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Chen G, Stepanenko A, Borisjuk N. Contrasting patterns of 5S rDNA repeats in European and Asian ecotypes of greater duckweed, Spirodela polyrhiza (Lemnaceae). FRONTIERS IN PLANT SCIENCE 2024; 15:1378683. [PMID: 38711607 PMCID: PMC11070557 DOI: 10.3389/fpls.2024.1378683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 04/09/2024] [Indexed: 05/08/2024]
Abstract
Ribosomal DNA (rDNA) contains highly conserved, specifically organized sequences encoding ribosomal RNAs (rRNAs) separated by variable non-transcribed intergenic spacers (NTSs) and is abundant in eukaryotic genomes. These characteristics make the rDNA an informative molecular target to study genome organization, molecular evolution, and phylogenetics. In this study, we characterized the 5S rDNA repeats in the greater duckweed Spiroldela polyrhiza, a species known for its small size, rapid growth, highly conserved genome organization, and low mutation rate. Sequence analysis of at least 12 individually cloned PCR fragments containing the 5S rDNA units for each of six ecotypes that originated from Europe (Ukraine) and Asia (China) revealed two distinct types of 5S rDNA repeats containing NTSs of different lengths and nucleotide compositions. The shorter 5S rDNA repeat units had a highly homogeneous 400-bp NTS, with few ecotype- or region-specific single-nucleotide polymorphisms (SNPs). The longer 5S rDNA units had NTSs of 1056-1084 bp with characteristic intra- and inter-genomic variants due to specific SNPs and insertions/deletions of 4-15-bp DNA elements. We also detected significant variability in the ratio of short/long 5S rDNA variants between ecotypes of S. polyrhiza. The contrasting dynamics of the two types of 5S rDNA units, combined with the unusually low repeat copy number (for plants) in S. polyrhiza (46-220 copies per genome), shows that this species could serve as an excellent model for examining the mechanisms of concerted evolution and functional significance of rDNA variability.
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Affiliation(s)
- Guimin Chen
- School of Life Sciences, Huaiyin Normal University, Huai’an, China
| | - Anton Stepanenko
- School of Life Sciences, Huaiyin Normal University, Huai’an, China
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
- Department of Molecular Genetics, Institute of Cell Biology and Genetic Engineering, Kyiv, Ukraine
| | - Nikolai Borisjuk
- School of Life Sciences, Huaiyin Normal University, Huai’an, China
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Garcia S, Kovarik A, Maiwald S, Mann L, Schmidt N, Pascual-Díaz JP, Vitales D, Weber B, Heitkam T. The Dynamic Interplay Between Ribosomal DNA and Transposable Elements: A Perspective From Genomics and Cytogenetics. Mol Biol Evol 2024; 41:msae025. [PMID: 38306580 PMCID: PMC10946416 DOI: 10.1093/molbev/msae025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 12/06/2023] [Accepted: 01/29/2024] [Indexed: 02/04/2024] Open
Abstract
Although both are salient features of genomes, at first glance ribosomal DNAs and transposable elements are genetic elements with not much in common: whereas ribosomal DNAs are mainly viewed as housekeeping genes that uphold all prime genome functions, transposable elements are generally portrayed as selfish and disruptive. These opposing characteristics are also mirrored in other attributes: organization in tandem (ribosomal DNAs) versus organization in a dispersed manner (transposable elements); evolution in a concerted manner (ribosomal DNAs) versus evolution by diversification (transposable elements); and activity that prolongs genomic stability (ribosomal DNAs) versus activity that shortens it (transposable elements). Re-visiting relevant instances in which ribosomal DNA-transposable element interactions have been reported, we note that both repeat types share at least four structural and functional hallmarks: (1) they are repetitive DNAs that shape genomes in evolutionary timescales, (2) they exchange structural motifs and can enter co-evolution processes, (3) they are tightly controlled genomic stress sensors playing key roles in senescence/aging, and (4) they share common epigenetic marks such as DNA methylation and histone modification. Here, we give an overview of the structural, functional, and evolutionary characteristics of both ribosomal DNAs and transposable elements, discuss their roles and interactions, and highlight trends and future directions as we move forward in understanding ribosomal DNA-transposable element associations.
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Affiliation(s)
- Sònia Garcia
- Institut Botànic de Barcelona (IBB), CSIC-CMCNB, 08038 Barcelona, Catalonia, Spain
| | - Ales Kovarik
- Institute of Biophysics, Academy of Sciences of the Czech Republic, 61265 Brno, Czech Republic
| | - Sophie Maiwald
- Faculty of Biology, Technische Universität Dresden, D-01069 Dresden, Germany
| | - Ludwig Mann
- Faculty of Biology, Technische Universität Dresden, D-01069 Dresden, Germany
| | - Nicola Schmidt
- Faculty of Biology, Technische Universität Dresden, D-01069 Dresden, Germany
| | | | - Daniel Vitales
- Institut Botànic de Barcelona (IBB), CSIC-CMCNB, 08038 Barcelona, Catalonia, Spain
- Laboratori de Botànica–Unitat Associada CSIC, Facultat de Farmàcia i Ciències de l’Alimentació, Universitat de Barcelona, 08028 Barcelona, Catalonia, Spain
| | - Beatrice Weber
- Faculty of Biology, Technische Universität Dresden, D-01069 Dresden, Germany
| | - Tony Heitkam
- Faculty of Biology, Technische Universität Dresden, D-01069 Dresden, Germany
- Institute of Biology, NAWI Graz, Karl-Franzens-Universität, A-8010 Graz, Austria
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Schreiber M, Jayakodi M, Stein N, Mascher M. Plant pangenomes for crop improvement, biodiversity and evolution. Nat Rev Genet 2024:10.1038/s41576-024-00691-4. [PMID: 38378816 DOI: 10.1038/s41576-024-00691-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2023] [Indexed: 02/22/2024]
Abstract
Plant genome sequences catalogue genes and the genetic elements that regulate their expression. Such inventories further research aims as diverse as mapping the molecular basis of trait diversity in domesticated plants or inquiries into the origin of evolutionary innovations in flowering plants millions of years ago. The transformative technological progress of DNA sequencing in the past two decades has enabled researchers to sequence ever more genomes with greater ease. Pangenomes - complete sequences of multiple individuals of a species or higher taxonomic unit - have now entered the geneticists' toolkit. The genomes of crop plants and their wild relatives are being studied with translational applications in breeding in mind. But pangenomes are applicable also in ecological and evolutionary studies, as they help classify and monitor biodiversity across the tree of life, deepen our understanding of how plant species diverged and show how plants adapt to changing environments or new selection pressures exerted by human beings.
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Affiliation(s)
- Mona Schreiber
- Department of Biology, University of Marburg, Marburg, Germany
| | - Murukarthick Jayakodi
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Seeland, Germany
| | - Nils Stein
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Seeland, Germany
- Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Martin Mascher
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Seeland, Germany.
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany.
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Raimondeau P, Bianconi ME, Pereira L, Parisod C, Christin PA, Dunning LT. Lateral gene transfer generates accessory genes that accumulate at different rates within a grass lineage. THE NEW PHYTOLOGIST 2023; 240:2072-2084. [PMID: 37793435 DOI: 10.1111/nph.19272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 08/30/2023] [Indexed: 10/06/2023]
Abstract
Lateral gene transfer (LGT) is the movement of DNA between organisms without sexual reproduction. The acquired genes represent genetic novelties that have independently evolved in the donor's genome. Phylogenetic methods have shown that LGT is widespread across the entire grass family, although we know little about the underlying dynamics. We identify laterally acquired genes in five de novo reference genomes from the same grass genus (four Alloteropsis semialata and one Alloteropsis angusta). Using additional resequencing data for a further 40 Alloteropsis individuals, we place the acquisition of each gene onto a phylogeny using stochastic character mapping, and then infer rates of gains and losses. We detect 168 laterally acquired genes in the five reference genomes (32-100 per genome). Exponential decay models indicate that the rate of LGT acquisitions (6-28 per Ma) and subsequent losses (11-24% per Ma) varied significantly among lineages. Laterally acquired genes were lost at a higher rate than vertically inherited loci (0.02-0.8% per Ma). This high turnover creates intraspecific gene content variation, with a preponderance of them occurring as accessory genes in the Alloteropsis pangenome. This rapid turnover generates standing variation that can ultimately fuel local adaptation.
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Affiliation(s)
- Pauline Raimondeau
- Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
- Laboratoire Evolution et Diversité Biologique, UMR5174, CNRS/IRD/Université Toulouse 3, Toulouse, 31062, France
| | - Matheus E Bianconi
- Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Lara Pereira
- Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Christian Parisod
- Department of Biology, University of Fribourg, Chemin du Musée 10, Fribourg, 1700, Switzerland
| | - Pascal-Antoine Christin
- Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
- Department of Biology, University of Fribourg, Chemin du Musée 10, Fribourg, 1700, Switzerland
| | - Luke T Dunning
- Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
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Wang W, Zhang X, Garcia S, Leitch AR, Kovařík A. Intragenomic rDNA variation - the product of concerted evolution, mutation, or something in between? Heredity (Edinb) 2023; 131:179-188. [PMID: 37402824 PMCID: PMC10462631 DOI: 10.1038/s41437-023-00634-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 06/12/2023] [Accepted: 06/12/2023] [Indexed: 07/06/2023] Open
Abstract
The classical model of concerted evolution states that hundreds to thousands of ribosomal DNA (rDNA) units undergo homogenization, making the multiple copies of the individual units more uniform across the genome than would be expected given mutation frequencies and gene redundancy. While the universality of this over 50-year-old model has been confirmed in a range of organisms, advanced high throughput sequencing techniques have also revealed that rDNA homogenization in many organisms is partial and, in rare cases, even apparently failing. The potential underpinning processes leading to unexpected intragenomic variation have been discussed in a number of studies, but a comprehensive understanding remains to be determined. In this work, we summarize information on variation or polymorphisms in rDNAs across a wide range of taxa amongst animals, fungi, plants, and protists. We discuss the definition and description of concerted evolution and describe whether incomplete concerted evolution of rDNAs predominantly affects coding or non-coding regions of rDNA units and if it leads to the formation of pseudogenes or not. We also discuss the factors contributing to rDNA variation, such as interspecific hybridization, meiotic cycles, rDNA expression status, genome size, and the activity of effector genes involved in genetic recombination, epigenetic modifications, and DNA editing. Finally, we argue that a combination of approaches is needed to target genetic and epigenetic phenomena influencing incomplete concerted evolution, to give a comprehensive understanding of the evolution and functional consequences of intragenomic variation in rDNA.
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Affiliation(s)
- Wencai Wang
- Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - Xianzhi Zhang
- Department of Horticulture, College of Horticulture and Landscape Architecture, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Sònia Garcia
- Institut Botànic de Barcelona, IBB (CSIC - Ajuntament de Barcelona), Barcelona, Spain
| | - Andrew R Leitch
- School of Biological and Behavioral Sciences, Queen Mary University of London, London, E1 4NS, UK
| | - Aleš Kovařík
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, CZ-61200, Czech Republic.
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Nasiri A, Kazempour-Osaloo S, Hamzehee B, Bull RD, Saarela JM. A phylogenetic analysis of Bromus (Poaceae: Pooideae: Bromeae) based on nuclear ribosomal and plastid data, with a focus on Bromus sect. Bromus. PeerJ 2022; 10:e13884. [PMID: 36193423 PMCID: PMC9526414 DOI: 10.7717/peerj.13884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 07/21/2022] [Indexed: 01/18/2023] Open
Abstract
To investigate phylogenetic relationships among and within major lineages of Bromus, with focus on Bromus sect. Bromus, we analyzed DNA sequences from two nuclear ribosomal (ITS, ETS) and two plastid (rpl32-trnLUAG , matK) regions. We sampled 103 ingroup accessions representing 26 taxa of B. section Bromus and 15 species of other Bromus sections. Our analyses confirm the monophyly of Bromus s.l. and identify incongruence between nuclear ribosomal and plastid data partitions for relationships within and among major Bromus lineages. Results support classification of B. pumilio and B. gracillimus within B. sect. Boissiera and B. sect. Nevskiella, respectively. These species are sister groups and are closely related to B. densus (B. sect. Mexibromus) in nrDNA trees and Bromus sect. Ceratochloa in plastid trees. Bromus sect. Bromopsis is paraphyletic. In nrDNA trees, species of Bromus sects. Bromopsis, Ceratochloa, Neobromus, and Genea plus B. rechingeri of B. sect. Bromus form a clade, in which B. tomentellus is sister to a B. sect. Genea-B. rechingeri clade. In the plastid trees, by contrast, B. sect. Bromopsis species except B. tomentosus form a clade, and B. tomentosus is sister to a clade comprising B. sect. Bromus and B. sect. Genea species. Affinities of B. gedrosianus, B. pulchellus, and B. rechingeri (members of the B. pectinatus complex), as well as B. oxyodon and B. sewerzowii, are discordant between nrDNA and plastid trees. We infer these species may have obtained their plastomes via chloroplast capture from species of B. sect. Bromus and B. sect. Genea. Within B. sect. Bromus, B. alopecuros subsp. caroli-henrici, a clade comprising B. hordeaceus and B. interruptus, and B. scoparius are successive sister groups to the rest of the section in the nrDNA phylogeny. Most relationships among the remaining species of B. sect. Bromus are unresolved in the nrDNA and plastid trees. Given these results, we infer that most B. sect. Bromus species likely diversified relatively recently. None of the subdivisional taxa proposed for Bromus sect. Bromus over the last century correspond to natural groups identified in our phylogenetic analyses except for a group including B. hordeaceus and B. interruptus.
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Affiliation(s)
- Akram Nasiri
- Department of Plant Biology, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran,Beaty Centre for Species Discovery and Botany Section, Canadian Museum of Nature, Ottawa, Ontario, Canada
| | - Shahrokh Kazempour-Osaloo
- Department of Plant Biology, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Behnam Hamzehee
- Botany Research Division, Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran
| | - Roger D. Bull
- Beaty Centre for Species Discovery and Botany Section, Canadian Museum of Nature, Ottawa, Ontario, Canada
| | - Jeffery M. Saarela
- Beaty Centre for Species Discovery and Botany Section, Canadian Museum of Nature, Ottawa, Ontario, Canada
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Philips JG, Martin-Avila E, Robold AV. Horizontal gene transfer from genetically modified plants - Regulatory considerations. Front Bioeng Biotechnol 2022; 10:971402. [PMID: 36118580 PMCID: PMC9471246 DOI: 10.3389/fbioe.2022.971402] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 08/05/2022] [Indexed: 11/13/2022] Open
Abstract
Gene technology regulators receive applications seeking permission for the environmental release of genetically modified (GM) plants, many of which possess beneficial traits such as improved production, enhanced nutrition and resistance to drought, pests and diseases. The regulators must assess the risks to human and animal health and to the environment from releasing these GM plants. One such consideration, of many, is the likelihood and potential consequence of the introduced or modified DNA being transferred to other organisms, including people. While such gene transfer is most likely to occur to sexually compatible relatives (vertical gene transfer), horizontal gene transfer (HGT), which is the acquisition of genetic material that has not been inherited from a parent, is also a possibility considered during these assessments. Advances in HGT detection, aided by next generation sequencing, have demonstrated that HGT occurrence may have been previously underestimated. In this review, we provide updated evidence on the likelihood, factors and the barriers for the introduced or modified DNA in GM plants to be horizontally transferred into a variety of recipients. We present the legislation and frameworks the Australian Gene Technology Regulator adheres to with respect to the consideration of risks posed by HGT. Such a perspective may generally be applicable to regulators in other jurisdictions as well as to commercial and research organisations who develop GM plants.
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Bartha L, Mandáková T, Kovařík A, Bulzu PA, Rodde N, Mahelka V, Lysak MA, Fustier MA, Šafář J, Cápal P, Keresztes L, Banciu HL. Intact ribosomal DNA arrays of Potentilla origin detected in Erythronium nucleus suggest recent eudicot-to-monocot horizontal transfer. THE NEW PHYTOLOGIST 2022; 235:1246-1259. [PMID: 35460285 DOI: 10.1111/nph.18171] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 04/07/2022] [Indexed: 06/14/2023]
Abstract
During our initial phylogenetic study of the monocot genus Erythronium (Liliaceae), we observed peculiar eudicot-type internal transcribed spacer (ITS) sequences in a dataset derived from genomic DNA of Erythronium dens-canis. This raised the possibility of horizontal transfer of a eudicot alien ribosomal DNA (rDNA) into the Erythronium genome. In this work we aimed to support this hypothesis by carrying out genomic, molecular, and cytogenetic analyses. Genome skimming coupled by PacBio HiFi sequencing of a bacterial artificial chromosome clone derived from flow-sorted nuclei was used to characterise the alien 45S rDNA. Integration of alien rDNA in the recipient genome was further proved by Southern blotting and fluorescence in situ hybridization using specific probes. Alien rDNA, nested among Potentilla species in phylogenetic analysis, likely entered the Erythronium lineage in the common ancestor of E. dens-canis and E. caucasicum. Transferred eudicot-type rDNA preserved its tandemly arrayed feature on a single chromosome and was found to be transcribed in the monocot host, albeit much less efficiently than the native counterpart. This study adds a new example to the rarely documented nuclear-to-nuclear jumps of DNA between eudicots and monocots while holding the scientific community continually in suspense about the mode of DNA transfer.
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Affiliation(s)
- László Bartha
- Molecular Biology Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babeş-Bolyai University, 400271, Cluj-Napoca, Romania
| | - Terezie Mandáková
- Central European Institute of Technology (CEITEC), Masaryk University, 625 00, Brno, Czech Republic
| | - Aleš Kovařík
- Laboratory of Molecular Epigenetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, 61265, Brno, Czech Republic
| | - Paul-Adrian Bulzu
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Academy of Sciences of the Czech Republic, 370 05, České Budějovice, Czech Republic
| | - Nathalie Rodde
- French Plant Genomic Resource Center, INRAE-CNRGV, 31320, Castanet Tolosan, France
| | - Václav Mahelka
- Institute of Botany, Czech Academy of Sciences, 25243, Průhonice, Czech Republic
| | - Martin A Lysak
- Central European Institute of Technology (CEITEC), Masaryk University, 625 00, Brno, Czech Republic
| | | | - Jan Šafář
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of the Region Haná for Biotechnological and Agricultural Research, 779 00, Olomouc, Czech Republic
| | - Petr Cápal
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of the Region Haná for Biotechnological and Agricultural Research, 779 00, Olomouc, Czech Republic
| | - Lujza Keresztes
- Hungarian Department of Biology and Ecology, Babeş-Bolyai University, 400006, Cluj-Napoca, Romania
- Centre of Systems Biology, Biodiversity and Bioresources (3B), Babeş-Bolyai University, 400006, Cluj-Napoca, Romania
| | - Horia L Banciu
- Molecular Biology Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babeş-Bolyai University, 400271, Cluj-Napoca, Romania
- Centre of Systems Biology, Biodiversity and Bioresources (3B), Babeş-Bolyai University, 400006, Cluj-Napoca, Romania
- Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeş-Bolyai University, 400006, Cluj-Napoca, Romania
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Wu D, Jiang B, Ye CY, Timko MP, Fan L. Horizontal transfer and evolution of the biosynthetic gene cluster for benzoxazinoids in plants. PLANT COMMUNICATIONS 2022; 3:100320. [PMID: 35576160 PMCID: PMC9251436 DOI: 10.1016/j.xplc.2022.100320] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 03/07/2022] [Accepted: 03/23/2022] [Indexed: 05/11/2023]
Abstract
Benzoxazinoids are a class of protective and allelopathic plant secondary metabolites that have been identified in multiple grass species and are encoded by the Bx biosynthetic gene cluster (BGC) in maize. Data mining of 41 high-quality grass genomes identified complete Bx clusters (containing genes Bx1-Bx5 and Bx8) in three genera (Zea, Echinochloa, and Dichanthelium) of Panicoideae and partial clusters in Triticeae. The Bx cluster probably originated from gene duplication and chromosomal translocation of native homologs of Bx genes. An ancient Bx cluster that included additional Bx genes (e.g., Bx6) is presumed to have been present in ancestral Panicoideae. The ancient Bx cluster was putatively gained by the Triticeae ancestor via horizontal transfer (HT) from the ancestral Panicoideae and later separated into multiple segments on different chromosomes. Bx6 appears to have been under less constrained selection compared with the Bx cluster during the evolution of Panicoideae, as evidenced by the fact that it was translocated away from the Bx cluster in Zea mays, moved to other chromosomes in Echinochloa, and even lost in Dichanthelium. Further investigations indicate that purifying selection and polyploidization have shaped the evolutionary trajectory of Bx clusters in the grass family. This study provides the first candidate case of HT of a BGC between plants and sheds new light on the evolution of BGCs.
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Affiliation(s)
- Dongya Wu
- Hainan Institute of Zhejiang University, Yonyou Industrial Park, Sanya 572025, China; Institute of Crop Science & Institute of Bioinformatics, Zhejiang University, Hangzhou 310058, China
| | - Bowen Jiang
- Institute of Crop Science & Institute of Bioinformatics, Zhejiang University, Hangzhou 310058, China
| | - Chu-Yu Ye
- Institute of Crop Science & Institute of Bioinformatics, Zhejiang University, Hangzhou 310058, China
| | - Michael P Timko
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA
| | - Longjiang Fan
- Hainan Institute of Zhejiang University, Yonyou Industrial Park, Sanya 572025, China; Institute of Crop Science & Institute of Bioinformatics, Zhejiang University, Hangzhou 310058, China.
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Stepanenko A, Chen G, Hoang PTN, Fuchs J, Schubert I, Borisjuk N. The Ribosomal DNA Loci of the Ancient Monocot Pistia stratiotes L. (Araceae) Contain Different Variants of the 35S and 5S Ribosomal RNA Gene Units. FRONTIERS IN PLANT SCIENCE 2022; 13:819750. [PMID: 35310643 PMCID: PMC8928438 DOI: 10.3389/fpls.2022.819750] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 02/10/2022] [Indexed: 06/14/2023]
Abstract
The freshwater plant water lettuce (Pistia stratiotes L.) grows in warm climatic zones and is used for phytoremediation and biomass production. P. stratiotes belongs to the Araceae, an ecologically and structurally diverse early monocot family, but the phylogenetic relationships among Araceae members are poorly understood. Ribosomal DNAs (rDNAs), including the 35S and 5S rDNA, encode the RNA components of ribosomes and are widely used in phylogenetic and evolutionary studies of various plant taxa. Here, we comprehensively characterized the chromosomal locations and molecular organization of 35S and 5S rDNA genes in water lettuce using karyological and molecular methods. Fluorescence in situ hybridization revealed a single location for the 35S and 5S rDNA loci, each on a different pair of the species' 28 chromosomes. Molecular cloning and nucleotide sequencing of 35S rDNA of P. stratiotes, the first representative Araceae sensu stricto in which such a study was performed, displayed typical structural characteristics. The full-length repeat showed high sequence conservation of the regions producing the 18S, 5.8S, and 25S rRNAs and divergence of the internal transcribed spacers ITS1 and ITS2 as well as the large intergenic spacer (IGS). Alignments of the deduced sequence of 18S rDNA with the sequences available for other Araceae and representatives of other clades were used for phylogenetic analysis. Examination of 11 IGS sequences revealed significant intra-genomic length variability due to variation in subrepeat number, with four types of units detected within the 35S rDNA locus of the P. stratiotes genome (estimated size 407 Mb/1C). Similarly, the 5S rDNA locus harbors gene units comprising a conserved 119-bp sequence encoding 5S rRNA and two types of non-transcribed spacer (NTS) sequences. Type I was classified into four subtypes, which apparently originated via progressive loss of subrepeats within the duplicated NTS region containing the 3' part of the 5S rRNA gene. The minor Type II NTS is shorter than Type I and differs in nucleotide composition. Some DNA clones containing two or three consecutive 5S rDNA repeats harbored 5S rDNA genes with different types of NTSs, confirming the mosaic composition of the 5S rDNA locus.
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Affiliation(s)
- Anton Stepanenko
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology Around Hongze Lake and Jiangsu Collaborative Innovation Centre of Regional Modern Agriculture and Environmental Protection, School of Life Sciences, Huaiyin Normal University, Huai’an, China
| | - Guimin Chen
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology Around Hongze Lake and Jiangsu Collaborative Innovation Centre of Regional Modern Agriculture and Environmental Protection, School of Life Sciences, Huaiyin Normal University, Huai’an, China
| | - Phuong T. N. Hoang
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
- Faculty of Biology, Dalat University, Đà Lạt, Vietnam
| | - Jörg Fuchs
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
| | - Ingo Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
| | - Nikolai Borisjuk
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology Around Hongze Lake and Jiangsu Collaborative Innovation Centre of Regional Modern Agriculture and Environmental Protection, School of Life Sciences, Huaiyin Normal University, Huai’an, China
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Park M, Christin PA, Bennetzen JL. Sample Sequence Analysis Uncovers Recurrent Horizontal Transfers of Transposable Elements among Grasses. Mol Biol Evol 2021; 38:3664-3675. [PMID: 33964159 PMCID: PMC8382918 DOI: 10.1093/molbev/msab133] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Limited genome resources are a bottleneck in the study of horizontal transfer (HT) of DNA in plants. To solve this issue, we tested the usefulness of low-depth sequencing data generated from 19 previously uncharacterized panicoid grasses for HT investigation. We initially searched for horizontally transferred LTR-retrotransposons by comparing the 19 sample sequences to 115 angiosperm genome sequences. Frequent HTs of LTR-retrotransposons were identified solely between panicoids and rice (Oryza sativa). We consequently focused on additional Oryza species and conducted a nontargeted investigation of HT involving the panicoid genus Echinochloa, which showed the most HTs in the first set of analyses. The comparison of nine Echinochloa samples and ten Oryza species identified recurrent HTs of diverse transposable element (TE) types at different points in Oryza history, but no confirmed cases of HT for sequences other than TEs. One case of HT was observed from one Echinochloa species into one Oryza species with overlapping geographic distributions. Variation among species and data sets highlights difficulties in identifying all HT, but our investigations showed that sample sequence analyses can reveal the importance of HT for the diversification of the TE repertoire of plants.
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Affiliation(s)
- Minkyu Park
- Department of Genetics, University of Georgia, Athens, GA, USA
| | | | - Jeffrey L Bennetzen
- Department of Genetics, University of Georgia, Athens, GA, USA
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, China
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González ML, Chiapella JO, Urdampilleta JD. The Antarctic and South American species of Deschampsia: phylogenetic relationships and cytogenetic differentiation. SYST BIODIVERS 2021. [DOI: 10.1080/14772000.2020.1860151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- María Laura González
- Instituto Multidisciplinario de Biologıa Vegetal (Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Cordoba), C.C. 495, Cordoba, Argentina
| | - Jorge O. Chiapella
- Instituto de Investigaciones en Biodiversidad y Medioambiente (Consejo Nacional de Investigaciones Científicas y Técnicas – Universidad Nacional del Comahue), Quintral 1250, 8400 Bariloche, Río Negro, Argentina
| | - Juan Domingo Urdampilleta
- Instituto Multidisciplinario de Biologıa Vegetal (Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Cordoba), C.C. 495, Cordoba, Argentina
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13
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Chen G, Stepanenko A, Borisjuk N. Mosaic Arrangement of the 5S rDNA in the Aquatic Plant Landoltia punctata (Lemnaceae). FRONTIERS IN PLANT SCIENCE 2021; 12:678689. [PMID: 34249048 PMCID: PMC8264772 DOI: 10.3389/fpls.2021.678689] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 05/31/2021] [Indexed: 06/13/2023]
Abstract
Duckweeds are a group of monocotyledonous aquatic plants in the Araceae superfamily, represented by 37 species divided into five genera. Duckweeds are the fastest growing flowering plants and are distributed around the globe; moreover, these plants have multiple applications, including biomass production, wastewater remediation, and making pharmaceutical proteins. Dotted duckweed (Landoltia punctata), the sole species in genus Landoltia, is one of the most resilient duckweed species. The ribosomal DNA (rDNA) encodes the RNA components of ribosomes and represents a significant part of plant genomes but has not been comprehensively studied in duckweeds. Here, we characterized the 5S rDNA genes in L. punctata by cloning and sequencing 25 PCR fragments containing the 5S rDNA repeats. No length variation was detected in the 5S rDNA gene sequence, whereas the nontranscribed spacer (NTS) varied from 151 to 524 bp. The NTS variants were grouped into two major classes, which differed both in nucleotide sequence and the type and arrangement of the spacer subrepeats. The dominant class I NTS, with a characteristic 12-bp TC-rich sequence present in 3-18 copies, was classified into four subclasses, whereas the minor class II NTS, with shorter, 9-bp nucleotide repeats, was represented by two identical sequences. In addition to these diverse subrepeats, class I and class II NTSs differed in their representation of cis-elements and the patterns of predicted G-quadruplex structures, which may influence the transcription of the 5S rDNA. Similar to related duckweed species in the genus Spirodela, L. punctata has a relatively low rDNA copy number, but in contrast to Spirodela and the majority of other plants, the arrangement of the 5S rDNA units demonstrated an unusual, heterogeneous pattern in L. punctata, as revealed by analyzing clones containing double 5S rDNA neighboring units. Our findings may further stimulate the research on the evolution of the plant rDNA and discussion of the molecular forces driving homogenization of rDNA repeats in concerted evolution.
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Affiliation(s)
- Guimin Chen
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology Around Hongze Lake, School of Life Sciences, Huaiyin Normal University, Huai’an, China
- Jiangsu Collaborative Innovation Centre of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University, Huai’an, China
| | - Anton Stepanenko
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology Around Hongze Lake, School of Life Sciences, Huaiyin Normal University, Huai’an, China
- Jiangsu Collaborative Innovation Centre of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University, Huai’an, China
| | - Nikolai Borisjuk
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology Around Hongze Lake, School of Life Sciences, Huaiyin Normal University, Huai’an, China
- Jiangsu Collaborative Innovation Centre of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University, Huai’an, China
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14
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Hibdige SGS, Raimondeau P, Christin PA, Dunning LT. Widespread lateral gene transfer among grasses. THE NEW PHYTOLOGIST 2021; 230:2474-2486. [PMID: 33887801 DOI: 10.1111/nph.17328] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 02/28/2021] [Indexed: 06/12/2023]
Abstract
Lateral gene transfer (LGT) occurs in a broad range of prokaryotes and eukaryotes, occasionally promoting adaptation. LGT of functional nuclear genes has been reported among some plants, but systematic studies are needed to assess the frequency and facilitators of LGT. We scanned the genomes of a diverse set of 17 grass species that span more than 50 Ma of divergence and include major crops to identify grass-to-grass protein-coding LGT. We identified LGTs in 13 species, with significant variation in the amount each received. Rhizomatous species acquired statistically more genes, probably because this growth habit boosts opportunities for transfer into the germline. In addition, the amount of LGT increases with phylogenetic relatedness, which might reflect genomic compatibility among close relatives facilitating successful transfers. However, genetic exchanges among highly divergent species indicates that transfers can occur across almost the entire family. Overall, we showed that LGT is a widespread phenomenon in grasses that has moved functional genes across the grass family into domesticated and wild species alike. Successful LGTs appear to increase with both opportunity and compatibility.
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Affiliation(s)
- Samuel G S Hibdige
- Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Pauline Raimondeau
- Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | | | - Luke T Dunning
- Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
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15
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Krak K, Caklová P, Kopecký D, Blattner FR, Mahelka V. Horizontally Acquired nrDNAs Persist in Low Amounts in Host Hordeum Genomes and Evolve Independently of Native nrDNA. FRONTIERS IN PLANT SCIENCE 2021; 12:672879. [PMID: 34079572 PMCID: PMC8165317 DOI: 10.3389/fpls.2021.672879] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/22/2021] [Indexed: 06/12/2023]
Abstract
Nuclear ribosomal DNA (nrDNA) has displayed extraordinary dynamics during the evolution of plant species. However, the patterns and evolutionary significance of nrDNA array expansion or contraction are still relatively unknown. Moreover, only little is known of the fate of minority nrDNA copies acquired between species via horizontal transfer. The barley genus Hordeum (Poaceae) represents a good model for such a study, as species of section Stenostachys acquired nrDNA via horizontal transfer from at least five different panicoid genera, causing long-term co-existence of native (Hordeum-like) and non-native (panicoid) nrDNAs. Using quantitative PCR, we investigated copy number variation (CNV) of nrDNA in the diploid representatives of the genus Hordeum. We estimated the copy number of the foreign, as well as of the native ITS types (ribotypes), and followed the pattern of their CNV in relation to the genus' phylogeny, species' genomes size and the number of nrDNA loci. For the native ribotype, we encountered an almost 19-fold variation in the mean copy number among the taxa analysed, ranging from 1689 copies (per 2C content) in H. patagonicum subsp. mustersii to 31342 copies in H. murinum subsp. glaucum. The copy numbers did not correlate with any of the genus' phylogeny, the species' genome size or the number of nrDNA loci. The CNV was high within the recognised groups (up to 13.2 × in the American I-genome species) as well as between accessions of the same species (up to 4×). Foreign ribotypes represent only a small fraction of the total number of nrDNA copies. Their copy numbers ranged from single units to tens and rarely hundreds of copies. They amounted, on average, to between 0.1% (Setaria ribotype) and 1.9% (Euclasta ribotype) of total nrDNA. None of the foreign ribotypes showed significant differences with respect to phylogenetic groups recognised within the sect. Stenostachys. Overall, no correlation was found between copy numbers of native and foreign nrDNAs suggesting the sequestration and independent evolution of native and non-native nrDNA arrays. Therefore, foreign nrDNA in Hordeum likely poses a dead-end by-product of horizontal gene transfer events.
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Affiliation(s)
- Karol Krak
- Czech Academy of Sciences, Institute of Botany, Prùhonice, Czechia
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Prague 6, Czechia
| | - Petra Caklová
- Czech Academy of Sciences, Institute of Botany, Prùhonice, Czechia
| | - David Kopecký
- Czech Academy of Sciences, Institute of Experimental Botany, Centre of the Region Haná for Biotechnological and Agricultural Research, Olomouc, Czechia
| | - Frank R. Blattner
- Experimental Taxonomy, Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany
- German Centre of Integrative Biodiversity Research (iDiv) Halle–Jena–Leipzig, Leipzig, Germany
| | - Václav Mahelka
- Czech Academy of Sciences, Institute of Botany, Prùhonice, Czechia
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Verhage L. A hitchhiker's guide to foreign genomes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:1139-1140. [PMID: 33720471 DOI: 10.1111/tpj.15192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
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17
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Mahelka V, Krak K, Fehrer J, Caklová P, Nagy Nejedlá M, Čegan R, Kopecký D, Šafář J. A Panicum-derived chromosomal segment captured by Hordeum a few million years ago preserves a set of stress-related genes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:1141-1164. [PMID: 33484020 DOI: 10.1111/tpj.15167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/15/2021] [Accepted: 01/19/2021] [Indexed: 06/12/2023]
Abstract
Intra-specific variability is a cornerstone of evolutionary success of species. Acquiring genetic material from distant sources is an important adaptive mechanism in bacteria, but it can also play a role in eukaryotes. In this paper, we investigate the nature and evolution of a chromosomal segment of panicoid (Poaceae, Panicoideae) origin occurring in the nuclear genomes of species of the barley genus Hordeum (Pooideae). The segment, spanning over 440 kb in the Asian Hordeum bogdanii and 219 kb in the South American Hordeum pubiflorum, resides on a pair of nucleolar organizer region (NOR)-bearing chromosomes. Conserved synteny and micro-collinearity of the segment in both species indicate a common origin of the segment, which was acquired before the split of the respective barley lineages 5-1.7 million years ago. A major part of the foreign DNA consists of several approximately 68 kb long repeated blocks containing five stress-related protein-coding genes and transposable elements (TEs). Whereas outside these repeats, the locus was invaded by multiple TEs from the host genome, the repeated blocks are rather intact and appear to be preserved. The protein-coding genes remained partly functional, as indicated by conserved reading frames, a low amount of non-synonymous mutations, and expression of mRNA. A screen across Hordeum species targeting the panicoid protein-coding genes revealed the presence of the genes in all species of the section Stenostachys. In summary, our study shows that grass genomes can contain large genomic segments obtained from distantly related species. These segments usually remain undetected, but they may play an important role in the evolution and adaptation of species.
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Affiliation(s)
- Václav Mahelka
- Institute of Botany, Czech Academy of Sciences, Průhonice, 25243, Czech Republic
| | - Karol Krak
- Institute of Botany, Czech Academy of Sciences, Průhonice, 25243, Czech Republic
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Prague 6, 16500, Czech Republic
| | - Judith Fehrer
- Institute of Botany, Czech Academy of Sciences, Průhonice, 25243, Czech Republic
| | - Petra Caklová
- Institute of Botany, Czech Academy of Sciences, Průhonice, 25243, Czech Republic
| | | | - Radim Čegan
- Institute of Biophysics, Czech Academy of Sciences, Brno, 61265, Czech Republic
| | - David Kopecký
- Institute of Experimental Botany, Czech Academy of Sciences, Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31, Olomouc, 77900, Czech Republic
| | - Jan Šafář
- Institute of Experimental Botany, Czech Academy of Sciences, Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31, Olomouc, 77900, Czech Republic
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18
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Chen R, Huangfu L, Lu Y, Fang H, Xu Y, Li P, Zhou Y, Xu C, Huang J, Yang Z. Adaptive innovation of green plants by horizontal gene transfer. Biotechnol Adv 2020; 46:107671. [PMID: 33242576 DOI: 10.1016/j.biotechadv.2020.107671] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 11/18/2020] [Accepted: 11/20/2020] [Indexed: 12/16/2022]
Abstract
Horizontal gene transfer (HGT) refers to the movement of genetic material between distinct species by means other than sexual reproduction. HGT has contributed tremendously to the genome plasticity and adaptive evolution of prokaryotes and certain unicellular eukaryotes. The evolution of green plants from chlorophyte algae to angiosperms and from water to land represents a process of adaptation to diverse environments, which has been facilitated by acquisition of genetic material from other organisms. In this article, we review the occurrence of HGT in major lineages of green plants, including chlorophyte and charophyte green algae, bryophytes, lycophytes, ferns, and seed plants. In addition, we discuss the significance of horizontally acquired genes in the adaptive innovations of green plants and their potential applications to crop breeding and improvement.
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Affiliation(s)
- Rujia Chen
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Agricultural College of Yangzhou University, Yangzhou 225009, China; Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China
| | - Liexiang Huangfu
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Agricultural College of Yangzhou University, Yangzhou 225009, China; Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China
| | - Yue Lu
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Agricultural College of Yangzhou University, Yangzhou 225009, China; Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China
| | - Huimin Fang
- Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China
| | - Yang Xu
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Agricultural College of Yangzhou University, Yangzhou 225009, China; Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China
| | - Pengcheng Li
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Agricultural College of Yangzhou University, Yangzhou 225009, China; Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China
| | - Yong Zhou
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Agricultural College of Yangzhou University, Yangzhou 225009, China; Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China
| | - Chenwu Xu
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Agricultural College of Yangzhou University, Yangzhou 225009, China; Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China.
| | - Jinling Huang
- Department of Biology, East Carolina University, Greenville, NC 28590, USA; State Key Laboratory of Crop Stress Adaptation and Improvement, Key Laboratory of Plant Stress Biology, School of Life Sciences, Henan University, Kaifeng 475004, China; Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China.
| | - Zefeng Yang
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Agricultural College of Yangzhou University, Yangzhou 225009, China; Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China.
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Zhang HH, Peccoud J, Xu MRX, Zhang XG, Gilbert C. Horizontal transfer and evolution of transposable elements in vertebrates. Nat Commun 2020; 11:1362. [PMID: 32170101 PMCID: PMC7070016 DOI: 10.1038/s41467-020-15149-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 02/20/2020] [Indexed: 11/13/2022] Open
Abstract
Horizontal transfer of transposable elements (HTT) is an important process shaping eukaryote genomes, yet very few studies have quantified this phenomenon on a large scale or have evaluated the selective constraints acting on transposable elements (TEs) during vertical and horizontal transmission. Here we screen 307 vertebrate genomes and infer a minimum of 975 independent HTT events between lineages that diverged more than 120 million years ago. HTT distribution greatly differs from null expectations, with 93.7% of these transfers involving ray-finned fishes and less than 3% involving mammals and birds. HTT incurs purifying selection (conserved protein evolution) on all TEs, confirming that producing functional transposition proteins is required for a TE to invade new genomes. In the absence of HTT, DNA transposons appear to evolve neutrally within genomes, unlike most retrotransposons, which evolve under purifying selection. This selection regime indicates that proteins of most retrotransposon families tend to process their own encoding RNA (cis-preference), which helps retrotransposons to persist within host lineages over long time periods. Horizontal transfer (HT) and evolution of transposable elements (TEs) has rarely been quantified on a large scale. Here, the authors screen 307 vertebrate genomes and infer 975 HT events (93% in ray-finned fishes); all TEs involved in HT evolve within genomes under purifying selection, as do most retrotransposons.
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Affiliation(s)
- Hua-Hao Zhang
- College of Pharmacy and Life Science, Jiujiang University, 332000, Jiujiang, China
| | - Jean Peccoud
- UMR CNRS 7267 Ecologie et Biologie des Interactions, Equipe Ecologie Evolution Symbiose, Université de Poitiers, 86073, Poitiers, France
| | - Min-Rui-Xuan Xu
- College of Pharmacy and Life Science, Jiujiang University, 332000, Jiujiang, China
| | - Xiao-Gu Zhang
- College of Pharmacy and Life Science, Jiujiang University, 332000, Jiujiang, China.
| | - Clément Gilbert
- Laboratoire Evolution, Génomes, Comportement, Écologie, UMR 9191 CNRS, UMR 247 IRD, Université Paris-Saclay, 91198, Gif-sur-Yvette, France.
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Olofsson JK, Dunning LT, Lundgren MR, Barton HJ, Thompson J, Cuff N, Ariyarathne M, Yakandawala D, Sotelo G, Zeng K, Osborne CP, Nosil P, Christin PA. Population-Specific Selection on Standing Variation Generated by Lateral Gene Transfers in a Grass. Curr Biol 2019; 29:3921-3927.e5. [DOI: 10.1016/j.cub.2019.09.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 09/06/2019] [Accepted: 09/10/2019] [Indexed: 12/26/2022]
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Paštová L, Belyayev A, Mahelka V. Molecular cytogenetic characterisation of Elytrigia ×mucronata, a natural hybrid of E. intermedia and E. repens (Triticeae, Poaceae). BMC PLANT BIOLOGY 2019; 19:230. [PMID: 31151385 PMCID: PMC6544950 DOI: 10.1186/s12870-019-1806-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 04/26/2019] [Indexed: 05/18/2023]
Abstract
BACKGROUND Interspecific hybridisation resulting in polyploidy is one of the major driving forces in plant evolution. Here, we present data from the molecular cytogenetic analysis of three cytotypes of Elytrigia ×mucronata using sequential fluorescence (5S rDNA, 18S rDNA and pSc119.2 probes) and genomic in situ hybridisation (four genomic probes of diploid taxa, i.e., Aegilops, Dasypyrum, Hordeum and Pseudoroegneria). RESULTS The concurrent presence of Hordeum (descended from E. repens) and Dasypyrum + Aegilops (descended from E. intermedia) chromosome sets in all cytotypes of E. ×mucronata confirmed the assumed hybrid origin of the analysed plants. The following different genomic constitutions were observed for E. ×mucronata. Hexaploid plants exhibited three chromosome sets from Pseudoroegneria and one chromosome set each from Aegilops, Hordeum and Dasypyrum. Heptaploid plants harboured the six chromosome sets of the hexaploid plants and an additional Pseudoroegneria chromosome set. Nonaploid cytotypes differed in their genomic constitutions, reflecting different origins through the fusion of reduced and unreduced gametes. The hybridisation patterns of repetitive sequences (5S rDNA, 18S rDNA, and pSc119.2) in E. ×mucronata varied between and within cytotypes. Chromosome alterations that were not identified in the parental species were found in both heptaploid and some nonaploid plants. CONCLUSIONS The results confirmed that both homoploid hybridisation and heteroploid hybridisation that lead to the coexistence of four different haplomes within single hybrid genomes occur in Elytrigia allopolyploids. The chromosomal alterations observed in both heptaploid and some nonaploid plants indicated that genome restructuring occurs during and/or after the hybrids arose. Moreover, a specific chromosomal translocation detected in one of the nonaploids indicated that it was not a primary hybrid. Therefore, at least some of the hybrids are fertile. Hybridisation in Triticeae allopolyploids clearly and significantly contributes to genomic diversity. Different combinations of parental haplomes coupled with chromosomal alterations may result in the establishment of unique lineages, thus providing raw material for selection.
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Affiliation(s)
- Ladislava Paštová
- Institute of Botany, Czech Academy of Sciences, Zámek 1, 252 43 Průhonice, Czech Republic
- Department of Botany, Charles University, Benátská 2, 128 01 Prague, Czech Republic
| | - Alexander Belyayev
- Institute of Botany, Czech Academy of Sciences, Zámek 1, 252 43 Průhonice, Czech Republic
| | - Václav Mahelka
- Institute of Botany, Czech Academy of Sciences, Zámek 1, 252 43 Průhonice, Czech Republic
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Cusimano N, Renner SS. Sequential horizontal gene transfers from different hosts in a widespread Eurasian parasitic plant, Cynomorium coccineum. AMERICAN JOURNAL OF BOTANY 2019; 106:679-689. [PMID: 31081928 DOI: 10.1002/ajb2.1286] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 03/19/2019] [Indexed: 06/09/2023]
Abstract
PREMISE Parasitic plants with large geographic ranges, and different hosts in parts of their range, may acquire horizontally transferred genes (HGTs), which might sometimes leave a footprint of gradual host and range expansion. Cynomorium coccineum, the only member of the Saxifragales family Cynomoriaceae, is a root holoparasite that occurs in water-stressed habitats from western China to the Canary Islands. It parasitizes at least 10 angiosperm families from different orders, some of them only in parts of its range. This parasite therefore offers an opportunity to trace HGTs as long as parasite-host pairs can be obtained and sequenced. METHODS By sequencing mitochondrial, plastid, and nuclear loci from parasite-host pairs from throughout the parasite's range and with prior information from completely assembled mitochondrial and plastid genomes, we detected 10 HGTs of five mitochondrial genes. RESULTS The 10 HGTs appear to have occurred sequentially as C. coccineum expanded from East to West. Molecular-clock models yield Cynomorium stem ages between 66 and 156 Myr, with relaxed clocks converging on 66-67 Myr. Chinese Sapindales, probably Nitraria, were the first source of transferred genes, followed by Iranian and Mediterranean Caryophyllales. The most recently acquired gene appears to come from a Tamarix host in the Iberian Peninsula. CONCLUSIONS Data on HGTs that have accumulated over the past 15 years, along with this discovery of multiple HGTs within a single widespread species, underline the need for more whole-genome data from parasite-host pairs to investigate whether and how transferred copies coexist with, or replace, native functional genes.
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Affiliation(s)
- Natalie Cusimano
- Systematic Botany and Mycology, Faculty of Biology, University of Munich (LMU), Munich, Germany
| | - Susanne S Renner
- Systematic Botany and Mycology, Faculty of Biology, University of Munich (LMU), Munich, Germany
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Abstract
A fundamental tenet of multicellular eukaryotic evolution is that vertical inheritance is paramount, with natural selection acting on genetic variants transferred from parents to offspring. This lineal process means that an organism's adaptive potential can be restricted by its evolutionary history, the amount of standing genetic variation, and its mutation rate. Lateral gene transfer (LGT) theoretically provides a mechanism to bypass many of these limitations, but the evolutionary importance and frequency of this process in multicellular eukaryotes, such as plants, remains debated. We address this issue by assembling a chromosome-level genome for the grass Alloteropsis semialata, a species surmised to exhibit two LGTs, and screen it for other grass-to-grass LGTs using genomic data from 146 other grass species. Through stringent phylogenomic analyses, we discovered 57 additional LGTs in the A. semialata nuclear genome, involving at least nine different donor species. The LGTs are clustered in 23 laterally acquired genomic fragments that are up to 170 kb long and have accumulated during the diversification of Alloteropsis. The majority of the 59 LGTs in A. semialata are expressed, and we show that they have added functions to the recipient genome. Functional LGTs were further detected in the genomes of five other grass species, demonstrating that this process is likely widespread in this globally important group of plants. LGT therefore appears to represent a potent evolutionary force capable of spreading functional genes among distantly related grass species.
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Catoni M, Noris E, Vaira AM, Jonesman T, Matić S, Soleimani R, Behjatnia SAA, Vinals N, Paszkowski J, Accotto GP. Virus-mediated export of chromosomal DNA in plants. Nat Commun 2018; 9:5308. [PMID: 30546019 PMCID: PMC6293997 DOI: 10.1038/s41467-018-07775-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 11/23/2018] [Indexed: 11/09/2022] Open
Abstract
The propensity of viruses to acquire genetic material from relatives and possibly from infected hosts makes them excellent candidates as vectors for horizontal gene transfer. However, virus-mediated acquisition of host genetic material, as deduced from historical events, appears to be rare. Here, we report spontaneous and surprisingly efficient generation of hybrid virus/host DNA molecules in the form of minicircles during infection of Beta vulgaris by Beet curly top Iran virus (BCTIV), a single-stranded DNA virus. The hybrid minicircles replicate, become encapsidated into viral particles, and spread systemically throughout infected plants in parallel with the viral infection. Importantly, when co-infected with BCTIV, B. vulgaris DNA captured in minicircles replicates and is transcribed in other plant species that are sensitive to BCTIV infection. Thus, we have likely documented in real time the initial steps of a possible path of virus-mediated horizontal transfer of chromosomal DNA between plant species.
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Affiliation(s)
- Marco Catoni
- The Sainsbury Laboratory, University of Cambridge, Cambridge, CB2 1LR, UK
- School of Biosciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Emanuela Noris
- Institute for Sustainable Plant Protection, National Research Council of Italy, Torino, 10135, Italy
| | - Anna Maria Vaira
- Institute for Sustainable Plant Protection, National Research Council of Italy, Torino, 10135, Italy
| | - Thomas Jonesman
- The Sainsbury Laboratory, University of Cambridge, Cambridge, CB2 1LR, UK
| | - Slavica Matić
- Institute for Sustainable Plant Protection, National Research Council of Italy, Torino, 10135, Italy
| | - Reihaneh Soleimani
- Plant Virology Research Center, College of Agriculture, Shiraz University, Shiraz, 71441-65186, Iran
- Department of Plant Protection, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, 81595-158, Iran
| | - Seyed Ali Akbar Behjatnia
- Plant Virology Research Center, College of Agriculture, Shiraz University, Shiraz, 71441-65186, Iran
| | - Nestor Vinals
- Institute for Sustainable Plant Protection, National Research Council of Italy, Torino, 10135, Italy
| | - Jerzy Paszkowski
- The Sainsbury Laboratory, University of Cambridge, Cambridge, CB2 1LR, UK
| | - Gian Paolo Accotto
- Institute for Sustainable Plant Protection, National Research Council of Italy, Torino, 10135, Italy.
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Rodionov AV, Dobryakova KS, Punina EO. Polymorphic Sites in ITS1-5.8S rDNA-ITS2 Region in Hybridogenic Genus × Elyhordeum and Putative Interspecific Hybrids Elymus (Poaceae: Triticeae). RUSS J GENET+ 2018. [DOI: 10.1134/s1022795418090120] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Schmickl R, Marburger S, Bray S, Yant L. Hybrids and horizontal transfer: introgression allows adaptive allele discovery. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:5453-5470. [PMID: 29096001 DOI: 10.1093/jxb/erx297] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Evolution has devised countless remarkable solutions to diverse challenges. Understanding the mechanistic basis of these solutions provides insights into how biological systems can be subtly tweaked without maladaptive consequences. The knowledge gained from illuminating these mechanisms is equally important to our understanding of fundamental evolutionary mechanisms as it is to our hopes of developing truly rational plant breeding and synthetic biology. In particular, modern population genomic approaches are proving very powerful in the detection of candidate alleles for mediating consequential adaptations that can be tested functionally. Especially striking are signals gained from contexts involving genetic transfers between populations, closely related species, or indeed between kingdoms. Here we discuss two major classes of these scenarios, adaptive introgression and horizontal gene flow, illustrating discoveries made across kingdoms.
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Affiliation(s)
- Roswitha Schmickl
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, 252 43 Průhonice, Czech Republic
- Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, 128 01 Prague, Czech Republic
| | - Sarah Marburger
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom
| | - Sian Bray
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom
| | - Levi Yant
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom
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