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Xavier A, Yadav R, Gowda V. Evolutionary patterns of variations in chromosome counts and genome sizes show positive correlations with taxonomic diversity in tropical gingers. AMERICAN JOURNAL OF BOTANY 2024; 111:e16334. [PMID: 38825815 DOI: 10.1002/ajb2.16334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 04/16/2024] [Accepted: 04/17/2024] [Indexed: 06/04/2024]
Abstract
PREMISE Cytogenetic traits such as an organism's chromosome number and genome size are taxonomically critical as they are instrumental in defining angiosperm diversity. Variations in these traits can be traced to evolutionary processes such as polyploidization, although geographic variations across cytogenetic traits remain underexplored. In the pantropical monocot family Zingiberaceae (~1500 species), cytogenetic traits have been well documented; however, the role of these traits in shaping taxonomic diversity and biogeographic patterns of gingers is not known. METHODS A time-calibrated Bayesian phylogenetic tree was constructed for 290 taxa covering three of the four subfamilies in Zingiberaceae. We tested models of chromosome number and genome size evolution within the family and whether lineage age, taxonomic diversity, and distributional range explain the variations in the cytogenetic traits. Tests were carried out at two taxonomic ranks: within Zingiberaceae and within genus Hedychium using correlations, generalized linear models and phylogenetic least square models. RESULTS The most frequent changes in chromosome number within Zingiberaceae were noted to be demi-polyploidization and polyploidization (~57% of the time), followed by ascending dysploidy (~27%). The subfamily Zingiberoideae showed descending dysploidy at its base, while Alpinioideae showed polyploidization at its internal nodes. Although chromosome counts and genome sizes did not corroborate with each other, suggesting that they are not equivalent; higher chromosome number variations and higher genome size variations were associated with higher taxonomic diversity and wider biogeographic distribution. CONCLUSIONS Within Zingiberaceae, multiple incidences of polyploidization were discovered, and cytogenetic events appear to have reduced the genome sizes and increased taxonomic diversity, distributional ranges and invasiveness.
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Affiliation(s)
- Aleena Xavier
- Tropical Ecology and Evolution (TrEE) Lab, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Bhopal, 462066, Madhya Pradesh, India
| | - Ritu Yadav
- Tropical Ecology and Evolution (TrEE) Lab, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Bhopal, 462066, Madhya Pradesh, India
| | - Vinita Gowda
- Tropical Ecology and Evolution (TrEE) Lab, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Bhopal, 462066, Madhya Pradesh, India
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2
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Barker MS, Jiao Y, Glennon KL. Doubling down on polyploid discoveries: Global advances in genomics and ecological impacts of polyploidy. AMERICAN JOURNAL OF BOTANY 2024; 111:e16395. [PMID: 39164922 DOI: 10.1002/ajb2.16395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2024] [Accepted: 08/06/2024] [Indexed: 08/22/2024]
Abstract
All flowering plants are now recognized as diploidized paleopolyploids (Jiao et al., 2011; One Thousand Plant Transcriptomes Initiative, 2019), and polyploid species comprise approximately 30% of contemporary plant species (Wood et al., 2009; Barker et al., 2016a). A major implication of these discoveries is that, to appreciate the evolution of plant diversity, we need to understand the fundamental biology of polyploids and diploidization. This need is broadly recognized by our community as there is a continued, growing interest in polyploidy as a research topic. Over the past 25 years, the sequencing and analysis of plant genomes has revolutionized our understanding of the importance of polyploid speciation to the evolution of land plants.
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Affiliation(s)
- Michael S Barker
- Department of Ecology & Evolutionary Biology, University of Arizona, Tucson, 85721, AZ, USA
| | - Yuannian Jiao
- State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Kelsey L Glennon
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa
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3
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Goulet-Scott BE, Farnitano MC, Brown ALM, Hale CO, Blumstein M, Hopkins R. A multidimensional selective landscape drives adaptive divergence between and within closely related Phlox species. Nat Commun 2024; 15:4661. [PMID: 38821972 PMCID: PMC11143288 DOI: 10.1038/s41467-024-49075-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 05/20/2024] [Indexed: 06/02/2024] Open
Abstract
Selection causes local adaptation across populations within species and simultaneously divergence between species. However, it is unclear if either the force of or the response to selection is similar across these scales. We show that natural selection drives divergence between closely related species in a pattern that is distinct from local adaptation within species. We use reciprocal transplant experiments across three species of Phlox wildflowers to characterize widespread adaptive divergence. Using provenance trials, we also find strong local adaptation between populations within a species. Comparing divergence and selection between these two scales of diversity we discover that one suite of traits predicts fitness differences between species and that an independent suite of traits predicts fitness variation within species. Selection drives divergence between species, contributing to speciation, while simultaneously favoring extensive diversity that is maintained across populations within a species. Our work demonstrates how the selection landscape is complex and multidimensional.
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Affiliation(s)
- Benjamin E Goulet-Scott
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
- Harvard Forest, Harvard University, Petersham, MA, 01366, USA
| | - Matthew C Farnitano
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
- Department of Genetics, University of Georgia, Athens, GA, 30602, USA
| | - Andrea L M Brown
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
- Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA, 94720, USA
| | - Charles O Hale
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
- Institute for Genomic Diversity, Cornell University, Ithaca, NY, 14853, USA
| | - Meghan Blumstein
- Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Robin Hopkins
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA.
- Arnold Arboretum of Harvard University, Boston, MA, 02131, USA.
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4
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Kauai F, Bafort Q, Mortier F, Van Montagu M, Bonte D, Van de Peer Y. Interspecific transfer of genetic information through polyploid bridges. Proc Natl Acad Sci U S A 2024; 121:e2400018121. [PMID: 38748576 PMCID: PMC11126971 DOI: 10.1073/pnas.2400018121] [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: 01/01/2024] [Accepted: 04/15/2024] [Indexed: 05/27/2024] Open
Abstract
Hybridization blurs species boundaries and leads to intertwined lineages resulting in reticulate evolution. Polyploidy, the outcome of whole genome duplication (WGD), has more recently been implicated in promoting and facilitating hybridization between polyploid species, potentially leading to adaptive introgression. However, because polyploid lineages are usually ephemeral states in the evolutionary history of life it is unclear whether WGD-potentiated hybridization has any appreciable effect on their diploid counterparts. Here, we develop a model of cytotype dynamics within mixed-ploidy populations to demonstrate that polyploidy can in fact serve as a bridge for gene flow between diploid lineages, where introgression is fully or partially hampered by the species barrier. Polyploid bridges emerge in the presence of triploid organisms, which despite critically low levels of fitness, can still allow the transfer of alleles between diploid states of independently evolving mixed-ploidy species. Notably, while marked genetic divergence prevents polyploid-mediated interspecific gene flow, we show that increased recombination rates can offset these evolutionary constraints, allowing a more efficient sorting of alleles at higher-ploidy levels before introgression into diploid gene pools. Additionally, we derive an analytical approximation for the rate of gene flow at the tetraploid level necessary to supersede introgression between diploids with nonzero introgression rates, which is especially relevant for plant species complexes, where interspecific gene flow is ubiquitous. Altogether, our results illustrate the potential impact of polyploid bridges on the (re)distribution of genetic material across ecological communities during evolution, representing a potential force behind reticulation.
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Affiliation(s)
- Felipe Kauai
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Gent9052, Belgium
- Center for Plant Systems Biology, Bioinformatics and Evolutionary Genomics, VIB, Gent9052, Belgium
- Department of Biology, Terrestrial Ecology Unit, Ghent University, Gent9000, Belgium
| | - Quinten Bafort
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Gent9052, Belgium
- Center for Plant Systems Biology, Bioinformatics and Evolutionary Genomics, VIB, Gent9052, Belgium
| | - Frederik Mortier
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Gent9052, Belgium
- Center for Plant Systems Biology, Bioinformatics and Evolutionary Genomics, VIB, Gent9052, Belgium
- Department of Biology, Terrestrial Ecology Unit, Ghent University, Gent9000, Belgium
| | - Marc Van Montagu
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Gent9052, Belgium
- Center for Plant Systems Biology, Bioinformatics and Evolutionary Genomics, VIB, Gent9052, Belgium
| | - Dries Bonte
- Department of Biology, Terrestrial Ecology Unit, Ghent University, Gent9000, Belgium
| | - Yves Van de Peer
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Gent9052, Belgium
- Center for Plant Systems Biology, Bioinformatics and Evolutionary Genomics, VIB, Gent9052, Belgium
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria0028, South Africa
- College of Horticulture, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing210095, China
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Chumová Z, Monier Z, Šemberová K, Havlíčková E, Euston-Brown D, Muasya AM, Bergh NG, Trávníček P. Diploid and tetraploid cytotypes of the flagship Cape species Dicerothamnus rhinocerotis (Asteraceae): variation in distribution, ecological niche, morphology and genetics. ANNALS OF BOTANY 2024; 133:851-870. [PMID: 37410810 PMCID: PMC11082512 DOI: 10.1093/aob/mcad084] [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: 04/29/2023] [Accepted: 07/04/2023] [Indexed: 07/08/2023]
Abstract
BACKGROUND AND AIMS The Greater Cape Floristic Region is one of the world's biodiversity hotspots and is considered poor in polyploids. To test this assumption, ploidy variation was investigated in a widespread Cape shrub, Dicerothamnus rhinocerotis (renosterbos, Asteraceae). The aim was to elucidate the cytotype distribution and population composition across the species range, and to assess differences in morphology, environmental niches and genetics. METHODS Ploidy level and genome size were determined via flow cytometry and cytotype assignment was confirmed by chromosome counting. Restriction site-associated DNA sequencing (RADseq) analyses were used to infer genetic relationships. Cytotype climatic and environmental niches were compared using a range of environmental layers and a soil model, while morphological differences were examined using multivariate methods. KEY RESULTS The survey of 171 populations and 2370 individuals showed that the species comprises diploid and tetraploid cytotypes, no intermediates and only 16.8 % of mixed populations. Mean 2C values were 1.80-2.06 pg for diploids and 3.48-3.80 pg for tetraploids, with very similar monoploid genome sizes. Intra-cytotype variation showed a significant positive correlation with altitude and longitude in both cytotypes and with latitude in diploids. Although niches of both cytotypes were highly equivalent and similar, their optima and breadth were shifted due to differences mainly in isothermality and available water capacity. Morphometric analyses showed significant differences in the leaves and corolla traits, the number of florets per capitulum, and cypsela dimensions between the two cytotypes. Genetic analyses revealed four groups, three of them including both cytotypes. CONCLUSIONS Dicerothamnus rhinocerotis includes two distinct cytotypes that are genetically similar. While tetraploids arise several times independently within different genetic groups, morphological and ecological differences are evident between cytotypes. Our results open up new avenues for questions regarding the importance of ploidy in the megadiverse Cape flora, and exemplify the need for population-based studies focused on ploidy variation.
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Affiliation(s)
- Zuzana Chumová
- Institute of Botany of the Czech Academy of Sciences, Zámek 1, Průhonice, 252 43, Czech Republic
| | - Zafar Monier
- Bolus Herbarium, Department of Biological Sciences, University of Cape Town, Cape Town, 7707, South Africa
| | - Kristýna Šemberová
- Institute of Botany of the Czech Academy of Sciences, Zámek 1, Průhonice, 252 43, Czech Republic
| | - Eliška Havlíčková
- Institute of Botany of the Czech Academy of Sciences, Zámek 1, Průhonice, 252 43, Czech Republic
- Department of Botany, Faculty of Science, Charles University, Benátská 2, Prague, 120 00, Czech Republic
| | | | - A Muthama Muasya
- Bolus Herbarium, Department of Biological Sciences, University of Cape Town, Cape Town, 7707, South Africa
| | - Nicola G Bergh
- Bolus Herbarium, Department of Biological Sciences, University of Cape Town, Cape Town, 7707, South Africa
- The Compton Herbarium, Kirstenbosch National Botanical Gardens, Cape Town, 7735, South Africa
| | - Pavel Trávníček
- Institute of Botany of the Czech Academy of Sciences, Zámek 1, Průhonice, 252 43, Czech Republic
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Wefferling KM, Castro M, Castro S, Holmlund H, Loureiro J, Rothfels CJ, Schuettpelz E. Polyploid goldback and silverback ferns (Pentagramma) occupy a wider, colder, and wetter bioclimatic niche than diploid counterparts. AMERICAN JOURNAL OF BOTANY 2024; 111:e16305. [PMID: 38517199 DOI: 10.1002/ajb2.16305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 01/22/2024] [Accepted: 01/22/2024] [Indexed: 03/23/2024]
Abstract
PREMISE The western North American fern genus Pentagramma (Pteridaceae) is characterized by complex patterns of ploidy variation, an understanding of which is critical to comprehending both the evolutionary processes within the genus and its current diversity. METHODS We undertook a cytogeographic study across the range of the genus, using a combination of chromosome counts and flow cytometry to infer ploidy level. Bioclimatic variables and elevation were used to compare niches. RESULTS We found that diploids and tetraploids are common and widespread, and triploids are rare and sporadic; in contrast with genome size inferences in earlier studies, no hexaploids were found. Diploids and tetraploids show different geographic ranges: only tetraploids were found in the northernmost portion of the range (Washington, Oregon, and British Columbia) and only diploids were found in the Sierra Nevada of California. Diploid, triploid, and tetraploid cytotypes were found to co-occur in relatively few localities: in the southern (San Diego County, California) and desert Southwest (Arizona) parts of the range, and along the Pacific Coast of California. CONCLUSIONS Tetraploids occupy a wider bioclimatic niche than diploids both within P. triangularis and at the genus-wide scale. It is unknown whether the wider niche of tetraploids is due to their expansion upon the diploid niche, if diploids have contracted their niche due to competition or changing abiotic conditions, or if this wider niche occupancy is due to multiple origins of tetraploids.
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Affiliation(s)
- Keir M Wefferling
- Department of Biology, Gary A. Fewless Herbarium, Cofrin Center for Biodiversity, University of Wisconsin-Green Bay, Green Bay, 54311, Wisconsin, USA
| | - Mariana Castro
- Department of Life Sciences, Centre for Functional Ecology, University of Coimbra, Coimbra, Portugal
| | - Sílvia Castro
- Department of Life Sciences, Centre for Functional Ecology, University of Coimbra, Coimbra, Portugal
| | - Helen Holmlund
- Natural Science Division, Pepperdine University, Malibu, 90263, California, USA
| | - João Loureiro
- Department of Life Sciences, Centre for Functional Ecology, University of Coimbra, Coimbra, Portugal
| | - Carl J Rothfels
- Department of Biology, Ecology Center, and Intermountain Herbarium, Utah State University, Logan, 84322, Utah, USA
| | - Eric Schuettpelz
- Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington, 20560, DC, USA
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7
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Busoms S, Fischer S, Yant L. Chasing the mechanisms of ecologically adaptive salinity tolerance. PLANT COMMUNICATIONS 2023; 4:100571. [PMID: 36883005 PMCID: PMC10721451 DOI: 10.1016/j.xplc.2023.100571] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 02/12/2023] [Accepted: 03/03/2023] [Indexed: 06/18/2023]
Abstract
Plants adapted to challenging environments offer fascinating models of evolutionary change. Importantly, they also give information to meet our pressing need to develop resilient, low-input crops. With mounting environmental fluctuation-including temperature, rainfall, and soil salinity and degradation-this is more urgent than ever. Happily, solutions are hiding in plain sight: the adaptive mechanisms from natural adapted populations, once understood, can then be leveraged. Much recent insight has come from the study of salinity, a widespread factor limiting productivity, with estimates of 20% of all cultivated lands affected. This is an expanding problem, given increasing climate volatility, rising sea levels, and poor irrigation practices. We therefore highlight recent benchmark studies of ecologically adaptive salt tolerance in plants, assessing macro- and microevolutionary mechanisms, and the recently recognized role of ploidy and the microbiome on salinity adaptation. We synthesize insight specifically on naturally evolved adaptive salt-tolerance mechanisms, as these works move substantially beyond traditional mutant or knockout studies, to show how evolution can nimbly "tweak" plant physiology to optimize function. We then point to future directions to advance this field that intersect evolutionary biology, abiotic-stress tolerance, breeding, and molecular plant physiology.
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Affiliation(s)
- Silvia Busoms
- Plant Physiology Laboratory, Bioscience Faculty, Universitat Autònoma de Barcelona, Bellaterra, Barcelona E-08193, Spain
| | - Sina Fischer
- Future Food Beacon of Excellence, University of Nottingham, Nottingham NG7 2RD, UK; School of Biosciences, University of Nottingham, Nottingham NG7 2RD, UK
| | - Levi Yant
- Future Food Beacon of Excellence, University of Nottingham, Nottingham NG7 2RD, UK; School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK.
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8
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Schvarzstein M, Alam F, Toure M, Yanowitz JL. An Emerging Animal Model for Querying the Role of Whole Genome Duplication in Development, Evolution, and Disease. J Dev Biol 2023; 11:26. [PMID: 37367480 PMCID: PMC10299280 DOI: 10.3390/jdb11020026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 05/23/2023] [Accepted: 06/01/2023] [Indexed: 06/28/2023] Open
Abstract
Whole genome duplication (WGD) or polyploidization can occur at the cellular, tissue, and organismal levels. At the cellular level, tetraploidization has been proposed as a driver of aneuploidy and genome instability and correlates strongly with cancer progression, metastasis, and the development of drug resistance. WGD is also a key developmental strategy for regulating cell size, metabolism, and cellular function. In specific tissues, WGD is involved in normal development (e.g., organogenesis), tissue homeostasis, wound healing, and regeneration. At the organismal level, WGD propels evolutionary processes such as adaptation, speciation, and crop domestication. An essential strategy to further our understanding of the mechanisms promoting WGD and its effects is to compare isogenic strains that differ only in their ploidy. Caenorhabditis elegans (C. elegans) is emerging as an animal model for these comparisons, in part because relatively stable and fertile tetraploid strains can be produced rapidly from nearly any diploid strain. Here, we review the use of Caenorhabditis polyploids as tools to understand important developmental processes (e.g., sex determination, dosage compensation, and allometric relationships) and cellular processes (e.g., cell cycle regulation and chromosome dynamics during meiosis). We also discuss how the unique characteristics of the C. elegans WGD model will enable significant advances in our understanding of the mechanisms of polyploidization and its role in development and disease.
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Affiliation(s)
- Mara Schvarzstein
- Biology Department, Brooklyn College at the City University of New York, Brooklyn, NY 11210, USA
- Biology Department, The Graduate Center at the City University of New York, New York, NY 10016, USA
- Biochemistry Department, The Graduate Center at the City University of New York, New York, NY 10016, USA
| | - Fatema Alam
- Biology Department, Brooklyn College at the City University of New York, Brooklyn, NY 11210, USA
| | - Muhammad Toure
- Biology Department, Brooklyn College at the City University of New York, Brooklyn, NY 11210, USA
| | - Judith L. Yanowitz
- Magee-Womens Research Institute, Pittsburgh, PA 15213, USA;
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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Kauai F, Mortier F, Milosavljevic S, Van de Peer Y, Bonte D. Neutral processes underlying the macro eco-evolutionary dynamics of mixed-ploidy systems. Proc Biol Sci 2023; 290:20222456. [PMID: 36946113 PMCID: PMC10031433 DOI: 10.1098/rspb.2022.2456] [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: 12/08/2022] [Accepted: 02/24/2023] [Indexed: 03/23/2023] Open
Abstract
Polyploidy, i.e. the occurrence of multiple sets of chromosomes, is regarded as an important phenomenon in plant ecology and evolution, with all flowering plants likely having a polyploid ancestry. Owing to genome shock, minority cytotype exclusion and reduced fertility, polyploids emerging in diploid populations are expected to face significant challenges to successful establishment. Their establishment and persistence are often explained by possible fitness or niche differences that would relieve the competitive pressure with diploid progenitors. Experimental evidence for such advantages is, however, not unambiguous, and considerable niche overlap exists among most polyploid species and their diploid counterparts. Here, we develop a neutral spatially explicit eco-evolutionary model to understand whether neutral processes can explain the eco-evolutionary patterns of polyploids. We present a general mechanism for polyploid establishment by showing that sexually reproducing organisms assemble in space in an iterative manner, reducing frequency-dependent mating disadvantages and overcoming potential reduced fertility issues. Moreover, we construct a mechanistic theoretical framework that allows us to understand the long-term evolution of mixed-ploidy populations and show that our model is remarkably consistent with recent phylogenomic estimates of species extinctions in the Brassicaceae family.
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Affiliation(s)
- Felipe Kauai
- Department of Biology, Terrestrial Ecology Unit, Ghent University, BE-9000 Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, BE-9000 Ghent, Belgium
- Center for Plant Systems Biology, VIB, B-9052 Ghent, Belgium
| | - Frederik Mortier
- Department of Biology, Terrestrial Ecology Unit, Ghent University, BE-9000 Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, BE-9000 Ghent, Belgium
- Center for Plant Systems Biology, VIB, B-9052 Ghent, Belgium
| | - Silvija Milosavljevic
- Department of Biology, Terrestrial Ecology Unit, Ghent University, BE-9000 Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, BE-9000 Ghent, Belgium
- Center for Plant Systems Biology, VIB, B-9052 Ghent, Belgium
| | - Yves Van de Peer
- Department of Plant Biotechnology and Bioinformatics, Ghent University, BE-9000 Ghent, Belgium
- Center for Plant Systems Biology, VIB, B-9052 Ghent, Belgium
- Center for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0002, South Africa
- College of Horticulture, Nanjing Agricultural University, Nanjing 210095, People's Republic of China
| | - Dries Bonte
- Department of Biology, Terrestrial Ecology Unit, Ghent University, BE-9000 Ghent, Belgium
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10
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Šemberová K, Svitok M, Marhold K, Suda J, Schmickl RE. Morphological and environmental differentiation as prezygotic reproductive barriers between parapatric and allopatric Campanula rotundifolia agg. cytotypes. ANNALS OF BOTANY 2023; 131:71-86. [PMID: 34559179 PMCID: PMC9904352 DOI: 10.1093/aob/mcab123] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 09/21/2021] [Indexed: 05/25/2023]
Abstract
BACKGROUND AND AIMS Reproductive isolation and local establishment are necessary for plant speciation. Polyploidy, the possession of more than two complete chromosome sets, creates a strong postzygotic reproductive barrier between diploid and tetraploid cytotypes. However, this barrier weakens between polyploids (e.g. tetraploids and hexaploids). Reproductive isolation may be enhanced by cytotype morphological and environmental differentiation. Moreover, morphological adaptations to local conditions contribute to plant establishment. However, the relative contributions of ploidy level and the environment to morphology have generally been neglected. Thus, the extent of morphological variation driven by ploidy level and the environment was modelled for diploid, tetraploid and hexaploid cytotypes of Campanula rotundifolia agg. Cytotype distribution was updated, and morphological and environmental differentiation was tested in the presence and absence of natural contact zones. METHODS Cytotype distribution was assessed from 231 localities in Central Europe, including 48 localities with known chromosome counts, using flow cytometry. Differentiation in environmental niche and morphology was tested for cytotype pairs using discriminant analyses. A structural equation model was used to explore the synergies between cytotype, environment and morphology. KEY RESULTS Tremendous discrepancies were revealed between the reported and detected cytotype distribution. Neither mixed-ploidy populations nor interploidy hybrids were detected in the contact zones. Diploids had the broadest environmental niche, while hexaploids had the smallest and specialized niche. Hexaploids and spatially isolated cytotype pairs differed morphologically, including allopatric tetraploids. While leaf and shoot morphology were influenced by environmental conditions and polyploidy, flower morphology depended exclusively on the cytotype. CONCLUSIONS Reproductive isolation mechanisms vary between cytotypes. While diploids and polyploids are isolated postzygotically, the environmental niche shift is essential between higher polyploids. The impact of polyploidy and the environment on plant morphology implies the adaptive potential of polyploids, while the exclusive relationship between flower morphology and cytotype highlights the role of polyploidy in reproductive isolation.
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Affiliation(s)
| | - Marek Svitok
- Faculty of Ecology and Environmental Sciences, Technical University in Zvolen, T. G. Masaryka, Zvolen, Slovakia
- Faculty of Science, Department of Ecosystem Biology, University of South Bohemia, Branišovská, České Budějovice, Czech Republic
| | - Karol Marhold
- Faculty of Science, Department of Botany, Charles University, Benátská, Prague, Czech Republic
- Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Dúbravská cesta, Bratislava, Slovakia
| | | | - Roswitha E Schmickl
- Faculty of Science, Department of Botany, Charles University, Benátská, Prague, Czech Republic
- Czech Academy of Sciences, Institute of Botany, Department of Evolutionary Plant Biology, Zámek, Průhonice, Czech Republic
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11
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Zhong DL, Li YC, Zhang JQ. Allopolyploid origin and niche expansion of Rhodiola integrifolia (Crassulaceae). PLANT DIVERSITY 2023; 45:36-44. [PMID: 36876317 PMCID: PMC9975476 DOI: 10.1016/j.pld.2022.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 08/18/2022] [Accepted: 08/19/2022] [Indexed: 06/18/2023]
Abstract
Polyploidy after hybridization between species can lead to immediate post-zygotic isolation, causing saltatory origin of new species. Although the incidence of polyploidization in plants is high, it is thought that a new polyploid lineage can succeed only if it establishes a new ecological niche divergent from its progenitor lineages. We tested the hypothesis that Rhodiola integrifolia from North America is an allopolyploid produced by R. rhodantha and R. rosea and determined whether its survival can be explained by the niche divergence hypothesis. To this end, we sequenced two low-copy nuclear genes (ncpGS and rpb2) in a phylogenetic analysis of 42 Rhodiola species and tested for niche equivalency and similarity using Schoener's D as the index of niche overlap. Our phylogeny-based approach showed that R. integrifolia possesses alleles from both R. rhodantha and R. rosea. Dating analysis showed that the hybridization event that led to R. integrifolia occurred ca. 1.67 Mya and niche modeling analysis showed that at this time, both R. rosea and R. rhodantha may have been present in Beringia, providing the opportunity for the hybridization event. We also found that the niche of R. integrifolia differs from that of its progenitors in both niche breadth and optimum. Taken together, these results confirm the hybrid origin of R. integrifolia and support the niche divergence hypothesis for this tetraploid species. Our results underscore the fact that lineages with no current overlapping distribution could produce hybrid descendants in the past, when climate oscillations made their distributions overlap.
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12
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Kaplenig D, Bertel C, Arc E, Villscheider R, Ralser M, Kolář F, Wos G, Hülber K, Kranner I, Neuner G. Repeated colonization of alpine habitats by Arabidopsis arenosa viewed through freezing resistance and ice management strategies. PLANT BIOLOGY (STUTTGART, GERMANY) 2022; 24:939-949. [PMID: 35833328 PMCID: PMC9804731 DOI: 10.1111/plb.13454] [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: 10/07/2021] [Accepted: 06/15/2022] [Indexed: 05/17/2023]
Abstract
Success or failure of plants to cope with freezing temperatures can critically influence plant distribution and adaptation to new habitats. Especially in alpine environments, frost is a likely major selective force driving adaptation. In Arabidopsis arenosa (L.) Lawalrée, alpine populations have evolved independently in different mountain ranges, enabling studying mechanisms of acclimation and adaptation to alpine environments. We tested for heritable, parallel differentiation in freezing resistance, cold acclimation potential and ice management strategies using eight alpine and eight foothill populations. Plants from three European mountain ranges (Niedere Tauern, Făgăraș and Tatra Mountains) were grown from seeds of tetraploid populations in four common gardens, together with diploid populations from the Tatra Mountains. Freezing resistance was assessed using controlled freezing treatments and measuring effective quantum yield of photosystem II, and ice management strategies by infrared video thermography and cryomicroscopy. The alpine ecotype had a higher cold acclimation potential than the foothill ecotype, whereby this differentiation was more pronounced in tetraploid than diploid populations. However, no ecotypic differentiation was found in one region (Făgăraș), where the ancient lineage had a different evolutionary history. Upon freezing, an ice lens within a lacuna between the palisade and spongy parenchyma tissues was formed by separation of leaf tissues, a mechanism not previously reported for herbaceous species. The dynamic adjustment of freezing resistance to temperature conditions may be particularly important in alpine environments characterized by large temperature fluctuations. Furthermore, the formation of an extracellular ice lens may be a useful strategy to avoid tissue damage during freezing.
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Affiliation(s)
- D. Kaplenig
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
| | - C. Bertel
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
| | - E. Arc
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
| | | | - M. Ralser
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
| | - F. Kolář
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
- Department of BotanyCharles University of PraguePragueCzech Republic
| | - G. Wos
- Department of BotanyCharles University of PraguePragueCzech Republic
| | - K. Hülber
- Department of Botany and Biodiversity ResearchUniversity of ViennaViennaAustria
| | - I. Kranner
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
| | - G. Neuner
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
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13
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Ashokan A, Xavier A, Suksathan P, Ardiyani M, Leong-Škorničková J, Newman M, Kress WJ, Gowda V. Himalayan orogeny and monsoon intensification explain species diversification in an endemic ginger (Hedychium: Zingiberaceae) from the Indo-Malayan Realm. Mol Phylogenet Evol 2022; 170:107440. [PMID: 35192919 DOI: 10.1016/j.ympev.2022.107440] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 02/08/2022] [Accepted: 02/10/2022] [Indexed: 11/26/2022]
Abstract
The Indo-Malayan Realm is a biogeographic realm that extends from the Indian Subcontinent to the islands of Southeast Asia (Malay Archipelago). Despite being megadiverse, evolutionary hypotheses explaining taxonomic diversity in this region have been rare. Here, we investigate the role of geoclimatic events such as Himalayan orogeny and monsoon intensification in the diversification of the ginger-lilies (Hedychium J.Koenig: Zingiberaceae). We first built a comprehensive, time-calibrated phylogeny of Hedychium with 75% taxonomic and geographic sampling. We found that Hedychium is a very young lineage that originated in Northern Indo-Burma, in the Late Miocene (c. 10.6 Ma). This was followed by a late Neogene and early Quaternary diversification, with multiple dispersal events to Southern Indo-Burma, Himalayas, Peninsular India, and the Malay Archipelago. The most speciose clade IV i.e., the predominantly Indo-Burmese clade also showed a higher diversification rate, suggesting its recent rapid radiation. Our divergence dating and GeoHiSSE results demonstrate that the diversification of Hedychium was shaped by both the intensifications in the Himalayan uplift as well as the Asian monsoon. Ancestral character-state reconstructions identified the occurrence of vegetative dormancy in both clades I and II, whereas the strictly epiphytic growth behavior, island dwarfism, lack of dormancy, and a distinct environmental niche were observed only in the predominantly island clade i.e., clade III. Finally, we show that the occurrence of epiphytism in clade III corresponds with submergence due to sea-level changes, suggesting it to be an adaptive trait. Our study highlights the role of recent geoclimatic events and environmental factors in the diversification of plants within the Indo-Malayan Realm and the need for collaborative work to understand biogeographic patterns within this understudied region. This study opens new perspectives for future biogeographic studies in this region and provides a framework to explain the taxonomic hyperdiversity of the Indo-Malayan Realm.
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Affiliation(s)
- Ajith Ashokan
- Tropical Ecology and Evolution (TrEE) Lab, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal, Madhya Pradesh 462066, India.
| | - Aleena Xavier
- Tropical Ecology and Evolution (TrEE) Lab, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal, Madhya Pradesh 462066, India
| | - Piyakaset Suksathan
- Herbarium (QBG), Queen Sirikit Botanic Garden, P.O. Box 7, Mae Rim, Chiang Mai 50180, Thailand
| | - Marlina Ardiyani
- Herbarium Bogoriense, Research Center for Biology, Indonesian Institute of Sciences/Lembaga Ilmu Pengetahuan Indonesia (LIPI), Cibinong Science Center, Jl Raya Bogor Km. 46, Cibinong 16912, Indonesia
| | - Jana Leong-Škorničková
- Research & Conservation Branch, Singapore Botanic Gardens, 1 Cluny Road, 259569, Singapore
| | - Mark Newman
- Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh EH3 5LR, Scotland, United Kingdom
| | - W John Kress
- Department of Botany, MRC-166, National Museum of Natural History, Smithsonian Institution, P. O. Box 37012, Washington, DC 20013-7012, United States
| | - Vinita Gowda
- Tropical Ecology and Evolution (TrEE) Lab, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal, Madhya Pradesh 462066, India.
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14
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Hernández‐Agüero JA, Ruiz‐Tapiador I, Cayuela L. What feeds on
Quercus ilex
L.? A biogeographical approach to studying trophic interactions in a Mediterranean keystone species. DIVERS DISTRIB 2021. [DOI: 10.1111/ddi.13413] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
| | | | - Luis Cayuela
- Departamento de Biología y Geología Física y Química Inorgánica Universidad Rey Juan Carlos Madrid Spain
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15
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Westermann J. Two Is Company, but Four Is a Party-Challenges of Tetraploidization for Cell Wall Dynamics and Efficient Tip-Growth in Pollen. PLANTS (BASEL, SWITZERLAND) 2021; 10:plants10112382. [PMID: 34834745 PMCID: PMC8623246 DOI: 10.3390/plants10112382] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/01/2021] [Accepted: 11/03/2021] [Indexed: 05/27/2023]
Abstract
Some cells grow by an intricately coordinated process called tip-growth, which allows the formation of long tubular structures by a remarkable increase in cell surface-to-volume ratio and cell expansion across vast distances. On a broad evolutionary scale, tip-growth has been extraordinarily successful, as indicated by its recurrent 're-discovery' throughout evolutionary time in all major land plant taxa which allowed for the functional diversification of tip-growing cell types across gametophytic and sporophytic life-phases. All major land plant lineages have experienced (recurrent) polyploidization events and subsequent re-diploidization that may have positively contributed to plant adaptive evolutionary processes. How individual cells respond to genome-doubling on a shorter evolutionary scale has not been addressed as elaborately. Nevertheless, it is clear that when polyploids first form, they face numerous important challenges that must be overcome for lineages to persist. Evidence in the literature suggests that tip-growth is one of those processes. Here, I discuss the literature to present hypotheses about how polyploidization events may challenge efficient tip-growth and strategies which may overcome them: I first review the complex and multi-layered processes by which tip-growing cells maintain their cell wall integrity and steady growth. I will then discuss how they may be affected by the cellular changes that accompany genome-doubling. Finally, I will depict possible mechanisms polyploid plants may evolve to compensate for the effects caused by genome-doubling to regain diploid-like growth, particularly focusing on cell wall dynamics and the subcellular machinery they are controlled by.
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Affiliation(s)
- Jens Westermann
- Institute of Molecular Plant Biology, Department of Biology, ETH Zürich, Universitätsstrasse 2, 8092 Zürich, Switzerland
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16
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Parallel adaptation in autopolyploid Arabidopsis arenosa is dominated by repeated recruitment of shared alleles. Nat Commun 2021; 12:4979. [PMID: 34404804 PMCID: PMC8370997 DOI: 10.1038/s41467-021-25256-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 07/21/2021] [Indexed: 01/26/2023] Open
Abstract
Relative contributions of pre-existing vs de novo genomic variation to adaptation are poorly understood, especially in polyploid organisms. We assess this in high resolution using autotetraploid Arabidopsis arenosa, which repeatedly adapted to toxic serpentine soils that exhibit skewed elemental profiles. Leveraging a fivefold replicated serpentine invasion, we assess selection on SNPs and structural variants (TEs) in 78 resequenced individuals and discover significant parallelism in candidate genes involved in ion homeostasis. We further model parallel selection and infer repeated sweeps on a shared pool of variants in nearly all these loci, supporting theoretical expectations. A single striking exception is represented by TWO PORE CHANNEL 1, which exhibits convergent evolution from independent de novo mutations at an identical, otherwise conserved site at the calcium channel selectivity gate. Taken together, this suggests that polyploid populations can rapidly adapt to environmental extremes, calling on both pre-existing variation and novel polymorphisms. Relative contributions of pre-existing versus de novo genomic variation to adaptation remain unclear. Here, the authors address this problem by examining the adaptation of autotetraploid Arabidopsis arenosa to serpentine soils and find that both types of variations contribute to rapid adaptation.
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17
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Wang Z, Zhong C, Li D, Yan C, Yao X, Li Z. Cytotype distribution and chloroplast phylogeography of the Actinidia chinensis complex. BMC PLANT BIOLOGY 2021; 21:325. [PMID: 34229602 PMCID: PMC8259359 DOI: 10.1186/s12870-021-03099-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 06/11/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Plant phylogeographic studies of species in subtropical China have mainly focused on rare and endangered species, whereas few studies have been conducted on taxa with relatively wide distribution, especially polyploid species. We investigated the cytotype and haplotype distribution pattern of the Actinidia chinensis complex, a widespread geographically woody liana with variable ploidy in subtropical China comprising two varieties, with three chloroplast fragments DNA (ndhF-rpl132, rps16-trnQ and trnE-trnT). Macroevolutionary, microevolutionary and niche modeling tools were also combined to disentangle the origin and the demographic history of the species or cytotypes. RESULTS The ploidy levels of 3338 individuals from 128 populations sampled throughout the species distribution range were estimated with flow cytometry. The widespread cytotypes were diploids followed by tetraploids and hexaploids, whereas triploids and octoploids occurred in a few populations. Thirty-one chloroplast haplotypes were detected. The genetic diversity and genetic structure were found to be high between varieties (or ploidy races) chinensis and deliciosa. Our results revealed that these two varieties inhabit significantly different climatic niche spaces. Ecological niche models (ENMs) indicate that all varieties' ranges contracted during the Last Inter Glacial (LIG), and expanded eastward or northward during the Last Glacial Maximum (LGM). CONCLUSIONS Pliocene and Plio-Pleistocene climatic fluctuations and vicariance appear to have played key roles in shaping current population structure and historical demography in the A. chinensis complex. The polyploidization process also appears to have played an important role in the historical demography of the complex through improving their adaptability to environmental changes.
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Affiliation(s)
- Zhi Wang
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Chinese Academy of Sciences, Wuhan, 430074, Hubei, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Caihong Zhong
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Chinese Academy of Sciences, Wuhan, 430074, Hubei, China
| | - Dawei Li
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Chinese Academy of Sciences, Wuhan, 430074, Hubei, China
| | - Chunlin Yan
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Chinese Academy of Sciences, Wuhan, 430074, Hubei, China
| | - Xiaohong Yao
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Chinese Academy of Sciences, Wuhan, 430074, Hubei, China.
| | - Zuozhou Li
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Chinese Academy of Sciences, Wuhan, 430074, Hubei, China.
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18
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Alavez V, Cuervo-Robayo ÁP, Martínez-Meyer E, Wegier A. Eco-Geography of Feral Cotton: A Missing Piece in the Puzzle of Gene Flow Dynamics Among Members of Gossypium hirsutum Primary Gene Pool. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.653271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mexico is the center of origin and genetic diversity of upland cotton (Gossypium hirsutum L.), the most important source of natural fiber in the world. Currently, wild and domesticated populations (including genetically modified [GM] varieties) occur in this country and gene flow among them has shaped the species’ genetic diversity and structure, setting a complex and challenging scenario for its conservation. Moreover, recent gene flow from GM cultivars to wild Mexican cotton populations has been reported since 2011. In situ conservation of G. hirsutum requires knowledge about the extent of its geographic distribution, both wild and domesticated, as well as the possible routes and mechanisms that contribute to gene flow between the members of the species wild-to-domesticated continuum (i.e., the primary gene pool). However, little is known about the distribution of feral populations that could facilitate gene flow by acting as bridges. In this study, we analyzed the potential distribution of feral cotton based on an ecological niche modeling approach and discussed its implications in the light of the distribution of wild and domesticated cotton. Then, we examined the processes that could be leading to the escape of seeds from the cultivated fields. Our results indicate that the climatic suitability of feral plants in the environmental and geographic space is broad and overlaps with areas of wild cotton habitat and crop fields, suggesting a region that could bridge cultivated cotton and its wild relatives by allowing gene flow between them. This study provides information for management efforts focused on the conservation of wild populations, native landraces, and non-GM domesticated cotton at its center of origin and genetic diversity.
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19
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Evidence of Constrained Divergence and Conservatism in Climatic Niches of the Temperate Maples (Acer L.). FORESTS 2021. [DOI: 10.3390/f12050535] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Research highlights: The availability of global distribution data and new, fossil-calibrated phylogenies has made it possible to compare the climatic niches of the temperate maple (Acer L.) taxa and assess phylogenetic and continental patterns in niche overlap. Background and Objectives: The maples have radiated from East Asia into two other temperate continental bioregions, North America and Eurasia (Europe and West Asia), over a roughly 60-million-year period. During this time, the Earth’s climate experienced pronounced cooling and drying, culminating in cyclic periods of widespread temperate glaciation in the Pliocene to Pleistocene. The objective of this study is to use newly available data to model the climatic niches of 60% of the temperate maples and assess patterns of niche divergence, constraint, and conservatism in the genus’s radiation out of East Asia. Materials and Methods: I assembled global occurrence data and associated climatic information for 71 maple taxa, including all species endemic to temperate North America and Eurasia and their closely related East Asian congeners. I constructed Maxent niche models for all taxa and compared the climatic niches of 184 taxa pairs and assessed phylogenetic signal in key niche axes for each taxon and in niche overlap at the continental and global scale. Results: Maxent models define a fundamental climatic niche for temperate maples and suggest that drought-intolerant taxa have been lost from the Eurasian maple flora, with little continental difference in temperature optima or breadth. Niche axes and niche overlap show minimal evidence of phylogenetic signal, suggesting adaptive evolution. Pairwise niche comparisons reveal infrequent niche overlap continentally and globally, even among sister pairs, with few taxa pairs sharing ecological niche space, providing evidence for constrained divergence within the genus’s fundamental climatic niche. Evidence of niche conservatism is limited to three somewhat geographically isolated regions of high maple diversity (western North America, the Caucasus, and Japan). Conclusions: Over 60 million years of hemispheric radiation on a cooling and drying planet, the maple genus experienced divergent, though constrained, climatic niche evolution. High climatic niche diversity across spatial and phylogenetic scales along with very limited niche overlap or conservatism suggests that the radiation of the genus has largely been one of adaptive diversification.
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20
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Schmickl R, Yant L. Adaptive introgression: how polyploidy reshapes gene flow landscapes. THE NEW PHYTOLOGIST 2021; 230:457-461. [PMID: 33454987 DOI: 10.1111/nph.17204] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
Rare yet accumulating evidence in both plants and animals shows that whole genome duplication (WGD, leading to polyploidy) can break down reproductive barriers, facilitating gene flow between otherwise isolated species. Recent population genomic studies in wild, outcrossing Arabidopsis arenosa and Arabidopsis lyrata indicate that this WGD-potentiated gene flow can be adaptive and highly specific in response to particular environmental and intracellular challenges. The mechanistic basis of WGD-mediated easing of species barrier strength seems to primarily lie in the relative dosage of each parental genome in the endosperm. While generalisations about polyploids can be fraught, this evidence indicates that the breakdown of these barriers, combined with diploid to polyploid gene flow and gene flow between polyploids, allows some polyploids to act as adaptable 'allelic sponges', enjoying increased potential to respond to challenging environments.
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Affiliation(s)
- Roswitha Schmickl
- Department of Botany, Faculty of Science, Charles University, Benátská 2, Prague, 128 01, Czech Republic
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, Průhonice, 252 43, Czech Republic
| | - Levi Yant
- Future Food Beacon and School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD, UK
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21
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Bohutínská M, Alston M, Monnahan P, Mandáková T, Bray S, Paajanen P, Kolář F, Yant L. Novelty and convergence in adaptation to whole genome duplication. Mol Biol Evol 2021; 38:3910-3924. [PMID: 33783509 PMCID: PMC8382928 DOI: 10.1093/molbev/msab096] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 03/08/2021] [Accepted: 03/29/2021] [Indexed: 12/26/2022] Open
Abstract
Whole genome duplication (WGD) can promote adaptation but is disruptive to conserved processes, especially meiosis. Studies in Arabidopsis arenosa revealed a coordinated evolutionary response to WGD involving interacting proteins controlling meiotic crossovers, which are minimised in an autotetraploid (within-species polyploid) to avoid mis-segregation. Here we test whether this surprising flexibility of a conserved essential process, meiosis, is recapitulated in an independent WGD system, Cardamine amara, 17 million years diverged from A. arenosa. We assess meiotic stability and perform population-based scans for positive selection, contrasting the genomic response to WGD in C. amara with that of A. arenosa. We found in C. amara the strongest selection signals at genes with predicted functions thought important to adaptation to WGD: meiosis, chromosome remodelling, cell cycle, and ion transport. However, genomic responses to WGD in the two species differ: minimal ortholog-level convergence emerged, with none of the meiosis genes found in A. arenosa exhibiting strong signal in C. amara. This is consistent with our observations of lower meiotic stability and occasional clonal spreading in diploid C. amara, suggesting that nascent C. amara autotetraploid lineages were preadapted by their diploid lifestyle to survive while enduring reduced meiotic fidelity. However, in contrast to a lack of ortholog convergence, we see process-level and network convergence in DNA management, chromosome organisation, stress signalling, and ion homeostasis processes. This gives the first insight into the salient adaptations required to meet the challenges of a WGD state and shows that autopolyploids can utilize multiple evolutionary trajectories to adapt to WGD.
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Affiliation(s)
- Magdalena Bohutínská
- Department of Botany, Faculty of Science, Charles University, Prague, Czech Republic.,Institute of Botany, The Czech Academy of Sciences, Průhonice, Czech Republic
| | - Mark Alston
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, UK
| | - Patrick Monnahan
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, UK
| | - Terezie Mandáková
- CEITEC - Central European Institute of Technology, and Faculty of Science, Masaryk University, Kamenice, Czech Republic
| | - Sian Bray
- Future Food Beacon of Excellence, University of Nottingham, Nottingham, UK.,School of Biosciences University of Nottingham, Nottingham, UK
| | - Pirita Paajanen
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, UK
| | - Filip Kolář
- Department of Botany, Faculty of Science, Charles University, Prague, Czech Republic.,Institute of Botany, The Czech Academy of Sciences, Průhonice, Czech Republic.,Natural History Museum, University of Oslo, Oslo, Norway
| | - Levi Yant
- Future Food Beacon of Excellence, University of Nottingham, Nottingham, UK.,School of Life Sciences University of Nottingham, Nottingham, UK
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22
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Bomblies K. When everything changes at once: finding a new normal after genome duplication. Proc Biol Sci 2020; 287:20202154. [PMID: 33203329 PMCID: PMC7739491 DOI: 10.1098/rspb.2020.2154] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 10/26/2020] [Indexed: 12/14/2022] Open
Abstract
Whole-genome duplication (WGD), which leads to polyploidy, is implicated in adaptation and speciation. But what are the immediate effects of WGD and how do newly polyploid lineages adapt to them? With many studies of new and evolved polyploids now available, along with studies of genes under selection in polyploids, we are in an increasingly good position to understand how polyploidy generates novelty. Here, I will review consistent effects of WGD on the biology of plants, such as an increase in cell size, increased stress tolerance and more. I will discuss how a change in something as fundamental as cell size can challenge the function of some cell types in particular. I will also discuss what we have learned about the short- to medium-term evolutionary response to WGD. It is now clear that some of this evolutionary response may 'lock in' traits that happen to be beneficial, while in other cases, it might be more of an 'emergency response' to work around physiological changes that are either deleterious, or cannot be undone in the polyploid context. Yet, other traits may return rapidly to a diploid-like state. Polyploids may, by re-jigging many inter-related processes, find a new, conditionally adaptive, normal.
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Affiliation(s)
- Kirsten Bomblies
- Institute of Molecular Plant Biology, Department of Biology, ETH Zürich, Zürich, Switzerland
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23
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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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Morgan EJ, Čertner M, Lučanová M, Kubíková K, Marhold K, Kolář F. Niche similarity in diploid-autotetraploid contact zones of Arabidopsis arenosa across spatial scales. AMERICAN JOURNAL OF BOTANY 2020; 107:1375-1388. [PMID: 32974906 DOI: 10.1002/ajb2.1534] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 06/21/2020] [Indexed: 06/11/2023]
Abstract
PREMISE Whole genome duplication is a major evolutionary event, but its role in ecological divergence remains equivocal. When populations of different ploidy (cytotypes) overlap in space, "contact zones" are formed, allowing the study of evolutionary mechanisms contributing toward ploidy divergence. Multiple contact zones per species' range are often described but rarely leveraged as natural replicates. We explored whether the strength of niche differentiation of diploid and autotetraploid Arabidopsis arenosa varies over distinct contact zones and if the frequency of triploids decreases from seedling to adult stage. METHODS We characterized ploidy composition and habitat preferences in 264 populations across three contact zones using climatic niche modeling. Ecological differences of cytotypes were also assessed using local vegetation surveys at 110 populations within two contact zones, and at the finer scale within five mixed-ploidy sites. This was complemented by flow cytometry of seedlings. RESULTS We found no niche differences between diploid and tetraploid populations within contact zones for either climatic or local environmental variables. Comparisons of cytotypes within mixed-ploidy sites found weak niche differences that were inconsistent in direction. Triploid individuals were virtually absent (0.14%) in the field, and they were at a similarly low frequency (0.2%) in ex situ germinated seedlings. CONCLUSIONS This study demonstrates the strength in investigating different spatial scales across several contact zones when addressing ecological niche differentiation between ploidies. The lack of consistent habitat differentiation of ploidies across the scales and locations supports the recently emerging picture that processes other than ecological differentiation may underlie ploidy coexistence in diploid-autopolyploid systems.
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Affiliation(s)
- Emma J Morgan
- Department of Botany, Faculty of Science, Charles University, Benátská 2, CZ-128 01, Prague, Czech Republic
| | - Martin Čertner
- Department of Botany, Faculty of Science, Charles University, Benátská 2, CZ-128 01, Prague, Czech Republic
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic
| | - Magdalena Lučanová
- Department of Botany, Faculty of Science, Charles University, Benátská 2, CZ-128 01, Prague, Czech Republic
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic
- Department of Botany, Faculty of Science, University of South Bohemia, Branišovská 31, CZ-370 05, České Budějovice, Czech Republic
| | - Kateřina Kubíková
- Department of Botany, Faculty of Science, Charles University, Benátská 2, CZ-128 01, Prague, Czech Republic
| | - Karol Marhold
- Department of Botany, Faculty of Science, Charles University, Benátská 2, CZ-128 01, Prague, Czech Republic
- Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 23, Bratislava, Slovak Republic
| | - Filip Kolář
- Department of Botany, Faculty of Science, Charles University, Benátská 2, CZ-128 01, Prague, Czech Republic
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic
- Institute of Botany, University of Innsbruck, Sternwartestrasse 15, AT-6020, Innsbruck, Austria
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Román-Palacios C, Molina-Henao YF, Barker MS. Polyploids increase overall diversity despite higher turnover than diploids in the Brassicaceae. Proc Biol Sci 2020; 287:20200962. [PMID: 32873209 PMCID: PMC7542780 DOI: 10.1098/rspb.2020.0962] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 08/10/2020] [Indexed: 12/21/2022] Open
Abstract
Although polyploidy is widespread across the plant Tree of Life, its long-term evolutionary significance is still poorly understood. Here, we examine the effects of polyploidy in explaining the large-scale evolutionary patterns within angiosperms by focusing on a single family exhibiting extensive interspecific variation in chromosome numbers. We inferred ploidy from haploid chromosome numbers for 80% of species in the most comprehensive species-level chronogram for the Brassicaceae. After evaluating a total of 94 phylogenetic models of diversification, we found that ploidy influences diversification rates across the Brassicaceae. We also found that despite diversifying at a similar rate to diploids, polyploids have played a significant role in driving present-day differences in species richness among clades. Overall, in addition to highlighting the complexity in the evolutionary consequences of polyploidy, our results suggest that rare successful polyploids persist while significantly contributing to the long-term evolution of clades. Our findings further indicate that polyploidy has played a major role in driving the long-term evolution of the Brassicaceae and highlight the potential of polyploidy in shaping present-day diversity patterns across the plant Tree of Life.
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Affiliation(s)
- Cristian Román-Palacios
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA
| | - Y. Franchesco Molina-Henao
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
- The Arnold Arboretum, Harvard University, Boston, MA 02131, USA
- Departamento de Biología, Universidad del Valle, Cali, Valle 760032, Colombia
| | - Michael S. Barker
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA
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Garmendia A, Ferriol M, Benavent D, Ferrer-Gallego PP, Merle H. Intra- and Inter-Specific Crosses among Centaurea aspera L. (Asteraceae) Polyploid Relatives-Influences on Distribution and Polyploid Establishment. PLANTS (BASEL, SWITZERLAND) 2020; 9:E1142. [PMID: 32899362 PMCID: PMC7569768 DOI: 10.3390/plants9091142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 08/31/2020] [Accepted: 09/02/2020] [Indexed: 05/24/2023]
Abstract
How polyploids become established is a long-debated question, especially for autopolyploids that seem to have no evolutionary advantage over their progenitors. The Centaurea aspera polyploid complex includes diploid C. aspera and two related tetraploids C. seridis and C. gentilii. Our purpose was to study the mating system among these three taxa and to analyze its influence on polyploid establishment. The distribution and ploidy level of the Moroccan populations, and forced intra- and inter-specific crosses were assessed. Allotetraploid C. seridis produced more cypselae per capitulum in the intra-specific crosses. It is a bigger plant and autogamous, and previous studies indicated that selfing forces the asymmetric formation of sterile hybrids. All these characteristics help C. seridis to avoid the minority-cytotype-exclusion effect and become established. Inter-specific hybridization was possible between C. aspera and C. gentilii, and with the symmetric formation of hybrids. However, 49% of the hybrid cypselae were empty, which probably reveals postzygotic barriers. Autotetraploid C. gentilii produced the same number of cypselae per capitulum as those of the diploid parental, has an indistinguishable field phenotype, is allogamous, and symmetrically produces hybrids. Therefore, C. gentilii does not seem to have the same competitive advantages as those of C. seridis.
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Affiliation(s)
- Alfonso Garmendia
- Instituto Agroforestal Mediterráneo, Universitat Politècnica de València, ES-46022 Valencia, Spain; (A.G.); (M.F.)
| | - María Ferriol
- Instituto Agroforestal Mediterráneo, Universitat Politècnica de València, ES-46022 Valencia, Spain; (A.G.); (M.F.)
| | - David Benavent
- Departamento de Ecosistemas Agroforestales, Universitat Politècnica de València, ES-46022 Valencia, Spain;
| | - P. Pablo Ferrer-Gallego
- Servicio de Vida Silvestre, Centro para la Investigación y la Experimentación Forestal - VAERSA, Generalitat Valenciana, Avda. Comarques del País Valencià 114, Quart de Poblet, ES-46930 Valencia, Spain;
| | - Hugo Merle
- Departamento de Ecosistemas Agroforestales, Universitat Politècnica de València, ES-46022 Valencia, Spain;
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Castro M, Loureiro J, Figueiredo A, Serrano M, Husband BC, Castro S. Different Patterns of Ecological Divergence Between Two Tetraploids and Their Diploid Counterpart in a Parapatric Linear Coastal Distribution Polyploid Complex. FRONTIERS IN PLANT SCIENCE 2020; 11:315. [PMID: 32265966 PMCID: PMC7098452 DOI: 10.3389/fpls.2020.00315] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 03/03/2020] [Indexed: 05/24/2023]
Abstract
Polyploidization is a widespread mechanism of evolutionary divergence in flowering plants. Ecological divergence of polyploid lineages has been proposed as a key process shaping the distribution of cytotypes in nature (niche shift hypothesis); however, evidence for the role of niche separation in replicated diploid-polyploid species pairs is still needed. This study aimed to assess the role of abiotic factors shaping current cytotype distributions. For that, we examined the distribution and environmental niches of two varieties recognized in diploid-tetraploid Jasione maritima across the species range and within a putative contact zone on the Iberian Peninsula. We counted chromosomes, screened for ploidy across Iberian Peninsula and characterized environmental requirements using niche modeling tools. We found that J. maritima var. maritima is composed by diploids with disjunct distribution in the west coast of France and northwest Iberian Peninsula, and by tetraploids in Iberian Peninsula, while var. sabularia is tetraploid. In the Iberian Peninsula, two parapatric contact zones along a linear coastal distribution were detected, one between diploid and tetraploid var. maritima, and the other between tetraploids of the two varieties. Environmental variables of diploid populations from France are distinct from those of southern diploid populations, which are more similar to tetraploids. In general, niche modeling results are congruent with the observed distribution patterns, although the results suggest a wider contact zone between varieties and cytotypes. Tetraploids of both varieties revealed different degrees of environmental divergence in comparison with their diploid counterpart. Tetraploid var. sabularia differed environmentally from diploids suggesting niche divergence. In contrast, tetraploid var. maritima overlapped with diploid environmental niche and currently occupies its entire predicted range, whereas diploids are restricted to northern areas of their suitable environment. Differences in ecological envelopes facilitate the recognition of functional units of biodiversity within polyploid groups, allowing the study of factors related to post-polyploidization divergence. Thus, whereas changes in environmental requirements may have allowed tetraploid var. sabularia to spread in habitats not favorable to diploids, other factors are involved with the distribution of diploid and tetraploid var. maritima.
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Affiliation(s)
- Mariana Castro
- Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Coimbra, Portugal
| | - João Loureiro
- Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Coimbra, Portugal
| | - Albano Figueiredo
- Centre for Studies in Geography and Spatial Planning, Department of Geography and Tourism, Faculty of Arts and Humanities, University of Coimbra, Coimbra, Portugal
| | - Miguel Serrano
- Department of Botany, Faculty of Pharmacy, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Brian C. Husband
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
| | - Sílvia Castro
- Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Coimbra, Portugal
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Manzoor SA, Griffiths G, Obiakara MC, Esparza-Estrada CE, Lukac M. Evidence of ecological niche shift in Rhododendron ponticum (L.) in Britain: Hybridization as a possible cause of rapid niche expansion. Ecol Evol 2020; 10:2040-2050. [PMID: 32128136 PMCID: PMC7042765 DOI: 10.1002/ece3.6036] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 01/02/2020] [Accepted: 01/06/2020] [Indexed: 01/21/2023] Open
Abstract
Biological invasions threaten global biodiversity and natural resources. Anticipating future invasions is central to strategies for combating the spread of invasive species. Ecological niche models are thus increasingly used to predict potential distribution of invasive species. In this study, we compare ecological niches of Rhododendron ponticum in its native (Iberian Peninsula) and invasive (Britain) ranges. Here, we test the conservation of ecological niche between invasive and native populations of R. ponticum using principal component analysis, niche dynamics analysis, and MaxEnt-based reciprocal niche modeling. We show that niche overlap between native and invasive populations is very low, leading us to the conclusion that the two niches are not equivalent and are dissimilar. We conclude that R. ponticum occupies novel environmental conditions in Britain. However, the evidence of niche shift presented in this study should be treated with caution because of nonanalogue climatic conditions between native and invasive ranges and a small population size in the native range. We then frame our results in the context of contradicting genetic evidence on possible hybridization of this invasive species in Britain. We argue that the existing contradictory studies on whether hybridization caused niche shift in R. ponticum are not sufficient to prove or disprove this hypothesis. However, we present a series of theoretical arguments which indicate that hybridization is a likely cause of the observed niche expansion of R. ponticum in Britain.
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Affiliation(s)
- Syed Amir Manzoor
- School of Agriculture, Policy and Development University of Reading Reading UK
- Department of Forestry & Range Management FAS&T Bahauddin Zakariya University Multan Multan Pakistan
| | - Geoffrey Griffiths
- Department of Geography and Environmental Science University of Reading Reading UK
| | | | | | - Martin Lukac
- School of Agriculture, Policy and Development University of Reading Reading UK
- Faculty of Forestry and Wood Sciences Czech University of Life Sciences Prague Prague Czech Republic
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Relaxed purifying selection in autopolyploids drives transposable element over-accumulation which provides variants for local adaptation. Nat Commun 2019; 10:5818. [PMID: 31862875 PMCID: PMC6925279 DOI: 10.1038/s41467-019-13730-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 11/21/2019] [Indexed: 11/28/2022] Open
Abstract
Polyploidization is frequently associated with increased transposable element (TE) content. However, what drives TE dynamics following whole genome duplication (WGD) and the evolutionary implications remain unclear. Here, we leverage whole-genome resequencing data available for ~300 individuals of Arabidopsis arenosa, a well characterized natural diploid-autotetraploid plant species, to address these questions. Based on 43,176 TE insertions we detect in these genomes, we demonstrate that relaxed purifying selection rather than transposition bursts is the main driver of TE over-accumulation after WGD. Furthermore, the increased pool of TE insertions in tetraploids is especially enriched within or near environmentally responsive genes. Notably, we show that the major flowering-time repressor gene FLC is disrupted by a TE insertion specifically in the rapid-cycling tetraploid lineage that colonized mainland railways. Together, our findings indicate that tetrasomy leads to an enhanced accumulation of genic TE insertions, some of which likely contribute to local adaptation. Why transposable elements (TEs) accumulate in polyploids and the evolutionary implications remain unclear. Here, the authors show that following whole genome duplication, relaxed purifying selection is the main driver of TE over-accumulation, which provides variants for rapid local adaptation.
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30
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Wos G, Mořkovská J, Bohutínská M, Šrámková G, Knotek A, Lučanová M, Španiel S, Marhold K, Kolář F. Role of ploidy in colonization of alpine habitats in natural populations of Arabidopsis arenosa. ANNALS OF BOTANY 2019; 124:255-268. [PMID: 31185073 PMCID: PMC6758580 DOI: 10.1093/aob/mcz070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 05/17/2019] [Indexed: 05/13/2023]
Abstract
BACKGROUND AND AIMS Polyploidy is an important driver of plant diversification and adaptation to novel environments. As a consequence of genome doubling, polyploids often exhibit greater colonizing ability or occupy a wider ecological niche than diploids. Although elevation has been traditionally considered as a key driver structuring ploidy variation, we do not know if environmental and phenotypic differentiation among ploidy cytotypes varies along an elevational gradient. Here, we tested for the consequences of genome duplication on genetic diversity, phenotypic variation and habitat preferences on closely related diploid and tetraploid populations that coexist along approx. 2300 m of varying elevation. METHODS We sampled and phenotyped 45 natural diploid and tetraploid populations of Arabidopsis arenosa in one mountain range in Central Europe (Western Carpathians) and recorded abiotic and biotic variables at each collection site. We inferred genetic variation, population structure and demographic history in a sub-set of 29 populations genotyped for approx. 36 000 single nucleotide polymorphisms. KEY RESULTS We found minor effects of polyploidy on colonization of alpine stands and low genetic differentiation between the two cytotypes, mirroring recent divergence of the polyploids from the local diploid lineage and repeated reticulation events among the cytotypes. This pattern was corroborated by the absence of ecological niche differentiation between the two cytotypes and overall phenotypic similarity at a given elevation. CONCLUSIONS The case of A. arenosa contrasts with previous studies that frequently showed clear niche differentiation between cytotypes. Our work stresses the importance of considering genetic structure and past demographic processes when interpreting the patterns of ploidy distributions, especially in species that underwent recent polyploidization events.
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Affiliation(s)
- Guillaume Wos
- Department of Botany, Charles University, Prague, Czech Republic
| | - Jana Mořkovská
- Department of Botany, Charles University, Prague, Czech Republic
| | - Magdalena Bohutínská
- Department of Botany, Charles University, Prague, Czech Republic
- Institute of Botany, The Czech Academy of Sciences, Průhonice, Czech Republic
| | | | - Adam Knotek
- Department of Botany, Charles University, Prague, Czech Republic
| | - Magdalena Lučanová
- Department of Botany, Charles University, Prague, Czech Republic
- Institute of Botany, The Czech Academy of Sciences, Průhonice, Czech Republic
| | - Stanislav Španiel
- Department of Botany, Charles University, Prague, Czech Republic
- Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - Karol Marhold
- Department of Botany, Charles University, Prague, Czech Republic
- Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - Filip Kolář
- Department of Botany, Charles University, Prague, Czech Republic
- Institute of Botany, The Czech Academy of Sciences, Průhonice, Czech Republic
- Institute of Botany, University of Innsbruck, Innsbruck, Austria
- For correspondence. E-mail
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31
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Hadle JJ, Russell FL, Beck JB. Are buffalograss (Buchloë dactyloides) cytotypes spatially and ecologically differentiated? AMERICAN JOURNAL OF BOTANY 2019; 106:1116-1125. [PMID: 31334845 DOI: 10.1002/ajb2.1327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 05/13/2019] [Indexed: 06/10/2023]
Abstract
PREMISE Although autopolyploidy is common among dominant Great Plains grasses, the distribution of cytotypes within a given species is typically poorly understood. This study aims to establish the geographic distribution of cytotypes within buffalograss (Buchloë dactyloides) and to assess whether individual cytotypes have differing ecological tolerances. METHODS A range-wide set of 578 B. dactyloides individuals was obtained through field collecting and sampling from herbarium specimens. The cytotype of each sample was estimated by determining allele numbers at 13 simple sequence repeat loci, a strategy that was assessed by comparing estimated to known cytotype in 79 chromosome-counted samples. Ecological differentiation between the dominant tetraploid and hexaploid cytotypes was assessed with analyses of macroclimatic variables. RESULTS Simple sequence repeat variation accurately estimated cytotype in 89% of samples from which a chromosome count had been obtained. Applying this approach to samples of unknown ploidy established that diploids and pentaploids are rare, with the common tetraploid and hexaploid cytotypes generally occurring in sites to the north/west (tetraploid) or south/east (hexaploid) portions of the species range. Both MANOVA and niche modeling approaches identified significant but subtle differences in macroclimatic conditions at the set of locations occupied by these two dominant cytotypes. CONCLUSIONS Incorporating chromosome count vouchers and cytotype-estimated herbarium records allowed us to perform the largest study of cytotype niche differentiation to date. Buffalograss cytotypes differ greatly in frequency, the common tetraploid and hexaploid cytotypes are non-randomly distributed, and these two cytotypes are subtly ecologically differentiated.
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Affiliation(s)
- Jacob J Hadle
- Department of Biological Sciences, Wichita State University, Wichita, KS, 67260, USA
| | - F Leland Russell
- Department of Biological Sciences, Wichita State University, Wichita, KS, 67260, USA
| | - James B Beck
- Department of Biological Sciences, Wichita State University, Wichita, KS, 67260, USA
- Botanical Research Institute of Texas, Fort Worth, TX, 76107, USA
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