN in microtubule organization during sexual reproduction in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 87:188-201. [PMID: 27121542 DOI: 10.1111/tpj.13192] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 04/03/2016] [Accepted: 04/05/2016] [Indexed: 06/05/2023]
Abstract
In flowering plants, male gametes arise via meiosis of diploid pollen mother cells followed by two rounds of mitotic division. Haploid microspores undergo polar nuclear migration and asymmetric division at pollen mitosis I to segregate the male germline, followed by division of the germ cell to generate a pair of sperm cells. We previously reported two gemini pollen (gem) mutants that produced twin-celled pollen arising from polarity and cytokinesis defects at pollen mitosis I in Arabidopsis. Here, we report an independent mutant, gem3, with a similar division phenotype and severe genetic transmission defects through pollen. Cytological analyses revealed that gem3 disrupts cell division during male meiosis, at pollen mitosis I and during female gametophyte development. We show that gem3 is a hypomorphic allele (aug6-1) of AUGMIN subunit 6, encoding a conserved component in the augmin complex, which mediates microtubule (MT)-dependent MT nucleation in acentrosomal cells. We show that MT arrays are disturbed in gem3/aug6-1 during male meiosis and pollen mitosis I using fluorescent MT-markers. Our results demonstrate a broad role for the augmin complex in MT organization during sexual reproduction, and highlight gem3/aug6-1 mutants as a valuable tool for the investigation of augmin-dependent MT nucleation and dynamics in plant cells.
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Affiliation(s)
- Sung-Aeong Oh
- School of Applied Biosciences, Kyungpook National University, Daegu, 41566, Korea
| | - Jien Jeon
- School of Applied Biosciences, Kyungpook National University, Daegu, 41566, Korea
| | - Hyo-Jin Park
- School of Applied Biosciences, Kyungpook National University, Daegu, 41566, Korea
| | - Paul Eivind Grini
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, 0316, Oslo, Norway
| | - David Twell
- Department of Genetics, University of Leicester, University Road, Leicester, LE1 7RH, UK
| | - Soon Ki Park
- School of Applied Biosciences, Kyungpook National University, Daegu, 41566, Korea
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85
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Hafidh S, Fíla J, Honys D. Male gametophyte development and function in angiosperms: a general concept. PLANT REPRODUCTION 2016; 29:31-51. [PMID: 26728623 DOI: 10.1007/s00497-015-0272-4] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Accepted: 12/19/2015] [Indexed: 05/23/2023]
Abstract
Overview of pollen development. Male gametophyte development of angiosperms is a complex process that requires coordinated activity of different cell types and tissues of both gametophytic and sporophytic origin and the appropriate specific gene expression. Pollen ontogeny is also an excellent model for the dissection of cellular networks that control cell growth, polarity, cellular differentiation and cell signaling. This article describes two sequential phases of angiosperm pollen ontogenesis-developmental phase leading to the formation of mature pollen grains, and a functional or progamic phase, beginning with the impact of the grains on the stigma surface and ending at double fertilization. Here we present an overview of important cellular processes in pollen development and explosive pollen tube growth stressing the importance of reserves accumulation and mobilization and also the mutual activation of pollen tube and pistil tissues, pollen tube guidance and the communication between male and female gametophytes. We further describe the recent advances in regulatory mechanisms involved such as posttranscriptional regulation (including mass transcript storage) and posttranslational modifications to modulate protein function, intracellular metabolic signaling, ionic gradients such as Ca(2+) and H(+) ions, cell wall synthesis, protein secretion and intercellular signaling within the reproductive tissues.
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Affiliation(s)
- Said Hafidh
- Institute of Experimental Botany ASCR, v.v.i., Rozvojová 263, 165 00, Prague 6, Czech Republic
| | - Jan Fíla
- Institute of Experimental Botany ASCR, v.v.i., Rozvojová 263, 165 00, Prague 6, Czech Republic
| | - David Honys
- Institute of Experimental Botany ASCR, v.v.i., Rozvojová 263, 165 00, Prague 6, Czech Republic.
- Department of Experimental Plant Biology, Faculty of Science, Charles University in Prague, Viničná 5, 128 44, Prague 2, Czech Republic.
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86
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Heilmann I, Ischebeck T. Male functions and malfunctions: the impact of phosphoinositides on pollen development and pollen tube growth. PLANT REPRODUCTION 2016; 29:3-20. [PMID: 26676144 DOI: 10.1007/s00497-015-0270-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Accepted: 11/17/2015] [Indexed: 05/12/2023]
Abstract
Phosphoinositides in pollen. In angiosperms, sexual reproduction is a series of complex biological events that facilitate the distribution of male generative cells for double fertilization. Angiosperms have no motile gametes, and the distribution units of generative cells are pollen grains, passively mobile desiccated structures, capable of delivering genetic material to compatible flowers over long distances and in an adverse environment. The development of pollen (male gametogenesis) and the formation of a pollen tube after a pollen grain has reached a compatible flower (pollen tube growth) are important aspects of plant developmental biology. In recent years, a wealth of information has been gathered about the molecular control of cell polarity, membrane trafficking and cytoskeletal dynamics underlying these developmental processes. In particular, it has been found that regulatory membrane phospholipids, such as phosphoinositides (PIs), are critical regulatory players, controlling key steps of trafficking and polarization. Characteristic features of PIs are the inositol phosphate headgroups of the lipids, which protrude from the cytosolic surfaces of membranes, enabling specific binding and recruitment of numerous protein partners containing specific PI-binding domains. Such recruitment is globally an early event in polarization processes of eukaryotic cells and also of key importance to pollen development and tube growth. Additionally, PIs serve as precursors of other signaling factors with importance to male gametogenesis. This review highlights the recent advances about the roles of PIs in pollen development and pollen function.
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Affiliation(s)
- Ingo Heilmann
- Department of Cellular Biochemistry, Institute for Biochemistry, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Str. 3, 06120, Halle (Saale), Germany.
| | - Till Ischebeck
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University Göttingen, Justus-von-Liebig-Weg 11, 37077, Göttingen, Germany.
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87
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Walbot V, Egger RL. Pre-Meiotic Anther Development: Cell Fate Specification and Differentiation. ANNUAL REVIEW OF PLANT BIOLOGY 2016; 67:365-95. [PMID: 26735065 DOI: 10.1146/annurev-arplant-043015-111804] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Research into anther ontogeny has been an active and developing field, transitioning from a strictly lineage-based view of cellular differentiation events to a more complex understanding of cell fate specification. Here we describe the modern interpretation of pre-meiotic anther development, from the earliest cell specifications within the anther lobes through SPL/NZZ-, MSP1-, and MEL1-dependent pathways as well as the initial setup of the abaxial and adaxial axes and outgrowth of the anther lobes. We then continue with a look at the known information regarding further differentiation of the somatic layers of the anther (the epidermis, endothecium, middle layer, and tapetum), with an emphasis on male-sterile mutants identified as defective in somatic cell specification. We also describe the differences in developmental stages among species and use this information to discuss molecular studies that have analyzed transcriptome, proteome, and small-RNA information in the anther.
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Affiliation(s)
- Virginia Walbot
- Department of Biology, Stanford University, Stanford, California 94305-5020; ,
| | - Rachel L Egger
- Department of Biology, Stanford University, Stanford, California 94305-5020; ,
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88
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Lipids in pollen - They are different. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1315-1328. [PMID: 27033152 DOI: 10.1016/j.bbalip.2016.03.023] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Revised: 03/15/2016] [Accepted: 03/20/2016] [Indexed: 01/01/2023]
Abstract
During evolution, the male gametophyte of Angiosperms has been severely reduced to the pollen grain, consisting of a vegetative cell containing two sperm cells. This vegetative cell has to deliver the sperm cells from the stigma through the style to the ovule. It does so by producing a pollen tube and elongating it to many centimeters in length in some species, requiring vast amounts of fatty acid and membrane lipid synthesis. In order to optimize this polar tip growth, a unique lipid composition in the pollen has evolved. Pollen tubes produce extraplastidial galactolipids and store triacylglycerols in lipid droplets, probably needed as precursors of glycerolipids or for acyl editing. They also possess special sterol and sphingolipid moieties that might together form microdomains in the membranes. The individual lipid classes, the proteins involved in their synthesis as well as the corresponding Arabidopsis knockout mutant phenotypes are discussed in this review. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner.
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89
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Yang H, Yang N, Wang T. Proteomic analysis reveals the differential histone programs between male germline cells and vegetative cells in Lilium davidii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 85:660-674. [PMID: 26846354 DOI: 10.1111/tpj.13133] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 01/12/2016] [Accepted: 01/25/2016] [Indexed: 06/05/2023]
Abstract
In flowering plants, male germline fate is determined after asymmetric division of the haploid microspore. Daughter cells have distinct fates: the generative cell (GC) undergoes further mitosis to generate sperm cells (SCs), and the vegetative cell (VC) terminally differentiates. However, our understanding of the mechanisms underlying germline development remains limited. Histone variants and modifications define chromatin states, and contribute to establishing and maintaining cell identities by affecting gene expression. Here, we constructed a lily protein database, then extracted and detailed histone entries into a comprehensive lily histone database. We isolated large amounts of nuclei from VCs, GCs and SCs from lily, and profiled histone variants of all five histone families in all three cell types using proteomics approaches. We revealed 92 identities representing 32 histone variants: six for H1, 11 for H2A, eight for H2B, five for H3 and two for H4. Nine variants, including five H1, two H2B, one H3 and one H4 variant, specifically accumulated in GCs and SCs. We also detected H3 modification patterns in the three cell types. GCs and SCs had almost identical histone profiles and similar H3 modification patterns, which were significantly different from those of VCs. Our study also revealed the presence of multiple isoforms, and differential expression patterns between isoforms of a variant. The results suggest that differential histone programs between the germline and companion VCs may be established following the asymmetric division, and are important for identity establishment and differentiation of the male germline as well as the VC.
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Affiliation(s)
- Hao Yang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ning Yang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Tai Wang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
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90
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Higo A, Niwa M, Yamato KT, Yamada L, Sawada H, Sakamoto T, Kurata T, Shirakawa M, Endo M, Shigenobu S, Yamaguchi K, Ishizaki K, Nishihama R, Kohchi T, Araki T. Transcriptional Framework of Male Gametogenesis in the Liverwort Marchantia polymorpha L. PLANT & CELL PHYSIOLOGY 2016; 57:325-38. [PMID: 26858289 DOI: 10.1093/pcp/pcw005] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 12/31/2015] [Indexed: 05/19/2023]
Abstract
In land plants, there are two types of male gametes: one is a non-motile sperm cell which is delivered to the egg cell by a pollen tube, and the other is a motile sperm cell with flagella. The molecular mechanism underlying the sexual reproduction with the egg and pollen-delivered sperm cell is well understood from studies using model plants such as Arabidopsis and rice. On the other hand, the sexual reproduction with motile sperm has remained poorly characterized, due to the lack of suitable models. Marchantia polymorpha L. is a model basal land plant with sexual reproduction involving an egg cell and bi-flagellated motile sperm. To understand the differentiation process of plant motile sperm, we analyzed the gene expression profile of developing antheridia of M. polymorpha. We performed RNA-sequencing experiments and compared transcript profiles of the male sexual organ (antheridiophore and antheridium contained therein), female sexual organ (archegoniophore) and a vegetative organ (thallus). Transcriptome analysis showed that the antheridium expresses nearly half of the protein-coding genes predicted in the genome, but it also has unique features. The antheridium transcriptome shares some common features with male gamete transcriptomes of angiosperms and animals, and homologs of genes involved in male gamete formation and function in angiosperms and animals were identified. In addition, we showed that some of them had distinct expression patterns in the spermatogenous tissue of developing antheridia. This study provides a transcriptional framework on which to study the molecular mechanism of plant motile sperm development in M. polymorpha as a model.
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Affiliation(s)
- Asuka Higo
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8501 Japan
| | - Masaki Niwa
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8501 Japan
| | - Katsuyuki T Yamato
- Faculty of Biology-Oriented Science and Technology, Kinki University, Kinokawa, 649-6493 Japan
| | - Lixy Yamada
- Sugashima Marine Biological Laboratory, Graduate School of Science, Nagoya University, Toba, 517-0004 Japan
| | - Hitoshi Sawada
- Sugashima Marine Biological Laboratory, Graduate School of Science, Nagoya University, Toba, 517-0004 Japan
| | - Tomoaki Sakamoto
- Plant Global Education Project, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, 630-0192 Japan Present address: Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, 603-8555 Japan
| | - Tetsuya Kurata
- Plant Global Education Project, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, 630-0192 Japan Present address: Graduate School of Life Sciences, Tohoku University, Sendai, 980-8578 Japan
| | - Makoto Shirakawa
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8501 Japan Present address: Department of Botany, Faculty of Science, University of British Columbia, Vancouver, Canada V6T 1Z4
| | - Motomu Endo
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8501 Japan
| | - Shuji Shigenobu
- National Institute for Basic Biology, Okazaki, 444-8585 Japan
| | | | | | - Ryuichi Nishihama
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8501 Japan
| | - Takayuki Kohchi
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8501 Japan
| | - Takashi Araki
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8501 Japan
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91
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Kim MJ, Kim J. Semi-thin Sectioning, Light and Fluorescence Microscopy of Floral Bud to Study Microspore Development in Arabidopsis. Bio Protoc 2016. [DOI: 10.21769/bioprotoc.1752] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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92
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Cui HH, Liao HZ, Tang Y, Du XY, Chen LQ, Ye D, Zhang XQ. ABORTED GAMETOPHYTE 1 is required for gametogenesis in Arabidopsis. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2015; 57:1003-1016. [PMID: 25693728 DOI: 10.1111/jipb.12341] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 02/11/2015] [Indexed: 06/04/2023]
Abstract
In flowering plants, the male and female gametogenesis is a crucial step of sexual reproduction. Although many genes have been identified as being involved in the gametogenesis process, the genetic mechanisms underlying gametogenesis remains poorly understood. We reported here characterization of the gene, ABORTED GAMETOPHYTE 1 (AOG1) that is newly identified as essential for gametogenesis in Arabidopsis thaliana. AOG1 is expressed predominantly in reproductive tissues including the developing pollen grains and ovules. The AOG1 protein shares no significant amino acid sequence similarity with other documented proteins and is located mainly in nuclei of the cells. Mutation in AOG1 caused degeneration of pollen at the uninucleate microspore stage and severe defect in embryo sacs, leading to a significant reduction in male and female fertility. Furthermore, the molecular analyses showed that the aog1 mutant significantly affected the expression of several genes, which are required for gametogenesis. Our results suggest that AOG1 plays important roles in gametogenesis at the stage prior to pollen mitosis I (PMI) in Arabidopsis, possibly through collaboration with other genes.
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Affiliation(s)
- Hong-Hui Cui
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Hong-Ze Liao
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Yu Tang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Xin-Yu Du
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Li-Qun Chen
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - De Ye
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Xue-Qin Zhang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
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93
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Li L, He Y, Wang Y, Zhao S, Chen X, Ye T, Wu Y, Wu Y. Arabidopsis PLC2 is involved in auxin-modulated reproductive development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 84:504-15. [PMID: 26340337 DOI: 10.1111/tpj.13016] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 08/22/2015] [Accepted: 08/26/2015] [Indexed: 05/08/2023]
Abstract
Phospholipase C (PLC) is an enzyme that plays crucial roles in various signal transduction pathways in mammalian cells. However, the role of PLC in plant development is poorly understood. Here we report involvement of PLC2 in auxin-mediated reproductive development in Arabidopsis. Disruption of PLC2 led to sterility, indicating a significant role for PLC2 in reproductive development. Development of both male and female gametophytes was severely perturbed in plc2 mutants. Moreover, elevated auxin levels were observed in plc2 floral tissues, suggesting that the infertility of plc2 plants may be associated with increased auxin concentrations in the reproductive organs. We show that expression levels of the auxin reporters DR5:GUS and DR5:GFP were elevated in plc2 anthers and ovules. In addition, we found that expression of the auxin biosynthetic YUCCA genes was increased in plc2 plants. We conclude that PLC2 is involved in auxin biosynthesis and signaling, thus modulating development of both male and female gametophytes in Arabidopsis.
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Affiliation(s)
- Lin Li
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Yuqing He
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Yarui Wang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Shujuan Zhao
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Xi Chen
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Tiantian Ye
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Yuxuan Wu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Yan Wu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
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94
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Takatani S, Otani K, Kanazawa M, Takahashi T, Motose H. Structure, function, and evolution of plant NIMA-related kinases: implication for phosphorylation-dependent microtubule regulation. JOURNAL OF PLANT RESEARCH 2015; 128:875-91. [PMID: 26354760 DOI: 10.1007/s10265-015-0751-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 08/20/2015] [Indexed: 05/25/2023]
Abstract
Microtubules are highly dynamic structures that control the spatiotemporal pattern of cell growth and division. Microtubule dynamics are regulated by reversible protein phosphorylation involving both protein kinases and phosphatases. Never in mitosis A (NIMA)-related kinases (NEKs) are a family of serine/threonine kinases that regulate microtubule-related mitotic events in fungi and animal cells (e.g. centrosome separation and spindle formation). Although plants contain multiple members of the NEK family, their functions remain elusive. Recent studies revealed that NEK6 of Arabidopsis thaliana regulates cell expansion and morphogenesis through β-tubulin phosphorylation and microtubule destabilization. In addition, plant NEK members participate in organ development and stress responses. The present phylogenetic analysis indicates that plant NEK genes are diverged from a single NEK6-like gene, which may share a common ancestor with other kinases involved in the control of microtubule organization. On the contrary, another mitotic kinase, polo-like kinase, might have been lost during the evolution of land plants. We propose that plant NEK members have acquired novel functions to regulate cell growth, microtubule organization, and stress responses.
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Affiliation(s)
- Shogo Takatani
- Division of Bioscience, Graduate School of Natural Science and Technology, Okayama University, Tsushimanaka 3-1-1, Okayama, 700-8530, Japan
| | - Kento Otani
- Division of Bioscience, Graduate School of Natural Science and Technology, Okayama University, Tsushimanaka 3-1-1, Okayama, 700-8530, Japan
| | - Mai Kanazawa
- Department of Biology, Faculty of Science, Okayama University, Tsushimanaka 3-1-1, Okayama, 700-8530, Japan
| | - Taku Takahashi
- Division of Bioscience, Graduate School of Natural Science and Technology, Okayama University, Tsushimanaka 3-1-1, Okayama, 700-8530, Japan
- Department of Biology, Faculty of Science, Okayama University, Tsushimanaka 3-1-1, Okayama, 700-8530, Japan
| | - Hiroyasu Motose
- Division of Bioscience, Graduate School of Natural Science and Technology, Okayama University, Tsushimanaka 3-1-1, Okayama, 700-8530, Japan.
- Department of Biology, Faculty of Science, Okayama University, Tsushimanaka 3-1-1, Okayama, 700-8530, Japan.
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95
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Borg M, Berger F. Chromatin remodelling during male gametophyte development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 83:177-188. [PMID: 25892182 DOI: 10.1111/tpj.12856] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 04/10/2015] [Accepted: 04/14/2015] [Indexed: 05/28/2023]
Abstract
The plant life cycle alternates between a diploid sporophytic phase and haploid gametophytic phase, with the latter giving rise to the gametes. Male gametophyte development encompasses two mitotic divisions that results in a simple three-celled structure knows as the pollen grain, in which two sperm cells are encased within a larger vegetative cell. Both cell types exhibit a very different type of chromatin organization - highly condensed in sperm cell nuclei and highly diffuse in the vegetative cell. Distinct classes of histone variants have dynamic and differential expression in the two cell lineages of the male gametophyte. Here we review how the dynamics of histone variants are linked to reprogramming of chromatin activities in the male gametophyte, compaction of the sperm cell genome and zygotic transitions post-fertilization.
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Affiliation(s)
- Michael Borg
- Gregor Mendel Institute, Vienna Biocenter, Dr. Bohr-Gasse 3, 1030, Vienna, Austria
| | - Frédéric Berger
- Gregor Mendel Institute, Vienna Biocenter, Dr. Bohr-Gasse 3, 1030, Vienna, Austria
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96
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Same same but different: sperm-activating EC1 and ECA1 gametogenesis-related family proteins. Biochem Soc Trans 2015; 42:401-7. [PMID: 24646251 DOI: 10.1042/bst20140039] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
During double fertilization in Arabidopsis thaliana, the egg cell secretes small cysteine-rich EC1 (egg cell 1) proteins, which enable the arriving sperm pair to rapidly interact with the two female gametes. EC1 proteins are members of the large and unexplored group of ECA1 (early culture abundant 1) gametogenesis-related family proteins, characterized by a prolamin-like domain with six conserved cysteine residues that may form three pairs of disulfide bonds. The distinguishing marks of egg-cell-expressed EC1 proteins are, however, two short amino acid sequence motifs present in all EC1-like proteins. EC1 genes appear to encode the major CRPs (cysteine-rich proteins) expressed by the plant egg cell, and they are restricted to flowering plants, including the most basal extant flowering plant Amborella trichopoda. Many other ECA1 gametogenesis-related family genes are preferentially expressed in the synergid cell. Functional diversification among the ECA1 gametogenesis-related family is suggested by the different patterns of expression in the female gametophyte and the low primary sequence conservation.
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97
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Lu Y, Wei L, Wang T. Methods to isolate a large amount of generative cells, sperm cells and vegetative nuclei from tomato pollen for "omics" analysis. FRONTIERS IN PLANT SCIENCE 2015; 6:391. [PMID: 26082789 PMCID: PMC4451641 DOI: 10.3389/fpls.2015.00391] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 05/16/2015] [Indexed: 05/05/2023]
Abstract
The development of sperm cells (SCs) from microspores involves a set of finely regulated molecular and cellular events and the coordination of these events. The mechanisms underlying these events and their interconnections remain a major challenge. Systems analysis of genome-wide molecular networks and functional modules with high-throughput "omics" approaches is crucial for understanding the mechanisms; however, this study is hindered because of the difficulty in isolating a large amount of cells of different types, especially generative cells (GCs), from the pollen. Here, we optimized the conditions of tomato pollen germination and pollen tube growth to allow for long-term growth of pollen tubes in vitro with SCs generated in the tube. Using this culture system, we developed methods for isolating GCs, SCs and vegetative cell nuclei (VN) from just-germinated tomato pollen grains and growing pollen tubes and their purification by Percoll density gradient centrifugation. The purity and viability of isolated GCs and SCs were confirmed by microscopy examination and fluorescein diacetate staining, respectively, and the integrity of VN was confirmed by propidium iodide staining. We could obtain about 1.5 million GCs and 2.0 million SCs each from 180 mg initiated pollen grains, and 10 million VN from 270 mg initiated pollen grains germinated in vitro in each experiment. These methods provide the necessary preconditions for systematic biology studies of SC development and differentiation in higher plants.
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Affiliation(s)
- Yunlong Lu
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of SciencesBeijing, China
- University of Chinese Academy of SciencesBeijing, China
| | - Liqin Wei
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of SciencesBeijing, China
| | - Tai Wang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of SciencesBeijing, China
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98
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Ronceret A, Vielle-Calzada JP. Meiosis, unreduced gametes, and parthenogenesis: implications for engineering clonal seed formation in crops. PLANT REPRODUCTION 2015; 28:91-102. [PMID: 25796397 DOI: 10.1007/s00497-015-0262-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 03/09/2015] [Indexed: 05/18/2023]
Abstract
Meiosis and unreduced gametes. Sexual flowering plants produce meiotically derived cells that give rise to the male and female haploid gametophytic phase. In the ovule, usually a single precursor (the megaspore mother cell) undergoes meiosis to form four haploid megaspores; however, numerous mutants result in the formation of unreduced gametes, sometimes showing female specificity, a phenomenon reminiscent of the initiation of gametophytic apomixis. Here, we review the developmental events that occur during female meiosis and megasporogenesis at the light of current possibilities to engineer unreduced gamete formation. We also provide an overview of the current understanding of mechanisms leading to parthenogenesis and discuss some of the conceptual implications for attempting the induction of clonal seed production in cultivated plants.
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Affiliation(s)
- Arnaud Ronceret
- Group of Reproductive Development and Apomixis, UGA Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV Irapuato, Km 9.6 Libramiento Norte Carretera Irapuato-León, CP 36821, Irapuato, Guanajuato, Mexico
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99
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Panoli A, Martin MV, Alandete-Saez M, Simon M, Neff C, Swarup R, Bellido A, Yuan L, Pagnussat GC, Sundaresan V. Auxin Import and Local Auxin Biosynthesis Are Required for Mitotic Divisions, Cell Expansion and Cell Specification during Female Gametophyte Development in Arabidopsis thaliana. PLoS One 2015; 10:e0126164. [PMID: 25970627 PMCID: PMC4430233 DOI: 10.1371/journal.pone.0126164] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 03/29/2015] [Indexed: 11/18/2022] Open
Abstract
The female gametophyte of flowering plants, called the embryo sac, develops from a haploid cell named the functional megaspore, which is specified after meiosis by the diploid sporophyte. In Arabidopsis, the functional megaspore undergoes three syncitial mitotic divisions followed by cellularization to form seven cells of four cell types including two female gametes. The plant hormone auxin is important for sporophytic developmental processes, and auxin levels are known to be regulated by biosynthesis and transport. Here, we investigated the role of auxin biosynthetic genes and auxin influx carriers in embryo sac development. We find that genes from the YUCCA/TAA pathway (YUC1, YUC2, YUC8, TAA1, TAR2) are expressed asymmetrically in the developing ovule and embryo sac from the two-nuclear syncitial stage until cellularization. Mutants for YUC1 and YUC2 exhibited defects in cell specification, whereas mutations in YUC8, as well as mutations in TAA1 and TAR2, caused defects in nuclear proliferation, vacuole formation and anisotropic growth of the embryo sac. Additionally, expression of the auxin influx carriers AUX1 and LAX1 were observed at the micropylar pole of the embryo sac and in the adjacent cells of the ovule, and the aux1 lax1 lax2 triple mutant shows multiple gametophyte defects. These results indicate that both localized auxin biosynthesis and auxin import, are required for mitotic divisions, cell expansion and patterning during embryo sac development.
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Affiliation(s)
- Aneesh Panoli
- Department of Plant Biology, University of California Davis, Davis, California, 95616, United States of America
| | - Maria Victoria Martin
- Institute of Biological Research IIB-CONICET, Universidad Nacional de Mar del Plata, 7600, Mar del Plata, Argentina
| | - Monica Alandete-Saez
- Department of Plant Biology, University of California Davis, Davis, California, 95616, United States of America
- PIPRA, University of California Davis, Davis, California, 95616, United States of America
| | - Marissa Simon
- Department of Plant Biology, University of California Davis, Davis, California, 95616, United States of America
| | - Christina Neff
- Department of Plant Biology, University of California Davis, Davis, California, 95616, United States of America
| | - Ranjan Swarup
- University of Nottingham, Nottingham, United Kingdom
| | - Andrés Bellido
- Institute of Biological Research IIB-CONICET, Universidad Nacional de Mar del Plata, 7600, Mar del Plata, Argentina
| | - Li Yuan
- Department of Plant Biology, University of California Davis, Davis, California, 95616, United States of America
| | - Gabriela C. Pagnussat
- Institute of Biological Research IIB-CONICET, Universidad Nacional de Mar del Plata, 7600, Mar del Plata, Argentina
- * E-mail: (GCP); (VS)
| | - Venkatesan Sundaresan
- Department of Plant Biology, University of California Davis, Davis, California, 95616, United States of America
- Department of Plant Sciences, University of California Davis, Davis, California, 95616, United States of America
- * E-mail: (GCP); (VS)
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100
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Light signaling controls nuclear architecture reorganization during seedling establishment. Proc Natl Acad Sci U S A 2015; 112:E2836-44. [PMID: 25964332 DOI: 10.1073/pnas.1503512112] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The spatial organization of chromatin can be subject to extensive remodeling in plant somatic cells in response to developmental and environmental signals. However, the mechanisms controlling these dynamic changes and their functional impact on nuclear activity are poorly understood. Here, we determined that light perception triggers a switch between two different nuclear architectural schemes during Arabidopsis postembryonic development. Whereas progressive nucleus expansion and heterochromatin rearrangements in cotyledon cells are achieved similarly under light and dark conditions during germination, the later steps that lead to mature nuclear phenotypes are intimately associated with the photomorphogenic transition in an organ-specific manner. The light signaling integrators DE-ETIOLATED 1 and CONSTITUTIVE PHOTOMORPHOGENIC 1 maintain heterochromatin in a decondensed state in etiolated cotyledons. In contrast, under light conditions cryptochrome-mediated photoperception releases nuclear expansion and heterochromatin compaction within conspicuous chromocenters. For all tested loci, chromatin condensation during photomorphogenesis does not detectably rely on DNA methylation-based processes. Notwithstanding, the efficiency of transcriptional gene silencing may be impacted during the transition, as based on the reactivation of transposable element-driven reporter genes. Finally, we report that global engagement of RNA polymerase II in transcription is highly increased under light conditions, suggesting that cotyledon photomorphogenesis involves a transition from globally quiescent to more active transcriptional states. Given these findings, we propose that light-triggered changes in nuclear architecture underlie interplays between heterochromatin reorganization and transcriptional reprogramming associated with the establishment of photosynthesis.
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