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Ren L, Tang D, Zhao T, Zhang F, Liu C, Xue Z, Shi W, Du G, Shen Y, Li Y, Cheng Z. OsSPL regulates meiotic fate acquisition in rice. THE NEW PHYTOLOGIST 2018; 218:789-803. [PMID: 29479720 DOI: 10.1111/nph.15017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 12/28/2017] [Indexed: 05/20/2023]
Abstract
In angiosperms, the key step in sexual reproduction is successful acquisition of meiotic fate. However, the molecular mechanism determining meiotic fate remains largely unknown. Here, we report that OsSPOROCYTELESS (OsSPL) is critical for meiotic entry in rice (Oryza sativa). We performed a large-scale genetic screen of rice sterile mutants aimed to identify genes regulating meiotic entry and identified OsSPL using map-based cloning. We showed that meiosis-specific callose deposition, chromatin organization, and centromere-specific histone H3 loading were altered in the cells corresponding to pollen mother cells in Osspl anthers. Global transcriptome analysis showed that the enriched differentially expressed genes in Osspl were mainly related to redox status, meiotic process, and parietal cell development. OsSPL might form homodimers and interact with TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factor OsTCP5 via the SPL dimerization and TCP interaction domain. OsSPL also interacts with TPL (TOPLESS) corepressors, OsTPL2 and OsTPL3, via the EAR motif. Our results suggest that the OsSPL-mediated signaling pathway plays a crucial role in rice meiotic entry, which appears to be a conserved regulatory mechanism for meiotic fate acquisition in angiosperms.
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Affiliation(s)
- Lijun Ren
- State Key Laboratory of Plant Genomics and Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ding Tang
- State Key Laboratory of Plant Genomics and Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Tingting Zhao
- State Key Laboratory of Plant Genomics and Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Fanfan Zhang
- State Key Laboratory of Plant Genomics and Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Changzhen Liu
- State Key Laboratory of Plant Genomics and Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhihui Xue
- State Key Laboratory of Plant Genomics and Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Wenqing Shi
- State Key Laboratory of Plant Genomics and Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Guijie Du
- State Key Laboratory of Plant Genomics and Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yi Shen
- State Key Laboratory of Plant Genomics and Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yafei Li
- State Key Laboratory of Plant Genomics and Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Zhukuan Cheng
- State Key Laboratory of Plant Genomics and Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Co-Innovation Center for Modern Production Technology of Grain Crops of Jiangsu Province, College of Agriculture, Yangzhou University, Yangzhou, 225009, China
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Cao L, Wang S, Venglat P, Zhao L, Cheng Y, Ye S, Qin Y, Datla R, Zhou Y, Wang H. Arabidopsis ICK/KRP cyclin-dependent kinase inhibitors function to ensure the formation of one megaspore mother cell and one functional megaspore per ovule. PLoS Genet 2018. [PMID: 29513662 PMCID: PMC5858843 DOI: 10.1371/journal.pgen.1007230] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
In most plants, the female germline starts with the differentiation of one megaspore mother cell (MMC) in each ovule that produces four megaspores through meiosis, one of which survives to become the functional megaspore (FM). The FM further develops into an embryo sac. Little is known regarding the control of MMC formation to one per ovule and the selective survival of the FM. The ICK/KRPs (interactor/inhibitor of cyclin-dependent kinase (CDK)/Kip-related proteins) are plant CDK inhibitors and cell cycle regulators. Here we report that in the ovules of Arabidopsis mutant with all seven ICK/KRP genes inactivated, supernumerary MMCs, FMs and embryo sacs were formed and the two embryo sacs could be fertilized to form two embryos with separate endosperm compartments. Twin seedlings were observed in about 2% seeds. Further, in the mutant ovules the number and position of surviving megaspores from one MMC were variable, indicating that the positional signal for determining the survival of megaspore was affected. Strikingly, ICK4 fusion protein with yellow fluorescence protein was strongly present in the degenerative megaspores but absent in the FM, suggesting an important role of ICKs in the degeneration of non-functional megaspores. The absence of or much weaker phenotypes in lower orders of mutants and complementation of the septuple mutant by ICK4 or ICK7 indicate that multiple ICK/KRPs function redundantly in restricting the formation of more than one MMC and in the selective survival of FM, which are critical to ensure the development of one embryo sac and one embryo per ovule. In most plants, the female germline starts with the differentiation of one megaspore mother cell (MMC) in each ovule that produces multiple megaspores through meiosis. One of the megaspores in a fixed position survives to become the functional megaspore (FM) while the other megaspores undergo degeneration. The FM further develops into an embryo sac. We have been working on the functions and regulation of a family of plant cyclin-dependent kinase inhibitors called ICKs or KRPs. We observed that in the ovules of Arabidopsis mutant with all seven ICK/KRP genes inactivated, multiple MMCs, FMs and embryo sacs were formed, and the embryo sacs could be fertilized to produce two embryos with separate endosperm compartments. Further, in mutant ovules the number and position of surviving megaspores from one MMC were variable and ICK4-YFP (yellow fluorescence protein) fusion protein was strongly expressed in the degenerative megaspores but absent in the FM. Those findings together with other results in our study indicate that multiple ICK/KRPs function redundantly in controlling the formation of one MMC per ovule and also in the degeneration of non-functional megaspores, which are critical for the subsequent development of one embryo sac per ovule and one embryo per seed.
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Affiliation(s)
- Ling Cao
- National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Dept. of Biochemistry, University of Saskatchewan, Saskatoon, SK, Canada
| | - Sheng Wang
- Dept. of Biochemistry, University of Saskatchewan, Saskatoon, SK, Canada
| | | | - Lihua Zhao
- Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Yan Cheng
- National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Dept. of Biochemistry, University of Saskatchewan, Saskatoon, SK, Canada
| | - Shengjian Ye
- Dept. of Biochemistry, University of Saskatchewan, Saskatoon, SK, Canada
| | - Yuan Qin
- Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Raju Datla
- National Research Council Canada, Saskatoon, SK, Canada
| | - Yongming Zhou
- National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- * E-mail: (HW); (YZ)
| | - Hong Wang
- Dept. of Biochemistry, University of Saskatchewan, Saskatoon, SK, Canada
- * E-mail: (HW); (YZ)
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Li HJ, Meng JG, Yang WC. Multilayered signaling pathways for pollen tube growth and guidance. PLANT REPRODUCTION 2018; 31:31-41. [PMID: 29441420 DOI: 10.1007/s00497-018-0324-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 01/24/2018] [Indexed: 05/22/2023]
Abstract
Sexual reproductive success is essential for the survival of all higher organisms. As the most prosperous and diverse group of land plants on earth, flowering plants evolved highly sophisticated fertilization mechanisms. To adapt to the terrestrial environment, a tubular structure pollen tube has been evolved to deliver the immobile sperm cells to the egg and central cell enclosed within the ovule. The pollen tube is generated from the vegetative cell of the pollen (male gametophyte), where two sperm cells are hosted. Pollen tube elongation in the maternal tissue and navigation to the ovule require intimate cell-cell interactions between the tube and female tissues. Questions on how the single-celled pollen tube accomplishes such task and how the female tissues accommodate the tube have attracted many plant biologists. Here, we review recent progresses and concepts in understanding the molecular mechanisms governing pollen tube growth and its interactions with the female tissues. We will also discuss the future perspective in this field.
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Affiliation(s)
- Hong-Ju Li
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, East Lincui Road, Beijing, 100101, China.
- The University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing, 100049, China.
| | - Jiang-Guo Meng
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, East Lincui Road, Beijing, 100101, China
- The University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing, 100049, China
| | - Wei-Cai Yang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, East Lincui Road, Beijing, 100101, China.
- The University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing, 100049, China.
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54
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Su S, Higashiyama T. Arabinogalactan proteins and their sugar chains: functions in plant reproduction, research methods, and biosynthesis. PLANT REPRODUCTION 2018; 31:67-75. [PMID: 29470639 DOI: 10.1007/s00497-018-0329-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 02/19/2018] [Indexed: 05/21/2023]
Abstract
The arabinogalactan protein (AGP) family is one of the most complex protein families and is ubiquitous in the plant kingdom. Moreover, it has been demonstrated to play various roles during plant reproduction. A typical AGP contains a hydroxyproline-rich core protein with high heterogeneity and varying numbers of polysaccharide side chains. However, the functions of the polysaccharide components (i.e. AG sugar chains) remain largely unknown due to the general difficulties associated with studying sugar chains in glycobiology. In recent years, methodological breakthroughs have resulted in substantial progress in AGP research. Here, we summarise the multiple roles of AGPs during plant gametophyte development and male-female communication, with a focus on recent advances. In addition, we discuss the analytical tools used in AGP research, and the biosynthesis and function of AG sugar chains. A comprehensive understanding of the AGP family will help clarify the mechanisms precisely controlling reproductive processes.
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Affiliation(s)
- Shihao Su
- Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo-Cho, Chikusa-Ku, Nagoya, Aichi, 464-8601, Japan
| | - Tetsuya Higashiyama
- Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo-Cho, Chikusa-Ku, Nagoya, Aichi, 464-8601, Japan.
- Graduate School of Science, Nagoya University, Furo-Cho, Chikusa-Ku, Nagoya, Aichi, 464-8602, Japan.
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55
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Ferreira LG, de Alencar Dusi DM, Irsigler AST, Gomes ACMM, Mendes MA, Colombo L, de Campos Carneiro VT. GID1 expression is associated with ovule development of sexual and apomictic plants. PLANT CELL REPORTS 2018; 37:293-306. [PMID: 29080908 DOI: 10.1007/s00299-017-2230-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 10/18/2017] [Indexed: 06/07/2023]
Abstract
BbrizGID1 is expressed in the nucellus of apomictic Brachiaria brizantha, previous to aposporous initial differentiation. AtGID1a overexpression triggers differentiation of Arabidopsis thaliana MMC-like cells, suggesting its involvement in ovule development. GIBBERELLIN-INSENSITIVE DWARF1 (GID1) is a gibberellin receptor previously identified in plants and associated with reproductive development, including ovule formation. In this work, we characterized the Brachiaria brizantha GID1 gene (BbrizGID1). BbrizGID1 showed up to 92% similarity to GID1-like gibberellin receptors of other plants of the Poaceae family and around 58% to GID1-like gibberellin receptors of Arabidopsis thaliana. BbrizGID1 was more expressed in ovaries at megasporogenesis than in ovaries at megagametogenesis of both sexual and apomictic plants. In ovules, BbrizGID1 transcripts were detected in the megaspore mother cell (MMC) of sexual and apomictic B. brizantha. Only in the apomictic plants, expression was also observed in the surrounding nucellar cells, a region in which aposporous initial cells differentiate to form the aposporic embryo sac. AtGID1a ectopic expression in Arabidopsis determines the formation of MMC-like cells in the nucellus, close to the MMC, that did not own MMC identity. Our results suggest that GID1 might be involved in the proper differentiation of a single MMC during ovule development and provide valuable information on the role of GID1 in sexual and apomictic reproduction.
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Affiliation(s)
- Luciana Gomes Ferreira
- Department of Biology, University of Brasília-UnB, Campus Darcy Ribeiro S/N-Asa Norte, Brasília, DF, 70910-900, Brazil
- Embrapa Genetic Resources and Biotechnology, Parque Estação Biológica, PqEB Av. W5 Norte, Caixa Postal 02372, Brasília, DF, 70770-917, Brazil
| | - Diva Maria de Alencar Dusi
- Embrapa Genetic Resources and Biotechnology, Parque Estação Biológica, PqEB Av. W5 Norte, Caixa Postal 02372, Brasília, DF, 70770-917, Brazil
| | - André Southernman Teixeira Irsigler
- Embrapa Genetic Resources and Biotechnology, Parque Estação Biológica, PqEB Av. W5 Norte, Caixa Postal 02372, Brasília, DF, 70770-917, Brazil
| | - Ana Cristina Meneses Mendes Gomes
- Embrapa Genetic Resources and Biotechnology, Parque Estação Biológica, PqEB Av. W5 Norte, Caixa Postal 02372, Brasília, DF, 70770-917, Brazil
| | - Marta Adelina Mendes
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, 20133, Milan, Italy
| | - Lucia Colombo
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, 20133, Milan, Italy
| | - Vera Tavares de Campos Carneiro
- Department of Biology, University of Brasília-UnB, Campus Darcy Ribeiro S/N-Asa Norte, Brasília, DF, 70910-900, Brazil.
- Embrapa Genetic Resources and Biotechnology, Parque Estação Biológica, PqEB Av. W5 Norte, Caixa Postal 02372, Brasília, DF, 70770-917, Brazil.
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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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57
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Liu Z, Miao L, Huo R, Song X, Johnson C, Kong L, Sundaresan V, Yu X. ARF2-ARF4 and ARF5 are Essential for Female and Male Gametophyte Development in Arabidopsis. PLANT & CELL PHYSIOLOGY 2018; 59:179-189. [PMID: 29145642 DOI: 10.1093/pcp/pcx174] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 11/07/2017] [Indexed: 05/14/2023]
Abstract
The plant hormone auxin plays critical roles in plant growth and development. Auxin response factors (ARFs) are a class of transcription factors which regulate auxin-mediated gene expression. While the functions of ARFs in sporophytic development have been well characterized, their functions specific to gametophytic development have not been studied extensively. In this study, Arabidopsis ARF genes were selectively down-regulated in gametophytes by misexpression of targeted microRNAs (amiRARF234, amiRARFMP and MIR167a) to silence AtARF2-AtAEF4, AtARF5, AtARF6 and AtARF8. Embryo sacs in amiRARF234- and amiRARFMP-expressing plants exhibited identity defects in cells at the micropylar pole, such as formation of two cells with egg cell-like morphology, concomitant with loss of synergid marker expression and seed abortion. The pollen grains of the transgenic plants were morphologically aberrant and unviable, and the inclusions and nuclei were lost in the abnormal pollen grains. However, plants misexpressing MIR167a showed no obvious abnormal phenotypes in the embryo sacs and pollen grains. Overall, these results provide evidence that AtARF2-AtARF4 and AtARF5 play significant roles in regulating both female and male gametophyte development in Arabidopsis.
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MESH Headings
- Arabidopsis/genetics
- Arabidopsis/growth & development
- Arabidopsis Proteins/genetics
- Base Sequence
- DNA-Binding Proteins/genetics
- Down-Regulation
- Gametogenesis, Plant/genetics
- Gene Expression Regulation, Developmental
- Gene Expression Regulation, Plant
- Germ Cells, Plant/growth & development
- Germ Cells, Plant/metabolism
- Germ Cells, Plant/ultrastructure
- Microscopy, Electron, Transmission
- Nuclear Proteins/genetics
- Plants, Genetically Modified
- Repressor Proteins/genetics
- Seeds/genetics
- Seeds/growth & development
- Sequence Homology, Nucleic Acid
- Transcription Factors/genetics
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Affiliation(s)
- Zhenning Liu
- Institute of Vegetable Science, Zhejiang University, Hangzhou 310058, China
- College of Agriculture and Forestry Sciences, Linyi University, Linyi, Shandong 276000, China
- Department of Plant Biology, University of California, Davis, CA 95616, USA
| | - Liming Miao
- Institute of Vegetable Science, Zhejiang University, Hangzhou 310058, China
| | - Ruxue Huo
- College of Agriculture and Forestry Sciences, Linyi University, Linyi, Shandong 276000, China
| | - Xiaoya Song
- Department of Plant Biology, University of California, Davis, CA 95616, USA
| | - Cameron Johnson
- Department of Plant Biology, University of California, Davis, CA 95616, USA
| | - Lijun Kong
- Institute of Vegetable Science, Zhejiang University, Hangzhou 310058, China
| | | | - Xiaolin Yu
- Institute of Vegetable Science, Zhejiang University, Hangzhou 310058, China
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58
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KLU suppresses megasporocyte cell fate through SWR1-mediated activation of WRKY28 expression in Arabidopsis. Proc Natl Acad Sci U S A 2017; 115:E526-E535. [PMID: 29288215 DOI: 10.1073/pnas.1716054115] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Germ-line specification is essential for sexual reproduction. In the ovules of most flowering plants, only a single hypodermal cell enlarges and differentiates into a megaspore mother cell (MMC), the founder cell of the female germ-line lineage. The molecular mechanisms restricting MMC specification to a single cell remain elusive. We show that the Arabidopsis transcription factor WRKY28 is exclusively expressed in hypodermal somatic cells surrounding the MMC and is required to repress these cells from acquiring MMC-like cell identity. In this process, the SWR1 chromatin remodeling complex mediates the incorporation of the histone variant H2A.Z at the WRKY28 locus. Moreover, the cytochrome P450 gene KLU, expressed in inner integument primordia, non-cell-autonomously promotes WRKY28 expression through H2A.Z deposition at WRKY28. Taken together, our findings show how somatic cells in ovule primordia cooperatively use chromatin remodeling to restrict germ-line cell specification to a single cell.
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59
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Genome-Wide Analysis of DNA Methylation During Ovule Development of Female-Sterile Rice fsv1. G3-GENES GENOMES GENETICS 2017; 7:3621-3635. [PMID: 28877971 PMCID: PMC5677159 DOI: 10.1534/g3.117.300243] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The regulation of female fertility is an important field of rice sexual reproduction research. DNA methylation is an essential epigenetic modification that dynamically regulates gene expression during development processes. However, few reports have described the methylation profiles of female-sterile rice during ovule development. In this study, ovules were continuously acquired from the beginning of megaspore mother cell meiosis until the mature female gametophyte formation period, and global DNA methylation patterns were compared in the ovules of a high-frequency female-sterile line (fsv1) and a wild-type rice line (Gui99) using whole-genome bisulfite sequencing (WGBS). Profiling of the global DNA methylation revealed hypo-methylation, and 3471 significantly differentially methylated regions (DMRs) were observed in fsv1 ovules compared with Gui99. Based on functional annotation and Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis of differentially methylated genes (DMGs), we observed more DMGs enriched in cellular component, reproduction regulation, metabolic pathway, and other pathways. In particular, many ovule development genes and plant hormone-related genes showed significantly different methylation patterns in the two rice lines, and these differences may provide important clues for revealing the mechanism of female gametophyte abortion.
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60
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Hao L, Wei X, Zhu J, Shi J, Liu J, Gu H, Tsuge T, Qu LJ. SNAIL1 is essential for female gametogenesis in Arabidopsis thaliana. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2017; 59:629-641. [PMID: 28776932 DOI: 10.1111/jipb.12572] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 08/02/2017] [Indexed: 06/07/2023]
Abstract
Two yeast Brix family members Ssf1 and Ssf2, involved in large ribosomal subunit synthesis, are essential for yeast cell viability and mating efficiency. Their putative homologs exist in the Arabidopsis genome; however, their role in plant development is unknown. Here, we show that Arabidopsis thaliana SNAIL1 (AtSNAIL1), a protein sharing high sequence identity with yeast Ssf1 and Ssf2, is critical to mitosis progression of female gametophyte development. The snail1 homozygous mutant was nonviable and its heterozygous mutant was semi-sterile with shorter siliques. The mutation in SNAIL1 led to absence of female transmission and reduced male transmission. Further phenotypic analysis showed that the synchronic development of female gametophyte in the snail1 heterozygous mutant was greatly impaired and the snail1 pollen tube growth, in vivo, was also compromised. Furthermore, SNAIL1 was a nucleolar-localized protein with a putative role in protein synthesis. Our data suggest that SNAIL1 may function in ribosome biogenesis like Ssf1 and Ssf2 and plays an important role during megagametogenesis in Arabidopsis.
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Affiliation(s)
- Lihong Hao
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China
| | - Xiaolin Wei
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China
| | - Jiulei Zhu
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China
| | - Jiao Shi
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China
| | - Jingjing Liu
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China
- National Plant Gene Research Center (Beijing), Beijing 100101, China
| | - Hongya Gu
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China
- National Plant Gene Research Center (Beijing), Beijing 100101, China
| | - Tomohiko Tsuge
- Institute for Chemical Research, Kyoto University, Gokasho Uji, Kyoto 611-0011, Japan
| | - Li-Jia Qu
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China
- National Plant Gene Research Center (Beijing), Beijing 100101, China
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61
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Su Z, Zhao L, Zhao Y, Li S, Won S, Cai H, Wang L, Li Z, Chen P, Qin Y, Chen X. The THO Complex Non-Cell-Autonomously Represses Female Germline Specification through the TAS3-ARF3 Module. Curr Biol 2017; 27:1597-1609.e2. [PMID: 28552357 DOI: 10.1016/j.cub.2017.05.021] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 04/12/2017] [Accepted: 05/05/2017] [Indexed: 12/21/2022]
Abstract
In most sexually reproducing plants, a single somatic, sub-epidermal cell in an ovule is selected to differentiate into a megaspore mother cell, which is committed to giving rise to the female germline. However, it remains unclear how intercellular signaling among somatic cells results in only one cell in the sub-epidermal layer differentiating into the megaspore mother cell. Here we uncovered a role of the THO complex in restricting the megaspore mother cell fate to a single cell. Mutations in TEX1, HPR1, and THO6, components of the THO/TREX complex, led to the formation of multiple megaspore mother cells, which were able to initiate gametogenesis. We demonstrated that TEX1 repressed the megaspore mother cell fate by promoting the biogenesis of TAS3-derived trans-acting small interfering RNA (ta-siRNA), which represses ARF3 expression. The TEX1 protein was present in epidermal cells, but not in the germline, and, through TAS3-derived ta-siRNA, restricted ARF3 expression to the medio domain of ovule primordia. Expansion of ARF3 expression into lateral epidermal cells in a TAS3 ta-siRNA-insensitive mutant led to the formation of supernumerary megaspore mother cells, suggesting that TEX1- and TAS3-mediated restriction of ARF3 expression limits excessive megaspore mother cell formation non-cell-autonomously. Our findings reveal the role of a small-RNA pathway in the regulation of female germline specification in Arabidopsis.
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Affiliation(s)
- Zhenxia Su
- Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Lab of Genetics, Breeding, and Multiple Utilization of Crops, Ministry of Education, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Center for Genomics and Biotechnology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian Province, China; Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA, 92521, USA
| | - Lihua Zhao
- Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Lab of Genetics, Breeding, and Multiple Utilization of Crops, Ministry of Education, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Center for Genomics and Biotechnology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian Province, China
| | - Yuanyuan Zhao
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA, 92521, USA
| | - Shaofang Li
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA, 92521, USA
| | - SoYoun Won
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA, 92521, USA
| | - Hanyang Cai
- Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Lab of Genetics, Breeding, and Multiple Utilization of Crops, Ministry of Education, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Center for Genomics and Biotechnology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian Province, China
| | - Lulu Wang
- Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Lab of Genetics, Breeding, and Multiple Utilization of Crops, Ministry of Education, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Center for Genomics and Biotechnology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian Province, China
| | - Zhenfang Li
- Crop Science College, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian Province, China
| | - Piaojuan Chen
- Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Lab of Genetics, Breeding, and Multiple Utilization of Crops, Ministry of Education, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Center for Genomics and Biotechnology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian Province, China
| | - Yuan Qin
- Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Lab of Genetics, Breeding, and Multiple Utilization of Crops, Ministry of Education, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Center for Genomics and Biotechnology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian Province, China.
| | - Xuemei Chen
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA, 92521, USA; Howard Hughes Medical Institute, Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, Riverside, CA, 92521, USA.
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Tedeschi F, Rizzo P, Rutten T, Altschmied L, Bäumlein H. RWP-RK domain-containing transcription factors control cell differentiation during female gametophyte development in Arabidopsis. THE NEW PHYTOLOGIST 2017; 213:1909-1924. [PMID: 27870062 DOI: 10.1111/nph.14293] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 09/17/2016] [Indexed: 05/02/2023]
Abstract
The formation of gametes is a prerequisite for any sexually reproducing organism in order to complete its life cycle. In plants, female gametes are formed in a multicellular tissue, the female gametophyte or embryo sac. Although the events leading to the formation of the female gametophyte have been morphologically characterized, the molecular control of embryo sac development remains elusive. We used single and double mutants as well as cell-specific marker lines to characterize a novel class of gene regulators in Arabidopsis thaliana, the RWP-RK domain-containing (RKD) transcription factors. Morphological and histological analyses were conducted using confocal laser scanning and differential interference contrast microscopy. Gene expression and transcriptome analyses were performed using quantitative reverse transcription-PCR and RNA sequencing, respectively. Our results showed that RKD genes are expressed during distinct stages of embryo sac development. Morphological analysis of the mutants revealed severe distortions in gametophyte polarity and cell differentiation. Transcriptome analysis revealed changes in the expression of several gametophyte-specific gene families (RKD2 and RKD3) and ovule development-specific genes (RKD3), and identified pleiotropic effects on phytohormone pathways (RKD5). Our data provide novel insight into the regulatory control of female gametophyte development. RKDs are involved in the control of cell differentiation and are required for normal gametophytic development.
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Affiliation(s)
- Francesca Tedeschi
- Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), D-06466, Seeland, OT Gatersleben, Germany
| | - Paride Rizzo
- Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), D-06466, Seeland, OT Gatersleben, Germany
| | - Twan Rutten
- Department of Physiology and Cell Biology, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), D-06466, Seeland, OT Gatersleben, Germany
| | - Lothar Altschmied
- Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), D-06466, Seeland, OT Gatersleben, Germany
| | - Helmut Bäumlein
- Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), D-06466, Seeland, OT Gatersleben, Germany
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63
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Lu C, Yu F, Tian L, Huang X, Tan H, Xie Z, Hao X, Li D, Luan S, Chen L. RPS9M, a Mitochondrial Ribosomal Protein, Is Essential for Central Cell Maturation and Endosperm Development in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2017; 8:2171. [PMID: 29312411 PMCID: PMC5744018 DOI: 10.3389/fpls.2017.02171] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Accepted: 12/11/2017] [Indexed: 05/15/2023]
Abstract
During double fertilization of angiosperms, the central cell of the female gametophyte fuses with a sperm cell to produce the endosperm, a storage tissue that nourishes the developing embryo within the seed. Although many genetic mutants defective in female gametophytic functions have been characterized, the molecular mechanisms controlling the specification and differentiation of the central cell are still not fully understood. Here, we report a mitochondrial ribosomal protein, RPS9M, is required for central cell maturation. RPS9M was highly expressed in the male and female gametophytes before and after double fertilization. The female gametophytes were defective in the rps9m mutant specifically concerning maturation of central cells. The morphological defects include unfused polar nuclei and smaller central vacuole in central cells. In addition, embryo initiation and early endosperm development were also severely affected in rps9m female gametophytes even after fertilized with wild type pollens. The RPS9M can interact with ANK6, an ankyrin-repeat protein in mitochondria previously reported to be required for fertilization. The expression pattern and mutant phenotype of RPS9M are similar to those of ANK6 as well, suggesting that RPS9M may work together with ANK6 in controlling female gametophyte development, possibly by regulating the expression of some mitochondrial proteins.
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Affiliation(s)
- Changqing Lu
- Hunan Province Key Laboratory of Crop Sterile Germplasm Resource Innovation and Application, Hunan Normal University, Changsha, China
| | - Feng Yu
- Hunan Province Key Laboratory of Crop Sterile Germplasm Resource Innovation and Application, Hunan Normal University, Changsha, China
| | - Lianfu Tian
- Hunan Province Key Laboratory of Crop Sterile Germplasm Resource Innovation and Application, Hunan Normal University, Changsha, China
| | - Xiaoying Huang
- Hunan Province Key Laboratory of Crop Sterile Germplasm Resource Innovation and Application, Hunan Normal University, Changsha, China
| | - Hong Tan
- Hunan Province Key Laboratory of Crop Sterile Germplasm Resource Innovation and Application, Hunan Normal University, Changsha, China
| | - Zijing Xie
- Hunan Province Key Laboratory of Crop Sterile Germplasm Resource Innovation and Application, Hunan Normal University, Changsha, China
| | - Xiaohua Hao
- Hunan Province Key Laboratory of Crop Sterile Germplasm Resource Innovation and Application, Hunan Normal University, Changsha, China
| | - Dongping Li
- Hunan Province Key Laboratory of Crop Sterile Germplasm Resource Innovation and Application, Hunan Normal University, Changsha, China
- *Correspondence: Dongping Li, Sheng Luan, Liangbi Chen,
| | - Sheng Luan
- Hunan Province Key Laboratory of Crop Sterile Germplasm Resource Innovation and Application, Hunan Normal University, Changsha, China
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, United States
- *Correspondence: Dongping Li, Sheng Luan, Liangbi Chen,
| | - Liangbi Chen
- Hunan Province Key Laboratory of Crop Sterile Germplasm Resource Innovation and Application, Hunan Normal University, Changsha, China
- *Correspondence: Dongping Li, Sheng Luan, Liangbi Chen,
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64
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Wilkinson LG, Tucker MR. An optimised clearing protocol for the quantitative assessment of sub-epidermal ovule tissues within whole cereal pistils. PLANT METHODS 2017; 13:67. [PMID: 28824704 PMCID: PMC5558753 DOI: 10.1186/s13007-017-0217-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 08/08/2017] [Indexed: 05/03/2023]
Abstract
BACKGROUND Seed development in the angiosperms requires the production of a female gametophyte (embryo sac) within the ovule. Many aspects of female reproductive development in cereal crops are yet to be described, largely due to the technical difficulty in obtaining phenotypic information at the cellular or sub-cellular level. Hoyer's solution is currently well established as a solution for clearing thin tissues samples, such as sections or whole tissues of bryophytes, mycorrhizal fungi, and small model organisms (e.g. Arabidopsis thaliana). RESULTS Here we report a Hoyer's solution-based clearing method to facilitate clearing of the whole barley pistil, with high reproducibility. The clearing process takes 10 days from fixation to visualisation, whereupon tissue is sufficiently clear to obtain multiple phenotypic measurements from sub-epidermal tissues and cells within the ovule. CONCLUSION Visualisation of cereal ovules that have not been dissected from the pistil allows an unprecedented capability to collect quantitative morphological information from the developing ovule, integument, nucellus and embryo sac. This will enable comparisons with genetic data to reveal the contribution of pre-fertilisation ovule tissues towards downstream seed development.
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Affiliation(s)
- Laura G. Wilkinson
- ARC Centre of Excellence in Plant Cell Walls and School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Urrbrae, SA Australia
| | - Matthew R. Tucker
- School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Urrbrae, SA Australia
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65
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Bartoli G, Felici C, Ruffini Castiglione M. Female gametophyte and embryo development in Helleborus bocconei Ten. (Ranunculaceae). PROTOPLASMA 2017; 254:491-504. [PMID: 27048178 DOI: 10.1007/s00709-016-0969-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 03/29/2016] [Indexed: 06/05/2023]
Abstract
In this study, we investigated cytohistochemistry, cycle progression, and relative DNA content of the female gametophyte cells of Helleborus bocconei Ten. before and after fertilization process. The early stages of embryo development were also investigated. H. bocconei possesses a monosporic seven-celled/eight-nucleate Polygonum type female gametophyte, characterized by a morpho-functional polarity. The cells of the embryo sac showed abundant reserves of polysaccharides, strongly increasing in the egg cell just before fertilization. With different timing in DNA replication during cell cycle progression, synergids, egg cells, and polar nuclei showed a haploid DNA content at the end of their differentiation, while antipodes underwent three DNA endoreduplication cycles. Programmed cell death symptoms were detectable in synergid and antipodal cells. After double fertilization, the central cell quickly underwent many mitotic cycles forming the endosperm, which exhibited a progressive increase in protein bodies and starch grains. Close to the developing embryo, the endosperm differentiated a well-defined region rich in a fibrillar carbohydrate matrix. The zygote, that does not start immediately to divide after double fertilization, developed in to an embryo that reached the heart stage at fruit maturation time. A weakly differentiated embryo at this time indicates a morpho-physiological dormancy of seeds, as a survival strategy imposed by the life cycle of this plant with seed dispersal in spring and their germination in the following winter.
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Affiliation(s)
- Giacomo Bartoli
- Department of Biology, University of Pisa, via Ghini 13, Pisa, I-56126, Italy
| | - Cristiana Felici
- Department of Biology, University of Pisa, via Ghini 13, Pisa, I-56126, Italy
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66
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An Efficient Antipodal Cell Isolation Method for Screening of Cell Type-Specific Genes in Arabidopsis thaliana. PLoS One 2016; 11:e0166390. [PMID: 27875553 PMCID: PMC5119737 DOI: 10.1371/journal.pone.0166390] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Accepted: 10/27/2016] [Indexed: 11/19/2022] Open
Abstract
In flowering plants, the mature embryo sac consists of seven cells, namely two synergid cells and an egg cell at the micropylar end, one central cell, and three antipodal cells at the chalazal end. Excluding the antipodal cell, as a model for the study of cell fate determination and cell type specification, the roles of these embryo sac component cells in fertilization and seed formation have been widely investigated. At this time, little is known regarding the function of antipodal cells and their cell type-specific gene expression patterns. One reason for this is difficulties related to the observation and isolation of cells for detailed functional analyses. Here, we report a method for antipodal cell isolation and transcriptome analysis. We identified antipodal cell-specific marker line K44-1, and based on this marker line, established a procedure allowing us to isolate antipodal cells with both high quality and quantity. PCR validation of antipodal-specific genes from antipodal cell cDNA showed that the isolated cells are qualified and can be used for transcriptome analysis and screening of cell type-specific marker genes. The isolated cells could keep viable for a week in culture condition. This method can be used to efficiently isolate antipodal cells of high quality and will promote the functional investigation of antipodal cells in Arabidopsis thaliana. This increases our understanding of the molecular regulatory mechanism of antipodal cell specification.
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67
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Yang L, Wu Y, Yu M, Mao B, Zhao B, Wang J. Genome-wide transcriptome analysis of female-sterile rice ovule shed light on its abortive mechanism. PLANTA 2016; 244:1011-1028. [PMID: 27357232 DOI: 10.1007/s00425-016-2563-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 06/23/2016] [Indexed: 05/03/2023]
Abstract
The comprehensive transcriptome analysis of rice female-sterile line and wild-type line ovule provides an important clue for exploring the regulatory network of the formation of rice fertile female gametophyte. Ovules are the female reproductive tissues of rice (Oryza sativa L.) and play a major role in sexual reproduction. To investigate the potential mechanism of rice female gametophyte fertility, we used RNA sequencing, combined with genetic subtraction, to compare the transcriptome of the ovules of a high-frequency female-sterile line (fsv1) and a rice wild-type line (Gui 99) during ovule development. Ovules were harvested at three developmental stages: ovule containing megaspore mother cell in meiosis process (stage 1), ovule containing functional megaspore in mitosis process (stage 2), and ovule containing mature female gametophyte (stage 3). Six cDNA libraries generated a total of 42.2 million high-quality clean reads that aligned with 30,204 genes. The comparison between the fsv1 and Gui 99 ovules identified a large number of differentially expressed genes (DEGs), i.e., 45, 495, and 932 DEGs at the three ovule developmental stages, respectively. From the comparison of the two rice lines, Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and MapMan analyses indicated that a large number of DEGs associated with starch and sucrose metabolism, plant hormone signal transduction, protein modification and degradation, oxidative phosphorylation, and receptor kinase. These DEGs might play roles in ovule development and fertile female gametophyte formation. Many transcription factor genes and epigenetic-related genes also exhibit different expression patterns and significantly different expression levels in two rice lines during ovule development, which might provide important information regarding the abortive mechanism of the female gametophyte in rice.
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Affiliation(s)
- Liyu Yang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Ya Wu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Meiling Yu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Bigang Mao
- State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha, 410125, China
| | - Bingran Zhao
- State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha, 410125, China.
| | - Jianbo Wang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China.
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68
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Zhu DZ, Zhao XF, Liu CZ, Ma FF, Wang F, Gao XQ, Zhang XS. Interaction between RNA helicase ROOT INITIATION DEFECTIVE 1 and GAMETOPHYTIC FACTOR 1 is involved in female gametophyte development in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:5757-5768. [PMID: 27683728 PMCID: PMC5066494 DOI: 10.1093/jxb/erw341] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
ROOT INITIATION DEFECTIVE 1 (RID1) is an Arabidopsis DEAH/RHA RNA helicase. It functions in hypocotyl de-differentiation, de novo meristem formation, and cell specification of the mature female gametophyte (FG). However, it is unclear how RID1 regulates FG development. In this study, we observed that mutations to RID1 disrupted the developmental synchrony and retarded the progression of FG development. RID1 exhibited RNA helicase activity, with a preference for unwinding double-stranded RNA in the 3' to 5' direction. Furthermore, we found that RID1 interacts with GAMETOPHYTIC FACTOR 1 (GFA1), which is an integral protein of the spliceosome component U5 small nuclear ribonucleoprotein (snRNP) particle. Substitution of specific RID1 amino acids (Y266F and T267I) inhibited the interaction with GFA1. In addition, the mutated RID1 could not complement the seed-abortion phenotype of the rid1 mutant. The rid1 and gfa1 mutants exhibited similar abnormalities in pre-mRNA splicing and down-regulated expression of some genes involved in FG development. Our results suggest that an interaction between RID1 and the U5 snRNP complex regulates essential pre-mRNA splicing of the genes required for FG development. This study provides new information regarding the mechanism underlying the FG developmental process.
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Affiliation(s)
- Dong Zi Zhu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian 271018, China
| | - Xue Fang Zhao
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian 271018, China
| | - Chang Zhen Liu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian 271018, China
| | - Fang Fang Ma
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian 271018, China
| | - Fang Wang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian 271018, China
| | - Xin-Qi Gao
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian 271018, China
| | - Xian Sheng Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian 271018, China
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69
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Zhou JM, Yang WC. Receptor-like kinases take center stage in plant biology. SCIENCE CHINA-LIFE SCIENCES 2016; 59:863-6. [DOI: 10.1007/s11427-016-5112-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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70
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RLKs orchestrate the signaling in plant male-female interaction. SCIENCE CHINA-LIFE SCIENCES 2016; 59:867-77. [DOI: 10.1007/s11427-016-0118-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Accepted: 05/16/2016] [Indexed: 11/26/2022]
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71
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Figueiredo DD, Köhler C. Bridging the generation gap: communication between maternal sporophyte, female gametophyte and fertilization products. CURRENT OPINION IN PLANT BIOLOGY 2016; 29:16-20. [PMID: 26658334 DOI: 10.1016/j.pbi.2015.10.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 10/16/2015] [Accepted: 10/19/2015] [Indexed: 05/08/2023]
Abstract
In seed plants, as in placental animals, gamete formation and zygotic development take place within the parental tissues. To ensure timely onset and to coordinate the development of the new generation, communication between the parent plant with the filial tissues and its precursors is of utmost importance. During female gametogenesis the maternal tissues tightly regulate megagametophyte formation and the interplay between the sporophyte and the fertilization products, embryo and endosperm, has major implications in the formation of a viable seed. We review the current knowledge on these interactions and highlight the many questions that still remain unanswered, in particular the nature of the pathways involved in these signaling events.
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Affiliation(s)
- Duarte D Figueiredo
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center of Plant Biology, Uppsala, Sweden
| | - Claudia Köhler
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center of Plant Biology, Uppsala, Sweden.
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72
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Schmid MW, Schmidt A, Grossniklaus U. The female gametophyte: an emerging model for cell type-specific systems biology in plant development. FRONTIERS IN PLANT SCIENCE 2015; 6:907. [PMID: 26579157 PMCID: PMC4630298 DOI: 10.3389/fpls.2015.00907] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 10/10/2015] [Indexed: 05/03/2023]
Abstract
Systems biology, a holistic approach describing a system emerging from the interactions of its molecular components, critically depends on accurate qualitative determination and quantitative measurements of these components. Development and improvement of large-scale profiling methods ("omics") now facilitates comprehensive measurements of many relevant molecules. For multicellular organisms, such as animals, fungi, algae, and plants, the complexity of the system is augmented by the presence of specialized cell types and organs, and a complex interplay within and between them. Cell type-specific analyses are therefore crucial for the understanding of developmental processes and environmental responses. This review first gives an overview of current methods used for large-scale profiling of specific cell types exemplified by recent advances in plant biology. The focus then lies on suitable model systems to study plant development and cell type specification. We introduce the female gametophyte of flowering plants as an ideal model to study fundamental developmental processes. Moreover, the female reproductive lineage is of importance for the emergence of evolutionary novelties such as an unequal parental contribution to the tissue nurturing the embryo or the clonal production of seeds by asexual reproduction (apomixis). Understanding these processes is not only interesting from a developmental or evolutionary perspective, but bears great potential for further crop improvement and the simplification of breeding efforts. We finally highlight novel methods, which are already available or which will likely soon facilitate large-scale profiling of the specific cell types of the female gametophyte in both model and non-model species. We conclude that it may take only few years until an evolutionary systems biology approach toward female gametogenesis may decipher some of its biologically most interesting and economically most valuable processes.
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Affiliation(s)
| | | | - Ueli Grossniklaus
- Department of Plant & Microbial Biology and Zurich-Basel Plant Science Center, University of ZurichZurich, Switzerland
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73
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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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74
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Abstract
The evolution of seeds was a major reason for the rise of angiosperms to ecological dominance. Seeds of angiosperms are composed of three main structures: the embryo, which will give rise to the next generation; the endosperm, a nurturing tissue whose main function is to deliver nutrients from the mother plant to the embryo; and the seed coat (or testa), a tissue that is derived from the maternal integuments and which provides support and protection to the growing embryo. All three seed components need to exchange signals to ensure co-ordinated growth and development. The present review discusses the structure of the seed coat, its interaction with the endosperm, and bidirectional signalling events between endosperm and seed coat that co-ordinate growth of both tissues. Angiosperm seeds are not only of evolutionary significance, but also of major agronomic importance, demanding a thorough understanding of the events governing seed growth and development.
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75
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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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76
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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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Abstract
Seed size is a key determinant of evolutionary fitness, and is also one of the most important components of seed yield. In angiosperms, seed development begins with double fertilization, which leads to the formation of a diploid embryo and a triploid endosperm. The outermost layer of the seed is the seed coat, which differentiates from maternal integuments. Therefore, the size of a seed is determined by the co-ordinated growth of the embryo, endosperm, and maternal tissue. Recent studies have identified several factors that act maternally or zygotically to regulate seed size, and revealed possible mechanisms that underlie seed size control in Arabidopsis and rice. In this review, we summarize current research progress in maternal control of seed size and discuss the roles of several newly identified regulators in maternal regulation of seed growth.
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Affiliation(s)
- Na Li
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yunhai Li
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
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78
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Twin plants from supernumerary egg cells in Arabidopsis. Curr Biol 2014; 25:225-230. [PMID: 25544612 DOI: 10.1016/j.cub.2014.11.021] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 10/20/2014] [Accepted: 11/07/2014] [Indexed: 01/19/2023]
Abstract
Sexual reproduction of flowering plants is distinguished by double fertilization—the two sperm cells delivered by a pollen tube fuse with the two gametic cells of the female gametophyte, the egg and the central cell—inside the ovule to give rise to the embryo and the nutritive endosperm, respectively. The pollen tube is attracted by nongametic synergid cells, and how these two cells of the female gametophyte are specified is currently unclear. Here, we show that ALTERED MERISTEM PROGRAM 1 (AMP1), encoding a protein associated with the endoplasmic reticulum, is required for synergid cell fate during Arabidopsis female gametophyte development. Loss of AMP1 function leads to supernumerary egg cells at the expense of synergids, enabling the generation of dizygotic twins. However, if twin embryos are formed, endosperm formation is prevented, eventually resulting in ovule abortion. The latter can be overcome by the delivery of supernumerary sperm cells in tetraspore (tes) pollen, enabling the formation of twin plants. Thus, both primary and supernumerary egg cells are fully functional in amp1 mutant plants. Sporophytic AMP1 expression is sufficient to prevent cell-fate change of synergids, indicating that one or more AMP1-dependent mobile signals from outside the female gametophyte can contribute to its patterning, in addition to the previously reported lateral inhibition between gametophytic cells. Our results provide insight into the mechanism of synergid fate specification and emphasize the importance of specifying only one egg cell within the female gametophyte to ensure central-cell fertilization by the second sperm cell.
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79
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The molecular mechanism of sporocyteless/nozzle in controlling Arabidopsis ovule development. Cell Res 2014; 25:121-34. [PMID: 25378179 PMCID: PMC4650584 DOI: 10.1038/cr.2014.145] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 10/07/2014] [Accepted: 10/09/2014] [Indexed: 11/09/2022] Open
Abstract
Ovules are essential for plant reproduction and develop into seeds after fertilization. Sporocyteless/nozzle (SPL/NZZ) has been known for more than 15 years as an essential factor for ovule development in Arabidopsis, but the biochemical nature of SPL function has remained unsolved. Here, we demonstrate that SPL functions as an adaptor-like transcriptional repressor. We show that SPL recruits topless/topless-related (TPL/TPR) co-repressors to inhibit the Cincinnata (CIN)-like Teosinte branched1/cycloidea/PCF (TCP) transcription factors. We reveal that SPL uses its EAR motif at the C-terminal end to recruit TPL/TPRs and its N-terminal part to bind and inhibit the TCPs. We demonstrate that either disruption of TPL/TPRs or overexpression of TCPs partially phenocopies the defects of megasporogenesis in spl. Moreover, disruption of TCPs causes phenotypes that resemble spl-D gain-of-function mutants. These results define the action mechanism for SPL, which along with TPL/TPRs controls ovule development by repressing the activities of key transcription factors. Our findings suggest that a similar gene repression strategy is employed by both plants and fungi to control sporogenesis.
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80
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Hisanaga T, Miyashima S, Nakajima K. Small RNAs as positional signal for pattern formation. CURRENT OPINION IN PLANT BIOLOGY 2014; 21:37-42. [PMID: 25005923 DOI: 10.1016/j.pbi.2014.06.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Revised: 06/12/2014] [Accepted: 06/13/2014] [Indexed: 06/03/2023]
Abstract
Pattern formation in plant relies on intimate cell-cell communication exchanging positional information. While ligand-receptor interaction is commonly used by plants and animals as a means to transmit positional information, plant cells can directly exchange regulatory molecules such as transcription factors through a cytoplasmic continuum called the plasmodesmata. Recently endogenous small RNAs (sRNAs) of various biogenetic origins have been shown to function non-cell-autonomously. To date, non-cell-autonomous sRNAs have been shown to regulate leaf polarity, root vascular patterning, meristem formation in embryos, shoot meristem maintenance and female gametogenesis. All these developmental processes are fundamental to the life cycle and architecture of flowering plants, suggesting that sRNA-mediated cell-to-cell signaling has been adopted to achieve novel morphology in the course of plant evolution.
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Affiliation(s)
- Tetsuya Hisanaga
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Shunsuke Miyashima
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Keiji Nakajima
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan; PRESTO, Japan Science and Technology Agency, 4-1-8, Honcho, Kawaguchi, Saitama 332-0012, Japan.
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81
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González-Gutiérrez AG, Gutiérrez-Mora A, Rodríguez-Garay B. Embryo sac formation and early embryo development in Agave tequilana (Asparagaceae). SPRINGERPLUS 2014; 3:575. [PMID: 25332875 PMCID: PMC4192144 DOI: 10.1186/2193-1801-3-575] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Accepted: 09/24/2014] [Indexed: 11/30/2022]
Abstract
Agave tequilana is an angiosperm species that belongs to the family Asparagaceae (formerly Agavaceae). Even though there is information regarding to some aspects related to the megagametogenesis of A. tequilana, this is the first report describing the complete process of megasporogenesis, megagametogenesis, the early embryo and endosperm development process in detail. The objective of this work was to study and characterize all the above processes and the distinctive morphological changes of the micropylar and chalazal extremes after fertilization in this species. The agave plant material for the present study was collected from commercial plantations in the state of Jalisco, Mexico. Ovules and immature seeds, previously fixed in FAA and kept in ethanol 70%, were stained based on a tissue clarification technique by using a Mayer’s-Hematoxylin solution. The tissue clarification technique was successfully used for the characterization of the megasporogenesis, megagametogenesis, mature embryo sac formation, the early embryo and endosperm development processes by studying intact cells. The embryo sac of A. tequilana was confirmed to be of the monosporic Polygonum-type and an helobial endosperm formation. Also, the time-lapse of the developmental processes studied was recorded.
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Affiliation(s)
- Alejandra G González-Gutiérrez
- Unidad de Biotecnología Vegetal, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, A.C. (CIATEJ), Av. Normalistas No. 800, Col. Colinas de la Normal, Guadalajara, Jalisco 44270 México
| | - Antonia Gutiérrez-Mora
- Unidad de Biotecnología Vegetal, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, A.C. (CIATEJ), Av. Normalistas No. 800, Col. Colinas de la Normal, Guadalajara, Jalisco 44270 México
| | - Benjamín Rodríguez-Garay
- Unidad de Biotecnología Vegetal, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, A.C. (CIATEJ), Av. Normalistas No. 800, Col. Colinas de la Normal, Guadalajara, Jalisco 44270 México
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82
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Dwivedi KK, Roche DJ, Clemente TE, Ge Z, Carman JG. The OCL3 promoter from Sorghum bicolor directs gene expression to abscission and nutrient-transfer zones at the bases of floral organs. ANNALS OF BOTANY 2014; 114:489-98. [PMID: 25081518 PMCID: PMC4204675 DOI: 10.1093/aob/mcu148] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 06/11/2014] [Indexed: 05/24/2023]
Abstract
BACKGROUND AND AIMS During seed fill in cereals, nutrients are symplasmically unloaded to vascular parenchyma in ovules, but thereafter nutrient transport is less certain. In Zea mays, two mechanisms of nutrient passage through the chalaza and nucellus have been hypothesized, apoplasmic and symplasmic. In a recent study, nutrients first passed non-selectively to the chalazal apoplasm and were then selectively absorbed by the nucellus before being released to the endosperm apoplasm. This study reports that the promoter of OUTER CELL LAYER3 (PSbOCL3) from Sorghum bicolor (sorghum) directs gene expression to chalazal cells where the apoplasmic barrier is thought to form. The aims were to elucidate PSbOCL3 expression patterns in sorghum and relate them to processes of nutrient pathway development in kernels and to recognized functions of the homeodomain-leucine zipper (HD-Zip) IV transcription factor family to which the promoter belongs. METHODS PSbOCL3 was cloned and transformed into sorghum as a promoter-GUS (β-glucuronidase) construct. Plant tissues from control and transformed plants were then stained for GUS, and kernels were cleared and characterized using differential interference contrast microscopy. KEY RESULTS A symplasmic disconnect between the chalaza and nucellus during seed fill is inferred by the combination of two phenomena: differentiation of a distinct nucellar epidermis adjacent to the chalaza, and lysis of GUS-stained chalazal cells immediately proximal to the nucellar epidermis. Compression of the GUS-stained chalazal cells during kernel maturation produced the kernel abscission zone (closing layer). CONCLUSIONS The results suggest that the HD-Zip IV transcription factor SbOCL3 regulates kernel nutrition and abscission. The latter is consistent with evidence that members of this transcription factor group regulate silique abscission and dehiscence in Arabidopsis thaliana. Collectively, the findings suggest that processes of floral organ abscission are conserved among angiosperms and may in some respects differ from processes of leaf abscission.
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Affiliation(s)
- Krishna K Dwivedi
- Caisson Laboratories, Inc., 1740 Research Park Way, North Logan, UT 84341, USA Crop Improvement Division, Indian Grassland and Fodder Research Institute, Jhansi (UP) 284003, India Plants, Soils and Climate Department, Utah State University, Logan, UT 84322-4820, USA
| | - Dominique J Roche
- Caisson Laboratories, Inc., 1740 Research Park Way, North Logan, UT 84341, USA PhytoGen Seed Co. LLC, Western Research Station, 850 Plymouth Avenue, Corcoran, CA 93212, USA
| | - Tom E Clemente
- Department of Agronomy and Horticulture, Center for Plant Science Innovation, University of Nebraska, Lincoln, NE 68588, USA
| | - Zhengxiang Ge
- Department of Agronomy and Horticulture, Center for Plant Science Innovation, University of Nebraska, Lincoln, NE 68588, USA
| | - John G Carman
- Caisson Laboratories, Inc., 1740 Research Park Way, North Logan, UT 84341, USA Plants, Soils and Climate Department, Utah State University, Logan, UT 84322-4820, USA
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83
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Somatic embryogenesis - Stress-induced remodeling of plant cell fate. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1849:385-402. [PMID: 25038583 DOI: 10.1016/j.bbagrm.2014.07.005] [Citation(s) in RCA: 211] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 07/08/2014] [Accepted: 07/10/2014] [Indexed: 01/13/2023]
Abstract
Plants as sessile organisms have remarkable developmental plasticity ensuring heir continuous adaptation to the environment. An extreme example is somatic embryogenesis, the initiation of autonomous embryo development in somatic cells in response to exogenous and/or endogenous signals. In this review I briefly overview the various pathways that can lead to embryo development in plants in addition to the fertilization of the egg cell and highlight the importance of the interaction of stress- and hormone-regulated pathways during the induction of somatic embryogenesis. Somatic embryogenesis can be initiated in planta or in vitro, directly or indirectly, and the requirement for dedifferentiation as well as the way to achieve developmental totipotency in the various systems is discussed in light of our present knowledge. The initiation of all forms of the stress/hormone-induced in vitro as well as the genetically provoked in planta somatic embryogenesis requires extensive and coordinated genetic reprogramming that has to take place at the chromatin level, as the embryogenic program is under strong epigenetic repression in vegetative plant cells. Our present knowledge on chromatin-based mechanisms potentially involved in the somatic-to-embryogenic developmental transition is summarized emphasizing the potential role of the chromatin to integrate stress, hormonal, and developmental pathways leading to the activation of the embryogenic program. The role of stress-related chromatin reorganization in the genetic instability of in vitro cultures is also discussed. This article is part of a Special Issue entitled: Stress as a fundamental theme in cell plasticity.
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84
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Liu M, Shi S, Zhang S, Xu P, Lai J, Liu Y, Yuan D, Wang Y, Du J, Yang C. SUMO E3 ligase AtMMS21 is required for normal meiosis and gametophyte development in Arabidopsis. BMC PLANT BIOLOGY 2014; 14:153. [PMID: 24893774 PMCID: PMC4189105 DOI: 10.1186/1471-2229-14-153] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Accepted: 05/28/2014] [Indexed: 05/18/2023]
Abstract
BACKGROUND MMS21 is a SUMO E3 ligase that is conserved in eukaryotes, and has previously been shown to be required for DNA repair and maintenance of chromosome integrity. Loss of the Arabidopsis MMS21 causes defective meristems and dwarf phenotypes. RESULTS Here, we show a role for AtMMS21 during gametophyte development. AtMMS21 deficient plants are semisterile with shorter mature siliques and abortive seeds. The mms21-1 mutant shows reduced pollen number, and viability, and germination and abnormal pollen tube growth. Embryo sac development is also compromised in the mutant. During meiosis, chromosome mis-segregation and fragmentation is observed, and the products of meiosis are frequently dyads or irregular tetrads. Several transcripts for meiotic genes related to chromosome maintenance and behavior are altered. Moreover, accumulation of SUMO-protein conjugates in the mms21-1 pollen grains is distinct from that in wild-type. CONCLUSIONS Thus, these results suggest that AtMMS21 mediated SUMOylation may stabilize the expression and accumulation of meiotic proteins and affect gametophyte development.
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Affiliation(s)
- Ming Liu
- Guangdong Key Lab of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou 510631, China
- Vegetable Research Institute Guangdong Academy of Agriculture Sciences, Guangzhou, Guangdong 510640, China
| | - Songfeng Shi
- Guangdong Key Lab of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou 510631, China
| | - Shengchun Zhang
- Guangdong Key Lab of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou 510631, China
| | - Panglian Xu
- Guangdong Key Lab of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou 510631, China
| | - Jianbin Lai
- Guangdong Key Lab of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou 510631, China
| | - Yiyang Liu
- Guangdong Key Lab of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou 510631, China
| | - Dongke Yuan
- Guangdong Key Lab of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou 510631, China
| | - Yaqin Wang
- Guangdong Key Lab of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou 510631, China
| | - Jinju Du
- Guangdong Key Lab of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou 510631, China
| | - Chengwei Yang
- Guangdong Key Lab of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou 510631, China
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85
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Kianian PMA, Kianian SF. Mitochondrial dynamics and the cell cycle. FRONTIERS IN PLANT SCIENCE 2014; 5:222. [PMID: 24904617 PMCID: PMC4035010 DOI: 10.3389/fpls.2014.00222] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 05/04/2014] [Indexed: 05/25/2023]
Abstract
Nuclear-mitochondrial (NM) communication impacts many aspects of plant development including vigor, sterility, and viability. Dynamic changes in mitochondrial number, shape, size, and cellular location takes place during the cell cycle possibly impacting the process itself and leading to distribution of this organelle into daughter cells. The genes that underlie these changes are beginning to be identified in model plants such as Arabidopsis. In animals disruption of the drp1 gene, a homolog to the plant drp3A and drp3B, delays mitochondrial division. This mutation results in increased aneuploidy due to chromosome mis-segregation. It remains to be discovered if a similar outcome is observed in plants. Alloplasmic lines provide an opportunity to understand the communication between the cytoplasmic organelles and the nucleus. Examples of studies in these lines, especially from the extensive collection in wheat, point to the role of mitochondria in chromosome movement, pollen fertility and other aspects of development.
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Affiliation(s)
- Penny M. A. Kianian
- Department of Horticultural Science, University of MinnesotaSt. Paul, MN, USA
| | - Shahryar F. Kianian
- Cereal Disease Laboratory, United States Department of Agriculture – Agricultural Research ServiceSt. Paul, MN, USA
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86
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Wang H, Liu R, Wang J, Wang P, Shen Y, Liu G. The Arabidopsis kinesin gene AtKin-1 plays a role in the nuclear division process during megagametogenesis. PLANT CELL REPORTS 2014; 33:819-828. [PMID: 24667993 DOI: 10.1007/s00299-014-1594-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 01/15/2014] [Accepted: 02/26/2014] [Indexed: 06/03/2023]
Abstract
Atkin - 1 , the only Kinesin-1 member of Arabidopsis thaliana , plays a role during female gametogenesis through regulation of nuclear division cycles. Kinesins are microtubule-dependent motor proteins found in eukaryotic organisms. They constitute a superfamily that can be further classified into at least 14 families. In the Kinesin-1 family, members from animal and fungi play roles in long-distance transport of organelles and vesicles. Although Kinesin-1-like sequences have been identified in higher plants, little is known about their function in plant cells, other than in a recently identified Kinesin-1-like protein in a rice pollen semi-sterile mutant. In this study, the gene encoding the only Kinesin-1 member in Arabidopsis, AtKin-1 was found to be specifically expressed in ovules and anthers. AtKin-1 loss-of-function mutants showed substantially aborted ovules in siliques, and this finding was supported by complementation testing. Reciprocal crossing between mutant and wild-type plants indicated that a defect in AtKin-1 results in partially aborted megagametophytes, with no observable effects on pollen fertility. Further observation of ovule development in the mutant pistils indicated that the enlargement of the megaspore was blocked and nuclear division arrested at the one-nucleate stage during embryo sac formation. Our data suggest that AtKin-1 plays a role in the nuclear division cycles during megagametogenesis.
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Affiliation(s)
- Haiqing Wang
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Plateau Institute of Biology, Chinese Academy of Sciences, 23 Xinning Road, Xining, 810001, China,
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87
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Chong K, Xu Z. Investment in plant research and development bears fruit in China. PLANT CELL REPORTS 2014; 33:541-50. [PMID: 24615161 PMCID: PMC3976507 DOI: 10.1007/s00299-014-1587-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 02/05/2014] [Accepted: 02/07/2014] [Indexed: 05/15/2023]
Abstract
Recent rapid progress in plant science and biotechnology in China demonstrates that China's stronger support for funding in plant research and development (R&D) has borne fruit. Chinese groups have contributed major advances in a range of fields, such as rice biology, plant hormone and developmental biology, genomics and evolution, plant genetics and epigenetics, as well as plant biotechnology. Strigolactone studies including those identifying its receptor and dissecting its complex structure and signaling are representative of the recent researches from China at the forefront of the field. These advances are attributable in large part to interdisciplinary studies among scientists from plant science, chemistry, bioinformatics, structural biology, and agronomy. The platforms provided by national facilities facilitate this collaboration. As well, efficient restructuring of the top-down organization of state programs and free exploration of scientists' interests have accelerated achievements by Chinese researchers. Here, we provide a general outline of China's progress in plant R&D to highlight fields in which Chinese research has made significant contributions.
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Affiliation(s)
- Kang Chong
- CAS Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093 China
| | - Zhihong Xu
- College of Life Sciences, Peking University, Beijing, 100871 China
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88
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Ingouff M. Imaging sexual reproduction in Arabidopsis using fluorescent markers. Methods Mol Biol 2014; 1112:117-24. [PMID: 24478011 DOI: 10.1007/978-1-62703-773-0_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Sexual reproduction in higher plants is a stealth process as most events occur within tissues protected by multiple surrounding cell layers. Female gametes are produced inside the embryo sac surrounded by layers of ovule integument cells. Upon double fertilization, two male gametes are released at one end of the embryo sac and migrate towards their respective female partner to generate the embryo and its feeding tissue, the endosperm, within a seed. Since the early discovery of plant reproduction, advances in microscopy have contributed enormously to our understanding of this process (Faure and Dumas, Plant Physiol 125:102-104, 2001). Recently, live imaging of double fertilization has been possible using a set of fluorescent markers for gametes in Arabidopsis. The following chapter will detail protocols to study male and female gametogenesis and double fertilization in living tissues using fluorescent markers.
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Affiliation(s)
- Mathieu Ingouff
- Faculté des Sciences, Université Montpellier2, Montpellier, France
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Molecular cell biology of male meiotic chromosomes and isolation of male meiocytes in Arabidopsis thaliana. Methods Mol Biol 2014; 1110:217-30. [PMID: 24395259 DOI: 10.1007/978-1-4614-9408-9_10] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Plants typically produce numerous flowers whose meiotic chromosomes are relatively easy to observe, making them excellent structures for studying the cellular processes underlying meiosis. In recent years, breakthroughs in light and electron microscopic technologies for small chromosomes, combined with molecular genetic methods, have resulted in major advances in the understanding of meiosis in the model plant Arabidopsis thaliana. In this chapter, we summarize protocols for basic cytology, fluorescence in situ hybridization, immunofluorescence, electron microscopy, and isolation of male meiocytes for the analysis of Arabidopsis meiosis.
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90
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MYB64 and MYB119 are required for cellularization and differentiation during female gametogenesis in Arabidopsis thaliana. PLoS Genet 2013; 9:e1003783. [PMID: 24068955 PMCID: PMC3778002 DOI: 10.1371/journal.pgen.1003783] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 07/25/2013] [Indexed: 11/25/2022] Open
Abstract
In angiosperms, the egg cell forms within the multicellular, haploid female gametophyte. Female gametophyte and egg cell development occurs through a unique process in which a haploid spore initially undergoes several rounds of synchronous nuclear divisions without cytokinesis, resulting in a single cell containing multiple nuclei. The developing gametophyte then forms cell walls (cellularization) and the resulting cells differentiate to generate the egg cell and several accessory cells. The switch between free nuclear divisions and cellularization-differentiation occurs during developmental stage FG5 in Arabidopsis, and we refer to it as the FG5 transition. The molecular regulators that initiate the FG5 transition during female gametophyte development are unknown. In this study, we show using mutant analysis that two closely related MYB transcription factors, MYB64 and MYB119, act redundantly to promote this transition. MYB64 and MYB119 are expressed during the FG5 transition, and most myb64 myb119 double mutant gametophytes fail to initiate the FG5 transition, resulting in uncellularized gametophytes with supernumerary nuclei. Analysis of cell-specific markers in myb64 myb119 gametophytes that do cellularize suggests that gametophytic polarity and differentiation are also affected. We also show using multiple-mutant analysis that MYB119 expression is regulated by the histidine kinase CKI1, the primary activator of two-component signaling (TCS) during female gametophyte development. Our data establish a molecular pathway regulating the FG5 transition and implicates CKI1-dependent TCS in the promotion of cellularization, differentiation, and gamete specification during female gametogenesis. Female gamete formation in angiosperms occurs through a unique process in which a haploid spore initially undergoes a series of free nuclear divisions without cytokinesis, resulting in a single cell containing multiple nuclei. The nuclei then differentiate and are partitioned with cell walls to generate the egg cell and several accessory cells. The molecular regulators that initiate the switch between free nuclear divisions and differentiation during female gametophyte development are unknown. In this study we show that two transcription factors, MYB64 and MYB119, redundantly act to promote this process in the model organism Arabidopsis. We also show that one of them, MYB119, is transcriptionally regulated by the histidine-kinase CKI1. Our data establish the framework of a gene regulatory network required to promote cellularization, differentiation, and gamete specification during female gametogenesis.
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91
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Bulankova P, Akimcheva S, Fellner N, Riha K. Identification of Arabidopsis meiotic cyclins reveals functional diversification among plant cyclin genes. PLoS Genet 2013; 9:e1003508. [PMID: 23671425 PMCID: PMC3649987 DOI: 10.1371/journal.pgen.1003508] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 03/26/2013] [Indexed: 11/18/2022] Open
Abstract
Meiosis is a modified cell division in which a single S-phase is followed by two rounds of chromosome segregation resulting in the production of haploid gametes. The meiotic mode of chromosome segregation requires extensive remodeling of the basic cell cycle machinery and employment of unique regulatory mechanisms. Cyclin-dependent kinases (CDKs) and cyclins represent an ancient molecular module that drives and regulates cell cycle progression. The cyclin gene family has undergone a massive expansion in angiosperm plants, but only a few cyclins were thoroughly characterized. In this study we performed a systematic immunolocalization screen to identify Arabidopsis thaliana A- and B-type cyclins expressed in meiosis. Many of these cyclins exhibit cell-type-specific expression in vegetative tissues and distinct subcellular localization. We found six A-type cyclins and a single B-type cyclin (CYCB3;1) to be expressed in male meiosis. Mutant analysis revealed that these cyclins contribute to distinct meiosis-related processes. While A2 cyclins are important for chromosome segregation, CYCB3;1 prevents ectopic cell wall formation. We further show that cyclin SDS does not contain a D-box and is constitutively expressed throughout meiosis. Analysis of plants carrying cyclin SDS with an introduced D-box motif determined that, in addition to its function in recombination, SDS acts together with CYCB3;1 in suppressing unscheduled cell wall synthesis. Our phenotypic and expression data provide extensive evidence that multiplication of cyclins is in plants accompanied by functional diversification. The alteration of haploid and diploid cell generations during the sexual life cycle requires meiosis, a specialized cell division that enables the formation of haploid gametes from diploid cells. Meiosis occurs only once during the life cycle, and the transition from the mitotic to meiotic mode of chromosome partitioning requires extensive remodeling of the cell cycle machinery. The cell cycle progression is driven by cyclin-dependent kinases and associated cyclins that regulate CDK activity and confer substrate specificity. Cyclin gene families have undergone a massive expansion in plants, which has raised the question of whether some of these cyclins evolved specific meiotic functions. We systematically analyzed two cyclin gene families in Arabidopsis to identify plant cyclins that are meiotically expressed. We found in total eight cyclins to be expressed in male meiotic cells, and functional characterization revealed their involvement in diverse meiotic processes. Interestingly, none of the cyclins appear to be essential for meiotic progression, indicating that plant meiosis is governed by unorthodox cell cycle regulators.
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Affiliation(s)
- Petra Bulankova
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna, Austria
| | | | - Nicole Fellner
- Campus Science Support Facilities, Electron Microscopy Facility, Vienna, Austria
| | - Karel Riha
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna, Austria
- * E-mail:
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92
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Kubo T, Fujita M, Takahashi H, Nakazono M, Tsutsumi N, Kurata N. Transcriptome analysis of developing ovules in rice isolated by laser microdissection. PLANT & CELL PHYSIOLOGY 2013; 54:750-65. [PMID: 23411663 DOI: 10.1093/pcp/pct029] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Comprehensive genome-wide gene expression profiles during plant male gametogenesis have been thoroughly analyzed over the last decade. In contrast, gene expression profiles during female gametogenesis have been studied relatively little, and our knowledge concerning plant female gametogenesis is limited. We determined the genome-wide gene expression profiles of developing ovules containing female gametophytes from the megaspore mother cell at the pre-meiotic stage to the mature embryo sac in rice (Oryza sativa) using microarrays. In order to separate ovules from scutellum, we used a laser microdissection (LM) technique. Dynamic gene expression was revealed in developing ovules, and a major transition of the transcriptome was observed between middle and late meiotic stages, where many genes were down-regulated >10-fold. Many potential players in female gametogenesis, that showed dynamic or enriched expression, were highlighted. We identified the temporal and dramatic up-regulation of a subset of transposable elements during female meiotic stages that were not observed in males. Transcription factor genes enriched in developing ovules were also uncovered, which may play crucial roles during female gametogenesis. This is the first report of comprehensive genome-wide gene expression profiles during female gametogenesis useful for plant reproductive studies. Combined with additional experiments, our data may provide important clues to understand female gametogenesis in plants.
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Affiliation(s)
- Takahiko Kubo
- Plant Genetics Laboratory, National Institute of Genetics, Mishima, 411-8540 Japan
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93
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Demesa-Arévalo E, Vielle-Calzada JP. The classical arabinogalactan protein AGP18 mediates megaspore selection in Arabidopsis. THE PLANT CELL 2013; 25:1274-87. [PMID: 23572547 PMCID: PMC3663267 DOI: 10.1105/tpc.112.106237] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 02/28/2013] [Accepted: 03/21/2013] [Indexed: 05/03/2023]
Abstract
Female gametogenesis in most flowering plants depends on the predetermined selection of a single meiotically derived cell, as the three other megaspores die without further division or differentiation. Although in Arabidopsis thaliana the formation of the functional megaspore (FM) is crucial for the establishment of the gametophytic generation, the mechanisms that determine the specification and fate of haploid cells remain unknown. Here, we show that the classical arabinogalactan protein 18 (AGP18) exerts an active regulation over the selection and survival of megaspores in Arabidopsis. During meiosis, AGP18 is expressed in integumentary cells located in the abaxial region of the ovule. Overexpression of AGP18 results in the abnormal maintenance of surviving megaspores that can acquire a FM identity but is not sufficient to induce FM differentiation before meiosis, indicating that AGP18 positively promotes the selection of viable megaspores. We also show that all four meiotically derived cells in the ovule of Arabidopsis are competent to differentiate into a gametic precursor and that the function of AGP18 is important for their selection and viability. Our results suggest an evolutionary role for arabinogalactan proteins in the acquisition of monospory and the developmental plasticity that is intrinsic to sexual reproduction in flowering plants.
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Affiliation(s)
- Edgar Demesa-Arévalo
- Grupo de Desarrollo Reproductivo y Apomixis, Laboratorio Nacional de Genómica para la Biodiversidad y Departamento de Ingeniería Genética de Plantas, Cinvestav Irapuato CP36821 Guanajuato, Mexico
| | - Jean-Philippe Vielle-Calzada
- Grupo de Desarrollo Reproductivo y Apomixis, Laboratorio Nacional de Genómica para la Biodiversidad y Departamento de Ingeniería Genética de Plantas, Cinvestav Irapuato CP36821 Guanajuato, Mexico
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94
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Lee DS, Chen LJ, Li CY, Liu Y, Tan XL, Lu BR, Li J, Gan SX, Kang SG, Suh HS, Zhu Y. The Bsister MADS gene FST determines ovule patterning and development of the zygotic embryo and endosperm. PLoS One 2013; 8:e58748. [PMID: 23527017 PMCID: PMC3602522 DOI: 10.1371/journal.pone.0058748] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 02/05/2013] [Indexed: 11/19/2022] Open
Abstract
Many homeotic MADS-box genes have been identified as controllers of the floral transition and floral development. However, information regarding Bsister (Bs)-function genes in monocots is still limited. Here, we describe the functional characterization of a Bs-group MADS-box gene FEMALE-STERILE (FST), whose frame-shift mutation (fst) results in abnormal ovules and the complete abortion of zygotic embryos and endosperms in rice. Anatomical analysis showed that the defective development in the fst mutant exclusively occurred in sporophytic tissues including integuments, fertilized proembryos and endosperms. Analyses of the spatio-temporal expression pattern revealed that the prominent FST gene products accumulated in the inner integument, nucellar cell of the micropylar side, apical and base of the proembryos and free endosperm nuclei. Microarray and gene ontology analysis unraveled substantial changes in the expression level of many genes in the fst mutant ovules and seeds, with a subset of genes involved in several developmental and hormonal pathways appearing to be down-regulated. Using both forward and reverse genetics approaches, we demonstrated that rice FST plays indispensable roles and multiple functions during ovule and early seed development. These findings support a novel function for the Bs-group MADS-box genes in plants.
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Affiliation(s)
- Dong Sun Lee
- Key Lab of Agro-Biodiversity and Pest Management of Education Ministry, Yunnan Agricultural University, Kunming, China
- Rice Research Institute, Yunnan Agricultural University, Kunming, China
| | - Li Juan Chen
- Rice Research Institute, Yunnan Agricultural University, Kunming, China
- Key Lab of Molecular Breeding for Dian-Type Japonica Hybrid Rice of Yunnan Education Department, Yunnan Agricultural University, Kunming, China
| | - Cheng Yun Li
- Key Lab of Agro-Biodiversity and Pest Management of Education Ministry, Yunnan Agricultural University, Kunming, China
| | - Yongsheng Liu
- Ministry of Education Key Lab for Bio-resource and Eco-environment, College of Life Science, State Key Lab of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, China
| | - Xue Lin Tan
- Rice Research Institute, Yunnan Agricultural University, Kunming, China
- Key Lab of Molecular Breeding for Dian-Type Japonica Hybrid Rice of Yunnan Education Department, Yunnan Agricultural University, Kunming, China
| | - Bao-Rong Lu
- Ministry of Education Key Lab for Biodiversity and Ecological Engineering, Institute of Biodiversity Science, Fudan University, Shanghai, China
| | - Juan Li
- Rice Research Institute, Yunnan Agricultural University, Kunming, China
- Key Lab of Molecular Breeding for Dian-Type Japonica Hybrid Rice of Yunnan Education Department, Yunnan Agricultural University, Kunming, China
| | - Shu Xian Gan
- Rice Research Institute, Yunnan Agricultural University, Kunming, China
- Key Lab of Molecular Breeding for Dian-Type Japonica Hybrid Rice of Yunnan Education Department, Yunnan Agricultural University, Kunming, China
| | - Sang Gu Kang
- School of Biotechnology, Yeungnam University, Gyeongsan, Korea
| | - Hak Soo Suh
- School of Biological Resources, Yeungnam University, Gyeongsan, Korea
| | - Youyong Zhu
- Key Lab of Agro-Biodiversity and Pest Management of Education Ministry, Yunnan Agricultural University, Kunming, China
- * E-mail:
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95
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Domoki M, Szűcs A, Jäger K, Bottka S, Barnabás B, Fehér A. Identification of genes preferentially expressed in wheat egg cells and zygotes. PLANT CELL REPORTS 2013; 32:339-48. [PMID: 23160639 DOI: 10.1007/s00299-012-1367-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 09/28/2012] [Accepted: 10/31/2012] [Indexed: 05/14/2023]
Abstract
KEY MESSAGE : Wheat genes differentially expressed in the egg cell before and after fertilization were identified. The data support zygotic gene activation before the first cell division in wheat. To have an insight into fertilization-induced gene expression, cDNA libraries have been prepared from isolated wheat egg cells and one-celled zygotes. Two-hundred and twenty-six egg cell and 253 zygote-expressed EST sequences were determined. Most of the represented transcripts were detected in the wheat egg cell or zygote transcriptome at the first time. Expression analysis of fourteen of the identified genes and three controls was carried out by real-time quantitative PCR. The preferential expression of all investigated genes in the female gametophyte-derived samples (egg cells, zygotes, two-celled proembryos, and basal ovule parts with synergids) in comparison to the anthers, and the leaves were verified. Three genes with putative signaling/regulatory functions were expressed at a low level in the egg cell but exhibited increased (2-to-33-fold) relative expression in the zygote and the proembryo. Genes with high EST abundance in cDNA libraries exhibited strong expression in the egg cell and the zygote, while the ones coding for unknown or hypothetical proteins exhibited differential expression patterns with preferential transcript accumulation in egg cells and/or zygotes. The obtained data support the activation of the zygotic genome before the first cell division in wheat.
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Affiliation(s)
- Mónika Domoki
- Biological Research Centre, Institute of Plant Biology, Hungarian Academy of Sciences, Temesvári krt. 62, Szeged, 6726, Hungary
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96
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Hosseinpour B, HajiHoseini V, Kashfi R, Ebrahimie E, Hemmatzadeh F. Protein interaction network of Arabidopsis thaliana female gametophyte development identifies novel proteins and relations. PLoS One 2012; 7:e49931. [PMID: 23239973 PMCID: PMC3519845 DOI: 10.1371/journal.pone.0049931] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Accepted: 10/17/2012] [Indexed: 01/01/2023] Open
Abstract
Although the female gametophyte in angiosperms consists of just seven cells, it has a complex biological network. In this study, female gametophyte microarray data from Arabidopsis thaliana were integrated into the Arabidopsis interactome database to generate a putative interaction map of the female gametophyte development including proteome map based on biological processes and molecular functions of proteins. Biological and functional groups as well as topological characteristics of the network were investigated by analyzing phytohormones, plant defense, cell death, transporters, regulatory factors, and hydrolases. This approach led to the prediction of critical members and bottlenecks of the network. Seventy-four and 24 upregulated genes as well as 171 and 3 downregulated genes were identified in subtracted networks based on biological processes and molecular function respectively, including novel genes such as the pathogenesis-related protein 4, ER type Ca(2+) ATPase 3, dihydroflavonol reductase, and ATP disulfate isomerase. Biologically important relationships between genes, critical nodes, and new essential proteins such as AT1G26830, AT5G20850, CYP74A, AT1G42396, PR4 and MEA were found in the interactome's network. The positions of novel genes, both upregulated and downregulated, and their relationships with biological pathways, in particular phytohormones, were highlighted in this study.
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Affiliation(s)
- Batool Hosseinpour
- Institute of Agriculture, Iranian Research Organization for Science and Technology, Tehran, Iran
| | - Vahid HajiHoseini
- Department of Biotechnology, College of Science, University of Tehran, Tehran, Iran
| | - Rafieh Kashfi
- Department of Crop Production & Plant Breeding, College of Agriculture, Shiraz University, Shiraz, Iran
| | - Esmaeil Ebrahimie
- Department of Crop Production & Plant Breeding, College of Agriculture, Shiraz University, Shiraz, Iran
- School of Molecular and Biomedical Science, The University of Adelaide, Adelaide, South Australia, Australia
- * E-mail: (EE); (FH)
| | - Farhid Hemmatzadeh
- School of Animal and Veterinary Sciences, The University of Adelaide, Adelaide, South Australia, Australia
- * E-mail: (EE); (FH)
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97
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Juranić M, Srilunchang KO, Krohn NG, Leljak-Levanić D, Sprunck S, Dresselhaus T. Germline-specific MATH-BTB substrate adaptor MAB1 regulates spindle length and nuclei identity in maize. THE PLANT CELL 2012; 24:4974-91. [PMID: 23250449 PMCID: PMC3556970 DOI: 10.1105/tpc.112.107169] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 11/05/2012] [Accepted: 11/28/2012] [Indexed: 05/03/2023]
Abstract
Germline and early embryo development constitute ideal model systems to study the establishment of polarity, cell identity, and asymmetric cell divisions (ACDs) in plants. We describe here the function of the MATH-BTB domain protein MAB1 that is exclusively expressed in the germ lineages and the zygote of maize (Zea mays). mab1 (RNA interference [RNAi]) mutant plants display chromosome segregation defects and short spindles during meiosis that cause insufficient separation and migration of nuclei. After the meiosis-to-mitosis transition, two attached nuclei of similar identity are formed in mab1 (RNAi) mutants leading to an arrest of further germline development. Transient expression studies of MAB1 in tobacco (Nicotiana tabacum) Bright Yellow-2 cells revealed a cell cycle-dependent nuclear localization pattern but no direct colocalization with the spindle apparatus. MAB1 is able to form homodimers and interacts with the E3 ubiquitin ligase component Cullin 3a (CUL3a) in the cytoplasm, likely as a substrate-specific adapter protein. The microtubule-severing subunit p60 of katanin was identified as a candidate substrate for MAB1, suggesting that MAB1 resembles the animal key ACD regulator Maternal Effect Lethal 26 (MEL-26). In summary, our findings provide further evidence for the importance of posttranslational regulation for asymmetric divisions and germline progression in plants and identified an unstable key protein that seems to be involved in regulating the stability of a spindle apparatus regulator(s).
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Affiliation(s)
- Martina Juranić
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93053 Regensburg, Germany
- Department of Molecular Biology, Faculty of Science and Mathematics, University of Zagreb, 10000 Zagreb, Croatia
| | | | - Nádia Graciele Krohn
- Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirao Preto 14040-903, Brazil
| | - Dunja Leljak-Levanić
- Department of Molecular Biology, Faculty of Science and Mathematics, University of Zagreb, 10000 Zagreb, Croatia
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93053 Regensburg, Germany
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93053 Regensburg, Germany
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98
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Wu JJ, Peng XB, Li WW, He R, Xin HP, Sun MX. Mitochondrial GCD1 dysfunction reveals reciprocal cell-to-cell signaling during the maturation of Arabidopsis female gametes. Dev Cell 2012; 23:1043-58. [PMID: 23085019 DOI: 10.1016/j.devcel.2012.09.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2011] [Revised: 06/11/2012] [Accepted: 09/17/2012] [Indexed: 12/27/2022]
Abstract
Cell-to-cell communication in embryo sacs is thought to regulate the development of female gametes in flowering plants, but the details remain poorly understood. Here, we report a mitochondrial protein, GAMETE CELL DEFECTIVE 1 (GCD1), enriched in gametophytes that is essential for final maturation of female gametes. Using Arabidopsis gcd1 mutants, we found that final maturation of the egg and central cells is not required for double fertilization but is necessary for embryogenesis initiation and endosperm development. Furthermore, nonautonomous effects, observed when GCD1 or AAC2 function is disrupted, suggest that mitochondrial function influences reciprocal signaling between central and egg cells to regulate maturation of the partner (egg or central) cell. Our findings confirm that cell-to-cell communication is important in functional maturation of female gametic cells and suggest that both egg and central cells sense and transmit their mitochondrial metabolic status as an important cue that regulates the coordination of gamete maturation.
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Affiliation(s)
- Jian-Jun Wu
- Department of Cell and Development Biology, College of Life Science, State Key Laboratory of Plant Hybrid Rice, Wuhan University, Wuhan 430072, China
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99
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Krohn NG, Lausser A, Juranić M, Dresselhaus T. Egg cell signaling by the secreted peptide ZmEAL1 controls antipodal cell fate. Dev Cell 2012; 23:219-25. [PMID: 22749416 DOI: 10.1016/j.devcel.2012.05.018] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 03/30/2012] [Accepted: 05/23/2012] [Indexed: 02/08/2023]
Abstract
Unlike in animals, female gametes of flowering plants are not the direct products of meiosis but develop from a functional megaspore after three rounds of free mitotic divisions. After nuclei migration and positioning, the eight-nucleate syncytium differentiates into the embryo sac, which contains two female gametes as well as accessory cells at the micropylar and chalazal pole, respectively. We report that an egg-cell-specific gene, ZmEAL1, is activated at the micropylar pole of the eight-nucleate syncytium. ZmEAL1 translation is restricted to the egg cell, resulting in the generation of peptide-containing vesicles directed toward its chalazal pole. RNAi knockdown studies show that ZmEAL1 is required for robust expression of the proliferation-regulatory gene IG1 at the chalazal pole of the embryo sac in antipodal cells. We further show that ZmEAL1 is required to prevent antipodal cells from adopting central cell fate. These findings show how egg cells orchestrate differentiation of the embryo sac.
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Affiliation(s)
- Nadia Graciele Krohn
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, Universitätsstraße 31, Regensburg, Germany
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100
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Tucker MR, Okada T, Johnson SD, Takaiwa F, Koltunow AMG. Sporophytic ovule tissues modulate the initiation and progression of apomixis in Hieracium. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:3229-41. [PMID: 22378948 PMCID: PMC3350933 DOI: 10.1093/jxb/ers047] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 01/30/2012] [Accepted: 01/31/2012] [Indexed: 05/21/2023]
Abstract
Apomixis in Hieracium subgenus Pilosella initiates in ovules when sporophytic cells termed aposporous initial (AI) cells enlarge near sexual cells undergoing meiosis. AI cells displace the sexual structures and divide by mitosis to form unreduced embryo sac(s) without meiosis (apomeiosis) that initiate fertilization-independent embryo and endosperm development. In some Hieracium subgenus Pilosella species, these events are controlled by the dominant LOSS OF APOMEIOSIS (LOA) and LOSS OF PARTHENOGENESIS (LOP) loci. In H. praealtum and H. piloselloides, which both contain the same core LOA locus, the timing and frequency of AI cell formation is altered in derived mutants exhibiting abnormal funiculus growth and in transgenic plants expressing rolB which alters cellular sensitivity to auxin. The impact on apomictic and sexual reproduction was examined here when a chimeric RNAse gene was targeted to the funiculus and basal portions of the ovule, and also when polar auxin transport was inhibited during ovule development following N-1-naphthylphthalamic acid (NPA) application. Both treatments led to ovule deformity in the funiculus and distal parts of the ovule and LOA-dependent alterations in the timing, position, and frequency of AI cell formation. In the case of NPA treatment, this correlated with increased expression of DR5:GFP in the ovule, which marks the accumulation of the plant hormone auxin. Our results show that sporophytic information potentiated by funiculus growth and polar auxin transport influences ovule development, the initiation of apomixis, and the progression of embryo sac development in Hieracium. Signals associated with ovule pattern formation and auxin distribution or perception may influence the capacity of sporophytic ovule cells to respond to LOA.
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Affiliation(s)
- Matthew R. Tucker
- CSIRO Plant Industry, Waite Campus, Hartley Grove, Urrbrae SA 5064, Australia
| | - Takashi Okada
- CSIRO Plant Industry, Waite Campus, Hartley Grove, Urrbrae SA 5064, Australia
| | - Susan D. Johnson
- CSIRO Plant Industry, Waite Campus, Hartley Grove, Urrbrae SA 5064, Australia
| | - Fumio Takaiwa
- Transgenic Crop Research and Development Centre, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan
| | - Anna M. G. Koltunow
- CSIRO Plant Industry, Waite Campus, Hartley Grove, Urrbrae SA 5064, Australia
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