1
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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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2
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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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3
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Deans NC, Talbot JERB, Li M, Sáez-González C, Hövel I, Heavens D, Stam M, Hollick JB. Paramutation at the maize pl1 locus is associated with RdDM activity at distal tandem repeats. PLoS Genet 2024; 20:e1011296. [PMID: 38814980 PMCID: PMC11166354 DOI: 10.1371/journal.pgen.1011296] [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: 01/09/2024] [Revised: 06/11/2024] [Accepted: 05/08/2024] [Indexed: 06/01/2024] Open
Abstract
Exceptions to Mendelian inheritance often highlight novel chromosomal behaviors. The maize Pl1-Rhoades allele conferring plant pigmentation can display inheritance patterns deviating from Mendelian expectations in a behavior known as paramutation. However, the chromosome features mediating such exceptions remain unknown. Here we show that small RNA production reflecting RNA polymerase IV function within a distal downstream set of five tandem repeats is coincident with meiotically-heritable repression of the Pl1-Rhoades transcription unit. A related pl1 haplotype with three, but not one with two, repeat units also displays the trans-homolog silencing typifying paramutations. 4C interactions, CHD3a-dependent small RNA profiles, nuclease sensitivity, and polyadenylated RNA levels highlight a repeat subregion having regulatory potential. Our comparative and mutant analyses show that transcriptional repression of Pl1-Rhoades correlates with 24-nucleotide RNA production and cytosine methylation at this subregion indicating the action of a specific DNA-dependent RNA polymerase complex. These findings support a working model in which pl1 paramutation depends on trans-chromosomal RNA-directed DNA methylation operating at a discrete cis-linked and copy-number-dependent transcriptional regulatory element.
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Affiliation(s)
- Natalie C. Deans
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
- Centers for Applied Plant Sciences and RNA Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Joy-El R. B. Talbot
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, California, United States of America
| | - Mowei Li
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
- Centers for Applied Plant Sciences and RNA Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Cristian Sáez-González
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
| | - Iris Hövel
- Swammerdam Institute for Life Sciences, Universiteit van Amsterdam, Amsterdam, The Netherlands
| | | | - Maike Stam
- Swammerdam Institute for Life Sciences, Universiteit van Amsterdam, Amsterdam, The Netherlands
| | - Jay B. Hollick
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
- Centers for Applied Plant Sciences and RNA Biology, The Ohio State University, Columbus, Ohio, United States of America
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
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4
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Xu D, Zeng L, Wang L, Yang DL. Rice requires a chromatin remodeler for Polymerase IV-small interfering RNA production and genomic immunity. PLANT PHYSIOLOGY 2024; 194:2149-2164. [PMID: 37992039 DOI: 10.1093/plphys/kiad624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 10/19/2023] [Accepted: 10/19/2023] [Indexed: 11/24/2023]
Abstract
Transgenes are often spontaneously silenced, which hinders the application of genetic modifications to crop breeding. While gene silencing has been extensively studied in Arabidopsis (Arabidopsis thaliana), the molecular mechanism of transgene silencing remains elusive in crop plants. We used rice (Oryza sativa) plants silenced for a 35S::OsGA2ox1 (Gibberellin 2-oxidase 1) transgene to isolate five elements mountain (fem) mutants showing restoration of transgene expression. In this study, we isolated multiple fem2 mutants defective in a homolog of Required to Maintain Repression 1 (RMR1) of maize (Zea mays) and CLASSY (CLSY) of Arabidopsis. In addition to failing to maintain transgene silencing, as occurs in fem3, in which mutation occurs in NUCLEAR RNA POLYMERASE E1 (OsNRPE1), the fem2 mutant failed to establish transgene silencing of 35S::OsGA2ox1. Mutation in FEM2 eliminated all RNA POLYMERASE IV (Pol-IV)-FEM1/OsRDR2 (RNA-DEPENDENT RNA POLYMERASE 2)-dependent small interfering RNAs (siRNAs), reduced DNA methylation on genome-wide scale in rice seedlings, caused pleiotropic developmental defects, and increased disease resistance. Simultaneous mutation in 2 FEM2 homologous genes, FEM2-Like 1 (FEL1) and FEL2, however, did not affect DNA methylation and rice development and disease resistance. The predominant expression of FEM2 over FEL1 and FEL2 in various tissues was likely caused by epigenetic states. Overexpression of FEL1 but not FEL2 partially rescued hypomethylation of fem2, indicating that FEL1 maintains the cryptic function. In summary, FEM2 is essential for establishing and maintaining gene silencing; moreover, FEM2 is solely required for Pol IV-FEM1 siRNA biosynthesis and de novo DNA methylation.
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Affiliation(s)
- Dachao Xu
- National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Longjun Zeng
- Institute of Crop Sciences, Yichun Academy of Sciences, Yichun, 336000 Jiangxi, China
| | - Lili Wang
- National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Dong-Lei Yang
- National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
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5
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Xu G, Law JA. Loops, crosstalk, and compartmentalization: it takes many layers to regulate DNA methylation. Curr Opin Genet Dev 2024; 84:102147. [PMID: 38176333 PMCID: PMC10922829 DOI: 10.1016/j.gde.2023.102147] [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: 10/08/2023] [Revised: 12/06/2023] [Accepted: 12/06/2023] [Indexed: 01/06/2024]
Abstract
DNA methylation is a conserved epigenetic modification associated with transposon silencing and gene regulation. The stability of this modification relies on intimate connections between DNA and histone modifications that generate self-reinforcing loops wherein the presence of one mark promotes the other. However, it is becoming increasingly clear that the efficiency of these loops is affected by cross-talk between pathways and by chromatin accessibility, which is heavily influenced by histone variants. Focusing primarily on plants, this review provides an update on the aforementioned self-reinforcing loops, highlights recent advances in understanding how DNA methylation pathways are restricted to prevent encroachment on genes, and discusses the roles of histone variants in compartmentalizing epigenetic pathways within the genome. This multilayered approach facilitates two essential, yet opposing functions, the ability to maintain heritable DNA methylation patterns while retaining the flexibility to modify these patterns during development.
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Affiliation(s)
- Guanghui Xu
- Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA. https://twitter.com/@GuanghuiXu1
| | - Julie A Law
- Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA.
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6
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Felgines L, Rymen B, Martins LM, Xu G, Matteoli C, Himber C, Zhou M, Eis J, Coruh C, Böhrer M, Kuhn L, Chicher J, Pandey V, Hammann P, Wohlschlegel J, Waltz F, Law JA, Blevins T. CLSY docking to Pol IV requires a conserved domain critical for small RNA biogenesis and transposon silencing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.26.573199. [PMID: 38234754 PMCID: PMC10793415 DOI: 10.1101/2023.12.26.573199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Eukaryotes must balance the need for gene transcription by RNA polymerase II (Pol II) against the danger of mutations caused by transposable element (TE) proliferation. In plants, these gene expression and TE silencing activities are divided between different RNA polymerases. Specifically, RNA polymerase IV (Pol IV), which evolved from Pol II, transcribes TEs to generate small interfering RNAs (siRNAs) that guide DNA methylation and block TE transcription by Pol II. While the Pol IV complex is recruited to TEs via SNF2-like CLASSY (CLSY) proteins, how Pol IV partners with the CLSYs remains unknown. Here we identified a conserved CYC-YPMF motif that is specific to Pol IV and is positioned on the complex exterior. Furthermore, we found that this motif is essential for the co-purification of all four CLSYs with Pol IV, but that only one CLSY is present in any given Pol IV complex. These findings support a "one CLSY per Pol IV" model where the CYC-YPMF motif acts as a CLSY-docking site. Indeed, mutations in and around this motif phenocopy pol iv null mutants. Together, these findings provide structural and functional insights into a critical protein feature that distinguishes Pol IV from other RNA polymerases, allowing it to promote genome stability by targeting TEs for silencing.
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7
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Liu B, Zhao M. How transposable elements are recognized and epigenetically silenced in plants? CURRENT OPINION IN PLANT BIOLOGY 2023; 75:102428. [PMID: 37481986 DOI: 10.1016/j.pbi.2023.102428] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 07/25/2023]
Abstract
Plant genomes are littered with transposable elements (TEs). Because TEs are potentially highly mutagenic, host organisms have evolved a set of defense mechanisms to recognize and epigenetically silence them. Although the maintenance of TE silencing is well studied, our understanding of the initiation of TE silencing is limited, but it clearly involves small RNAs and DNA methylation. Once TEs are silent, the silent state can be maintained to subsequent generations. However, under some circumstances, such inheritance is unstable, leading to the escape of TEs to the silencing machinery, resulting in the transcriptional activation of TEs. Epigenetic control of TEs has been found to be closely linked to many other epigenetic phenomena, such as genomic imprinting, and is known to contribute to regulation of genes, especially those near TEs. Here we review and discuss the current models of TE silencing, its unstable inheritance after hybridization, and the effects of epigenetic regulation of TEs on genomic imprinting.
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Affiliation(s)
- Beibei Liu
- Department of Biology, Miami University, Oxford, OH 45056, USA
| | - Meixia Zhao
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA.
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8
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Liu P, Liu R, Xu Y, Zhang C, Niu Q, Lang Z. DNA cytosine methylation dynamics and functional roles in horticultural crops. HORTICULTURE RESEARCH 2023; 10:uhad170. [PMID: 38025976 PMCID: PMC10660380 DOI: 10.1093/hr/uhad170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 08/20/2023] [Indexed: 12/01/2023]
Abstract
Methylation of cytosine is a conserved epigenetic modification that maintains the dynamic balance of methylation in plants under the regulation of methyltransferases and demethylases. In recent years, the study of DNA methylation in regulating the growth and development of plants and animals has become a key area of research. This review describes the regulatory mechanisms of DNA cytosine methylation in plants. It summarizes studies on epigenetic modifications of DNA methylation in fruit ripening, development, senescence, plant height, organ size, and under biotic and abiotic stresses in horticultural crops. The review provides a theoretical basis for understanding the mechanisms of DNA methylation and their relevance to breeding, genetic improvement, research, innovation, and exploitation of new cultivars of horticultural crops.
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Affiliation(s)
- Peipei Liu
- National Engineering Laboratory of Crop Stress Resistance Breeding, School of Life Sciences, Anhui Agricultural University, Hefei, 230036, China
| | - Ruie Liu
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yaping Xu
- Shanghai Center for Plant Stress Biology, National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, China
| | - Caixi Zhang
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qingfeng Niu
- National Engineering Laboratory of Crop Stress Resistance Breeding, School of Life Sciences, Anhui Agricultural University, Hefei, 230036, China
| | - Zhaobo Lang
- Institute of Advanced Biotechnology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
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9
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Martins LM, Law JA. Moving targets: Mechanisms regulating siRNA production and DNA methylation during plant development. CURRENT OPINION IN PLANT BIOLOGY 2023; 75:102435. [PMID: 37598540 PMCID: PMC10581331 DOI: 10.1016/j.pbi.2023.102435] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/29/2023] [Accepted: 07/10/2023] [Indexed: 08/22/2023]
Abstract
DNA methylation is a conserved modification that must be precisely regulated during development to facilitate its roles in silencing transposable elements and regulating gene expression. In plants, DNA methylation changes during reproduction are widely documented and, in many cases, the underlying mechanisms are well understood. In somatic tissues, the diversity of methylation patterns are only recently emerging but they are often associated with the RNA-directed DNA methylation (RdDM) pathway. Here, we discuss advances in our understanding of how the locus-specific targeting and tissue-specific expression of RdDM proteins regulate methylation patterns, how the targeting of methylation at loci with imperfect homology expands the purview of RdDM, and how natural variation within RdDM factors impacts DNA methylation patterns.
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Affiliation(s)
- Laura M Martins
- Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Julie A Law
- Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA; Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA.
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10
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Yang DL, Huang K, Deng D, Zeng Y, Wang Z, Zhang Y. DNA-dependent RNA polymerases in plants. THE PLANT CELL 2023; 35:3641-3661. [PMID: 37453082 PMCID: PMC10533338 DOI: 10.1093/plcell/koad195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 06/09/2023] [Accepted: 05/29/2023] [Indexed: 07/18/2023]
Abstract
DNA-dependent RNA polymerases (Pols) transfer the genetic information stored in genomic DNA to RNA in all organisms. In eukaryotes, the typical products of nuclear Pol I, Pol II, and Pol III are ribosomal RNAs, mRNAs, and transfer RNAs, respectively. Intriguingly, plants possess two additional Pols, Pol IV and Pol V, which produce small RNAs and long noncoding RNAs, respectively, mainly for silencing transposable elements. The five plant Pols share some subunits, but their distinct functions stem from unique subunits that interact with specific regulatory factors in their transcription cycles. Here, we summarize recent advances in our understanding of plant nucleus-localized Pols, including their evolution, function, structures, and transcription cycles.
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Affiliation(s)
- Dong-Lei Yang
- National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Kun Huang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Deyin Deng
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang Agriculture and Forestry University, Lin’an, Hangzhou 311300, China
| | - Yuan Zeng
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Zhenxing Wang
- College of Horticulture, National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yu Zhang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
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11
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Zhang Y, Toivainen T, Mackenzie K, Yakovlev I, Krokene P, Hytönen T, Grini PE, Fossdal CG. Methylome, transcriptome, and phenotype changes induced by temperature conditions experienced during sexual reproduction in Fragaria vesca. PHYSIOLOGIA PLANTARUM 2023; 175:e13963. [PMID: 37340851 DOI: 10.1111/ppl.13963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/29/2023] [Accepted: 06/19/2023] [Indexed: 06/22/2023]
Abstract
Temperature conditions experienced during embryogenesis and seed development may induce epigenetic changes that increase phenotypic variation in plants. Here we investigate if embryogenesis and seed development at two different temperatures (28 vs. 18°C) result in lasting phenotypic effects and DNA methylation changes in woodland strawberry (Fragaria vesca). Using five European ecotypes from Spain (ES12), Iceland (ICE2), Italy (IT4), and Norway (NOR2 and NOR29), we found statistically significant differences between plants from seeds produced at 18 or 28°C in three of four phenotypic features investigated under common garden conditions. This indicates the establishment of a temperature-induced epigenetic memory-like response during embryogenesis and seed development. The memory effect was significant in two ecotypes: in NOR2 flowering time, number of growth points and petiole length were affected, and in ES12 number of growth points was affected. This indicates that genetic differences between ecotypes in their epigenetic machinery, or other allelic differences, impact this type of plasticity. We observed statistically significant differences between ecotypes in DNA methylation marks in repetitive elements, pseudogenes, and genic elements. Leaf transcriptomes were also affected by embryonic temperature in an ecotype-specific manner. Although we observed significant and lasting phenotypic change in at least some ecotypes, there was considerable variation in DNA methylation between individual plants within each temperature treatment. This within-treatment variability in DNA methylation marks in F. vesca progeny may partly be a result of allelic redistribution from recombination during meiosis and subsequent epigenetic reprogramming during embryogenesis.
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Affiliation(s)
- Yupeng Zhang
- Department of Molecular Plant Biology, Norwegian Institute of Bioeconomy Research, Ås, Norway
- EVOGENE, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Tuomas Toivainen
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Kathryn Mackenzie
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Igor Yakovlev
- Department of Molecular Plant Biology, Norwegian Institute of Bioeconomy Research, Ås, Norway
| | - Paal Krokene
- Department of Molecular Plant Biology, Norwegian Institute of Bioeconomy Research, Ås, Norway
| | - Timo Hytönen
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Paul E Grini
- EVOGENE, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Carl Gunnar Fossdal
- Department of Molecular Plant Biology, Norwegian Institute of Bioeconomy Research, Ås, Norway
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12
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Fu W, Yu Y, Shu J, Yu Z, Zhong Y, Zhu T, Zhang Z, Liang Z, Cui Y, Chen C, Li C. Organization, genomic targeting, and assembly of three distinct SWI/SNF chromatin remodeling complexes in Arabidopsis. THE PLANT CELL 2023; 35:2464-2483. [PMID: 37062961 PMCID: PMC10291025 DOI: 10.1093/plcell/koad111] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 03/21/2023] [Accepted: 03/26/2023] [Indexed: 06/19/2023]
Abstract
Switch defective/sucrose nonfermentable (SWI/SNF) complexes are evolutionarily conserved multisubunit machines that play vital roles in chromatin architecture regulation for modulating gene expression via sliding or ejection of nucleosomes in eukaryotes. In plants, perturbations of SWI/SNF subunits often result in severe developmental disorders. However, the subunit composition, pathways of assembly, and genomic targeting of the plant SWI/SNF complexes are poorly understood. Here, we report the organization, genomic targeting, and assembly of 3 distinct SWI/SNF complexes in Arabidopsis thaliana: BRAHMA-Associated SWI/SNF complexes (BAS), SPLAYED-Associated SWI/SNF complexes (SAS), and MINUSCULE-Associated SWI/SNF complexes (MAS). We show that BAS complexes are equivalent to human ncBAF, whereas SAS and MAS complexes evolve in multiple subunits unique to plants, suggesting plant-specific functional evolution of SWI/SNF complexes. We further show overlapping and specific genomic targeting of the 3 plant SWI/SNF complexes on chromatin and reveal that SAS complexes are necessary for the correct genomic localization of the BAS complexes. Finally, we define the role of the core module subunit in the assembly of plant SWI/SNF complexes and highlight that ATPase module subunit is required for global complex stability and the interaction of core module subunits in Arabidopsis SAS and BAS complexes. Together, our work highlights the divergence of SWI/SNF chromatin remodelers during eukaryote evolution and provides a comprehensive landscape for understanding plant SWI/SNF complex organization, assembly, genomic targeting, and function.
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Affiliation(s)
- Wei Fu
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Yaoguang Yu
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Jie Shu
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong 510650, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Zewang Yu
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Yixiong Zhong
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Tao Zhu
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Zhihao Zhang
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Zhenwei Liang
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Yuhai Cui
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, Ontario, Canada N5V 4T3
| | - Chen Chen
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong 510650, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Chenlong Li
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
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13
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Hari Sundar G V, Swetha C, Basu D, Pachamuthu K, Raju S, Chakraborty T, Mosher RA, Shivaprasad PV. Plant polymerase IV sensitizes chromatin through histone modifications to preclude spread of silencing into protein-coding domains. Genome Res 2023; 33:715-728. [PMID: 37277199 PMCID: PMC10317121 DOI: 10.1101/gr.277353.122] [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: 09/22/2022] [Accepted: 04/16/2023] [Indexed: 06/07/2023]
Abstract
Across eukaryotes, gene regulation is manifested via chromatin states roughly distinguished as heterochromatin and euchromatin. The establishment, maintenance, and modulation of the chromatin states is mediated using several factors including chromatin modifiers. However, factors that avoid the intrusion of silencing signals into protein-coding genes are poorly understood. Here we show that a plant specific paralog of RNA polymerase (Pol) II, named Pol IV, is involved in avoidance of facultative heterochromatic marks in protein-coding genes, in addition to its well-established functions in silencing repeats and transposons. In its absence, H3K27 trimethylation (me3) mark intruded the protein-coding genes, more profoundly in genes embedded with repeats. In a subset of genes, spurious transcriptional activity resulted in small(s) RNA production, leading to post-transcriptional gene silencing. We show that such effects are significantly pronounced in rice, a plant with a larger genome with distributed heterochromatin compared with Arabidopsis Our results indicate the division of labor among plant-specific polymerases, not just in establishing effective silencing via sRNAs and DNA methylation but also in influencing chromatin boundaries.
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Affiliation(s)
- Vivek Hari Sundar G
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bangalore 560065, India
| | - Chenna Swetha
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bangalore 560065, India
| | - Debjani Basu
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bangalore 560065, India
| | - Kannan Pachamuthu
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bangalore 560065, India
| | - Steffi Raju
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bangalore 560065, India
| | - Tania Chakraborty
- School of Plant Sciences, The University of Arizona, Tucson, Arizona 85721, USA
| | - Rebecca A Mosher
- School of Plant Sciences, The University of Arizona, Tucson, Arizona 85721, USA
| | - P V Shivaprasad
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bangalore 560065, India;
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14
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Ortiz-Vasquez Q, León-Martínez G, Barragán-Rosillo C, González-Orozco E, Deans S, Aldridge B, Vickers M, Feng X, Vielle-Calzada JP. Genomic methylation patterns in pre-meiotic gynoecia of wild-type and RdDM mutants of Arabidopsis. FRONTIERS IN PLANT SCIENCE 2023; 14:1123211. [PMID: 36993852 PMCID: PMC10040562 DOI: 10.3389/fpls.2023.1123211] [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: 12/13/2022] [Accepted: 02/02/2023] [Indexed: 06/19/2023]
Abstract
INTRODUCTION Although DNA methylation patterns are generally considered to be faithfully inherited in Arabidopsis thaliana (Arabidopsis), there is evidence of reprogramming during both male and female gametogenesis. The gynoecium is the floral reproductive organ from which the ovules develop and generate meiotically derived cells that give rise to the female gametophyte. It is not known whether the gynoecium can condition genomic methylation in the ovule or the developing female gametophyte. METHODS We performed whole genome bisulfite sequencing to characterize the methylation patterns that prevail in the genomic DNA of pre-meiotic gynoecia of wild-type and three mutants defective in genes of the RNA-directed DNA methylation pathway (RdDM): ARGONAUTE4 (AGO4), ARGONAUTE9 (AGO9), and RNA-DEPENDENT RNA POLYMERASE6 (RDR6). RESULTS By globally analyzing transposable elements (TEs) and genes located across the Arabidopsis genome, we show that DNA methylation levels are similar to those of gametophytic cells rather than those of sporophytic organs such as seedlings and rosette leaves. We show that none of the mutations completely abolishes RdDM, suggesting strong redundancy within the methylation pathways. Among all, ago4 mutation has the strongest effect on RdDM, causing more CHH hypomethylation than ago9 and rdr6. We identify 22 genes whose DNA methylation is significantly reduced in ago4, ago9 and rdr6 mutants, revealing potential targets regulated by the RdDM pathway in premeiotic gyneocia. DISCUSSION Our results indicate that drastic changes in methylation levels in all three contexts occur in female reproductive organs at the sporophytic level, prior to the alternation of generations within the ovule primordium, offering a possibility to start identifying the function of specific genes acting in the establishment of the female gametophytic phase of the Arabidopsis life cycle.
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Affiliation(s)
- Quetzely Ortiz-Vasquez
- Grupo de Desarrollo Reproductivo y Apomixis, Unidad de Genómica Avanzada Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV, Irapuato, Guanajuato, Mexico
| | - Gloria León-Martínez
- Grupo de Desarrollo Reproductivo y Apomixis, Unidad de Genómica Avanzada Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV, Irapuato, Guanajuato, Mexico
| | - Carlos Barragán-Rosillo
- Grupo de Desarrollo Reproductivo y Apomixis, Unidad de Genómica Avanzada Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV, Irapuato, Guanajuato, Mexico
| | - Eduardo González-Orozco
- Grupo de Desarrollo Reproductivo y Apomixis, Unidad de Genómica Avanzada Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV, Irapuato, Guanajuato, Mexico
| | - Samuel Deans
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
| | - Billy Aldridge
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
| | - Martin Vickers
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
| | - Xiaoqi Feng
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
| | - Jean-Philippe Vielle-Calzada
- Grupo de Desarrollo Reproductivo y Apomixis, Unidad de Genómica Avanzada Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV, Irapuato, Guanajuato, Mexico
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15
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Xiang R, Ahmad B, Liang C, Shi X, Yang L, Du G, Wang L. Systematic genome-wide and expression analysis of RNA-directed DNA methylation pathway genes in grapes predicts their involvement in multiple biological processes. FRONTIERS IN PLANT SCIENCE 2022; 13:1089392. [PMID: 36570893 PMCID: PMC9780290 DOI: 10.3389/fpls.2022.1089392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 11/25/2022] [Indexed: 06/17/2023]
Abstract
RNA-directed DNA methylation (RdDM) is an important epigenetic pathway in plants and mediates transcriptional silencing by siRNAs. Different gene families have role in the regulation of the RdDM pathway and there is a lack of information about these gene families in the grapes (Vitis vinifera L.). Here, we mentioned the genome-wide identification, bioinformatics analysis, evolutionary history, and expression profiling of VvRdDM pathway genes against various stresses, hormonal treatments as well as in different organs. Sixty VvRdDM genes belonging to fourteen different families were identified. All the genes were unevenly distributed and chromosome 4 contained the highest number of genes (7). Most of the genes showed similar exon-intron and motif distribution patterns within the same subfamilies. Out of 14 families, only members of 4 families underwent duplication events during the evolutionary process and 50% of members of the AGO family are the result of duplication events. Based on Ka/Ks ratio all duplicated gene pairs have a negative mode of selection. VvRdDM pathway genes showed differential spatiotemporal expression patterns against different hormone and stress treatments. Further, with multiple transcriptome analysis, some VvRdDM genes showed a broad spectrum of high expression in different organs at various stages, and VvRdDM genes also displayed different expression in seeded and seedless cultivars during different phases of seed development. This proposed that VvRdDM genes may play multiple roles in grape growth and development, especially in seed development. qRT-PCR analysis of selected genes further verified the critical roles of RdDM genes in multiple biological processes, especially in seed development/ovule abortion i.e., VvIDN2a, VvDRD1a, VvRDR1a, and VvRDR6. Our study provides detailed information about VvRdDM genes in perspective of gene structure and evolution, as well as expression pattern against different stress, hormones and in different plants parts. It provides new candidate gene resources for further functional characterization and molecular breeding of grapes.
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Affiliation(s)
- Rui Xiang
- College of Horticulture, Hebei Agricultural University, Baoding, China
| | - Bilal Ahmad
- College of Horticulture, Hebei Agricultural University, Baoding, China
- Department of Horticulture, Muhammad Nawaz Sharif (MNS)-University of Agriculture Multan, Multan, Pakistan
| | - Chen Liang
- College of Horticulture, Hebei Agricultural University, Baoding, China
| | - Xiaoxin Shi
- College of Horticulture, Hebei Agricultural University, Baoding, China
| | - Lili Yang
- Shijiazhuang Fruit Research Institute, Hebei Academy of Agricultural and Forestry Sciences, Shijiazhuang, China
| | - Guoqiang Du
- College of Horticulture, Hebei Agricultural University, Baoding, China
| | - Li Wang
- College of Horticulture, Hebei Agricultural University, Baoding, China
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16
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Zhang H, Gong Z, Zhu JK. Active DNA demethylation in plants: 20 years of discovery and beyond. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2022; 64:2217-2239. [PMID: 36478523 DOI: 10.1111/jipb.13423] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
Maintaining proper DNA methylation levels in the genome requires active demethylation of DNA. However, removing the methyl group from a modified cytosine is chemically difficult and therefore, the underlying mechanism of demethylation had remained unclear for many years. The discovery of the first eukaryotic DNA demethylase, Arabidopsis thaliana REPRESSOR OF SILENCING 1 (ROS1), led to elucidation of the 5-methylcytosine base excision repair mechanism of active DNA demethylation. In the 20 years since ROS1 was discovered, our understanding of this active DNA demethylation pathway, as well as its regulation and biological functions in plants, has greatly expanded. These exciting developments have laid the groundwork for further dissecting the regulatory mechanisms of active DNA demethylation, with potential applications in epigenome editing to facilitate crop breeding and gene therapy.
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Affiliation(s)
- Heng Zhang
- State Key Laboratory of Molecular Plant Genetics, Shanghai Centre for Plant Stress Biology, Centre for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Zhizhong Gong
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
- School of Life Sciences, Institute of Life Science and Green Development, Hebei University, Baoding, 071002, China
| | - Jian-Kang Zhu
- School of Life Sciences, Institute of Advanced Biotechnology, Southern University of Science and Technology, Shenzhen, 518055, China
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17
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Wang Y, Le BH, Wang J, You C, Zhao Y, Galli M, Xu Y, Gallavotti A, Eulgem T, Mo B, Chen X. ZMP recruits and excludes Pol IV-mediated DNA methylation in a site-specific manner. SCIENCE ADVANCES 2022; 8:eadc9454. [PMID: 36427317 PMCID: PMC9699677 DOI: 10.1126/sciadv.adc9454] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 10/06/2022] [Indexed: 06/16/2023]
Abstract
In plants, RNA-directed DNA methylation (RdDM) uses small interfering RNAs (siRNAs) to target transposable elements (TEs) but usually avoids genes. RNA polymerase IV (Pol IV) shapes the landscape of DNA methylation through its pivotal role in siRNA biogenesis. However, how Pol IV is recruited to specific loci, particularly how it avoids genes, is poorly understood. Here, we identified a Pol IV-interacting protein, ZMP (zinc finger, mouse double-minute/switching complex B, Plus-3 protein), which exerts a dual role in regulating siRNA biogenesis and DNA methylation at specific genomic regions. ZMP is required for siRNA biogenesis at some pericentromeric regions and prevents Pol IV from targeting a subset of TEs and genes at euchromatic loci. As a chromatin-associated protein, ZMP prefers regions with depleted histone H3 lysine 4 (H3K4) methylation abutted by regions with H3K4 methylation, probably monitoring changes in local H3K4 methylation status to regulate Pol IV's chromatin occupancy. Our findings uncover a mechanism governing the specificity of RdDM.
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Affiliation(s)
- Yuan Wang
- Guangdong Provincial Key Laboratory for Plant Epigenetics, Longhua Institute of Innovative Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, 518060 Shenzhen, China
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, 518060 Shenzhen, China
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
- Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Brandon H. Le
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
- Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Jianqiang Wang
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
- Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Chenjiang You
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Institute of Plant Biology, Fudan University, Shanghai 200438, China
| | - Yonghui Zhao
- Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
| | - Mary Galli
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ 08854-8020, USA
| | - Ye Xu
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
- Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Andrea Gallavotti
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ 08854-8020, USA
| | - Thomas Eulgem
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
- Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
| | - Beixin Mo
- Guangdong Provincial Key Laboratory for Plant Epigenetics, Longhua Institute of Innovative Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, 518060 Shenzhen, China
| | - Xuemei Chen
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
- Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA
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18
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Structure and Mechanism of Plant DNA Methyltransferases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1389:137-157. [PMID: 36350509 PMCID: PMC10112988 DOI: 10.1007/978-3-031-11454-0_6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
DNA methylation is an important epigenetic mark conserved in eukaryotes from fungi to animals and plants, where it plays a crucial role in regulating gene expression and transposon silencing. Once the methylation mark is established by de novo DNA methyltransferases, specific regulatory mechanisms are required to maintain the methylation state during chromatin replication, both during meiosis and mitosis. Plant DNA methylation is found in three contexts; CG, CHG, and CHH (H = A, T, C), which are established and maintained by a unique set of DNA methyltransferases and are regulated by plant-specific pathways. DNA methylation in plants is often associated with other epigenetic modifications, such as noncoding RNA and histone modifications. This chapter focuses on the structure, function, and regulatory mechanism of plant DNA methyltransferases and their crosstalk with other epigenetic pathways.
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19
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Diego-Martin B, Pérez-Alemany J, Candela-Ferre J, Corbalán-Acedo A, Pereyra J, Alabadí D, Jami-Alahmadi Y, Wohlschlegel J, Gallego-Bartolomé J. The TRIPLE PHD FINGERS proteins are required for SWI/SNF complex-mediated +1 nucleosome positioning and transcription start site determination in Arabidopsis. Nucleic Acids Res 2022; 50:10399-10417. [PMID: 36189880 PMCID: PMC9561266 DOI: 10.1093/nar/gkac826] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 09/08/2022] [Accepted: 09/16/2022] [Indexed: 11/14/2022] Open
Abstract
Eukaryotes have evolved multiple ATP-dependent chromatin remodelers to shape the nucleosome landscape. We recently uncovered an evolutionarily conserved SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodeler complex in plants reminiscent of the mammalian BAF subclass, which specifically incorporates the MINUSCULE (MINU) catalytic subunits and the TRIPLE PHD FINGERS (TPF) signature subunits. Here we report experimental evidence that establishes the functional relevance of TPF proteins for the complex activity. Our results show that depletion of TPF triggers similar pleiotropic phenotypes and molecular defects to those found in minu mutants. Moreover, we report the genomic location of MINU2 and TPF proteins as representative members of this SWI/SNF complex and their impact on nucleosome positioning and transcription. These analyses unravel the binding of the complex to thousands of genes where it modulates the position of the +1 nucleosome. These targets tend to produce 5′-shifted transcripts in the tpf and minu mutants pointing to the participation of the complex in alternative transcription start site usage. Interestingly, there is a remarkable correlation between +1 nucleosome shift and 5′ transcript length change suggesting their functional connection. In summary, this study unravels the function of a plant SWI/SNF complex involved in +1 nucleosome positioning and transcription start site determination.
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Affiliation(s)
- Borja Diego-Martin
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC-Universitat Politècnica de València, Valencia, 46022, Spain
| | - Jaime Pérez-Alemany
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC-Universitat Politècnica de València, Valencia, 46022, Spain
| | - Joan Candela-Ferre
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC-Universitat Politècnica de València, Valencia, 46022, Spain
| | - Antonio Corbalán-Acedo
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC-Universitat Politècnica de València, Valencia, 46022, Spain
| | - Juan Pereyra
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC-Universitat Politècnica de València, Valencia, 46022, Spain
| | - David Alabadí
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC-Universitat Politècnica de València, Valencia, 46022, Spain
| | - Yasaman Jami-Alahmadi
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA
| | - James Wohlschlegel
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA
| | - Javier Gallego-Bartolomé
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC-Universitat Politècnica de València, Valencia, 46022, Spain
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20
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Velay F, Méteignier LV, Laloi C. You shall not pass! A Chromatin barrier story in plants. FRONTIERS IN PLANT SCIENCE 2022; 13:888102. [PMID: 36212303 PMCID: PMC9540200 DOI: 10.3389/fpls.2022.888102] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 08/15/2022] [Indexed: 06/16/2023]
Abstract
As in other eukaryotes, the plant genome is functionally organized in two mutually exclusive chromatin fractions, a gene-rich and transcriptionally active euchromatin, and a gene-poor, repeat-rich, and transcriptionally silent heterochromatin. In Drosophila and humans, the molecular mechanisms by which euchromatin is preserved from heterochromatin spreading have been extensively studied, leading to the identification of insulator DNA elements and associated chromatin factors (insulator proteins), which form boundaries between chromatin domains with antagonistic features. In contrast, the identity of factors assuring such a barrier function remains largely elusive in plants. Nevertheless, several genomic elements and associated protein factors have recently been shown to regulate the spreading of chromatin marks across their natural boundaries in plants. In this minireview, we focus on recent findings that describe the spreading of chromatin and propose avenues to improve the understanding of how plant chromatin architecture and transitions between different chromatin domains are defined.
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Affiliation(s)
- Florent Velay
- Aix Marseille Université, CEA, CNRS, Biosciences and Biotechnologies Institute of Aix-Marseille (BIAM), Equipe de Luminy de Génétique et Biophysique des Plantes, Marseille, F-13009, France
| | - Louis-Valentin Méteignier
- Aix Marseille Université, CEA, CNRS, Biosciences and Biotechnologies Institute of Aix-Marseille (BIAM), Equipe de Luminy de Génétique et Biophysique des Plantes, Marseille, F-13009, France
- EA2106 Biomolécules et Biotechnologies Végétales, Université de Tours, Tours, France
| | - Christophe Laloi
- Aix Marseille Université, CEA, CNRS, Biosciences and Biotechnologies Institute of Aix-Marseille (BIAM), Equipe de Luminy de Génétique et Biophysique des Plantes, Marseille, F-13009, France
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21
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Hernández-García J, Diego-Martin B, Kuo PH, Jami-Alahmadi Y, Vashisht AA, Wohlschlegel J, Jacobsen SE, Blázquez MA, Gallego-Bartolomé J. Comprehensive identification of SWI/SNF complex subunits underpins deep eukaryotic ancestry and reveals new plant components. Commun Biol 2022; 5:549. [PMID: 35668117 PMCID: PMC9170682 DOI: 10.1038/s42003-022-03490-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 05/16/2022] [Indexed: 01/19/2023] Open
Abstract
Over millions of years, eukaryotes evolved from unicellular to multicellular organisms with increasingly complex genomes and sophisticated gene expression networks. Consequently, chromatin regulators evolved to support this increased complexity. The ATP-dependent chromatin remodelers of the SWI/SNF family are multiprotein complexes that modulate nucleosome positioning and appear under different configurations, which perform distinct functions. While the composition, architecture, and activity of these subclasses are well understood in a limited number of fungal and animal model organisms, the lack of comprehensive information in other eukaryotic organisms precludes the identification of a reliable evolutionary model of SWI/SNF complexes. Here, we performed a systematic analysis using 36 species from animal, fungal, and plant lineages to assess the conservation of known SWI/SNF subunits across eukaryotes. We identified evolutionary relationships that allowed us to propose the composition of a hypothetical ancestral SWI/SNF complex in the last eukaryotic common ancestor. This last common ancestor appears to have undergone several rounds of lineage-specific subunit gains and losses, shaping the current conformation of the known subclasses in animals and fungi. In addition, our results unravel a plant SWI/SNF complex, reminiscent of the animal BAF subclass, which incorporates a set of plant-specific subunits of still unknown function.
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Affiliation(s)
- Jorge Hernández-García
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC-Universitat Politècnica de València, Valencia, 46022, Spain
- Laboratory of Biochemistry, Wageningen University & Research, 6703 WE, Stippeneng 4, Wageningen, The Netherlands
| | - Borja Diego-Martin
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC-Universitat Politècnica de València, Valencia, 46022, Spain
| | - Peggy Hsuanyu Kuo
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, 90095, CA, USA
| | - Yasaman Jami-Alahmadi
- Department of Biological Chemistry, University of California Los Angeles, Los Angeles, 90095, CA, USA
- David Geffen School of Medicine, University of California Los Angeles, Los Angeles, 90095, CA, USA
| | - Ajay A Vashisht
- Department of Biological Chemistry, University of California Los Angeles, Los Angeles, 90095, CA, USA
- David Geffen School of Medicine, University of California Los Angeles, Los Angeles, 90095, CA, USA
| | - James Wohlschlegel
- Department of Biological Chemistry, University of California Los Angeles, Los Angeles, 90095, CA, USA
- David Geffen School of Medicine, University of California Los Angeles, Los Angeles, 90095, CA, USA
| | - Steven E Jacobsen
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, 90095, CA, USA
- Eli & Edythe Broad Center of Regenerative Medicine & Stem Cell Research, University of California at Los Angeles, Los Angeles, 90095, CA, USA
- Howard Hughes Medical Institute, University of California at Los Angeles, Los Angeles, 90095, CA, USA
| | - Miguel A Blázquez
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC-Universitat Politècnica de València, Valencia, 46022, Spain
| | - Javier Gallego-Bartolomé
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC-Universitat Politècnica de València, Valencia, 46022, Spain.
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22
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Du X, Yang Z, Ariza AJF, Wang Q, Xie G, Li S, Du J. Structure of plant RNA-DEPENDENT RNA POLYMERASE 2, an enzyme involved in small interfering RNA production. THE PLANT CELL 2022; 34:2140-2149. [PMID: 35188193 PMCID: PMC9134047 DOI: 10.1093/plcell/koac067] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 02/10/2022] [Indexed: 06/14/2023]
Abstract
In plants, the biogenesis of small interfering RNA (siRNA) requires a family of RNA-dependent RNA polymerases that convert single-stranded RNA (ssRNA) into double-stranded RNA (dsRNA), which is subsequently cleaved into defined lengths by Dicer endonucleases. Here, we determined the structure of maize (Zea mays) RNA-DEPENDENT RNA POLYMERASE 2 (ZmRDR2) in the closed and open conformations. The core catalytic region of ZmRDR2 possesses the canonical DNA-dependent RNA polymerase (DdRP) catalytic sites, pointing to a shared RNA production mechanism between DdRPs and plant RDR-family proteins. Apo-ZmRDR2 adopts a highly compact structure, representing an inactive closed conformation. By contrast, adding RNA induced a significant conformational change in the ZmRDR2 Head domain that opened the RNA binding tunnel, suggesting this is an active elongation conformation of ZmRDR2. Overall, our structural studies trapped both the active and inactive conformations of ZmRDR2, providing insights into the molecular mechanism of dsRNA synthesis during plant siRNA production.
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Affiliation(s)
- Xuan Du
- Department of Biochemistry and Molecular Biology, International Cancer Center, Shenzhen University Health Science Center, Shenzhen 518060, China
- Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Shenzhen University Health Science Center, Shenzhen 518060, China
| | - Zhenlin Yang
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, California 94720, USA
- Howard Hughes Medical Institute, University of California, Berkeley, California 94720, USA
- 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 Science, Southern University of Science and Technology, Shenzhen 518055, China
| | - Alfredo Jose Florez Ariza
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, California 94720, USA
- Biophysics Graduate Group, University of California, Berkeley, California 94720, USA
| | - Qian Wang
- 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 Science, Southern University of Science and Technology, Shenzhen 518055, China
| | - Guohui Xie
- 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 Science, Southern University of Science and Technology, Shenzhen 518055, China
| | - Sisi Li
- Department of Biochemistry and Molecular Biology, International Cancer Center, Shenzhen University Health Science Center, Shenzhen 518060, 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 Science, Southern University of Science and Technology, Shenzhen 518055, China
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Decoding the sorghum methylome: understanding epigenetic contributions to agronomic traits. Biochem Soc Trans 2022; 50:583-596. [PMID: 35212360 PMCID: PMC9022969 DOI: 10.1042/bst20210908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 02/01/2022] [Accepted: 02/14/2022] [Indexed: 12/18/2022]
Abstract
DNA methylation is a chromatin modification that plays an essential role in regulating gene expression and genome stability and it is typically associated with gene silencing and heterochromatin. Owing to its heritability, alterations in the patterns of DNA methylation have the potential to provide for epigenetic inheritance of traits. Contemporary epigenomic technologies provide information beyond sequence variation and could supply alternative sources of trait variation for improvement in crops such as sorghum. Yet, compared with other species such as maize and rice, the sorghum DNA methylome is far less well understood. The distribution of CG, CHG, and CHH methylation in the genome is different compared with other species. CG and CHG methylation levels peak around centromeric segments in the sorghum genome and are far more depleted in the gene dense chromosome arms. The genes regulating DNA methylation in sorghum are also yet to be functionally characterised; better understanding of their identity and functional analysis of DNA methylation machinery mutants in diverse genotypes will be important to better characterise the sorghum methylome. Here, we catalogue homologous genes encoding methylation regulatory enzymes in sorghum based on genes in Arabidopsis, maize, and rice. Discovering variation in the methylome may uncover epialleles that provide extra information to explain trait variation and has the potential to be applied in epigenome-wide association studies or genomic prediction. DNA methylation can also improve genome annotations and discover regulatory elements underlying traits. Thus, improving our knowledge of the sorghum methylome can enhance our understanding of the molecular basis of traits and may be useful to improve sorghum performance.
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Multi-omics data integration reveals link between epigenetic modifications and gene expression in sugar beet (Beta vulgaris subsp. vulgaris) in response to cold. BMC Genomics 2022; 23:144. [PMID: 35176993 PMCID: PMC8855596 DOI: 10.1186/s12864-022-08312-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 01/13/2022] [Indexed: 12/19/2022] Open
Abstract
Background DNA methylation is thought to influence the expression of genes, especially in response to changing environmental conditions and developmental changes. Sugar beet (Beta vulgaris ssp. vulgaris), and other biennial or perennial plants are inevitably exposed to fluctuating temperatures throughout their lifecycle and might even require such stimulus to acquire floral competence. Therefore, plants such as beets, need to fine-tune their epigenetic makeup to ensure phenotypic plasticity towards changing environmental conditions while at the same time steering essential developmental processes. Different crop species may show opposing reactions towards the same abiotic stress, or, vice versa, identical species may respond differently depending on the specific kind of stress. Results In this study, we investigated common effects of cold treatment on genome-wide DNA methylation and gene expression of two Beta vulgaris accessions via multi-omics data analysis. Cold exposure resulted in a pronounced reduction of DNA methylation levels, which particularly affected methylation in CHH context (and to a lesser extent CHG) and was accompanied by transcriptional downregulation of the chromomethyltransferase CMT2 and strong upregulation of several genes mediating active DNA demethylation. Conclusion Integration of methylomic and transcriptomic data revealed that, rather than methylation having directly influenced expression, epigenetic modifications correlated with changes in expression of known players involved in DNA (de)methylation. In particular, cold triggered upregulation of genes putatively contributing to DNA demethylation via the ROS1 pathway. Our observations suggest that these transcriptional responses precede the cold-induced global DNA-hypomethylation in non-CpG, preparing beets for additional transcriptional alterations necessary for adapting to upcoming environmental changes. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08312-2.
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25
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Wang L, Zheng K, Zeng L, Xu D, Zhu T, Yin Y, Zhan H, Wu Y, Yang DL. Reinforcement of CHH methylation through RNA-directed DNA methylation ensures sexual reproduction in rice. PLANT PHYSIOLOGY 2022; 188:1189-1209. [PMID: 34791444 PMCID: PMC8825330 DOI: 10.1093/plphys/kiab531] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 10/15/2021] [Indexed: 05/23/2023]
Abstract
DNA methylation is an important epigenetic mark that regulates the expression of genes and transposons. RNA-directed DNA methylation (RdDM) is the main molecular pathway responsible for de novo DNA methylation in plants. Although the mechanism of RdDM has been well studied in Arabidopsis (Arabidopsis thaliana), most mutations in RdDM genes cause no remarkable developmental defects in Arabidopsis. Here, we isolated and cloned Five Elements Mountain 1 (FEM1), which encodes RNA-dependent RNA polymerase 2 (OsRDR2) in rice (Oryza sativa). Mutation in OsRDR2 abolished the accumulation of 24-nt small interfering RNAs, and consequently substantially decreased genome-wide CHH (H = A, C, or T) methylation. Moreover, male and female reproductive development was disturbed, which led to sterility in osrdr2 mutants. We discovered that OsRDR2-dependent DNA methylation may regulate the expression of multiple key genes involved in stamen development, meiosis, and pollen viability. In wild-type (WT) plants but not in osrdr2 mutants, genome-wide CHH methylation levels were greater in panicles, stamens, and pistils than in seedlings. The global increase of CHH methylation in reproductive organs of the WT was mainly explained by the enhancement of RdDM activity, which includes OsRDR2 activity. Our results, which revealed a global increase in CHH methylation through enhancement of RdDM activity in reproductive organs, suggest a crucial role for OsRDR2 in the sexual reproduction of rice.
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Affiliation(s)
- Lili Wang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Kezhi Zheng
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Longjun Zeng
- Yichun Academy of Science, Yichun 336000, Jiangxi Province, China
| | - Dachao Xu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Tianxin Zhu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Yumeng Yin
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Huadong Zhan
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Yufeng Wu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
| | - Dong-Lei Yang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
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26
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Zhou M, Coruh C, Xu G, Martins LM, Bourbousse C, Lambolez A, Law JA. The CLASSY family controls tissue-specific DNA methylation patterns in Arabidopsis. Nat Commun 2022; 13:244. [PMID: 35017514 PMCID: PMC8752594 DOI: 10.1038/s41467-021-27690-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 12/06/2021] [Indexed: 12/15/2022] Open
Abstract
DNA methylation shapes the epigenetic landscape of the genome, plays critical roles in regulating gene expression, and ensures transposon silencing. As is evidenced by the numerous defects associated with aberrant DNA methylation landscapes, establishing proper tissue-specific methylation patterns is critical. Yet, how such differences arise remains a largely open question in both plants and animals. Here we demonstrate that CLASSY1-4 (CLSY1-4), four locus-specific regulators of DNA methylation, also control tissue-specific methylation patterns, with the most striking pattern observed in ovules where CLSY3 and CLSY4 control DNA methylation at loci with a highly conserved DNA motif. On a more global scale, we demonstrate that specific clsy mutants are sufficient to shift the epigenetic landscape between tissues. Together, these findings reveal substantial epigenetic diversity between tissues and assign these changes to specific CLSY proteins, elucidating how locus-specific targeting combined with tissue-specific expression enables the CLSYs to generate epigenetic diversity during plant development. CLASSY (CLSY) proteins regulate DNA methylation at specific loci in the Arabidopsis genome. Here the authors show that the CLSYs also control tissue-specific DNA methylation, including at siren loci in ovules, and that the lack of an individual CLSYs can shift the epigenetic landscape between tissues.
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Affiliation(s)
- Ming Zhou
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.,Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, 92037, USA
| | - Ceyda Coruh
- Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, 92037, USA
| | - Guanghui Xu
- Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, 92037, USA
| | - Laura M Martins
- Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, 92037, USA
| | - Clara Bourbousse
- Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, 92037, USA.,Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France
| | - Alice Lambolez
- Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, 92037, USA.,RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi, Yokohama, Kanagawa, 230-0045, Japan.,Department of Biological Sciences, Faculty of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyō-ku, Tōkyō, 113-8654, Japan
| | - Julie A Law
- Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, 92037, USA. .,Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093, USA.
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27
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Fernández-Parras I, Ramírez-Tejero JA, Luque F, Navarro F. Several Isoforms for Each Subunit Shared by RNA Polymerases are Differentially Expressed in the Cultivated Olive Tree ( Olea europaea L.). Front Mol Biosci 2022; 8:679292. [PMID: 34988111 PMCID: PMC8721170 DOI: 10.3389/fmolb.2021.679292] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 10/07/2021] [Indexed: 11/13/2022] Open
Abstract
Plants contain five nuclear RNA polymerases, with RNA pols IV and V in addition to conserved eukaryotic RNA pols I, II, and III. These transcriptional complexes share five common subunits, which have been extensively analyzed only in yeasts. By taking advantage of the recently published olive tree cultivar (Olea europaea L. cv. Picual) genome, we performed a genome-wide analysis of the genomic composition corresponding to subunits common to RNA pols. The cultivated olive tree genome is quite complex and contains many genes with several copies. We also investigated, for the first time, gene expression patterns for subunits common to RNA pols using RNA-Seq under different economically and biologically relevant conditions for the cultivar "Picual": tissues/organs, biotic and abiotic stresses, and early development from seeds. Our results demonstrated the existence of a multigene family of subunits common to RNA pols, and a variable number of paralogs for each subunit in the olive cultivar "Picual." Furthermore, these isoforms display specific and differentiated expression profiles depending on the isoform and growth conditions, which may be relevant for their role in olive tree biology.
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Affiliation(s)
| | | | - Francisco Luque
- Departamento de Biología Experimental-Genética, Jaén, Spain.,Centro de Estudios Avanzados en Aceite de Oliva y Olivar, Universidad de Jaén, Jaén, Spain
| | - Francisco Navarro
- Departamento de Biología Experimental-Genética, Jaén, Spain.,Centro de Estudios Avanzados en Aceite de Oliva y Olivar, Universidad de Jaén, Jaén, Spain
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28
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Huang CY, Jin H. Coordinated Epigenetic Regulation in Plants: A Potent Managerial Tool to Conquer Biotic Stress. FRONTIERS IN PLANT SCIENCE 2022; 12:795274. [PMID: 35046981 PMCID: PMC8762163 DOI: 10.3389/fpls.2021.795274] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 11/29/2021] [Indexed: 05/10/2023]
Abstract
Plants have evolved variable phenotypic plasticity to counteract different pathogens and pests during immobile life. Microbial infection invokes multiple layers of host immune responses, and plant gene expression is swiftly and precisely reprogramed at both the transcriptional level and post-transcriptional level. Recently, the importance of epigenetic regulation in response to biotic stresses has been recognized. Changes in DNA methylation, histone modification, and chromatin structures have been observed after microbial infection. In addition, epigenetic modifications may be preserved as transgenerational memories to allow the progeny to better adapt to similar environments. Epigenetic regulation involves various regulatory components, including non-coding small RNAs, DNA methylation, histone modification, and chromatin remodelers. The crosstalk between these components allows precise fine-tuning of gene expression, giving plants the capability to fight infections and tolerant drastic environmental changes in nature. Fully unraveling epigenetic regulatory mechanisms could aid in the development of more efficient and eco-friendly strategies for crop protection in agricultural systems. In this review, we discuss the recent advances on the roles of epigenetic regulation in plant biotic stress responses.
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Affiliation(s)
| | - Hailing Jin
- Department of Microbiology and Plant Pathology, Institute for Integrative Genome Biology, University of California, Riverside, Riverside, CA, United States
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29
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Huang K, Wu XX, Fang CL, Xu ZG, Zhang HW, Gao J, Zhou CM, You LL, Gu ZX, Mu WH, Feng Y, Wang JW, Zhang Y. Pol IV and RDR2: A two-RNA-polymerase machine that produces double-stranded RNA. Science 2021; 374:1579-1586. [DOI: 10.1126/science.abj9184] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Kun Huang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiao-Xian Wu
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Cheng-Li Fang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhou-Geng Xu
- University of Chinese Academy of Sciences, Beijing 100049, China
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Hong-Wei Zhang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jian Gao
- University of Chinese Academy of Sciences, Beijing 100049, China
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Chuan-Miao Zhou
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Lin-Lin You
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhan-Xi Gu
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wen-Hui Mu
- Key Laboratory of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Yu Feng
- Department of Biophysics, and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Jia-Wei Wang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Yu Zhang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
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30
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Choi J, Lyons DB, Zilberman D. Histone H1 prevents non-CG methylation-mediated small RNA biogenesis in Arabidopsis heterochromatin. eLife 2021; 10:72676. [PMID: 34850679 PMCID: PMC8828055 DOI: 10.7554/elife.72676] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 11/30/2021] [Indexed: 11/27/2022] Open
Abstract
Flowering plants utilize small RNA (sRNA) molecules to guide DNA methyltransferases to genomic sequences. This RNA-directed DNA methylation (RdDM) pathway preferentially targets euchromatic transposable elements. However, RdDM is thought to be recruited by methylation of histone H3 at lysine 9 (H3K9me), a hallmark of heterochromatin. How RdDM is targeted to euchromatin despite an affinity for H3K9me is unclear. Here, we show that loss of histone H1 enhances heterochromatic RdDM, preferentially at nucleosome linker DNA. Surprisingly, this does not require SHH1, the RdDM component that binds H3K9me. Furthermore, H3K9me is dispensable for RdDM, as is CG DNA methylation. Instead, we find that non-CG methylation is specifically associated with sRNA biogenesis, and without H1 sRNA production quantitatively expands to non-CG-methylated loci. Our results demonstrate that H1 enforces the separation of euchromatic and heterochromatic DNA methylation pathways by excluding the sRNA-generating branch of RdDM from non-CG-methylated heterochromatin. Cells adapt to different roles by turning different groups of genes on and off. One way cells control which genes are on or off is by creating regions of active and inactive DNA, which are created and maintained by different groups of proteins. Genes in active DNA regions can be turned on, while genes in inactive regions are switched off or silenced. Silenced DNA regions also turn off ‘transposable elements’: pieces of DNA that can copy themselves and move to other regions of the genome if they become active. Transposons can be dangerous if they are activated, because they can disrupt genes or regulatory sequences when they move. There are different types of active and inactive DNA, but it is not always clear why these differences exist, or how they are maintained over time. In plants, such as the commonly-studied weed Arabidopsis thaliana, there are two types of inactive DNA, called E and H, that can silence transposons. In both types, DNA has small chemicals called methyl groups attached to it, which help inactivate the DNA. Type E DNA is methylated by a process called RNA-directed DNA methylation (RdDM), but RdDM is rarely seen in type H DNA. Choi, Lyons and Zilberman showed that RdDM is attracted to E and H regions by previously existing methylated DNA. However, in the H regions, a protein called histone H1 blocks RdDM from attaching methyl groups. This helps focus RdDM onto E regions where it is most needed, because E regions contain the types of transposons RdDM is best suited to silence. When Choi, Lyons and Zilberman examined genetically modified A. thaliana plants that do not produce histone H1, they found that RdDM happened in both E and H regions. There are many more H regions than E regions, so stretching RdDM across both made it less effective at silencing DNA. This work shows how different DNA silencing processes are focused onto specific genetic regions, helping explain why there are different types of active and inactive DNA within cells. RdDM has been studied as a way to affect crop growth and yield by altering DNA methylation. These results may help such studies by explaining how RdDM is naturally targeted.
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Affiliation(s)
- Jaemyung Choi
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
| | - David B Lyons
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
| | - Daniel Zilberman
- Department of Cell and Developmental Biology, John Innes Centre, Klosterneuburg, Austria
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31
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Zhu X, Xie S, Tang K, Kalia RK, Liu N, Ma J, Bressan RA, Zhu JK. Non-CG DNA methylation-deficiency mutations enhance mutagenesis rates during salt adaptation in cultured Arabidopsis cells. STRESS BIOLOGY 2021; 1:12. [PMID: 37676538 PMCID: PMC10441993 DOI: 10.1007/s44154-021-00013-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 10/20/2021] [Indexed: 09/08/2023]
Abstract
Much has been learned about how plants acclimate to stressful environments, but the molecular basis of stress adaptation and the potential involvement of epigenetic regulation remain poorly understood. Here, we examined if salt stress induces mutagenesis in suspension cultured plant cells and if DNA methylation affects the mutagenesis using whole genome resequencing analysis. We generated suspension cell cultures from two Arabidopsis DNA methylation-deficient mutants and wild-type plants, and subjected the cultured cells to stepwise increases in salt stress intensity over 40 culture cycles. We show that ddc (drm1 drm2 cmt3) mutant cells can adapt to grow in 175 mM NaCl-containing growth medium and exhibit higher adaptability compared to wild type Col-0 and nrpe1 cells, which can adapt to grow in only 125 mM NaCl-containing growth medium. Salt treated nrpe1 and ddc cells but not wild type cells accumulate more mutations compared with their respective untreated cells. There is no enrichment of stress responsive genes in the list of mutated genes in salt treated cells compared to the list of mutated genes in untreated cells. Our results suggest that DNA methylation prevents the induction of mutagenesis by salt stress in plant cells during stress adaptation.
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Affiliation(s)
- Xiaohong Zhu
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China.
- State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, China.
| | - Shaojun Xie
- Bioinformatics Core, Purdue University, West Lafayette, IN, 47907, USA
| | - Kai Tang
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, 47907, USA
| | - Rajwant K Kalia
- Central Arid Zone Research Institute, Jodhpur, 342003, India
| | - Na Liu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Vegetables, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Jinbiao Ma
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences 830011, Urumqi, China
| | - Ray A Bressan
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, 47907, USA
| | - Jian-Kang Zhu
- Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
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32
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Nicolau M, Picault N, Moissiard G. The Evolutionary Volte-Face of Transposable Elements: From Harmful Jumping Genes to Major Drivers of Genetic Innovation. Cells 2021; 10:cells10112952. [PMID: 34831175 PMCID: PMC8616336 DOI: 10.3390/cells10112952] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/20/2021] [Accepted: 10/20/2021] [Indexed: 12/25/2022] Open
Abstract
Transposable elements (TEs) are self-replicating DNA elements that constitute major fractions of eukaryote genomes. Their ability to transpose can modify the genome structure with potentially deleterious effects. To repress TE activity, host cells have developed numerous strategies, including epigenetic pathways, such as DNA methylation or histone modifications. Although TE neo-insertions are mostly deleterious or neutral, they can become advantageous for the host under specific circumstances. The phenomenon leading to the appropriation of TE-derived sequences by the host is known as TE exaptation or co-option. TE exaptation can be of different natures, through the production of coding or non-coding DNA sequences with ultimately an adaptive benefit for the host. In this review, we first give new insights into the silencing pathways controlling TE activity. We then discuss a model to explain how, under specific environmental conditions, TEs are unleashed, leading to a TE burst and neo-insertions, with potential benefits for the host. Finally, we review our current knowledge of coding and non-coding TE exaptation by providing several examples in various organisms and describing a method to identify TE co-option events.
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Affiliation(s)
- Melody Nicolau
- LGDP-UMR5096, CNRS, 66860 Perpignan, France; (M.N.); (N.P.)
- LGDP-UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Nathalie Picault
- LGDP-UMR5096, CNRS, 66860 Perpignan, France; (M.N.); (N.P.)
- LGDP-UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
| | - Guillaume Moissiard
- LGDP-UMR5096, CNRS, 66860 Perpignan, France; (M.N.); (N.P.)
- LGDP-UMR5096, Université de Perpignan Via Domitia, 66860 Perpignan, France
- Correspondence:
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33
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Huang P, Huang H, Lin X, Liu P, Zhao L, Nie W, Zhu J, Lang Z. MSI4/FVE is required for accumulation of 24-nt siRNAs and DNA methylation at a subset of target regions of RNA-directed DNA methylation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 108:347-357. [PMID: 34314526 PMCID: PMC9292519 DOI: 10.1111/tpj.15441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 07/20/2021] [Indexed: 05/20/2023]
Abstract
DNA methylation is an important epigenetic mark. In plants, de novo DNA methylation occurs mainly through the RNA-directed DNA methylation (RdDM) pathway. Researchers have previously inferred that a flowering regulator, MULTICOPY SUPPRESSOR OF IRA1 4 (MSI4)/FVE, is involved in non-CG methylation at several RdDM targets, suggesting a role of FVE in RdDM. However, whether and how FVE affects RdDM genome-wide is not known. Here, we report that FVE is required for DNA methylation at thousands of RdDM target regions. In addition, dysfunction of FVE significantly reduces 24-nucleotide siRNA accumulation that is dependent on factors downstream in the RdDM pathway. By using chromatin immunoprecipitation and sequencing (ChIP-seq), we show that FVE directly binds to FVE-dependent 24-nucleotide siRNA cluster regions. Our results also indicate that FVE may function in RdDM by physically interacting with RDM15, a downstream factor in the RdDM pathway. Our study has therefore revealed that FVE, by associating with RDM15, directly regulates DNA methylation and siRNA accumulation at a subset of RdDM targets.
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Affiliation(s)
- Pei Huang
- Shanghai Center for Plant Stress BiologyNational Key Laboratory of Plant Molecular GeneticsCenter for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghai201602China
- University of Chinese Academy of SciencesNo.19 Yuquan Road, Shijingshan DistrictBeijing100049China
| | - Huan Huang
- Shanghai Center for Plant Stress BiologyNational Key Laboratory of Plant Molecular GeneticsCenter for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghai201602China
| | - Xueqiang Lin
- Shanghai Center for Plant Stress BiologyNational Key Laboratory of Plant Molecular GeneticsCenter for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghai201602China
| | - Pan Liu
- Shanghai Center for Plant Stress BiologyNational Key Laboratory of Plant Molecular GeneticsCenter for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghai201602China
| | - Lun Zhao
- Shanghai Center for Plant Stress BiologyNational Key Laboratory of Plant Molecular GeneticsCenter for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghai201602China
- National Key Laboratory of Crop Genetic ImprovementNational Center of Rapeseed ImprovementHuazhong Agricultural UniversityWuhan430070China
| | - Wen‐Feng Nie
- Department of HorticultureCollege of Horticulture and Plant ProtectionYangzhou UniversityYangzhouJiangsu225009China
| | - Jian‐Kang Zhu
- Shanghai Center for Plant Stress BiologyNational Key Laboratory of Plant Molecular GeneticsCenter for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghai201602China
| | - Zhaobo Lang
- Shanghai Center for Plant Stress BiologyNational Key Laboratory of Plant Molecular GeneticsCenter for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghai201602China
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Rothi MH, Tsuzuki M, Sethuraman S, Wierzbicki AT. Reinforcement of transcriptional silencing by a positive feedback between DNA methylation and non-coding transcription. Nucleic Acids Res 2021; 49:9799-9808. [PMID: 34469565 PMCID: PMC8464056 DOI: 10.1093/nar/gkab746] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 07/09/2021] [Accepted: 08/23/2021] [Indexed: 11/12/2022] Open
Abstract
Non-coding transcription is an important determinant of heterochromatin formation. In Arabidopsis thaliana a specialized RNA polymerase V (Pol V) transcribes pervasively and produces long non-coding RNAs. These transcripts work with small interfering RNA to facilitate locus-specific establishment of RNA-directed DNA methylation (RdDM). Subsequent maintenance of RdDM is associated with elevated levels of Pol V transcription. However, the impact of DNA methylation on Pol V transcription remained unresolved. We found that DNA methylation strongly enhances Pol V transcription. The level of Pol V transcription is reduced in mutants defective in RdDM components working downstream of Pol V, indicating that RdDM is maintained by a mutual reinforcement of DNA methylation and Pol V transcription. Pol V transcription is affected only on loci that lose DNA methylation in all sequence contexts in a particular mutant, including mutants lacking maintenance DNA methyltransferases, which suggests that RdDM works in a complex crosstalk with other silencing pathways.
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Affiliation(s)
- M Hafiz Rothi
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Masayuki Tsuzuki
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA.,Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo 153-8902, Japan
| | - Shriya Sethuraman
- Bioinformatics Graduate Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Andrzej T Wierzbicki
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
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The effect of RNA polymerase V on 24-nt siRNA accumulation depends on DNA methylation contexts and histone modifications in rice. Proc Natl Acad Sci U S A 2021; 118:2100709118. [PMID: 34290143 DOI: 10.1073/pnas.2100709118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
RNA-directed DNA methylation (RdDM) functions in de novo methylation in CG, CHG, and CHH contexts. Here, we performed map-based cloning of OsNRPE1, which encodes the largest subunit of RNA polymerase V (Pol V), a key regulator of gene silencing and reproductive development in rice. We found that rice Pol V is required for CHH methylation on RdDM loci by transcribing long noncoding RNAs. Pol V influences the accumulation of 24-nucleotide small interfering RNAs (24-nt siRNAs) in a locus-specific manner. Biosynthesis of 24-nt siRNAs on loci with high CHH methylation levels and low CG and CHG methylation levels tends to depend on Pol V. In contrast, low methylation levels in the CHH context and high methylation levels in CG and CHG contexts predisposes 24-nt siRNA accumulation to be independent of Pol V. H3K9me1 and H3K9me2 tend to be enriched on Pol V-independent 24-nt siRNA loci, whereas various active histone modifications are enriched on Pol V-dependent 24-nt siRNA loci. DNA methylation is required for 24-nt siRNAs biosynthesis on Pol V-dependent loci but not on Pol V-independent loci. Our results reveal the function of rice Pol V for long noncoding RNA production, DNA methylation, 24-nt siRNA accumulation, and reproductive development.
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36
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Niu Q, Song Z, Tang K, Chen L, Wang L, Ban T, Guo Z, Kim C, Zhang H, Duan CG, Zhang H, Zhu JK, Du J, Lang Z. A histone H3K4me1-specific binding protein is required for siRNA accumulation and DNA methylation at a subset of loci targeted by RNA-directed DNA methylation. Nat Commun 2021; 12:3367. [PMID: 34099688 PMCID: PMC8184781 DOI: 10.1038/s41467-021-23637-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 04/21/2021] [Indexed: 12/31/2022] Open
Abstract
In plants, RNA-directed DNA methylation (RdDM) is a well-known de novo DNA methylation pathway that involves two plant-specific RNA polymerases, Pol IV and Pol V. In this study, we discovered and characterized an RdDM factor, RDM15. Through DNA methylome and genome-wide siRNA analyses, we show that RDM15 is required for RdDM-dependent DNA methylation and siRNA accumulation at a subset of RdDM target loci. We show that RDM15 contributes to Pol V-dependent downstream siRNA accumulation and interacts with NRPE3B, a subunit specific to Pol V. We also show that the C-terminal tudor domain of RDM15 specifically recognizes the histone 3 lysine 4 monomethylation (H3K4me1) mark. Structure analysis of RDM15 in complex with the H3K4me1 peptide showed that the RDM15 tudor domain specifically recognizes the monomethyllysine through an aromatic cage and a specific hydrogen bonding network; this chemical feature-based recognition mechanism differs from all previously reported monomethyllysine recognition mechanisms. RDM15 and H3K4me1 have similar genome-wide distribution patterns at RDM15-dependent RdDM target loci, establishing a link between H3K4me1 and RDM15-mediated RdDM in vivo. In summary, we have identified and characterized a histone H3K4me1-specific binding protein as an RdDM component, and structural analysis of RDM15 revealed a chemical feature-based lower methyllysine recognition mechanism. In plants, RNA-directed DNA methylation (RdDM) is a de novo DNA methylation pathway that is responsible for transcriptional silencing of repetitive elements. Here, the authors characterized a new RdDM factor, RDM15, and show that it is required for RdDM-dependent DNA methylation and siRNA accumulation at a subset of RdDM target loci.
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Affiliation(s)
- Qingfeng Niu
- Shanghai Center for Plant Stress Biology, National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Zhe Song
- Shanghai Center for Plant Stress Biology, National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Kai Tang
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, USA
| | - Lixian Chen
- Shanghai Center for Plant Stress Biology, National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Lisi Wang
- Shanghai Center for Plant Stress Biology, National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Ting Ban
- Shanghai Center for Plant Stress Biology, National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Zhongxin Guo
- Vector-borne Virus Research Center, College of Plant Protection, Fujian Agriculture and Forestry Universtiy, Fuzhou, China
| | - Chanhong Kim
- Shanghai Center for Plant Stress Biology, National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Heng Zhang
- Shanghai Center for Plant Stress Biology, National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Cheng-Guo Duan
- Shanghai Center for Plant Stress Biology, National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Huiming Zhang
- Shanghai Center for Plant Stress Biology, National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jian-Kang Zhu
- Shanghai Center for Plant Stress Biology, National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jiamu Du
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Science, Southern University of Science and Technology, Shenzhen, Guangdong, China.
| | - Zhaobo Lang
- Shanghai Center for Plant Stress Biology, National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China.
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37
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DNA methylation: from model plants to vegetable crops. Biochem Soc Trans 2021; 49:1479-1487. [PMID: 34060587 DOI: 10.1042/bst20210353] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/29/2021] [Accepted: 05/07/2021] [Indexed: 11/17/2022]
Abstract
As a subgroup of horticultural crops, vegetable food is a kind of indispensable energy source for human beings, providing necessary nutritional components including vitamins, carbohydrates, dietary fiber, and active substances such as carotenoids and flavonoids. The developmental process of vegetable crops is not only regulated by environmental stimulations, but also manipulated by both genetic and epigenetic modifications. Epigenetic modifications are composed by several regulatory mechanisms, including DNA methylation, histone modification, chromatin remodeling, and non-coding RNAs. Among these modifications, DNA methylation functions in multiple biological pathways ranging from fundamental development to environmental stimulations by mediating transcriptomic alterations, resulting in the activation or silencing of target genes. In recent years, intensive studies have revealed that DNA methylation is essential to fruit development and ripening, indicating that the epigenome of fruit crops could be dynamically modified according to the specific requirements in the commercial production. Firstly, this review will present the mechanisms of DNA methylation, and update the understanding on active DNA demethylation in Arabidopsis thaliana. Secondly, this review will summarize the recent progress on the function of DNA methylation in regulating fruit ripening. Moreover, the possible functions of DNA methylation on controlling the expansion of edible organs, senescence of leafy vegetables, and anthocyanin pigmentation in several important vegetable crops will be discussed. Finally, this review will highlight the intractable issues that need to be resolved in the application of epigenome in vegetable crops, and provide perspectives for the potential challenges in the further studies.
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38
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Zhang P, Gao J, Li X, Feng Y, Shi M, Shi Y, Zhang W. Interplay of DNA and RNA N 6 -methyladenine with R-loops in regulating gene transcription in Arabidopsis. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2021; 27:1163-1171. [PMID: 34177142 PMCID: PMC8212284 DOI: 10.1007/s12298-021-01010-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/14/2021] [Accepted: 05/19/2021] [Indexed: 06/01/2023]
Abstract
UNLABELLED R-loops and covalent modifications of N 6 -methyladenine on DNA (D-6 mA) or RNA (R-m6A) have been documented to function in various cellular processes in eukaryotes. However, the relationships between R-loops and both covalent modifications are still elusive in plants. Here, we integrated existing ssDRIP-seq with D-6 mA and R-m6A data from Arabidopsis thaliana. We found that the presence of either of both modifications facilitates R-loop formation and transcription of overlapping genes. Interestingly, our study suggests that the presence of R-m6A is key to affect R-loop intensity and positively regulate gene transcription. Moreover, the presence of D-6 mA plays an additive role to facilitate the effect of R-m6A on R-loop intensity, however, D-6 mA may negatively regulate gene transcription when coexisted with R-m6A. Our analyses indicate that D-6 mA, R-m6A, or histone marks may act individually and cooperatively with R-loops in regulating gene transcription. Our study is the first to link R-loops with D-6 mA and R-m6A in plants, thereby providing new insights into interactions between R-loops with D-6 mA, R-m6A, and histone marks for regulating gene transcription. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s12298-021-01010-5.
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Affiliation(s)
- Pengyue Zhang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu 210095 People’s Republic of China
| | - Jingjing Gao
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu 210095 People’s Republic of China
| | - Xinxu Li
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu 210095 People’s Republic of China
| | - Yilong Feng
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu 210095 People’s Republic of China
| | - Manli Shi
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu 210095 People’s Republic of China
| | - Yining Shi
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, JiangSu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu 210095 People’s Republic of China
| | - Wenli Zhang
- College of agronomy,
Nanjing Agricultural University
, Nanjing, 210095 People’s Republic of China
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39
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Wang Y, Zhou X, Luo J, Lv S, Liu R, Du X, Jia B, Yuan F, Zhang H, Du J. Recognition of H3K9me1 by maize RNA-directed DNA methylation factor SHH2. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2021; 63:1091-1096. [PMID: 33913587 DOI: 10.1111/jipb.13103] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 04/20/2021] [Indexed: 06/12/2023]
Abstract
RNA-directed DNA methylation (RdDM) is a plant-specific de novo DNA methylation pathway, which has extensive cross-talk with histone modifications. Here, we report that the maize RdDM regulator SAWADEE HOMEODOMAIN HOMOLOG 2 (SHH2) is an H3K9me1 reader. Our structural studies reveal that H3K9me1 recognition is achieved by recognition of the methyl group via a classic aromatic cage and hydrogen-bonding and salt-bridge interactions with the free protons of the mono-methyllysine. The di- and tri-methylation states disrupt the polar interactions, decreasing the binding affinity. Our study reveals a mono-methyllysine recognition mechanism which potentially links RdDM to H3K9me1 in maize.
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Affiliation(s)
- Yuhua Wang
- National Key Laboratory of Plant Molecular Genetics and Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, The Chinese Academy of Sciences, Shanghai, 201602, China
| | - Xuelin Zhou
- National Key Laboratory of Plant Molecular Genetics and Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, The Chinese Academy of Sciences, Shanghai, 201602, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jinyan Luo
- National Key Laboratory of Plant Molecular Genetics and Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, The Chinese Academy of Sciences, Shanghai, 201602, China
| | - Suhui Lv
- School of Life Science, Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Rui Liu
- School of Life Science, Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Xuan Du
- School of Life Science, Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Bei Jia
- National Key Laboratory of Plant Molecular Genetics and Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, The Chinese Academy of Sciences, Shanghai, 201602, China
| | - Fengtong Yuan
- National Key Laboratory of Plant Molecular Genetics and Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, The Chinese Academy of Sciences, Shanghai, 201602, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Heng Zhang
- National Key Laboratory of Plant Molecular Genetics and Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, The Chinese Academy of Sciences, Shanghai, 201602, China
| | - Jiamu Du
- School of Life Science, Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
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40
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In Response to Abiotic Stress, DNA Methylation Confers EpiGenetic Changes in Plants. PLANTS 2021; 10:plants10061096. [PMID: 34070712 PMCID: PMC8227271 DOI: 10.3390/plants10061096] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/26/2021] [Accepted: 05/27/2021] [Indexed: 02/07/2023]
Abstract
Epigenetics involves the heritable changes in patterns of gene expression determined by developmental and abiotic stresses, i.e., drought, cold, salinity, trace metals, and heat. Gene expression is driven by changes in DNA bases, histone proteins, the biogenesis of ncRNA, and changes in the nucleotide sequence. To cope with abiotic stresses, plants adopt certain changes driven by a sophisticated biological system. DNA methylation is a primary mechanism for epigenetic variation, which can induce phenotypic alterations in plants under stress. Some of the stress-driven changes in plants are temporary, while some modifications may be stable and inheritable to the next generations to allow them to cope with such extreme stress challenges in the future. In this review, we discuss the pivotal role of epigenetically developed phenotypic characteristics in plants as an evolutionary process participating in adaptation and tolerance responses to abiotic and biotic stresses that alter their growth and development. We emphasize the molecular process underlying changes in DNA methylation, differential variation for different species, the roles of non-coding RNAs in epigenetic modification, techniques for studying DNA methylation, and its role in crop improvement in tolerance to abiotic stress (drought, salinity, and heat). We summarize DNA methylation as a significant future research priority for tailoring crops according to various challenging environmental issues.
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Bourguet P, Picard CL, Yelagandula R, Pélissier T, Lorković ZJ, Feng S, Pouch-Pélissier MN, Schmücker A, Jacobsen SE, Berger F, Mathieu O. The histone variant H2A.W and linker histone H1 co-regulate heterochromatin accessibility and DNA methylation. Nat Commun 2021; 12:2683. [PMID: 33976212 PMCID: PMC8113232 DOI: 10.1038/s41467-021-22993-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 04/09/2021] [Indexed: 12/12/2022] Open
Abstract
In flowering plants, heterochromatin is demarcated by the histone variant H2A.W, elevated levels of the linker histone H1, and specific epigenetic modifications, such as high levels of DNA methylation at both CG and non-CG sites. How H2A.W regulates heterochromatin organization and interacts with other heterochromatic features is unclear. Here, we create a h2a.w null mutant via CRISPR-Cas9, h2a.w-2, to analyze the in vivo function of H2A.W. We find that H2A.W antagonizes deposition of H1 at heterochromatin and that non-CG methylation and accessibility are moderately decreased in h2a.w-2 heterochromatin. Compared to H1 loss alone, combined loss of H1 and H2A.W greatly increases accessibility and facilitates non-CG DNA methylation in heterochromatin, suggesting co-regulation of heterochromatic features by H2A.W and H1. Our results suggest that H2A.W helps maintain optimal heterochromatin accessibility and DNA methylation by promoting chromatin compaction together with H1, while also inhibiting excessive H1 incorporation.
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Affiliation(s)
- Pierre Bourguet
- CNRS, Université Clermont Auvergne, Inserm, Institut Génétique Reproduction et Développement (iGReD), Clermont-Ferrand, France
| | - Colette L Picard
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, USA
| | - Ramesh Yelagandula
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), Vienna, Austria
| | - Thierry Pélissier
- CNRS, Université Clermont Auvergne, Inserm, Institut Génétique Reproduction et Développement (iGReD), Clermont-Ferrand, France
| | - Zdravko J Lorković
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Suhua Feng
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, USA
| | - Marie-Noëlle Pouch-Pélissier
- CNRS, Université Clermont Auvergne, Inserm, Institut Génétique Reproduction et Développement (iGReD), Clermont-Ferrand, France
| | - Anna Schmücker
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Steven E Jacobsen
- Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA, USA
- Howard Hughes Medical Institute, University of California at Los Angeles, Los Angeles, CA, USA
| | - Frédéric Berger
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Olivier Mathieu
- CNRS, Université Clermont Auvergne, Inserm, Institut Génétique Reproduction et Développement (iGReD), Clermont-Ferrand, France.
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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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43
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Zeng W, Huang H, Lin X, Zhu C, Kosami K, Huang C, Zhang H, Duan C, Zhu J, Miki D. Roles of DEMETER in regulating DNA methylation in vegetative tissues and pathogen resistance. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2021; 63:691-706. [PMID: 33236824 PMCID: PMC8251943 DOI: 10.1111/jipb.13037] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 11/03/2020] [Indexed: 05/06/2023]
Abstract
DNA methylation is an epigenetic mark important for genome stability and gene expression. In Arabidopsis thaliana, the 5-methylcytosine DNA glycosylase/demethylase DEMETER (DME) controls active DNA demethylation during the reproductive stage; however, the lethality of loss-of-function dme mutations has made it difficult to assess DME function in vegetative tissues. Here, we edited DME using clustered regularly interspaced short palindromic repeats (CRISPR) /CRISPR-associated protein 9 and created three weak dme mutants that produced a few viable seeds. We also performed central cell-specific complementation in a strong dme mutant and combined this line with mutations in the other three Arabidopsis demethylase genes to generate the dme ros1 dml2 dml3 (drdd) quadruple mutant. A DNA methylome analysis showed that DME is required for DNA demethylation at hundreds of genomic regions in vegetative tissues. A transcriptome analysis of the drdd mutant revealed that DME and the other three demethylases are important for plant responses to biotic and abiotic stresses in vegetative tissues. Despite the limited role of DME in regulating DNA methylation in vegetative tissues, the dme mutants showed increased susceptibility to bacterial and fungal pathogens. Our study highlights the important functions of DME in vegetative tissues and provides valuable genetic tools for future investigations of DNA demethylation in plants.
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Affiliation(s)
- Wenjie Zeng
- Shanghai Center for Plant Stress Biology and Center of Excellence for Molecular Plant Sciencesthe Chinese Academy of SciencesShanghai210602China
- University of the Chinese Academy of SciencesShanghai201602China
| | - Huan Huang
- Shanghai Center for Plant Stress Biology and Center of Excellence for Molecular Plant Sciencesthe Chinese Academy of SciencesShanghai210602China
| | - Xueqiang Lin
- Shanghai Center for Plant Stress Biology and Center of Excellence for Molecular Plant Sciencesthe Chinese Academy of SciencesShanghai210602China
- University of the Chinese Academy of SciencesShanghai201602China
| | - Chen Zhu
- Shanghai Center for Plant Stress Biology and Center of Excellence for Molecular Plant Sciencesthe Chinese Academy of SciencesShanghai210602China
| | - Ken‐ichi Kosami
- Shanghai Center for Plant Stress Biology and Center of Excellence for Molecular Plant Sciencesthe Chinese Academy of SciencesShanghai210602China
- Fruit Tree Research Center, Ehime Research Institute of Agriculture, Forestry and FisheriesEhime7910112Japan
| | - Chaofeng Huang
- Shanghai Center for Plant Stress Biology and Center of Excellence for Molecular Plant Sciencesthe Chinese Academy of SciencesShanghai210602China
| | - Huiming Zhang
- Shanghai Center for Plant Stress Biology and Center of Excellence for Molecular Plant Sciencesthe Chinese Academy of SciencesShanghai210602China
| | - Cheng‐Guo Duan
- Shanghai Center for Plant Stress Biology and Center of Excellence for Molecular Plant Sciencesthe Chinese Academy of SciencesShanghai210602China
| | - Jian‐Kang Zhu
- Shanghai Center for Plant Stress Biology and Center of Excellence for Molecular Plant Sciencesthe Chinese Academy of SciencesShanghai210602China
- Department of Horticulture and Landscape ArchitecturePurdue UniversityWest LafayetteIndiana47907USA
| | - Daisuke Miki
- Shanghai Center for Plant Stress Biology and Center of Excellence for Molecular Plant Sciencesthe Chinese Academy of SciencesShanghai210602China
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Song ZT, Liu JX, Han JJ. Chromatin remodeling factors regulate environmental stress responses in plants. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2021; 63:438-450. [PMID: 33421288 DOI: 10.1111/jipb.13064] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 12/23/2020] [Indexed: 05/14/2023]
Abstract
Environmental stress from climate change and agricultural activity threatens global plant biodiversity as well as crop yield and quality. As sessile organisms, plants must maintain the integrity of their genomes and adjust gene expression to adapt to various environmental changes. In eukaryotes, nucleosomes are the basic unit of chromatin around which genomic DNA is packaged by condensation. To enable dynamic access to packaged DNA, eukaryotes have evolved Snf2 (sucrose nonfermenting 2) family proteins as chromatin remodeling factors (CHRs) that modulate the position of nucleosomes on chromatin. During plant stress responses, CHRs are recruited to specific genomic loci, where they regulate the distribution or composition of nucleosomes, which in turn alters the accessibility of these loci to general transcription or DNA damage repair machinery. Moreover, CHRs interplay with other epigenetic mechanisms, including DNA methylation, histone modifications, and deposition of histone variants. CHRs are also involved in RNA processing at the post-transcriptional level. In this review, we discuss major advances in our understanding of the mechanisms by which CHRs function during plants' response to environmental stress.
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Affiliation(s)
- Ze-Ting Song
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, 650500, China
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310027, China
| | - Jian-Xiang Liu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310027, China
| | - Jia-Jia Han
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, 650500, China
- Laboratory of Ecology and Evolutionary Biology, State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, 650500, China
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Kumar S, Mohapatra T. Dynamics of DNA Methylation and Its Functions in Plant Growth and Development. FRONTIERS IN PLANT SCIENCE 2021; 12:596236. [PMID: 34093600 PMCID: PMC8175986 DOI: 10.3389/fpls.2021.596236] [Citation(s) in RCA: 73] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 04/19/2021] [Indexed: 05/20/2023]
Abstract
Epigenetic modifications in DNA bases and histone proteins play important roles in the regulation of gene expression and genome stability. Chemical modification of DNA base (e.g., addition of a methyl group at the fifth carbon of cytosine residue) switches on/off the gene expression during developmental process and environmental stresses. The dynamics of DNA base methylation depends mainly on the activities of the writer/eraser guided by non-coding RNA (ncRNA) and regulated by the developmental/environmental cues. De novo DNA methylation and active demethylation activities control the methylation level and regulate the gene expression. Identification of ncRNA involved in de novo DNA methylation, increased DNA methylation proteins guiding DNA demethylase, and methylation monitoring sequence that helps maintaining a balance between DNA methylation and demethylation is the recent developments that may resolve some of the enigmas. Such discoveries provide a better understanding of the dynamics/functions of DNA base methylation and epigenetic regulation of growth, development, and stress tolerance in crop plants. Identification of epigenetic pathways in animals, their existence/orthologs in plants, and functional validation might improve future strategies for epigenome editing toward climate-resilient, sustainable agriculture in this era of global climate change. The present review discusses the dynamics of DNA methylation (cytosine/adenine) in plants, its functions in regulating gene expression under abiotic/biotic stresses, developmental processes, and genome stability.
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Affiliation(s)
- Suresh Kumar
- Division of Biochemistry, ICAR-Indian Agricultural Research Institute, New Delhi, India
- *Correspondence: Suresh Kumar, ; , orcid.org/0000-0002-7127-3079
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Broad noncoding transcription suggests genome surveillance by RNA polymerase V. Proc Natl Acad Sci U S A 2020; 117:30799-30804. [PMID: 33199612 DOI: 10.1073/pnas.2014419117] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Eukaryotic genomes are pervasively transcribed, yet most transcribed sequences lack conservation or known biological functions. In Arabidopsis thaliana, RNA polymerase V (Pol V) produces noncoding transcripts, which base pair with small interfering RNA (siRNA) and allow specific establishment of RNA-directed DNA methylation (RdDM) on transposable elements. Here, we show that Pol V transcribes much more broadly than previously expected, including subsets of both heterochromatic and euchromatic regions. At already established RdDM targets, Pol V and siRNA work together to maintain silencing. In contrast, some euchromatic sequences do not give rise to siRNA but are covered by low levels of Pol V transcription, which is needed to establish RdDM de novo if a transposon is reactivated. We propose a model where Pol V surveils the genome to make it competent to silence newly activated or integrated transposons. This indicates that pervasive transcription of nonconserved sequences may serve an essential role in maintenance of genome integrity.
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Rymen B, Ferrafiat L, Blevins T. Non-coding RNA polymerases that silence transposable elements and reprogram gene expression in plants. Transcription 2020; 11:172-191. [PMID: 33180661 PMCID: PMC7714444 DOI: 10.1080/21541264.2020.1825906] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Multisubunit RNA polymerase (Pol) complexes are the core machinery for gene expression in eukaryotes. The enzymes Pol I, Pol II and Pol III transcribe distinct subsets of nuclear genes. This family of nuclear RNA polymerases expanded in terrestrial plants by the duplication of Pol II subunit genes. Two Pol II-related enzymes, Pol IV and Pol V, are highly specialized in the production of regulatory, non-coding RNAs. Pol IV and Pol V are the central players of RNA-directed DNA methylation (RdDM), an RNA interference pathway that represses transposable elements (TEs) and selected genes. Genetic and biochemical analyses of Pol IV/V subunits are now revealing how these enzymes evolved from ancestral Pol II to sustain non-coding RNA biogenesis in silent chromatin. Intriguingly, Pol IV-RdDM regulates genes that influence flowering time, reproductive development, stress responses and plant–pathogen interactions. Pol IV target genes vary among closely related taxa, indicating that these regulatory circuits are often species-specific. Data from crops like maize, rice, tomato and Brassicarapa suggest that dynamic repositioning of TEs, accompanied by Pol IV targeting to TE-proximal genes, leads to the reprogramming of plant gene expression over short evolutionary timescales.
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Affiliation(s)
- Bart Rymen
- Institut de biologie moléculaire des plantes, Université de Strasbourg , Strasbourg, France
| | - Laura Ferrafiat
- Institut de biologie moléculaire des plantes, Université de Strasbourg , Strasbourg, France
| | - Todd Blevins
- Institut de biologie moléculaire des plantes, Université de Strasbourg , Strasbourg, France
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Abstract
RNA-directed DNA methylation (RdDM) is a biological process in which non-coding RNA molecules direct the addition of DNA methylation to specific DNA sequences. The RdDM pathway is unique to plants, although other mechanisms of RNA-directed chromatin modification have also been described in fungi and animals. To date, the RdDM pathway is best characterized within angiosperms (flowering plants), and particularly within the model plant Arabidopsis thaliana. However, conserved RdDM pathway components and associated small RNAs (sRNAs) have also been found in other groups of plants, such as gymnosperms and ferns. The RdDM pathway closely resembles other sRNA pathways, particularly the highly conserved RNAi pathway found in fungi, plants, and animals. Both the RdDM and RNAi pathways produce sRNAs and involve conserved Argonaute, Dicer and RNA-dependent RNA polymerase proteins. RdDM has been implicated in a number of regulatory processes in plants. The DNA methylation added by RdDM is generally associated with transcriptional repression of the genetic sequences targeted by the pathway. Since DNA methylation patterns in plants are heritable, these changes can often be stably transmitted to progeny. As a result, one prominent role of RdDM is the stable, transgenerational suppression of transposable element (TE) activity. RdDM has also been linked to pathogen defense, abiotic stress responses, and the regulation of several key developmental transitions. Although the RdDM pathway has a number of important functions, RdDM-defective mutants in Arabidopsis thaliana are viable and can reproduce, which has enabled detailed genetic studies of the pathway. However, RdDM mutants can have a range of defects in different plant species, including lethality, altered reproductive phenotypes, TE upregulation and genome instability, and increased pathogen sensitivity. Overall, RdDM is an important pathway in plants that regulates a number of processes by establishing and reinforcing specific DNA methylation patterns, which can lead to transgenerational epigenetic effects on gene expression and phenotype.
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Zhou HR, Lin RN, Huang HW, Li L, Cai T, Zhu JK, Chen S, He XJ. The CCR4-NOT complex component NOT1 regulates RNA-directed DNA methylation and transcriptional silencing by facilitating Pol IV-dependent siRNA production. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:1503-1515. [PMID: 32412137 DOI: 10.1111/tpj.14818] [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: 03/03/2020] [Revised: 04/29/2020] [Accepted: 05/07/2020] [Indexed: 05/20/2023]
Abstract
Small interfering RNAs (siRNAs) are responsible for establishing and maintaining DNA methylation through the RNA-directed DNA methylation (RdDM) pathway in plants. Although siRNA biogenesis is well known, it is relatively unclear about how the process is regulated. By a forward genetic screen in Arabidopsis thaliana, we identified a mutant defective in NOT1 and demonstrated that NOT1 is required for transcriptional silencing at RdDM target genomic loci. We demonstrated that NOT1 is required for Pol IV-dependent siRNA accumulation and DNA methylation at a subset of RdDM target genomic loci. Furthermore, we revealed that NOT1 is a constituent of a multi-subunit CCR4-NOT deadenylase complex by immunoprecipitation combined with mass spectrometry and demonstrated that the CCR4-NOT components can function as a whole to mediate chromatin silencing. Therefore, our work establishes that the CCR4-NOT complex regulates the biogenesis of Pol IV-dependent siRNAs, and hence facilitates DNA methylation and transcriptional silencing in Arabidopsis.
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Affiliation(s)
- Hao-Ran Zhou
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Rong-Nan Lin
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Huan-Wei Huang
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Lin Li
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Tao Cai
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Jian-Kang Zhu
- Shanghai Center for Plant Stress Biology and Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
| | - She Chen
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Xin-Jian He
- National Institute of Biological Sciences, Beijing, 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
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Xu L, Yuan K, Yuan M, Meng X, Chen M, Wu J, Li J, Qi Y. Regulation of Rice Tillering by RNA-Directed DNA Methylation at Miniature Inverted-Repeat Transposable Elements. MOLECULAR PLANT 2020; 13:851-863. [PMID: 32087371 DOI: 10.1016/j.molp.2020.02.009] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 11/15/2019] [Accepted: 12/20/2019] [Indexed: 05/24/2023]
Abstract
Tillering is a major determinant of rice plant architecture and grain yield. Here, we report that depletion of rice OsNRPD1a and OsNRPD1b, two orthologs of the largest subunit of RNA polymerase IV, leads to a high-tillering phenotype, in addition to dwarfism and smaller panicles. OsNRPD1a and OsNRPD1b are required for the production of 24-nt small interfering RNAs that direct DNA methylation at transposable elements (TEs) including miniature inverted-repeat TEs (MITEs). Interestingly, many genes are regulated either positively or negatively by TE methylation. Among them, OsMIR156d and OsMIR156j, which promote rice tillering, are repressed by CHH methylation at two MITEs in the promoters. By contrast, D14, which suppresses rice tillering, is activated by CHH methylation at an MITE in its downstream. Our findings reveal regulation of rice tillering by RNA-directed DNA methylation at MITEs and provide potential targets for agronomic trait enhancement through epigenome editing.
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Affiliation(s)
- Le Xu
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Kun Yuan
- Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Meng Yuan
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Xiangbing Meng
- Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Min Chen
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Jianguo Wu
- Vector-borne Virus Research Center, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Jiayang Li
- Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
| | - Yijun Qi
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China.
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