1
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Rojek J, Ohad N. The phenomenon of autonomous endosperm in sexual and apomictic plants. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:4324-4348. [PMID: 37155961 PMCID: PMC10433939 DOI: 10.1093/jxb/erad168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 05/04/2023] [Indexed: 05/10/2023]
Abstract
Endosperm is a key nutritive tissue that supports the developing embryo or seedling, and serves as a major nutritional source for human and livestock feed. In sexually-reproducing flowering plants, it generally develops after fertilization. However, autonomous endosperm (AE) formation (i.e. independent of fertilization) is also possible. Recent findings of AE loci/ genes and aberrant imprinting in native apomicts, together with a successful initiation of parthenogenesis in rice and lettuce, have enhanced our understanding of the mechanisms bridging sexual and apomictic seed formation. However, the mechanisms driving AE development are not well understood. This review presents novel aspects related to AE development in sexual and asexual plants underlying stress conditions as the primary trigger for AE. Both application of hormones to unfertilized ovules and mutations that impair epigenetic regulation lead to AE development in sexual Arabidopsis thaliana, which may point to a common pathway for both phenomena. Apomictic-like AE development under experimental conditions can take place due to auxin-dependent gene expression and/or DNA methylation.
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Affiliation(s)
- Joanna Rojek
- Department of Plant Cytology and Embryology, Faculty of Biology, University of Gdansk, Gdansk, Poland
| | - Nir Ohad
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel
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2
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Li J, Wang L, Wan J, Dang K, Lin Y, Meng S, Qiu X, Wang Q, Zhao J, Mu L, Luo H, Ding D, Chen Z, Tang J. Dynamic patterns of gene expression and regulatory variation in the maize seed coat. BMC PLANT BIOLOGY 2023; 23:82. [PMID: 36750803 PMCID: PMC9903604 DOI: 10.1186/s12870-023-04078-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 01/19/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Seed size is an important factor contributing to maize yield, but its molecular mechanism remains unclear. The seed coat, which serves as one of the three components of the maize grain, determines seed size to a certain extent. The seed coat also shares the maternal genotype and is an ideal material for studying heterosis. RESULTS In this study, the self-pollinated seeds of the maize hybrid Yudan888 and its parental lines were continuously collected from 0 day after pollination (DAP) to 15 DAP for phenotyping, cytological observation and RNA-seq. The phenotypic data showed that 3 DAP and 8 DAP are the best time points to study maize seed coat heterosis. Cytological observations indicated that maize seed coat heterosis might be the result of the coordination between cell number and cell size. Furthermore, the RNA-seq results showed that the nonadditive genes changed significantly between 3 and 8 DAP. However, the number of genes expressed additively was not significantly different. Our findings suggest that seed coat heterosis in hybrid is the result of nonadditive expression caused by dynamic changes in genes at different time points during seed expansion and seed coat development. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment indicated that genes related to DNA replication, cell cycle regulation, circadian rhythms and metabolite accumulation contributed significantly to hybrid seed coat heterosis. CONCLUSION Maize seed coat phenotyping allowed us to infer that 3 DAP and 8 DAP are important time points in the study of seed coat heterosis. Our findings provide evidence for genes involved in DNA replication, cell cycle regulation, circadian rhythms and metabolite accumulation in hybrid with high or low parental expression as major contributors to hybrid seed coat heterosis.
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Affiliation(s)
- Juan Li
- College of Agronomy, Hunan Agricultural University, Changsha, 410128, China
- National Key Laboratory of Wheat and Maize Crop Science; Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
- Institute of Crop Germplasm Resources, Guizhou Academy of Agricultural Sciences, Guiyang, 550006, China
| | - Liangfa Wang
- College of Agronomy, Hunan Agricultural University, Changsha, 410128, China
- National Key Laboratory of Wheat and Maize Crop Science; Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
- Hebi Academy of Agricultural Sciences, Hebi, 458030, China
| | - Jiong Wan
- National Key Laboratory of Wheat and Maize Crop Science; Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Kuntai Dang
- National Key Laboratory of Wheat and Maize Crop Science; Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Yuan Lin
- Hebi Academy of Agricultural Sciences, Hebi, 458030, China
| | - Shujun Meng
- National Key Laboratory of Wheat and Maize Crop Science; Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Xiaoqian Qiu
- National Key Laboratory of Wheat and Maize Crop Science; Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Qiyue Wang
- Hebi Academy of Agricultural Sciences, Hebi, 458030, China
| | - Jiawen Zhao
- National Key Laboratory of Wheat and Maize Crop Science; Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Liqin Mu
- National Key Laboratory of Wheat and Maize Crop Science; Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Hongbing Luo
- College of Agronomy, Hunan Agricultural University, Changsha, 410128, China
| | - Dong Ding
- National Key Laboratory of Wheat and Maize Crop Science; Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China.
| | - Zehui Chen
- College of Agronomy, Hunan Agricultural University, Changsha, 410128, China.
- Institute of Upland Food Crops, Guizhou Academy of Agricultural Sciences, Guiyang, 550006, China.
| | - Jihua Tang
- National Key Laboratory of Wheat and Maize Crop Science; Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China.
- The Shennong Laboratory, Zhengzhou, 450002, China.
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3
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Li L, Hou S, Xiang W, Song Z, Wang Y, Zhang L, Li J, Gu H, Dong J, Dresselhaus T, Zhong S, Qu LJ. The egg cell is preferentially fertilized in Arabidopsis double fertilization. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2022; 64:2039-2046. [PMID: 36165373 PMCID: PMC9968529 DOI: 10.1111/jipb.13370] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 09/23/2022] [Indexed: 05/28/2023]
Abstract
In flowering plants (angiosperms), fertilization of the egg cell by one sperm cell produces an embryo, whereas fusion of a second sperm cell with the central cell generates the endosperm. In most angiosperms like Arabidopsis, a pollen grain contains two isomorphic sperm cells required for this double fertilization process. A long-standing unsolved question is whether the two fertilization events have any preference. A tool to address this question is the usage of the cyclin-dependent kinase a1 (cdka;1) mutant pollen, which produces a single sperm-like cell (SLC). Here, we first adopt a complementation-based fluorescence-labeling method to successfully separate and collect cdka;1 mutant pollen containing a single SLC. Single-cell RNA-sequencing analysis revealed that cdka;1 SLCs show a gene expression profile highly similar to that of sperm cells and not to the generative cell, precursor of the two sperm cells. Pollination assays using a limited number of cdka;1 mutant pollen revealed that in 98.2% of the ovules, single fertilization of the egg cell occurred. Pollination of pistils with excessive cdka;1 mutant pollen allowed the delivery of a second SLC via fertilization recovery, which fertilized the central cell, resulting in 20.7% double-fertilized ovules. This indicates that cdka;1 SLCs are able to fertilize both the egg and the central cell. Taken together, our findings have answered a long-standing question and support that preferential fertilization of the egg cell is evident in Arabidopsis.
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Affiliation(s)
- Ling Li
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
| | - Saiying Hou
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
| | - Wei Xiang
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
| | - Zihan Song
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
| | - Yuan Wang
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
| | - Li Zhang
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
| | - Jing Li
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, College of Bioscience and Resources Environment, Beijing University of Agriculture, Beijing 102206, China
| | - Hongya Gu
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
- The National Plant Gene Research Center, Beijing 100101, China
| | - Juan Dong
- The Waksman Institute of Microbiology, Rutgers the State University of New Jersey, Piscataway, NJ“2” 08854, USA
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg 93053, Germany
| | - Sheng Zhong
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
| | - Li-Jia Qu
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
- The National Plant Gene Research Center, Beijing 100101, China
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4
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Underwood CJ, Mercier R. Engineering Apomixis: Clonal Seeds Approaching the Fields. ANNUAL REVIEW OF PLANT BIOLOGY 2022; 73:201-225. [PMID: 35138881 DOI: 10.1146/annurev-arplant-102720-013958] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Apomixis is a form of reproduction leading to clonal seeds and offspring that are genetically identical to the maternal plant. While apomixis naturally occurs in hundreds of plant species distributed across diverse plant families, it is absent in major crop species. Apomixis has a revolutionary potential in plant breeding, as it could allow the instant fixation and propagation though seeds of any plant genotype, most notably F1 hybrids. Mastering and implementing apomixis would reduce the cost of hybrid seed production, facilitate new types of hybrid breeding, and make it possible to harness hybrid vigor in crops that are not presently cultivated as hybrids. Synthetic apomixis can be engineered by combining modifications of meiosis and fertilization. Here, we review the current knowledge and recent major achievements toward the development of efficient apomictic systems usable in agriculture.
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Affiliation(s)
- Charles J Underwood
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany; ,
| | - Raphael Mercier
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany; ,
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5
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Song J, Xie X, Cui Y, Zou J. Endosperm-Embryo Communications: Recent Advances and Perspectives. PLANTS (BASEL, SWITZERLAND) 2021; 10:plants10112511. [PMID: 34834874 PMCID: PMC8625250 DOI: 10.3390/plants10112511] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Revised: 11/16/2021] [Accepted: 11/17/2021] [Indexed: 05/22/2023]
Abstract
Seed maturation depends on well-coordinated communications between the processes of endosperm and embryo development. The endosperm is considered to be destined to support embryo development and the timing of endosperm cellularization is critical for embryo growth. Recent findings suggest that the endosperm development and the onset of embryo maturation are two independent processes during seed development. Meanwhile, it is lately reported that several mobile regulators originating from the endosperm are needed to ensure proper embryo growth and seed maturation. In this opinion article, we highlight processes on how endosperm communicates with embryo during seed development and discuss some intriguing questions in light of the latest advancements.
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Affiliation(s)
- Jingpu Song
- Aquatic and Crop Resource Development Research Centre, National Research Council of Canada, Saskatoon, SK S7N 0W9, Canada;
- Correspondence:
| | - Xin Xie
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON N5V 4T3, Canada; (X.X.); (Y.C.)
- Department of Biology, Western University, London, ON N6A 3K7, Canada
| | - Yuhai Cui
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON N5V 4T3, Canada; (X.X.); (Y.C.)
- Department of Biology, Western University, London, ON N6A 3K7, Canada
| | - Jitao Zou
- Aquatic and Crop Resource Development Research Centre, National Research Council of Canada, Saskatoon, SK S7N 0W9, Canada;
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6
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Kinser TJ, Smith RD, Lawrence AH, Cooley AM, Vallejo-Marín M, Conradi Smith GD, Puzey JR. Endosperm-based incompatibilities in hybrid monkeyflowers. THE PLANT CELL 2021; 33:2235-2257. [PMID: 33895820 PMCID: PMC8364248 DOI: 10.1093/plcell/koab117] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 04/15/2021] [Indexed: 05/31/2023]
Abstract
Endosperm is an angiosperm innovation central to their reproduction whose development, and thus seed viability, is controlled by genomic imprinting, where expression from certain genes is parent-specific. Unsuccessful imprinting has been linked to failed inter-specific and inter-ploidy hybridization. Despite their importance in plant speciation, the underlying mechanisms behind these endosperm-based barriers remain poorly understood. Here, we describe one such barrier between diploid Mimulus guttatus and tetraploid Mimulus luteus. The two parents differ in endosperm DNA methylation, expression dynamics, and imprinted genes. Hybrid seeds suffer from underdeveloped endosperm, reducing viability, or arrested endosperm and seed abortion when M. guttatus or M. luteus is seed parent, respectively, and transgressive methylation and expression patterns emerge. The two inherited M. luteus subgenomes, genetically distinct but epigenetically similar, are expressionally dominant over the M. guttatus genome in hybrid embryos and especially their endosperm, where paternal imprints are perturbed. In aborted seeds, de novo methylation is inhibited, potentially owing to incompatible paternal instructions of imbalanced dosage from M. guttatus imprints. We suggest that diverged epigenetic/regulatory landscapes between parental genomes induce epigenetic repatterning and global shifts in expression, which, in endosperm, may uniquely facilitate incompatible interactions between divergent imprinting schemes, potentially driving rapid barriers.
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Affiliation(s)
- Taliesin J. Kinser
- Biology Department, College of William and Mary, Williamsburg, Virginia 23185
| | - Ronald D. Smith
- Department of Applied Science, College of William and Mary, Williamsburg, Virginia 23185
| | - Amelia H. Lawrence
- Biology Department, College of William and Mary, Williamsburg, Virginia 23185
| | | | - Mario Vallejo-Marín
- Biological and Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling, Scotland FK9 4LA, UK
| | | | - Joshua R. Puzey
- Biology Department, College of William and Mary, Williamsburg, Virginia 23185
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7
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Simonini S, Bemer M, Bencivenga S, Gagliardini V, Pires ND, Desvoyes B, van der Graaff E, Gutierrez C, Grossniklaus U. The Polycomb group protein MEDEA controls cell proliferation and embryonic patterning in Arabidopsis. Dev Cell 2021; 56:1945-1960.e7. [PMID: 34192526 PMCID: PMC8279741 DOI: 10.1016/j.devcel.2021.06.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 04/22/2021] [Accepted: 06/07/2021] [Indexed: 12/13/2022]
Abstract
Establishing the embryonic body plan of multicellular organisms relies on precisely orchestrated cell divisions coupled with pattern formation, which, in animals, are regulated by Polycomb group (PcG) proteins. The conserved Polycomb Repressive Complex 2 (PRC2) mediates H3K27 trimethylation and comes in different flavors in Arabidopsis. The PRC2 catalytic subunit MEDEA is required for seed development; however, a role for PRC2 in embryonic patterning has been dismissed. Here, we demonstrate that embryos derived from medea eggs abort because MEDEA is required for patterning and cell lineage determination in the early embryo. Similar to PcG proteins in mammals, MEDEA regulates embryonic patterning and growth by controlling cell-cycle progression through repression of CYCD1;1, which encodes a core cell-cycle component. Thus, Arabidopsis embryogenesis is epigenetically regulated by PcG proteins, revealing that the PRC2-dependent modulation of cell-cycle progression was independently recruited to control embryonic cell proliferation and patterning in animals and plants. MEDEA, a Polycomb Repressive Complex 2 (PRC2) subunit, is required in embryo and endosperm MEDEA links cell proliferation and differentiation during embryonic pattern formation The PRC2 protein MEDEA directly regulates core cell-cycle components, i.e., cyclin CYCD1;1 Body plan and cell proliferation are epigenetically regulated in both animals and plants
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Affiliation(s)
- Sara Simonini
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zollikerstrasse 107, 8008 Zurich, Switzerland
| | - Marian Bemer
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zollikerstrasse 107, 8008 Zurich, Switzerland
| | - Stefano Bencivenga
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zollikerstrasse 107, 8008 Zurich, Switzerland
| | - Valeria Gagliardini
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zollikerstrasse 107, 8008 Zurich, Switzerland
| | - Nuno D Pires
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zollikerstrasse 107, 8008 Zurich, Switzerland
| | - Bénédicte Desvoyes
- Centro de Biología Molecular Severo Ochoa CSIC-UAM, Nicolás Cabrera 1, Cantoblanco 28049, Madrid, Spain
| | - Eric van der Graaff
- BIOSS Centre for Biological Signaling Studies, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany
| | - Crisanto Gutierrez
- Centro de Biología Molecular Severo Ochoa CSIC-UAM, Nicolás Cabrera 1, Cantoblanco 28049, Madrid, Spain
| | - Ueli Grossniklaus
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zollikerstrasse 107, 8008 Zurich, Switzerland.
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8
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Song J, Xie X, Chen C, Shu J, Thapa RK, Nguyen V, Bian S, Kohalmi SE, Marsolais F, Zou J, Cui Y. LEAFY COTYLEDON1 expression in the endosperm enables embryo maturation in Arabidopsis. Nat Commun 2021; 12:3963. [PMID: 34172749 PMCID: PMC8233312 DOI: 10.1038/s41467-021-24234-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 06/03/2021] [Indexed: 11/09/2022] Open
Abstract
The endosperm provides nutrients and growth regulators to the embryo during seed development. LEAFY COTYLEDON1 (LEC1) has long been known to be essential for embryo maturation. LEC1 is expressed in both the embryo and the endosperm; however, the functional relevance of the endosperm-expressed LEC1 for seed development is unclear. Here, we provide genetic and transgenic evidence demonstrating that endosperm-expressed LEC1 is necessary and sufficient for embryo maturation. We show that endosperm-synthesized LEC1 is capable of orchestrating full seed maturation in the absence of embryo-expressed LEC1. Inversely, without LEC1 expression in the endosperm, embryo development arrests even in the presence of functional LEC1 alleles in the embryo. We further reveal that LEC1 expression in the endosperm begins at the zygote stage and the LEC1 protein is then trafficked to the embryo to activate processes of seed maturation. Our findings thus establish a key role for endosperm in regulating embryo development.
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Affiliation(s)
- Jingpu Song
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, Canada. .,Aquatic and Crop Resource Development Research Centre, National Research Council of Canada, Saskatoon, SK, Canada. .,Department of Biology, Western University, London, ON, Canada.
| | - Xin Xie
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, Canada.,Department of Biology, Western University, London, ON, Canada
| | - Chen Chen
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, Canada.,Department of Biology, Western University, London, ON, Canada.,Molecular Analysis and Genetic Improvement Center, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Jie Shu
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, Canada.,Department of Biology, Western University, London, ON, Canada.,Molecular Analysis and Genetic Improvement Center, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Raj K Thapa
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, Canada.,Department of Biology, Western University, London, ON, Canada
| | - Vi Nguyen
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, Canada
| | - Shaomin Bian
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, Canada.,College of Plant Science, Jilin University, Changchun, China
| | | | - Frédéric Marsolais
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, Canada.,Department of Biology, Western University, London, ON, Canada
| | - Jitao Zou
- Aquatic and Crop Resource Development Research Centre, National Research Council of Canada, Saskatoon, SK, Canada.
| | - Yuhai Cui
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, Canada. .,Department of Biology, Western University, London, ON, Canada.
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9
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Schmücker A, Lei B, Lorković ZJ, Capella M, Braun S, Bourguet P, Mathieu O, Mechtler K, Berger F. Crosstalk between H2A variant-specific modifications impacts vital cell functions. PLoS Genet 2021; 17:e1009601. [PMID: 34086674 PMCID: PMC8208582 DOI: 10.1371/journal.pgen.1009601] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 06/16/2021] [Accepted: 05/14/2021] [Indexed: 12/15/2022] Open
Abstract
Selection of C-terminal motifs participated in evolution of distinct histone H2A variants. Hybrid types of variants combining motifs from distinct H2A classes are extremely rare. This suggests that the proximity between the motif cases interferes with their function. We studied this question in flowering plants that evolved sporadically a hybrid H2A variant combining the SQ motif of H2A.X that participates in the DNA damage response with the KSPK motif of H2A.W that stabilizes heterochromatin. Our inventory of PTMs of H2A.W variants showed that in vivo the cell cycle-dependent kinase CDKA phosphorylates the KSPK motif of H2A.W but only in absence of an SQ motif. Phosphomimicry of KSPK prevented DNA damage response by the SQ motif of the hybrid H2A.W/X variant. In a synthetic yeast expressing the hybrid H2A.W/X variant, phosphorylation of KSPK prevented binding of the BRCT-domain protein Mdb1 to phosphorylated SQ and impaired response to DNA damage. Our findings illustrate that PTMs mediate interference between the function of H2A variant specific C-terminal motifs. Such interference could explain the mutual exclusion of motifs that led to evolution of H2A variants.
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Affiliation(s)
- Anna Schmücker
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Bingkun Lei
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Zdravko J. Lorković
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Matías Capella
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-University of Munich, Planegg-Martinsried, Germany
| | - Sigurd Braun
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-University of Munich, Planegg-Martinsried, Germany
- International Max Planck Research School for Molecular and Cellular Life Sciences, Planegg-Martinsried, Germany
| | - Pierre Bourguet
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
- CNRS, Université Clermont Auvergne, Inserm, Génétique Reproduction et Développement, Clermont-Ferrand, France
| | - Olivier Mathieu
- CNRS, Université Clermont Auvergne, Inserm, Génétique Reproduction et Développement, Clermont-Ferrand, France
| | - Karl Mechtler
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Frédéric Berger
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
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10
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Paolo D, Rotasperti L, Schnittger A, Masiero S, Colombo L, Mizzotti C. The Arabidopsis MADS-Domain Transcription Factor SEEDSTICK Controls Seed Size via Direct Activation of E2Fa. PLANTS 2021; 10:plants10020192. [PMID: 33498552 PMCID: PMC7909557 DOI: 10.3390/plants10020192] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/08/2021] [Accepted: 01/16/2021] [Indexed: 02/06/2023]
Abstract
Seed size is the result of complex molecular networks controlling the development of the seed coat (of maternal origin) and the two fertilization products, the embryo and the endosperm. In this study we characterized the role of Arabidopsis thaliana MADS-domain transcription factor SEEDSTICK (STK) in seed size control. STK is known to regulate the differentiation of the seed coat as well as the structural and mechanical properties of cell walls in developing seeds. In particular, we further characterized stk mutant seeds. Genetic evidence (reciprocal crosses) of the inheritance of the small-seed phenotype, together with the provided analysis of cell division activity (flow cytometry), demonstrate that STK acts in the earlier phases of seed development as a maternal activator of growth. Moreover, we describe a molecular mechanism underlying this activity by reporting how STK positively regulates cell cycle progression via directly activating the expression of E2Fa, a key regulator of the cell cycle. Altogether, our results unveil a new genetic network active in the maternal control of seed size in Arabidopsis.
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Affiliation(s)
- Dario Paolo
- Dipartimento di BioScienze, Università degli Studi di Milano, 20133 Milano, Italy; (D.P.); (L.R.); (S.M.); (L.C.)
| | - Lisa Rotasperti
- Dipartimento di BioScienze, Università degli Studi di Milano, 20133 Milano, Italy; (D.P.); (L.R.); (S.M.); (L.C.)
| | - Arp Schnittger
- Abteilung für Entwicklungsbiologie, Institut für Pflanzenforschung und Mikrobiologie, Universität Hamburg, 22609 Hamburg, Germany;
| | - Simona Masiero
- Dipartimento di BioScienze, Università degli Studi di Milano, 20133 Milano, Italy; (D.P.); (L.R.); (S.M.); (L.C.)
| | - Lucia Colombo
- Dipartimento di BioScienze, Università degli Studi di Milano, 20133 Milano, Italy; (D.P.); (L.R.); (S.M.); (L.C.)
| | - Chiara Mizzotti
- Dipartimento di BioScienze, Università degli Studi di Milano, 20133 Milano, Italy; (D.P.); (L.R.); (S.M.); (L.C.)
- Correspondence: ; Tel.: +39-02-503-14838
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11
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Maruyama D, Higashiyama T, Endo T, Nishikawa SI. Fertilization-Coupled Sperm Nuclear Fusion Is Required for Normal Endosperm Nuclear Proliferation. PLANT & CELL PHYSIOLOGY 2020; 61:29-40. [PMID: 31410484 DOI: 10.1093/pcp/pcz158] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Accepted: 08/07/2019] [Indexed: 05/13/2023]
Abstract
Angiosperms exhibit double fertilization, a process in which one of the sperm cells released from the pollen tube fertilizes the egg, while the other sperm cell fertilizes the central cell, giving rise to the embryo and endosperm, respectively. We have previously reported two polar nuclear fusion-defective double knockout mutants of Arabidopsis thaliana immunoglobulin binding protein (BiP), a molecular chaperone of the heat shock protein 70 (Hsp70) localized in the endoplasmic reticulum (ER), (bip1 bip2) and its partner ER-resident J-proteins, ERdj3A and P58IPK (erdj3a p58ipk). These mutants are defective in the fusion of outer nuclear membrane and exhibit characteristic seed developmental defects after fertilization with wild-type pollen, which are accompanied by aberrant endosperm nuclear proliferation. In this study, we used time-lapse live-cell imaging analysis to determine the cause of aberrant endosperm nuclear division in these mutant seeds. We found that the central cell of bip1 bip2 or erdj3a p58ipk double mutant female gametophytes was also defective in sperm nuclear fusion at fertilization. Sperm nuclear fusion was achieved after the onset of the first endosperm nuclear division. However, division of the condensed sperm nucleus resulted in aberrant endosperm nuclear divisions and delayed expression of paternally derived genes. By contrast, the other double knockout mutant, erdj3b p58ipk, which is defective in the fusion of inner membrane of polar nuclei but does not show aberrant endosperm nuclear proliferation, was not defective in sperm nuclear fusion at fertilization. We thus propose that premitotic sperm nuclear fusion in the central cell is critical for normal endosperm nuclear proliferation.
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Affiliation(s)
- Daisuke Maruyama
- Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya, 464-8602 Japan
- Kihara Institute for Biological Research, Yokohama City University, 641-12 Maioka-cho, Totsuka-ku, Yokohama, 244-0813 Japan
| | - Tetsuya Higashiyama
- Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya, 464-8602 Japan
- WPI-Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8601 Japan
| | - Toshiya Endo
- Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya, 464-8602 Japan
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto, 603-8555 Japan
| | - Shuh-Ichi Nishikawa
- Department of Biology, Faculty of Science, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata, 950-2181 Japan
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12
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Han Q, Bartels A, Cheng X, Meyer A, An YQC, Hsieh TF, Xiao W. Epigenetics Regulates Reproductive Development in Plants. PLANTS 2019; 8:plants8120564. [PMID: 31810261 PMCID: PMC6963493 DOI: 10.3390/plants8120564] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 11/23/2019] [Accepted: 11/27/2019] [Indexed: 12/20/2022]
Abstract
Seed, resulting from reproductive development, is the main nutrient source for human beings, and reproduction has been intensively studied through genetic, molecular, and epigenetic approaches. However, how different epigenetic pathways crosstalk and integrate to regulate seed development remains unknown. Here, we review the recent progress of epigenetic changes that affect chromatin structure, such as DNA methylation, polycomb group proteins, histone modifications, and small RNA pathways in regulating plant reproduction. In gametogenesis of flowering plants, epigenetics is dynamic between the companion cell and gametes. Cytosine DNA methylation occurs in CG, CHG, CHH contexts (H = A, C, or T) of genes and transposable elements, and undergoes dynamic changes during reproduction. Cytosine methylation in the CHH context increases significantly during embryogenesis, reaches the highest levels in mature embryos, and decreases as the seed germinates. Polycomb group proteins are important transcriptional regulators during seed development. Histone modifications and small RNA pathways add another layer of complexity in regulating seed development. In summary, multiple epigenetic pathways are pivotal in regulating seed development. It remains to be elucidated how these epigenetic pathways interplay to affect dynamic chromatin structure and control reproduction.
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Affiliation(s)
- Qiang Han
- Department of Biology, Saint Louis University, St. Louis, MO 63103, USA (A.B.); (X.C.)
| | - Arthur Bartels
- Department of Biology, Saint Louis University, St. Louis, MO 63103, USA (A.B.); (X.C.)
| | - Xi Cheng
- Department of Biology, Saint Louis University, St. Louis, MO 63103, USA (A.B.); (X.C.)
| | - Angela Meyer
- Department of Biology, Saint Louis University, St. Louis, MO 63103, USA (A.B.); (X.C.)
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Yong-Qiang Charles An
- US Department of Agriculture, Agricultural Research Service, Midwest Area, Plant Genetics Research Unit, Donald Danforth Plant Science Center, MO 63132, USA;
| | - Tzung-Fu Hsieh
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA;
- Plants for Human Health Institute, North Carolina State University, North Carolina Research Campus, Kannapolis, NC 28081, USA
| | - Wenyan Xiao
- Department of Biology, Saint Louis University, St. Louis, MO 63103, USA (A.B.); (X.C.)
- Correspondence: ; Tel.: +1-314-977-2547
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13
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Ruta V, Longo C, Boccaccini A, Madia VN, Saccoliti F, Tudino V, Di Santo R, Lorrai R, Dello Ioio R, Sabatini S, Costi R, Costantino P, Vittorioso P. Inhibition of Polycomb Repressive Complex 2 activity reduces trimethylation of H3K27 and affects development in Arabidopsis seedlings. BMC PLANT BIOLOGY 2019; 19:429. [PMID: 31619182 PMCID: PMC6796367 DOI: 10.1186/s12870-019-2057-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 09/26/2019] [Indexed: 05/21/2023]
Abstract
BACKGROUND Polycomb repressive complex 2 (PRC2) is an epigenetic transcriptional repression system, whose catalytic subunit (ENHANCER OF ZESTE HOMOLOG 2, EZH2 in animals) is responsible for trimethylating histone H3 at lysine 27 (H3K27me3). In mammals, gain-of-function mutations as well as overexpression of EZH2 have been associated with several tumors, therefore making this subunit a suitable target for the development of selective inhibitors. Indeed, highly specific small-molecule inhibitors of EZH2 have been reported. In plants, mutations in some PRC2 components lead to embryonic lethality, but no trial with any inhibitor has ever been reported. RESULTS We show here that the 1,5-bis (3-bromo-4-methoxyphenyl)penta-1,4-dien-3-one compound (RDS 3434), previously reported as an EZH2 inhibitor in human leukemia cells, is active on the Arabidopsis catalytic subunit of PRC2, since treatment with the drug reduces the total amount of H3K27me3 in a dose-dependent fashion. Consistently, we show that the expression level of two PRC2 targets is significantly increased following treatment with the RDS 3434 compound. Finally, we show that impairment of H3K27 trimethylation in Arabidopsis seeds and seedlings affects both seed germination and root growth. CONCLUSIONS Our results provide a useful tool for the plant community in investigating how PRC2 affects transcriptional control in plant development.
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Affiliation(s)
- Veronica Ruta
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Chiara Longo
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Alessandra Boccaccini
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Valentina Noemi Madia
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Chimica e Tecnologie del Farmaco, Dipartimento di Eccellenza 2018-2022, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Francesco Saccoliti
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Chimica e Tecnologie del Farmaco, Dipartimento di Eccellenza 2018-2022, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Valeria Tudino
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Chimica e Tecnologie del Farmaco, Dipartimento di Eccellenza 2018-2022, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Roberto Di Santo
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Chimica e Tecnologie del Farmaco, Dipartimento di Eccellenza 2018-2022, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Riccardo Lorrai
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Raffaele Dello Ioio
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Sabrina Sabatini
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Roberta Costi
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Chimica e Tecnologie del Farmaco, Dipartimento di Eccellenza 2018-2022, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Paolo Costantino
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Paola Vittorioso
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
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14
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Yang C, Sofroni K, Wijnker E, Hamamura Y, Carstens L, Harashima H, Stolze SC, Vezon D, Chelysheva L, Orban-Nemeth Z, Pochon G, Nakagami H, Schlögelhofer P, Grelon M, Schnittger A. The Arabidopsis Cdk1/Cdk2 homolog CDKA;1 controls chromosome axis assembly during plant meiosis. EMBO J 2019; 39:e101625. [PMID: 31556459 PMCID: PMC6996576 DOI: 10.15252/embj.2019101625] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 09/02/2019] [Accepted: 09/04/2019] [Indexed: 12/12/2022] Open
Abstract
Meiosis is key to sexual reproduction and genetic diversity. Here, we show that the Arabidopsis cyclin-dependent kinase Cdk1/Cdk2 homolog CDKA;1 is an important regulator of meiosis needed for several aspects of meiosis such as chromosome synapsis. We identify the chromosome axis protein ASYNAPTIC 1 (ASY1), the Arabidopsis homolog of Hop1 (homolog pairing 1), essential for synaptonemal complex formation, as a target of CDKA;1. The phosphorylation of ASY1 is required for its recruitment to the chromosome axis via ASYNAPTIC 3 (ASY3), the Arabidopsis reductional division 1 (Red1) homolog, counteracting the disassembly activity of the AAA+ ATPase PACHYTENE CHECKPOINT 2 (PCH2). Furthermore, we have identified the closure motif in ASY1, typical for HORMA domain proteins, and provide evidence that the phosphorylation of ASY1 regulates the putative self-polymerization of ASY1 along the chromosome axis. Hence, the phosphorylation of ASY1 by CDKA;1 appears to be a two-pronged mechanism to initiate chromosome axis formation in meiosis.
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Affiliation(s)
- Chao Yang
- Department of Developmental Biology, University of Hamburg, Hamburg, Germany
| | - Kostika Sofroni
- Department of Developmental Biology, University of Hamburg, Hamburg, Germany
| | - Erik Wijnker
- Department of Developmental Biology, University of Hamburg, Hamburg, Germany
| | - Yuki Hamamura
- Department of Developmental Biology, University of Hamburg, Hamburg, Germany
| | - Lena Carstens
- Department of Developmental Biology, University of Hamburg, Hamburg, Germany
| | | | | | - Daniel Vezon
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, Versailles, France
| | - Liudmila Chelysheva
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, Versailles, France
| | - Zsuzsanna Orban-Nemeth
- Department of Chromosome Biology, Max F. Perutz Laboratories, Vienna Biocenter, University of Vienna, Vienna, Austria
| | - Gaëtan Pochon
- Department of Developmental Biology, University of Hamburg, Hamburg, Germany
| | | | - Peter Schlögelhofer
- Department of Chromosome Biology, Max F. Perutz Laboratories, Vienna Biocenter, University of Vienna, Vienna, Austria
| | - Mathilde Grelon
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, Versailles, France
| | - Arp Schnittger
- Department of Developmental Biology, University of Hamburg, Hamburg, Germany
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15
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Abstract
Little is known how patterns of cross-over (CO) numbers and distribution during meiosis are established. Here, we reveal that cyclin-dependent kinase A;1 (CDKA;1), the homolog of human Cdk1 and Cdk2, is a major regulator of meiotic recombination in Arabidopsis Arabidopsis plants with reduced CDKA;1 activity experienced a decrease of class I COs, especially lowering recombination rates in centromere-proximal regions. Interestingly, this reduction of type I CO did not affect CO assurance, a mechanism by which each chromosome receives at least one CO, resulting in all chromosomes exhibiting similar genetic lengths in weak loss-of-function cdka ;1 mutants. Conversely, an increase of CDKA;1 activity resulted in elevated recombination frequencies. Thus, modulation of CDKA;1 kinase activity affects the number and placement of COs along the chromosome axis in a dose-dependent manner.
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16
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Kosmacz M, Gorka M, Schmidt S, Luzarowski M, Moreno JC, Szlachetko J, Leniak E, Sokolowska EM, Sofroni K, Schnittger A, Skirycz A. Protein and metabolite composition of Arabidopsis stress granules. THE NEW PHYTOLOGIST 2019; 222:1420-1433. [PMID: 30664249 DOI: 10.1111/nph.15690] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 01/11/2019] [Indexed: 05/06/2023]
Abstract
Stress granules (SGs) are evolutionary conserved aggregates of proteins and untranslated mRNAs formed in response to stress. Despite their importance for stress adaptation, no complete proteome composition has been reported for plant SGs. In this study, we addressed the existing gap. Importantly, we also provide evidence for metabolite sequestration within the SGs. To isolate SGs we used Arabidopsis seedlings expressing green fluorescent protein (GFP) fusion of the SGs marker protein, Rbp47b, and an experimental protocol combining differential centrifugation with affinity purification (AP). SGs isolates were analysed using mass spectrometry-based proteomics and metabolomics. A quarter of the identified proteins constituted known or predicted SG components. Intriguingly, the remaining proteins were enriched in key enzymes and regulators, such as cyclin-dependent kinase A (CDKA), that mediate plant responses to stress. In addition to proteins, nucleotides, amino acids and phospholipids also accumulated in SGs. Taken together, our results indicated the presence of a preexisting SG protein interaction network; an evolutionary conservation of the proteins involved in SG assembly and dynamics; an important role for SGs in moderation of stress responses by selective storage of proteins and metabolites.
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Affiliation(s)
- Monika Kosmacz
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam, Germany
| | - Michał Gorka
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam, Germany
| | - Stephan Schmidt
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam, Germany
| | - Marcin Luzarowski
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam, Germany
| | - Juan C Moreno
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam, Germany
| | - Jagoda Szlachetko
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam, Germany
| | - Ewa Leniak
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam, Germany
| | | | - Kostika Sofroni
- Department of Developmental Biology, University of Hamburg, 22069, Hamburg, Germany
| | - Arp Schnittger
- Department of Developmental Biology, University of Hamburg, 22069, Hamburg, Germany
| | - Aleksandra Skirycz
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam, Germany
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17
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Abstract
This review by Figueiredo and Köhler describes the molecular mechanisms driving seed development. They review the role of the hormone auxin for the initial development of the three seed structures and as a trigger of fertilization-independent seed development. The evolution of seeds defines a remarkable landmark in the history of land plants. A developing seed contains three genetically distinct structures: the embryo, the nourishing tissue, and the seed coat. While fertilization is necessary to initiate seed development in most plant species, apomicts have evolved mechanisms allowing seed formation independently of fertilization. Despite their socio–economical relevance, the molecular mechanisms driving seed development have only recently begun to be understood. Here we review the current knowledge on the role of the hormone auxin for the initial development of the three seed structures and as a trigger of fertilization-independent seed development.
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Affiliation(s)
- Duarte D Figueiredo
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala SE-750 07, Sweden
| | - Claudia Köhler
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala SE-750 07, Sweden
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18
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de Souza GA, Dos Santos Dias DCF, Pimenta TM, Almeida AL, de Toledo Picoli EA, de Pádua Alvarenga A, da Silva JCF. Sugar metabolism and developmental stages of rubber tree (Hevea brasiliensis L.) seeds. PHYSIOLOGIA PLANTARUM 2018; 162:495-505. [PMID: 28991376 DOI: 10.1111/ppl.12650] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 10/03/2017] [Accepted: 10/04/2017] [Indexed: 06/07/2023]
Abstract
Changes in the concentration of sugars and sucrose metabolism enzymes can characterize the developmental stages of a seed. In recalcitrant species such as Hevea brasiliensis L., little is known about these changes. We aimed to evaluate the three main stages of development of rubber tree seeds - histodifferentiation, cell elongation and accumulation of reserves. The activities of acid and neutral invertases (E.C. 3.2.1.26) and sucrose synthase (EC 2.4.1.13), and the concentrations of reducing sugars (RS), total soluble sugars (TSS) and sucrose (Suc) were determined concomitantly with the histochemical and anatomical evaluation of seed structure. Histodifferentiation in rubber tree seeds occurs up to 75 days after anthesis (DAA). The concentration of RS is high and of Suc is low during seed histodifferentiation, which occurs along with a visible increase in the number of cell divisions. After that period, there is an increase in the concentration of Suc (mg g-1 ) and in the number and size of starch granules, and a decrease in the concentration of RS (mg g-1 ). At that point, cell elongation occurs. At 135 DAA, there is an inversion in the concentration of these two sugars and an increase in reserve accumulation. Thus, in seeds of the evaluated clone, the period up to 75 DAA is characterized as the histodifferentiation stage, while from that time up to 120 DAA the cell elongation stage takes place. The final stage of seed maturation and reserve accumulation begins at 135 DAA, and the seed, including the embryo, is completely formed at 175 DAA.
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Affiliation(s)
- Genaina Aparecida de Souza
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Campus Universitário, s/n, Viçosa, MG, 36570-000, Brazil
| | | | - Thaline Martins Pimenta
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Campus Universitário, s/n, Viçosa, MG, 36570-000, Brazil
| | - Andrea Lanna Almeida
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Campus Universitário, s/n, Viçosa, MG, 36570-000, Brazil
| | | | - Antônio de Pádua Alvarenga
- Empresa de Pesquisa Agropecuária de Minas Gerais, EPAMIG, Unidade Sudeste, Universidade Federal de Viçosa, Campus Universitário, s/n, Viçosa, MG, 36570-000, Brazil
| | - José Cleydson Ferreira da Silva
- Laboratório de Biologia Molecular de Plantas - BIOAGRO, Universidade Federal de Viçosa, Campus Universitário, s/n, Viçosa, MG, 36570-000, Brazil
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19
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Bouyer D, Kramdi A, Kassam M, Heese M, Schnittger A, Roudier F, Colot V. DNA methylation dynamics during early plant life. Genome Biol 2017; 18:179. [PMID: 28942733 PMCID: PMC5611644 DOI: 10.1186/s13059-017-1313-0] [Citation(s) in RCA: 124] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 08/30/2017] [Indexed: 12/29/2022] Open
Abstract
Background Cytosine methylation is crucial for gene regulation and silencing of transposable elements in mammals and plants. While this epigenetic mark is extensively reprogrammed in the germline and early embryos of mammals, the extent to which DNA methylation is reset between generations in plants remains largely unknown. Results Using Arabidopsis as a model, we uncovered distinct DNA methylation dynamics over transposable element sequences during the early stages of plant development. Specifically, transposable elements and their relics show invariably high methylation at CG sites but increasing methylation at CHG and CHH sites. This non-CG methylation culminates in mature embryos, where it reaches saturation for a large fraction of methylated CHH sites, compared to the typical 10–20% methylation level observed in seedlings or adult plants. Moreover, the increase in CHH methylation during embryogenesis matches the hypomethylated state in the early endosperm. Finally, we show that interfering with the embryo-to-seedling transition results in the persistence of high CHH methylation levels after germination, specifically over sequences that are targeted by the RNA-directed DNA methylation (RdDM) machinery. Conclusion Our findings indicate the absence of extensive resetting of DNA methylation patterns during early plant life and point instead to an important role of RdDM in reinforcing DNA methylation of transposable element sequences in every cell of the mature embryo. Furthermore, we provide evidence that this elevated RdDM activity is a specific property of embryogenesis. Electronic supplementary material The online version of this article (doi:10.1186/s13059-017-1313-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Daniel Bouyer
- Institut de Biologie Moléculaire des Plantes du CNRS - UPR2357, Université de Strasbourg, Strasbourg, France. .,Institut de Biologie de l'Ecole Normale Supérieure, CNRS UMR 8197-INSERM U 1024, F-75230, Paris, France.
| | - Amira Kramdi
- Institut de Biologie de l'Ecole Normale Supérieure, CNRS UMR 8197-INSERM U 1024, F-75230, Paris, France
| | - Mohamed Kassam
- Institut de Biologie de l'Ecole Normale Supérieure, CNRS UMR 8197-INSERM U 1024, F-75230, Paris, France.,Present address: Nestlé Institute of Health Sciences, Functional Genomics, Lausanne, Switzerland
| | - Maren Heese
- Institut de Biologie Moléculaire des Plantes du CNRS - UPR2357, Université de Strasbourg, Strasbourg, France.,Department of Developmental Biology, University of Hamburg, Biozentrum Klein Flottbek, Hamburg, Germany
| | - Arp Schnittger
- Institut de Biologie Moléculaire des Plantes du CNRS - UPR2357, Université de Strasbourg, Strasbourg, France.,Department of Developmental Biology, University of Hamburg, Biozentrum Klein Flottbek, Hamburg, Germany
| | - François Roudier
- Institut de Biologie de l'Ecole Normale Supérieure, CNRS UMR 8197-INSERM U 1024, F-75230, Paris, France.,Present address: Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, F-69342, Lyon, France
| | - Vincent Colot
- Institut de Biologie de l'Ecole Normale Supérieure, CNRS UMR 8197-INSERM U 1024, F-75230, Paris, France
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20
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Xiao J, Jin R, Wagner D. Developmental transitions: integrating environmental cues with hormonal signaling in the chromatin landscape in plants. Genome Biol 2017; 18:88. [PMID: 28490341 PMCID: PMC5425979 DOI: 10.1186/s13059-017-1228-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Plant development is predominantly postembryonic and tuned in to respond to environmental cues. All living plant cells can be triggered to de-differentiate, assume different cell identities, or form a new organism. This developmental plasticity is thought to be an adaptation to the sessile lifestyle of plants. Recent discoveries have advanced our understanding of the orchestration of plant developmental switches by transcriptional master regulators, chromatin state changes, and hormone response pathways. Here, we review these recent advances with emphasis on the earliest stages of plant development and on the switch from pluripotency to differentiation in different plant organ systems.
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Affiliation(s)
- Jun Xiao
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Run Jin
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Doris Wagner
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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21
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Abstract
Genomic imprinting, an inherently epigenetic phenomenon defined by parent of origin-dependent gene expression, is observed in mammals and flowering plants. Genome-scale surveys of imprinted expression and the underlying differential epigenetic marks have led to the discovery of hundreds of imprinted plant genes and confirmed DNA and histone methylation as key regulators of plant imprinting. However, the biological roles of the vast majority of imprinted plant genes are unknown, and the evolutionary forces shaping plant imprinting remain rather opaque. Here, we review the mechanisms of plant genomic imprinting and discuss theories of imprinting evolution and biological significance in light of recent findings.
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Affiliation(s)
- Jessica A Rodrigues
- Department of Plant and Microbial Biology, University of California at Berkeley, Berkeley, California 94720, USA
| | - Daniel Zilberman
- Department of Plant and Microbial Biology, University of California at Berkeley, Berkeley, California 94720, USA
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22
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Lafon-Placette C, Köhler C. Endosperm-based postzygotic hybridization barriers: developmental mechanisms and evolutionary drivers. Mol Ecol 2016; 25:2620-9. [PMID: 26818717 DOI: 10.1111/mec.13552] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 12/28/2015] [Indexed: 01/06/2023]
Abstract
The endosperm is a nourishing tissue that serves to support embryo growth. Failure of endosperm development will ultimately cause embryo arrest and seed lethality, a phenomenon that is frequently observed upon hybridization of related plant species or species that differ in ploidy. Endosperm-based interspecies or interploidy hybridization barriers depend on the direction of the hybridization, causing nonreciprocal seed defects. This reveals that the parental genomes are not equivalent, implicating parent-of-origin specific genes generating this type of hybridization barrier. Recent work revealed that endosperm-based hybridization barriers are rapidly evolving. In this review, we discuss the developmental mechanisms causing hybrid seed lethality in angiosperms as well as the evolutionary forces establishing endosperm-based postzygotic hybridization barriers.
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Affiliation(s)
- Clément Lafon-Placette
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, 750 07, Uppsala, Sweden
| | - Claudia Köhler
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, 750 07, Uppsala, Sweden
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23
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Khanduri P, Sharma R, Bhat V, Tandon R. Isolation, expression and evolution of FERTILIZATION INDEPENDENT ENDOSPERM homologs in Podostemaceae. JOURNAL OF PLANT RESEARCH 2016; 129:241-250. [PMID: 26649869 DOI: 10.1007/s10265-015-0771-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 10/13/2015] [Indexed: 06/05/2023]
Abstract
Podostemaceae is an interesting family of angiosperms with unusual development and morphology. Among these, double fertilization, a defining feature of angiosperms is invariably missing in the family. Consequently, embryo development in the seeds takes place without endosperm. In recent years, the role of polycomb genes has garnered much interest because of their crucial role in seed development. Some of these genes have been reported from many unrelated species, underlining their high conservation. Thus, it becomes exciting to know the role of these genes in podostemads, which are devoid of double fertilization and endosperm. Here, we report the isolation, characterization and expression patterns of homologs of Fertilization Independent Endosperm (FIE) in two species of Podostemaceae, Zeylanidium olivaceum and Polypleurum stylosum. FIE like homologs could be identified in Z. olivaceum (ZoFIE) and P. stylosum (PsFIE). The predicted amino acid sequence of FIE homologs showed similarity to other homologs, containing the conserved seven WD40 repeats. Expression studies revealed that ZoFIE and PsFIE transcripts were present in the vegetative tissue (thallus in Podostemaceae) and the seedlings, similar to the model plants. However, the ZoFIE and PsFIE expression disappeared in the flowering stages. This unique pattern of expression suggests that in the absence of double fertilization and endosperm the expression of FIS complex genes perhaps is obliterated in Podostemaceae.
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Affiliation(s)
| | - Roopam Sharma
- Department of Plant Sciences, University of Saskatchewan, Saskatoon, SK, S7N 5A8, Canada
| | - Vishnu Bhat
- Department of Botany, University of Delhi, Delhi, 110007, India
| | - Rajesh Tandon
- Department of Botany, University of Delhi, Delhi, 110007, India.
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24
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Förderer A, Zhou Y, Turck F. The age of multiplexity: recruitment and interactions of Polycomb complexes in plants. CURRENT OPINION IN PLANT BIOLOGY 2016; 29:169-78. [PMID: 26826786 DOI: 10.1016/j.pbi.2015.11.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 11/23/2015] [Accepted: 11/28/2015] [Indexed: 05/08/2023]
Abstract
Polycomb group (PcG) proteins form distinct complexes that modify chromatin by histone H3 methylation and H2A mono-ubiquitination leading to chromatin compaction and epigenetic repression of target genes. A network of PcG protein complexes, associated partners and antagonistically acting chromatin modifiers is essential to regulate developmental transitions and cell fate in all multicellular eukaryotes. In this review, we discuss insights on the subfunctionalization of PcG complexes and their modes of recruitment to target sites based on data from the model organism Arabidopsis thaliana.
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Affiliation(s)
- Alexander Förderer
- Max Planck Institute for Plant Breeding Research, Department Plant Developmental Biology, Carl von Linne Weg 10, 50829 Köln, Germany
| | - Yue Zhou
- Max Planck Institute for Plant Breeding Research, Department Plant Developmental Biology, Carl von Linne Weg 10, 50829 Köln, Germany
| | - Franziska Turck
- Max Planck Institute for Plant Breeding Research, Department Plant Developmental Biology, Carl von Linne Weg 10, 50829 Köln, Germany.
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25
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Motomura K, Berger F, Kawashima T, Kinoshita T, Higashiyama T, Maruyama D. Fertilization-independent Cell-fusion between the Synergid and Central Cell in the Polycomb Mutant. Cell Struct Funct 2016; 41:121-5. [DOI: 10.1247/csf.16010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Kazuki Motomura
- Institute of Transformative Bio-Molecules (ITbM), Nagoya University
| | - Frédéric Berger
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC)
| | - Tomokazu Kawashima
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC)
| | - Tetsu Kinoshita
- Kihara Institute for Biological Research, Yokohama City University
| | - Tetsuya Higashiyama
- Institute of Transformative Bio-Molecules (ITbM), Nagoya University
- Division of Biological Science, Graduate School of Science, Nagoya University
- JST ERATO Higashiyama Live-Holonics Project, Nagoya University
| | - Daisuke Maruyama
- Institute of Transformative Bio-Molecules (ITbM), Nagoya University
- Kihara Institute for Biological Research, Yokohama City University
- Institute for Advanced Research, Nagoya University
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26
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Orozco-Arroyo G, Paolo D, Ezquer I, Colombo L. Networks controlling seed size in Arabidopsis. PLANT REPRODUCTION 2015; 28:17-32. [PMID: 25656951 DOI: 10.1007/s00497-015-0255-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Accepted: 01/16/2015] [Indexed: 05/07/2023]
Abstract
Key message: Overview of seed size control. Human and livestock nutrition is largely based on calories derived from seeds, in particular cereals and legumes. Unveiling the control of seed size is therefore of remarkable importance in the frame of developing new strategies for crop improvement. The networks controlling the development of the seed coat, the endosperm and the embryo, as well as their interplay, have been described in Arabidopsis thaliana. In this review, we provide a comprehensive description of the current knowledge regarding the molecular mechanisms controlling seed size in Arabidopsis.
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Affiliation(s)
- Gregorio Orozco-Arroyo
- Dipartimento di BioScienze, Università degli Studi di Milano, Via Giovanni Celoria 26, 20133, Milan, Italy
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27
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Köhler C, Lafon-Placette C. Evolution and function of epigenetic processes in the endosperm. FRONTIERS IN PLANT SCIENCE 2015; 6:130. [PMID: 25806038 PMCID: PMC4353180 DOI: 10.3389/fpls.2015.00130] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 02/18/2015] [Indexed: 05/22/2023]
Abstract
The endosperm is an ephemeral tissue surrounding the embryo that is essential for its development. Aside from the embryo nourishing function, the endosperm serves as a battlefield for epigenetic processes that have been hypothesized to reinforce transposable element silencing in the embryo. Specifically, global DNA demethylation in the central cell may serve to produce small RNAs that migrate to egg cell and embryo to induce de novo DNA methylation. The Polycomb Repressive Complex 2 (PRC2) is particularly targeted to DNA hypomethylated regions, possibly alleviating the negative effects associated with loss of DNA methylation in the endosperm. The functional requirement of the PRC2 in the endosperm can be bypassed by increasing the maternal genome dosage in the endosperm, suggesting a main functional role of the endosperm PRC2 in reducing sexual conflict. We therefore propose that the functional requirement of an endosperm PRC2 was coupled to the evolution of a sexual endosperm and mechanisms enforcing transposon silencing in the embryo. The evolutionary consequences of this scenario for genome expansion will be discussed.
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Affiliation(s)
- Claudia Köhler
- *Correspondence: Claudia Köhler, Department of Plant Biology, Uppsala BioCenter, Linnean Center of Plant Biology, Swedish University of Agricultural Sciences, P.O. Box 7080, Almas Allé 5, SE-75007 Uppsala, Sweden e-mail:
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28
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Sehgal A, Mann N, Mohan Ram HY. Structural and developmental variability in the female gametophyte of Griffithella hookeriana, Polypleurum stylosum, and Zeylanidium lichenoides and its bearing on the occurrence of single fertilization in Podostemaceae. PLANT REPRODUCTION 2014; 27:205-23. [PMID: 25394544 DOI: 10.1007/s00497-014-0252-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 10/30/2014] [Indexed: 05/20/2023]
Abstract
Angiosperms are characterized by the phenomenon of double fertilization with Podostemaceae as an exception that appears to extend to the entire family. Our earlier work demonstrated the cause of failure of double fertilization and ascertained the occurrence of single fertilization in Dalzellia zeylanica (Tristichoideae, Podostemaceae). In continuation with this work, three more members, i.e., Griffithella hookeriana (Tul.) Warming, Polypleurum stylosum (Wight) Hall, and Zeylanidium lichenoides (Kurz) Engl. (Podostemoideae), have been investigated in the present work. We studied the ontogenetic development of female gametophyte and tracked the path of the two sperm cells from the time of their formation in the pollen tube through their entry into the synergid and gamete fusion. We report the occurrence of a remarkably reduced 3-nucleate, 3-celled mature female gametophyte consisting of an egg cell and two synergids in all the three genera. Interestingly, the central cell is formed during female gametophyte development, but exhibits a species-specific, limited life span, and eventually degenerates prior to the entry of the pollen tube into the synergid, resulting in a failure of double fertilization. Sperm dimorphism on the basis of fluorochrome stainability has been recorded in Z. lichenoides. Further, morphogenetic constraints on the part of male (sperm selection, functional reductionism) and female gametophyte (structural reductionism, inaccessibility of central cell) presumably ensure the failure of double fertilization in these species. Thus, loss of double fertilization in this family is likely a derived condition.
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Affiliation(s)
- Anita Sehgal
- Department of Botany, Miranda House, University of Delhi, Delhi, 110007, India,
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29
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Abstract
Cellular context can be crucial when studying developmental processes as well as responses to environmental variation. Several different tools have been developed in recent years to isolate specific tissues or cell types. Laser-assisted microdissection (LAM) allows for the isolation of such specific tissue or single cell-types purely based on morphology and cytology. This has the advantage that (1) cell types that are rare can be isolated from heterogeneous tissue, (2) no marker line with cell type-specific expression needs to be established, and (3) the method can be applied to non-model species and species that are difficult to genetically transform. The rapid development of next-generation sequencing (NGS) approaches has greatly advanced the possibilities to perform molecular analyses in diverse organisms. However, there is a mismatch between currently available cell isolation tools and their applicability to non-model organisms. Therefore, LAM will become increasingly popular in the study of diverse agriculturally or ecologically relevant plant species. Here, we describe a protocol that has been successfully used for LAM to isolate either whole floral organs or even single cell types in plants, e.g., Arabidopsis thaliana, Boechera spp., or tomato.
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Affiliation(s)
- Samuel E Wuest
- Institute of Plant Biology and Zürich-Basel Plant Science Center, University of Zürich, Zürich, Switzerland
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30
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An imprinted gene underlies postzygotic reproductive isolation in Arabidopsis thaliana. Dev Cell 2013; 26:525-35. [PMID: 24012484 DOI: 10.1016/j.devcel.2013.08.006] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 06/18/2013] [Accepted: 08/10/2013] [Indexed: 12/18/2022]
Abstract
Postzygotic reproductive isolation in response to interploidy hybridizations is a well-known phenomenon in plants that forms a major path for sympatric speciation. A main determinant for the failure of interploidy hybridizations is the endosperm, a nutritious tissue supporting embryo growth, similar to the functional role of the placenta in mammals. Although it has been suggested that deregulated imprinted genes underpin dosage sensitivity of the endosperm, the molecular basis for this phenomenon remained unknown. In a genetic screen for suppressors of triploid seed abortion, we have identified the paternally expressed imprinted gene ADMETOS (ADM). Here, we present evidence that increased dosage of ADM causes triploid seed arrest. A large body of theoretical work predicted that deregulated imprinted genes establish the barrier to interploidy hybridization. Our study thus provides evidence strongly supporting this hypothesis and generates the molecular basis for our understanding of postzygotic hybridization barriers in plants.
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31
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Wang L, Ruan YL. Regulation of cell division and expansion by sugar and auxin signaling. FRONTIERS IN PLANT SCIENCE 2013; 4:163. [PMID: 23755057 PMCID: PMC3667240 DOI: 10.3389/fpls.2013.00163] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 05/10/2013] [Indexed: 05/18/2023]
Abstract
Plant growth and development are modulated by concerted actions of a variety of signaling molecules. In recent years, evidence has emerged on the roles of sugar and auxin signals network in diverse aspects of plant growth and development. Here, based on recent progress of genetic analyses and gene expression profiling studies, we summarize the functional similarities, diversities, and their interactions of sugar and auxin signals in regulating two major processes of plant development: cell division and cell expansion. We focus on roles of sugar and auxin signaling in both vegetative and reproductive tissues including developing seed.
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Affiliation(s)
- Lu Wang
- Department of Biology, School of Environmental and Life Sciences, The University of NewcastleCallaghan, NSW, Australia
- Australia-China Research Centre for Crop Improvement, The University of NewcastleCallaghan, NSW, Australia
| | - Yong-Ling Ruan
- Department of Biology, School of Environmental and Life Sciences, The University of NewcastleCallaghan, NSW, Australia
- Australia-China Research Centre for Crop Improvement, The University of NewcastleCallaghan, NSW, Australia
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32
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Independent Control by Each Female Gamete Prevents the Attraction of Multiple Pollen Tubes. Dev Cell 2013; 25:317-23. [DOI: 10.1016/j.devcel.2013.03.013] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2012] [Revised: 01/24/2013] [Accepted: 03/18/2013] [Indexed: 11/18/2022]
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33
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Nallamilli BRR, Zhang J, Mujahid H, Malone BM, Bridges SM, Peng Z. Polycomb group gene OsFIE2 regulates rice (Oryza sativa) seed development and grain filling via a mechanism distinct from Arabidopsis. PLoS Genet 2013; 9:e1003322. [PMID: 23505380 PMCID: PMC3591265 DOI: 10.1371/journal.pgen.1003322] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2012] [Accepted: 12/29/2012] [Indexed: 11/19/2022] Open
Abstract
Cereal endosperm represents 60% of the calories consumed by human beings worldwide. In addition, cereals also serve as the primary feedstock for livestock. However, the regulatory mechanism of cereal endosperm and seed development is largely unknown. Polycomb complex has been shown to play a key role in the regulation of endosperm development in Arabidopsis, but its role in cereal endosperm development remains obscure. Additionally, the enzyme activities of the polycomb complexes have not been demonstrated in plants. Here we purified the rice OsFIE2-polycomb complex using tandem affinity purification and demonstrated its specific H3 methyltransferase activity. We found that the OsFIE2 gene product was responsible for H3K27me3 production specifically in vivo. Genetic studies showed that a reduction of OsFIE2 expression led to smaller seeds, partially filled seeds, and partial loss of seed dormancy. Gene expression and proteomics analyses found that the starch synthesis rate limiting step enzyme and multiple storage proteins are down-regulated in OsFIE2 reduction lines. Genome wide ChIP–Seq data analysis shows that H3K27me3 is associated with many genes in the young seeds. The H3K27me3 modification and gene expression in a key helix-loop-helix transcription factor is shown to be regulated by OsFIE2. Our results suggest that OsFIE2-polycomb complex positively regulates rice endosperm development and grain filling via a mechanism highly different from that in Arabidopsis. Rice is the staple food for over half of the world's population and an important feedstock for livestock. The rice grain is mainly endosperm tissue. The regulatory mechanism of rice endosperm development is still largely unknown thus far. Understanding the underlying mechanism will lead to crop yield and quality improvement in the long term, besides gaining new knowledge. Polycomb complex is a protein complex with a potential role in endosperm development according to prior publications. In this manuscript, we purified the rice OsFIE2-polycomb protein complex and demonstrated the enzyme activity of the complex. Genetic studies showed that a reduction of polycomb group gene OsFIE2 expression led to smaller seeds, partially filled seeds, and seed germination before seed maturation. Gene expression and proteomics analyses found that the starch synthesis rate limiting step enzyme and multiple storage proteins are down-regulated while a key transcription factor is up-regulated in OsFIE2 reduction lines. In addition, we identified many loci in the rice genome whose histone proteins are modified by the polycomb complex enzyme via a method called ChIP–Seq. Our results demonstrate that OsFIE2-polycomb complex positively regulates rice grain development via a mechanism distinct from that in Arabidopsis and provide new insight into the regulation of rice grain development.
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Affiliation(s)
- Babi Ramesh Reddy Nallamilli
- Department of Biochemistry and Molecular Biology, Mississippi State University, Mississippi State, Mississippi, United States of America
| | - Jian Zhang
- Department of Biochemistry and Molecular Biology, Mississippi State University, Mississippi State, Mississippi, United States of America
| | - Hana Mujahid
- Department of Biochemistry and Molecular Biology, Mississippi State University, Mississippi State, Mississippi, United States of America
| | - Brandon M. Malone
- Department of Computer Science and Engineering, Mississippi State University, Mississippi State, Mississippi, United States of America
- Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, Mississippi, United States of America
| | - Susan M. Bridges
- Department of Computer Science and Engineering, Mississippi State University, Mississippi State, Mississippi, United States of America
- Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, Mississippi, United States of America
| | - Zhaohua Peng
- Department of Biochemistry and Molecular Biology, Mississippi State University, Mississippi State, Mississippi, United States of America
- * E-mail:
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34
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Wang L, Liao S, Ruan YL. Cell wall invertase as a regulator in determining sequential development of endosperm and embryo through glucose signaling early in seed development. PLANT SIGNALING & BEHAVIOR 2013; 8:e22722. [PMID: 23221750 PMCID: PMC3745577 DOI: 10.4161/psb.22722] [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: 10/30/2012] [Accepted: 10/30/2012] [Indexed: 05/24/2023]
Abstract
Seed development depends on coordination among embryo, endosperm and seed coat. Endosperm undergoes nuclear division soon after fertilization, whereas embryo remains quiescent for a while. Such a developmental sequence is of great importance for proper seed development. However, the underlying mechanism remains unclear. Recent results on the cellular domain- and stage-specific expression of invertase genes in cotton and Arabidopsis revealed that cell wall invertase may positively and specifically regulate nuclear division of endosperm after fertilization, thereby playing a role in determining the sequential development of endosperm and embryo, probably through glucose signaling.
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Affiliation(s)
- Lu Wang
- School of Environmental and Life Sciences; The University of Newcastle; Callaghan, NSW Australia
- Australia-China Research Centre for Crop Improvement; The University of Newcastle; Callaghan, NSW Australia
| | - Shengjin Liao
- School of Environmental and Life Sciences; The University of Newcastle; Callaghan, NSW Australia
| | - Yong-Ling Ruan
- School of Environmental and Life Sciences; The University of Newcastle; Callaghan, NSW Australia
- Australia-China Research Centre for Crop Improvement; The University of Newcastle; Callaghan, NSW Australia
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35
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Zhao X, Harashima H, Dissmeyer N, Pusch S, Weimer AK, Bramsiepe J, Bouyer D, Rademacher S, Nowack MK, Novak B, Sprunck S, Schnittger A. A general G1/S-phase cell-cycle control module in the flowering plant Arabidopsis thaliana. PLoS Genet 2012; 8:e1002847. [PMID: 22879821 PMCID: PMC3410867 DOI: 10.1371/journal.pgen.1002847] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Accepted: 06/05/2012] [Indexed: 01/12/2023] Open
Abstract
The decision to replicate its DNA is of crucial importance for every cell and, in many organisms, is decisive for the progression through the entire cell cycle. A comparison of animals versus yeast has shown that, although most of the involved cell-cycle regulators are divergent in both clades, they fulfill a similar role and the overall network topology of G1/S regulation is highly conserved. Using germline development as a model system, we identified a regulatory cascade controlling entry into S phase in the flowering plant Arabidopsis thaliana, which, as a member of the Plantae supergroup, is phylogenetically only distantly related to Opisthokonts such as yeast and animals. This module comprises the Arabidopsis homologs of the animal transcription factor E2F, the plant homolog of the animal transcriptional repressor Retinoblastoma (Rb)-related 1 (RBR1), the plant-specific F-box protein F-BOX-LIKE 17 (FBL17), the plant specific cyclin-dependent kinase (CDK) inhibitors KRPs, as well as CDKA;1, the plant homolog of the yeast and animal Cdc2⁺/Cdk1 kinases. Our data show that the principle of a double negative wiring of Rb proteins is highly conserved, likely representing a universal mechanism in eukaryotic cell-cycle control. However, this negative feedback of Rb proteins is differently implemented in plants as it is brought about through a quadruple negative regulation centered around the F-box protein FBL17 that mediates the degradation of CDK inhibitors but is itself directly repressed by Rb. Biomathematical simulations and subsequent experimental confirmation of computational predictions revealed that this regulatory circuit can give rise to hysteresis highlighting the here identified dosage sensitivity of CDK inhibitors in this network.
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Affiliation(s)
- Xin'Ai Zhao
- Department of Molecular Mechanisms of Phenotypic Plasticity, Institut de Biologie Mole´culaire des Plantes, Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
| | - Hirofumi Harashima
- Department of Molecular Mechanisms of Phenotypic Plasticity, Institut de Biologie Mole´culaire des Plantes, Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
- Trinationales Institut für Pflanzenforschung, Strasbourg, France
| | - Nico Dissmeyer
- Department of Molecular Mechanisms of Phenotypic Plasticity, Institut de Biologie Mole´culaire des Plantes, Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
| | - Stefan Pusch
- Unigruppe am Max-Planck-Institut für Pflanzenzü chtungsforschung, Lehrstuhl für Botanik III, Universität zu Köln, Köln, Germany
| | - Annika K. Weimer
- Department of Molecular Mechanisms of Phenotypic Plasticity, Institut de Biologie Mole´culaire des Plantes, Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
| | - Jonathan Bramsiepe
- Department of Molecular Mechanisms of Phenotypic Plasticity, Institut de Biologie Mole´culaire des Plantes, Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
| | - Daniel Bouyer
- Department of Molecular Mechanisms of Phenotypic Plasticity, Institut de Biologie Mole´culaire des Plantes, Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
| | - Svenja Rademacher
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Moritz K. Nowack
- Department of Plant Systems Biology, VIB, Gent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Gent, Belgium
| | - Bela Novak
- Oxford Centre for Integrative Systems Biology, Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Arp Schnittger
- Department of Molecular Mechanisms of Phenotypic Plasticity, Institut de Biologie Mole´culaire des Plantes, Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
- Trinationales Institut für Pflanzenforschung, Strasbourg, France
- Unigruppe am Max-Planck-Institut für Pflanzenzü chtungsforschung, Lehrstuhl für Botanik III, Universität zu Köln, Köln, Germany
- * E-mail:
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36
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Collins C, Dewitte W, Murray JAH. D-type cyclins control cell division and developmental rate during Arabidopsis seed development. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:3571-86. [PMID: 22412186 PMCID: PMC3388828 DOI: 10.1093/jxb/ers015] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 12/13/2011] [Accepted: 01/10/2012] [Indexed: 05/20/2023]
Abstract
Seed development in Arabidopsis is characterized by stereotypical division patterns, suggesting that coordinated control of cell cycle may be required for correct patterning and growth of the embryo and endosperm. D-type cyclins (CYCD) are key cell cycle regulators with roles in developmental processes, but knowledge regarding their involvement in seed development remains limited. Here, a family-wide gene expression, and loss- and gain-of-function approach was adopted to reveal additional functions for CYCDs in the development of seed tissues. CYCD genes have both discrete and overlapping tissue-specific expression patterns in the seed as revealed by GUS reporter gene expression. Analysis of different mutant combinations revealed that correct CYCD levels are required in seed development. The CYCD3 subgroup is specifically required as its loss caused delayed development, whereas overexpression in the embryo and endosperm of CYCD3;1 or a previously uncharacterized gene, CYCD7;1, variously leads to induced proliferation, abnormal phenotypes, and elevated seed abortion. CYCD3;1 overexpression provoked a delay in embryonic developmental progression and abnormalities including additional divisions of the hypophysis and suspensor, regions where CYCD3 genes are normally expressed, but did not affect endosperm development. Overexpression of CYCD7;1, not normally expressed in seed development, promoted overgrowth of both embryo and endosperm through increased division and cell enlargement. In contrast to post-germination growth, where pattern and organ size is not generally related to division, results suggest that a close control of cell division through regulation of CYCD activity is important during seed development in conferring both developmental rate and correct patterning.
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Affiliation(s)
- Carl Collins
- Institute of Biotechnology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QT, UK
- Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK
- To whom correspondence should be addressed. E-mail: or
| | - Walter Dewitte
- Institute of Biotechnology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QT, UK
- Cardiff School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, UK
| | - James A. H. Murray
- Institute of Biotechnology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QT, UK
- Cardiff School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, UK
- To whom correspondence should be addressed. E-mail: or
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Nowack M, Harashima H, Dissmeyer N, Zhao X, Bouyer D, Weimer A, De Winter F, Yang F, Schnittger A. Genetic Framework of Cyclin-Dependent Kinase Function in Arabidopsis. Dev Cell 2012; 22:1030-40. [DOI: 10.1016/j.devcel.2012.02.015] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Revised: 12/15/2011] [Accepted: 02/29/2012] [Indexed: 10/28/2022]
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Mizzotti C, Mendes MA, Caporali E, Schnittger A, Kater MM, Battaglia R, Colombo L. The MADS box genes SEEDSTICK and ARABIDOPSIS Bsister play a maternal role in fertilization and seed development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 70:409-20. [PMID: 22176531 DOI: 10.1111/j.1365-313x.2011.04878.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The haploid generation of flowering plants develops within the sporophytic tissues of the ovule. After fertilization, the maternal seed coat develops in a coordinated manner with formation of the embryo and endosperm. In the arabidopsis bsister (abs) mutant, the endothelium, which is the most inner cell layer of the integuments that surround the haploid embryo sac, does not accumulate proanthocyanidins and the cells have an abnormal morphology. However, fertility is not affected in abs single mutants. SEEDSTICK regulates ovule identity redundantly with SHATTERPROOF 1 (SHP1) and SHP2 while a role in the control of fertility was not reported previously. Here we describe the characterization of the abs stk double mutant. This double mutant develops very few seeds due to both a reduced number of fertilized ovules and seed abortions later during development. Morphological analysis revealed a total absence of endothelium in this double mutant. Additionally, massive starch accumulation was observed in the embryo sac. The phenotype of the abs stk double mutant highlights the importance of the maternal-derived tissues, particularly the endothelium, for the development of the next generation.
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Affiliation(s)
- Chiara Mizzotti
- Dipartimento di Biologia, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
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39
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Köhler C, Kradolfer D. Epigenetic mechanisms in the endosperm and their consequences for the evolution of flowering plants. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2011; 1809:438-43. [PMID: 21549229 DOI: 10.1016/j.bbagrm.2011.04.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 04/13/2011] [Accepted: 04/15/2011] [Indexed: 01/03/2023]
Abstract
The sudden rise of angiosperms to ecological dominance was an "abominable mystery" to Charles Darwin, and understanding the underlying evolutionary driving force has remained a scientific challenge since then. The recognition of polyploidization as an important factor for plant speciation is likely to hold a key to this mystery and we will discuss possible mechanisms underlying this phenomenon. Polyploidization raises an immediate reproductive barrier in the endosperm, pointing towards an important but greatly underestimated role of the endosperm in preventing interploidy hybridizations. Parent-of-origin-specific gene expression is largely restricted to the endosperm, providing an explanation for the dosage sensitivity of the endosperm. Here, we review epigenetic mechanisms causing endosperm dosage sensitivity, their possible consequences for raising interploidy and interspecies hybridization barriers and their impact on flowering plant evolution. This article is part of a Special Issue entitled: Epigenetic Control.
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Affiliation(s)
- Claudia Köhler
- Department of Biology, Swiss Federal Institute of Technology, Zurich, Switzerland.
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40
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Bauer MJ, Fischer RL. Genome demethylation and imprinting in the endosperm. CURRENT OPINION IN PLANT BIOLOGY 2011; 14:162-7. [PMID: 21435940 PMCID: PMC3082360 DOI: 10.1016/j.pbi.2011.02.006] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Revised: 01/07/2011] [Accepted: 02/21/2011] [Indexed: 05/19/2023]
Abstract
Imprinting occurs in the endosperm of flowering plants. The endosperm, a product of central cell fertilization, is critical for embryo and seed development. Imprinting in the endosperm is mainly due to the inherited differences in gamete epigenetic composition. Studies have also shown that there are differences in genomic DNA methylation patterns between embryo and endosperm. Examining those differences, along with mutations in the DNA demethylase gene DEMETER, gives insight into the number of imprinted genes and how an antagonistic relationship between TE defense and gene regulation could evolutionarily affect imprinting establishment. Finally, studies demonstrate that DEMETER demethylase activity influences endosperm chromatin composition, and could possibly enhance DNA de novo methylation activity.
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Affiliation(s)
| | - Robert L. Fischer
- Corresponding author: , Telephone: +1-510-642-1314, Fax: +1-510-642-4995
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41
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Bouyer D, Roudier F, Heese M, Andersen ED, Gey D, Nowack MK, Goodrich J, Renou JP, Grini PE, Colot V, Schnittger A. Polycomb repressive complex 2 controls the embryo-to-seedling phase transition. PLoS Genet 2011; 7:e1002014. [PMID: 21423668 PMCID: PMC3053347 DOI: 10.1371/journal.pgen.1002014] [Citation(s) in RCA: 268] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 01/11/2011] [Indexed: 11/18/2022] Open
Abstract
Polycomb repressive complex 2 (PRC2) is a key regulator of epigenetic states catalyzing histone H3 lysine 27 trimethylation (H3K27me3), a repressive chromatin mark. PRC2 composition is conserved from humans to plants, but the function of PRC2 during the early stage of plant life is unclear beyond the fact that it is required for the development of endosperm, a nutritive tissue that supports embryo growth. Circumventing the requirement of PRC2 in endosperm allowed us to generate viable homozygous null mutants for FERTILIZATION INDEPENDENT ENDOSPERM (FIE), which is the single Arabidopsis homolog of Extra Sex Combs, an indispensable component of Drosophila and mammalian PRC2. Here we show that H3K27me3 deposition is abolished genome-wide in fie mutants demonstrating the essential function of PRC2 in placing this mark in plants as in animals. In contrast to animals, we find that PRC2 function is not required for initial body plan formation in Arabidopsis. Rather, our results show that fie mutant seeds exhibit enhanced dormancy and germination defects, indicating a deficiency in terminating the embryonic phase. After germination, fie mutant seedlings switch to generative development that is not sustained, giving rise to neoplastic, callus-like structures. Further genome-wide studies showed that only a fraction of PRC2 targets are transcriptionally activated in fie seedlings and that this activation is accompanied in only a few cases with deposition of H3K4me3, a mark associated with gene activity and considered to act antagonistically to H3K27me3. Up-regulated PRC2 target genes were found to act at different hierarchical levels from transcriptional master regulators to a wide range of downstream targets. Collectively, our findings demonstrate that PRC2-mediated regulation represents a robust system controlling developmental phase transitions, not only from vegetative phase to flowering but also especially from embryonic phase to the seedling stage.
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Affiliation(s)
- Daniel Bouyer
- Department of Molecular Mechanisms of Phenotypic Plasticity, Institut de Biologie Moléculaire des Plantes du CNRS, Université de Strasbourg, Strasbourg, France
| | - Francois Roudier
- Institut de Biologie de l'Ecole Normale Supérieure, CNRS UMR 8197–INSERM U 1024, Paris, France
| | - Maren Heese
- Department of Molecular Mechanisms of Phenotypic Plasticity, Institut de Biologie Moléculaire des Plantes du CNRS, Université de Strasbourg, Strasbourg, France
| | - Ellen D. Andersen
- Department of Molecular Biosciences, University of Oslo, Oslo, Norway
| | - Delphine Gey
- Department of Plant Genomics Research, CNRS/INRA, Evry, France
| | - Moritz K. Nowack
- Department of Plant Systems Biology, VIB, Gent, Belgium
- Department of Plant Biotechnology and Genetics, Ghent University, Gent, Belgium
| | - Justin Goodrich
- Institute of Molecular Plant Science, University of Edinburgh, Edinburgh, United Kingdom
| | | | - Paul E. Grini
- Department of Molecular Biosciences, University of Oslo, Oslo, Norway
| | - Vincent Colot
- Institut de Biologie de l'Ecole Normale Supérieure, CNRS UMR 8197–INSERM U 1024, Paris, France
| | - Arp Schnittger
- Department of Molecular Mechanisms of Phenotypic Plasticity, Institut de Biologie Moléculaire des Plantes du CNRS, Université de Strasbourg, Strasbourg, France
- * E-mail:
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42
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A plant-specific transcription factor IIB-related protein, pBRP2, is involved in endosperm growth control. PLoS One 2011; 6:e17216. [PMID: 21390310 PMCID: PMC3044737 DOI: 10.1371/journal.pone.0017216] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Accepted: 01/26/2011] [Indexed: 11/19/2022] Open
Abstract
General transcription factor IIB (TFIIB) and TFIIB-related factor (BRF), are conserved RNA polymerase II/III (RNAPII/III) selectivity factors that are involved in polymerase recruitment and transcription initiation in eukaryotes. Recent findings have shown that plants have evolved a third type of B-factor, plant-specific TFIIB-related protein 1 (pBRP1), which seems to be involved in RNAPI transcription. Here, we extend the repertoire of B-factors in plants by reporting the characterization of a novel TFIIB-related protein, plant-specific TFIIB-related protein 2 (pBRP2), which is found to date only in the Brassicacea family. Unlike other B-factors that are ubiquitously expressed, PBRP2 expression is restricted to reproductive organs and seeds as shown by RT-PCR, immunofluorescence labelling and GUS staining experiments. Interestingly, pbrp2 loss-of-function specifically affects the development of the syncytial endosperm, with both parental contributions required for wild-type development. pBRP2, is the first B-factor to exhibit cell-specific expression and regulation in eukaryotes, and might play a role in enforcing bi-parental reproduction in angiosperms.
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43
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Genome-wide transcript profiling of endosperm without paternal contribution identifies parent-of-origin-dependent regulation of AGAMOUS-LIKE36. PLoS Genet 2011; 7:e1001303. [PMID: 21379330 PMCID: PMC3040660 DOI: 10.1371/journal.pgen.1001303] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Accepted: 01/11/2011] [Indexed: 11/26/2022] Open
Abstract
Seed development in angiosperms is dependent on the interplay among different transcriptional programs operating in the embryo, the endosperm, and the maternally-derived seed coat. In angiosperms, the embryo and the endosperm are products of double fertilization during which the two pollen sperm cells fuse with the egg cell and the central cell of the female gametophyte. In Arabidopsis, analyses of mutants in the cell-cycle regulator CYCLIN DEPENDENT KINASE A;1 (CKDA;1) have revealed the importance of a paternal genome for the effective development of the endosperm and ultimately the seed. Here we have exploited cdka;1 fertilization as a novel tool for the identification of seed regulators and factors involved in parent-of-origin–specific regulation during seed development. We have generated genome-wide transcription profiles of cdka;1 fertilized seeds and identified approximately 600 genes that are downregulated in the absence of a paternal genome. Among those, AGAMOUS-LIKE (AGL) genes encoding Type-I MADS-box transcription factors were significantly overrepresented. Here, AGL36 was chosen for an in-depth study and shown to be imprinted. We demonstrate that AGL36 parent-of-origin–dependent expression is controlled by the activity of METHYLTRANSFERASE1 (MET1) maintenance DNA methyltransferase and DEMETER (DME) DNA glycosylase. Interestingly, our data also show that the active maternal allele of AGL36 is regulated throughout endosperm development by components of the FIS Polycomb Repressive Complex 2 (PRC2), revealing a new type of dual epigenetic regulation in seeds. Seeds of flowering plants consist of three different organisms that develop in parallel. In contrast to animals, a double fertilization event takes place in plants, producing two fertilization products, the embryo and the endosperm. Imprinting, the parent-of-origin–specific expression of genes, typically takes place in the mammalian placenta and in the plant endosperm. A prevailing hypothesis predicts that a parental tug-of-war on the allocation of available recourses to the developing progeny has led to the evolution of imprinting systems where genes expressed from the mother dampen growth whereas genes expressed from the father are growth enhancers. The number of imprinted genes identified in plants is low compared to mammals, and this precludes the elucidation of the epigenetic mechanisms responsible for this specialized expression system. Here, we have used genome-wide transcript profiling of endosperm without paternal contribution to identify seed regulators and, among these, imprinted genes. We identified a cluster of downregulated MADS-box transcription factors, including AGL36, that was subsequently shown to be imprinted by an epigenetic mechanism involving the DNA methylase MET1 and the glycosylase DME. In addition, the expression of the active AGL36 allele was dampened by the FIS Polycomb Repressive Complex, identifying a novel mode of regulation of imprinted genes.
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44
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Liu Y, Yan Z, Chen N, Di X, Huang J, Guo G. Development and function of central cell in angiosperm female gametophyte. Genesis 2011; 48:466-78. [PMID: 20506265 DOI: 10.1002/dvg.20647] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The central cell characterizes the angiosperm female gametophyte (embryo sac or megagametophyte) in that it directly participates in "double fertilization" to initiate endosperm development, a feature distinguishing angiosperm from all other plant taxa. Polygonum-type central cell is a binucleate cell that, upon fertilization with one of the two sperm cells, forms triploid endosperm to nourish embryo development. Although the formation and the structure of central cell have well been elucidated, the molecular mechanisms for its specification and development remain largely unknown. The central cell plays a critical role in pollen tube guidance during pollination and in endosperm initiation after fertilization. Recently, a group of mutants affecting specific steps of central cell development and function have been identified, providing some clues in understanding these questions. This review summarizes our current knowledge about central cell development and function, and presents overview about hypotheses for its evolution.
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Affiliation(s)
- Yan Liu
- Institute of Cell Biology, School of Life Sciences, Lanzhou University, Lanzhou, People's Republic of China
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45
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de Jong TJ, Hermans CM, van der Veen-van Wijk KCAM. Paternal effects on seed mass in Arabidopsis thaliana. PLANT BIOLOGY (STUTTGART, GERMANY) 2011; 13 Suppl 1:71-7. [PMID: 21134089 DOI: 10.1111/j.1438-8677.2009.00287.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Who is in control of seed size, and do some fathers sire bigger seeds than others? We used isogenic male-sterile genotypes of the Arabidopsis thaliana accessions Col and Ler. By fertilising flowers side-by-side with either pollen from the same accession ('self-pollination') or pollen from another accession (outcrossing), we compared, on the same mother plant, seed set of flowers that were very similar in resource status. Some paternal genotypes had a significant effect on seed mass, with the most extreme father siring seeds 15.3% heavier than seeds resulting from 'self-pollination'. There was no correlation between seed mass of paternal parents and the seeds they sired. We discuss the evolution of seed size as a tug-of-war between parent and offspring.
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Affiliation(s)
- T J de Jong
- Ecology and Phytochemistry, Institute of Biology, Leiden University, Leiden, the Netherlands.
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46
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The gametic central cell of Arabidopsis determines the lifespan of adjacent accessory cells. Proc Natl Acad Sci U S A 2010; 107:22350-5. [PMID: 21135240 DOI: 10.1073/pnas.1012795108] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Plant germ cells develop in specialized haploid structures, termed gametophytes. The female gametophyte patterns of flowering plants are diverse, with often unknown adaptive value. Here we present the Arabidopsis fiona mutant, which forms a female gametophyte that is structurally and functionally reminiscent of a phylogenetic distant female gametophyte. The respective changes include a modified reproductive behavior of one of the female germ cells (central cell) and an extended lifespan of three adjacent accessory cells (antipodals). FIONA encodes the cysteinyl t-RNA synthetase SYCO ARATH (SYCO), which is expressed and required in the central cell but not in the antipodals, suggesting that antipodal lifespan is controlled by the adjacent gamete. SYCO localizes to the mitochondria, and ultrastructural analysis of mutant central cells revealed that the protein is necessary for mitochondrial cristae integrity. Furthermore, a dominant ATP/ADP translocator caused mitochondrial cristae degeneration and extended antipodal lifespan when expressed in the central cell of wild-type plants. Notably, this construct did not affect antipodal lifespan when expressed in antipodals. Our results thus identify an unexpected noncell autonomous role for mitochondria in the regulation of cellular lifespan and provide a basis for the coordinated development of gametic and nongametic cells.
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47
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Abstract
Epigenetic research is at the forefront of plant biology and molecular genetics. Studies on higher plants underscore the significant role played by epigenetics in both plant development and stress response. Relatively recent advances in analytical methodology have allowed for a significant expansion of what is known about genome-wide mapping of DNA methylation and histone modifications. In this review, we explore the different modification patterns in plant epigenetics, and the key factors involved in the epigenetic process, in order to illustrate various putative mechanisms. Experimental technology to exploit these modifications, and proposed focus areas for future plant epigenetic research, are also presented.
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Affiliation(s)
- Ming Chen
- Department of Bioinformatics, College of Life Sciences, Zhejiang University, Hangzhou, China.
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48
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Henriques R, Magyar Z, Monardes A, Khan S, Zalejski C, Orellana J, Szabados L, de la Torre C, Koncz C, Bögre L. Arabidopsis S6 kinase mutants display chromosome instability and altered RBR1-E2F pathway activity. EMBO J 2010; 29:2979-93. [PMID: 20683442 DOI: 10.1038/emboj.2010.164] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Accepted: 06/29/2010] [Indexed: 12/27/2022] Open
Abstract
The 40S ribosomal protein S6 kinase (S6K) is a conserved component of signalling pathways controlling growth in eukaryotes. To study S6K function in plants, we isolated single- and double-knockout mutations and RNA-interference (RNAi)-silencing lines in the linked Arabidopsis S6K1 and S6K2 genes. Hemizygous s6k1s6k2/++ mutant and S6K1 RNAi lines show high phenotypic instability with variation in size, increased trichome branching, produce non-viable pollen and high levels of aborted seeds. Analysis of their DNA content by flow cytometry, as well as chromosome counting using DAPI staining and fluorescence in situ hybridization, revealed an increase in ploidy and aneuploidy. In agreement with this data, we found that S6K1 associates with the Retinoblastoma-related 1 (RBR1)-E2FB complex and this is partly mediated by its N-terminal LVxCxE motif. Moreover, the S6K1-RBR1 association regulates RBR1 nuclear localization, as well as E2F-dependent expression of cell cycle genes. Arabidopsis cells grown under nutrient-limiting conditions require S6K for repression of cell proliferation. The data suggest a new function for plant S6K as a repressor of cell proliferation and required for maintenance of chromosome stability and ploidy levels.
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Affiliation(s)
- Rossana Henriques
- Royal Holloway, University of London, School of Biological Sciences, Egham Hill, Egham, UK.
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49
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Zhang HY, Xu PZ, Yang H, Wu XJ. [Imprinting genes and it's expression in Arabidopsis]. YI CHUAN = HEREDITAS 2010; 32:670-6. [PMID: 20650847 DOI: 10.3724/sp.j.1005.2010.00670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Genomic imprinting refers to the phenomenon that the expression of a gene copy depends on its parent of origin. The Arabidopsis imprinted FIS (Fertilisation-independent seed) genes, mea, fis2, and fie, play essential roles in the repression of central cell and the regulation of early endosperm development. fis mutants display two phenotypes: autonomous diploid endosperm development when fertilization is absent and un-cellularised endosperm formation when fertilization occurs. The FIS Polycomb protein complex including the above three FIS proteins catalyzes histone H3 K27 tri-methylation on target loci. DME (DEMETER), a DNA glycosylase, and AtMET1 (Methyltransferase1), a DNA methyltransferase, are involved in the regulation of imprinted expression of both mea and fis2. This review summarizes the studies on the Arabidopsis imprinted FIS genes and other related genes. Recent works have shown that the insertion of transposons may affect nearby gene expression, which may be the main driving force behind the evolution of genomic imprinting. This summary covers the achievements on Arabidopsis imprinted genes will provide important information for studies on genomic imprinting in the important crops such as rice and maize.
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Affiliation(s)
- Hong-Yu Zhang
- Rice Research Institute of Sichuan Agricultural University, Wenjiang 611130, China.
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50
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Aw SJ, Hamamura Y, Chen Z, Schnittger A, Berger F. Sperm entry is sufficient to trigger division of the central cell but the paternal genome is required for endosperm development in Arabidopsis. Development 2010; 137:2683-90. [PMID: 20610483 DOI: 10.1242/dev.052928] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Fertilization in flowering plants involves two sperm cells and two female gametes, the egg cell and the central cell, progenitors of the embryo and the endosperm, respectively. The mechanisms triggering zygotic development are unknown and whether both parental genomes are required for zygotic development is unclear. In Arabidopsis, previous studies reported that loss-of-function mutations in CYCLIN DEPENDENT KINASE A1 (CDKA;1) impedes cell cycle progression in the pollen leading to the production of a single sperm cell. Here, we report that a significant proportion of single cdka;1 pollen delivers two sperm cells, leading to a new assessment of the cdka;1 phenotype. We performed fertilization of wild-type ovules with cdka;1 mutant sperm cells and monitored in vivo the fusion of the male and female nuclei using fluorescent markers. When a single cdka;1 sperm was delivered, either female gamete could be fertilized leading to similar proportions of seeds containing either a single endosperm or a single embryo. When two cdka;1 sperm cells were released, they fused to each female gamete. Embryogenesis was initiated but the fusion between the nuclei of the sperm cell and the central cell failed. The failure of karyogamy in the central cell prevented incorporation of the paternal genome, impaired endosperm development and caused seed abortion. Our results thus support that the paternal genome plays an essential role during early seed development. However, sperm entry was sufficient to trigger central cell mitotic division, suggesting the existence of signaling events associated with sperm cell fusion with female gametes.
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Affiliation(s)
- Sze Jet Aw
- Temasek Life Science Laboratory, National University of Singapore, Singapore
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