201
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Yu C, Yan C, Liu Y, Liu Y, Jia Y, Lavelle D, An G, Zhang W, Zhang L, Han R, Larkin RM, Chen J, Michelmore RW, Kuang H. Upregulation of a KN1 homolog by transposon insertion promotes leafy head development in lettuce. Proc Natl Acad Sci U S A 2020; 117:33668-33678. [PMID: 33288708 PMCID: PMC7776633 DOI: 10.1073/pnas.2019698117] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Leafy head is a unique type of plant architecture found in some vegetable crops, with leaves bending inward to form a compact head. The genetic and molecular mechanisms underlying leafy head in vegetables remain poorly understood. We genetically fine-mapped and cloned a major quantitative trait locus controlling heading in lettuce. The candidate gene (LsKN1) is a homolog of knotted 1 (KN1) from Zea mays Complementation and CRISPR/Cas9 knockout experiments confirmed the role of LsKN1 in heading. In heading lettuce, there is a CACTA-like transposon inserted into the first exon of LsKN1 (LsKN1▽). The transposon sequences act as a promoter rather than an enhancer and drive high expression of LsKN1▽. The enhanced expression of LsKN1▽ is necessary but not sufficient for heading in lettuce. Data from ChIP-sequencing, electrophoretic mobility shift assays, and dual luciferase assays indicate that the LsKN1▽ protein binds the promoter of LsAS1 and down-regulates its expression to alter leaf dorsoventrality. This study provides insight into plant leaf development and will be useful for studies on heading in other vegetable crops.
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Affiliation(s)
- Changchun Yu
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Key Laboratory of Horticultural Crop Biology and Genetic improvement (Central Region), Ministry of Agriculture (MOA), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, 430070 Wuhan, People's Republic of China
| | - Chenghuan Yan
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Key Laboratory of Horticultural Crop Biology and Genetic improvement (Central Region), Ministry of Agriculture (MOA), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, 430070 Wuhan, People's Republic of China
| | - Yuling Liu
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Key Laboratory of Horticultural Crop Biology and Genetic improvement (Central Region), Ministry of Agriculture (MOA), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, 430070 Wuhan, People's Republic of China
| | - Yali Liu
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Key Laboratory of Horticultural Crop Biology and Genetic improvement (Central Region), Ministry of Agriculture (MOA), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, 430070 Wuhan, People's Republic of China
| | - Yue Jia
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Key Laboratory of Horticultural Crop Biology and Genetic improvement (Central Region), Ministry of Agriculture (MOA), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, 430070 Wuhan, People's Republic of China
| | - Dean Lavelle
- Genome Center and Department of Plant Sciences, University of California, Davis, CA 95616
| | - Guanghui An
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Key Laboratory of Horticultural Crop Biology and Genetic improvement (Central Region), Ministry of Agriculture (MOA), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, 430070 Wuhan, People's Republic of China
| | - Weiyi Zhang
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Key Laboratory of Horticultural Crop Biology and Genetic improvement (Central Region), Ministry of Agriculture (MOA), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, 430070 Wuhan, People's Republic of China
| | - Lei Zhang
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Key Laboratory of Horticultural Crop Biology and Genetic improvement (Central Region), Ministry of Agriculture (MOA), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, 430070 Wuhan, People's Republic of China
| | - Rongkui Han
- Genome Center and Department of Plant Sciences, University of California, Davis, CA 95616
| | - Robert M Larkin
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Key Laboratory of Horticultural Crop Biology and Genetic improvement (Central Region), Ministry of Agriculture (MOA), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, 430070 Wuhan, People's Republic of China
| | - Jiongjiong Chen
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Key Laboratory of Horticultural Crop Biology and Genetic improvement (Central Region), Ministry of Agriculture (MOA), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, 430070 Wuhan, People's Republic of China
| | - Richard W Michelmore
- Genome Center and Department of Plant Sciences, University of California, Davis, CA 95616
| | - Hanhui Kuang
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Key Laboratory of Horticultural Crop Biology and Genetic improvement (Central Region), Ministry of Agriculture (MOA), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, 430070 Wuhan, People's Republic of China;
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202
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Wu L, Williams JS, Sun L, Kao TH. Sequence analysis of the Petunia inflata S-locus region containing 17 S-Locus F-Box genes and the S-RNase gene involved in self-incompatibility. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 104:1348-1368. [PMID: 33048387 DOI: 10.1111/tpj.15005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/28/2020] [Accepted: 09/01/2020] [Indexed: 06/11/2023]
Abstract
Self-incompatibility in Petunia is controlled by the polymorphic S-locus, which contains S-RNase encoding the pistil determinant and 16-20 S-locus F-box (SLF) genes collectively encoding the pollen determinant. Here we sequenced and assembled approximately 3.1 Mb of the S2 -haplotype of the S-locus in Petunia inflata using bacterial artificial chromosome clones collectively containing all 17 SLF genes, SLFLike1, and S-RNase. Two SLF pseudogenes and 28 potential protein-coding genes were identified, 20 of which were also found at the S-loci of both the S6a -haplotype of P. inflata and the SN -haplotype of self-compatible Petunia axillaris, but not in the S-locus remnants of self-compatible potato (Solanum tuberosum) and tomato (Solanum lycopersicum). Comparative analyses of S-locus sequences of these three S-haplotypes revealed potential genetic exchange in the flanking regions of SLF genes, resulting in highly similar flanking regions between different types of SLF and between alleles of the same type of SLF of different S-haplotypes. The high degree of sequence similarity in the flanking regions could often be explained by the presence of similar long terminal repeat retroelements, which were enriched at the S-loci of all three S-haplotypes and in the flanking regions of all S-locus genes examined. We also found evidence of the association of transposable elements with SLF pseudogenes. Based on the hypothesis that SLF genes were derived by retrotransposition, we identified 10 F-box genes as putative SLF parent genes. Our results shed light on the importance of non-coding sequences in the evolution of the S-locus, and on possible evolutionary mechanisms of generation, proliferation, and deletion of SLF genes.
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Affiliation(s)
- Lihua Wu
- Intercollege Graduate Degree Program in Plant Biology, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - Justin S Williams
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - Linhan Sun
- Intercollege Graduate Degree Program in Plant Biology, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - Teh-Hui Kao
- Intercollege Graduate Degree Program in Plant Biology, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
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203
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Fambrini M, Usai G, Vangelisti A, Mascagni F, Pugliesi C. The plastic genome: The impact of transposable elements on gene functionality and genomic structural variations. Genesis 2020; 58:e23399. [DOI: 10.1002/dvg.23399] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/07/2020] [Accepted: 11/10/2020] [Indexed: 12/15/2022]
Affiliation(s)
- Marco Fambrini
- Department of Agriculture, Food and Environment (DAFE) University of Pisa Pisa Italy
| | - Gabriele Usai
- Department of Agriculture, Food and Environment (DAFE) University of Pisa Pisa Italy
| | - Alberto Vangelisti
- Department of Agriculture, Food and Environment (DAFE) University of Pisa Pisa Italy
| | - Flavia Mascagni
- Department of Agriculture, Food and Environment (DAFE) University of Pisa Pisa Italy
| | - Claudio Pugliesi
- Department of Agriculture, Food and Environment (DAFE) University of Pisa Pisa Italy
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204
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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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205
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Martínez-Gómez J, Galimba KD, Coté EY, Sullivan AM, Di Stilio VS. Spontaneous homeotic mutants and genetic control of floral organ identity in a ranunculid. Evol Dev 2020; 23:197-214. [PMID: 33179410 DOI: 10.1111/ede.12357] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/11/2020] [Accepted: 09/14/2020] [Indexed: 12/25/2022]
Abstract
The regulation of floral organ identity was investigated using a forward genetic approach in five floral homeotic mutants of Thalictrum, a noncore eudicot. We hypothesized that these mutants carry defects in the floral patterning genes. Mutant characterization comprised comparative floral morphology and organ identity gene expression at early and late developmental stages, followed by sequence analysis of coding and intronic regions to identify transcription factor binding sites and protein-protein interaction (PPI) motifs. Mutants exhibited altered expression of floral MADS-box genes, which further informed the function of paralogs arising from gene duplications not found in reference model systems. The ensuing modified BCE models for the mutants supported instances of neofunctionalization (e.g., B-class genes expressed ectopically in sepals), partial redundancy (E-class), or subfunctionalization (C-class) of paralogs. A lack of deleterious mutations in the coding regions of candidate floral MADS-box genes suggested that cis-regulatory or trans-acting mutations are at play. Consistent with this hypothesis, double-flower mutants had transposon insertions or showed signs of transposon activity in the regulatory intron of AGAMOUS (AG) orthologs. Single amino acid substitutions were also found, yet they did not fall on any of the identified DNA binding or PPI motifs. In conclusion, we present evidence suggesting that transposon activity and regulatory mutations in floral homeotic genes likely underlie the striking phenotypes of these Thalictrum floral homeotic mutants.
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Affiliation(s)
| | - Kelsey D Galimba
- Department of Biology, University of Washington, Seattle, Washington, USA
| | - Erin Y Coté
- Department of Biology, University of Washington, Seattle, Washington, USA
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206
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Novák P, Guignard MS, Neumann P, Kelly LJ, Mlinarec J, Koblížková A, Dodsworth S, Kovařík A, Pellicer J, Wang W, Macas J, Leitch IJ, Leitch AR. Repeat-sequence turnover shifts fundamentally in species with large genomes. NATURE PLANTS 2020; 6:1325-1329. [PMID: 33077876 DOI: 10.1038/s41477-020-00785-x] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 09/14/2020] [Indexed: 05/04/2023]
Abstract
Given the 2,400-fold range of genome sizes (0.06-148.9 Gbp (gigabase pair)) of seed plants (angiosperms and gymnosperms) with a broadly similar gene content (amounting to approximately 0.03 Gbp), the repeat-sequence content of the genome might be expected to increase with genome size, resulting in the largest genomes consisting almost entirely of repetitive sequences. Here we test this prediction, using the same bioinformatic approach for 101 species to ensure consistency in what constitutes a repeat. We reveal a fundamental change in repeat turnover in genomes above around 10 Gbp, such that species with the largest genomes are only about 55% repetitive. Given that genome size influences many plant traits, habits and life strategies, this fundamental shift in repeat dynamics is likely to affect the evolutionary trajectory of species lineages.
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Affiliation(s)
- Petr Novák
- Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Maïté S Guignard
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, UK
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
| | - Pavel Neumann
- Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Laura J Kelly
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, UK
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
| | - Jelena Mlinarec
- Division of Molecular Biology, Department of Biology, University of Zagreb, Zagreb, Croatia
| | - Andrea Koblížková
- Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Steven Dodsworth
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
- School of Life Sciences, University of Bedfordshire, Luton, UK
| | - Aleš Kovařík
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic
| | - Jaume Pellicer
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, UK
- Institut Botànic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), Barcelona, Spain
| | - Wencai Wang
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
- Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Jiří Macas
- Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic.
| | - Ilia J Leitch
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, UK.
| | - Andrew R Leitch
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK.
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207
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Alseekh S, Scossa F, Fernie AR. Mobile Transposable Elements Shape Plant Genome Diversity. TRENDS IN PLANT SCIENCE 2020; 25:1062-1064. [PMID: 32863103 DOI: 10.1016/j.tplants.2020.08.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 08/04/2020] [Accepted: 08/07/2020] [Indexed: 05/27/2023]
Abstract
The presence of various types of structural variants, including transposons, make up the major part of the genomic differences among plant species. Two recent papers, Domínguez et al. and Alonge et al. explore specifically the impact that retrotransposons and other structural variants had on several tomato phenotypes of agricultural importance.
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Affiliation(s)
- Saleh Alseekh
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany; Center of Plant Systems Biology and Biotechnology, Ruski Blvd. 139, Plovdiv, 4000, Bulgaria
| | - Federico Scossa
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany; Council for Agricultural Research and Economics (CREA), Research Centre for Genomics and Bioinformatics (CREA-GB), Rome, Italy
| | - Alisdair R Fernie
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany; Center of Plant Systems Biology and Biotechnology, Ruski Blvd. 139, Plovdiv, 4000, Bulgaria.
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208
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Li Y, Wei H, Yang J, Du K, Li J, Zhang Y, Qiu T, Liu Z, Ren Y, Song L, Kang X. High-quality de novo assembly of the Eucommia ulmoides haploid genome provides new insights into evolution and rubber biosynthesis. HORTICULTURE RESEARCH 2020; 7:183. [PMID: 33328448 PMCID: PMC7603500 DOI: 10.1038/s41438-020-00406-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 08/13/2020] [Accepted: 09/04/2020] [Indexed: 05/06/2023]
Abstract
We report the acquisition of a high-quality haploid chromosome-scale genome assembly for the first time in a tree species, Eucommia ulmoides, which is known for its rubber biosynthesis and medicinal applications. The assembly was obtained by applying PacBio and Hi-C technologies to a haploid that we specifically generated. Compared to the initial genome release, this one has significantly improved assembly quality. The scaffold N50 (53.15 MB) increased 28-fold, and the repetitive sequence content (520 Mb) increased by 158.24 Mb, whereas the number of gaps decreased from 104,772 to 128. A total of 92.87% of the 26,001 predicted protein-coding genes identified with multiple strategies were anchored to the 17 chromosomes. A new whole-genome duplication event was superimposed on the earlier γ paleohexaploidization event, and the expansion of long terminal repeats contributed greatly to the evolution of the genome. The more primitive rubber biosynthesis of this species, as opposed to that in Hevea brasiliensis, relies on the methylerythritol-phosphate pathway rather than the mevalonate pathway to synthesize isoprenyl diphosphate, as the MEP pathway operates predominantly in trans-polyisoprene-containing leaves and central peels. Chlorogenic acid biosynthesis pathway enzymes were preferentially expressed in leaves rather than in bark. This assembly with higher sequence contiguity can foster not only studies on genome structure and evolution, gene mapping, epigenetic analysis and functional genomics but also efforts to improve E. ulmoides for industrial and medical uses through genetic engineering.
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Affiliation(s)
- Yun Li
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, 100083, Beijing, People's Republic of China
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, 100083, Beijing, People's Republic of China
- College of Biological Sciences and Technology, Beijing Forestry University, 100083, Beijing, People's Republic of China
| | - Hairong Wei
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, 100083, Beijing, People's Republic of China
- School of Forest Resources and Environmental, Science, Michigan Technological University, Houghton, MI, 49931, USA
| | - Jun Yang
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, 100083, Beijing, People's Republic of China
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, 100083, Beijing, People's Republic of China
- College of Biological Sciences and Technology, Beijing Forestry University, 100083, Beijing, People's Republic of China
| | - Kang Du
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, 100083, Beijing, People's Republic of China
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, 100083, Beijing, People's Republic of China
- College of Biological Sciences and Technology, Beijing Forestry University, 100083, Beijing, People's Republic of China
| | - Jiang Li
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, 100083, Beijing, People's Republic of China
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, 100083, Beijing, People's Republic of China
- College of Biological Sciences and Technology, Beijing Forestry University, 100083, Beijing, People's Republic of China
| | - Ying Zhang
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, 100083, Beijing, People's Republic of China
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, 100083, Beijing, People's Republic of China
- College of Biological Sciences and Technology, Beijing Forestry University, 100083, Beijing, People's Republic of China
| | - Tong Qiu
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, 100083, Beijing, People's Republic of China
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, 100083, Beijing, People's Republic of China
- College of Biological Sciences and Technology, Beijing Forestry University, 100083, Beijing, People's Republic of China
| | - Zhao Liu
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, 100083, Beijing, People's Republic of China
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, 100083, Beijing, People's Republic of China
- College of Biological Sciences and Technology, Beijing Forestry University, 100083, Beijing, People's Republic of China
| | - Yongyu Ren
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, 100083, Beijing, People's Republic of China
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, 100083, Beijing, People's Republic of China
- College of Biological Sciences and Technology, Beijing Forestry University, 100083, Beijing, People's Republic of China
| | - Lianjun Song
- Hebei Huayang Fine Seeds and Seedlings Co., Ltd., 054700, Hebei, People's Republic of China
| | - Xiangyang Kang
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, 100083, Beijing, People's Republic of China.
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, 100083, Beijing, People's Republic of China.
- College of Biological Sciences and Technology, Beijing Forestry University, 100083, Beijing, People's Republic of China.
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209
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Li M, Dong L, Li B, Wang Z, Xie J, Qiu D, Li Y, Shi W, Yang L, Wu Q, Chen Y, Lu P, Guo G, Zhang H, Zhang P, Zhu K, Li Y, Zhang Y, Wang R, Yuan C, Liu W, Yu D, Luo MC, Fahima T, Nevo E, Li H, Liu Z. A CNL protein in wild emmer wheat confers powdery mildew resistance. THE NEW PHYTOLOGIST 2020; 228:1027-1037. [PMID: 32583535 DOI: 10.1111/nph.16761] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 05/29/2020] [Indexed: 05/18/2023]
Abstract
Powdery mildew, a fungal disease caused by Blumeria graminis f. sp. tritici (Bgt), has a serious impact on wheat production. Loss of resistance in cultivars prompts a continuing search for new sources of resistance. Wild emmer wheat (Triticum turgidum ssp. dicoccoides, WEW), the progenitor of both modern tetraploid and hexaploid wheats, harbors many powdery mildew resistance genes. We report here the positional cloning and functional characterization of Pm41, a powdery mildew resistance gene derived from WEW, which encodes a coiled-coil, nucleotide-binding site and leucine-rich repeat protein (CNL). Mutagenesis and stable genetic transformation confirmed the function of Pm41 against Bgt infection in wheat. We demonstrated that Pm41 was present at a very low frequency (1.81%) only in southern WEW populations. It was absent in other WEW populations, domesticated emmer, durum, and common wheat, suggesting that the ancestral Pm41 was restricted to its place of origin and was not incorporated into domesticated wheat. Our findings emphasize the importance of conservation and exploitation of the primary WEW gene pool, as a valuable resource for discovery of resistance genes for improvement of modern wheat cultivars.
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Affiliation(s)
- Miaomiao Li
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Lingli Dong
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Beibei Li
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | | | - Jingzhong Xie
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Dan Qiu
- The National Engineering Laboratory of Crop Molecular Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Yahui Li
- The National Engineering Laboratory of Crop Molecular Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Wenqi Shi
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural Sciences, Wuhan, 430064, China
| | - Lijun Yang
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural Sciences, Wuhan, 430064, China
| | - Qiuhong Wu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yongxing Chen
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ping Lu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Guanghao Guo
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Huaizhi Zhang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Panpan Zhang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Keyu Zhu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yiwen Li
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yan Zhang
- China Agricultural University, Beijing, 100193, China
| | - Rongge Wang
- Hebei Gaoyi Seeds Farm, Gaoyi, Hebei, 051330, China
| | | | - Wei Liu
- Beijing Dabeinong Technology Group Co. Ltd, Beijing, 100080, China
| | - Dazhao Yu
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural Sciences, Wuhan, 430064, China
| | - Ming-Cheng Luo
- Department of Plant Sciences, University of California, Davis, CA, 95616, USA
| | - Tzion Fahima
- Institute of Evolution, University of Haifa, Mt. Carmel, 3498838, Israel
| | - Eviatar Nevo
- Institute of Evolution, University of Haifa, Mt. Carmel, 3498838, Israel
| | - Hongjie Li
- The National Engineering Laboratory of Crop Molecular Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Zhiyong Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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210
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Pérez-Vargas I, Portero Álvarez AM, Pérez de Paz PL, PÉrez JA. Retrotransposon-based molecular markers as a tool in delimiting species in section Ryncholotus, a recent radiation group of Macaronesian Lotus. SYST BIODIVERS 2020. [DOI: 10.1080/14772000.2020.1827076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Israel Pérez-Vargas
- Departamento de Botánica, Ecología y Fisiología Vegetal. Área de Botánica. Facultad de Farmacia, Universidad de La Laguna, San Cristóbal de La Laguna, Tenerife, Spain
| | - Ana M. Portero Álvarez
- Departamento de Botánica, Ecología y Fisiología Vegetal. Área de Botánica. Facultad de Farmacia, Universidad de La Laguna, San Cristóbal de La Laguna, Tenerife, Spain
| | - Pedro L. Pérez de Paz
- Departamento de Botánica, Ecología y Fisiología Vegetal. Área de Botánica. Facultad de Farmacia, Universidad de La Laguna, San Cristóbal de La Laguna, Tenerife, Spain
| | - JosÉ A. PÉrez
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Área de Genética, Universidad de La Laguna, San Cristóbal de La Laguna, Tenerife, Spain
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211
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Scarrow M, Wang Y, Sun G. Molecular regulatory mechanisms underlying the adaptability of polyploid plants. Biol Rev Camb Philos Soc 2020; 96:394-407. [PMID: 33098261 DOI: 10.1111/brv.12661] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 10/13/2020] [Accepted: 10/15/2020] [Indexed: 12/11/2022]
Abstract
Polyploidization influences the genetic composition and gene expression of an organism. This multi-level genetic change allows the formation of new regulatory pathways leading to increased adaptability. Although both forms of polyploidization provide advantages, autopolyploids were long thought to have little impact on plant divergence compared to allopolyploids due to their formation through genome duplication only, rather than in combination with hybridization. Recent advances have begun to clarify the molecular regulatory mechanisms such as microRNAs, alternative splicing, RNA-binding proteins, histone modifications, chromatin remodelling, DNA methylation, and N6 -methyladenosine (m6A) RNA methylation underlying the evolutionary success of polyploids. Such research is expanding our understanding of the evolutionary adaptability of polyploids and the regulatory pathways that allow adaptive plasticity in a variety of plant species. Herein we review the roles of individual molecular regulatory mechanisms and their potential synergistic pathways underlying plant evolution and adaptation. Notably, increasing interest in m6A methylation has provided a new component in potential mechanistic coordination that is still predominantly unexplored. Future research should attempt to identify and functionally characterize the evolutionary impact of both individual and synergistic pathways in polyploid plant species.
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Affiliation(s)
- Margaret Scarrow
- Department of Biology, Saint Mary's University, Halifax, Nova Scotia, B3H 3C3, Canada
| | - Yiling Wang
- College of Life Science, Shanxi Normal University, Linfen, Shanxi, 041000, China
| | - Genlou Sun
- Department of Biology, Saint Mary's University, Halifax, Nova Scotia, B3H 3C3, Canada
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212
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Epigenetics and epigenomics: underlying mechanisms, relevance, and implications in crop improvement. Funct Integr Genomics 2020; 20:739-761. [PMID: 33089419 DOI: 10.1007/s10142-020-00756-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 10/12/2020] [Accepted: 10/14/2020] [Indexed: 01/21/2023]
Abstract
Epigenetics is defined as changes in gene expression that are not associated with changes in DNA sequence but due to the result of methylation of DNA and post-translational modifications to the histones. These epigenetic modifications are known to regulate gene expression by bringing changes in the chromatin state, which underlies plant development and shapes phenotypic plasticity in responses to the environment and internal cues. This review articulates the role of histone modifications and DNA methylation in modulating biotic and abiotic stresses, as well as crop improvement. It also highlights the possibility of engineering epigenomes and epigenome-based predictive models for improving agronomic traits.
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213
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Baguette M, Bertrand JAM, Stevens VM, Schatz B. Why are there so many bee-orchid species? Adaptive radiation by intra-specific competition for mnesic pollinators. Biol Rev Camb Philos Soc 2020; 95:1630-1663. [PMID: 32954662 DOI: 10.1111/brv.12633] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 06/09/2020] [Accepted: 06/15/2020] [Indexed: 01/08/2023]
Abstract
Adaptive radiations occur mostly in response to environmental variation through the evolution of key innovations that allow emerging species to occupy new ecological niches. Such biological innovations may play a major role in niche divergence when emerging species are engaged in reciprocal ecological interactions. To demonstrate coevolution is a difficult task; only a few studies have confirmed coevolution as driver of speciation and diversification. Herein we review current knowledge about bee orchid (Ophrys spp.) reproductive biology. We propose that the adaptive radiation of the Mediterranean orchid genus Ophrys, comprising several hundred species, is due to coevolutionary dynamics between these plants and their pollinators. We suggest that pollination by sexual swindling used by Ophrys orchids is the main driver of this coevolution. Flowers of each Ophrys species mimic a sexually receptive female of one particular insect species, mainly bees. Male bees are first attracted by pseudo-pheromones emitted by Ophrys flowers that are similar to the sexual pheromones of their females. Males then are lured by the flower shape, colour and hairiness, and attempt to copulate with the flower, which glues pollen onto their bodies. Pollen is later transferred to the stigma of another flower of the same Ophrys species during similar copulation attempts. In contrast to rewarding pollination strategies, Ophrys pollinators appear to be parasitized. Here we propose that this apparent parasitism is in fact a coevolutionary relationship between Ophrys and their pollinators. For plants, pollination by sexual swindling could ensure pollination efficiency and specificity, and gene flow among populations. For pollinators, pollination by sexual swindling could allow habitat matching and inbreeding avoidance. Pollinators might use the pseudo-pheromones emitted by Ophrys to locate suitable habitats from a distance within complex landscapes. In small populations, male pollinators would disperse once they have memorized the local diversity of sexual pseudo-pheromone bouquets or if all Ophrys flowers are fertilized and thus repel pollinators via production of repulsive pheromones that mimic those produced by fertilized female bees. We propose the following evolutionary scenario: Ophrys radiation is driven by strong intra-specific competition among Ophrys individuals for the attraction of species-specific pollinators, which is a consequence of the high cognitive abilities of pollinators. Male bees record the pheromone signatures of kin or of previously courted partners to avoid further copulation attempts, thereby inducing strong selection on Ophrys for variation in odour bouquets emitted by individual flowers. The resulting odour bouquets could by chance correspond to pseudo-pheromones of the females of another bee species, and thus attract a new pollinator. If such pollinator shifts occur simultaneously in several indivuals, pollen exchanges might occur and initiate speciation. To reinforce the attraction of the new pollinator and secure prezygotic isolation, the following step is directional selection on flower phenotypes (shape, colour and hairiness) towards a better match with the body of the pollinator's female. Pollinator shift and the resulting prezygotic isolation is adaptive for new Ophrys species because they may benefit from competitor-free space for limited pollinators. We end our review by proritizing several critical research avenues.
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Affiliation(s)
- Michel Baguette
- Institut Systématique, Evolution, Biodiversité (ISYEB), UMR 7205 Museum National d'Histoire Naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, F-75005, Paris, France.,Centre National de la Recherche Scientifique and Université Paul Sabatier Toulouse III, SETE Station d'Ecologie Théorique et Expérimentale, UMR 5321, F-09200, Moulis, France
| | - Joris A M Bertrand
- LGDP (Laboratoire Génome et Développement des Plantes) UMR5096, Université de Perpignan Via Domitia -CNRS, F-66860, Perpignan, France
| | - Virginie M Stevens
- Centre National de la Recherche Scientifique and Université Paul Sabatier Toulouse III, SETE Station d'Ecologie Théorique et Expérimentale, UMR 5321, F-09200, Moulis, France
| | - Bertrand Schatz
- CEFE (Centre d'Ecologie Fonctionnelle et Evolutive) UMR 5175, CNRS - Université de Montpellier - Université Paul Valéry - EPHE, 1919 Route de Mende, 34293, Montpellier, France
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214
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Mata-Sucre Y, Sader M, Van-Lume B, Gagnon E, Pedrosa-Harand A, Leitch IJ, Lewis GP, Souza G. How diverse is heterochromatin in the Caesalpinia group? Cytogenomic characterization of Erythrostemon hughesii Gagnon & G.P. Lewis (Leguminosae: Caesalpinioideae). PLANTA 2020; 252:49. [PMID: 32918627 DOI: 10.1007/s00425-020-03453-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 08/27/2020] [Indexed: 05/25/2023]
Abstract
Cytogenomic characterization of Erythrostemon hughesii reveals a heterogeneity of repeats in its subtelomeric heterochromatin. Comparative analyses with other Caesalpinia group species reveal a significant reduction in the abundance of Ty3-gypsy/Chromovirus Tekay retrotransposons during its evolution. In numerically stable karyotypes, repetitive DNA variability is one of the main causes of genome and chromosome variation and evolution. Species from the Caesalpinia group (Leguminosae) are karyotypically characterized by 2n = 24, with small chromosomes and highly variable CMA+ heterochromatin banding patterns that correlate with environmental variables. Erythrostemon hughesii differs from other species of the group examined to date for having subtelomeric CMA+ bands; this contrasts with most species in the group which have proximal bands. Here we analyse the repeatome of E. hughesii using genome skimming and chromosomal mapping approaches to characterize the identity of the most abundant repetitive elements and their physical location. The repetitive fraction of E. hughesii comprises 28.73% of the genome. The most abundant elements were retrotransposons (RT) with long terminal repeats (LTR-RT; 9.76%) and satellite DNAs (7.83%). Within the LTR-RTs, the most abundant lineages were: Ty1/copia-Ale (1%), Ty3/gypsy CRM (0.88%) and Ty3/gypsy Athila (0.75%). Using fluorescent in situ hybridization four satellite DNAs and several LTR-RT elements were shown to be present in most subtelomeric CMA+ bands. These results highlight how the repeatome in E. hughesii, a species from Oaxaca state in Mexico, is clearly distinct from Northeast Brazilian species of the Caesalpinia group, mainly due to its high diversity of repeats in its subtelomeric heterochromatic bands and low amount of LTR-RT Ty3/gypsy-Tekay elements. Comparative sequence analysis of Tekay elements from different species is congruent with a clade-specific origin of this LTR-RT after the divergence of the Caesalpinia group. We hypothesize that repeat-rich heterochromatin may play a role in leading to faster genomic divergence between individuals, increasing speciation and diversification.
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Affiliation(s)
- Yennifer Mata-Sucre
- Laboratory of Plant Cytogenetics and Evolution, Department of Botany, Federal University of Pernambuco, Rua Nelson Chaves S/N, Cidade Universitaria, Recife, PE, 50670-420, Brazil
| | - Mariela Sader
- Laboratory of Plant Cytogenetics and Evolution, Department of Botany, Federal University of Pernambuco, Rua Nelson Chaves S/N, Cidade Universitaria, Recife, PE, 50670-420, Brazil
| | - Brena Van-Lume
- Laboratory of Plant Cytogenetics and Evolution, Department of Botany, Federal University of Pernambuco, Rua Nelson Chaves S/N, Cidade Universitaria, Recife, PE, 50670-420, Brazil
| | - Edeline Gagnon
- Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh, EH3 5NZ, UK
| | - Andrea Pedrosa-Harand
- Laboratory of Plant Cytogenetics and Evolution, Department of Botany, Federal University of Pernambuco, Rua Nelson Chaves S/N, Cidade Universitaria, Recife, PE, 50670-420, Brazil
| | - Ilia J Leitch
- Comparative Plant and Fungal Biology Department, Royal Botanic Gardens, Kew, Richmond, TW9 3AB, Surrey, UK
| | - Gwilym P Lewis
- Comparative Plant and Fungal Biology Department, Royal Botanic Gardens, Kew, Richmond, TW9 3AB, Surrey, UK
| | - Gustavo Souza
- Laboratory of Plant Cytogenetics and Evolution, Department of Botany, Federal University of Pernambuco, Rua Nelson Chaves S/N, Cidade Universitaria, Recife, PE, 50670-420, Brazil.
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215
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Abstract
The importance of tree genetic variability in the ability of forests to respond and adapt to environmental changes is crucial in forest management and conservation. Along with genetics, recent advances have highlighted “epigenetics” as an emerging and promising field of research for the understanding of tree phenotypic plasticity and adaptive responses. In this paper, we review recent advances in this emerging field and their potential applications for tree researchers and breeders, as well as for forest managers. First, we present the basics of epigenetics in plants before discussing its potential for trees. We then propose a bibliometric and overview of the literature on epigenetics in trees, including recent advances on tree priming. Lastly, we outline the promises of epigenetics for forest research and management, along with current gaps and future challenges. Research in epigenetics could use highly diverse paths to help forests adapt to global change by eliciting different innovative silvicultural approaches for natural- and artificial-based forest management.
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216
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Orozco-Arias S, Tobon-Orozco N, Piña JS, Jiménez-Varón CF, Tabares-Soto R, Guyot R. TIP_finder: An HPC Software to Detect Transposable Element Insertion Polymorphisms in Large Genomic Datasets. BIOLOGY 2020; 9:E281. [PMID: 32917036 PMCID: PMC7563458 DOI: 10.3390/biology9090281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/01/2020] [Accepted: 09/07/2020] [Indexed: 12/12/2022]
Abstract
Transposable elements (TEs) are non-static genomic units capable of moving indistinctly from one chromosomal location to another. Their insertion polymorphisms may cause beneficial mutations, such as the creation of new gene function, or deleterious in eukaryotes, e.g., different types of cancer in humans. A particular type of TE called LTR-retrotransposons comprises almost 8% of the human genome. Among LTR retrotransposons, human endogenous retroviruses (HERVs) bear structural and functional similarities to retroviruses. Several tools allow the detection of transposon insertion polymorphisms (TIPs) but fail to efficiently analyze large genomes or large datasets. Here, we developed a computational tool, named TIP_finder, able to detect mobile element insertions in very large genomes, through high-performance computing (HPC) and parallel programming, using the inference of discordant read pair analysis. TIP_finder inputs are (i) short pair reads such as those obtained by Illumina, (ii) a chromosome-level reference genome sequence, and (iii) a database of consensus TE sequences. The HPC strategy we propose adds scalability and provides a useful tool to analyze huge genomic datasets in a decent running time. TIP_finder accelerates the detection of transposon insertion polymorphisms (TIPs) by up to 55 times in breast cancer datasets and 46 times in cancer-free datasets compared to the fastest available algorithms. TIP_finder applies a validated strategy to find TIPs, accelerates the process through HPC, and addresses the issues of runtime for large-scale analyses in the post-genomic era. TIP_finder version 1.0 is available at https://github.com/simonorozcoarias/TIP_finder.
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Affiliation(s)
- Simon Orozco-Arias
- Department of Computer Science, Universidad Autónoma de Manizales, Manizales 170002, Colombia; (N.T.-O.); (J.S.P.)
- Department of Systems and Informatics, Universidad de Caldas, Manizales 170002, Colombia
| | - Nicolas Tobon-Orozco
- Department of Computer Science, Universidad Autónoma de Manizales, Manizales 170002, Colombia; (N.T.-O.); (J.S.P.)
| | - Johan S. Piña
- Department of Computer Science, Universidad Autónoma de Manizales, Manizales 170002, Colombia; (N.T.-O.); (J.S.P.)
| | | | - Reinel Tabares-Soto
- Department of Electronics and Automation, Universidad Autónoma de Manizales, Manizales 170002, Colombia;
| | - Romain Guyot
- Department of Electronics and Automation, Universidad Autónoma de Manizales, Manizales 170002, Colombia;
- Institut de Recherche pour le Développement (IRD), CIRAD, Université de Montpellier, 34394 Montpellier, France
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217
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Benoit M. In the Transcripts: Long-Read Transcriptomics Enables a Novel Type of Transposable Element Annotation in Plants. THE PLANT CELL 2020; 32:2661-2662. [PMID: 32665309 PMCID: PMC7474303 DOI: 10.1105/tpc.20.00523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Affiliation(s)
- Matthias Benoit
- Howard Hughes Medical InstituteCold Spring Harbor LaboratoryCold Spring Harbor, New York
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218
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Lei GJ, Fujii-Kashino M, Wu DZ, Hisano H, Saisho D, Deng F, Yamaji N, Sato K, Zhao FJ, Ma JF. Breeding for low cadmium barley by introgression of a Sukkula-like transposable element. ACTA ACUST UNITED AC 2020; 1:489-499. [PMID: 37128077 DOI: 10.1038/s43016-020-0130-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 07/15/2020] [Indexed: 01/04/2023]
Abstract
Barley is the fourth most produced cereal crop in the world and one of the major dietary sources of cadmium (Cd), which poses serious threats to human health. Here, we identify a gene that encodes a P-type heavy metal ATPase 3 (HvHMA3) responsible for grain Cd accumulation in barley. HvHMA3 from the high Cd barley variety Haruna Nijo in Japan and the low Cd variety BCS318 in Afghanistan shared 97% identity at the amino acid level. In addition, the HvHMA3 from both varieties showed similar transport activity for Cd and the same subcellular localization at the tonoplast. However, the expression of HvHMA3 was double in BCS318 than in Haruna Nijo. A 3.3-kilobase Sukkula-like transposable element was found to be inserted upstream of the gene in the low Cd variety, which functioned as a promoter and enhanced the expression of HvHMA3. Introgression of this insertion to an elite barley cultivar through backcrossing resulted in decreased Cd accumulation in the grain grown in Cd-contaminated soil without yield penalty. The decreased Cd accumulation resulting from the insertion was also found in some other barley landraces in the world. Our results indicate that insertion of the Sukkula-like transposable element plays an important role in upregulating HvHMA3 expression.
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219
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Abstract
Tomatoes come in a multitude of shapes and flavors despite a narrow genetic pool. Here, we leverage whole-genome resequencing data available for 602 cultivated and wild accessions to determine the contribution of transposable elements (TEs) to tomato diversity. We identify 6,906 TE insertions polymorphisms (TIPs), which result from the mobilization of 337 distinct TE families. Most TIPs are low frequency variants and TIPs are disproportionately located within or adjacent to genes involved in environmental responses. In addition, genic TE insertions tend to have strong transcriptional effects and they can notably lead to the generation of multiple transcript isoforms. Using genome-wide association studies (GWAS), we identify at least 40 TIPs robustly associated with extreme variation in major agronomic traits or secondary metabolites and in most cases, no SNP tags the TE insertion allele. Collectively, these findings highlight the unique role of TE mobilization in tomato diversification, with important implications for breeding. Transposable element insertion polymorphisms (TIPs) are a potential source of large effect alleles. Here, the authors use genome resequencing data for 602 tomato accessions together with transcriptomic and extensive phenotypic information to investigate the contribution of TIPs to tomato diversity.
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220
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Quadrana L. The contribution of transposable elements to transcriptional novelty in plants: the FLC affair. Transcription 2020; 11:192-198. [PMID: 32783496 PMCID: PMC7714446 DOI: 10.1080/21541264.2020.1803031] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Transposable elements (TEs) are repetitive DNA sequences with the ability to replicate across genomes and generate mutations with major transcriptional effects. Epigenetic silencing mechanisms that target TEs to limit their activity, including DNA methylation, add to the range of gene expression variants generated by TEs. Here, using the iconic gene flowering locus C (FLC) as a case study I discuss the multiple ways by which TEs can affect the expression of genes and contribute to the adaptation of plants to changing environments
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Affiliation(s)
- Leandro Quadrana
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), Ecole Normale Supérieure, PSL Research University , Paris, France
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221
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Pinosio S, Marroni F, Zuccolo A, Vitulo N, Mariette S, Sonnante G, Aravanopoulos FA, Ganopoulos I, Palasciano M, Vidotto M, Magris G, Iezzoni A, Vendramin GG, Morgante M. A draft genome of sweet cherry (Prunus avium L.) reveals genome-wide and local effects of domestication. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:1420-1432. [PMID: 32391598 DOI: 10.1111/tpj.14809] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 04/24/2020] [Accepted: 05/01/2020] [Indexed: 05/26/2023]
Abstract
Sweet cherry (Prunus avium L.) trees are both economically important fruit crops but also important components of natural forest ecosystems in Europe, Asia and Africa. Wild and domesticated trees currently coexist in the same geographic areas with important questions arising on their historical relationships. Little is known about the effects of the domestication process on the evolution of the sweet cherry genome. We assembled and annotated the genome of the cultivated variety "Big Star*" and assessed the genetic diversity among 97 sweet cherry accessions representing three different stages in the domestication and breeding process (wild trees, landraces and modern varieties). The genetic diversity analysis revealed significant genome-wide losses of variation among the three stages and supports a clear distinction between wild and domesticated trees, with only limited gene flow being detected between wild trees and domesticated landraces. We identified 11 domestication sweeps and five breeding sweeps covering, respectively, 11.0 and 2.4 Mb of the P. avium genome. A considerable fraction of the domestication sweeps overlaps with those detected in the related species, Prunus persica (peach), indicating that artificial selection during domestication may have acted independently on the same regions and genes in the two species. We detected 104 candidate genes in sweep regions involved in different processes, such as the determination of fruit texture, the regulation of flowering and fruit ripening and the resistance to pathogens. The signatures of selection identified will enable future evolutionary studies and provide a valuable resource for genetic improvement and conservation programs in sweet cherry.
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Affiliation(s)
- Sara Pinosio
- Institute of Biosciences and Bioresources (IBBR), National Research Council, Via Madonna del Piano 10, Sesto Fiorentino, 50019, Italy
- Istituto di Genomica Applicata (IGA), Via Jacopo Linussio 51, Udine, 33100, Italy
| | - Fabio Marroni
- Istituto di Genomica Applicata (IGA), Via Jacopo Linussio 51, Udine, 33100, Italy
- Dipartimento di Scienze Agro-alimentari Ambientali e Animali (DI4A), Università di Udine, via delle Scienze 206, Udine, 33100, Italy
| | - Andrea Zuccolo
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, 56124, Italy
| | - Nicola Vitulo
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada Le Grazie 15, Verona, 37134, Italy
| | - Stephanie Mariette
- BIOGECO, INRA, University of Bordeaux, route d'Arcachon 69, Cestas, 33612, France
| | - Gabriella Sonnante
- Institute of Biosciences and Bioresources (IBBR), National Research Council, via Amendola 165/A, Bari, 70126, Italy
| | - Filippos A Aravanopoulos
- Faculty of Forestry and Natural Environment, Laboratory of Forest Genetics and Tree Breeding, Aristotle University of Thessaloniki, Thessaloníki, 54124, Greece
| | - Ioannis Ganopoulos
- Institute of Plant Breeding and Genetic Resources, Hellenic Agricultural Organization-DEMETER, Thermi, 57001, Greece
| | - Marino Palasciano
- Dipartimento di Scienze del Suolo, Università degli Studi di Bari Aldo Moro, della Pianta e degli Alimenti, Piazza Umberto I, Bari, 70121, Italy
| | - Michele Vidotto
- Istituto di Genomica Applicata (IGA), Via Jacopo Linussio 51, Udine, 33100, Italy
| | - Gabriele Magris
- Istituto di Genomica Applicata (IGA), Via Jacopo Linussio 51, Udine, 33100, Italy
- Dipartimento di Scienze Agro-alimentari Ambientali e Animali (DI4A), Università di Udine, via delle Scienze 206, Udine, 33100, Italy
| | - Amy Iezzoni
- Department of Horticulture, Michigan State University, 1066 Bogue Street, East Lansing, MI, 48824-1325, USA
| | - Giovanni G Vendramin
- Institute of Biosciences and Bioresources (IBBR), National Research Council, Via Madonna del Piano 10, Sesto Fiorentino, 50019, Italy
| | - Michele Morgante
- Istituto di Genomica Applicata (IGA), Via Jacopo Linussio 51, Udine, 33100, Italy
- Dipartimento di Scienze Agro-alimentari Ambientali e Animali (DI4A), Università di Udine, via delle Scienze 206, Udine, 33100, Italy
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222
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Nieto Feliner G, Casacuberta J, Wendel JF. Genomics of Evolutionary Novelty in Hybrids and Polyploids. Front Genet 2020; 11:792. [PMID: 32849797 PMCID: PMC7399645 DOI: 10.3389/fgene.2020.00792] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/03/2020] [Indexed: 12/15/2022] Open
Abstract
It has long been recognized that hybridization and polyploidy are prominent processes in plant evolution. Although classically recognized as significant in speciation and adaptation, recognition of the importance of interspecific gene flow has dramatically increased during the genomics era, concomitant with an unending flood of empirical examples, with or without genome doubling. Interspecific gene flow is thus increasingly thought to lead to evolutionary innovation and diversification, via adaptive introgression, homoploid hybrid speciation and allopolyploid speciation. Less well understood, however, are the suite of genetic and genomic mechanisms set in motion by the merger of differentiated genomes, and the temporal scale over which recombinational complexity mediated by gene flow might be expressed and exposed to natural selection. We focus on these issues here, considering the types of molecular genetic and genomic processes that might be set in motion by the saltational event of genome merger between two diverged species, either with or without genome doubling, and how these various processes can contribute to novel phenotypes. Genetic mechanisms include the infusion of new alleles and the genesis of novel structural variation including translocations and inversions, homoeologous exchanges, transposable element mobilization and novel insertional effects, presence-absence variation and copy number variation. Polyploidy generates massive transcriptomic and regulatory alteration, presumably set in motion by disrupted stoichiometries of regulatory factors, small RNAs and other genome interactions that cascade from single-gene expression change up through entire networks of transformed regulatory modules. We highlight both these novel combinatorial possibilities and the range of temporal scales over which such complexity might be generated, and thus exposed to natural selection and drift.
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Affiliation(s)
- Gonzalo Nieto Feliner
- Department of Biodiversity and Conservation, Real Jardín Botánico, CSIC, Madrid, Spain
| | - Josep Casacuberta
- Center for Research in Agricultural Genomics, CRAG (CSIC-IRTA-UAB-UB), Barcelona, Spain
| | - Jonathan F. Wendel
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, United States
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Quesneville H. Twenty years of transposable element analysis in the Arabidopsis thaliana genome. Mob DNA 2020; 11:28. [PMID: 32742313 PMCID: PMC7385966 DOI: 10.1186/s13100-020-00223-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 07/16/2020] [Indexed: 11/10/2022] Open
Abstract
Transposable elements (TEs) are mobile repetitive DNA sequences shown to be major drivers of genome evolution. As the first plant to have its genome sequenced and analyzed at the genomic scale, Arabidopsis thaliana has largely contributed to our TE knowledge. The present report describes 20 years of accumulated TE knowledge gained through the study of the Arabidopsis genome and covers the known TE families, their relative abundance, and their genomic distribution. It presents our knowledge of the different TE family activities, mobility, population and long-term evolutionary dynamics. Finally, the role of TE as substrates for new genes and their impact on gene expression is illustrated through a few selected demonstrative cases. Promising future directions for TE studies in this species conclude the review.
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Kartal Ö, Schmid MW, Grossniklaus U. Cell type-specific genome scans of DNA methylation divergence indicate an important role for transposable elements. Genome Biol 2020; 21:172. [PMID: 32660534 PMCID: PMC7359245 DOI: 10.1186/s13059-020-02068-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 06/10/2020] [Indexed: 01/01/2023] Open
Abstract
In population genomics, genetic diversity measures play an important role in genome scans for divergent sites. In population epigenomics, comparable tools are rare although the epigenome can vary at several levels of organization. We propose a model-free, information-theoretic approach, the Jensen-Shannon divergence (JSD), as a flexible diversity index for epigenomic diversity. Here, we demonstrate how JSD uncovers the relationship between genomic features and cell type-specific methylome diversity in Arabidopsis thaliana. However, JSD is applicable to any epigenetic mark and any collection of individuals, tissues, or cells, for example to assess the heterogeneity in healthy organs and tumors.
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Affiliation(s)
- Önder Kartal
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zollikerstrasse 107, Zurich, 8008 Switzerland
- Creoptix AG, Zugerstrasse 76, Wädenswil, 8820 Switzerland
| | - Marc W. Schmid
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zollikerstrasse 107, Zurich, 8008 Switzerland
- MWSchmid GmbH, Möhrlistrasse 25, Zurich, 8006 Switzerland
| | - Ueli Grossniklaus
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zollikerstrasse 107, Zurich, 8008 Switzerland
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225
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Zhang X, Zhao M, McCarty DR, Lisch D. Transposable elements employ distinct integration strategies with respect to transcriptional landscapes in eukaryotic genomes. Nucleic Acids Res 2020; 48:6685-6698. [PMID: 32442316 PMCID: PMC7337890 DOI: 10.1093/nar/gkaa370] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 04/24/2020] [Accepted: 04/29/2020] [Indexed: 12/27/2022] Open
Abstract
Transposable elements (TEs) are ubiquitous DNA segments capable of moving from one site to another within host genomes. The extant distributions of TEs in eukaryotic genomes have been shaped by both bona fide TE integration preferences in eukaryotic genomes and by selection following integration. Here, we compare TE target site distribution in host genomes using multiple de novo transposon insertion datasets in both plants and animals and compare them in the context of genome-wide transcriptional landscapes. We showcase two distinct types of transcription-associated TE targeting strategies that suggest a process of convergent evolution among eukaryotic TE families. The integration of two precision-targeting elements are specifically associated with initiation of RNA Polymerase II transcription of highly expressed genes, suggesting the existence of novel mechanisms of precision TE targeting in addition to passive targeting of open chromatin. We also highlight two features that can facilitate TE survival and rapid proliferation: tissue-specific transposition and minimization of negative impacts on nearby gene function due to precision targeting.
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Affiliation(s)
- Xinyan Zhang
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA
| | - Meixia Zhao
- Department of Biology, Miami University, Oxford, OH 45056, USA
| | - Donald R McCarty
- Horticultural Sciences Department, University of Florida, Gainesville, FL 32611, USA
| | - Damon Lisch
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA
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226
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Kuriyama K, Tabara M, Moriyama H, Kanazawa A, Koiwa H, Takahashi H, Fukuhara T. Disturbance of floral colour pattern by activation of an endogenous pararetrovirus, petunia vein clearing virus, in aged petunia plants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:497-511. [PMID: 32100385 PMCID: PMC7496347 DOI: 10.1111/tpj.14728] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 02/04/2020] [Indexed: 05/22/2023]
Abstract
White areas of star-type bicolour petals of petunia (Petunia hybrida) are caused by post-transcriptional gene silencing (PTGS) of the key enzyme of anthocyanin biosynthesis. We observed blotched flowers and a vein-clearing symptom in aged petunia plants. To determine the cause of blotched flowers, we focused on an endogenous pararetrovirus, petunia vein clearing virus (PVCV), because this virus may have a suppressor of PTGS (VSR). Transcripts and episomal DNAs derived from proviral PVCVs accumulated in aged plants, indicating that PVCV was activated as the host plant aged. Furthermore, DNA methylation of CG and CHG sites in the promoter region of proviral PVCV decreased in aged plants, suggesting that poor maintenance of DNA methylation activates PVCV. In parallel, de novo DNA methylation of CHH sites in its promoter region was also detected. Therefore, both activation and inactivation of PVCV occurred in aged plants. The accumulation of PVCV transcripts and episomal DNAs in blotched regions and the detection of VSR activity support a mechanism in which suppression of PTGS by PVCV causes blotched flowers.
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Affiliation(s)
- Kazunori Kuriyama
- Department of Applied Biological SciencesTokyo University of Agriculture and Technology3‐5‐8 SaiwaichoFuchuTokyo183‐8509Japan
| | - Midori Tabara
- Department of Applied Biological SciencesTokyo University of Agriculture and Technology3‐5‐8 SaiwaichoFuchuTokyo183‐8509Japan
- Institute of Global Innovation ResearchTokyo University of Agriculture and Technology3‐5‐8 SaiwaichoFuchuTokyo183‐8509Japan
| | - Hiromitsu Moriyama
- Department of Applied Biological SciencesTokyo University of Agriculture and Technology3‐5‐8 SaiwaichoFuchuTokyo183‐8509Japan
| | - Akira Kanazawa
- Research Faculty of AgricultureHokkaido UniversityKita 9, Nishi 9, Kita‐kuSapporo060‐8589Japan
| | - Hisashi Koiwa
- Institute of Global Innovation ResearchTokyo University of Agriculture and Technology3‐5‐8 SaiwaichoFuchuTokyo183‐8509Japan
- Department of Horticultural SciencesTexas A&M UniversityCollege StationTX77843USA
| | - Hideki Takahashi
- Graduate School of Agricultural ScienceTohoku University468‐1, Aramaki‐Aza‐AobaSendai980‐0845Japan
| | - Toshiyuki Fukuhara
- Department of Applied Biological SciencesTokyo University of Agriculture and Technology3‐5‐8 SaiwaichoFuchuTokyo183‐8509Japan
- Institute of Global Innovation ResearchTokyo University of Agriculture and Technology3‐5‐8 SaiwaichoFuchuTokyo183‐8509Japan
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227
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Le NT, Harukawa Y, Miura S, Boer D, Kawabe A, Saze H. Epigenetic regulation of spurious transcription initiation in Arabidopsis. Nat Commun 2020; 11:3224. [PMID: 32591528 PMCID: PMC7319988 DOI: 10.1038/s41467-020-16951-w] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 06/01/2020] [Indexed: 01/01/2023] Open
Abstract
In plants, epigenetic regulation is critical for silencing transposons and maintaining proper gene expression. However, its impact on the genome-wide transcription initiation landscape remains elusive. By conducting a genome-wide analysis of transcription start sites (TSSs) using cap analysis of gene expression (CAGE) sequencing, we show that thousands of TSSs are exclusively activated in various epigenetic mutants of Arabidopsis thaliana and referred to as cryptic TSSs. Many have not been identified in previous studies, of which up to 65% are contributed by transposons. They possess similar genetic features to regular TSSs and their activation is strongly associated with the ectopic recruitment of RNAPII machinery. The activation of cryptic TSSs significantly alters transcription of nearby TSSs, including those of genes important for development and stress responses. Our study, therefore, sheds light on the role of epigenetic regulation in maintaining proper gene functions in plants by suppressing transcription from cryptic TSSs. Epigenetic regulation can silence transposons and maintain gene expression. Here the authors survey Arabidopsis mutants defective in epigenetic regulation and show ectopic activation of thousands of cryptic TSSs and altered expression of nearby genes demonstrating the importance of suppressing spurious transcription.
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Affiliation(s)
- Ngoc Tu Le
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan
| | - Yoshiko Harukawa
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan
| | - Saori Miura
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan
| | - Damian Boer
- Wageningen University & Research, Droevendaalsesteeg 4, 6708 PB Wageningen, Netherlands
| | - Akira Kawabe
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, 603-8555, Japan
| | - Hidetoshi Saze
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology (OIST), 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan.
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228
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Lanciano S, Cristofari G. Measuring and interpreting transposable element expression. Nat Rev Genet 2020; 21:721-736. [PMID: 32576954 DOI: 10.1038/s41576-020-0251-y] [Citation(s) in RCA: 164] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/19/2020] [Indexed: 12/21/2022]
Abstract
Transposable elements (TEs) are insertional mutagens that contribute greatly to the plasticity of eukaryotic genomes, influencing the evolution and adaptation of species as well as physiology or disease in individuals. Measuring TE expression helps to understand not only when and where TE mobilization can occur but also how this process alters gene expression, chromatin accessibility or cellular signalling pathways. Although genome-wide gene expression assays such as RNA sequencing include transposon-derived transcripts, most computational analytical tools discard or misinterpret TE-derived reads. Emerging approaches are improving the identification of expressed TE loci and helping to discriminate TE transcripts that permit TE mobilization from chimeric gene-TE transcripts or pervasive transcription. Here we review the main challenges associated with the detection of TE expression, including mappability, insertional and internal sequence polymorphisms, and the diversity of the TE transcriptional landscape, as well as the different experimental and computational strategies to solve them.
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229
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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: 44] [Impact Index Per Article: 11.0] [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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230
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Lancíková V, Žiarovská J. Inter-retrotransposon amplified polymorphism markers revealed long terminal repeat retrotransposon insertion polymorphism in flax cultivated on the experimental fields around Chernobyl. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2020; 55:957-963. [PMID: 32378983 DOI: 10.1080/10934529.2020.1760016] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 04/14/2020] [Accepted: 04/16/2020] [Indexed: 06/11/2023]
Abstract
Ionizing radiation in environment comes from various natural and anthropogenic sources. The effect of radioactivity released after the CNPP (Chernobyl Nuclear Power Plant) on plant systems remains of great interest. Even now, more than three decades after the nuclear accident, the long-lived radionuclides represent a strong stress factor. Herein, the emphasis has been placed on analysis of genetic variability represented by activation of LTR (Long Terminal Repeat)-retrotransposons. Polymorphism in LTR-retrotransposon insertions has been investigated throughout the genome of two flax varieties, Kyivskyi and Bethune. For this purpose, two retrotransposon-based marker techniques, IRAP (Inter-Retrotransposon Amplified Polymorphism) and iPBS (inter-Primer Binding Site), have been employed. The hypothesis that chronic radioactive stress may induce mechanism of retransposition has been supported by the activation of FL9, FL11 and FL12 LTR-retrotransposons in flax seeds harvested from radioactive environment. Out of two retrotransposon-based approaches, IRAP appears to be more suitable for identification of LTR-retrotransposon polymorphism. Even though the LTR-retrotransposon polymorphism was identified, the results suggest the high level of plant adaptation in the radioactive Chernobyl area. However, it is not really surprising that plants developed an effective strategy to survive in radio-contaminated environment over the past 30 years.
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Affiliation(s)
- Veronika Lancíková
- Plant Science and Biodiversity Center, Institute of Plant Genetics and Biotechnology, Slovak Academy of Sciences, Nitra, Slovakia
| | - Jana Žiarovská
- Department of Genetics and Plant Breeding, Faculty of Agrobiology and Food Resources, Slovak University of Agriculture, Nitra, Slovakia
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231
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Ourari M, Coriton O, Martin G, Huteau V, Keller J, Ainouche ML, Amirouche R, Ainouche A. Screening diversity and distribution of Copia retrotransposons reveals a specific amplification of BARE1 elements in genomes of the polyploid Hordeum murinum complex. Genetica 2020; 148:109-123. [PMID: 32361835 DOI: 10.1007/s10709-020-00094-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 04/24/2020] [Indexed: 10/24/2022]
Abstract
We explored diversity, distribution and evolutionary dynamics of Ty1-Copia retrotransposons in the genomes of the Hordeum murinum polyploid complex and related taxa. Phylogenetic and fluorescent in situ hybridization (FISH) analyses of reverse transcriptase sequences identified four Copia families in these genomes: the predominant BARE1 (including three groups or subfamilies, A, B and C), and the less represented RIRE1, IKYA and TAR-1. Within the BARE1 family, BARE1-A elements and a subgroup of BARE1-B elements (named B1) have proliferated in the allopolyploid members of the H. murinum complex (H. murinum and H. leporinum), and in their extant diploid progenitor, subsp. glaucum. Moreover, we found a specific amplification of BARE1-B elements within each Hordeum species surveyed. The low occurrence of RIRE1, IKYA and TAR-1 elements in the allopolyploid cytotypes suggests that they are either weakly represented or highly degenerated in their diploid progenitors. The results demonstrate that BARE1-A and BARE1-B1 Copia elements are particularly well represented in the genomes of the H. murinum complex and constitute its genomic hallmark. No BARE1-A and -B1 homologs were detected in the reference barley genome. The similar distribution of RT-Copia probes across chromosomes of diploid, tetraploid and hexaploid taxa of the murinum complex shows no evidence of proliferation following polyploidization.
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Affiliation(s)
- Malika Ourari
- Laboratory of Ecology and Environment, Department of Environment Biological Sciences, Faculty of Nature and Life Sciences, Université de Bejaia, Targa Ouzemmour, 06000, Bejaia, Algeria
| | - Olivier Coriton
- Institut National de Recherche en Agriculture, Alimentation et Environnement, UMR1349 INRAE-AgroCampus Ouest-Université de Rennes 1, Bât 301, INRA Centre de Bretagne-Normandie, BP 35327, 35653, Le Rheu Cedex, France
| | - Guillaume Martin
- CIRAD, UMR AGAP, 34398, Montpellier, France.,Université de Montpellier, AGAP, CIRAD, INRA, Montpellier SupAgro, Montpellier, France
| | - Virginie Huteau
- Institut National de Recherche en Agriculture, Alimentation et Environnement, UMR1349 INRAE-AgroCampus Ouest-Université de Rennes 1, Bât 301, INRA Centre de Bretagne-Normandie, BP 35327, 35653, Le Rheu Cedex, France
| | - Jean Keller
- Université de Toulouse, LRSV, CNRS, UPS, 24 chemin de Borde Rouge, Auzeville, 31320, Auzeville-Tolosane, France
| | - Malika-Lily Ainouche
- Université de Rennes 1, UMR-CNRS 6553, EcoBio, Campus Scientifique de Beaulieu, Bât. 14A, 35042, Rennes Cedex, France
| | - Rachid Amirouche
- Université des Sciences et de la Technologie Houari Boumediene, Faculté des Sciences Biologiques, Lab. LBPO, USTHB, BP 32 El-Alia, Bab-Ezzouar, 16111, Alger, Algerie.
| | - Abdelkader Ainouche
- Université de Rennes 1, UMR-CNRS 6553, EcoBio, Campus Scientifique de Beaulieu, Bât. 14A, 35042, Rennes Cedex, France
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232
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da Silva FA, Corrêa Guimarães EM, Carvalho ND, Ferreira AM, Schneider CH, Carvalho-Zilse GA, Feldberg E, Gross MC. Transposable DNA Elements in Amazonian Fish: From Genome Enlargement to Genetic Adaptation to Stressful Environments. Cytogenet Genome Res 2020; 160:148-155. [DOI: 10.1159/000507104] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Accepted: 03/09/2020] [Indexed: 11/19/2022] Open
Abstract
Transposable elements have driven genome evolution and plasticity in many ways across a range of organisms. Different types of biotic and abiotic stresses can stimulate the expression or transposition of these mobile elements. Here, we cytogenetically analyzed natural fish populations of the same species living under different environmental conditions to test the influence and organization of transposable elements in their genome. Differential behavior was observed for the markers Rex 1, Rex 3, and Rex 6 in the chromosomes of individuals of the same species but coming from different environments (polluted and unpolluted). An increase in the number of Rex transposable elements in the chromosomes and their influence on the genome of populations living in a polluted environment indicates that they must be under constant adaptive evolution.
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233
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Vitales D, Álvarez I, Garcia S, Hidalgo O, Nieto Feliner G, Pellicer J, Vallès J, Garnatje T. Genome size variation at constant chromosome number is not correlated with repetitive DNA dynamism in Anacyclus (Asteraceae). ANNALS OF BOTANY 2020; 125:611-623. [PMID: 31697800 PMCID: PMC7103019 DOI: 10.1093/aob/mcz183] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 11/06/2019] [Indexed: 05/02/2023]
Abstract
BACKGROUND AND AIMS Changes in the amount of repetitive DNA (dispersed and tandem repeats) are considered the main contributors to genome size variation across plant species in the absence of polyploidy. However, the study of repeatome dynamism in groups showing contrasting genomic features and complex evolutionary histories is needed to determine whether other processes underlying genome size variation may have been overlooked. The main aim here was to elucidate which mechanism best explains genome size evolution in Anacyclus (Asteraceae). METHODS Using data from Illumina sequencing, we analysed the repetitive DNA in all species of Anacyclus, a genus with a reticulate evolutionary history, which displays significant genome size and karyotype diversity albeit presenting a stable chromosome number. KEY RESULTS By reconstructing ancestral genome size values, we inferred independent episodes of genome size expansions and contractions during the evolution of the genus. However, analysis of the repeatome revealed a similar DNA repeat composition across species, both qualitative and quantitative. Using comparative methods to study repeatome dynamics in the genus, we found no evidence for repeat activity causing genome size variation among species. CONCLUSIONS Our results, combined with previous cytogenetic data, suggest that genome size differences in Anacyclus are probably related to chromosome rearrangements involving losses or gains of chromosome fragments, possibly associated with homoploid hybridization. These could represent balanced rearrangements that do not disrupt gene dosage in merged genomes, for example via chromosome segment exchanges.
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Affiliation(s)
- Daniel Vitales
- Institut Botànic de Barcelona (IBB, CSIC-ICUB), Passeig del Migdia sn, 08038 Barcelona, Catalonia, Spain
- For correspondence. Email
| | - Inés Álvarez
- Department of Biodiversity and Conservation, Real Jardín Botánico (CSIC), Plaza de Murillo 2, 28014 Madrid, Spain
| | - Sònia Garcia
- Institut Botànic de Barcelona (IBB, CSIC-ICUB), Passeig del Migdia sn, 08038 Barcelona, Catalonia, Spain
| | - Oriane Hidalgo
- Laboratori de Botànica – Unitat associada CSIC, Facultat de Farmàcia i Ciències de l’Alimentació, Universitat de Barcelona, Av. Joan XXIII 27–31, 08028 Barcelona, Catalonia, Spain
- Comparative Plant and Fungal Biology Department, Royal Botanic Gardens, Kew, Richmond, UK
| | - Gonzalo Nieto Feliner
- Department of Biodiversity and Conservation, Real Jardín Botánico (CSIC), Plaza de Murillo 2, 28014 Madrid, Spain
| | - Jaume Pellicer
- Comparative Plant and Fungal Biology Department, Royal Botanic Gardens, Kew, Richmond, UK
| | - Joan Vallès
- Laboratori de Botànica – Unitat associada CSIC, Facultat de Farmàcia i Ciències de l’Alimentació, Universitat de Barcelona, Av. Joan XXIII 27–31, 08028 Barcelona, Catalonia, Spain
| | - Teresa Garnatje
- Institut Botànic de Barcelona (IBB, CSIC-ICUB), Passeig del Migdia sn, 08038 Barcelona, Catalonia, Spain
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234
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Low Long Terminal Repeat (LTR)-Retrotransposon Expression in Leaves of the Marine Phanerogam Posidonia Oceanica L. Life (Basel) 2020; 10:life10030030. [PMID: 32213979 PMCID: PMC7151569 DOI: 10.3390/life10030030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/14/2020] [Accepted: 03/21/2020] [Indexed: 12/29/2022] Open
Abstract
Seagrasses as Posidonia oceanica reproduce mostly by vegetative propagation, which can reduce genetic variability within populations. Since, in clonally propagated species, insurgence of genetic variability can be determined by the activity of transposable elements, we have estimated the activity of such repeat elements by measuring their expression level in the leaves of plants from a Mediterranean site, for which Illumina complementary DNA (cDNA) sequence reads (produced from RNAs isolated by leaves of plants from deep and shallow meadows) were publicly available. Firstly, we produced a collection of retrotransposon-related sequences and then mapped Illumina cDNA reads onto these sequences. With this approach, it was evident that Posidonia retrotransposons are, in general, barely expressed; only nine elements resulted transcribed at levels comparable with those of reference genes encoding tubulins and actins. Differences in transcript abundance were observed according to the superfamily and the lineage to which the retrotransposons belonged. Only small differences were observed between retrotransposon expression levels in leaves of shallow and deep Posidonia meadow stands, whereas one TAR/Tork element resulted differentially expressed in deep plants exposed to heat. It can be concluded that, in P. oceanica, the contribution of retrotransposon activity to genetic variability is reduced, although the nine specific active elements could actually produce new structural variations.
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235
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Cerbin S, Wai CM, VanBuren R, Jiang N. GingerRoot: A Novel DNA Transposon Encoding Integrase-Related Transposase in Plants and Animals. Genome Biol Evol 2020; 11:3181-3193. [PMID: 31633753 PMCID: PMC6839031 DOI: 10.1093/gbe/evz230] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/20/2019] [Indexed: 02/06/2023] Open
Abstract
Transposable elements represent the largest components of many eukaryotic genomes and different genomes harbor different combinations of elements. Here, we discovered a novel DNA transposon in the genome of the clubmoss Selaginella lepidophylla. Further searching for related sequences to the conserved DDE region uncovered the presence of this superfamily of elements in fish, coral, sea anemone, and other animal species. However, this element appears restricted to Bryophytes and Lycophytes in plants. This transposon, named GingerRoot, is associated with a 6 bp (base pair) target site duplication, and 100-150 bp terminal inverted repeats. Analysis of transposase sequences identified the DDE motif, a catalytic domain, which shows similarity to the integrase of Gypsy-like long terminal repeat retrotransposons, the most abundant component in plant genomes. A total of 77 intact and several hundred truncated copies of GingerRoot elements were identified in S. lepidophylla. Like Gypsy retrotransposons, GingerRoots show a lack of insertion preference near genes, which contrasts to the compact genome size of about 100 Mb. Nevertheless, a considerable portion of GingerRoot elements was found to carry gene fragments, suggesting the capacity of duplicating gene sequences is unlikely attributed to the proximity to genes. Elements carrying gene fragments appear to be less methylated, more diverged, and more distal to genes than those without gene fragments, indicating they are preferentially retained in gene-poor regions. This study has identified a broadly dispersed, novel DNA transposon, and the first plant DNA transposon with an integrase-related transposase, suggesting the possibility of de novo formation of Gypsy-like elements in plants.
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Affiliation(s)
- Stefan Cerbin
- Department of Horticulture, Michigan State University, East Lansing, MI 48824
| | - Ching Man Wai
- Department of Horticulture, Michigan State University, East Lansing, MI 48824
| | - Robert VanBuren
- Department of Horticulture, Michigan State University, East Lansing, MI 48824
| | - Ning Jiang
- Department of Horticulture, Michigan State University, East Lansing, MI 48824
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236
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de Assis R, Baba VY, Cintra LA, Gonçalves LSA, Rodrigues R, Vanzela ALL. Genome relationships and LTR-retrotransposon diversity in three cultivated Capsicum L. (Solanaceae) species. BMC Genomics 2020; 21:237. [PMID: 32183698 PMCID: PMC7076952 DOI: 10.1186/s12864-020-6618-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 02/24/2020] [Indexed: 01/08/2023] Open
Abstract
Background Plant genomes are rich in repetitive sequences, and transposable elements (TEs) are the most accumulated of them. This mobile fraction can be distinguished as Class I (retrotransposons) and Class II (transposons). Retrotransposons that are transposed using an intermediate RNA and that accumulate in a “copy-and-paste” manner were screened in three genomes of peppers (Solanaceae). The present study aimed to understand the genome relationships among Capsicum annuum, C. chinense, and C. baccatum, based on a comparative analysis of the function, diversity and chromosome distribution of TE lineages in the Capsicum karyotypes. Due to the great commercial importance of pepper in natura, as a spice or as an ornamental plant, these genomes have been widely sequenced, and all of the assemblies are available in the SolGenomics group. These sequences were used to compare all repetitive fractions from a cytogenomic point of view. Results The qualification and quantification of LTR-retrotransposons (LTR-RT) families were contrasted with molecular cytogenetic data, and the results showed a strong genome similarity between C. annuum and C. chinense as compared to C. baccatum. The Gypsy superfamily is more abundant than Copia, especially for Tekay/Del lineage members, including a high representation in C. annuum and C. chinense. On the other hand, C. baccatum accumulates more Athila/Tat sequences. The FISH results showed retrotransposons differentially scattered along chromosomes, except for CRM lineage sequences, which mainly have a proximal accumulation associated with heterochromatin bands. Conclusions The results confirm a close genomic relationship between C. annuum and C. chinense in comparison to C. baccatum. Centromeric GC-rich bands may be associated with the accumulation regions of CRM elements, whereas terminal and subterminal AT- and GC-rich bands do not correspond to the accumulation of the retrotransposons in the three Capsicum species tested.
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Affiliation(s)
- Rafael de Assis
- Laboratório de Citogenética e Diversidade Vegetal, Universidade Estadual de Londrina, 86057-970, Londrina, Paraná, Brazil
| | - Viviane Yumi Baba
- Departamento de Agronomia, Universidade Estadual de Londrina, 86057-970, Londrina, Paraná, Brazil
| | - Leonardo Adabo Cintra
- Laboratório de Citogenética e Diversidade Vegetal, Universidade Estadual de Londrina, 86057-970, Londrina, Paraná, Brazil
| | | | - Rosana Rodrigues
- Laboratório de Melhoramento Genético Vegetal, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro, 28013-602, Brazil
| | - André Luís Laforga Vanzela
- Laboratório de Citogenética e Diversidade Vegetal, Universidade Estadual de Londrina, 86057-970, Londrina, Paraná, Brazil.
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237
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On the Trail of Tetu1: Genome-Wide Discovery of CACTA Transposable Elements in Sunflower Genome. Int J Mol Sci 2020; 21:ijms21062021. [PMID: 32188063 PMCID: PMC7139988 DOI: 10.3390/ijms21062021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 03/13/2020] [Accepted: 03/14/2020] [Indexed: 11/17/2022] Open
Abstract
Much has been said about sunflower (Helianthus annuus L.) retrotransposons, representing the majority of the sunflower’s repetitive component. By contrast, class II transposons remained poorly described within this species, as they present low sequence conservation and are mostly lacking coding domains, making the identification and characterization of these transposable elements difficult. The transposable element Tetu1, is a non-autonomous CACTA-like element that has been detected in the coding region of a CYCLOIDEA (CYC) gene of a sunflower mutant, tubular ray flower (turf). Based on our knowledge of Tetu1, the publicly available genome of sunflower was fully scanned. A combination of bioinformatics analyses led to the discovery of 707 putative CACTA sequences: 84 elements with complete ends and 623 truncated elements. A detailed characterization of the identified elements allowed further classification into three subgroups of 347 elements on the base of their terminal repeat sequences. Only 39 encode a protein similar to known transposases (TPase), with 10 TPase sequences showing signals of activation. Finally, an analysis of the proximity of CACTA transposons to sunflower genes showed that the majority of CACTA elements are close to the nearest gene, whereas a relevant fraction resides within gene-encoding sequences, likely interfering with sunflower genome functionality and organization.
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238
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Li Q, Sapkota M, van der Knaap E. Perspectives of CRISPR/Cas-mediated cis-engineering in horticulture: unlocking the neglected potential for crop improvement. HORTICULTURE RESEARCH 2020; 7:36. [PMID: 32194972 PMCID: PMC7072075 DOI: 10.1038/s41438-020-0258-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 01/09/2020] [Accepted: 02/11/2020] [Indexed: 05/14/2023]
Abstract
Directed breeding of horticultural crops is essential for increasing yield, nutritional content, and consumer-valued characteristics such as shape and color of the produce. However, limited genetic diversity restricts the amount of crop improvement that can be achieved through conventional breeding approaches. Natural genetic changes in cis-regulatory regions of genes play important roles in shaping phenotypic diversity by altering their expression. Utilization of CRISPR/Cas editing in crop species can accelerate crop improvement through the introduction of genetic variation in a targeted manner. The advent of CRISPR/Cas-mediated cis-regulatory region engineering (cis-engineering) provides a more refined method for modulating gene expression and creating phenotypic diversity to benefit crop improvement. Here, we focus on the current applications of CRISPR/Cas-mediated cis-engineering in horticultural crops. We describe strategies and limitations for its use in crop improvement, including de novo cis-regulatory element (CRE) discovery, precise genome editing, and transgene-free genome editing. In addition, we discuss the challenges and prospects regarding current technologies and achievements. CRISPR/Cas-mediated cis-engineering is a critical tool for generating horticultural crops that are better able to adapt to climate change and providing food for an increasing world population.
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Affiliation(s)
- Qiang Li
- College of Horticultural Science and Engineering, Shandong Agricultural University, Tai’an, China
- Center for Applied Genetic Technologies, University of Georgia, Athens, GA USA
| | - Manoj Sapkota
- Institute for Plant Breeding, Genetics and Genomics, University of Georgia, Athens, GA USA
| | - Esther van der Knaap
- Center for Applied Genetic Technologies, University of Georgia, Athens, GA USA
- Institute for Plant Breeding, Genetics and Genomics, University of Georgia, Athens, GA USA
- Department of Horticulture, University of Georgia, Athens, GA USA
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239
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Li Q, Ramasamy S, Singh P, Hagel JM, Dunemann SM, Chen X, Chen R, Yu L, Tucker JE, Facchini PJ, Yeaman S. Gene clustering and copy number variation in alkaloid metabolic pathways of opium poppy. Nat Commun 2020; 11:1190. [PMID: 32132540 PMCID: PMC7055283 DOI: 10.1038/s41467-020-15040-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 02/10/2020] [Indexed: 02/08/2023] Open
Abstract
Genes in plant secondary metabolic pathways enable biosynthesis of a range of medically and industrially important compounds, and are often clustered on chromosomes. Here, we study genomic clustering in the benzylisoquinoline alkaloid (BIA) pathway in opium poppy (Papaver somniferum), exploring relationships between gene expression, copy number variation, and metabolite production. We use Hi-C to improve the existing draft genome assembly, yielding chromosome-scale scaffolds that include 35 previously unanchored BIA genes. We find that co-expression of BIA genes increases within clusters and identify candidates with unknown function based on clustering and covariation in expression and alkaloid production. Copy number variation in critical BIA genes correlates with stark differences in alkaloid production, linking noscapine production with an 11-gene deletion, and increased thebaine/decreased morphine production with deletion of a T6ODM cluster. Our results show that the opium poppy genome is still dynamically evolving in ways that contribute to medically and industrially important phenotypes.
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Affiliation(s)
- Qiushi Li
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Sukanya Ramasamy
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Pooja Singh
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Jillian M Hagel
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
- Willow Biosciences Inc., 3655 36 Street N.W., Calgary, Alberta, T2L 1Y8, Canada
| | - Sonja M Dunemann
- Department of Ecosystem and Public Health, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Xue Chen
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
- Willow Biosciences Inc., 3655 36 Street N.W., Calgary, Alberta, T2L 1Y8, Canada
| | - Rongji Chen
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Lisa Yu
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Joseph E Tucker
- Willow Biosciences Inc., 3655 36 Street N.W., Calgary, Alberta, T2L 1Y8, Canada
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Peter J Facchini
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
- Willow Biosciences Inc., 3655 36 Street N.W., Calgary, Alberta, T2L 1Y8, Canada
| | - Sam Yeaman
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, T2N 1N4, Canada.
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Espinas NA, Tu LN, Furci L, Shimajiri Y, Harukawa Y, Miura S, Takuno S, Saze H. Transcriptional regulation of genes bearing intronic heterochromatin in the rice genome. PLoS Genet 2020; 16:e1008637. [PMID: 32187179 PMCID: PMC7145194 DOI: 10.1371/journal.pgen.1008637] [Citation(s) in RCA: 17] [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: 05/29/2019] [Revised: 04/09/2020] [Accepted: 01/28/2020] [Indexed: 11/18/2022] Open
Abstract
Intronic regions of eukaryotic genomes accumulate many Transposable Elements (TEs). Intronic TEs often trigger the formation of transcriptionally repressive heterochromatin, even within transcription-permissive chromatin environments. Although TE-bearing introns are widely observed in eukaryotic genomes, their epigenetic states, impacts on gene regulation and function, and their contributions to genetic diversity and evolution, remain poorly understood. In this study, we investigated the genome-wide distribution of intronic TEs and their epigenetic states in the Oryza sativa genome, where TEs comprise 35% of the genome. We found that over 10% of rice genes contain intronic heterochromatin, most of which are associated with TEs and repetitive sequences. These heterochromatic introns are longer and highly enriched in promoter-proximal positions. On the other hand, introns also accumulate hypomethylated short TEs. Genes with heterochromatic introns are implicated in various biological functions. Transcription of genes bearing intronic heterochromatin is regulated by an epigenetic mechanism involving the conserved factor OsIBM2, mutation of which results in severe developmental and reproductive defects. Furthermore, we found that heterochromatic introns evolve rapidly compared to non-heterochromatic introns. Our study demonstrates that heterochromatin is a common epigenetic feature associated with actively transcribed genes in the rice genome.
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Affiliation(s)
- Nino A. Espinas
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
- Plant Immunity Research Group, RIKEN Center for Sustainable Resource Science (CSRS), Yokohama city, Kanagawa, Japan
| | - Le Ngoc Tu
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Leonardo Furci
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Yasuka Shimajiri
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
- EditForce, Fukuoka, Japan
| | - Yoshiko Harukawa
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Saori Miura
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Shohei Takuno
- Department of Evolutionary Studies of Biosystems, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa, Japan
| | - Hidetoshi Saze
- Plant Epigenetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
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241
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Dohmen E, Klasberg S, Bornberg-Bauer E, Perrey S, Kemena C. The modular nature of protein evolution: domain rearrangement rates across eukaryotic life. BMC Evol Biol 2020; 20:30. [PMID: 32059645 PMCID: PMC7023805 DOI: 10.1186/s12862-020-1591-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 01/31/2020] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Modularity is important for evolutionary innovation. The recombination of existing units to form larger complexes with new functionalities spares the need to create novel elements from scratch. In proteins, this principle can be observed at the level of protein domains, functional subunits which are regularly rearranged to acquire new functions. RESULTS In this study we analyse the mechanisms leading to new domain arrangements in five major eukaryotic clades (vertebrates, insects, fungi, monocots and eudicots) at unprecedented depth and breadth. This allows, for the first time, to directly compare rates of rearrangements between different clades and identify both lineage specific and general patterns of evolution in the context of domain rearrangements. We analyse arrangement changes along phylogenetic trees by reconstructing ancestral domain content in combination with feasible single step events, such as fusion or fission. Using this approach we explain up to 70% of all rearrangements by tracing them back to their precursors. We find that rates in general and the ratio between these rates for a given clade in particular, are highly consistent across all clades. In agreement with previous studies, fusions are the most frequent event leading to new domain arrangements. A lineage specific pattern in fungi reveals exceptionally high loss rates compared to other clades, supporting recent studies highlighting the importance of loss for evolutionary innovation. Furthermore, our methodology allows us to link domain emergences at specific nodes in the phylogenetic tree to important functional developments, such as the origin of hair in mammals. CONCLUSIONS Our results demonstrate that domain rearrangements are based on a canonical set of mutational events with rates which lie within a relatively narrow and consistent range. In addition, gained knowledge about these rates provides a basis for advanced domain-based methodologies for phylogenetics and homology analysis which complement current sequence-based methods.
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Affiliation(s)
- Elias Dohmen
- Institute for Evolution and Biodiversity, University of Münster, Hüfferstrasse 1, Münster, 48149, Germany.,Institute for Bioinformatics and Chemoinformatics, Westphalian University of Applied Sciences, August-Schmidt-Ring 10, Recklinghausen, 45665, Germany
| | - Steffen Klasberg
- Institute for Evolution and Biodiversity, University of Münster, Hüfferstrasse 1, Münster, 48149, Germany
| | - Erich Bornberg-Bauer
- Institute for Evolution and Biodiversity, University of Münster, Hüfferstrasse 1, Münster, 48149, Germany
| | - Sören Perrey
- Institute for Bioinformatics and Chemoinformatics, Westphalian University of Applied Sciences, August-Schmidt-Ring 10, Recklinghausen, 45665, Germany
| | - Carsten Kemena
- Institute for Evolution and Biodiversity, University of Münster, Hüfferstrasse 1, Münster, 48149, Germany.
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242
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Debladis E, Lee TF, Huang YJ, Lu JH, Mathioni SM, Carpentier MC, Llauro C, Pierron D, Mieulet D, Guiderdoni E, Chen PY, Meyers BC, Panaud O, Lasserre E. Construction and characterization of a knock-down RNA interference line of OsNRPD1 in rice ( Oryza sativa ssp japonica cv Nipponbare). Philos Trans R Soc Lond B Biol Sci 2020; 375:20190338. [PMID: 32075556 DOI: 10.1098/rstb.2019.0338] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
In plants, RNA-directed DNA methylation (RdDM) is a silencing mechanism relying on the production of 24-nt small interfering RNAs (siRNAs) by RNA POLYMERASE IV (Pol IV) to trigger methylation and inactivation of transposable elements (TEs). We present the construction and characterization of osnrpd1, a knock-down RNA interference line of OsNRPD1 gene that encodes the largest subunit of Pol IV in rice (Oryza sativa ssp japonica cv Nipponbare). We show that osnrpd1 displays a lower accumulation of OsNRPD1 transcripts, associated with an overall reduction of 24-nt siRNAs and DNA methylation level in all three contexts, CG, CHG and CHH. We uncovered new insertions of known active TEs, the LTR retrotransposons Tos17 and Lullaby and the long interspersed nuclear element-type retrotransposon Karma. However, we did not observe any clear developmental phenotype, contrary to what was expected for a mutant severely affected in RdDM. In addition, despite the presence of many putatively functional TEs in the rice genome, we found no evidence of in planta global reactivation of transposition. This knock-down of OsNRPD1 likely led to a weakly affected line, with no effect on development and a limited effect on transposition. We discuss the possibility that a knock-out mutation of OsNRPD1 would cause sterility in rice. This article is part of a discussion meeting issue 'Crossroads between transposons and gene regulation'.
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Affiliation(s)
- Emilie Debladis
- Laboratoire Génome et Développement des Plantes, Université de Perpignan Via Domitia, 52, Avenue Paul alduy, 66860 Perpignan Cedex, France.,Laboratoire Génome et Développement des Plantes, Centre National de la Recherche Scientifique, 52, Avenue Paul alduy, 66860 Perpignan Cedex, France
| | - Tzuu-Fen Lee
- Donald Danforth Plant Science Center, St Louis, MO 63132, USA
| | - Yan-Jiun Huang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Jui-Hsien Lu
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | | | - Marie-Christine Carpentier
- Laboratoire Génome et Développement des Plantes, Université de Perpignan Via Domitia, 52, Avenue Paul alduy, 66860 Perpignan Cedex, France.,Laboratoire Génome et Développement des Plantes, Centre National de la Recherche Scientifique, 52, Avenue Paul alduy, 66860 Perpignan Cedex, France
| | - Christel Llauro
- Laboratoire Génome et Développement des Plantes, Université de Perpignan Via Domitia, 52, Avenue Paul alduy, 66860 Perpignan Cedex, France.,Laboratoire Génome et Développement des Plantes, Centre National de la Recherche Scientifique, 52, Avenue Paul alduy, 66860 Perpignan Cedex, France
| | - Davy Pierron
- Laboratoire Génome et Développement des Plantes, Université de Perpignan Via Domitia, 52, Avenue Paul alduy, 66860 Perpignan Cedex, France.,Laboratoire Génome et Développement des Plantes, Centre National de la Recherche Scientifique, 52, Avenue Paul alduy, 66860 Perpignan Cedex, France
| | | | | | - Pao-Yang Chen
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Blake C Meyers
- Donald Danforth Plant Science Center, St Louis, MO 63132, USA.,Division of Plant Sciences, University of Missouri-Columbia, Columbia, MO 65211, USA
| | - Olivier Panaud
- Laboratoire Génome et Développement des Plantes, Université de Perpignan Via Domitia, 52, Avenue Paul alduy, 66860 Perpignan Cedex, France.,Laboratoire Génome et Développement des Plantes, Centre National de la Recherche Scientifique, 52, Avenue Paul alduy, 66860 Perpignan Cedex, France.,Institut Universitaire de France, Paris, France
| | - Eric Lasserre
- Laboratoire Génome et Développement des Plantes, Université de Perpignan Via Domitia, 52, Avenue Paul alduy, 66860 Perpignan Cedex, France.,Laboratoire Génome et Développement des Plantes, Centre National de la Recherche Scientifique, 52, Avenue Paul alduy, 66860 Perpignan Cedex, France
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243
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Iwabuchi K, Shimada TL, Yamada T, Hara-Nishimura I. A space-saving visual screening method, Glycine max FAST, for generating transgenic soybean. PLANT SIGNALING & BEHAVIOR 2020; 15:1722911. [PMID: 32019401 PMCID: PMC7053950 DOI: 10.1080/15592324.2020.1722911] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 01/23/2020] [Accepted: 01/23/2020] [Indexed: 05/27/2023]
Abstract
Establishing homozygous transgenic lines of Glycine max is time-consuming and laborious. To overcome the difficulties, we developed a powerful method for selecting transgenic soybean plants, Fluorescence-Accumulating Seed Technology (GmFAST). GmFAST uses a marker composed of a soybean seed-specific promoter coupled to the OLE1-GFP gene, which encodes a GFP fusion of the oil-body membrane protein OLEOSIN1 of Arabidopsis thaliana. We introduced the marker gene into cotyledonary nodes of G. max Kariyutaka via Agrobacterium-mediated transformation and regenerated heterozygous transgenic plants. OLE1-GFP-expressing soybean seeds can be selected nondestructively with a fluorescence stereomicroscope. Among T2 seeds, the most strongly fluorescent seeds were homozygous. GmFAST enables to reduce the growing space by one-tenth compared with the conventional method. With this method, we obtained the soybean line that had higher levels of seed pods and oil production. The phenotypes are presumably caused by overexpression of Glyma13g30950, suggesting that Glyma13g30950 regulates seed pod formation in soybean plants. An increase in seed pod number was confirmed in A. thaliana plants that overexpressed the Arabidopsis ortholog of Glyma13g30950, E6L1.Taken together, GmFAST provides a space-saving visual and nondestructive screening method for soybean transformation, thereby increasing the chance of developing useful soybean lines.
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Affiliation(s)
- Kosei Iwabuchi
- Graduate School of Science, Kyoto University, Kyoto, Japan
- Faculty of Science and Engineering, Konan University, Kobe, Japan
| | | | - Tetsuya Yamada
- Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| | - Ikuko Hara-Nishimura
- Graduate School of Science, Kyoto University, Kyoto, Japan
- Faculty of Science and Engineering, Konan University, Kobe, Japan
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244
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Vercruysse J, Van Bel M, Osuna‐Cruz CM, Kulkarni SR, Storme V, Nelissen H, Gonzalez N, Inzé D, Vandepoele K. Comparative transcriptomics enables the identification of functional orthologous genes involved in early leaf growth. PLANT BIOTECHNOLOGY JOURNAL 2020; 18:553-567. [PMID: 31361386 PMCID: PMC6953196 DOI: 10.1111/pbi.13223] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 07/10/2019] [Accepted: 07/25/2019] [Indexed: 05/20/2023]
Abstract
Leaf growth is a complex trait for which many similarities exist in different plant species, suggesting functional conservation of the underlying pathways. However, a global view of orthologous genes involved in leaf growth showing conserved expression in dicots and monocots is currently missing. Here, we present a genome-wide comparative transcriptome analysis between Arabidopsis and maize, identifying conserved biological processes and gene functions active during leaf growth. Despite the orthology complexity between these distantly related plants, 926 orthologous gene groups including 2829 Arabidopsis and 2974 maize genes with similar expression during leaf growth were found, indicating conservation of the underlying molecular networks. We found 65% of these genes to be involved in one-to-one orthology, whereas only 28.7% of the groups with divergent expression had one-to-one orthology. Within the pool of genes with conserved expression, 19 transcription factor families were identified, demonstrating expression conservation of regulators active during leaf growth. Additionally, 25 Arabidopsis and 25 maize putative targets of the TCP transcription factors with conserved expression were determined based on the presence of enriched transcription factor binding sites. Based on large-scale phenotypic data, we observed that genes with conserved expression have a higher probability to be involved in leaf growth and that leaf-related phenotypes are more frequently present for genes having orthologues between dicots and monocots than clade-specific genes. This study shows the power of integrating transcriptomic with orthology data to identify or select candidates for functional studies during leaf development in flowering plants.
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Affiliation(s)
- Jasmien Vercruysse
- Department of Plant Biotechnology and BioinformaticsGhent UniversityGentBelgium
- Center for Plant Systems BiologyVIBGentBelgium
| | - Michiel Van Bel
- Department of Plant Biotechnology and BioinformaticsGhent UniversityGentBelgium
- Center for Plant Systems BiologyVIBGentBelgium
| | - Cristina M. Osuna‐Cruz
- Department of Plant Biotechnology and BioinformaticsGhent UniversityGentBelgium
- Center for Plant Systems BiologyVIBGentBelgium
| | - Shubhada R. Kulkarni
- Department of Plant Biotechnology and BioinformaticsGhent UniversityGentBelgium
- Center for Plant Systems BiologyVIBGentBelgium
| | - Véronique Storme
- Department of Plant Biotechnology and BioinformaticsGhent UniversityGentBelgium
- Center for Plant Systems BiologyVIBGentBelgium
| | - Hilde Nelissen
- Department of Plant Biotechnology and BioinformaticsGhent UniversityGentBelgium
- Center for Plant Systems BiologyVIBGentBelgium
| | - Nathalie Gonzalez
- Department of Plant Biotechnology and BioinformaticsGhent UniversityGentBelgium
- Center for Plant Systems BiologyVIBGentBelgium
- INRAUMR1332 Biologie du fruit et PathologieINRA Bordeaux AquitaineVillenave d'Ornon CedexFrance
| | - Dirk Inzé
- Department of Plant Biotechnology and BioinformaticsGhent UniversityGentBelgium
- Center for Plant Systems BiologyVIBGentBelgium
| | - Klaas Vandepoele
- Department of Plant Biotechnology and BioinformaticsGhent UniversityGentBelgium
- Center for Plant Systems BiologyVIBGentBelgium
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Huang L, Feng G, Yan H, Zhang Z, Bushman BS, Wang J, Bombarely A, Li M, Yang Z, Nie G, Xie W, Xu L, Chen P, Zhao X, Jiang W, Zhang X. Genome assembly provides insights into the genome evolution and flowering regulation of orchardgrass. PLANT BIOTECHNOLOGY JOURNAL 2020; 18:373-388. [PMID: 31276273 PMCID: PMC6953241 DOI: 10.1111/pbi.13205] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 05/27/2019] [Accepted: 06/29/2019] [Indexed: 05/18/2023]
Abstract
Orchardgrass (Dactylis glomerata L.) is an important forage grass for cultivating livestock worldwide. Here, we report an ~1.84-Gb chromosome-scale diploid genome assembly of orchardgrass, with a contig N50 of 0.93 Mb, a scaffold N50 of 6.08 Mb and a super-scaffold N50 of 252.52 Mb, which is the first chromosome-scale assembled genome of a cool-season forage grass. The genome includes 40 088 protein-coding genes, and 69% of the assembled sequences are transposable elements, with long terminal repeats (LTRs) being the most abundant. The LTRretrotransposons may have been activated and expanded in the grass genome in response to environmental changes during the Pleistocene between 0 and 1 million years ago. Phylogenetic analysis reveals that orchardgrass diverged after rice but before three Triticeae species, and evolutionarily conserved chromosomes were detected by analysing ancient chromosome rearrangements in these grass species. We also resequenced the whole genome of 76 orchardgrass accessions and found that germplasm from Northern Europe and East Asia clustered together, likely due to the exchange of plants along the 'Silk Road' or other ancient trade routes connecting the East and West. Last, a combined transcriptome, quantitative genetic and bulk segregant analysis provided insights into the genetic network regulating flowering time in orchardgrass and revealed four main candidate genes controlling this trait. This chromosome-scale genome and the online database of orchardgrass developed here will facilitate the discovery of genes controlling agronomically important traits, stimulate genetic improvement of and functional genetic research on orchardgrass and provide comparative genetic resources for other forage grasses.
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Affiliation(s)
- Linkai Huang
- Department of Grassland ScienceAnimal Science and Technology CollegeSichuan Agricultural UniversityChengduChina
| | - Guangyan Feng
- Department of Grassland ScienceAnimal Science and Technology CollegeSichuan Agricultural UniversityChengduChina
| | - Haidong Yan
- Department of Grassland ScienceAnimal Science and Technology CollegeSichuan Agricultural UniversityChengduChina
- School of Plant and Environmental SciencesVirginia TechBlacksburgVAUSA
| | | | | | - Jianping Wang
- Agronomy DepartmentUniversity of FloridaGainesvilleFLUSA
| | | | - Mingzhou Li
- Animal Science and Technology CollegeSichuan Agricultural UniversityChengduChina
| | - Zhongfu Yang
- Department of Grassland ScienceAnimal Science and Technology CollegeSichuan Agricultural UniversityChengduChina
| | - Gang Nie
- Department of Grassland ScienceAnimal Science and Technology CollegeSichuan Agricultural UniversityChengduChina
| | - Wengang Xie
- State Key Laboratory of Grassland Agro‐EcosystemsCollege of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhouChina
| | - Lei Xu
- Department of Grassland ScienceAnimal Science and Technology CollegeSichuan Agricultural UniversityChengduChina
| | - Peilin Chen
- Department of Grassland ScienceAnimal Science and Technology CollegeSichuan Agricultural UniversityChengduChina
| | - Xinxin Zhao
- Department of Grassland ScienceAnimal Science and Technology CollegeSichuan Agricultural UniversityChengduChina
| | | | - Xinquan Zhang
- Department of Grassland ScienceAnimal Science and Technology CollegeSichuan Agricultural UniversityChengduChina
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246
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Mascagni F, Vangelisti A, Usai G, Giordani T, Cavallini A, Natali L. A computational genome-wide analysis of long terminal repeats retrotransposon expression in sunflower roots (Helianthus annuus L.). Genetica 2020; 148:13-23. [PMID: 31960179 DOI: 10.1007/s10709-020-00085-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Accepted: 01/17/2020] [Indexed: 11/24/2022]
Abstract
Long terminal repeats (LTR) retrotransposons have a major role in determining genome size, structure and function, thanks to their ability to transpose. We performed a meta-analysis of LTR-retrotransposon expression in roots of sunflower plantlets treated with different plant hormones, chemicals and NaCl. By using Illumina cDNA libraries, available from public repositories, we measured the number of reads matching the retrotranscriptase domains isolated from a whole genome library of retrotransposons. LTR-retrotransposons resulted in general barely expressed, except for 4 elements, all belonging to the AleII lineage, which showed high transcription levels in roots of both control and treated plants. The expression of retrotransposons in treated plants was slightly higher than in the control. Transcribed elements belonged to specific chromosomal loci and were not abundant in the genome. A few elements resulted differentially expressed depending on the treatment. Results suggest that, although most retrotransposons are not expressed, the transcription of such elements is related to their abundance, to their position in the chromosome and to their lineage.
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Affiliation(s)
- Flavia Mascagni
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124, Pisa, Italy
| | - Alberto Vangelisti
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124, Pisa, Italy
| | - Gabriele Usai
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124, Pisa, Italy
| | - Tommaso Giordani
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124, Pisa, Italy
| | - Andrea Cavallini
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124, Pisa, Italy.
| | - Lucia Natali
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124, Pisa, Italy.
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248
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Hu L, Li N, Zhang Z, Meng X, Dong Q, Xu C, Gong L, Liu B. CG hypomethylation leads to complex changes in DNA methylation and transpositional burst of diverse transposable elements in callus cultures of rice. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 101:188-203. [PMID: 31529551 DOI: 10.1111/tpj.14531] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 09/01/2019] [Accepted: 09/05/2019] [Indexed: 06/10/2023]
Abstract
CG methylation (m CG) is essential for preserving genome stability in mammals, but this link remains obscure in plants. OsMET1-2, a major rice DNA methyltransferase, plays critical roles in maintaining m CG in rice. Null mutation of OsMET1-2 causes massive CG hypomethylation, rendering the mutant suitable to address the role of m CG in maintaining genome integrity in plants. Here, we analyzed m CG dynamics and genome stability in tissue cultures of OsMET1-2 homozygous (-/-) and heterozygous (+/-) mutants, and isogenic wild-type (WT). We found m CG levels in cultures of -/- were substantially lower than in those of WT and +/-, as expected. Unexpectedly, m CG levels in 1- and 3-year cultures of -/- were 77.6% and 48.7% higher, respectively, than in shoot, from which the cultures were initiated, suggesting substantial regain of m CG in -/- cultures, which contrasts to the general trend of m CG loss in all WT plant tissue cultures hitherto studied. Transpositional burst of diverse transposable elements (TEs) occurred only in -/- cultures, although no elevation of genome-wide mutation rate in the form of single nucleotide polymorphisms was detected. Altogether, our results establish an essential role of m CG in retaining TE immobility and hence genome stability in rice and likely in plants in general.
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Affiliation(s)
- Lanjuan Hu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
- College of Plant Sciences, Faculty of Agriculture, Jilin University, Changchun, 130062, China
| | - Ning Li
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Zhibin Zhang
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Xinchao Meng
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Qianli Dong
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Chunming Xu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Lei Gong
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
| | - Bao Liu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, China
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249
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Zhang X, Zhao M, Lisch D. Cost-Effective Profiling of Mutator Transposon Insertions in Maize by Next-Generation Sequencing. Methods Mol Biol 2020; 2072:39-50. [PMID: 31541437 DOI: 10.1007/978-1-4939-9865-4_5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Transposable elements can be highly mutagenic because when they transpose they can insert into genes and disrupt their function, a propensity which has been exploited in many organisms to generate tagged mutant alleles. The Mutator (Mu) family transposon is a family of DNA-type transposons in maize with a particularly high duplication frequency, which results in large numbers of new mutations in lineages that carry active Mu elements. Here we describe a rapid and cost-effective Miseq-based Mu transposon profiling pipeline. This method can also be used for identifying flanking sequences of other types of long insertions such as T-DNAs.
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Affiliation(s)
- Xinyan Zhang
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA
| | - Meixia Zhao
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA
| | - Damon Lisch
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA.
- Center for Plant Biology, Purdue University, West Lafayette, IN, USA.
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250
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Keidar-Friedman D, Bariah I, Domb K, Kashkush K. The Evolutionary Dynamics of a Novel Miniature Transposable Element in the Wheat Genome. FRONTIERS IN PLANT SCIENCE 2020; 11:1173. [PMID: 32903772 PMCID: PMC7438880 DOI: 10.3389/fpls.2020.01173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 07/20/2020] [Indexed: 05/02/2023]
Abstract
The discovery of Mariam, a wheat-unique miniature transposable element family, was reported in our previous study. We have also shown the possible impact of Mariam insertions on the expression of wheat genes. However, the evolutionary dynamics of Mariam was not studied in detail. In this study, we have assessed the insertion sites of Mariam family in different wheat species. In-silico analysis of Mariam insertions has allowed the discovery of two different sequence versions of Mariam, and that Mariam might have been recently active in wild emmer wheat genome (T. turgidum ssp diccocoides). In addition, the analysis of Mariam insertional polymorphism has facilitated the discovery of large genomic rearrangement events, such as deletions and introgressions in the wheat genome. The dynamics of Mariam family sheds light on the evolution of wheat.
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