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Mateo-Bonmatí E, Montez M, Maple R, Fiedler M, Fang X, Saalbach G, Passmore LA, Dean C. A CPF-like phosphatase module links transcription termination to chromatin silencing. Mol Cell 2024; 84:2272-2286.e7. [PMID: 38851185 DOI: 10.1016/j.molcel.2024.05.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 02/28/2024] [Accepted: 05/15/2024] [Indexed: 06/10/2024]
Abstract
The interconnections between co-transcriptional regulation, chromatin environment, and transcriptional output remain poorly understood. Here, we investigate the mechanism underlying RNA 3' processing-mediated Polycomb silencing of Arabidopsis FLOWERING LOCUS C (FLC). We show a requirement for ANTHESIS PROMOTING FACTOR 1 (APRF1), a homolog of yeast Swd2 and human WDR82, known to regulate RNA polymerase II (RNA Pol II) during transcription termination. APRF1 interacts with TYPE ONE SERINE/THREONINE PROTEIN PHOSPHATASE 4 (TOPP4) (yeast Glc7/human PP1) and LUMINIDEPENDENS (LD), the latter showing structural features found in Ref2/PNUTS, all components of the yeast and human phosphatase module of the CPF 3' end-processing machinery. LD has been shown to co-associate in vivo with the histone H3 K4 demethylase FLOWERING LOCUS D (FLD). This work shows how the APRF1/LD-mediated polyadenylation/termination process influences subsequent rounds of transcription by changing the local chromatin environment at FLC.
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Affiliation(s)
- Eduardo Mateo-Bonmatí
- Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK; Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)/CSIC, Pozuelo de Alarcón, Madrid 28223, Spain.
| | - Miguel Montez
- Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Robert Maple
- Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Marc Fiedler
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Xiaofeng Fang
- Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Gerhard Saalbach
- Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | | | - Caroline Dean
- Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK; MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK.
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2
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Menon G, Mateo-Bonmati E, Reeck S, Maple R, Wu Z, Ietswaart R, Dean C, Howard M. Proximal termination generates a transcriptional state that determines the rate of establishment of Polycomb silencing. Mol Cell 2024; 84:2255-2271.e9. [PMID: 38851186 DOI: 10.1016/j.molcel.2024.05.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 02/28/2024] [Accepted: 05/14/2024] [Indexed: 06/10/2024]
Abstract
The mechanisms and timescales controlling de novo establishment of chromatin-mediated transcriptional silencing by Polycomb repressive complex 2 (PRC2) are unclear. Here, we investigate PRC2 silencing at Arabidopsis FLOWERING LOCUS C (FLC), known to involve co-transcriptional RNA processing, histone demethylation activity, and PRC2 function, but so far not mechanistically connected. We develop and test a computational model describing proximal polyadenylation/termination mediated by the RNA-binding protein FCA that induces H3K4me1 removal by the histone demethylase FLD. H3K4me1 removal feeds back to reduce RNA polymerase II (RNA Pol II) processivity and thus enhance early termination, thereby repressing productive transcription. The model predicts that this transcription-coupled repression controls the level of transcriptional antagonism to PRC2 action. Thus, the effectiveness of this repression dictates the timescale for establishment of PRC2/H3K27me3 silencing. We experimentally validate these mechanistic model predictions, revealing that co-transcriptional processing sets the level of productive transcription at the locus, which then determines the rate of the ON-to-OFF switch to PRC2 silencing.
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Affiliation(s)
- Govind Menon
- Department of Computational and Systems Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Eduardo Mateo-Bonmati
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Svenja Reeck
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Robert Maple
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Zhe Wu
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Robert Ietswaart
- Harvard Medical School, Department of Genetics, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Caroline Dean
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
| | - Martin Howard
- Department of Computational and Systems Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
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3
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Bergis-Ser C, Reji M, Latrasse D, Bergounioux C, Benhamed M, Raynaud C. Chromatin dynamics and RNA metabolism are double-edged swords for the maintenance of plant genome integrity. NATURE PLANTS 2024; 10:857-873. [PMID: 38658791 DOI: 10.1038/s41477-024-01678-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Accepted: 03/27/2024] [Indexed: 04/26/2024]
Abstract
Maintenance of genome integrity is an essential process in all organisms. Mechanisms avoiding the formation of DNA lesions or mutations are well described in animals because of their relevance to human health and cancer. In plants, they are of growing interest because DNA damage accumulation is increasingly recognized as one of the consequences of stress. Although the cellular response to DNA damage is mostly studied in response to genotoxic treatments, the main source of DNA lesions is cellular activity itself. This can occur through the production of reactive oxygen species as well as DNA processing mechanisms such as DNA replication or transcription and chromatin dynamics. In addition, how lesions are formed and repaired is greatly influenced by chromatin features and dynamics and by DNA and RNA metabolism. Notably, actively transcribed regions or replicating DNA, because they are less condensed and are sites of DNA processing, are more exposed to DNA damage. However, at the same time, a wealth of cellular mechanisms cooperate to favour DNA repair at these genomic loci. These intricate relationships that shape the distribution of mutations along the genome have been studied extensively in animals but much less in plants. In this Review, we summarize how chromatin dynamics influence lesion formation and DNA repair in plants, providing a comprehensive view of current knowledge and highlighting open questions with regard to what is known in other organisms.
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Affiliation(s)
- Clara Bergis-Ser
- Université Paris-Saclay, CNRS, INRAE, Université d'Evry, Institute of Plant Sciences Paris-Saclay, Orsay, France
| | - Meega Reji
- Université Paris-Saclay, CNRS, INRAE, Université d'Evry, Institute of Plant Sciences Paris-Saclay, Orsay, France
- Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, India
| | - David Latrasse
- Université Paris-Saclay, CNRS, INRAE, Université d'Evry, Institute of Plant Sciences Paris-Saclay, Orsay, France
| | - Catherine Bergounioux
- Université Paris-Saclay, CNRS, INRAE, Université d'Evry, Institute of Plant Sciences Paris-Saclay, Orsay, France
| | - Moussa Benhamed
- Université Paris-Saclay, CNRS, INRAE, Université d'Evry, Institute of Plant Sciences Paris-Saclay, Orsay, France
- Université Paris Cité, Institute of Plant Sciences Paris-Saclay, Gif-sur-Yvette, France
- Institut Universitaire de France, Orsay, France
| | - Cécile Raynaud
- Université Paris-Saclay, CNRS, INRAE, Université d'Evry, Institute of Plant Sciences Paris-Saclay, Orsay, France.
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4
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Li J, Zhang Q, Wang Z, Liu Q. The roles of epigenetic regulators in plant regeneration: Exploring patterns amidst complex conditions. PLANT PHYSIOLOGY 2024; 194:2022-2038. [PMID: 38290051 PMCID: PMC10980418 DOI: 10.1093/plphys/kiae042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/06/2023] [Accepted: 12/17/2023] [Indexed: 02/01/2024]
Abstract
Plants possess remarkable capability to regenerate upon tissue damage or optimal environmental stimuli. This ability not only serves as a crucial strategy for immobile plants to survive through harsh environments, but also made numerous modern plant improvements techniques possible. At the cellular level, this biological process involves dynamic changes in gene expression that redirect cell fate transitions. It is increasingly recognized that chromatin epigenetic modifications, both activating and repressive, intricately interact to regulate this process. Moreover, the outcomes of epigenetic regulation on regeneration are influenced by factors such as the differences in regenerative plant species and donor tissue types, as well as the concentration and timing of hormone treatments. In this review, we focus on several well-characterized epigenetic modifications and their regulatory roles in the expression of widely studied morphogenic regulators, aiming to enhance our understanding of the mechanisms by which epigenetic modifications govern plant regeneration.
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Affiliation(s)
- Jiawen Li
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences, Peking University, Beijing 100871, China
| | - Qiyan Zhang
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences, Peking University, Beijing 100871, China
| | - Zejia Wang
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences, Peking University, Beijing 100871, China
| | - Qikun Liu
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences, Peking University, Beijing 100871, China
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5
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Nielsen M, Menon G, Zhao Y, Mateo-Bonmati E, Wolff P, Zhou S, Howard M, Dean C. COOLAIR and PRC2 function in parallel to silence FLC during vernalization. Proc Natl Acad Sci U S A 2024; 121:e2311474121. [PMID: 38236739 PMCID: PMC10823242 DOI: 10.1073/pnas.2311474121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 12/11/2023] [Indexed: 01/23/2024] Open
Abstract
Noncoding transcription induces chromatin changes that can mediate environmental responsiveness, but the causes and consequences of these mechanisms are still unclear. Here, we investigate how antisense transcription (termed COOLAIR) interfaces with Polycomb Repressive Complex 2 (PRC2) silencing during winter-induced epigenetic regulation of Arabidopsis FLOWERING LOCUS C (FLC). We use genetic and chromatin analyses on lines ineffective or hyperactive for the antisense pathway in combination with computational modeling to define the mechanisms underlying FLC repression. Our results show that FLC is silenced through pathways that function with different dynamics: a COOLAIR transcription-mediated pathway capable of fast response and in parallel a slow PRC2 switching mechanism that maintains each allele in an epigenetically silenced state. Components of both the COOLAIR and PRC2 pathways are regulated by a common transcriptional regulator (NTL8), which accumulates by reduced dilution due to slow growth at low temperature. The parallel activities of the regulatory steps, and their control by temperature-dependent growth dynamics, create a flexible system for registering widely fluctuating natural temperature conditions that change year on year, and yet ensure robust epigenetic silencing of FLC.
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Affiliation(s)
- Mathias Nielsen
- Department of Cell and Developmental Biology, John Innes Centre, NorwichNR4 7UH, United Kingdom
| | - Govind Menon
- Computational and Systems Biology, John Innes Centre, NorwichNR4 7UH, United Kingdom
| | - Yusheng Zhao
- Department of Cell and Developmental Biology, John Innes Centre, NorwichNR4 7UH, United Kingdom
| | - Eduardo Mateo-Bonmati
- Department of Cell and Developmental Biology, John Innes Centre, NorwichNR4 7UH, United Kingdom
| | - Philip Wolff
- Department of Cell and Developmental Biology, John Innes Centre, NorwichNR4 7UH, United Kingdom
| | - Shaoli Zhou
- Department of Cell and Developmental Biology, John Innes Centre, NorwichNR4 7UH, United Kingdom
| | - Martin Howard
- Computational and Systems Biology, John Innes Centre, NorwichNR4 7UH, United Kingdom
| | - Caroline Dean
- Department of Cell and Developmental Biology, John Innes Centre, NorwichNR4 7UH, United Kingdom
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6
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Zhu P, Schon M, Questa J, Nodine M, Dean C. Causal role of a promoter polymorphism in natural variation of the Arabidopsis floral repressor gene FLC. Curr Biol 2023; 33:4381-4391.e3. [PMID: 37729909 DOI: 10.1016/j.cub.2023.08.079] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 07/06/2023] [Accepted: 08/25/2023] [Indexed: 09/22/2023]
Abstract
Noncoding polymorphism frequently associates with phenotypic variation, but causation and mechanism are rarely established. Noncoding single-nucleotide polymorphisms (SNPs) characterize the major haplotypes of the Arabidopsis thaliana floral repressor gene FLOWERING LOCUS C (FLC). This noncoding polymorphism generates a range of FLC expression levels, determining the requirement for and the response to winter cold. The major adaptive determinant of these FLC haplotypes was shown to be the autumnal levels of FLC expression. Here, we investigate how noncoding SNPs influence FLC transcriptional output. We identify an upstream transcription start site (uTSS) cluster at FLC, whose usage is increased by an A variant at the promoter SNP-230. This variant is present in relatively few Arabidopsis accessions, with the majority containing G at this site. We demonstrate a causal role for the A variant at -230 in reduced FLC transcriptional output. The G variant upregulates FLC expression redundantly with the major transcriptional activator FRIGIDA (FRI). We demonstrate an additive interaction of SNP-230 with an intronic SNP+259, which also differentially influences uTSS usage. Combinatorial interactions between noncoding SNPs and transcriptional activators thus generate quantitative variation in FLC transcription that has facilitated the adaptation of Arabidopsis accessions to distinct climates.
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Affiliation(s)
- Pan Zhu
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Michael Schon
- Laboratory of Molecular Biology, Wageningen University, Wageningen 6708 PB, the Netherlands; Gregor Mendel Institute, Vienna Biocenter, Vienna 1030, Austria
| | - Julia Questa
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Michael Nodine
- Laboratory of Molecular Biology, Wageningen University, Wageningen 6708 PB, the Netherlands; Gregor Mendel Institute, Vienna Biocenter, Vienna 1030, Austria
| | - Caroline Dean
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
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7
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Wang Y, He S, Fang X. Emerging roles of phase separation in plant transcription and chromatin organization. CURRENT OPINION IN PLANT BIOLOGY 2023; 75:102387. [PMID: 37311366 DOI: 10.1016/j.pbi.2023.102387] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/07/2023] [Accepted: 05/10/2023] [Indexed: 06/15/2023]
Abstract
Transcription is a core step in gene expression. Regulation of transcription is achieved at the level of transcription machinery, local chromatin environment as well as higher-order chromatin organization. Our understanding of transcriptional regulation was advanced by recent introduction of transcription and chromatin-associated condensates, which typically arise via phase separation of proteins and nucleic acids. While studies from mammalian cells are unveiling the mechanisms of phase separation in transcription regulation, those in plants further broaden and deepen our understanding of this process. In this review, we discuss recent progress in plants how phase separation operates in RNA-mediated chromatin silencing, transcription activity, and chromatin compartmentalization.
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Affiliation(s)
- Yunhe Wang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Shengbo He
- Guangdong Laboratory for Lingnan Modern Agriculture, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Provincial Key Laboratory of Plant Molecular Breeding, South China Agricultural University, Guangzhou 510642, China.
| | - Xiaofeng Fang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
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8
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Field S, Jang GJ, Dean C, Strader LC, Rhee SY. Plants use molecular mechanisms mediated by biomolecular condensates to integrate environmental cues with development. THE PLANT CELL 2023; 35:3173-3186. [PMID: 36879427 PMCID: PMC10473230 DOI: 10.1093/plcell/koad062] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 02/01/2023] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
This review highlights recent literature on biomolecular condensates in plant development and discusses challenges for fully dissecting their functional roles. Plant developmental biology has been inundated with descriptive examples of biomolecular condensate formation, but it is only recently that mechanistic understanding has been forthcoming. Here, we discuss recent examples of potential roles biomolecular condensates play at different stages of the plant life cycle. We group these examples based on putative molecular functions, including sequestering interacting components, enhancing dwell time, and interacting with cytoplasmic biophysical properties in response to environmental change. We explore how these mechanisms could modulate plant development in response to environmental inputs and discuss challenges and opportunities for further research into deciphering molecular mechanisms to better understand the diverse roles that biomolecular condensates exert on life.
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Affiliation(s)
- Sterling Field
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Geng-Jen Jang
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Caroline Dean
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Lucia C Strader
- Department of Biology, Duke University, Durham, NC 27708, USA
| | - Seung Y Rhee
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
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9
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Palos K, Yu L, Railey CE, Nelson Dittrich AC, Nelson ADL. Linking discoveries, mechanisms, and technologies to develop a clearer perspective on plant long noncoding RNAs. THE PLANT CELL 2023; 35:1762-1786. [PMID: 36738093 PMCID: PMC10226578 DOI: 10.1093/plcell/koad027] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 12/19/2022] [Accepted: 12/22/2022] [Indexed: 05/30/2023]
Abstract
Long noncoding RNAs (lncRNAs) are a large and diverse class of genes in eukaryotic genomes that contribute to a variety of regulatory processes. Functionally characterized lncRNAs play critical roles in plants, ranging from regulating flowering to controlling lateral root formation. However, findings from the past decade have revealed that thousands of lncRNAs are present in plant transcriptomes, and characterization has lagged far behind identification. In this setting, distinguishing function from noise is challenging. However, the plant community has been at the forefront of discovery in lncRNA biology, providing many functional and mechanistic insights that have increased our understanding of this gene class. In this review, we examine the key discoveries and insights made in plant lncRNA biology over the past two and a half decades. We describe how discoveries made in the pregenomics era have informed efforts to identify and functionally characterize lncRNAs in the subsequent decades. We provide an overview of the functional archetypes into which characterized plant lncRNAs fit and speculate on new avenues of research that may uncover yet more archetypes. Finally, this review discusses the challenges facing the field and some exciting new molecular and computational approaches that may help inform lncRNA comparative and functional analyses.
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Affiliation(s)
- Kyle Palos
- Boyce Thompson Institute, Cornell University, Ithaca, NY 14853, USA
| | - Li’ang Yu
- Boyce Thompson Institute, Cornell University, Ithaca, NY 14853, USA
| | - Caylyn E Railey
- Boyce Thompson Institute, Cornell University, Ithaca, NY 14853, USA
- Plant Biology Graduate Field, Cornell University, Ithaca, NY 14853, USA
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10
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Zeng J, Yang L, Tian M, Xie X, Liu C, Ruan Y. SDG26 Is Involved in Trichome Control in Arabidopsis thaliana: Affecting Phytohormones and Adjusting Accumulation of H3K27me3 on Genes Related to Trichome Growth and Development. PLANTS (BASEL, SWITZERLAND) 2023; 12:plants12081651. [PMID: 37111875 PMCID: PMC10143075 DOI: 10.3390/plants12081651] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 04/07/2023] [Accepted: 04/12/2023] [Indexed: 06/12/2023]
Abstract
Plant trichomes formed by specialized epidermal cells play a role in protecting plants from biotic and abiotic stresses and can also influence the economic and ornamental value of plant products. Therefore, further studies on the molecular mechanisms of plant trichome growth and development are important for understanding trichome formation and agricultural production. SET Domain Group 26 (SDG26) is a histone lysine methyltransferase. Currently, the molecular mechanism by which SDG26 regulates the growth and development of Arabidopsis leaf trichomes is still unclear. We found that the mutant of Arabidopsis (sdg26) possessed more trichomes on its rosette leaves compared to the wild type (Col-0), and the trichome density per unit area of sdg26 is significantly higher than that of Col-0. The content of cytokinins and jasmonic acid was higher in sdg26 than in Col-0, while the content of salicylic acid was lower in sdg26 than in Col-0, which is conducive to trichome growth. By measuring the expression levels of trichome-related genes, we found that the expression of genes that positively regulate trichome growth and development were up-regulated, while the negatively regulated genes were down-regulated in sdg26. Through chromatin immunoprecipitation sequencing (ChIP-seq) analysis, we found that SDG26 can directly regulate the expression of genes related to trichome growth and development such as ZFP1, ZFP5, ZFP6, GL3, MYB23, MYC1, TT8, GL1, GIS2, IPT1, IPT3, and IPT5 by increasing the accumulation of H3K27me3 on these genes, which further affects the growth and development of trichomes. This study reveals the mechanism by which SDG26 affects the growth and development of trichomes through histone methylation. The current study provides a theoretical basis for studying the molecular mechanism of histone methylation in regulating leaf trichome growth and development and perhaps guiding the development of new crop varieties.
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Affiliation(s)
- Jing Zeng
- Key Laboratory of Hunan Provincial on Crop Epigenetic Regulation and Development, Hunan Agricultural University, Changsha 410128, China
- Key Laboratory of Crop Physiology and Molecular Biology of Ministry of Education, Hunan Agricultural University, Changsha 410128, China
| | - Lanpeng Yang
- School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong 999077, China
| | - Minyu Tian
- Key Laboratory of Hunan Provincial on Crop Epigenetic Regulation and Development, Hunan Agricultural University, Changsha 410128, China
- Key Laboratory of Crop Physiology and Molecular Biology of Ministry of Education, Hunan Agricultural University, Changsha 410128, China
| | - Xiang Xie
- Key Laboratory of Crop Physiology and Molecular Biology of Ministry of Education, Hunan Agricultural University, Changsha 410128, China
| | - Chunlin Liu
- Key Laboratory of Hunan Provincial on Crop Epigenetic Regulation and Development, Hunan Agricultural University, Changsha 410128, China
- Key Laboratory of Crop Physiology and Molecular Biology of Ministry of Education, Hunan Agricultural University, Changsha 410128, China
| | - Ying Ruan
- Key Laboratory of Hunan Provincial on Crop Epigenetic Regulation and Development, Hunan Agricultural University, Changsha 410128, China
- Key Laboratory of Crop Physiology and Molecular Biology of Ministry of Education, Hunan Agricultural University, Changsha 410128, China
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11
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Gullotta G, Korte A, Marquardt S. Functional variation in the non-coding genome: molecular implications for food security. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:2338-2351. [PMID: 36316269 DOI: 10.1093/jxb/erac395] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 10/06/2022] [Indexed: 06/06/2023]
Abstract
The growing world population, in combination with the anticipated effects of climate change, is pressuring food security. Plants display an impressive arsenal of cellular mechanisms conferring resilience to adverse environmental conditions, and humans rely on these mechanisms for stable food production. The elucidation of the molecular basis of the mechanisms used by plants to achieve resilience promises knowledge-based approaches to enhance food security. DNA sequence polymorphisms can reveal genomic regions that are linked to beneficial traits of plants. However, our ability to interpret how a given DNA sequence polymorphism confers a fitness advantage at the molecular level often remains poor. A key factor is that these polymorphisms largely localize to the enigmatic non-coding genome. Here, we review the functional impact of sequence variations in the non-coding genome on plant biology in the context of crop breeding and agricultural traits. We focus on examples of non-coding with particularly convincing functional support. Our survey combines findings that are consistent with the view that the non-coding genome contributes to cellular mechanisms assisting many plant traits. Understanding how DNA sequence polymorphisms in the non-coding genome shape plant traits at the molecular level offers a largely unexplored reservoir of solutions to address future challenges in plant growth and resilience.
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Affiliation(s)
- Giorgio Gullotta
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Bülowsvej 21A, 1871 Frederiksberg, Denmark
| | - Arthur Korte
- Center for Computational and Theoretical Biology, University of Würzburg, Hubland Nord 32, 97074 Würzburg, Germany
| | - Sebastian Marquardt
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Bülowsvej 21A, 1871 Frederiksberg, Denmark
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12
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Jeon M, Jeong G, Yang Y, Luo X, Jeong D, Kyung J, Hyun Y, He Y, Lee I. Vernalization-triggered expression of the antisense transcript COOLAIR is mediated by CBF genes. eLife 2023; 12:84594. [PMID: 36722843 PMCID: PMC10036118 DOI: 10.7554/elife.84594] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 01/31/2023] [Indexed: 02/02/2023] Open
Abstract
To synchronize flowering time with spring, many plants undergo vernalization, a floral-promotion process triggered by exposure to long-term winter cold. In Arabidopsis thaliana, this is achieved through cold-mediated epigenetic silencing of the floral repressor, FLOWERING LOCUS C (FLC). COOLAIR, a cold-induced antisense RNA transcribed from the FLC locus, has been proposed to facilitate FLC silencing. Here, we show that C-repeat (CRT)/dehydration-responsive elements (DREs) at the 3'-end of FLC and CRT/DRE-binding factors (CBFs) are required for cold-mediated expression of COOLAIR. CBFs bind to CRT/DREs at the 3'-end of FLC, both in vitro and in vivo, and CBF levels increase gradually during vernalization. Cold-induced COOLAIR expression is severely impaired in cbfs mutants in which all CBF genes are knocked-out. Conversely, CBF-overexpressing plants show increased COOLAIR levels even at warm temperatures. We show that COOLAIR is induced by CBFs during early stages of vernalization but COOLAIR levels decrease in later phases as FLC chromatin transitions to an inactive state to which CBFs can no longer bind. We also demonstrate that cbfs and FLCΔCOOLAIR mutants exhibit a normal vernalization response despite their inability to activate COOLAIR expression during cold, revealing that COOLAIR is not required for the vernalization process.
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Affiliation(s)
- Myeongjune Jeon
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
- Research Center for Plant Plasticity, Seoul National University, Seoul, Republic of Korea
| | - Goowon Jeong
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
- Research Center for Plant Plasticity, Seoul National University, Seoul, Republic of Korea
| | - Yupeng Yang
- Shanghai Center for Plant Stress Biology & National Key Laboratory for Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Xiao Luo
- Peking University Institute of Advanced Agricultural Sciences, Weifang, China
| | - Daesong Jeong
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
- Research Center for Plant Plasticity, Seoul National University, Seoul, Republic of Korea
| | - Jinseul Kyung
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
- Research Center for Plant Plasticity, Seoul National University, Seoul, Republic of Korea
| | - Youbong Hyun
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
- Research Center for Plant Plasticity, Seoul National University, Seoul, Republic of Korea
| | - Yuehui He
- Shanghai Center for Plant Stress Biology & National Key Laboratory for Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
- Peking University Institute of Advanced Agricultural Sciences, Weifang, China
| | - Ilha Lee
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
- Research Center for Plant Plasticity, Seoul National University, Seoul, Republic of Korea
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13
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Kyung J, Jeon M, Lee I. Recent advances in the chromatin-based mechanism of FLOWERING LOCUS C repression through autonomous pathway genes. FRONTIERS IN PLANT SCIENCE 2022; 13:964931. [PMID: 36035698 PMCID: PMC9411803 DOI: 10.3389/fpls.2022.964931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 07/19/2022] [Indexed: 06/15/2023]
Abstract
Proper timing of flowering, a phase transition from vegetative to reproductive development, is crucial for plant fitness. The floral repressor FLOWERING LOCUS C (FLC) is the major determinant of flowering in Arabidopsis thaliana. In rapid-cycling A. thaliana accessions, which bloom rapidly, FLC is constitutively repressed by autonomous pathway (AP) genes, regardless of photoperiod. Diverse AP genes have been identified over the past two decades, and most of them repress FLC through histone modifications. However, the detailed mechanism underlying such modifications remains unclear. Several recent studies have revealed novel mechanisms to control FLC repression in concert with histone modifications. This review summarizes the latest advances in understanding the novel mechanisms by which AP proteins regulate FLC repression, including changes in chromatin architecture, RNA polymerase pausing, and liquid-liquid phase separation- and ncRNA-mediated gene silencing. Furthermore, we discuss how each mechanism is coupled with histone modifications in FLC chromatin.
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Affiliation(s)
- Jinseul Kyung
- School of Biological Sciences, Seoul National University, Seoul, South Korea
- Research Center for Plant Plasticity, Seoul National University, Seoul, South Korea
| | - Myeongjune Jeon
- School of Biological Sciences, Seoul National University, Seoul, South Korea
- Research Center for Plant Plasticity, Seoul National University, Seoul, South Korea
| | - Ilha Lee
- School of Biological Sciences, Seoul National University, Seoul, South Korea
- Research Center for Plant Plasticity, Seoul National University, Seoul, South Korea
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14
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Xiao M, Wang J, Xu F. Methylation hallmarks on the histone tail as a linker of osmotic stress and gene transcription. FRONTIERS IN PLANT SCIENCE 2022; 13:967607. [PMID: 36035677 PMCID: PMC9399788 DOI: 10.3389/fpls.2022.967607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 07/25/2022] [Indexed: 06/12/2023]
Abstract
Plants dynamically manipulate their gene expression in acclimation to the challenging environment. Hereinto, the histone methylation tunes the gene transcription via modulation of the chromatin accessibility to transcription machinery. Osmotic stress, which is caused by water deprivation or high concentration of ions, can trigger remarkable changes in histone methylation landscape and genome-wide reprogramming of transcription. However, the dynamic regulation of genes, especially how stress-inducible genes are timely epi-regulated by histone methylation remains largely unclear. In this review, recent findings on the interaction between histone (de)methylation and osmotic stress were summarized, with emphasis on the effects on histone methylation profiles imposed by stress and how histone methylation works to optimize the performance of plants under stress.
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15
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Mellor C, Perez C, Sale JE. Creation and resolution of non-B-DNA structural impediments during replication. Crit Rev Biochem Mol Biol 2022; 57:412-442. [PMID: 36170051 PMCID: PMC7613824 DOI: 10.1080/10409238.2022.2121803] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 08/02/2022] [Accepted: 08/25/2022] [Indexed: 01/27/2023]
Abstract
During replication, folding of the DNA template into non-B-form secondary structures provides one of the most abundant impediments to the smooth progression of the replisome. The core replisome collaborates with multiple accessory factors to ensure timely and accurate duplication of the genome and epigenome. Here, we discuss the forces that drive non-B structure formation and the evidence that secondary structures are a significant and frequent source of replication stress that must be actively countered. Taking advantage of recent advances in the molecular and structural biology of the yeast and human replisomes, we examine how structures form and how they may be sensed and resolved during replication.
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Affiliation(s)
- Christopher Mellor
- Division of Protein & Nucleic Acid Chemistry, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Consuelo Perez
- Division of Protein & Nucleic Acid Chemistry, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Julian E Sale
- Division of Protein & Nucleic Acid Chemistry, MRC Laboratory of Molecular Biology, Cambridge, UK
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16
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Yang D, Zhao F, Zhu D, Chen X, Kong X, Wu Y, Chen M, Du J, Qu LJ, Wu Z. Progressive chromatin silencing of ABA biosynthesis genes permits seed germination in Arabidopsis. THE PLANT CELL 2022; 34:2871-2891. [PMID: 35522002 PMCID: PMC9338806 DOI: 10.1093/plcell/koac134] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 04/28/2022] [Indexed: 05/08/2023]
Abstract
Seed germination represents a major developmental switch in plants that is vital to agriculture, but how this process is controlled at the chromatin level remains obscure. Here we demonstrate that successful germination in Arabidopsis thaliana requires a chromatin mechanism that progressively silences 9-CIS-EPOXYCAROTENOID DIOXYGENASE 6 (NCED6), which encodes a rate-limiting enzyme in abscisic acid (ABA) biosynthesis, through the cooperative action of the RNA-binding protein RZ-1 and the polycomb repressive complex 2 (PRC2). Simultaneous inactivation of RZ-1 and PRC2 blocked germination and synergistically derepressed NCEDs and hundreds of genes. At NCED6, in part by promoting H3 deacetylation and suppressing H3K4me3, RZ-1 facilitates transcriptional silencing and also an H3K27me3 accumulation process that occurs during seed germination and early seedling growth. Genome-wide analysis revealed that RZ-1 is preferentially required for transcriptional silencing of many PRC2 targets early during seed germination, when H3K27me3 is not yet established. We propose RZ-1 confers a novel silencing mechanism to compensate for and synergize with PRC2. Our work highlights the progressive chromatin silencing of ABA biosynthesis genes via the RNA-binding protein RZ-1 and PRC2 acting in synergy, a process that is vital for seed germination.
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Affiliation(s)
| | | | - Danling Zhu
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xi Chen
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xiangxiong Kong
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yufeng Wu
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Bioinformatics Center, Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
| | - Min Chen
- State Key Laboratory of Crop Stress Adaptation and Improvement, Henan University, Kaifeng 475000, China
| | - Jiamu Du
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Li-Jia Qu
- State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, College of Life Sciences, Peking University, Beijing 100871, China
| | - Zhe Wu
- Author for correspondence:
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17
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Qi PL, Zhou HR, Zhao QQ, Feng C, Ning YQ, Su YN, Cai XW, Yuan DY, Zhang ZC, Su XM, Chen SS, Li L, Chen S, He XJ. Characterization of an autonomous pathway complex that promotes flowering in Arabidopsis. Nucleic Acids Res 2022; 50:7380-7395. [PMID: 35766439 PMCID: PMC9303297 DOI: 10.1093/nar/gkac551] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 05/24/2022] [Accepted: 06/27/2022] [Indexed: 11/16/2022] Open
Abstract
Although previous studies have identified several autonomous pathway components that are required for the promotion of flowering, little is known about how these components cooperate. Here, we identified an autonomous pathway complex (AuPC) containing both known components (FLD, LD and SDG26) and previously unknown components (EFL2, EFL4 and APRF1). Loss-of-function mutations of all of these components result in increased FLC expression and delayed flowering. The delayed-flowering phenotype is independent of photoperiod and can be overcome by vernalization, confirming that the complex specifically functions in the autonomous pathway. Chromatin immunoprecipitation combined with sequencing indicated that, in the AuPC mutants, the histone modifications (H3Ac, H3K4me3 and H3K36me3) associated with transcriptional activation are increased, and the histone modification (H3K27me3) associated with transcriptional repression is reduced, suggesting that the AuPC suppresses FLC expression at least partially by regulating these histone modifications. Moreover, we found that the AuPC component SDG26 associates with FLC chromatin via a previously uncharacterized DNA-binding domain and regulates FLC expression and flowering time independently of its histone methyltransferase activity. Together, these results provide a framework for understanding the molecular mechanism by which the autonomous pathway regulates flowering time.
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Affiliation(s)
- Pei-Lin Qi
- National Institute of Biological Sciences, Beijing 102206, China.,PTN Joint Graduate Program, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Hao-Ran Zhou
- National Institute of Biological Sciences, Beijing 102206, China
| | - Qiang-Qiang Zhao
- National Institute of Biological Sciences, Beijing 102206, China.,Graduate School of Peking Union Medical College, Beijing 100730, China
| | - Chao Feng
- National Institute of Biological Sciences, Beijing 102206, China
| | - Yong-Qiang Ning
- National Institute of Biological Sciences, Beijing 102206, China
| | - Yin-Na Su
- National Institute of Biological Sciences, Beijing 102206, China
| | - Xue-Wei Cai
- National Institute of Biological Sciences, Beijing 102206, China
| | - Dan-Yang Yuan
- National Institute of Biological Sciences, Beijing 102206, China
| | - Zhao-Chen Zhang
- National Institute of Biological Sciences, Beijing 102206, China
| | - Xiao-Min Su
- National Institute of Biological Sciences, Beijing 102206, China
| | - Shan-Shan Chen
- National Institute of Biological Sciences, Beijing 102206, China
| | - Lin Li
- National Institute of Biological Sciences, Beijing 102206, China
| | - She Chen
- National Institute of Biological Sciences, Beijing 102206, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 100084, China
| | - Xin-Jian He
- National Institute of Biological Sciences, Beijing 102206, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 100084, China
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18
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The Arabidopsis DREAM complex antagonizes WDR5A to modulate histone H3K4me2/3 deposition for a subset of genome repression. Proc Natl Acad Sci U S A 2022; 119:e2206075119. [PMID: 35759663 PMCID: PMC9271193 DOI: 10.1073/pnas.2206075119] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The master transcriptional repressor DREAM (dimerization partner, RB-like, E2F and multivulval class B) complex regulates the cell cycle in eukaryotes, but much remains unknown about how it transmits repressive signals on chromatin to the primary transcriptional machinery (e.g., RNA polymerase II [Pol II]). Through a forward genetic screen, we identified BTE1 (barrier of transcription elongation 1), a plant-specific component of the DREAM complex. The subsequent characterization demonstrated that DREAM complex containing BTE1 antagonizes the activity of Complex Proteins Associated with Set1 (COMPASS)-like complex to repress H3K4me3 occupancy and inhibits Pol II elongation at DREAM target genes. We showed that BTE1 is recruited to chromatin at the promoter-proximal regions of target genes by E2F transcription factors. DREAM target genes exhibit characteristic enrichment of H2A.Z and H3K4me2 modification on chromatin. We further showed that BTE1 directly interacts with WDR5A, a core component of COMPASS-like complex, repressing WDR5A chromatin binding and the elongation of transcription on DREAM target genes. H3K4me3 is known to correlate with the Pol II transcription activation and promotes efficient elongation. Thus, our study illustrates a transcriptional repression mechanism by which the DREAM complex dampens H3K4me3 deposition at a set of genes through its interaction with WDR5A.
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19
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Lei Z, Wang L, Kim EY, Cho J. Phase separation of chromatin and small RNA pathways in plants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 108:1256-1265. [PMID: 34585805 DOI: 10.1111/tpj.15517] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 09/18/2021] [Accepted: 09/25/2021] [Indexed: 06/13/2023]
Abstract
Gene expression can be modulated by epigenetic mechanisms, including chromatin modifications and small regulatory RNAs. These pathways are unevenly distributed within a cell and usually take place in specific intracellular regions. Unfortunately, the fundamental driving force and biological relevance of such spatial differentiation is largely unknown. Liquid-liquid phase separation (LLPS) is a natural propensity of demixing liquid phases and has been recently suggested to mediate the formation of biomolecular condensates that are relevant to diverse cellular processes. LLPS provides a mechanistic explanation for the self-assembly of subcellular structures by which the efficiency and specificity of certain cellular reactions are achieved. In plants, LLPS has been observed for several key factors in the chromatin and small RNA pathways. For example, the formation of facultative and obligate heterochromatin involves the LLPS of multiple relevant factors. In addition, phase separation is observed in a set of proteins acting in microRNA biogenesis and the small interfering RNA pathway. In this Focused Review, we highlight and discuss the recent findings regarding phase separation in the epigenetic mechanisms of plants.
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Affiliation(s)
- Zhen Lei
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences (CEMPS), Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ling Wang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences (CEMPS), Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Eun Yu Kim
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences (CEMPS), Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Jungnam Cho
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences (CEMPS), Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- CAS-JIC Centre of Excellence for Plant and Microbial Science (CEPAMS), Chinese Academy of Sciences, Shanghai, 200032, China
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20
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Xu C, Fang X, Lu T, Dean C. Antagonistic cotranscriptional regulation through ARGONAUTE1 and the THO/TREX complex orchestrates FLC transcriptional output. Proc Natl Acad Sci U S A 2021; 118:e2113757118. [PMID: 34789567 PMCID: PMC8617408 DOI: 10.1073/pnas.2113757118] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 10/19/2021] [Indexed: 12/14/2022] Open
Abstract
Quantitative transcriptional control is essential for physiological and developmental processes in many organisms. Transcriptional output is influenced by cotranscriptional processes interconnected to chromatin regulation, but how the functions of different cotranscriptional regulators are integrated is poorly understood. The Arabidopsis floral repressor locus FLOWERING LOCUS C (FLC) is cotranscriptionally repressed by alternative processing of the antisense transcript COOLAIR. Proximal 3'-end processing of COOLAIR resolves a cotranscriptionally formed R-loop, and this process physically links to a histone-modifying complex FLD/SDG26/LD. This induces a chromatin environment locally that determines low transcription initiation and a slow elongation rate to both sense and antisense strands. Here, we show that ARGONAUTE1 (AGO1) genetically functions in this cotranscriptional repression mechanism. AGO1 associates with COOLAIR and influences COOLAIR splicing dynamics to promote proximal COOLAIR, R-loop resolution, and chromatin silencing. Proteomic analyses revealed physical associations between AGO1, subunits of RNA Polymerase II (Pol II), the splicing-related proteins-the spliceosome NineTeen Complex (NTC) and related proteins (NTR)-and the THO/TREX complex. We connect these activities by demonstrating that the THO/TREX complex activates FLC expression acting antagonistically to AGO1 in COOLAIR processing. Together these data reveal that antagonistic cotranscriptional regulation through AGO1 or THO/TREX influences COOLAIR processing to deliver a local chromatin environment that determines FLC transcriptional output. The involvement of these conserved cotranscriptional regulators suggests similar mechanisms may underpin quantitative transcriptional regulation generally.
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Affiliation(s)
- Congyao Xu
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Xiaofeng Fang
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Tiancong Lu
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Caroline Dean
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom
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21
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Yu X, Martin PGP, Zhang Y, Trinidad JC, Xu F, Huang J, Thum KE, Li K, Zhao S, Gu Y, Wang X, Michaels SD. The BORDER family of negative transcription elongation factors regulates flowering time in Arabidopsis. Curr Biol 2021; 31:5377-5384.e5. [PMID: 34666004 DOI: 10.1016/j.cub.2021.09.074] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 07/20/2021] [Accepted: 09/27/2021] [Indexed: 11/27/2022]
Abstract
Transcription initiation has long been considered a primary regulatory step in gene expression. Recent work, however, shows that downstream events, such as transcription elongation, can also play important roles.1-3 A well-characterized example from animals is promoter-proximal pausing, where transcriptionally engaged Pol II accumulates 30-50 bp downstream of the transcription start site (TSS) and is thought to enable rapid gene activation.2 Plants do not make widespread use of promoter-proximal pausing; however, in a phenomenon known as 3' pausing, a significant increase in Pol II is observed near the transcript end site (TES) of many genes.4-6 Previous work has shown that 3' pausing is promoted by the BORDER (BDR) family of negative transcription elongation factors. Here we show that BDR proteins play key roles in gene repression. Consistent with BDR proteins acting to slow or pause elongating Pol II, BDR-repressed genes are characterized by high levels of Pol II occupancy, yet low levels of mRNA. The BDR proteins physically interact with FPA,7 one of approximately two dozen genes collectively referred to as the autonomous floral-promotion pathway,8 which are necessary for the repression of the flowering time gene FLOWERING LOCUS C (FLC).9-11 In early-flowering strains, FLC expression is repressed by repressive histone modifications, such as histone H3 lysine 27 trimethylation (H3K27me3), thereby allowing the plants to flower early. These results suggest that the repression of transcription elongation by BDR proteins may allow for the temporary pausing of transcription or facilitate the long-term repression of genes by repressive histone modifications.
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Affiliation(s)
- Xuhong Yu
- Department of Biology, Indiana University, 915 East Third Street, Bloomington, IN 47405, USA.
| | - Pascal G P Martin
- Department of Biology, Indiana University, 915 East Third Street, Bloomington, IN 47405, USA
| | - Yixiang Zhang
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Jonathan C Trinidad
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA; Laboratory for Biological Mass Spectrometry, Department of Chemistry, Indiana University Bloomington, Bloomington, IN, USA
| | - Feifei Xu
- Institute of Nuclear Agricultural Sciences, Key Laboratory for Nuclear Agricultural Sciences of Zhejiang Province and Ministry of Agriculture and Rural Affairs, Zhejiang University, Zijingang Campus, Hangzhou 310058, China
| | - Jie Huang
- Center for Genomics and Bioinformatics, Indiana University, 915 East Third Street, Bloomington, IN 47405, USA
| | - Karen E Thum
- Department of Biology, Indiana University, 915 East Third Street, Bloomington, IN 47405, USA
| | - Ke Li
- Department of Biology, Indiana University, 915 East Third Street, Bloomington, IN 47405, USA
| | - ShuZhen Zhao
- Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Biotechnology Research Center, Shandong Academy of Agricultural Sciences, Jinan 250100, China
| | - Yangnan Gu
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Xingjun Wang
- Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Biotechnology Research Center, Shandong Academy of Agricultural Sciences, Jinan 250100, China
| | - Scott D Michaels
- Department of Biology, Indiana University, 915 East Third Street, Bloomington, IN 47405, USA.
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22
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Kim HS. Genetic Interaction Between Site-Specific Epigenetic Marks and Roles of H4v in Transcription Termination in Trypanosoma brucei. Front Cell Dev Biol 2021; 9:744878. [PMID: 34722526 PMCID: PMC8551723 DOI: 10.3389/fcell.2021.744878] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 09/15/2021] [Indexed: 11/13/2022] Open
Abstract
In Trypanosoma brucei, genes are assembled in polycistronic transcription units (PTUs). Boundaries of PTUs are designated transcription start sites and transcription termination sites (TTSs). Messenger RNAs are generated by trans-splicing and polyadenylation of precursor RNAs, and regulatory information in the 3' un-translated region (UTR), rather than promoter activity/sequence-specific transcription factors, controls mRNA levels. Given this peculiar genome structure, special strategies must be utilized to control transcription in T. brucei. TTSs are deposition sites for three non-essential chromatin factors-two of non-canonical histone variants (H3v and H4v) and a DNA modification (base J, which is a hydroxyl-glucosyl dT). This association generated the hypothesis that these three chromatin marks define a transcription termination site in T. brucei. Using a panel of null mutants lacking H3v, H4v, and base J, here I show that H4v is a major sign for transcription termination at TTSs. While having a secondary function at TTSs, H3v is important for monoallelic transcription of telomeric antigen genes. The simultaneous absence of both histone variants leads to proliferation and replication defects, which are exacerbated by the J absence, accompanied by accumulation of sub-G1 population. Thus, I propose that the coordinated actions of H3v, H4v, and J provide compensatory mechanisms for each other in chromatin organization, transcription, replication, and cell-cycle progression.
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Affiliation(s)
- Hee-Sook Kim
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, United States
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23
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Phase Separation in RNA Biology. J Genet Genomics 2021; 48:872-880. [PMID: 34371110 DOI: 10.1016/j.jgg.2021.07.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 07/19/2021] [Accepted: 07/20/2021] [Indexed: 11/23/2022]
Abstract
Formation of biomolecular condensates via liquid-liquid phase separation (LLPS) is an advantageous strategy for cells to organize subcellular compartments for diverse functions. The involvement of LLPS is more widespread and overrepresented in RNA-related biological processes. This is in part because that RNAs are intrinsically multivalent macromolecules and the presence of RNAs affects the formation, dissolution and biophysical properties of biomolecular condensates formed by LLPS. Emerging studies have illustrated how LLPS participates in RNA transcription, splicing, processing, quality control, translation and function. The interconnected regulation between LLPS and RNAs ensures tight control of RNA-related cellular functions.
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24
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Plant long non-coding RNAs in the regulation of transcription. Essays Biochem 2021; 65:751-760. [PMID: 34296250 DOI: 10.1042/ebc20200090] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/19/2021] [Accepted: 06/17/2021] [Indexed: 01/22/2023]
Abstract
Eukaryotic genomes are pervasively transcribed, producing large numbers of non-coding RNAs (ncRNAs), including tens of thousands of long ncRNAs (lncRNAs), defined as ncRNAs longer than 200 nucleotides. Recent studies have revealed the important roles lncRNAs play in the regulation of gene expression at various levels in all eukaryotes; moreover, emerging research in plants has identified roles for lncRNAs in key processes such as flowering time control, root organogenesis, reproduction, and adaptation to environmental changes. LncRNAs participate in regulating most steps of gene expression, including reshaping nuclear organization and chromatin structure; governing multiple steps of transcription, splicing, mRNA stability, and translation; and affecting post-translational protein modifications. In this review, I present the latest progress on the lncRNA-mediated regulatory mechanisms modulating transcription in Arabidopsis thaliana, focusing on their functions in regulation of gene expression via chromatin structure and interactions with the transcriptional machinery.
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25
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Singh RK, Prasad M. Delineating the epigenetic regulation of heat and drought response in plants. Crit Rev Biotechnol 2021; 42:548-561. [PMID: 34289772 DOI: 10.1080/07388551.2021.1946004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Being sessile in nature, plants cannot overlook the incursion of unfavorable environmental conditions, including heat and drought. Heat and drought severely affect plant growth, development, reproduction and therefore productivity which poses a severe threat to global food security. Plants respond to these hostile environmental circumstances by rearranging their genomic and molecular architecture. One such modification commonly known as epigenetic changes involves the perishable to inheritable changes in DNA or DNA-binding histone proteins leading to modified chromatin organization. Reversible epigenetic modifications include DNA methylation, exchange of histone variants, histone methylation, histone acetylation, ATP-dependent nucleosome remodeling, and others. These modifications are employed to regulate the spatial and temporal expression of genes in response to external stimuli or specific developmental requirements. Understanding the epigenetic regulation of stress-related gene expression in response to heat and drought would commence manifold avenues for crop improvement through molecular breeding or biotechnological approaches.
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Affiliation(s)
| | - Manoj Prasad
- National Institute of Plant Genome Research, New Delhi, India
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26
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Baxter CL, Šviković S, Sale JE, Dean C, Costa S. The intersection of DNA replication with antisense 3' RNA processing in Arabidopsis FLC chromatin silencing. Proc Natl Acad Sci U S A 2021; 118:e2107483118. [PMID: 34260408 PMCID: PMC8285979 DOI: 10.1073/pnas.2107483118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
How noncoding transcription influences chromatin states is still unclear. The Arabidopsis floral repressor gene FLC is quantitatively regulated through an antisense-mediated chromatin silencing mechanism. The FLC antisense transcripts form a cotranscriptional R-loop that is dynamically resolved by RNA 3' processing factors (FCA and FY), and this is linked to chromatin silencing. Here, we investigate this silencing mechanism and show, using single-molecule DNA fiber analysis, that FCA and FY are required for unimpeded replication fork progression across the Arabidopsis genome. We then employ the chicken DT40 cell line system, developed to investigate sequence-dependent replication and chromatin inheritance, and find that FLC R-loop sequences have an orientation-dependent ability to stall replication forks. These data suggest a coordination between RNA 3' processing of antisense RNA and replication fork progression in the inheritance of chromatin silencing at FLC.
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Affiliation(s)
- Colette L Baxter
- Cell and Developmental Biology Department, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Saša Šviković
- Division of Protein & Nucleic Acid Chemistry, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Julian E Sale
- Division of Protein & Nucleic Acid Chemistry, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Caroline Dean
- Cell and Developmental Biology Department, John Innes Centre, Norwich NR4 7UH, United Kingdom;
| | - Silvia Costa
- Cell and Developmental Biology Department, John Innes Centre, Norwich NR4 7UH, United Kingdom;
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27
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Abstract
Plants have an extraordinary diversity of transcription machineries, including five nuclear DNA-dependent RNA polymerases. Four of these enzymes are dedicated to the production of long noncoding RNAs (lncRNAs), which are ribonucleic acids with functions independent of their protein-coding potential. lncRNAs display a broad range of lengths and structures, but they are distinct from the small RNA guides of RNA interference (RNAi) pathways. lncRNAs frequently serve as structural, catalytic, or regulatory molecules for gene expression. They can affect all elements of genes, including promoters, untranslated regions, exons, introns, and terminators, controlling gene expression at various levels, including modifying chromatin accessibility, transcription, splicing, and translation. Certain lncRNAs protect genome integrity, while others respond to environmental cues like temperature, drought, nutrients, and pathogens. In this review, we explain the challenge of defining lncRNAs, introduce the machineries responsible for their production, and organize this knowledge by viewing the functions of lncRNAs throughout the structure of a typical plant gene.
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Affiliation(s)
- Andrzej T Wierzbicki
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109, USA;
| | - Todd Blevins
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, F-67084 Strasbourg, France;
| | - Szymon Swiezewski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland;
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28
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Zhao Y, Zhu P, Hepworth J, Bloomer R, Antoniou-Kourounioti RL, Doughty J, Heckmann A, Xu C, Yang H, Dean C. Natural temperature fluctuations promote COOLAIR regulation of FLC. Genes Dev 2021; 35:888-898. [PMID: 33985972 PMCID: PMC8168555 DOI: 10.1101/gad.348362.121] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/12/2021] [Indexed: 12/17/2022]
Abstract
In this study, Zhao et al. set out to characterize how plants respond to cold through regulation of FLC expression. Using genetics and genomics approaches, the authors reveal how natural temperature fluctuations promote COOLAIR regulation of FLC, with the first autumn frost acting as a key indicator of autumn/winter arrival. Plants monitor many aspects of their fluctuating environments to help align their development with seasons. Molecular understanding of how noisy temperature cues are registered has emerged from dissection of vernalization in Arabidopsis, which involves a multiphase cold-dependent silencing of the floral repressor locus FLOWERING LOCUS C (FLC). Cold-induced transcriptional silencing precedes a low probability PRC2 epigenetic switching mechanism. The epigenetic switch requires the absence of warm temperatures as well as long-term cold exposure. However, the natural temperature inputs into the earlier transcriptional silencing phase are less well understood. Here, through investigation of Arabidopsis accessions in natural and climatically distinct field sites, we show that the first seasonal frost strongly induces expression of COOLAIR, the antisense transcripts at FLC. Chamber experiments delivering a constant mean temperature with different fluctuations showed the freezing induction of COOLAIR correlates with stronger repression of FLC mRNA. Identification of a mutant that ectopically activates COOLAIR revealed how COOLAIR up-regulation can directly reduce FLC expression. Consistent with this, transgenes designed to knockout COOLAIR perturbed the early phase of FLC silencing. However, all transgenes designed to remove COOLAIR resulted in increased production of novel convergent FLC antisense transcripts. Our study reveals how natural temperature fluctuations promote COOLAIR regulation of FLC, with the first autumn frost acting as a key indicator of autumn/winter arrival.
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Affiliation(s)
- Yusheng Zhao
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Pan Zhu
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Jo Hepworth
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Rebecca Bloomer
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | | | - Jade Doughty
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Amelie Heckmann
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Congyao Xu
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Hongchun Yang
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Caroline Dean
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
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29
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Schon M, Baxter C, Xu C, Enugutti B, Nodine MD, Dean C. Antagonistic activities of cotranscriptional regulators within an early developmental window set FLC expression level. Proc Natl Acad Sci U S A 2021; 118:e2102753118. [PMID: 33879620 PMCID: PMC8092400 DOI: 10.1073/pnas.2102753118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Quantitative variation in expression of the Arabidopsis floral repressor FLC influences whether plants overwinter before flowering, or have a rapid cycling habit enabling multiple generations a year. Genetic analysis has identified activators and repressors of FLC expression but how they interact to set expression level is poorly understood. Here, we show that antagonistic functions of the FLC activator FRIGIDA (FRI) and the repressor FCA, at a specific stage of embryo development, determine FLC expression and flowering. FRI antagonizes an FCA-induced proximal polyadenylation to increase FLC expression and delay flowering. Sector analysis shows that FRI activity during the early heart stage of embryo development maximally delays flowering. Opposing functions of cotranscriptional regulators during an early embryonic developmental window thus set FLC expression levels and determine flowering time.
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Affiliation(s)
- Michael Schon
- Gregor Mendel Institute, Vienna Biocenter, 1030 Vienna, Austria
| | - Catherine Baxter
- Department of Cell & Developmental Biology, John Innes Centre, NR4 7UH Norwich, United Kingdom
| | - Congyao Xu
- Department of Cell & Developmental Biology, John Innes Centre, NR4 7UH Norwich, United Kingdom
| | - Balaji Enugutti
- Gregor Mendel Institute, Vienna Biocenter, 1030 Vienna, Austria
| | - Michael D Nodine
- Gregor Mendel Institute, Vienna Biocenter, 1030 Vienna, Austria;
- Laboratory of Molecular Biology, Wageningen University, Wageningen, 6708 PB, The Netherlands
| | - Caroline Dean
- Department of Cell & Developmental Biology, John Innes Centre, NR4 7UH Norwich, United Kingdom;
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30
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R-loop resolution promotes co-transcriptional chromatin silencing. Nat Commun 2021; 12:1790. [PMID: 33741984 PMCID: PMC7979926 DOI: 10.1038/s41467-021-22083-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 02/15/2021] [Indexed: 11/09/2022] Open
Abstract
RNA-mediated chromatin silencing is central to genome regulation in many organisms. However, how nascent non-coding transcripts regulate chromatin is poorly understood. Here, through analysis of Arabidopsis FLC, we show that resolution of a nascent-transcript-induced R-loop promotes chromatin silencing. Stabilization of an antisense-induced R-loop at the 3' end of FLC enables an RNA binding protein FCA, with its direct partner FY/WDR33 and other 3'-end processing factors, to polyadenylate the nascent antisense transcript. This clears the R-loop and recruits the chromatin modifiers demethylating H3K4me1. FCA immunoprecipitates with components of the m6A writer complex, and m6A modification affects dynamics of FCA nuclear condensates, and promotes FLC chromatin silencing. This mechanism also targets other loci in the Arabidopsis genome, and consistent with this fca and fy are hypersensitive to a DNA damage-inducing drug. These results show how modulation of R-loop stability by co-transcriptional RNA processing can trigger chromatin silencing.
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31
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Inagaki S, Takahashi M, Takashima K, Oya S, Kakutani T. Chromatin-based mechanisms to coordinate convergent overlapping transcription. NATURE PLANTS 2021; 7:295-302. [PMID: 33649596 DOI: 10.1038/s41477-021-00868-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 02/01/2021] [Indexed: 06/12/2023]
Abstract
In eukaryotic genomes, the transcription units of genes often overlap with other protein-coding and/or noncoding transcription units1,2. In such intertwined genomes, the coordinated transcription of nearby or overlapping genes would be important to ensure the integrity of genome function3-6; however, the mechanisms underlying this coordination are largely unknown. Here, we show in Arabidopsis thaliana that genes with convergent orientation of transcription are major sources of antisense transcripts and that these genes transcribed on both strands are regulated by a putative Lysine-Specific Demethylase 1 family histone demethylase, FLOWERING LOCUS D (FLD)7,8. Our genome-wide chromatin profiling revealed that FLD, as well as its associating factor LUMINIDEPENDENS9, downregulates histone H3K4me1 in regions with convergent overlapping transcription. FLD localizes to actively transcribed genes, where it colocalizes with elongating RNA polymerase II phosphorylated at the Ser2 or Ser5 sites. Genome-wide transcription analyses suggest that FLD-mediated H3K4me1 removal negatively regulates the transcription of genes with high levels of antisense transcription. Furthermore, the effect of FLD on transcription dynamics is antagonized by DNA topoisomerase I. Our study reveals chromatin-based mechanisms to cope with overlapping transcription, which may occur by modulating DNA topology. This global mechanism to cope with overlapping transcription could be co-opted for specific epigenetic processes, such as cellular memory of responses to the environment10.
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Affiliation(s)
- Soichi Inagaki
- Department of Biological Sciences, Faculty of Science, The University of Tokyo, Tokyo, Japan.
- National Institute of Genetics, Mishima, Japan.
- Department of Genetics, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Shonankokusaimura, Hayama, Japan.
- PRESTO, Japan Science and Technology Agency, Kawaguchi, Japan.
| | | | | | - Satoyo Oya
- Department of Biological Sciences, Faculty of Science, The University of Tokyo, Tokyo, Japan
| | - Tetsuji Kakutani
- Department of Biological Sciences, Faculty of Science, The University of Tokyo, Tokyo, Japan
- National Institute of Genetics, Mishima, Japan
- Department of Genetics, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Shonankokusaimura, Hayama, Japan
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32
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Kennedy A, Geuten K. The Role of FLOWERING LOCUS C Relatives in Cereals. FRONTIERS IN PLANT SCIENCE 2020; 11:617340. [PMID: 33414801 PMCID: PMC7783157 DOI: 10.3389/fpls.2020.617340] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 12/02/2020] [Indexed: 05/12/2023]
Abstract
FLOWERING LOCUS C (FLC) is one of the best characterized genes in plant research and is integral to vernalization-dependent flowering time regulation. Yet, despite the abundance of information on this gene and its relatives in Arabidopsis thaliana, the role FLC genes play in other species, in particular cereal crops and temperate grasses, remains elusive. This has been due in part to the comparative reduced availability of bioinformatic and mutant resources in cereals but also on the dominant effect in cereals of the VERNALIZATION (VRN) genes on the developmental process most associated with FLC in Arabidopsis. The strong effect of the VRN genes has led researchers to believe that the entire process of vernalization must have evolved separately in Arabidopsis and cereals. Yet, since the confirmation of the existence of FLC-like genes in monocots, new light has been shed on the roles these genes play in both vernalization and other mechanisms to fine tune development in response to specific environmental conditions. Comparisons of FLC gene function and their genetic and epigenetic regulation can now be made between Arabidopsis and cereals and how they overlap and diversify is coming into focus. With the advancement of genome editing techniques, further study on these genes is becoming increasingly easier, enabling us to investigate just how essential FLC-like genes are to modulating flowering time behavior in cereals.
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