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Li Z, Wang W, Yu X, Zhao P, Li W, Zhang X, Peng M, Li S, Ruan M. Integrated analysis of DNA methylome and transcriptome revealing epigenetic regulation of CRIR1-promoted cold tolerance. BMC PLANT BIOLOGY 2024; 24:631. [PMID: 38965467 PMCID: PMC11225538 DOI: 10.1186/s12870-024-05285-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 06/10/2024] [Indexed: 07/06/2024]
Abstract
BACKGROUND DNA methylation contributes to the epigenetic regulation of nuclear gene expression, and is associated with plant growth, development, and stress responses. Compelling evidence has emerged that long non-coding RNA (lncRNA) regulates DNA methylation. Previous genetic and physiological evidence indicates that lncRNA-CRIR1 plays a positive role in the responses of cassava plants to cold stress. However, it is unclear whether global DNA methylation changes with CRIR1-promoted cold tolerance. RESULTS In this study, a comprehensive comparative analysis of DNA methylation and transcriptome profiles was performed to reveal the gene expression and epigenetic dynamics after CRIR1 overexpression. Compared with the wild-type plants, CRIR1-overexpressing plants present gained DNA methylation in over 37,000 genomic regions and lost DNA methylation in about 16,000 genomic regions, indicating a global decrease in DNA methylation after CRIR1 overexpression. Declining DNA methylation is not correlated with decreased/increased expression of the DNA methylase/demethylase genes, but is associated with increased transcripts of a few transcription factors, chlorophyll metabolism and photosynthesis-related genes, which could contribute to the CRIR1-promoted cold tolerance. CONCLUSIONS In summary, a first set of transcriptome and epigenome data was integrated in this study to reveal the gene expression and epigenetic dynamics after CRIR1 overexpression, with the identification of several TFs, chlorophyll metabolism and photosynthesis-related genes that may be involved in CRIR1-promoted cold tolerance. Therefore, our study has provided valuable data for the systematic study of molecular insights for plant cold stress response.
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Affiliation(s)
- Zhibo Li
- National Key Laboratory for Tropical Crop Breeding, Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Sanya Research Institute of Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, P.R. China
| | - Wenjuan Wang
- National Key Laboratory for Tropical Crop Breeding, Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Sanya Research Institute of Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, P.R. China
- College of Tropical Crops, Hainan University, Haikou, 570228, P.R. China
| | - Xiaoling Yu
- National Key Laboratory for Tropical Crop Breeding, Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Sanya Research Institute of Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, P.R. China
| | - Pingjuan Zhao
- National Key Laboratory for Tropical Crop Breeding, Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Sanya Research Institute of Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, P.R. China
| | - Wenbin Li
- National Key Laboratory for Tropical Crop Breeding, Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Sanya Research Institute of Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, P.R. China
| | - Xiuchun Zhang
- National Key Laboratory for Tropical Crop Breeding, Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Sanya Research Institute of Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, P.R. China
| | - Ming Peng
- National Key Laboratory for Tropical Crop Breeding, Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Sanya Research Institute of Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, P.R. China
| | - Shuxia Li
- National Key Laboratory for Tropical Crop Breeding, Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Sanya Research Institute of Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, P.R. China.
| | - Mengbin Ruan
- National Key Laboratory for Tropical Crop Breeding, Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Sanya Research Institute of Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, P.R. China.
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Venios X, Gkizi D, Nisiotou A, Korkas E, Tjamos SE, Zamioudis C, Banilas G. Emerging Roles of Epigenetics in Grapevine and Winegrowing. PLANTS (BASEL, SWITZERLAND) 2024; 13:515. [PMID: 38498480 PMCID: PMC10893341 DOI: 10.3390/plants13040515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 02/10/2024] [Accepted: 02/12/2024] [Indexed: 03/20/2024]
Abstract
Epigenetics refers to dynamic chemical modifications to the genome that can perpetuate gene activity without changes in the DNA sequence. Epigenetic mechanisms play important roles in growth and development. They may also drive plant adaptation to adverse environmental conditions by buffering environmental variation. Grapevine is an important perennial fruit crop cultivated worldwide, but mostly in temperate zones with hot and dry summers. The decrease in rainfall and the rise in temperature due to climate change, along with the expansion of pests and diseases, constitute serious threats to the sustainability of winegrowing. Ongoing research shows that epigenetic modifications are key regulators of important grapevine developmental processes, including berry growth and ripening. Variations in epigenetic modifications driven by genotype-environment interplay may also lead to novel phenotypes in response to environmental cues, a phenomenon called phenotypic plasticity. Here, we summarize the recent advances in the emerging field of grapevine epigenetics. We primarily highlight the impact of epigenetics to grapevine stress responses and acquisition of stress tolerance. We further discuss how epigenetics may affect winegrowing and also shape the quality of wine.
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Affiliation(s)
- Xenophon Venios
- Department of Wine, Vine and Beverage Sciences, University of West Attica, Ag. Spyridonos 28, 12243 Athens, Greece; (X.V.); (D.G.); (E.K.)
| | - Danai Gkizi
- Department of Wine, Vine and Beverage Sciences, University of West Attica, Ag. Spyridonos 28, 12243 Athens, Greece; (X.V.); (D.G.); (E.K.)
| | - Aspasia Nisiotou
- Institute of Technology of Agricultural Products, Hellenic Agricultural Organization “Demeter”, Sofokli Venizelou 1, 14123 Lykovryssi, Greece;
| | - Elias Korkas
- Department of Wine, Vine and Beverage Sciences, University of West Attica, Ag. Spyridonos 28, 12243 Athens, Greece; (X.V.); (D.G.); (E.K.)
| | - Sotirios E. Tjamos
- Laboratory of Plant Pathology, Agricultural University of Athens, 75 Iera Odos Str., 11855 Athens, Greece;
| | - Christos Zamioudis
- Department of Agricultural Development, Democritus University of Thrace, Pantazidou 193, 68200 Orestiada, Greece;
| | - Georgios Banilas
- Department of Wine, Vine and Beverage Sciences, University of West Attica, Ag. Spyridonos 28, 12243 Athens, Greece; (X.V.); (D.G.); (E.K.)
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Lancíková V, Kačírová J, Hricová A. Identification and gene expression analysis of cytosine-5 DNA methyltransferase and demethylase genes in Amaranthus cruentus L. under heavy metal stress. FRONTIERS IN PLANT SCIENCE 2023; 13:1092067. [PMID: 36684770 PMCID: PMC9846163 DOI: 10.3389/fpls.2022.1092067] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 12/07/2022] [Indexed: 06/17/2023]
Abstract
Amaranth has become increasingly popular due to its highly nutritious grains and ability to tolerate environmental stress. The mechanism underlying defense and adaptation to environmental stress is a complicated process involving DNA methylation and demethylation. These epigenetic features have been well documented to play an important role in plant stress response, including heavy metal-induced stress. This study was aimed at the identification and analysis of cytosine-5 DNA methyltransferase (C5-MTase) and demethylase (DMTase) genes in Amaranthus cruentus. Eight C5-MTase and two DMTase genes were identified and described in response to individual heavy metals (Cd, Pb, Zn, Mn) and their combination (Cd/Pb, Cd/Zn, Pb/Zn) in root and leaf tissues. Studied heavy metals, individually and in combinations, differentially regulated C5-MTase and DMTase gene expression. Interestingly, most of the genes were transcriptionally altered under Zn exposure. Our results suggest that identified amaranth MTase and DMTase genes are involved in heavy metal stress responses through regulating DNA methylation and demethylation level in amaranth plants.
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Shao Z, Huang L, Zhang Y, Qiang S, Song X. Transgene Was Silenced in Hybrids between Transgenic Herbicide-Resistant Crops and Their Wild Relatives Utilizing Alien Chromosomes. PLANTS (BASEL, SWITZERLAND) 2022; 11:3187. [PMID: 36501227 PMCID: PMC9741405 DOI: 10.3390/plants11233187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/13/2022] [Accepted: 11/17/2022] [Indexed: 06/17/2023]
Abstract
The commercialization of transgenic herbicide-resistant (HR) crops may cause gene flow risk. If a transgene in progenies of transgenic crops and wild relatives is silencing, these progenies should be killed by the target herbicide, thus, the gene flow risk could be decreased. We obtained the progenies of backcross generations between wild Brassca juncea (AABB, 2n = 36) and glufosinate-resistant transgenic Brassica napus (AACC, 2n = 38, PAT gene located on the C-chromosome). They carried the HR gene but did not express it normally, i.e., gene silencing occurred. Meanwhile, six to nine methylation sites were found on the promoter of PAT in transgene-silencing progenies, while no methylation sites occurred on that in transgene-expressing progenies. In addition, transgene expressing and silencing backcross progenies showed similar fitness with wild Brassica juncea. In conclusion, we elaborate on the occurrence of transgene-silencing event in backcross progenies between transgenic crop utilizing alien chromosomes and their wild relatives, and the DNA methylation of the transgene promoter was an important factor leading to gene silencing. The insertion site of the transgene could be considered a strategy to reduce the ecological risk of transgenic crops, and applied to cultivate lower gene flow HR crops in the future.
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Affiliation(s)
| | | | | | | | - Xiaoling Song
- Weed Research Laboratory, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China; (Z.S.); (L.H.); (Y.Z.); (S.Q.)
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Zhao L, Zhou Q, He L, Deng L, Lozano-Duran R, Li G, Zhu JK. DNA methylation underpins the epigenomic landscape regulating genome transcription in Arabidopsis. Genome Biol 2022; 23:197. [PMID: 36127735 PMCID: PMC9487137 DOI: 10.1186/s13059-022-02768-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 09/08/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND It is challenging to determine the effect of DNA methylation on the epigenetic landscape and the function in higher organisms due to the lack of DNA methylation-free mutants. RESULTS Here, the analysis of a recently generated Arabidopsis mutant completely devoid of DNA methylation reveals that DNA methylation underpins the genome-wide landscape of histone modifications. Complete loss of DNA methylation causes an upheaval of the histone modification landscape, including complete loss of H3K9me2 and widespread redistribution of active and H3K27me3 histone marks, mostly owing to the role of DNA methylation in initiating H3K9me2 deposition and excluding active marks and repressive mark H3K27me3; CG and non-CG methylation can act independently at some genomic regions while they act cooperatively at many other regions. The transcriptional reprogramming upon loss of all DNA methylation correlates with the extensive redistribution or switches of the examined histone modifications. Histone modifications retained or gained in the DNA methylation-free mutant serve as DNA methylation-independent transcriptional regulatory signals: active marks promote genome transcription, whereas the repressive mark H3K27me3 compensates for the lack of DNA hypermethylation/H3K9me2 at multiple transposon families. CONCLUSIONS Our results show that an intact DNA methylome constitutes the scaffolding of the epigenomic landscape in Arabidopsis and is critical for controlled genome transcription and ultimately for proper growth and development.
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Affiliation(s)
- Lun Zhao
- National Key Laboratory of Crop Genetic Improvement, National Engineering Research Center of Rapeseed, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
- Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
| | - Qiangwei Zhou
- National Key Laboratory of Crop Genetic Improvement, National Engineering Research Center of Rapeseed, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Li He
- Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
| | - Li Deng
- National Key Laboratory of Crop Genetic Improvement, National Engineering Research Center of Rapeseed, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Rosa Lozano-Duran
- Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
- Department of Plant Biochemistry, Centre for Plant Molecular Biology (ZMBP), Eberhard Karls University, D-72076, Tübingen, Germany
| | - Guoliang Li
- National Key Laboratory of Crop Genetic Improvement, National Engineering Research Center of Rapeseed, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China.
- Hubei Key Laboratory of Agricultural Bioinformatics and Hubei Engineering Technology Research Center of Agricultural Big Data, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Jian-Kang Zhu
- Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China.
- Institute of Advanced Biotechnology and School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China.
- Center for Advanced Bioindustry Technologies, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
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Plant DNA Methylation: An Epigenetic Mark in Development, Environmental Interactions, and Evolution. Int J Mol Sci 2022; 23:ijms23158299. [PMID: 35955429 PMCID: PMC9368846 DOI: 10.3390/ijms23158299] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/21/2022] [Accepted: 07/24/2022] [Indexed: 01/06/2023] Open
Abstract
DNA methylation is an epigenetic modification of the genome involved in the regulation of gene expression and modulation of chromatin structure. Plant genomes are widely methylated, and the methylation generally occurs on the cytosine bases through the activity of specific enzymes called DNA methyltransferases. On the other hand, methylated DNA can also undergo demethylation through the action of demethylases. The methylation landscape is finely tuned and assumes a pivotal role in plant development and evolution. This review illustrates different molecular aspects of DNA methylation and some plant physiological processes influenced by this epigenetic modification in model species, crops, and ornamental plants such as orchids. In addition, this review aims to describe the relationship between the changes in plant DNA methylation levels and the response to biotic and abiotic stress. Finally, we discuss the possible evolutionary implications and biotechnological applications of DNA methylation.
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Pereira G, Pereira J, Santos RB, Figueiredo A. Uncovering the role of DNA methyltransferases in grapevine - Plasmopara viticola interaction: From genome-wide characterization to global methylation patterns. Gene 2022; 837:146693. [PMID: 35738444 DOI: 10.1016/j.gene.2022.146693] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 05/10/2022] [Accepted: 06/17/2022] [Indexed: 11/04/2022]
Abstract
Epigenetic regulation has recently gained prominence in the field of plant-pathogen interactions, providing a deeper understanding of the molecular mechanisms associated with plant infection. In grapevine interaction with pathogens, epigenetic regulation still remains a black box. In this work, we characterized grapevine DNA methyltransferase gene family and identified nine DNA methyltransferases genes across eight grapevine chromosomes coding for 17 proteins. We also assessed the modulation of global cytosine methylation and gene expression levels of these genes with the aim of establishing a connection between DNA methylation and grapevine resistance towards downy mildew. Our results revealed that, in the incompatible interaction, an early hypomethylation, coupled with downregulation of DNMT and CMT genes occurs very early after pathogen inoculation. Additionally, the compatible interaction is characterized by a hypermethylation at 6hpi. A temporal delay is evident between the shifts in DNA methyltransferases gene expression in both compatible and incompatible interactions which in turn may be reflected in the global methylation percentage. Overall, we present the first evidence of an epigenetic regulation role in grapevine defense against P. viticola.
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Affiliation(s)
- Gonçalo Pereira
- Grapevine Pathogen Systems Lab, BioISI - Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, Lisboa, Portugal
| | - João Pereira
- Grapevine Pathogen Systems Lab, BioISI - Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, Lisboa, Portugal
| | - Rita B Santos
- Grapevine Pathogen Systems Lab, BioISI - Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, Lisboa, Portugal; Plant Biology Department, Faculty of Sciences, BioISI, University of Lisbon, Lisboa, Portugal.
| | - Andreia Figueiredo
- Grapevine Pathogen Systems Lab, BioISI - Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, Lisboa, Portugal; Plant Biology Department, Faculty of Sciences, BioISI, University of Lisbon, Lisboa, Portugal
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8
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DNA methylation-free Arabidopsis reveals crucial roles of DNA methylation in regulating gene expression and development. Nat Commun 2022; 13:1335. [PMID: 35288562 PMCID: PMC8921224 DOI: 10.1038/s41467-022-28940-2] [Citation(s) in RCA: 77] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 02/16/2022] [Indexed: 12/17/2022] Open
Abstract
A contribution of DNA methylation to defense against invading nucleic acids and maintenance of genome integrity is uncontested; however, our understanding of the extent of involvement of this epigenetic mark in genome-wide gene regulation and plant developmental control is incomplete. Here, we knock out all five known DNA methyltransferases in Arabidopsis, generating DNA methylation-free plants. This quintuple mutant exhibits a suite of developmental defects, unequivocally demonstrating that DNA methylation is essential for multiple aspects of plant development. We show that CG methylation and non-CG methylation are required for a plethora of biological processes, including pavement cell shape, endoreduplication, cell death, flowering, trichome morphology, vasculature and meristem development, and root cell fate determination. Moreover, we find that DNA methylation has a strong dose-dependent effect on gene expression and repression of transposable elements. Taken together, our results demonstrate that DNA methylation is dispensable for Arabidopsis survival but essential for the proper regulation of multiple biological processes. Our understanding of the extent of involvement of DNA methylation in genome-wide gene regulation and plant developmental control is incomplete. Here, the authors knock out all five known DNA methyltransferases and show the developmental and gene expression changes in the DNA methylation-free Arabidopsis plants.
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Poór P, Nawaz K, Gupta R, Ashfaque F, Khan MIR. Ethylene involvement in the regulation of heat stress tolerance in plants. PLANT CELL REPORTS 2022; 41:675-698. [PMID: 33713206 DOI: 10.1007/s00299-021-02675-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 02/14/2021] [Indexed: 05/12/2023]
Abstract
Because of the rise in global temperature, heat stress has become a major concern for crop production. Heat stress deteriorates plant productivity and alters phenological and physiological responses that aid in precise monitoring and sensing of mild-to-severe transient heat stress. Plants have evolved several sophisticated mechanisms including hormone-signaling pathways to sense heat stimuli and acquire heat stress tolerance. In response to heat stress, ethylene, a gaseous hormone, is produced which is indispensable for plant growth and development and tolerance to various abiotic stresses including heat stress. The manipulation of ethylene in developing heat stress tolerance targeting ethylene biosynthesis and signaling pathways has brought promising out comes. Conversely increased ethylene biosynthesis and signaling seem to exhibit inhibitory effects in plant growth responses from primitive to maturity stages. This review mainly focuses on the recent studies of ethylene involvement in plant responses to heat stress and its functional regulation, and molecular mechanism underlying the plant responses in the mitigation of heat-induced damages. Furthermore, this review also describes the crosstalk between ethylene and other signaling molecules under heat stress and approaches to improve heat stress tolerance in plants.
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Affiliation(s)
- Peter Poór
- Department of Plant Biology, University of Szeged, Szeged, Hungary
| | - Kashif Nawaz
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
| | - Ravi Gupta
- Department of Botany, Jamia Hamdard, New Delhi, India
| | - Farha Ashfaque
- Department of Botany, Aligarh Muslim University, Aligarh, India
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Liang W, Li J, Sun L, Liu Y, Lan Z, Qian W. Deciphering the synergistic and redundant roles of CG and non-CG DNA methylation in plant development and transposable element silencing. THE NEW PHYTOLOGIST 2022; 233:722-737. [PMID: 34655488 PMCID: PMC9298111 DOI: 10.1111/nph.17804] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 10/11/2021] [Indexed: 05/10/2023]
Abstract
DNA methylation plays key roles in transposable element (TE) silencing and gene expression regulation. DNA methylation occurs at CG, CHG and CHH sequence contexts in plants. However, the synergistic and redundant roles of CG and non-CG methylation are poorly understood. By introducing CRISPR/Cas9-induced met1 mutation into the ddcc (drm1 drm2 cmt2 cmt3) mutant, we attempted to knock out all five DNA methyltransferases in Arabidopsis and then investigate the synergistic and redundant roles of CG and non-CG DNA methylation. We found that the homozygous ddcc met1 quintuple mutants are embryonically lethal, although met1 and ddcc mutants only display some developmental abnormalities. Unexpectedly, the ddcc met1 quintuple mutations only reduce transmission through the male gametophytes. The ddcc met1+/- mutants show apparent size divergence, which is not associated with difference in DNA methylation patterns, but associated with the difference in the levels of DNA damage. Finally, we show that a group of TEs are specifically activated in the ddcc met1+/- mutants. This work reveals that CG and non-CG DNA methylation synergistically and redundantly regulate plant reproductive development, vegetative development and TE silencing in Arabidopsis. Our findings provide insights into the roles of DNA methylation in plant development.
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Affiliation(s)
- Wenjie Liang
- State Key Laboratory of Protein and Plant Gene ResearchPeking‐Tsinghua Center for Life SciencesSchool of Life SciencesPeking UniversityBeijing100871China
| | - Jinchao Li
- State Key Laboratory of Protein and Plant Gene ResearchPeking‐Tsinghua Center for Life SciencesSchool of Life SciencesPeking UniversityBeijing100871China
- School of Advanced Agricultural SciencesPeking UniversityBeijing100871China
| | - Linhua Sun
- School of Advanced Agricultural SciencesPeking UniversityBeijing100871China
| | - Yi Liu
- State Key Laboratory of Protein and Plant Gene ResearchPeking‐Tsinghua Center for Life SciencesSchool of Life SciencesPeking UniversityBeijing100871China
| | - Zijun Lan
- State Key Laboratory of Protein and Plant Gene ResearchPeking‐Tsinghua Center for Life SciencesSchool of Life SciencesPeking UniversityBeijing100871China
| | - Weiqiang Qian
- State Key Laboratory of Protein and Plant Gene ResearchPeking‐Tsinghua Center for Life SciencesSchool of Life SciencesPeking UniversityBeijing100871China
- School of Advanced Agricultural SciencesPeking UniversityBeijing100871China
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11
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Zhang Z, He C, Chen Y, Li B, Tian S. DNA Methyltransferases Regulate Pathogenicity of Botrytis cinerea to Horticultural Crops. J Fungi (Basel) 2021; 7:jof7080659. [PMID: 34436198 PMCID: PMC8399656 DOI: 10.3390/jof7080659] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/05/2021] [Accepted: 08/09/2021] [Indexed: 11/18/2022] Open
Abstract
Botrytis cinerea is one of the most destructive fungal pathogens that cause gray mold rot in horticultural products, including fresh fruits, vegetables, and flowers, leading to serious economic losses. B. cinerea is difficult to control because it has strong stress resistance and complex infection modes. The pathogenic mechanisms of B. cinerea have been revealed at multiple levels, but little is known at the epigenetic level. In this study, we first revealed the important role of DNA methyltransferases in regulating the development and pathogenicity of B. cinerea. We showed that two DNA methyltransferases, BcDIM2 and BcRID2, showed a strong synergistic effect in regulating the pathogenicity of B. cinerea. The double knockout mutant ΔBcdim2rid2 showed slower mycelial growth, lower spore germination, attenuated oxidative tolerance, and complete pathogenicity loss on various hosts, which is related to the reduced expression of virulence-related genes in ΔBcdim2rid2 and the induced resistance of the host. Although B. cinerea has multiple DNA methyltransferases, the global methylation level is very low, and few 5mC sites can be detected by BS-seq. These results first revealed the important role and the action mode of DNA methyltransferases in B. cinerea.
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Affiliation(s)
- Zhanquan Zhang
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; (Z.Z.); (C.H.); (Y.C.); (B.L.)
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chang He
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; (Z.Z.); (C.H.); (Y.C.); (B.L.)
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yong Chen
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; (Z.Z.); (C.H.); (Y.C.); (B.L.)
| | - Boqiang Li
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; (Z.Z.); (C.H.); (Y.C.); (B.L.)
| | - Shiping Tian
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; (Z.Z.); (C.H.); (Y.C.); (B.L.)
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence:
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12
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Markulin L, Škiljaica A, Tokić M, Jagić M, Vuk T, Bauer N, Leljak Levanić D. Taking the Wheel - de novo DNA Methylation as a Driving Force of Plant Embryonic Development. FRONTIERS IN PLANT SCIENCE 2021; 12:764999. [PMID: 34777448 PMCID: PMC8585777 DOI: 10.3389/fpls.2021.764999] [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: 08/26/2021] [Accepted: 10/13/2021] [Indexed: 05/16/2023]
Abstract
During plant embryogenesis, regardless of whether it begins with a fertilized egg cell (zygotic embryogenesis) or an induced somatic cell (somatic embryogenesis), significant epigenetic reprogramming occurs with the purpose of parental or vegetative transcript silencing and establishment of a next-generation epigenetic patterning. To ensure genome stability of a developing embryo, large-scale transposon silencing occurs by an RNA-directed DNA methylation (RdDM) pathway, which introduces methylation patterns de novo and as such potentially serves as a global mechanism of transcription control during developmental transitions. RdDM is controlled by a two-armed mechanism based around the activity of two RNA polymerases. While PolIV produces siRNAs accompanied by protein complexes comprising the methylation machinery, PolV produces lncRNA which guides the methylation machinery toward specific genomic locations. Recently, RdDM has been proposed as a dominant methylation mechanism during gamete formation and early embryo development in Arabidopsis thaliana, overshadowing all other methylation mechanisms. Here, we bring an overview of current knowledge about different roles of DNA methylation with emphasis on RdDM during plant zygotic and somatic embryogenesis. Based on published chromatin immunoprecipitation data on PolV binding sites within the A. thaliana genome, we uncover groups of auxin metabolism, reproductive development and embryogenesis-related genes, and discuss possible roles of RdDM at the onset of early embryonic development via targeted methylation at sites involved in different embryogenesis-related developmental mechanisms.
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Dynamic DNA Methylation in Plant Growth and Development. Int J Mol Sci 2018; 19:ijms19072144. [PMID: 30041459 PMCID: PMC6073778 DOI: 10.3390/ijms19072144] [Citation(s) in RCA: 138] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 07/12/2018] [Accepted: 07/20/2018] [Indexed: 12/14/2022] Open
Abstract
DNA methylation is an epigenetic modification required for transposable element (TE) silencing, genome stability, and genomic imprinting. Although DNA methylation has been intensively studied, the dynamic nature of methylation among different species has just begun to be understood. Here we summarize the recent progress in research on the wide variation of DNA methylation in different plants, organs, tissues, and cells; dynamic changes of methylation are also reported during plant growth and development as well as changes in response to environmental stresses. Overall DNA methylation is quite diverse among species, and it occurs in CG, CHG, and CHH (H = A, C, or T) contexts of genes and TEs in angiosperms. Moderately expressed genes are most likely methylated in gene bodies. Methylation levels decrease significantly just upstream of the transcription start site and around transcription termination sites; its levels in the promoter are inversely correlated with the expression of some genes in plants. Methylation can be altered by different environmental stimuli such as pathogens and abiotic stresses. It is likely that methylation existed in the common eukaryotic ancestor before fungi, plants and animals diverged during evolution. In summary, DNA methylation patterns in angiosperms are complex, dynamic, and an integral part of genome diversity after millions of years of evolution.
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Xie X, Shippen DE. DDM1 guards against telomere truncation in Arabidopsis. PLANT CELL REPORTS 2018; 37:501-513. [PMID: 29392401 PMCID: PMC5880217 DOI: 10.1007/s00299-017-2245-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 12/26/2017] [Indexed: 05/20/2023]
Abstract
Prolonged hypomethylation of DNA leads to telomere truncation correlated with increased telomere recombination, transposon mobilization and stem cell death. Epigenetic pathways, including DNA methylation, are crucial for telomere maintenance. Deficient in DNA Methylation 1 (DDM1) encodes a nucleosome remodeling protein, required to maintain DNA methylation in Arabidopsis thaliana. Plants lacking DDM1 can be self-propagated, but in the sixth generation (G6) hypomethylation leads to rampant transposon activation and infertility. Here we examine the role of DDM1 in telomere length homeostasis through a longitudinal study of successive generations of ddm1-2 mutants. We report that bulk telomere length remains within the wild-type range for the first five generations (G1-G5), and then precipitously drops in G6. While telomerase activity becomes more variable in later generation ddm1-2 mutants, there is no correlation between enzyme activity and telomere length. Plants lacking DDM1 also exhibit no dysregulation of several known telomere-associated transcripts, including TERRA. Instead, telomere shortening coincides with increased G-overhangs and extra-chromosomal circles, consistent with deletional recombination. Telomere shortening also correlates with transcriptional activation of retrotransposons, and a hypersensitive DNA damage response in root apical meristems. Since abiotic stresses, including DNA damage, stimulate homologous recombination, we hypothesize that telomere deletion in G6 ddm1-2 mutants is a by-product of elevated genome-wide recombination in response to transposon mobilization. Further, we speculate that telomere truncation may be beneficial in adverse environmental conditions by accelerating the elimination of stem cells with aberrant genomes.
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Affiliation(s)
- Xiaoyuan Xie
- Department of Biochemistry and Biophysics, Texas A&M University, 2128 TAMU, College Station, TX, 77843-2128, USA
| | - Dorothy E Shippen
- Department of Biochemistry and Biophysics, Texas A&M University, 2128 TAMU, College Station, TX, 77843-2128, USA.
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An YQC, Goettel W, Han Q, Bartels A, Liu Z, Xiao W. Dynamic Changes of Genome-Wide DNA Methylation during Soybean Seed Development. Sci Rep 2017; 7:12263. [PMID: 28947812 PMCID: PMC5613027 DOI: 10.1038/s41598-017-12510-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 09/08/2017] [Indexed: 02/06/2023] Open
Abstract
Seed development is programmed by expression of many genes in plants. Seed maturation is an important developmental process to soybean seed quality and yield. DNA methylation is a major epigenetic modification regulating gene expression. However, little is known about the dynamic nature of DNA methylation and its effects on gene expression during plant development. Through whole-genome bisulfite sequencing, we showed that DNA methylation went through dynamic changes during seed maturation. An average of 66% CG, 45% CHG and 9% CHH contexts was methylated in cotyledons. CHH methylation levels in cotyledons changed greatly from 6% at the early stage to 11% at the late stage. Transcribed genes were approximately two-fold more likely to be differentially methylated than non-transcribed genes. We identified 40, 66 and 2136 genes containing differentially methylated regions (DMRs) with negative correlation between their expression and methylation in the CG, CHG and CHH contexts, respectively. The majority of the DMR genes in the CHH context were transcriptionally down-regulated as seeds mature: 99% of them during early maturation were down-regulated, and preferentially associated with DNA replication and cell division. The results provide novel insights into the dynamic nature of DNA methylation and its relationship with gene regulation in seed development.
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Affiliation(s)
- Yong-Qiang Charles An
- US Department of Agriculture, Agricultural Research Service, Midwest Area, Plant Genetics Research Unit, Donald Danforth Plant Science Center, St. Louis, MO, 63132, USA.
| | - Wolfgang Goettel
- US Department of Agriculture, Agricultural Research Service, Midwest Area, Plant Genetics Research Unit, Donald Danforth Plant Science Center, St. Louis, MO, 63132, USA
| | - Qiang Han
- Department of Biology, Saint Louis University, St. Louis, MO, 63103, USA
| | - Arthur Bartels
- Department of Biology, Saint Louis University, St. Louis, MO, 63103, USA
| | - Zongrang Liu
- US Department of Agriculture, Agricultural Research Service, Appalachian Fruit Research Station, Kearneysville, WV, 25430, USA
| | - Wenyan Xiao
- Department of Biology, Saint Louis University, St. Louis, MO, 63103, USA.
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Satyaki PRV, Gehring M. DNA methylation and imprinting in plants: machinery and mechanisms. Crit Rev Biochem Mol Biol 2017; 52:163-175. [PMID: 28118754 DOI: 10.1080/10409238.2017.1279119] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Imprinting is an epigenetic phenomenon in which genes are expressed selectively from either the maternal or paternal alleles. In plants, imprinted gene expression is found in a tissue called the endosperm. Imprinting is often set by a unique epigenomic configuration in which the maternal chromosomes are less DNA methylated than their paternal counterparts. In this review, we synthesize studies that paint a detailed molecular portrait of the distinctive endosperm methylome. We will also discuss the molecular machinery that shapes and modifies this methylome, and the role of DNA methylation in imprinting.
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Affiliation(s)
- P R V Satyaki
- a Whitehead Institute for Biomedical Research , Cambridge , MA , USA
| | - Mary Gehring
- a Whitehead Institute for Biomedical Research , Cambridge , MA , USA.,b Department of Biology , Massachusetts Institute of Technology , Cambridge , MA , USA
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17
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Ashapkin VV, Kutueva LI, Vanyushin BF. Plant DNA Methyltransferase Genes: Multiplicity, Expression, Methylation Patterns. BIOCHEMISTRY (MOSCOW) 2017; 81:141-51. [PMID: 27260394 DOI: 10.1134/s0006297916020085] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Expression and methylation patterns of genes encoding DNA methyltransferases and their functionally related proteins were studied in organs of Arabidopsis thaliana plants. Genes coding for the major maintenance-type DNA methyltransferases, MET1 and CMT3, and the major de novo-type DNA methyltransferase, DRM2, are actively expressed in all organs. Similar constitutively active expression was observed for genes encoding their functionally related proteins, a histone H3K9 methyltransferase KYP and a catalytically non-active protein DRM3. Expression of the MET1 and CMT3 genes is significantly lower in developing endosperm compared with embryo. Vice versa, expression of the MET2a, MET2b, MET3, and CMT2 genes in endosperm is much more active compared with embryo. A special maintenance DNA methylation system seems to operate in endosperm. The DNMT2 and N6AMT genes encoding putative methyltransferases are constitutively expressed at low levels. CMT1 and DRM1 genes are expressed rather weakly in all investigated organs. Most of the studied genes have methylation patterns conforming to the "body-methylated gene" prototype. A peculiar feature of the MET family genes is methylation at all three possible site types (CG, CHG, and CHH). The most weakly expressed among genes of their respective families, CMT1 and DRM1, are practically unmethylated. The MET3 and N6AMT genes have unusual methylation patterns, promoter region, and most of the gene body devoid of any methylation, and the 3'-end proximal part of the gene body is highly methylated.
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Affiliation(s)
- V V Ashapkin
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
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18
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Ansari J, Shackelford RE, El-Osta H. Epigenetics in non-small cell lung cancer: from basics to therapeutics. Transl Lung Cancer Res 2016; 5:155-71. [PMID: 27186511 DOI: 10.21037/tlcr.2016.02.02] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Lung cancer remains the number one cause of cancer-related deaths worldwide with 221,200 estimated new cases and 158,040 estimated deaths in 2015. Approximately 80% of cases are non-small cell lung cancer (NSCLC). The diagnosis is usually made at an advanced stage where the prognosis is poor and therapeutic options are limited. The evolution of lung cancer is a multistep process involving genetic, epigenetic, and environmental factor interactions that result in the dysregulation of key oncogenes and tumor suppressor genes, culminating in activation of cancer-related signaling pathways. The past decade has witnessed the discovery of multiple molecular aberrations that drive lung cancer growth, among which are epidermal growth factor receptor (EGFR) mutations and translocations involving the anaplastic lymphoma kinase (ALK) gene. This has translated into therapeutic agent developments that target these molecular alterations. The absence of targetable mutations in 50% of NSCLC cases and targeted therapy resistance development underscores the importance for developing alternative therapeutic strategies for treating lung cancer. Among these strategies, pharmacologic modulation of the epigenome has been used to treat lung cancer. Epigenetics approaches may circumvent the problem of tumor heterogeneity by affecting the expression of multiple tumor suppression genes (TSGs), halting tumor growth and survival. Moreover, it may be effective for tumors that are not driven by currently recognized druggable mutations. This review summarizes the molecular pathology of lung cancer epigenetic aberrations and discusses current efforts to target the epigenome with different pharmacological approaches. Our main focus will be on hypomethylating agents, histone deacetylase (HDAC) inhibitors, microRNA modulations, and the role of novel epigenetic biomarkers. Last, we will address the challenges that face this old-new strategy in treating lung cancer.
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Affiliation(s)
- Junaid Ansari
- 1 Department of Medicine, Feist-Weiller Cancer Center, LSU Health, Shreveport, LA, USA ; 2 Department of Pathology, LSU Health Shreveport, Shreveport, LA, USA
| | - Rodney E Shackelford
- 1 Department of Medicine, Feist-Weiller Cancer Center, LSU Health, Shreveport, LA, USA ; 2 Department of Pathology, LSU Health Shreveport, Shreveport, LA, USA
| | - Hazem El-Osta
- 1 Department of Medicine, Feist-Weiller Cancer Center, LSU Health, Shreveport, LA, USA ; 2 Department of Pathology, LSU Health Shreveport, Shreveport, LA, USA
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Hollwey E, Watson M, Meyer P. Expression of the C-Terminal Domain of Mammalian <i>TET</i>3 DNA Dioxygenase in <i>Arabidopsis thaliana</i> Induces Heritable Methylation Changes at <i>rDNA</i> Loci. ACTA ACUST UNITED AC 2016. [DOI: 10.4236/abb.2016.75023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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20
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Kim JY, Kwon YJ, Kim SI, Kim DY, Song JT, Seo HS. Ammonium Inhibits Chromomethylase 3-Mediated Methylation of the Arabidopsis Nitrate Reductase Gene NIA2. FRONTIERS IN PLANT SCIENCE 2015; 6:1161. [PMID: 26834755 PMCID: PMC4720742 DOI: 10.3389/fpls.2015.01161] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 12/07/2015] [Indexed: 05/10/2023]
Abstract
Gene methylation is an important mechanism regulating gene expression and genome stability. Our previous work showed that methylation of the nitrate reductase (NR) gene NIA2 was dependent on chromomethylase 3 (CMT3). Here, we show that CMT3-mediated NIA2 methylation is regulated by ammonium in Arabidopsis thaliana. CHG sequences (where H can be A, T, or C) were methylated in NIA2 but not in NIA1, and ammonium [(NH4)2SO4] treatment completely blocked CHG methylation in NIA2. By contrast, ammonium had no effect on CMT3 methylation, indicating that ammonium negatively regulates CMT3-mediated NIA2 methylation without affecting CMT3 methylation. Ammonium upregulated NIA2 mRNA expression, which was consistent with the repression of NIA2 methylation by ammonium. Ammonium treatment also reduced the overall genome methylation level of wild-type Arabidopsis. Moreover, CMT3 bound to specific promoter and intragenic regions of NIA2. These combined results indicate that ammonium inhibits CMT3-mediated methylation of NIA2 and that of other target genes, and CMT3 selectively binds to target DNA sequences for methylation.
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Affiliation(s)
- Joo Yong Kim
- Department of Plant Science and Research Institute for Agriculture and Life Sciences, Seoul National UniversitySeoul, South Korea
| | - Ye Jin Kwon
- Department of Plant Science and Research Institute for Agriculture and Life Sciences, Seoul National UniversitySeoul, South Korea
| | - Sung-Il Kim
- Department of Plant Science and Research Institute for Agriculture and Life Sciences, Seoul National UniversitySeoul, South Korea
| | - Do Youn Kim
- Department of Plant Science and Research Institute for Agriculture and Life Sciences, Seoul National UniversitySeoul, South Korea
| | - Jong Tae Song
- School of Applied Biosciences, Kyungpook National UniversityDaegu, South Korea
| | - Hak Soo Seo
- Department of Plant Science and Research Institute for Agriculture and Life Sciences, Seoul National UniversitySeoul, South Korea
- Plant Genomics and Breeding Institute, Seoul National UniversitySeoul, South Korea
- Bio-MAX Institute, Seoul National UniversitySeoul, South Korea
- *Correspondence: Hak Soo Seo,
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21
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Huang J, Wang H, Liang W, Xie X, Guo G. Developmental expression of Arabidopsis methyltransferase genes MET1, DRM2, and CMT3. Mol Biol 2014. [DOI: 10.1134/s0026893314050057] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Somatic embryogenesis - Stress-induced remodeling of plant cell fate. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1849:385-402. [PMID: 25038583 DOI: 10.1016/j.bbagrm.2014.07.005] [Citation(s) in RCA: 211] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 07/08/2014] [Accepted: 07/10/2014] [Indexed: 01/13/2023]
Abstract
Plants as sessile organisms have remarkable developmental plasticity ensuring heir continuous adaptation to the environment. An extreme example is somatic embryogenesis, the initiation of autonomous embryo development in somatic cells in response to exogenous and/or endogenous signals. In this review I briefly overview the various pathways that can lead to embryo development in plants in addition to the fertilization of the egg cell and highlight the importance of the interaction of stress- and hormone-regulated pathways during the induction of somatic embryogenesis. Somatic embryogenesis can be initiated in planta or in vitro, directly or indirectly, and the requirement for dedifferentiation as well as the way to achieve developmental totipotency in the various systems is discussed in light of our present knowledge. The initiation of all forms of the stress/hormone-induced in vitro as well as the genetically provoked in planta somatic embryogenesis requires extensive and coordinated genetic reprogramming that has to take place at the chromatin level, as the embryogenic program is under strong epigenetic repression in vegetative plant cells. Our present knowledge on chromatin-based mechanisms potentially involved in the somatic-to-embryogenic developmental transition is summarized emphasizing the potential role of the chromatin to integrate stress, hormonal, and developmental pathways leading to the activation of the embryogenic program. The role of stress-related chromatin reorganization in the genetic instability of in vitro cultures is also discussed. This article is part of a Special Issue entitled: Stress as a fundamental theme in cell plasticity.
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23
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Kim KD, El Baidouri M, Jackson SA. Accessing epigenetic variation in the plant methylome. Brief Funct Genomics 2014; 13:318-27. [PMID: 24562692 DOI: 10.1093/bfgp/elu003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Cytosine DNA methylation is the addition of a methyl group to the 5' position of a cytosine, which plays a crucial role in plant development and gene silencing. Genome-wide profiling of DNA methylation is now possible using various techniques and strategies. Using these technologies, we are beginning to elucidate the extent and impact of variation in DNA methylation between individuals and/or tissues. Here, we review the different techniques used to analyze the methylomes at the whole-genome level and their applications to better understand epigenetic variations in plants.
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24
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Colaneri AC, Jones AM. Genome-wide quantitative identification of DNA differentially methylated sites in Arabidopsis seedlings growing at different water potential. PLoS One 2013; 8:e59878. [PMID: 23577076 PMCID: PMC3620116 DOI: 10.1371/journal.pone.0059878] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 02/19/2013] [Indexed: 12/17/2022] Open
Abstract
Background In eukaryotes, the combinatorial usage of cis-regulatory elements enables the assembly of composite genetic switches to integrate multifarious, convergent signals within a single promoter. Plants as sessile organisms, incapable of seeking for optimal conditions, rely on the use of this resource to adapt to changing environments. Emerging evidence suggests that the transcriptional responses of plants to stress are associated with epigenetic processes that govern chromatin accessibility. However, the extent at which specific chromatin modifications contribute to gene regulation has not been assessed. Methodology/Principal Findings In the present work, we combined methyl-sensitive-cut counting and RNA-seq to follow the transcriptional and epigenetic response of plants to simulated drought. Comprehensive genome wide evidence supports the notion that the methylome is widely reactive to water potential. The predominant changes in methylomes were loci in the promoters of genes encoding for proteins suited to cope with the environmental challenge. Conclusion/Significance These selective changes in the methylome with corresponding changes in gene transcription suggest drought sets in motion an instructive mechanism guiding epigenetic machinery toward specific effectors genes.
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Affiliation(s)
- Alejandro C. Colaneri
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Alan M. Jones
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- * E-mail:
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Coleman-Derr D, Zilberman D. Deposition of histone variant H2A.Z within gene bodies regulates responsive genes. PLoS Genet 2012; 8:e1002988. [PMID: 23071449 PMCID: PMC3469445 DOI: 10.1371/journal.pgen.1002988] [Citation(s) in RCA: 258] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2012] [Accepted: 08/10/2012] [Indexed: 01/07/2023] Open
Abstract
The regulation of eukaryotic chromatin relies on interactions between many epigenetic factors, including histone modifications, DNA methylation, and the incorporation of histone variants. H2A.Z, one of the most conserved but enigmatic histone variants that is enriched at the transcriptional start sites of genes, has been implicated in a variety of chromosomal processes. Recently, we reported a genome-wide anticorrelation between H2A.Z and DNA methylation, an epigenetic hallmark of heterochromatin that has also been found in the bodies of active genes in plants and animals. Here, we investigate the basis of this anticorrelation using a novel h2a.z loss-of-function line in Arabidopsis thaliana. Through genome-wide bisulfite sequencing, we demonstrate that loss of H2A.Z in Arabidopsis has only a minor effect on the level or profile of DNA methylation in genes, and we propose that the global anticorrelation between DNA methylation and H2A.Z is primarily caused by the exclusion of H2A.Z from methylated DNA. RNA sequencing and genomic mapping of H2A.Z show that H2A.Z enrichment across gene bodies, rather than at the TSS, is correlated with lower transcription levels and higher measures of gene responsiveness. Loss of H2A.Z causes misregulation of many genes that are disproportionately associated with response to environmental and developmental stimuli. We propose that H2A.Z deposition in gene bodies promotes variability in levels and patterns of gene expression, and that a major function of genic DNA methylation is to exclude H2A.Z from constitutively expressed genes. Eukaryotes package their DNA to fit within the nucleus using well-conserved proteins, called histones, that form the building blocks of nucleosomes, the fundamental units of chromatin. Histone variants are specialized versions of these proteins that change the chromatin landscape by altering the biochemical properties and interacting partners of the nucleosome. H2A.Z, a conserved eukaryotic histone variant, is preferentially enriched at the beginnings of genes, though the significance of this enrichment remains unknown. We and others have shown that H2A.Z is conspicuously absent from methylated DNA across the genome in plants and animals. Typically considered a mark of epigenetic silencing, DNA methylation has more recently been discovered in the bodies of many genes. Here, we present evidence that the genome-wide anticorrelation between DNA methylation and H2A.Z enrichment in Arabidopsis is the result of DNA methylation acting to prevent H2A.Z incorporation. We demonstrate that the presence of H2A.Z within gene bodies is correlated with lower transcription levels and higher variability in expression patterns across tissue types and environmental conditions, and we propose that a major function of gene-body DNA methylation is to exclude H2A.Z from the bodies of highly and constitutively expressed genes.
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Affiliation(s)
| | - Daniel Zilberman
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, United States of America
- * E-mail:
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Zubko E, Gentry M, Kunova A, Meyer P. De novo DNA methylation activity of methyltransferase 1 (MET1) partially restores body methylation in Arabidopsis thaliana. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 71:1029-1037. [PMID: 22587613 DOI: 10.1111/j.1365-313x.2012.05051.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Arabidopsis METHYLTRANSFERASE 1 (MET1) controls faithful maintenance of cytosine methylation at CG sites in repetitive regions and central body regions of active genes. If MET1 is removed in a mutant background, CG methylation is lost and is only restored in specific heterochromatic regions that have maintained competence for re-methylation due to the presence of small RNAs and the RNA-directed DNA methylation pathway that controls de novo DNA methylation functions. We analysed re-methylation at a locus that loses body methylation in an met1 mutant. We found that body methylation at this locus is at least partially restored when MET1 is re-introduced into the met1 mutant background, either via genetic cross or DNA transfer. Re-methylation is region-specific but random with respect to individual CG targets, does not require passage through the germline, and its efficiency appears to be influenced by transcription. This suggests that, at least at some loci, MET1 has de novo methylation activity that can restore lost body methylation patterns. We propose that this activity helps to stabilize body methylation patterns, and the random target site selection probably also enhances the variability of body methylation patterns.
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Affiliation(s)
- Elena Zubko
- Center for Plant Sciences, University of Leeds, Leeds LS2 9JT, UK
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27
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Profile of small interfering RNAs from cotton plants infected with the polerovirus Cotton leafroll dwarf virus. BMC Mol Biol 2011; 12:40. [PMID: 21864377 PMCID: PMC3189115 DOI: 10.1186/1471-2199-12-40] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Accepted: 08/24/2011] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND In response to infection, viral genomes are processed by Dicer-like (DCL) ribonuclease proteins into viral small RNAs (vsRNAs) of discrete sizes. vsRNAs are then used as guides for silencing the viral genome. The profile of vsRNAs produced during the infection process has been extensively studied for some groups of viruses. However, nothing is known about the vsRNAs produced during infections of members of the economically important family Luteoviridae, a group of phloem-restricted viruses. Here, we report the characterization of a population of vsRNAs from cotton plants infected with Cotton leafroll dwarf virus (CLRDV), a member of the genus Polerovirus, family Luteoviridae. RESULTS Deep sequencing of small RNAs (sRNAs) from leaves of CLRDV-infected cotton plants revealed that the vsRNAs were 21- to 24-nucleotides (nt) long and that their sequences matched the viral genome, with higher frequencies of matches in the 3- region. There were equivalent amounts of sense and antisense vsRNAs, and the 22-nt class of small RNAs was predominant. During infection, cotton Dcl transcripts appeared to be up-regulated, while Dcl2 appeared to be down-regulated. CONCLUSIONS This is the first report on the profile of sRNAs in a plant infected with a virus from the family Luteoviridae. Our sequence data strongly suggest that virus-derived double-stranded RNA functions as one of the main precursors of vsRNAs. Judging by the profiled size classes, all cotton DCLs might be working to silence the virus. The possible causes for the unexpectedly high accumulation of 22-nt vsRNAs are discussed. CLRDV is the causal agent of Cotton blue disease, which occurs worldwide. Our results are an important contribution for understanding the molecular mechanisms involved in this and related diseases.
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Vanyushin BF, Ashapkin VV. DNA methylation in higher plants: past, present and future. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2011; 1809:360-8. [PMID: 21549230 DOI: 10.1016/j.bbagrm.2011.04.006] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 04/13/2011] [Accepted: 04/15/2011] [Indexed: 01/19/2023]
Abstract
A relatively high degree of nuclear DNA (nDNA) methylation is a specific feature of plant genomes. Targets for cytosine DNA methylation in plant genomes are CG, CHG and CHH (H is A, T, C) sequences. More than 30% total m(5)C in plant DNA is located in non-CG sites. DNA methylation in plants is species-, tissue-, organelle- and age-specific; it is involved in the control of all genetic functions including transcription, replication, DNA repair, gene transposition and cell differentiation. DNA methylation is engaged in gene silencing and parental imprinting, it controls expression of transgenes and foreign DNA in cell. Plants have much more complicated and sophisticated system of the multicomponent genome methylations compared to animals; DNA methylation in plant mitochondria is performed in other fashion as compared to that in nuclei. The nDNA methylation is carried out by cytosine DNA methyltransferases of, at least, three families. In contrast to animals the plants with the major maintenance methyltransferase MET1 (similar to animal Dnmt1) inactivated do survive. One and the same plant gene may be methylated at both adenine and cytosine residues; specific plant adenine DNA methyltransferase was described. Thus, two different systems of the genome modification based on methylation of cytosines and adenines seem to coexist in higher plants. This article is part of a Special Issue entitled: Epigenetic control of cellular and developmental processes in plants.
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Affiliation(s)
- Boris F Vanyushin
- A N Belozersky Institute of Physical and Chemical Biology, Moscow State University, Moscow, Russian Federation.
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Piperi C, Papavassiliou AG. Strategies for DNA methylation analysis in developmental studies. Dev Growth Differ 2011; 53:287-99. [PMID: 21447098 DOI: 10.1111/j.1440-169x.2011.01253.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Developmental processes in eukaryotes are highly dependent on DNA methylation. 5-methylcytosine (m(5) C) is the most prevalent and best understood DNA modification implicated in maintenance of genomic integrity and function across species. Although m(5) C occurs almost exclusively in symmetrical CpG context in vertebrates, additional asymmetrical distribution in CpHpG and CpHpH sites has been observed in plants and embryonic stem cells. To this end, accurate and reproducible methodology for full analysis of the DNA methylome is highly demanded. Fortunately, a variety of methods enable quantitative DNA methylation mapping at a single-base resolution and in a large scale. Here, we provide a critical overview of methods applied primarily to m(5) C detection with particular emphasis on technical improvements of the classical bisulfite-conversion protocol. We further describe strategies in combination with emerging technologies that allow acquisition of highly reliable data for developmental studies.
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Affiliation(s)
- Christina Piperi
- Department of Biological Chemistry, University of Athens Medical School, 11527 Athens, Greece
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Dyachenko OV, Shevchuk TV, Buryanov YI. Structural and functional features of the 5-methylcytosine distribution in the eukaryotic genome. Mol Biol 2010. [DOI: 10.1134/s0026893310020019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Lafos M, Schubert D. Balance of power--dynamic regulation of chromatin in plant development. Biol Chem 2009; 390:1113-23. [PMID: 19747083 DOI: 10.1515/bc.2009.129] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Chromatin states profoundly determine and maintain gene activity and gene repression in eukaryotic organisms. Regulation of chromatin involves chromatin remodeling, chromatin modifications and exchange of chromatin components and is linked to DNA methylation in some cases. In plants and other organisms, chromatin proteins control many developmental pathways, integrate changes in the environment and can confer a cellular memory of these cues. Here, we review the molecular mechanisms that provide a dynamic regulation of chromatin in a cell. In addition, we discuss how chromatin needs to be flexibly regulated during plant growth to confer stable expression states that can occasionally be reset, e.g., owing to changes in the environment and progression of development.
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Affiliation(s)
- Marcel Lafos
- Institute of Genetics, Heinrich Heine University Düsseldorf, D-40225 Düsseldorf, Germany
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Selective epigenetic control of retrotransposition in Arabidopsis. Nature 2009; 461:427-30. [PMID: 19734882 DOI: 10.1038/nature08328] [Citation(s) in RCA: 243] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2009] [Accepted: 07/27/2009] [Indexed: 11/08/2022]
Abstract
Retrotransposons are mobile genetic elements that populate chromosomes, where the host largely controls their activities. In plants and mammals, retrotransposons are transcriptionally silenced by DNA methylation, which in Arabidopsis is propagated at CG dinucleotides by METHYLTRANSFERASE 1 (MET1). In met1 mutants, however, mobilization of retrotransposons is not observed, despite their transcriptional activation. A post-transcriptional mechanism therefore seems to be preventing retrotransposition. Here we show that a copia-type retrotransposon (Evadé, French for 'fugitive') evaded suppression of its movement during inbreeding of hybrid epigenomes consisting of met1- and wild-type-derived chromosomes. Evadé (EVD) reinsertions caused a series of developmental mutations that allowed its identification. Genetic testing of host control of the EVD life cycle showed that transcriptional suppression occurred by CG methylation supported by RNA-directed DNA methylation. On transcriptional reactivation, subsequent steps of the EVD cycle were inhibited by plant-specific RNA polymerase IV/V and the histone methyltransferase KRYPTONITE (KYP). Moreover, genome resequencing demonstrated retrotransposition of EVD but no other potentially active retroelements when this combination of epigenetic mechanisms was compromised. Our results demonstrate that epigenetic control of retrotransposons extends beyond transcriptional suppression and can be individualized for particular elements.
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Zhang X, Bernatavichute YV, Cokus S, Pellegrini M, Jacobsen SE. Genome-wide analysis of mono-, di- and trimethylation of histone H3 lysine 4 in Arabidopsis thaliana. Genome Biol 2009; 10:R62. [PMID: 19508735 PMCID: PMC2718496 DOI: 10.1186/gb-2009-10-6-r62] [Citation(s) in RCA: 416] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Revised: 02/03/2009] [Accepted: 06/09/2009] [Indexed: 11/25/2022] Open
Abstract
Analysis of the genome-wide distribution patterns of histone H3 lysine4 methylation in Arabidopsis thaliana seedlings shows that it has widespread roles in regulating gene expression. Background Post-translational modifications of histones play important roles in maintaining normal transcription patterns by directly or indirectly affecting the structural properties of the chromatin. In plants, methylation of histone H3 lysine 4 (H3K4me) is associated with genes and required for normal plant development. Results We have characterized the genome-wide distribution patterns of mono-, di- and trimethylation of H3K4 (H3K4me1, H3K4me2 and H3K4me3, respectively) in Arabidopsis thaliana seedlings using chromatin immunoprecipitation and high-resolution whole-genome tiling microarrays (ChIP-chip). All three types of H3K4me are found to be almost exclusively genic, and two-thirds of Arabidopsis genes contain at least one type of H3K4me. H3K4me2 and H3K4me3 accumulate predominantly in promoters and 5' genic regions, whereas H3K4me1 is distributed within transcribed regions. In addition, H3K4me3-containing genes are highly expressed with low levels of tissue specificity, but H3K4me1 or H3K4me2 may not be directly involved in transcriptional activation. Furthermore, the preferential co-localization of H3K4me3 and H3K27me3 found in mammals does not appear to occur in plants at a genome-wide level, but H3K4me2 and H3K27me3 co-localize at a higher-than-expected frequency. Finally, we found that H3K4me2/3 and DNA methylation appear to be mutually exclusive, but surprisingly, H3K4me1 is highly correlated with CG DNA methylation in the transcribed regions of genes. Conclusions H3K4me plays widespread roles in regulating gene expression in plants. Although many aspects of the mechanisms and functions of H3K4me appear to be conserved among all three kingdoms, we observed significant differences in the relationship between H3K4me and transcription or other epigenetic pathways in plants and mammals.
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Affiliation(s)
- Xiaoyu Zhang
- Department of Plant Biology, University of Georgia, Green Street, Athens, GA 30602, USA.
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Abstract
Transposable elements make up a substantial proportion of most plant genomes. Because they are potentially highly mutagenic, transposons are controlled by a set of mechanisms whose function is to recognize and epigenetically silence them. Under most circumstances this process is highly efficient, and the vast majority of transposons are inactive. Nevertheless, transposons are activated by a variety of conditions likely to be encountered by natural populations, and even closely related species can have dramatic differences in transposon copy number. Transposon silencing has proved to be closely related to other epigenetic phenomena, and transposons are known to contribute directly and indirectly to regulation of host genes. Together, these observations suggest that naturally occurring changes in transposon activity may have had an important impact on the causes and consequences of epigenetic silencing in plants.
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Affiliation(s)
- Damon Lisch
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA.
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Describing Epigenomic Information in Arabidopsis. Epigenomics 2008. [DOI: 10.1007/978-1-4020-9187-2_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Zilberman D. The evolving functions of DNA methylation. CURRENT OPINION IN PLANT BIOLOGY 2008; 11:554-559. [PMID: 18774331 DOI: 10.1016/j.pbi.2008.07.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2008] [Revised: 07/30/2008] [Accepted: 07/31/2008] [Indexed: 05/26/2023]
Abstract
DNA methylation is an ancient process found in all domains of life. Although the enzymes that mediate methylation have remained highly conserved, DNA methylation has been adapted for a variety of uses throughout evolution, including defense against transposable elements and control of gene expression. Defects in DNA methylation are linked to human diseases, including cancer. Methylation has been lost several times in the course of animal and fungal evolution, thus limiting the opportunity for study in common model organisms. In the past decade, plants have emerged as a premier model system for genetic dissection of DNA methylation. A recent combination of plant genetics with powerful genomic approaches has led to a number of exciting discoveries and promises many more.
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Affiliation(s)
- Daniel Zilberman
- University of California, 211 Koshland Hall, Berkeley, CA 94720, United States.
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Chan SWL. Inputs and outputs for chromatin-targeted RNAi. TRENDS IN PLANT SCIENCE 2008; 13:383-389. [PMID: 18550415 DOI: 10.1016/j.tplants.2008.05.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Revised: 05/01/2008] [Accepted: 05/01/2008] [Indexed: 05/26/2023]
Abstract
Plant gene silencing is targeted to transposons and repeated sequences by small RNAs from the RNA interference (RNAi) pathway. Like classical RNAi, RNA-directed chromatin silencing involves the cleavage of double-stranded RNA by Dicer endonucleases to create small interfering RNAs (siRNAs), which bind to the Argonaute protein. The production of double-stranded RNA (dsRNA) must be carefully controlled to prevent inappropriate silencing. A plant-specific RNA polymerase IV (Pol IV) initiates siRNA production at silent heterochromatin, but Pol IV-independent mechanisms for making dsRNA also exist. Downstream of siRNA biogenesis, multiple chromatin marks might be targeted by Argonaute-siRNA complexes, yet mechanisms of chromatin modification remain poorly understood. Genomic studies of siRNA target loci promise to reveal novel biological functions for chromatin-targeted RNAi.
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Affiliation(s)
- Simon W-L Chan
- Department of Plant Biology, University of California, Davis, 1 Shields Avenue, Davis, CA 95616, USA.
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Gehring M, Henikoff S. DNA methylation and demethylation in Arabidopsis. THE ARABIDOPSIS BOOK 2008; 6:e0102. [PMID: 22303233 PMCID: PMC3243302 DOI: 10.1199/tab.0102] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Affiliation(s)
- Mary Gehring
- Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Seattle, WA 98109
| | - Steven Henikoff
- Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Seattle, WA 98109
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Abstract
In plants, DNA methylation, histone modifications, and RNA interference play critically important roles in regulating chromatin structure, thereby profoundly affecting transcription and other molecular events. Recent advances in microarray and high-throughput sequencing technologies have enabled genome-wide studies of these pathways in great detail. The vast amounts of "epigenomic" data generated so far have provided new insights into the mechanisms and functions of these pathways and have broadened our understanding of the structure and organization of plant chromatin as a whole.
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Affiliation(s)
- Xiaoyu Zhang
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA.
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Cokus SJ, Feng S, Zhang X, Chen Z, Merriman B, Haudenschild CD, Pradhan S, Nelson SF, Pellegrini M, Jacobsen SE. Shotgun bisulphite sequencing of the Arabidopsis genome reveals DNA methylation patterning. Nature 2008; 452:215-9. [PMID: 18278030 PMCID: PMC2377394 DOI: 10.1038/nature06745] [Citation(s) in RCA: 1537] [Impact Index Per Article: 96.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Accepted: 01/30/2008] [Indexed: 11/09/2022]
Abstract
Cytosine DNA methylation is important in regulating gene expression and in silencing transposons and other repetitive sequences. Recent genomic studies in Arabidopsis thaliana have revealed that many endogenous genes are methylated either within their promoters or within their transcribed regions, and that gene methylation is highly correlated with transcription levels. However, plants have different types of methylation controlled by different genetic pathways, and detailed information on the methylation status of each cytosine in any given genome is lacking. To this end, we generated a map at single-base-pair resolution of methylated cytosines for Arabidopsis, by combining bisulphite treatment of genomic DNA with ultra-high-throughput sequencing using the Illumina 1G Genome Analyser and Solexa sequencing technology. This approach, termed BS-Seq, unlike previous microarray-based methods, allows one to sensitively measure cytosine methylation on a genome-wide scale within specific sequence contexts. Here we describe methylation on previously inaccessible components of the genome and analyse the DNA methylation sequence composition and distribution. We also describe the effect of various DNA methylation mutants on genome-wide methylation patterns, and demonstrate that our newly developed library construction and computational methods can be applied to large genomes such as that of mouse.
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Affiliation(s)
- Shawn J Cokus
- Department of Molecular, Cell, and Developmental Biology, University of California at Los Angeles, Los Angeles, California 90095, USA
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Abstract
Cytosine methylation is the most common covalent modification of DNA in eukaryotes. DNA methylation has an important role in many aspects of biology, including development and disease. Methylation can be detected using bisulfite conversion, methylation-sensitive restriction enzymes, methyl-binding proteins and anti-methylcytosine antibodies. Combining these techniques with DNA microarrays and high-throughput sequencing has made the mapping of DNA methylation feasible on a genome-wide scale. Here we discuss recent developments and future directions for identifying and mapping methylation, in an effort to help colleagues to identify the approaches that best serve their research interests.
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Affiliation(s)
- Daniel Zilberman
- University of California, 211 Koshland Hall, Berkeley, CA 94720, USA
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