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Pungaršek Š, Frajman B. Influence of polyploidy on morphology and distribution of the Cypress Spurge (Euphorbia cyparissias, Euphorbiaceae). PLANT BIOLOGY (STUTTGART, GERMANY) 2024. [PMID: 38979801 DOI: 10.1111/plb.13685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Accepted: 05/26/2024] [Indexed: 07/10/2024]
Abstract
Polyploidy can cause differences in phenotypic and physiological traits among different cytotypes of the same species. Polyploids may have larger organs or occupy different ecological niches than their diploid counterparts, therefore they are hypothesized to have larger distributions or prosper in stressful environments, such as higher elevations. The Cypress spurge (Euphorbia cyparissias L.; Euphorbiaceae) is a widespread European heteroploid species including di- (2x), tetra- (4x) and hexaploid (6x) cytotypes. We tested the hypotheses that polyploids are more widespread and more abundant at higher elevations and have larger organs than their diploid ancestors in the case of E. cyparissias. We also analysed whether genome downsizing had occurred after polyploidisation. We conducted a comprehensive geographic sampling of 617 populations of E. cyparissias throughout Europe. We estimated their relative genome size using flow cytometry and inferred ploidy level of each population. We scored 13 morphological traits of vegetative and seed characters and performed statistical analyses. The study indicates that polyploidisation facilitated colonisation of new areas in E. cyparissias, where the tetraploids are most widespread, whereas the diploids are limited to putative Pleistocene refugia, mostly in southern Europe. On the other hand, the three ploidies do not differ in their elevational distribution. Although some quantitative morphological traits exhibited an increasing trend with increasing ploidy, most traits did not differ significantly among the three ploidies, and there was no overall phenotypic differentiation among them. Given that individuals of different ploidies thrive in similar habitats across the same elevations, we suggest that ecological segregation following polyploidisation is a more important trigger for morphological differentiation than polyploidisation itself in autopolyploid plants. The study demonstrates that polyploidisation can be crucial for the colonisation of new areas and for range expansion, but it does not necessarily influence elevational distribution nor confer a different phenotype.
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Affiliation(s)
- Š Pungaršek
- Department of Botany, University of Innsbruck, Innsbruck, Austria
- Slovenian Museum of Natural History, Ljubljana, Slovenia
| | - B Frajman
- Department of Botany, University of Innsbruck, Innsbruck, Austria
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Hörandl E. Apomixis and the paradox of sex in plants. ANNALS OF BOTANY 2024; 134:1-18. [PMID: 38497809 PMCID: PMC11161571 DOI: 10.1093/aob/mcae044] [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: 12/11/2023] [Accepted: 03/15/2024] [Indexed: 03/19/2024]
Abstract
BACKGROUND The predominance of sex in eukaryotes, despite the high costs of meiosis and mating, remains an evolutionary enigma. Many theories have been proposed, none of them being conclusive on its own, and they are, in part, not well applicable to land plants. Sexual reproduction is obligate in embryophytes for the great majority of species. SCOPE This review compares the main forms of sexual and asexual reproduction in ferns and angiosperms, based on the generation cycling of sporophyte and gametophyte (leaving vegetative propagation aside). The benefits of sexual reproduction for maintenance of genomic integrity in comparison to asexuality are discussed in the light of developmental, evolutionary, genetic and phylogenetic studies. CONCLUSIONS Asexual reproduction represents modifications of the sexual pathway, with various forms of facultative sexuality. For sexual land plants, meiosis provides direct DNA repair mechanisms for oxidative damage in reproductive tissues. The ploidy alternations of meiosis-syngamy cycles and prolonged multicellular stages in the haploid phase in the gametophytes provide a high efficiency of purifying selection against recessive deleterious mutations. Asexual lineages might buffer effects of such mutations via polyploidy and can purge the mutational load via facultative sexuality. The role of organelle-nuclear genome compatibility for maintenance of genome integrity is not well understood. In plants in general, the costs of mating are low because of predominant hermaphroditism. Phylogenetic patterns in the archaeplastid clade suggest that high frequencies of sexuality in land plants are concomitant with a stepwise increase of intrinsic and extrinsic stress factors. Furthermore, expansion of genome size in land plants would increase the potential mutational load. Sexual reproduction appears to be essential for keeping long-term genomic integrity, and only rare combinations of extrinsic and intrinsic factors allow for shifts to asexuality.
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Affiliation(s)
- Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants (with herbarium), University of Göttingen, Göttingen, Germany
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Guo L, Wang S, Jiao X, Ye X, Deng D, Liu H, Li Y, Van de Peer Y, Wu W. Convergent and/or parallel evolution of RNA-binding proteins in angiosperms after polyploidization. THE NEW PHYTOLOGIST 2024; 242:1377-1393. [PMID: 38436132 DOI: 10.1111/nph.19656] [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: 05/13/2023] [Accepted: 02/20/2024] [Indexed: 03/05/2024]
Abstract
Increasing studies suggest that the biased retention of stress-related transcription factors (TFs) after whole-genome duplications (WGDs) could rewire gene transcriptional networks, facilitating plant adaptation to challenging environments. However, the role of posttranscriptional factors (e.g. RNA-binding proteins, RBPs) following WGDs has been largely ignored. Uncovering thousands of RBPs in 21 representative angiosperm species, we integrate genomic, transcriptomic, regulatomic, and paleotemperature datasets to unravel their evolutionary trajectories and roles in adapting to challenging environments. We reveal functional enrichments of RBP genes in stress responses and identify their convergent retention across diverse angiosperms from independent WGDs, coinciding with global cooling periods. Numerous RBP duplicates derived from WGDs are then identified as cold-induced. A significant overlap of 29 orthogroups between WGD-derived and cold-induced RBP genes across diverse angiosperms highlights a correlation between WGD and cold stress. Notably, we unveil an orthogroup (Glycine-rich RNA-binding Proteins 7/8, GRP7/8) and relevant TF duplicates (CCA1/LHY, RVE4/8, CBF2/4, etc.), co-retained in different angiosperms post-WGDs. Finally, we illustrate their roles in rewiring circadian and cold-regulatory networks at both transcriptional and posttranscriptional levels during global cooling. Altogether, we underline the adaptive evolution of RBPs in angiosperms after WGDs during global cooling, improving our understanding of plants surviving periods of environmental turmoil.
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Affiliation(s)
- Liangyu Guo
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A&F University, Lin'an, Hangzhou, 311300, China
| | - Shuo Wang
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A&F University, Lin'an, Hangzhou, 311300, China
| | - Xi Jiao
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A&F University, Lin'an, Hangzhou, 311300, China
| | - Xiaoxue Ye
- Institute of Tropical Biosciences and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China
| | - Deyin Deng
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A&F University, Lin'an, Hangzhou, 311300, China
| | - Hua Liu
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A&F University, Lin'an, Hangzhou, 311300, China
| | - Yan Li
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A&F University, Lin'an, Hangzhou, 311300, China
| | - Yves Van de Peer
- Department of Plant Biotechnology and Bioinformatics, VIB - UGent Center for Plant Systems Biology, Ghent University, B-9052, Ghent, Belgium
- College of Horticulture, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing, 210095, China
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, 0028, South Africa
| | - Wenwu Wu
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A&F University, Lin'an, Hangzhou, 311300, China
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Sochor M, Duchoslav M, Forejtová V, Hroneš M, Konečná M, Trávníček B. Distinct geographic parthenogenesis in spite of niche conservatism and a single ploidy level: A case of Rubus ser. Glandulosi (Rosaceae). THE NEW PHYTOLOGIST 2024; 242:1348-1362. [PMID: 38407427 DOI: 10.1111/nph.19618] [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: 01/18/2024] [Accepted: 02/06/2024] [Indexed: 02/27/2024]
Abstract
Asexual organisms often differ in their geographic distributions from their sexual relatives. This phenomenon, termed geographic parthenogenesis, has long been known, but the underlying factors behind its diverse patterns have been under dispute. Particularly problematic is an association between asexuality and polyploidy in most taxa. Here, we present a new system of geographic parthenogenesis on the tetraploid level, promising new insights into this complex topic. We used flow cytometric seed screen and microsatellite genotyping to characterise the patterns of distribution of sexuals and apomicts and genotypic distributions in Rubus ser. Glandulosi across its range. Ecological modelling and local-scale vegetation and soil analyses were used to test for niche differentiation between the reproductive groups. Apomicts were detected only in North-western Europe, sexuals in the rest of the range in Europe and West Asia, with a sharp borderline stretched across Central Europe. Despite that, we found no significant differences in ecological niches. Genotypic richness distributions suggested independence of the reproductive groups and a secondary contact. We argue that unless a niche differentiation (resulting from polyploidy and/or hybridity) evolves, the main factors behind the patterns of geographic parthenogenesis in plants are phylogeographic history and neutral microevolutionary processes, such as clonal turnover.
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Affiliation(s)
- Michal Sochor
- Centre of the Region Haná for Biotechnological and Agricultural Research, Crop Research Institute, Šlechtitelů 29, Olomouc, 78371, Czech Republic
| | - Martin Duchoslav
- Plant Biosystematics and Ecology Research Group, Department of Botany, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc, 78371, Czech Republic
| | - Věra Forejtová
- Plant Biosystematics and Ecology Research Group, Department of Botany, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc, 78371, Czech Republic
- Station of Apple Breeding for Disease Resistance, Institute of Experimental Botany, Czech Academy of Sciences, Rozvojová 313, Prague 6-Lysolaje, 16502, Czech Republic
| | - Michal Hroneš
- Plant Biosystematics and Ecology Research Group, Department of Botany, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc, 78371, Czech Republic
| | - Michaela Konečná
- Plant Biosystematics and Ecology Research Group, Department of Botany, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc, 78371, Czech Republic
| | - Bohumil Trávníček
- Plant Biosystematics and Ecology Research Group, Department of Botany, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc, 78371, Czech Republic
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Kozlowski G, Fragnière Y, Clément B, Gilg O, Sittler B, Lang J, Eidesen PB, Lang SI, Wasowicz P, Meade C. Genome Size in the Arenaria ciliata Species Complex (Caryophyllaceae), with Special Focus on Northern Europe and the Arctic. PLANTS (BASEL, SWITZERLAND) 2024; 13:635. [PMID: 38475481 DOI: 10.3390/plants13050635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 02/20/2024] [Accepted: 02/23/2024] [Indexed: 03/14/2024]
Abstract
The main aim of the present study has been the completion of genome size data for the diverse arctic-alpine A. ciliata species complex, with special focus on the unexplored arctic taxon A. pseudofrigida, the north-European A. norvegica, and A. gothica from Gotland (Sweden). Altogether, 46 individuals of these three Nordic taxa have been sampled from seven different regions and their genome size estimated using flow cytometry. Three other alpine taxa in the A. ciliata complex (A. multicaulis, A. ciliata subsp. ciliata, and A. ciliata subsp. bernensis) were also collected and analyzed for standardization purposes, comprising 20 individuals from six regions. A mean 2c value of 1.65 pg of DNA was recorded for A. pseudofrigida, 2.80 pg for A. norvegica, and 4.14 pg for A. gothica, as against the reconfirmed 2c value of 1.63 pg DNA for the type taxon A. ciliata subsp. ciliata. Our results presenting the first estimations of genome sizes for the newly sampled taxa, corroborate ploidy levels described in the available literature, with A. pseudofrigida being tetraploid (2n = 4x = 40), A. norvegica possessing predominantly 2n = 8x = 80, and A. gothica with 2n = 10x = 100. The present study also reconfirms genome size and ploidy level estimations published previously for the alpine members of this species complex. Reflecting a likely complex recent biogeographic history, the A. ciliata species group comprises a polyploid arctic-alpine species complex characterized by reticulate evolution, polyploidizations and hybridizations, probably associated with rapid latitudinal and altitudinal migrations in the Pleistocene-Holocene period.
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Affiliation(s)
- Gregor Kozlowski
- Department of Biology and Botanical Garden, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
- Natural History Museum Fribourg, Chemin du Musée 6, 1700 Fribourg, Switzerland
- Eastern China Conservation Centre for Wild Endangered Plant Resources, Shanghai Chenshan Botanical Garden, 3888 Chenhua Road, Songjiang, Shanghai 201602, China
| | - Yann Fragnière
- Department of Biology and Botanical Garden, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Benoît Clément
- Department of Biology and Botanical Garden, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Olivier Gilg
- UMR 6249 Chrono-Environment, CNRS, Université de Bourgogne Franche-Comté, 25000 Besançon, France
- Groupe de Recherche en Ecologie Arctique (GREA), 16 rue de Vernot, 21440 Francheville, France
| | - Benoît Sittler
- Groupe de Recherche en Ecologie Arctique (GREA), 16 rue de Vernot, 21440 Francheville, France
- Nature Conservation and Landscape Ecology, University of Freiburg, Tannenbacherstrasse 4, 79106 Freiburg im Breisgau, Germany
| | - Johannes Lang
- Groupe de Recherche en Ecologie Arctique (GREA), 16 rue de Vernot, 21440 Francheville, France
- Arbeitsgruppe Wildtierforschung, Justus-Liebig-University Giessen, Frankfurter Strasse 114, 35392 Giessen, Germany
| | | | - Simone I Lang
- Department of Arctic Biology, The University Centre in Svalbard, P.O. Box 156, 9171 Longyearbyen, Norway
| | - Pawel Wasowicz
- Icelandic Institute of Natural History, Borgum við Norðurslóð, 600 Akureyri, Iceland
| | - Conor Meade
- Molecular Ecology & Biogeography Laboratory, Biology Department, Maynooth University, W23 F2H6 Maynooth, Ireland
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Phylogeography and population structure of the global, wide host-range hybrid pathogen Phytophthora × cambivora. IMA Fungus 2023; 14:4. [PMID: 36823663 PMCID: PMC9951538 DOI: 10.1186/s43008-023-00109-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 02/08/2023] [Indexed: 02/25/2023] Open
Abstract
Invasive, exotic plant pathogens pose a major threat to native and agricultural ecosystems. Phytophthora × cambivora is an invasive, destructive pathogen of forest and fruit trees causing severe damage worldwide to chestnuts (Castanea), apricots, peaches, plums, almonds and cherries (Prunus), apples (Malus), oaks (Quercus), and beech (Fagus). It was one of the first damaging invasive Phytophthora species to be introduced to Europe and North America, although its origin is unknown. We determined its population genetic history in Europe, North and South America, Australia and East Asia (mainly Japan) using genotyping-by-sequencing. Populations in Europe and Australia appear clonal, those in North America are highly clonal yet show some degree of sexual reproduction, and those in East Asia are partially sexual. Two clonal lineages, each of opposite mating type, and a hybrid lineage derived from these two lineages, dominated the populations in Europe and were predominantly found on fagaceous forest hosts (Castanea, Quercus, Fagus). Isolates from fruit trees (Prunus and Malus) belonged to a separate lineage found in Australia, North America, Europe and East Asia, indicating the disease on fruit trees could be caused by a distinct lineage of P. × cambivora, which may potentially be a separate sister species and has likely been moved with live plants. The highest genetic diversity was found in Japan, suggesting that East Asia is the centre of origin of the pathogen. Further surveys in unsampled, temperate regions of East Asia are needed to more precisely identify the location and range of the centre of diversity.
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7
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Hörandl E. Geographical Parthenogenesis in Alpine and Arctic Plants. PLANTS (BASEL, SWITZERLAND) 2023; 12:844. [PMID: 36840192 PMCID: PMC9959270 DOI: 10.3390/plants12040844] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/08/2023] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
The term "Geographical parthenogenesis" describes the phenomenon that asexual organisms usually occupy larger and more northern distribution areas than their sexual relatives, and tend to colonize previously glaciated areas. Several case studies on alpine and arctic plants confirm the geographical pattern, but the causal factors behind the phenomenon are still unclear. Research of the last decade in several plant families has shed light on the question and evaluated some of the classical evolutionary theories. Results confirmed, in general, that the advantages of uniparental reproduction enable apomictic plants to re-colonize faster in larger and more northern distribution areas. Associated factors like polyploidy seem to contribute mainly to the spatial separation of sexual and asexual cytotypes. Ecological studies suggest a better tolerance of apomicts to colder climates and temperate extremes, whereby epigenetic flexibility and phenotypic plasticity play an important role in occupying ecological niches under harsh conditions. Genotypic diversity appears to be of lesser importance for the distributional success of asexual plants. Classical evolutionary theories like a reduced pressure of biotic interactions in colder climates and hence an advantage to asexuals (Red Queen hypothesis) did not gain support from studies on plants. However, it is also still enigmatic why sexual outcrossing remains the predominant mode of reproduction also in alpine floras. Constraints for the origin of apomixis might play a role. Interestingly, some studies suggest an association of sexuality with abiotic stresses. Light stress in high elevations might explain why most alpine plants retain sexual reproduction despite other environmental factors that would favor apomixis. Directions for future research will be given.
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Affiliation(s)
- Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), University of Goettingen, 37073 Göttingen, Germany
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8
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Paetzold C, Barke BH, Hörandl E. Evolution of Transcriptomes in Early-Generation Hybrids of the Apomictic Ranunculus auricomus Complex ( Ranunculaceae). Int J Mol Sci 2022; 23:ijms232213881. [PMID: 36430360 PMCID: PMC9697309 DOI: 10.3390/ijms232213881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 11/03/2022] [Accepted: 11/09/2022] [Indexed: 11/12/2022] Open
Abstract
Hybridisation in plants may cause a shift from sexual to asexual seed formation (apomixis). Indeed, natural apomictic plants are usually hybrids, but it is still unclear how hybridisation could trigger the shift to apomixis. The genome evolution of older apomictic lineages is influenced by diverse processes such as polyploidy, mutation accumulation, and allelic sequence divergence. To disentangle the effects of hybridisation from these other factors, we analysed the transcriptomes of flowering buds from artificially produced, diploid F2 hybrids of the Ranunculus auricomus complex. The hybrids exhibited unreduced embryo sac formation (apospory) as one important component of apomixis, whereas their parental species were sexual. We revealed 2915 annotated single-copy genes that were mostly under purifying selection according to dN/dS ratios. However, pairwise comparisons revealed, after rigorous filtering, 79 genes under diversifying selection between hybrids and parents, whereby gene annotation assigned ten of them to reproductive processes. Four genes belong to the meiosis-sporogenesis phase (ASY1, APC1, MSP1, and XRI1) and represent, according to literature records, candidate genes for apospory. We conclude that hybridisation could combine novel (or existing) mutations in key developmental genes in certain hybrid lineages, and establish (together with altered gene expression profiles, as observed in other studies) a heritable regulatory mechanism for aposporous development.
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Affiliation(s)
- Claudia Paetzold
- Department of Botany and Molecular Evolution, Senckenberg Research Institute, 60325 Frankfurt am Main, Germany
| | - Birthe H. Barke
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), University of Goettingen, 37073 Goettingen, Germany
| | - Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), University of Goettingen, 37073 Goettingen, Germany
- Correspondence:
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9
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Janas AB, Marciniuk J, Szeląg Z, Musiał K. New facts about callose events in the young ovules of some sexual and apomictic species of the Asteraceae family. PROTOPLASMA 2022; 259:1553-1565. [PMID: 35304670 DOI: 10.1007/s00709-022-01755-0] [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: 12/09/2021] [Accepted: 03/07/2022] [Indexed: 06/14/2023]
Abstract
Callose (β-1,3-glucan) is one of the cell wall polymers that plays an important role in many biological processes in plants, including reproductive development. In angiosperms, timely deposition and degradation of callose during sporogenesis accompanies the transition of cells from somatic to generative identity. However, knowledge on the regulation of callose biosynthesis at specific sites of the megasporocyte wall remains limited and the data on its distribution are not conclusive. Establishing the callose deposition pattern in a large number of species can contribute to full understanding of its function in reproductive development. Previous studies focused on callose events in sexual species and only a few concerned apomicts. The main goal of our research was to establish and compare the pattern of callose deposition during early sexual and diplosporous processes in the ovules of some Hieracium, Pilosella and Taraxacum (Asteraceae) species; aniline blue staining technique was used for this purpose. Our findings indicate that callose deposition accompanies both meiotic and diplosporous development of the megaspore mother cell. This suggests that it has similar regulatory functions in intercellular communication regardless of the mode of reproduction. Interestingly, callose deposition followed a different pattern in the studied sexual and diplosporous species compared to most angiosperms as it usually began at the micropylar pole of the megasporocyte. Here, it was only in sexually reproducing H. transylvanicum that callose first appeared at the chalazal pole of the megasporocyte. The present paper additionally discusses the occurrence of aposporous initial cells with callose-rich walls in the ovules of diploid species.
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Affiliation(s)
- Agnieszka B Janas
- Department of Plant Cytology and Embryology, Institute of Botany, Jagiellonian University, Gronostajowa 9, 30-387, Cracow, Poland.
- The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239, Cracow, Poland.
| | - Jolanta Marciniuk
- Faculty of Exact and Natural Science, Siedlce University of Natural Sciences and Humanities, Prusa 14, 08-110, Siedlce, Poland
| | - Zbigniew Szeląg
- Institute of Biology, Pedagogical University of Cracow, Podchorążych 2, 30-084, Cracow, Poland
| | - Krystyna Musiał
- Department of Plant Cytology and Embryology, Institute of Botany, Jagiellonian University, Gronostajowa 9, 30-387, Cracow, Poland
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Syngelaki E, Paetzold C, Hörandl E. Gene Expression Profiles Suggest a Better Cold Acclimation of Polyploids in the Alpine Species Ranunculus kuepferi (Ranunculaceae). Genes (Basel) 2021; 12:genes12111818. [PMID: 34828424 PMCID: PMC8625111 DOI: 10.3390/genes12111818] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 11/16/2021] [Accepted: 11/17/2021] [Indexed: 12/17/2022] Open
Abstract
Alpine habitats are shaped by harsh abiotic conditions and cold climates. Temperature stress can affect phenotypic plasticity, reproduction, and epigenetic profiles, which may affect acclimation and adaptation. Distribution patterns suggest that polyploidy seems to be advantageous under cold conditions. Nevertheless, whether temperature stress can induce gene expression changes in different cytotypes, and how the response is initialized through gene set pathways and epigenetic control remain vague for non-model plants. The perennial alpine plant Ranunculus kuepferi was used to investigate the effect of cold stress on gene expression profiles. Diploid and autotetraploid individuals were exposed to cold and warm conditions in climate growth chambers and analyzed via transcriptome sequencing and qRT-PCR. Overall, cold stress changed gene expression profiles of both cytotypes and induced cold acclimation. Diploids changed more gene set pathways than tetraploids, and suppressed pathways involved in ion/cation homeostasis. Tetraploids mostly activated gene set pathways related to cell wall and plasma membrane. An epigenetic background for gene regulation in response to temperature conditions is indicated. Results suggest that perennial alpine plants can respond to temperature extremes via altered gene expression. Tetraploids are better acclimated to cold conditions, enabling them to colonize colder climatic areas in the Alps.
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Affiliation(s)
- Eleni Syngelaki
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Georg-August-Universität Göttingen, 37073 Göttingen, Germany;
- Correspondence:
| | - Claudia Paetzold
- Department of Botany and Molecular Evolution, Senckenberg Research Institute, 60325 Frankfurt am Main, Germany;
| | - Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Georg-August-Universität Göttingen, 37073 Göttingen, Germany;
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11
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Mráz P, Mrázová V. Greater reproductive assurance of asexual plant compared with sexual relative in a low-density sympatric population: Experimental evidence for pollen limitation. J Evol Biol 2021; 34:1503-1509. [PMID: 34331325 DOI: 10.1111/jeb.13910] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 05/07/2021] [Accepted: 07/20/2021] [Indexed: 11/30/2022]
Abstract
High reproductive assurance is regarded as a key advantage of uniparentally reproducing organisms for establishing a new population. This demographic benefit should especially be relevant for plants with autonomous apomixis, that is those which produce seeds completely independently from mates and pollinators. Indeed, many autonomous apomicts occupy larger distributional ranges when compared to their sexual relatives, showing geographical parthenogenesis patterns. However, uniparental reproduction advantage has only rarely been quantified in natural populations and results provided a mixed support, partly because allopatric sexual and asexual populations were exposed to different environmental and pollination conditions causing considerable between-population variation in the level of reproductive assurance. Here, we compared the level and stability of reproductive assurance between sexual self-incompatible and asexual autonomously apomictic plants of Hieracium alpinum (Asteraceae) cultivated in a sympatric low-density population with two levels of spatial clumping of sexual plants. Overall, we found that the realized seed set (i.e. proportion of well-developed seeds per capitulum) of asexuals was ca. 3 times greater than that of sexuals (83% vs. 27%), whereas the variance of this trait expressed as coefficient of variation was ca. 4 times smaller in asexuals compared with sexuals (19% vs. 83%). Solitary sexual plants had more than 2 times lower realized seed set when compared to clumps composed of two spatially close (20-30 cm) sexual plants (13% vs. 34%). Our study provides experimental evidence for benefit of uniparental reproduction of asexuals in a sympatric situation when the availability of mates is limited. This, together with unpredictability of pollinator environment could provide autonomous apomicts with an ultimate demographic superiority during colonization reflected in geographical parthenogenesis observed in this species.
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Affiliation(s)
- Patrik Mráz
- Herbarium Collections and Department of Botany, Charles University, Praha, Czechia
| | - Viera Mrázová
- Herbarium Collections and Department of Botany, Charles University, Praha, Czechia
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12
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Karbstein K, Tomasello S, Hodač L, Lorberg E, Daubert M, Hörandl E. Moving beyond assumptions: Polyploidy and environmental effects explain a geographical parthenogenesis scenario in European plants. Mol Ecol 2021; 30:2659-2675. [PMID: 33871107 DOI: 10.1111/mec.15919] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 03/31/2021] [Accepted: 04/01/2021] [Indexed: 11/28/2022]
Abstract
Geographical parthenogenesis (GP) describes the phenomenon that apomicts tend to have larger distribution areas and/or occur at higher altitudes or latitudes compared to sexual relatives. However, the complex effects of genome-wide heterozygosity, ploidy, reproduction mode (sexual vs. apomictic), and environment shaping GP of plants are still not well understood. We ascertained ploidy and reproduction mode by flow cytometry of 221 populations, and added genomic RADseq data (maximum 33,165 loci) of 80 taxa of the Ranunculus auricomus polyploid plant complex in temperate Europe. We observed 7% mainly diploid sexual, 28% facultative apomictic (mean sexuality 7.1%), and 65% obligate apomictic populations. Sexuals occupied a more southern, smaller distribution area, whereas apomicts expanded their range to higher latitudes. Within the complex, we detected three main genetic clusters and highly reticulate relationships. A genetically-informed path analysis using GLMMs revealed several significant relationships. Sexuality of populations (percent of sexual seeds) was higher in diploids compared to polyploids, associated with more petals, and similar between forests and open habitats. In contrast to other apomictic plant complexes, sexuality was mainly positively correlated to solar radiation and isothermality, which fits the southern distribution. We found up to three times higher heterozygosity in polyploids compared to diploids, and generally more heterozygous individuals in forests compared with open habitats. Interestingly, we revealed a previously unknown positive association between heterozygosity and temperature seasonality, suggesting a higher resistance of polyploids to more extreme climatic conditions. We provide empirical evidence for intrinsic and extrinsic factors shaping the GP pattern in a polyploid plant complex.
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Affiliation(s)
- Kevin Karbstein
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, Göttingen, Germany.,Georg-August University School of Science (GAUSS), University of Göttingen, Göttingen, Germany
| | - Salvatore Tomasello
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, Göttingen, Germany
| | - Ladislav Hodač
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, Göttingen, Germany
| | - Ellen Lorberg
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, Göttingen, Germany
| | - Mareike Daubert
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, Göttingen, Germany.,Institute of Biology and Environmental Sciences, Carl von Ossietzky University, Oldenburg, Germany
| | - Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, Göttingen, Germany
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13
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Wang C, Wang T, Yin M, Eller F, Liu L, Brix H, Guo W. Transcriptome Analysis of Tetraploid and Octoploid Common Reed ( Phragmites australis). FRONTIERS IN PLANT SCIENCE 2021; 12:653183. [PMID: 34025698 PMCID: PMC8132968 DOI: 10.3389/fpls.2021.653183] [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: 01/27/2021] [Accepted: 04/06/2021] [Indexed: 06/12/2023]
Abstract
Polyploidization in plants is thought to have occurred as coping mechanism with environmental stresses. Polyploidization-driven adaptation is often achieved through interplay of gene networks involved in differentially expressed genes, which triggers the plant to evolve special phenotypic traits for survival. Phragmites australis is a cosmopolitan species with highly variable phenotypic traits and high adaptation capacity to various habitats. The species' ploidy level varies from 3x to 12x, thus it is an ideal organism to investigate the molecular evolution of polyploidy and gene regulation mediated by different numbers of chromosome copies. In this study, we used high-throughput RNAseq data as a tool, to analyze the gene expression profiles in tetraploid and octoploid P. australis. The estimated divergence time between tetraploid and octoploid P. australis was dated to the border between Pliocene and Pleistocene. This study identified 439 up- and 956 down-regulated transcripts in tetraploids compared to octoploids. Gene ontology and pathway analysis revealed that tetraploids tended to express genes responsible for reproduction and seed germination to complete the reproduction cycle early, and expressed genes related to defense against UV-B light and fungi, whereas octoploids expressed mainly genes related to thermotolerance. Most differentially expressed genes were enriched in chaperones, folding catalysts and protein processing in endoplasmic reticulum pathways. Multiple biased isoform usage of the same gene was detected in differentially expressed genes, and the ones upregulated in octoploids were related to reduced DNA methylation. Our study provides new insights into the role of polyploidization on environmental responses and potential stress tolerance in grass species.
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Affiliation(s)
- Cui Wang
- Institute of Ecology and Biodiversity, Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, School of Life Sciences, Shandong University, Qingdao, China
- Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Tong Wang
- College of Landscape Architecture and Forestry, Qingdao Agricultural University, Qingdao, China
| | - Meiqi Yin
- Institute of Ecology and Biodiversity, Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, School of Life Sciences, Shandong University, Qingdao, China
| | | | - Lele Liu
- Institute of Ecology and Biodiversity, Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, School of Life Sciences, Shandong University, Qingdao, China
| | - Hans Brix
- Department of Biology, Aarhus University, Aarhus, Denmark
| | - Weihua Guo
- Institute of Ecology and Biodiversity, Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, School of Life Sciences, Shandong University, Qingdao, China
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14
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Soliman M, Podio M, Marconi G, Di Marsico M, Ortiz JPA, Albertini E, Delgado L. Differential Epigenetic Marks Are Associated with Apospory Expressivity in Diploid Hybrids of Paspalum rufum. PLANTS (BASEL, SWITZERLAND) 2021; 10:plants10040793. [PMID: 33920644 PMCID: PMC8072704 DOI: 10.3390/plants10040793] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/13/2021] [Accepted: 04/15/2021] [Indexed: 06/12/2023]
Abstract
Apomixis seems to emerge from the deregulation of preexisting genes involved in sexuality by genetic and/or epigenetic mechanisms. The trait is associated with polyploidy, but diploid individuals of Paspalum rufum can form aposporous embryo sacs and develop clonal seeds. Moreover, diploid hybrid families presented a wide apospory expressivity variation. To locate methylation changes associated with apomixis expressivity, we compare relative DNA methylation levels, at CG, CHG, and CHH contexts, between full-sib P. rufum diploid genotypes presenting differential apospory expressivity. The survey was performed using a methylation content-sensitive enzyme ddRAD (MCSeEd) strategy on samples at premeiosis/meiosis and postmeiosis stages. Based on the relative methylation level, principal component analysis and heatmaps, clearly discriminate samples with contrasting apospory expressivity. Differential methylated contigs (DMCs) showed 14% of homology to known transcripts of Paspalum notatum reproductive transcriptome, and almost half of them were also differentially expressed between apomictic and sexual samples. DMCs showed homologies to genes involved in flower growth, development, and apomixis. Moreover, a high proportion of DMCs aligned on genomic regions associated with apomixis in Setaria italica. Several stage-specific differential methylated sequences were identified as associated with apospory expressivity, which could guide future functional gene characterization in relation to apomixis success at diploid and tetraploid levels.
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Affiliation(s)
- Mariano Soliman
- CONICET-UNR/Laboratorio de Biología Molecular, Facultad de Ciencias Agrarias, Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR), Universidad Nacional de Rosario, Zavalla S2123, Argentina; (M.S.); (M.P.); (J.P.A.O.)
| | - Maricel Podio
- CONICET-UNR/Laboratorio de Biología Molecular, Facultad de Ciencias Agrarias, Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR), Universidad Nacional de Rosario, Zavalla S2123, Argentina; (M.S.); (M.P.); (J.P.A.O.)
| | - Gianpiero Marconi
- Department Agricultural, Food and Environmental Sciences, University of Perugia, 06121 Perugia, Italy; (G.M.); (M.D.M.)
| | - Marco Di Marsico
- Department Agricultural, Food and Environmental Sciences, University of Perugia, 06121 Perugia, Italy; (G.M.); (M.D.M.)
| | - Juan Pablo A. Ortiz
- CONICET-UNR/Laboratorio de Biología Molecular, Facultad de Ciencias Agrarias, Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR), Universidad Nacional de Rosario, Zavalla S2123, Argentina; (M.S.); (M.P.); (J.P.A.O.)
| | - Emidio Albertini
- Department Agricultural, Food and Environmental Sciences, University of Perugia, 06121 Perugia, Italy; (G.M.); (M.D.M.)
| | - Luciana Delgado
- CONICET-UNR/Laboratorio de Biología Molecular, Facultad de Ciencias Agrarias, Instituto de Investigaciones en Ciencias Agrarias de Rosario (IICAR), Universidad Nacional de Rosario, Zavalla S2123, Argentina; (M.S.); (M.P.); (J.P.A.O.)
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15
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Sun J, Sun R, Liu H, Chang L, Li S, Zhao M, Shennan C, Lei J, Dong J, Zhong C, Xue L, Gao Y, Wang G, Zhang Y. Complete chloroplast genome sequencing of ten wild Fragaria species in China provides evidence for phylogenetic evolution of Fragaria. Genomics 2021; 113:1170-1179. [PMID: 33705887 DOI: 10.1016/j.ygeno.2021.01.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 01/02/2021] [Accepted: 01/23/2021] [Indexed: 02/04/2023]
Abstract
Complete chloroplast genomes of ten wild Fragaria species native to China were sequenced. Phylogenetic analysis clustered Fragaria species into two clades: The south clade (F. iinumae, F. chinensis, F. pentaphylla, F. nilgerrensis, F. daltoniana, F. corymbosa, F. moupinensis, F. tibetica, F. nipponica, F. gracilis, and F. nubicola and north clade (F. viridis, F. orientalis, F. moschata, F. mandshurica, F. vesca, F. chiloensis, F. virginiana, and F. × ananassa), while F. iinumae is the oldest extant species. Molecular clock analysis suggested present Fragaria species share a common ancestor 3.57 million years ago (Ma), F. moschata and octoploid species evolve 0.89 and 0.97 Ma, respectively, but F. moschata be not directly involved in current octoploid species formation. Drastic global temperature change since the Palaeocene-Eocene, approx. 55 Ma, especially during uplifting of the Qinghai-Tibet plateau and quaternary glaciation may have driven the formation of Fragaria, separation of two groups and polyploidization.
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Affiliation(s)
- Jian Sun
- Beijing Academy of Forestry and Pomology Sciences; Beijing Engineering Research Center for Strawberry; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, 100093 Beijing, China
| | - Rui Sun
- Beijing Academy of Forestry and Pomology Sciences; Beijing Engineering Research Center for Strawberry; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, 100093 Beijing, China
| | - Huabo Liu
- Beijing Academy of Forestry and Pomology Sciences; Beijing Engineering Research Center for Strawberry; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, 100093 Beijing, China
| | - Linlin Chang
- Beijing Academy of Forestry and Pomology Sciences; Beijing Engineering Research Center for Strawberry; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, 100093 Beijing, China
| | - Shuangtao Li
- Beijing Academy of Forestry and Pomology Sciences; Beijing Engineering Research Center for Strawberry; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, 100093 Beijing, China
| | - Mizhen Zhao
- Institute of Pomology, Jiangsu Academy of Agricultural Sciences, 210014 Nanjing, China
| | - Carol Shennan
- Environmental Studies, University of California Santa Cruz, 95064 Santa Cruz, CA, USA.
| | - Jiajun Lei
- Department of Horticulture, Shenyang Agricultural University, 110866 Shenyang, China
| | - Jing Dong
- Beijing Academy of Forestry and Pomology Sciences; Beijing Engineering Research Center for Strawberry; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, 100093 Beijing, China
| | - Chuanfei Zhong
- Beijing Academy of Forestry and Pomology Sciences; Beijing Engineering Research Center for Strawberry; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, 100093 Beijing, China
| | - Li Xue
- Department of Horticulture, Shenyang Agricultural University, 110866 Shenyang, China
| | - Yongshun Gao
- Beijing Academy of Forestry and Pomology Sciences; Beijing Engineering Research Center for Strawberry; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, 100093 Beijing, China
| | - Guixia Wang
- Beijing Academy of Forestry and Pomology Sciences; Beijing Engineering Research Center for Strawberry; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, 100093 Beijing, China.
| | - Yuntao Zhang
- Beijing Academy of Forestry and Pomology Sciences; Beijing Engineering Research Center for Strawberry; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, 100093 Beijing, China.
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16
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The Application of Flow Cytometry for Estimating Genome Size, Ploidy Level Endopolyploidy, and Reproductive Modes in Plants. Methods Mol Biol 2021; 2222:325-361. [PMID: 33301101 DOI: 10.1007/978-1-0716-0997-2_17] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Over the years, the amount of DNA in a nucleus (genome size) has been estimated using a variety of methods, but increasingly, flow cytometry (FCM) has become the method of choice. The popularity of this technique lies in the ease of sample preparation and in the large number of particles (i.e., nuclei) that can be analyzed in a very short period of time. This chapter presents a step-by-step guide to estimating the nuclear DNA content of plant nuclei using FCM. Attempting to serve as a tool for daily laboratory practice, we list, in detail, the equipment required, specific reagents and buffers needed, as well as the most frequently used protocols to carry out nuclei isolation. In addition, solutions to the most common problems that users may encounter when working with plant material and troubleshooting advice are provided. Finally, information about the correct terminology to use and the importance of obtaining chromosome counts to avoid cytological misinterpretations of the FCM data are discussed.
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Duchoslav M, Jandová M, Kobrlová L, Šafářová L, Brus J, Vojtěchová K. Intricate Distribution Patterns of Six Cytotypes of Allium oleraceum at a Continental Scale: Niche Expansion and Innovation Followed by Niche Contraction With Increasing Ploidy Level. FRONTIERS IN PLANT SCIENCE 2020; 11:591137. [PMID: 33362819 PMCID: PMC7755979 DOI: 10.3389/fpls.2020.591137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 11/06/2020] [Indexed: 05/23/2023]
Abstract
The establishment and success of polyploids are thought to often be facilitated by ecological niche differentiation from diploids. Unfortunately, most studies compared diploids and polyploids, ignoring variation in ploidy level in polyploids. To fill this gap, we performed a large-scale study of 11,163 samples from 1,283 populations of the polyploid perennial geophyte Allium oleraceum with reported mixed-ploidy populations, revealed distribution ranges of cytotypes, assessed their niches and explored the pattern of niche change with increasing ploidy level. Altogether, six ploidy levels (3x-8x) were identified. The most common were pentaploids (53.6%) followed by hexaploids (22.7%) and tetraploids (21.6%). Higher cytotype diversity was found at lower latitudes than at higher latitudes (>52° N), where only tetraploids and pentaploids occurred. We detected 17.4% of mixed-ploidy populations, usually as a combination of two, rarely of three, cytotypes. The majority of mixed-ploidy populations were found in zones of sympatry of the participating cytotypes, suggesting they have arisen through migration (secondary contact zone). Using coarse-grained variables (climate, soil), we found evidence of both niche expansion and innovation in tetraploids related to triploids, whereas higher ploidy levels showed almost zero niche expansion, but a trend of increased niche unfilling of tetraploids. Niche unfilling in higher ploidy levels was caused by a contraction of niche envelopes toward lower continentality of the climate and resulted in a gradual decrease of niche breadth and a gradual shift in niche optima. Field-recorded data indicated wide habitat breadth of tetraploids and pentaploids, but also a pattern of increasing synanthropy in higher ploidy levels. Wide niche breadth of tetra- and pentaploids might be related to their multiple origins from different environmental conditions, higher "age", and retained sexuality, which likely preserve their adaptive potential. In contrast, other cytotypes with narrower niches are mostly asexual, probably originating from a limited range of contrasting environments. Persistence of local ploidy mixtures could be enabled by the perenniality of A. oleraceum and its prevalence of vegetative reproduction, facilitating the establishment and decreasing exclusion of minority cytotype due to its reproductive costs. Vegetative reproduction might also significantly accelerate colonization of new areas, including recolonization of previously glaciated areas.
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Affiliation(s)
- Martin Duchoslav
- Plant Biosystematics and Ecology RG, Department of Botany, Faculty of Science, Palacký University, Olomouc, Czechia
| | - Michaela Jandová
- Plant Biosystematics and Ecology RG, Department of Botany, Faculty of Science, Palacký University, Olomouc, Czechia
- Institute of Botany, Czech Academy of Sciences, Pruhonice, Czechia
| | - Lucie Kobrlová
- Plant Biosystematics and Ecology RG, Department of Botany, Faculty of Science, Palacký University, Olomouc, Czechia
| | - Lenka Šafářová
- Plant Biosystematics and Ecology RG, Department of Botany, Faculty of Science, Palacký University, Olomouc, Czechia
| | - Jan Brus
- Department of Geoinformatics, Faculty of Science, Palacký University, Olomouc, Czechia
| | - Kateřina Vojtěchová
- Plant Biosystematics and Ecology RG, Department of Botany, Faculty of Science, Palacký University, Olomouc, Czechia
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18
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Syngelaki E, Daubert M, Klatt S, Hörandl E. Phenotypic Responses, Reproduction Mode and Epigenetic Patterns under Temperature Treatments in the Alpine Plant Species Ranunculus kuepferi (Ranunculaceae). BIOLOGY 2020; 9:E315. [PMID: 33003474 PMCID: PMC7600421 DOI: 10.3390/biology9100315] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/18/2020] [Accepted: 09/26/2020] [Indexed: 12/04/2022]
Abstract
Plant life in alpine habitats is shaped by harsh abiotic conditions and cold climates. Phenotypic variation of morphological characters and reproduction can be influenced by temperature stress. Nevertheless, little is known about the performance of different cytotypes under cold stress and how epigenetic patterns could relate to phenotypic variation. Ranunculus kuepferi, a perennial alpine plant, served as a model system for testing the effect of cold stress on phenotypic plasticity, reproduction mode, and epigenetic variation. Diploid and autotetraploid individuals were placed in climate growth cabinets under warm and cold conditions. Morphological traits (height, leaves and flowers) and the proportion of well-developed seeds were measured as fitness indicators, while flow cytometric seed screening (FCSS) was utilized to determine the reproduction mode. Subsequently, comparisons with patterns of methylation-sensitive amplified fragment-length polymorphisms (AFLPs) were conducted. Diploids grew better under warm conditions, while tetraploids performed better in cold treatments. Epigenetic patterns were correlated with the expressed morphological traits. Cold stress reduced the reproduction fitness but did not induce apomixis in diploids. Overall, our study underlines the potential of phenotypic plasticity for acclimation under environmental conditions and confirms the different niche preferences of cytotypes in natural populations. Results help to understand the pattern of geographical parthenogenesis in the species.
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Affiliation(s)
- Eleni Syngelaki
- Albrecht-von-Haller-Institute for Plant Sciences, Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Georg-August-Universität Göttingen, 37073 Göttingen, Germany;
| | - Mareike Daubert
- Institute of Biology and Environmental Sciences, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany;
| | - Simone Klatt
- Section Safety and Environmental Protection, Georg-August-Universität Göttingen, 37073 Göttingen, Germany;
| | - Elvira Hörandl
- Albrecht-von-Haller-Institute for Plant Sciences, Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Georg-August-Universität Göttingen, 37073 Göttingen, Germany;
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19
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Nardi FD, Hülber K, Moser D, Alonso‐Marcos H, Tribsch A, Dobeš C. Occurrence of apomictic conspecifics and ecological preferences rather than colonization history govern the geographic distribution of sexual Potentilla puberula. Ecol Evol 2020; 10:7306-7319. [PMID: 32760530 PMCID: PMC7391561 DOI: 10.1002/ece3.6455] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/20/2020] [Accepted: 05/11/2020] [Indexed: 11/24/2022] Open
Abstract
The geographic distribution of sexual-apomictic taxa (i.e., comprising individuals usually reproducing either sexually or asexually via seeds) is traditionally thought to be driven by their ecological preferences and colonization histories. Where sexuals and apomicts get into contact with each other, competitive and reproductive interactions can interfere with these factors, an aspect which hitherto received little attention in biogeographic studies. We disentangled and quantified the relative effects of the three factors on the distribution of tetraploid sexuals in Potentilla puberula in a latitudinal transect through the Eastern European Alps, in which they are codistributed with penta-, hepta-, and octoploid apomictic conspecifics. Effects were explored by means of binomial generalized linear regression models combining a single with a multiple predictor approach. Postglacial colonization history was inferred from population genetic variation (AFLPs and cpDNA) and quantified using a cost distance metric. The study was based on 235 populations, which were purely sexual, purely apomictic, or of mixed reproductive mode. The occurrence of apomicts explained most of the variation in the distribution of sexuals (31%). Specifically, the presence of sexual tetraploids was negatively related to the presence of each of the three apomictic cytotypes. Effects of ecological preferences were substantial too (7% and 12% of the total variation explained by ecological preferences alone, or jointly with apomicts' occurrence, respectively). In contrast, colonization history had negligible effects on the occurrence of sexuals. Taken together, our results highlight the potentially high impact of reproductive interactions on the geographic distribution of sexual and apomictic conspecifics and that resultant mutual exclusion interrelates to ecological differentiation, a situation potentially promoting their local coexistence.
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Affiliation(s)
- Flavia Domizia Nardi
- Department of Forest GeneticsAustrian Research Centre for ForestsViennaAustria
- Department of BiosciencesUniversity of SalzburgSalzburgAustria
| | - Karl Hülber
- Department of Conservation Biology, Vegetation Ecology and Landscape EcologyUniversity of ViennaViennaAustria
| | - Dietmar Moser
- Department of Conservation Biology, Vegetation Ecology and Landscape EcologyUniversity of ViennaViennaAustria
| | - Henar Alonso‐Marcos
- Department of Forest GeneticsAustrian Research Centre for ForestsViennaAustria
- Department of Conservation Biology, Vegetation Ecology and Landscape EcologyUniversity of ViennaViennaAustria
| | - Andreas Tribsch
- Department of BiosciencesUniversity of SalzburgSalzburgAustria
| | - Christoph Dobeš
- Department of Forest GeneticsAustrian Research Centre for ForestsViennaAustria
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Chasing the Apomictic Factors in the Ranunculus auricomus Complex: Exploring Gene Expression Patterns in Microdissected Sexual and Apomictic Ovules. Genes (Basel) 2020; 11:genes11070728. [PMID: 32630035 PMCID: PMC7397075 DOI: 10.3390/genes11070728] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/10/2020] [Accepted: 06/27/2020] [Indexed: 12/24/2022] Open
Abstract
Apomixis, the asexual reproduction via seeds, is associated to polyploidy and hybridization. To identify possible signatures of apomixis, and possible candidate genes underlying the shift from sex to apomixis, microarray-based gene expression patterns of live microdissected ovules at four different developmental stages were compared between apomictic and sexual individuals of the Ranunculus auricomus complex. Following predictions from previous work on mechanisms underlying apomixis penetrance and expressivity in the genus, gene expression patterns were classified into three categories based on their relative expression in apomicts compared to their sexual parental ancestors. We found evidence of misregulation and differential gene expression between apomicts and sexuals, with the highest number of differences detected during meiosis progression and emergence of aposporous initial (AI) cells, a key developmental stage in the ovule of apomicts where a decision between divergent reproductive pathways takes place. While most of the differentially expressed genes (DEGs) could not be annotated, gene expression was classified into transgressive, parent of origin and ploidy effects. Genes related to gametogenesis and meiosis demonstrated patterns reflective of transgressive and genome dosage effects, which support the hypothesis of a dominant factor controlling apomixis in Ranunculus and modulated by secondary modifiers. Three genes with probable functions in sporogenesis and gametogenesis development are identified and characterized for future studies.
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21
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Karunarathne P, Reutemann AV, Schedler M, Glücksberg A, Martínez EJ, Honfi AI, Hojsgaard DH. Sexual modulation in a polyploid grass: a reproductive contest between environmentally inducible sexual and genetically dominant apomictic pathways. Sci Rep 2020; 10:8319. [PMID: 32433575 PMCID: PMC7239852 DOI: 10.1038/s41598-020-64982-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 04/25/2020] [Indexed: 12/24/2022] Open
Abstract
In systems alternating between sexual and asexual reproduction, sex increases under unfavorable environmental conditions. In plants producing sexual and asexual (apomictic) seeds, studies on the influence of environmental factors on sex are equivocal. We used Paspalum intermedium to study environmental effects on the expression of sexual and apomictic developments, and on resulting reproductive fitness variables. Flow cytometric and embryological analyses were performed to characterize ploidy and reproductive modes, and effects of local climatic conditions on sexual and apomictic ovule and seed frequencies were determined. Seed set and germination data were collected and used to estimate reproductive fitness. Frequencies of sexual and apomictic ovules and seeds were highly variable within and among populations. Apomictic development exhibited higher competitive ability but lower overall fitness. Frequencies of sexual reproduction in facultative apomictic plants increased at lower temperatures and wider mean diurnal temperature ranges. We identified a two-fold higher fitness advantage of sexuality and a Tug of War between factors intrinsic to apomixis and environmental stressors promoting sexuality which influence the distribution of sex in apomictic populations. This points toward a crucial role of local ecological conditions in promoting a reshuffling of genetic variability that may be shaping the adaptative landscape in apomictic P. intermedium plants.
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Affiliation(s)
- Piyal Karunarathne
- Department of Systematics, Biodiversity and Evolution of Plants, Albrecht-von-Haller Institute for Plant Sciences, University of Goettingen, Untere Karspuele 2, 37073, Goettingen, Germany.
- Georg-August University School of Science, University of Goettingen, Goettingen, Germany.
| | - Anna V Reutemann
- Department of Systematics, Biodiversity and Evolution of Plants, Albrecht-von-Haller Institute for Plant Sciences, University of Goettingen, Untere Karspuele 2, 37073, Goettingen, Germany
- Instituto de Botánica del Nordeste (IBONE), Facultad de Ciencias Agrarias, Universidad Nacional del Nordeste (FCA-UNNE), CC209, 3400, Corrientes, Argentina
| | - Mara Schedler
- Instituto de Botánica del Nordeste (IBONE), Facultad de Ciencias Agrarias, Universidad Nacional del Nordeste (FCA-UNNE), CC209, 3400, Corrientes, Argentina
| | - Adriana Glücksberg
- Instituto de Botánica del Nordeste (IBONE), Facultad de Ciencias Agrarias, Universidad Nacional del Nordeste (FCA-UNNE), CC209, 3400, Corrientes, Argentina
| | - Eric J Martínez
- Instituto de Botánica del Nordeste (IBONE), Facultad de Ciencias Agrarias, Universidad Nacional del Nordeste (FCA-UNNE), CC209, 3400, Corrientes, Argentina
| | - Ana I Honfi
- Programa de Estudios Florísticos y Genética Vegetal, Instituto de Biología Subtropical (CONICET-UNaM), Facultad de Ciencias Exactas, Químicas y Naturales, Universidad Nacional de Misiones, Rivadavia 2370, 3300, Posadas, Misiones, Argentina
| | - Diego H Hojsgaard
- Department of Systematics, Biodiversity and Evolution of Plants, Albrecht-von-Haller Institute for Plant Sciences, University of Goettingen, Untere Karspuele 2, 37073, Goettingen, Germany.
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Schinkel CCF, Syngelaki E, Kirchheimer B, Dullinger S, Klatt S, Hörandl E. Epigenetic Patterns and Geographical Parthenogenesis in the Alpine Plant Species Ranunculus kuepferi (Ranunculaceae). Int J Mol Sci 2020; 21:E3318. [PMID: 32392879 PMCID: PMC7247541 DOI: 10.3390/ijms21093318] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 05/04/2020] [Accepted: 05/05/2020] [Indexed: 12/31/2022] Open
Abstract
Polyploidization and the shift to apomictic reproduction are connected to changes in DNA cytosine-methylation. Cytosine-methylation is further sensitive to environmental conditions. We, therefore, hypothesize that DNA methylation patterns would differentiate within species with geographical parthenogenesis, i.e., when diploid sexual and polyploid apomictic populations exhibit different spatial distributions. On natural populations of the alpine plant Ranunculus kuepferi, we tested differences in methylation patterns across two cytotypes (diploid, tetraploid) and three reproduction modes (sexual, mixed, apomictic), and their correlation to environmental data and geographical distributions. We used methylation-sensitive amplified fragment-length polymorphism (methylation-sensitive AFLPs) and scored three types of epiloci. Methylation patterns differed independently between cytotypes versus modes of reproduction and separated three distinct combined groups (2x sexual + mixed, 4x mixed, and 4x apomictic), with differentiation of 4x apomicts in all epiloci. We found no global spatial autocorrelation, but instead correlations to elevation and temperature gradients in 22 and 36 epiloci, respectively. Results suggest that methylation patterns in R. kuepferi were altered by cold conditions during postglacial recolonization of the Alps, and by the concomitant shift to facultative apomixis, and by polyploidization. Obligate apomictic tetraploids at the highest elevations established a distinct methylation profile. Methylation patterns reflect an ecological gradient rather than the geographical differentiation.
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Affiliation(s)
- Christoph C. F. Schinkel
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), University of Goettingen, Untere Karspüle 2, 37073 Göttingen, Germany;
| | - Eleni Syngelaki
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), University of Goettingen, Untere Karspüle 2, 37073 Göttingen, Germany;
| | - Bernhard Kirchheimer
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030 Vienna, Austria; (B.K.); (S.D.)
| | - Stefan Dullinger
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030 Vienna, Austria; (B.K.); (S.D.)
| | - Simone Klatt
- Section Safety and Environmental Protection, University of Goettingen, Humboldtallee 15, 37073 Göttingen, Germany;
| | - Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), University of Goettingen, Untere Karspüle 2, 37073 Göttingen, Germany;
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Syngelaki E, Schinkel CCF, Klatt S, Hörandl E. Effects of Temperature Treatments on Cytosine-Methylation Profiles of Diploid and Autotetraploid Plants of the Alpine Species Ranunculus kuepferi (Ranunculaceae). FRONTIERS IN PLANT SCIENCE 2020; 11:435. [PMID: 32322263 PMCID: PMC7158262 DOI: 10.3389/fpls.2020.00435] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 03/25/2020] [Indexed: 05/23/2023]
Abstract
The exposure to environmental stress can trigger epigenetic variation, which may have several evolutionary consequences. Polyploidy seems to affect the DNA methylation profiles. Nevertheless, it abides unclear whether temperature stress can induce methylations changes in different cytotypes and to what extent a treatment shift is translated to an epigenetic response. A suitable model system for studying these questions is Ranunculus kuepferi, an alpine perennial herb. Diploid and autotetraploid individuals of R. kuepferi were exposed to cold (+7°C day/+2°C night; frost treatment -1°C cold shocks for 3 nights per week) and warm (+15° day/+10°C night) conditions in climate growth chambers for two consecutive flowering periods and shifted from one condition to the other after the first flowering period. Methylation-sensitive amplified fragment-length polymorphism markers were applied for both years, to track down possible alterations induced by the stress treatments. Patterns of methylation suggested that cytotypes differed significantly in their profiles, independent from year of treatment. Likewise, the treatment shift had an impact on both cytotypes, resulting in significantly less epiloci, regardless the shift's direction. The AMOVAs revealed higher variation within than among treatments in diploids. In tetraploids, internally-methylated loci had a higher variation among than within treatments, as a response to temperature's change in both directions, and support the hypothesis of temperature stress affecting the epigenetic variation. Results suggest that the temperature-sensitivity of DNA methylation patterns shows a highly dynamic phenotypic plasticity in R. kuepferi, as both cytotypes responded to temperature shifts. Furthermore, ploidy level, even without effects of hybridization, has an important effect on epigenetic background variation, which may be correlated with the DNA methylation dynamics during cold acclimation.
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Affiliation(s)
- Eleni Syngelaki
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Christoph C. F. Schinkel
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Simone Klatt
- Section Safety and Environmental Protection, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-Universität Göttingen, Göttingen, Germany
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24
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Ulum FB, Costa Castro C, Hörandl E. Ploidy-Dependent Effects of Light Stress on the Mode of Reproduction in the Ranunculus auricomus Complex (Ranunculaceae). FRONTIERS IN PLANT SCIENCE 2020; 11:104. [PMID: 32153611 PMCID: PMC7044147 DOI: 10.3389/fpls.2020.00104] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 01/23/2020] [Indexed: 05/04/2023]
Abstract
Polyploidy in angiosperms is an influential factor to trigger apomixis, the reproduction of asexual seeds. Apomixis is usually facultative, which means that both sexual and apomictic seeds can be formed by the same plant. Environmental abiotic stress, e.g. light stress, can change the frequency of apomixis. Previous work suggested effects of stress treatments on meiosis and megasporogenesis. We hypothesized that polyploidy would alter the stress response and hence reproductive phenotypes of different cytotypes. The main aims of this research were to explore with prolonged photoperiods, whether polyploidy alters proportions of sexual ovule and sexual seed formation under light stress conditions. We used three facultative apomictic, pseudogamous cytotypes of the Ranunculus auricomus complex (diploid, tetraploid, and hexaploid). Stress treatments were applied by extended light periods (16.5 h) and control (10 h) in climate growth chambers. Proportions of apomeiotic vs. meiotic development in the ovule were evaluated with clearing methods, and mode of seed formation was examined by single seed flow cytometric seed screening (ssFCSS). We further studied pollen stainability to understand effects of pollen quality on seed formation. Results revealed that under extended photoperiod, all cytotypes produced significantly more sexual ovules than in the control, with strongest effects on diploids. The stress treatment affected neither the frequency of seed set nor the proportion of sexual seeds nor pollen quality. Successful seed formation appears to be dependent on balanced maternal: paternal genome contributions. Diploid cytotypes had mostly sexual seed formation, while polyploid cytotypes formed predominantly apomictic seeds. Pollen quality was in hexaploids better than in diploids and tetraploids. These findings confirm our hypothesis that megasporogenesis is triggered by light stress treatments. Comparisons of cytotypes support the hypothesis that ovule development in polyploid plants is less sensitive to prolonged photoperiods and responds to a lesser extent with sexual ovule formation. Polyploids may better buffer environmental stress, which releases the potential for aposporous ovule development from somatic cells, and may facilitate the establishment of apomictic seed formation.
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Affiliation(s)
- Fuad Bahrul Ulum
- Department of Systematics, Biodiversity and Evolution of Plants, Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, Göttingen, Germany
- Biology Department, Faculty of Mathematics and Sciences, Jember University, Jember, Indonesia
| | - Camila Costa Castro
- Department of Systematics, Biodiversity and Evolution of Plants, Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, Göttingen, Germany
| | - Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants, Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, Göttingen, Germany
- *Correspondence: Elvira Hörandl,
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Ruiz M, Oustric J, Santini J, Morillon R. Synthetic Polyploidy in Grafted Crops. FRONTIERS IN PLANT SCIENCE 2020; 11:540894. [PMID: 33224156 PMCID: PMC7674608 DOI: 10.3389/fpls.2020.540894] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 09/28/2020] [Indexed: 05/05/2023]
Abstract
Synthetic polyploids have been extensively studied for breeding in the last decade. However, the use of such genotypes at the agronomical level is still limited. Polyploidization is known to modify certain plant phenotypes, while leaving most of the fundamental characteristics apparently untouched. For this reason, polyploid breeding can be very useful for improving specific traits of crop varieties, such as quality, yield, or environmental adaptation. Nevertheless, the mechanisms that underlie polyploidy-induced novelty remain poorly understood. Ploidy-induced phenotypes might also include some undesired effects that need to be considered. In the case of grafted or composite crops, benefits can be provided both by the rootstock's adaptation to the soil conditions and by the scion's excellent yield and quality. Thus, grafted crops provide an extraordinary opportunity to exploit artificial polyploidy, as the effects can be independently applied and explored at the root and/or scion level, increasing the chances of finding successful combinations. The use of synthetic tetraploid (4x) rootstocks may enhance adaptation to biotic and abiotic stresses in perennial crops such as apple or citrus. However, their use in commercial production is still very limited. Here, we will review the current and prospective use of artificial polyploidy for rootstock and scion improvement and the implications of their combination. The aim is to provide insight into the methods used to generate and select artificial polyploids and their limitations, the effects of polyploidy on crop phenotype (anatomy, function, quality, yield, and adaptation to stresses) and their potential agronomic relevance as scions or rootstocks in the context of climate change.
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Affiliation(s)
- Marta Ruiz
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias, Moncada, Spain
- Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA, United States
| | - Julie Oustric
- Laboratoire Biochimie et Biologie Moléculaire du Végétal, CNRS, UMR 6134 SPE, Université de Corse, Corte, France
| | - Jérémie Santini
- Laboratoire Biochimie et Biologie Moléculaire du Végétal, CNRS, UMR 6134 SPE, Université de Corse, Corte, France
| | - Raphaël Morillon
- CIRAD, UMR AGAP, Equipe SEAPAG, F-97170 Petit-Bourg, Guadeloupe, France - AGAP, Univ Montpellier, CIRAD, INRAE, Institut Agro, Montpellier, France
- *Correspondence: Raphaël Morillon,
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Tang Q, Xu Y, Deng C, Cheng C, Dai Z, Yang Z, Liu C, Su J. A Full-Length Reference Floral Transcriptome of Boehmeria tricuspis Provides Insights into Apomeiosis and Polyploidy. Int J Genomics 2019; 2019:4025747. [PMID: 31950027 PMCID: PMC6948294 DOI: 10.1155/2019/4025747] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 11/21/2019] [Indexed: 01/27/2023] Open
Abstract
Boehmeria tricuspis (Hance) Makino constitutes a hardy herbaceous or shrubby perennial native to East Asia that includes different ploidy levels and reproductive modes (diplosporous to sexual). Although several apomeiosis-associated genes have been described, the genetic control and molecular mechanisms underlying apomeiosis remain poorly understood. Moreover, the basis of the correlation between polyploidy and apomixis has not yet been clarified. We utilized long-read sequencing to produce a full-length reference floral transcriptome of B. tricuspis. Based on the generated database, gene expression of the female flowers of different ploidy levels and reproductive mode cytotypes was compared. Overall, 1,387 genes related to apomeiosis, 217 genes related to ploidy, and 9 genes associated with both apomixis and ploidy were identified. Gene Ontology analyses of this set of transcripts indicated reproductive genes, especially those related to "cell differentiation" and "cell cycle process," as significant factors regulating apomeiosis. Furthermore, our results suggested that different expressions of stress response genes might be important in the preparation for apomeiosis transition. In addition, our observations indicated that the expression of apomeiosis may not depend on polyploidy but rather on deregulation of the sexual pathway in B. tricuspis.
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Affiliation(s)
- Qing Tang
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205 Hunan, China
- Key Laboratory of Biology and Processing of Bast Fiber, Ministry of Agriculture and Rural Affairs, Changsha, 410205 Hunan, China
| | - Ying Xu
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205 Hunan, China
- Key Laboratory of Biology and Processing of Bast Fiber, Ministry of Agriculture and Rural Affairs, Changsha, 410205 Hunan, China
| | - Canhui Deng
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205 Hunan, China
- Key Laboratory of Biology and Processing of Bast Fiber, Ministry of Agriculture and Rural Affairs, Changsha, 410205 Hunan, China
| | - Chaohua Cheng
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205 Hunan, China
- Key Laboratory of Biology and Processing of Bast Fiber, Ministry of Agriculture and Rural Affairs, Changsha, 410205 Hunan, China
| | - Zhigang Dai
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205 Hunan, China
- Key Laboratory of Biology and Processing of Bast Fiber, Ministry of Agriculture and Rural Affairs, Changsha, 410205 Hunan, China
| | - Zemao Yang
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205 Hunan, China
- Key Laboratory of Biology and Processing of Bast Fiber, Ministry of Agriculture and Rural Affairs, Changsha, 410205 Hunan, China
| | - Chan Liu
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205 Hunan, China
- Key Laboratory of Biology and Processing of Bast Fiber, Ministry of Agriculture and Rural Affairs, Changsha, 410205 Hunan, China
| | - Jianguang Su
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205 Hunan, China
- Key Laboratory of Biology and Processing of Bast Fiber, Ministry of Agriculture and Rural Affairs, Changsha, 410205 Hunan, China
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27
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Brožová V, Koutecký P, Doležal J. Plant apomixis is rare in Himalayan high-alpine flora. Sci Rep 2019; 9:14386. [PMID: 31591463 PMCID: PMC6779868 DOI: 10.1038/s41598-019-50907-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 09/19/2019] [Indexed: 11/21/2022] Open
Abstract
Gametophytic apomixis is a way of asexual plant reproduction by seeds. It should be advantageous under stressful high altitude or latitude environment where short growing seasons, low temperatures, low pollinator activity or unstable weather may hamper sexual reproduction. However, this hypothesis remains largely untested. Here, we assess the reproductive mode in 257 species belonging to 45 families from the world's broadest alpine belt (2800-6150 m) in NW Himalayas using flow cytometric seed screen. We found only 12 apomictic species, including several members of Poaceae (Festuca, Poa and Stipa), Rosaceae (Potentilla) and Ranunculaceae (Halerpestes, Ranunculus), which are families typical for high apomict frequency. However, several apomictic species were newly discovered, including the first known apomictic species from the family Biebersteiniaceae (Biebersteinia odora), and first apomicts from the genera Stipa (Stipa splendens) and Halerpestes (Halerpestes lancifolia). Apomicts showed no preference for higher elevations, even in these extreme Himalayan alpine habitats. Additional trait-based analyses revealed that apomicts differed from sexuals in comprising more rhizomatous graminoids and forbs, higher soil moisture demands, sharing the syndrome of dominant species with broad geographical and elevation ranges typical for the late-successional habitats. Apomicts differ from non-apomicts in greater ability of clonal propagation and preference for wetter, more productive habitats.
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Affiliation(s)
- Viktorie Brožová
- Department of Botany, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic.
- Institute of Botany, The Czech Academy of Sciences, Dukelská 135, Třeboň, 379 01, Czech Republic.
| | - Petr Koutecký
- Department of Botany, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic
| | - Jiří Doležal
- Department of Botany, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic
- Institute of Botany, The Czech Academy of Sciences, Dukelská 135, Třeboň, 379 01, Czech Republic
- Laboratory of Tree Ring Research, University of Arizona, 1215 E. Lowell Street, Tucson, 85721, Arizona, USA
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28
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Abstract
This article is a Commentary on Wagner et al. 223: 2039–2053.
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Affiliation(s)
- Tod Stuessy
- Department of Botany and Biodiversity ResearchUniversity of ViennaRennweg 14A‐1030ViennaAustria
- Herbarium and Department of Evolution, Ecology, and Organismal BiologyThe Ohio State University1315 Kinnear AvenueColumbusOH43212USA
| | - Hanna Weiss‐Schneeweiss
- Department of Botany and Biodiversity ResearchUniversity of ViennaRennweg 14A‐1030ViennaAustria
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29
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Hojsgaard D, Hörandl E. The Rise of Apomixis in Natural Plant Populations. FRONTIERS IN PLANT SCIENCE 2019; 10:358. [PMID: 31001296 PMCID: PMC6454013 DOI: 10.3389/fpls.2019.00358] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 03/07/2019] [Indexed: 05/04/2023]
Abstract
Apomixis, the asexual reproduction via seed, has many potential applications for plant breeding by maintaining desirable genotypes over generations. Since most major crops do not express natural apomixis, it is useful to understand the origin and maintenance of apomixis in natural plant systems. Here, we review the state of knowledge on origin, establishment and maintenance of natural apomixis. Many studies suggest that hybridization, either on diploid or polyploid cytotypes, is a major trigger for the formation of unreduced female gametophytes, which represents the first step toward apomixis, and must be combined to parthenogenesis, the development of an unfertilized egg cell. Nevertheless, fertilization of endosperm is still needed for most apomictic plants. Coupling of these three steps appears to be a major constraint for shifts to natural apomixis. Adventitious embryony is another developmental pathway toward apomixis. Establishment of a newly arisen apomictic lineage is often fostered by side-effects of polyploidy. Polyploidy creates an immediate reproductive barrier against the diploid parental and progenitor populations; it can cause a breakdown of genetic self-incompatibility (SI) systems which is needed to establish self-fertility of pseudogamous apomictic lineages; and finally, polyploidy could indirectly help to establish an apomictic cytotype in a novel ecological niche by increasing adaptive potentials of the plants. This step may be followed by a phase of diversification and range expansion, mostly described as geographical parthenogenesis. The utilization of apomixis in crops must consider the potential risks of pollen transfer and introgression into sexual crop fields, which might be overcome by using pollen-sterile or cleistogamous variants. Another risk is the escape into natural vegetation and potential invasiveness of apomictic plants which needs careful management and consideration of ecological conditions.
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Kaushal P, Dwivedi KK, Radhakrishna A, Srivastava MK, Kumar V, Roy AK, Malaviya DR. Partitioning Apomixis Components to Understand and Utilize Gametophytic Apomixis. FRONTIERS IN PLANT SCIENCE 2019; 10:256. [PMID: 30906306 PMCID: PMC6418048 DOI: 10.3389/fpls.2019.00256] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 02/18/2019] [Indexed: 05/07/2023]
Abstract
Apomixis is a method of reproduction to generate clonal seeds and offers tremendous potential to fix heterozygosity and hybrid vigor. The process of apomictic seed development is complex and comprises three distinct components, viz., apomeiosis (leading to formation of unreduced egg cell), parthenogenesis (development of embryo without fertilization) and functional endosperm development. Recently, in many crops, these three components are reported to be uncoupled leading to their partitioning. This review provides insight into the recent status of our understanding surrounding partitioning apomixis components in gametophytic apomictic plants and research avenues that it offers to help understand the biology of apomixis. Possible consequences leading to diversity in seed developmental pathways, resources to understand apomixis, inheritance and identification of candidate gene(s) for partitioned components, as well as contribution towards creation of variability are all discussed. The potential of Panicum maximum, an aposporous crop, is also discussed as a model crop to study partitioning principle and effects. Modifications in cytogenetic status, as well as endosperm imprinting effects arising due to partitioning effects, opens up new opportunities to understand and utilize apomixis components, especially towards synthesizing apomixis in crops.
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Affiliation(s)
- Pankaj Kaushal
- ICAR-National Institute of Biotic Stress Management, Raipur, India
| | | | | | | | - Vinay Kumar
- ICAR-National Institute of Biotic Stress Management, Raipur, India
| | - Ajoy Kumar Roy
- ICAR-Indian Grassland and Fodder Research Institute, Jhansi, India
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31
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Alonso‐Marcos H, Nardi FD, Scheffknecht S, Tribsch A, Hülber K, Dobeš C. Difference in reproductive mode rather than ploidy explains niche differentiation in sympatric sexual and apomictic populations of Potentilla puberula. Ecol Evol 2019; 9:3588-3598. [PMID: 30988899 PMCID: PMC6434561 DOI: 10.1002/ece3.4992] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 01/16/2019] [Accepted: 01/23/2019] [Indexed: 01/02/2023] Open
Abstract
Apomicts tend to have larger geographical distributional ranges and to occur in ecologically more extreme environments than their sexual progenitors. However, the expression of apomixis is typically linked to polyploidy. Thus, it is a priori not clear whether intrinsic effects related to the change in the reproductive mode or rather in the ploidy drive ecological differentiation. We used sympatric sexual and apomictic populations of Potentilla puberula to test for ecological differentiation. To distinguish the effects of reproductive mode and ploidy on the ecology of cytotypes, we compared the niches (a) of sexuals (tetraploids) and autopolyploid apomicts (penta-, hepta-, and octoploids) and (b) of the three apomictic cytotypes. We based comparisons on a ploidy screen of 238 populations along a latitudinal transect through the Eastern European Alps and associated bioclimatic, and soil and topographic data. Sexual tetraploids preferred primary habitats at drier, steeper, more south-oriented slopes, while apomicts mostly occurred in human-made habitats with higher water availability. Contrariwise, we found no or only marginal ecological differentiation among the apomictic higher ploids. Based on the pronounced ecological differences found between sexuals and apomicts, in addition to the lack of niche differentiation among cytotypes of the same reproductive mode, we conclude that reproductive mode rather than ploidy is the main driver of the observed differences. Moreover, we compared our system with others from the literature, to stress the importance of identifying alternative confounding effects (such as hybrid origin). Finally, we underline the relevance of studying ecological parthenogenesis in sympatry, to minimize the effects of differential migration abilities.
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Affiliation(s)
- Henar Alonso‐Marcos
- Department of Forest GeneticsAustrian Research Centre for ForestsViennaAustria
- Department of Conservation Biology, Vegetation Ecology and Landscape EcologyUniversity of ViennaViennaAustria
| | - Flavia Domizia Nardi
- Department of Forest GeneticsAustrian Research Centre for ForestsViennaAustria
- Department of BiosciencesUniversity of SalzburgSalzburgAustria
| | - Susanne Scheffknecht
- Institute of BotanyUniversity of Natural Resources and Life SciencesViennaAustria
| | - Andreas Tribsch
- Department of BiosciencesUniversity of SalzburgSalzburgAustria
| | - Karl Hülber
- Department of Conservation Biology, Vegetation Ecology and Landscape EcologyUniversity of ViennaViennaAustria
| | - Christoph Dobeš
- Department of Forest GeneticsAustrian Research Centre for ForestsViennaAustria
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32
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Nardi FD, Dobeš C, Müller D, Grasegger T, Myllynen T, Alonso-Marcos H, Tribsch A. Sexual intraspecific recombination but not de novo origin governs the genesis of new apomictic genotypes in Potentilla puberula (Rosaceae). TAXON 2018; 67:1108-1131. [PMID: 30799883 PMCID: PMC6382066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Apomixis - asexual reproduction via seeds - might arise de novo following polyploidisation events, or via reproductive transfer of apomixis. Both processes can be obtained within species or via hybridisation. We aimed to determine the origin of apomictic genotypes in Potentilla puberula, a rosaceous species showing reproductive differentiation with ploidy: sexual tetraploids and apomictic penta- to octoploids, which regularly co-occur in sympatry. The study is based on 726 individuals, comprising all cytotypes, collected from 138 populations in the Eastern European Alps. We established relationships of cytotypes based on AFLP fingerprinting and cpDNA sequencing to test (1) whether the apomicts are of recurrent allopolyploid origin or originated from within the species via autopolyploidy, and (2) whether there are indications for reproductive transfer versus de novo origin of apomixis. Three principal pathways were identified which explain the origin of new apomictic genotypes, all involving at least one apomictic parent and thus compatible with the idea of reproductive transfer of the apomictic trait to the progeny: (1) self-fertilisation of unreduced egg cells in apomicts; (2) cross-fertilisation among apomicts; and (3) occasionally, heteroploid crosses among sexuals and apomicts. Autopolyploids derived from tetraploid sexuals were repeatedly observed, but did not express apomixis. Finally, our results suggest no role of other species in the origin of extant apomictic genotypes of P. puberula, although local hybrids with P. crantzii were identified. In conclusion, our results show that the formation of new apomictic genotypes required a genetic contribution from at least one apomictic parent. This finding is in accordance with the idea that apomixis is inheritable in P. puberula. On the contrary, lack of apomixis in penta- and hexaploids derived from sexual backgrounds did not support the hypothesis of a de novo origin of apomixis. Relatively high frequency of remnant sexuality in the apomicts involving different cytological pathways of seed formation can explain their high cytological and genotypic diversity. Finally, lack of global introgression from a third taxon is in support of P. puberula as a concise, although highly diverse, species.
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Affiliation(s)
- Flavia Domizia Nardi
- Austrian Research Centre for Forests, Department of Forest Genetics, Seckendorff-Gudent-Weg 8, 1131 Vienna, Austria
- University of Salzburg, Department of Biosciences, Hellbrunnerstraße 34, 5020 Salzburg, Austria
| | - Christoph Dobeš
- Austrian Research Centre for Forests, Department of Forest Genetics, Seckendorff-Gudent-Weg 8, 1131 Vienna, Austria
| | - Dorothee Müller
- University of Salzburg, Department of Biosciences, Hellbrunnerstraße 34, 5020 Salzburg, Austria
| | - Tobias Grasegger
- University of Salzburg, Department of Biosciences, Hellbrunnerstraße 34, 5020 Salzburg, Austria
| | - Tuuli Myllynen
- Austrian Research Centre for Forests, Department of Forest Genetics, Seckendorff-Gudent-Weg 8, 1131 Vienna, Austria
| | - Henar Alonso-Marcos
- Austrian Research Centre for Forests, Department of Forest Genetics, Seckendorff-Gudent-Weg 8, 1131 Vienna, Austria
| | - Andreas Tribsch
- University of Salzburg, Department of Biosciences, Hellbrunnerstraße 34, 5020 Salzburg, Austria
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Rushworth CA, Windham MD, Keith RA, Mitchell-Olds T. Ecological differentiation facilitates fine-scale coexistence of sexual and asexual Boechera. AMERICAN JOURNAL OF BOTANY 2018; 105:2051-2064. [PMID: 30548985 PMCID: PMC6685206 DOI: 10.1002/ajb2.1201] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 09/10/2018] [Indexed: 05/28/2023]
Abstract
PREMISE OF THE STUDY Ecological differentiation (ED) between sexual and asexual organisms may permit the maintenance of reproductive polymorphism. Several studies of sexual/asexual ED in plants have shown that the geographic ranges of asexuals extend beyond those of sexuals, often in areas of higher latitude or elevation. But very little is known about ED at fine scales, wherein coexistence of sexuals and asexuals may be permitted by differential niche occupation. METHODS We used 149 populations of sexual and apomictic lineages in the genus Boechera (rock cress) collected across a portion of this mustard's vast range. We characterized reproductive mode, ploidy, and species identity or hybrid parentage of each individual, and then used a multipronged statistical approach to (1) identify ED between sexuals and asexuals; (2) investigate the impacts of two confounding factors, polyploidy and hybridization, on ED; and (3) determine the environmental variables underlying ED. KEY RESULTS We found that sexuals and asexuals are significantly ecologically differentiated across the landscape, despite fine-scale interdigitation of these two reproductive forms. Asexual reproduction was strongly associated with greater disturbance, reduced slope, and greater environmental variability. Although ploidy had little effect on the patterns observed, hybridization has a unique impact on the relationships between asexual reproduction and specific environmental variables. CONCLUSIONS Ecological differentiation along the axes of disturbance, slope, and climatic variability, as well as the effects of heterozygosity, may contribute to the maintenance of sexuality and asexuality across the landscape, ultimately impacting the establishment and spread of asexual lineages.
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Affiliation(s)
- Catherine A. Rushworth
- Department of Biology, Box 90338, Duke University, Durham, NC 27708, USA
- University and Jepson Herbaria and Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
| | - Michael D. Windham
- Department of Biology, Box 90338, Duke University, Durham, NC 27708, USA
| | - Rose A. Keith
- Program in Genetics and Genomics, Duke University, Durham, NC 27708, USA
| | - Tom Mitchell-Olds
- Department of Biology, Box 90338, Duke University, Durham, NC 27708, USA
- Program in Genetics and Genomics, Duke University, Durham, NC 27708, USA
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Baduel P, Bray S, Vallejo-Marin M, Kolář F, Yant L. The “Polyploid Hop”: Shifting Challenges and Opportunities Over the Evolutionary Lifespan of Genome Duplications. Front Ecol Evol 2018. [DOI: 10.3389/fevo.2018.00117] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Barke BH, Daubert M, Hörandl E. Establishment of Apomixis in Diploid F 2 Hybrids and Inheritance of Apospory From F 1 to F 2 Hybrids of the Ranunculus auricomus Complex. FRONTIERS IN PLANT SCIENCE 2018; 9:1111. [PMID: 30123228 PMCID: PMC6085428 DOI: 10.3389/fpls.2018.01111] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 07/10/2018] [Indexed: 05/18/2023]
Abstract
Hybridization and polyploidization play important roles in plant evolution but it is still not fully clarified how these evolutionary forces contribute to the establishment of apomicts. Apomixis, the asexual reproduction via seed formation, comprises several essential alterations in development compared to the sexual pathway. Furthermore, most natural apomicts were found to be polyploids and/or hybrids. The Ranunculus auricomus complex comprises diploid sexual and polyploid apomictic species and represents an excellent model system to gain knowledge on origin and evolution of apomixis in natural plant populations. In this study, the second generation of synthetically produced homoploid (2x) and heteroploid (3x) hybrids derived from sexual R. auricomus species was analyzed for aposporous initial cell formation by DIC microscopy. Complete manifestation of apomixis was determined by measuring single mature seeds by flow cytometric seed screen. Microscopic analysis of the female gametophyte formation indicated spontaneous occurrence of aposporous initial cells and several developmental irregularities. The frequency of apospory was found to depend on dosage effects since a significant increase in apospory was observed, when both F1 parents, rather than just one, were aposporous. Other than in the F1 generation, diploid Ranunculus F2 hybrids formed BIII seeds and fully apomictic seeds. The results indicate that hybridization rather than polyploidization seems to be the functional activator of apomictic reproduction in the synthetic Ranunculus hybrids. In turn, at least two hybrid generations are required to establish apomictic seed formation.
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Affiliation(s)
- Birthe H. Barke
- Department of Systematics, Biodiversity and Evolution of Plants, Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, Göttingen, Germany
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Klatt S, Schinkel CCF, Kirchheimer B, Dullinger S, Hörandl E. Effects of cold treatments on fitness and mode of reproduction in the diploid and polyploid alpine plant Ranunculus kuepferi (Ranunculaceae). ANNALS OF BOTANY 2018; 121:1287-1298. [PMID: 29462249 PMCID: PMC6007502 DOI: 10.1093/aob/mcy017] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 01/25/2017] [Indexed: 05/20/2023]
Abstract
Background and Aims Alpine plants grow in harsh environments and are thought to face occasional frost during the sensitive reproductive phase. Apomixis (asexual reproduction via seed) can be advantageous when sexual reproduction is disturbed by cold stress. Apomictic polyploids tend to grow in colder climates than their sexual diploid relatives. Whether cold temperatures actually induce apomixis was unknown to date. Methods We tested experimentally in climate cabinets for effects of low temperatures and repeated frost on phenology, fitness and mode of reproduction in diploid and tetraploid cytotypes of the alpine species Ranunculus kuepferi. The reproduction mode was determined via flow cytometric seed screening (FCSS). Key Results Diploids produced the first flowers earlier than the tetraploids in all treatments. Cold treatments significantly reduced the fitness of both cytotypes regarding seed set, and increased the frequency of apomictic seed formation in diploids, but not in tetraploids. Over consecutive years, the degree of facultative apomixis showed individual phenotypic plasticity. Conclusions Cold stress is correlated to expression of apomixis in warm-adapted, diploid R. kuepferi, while temperature-tolerant tetraploids just maintain facultative apomixis as a possible adaptation to colder climates. However, expression of apomixis may not depend on polyploidy, but rather on failure of the sexual pathway.
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Affiliation(s)
- Simone Klatt
- Department of Systematics, Biodiversity and Evolution of Plants, University of Goettingen, Goettingen, Germany
| | - Christoph C F Schinkel
- Department of Systematics, Biodiversity and Evolution of Plants, University of Goettingen, Goettingen, Germany
| | - Bernhard Kirchheimer
- Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria
| | - Stefan Dullinger
- Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria
| | - Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants, University of Goettingen, Goettingen, Germany
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Ge J, Cai L, Bi GQ, Chen G, Sun W. Characterization of the Complete Chloroplast Genomes of Buddleja colvilei and B. sessilifolia: Implications for the Taxonomy of Buddleja L. Molecules 2018; 23:E1248. [PMID: 29882896 PMCID: PMC6100213 DOI: 10.3390/molecules23061248] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 05/19/2018] [Accepted: 05/21/2018] [Indexed: 11/17/2022] Open
Abstract
Buddleja colvilei Hook.f. & Thomson (Scrophulariaceae) is a threatened alpine plant with a distribution throughout the Himalayas, also used as an ornamental plant. The name Buddleja sessilifolia B.S. Sun ex S.Y. Pao was assigned in 1983 to a plant distributed throughout the Gaoligong Mountains, but the name was later placed in synonymy with B. colvilei in the Flora of China. In this study we sequenced the complete chloroplast (cp) genomes of two individuals of B. colvilei and three individuals of B. sessilifolia from across the range. Both molecular and morphological analysis support the revision of B. sessilifolia. The phylogenetic analysis constructed with the whole cp genomes, the large single-copy regions (LSC), small single-copy regions (SSC), inverted repeat (IR) and the nuclear genes 18S/ITS1/5.8S/ITS2/28S all supported B. sessilifolia as a distinct species. Additionally, coalescence-based species delimitation methods (bGMYC, bPTP) using the whole chloroplast datasets also supported B. sessilifolia as a distinct species. The results suggest that the B. sessilifolia lineage was early diverging among the Asian Buddleja species. Overall gene contents were similar and gene arrangements were found to be highly conserved in the two species, however, fixed differences were found between the two species. A total of 474 single nucleotide polymorphisms (SNPs) were identified between the two species. The Principal Coordinate Analysis of the morphological characters resolved two groups and supported B. sessilifolia as a distinct species. Discrimination of B. colvilei and B. sessilifolia using morphological characters and the redescription of B. sessilifolia are detailed here.
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Affiliation(s)
- Jia Ge
- Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming 650201, China.
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Lei Cai
- Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming 650201, China.
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Gui-Qi Bi
- Key Laboratory of Marine Genetics and Breeding (OUC), Ministry of Education, Qingdao 266100, China.
- College of Marine Life Sciences, Ocean University of China, Qingdao 266100, China.
| | - Gao Chen
- Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming 650201, China.
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China.
| | - Weibang Sun
- Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming 650201, China.
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China.
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Kirchheimer B, Wessely J, Gattringer A, Hülber K, Moser D, Schinkel CCF, Appelhans M, Klatt S, Caccianiga M, Dellinger A, Guisan A, Kuttner M, Lenoir J, Maiorano L, Nieto‐Lugilde D, Plutzar C, Svenning J, Willner W, Hörandl E, Dullinger S, Thrall P. Reconstructing geographical parthenogenesis: effects of niche differentiation and reproductive mode on Holocene range expansion of an alpine plant. Ecol Lett 2018; 21:392-401. [PMID: 29349850 PMCID: PMC5888191 DOI: 10.1111/ele.12908] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 09/23/2017] [Accepted: 11/27/2017] [Indexed: 12/25/2022]
Abstract
Asexual taxa often have larger ranges than their sexual progenitors, particularly in areas affected by Pleistocene glaciations. The reasons given for this 'geographical parthenogenesis' are contentious, with expansion of the ecological niche or colonisation advantages of uniparental reproduction assumed most important in case of plants. Here, we parameterized a spread model for the alpine buttercup Ranunculus kuepferi and reconstructed the joint Holocene range expansion of its sexual and apomictic cytotype across the European Alps under different simulation settings. We found that, rather than niche broadening or a higher migration rate, a shift of the apomict's niche towards colder conditions per se was crucial as it facilitated overcoming of topographical barriers, a factor likely relevant for many alpine apomicts. More generally, our simulations suggest potentially strong interacting effects of niche differentiation and reproductive modes on range formation of related sexual and asexual taxa arising from their differential sensitivity to minority cytotype disadvantage.
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Affiliation(s)
- Bernhard Kirchheimer
- Department of Botany and Biodiversity ResearchUniversity of ViennaRennweg 141030ViennaAustria
| | - Johannes Wessely
- Department of Botany and Biodiversity ResearchUniversity of ViennaRennweg 141030ViennaAustria
| | - Andreas Gattringer
- Department of Botany and Biodiversity ResearchUniversity of ViennaRennweg 141030ViennaAustria
| | - Karl Hülber
- Department of Botany and Biodiversity ResearchUniversity of ViennaRennweg 141030ViennaAustria
| | - Dietmar Moser
- Department of Botany and Biodiversity ResearchUniversity of ViennaRennweg 141030ViennaAustria
| | - Christoph C. F. Schinkel
- Department of Systematics, Biodiversity and Evolution of Plants (with herbarium)University of GoettingenUntere Karspüle 237073Göttingen
| | - Marc Appelhans
- Department of Systematics, Biodiversity and Evolution of Plants (with herbarium)University of GoettingenUntere Karspüle 237073Göttingen
| | - Simone Klatt
- Department of Systematics, Biodiversity and Evolution of Plants (with herbarium)University of GoettingenUntere Karspüle 237073Göttingen
| | - Marco Caccianiga
- Department of BiosciencesUniversity of MilanVia Giovanni Celoria 2620133MilanItaly
| | - Agnes Dellinger
- Department of Botany and Biodiversity ResearchUniversity of ViennaRennweg 141030ViennaAustria
| | - Antoine Guisan
- Department of Ecology & EvolutionBiophoreUniversity of Lausanne1015LausanneSwitzerland
- Institute of Earth Surface DynamicsGeopolisUniversity of Lausanne1015LausanneSwitzerland
| | - Michael Kuttner
- Department of Botany and Biodiversity ResearchUniversity of ViennaRennweg 141030ViennaAustria
| | - Jonathan Lenoir
- UR «Ecologie et Dynamique des Systèmes Anthropisés» (EDYSAN, FRE 3498 CNRS)Jules Verne University of Picardie1 Rue des LouvelsF‐80037Amiens Cedex 1France
| | - Luigi Maiorano
- Department of Biology and BiotechnologiesSapienza University of RomeViale dell'Università 32RomeItaly
| | - Diego Nieto‐Lugilde
- Departamento de BotánicaEcología y Fisiología VegetalUniversidad de Córdoba14071CórdobaSpain
| | - Christoph Plutzar
- Department of Botany and Biodiversity ResearchUniversity of ViennaRennweg 141030ViennaAustria
| | - Jens‐Christian Svenning
- Section for Ecoinformatics & BiodiversityDepartment of BioscienceAarhus UniversityNy Munkegade 114‐1168000Aarhus CDenmark
| | - Wolfgang Willner
- Vienna Institute for Nature Conservation and AnalysesGießergasse 6/71090ViennaAustria
| | - Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants (with herbarium)University of GoettingenUntere Karspüle 237073Göttingen
| | - Stefan Dullinger
- Department of Botany and Biodiversity ResearchUniversity of ViennaRennweg 141030ViennaAustria
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Hojsgaard D. Transient Activation of Apomixis in Sexual Neotriploids May Retain Genomically Altered States and Enhance Polyploid Establishment. FRONTIERS IN PLANT SCIENCE 2018; 9:230. [PMID: 29535745 PMCID: PMC5834478 DOI: 10.3389/fpls.2018.00230] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 02/09/2018] [Indexed: 05/19/2023]
Abstract
Polyploid genomes evolve and follow a series of dynamic transfigurations along with adaptation and speciation. The initial formation of a new polyploid individual within a diploid population usually involves a triploid bridge, a two-step mechanism of cell fusions between ubiquitous (reduced) and rare (unreduced) gametes. The primary fusion event creates an intermediate triploid individual with unbalanced genome sets, a situation of genomic-shock characterized by gene expression dysregulation, high dosage sensitivity, disturbed cell divisions, and physiological and reproductive attributes drastically altered. This near-sterile neotriploid must produce (even) eupolyploids through secondary fusion events to restore genome steadiness, meiotic balance, and fertility required for the demographic establishment of a nascent lineage. Natural conditions locate several difficulties to polyploid establishment, including the production of highly unbalanced and rarely unreduced (euploid) gametes, frequency-dependent disadvantages (minority cytotype exclusion), severe fitness loss, and ecological competition with diploid parents. Persistence and adaptation of neopolyploids depend upon genetic and phenotypic novelty coupled to joint selective forces that preserve shock-induced genomic changes (subgenome homeolog partitioning) and drive meiotic (reproductive) stabilization and ecological diversification. Thus, polyploid establishment through the triploid bridge is a feasible but not ubiquitous process that requires a number of low-probability events and singular circumstances. Yet, frequencies of polyploids suggest that polyploid establishment is a pervasive process. To explain this disparity, and supported in experimental evidence, I propose that situations like hybridization and ploidy-state transitions associated to genomic shock and substantial developmental alterations can transiently activate apomixis as a mechanism to halt genomic instability and cancel factors restraining neopolyploid's sexual fertility, particularly in triploids. Apomixis -as a temporal alternative to sex- skip meiosis and syngamy, and thus can freeze genomic attributes, avoid unbalanced chromosomal segregation and increase the formation of unreduced euploid gametes, elude frequency-dependent reproductive disadvantages by parthenogenetic development of the embryo and permissive development of endosperm during seed formation, and increase the effective population size of the neopolyploid lineage favoring the formation rate of eupolyploids compared to aneuploids. The subsequent action of genome resilience mechanisms that alleviate transcriptomic shock and selection upon gene interactions might restore a stable meiosis and sexual fertility within few generations, as observed in synthetic polyploids. Alternatively, provided that resilience mechanisms fail, the neopolyploid might retain apomixis and hold genomically and transcriptionally altered states for many generations.
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Affiliation(s)
- Diego Hojsgaard
- Department of Systematics, Biodiversity and Evolution of Plants, Albrecht-von-Haller Institute for Plant Sciences, Georg August University of Göttingen, Göttingen, Germany
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40
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Schinkel CCF, Kirchheimer B, Dullinger S, Geelen D, De Storme N, Hörandl E. Pathways to polyploidy: indications of a female triploid bridge in the alpine species Ranunculus kuepferi (Ranunculaceae). PLANT SYSTEMATICS AND EVOLUTION = ENTWICKLUNGSGESCHICHTE UND SYSTEMATIK DER PFLANZEN 2017; 303:1093-1108. [PMID: 29081576 PMCID: PMC5640749 DOI: 10.1007/s00606-017-1435-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 06/14/2017] [Indexed: 05/05/2023]
Abstract
Polyploidy is one of the most important evolutionary processes in plants. In natural populations, polyploids usually emerge from unreduced gametes which either fuse with reduced ones, resulting in triploid offspring (triploid bridge), or with other unreduced gametes, resulting in tetraploid embryos. The frequencies of these two pathways, and male versus female gamete contributions, however, are largely unexplored. Ranunculus kuepferi occurs with diploid, triploid and autotetraploid cytotypes in the Alps, whereby diploids are mostly sexual, while tetraploids are facultative apomicts. To test for the occurrence of polyploidization events by triploid bridge, we investigated 551 plants of natural populations via flow cytometric seed screening. We assessed ploidy shifts in the embryo to reconstruct female versus male gamete contributions to polyploid embryo and/or endosperm formation. Seed formation via unreduced egg cells (BIII hybrids) occurred in all three cytotypes, while only in one case both gametes were unreduced. Polyploids further formed seeds with reduced, unfertilized egg cells (polyhaploids and aneuploids). Pollen was highly variable in diameter, but only pollen >27 μm was viable, whereby diploids produced higher proportions of well-developed pollen. Pollen size was not informative for the formation of unreduced pollen. These results suggest that a female triploid bridge via unreduced egg cells is the major pathway toward polyploidization in R. kuepferi, maybe as a consequence of constraints of endosperm development. Triploids resulting from unreduced male gametes were not observed, which explains the lack of obligate sexual tetraploid individuals and populations. Unreduced egg cell formation in diploids represents the first step toward apomixis.
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Affiliation(s)
- Christoph C. F. Schinkel
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), University of Goettingen, Untere Karspüle 2, 37073 Göttingen, Germany
| | - Bernhard Kirchheimer
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030 Vienna, Austria
| | - Stefan Dullinger
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030 Vienna, Austria
| | - Danny Geelen
- Department of Plant Production, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Nico De Storme
- Department of Plant Production, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), University of Goettingen, Untere Karspüle 2, 37073 Göttingen, Germany
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Schinkel CCF, Kirchheimer B, Dullinger S, Geelen D, De Storme N, Hörandl E. Pathways to polyploidy: indications of a female triploid bridge in the alpine species Ranunculus kuepferi (Ranunculaceae). PLANT SYSTEMATICS AND EVOLUTION = ENTWICKLUNGSGESCHICHTE UND SYSTEMATIK DER PFLANZEN 2017; 303:1093-1108. [PMID: 29081576 DOI: 10.1007/s00606-017-1435-1436] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 06/14/2017] [Indexed: 05/20/2023]
Abstract
Polyploidy is one of the most important evolutionary processes in plants. In natural populations, polyploids usually emerge from unreduced gametes which either fuse with reduced ones, resulting in triploid offspring (triploid bridge), or with other unreduced gametes, resulting in tetraploid embryos. The frequencies of these two pathways, and male versus female gamete contributions, however, are largely unexplored. Ranunculus kuepferi occurs with diploid, triploid and autotetraploid cytotypes in the Alps, whereby diploids are mostly sexual, while tetraploids are facultative apomicts. To test for the occurrence of polyploidization events by triploid bridge, we investigated 551 plants of natural populations via flow cytometric seed screening. We assessed ploidy shifts in the embryo to reconstruct female versus male gamete contributions to polyploid embryo and/or endosperm formation. Seed formation via unreduced egg cells (BIII hybrids) occurred in all three cytotypes, while only in one case both gametes were unreduced. Polyploids further formed seeds with reduced, unfertilized egg cells (polyhaploids and aneuploids). Pollen was highly variable in diameter, but only pollen >27 μm was viable, whereby diploids produced higher proportions of well-developed pollen. Pollen size was not informative for the formation of unreduced pollen. These results suggest that a female triploid bridge via unreduced egg cells is the major pathway toward polyploidization in R. kuepferi, maybe as a consequence of constraints of endosperm development. Triploids resulting from unreduced male gametes were not observed, which explains the lack of obligate sexual tetraploid individuals and populations. Unreduced egg cell formation in diploids represents the first step toward apomixis.
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Affiliation(s)
- Christoph C F Schinkel
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), University of Goettingen, Untere Karspüle 2, 37073 Göttingen, Germany
| | - Bernhard Kirchheimer
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030 Vienna, Austria
| | - Stefan Dullinger
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030 Vienna, Austria
| | - Danny Geelen
- Department of Plant Production, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Nico De Storme
- Department of Plant Production, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), University of Goettingen, Untere Karspüle 2, 37073 Göttingen, Germany
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