1
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Khouider S, Gehring M. Parental dialectic: Epigenetic conversations in endosperm. CURRENT OPINION IN PLANT BIOLOGY 2024; 81:102591. [PMID: 38944896 PMCID: PMC11392645 DOI: 10.1016/j.pbi.2024.102591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 05/21/2024] [Accepted: 06/07/2024] [Indexed: 07/02/2024]
Abstract
Endosperm is a major evolutionary innovation of flowering plants, and its proper development critically impacts seed growth and viability. Epigenetic regulators have a key function in parental control of endosperm development. Notably, epigenetic regulation of parental genome dosage is a major determinant of seed development success, and disruption of this balance can produce inviable seed, as observed in some interploidy and interspecific crosses. These postzygotic reproduction barriers are also a potent driver of speciation. The molecular machinery and regulatory architecture governing endosperm development is proposed to have evolved under parental conflict. In this review, we emphasize parental conflict as a dialectic conflict and discuss recent findings about the epigenetic molecular machinery that mediates parental conflict in the endosperm.
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Affiliation(s)
- Souraya Khouider
- Whitehead Institute for Biomedical Research, Cambridge MA 02142, USA
| | - Mary Gehring
- Whitehead Institute for Biomedical Research, Cambridge MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge MA 02139, USA.
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2
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Pal AK, Gandhivel VHS, Nambiar AB, Shivaprasad PV. Upstream regulator of genomic imprinting in rice endosperm is a small RNA-associated chromatin remodeler. Nat Commun 2024; 15:7807. [PMID: 39242590 PMCID: PMC11379814 DOI: 10.1038/s41467-024-52239-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 08/29/2024] [Indexed: 09/09/2024] Open
Abstract
Genomic imprinting is observed in endosperm, a placenta-like seed tissue, where transposable elements (TEs) and repeat-derived small RNAs (sRNAs) mediate epigenetic changes in plants. In imprinting, uniparental gene expression arises due to parent-specific epigenetic marks on one allele but not on the other. The importance of sRNAs and their regulation in endosperm development or in imprinting is poorly understood in crops. Here we show that a previously uncharacterized CLASSY (CLSY)-family chromatin remodeler named OsCLSY3 is essential for rice endosperm development and imprinting, acting as an upstream player in the sRNA pathway. Comparative transcriptome and genetic analysis indicated its endosperm-preferred expression and its likely paternal imprinted nature. These important features are modulated by RNA-directed DNA methylation (RdDM) of tandemly arranged TEs in its promoter. Upon perturbation of OsCLSY3 in transgenic lines, we observe defects in endosperm development and a loss of around 70% of all sRNAs. Interestingly, well-conserved endosperm-specific sRNAs (siren) that are vital for reproductive fitness in angiosperms are also dependent on OsCLSY3. We observed that many imprinted genes and seed development-associated genes are under the control of OsCLSY3. These results support an essential role of OsCLSY3 in rice endosperm development and imprinting, and propose similar regulatory strategies involving CLSY3 homologs among other cereals.
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Affiliation(s)
- Avik Kumar Pal
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bangalore, India
| | - Vivek Hari-Sundar Gandhivel
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bangalore, India
| | - Amruta B Nambiar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bangalore, India
| | - P V Shivaprasad
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bangalore, India.
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3
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Zhang H, Zhu JK. Epigenetic gene regulation in plants and its potential applications in crop improvement. Nat Rev Mol Cell Biol 2024:10.1038/s41580-024-00769-1. [PMID: 39192154 DOI: 10.1038/s41580-024-00769-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2024] [Indexed: 08/29/2024]
Abstract
DNA methylation, also known as 5-methylcytosine, is an epigenetic modification that has crucial functions in plant growth, development and adaptation. The cellular DNA methylation level is tightly regulated by the combined action of DNA methyltransferases and demethylases. Protein complexes involved in the targeting and interpretation of DNA methylation have been identified, revealing intriguing roles of methyl-DNA binding proteins and molecular chaperones. Structural studies and in vitro reconstituted enzymatic systems have provided mechanistic insights into RNA-directed DNA methylation, the main pathway catalysing de novo methylation in plants. A better understanding of the regulatory mechanisms will enable locus-specific manipulation of the DNA methylation status. CRISPR-dCas9-based epigenome editing tools are being developed for this goal. Given that DNA methylation patterns can be stably transmitted through meiosis, and that large phenotypic variations can be contributed by epimutations, epigenome editing holds great promise in crop breeding by creating additional phenotypic variability on the same genetic material.
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Affiliation(s)
- Heng Zhang
- Department of Genetics and Developmental Science, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
| | - Jian-Kang Zhu
- Institute of Advanced Biotechnology and School of Medicine, Southern University of Science and Technology, Shenzhen, China.
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4
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Bente H, Köhler C. Molecular basis and evolutionary drivers of endosperm-based hybridization barriers. PLANT PHYSIOLOGY 2024; 195:155-169. [PMID: 38298124 PMCID: PMC11060687 DOI: 10.1093/plphys/kiae050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 01/05/2024] [Accepted: 01/06/2024] [Indexed: 02/02/2024]
Abstract
The endosperm, a transient seed tissue, plays a pivotal role in supporting embryo growth and germination. This unique feature sets flowering plants apart from gymnosperms, marking an evolutionary innovation in the world of seed-bearing plants. Nevertheless, the importance of the endosperm extends beyond its role in providing nutrients to the developing embryo by acting as a versatile protector, preventing hybridization events between distinct species and between individuals with different ploidy. This phenomenon centers on growth and differentiation of the endosperm and the speed at which both processes unfold. Emerging studies underscore the important role played by type I MADS-box transcription factors, including the paternally expressed gene PHERES1. These factors, along with downstream signaling pathways involving auxin and abscisic acid, are instrumental in regulating endosperm development and, consequently, the establishment of hybridization barriers. Moreover, mutations in various epigenetic regulators mitigate these barriers, unveiling a complex interplay of pathways involved in their formation. In this review, we discuss the molecular underpinnings of endosperm-based hybridization barriers and their evolutionary drivers.
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Affiliation(s)
- Heinrich Bente
- Department of Plant Reproductive Biology and Epigenetics, Max Planck Institute of Molecular Plant Physiology, Potsdam 14476, Germany
| | - Claudia Köhler
- Department of Plant Reproductive Biology and Epigenetics, Max Planck Institute of Molecular Plant Physiology, Potsdam 14476, Germany
- Department of Plant Biology, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala 75007, Sweden
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5
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Yang G, Feng M, Yu K, Cui G, Zhou Y, Sun L, Gao L, Zhang Y, Peng H, Yao Y, Hu Z, Rossi V, De Smet I, Ni Z, Sun Q, Xin M. Paternally imprinted LATE-FLOWERING2 transcription factor contributes to paternal-excess interploidy hybridization barriers in wheat. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2023; 65:2587-2603. [PMID: 37846823 DOI: 10.1111/jipb.13574] [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: 09/20/2023] [Accepted: 10/16/2023] [Indexed: 10/18/2023]
Abstract
Interploidy hybridization between hexaploid and tetraploid genotypes occurred repeatedly during genomic introgression events throughout wheat evolution, and is commonly employed in wheat breeding programs. Hexaploid wheat usually serves as maternal parent because the reciprocal cross generates progeny with severe defects and poor seed germination, but the underlying mechanism is poorly understood. Here, we performed detailed analysis of phenotypic variation in endosperm between two interploidy reciprocal crosses arising from tetraploid (Triticum durum, AABB) and hexaploid wheat (Triticum aestivum, AABBDD). In the paternal- versus the maternal-excess cross, the timing of endosperm cellularization was delayed and starch granule accumulation in the endosperm was repressed, causing reduced germination percentage. The expression profiles of genes involved in nutrient metabolism differed strongly between these endosperm types. Furthermore, expression patterns of parental alleles were dramatically disturbed in interploidy versus intraploidy crosses, leading to increased number of imprinted genes. The endosperm-specific TaLFL2 showed a paternally imprinted expression pattern in interploidy crosses partially due to allele-specific DNA methylation. Paternal TaLFL2 binds to and represses a nutrient accumulation regulator TaNAC019, leading to reduced storage protein and starch accumulation during endosperm development in paternal-excess cross, as confirmed by interploidy crosses between tetraploid wild-type and clustered regularly interspaced palindromic repeats (CRISPR) - CRISPR-associated protein 9 generated hexaploid mutants. These findings reveal a contribution of genomic imprinting to paternal-excess interploidy hybridization barriers during wheat evolution history and explains why experienced breeders preferentially exploit maternal-excess interploidy crosses in wheat breeding programs.
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Affiliation(s)
- Guanghui Yang
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China
| | - Man Feng
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China
| | - Kuohai Yu
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China
| | - Guangxian Cui
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China
| | - Yan Zhou
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China
| | - Lv Sun
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China
| | - Lulu Gao
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China
| | - Yumei Zhang
- Qingdao Agricultural University, Qingdao, 266109, China
| | - Huiru Peng
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China
| | - Yingyin Yao
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China
| | - Zhaorong Hu
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China
| | - Vincenzo Rossi
- Council for Agricultural Research and Economics, Research Centre for Cereal and Industrial Crops, Bergamo, 24126, Italy
| | - Ive De Smet
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, B-9052, Belgium
- VIB Center for Plant Systems Biology, Ghent, B-9052, Belgium
| | - Zhongfu Ni
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China
| | - Qixin Sun
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China
| | - Mingming Xin
- State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis Utilization (MOE), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China
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He H, Shiragaki K, Tezuka T. Understanding and overcoming hybrid lethality in seed and seedling stages as barriers to hybridization and gene flow. FRONTIERS IN PLANT SCIENCE 2023; 14:1219417. [PMID: 37476165 PMCID: PMC10354522 DOI: 10.3389/fpls.2023.1219417] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 06/20/2023] [Indexed: 07/22/2023]
Abstract
Hybrid lethality is a type of reproductive isolation barrier observed in two developmental stages, hybrid embryos (hybrid seeds) and hybrid seedlings. Hybrid lethality has been reported in many plant species and limits distant hybridization breeding including interspecific and intergeneric hybridization, which increases genetic diversity and contributes to produce new germplasm for agricultural purposes. Recent studies have provided molecular and genetic evidence suggesting that underlying causes of hybrid lethality involve epistatic interaction of one or more loci, as hypothesized by the Bateson-Dobzhansky-Muller model, and effective ploidy or endosperm balance number. In this review, we focus on the similarities and differences between hybrid seed lethality and hybrid seedling lethality, as well as methods of recovering seed/seedling activity to circumvent hybrid lethality. Current knowledge summarized in our article will provides new insights into the mechanisms of hybrid lethality and effective methods for circumventing hybrid lethality.
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Affiliation(s)
- Hai He
- School of Agriculture, Sun Yat-sen University, Shenzhen, China
| | - Kumpei Shiragaki
- Laboratory of Plant Breeding and Genetics, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Japan
| | - Takahiro Tezuka
- Laboratory of Breeding and Genetics, Graduate School of Agriculture, Osaka Metropolitan University, Sakai, Osaka, Japan
- Education and Research Field, School of Agriculture, Osaka Metropolitan University, Sakai, Osaka, Japan
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7
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Tonosaki K, Fujimoto R, Dennis ES, Raboy V, Osabe K. Will epigenetics be a key player in crop breeding? FRONTIERS IN PLANT SCIENCE 2022; 13:958350. [PMID: 36247549 PMCID: PMC9562705 DOI: 10.3389/fpls.2022.958350] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 09/12/2022] [Indexed: 06/16/2023]
Abstract
If food and feed production are to keep up with world demand in the face of climate change, continued progress in understanding and utilizing both genetic and epigenetic sources of crop variation is necessary. Progress in plant breeding has traditionally been thought to be due to selection for spontaneous DNA sequence mutations that impart desirable phenotypes. These spontaneous mutations can expand phenotypic diversity, from which breeders can select agronomically useful traits. However, it has become clear that phenotypic diversity can be generated even when the genome sequence is unaltered. Epigenetic gene regulation is a mechanism by which genome expression is regulated without altering the DNA sequence. With the development of high throughput DNA sequencers, it has become possible to analyze the epigenetic state of the whole genome, which is termed the epigenome. These techniques enable us to identify spontaneous epigenetic mutations (epimutations) with high throughput and identify the epimutations that lead to increased phenotypic diversity. These epimutations can create new phenotypes and the causative epimutations can be inherited over generations. There is evidence of selected agronomic traits being conditioned by heritable epimutations, and breeders may have historically selected for epiallele-conditioned agronomic traits. These results imply that not only DNA sequence diversity, but the diversity of epigenetic states can contribute to increased phenotypic diversity. However, since the modes of induction and transmission of epialleles and their stability differ from that of genetic alleles, the importance of inheritance as classically defined also differs. For example, there may be a difference between the types of epigenetic inheritance important to crop breeding and crop production. The former may depend more on longer-term inheritance whereas the latter may simply take advantage of shorter-term phenomena. With the advances in our understanding of epigenetics, epigenetics may bring new perspectives for crop improvement, such as the use of epigenetic variation or epigenome editing in breeding. In this review, we will introduce the role of epigenetic variation in plant breeding, largely focusing on DNA methylation, and conclude by asking to what extent new knowledge of epigenetics in crop breeding has led to documented cases of its successful use.
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Affiliation(s)
- Kaoru Tonosaki
- Kihara Institute for Biological Research, Yokohama City University, Yokohama, Japan
| | - Ryo Fujimoto
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Elizabeth S. Dennis
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Agriculture and Food, Canberra, ACT, Australia
- School of Life Sciences, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
| | - Victor Raboy
- Independent Researcher Portland, Portland, OR, United States
| | - Kenji Osabe
- Institute of Scientific and Industrial Research (SANKEN), Osaka University, Osaka, Japan
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8
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Trujillo JT, Long J, Aboelnour E, Ogas J, Wisecaver JH. CHD chromatin remodeling protein diversification yields novel clades and domains absent in classic model organisms. Genome Biol Evol 2022; 14:6582301. [PMID: 35524943 PMCID: PMC9113485 DOI: 10.1093/gbe/evac066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/05/2022] [Indexed: 11/20/2022] Open
Abstract
Chromatin remodelers play a fundamental role in the assembly of chromatin, regulation of transcription, and DNA repair. Biochemical and functional characterizations of the CHD family of chromatin remodelers from a variety of model organisms have shown that these remodelers participate in a wide range of activities. However, because the evolutionary history of CHD homologs is unclear, it is difficult to predict which of these activities are broadly conserved and which have evolved more recently in individual eukaryotic lineages. Here, we performed a comprehensive phylogenetic analysis of 8,042 CHD homologs from 1,894 species to create a model for the evolution of this family across eukaryotes with a particular focus on the timing of duplications that gave rise to the diverse copies observed in plants, animals, and fungi. Our analysis confirms that the three major subfamilies of CHD remodelers originated in the eukaryotic last common ancestor, and subsequent losses occurred independently in different lineages. Improved taxon sampling identified several subfamilies of CHD remodelers in plants that were absent or highly divergent in the model plant Arabidopsis thaliana. Whereas the timing of CHD subfamily expansions in vertebrates corresponds to whole genome duplication events, the mechanisms underlying CHD diversification in land plants appear more complicated. Analysis of protein domains reveals that CHD remodeler diversification has been accompanied by distinct transitions in domain architecture, contributing to the functional differences observed between these remodelers. This study demonstrates the importance of proper taxon sampling when studying ancient evolutionary events to prevent misinterpretation of subsequent lineage-specific changes and provides an evolutionary framework for functional and comparative analysis of this critical chromatin remodeler family across eukaryotes.
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Affiliation(s)
- Joshua T Trujillo
- Center for Plant Biology and Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907, USA
| | - Jiaxin Long
- Center for Plant Biology and Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907, USA
| | - Erin Aboelnour
- Center for Plant Biology and Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907, USA.,Helmholtz Pioneer Campus, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Joseph Ogas
- Center for Plant Biology and Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907, USA
| | - Jennifer H Wisecaver
- Center for Plant Biology and Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907, USA
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9
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Oliver C, Annacondia ML, Wang Z, Jullien PE, Slotkin RK, Köhler C, Martinez G. The miRNome function transitions from regulating developmental genes to transposable elements during pollen maturation. THE PLANT CELL 2022; 34:784-801. [PMID: 34755870 PMCID: PMC8824631 DOI: 10.1093/plcell/koab280] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 11/04/2021] [Indexed: 06/13/2023]
Abstract
Animal and plant microRNAs (miRNAs) are essential for the spatio-temporal regulation of development. Together with this role, plant miRNAs have been proposed to target transposable elements (TEs) and stimulate the production of epigenetically active small interfering RNAs. This activity is evident in the plant male gamete containing structure, the male gametophyte or pollen grain. How the dual role of plant miRNAs, regulating both genes and TEs, is integrated during pollen development and which mRNAs are regulated by miRNAs in this cell type at a genome-wide scale are unknown. Here, we provide a detailed analysis of miRNA dynamics and activity during pollen development in Arabidopsis thaliana using small RNA and degradome parallel analysis of RNA end high-throughput sequencing. Furthermore, we uncover miRNAs loaded into the two main active Argonaute (AGO) proteins in the uninuclear and mature pollen grain, AGO1 and AGO5. Our results indicate that the developmental progression from microspore to mature pollen grain is characterized by a transition from miRNAs targeting developmental genes to miRNAs regulating TE activity.
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Affiliation(s)
- Cecilia Oliver
- Department of Plant Biology, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala 75007, Sweden
| | - Maria Luz Annacondia
- Department of Plant Biology, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala 75007, Sweden
| | - Zhenxing Wang
- Department of Plant Biology, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala 75007, Sweden
- College of Horticulture and State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
- Key Laboratory of Landscaping, Ministry of Agriculture and Rural Affairs and Key Laboratory of Biology of Ornamental Plants in East China, National Forestry and Grassland Administration, Nanjing Agricultural University, Nanjing 210095, China
| | - Pauline E Jullien
- Institute of Plant Sciences, University of Bern, Bern 3013, Switzerland
| | - R Keith Slotkin
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132, USA
- Division of Biological Sciences, University of Missouri Columbia, Columbia, Missouri 65201, USA
| | - Claudia Köhler
- Department of Plant Biology, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala 75007, Sweden
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm 14476, Germany
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10
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Vigneau J, Borg M. The epigenetic origin of life history transitions in plants and algae. PLANT REPRODUCTION 2021; 34:267-285. [PMID: 34236522 PMCID: PMC8566409 DOI: 10.1007/s00497-021-00422-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 06/14/2021] [Indexed: 05/17/2023]
Abstract
Plants and algae have a complex life history that transitions between distinct life forms called the sporophyte and the gametophyte. This phenomenon-called the alternation of generations-has fascinated botanists and phycologists for over 170 years. Despite the mesmerizing array of life histories described in plants and algae, we are only now beginning to learn about the molecular mechanisms controlling them and how they evolved. Epigenetic silencing plays an essential role in regulating gene expression during multicellular development in eukaryotes, raising questions about its impact on the life history strategy of plants and algae. Here, we trace the origin and function of epigenetic mechanisms across the plant kingdom, from unicellular green algae through to angiosperms, and attempt to reconstruct the evolutionary steps that influenced life history transitions during plant evolution. Central to this evolutionary scenario is the adaption of epigenetic silencing from a mechanism of genome defense to the repression and control of alternating generations. We extend our discussion beyond the green lineage and highlight the peculiar case of the brown algae. Unlike their unicellular diatom relatives, brown algae lack epigenetic silencing pathways common to animals and plants yet display complex life histories, hinting at the emergence of novel life history controls during stramenopile evolution.
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Affiliation(s)
- Jérômine Vigneau
- Department of Algal Development and Evolution, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Michael Borg
- Department of Algal Development and Evolution, Max Planck Institute for Developmental Biology, Tübingen, Germany.
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11
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Jiang H, Guo D, Ye J, Gao Y, Liu H, Wang Y, Xue M, Yan Q, Chen J, Duan L, Li G, Li X, Xie L. Genome-wide analysis of genomic imprinting in the endosperm and allelic variation in flax. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 107:1697-1710. [PMID: 34228847 DOI: 10.1111/tpj.15411] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 06/30/2021] [Indexed: 06/13/2023]
Abstract
Genomic imprinting is an epigenetic phenomenon that causes biased expression of maternally and paternally inherited alleles. In flowering plants, genomic imprinting predominantly occurs in the triploid endosperm and plays a vital role in seed development. In this study, we identified 248 candidate imprinted genes including 114 maternally expressed imprinted genes (MEGs) and 134 paternally expressed imprinted genes (PEGs) in flax (Linum usitatissimum L.) endosperm using deep RNA sequencing. These imprinted genes were neither clustered in specific chromosomal regions nor well conserved among flax and other plant species. MEGs tended to be expressed specifically in the endosperm, whereas the expression of PEGs was not tissue-specific. Imprinted single nucleotide polymorphisms differentiated 200 flax cultivars into the oil flax, oil-fiber dual purpose flax and fiber flax subgroups, suggesting that genomic imprinting contributed to intraspecific variation in flax. The nucleotide diversity of imprinted genes in the oil flax subgroup was significantly higher than that in the fiber flax subgroup, indicating that some imprinted genes underwent positive selection during flax domestication from oil flax to fiber flax. Moreover, imprinted genes that underwent positive selection were related to flax functions. Thirteen imprinted genes related to flax seed size and weight were identified using a candidate gene-based association study. Therefore, our study provides information for further exploration of the function and genomic variation of imprinted genes in the flax population.
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Affiliation(s)
- Haixia Jiang
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, Xinjiang, China
| | - Dongliang Guo
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, Xinjiang, China
| | - Jiali Ye
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Yanfang Gao
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, Xinjiang, China
| | - Huiqing Liu
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, Xinjiang, China
| | - Yue Wang
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, Xinjiang, China
| | - Min Xue
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, Xinjiang, China
| | - Qingcheng Yan
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, Xinjiang, China
| | - Jiaxun Chen
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, Xinjiang, China
| | - Lepeng Duan
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, Xinjiang, China
| | - Gongze Li
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, Xinjiang, China
| | - Xiao Li
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, Xinjiang, China
| | - Liqiong Xie
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, Xinjiang, China
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12
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Wang Z, Butel N, Santos-González J, Simon L, Wärdig C, Köhler C. Transgenerational effect of mutants in the RNA-directed DNA methylation pathway on the triploid block in Arabidopsis. Genome Biol 2021; 22:141. [PMID: 33957942 PMCID: PMC8101200 DOI: 10.1186/s13059-021-02359-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 04/22/2021] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Hybridization of plants that differ in number of chromosome sets (ploidy) frequently causes endosperm failure and seed arrest, a phenomenon referred to as triploid block. In Arabidopsis, loss of function of NRPD1, encoding the largest subunit of the plant-specific RNA polymerase IV (Pol IV), can suppress the triploid block. Pol IV generates short RNAs required to guide de novo methylation in the RNA-directed DNA methylation (RdDM) pathway. Recent work suggests that suppression of the triploid block by mutants in RdDM components differs, depending on whether the diploid pollen is derived from tetraploid plants or from the omission in second division 1 (osd1) mutant. This study aims to understand this difference. RESULTS In this study, we find that the ability of mutants in the RdDM pathway to suppress the triploid block depends on their degree of inbreeding. While first homozygous generation mutants in RdDM components NRPD1, RDR2, NRPE1, and DRM2 have weak or no ability to rescue the triploid block, they are able to suppress the triploid block with successive generations of inbreeding. Inbreeding of nrpd1 was connected with a transgenerational loss of non-CG DNA methylation on sites jointly regulated by CHROMOMETHYLASES 2 and 3. CONCLUSIONS Our data reveal that loss of RdDM function differs in its effect in early and late generations, which has important implications when interpreting the effect of RdDM mutants.
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Affiliation(s)
- Zhenxing Wang
- Department of Plant Biology, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, 75007 Uppsala, Sweden
- Present address: College of Horticulture, Nanjing Agricultural University and State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing, 210095 China
| | - Nicolas Butel
- Department of Plant Biology, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, 75007 Uppsala, Sweden
| | - Juan Santos-González
- Department of Plant Biology, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, 75007 Uppsala, Sweden
| | - Lauriane Simon
- Department of Plant Biology, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, 75007 Uppsala, Sweden
| | - Cecilia Wärdig
- Department of Plant Biology, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, 75007 Uppsala, Sweden
| | - Claudia Köhler
- Department of Plant Biology, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, 75007 Uppsala, Sweden
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany
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13
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Köhler C, Dziasek K, Del Toro-De León G. Postzygotic reproductive isolation established in the endosperm: mechanisms, drivers and relevance. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200118. [PMID: 33866810 DOI: 10.1098/rstb.2020.0118] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The endosperm is a developmental innovation of angiosperms that supports embryo growth and germination. Aside from this essential reproductive function, the endosperm fuels angiosperm evolution by rapidly establishing reproductive barriers between incipient species. Specifically, the endosperm prevents hybridization of newly formed polyploids with their non-polyploid progenitors, a phenomenon termed the triploid block. Furthermore, recently diverged diploid species are frequently reproductively isolated by endosperm-based hybridization barriers. Current genetic approaches have revealed a prominent role for epigenetic processes establishing these barriers. In particular, imprinted genes, which are expressed in a parent-of-origin-specific manner, underpin the interploidy barrier in the model species Arabidopsis. We will discuss the mechanisms establishing hybridization barriers in the endosperm, the driving forces for these barriers and their impact for angiosperm evolution. This article is part of the theme issue 'How does epigenetics influence the course of evolution?'
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Affiliation(s)
- Claudia Köhler
- Department of Plant Biology, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala 75007, Sweden
| | - Katarzyna Dziasek
- Department of Plant Biology, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala 75007, Sweden
| | - Gerardo Del Toro-De León
- Department of Plant Biology, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala 75007, Sweden
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14
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Li C, Gong X, Zhang B, Liang Z, Wong CE, See BYH, Yu H. TOP1α, UPF1, and TTG2 regulate seed size in a parental dosage-dependent manner. PLoS Biol 2020; 18:e3000930. [PMID: 33156841 PMCID: PMC7673560 DOI: 10.1371/journal.pbio.3000930] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 11/18/2020] [Accepted: 09/24/2020] [Indexed: 11/19/2022] Open
Abstract
Cues of maternal and paternal origins interact to control seed development, and the underlying molecular mechanisms are still far from clear. Here, we show that TOPOISOMERASE Iα (TOP1α), UP-FRAMESHIFT SUPPRESSOR 1 (UPF1), and TRANSPARENT TESTA GLABRA2 (TTG2) gametophytically, biparentally regulate seed size in Arabidopsis. TOP1α and UPF1 are mainly expressed in antipodal cells, and loss of their function leads to ectopic TTG2 expression in these female gametophytic cells. We further demonstrate that TOP1α and UPF1 directly repress TTG2 expression through affecting its chromatin status and determine its relative expression in antipodal cells versus sperm cells, which controls seed size in a dosage-dependent and parent-of-origin-dependent manner. The molecular interplay among these three genes explains their biparental gametophytic effect during diploidy and interploidy reciprocal crosses. Taken together, our findings reveal a molecular framework of parental interaction for seed size control. Cues of maternal and paternal origin interact to control seed development, and the underlying molecular mechanisms are still far from clear. This study shows that in Arabidopsis, the relative dosage of the transcription factor TTG2 between antipodal cells and sperm cells at the beginning of seed development determines seed size under the control of TOP1α and UPF1.
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Affiliation(s)
- Chengxiang Li
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore
| | - Ximing Gong
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
| | - Bin Zhang
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore
| | - Zhe Liang
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
| | - Chui Eng Wong
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore
| | - Benjamin Yen How See
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
| | - Hao Yu
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore
- * E-mail:
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15
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Qi D, Wen Q, Meng Z, Yuan S, Guo H, Zhao H, Cui S. OsLFR is essential for early endosperm and embryo development by interacting with SWI/SNF complex members in Oryza sativa. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 104:901-916. [PMID: 32808364 DOI: 10.1111/tpj.14967] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 07/09/2020] [Accepted: 07/29/2020] [Indexed: 05/26/2023]
Abstract
Rice (Oryza sativa L.) endosperm provides the developing embryo with nutrients and provides human beings with a staple food. The embryo eventually develops into a new sporophyte generation. Despite their important roles, the molecular mechanisms underlying early-stage endosperm and embryo development remain elusive. Here, we established the fundamental functions of rice OsLFR, an ortholog of the Arabidopsis SWI/SNF chromatin-remodeling complex (CRC) component LFR. OsLFR was expressed primarily in the rice spikelets and seeds, and the OsLFR protein was localized to the nucleus. We conducted genetic, cellular and molecular analyses of loss-of-function mutants and transgenic rescue lines. OsLFR depletion resulted in homozygous lethality in the early seed stage through endosperm and embryo defects, which could be successfully recovered by the OsLFR genomic sequence. Cytological observations revealed that the oslfr endosperm had relatively fewer free nuclei, had abnormal and arrested cellularization, and demonstrated premature programed cell death: the embryo was reduced in size and failed to differentiate. Transcriptome profiling showed that many genes, involved in DNA replication, cell cycle, cell wall assembly and cell death, were differentially expressed in a knockout mutant of OsLFR (oslfr-1), which was consistent with the observed seed defects. Protein-protein interaction analysis showed that OsLFR physically interacts with several putative rice SWI/SNF CRC components. Our findings demonstrate that OsLFR, possibly as one component of the SWI/SNF CRC, is an essential regulator of rice seed development, and provide further insights into the regulatory mechanism of early-stage rice endosperm and embryo development.
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Affiliation(s)
- Dongmei Qi
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Normal University, Hebei, 050024, China
- Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Normal University, Hebei, 050024, China
- Hebei Collaboration Innovation Center for Cell Signaling, Hebei Normal University, Hebei, 050024, China
- College of Life Science, Hebei Normal University, Hebei, 050024, China
| | - Qingqing Wen
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Normal University, Hebei, 050024, China
- Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Normal University, Hebei, 050024, China
- Hebei Collaboration Innovation Center for Cell Signaling, Hebei Normal University, Hebei, 050024, China
- College of Life Science, Hebei Normal University, Hebei, 050024, China
| | - Ze Meng
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Normal University, Hebei, 050024, China
- Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Normal University, Hebei, 050024, China
- Hebei Collaboration Innovation Center for Cell Signaling, Hebei Normal University, Hebei, 050024, China
- College of Life Science, Hebei Normal University, Hebei, 050024, China
| | - Shan Yuan
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Normal University, Hebei, 050024, China
- Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Normal University, Hebei, 050024, China
- Hebei Collaboration Innovation Center for Cell Signaling, Hebei Normal University, Hebei, 050024, China
- College of Life Science, Hebei Normal University, Hebei, 050024, China
| | - Hong Guo
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Normal University, Hebei, 050024, China
- Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Normal University, Hebei, 050024, China
- Hebei Collaboration Innovation Center for Cell Signaling, Hebei Normal University, Hebei, 050024, China
- College of Life Science, Hebei Normal University, Hebei, 050024, China
| | - Hongtao Zhao
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Normal University, Hebei, 050024, China
- Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Normal University, Hebei, 050024, China
- Hebei Collaboration Innovation Center for Cell Signaling, Hebei Normal University, Hebei, 050024, China
- College of Life Science, Hebei Normal University, Hebei, 050024, China
| | - Sujuan Cui
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Normal University, Hebei, 050024, China
- Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Normal University, Hebei, 050024, China
- Hebei Collaboration Innovation Center for Cell Signaling, Hebei Normal University, Hebei, 050024, China
- College of Life Science, Hebei Normal University, Hebei, 050024, China
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16
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Abstract
In this review, Batista and Köhler revisit the current models explaining imprinting regulation in plants, and discuss novel regulatory mechanisms that could function independently of parental DNA methylation asymmetries in the establishment of imprinting. Genomic imprinting is an epigenetic phenomenon leading to parentally biased gene expression. Throughout the years, extensive efforts have been made to characterize the epigenetic marks underlying imprinting in animals and plants. As a result, DNA methylation asymmetries between parental genomes emerged as the primary factor controlling the imprinting status of many genes. Nevertheless, the data accumulated so far suggest that this process cannot solely explain the imprinting of all genes. In this review, we revisit the current models explaining imprinting regulation in plants, and discuss novel regulatory mechanisms that could function independently of parental DNA methylation asymmetries in the establishment of imprinting.
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Affiliation(s)
- Rita A Batista
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Centre for Plant Biology, Uppsala SE-750 07, Sweden
| | - Claudia Köhler
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Centre for Plant Biology, Uppsala SE-750 07, Sweden
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17
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Guo D, Jiang H, Yan W, Yang L, Ye J, Wang Y, Yan Q, Chen J, Gao Y, Duan L, Liu H, Xie L. Resequencing 200 Flax Cultivated Accessions Identifies Candidate Genes Related to Seed Size and Weight and Reveals Signatures of Artificial Selection. FRONTIERS IN PLANT SCIENCE 2020; 10:1682. [PMID: 32010166 PMCID: PMC6976528 DOI: 10.3389/fpls.2019.01682] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 11/29/2019] [Indexed: 05/13/2023]
Abstract
Seed size and weight are key traits determining crop yield, which often undergo strongly artificial selection during crop domestication. Although seed sizes differ significantly between oil flax and fiber flax, the genetic basis of morphological differences and artificial selection characteristics in seed size remains largely unclear. Here we re-sequenced 200 flax cultivated accessions to generate a genome variation map based on chromosome assembly reference genomes. We provide evidence that oil flax group is the ancestor of cultivated flax, and the oil-fiber dual purpose group (OF) is the evolutionary intermediate transition state between oil and fiber flax. Genome-wide association studies (GWAS) were combined with LD Heatmap to identify candidate regions related to seed size and weight, then candidate genes were screened based on detailed functional annotations and estimation of nucleotide polymorphism effects. Using this strategy, we obtained 13 candidate genes related to seed size and weight. Selective sweeps analysis indicates human-involved selection of small seeds during the oil to fiber flax transition. Our study shows the existence of elite alleles for seed size and weight in flax germplasm and provides molecular insights into approaches for further improvement.
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Affiliation(s)
- Dongliang Guo
- National Center of Melon Engineering and Technology, Molecular Breeding Laboratory, College of Life Science and Technology, Xinjiang University, Urumqi, China
| | - Haixia Jiang
- National Center of Melon Engineering and Technology, Molecular Breeding Laboratory, College of Life Science and Technology, Xinjiang University, Urumqi, China
| | - Wenliang Yan
- National Center for Soybean Improvement, Key Laboratory of Biology and Genetics and Breeding for Soybean, Ministry of Agriculture, State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
| | - Liangjie Yang
- Herbal Medicine Innovation Research Center, Agricultural Bureau of Zhaosu County, Yili, China
| | - Jiali Ye
- National Center of Melon Engineering and Technology, Molecular Breeding Laboratory, College of Life Science and Technology, Xinjiang University, Urumqi, China
| | - Yue Wang
- National Center of Melon Engineering and Technology, Molecular Breeding Laboratory, College of Life Science and Technology, Xinjiang University, Urumqi, China
| | - Qingcheng Yan
- National Center of Melon Engineering and Technology, Molecular Breeding Laboratory, College of Life Science and Technology, Xinjiang University, Urumqi, China
| | - Jiaxun Chen
- National Center of Melon Engineering and Technology, Molecular Breeding Laboratory, College of Life Science and Technology, Xinjiang University, Urumqi, China
| | - Yanfang Gao
- National Center of Melon Engineering and Technology, Molecular Breeding Laboratory, College of Life Science and Technology, Xinjiang University, Urumqi, China
| | - Lepeng Duan
- National Center of Melon Engineering and Technology, Molecular Breeding Laboratory, College of Life Science and Technology, Xinjiang University, Urumqi, China
| | - Huiqing Liu
- National Center of Melon Engineering and Technology, Molecular Breeding Laboratory, College of Life Science and Technology, Xinjiang University, Urumqi, China
| | - Liqiong Xie
- National Center of Melon Engineering and Technology, Molecular Breeding Laboratory, College of Life Science and Technology, Xinjiang University, Urumqi, China
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18
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Milutinovic M, Lindsey BE, Wijeratne A, Hernandez JM, Grotewold N, Fernández V, Grotewold E, Brkljacic J. Arabidopsis EMSY-like (EML) histone readers are necessary for post-fertilization seed development, but prevent fertilization-independent seed formation. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 285:99-109. [PMID: 31203898 DOI: 10.1016/j.plantsci.2019.04.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 04/07/2019] [Accepted: 04/09/2019] [Indexed: 06/09/2023]
Abstract
Seed development is a complex regulatory process that includes a transition from gametophytic to sporophytic program. The synchronized development of different seed compartments (seed coat, endosperm and embryo) depends on a balance in parental genome contributions. In the most severe cases, the disruption of the balance leads to seed abortion. This represents one of the main obstacles for the engineering of asexual reproduction through seeds (apomixis), and for generating new interspecies hybrids. The repression of auxin synthesis by the Polycomb Repressive Complex 2 (PRC2) is a major mechanism contributing to sensing genome balance. However, current efforts focusing on decreasing PRC2 or elevating auxin levels have not yet resulted in the production of apomictic seed. Here, we show that EMSY-Like Tudor/Agenet H3K36me3 histone readers EML1 and EML3 are necessary for early stages of seed development to proceed at a normal rate in Arabidopsis. We further demonstrate that both EML1 and EML3 are required to prevent the initiation of seed development in the absence of fertilization. Based on the whole genome expression analysis, we identify auxin transport and signaling genes as the most enriched downstream targets of EML1 and EML3. We hypothesize that EML1 and EML3 function to repress and soften paternal gene expression by fine-tuning auxin responses. Discovery of this pathway may contribute to the engineering of apomixis and interspecies hybrids.
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Affiliation(s)
- Milica Milutinovic
- Arabidopsis Biological Resource Center, The Ohio State University, Columbus, OH, 43210, USA
| | - Benson E Lindsey
- Arabidopsis Biological Resource Center, The Ohio State University, Columbus, OH, 43210, USA
| | - Asela Wijeratne
- Department of Molecular Genetics, Center for Applied Plant Sciences, The Ohio State University, Columbus, OH, 43210, USA
| | - J Marcela Hernandez
- Department of Molecular Genetics, Center for Applied Plant Sciences, The Ohio State University, Columbus, OH, 43210, USA
| | - Nikolas Grotewold
- Arabidopsis Biological Resource Center, The Ohio State University, Columbus, OH, 43210, USA
| | - Virginia Fernández
- Arabidopsis Biological Resource Center, The Ohio State University, Columbus, OH, 43210, USA
| | - Erich Grotewold
- Department of Molecular Genetics, Center for Applied Plant Sciences, The Ohio State University, Columbus, OH, 43210, USA.
| | - Jelena Brkljacic
- Arabidopsis Biological Resource Center, The Ohio State University, Columbus, OH, 43210, USA.
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19
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Chen H, Li S, Li L, Wu W, Ke X, Zou W, Zhao J. Nα-Acetyltransferases 10 and 15 are Required for the Correct Initiation of Endosperm Cellularization in Arabidopsis. PLANT & CELL PHYSIOLOGY 2018; 59:2113-2128. [PMID: 30020502 DOI: 10.1093/pcp/pcy135] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 07/06/2018] [Indexed: 06/08/2023]
Abstract
The endosperm and embryo originate from the fertilized central cell and egg cell through a programmed series of cell division and differentiation events. Characterization of more vital genes involved in endosperm and embryo development can help us to understand the regulatory mechanism in more depth. In this study, we found that loss of NAA10 and NAA15, the catalytic and auxiliary subunits of Arabidopsis thaliana N-terminal acetyltransferase A (AtNatA), respectively, led to severely delayed and incomplete endosperm cellularization, accompanied by disordered cell division in the early embryo. Studies on the marker genes/lines of the endosperm (AGL62-GFP, pDD19::GFP, pDD22::NLS-GFP and N9185) and embryo (STM, FIL, SCR and WOX5) in naa10/naa15 mutants showed that expression patterns of these markers were significantly affected, which were tightly associated with the defective feature of endosperm cellularization and embryo cell differentiation. Subsequently, embryonic complementation rescued the abortive embryos, but failed to initiate endosperm cellularization properly, further confirming the essential role of AtNatA in both endosperm and embryo development. Moreover, repression of AGL62 in naa10 and naa15 restored the endosperm cellularization, suggesting that NAA10/NAA15 functions in initiation of endosperm cellularization by inhibiting the expression of AGL62 in Arabidopsis. Therefore, NAA10 and NAA15 could be considered as crucial factors involved in promoting endosperm cellularization in Arabidopsis.
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Affiliation(s)
- Hongyu Chen
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Shuqin Li
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Lu Li
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Weiying Wu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Xiaolong Ke
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Wenxuan Zou
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Jie Zhao
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
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20
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Wang G, Jiang H, Del Toro de León G, Martinez G, Köhler C. Sequestration of a Transposon-Derived siRNA by a Target Mimic Imprinted Gene Induces Postzygotic Reproductive Isolation in Arabidopsis. Dev Cell 2018; 46:696-705.e4. [PMID: 30122632 DOI: 10.1016/j.devcel.2018.07.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 06/08/2018] [Accepted: 07/18/2018] [Indexed: 12/20/2022]
Abstract
Genomic imprinting is an epigenetic phenomenon occurring in mammals and flowering plants, causing genes to be expressed depending on their parent of origin. In plants, genomic imprinting is mainly confined to the endosperm, a nutritive tissue supporting embryo growth, similar to the placenta in mammals. Here, we show that the paternally expressed imprinted gene PEG2 transcript sequesters the transposable element (TE)-derived small interfering RNA (siRNA) siRNA854 in the endosperm. siRNA854 is present in the vegetative cell of pollen and transferred to the central cell of the female gametophyte after fertilization, where it is captured by PEG2. Depletion of siRNA854 as a consequence of increased PEG2 transcript levels establishes a reproductive barrier and prevents successful hybridizations between plants differing in chromosome number (ploidy). Thus, the balance of a male gamete accumulating TE-derived siRNA and a paternally expressed imprinted gene regulate triploid seed viability, revealing a transgenerational speciation mechanism.
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Affiliation(s)
- Guifeng Wang
- Department of Plant Biology, Swedish University of Agricultural Sciences, Linnean Center for Plant Biology, Uppsala 75007, Sweden; Key Laboratory of Wheat and Maize Crops Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450002, China
| | - Hua Jiang
- Department of Plant Biology, Swedish University of Agricultural Sciences, Linnean Center for Plant Biology, Uppsala 75007, Sweden
| | - Gerardo Del Toro de León
- Department of Plant Biology, Swedish University of Agricultural Sciences, Linnean Center for Plant Biology, Uppsala 75007, Sweden
| | - German Martinez
- Department of Plant Biology, Swedish University of Agricultural Sciences, Linnean Center for Plant Biology, Uppsala 75007, Sweden
| | - Claudia Köhler
- Department of Plant Biology, Swedish University of Agricultural Sciences, Linnean Center for Plant Biology, Uppsala 75007, Sweden.
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21
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Erdmann RM, Satyaki PRV, Klosinska M, Gehring M. A Small RNA Pathway Mediates Allelic Dosage in Endosperm. Cell Rep 2018; 21:3364-3372. [PMID: 29262317 DOI: 10.1016/j.celrep.2017.11.078] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 09/18/2017] [Accepted: 11/21/2017] [Indexed: 12/12/2022] Open
Abstract
Balance between maternal and paternal genomes within the triploid endosperm is necessary for normal seed development. The majority of endosperm genes are expressed in a 2:1 maternal:paternal ratio, reflecting genomic DNA content. Here, we find that the 2:1 transcriptional ratio is, unexpectedly, actively regulated. In A. thaliana and A. lyrata, endosperm 24-nt small RNAs are reduced in transposable elements and enriched in genes compared with the embryo. We find an inverse relationship between the parent of origin of sRNAs and mRNAs, with genes more likely to be associated with maternally than paternally biased sRNAs. Disruption of the Pol IV sRNA pathway causes a shift toward maternal allele mRNA expression for many genes. Furthermore, paternal inheritance of an RNA Pol IV mutation is sufficient to rescue seed abortion caused by excess paternal genome dosage. Thus, RNA Pol IV mediates the transcriptional balance between maternally and paternally inherited genomes in endosperm.
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Affiliation(s)
- Robert M Erdmann
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | - Maja Klosinska
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Mary Gehring
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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22
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Zhu QH, Yuan Y, Stiller W, Jia Y, Wang P, Pan Z, Du X, Llewellyn D, Wilson I. Genetic dissection of the fuzzless seed trait in Gossypium barbadense. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:997-1009. [PMID: 29351643 PMCID: PMC6018843 DOI: 10.1093/jxb/erx459] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 11/29/2017] [Indexed: 05/21/2023]
Abstract
Cotton fibres are single-celled trichomes arising from the epidermal cells of the seed coat and may be either long (lint) or very short (fuzz). The dominant fuzzless N1 of Gossypium hirsutum is a defective allele of the At-subgenome homoeolog of MYB25-like, but the genetic components underlying the recessive fuzzless trait from G. barbadense (Gb) are unknown. We have identified five genetic loci, including a major contributing locus containing MYB25-like_Dt, associated with Gb fuzzless seeds based on genotyping of fuzzy and fuzzless near isogenic lines (NILs) from an interspecies cross (G. barbadense × G. hirsutum). At 3 d post-anthesis when fuzz fibres are initiating, expression of MYB25-like_Dt was significantly lower in fuzzless NILs than in fuzzy seeded NILs, while higher MYB25-like_Dt expression was associated with more seed fuzz across different cotton genotypes. Phenotypic and genotypic analysis of MYB25-like homoeoalleles in cottons showing different fibre phenotypes and their crossing progeny indicated that both MYB25-like_At and MYB25-like_Dt are associated with lint development, and that fuzz development is mainly determined by the expression level of MYB25-like_Dt at ~3 d post-anthesis. Expression of Gb fuzzless seeds depends on genetic background and interactions amongst the multiple loci identified. MYB25-like_Dt is one of the best candidates for N2.
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Affiliation(s)
- Qian-Hao Zhu
- CSIRO Agriculture and Food, Canberra, ACT, Australia
- Correspondence: and
| | - Yuman Yuan
- CSIRO Agriculture and Food, Canberra, ACT, Australia
| | - Warwick Stiller
- CSIRO Agriculture and Food, Locked, Narrabri, NSW, Australia
| | - Yinhua Jia
- State Key Laboratory of Cotton Biology/Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China
| | - Pengpeng Wang
- State Key Laboratory of Cotton Biology/Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China
| | - Zhaoe Pan
- State Key Laboratory of Cotton Biology/Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China
| | - Xiongming Du
- State Key Laboratory of Cotton Biology/Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China
| | | | - Iain Wilson
- CSIRO Agriculture and Food, Canberra, ACT, Australia
- Correspondence: and
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Correction. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 91:928. [PMID: 28799189 DOI: 10.1111/tpj.13645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
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Jiang H, Moreno-Romero J, Santos-González J, De Jaeger G, Gevaert K, Van De Slijke E, Köhler C. Ectopic application of the repressive histone modification H3K9me2 establishes post-zygotic reproductive isolation in Arabidopsis thaliana. Genes Dev 2017; 31:1272-1287. [PMID: 28743695 PMCID: PMC5558928 DOI: 10.1101/gad.299347.117] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 06/27/2017] [Indexed: 11/24/2022]
Abstract
Hybrid seed lethality as a consequence of interspecies or interploidy hybridizations is a major mechanism of reproductive isolation in plants. This mechanism is manifested in the endosperm, a dosage-sensitive tissue supporting embryo growth. Deregulated expression of imprinted genes such as ADMETOS (ADM) underpin the interploidy hybridization barrier in Arabidopsis thaliana; however, the mechanisms of their action remained unknown. In this study, we show that ADM interacts with the AT hook domain protein AHL10 and the SET domain-containing SU(VAR)3-9 homolog SUVH9 and ectopically recruits the heterochromatic mark H3K9me2 to AT-rich transposable elements (TEs), causing deregulated expression of neighboring genes. Several hybrid incompatibility genes identified in Drosophila encode for dosage-sensitive heterochromatin-interacting proteins, which has led to the suggestion that hybrid incompatibilities evolve as a consequence of interspecies divergence of selfish DNA elements and their regulation. Our data show that imbalance of dosage-sensitive chromatin regulators underpins the barrier to interploidy hybridization in Arabidopsis, suggesting that reproductive isolation as a consequence of epigenetic regulation of TEs is a conserved feature in animals and plants.
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Affiliation(s)
- Hua Jiang
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Linnean Center of Plant Biology, Uppsala 75007, Sweden
| | - Jordi Moreno-Romero
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Linnean Center of Plant Biology, Uppsala 75007, Sweden
| | - Juan Santos-González
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Linnean Center of Plant Biology, Uppsala 75007, Sweden
| | - Geert De Jaeger
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent 9052, Belgium
- VIB Center for Plant Systems Biology, Ghent 9052, Belgium
| | - Kris Gevaert
- Department of Biochemistry, Ghent University, Ghent 9052, Belgium
- VIB Center for Medical Biotechnology, Ghent 9052, Belgium
| | - Eveline Van De Slijke
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent 9052, Belgium
- VIB Center for Plant Systems Biology, Ghent 9052, Belgium
| | - Claudia Köhler
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Linnean Center of Plant Biology, Uppsala 75007, Sweden
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