Abstract
Kerguelen Islands harbor a unique, probably very ancient flora with a high rate of endemism. However, the evolutionary history and characteristics of this flora still require investigation. This concerns in particular genome size and ploidy level variation, despite the evolutionary and ecological significance of those traits. Here we report the first assessment of genome size, using flow cytometry, for eight plant species of which two are endemics of Kerguelen Islands and four of the South Indian Ocean Province. The 2C DNA value ranged from 1.08 pg for Pringlea antiscorbutica to 11.88 pg for Ranunculus biternatus. The chromosome numbers of Colobanthus kerguelensis (2n = 80), Lyallia kerguelensis (2n = 96) and Poa kerguelensis (2n = 28) were also reported in this study for the first time. Overall, our data allowed to infer that all Kerguelen studied species are polyploid (from tetra- to octopolyploid). Intra-genus comparisons showed significant differences of 2C DNA values among Poa and among Ranunculus species, despite their identical ploidy level. In addition, our data highlight the existence of an intraspecific variability of genome size for the two octoploid species Colobanthus kerguelensis and Lyallia kerguelensis. Finally, our data also support the hypothesis regarding which polyploidy may have played a major role in the adaptation of flowering plants to high latitudes, as it has been suggested for arctic species.
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References
Abdeddaim-Boughanmi K, Garnatje T, Vitales D, Brown CS, Harche-Kaïd M, Siljak-Yakovlev S (2019) A single species, two basic chromosomal numbers: case of Lygeum spartum (Poaceae). Plant Biosyst 153:775–783. https://doi.org/10.1080/11263504.2018.1549608
Bartish IV, Ainouche A, Jia D, Bergstrom D, Chown SL, Winkworth RC, Hennion F (2012) Phylogeny and colonization history of Pringlea antiscorbutica (Brassicaceae), an emblematic endemic from the South Indian Ocean Province. Mol Phylogenet Evol 65:748–756. https://doi.org/10.1016/j.ympev.2012.07.023
Beaulieu JM, Leitch IJ, Patel S, Pendharkar A, Knight CA (2008) Genome size is a strong predictor of cell size and stomatal density in angiosperms. New Phytol 179:975–986. https://doi.org/10.1111/j.1469-8137.2008.02528.x
Bennett MD (1972) Nuclear DNA content and minimum generation time in herbaceous plants. Proc R Soc Lond B 181:109–135. https://doi.org/10.1098/rspb.1972.0042
Bennett MD (1987) Variation in genomic form in plants and its ecological implications. New Phytol 106:177–200. https://doi.org/10.1111/j.1469-8137.1987.tb04689.x
Bennett MD, Leitch IJ (2005) Nuclear DNA amounts in angiosperms: progress, problems, prospects. Ann Bot Lond 95:45–90. https://doi.org/10.1093/aob/mci003
Bennett MD, Bhandol P, Leitch I (2000) Nuclear DNA amounts in angiosperms and their modern uses—807 new estimates. Ann Bot 86:859–909. https://doi.org/10.1006/anbo.2000.125
Bennett MD, Smith JB, Lewis Smith RI (1982) DNA amounts of angiosperms from the Antarctic and South Georgia. Environ Exp Bot 22:307–318. https://doi.org/10.1016/0098-8472(82)90023-5
Bergstrom DM, Bricher PK, Raymond B, Terauds A, Doley D, McGeoch MA, Whinam J, Glen M, Yuan Z, Kiefer K, Shaw DJ, Bramely-Alves J, Rudman T, Mohammed C, Lucieer A, Visoiu M, van Vuuren J, Ball MC (2015) Rapid collapse of a sub-Antarctic alpine ecosystem: the role of climate and pathogens (M Cadotte, Ed.). J Appl Ecol 52:774–783. https://doi.org/10.1111/1365-2664.12436
Blackburn KB (1939) The Limosella plants of Glamorgan. Part II Chromosome and species. J Bot 77:67–71
Bou Dagher-Kharrat M, Abdel-Samad N, Douaihy BC, Abdel-Samad F, Bourge M, Siljak-Yakovlev S, Brown S (2013) Nuclear DNA C-values for biodiversity screening: case of the Lebanese flora. Plant biosys 147:1228–1237. https://doi.org/10.1080/11263504.2013.861530
Bourge M, Brown SC, Siljak-Yakovlev S (2018) Flow cytometry as tool in plant sciences, with emphasis on genome size and ploidy level assessment. Genet Appl 2:1–12
Brochmann C, Brysting AK, Alsos IG, Borgen L, Grundt HH, Scheen AC, Elven R (2004) Polyploidy in arctic plants. Biol J Linn Soc 82:521–536. https://doi.org/10.1111/j.1095-8312.2004.00337.x
Carta A, Peruzzi L (2015) Testing the large genome constraint hypothesis: plant traits, habitat and climate seasonality in Liliaceous. New Phytol 210:709–716. https://doi.org/10.1111/nph.13769
Cerbah M, Coulaud J, Brown SC, Siljak-Yakovlev S (1999) Evolutionary DNA variation in the genus Hypochoeris. Heredity 82:261–266. https://doi.org/10.1038/sj.hdy.6884690
Chown SL, Rodrigues ASL, Gremmen NJM, Gaston K (2001) World heritage status and conservation of Southern Ocean islands. Conserv Biol 15:550–557
Cuba-Diaz M, Cerda G, Rivera C, Gomez A (2017) Genome size comparison in Colobanthus quitensis populations show differences in species ploidy. Polar Biol 40:1475–1480. https://doi.org/10.1007/s00300-016-2058-z
Dawson MI (2000) Index of chromosome numbers of indigenous New Zealand spermatophytes. New Zea J Bot 38:47–150. https://doi.org/10.1080/0028825X.2000.9512673
Doležel J, Bartoš J, Voglmayr H, Greilhuber J (2003) Nuclear DNA content and genome size of trout and human. Cytometry 51:127–129. https://doi.org/10.1002/cyto.a.10013
Doležel J, Greilhuber J, Suda J (2007) Estimation of nuclear DNA content in plants using flow cytometry. Nat Protoc 2(9):2233–2244. https://doi.org/10.1038/nprot.2007.310
Dunn OJ (1964) Multiple comparisons using rank sums. Technometrics 6:241–252
Farhat P, Hidalgo O, Robert T, Siljak-Yakovlev S, Leitch JI, Adams R, Bou Dagher Kharrat M (2019a) Polyploidy in the conifer genus Juniperus: an unexpectedly high rate. Front Plant Sci 10:676. https://doi.org/10.3389/pls.2019.00676
Farhat P, Siljak-Yakovlev S, Adams PR, Bou Dagher Kharrat M, Robert T (2019b) Genome size variation and polyploidy in the geographical range of Juniperus sabina L. (Cupressaceae). Bot Lett 166:134–143. https://doi.org/10.1080/23818107.2019.1613262
Frenot Y, Aubry M, Misset MT, Gloaguen JC, Gourret JP, Lebouvier M (1999) Phenotypic plasticity and genetic diversity in Poa annua L. (Poaceae) at Crozet and Kerguelen Islands (subantarctic). Polar Biol 22:302–310. https://doi.org/10.1007/s003000050423
Frenot Y, Lebouvier M, Gloaguen J-C, Hennion F, Vernon Ph, Chapuis J-L (2006) Impact des changements climatiques et de la fréquentation humaine sur la biodiversité des îles subantarctiques françaises. Rev Belge Géo 3:363–371. https://doi.org/10.4000/belgeo.12097
Fyad-Lameche FZ, Iantcheva A, Siljak-Yakovlev S, Brown SC (2016) Chromosome number, genome size, seed storage protein profile and competence for direct somatic embryo formation in Algerian annual Medicago species. Plant Cell Tiss Org 124:531–540. https://doi.org/10.1007/s11240-015-0912-2
Garnatje T, Vilatersana R, Susanna A, Vallès J, Siljak-Yakovlev S (2004) Contribution to the karyological knowledge of Echinops (Asteraceae, Cardueae) and related genera. Bot J Linn Soc 145:337–344
Greilhuber J, Doležel J, Lysak MA, Bennett MD (2005) The origin, evolution and proposed stabilization of the terms genome size and C-value to describe nuclear DNA contents. Ann Bot 95:255–260. https://doi.org/10.1093/aob/mci019
Grime JP, Moworth MA (1982) Variation in genome size: an ecological interpretation. Nature 299:151–153. https://doi.org/10.1038/299151a0
Guerra M (2008) Chromosome numbers in plant cytotaxonomy: concepts and implications. Cytogenet Genome Res 120:339–350. https://doi.org/10.1159/000121083
Guignard MS, Nichols RA, Knell RJ, Macdonald A, Romila CA, Trimmer M, Leitch IJ, Leitch AR (2016) Genome size and ploidy influence angiosperm species’ biomass under nitrogen and phosphorus limitation. New Phytol 210:1195–1206. https://doi.org/10.1111/nph.13881
Hair JB, Beuzenberg EJ (1960) Contributions to a chromosome atlas of the New Zealand flora 4. Miscellaneous families. New Zeal J Sci 3:432–440
Hajrudinovic A, Siljak-Yakovlev S, Brown SC, Pustahija F, Bourge M, Ballian D, Bogunic F (2015) When sexual meets apomict-genome size, ploidy level and reproduction mode variation of Sorbus aria s.l. and S. austriaca (Rosaceae) in Bosnia and Herzegovina. Ann Bot 116:301–312. https://doi.org/10.1093/aob/mcv093
Hamel JL (1951) Note sur le noyau et les chromosomes somatiques du Pringlea antiscorbutica R.Br. ex Hook. f. Bull Mus Natl Hist Nat 23:548–551
Hennion F (1992) Etude des caractéristiques biologiques et génétiques de la flore endémique des iles Kerguelen. PhD Thesis, Muséum National d'Histoire Naturelle, Paris, 264pp
Hennion F, Couderc H (1992) Cytogenetical study of Pringlea antiscorbutica R. Br. And Ranunculus moseleyi Hook. F. from the Kerguelen Islands. Antarct Sci 4:57–58. https://doi.org/10.1017/S0954102092000117
Hennion F, Couderc H (1993) Cytogenetical variability of Ranunculus species from Iles Kerguelen. Antarct Sci 5:37–40. https://doi.org/10.1017/S0954102093000069
Hennion F, Walton DWH (1997) Ecology and seed morphology of endemic species from Kerguelen phytogeographic zone. Polar Biol 18:229–235. https://doi.org/10.1007/s003000050182
Hennion F, Fiasson LJ, Gluchoff-Fiasson K (1994) Morphological and phytochemical relationships between Ranunculus species from Iles Kerguelen. Biochem Syst Evol 22:533–542
Hennion F, Bouchereau A, Gauthier C, Hermant M, Vernon P, Prinzing A (2012) Variation in amine composition in plant species: how it integrates macroevolutionary and environmental signals. Am J Bot 99:36–45. https://doi.org/10.3732/ajb.1100211
Hermant M, Prinzing A, Vernon P, Convey P, Hennion F (2013) Endemic species have highly integrated phenotypes, environmental distributions and phenotype-environment relationships. J Biogeogr 40:1583–1594. https://doi.org/10.1111/jbi.12095
Hidalgo O, Garcia S, Garnatje T, Mumbrú M, Patterson A, Vigo J, Vallès J (2015) Genome size in aquatic and wetland plants: fitting with the large genome constraint hypothesis with a few relevant exceptions. Plant Syst Evol 301:1927–1936. https://doi.org/10.1007/s00606-015-1205-2
Holm S (1979) A simple sequentially rejective multiple test procedure. Scand J Stat 6:65–70. https://doi.org/10.2307/4615733
Hooker JD (1847) The Botany of the Antarctic Voyage of H.M. discovery ships Erebus and Terror in the years 1839–1843 under the command of Captain Sir James Clarke Ross. Flora Antarctica. II. Ed. Reeve Brothers, London, pp 207–574
Jomelli V, Schimmelpfennig I, Favier V, Mokadem F, Landais A, Rinterknecht V, Bourlès DL, Brunstein D, Verfaillie D, Legentil C, Aumaitre G, Keddadouche K (2018) Glacier extent in sub-Antarctic Kerguelen archipelago from MIS 3 period: evidence from 36Cl dating. Quat Sci Rev 183:110–123. https://doi.org/10.1016/j.quascirev.2018.01.008
Kagale S, Robinson SJ, Nixon J, Xiao R, Huebert T, Condie J, Kessler D, Clarke WE, Edger PP, Links MG, Sharpe AG, Parkin IAP (2014) Polyploid evolution of the Brassicaceae during the Cenozoic Era. Plant Cell 26:2777–2791. https://doi.org/10.1105/tpc.114.126391
Karrat-Souissi A, Siljak-Yakovlev S, Brown SC, Chaib M (2013) Cytogeography of 28 populations of three ploidy levels of Cenchrus ciliaris L. in Tunisia. Folia Geobot 48:95–113. https://doi.org/10.1007/s12224-012-9137-x
Knight CA, Molinari NA, Petrov DA (2005) The large genome constraint hypothesis: evolution, ecology and phenotype. Ann Bot (Oxford) 95:177–190. https://doi.org/10.1093/aob/mci011
Labarrere B, Prinzing A, Dorey T, Chesneau E, Hennion F (2019) Variations of secondary metabolites among natural populations of sub-Antarctic Ranunculus species suggest functional redundancy and versatility. Plants 8(7):234. https://doi.org/10.3390/plants8070234
Leitch IJ, Chase MW, Bennett MD (1998) Phylogenetic analysis of DNA C-values provides evidence for a small ancestral genome size in flowering plants. Ann Bot 82:85–94
Lehnebach C, Winkworth RC, Becker M, Lockhart PJ, Hennion F (2017) Around the pole: evolution of sub-Antarctic Ranunculus. J Biogeogr 44:875–886. https://doi.org/10.1111/jbi.12952
Lepers-Andrzejewski S, Siljak-Yakovlev S, Brown SC, Wong M, Dron M (2011) Diversity and dynamics of plant genome size:an example of polysomaty from a cytogenetic study of Tahitian Vanilla (Vanillaxtahitensis, Orchidaceae). Am J Bot 98:986–997. https://doi.org/10.3732/ajb.1000415
Le Roux PC, McGeoch MA, Nyakatya MJ, Chown SL (2005) Effects of a short-term climate change experiment on a sub-Antarctic keystone plant species. Glob Change Biol 11:1628–1639. https://doi.org/10.1111/j.1365-2486.2005.001022.x
Löve A, Löve D (1958) The American element in the flora of the Brithish Isles. Bot Notiser 111:376–388
Lysak MA, Berr A, Pecinka A, Schmidt R, McBreen K, Schubert I (2006) Mechanisms of chromosome number reduction in Arabidopsis thaliana and related Brassicaceae species. Proc Natl Acad Sci USA 103(13):5224–5229
Marie D, Brown SC (1993) A cytometric exercise in plant DNA histograms, with 2C values for 70 species. Biol Cell 78:41–51. https://doi.org/10.1016/0248-4900(93)90113-s
Niketic M, Siljak-Yakovlev S, Frajman B, Lazarevic M, Stevanovic B, Tomovic G, Stevanovic V (2013) Towards resolving the systematics of Cerastium subsect. Cerastium (Caryophyllaceae): a cytogenetic approach. Bot Jour Linn Soc 172:205–224. https://doi.org/10.1111/boj.12050
Nicolaysen K, Frey FA, Hodges KV, Weis D, Giret A (2000) 40Ara39Ar geochronology of £ood basalts from the Kerguelen Archipelago, southern Indian Ocean: implications for Cenozoic eruption rates of the Kerguelen plume. Earth Planet Sci Lett 174(313):328. https://doi.org/10.1016/s0012-821x(99)00271-x
Oron AP, Hoff PD (2006) Kruskal-Wallis and Friedman type tests for nested effects in hierarchical designs. Centre for Statistics and the Social Science, University of Washington, Washington
Pellicer J, Leitch I (2014) The Application of flow cytometry for estimating genomesize and ploidy level in plants. In: Besse P (ed) Molecular plant taxonomy: methods and protocols. Springer, New York
Pellicer J, Hidalgo O, Dodsworth S, Leitch IJ (2018) Genome size diversity and its impact on the evolution of land plants. Genes 9:88. https://doi.org/10.3390/genes9020088
Petrov DA (2001) Evolution of genome size: new approaches to an old problem. Trends Genet 17:23–28. https://doi.org/10.1016/S0168-9525(00)02157-0
Petrov DA (2002) Mutational equilibrium model of genome size evolution. Theor Popul Biol 61:531–544. https://doi.org/10.1006/tpbi.2002.1605
Price HJ, Johnston SJ (1996) Influence of light on DNA content of Helianthus annuus Linnaeus. Proc Natl Acad Sci USA 93:11264–11267. https://doi.org/10.1073/pnas.93.20.11264
Pustahija F, Brown CS, Bogunic F, Basic N, Muratovic E, Ollier S, Hidalgo O, Bourge M, Stevanović V, Siljak-Yakovlev S (2013) Small genomes dominate in plants growing on serpentine soils in West Balkans, an exhaustive study of 8 habitats covering 308 taxa. Plant Soil 373:427–453. https://doi.org/10.1007/s11104-013-1794-x
Razafinarivo NJ, Rakotomalala JJ, Brown SC, Bourge M, Hamon S, de Kochko A, Poncet V, Dubreuil-Tranchant C, Couturon E, Guyot R, Hamon P (2012) Geographical gradients in the genome size variation of wild coffee trees (Coffea) native to Africa and Indian Ocean islands. Tree Genet Genomes 8:1345–1358. https://doi.org/10.1007/s11295-012-0520-9
Rollins RC, Rüdenberg L (1971) Chromosome numbers of Cruciferae II. Contr Gray Herb 201:117–133
Siljak-Yakovlev S, Stevanovic V, Tomasevic M, Brown S, Stevanovic B (2008) Genome size variation and polyploidy in the resurrection plant genus Ramonda: cytogeography of living fossils. Environ Exp Bot 62:101–112. https://doi.org/10.1016/j.envexpbot.2007.07.017
Siljak-Yakovlev S, Pustahija F, Šolić EM, Bogunić F, Muratović E, Bašić N, Catrice O, Brown CS (2010) Towards a database of genome size and chromosome number of Balkan flora: C-values in 343 taxa with novel values for 252. Adv Sci Lett 3:190–213. https://doi.org/10.1166/asl.2010.1115
Siljak-Yakovlev S, Farhat P, Valentin N, Bareka P, Kamari G (2019) New estimates of nuclear DNA amount for 25 taxa from Cephalonia flora which xx are endemics. Bot Chron 22:87–108
Smith RIL (1984) Terrestrial plant biology of the sub-Antarctic and Antarctic. In: Laws RM (ed) Antarctic ecology. Academic Press, London, pp 61–162
Soltis PS, Soltis DE (2009) The role of hybridization in plant speciation. Annu Rev Plant Biol 60:561–588. https://doi.org/10.1146/annurev.arplant.043008.092039
Srisuwan S, Sihachakr D, Martin J, Valles J, Brown SC, Siljak-Yakovlev S (2019) Change in nuclear DNA content and pollen size during polyploidisation of the sweet potato Ipomoea batatas (Convolvulaceae) complex. Plant Biol 21:237–247. https://doi.org/10.1111/plb.12945
Suda J, Weiss-Schneeweiss H, Tribsch A, Schneeweiss GM, Trávníček P, Schönswetter P (2007) Complex distribution patterns of Di-, tetra-, and hexaploid cytotypes in the European high mountain plant Senecio carniolicus (Asteraceae). Am J Bot 94:1391–1401. https://doi.org/10.3732/ajb.94.8.1391
Swift H (1950) The constancy of deoxyribose nucleic acid in plant nuclei. Proc Natl Acad Sci USA 36:643–654
Šmarda P, Bureš P (2006) Intraspecific DNA content variability in Festuca pallens on different geographical scales and ploidy levels. Ann Bot 98:665–678. https://doi.org/10.1093/aob/mcl150
Šmarda P, Horová L, Bureš P, Hralová I, Marková M (2010) Stabilizing selection on genome size in a population of Festuca pallens under conditions of intensive intraspecific competition. New Phytol 187:1195–1204. https://doi.org/10.1111/j.1469-8137.2010.03335.x
Šmarda P, Hejcman M, Březinová A, Horová L, Steigerová H, Zedek F, Bureš P, Hejcmanová P, Schellberg J (2013) Effect of phosphorus availability on the selection of species with different ploidy levels and genome sizes in a long-term grassland fertilization experiment. New Phytol 200:911–921. https://doi.org/10.1111/nph.12399
Van de Peer Y, Mizrachi E, Marchal K (2017) The evolutionary significance of polyploidy. Nat Rev Genet 18:1–14. https://doi.org/10.1038/nrg.2017.26
Van der Putten N, Verbruggen C, Ochyra R, Verleyen E, Frenot Y (2010) Subantarctic flowering plants: pre-glacial survivors or post-glacial immigrants? J Biogeogr 37:582–592. https://doi.org/10.1111/j.1365-2699.2009.02217.x
Vekemans X, Lefebvre C, Coulaud J, Blaise S, Siljak-Yakovlev S (1996) Variation of nuclear DNA content at the species level in Armeria maritima (Mill.) Willd. Hereditas 124:237–242. https://doi.org/10.1111/j.1601-5223.1996.00237.x
Wagstaff SJ, Hennion F (2007) Evolution and biogeography of Lyallia and Hectorella (Portulacaceae), geographically isolated sisters from the Southern Hemisphere. Antarct Sci 19:417–426. https://doi.org/10.1017/S0954102007000648
Waltari E, Edwards SV (2002) Evolutionary dynamics of intron size, genome size, and physiological correlates in archosaurs. Am Nat 160:539–552. https://doi.org/10.1086/34207
Werth E (1911) Die Vegetation der Subantarktischen Inseln Kerguelen, Possession-und Heard-Eiland, Teil 2. In: Drygalski E (ed) Deutsche Südpolar-Expedition 1901–1903, Botanik Heft 3, pp 125–371
Winkworth RC, Hennion F, Prinzing A, Wagstaff SJ (2015) Explaining the disjunct distributions of austral plants: the roles of Antarctic and direct dispersal routes. J Biogeogr 42:1197–1209. https://doi.org/10.1111/jbi.12522
Acknowledgement
The present research project No 1116 PlantEvol (resp. F. Hennion) was performed at Kerguelen station and was supported by the French Polar Institute (IPEV). This research was also supported by CNRS IRP grant “AntarctPlantAdapt” (F. Hennion). We thank B. Labarrere, L. Marchand (UMR ECOBIO, Rennes, France) and G. Bouger (UMS OSUR, Rennes, France), V. Normand (UMR ESE, Orsay, France), K. Delord (Centre d’études biologiques de Chizé, CNRS, France), IPEV logistics, and Réserve naturelle Terres Australes et Antarctiques françaises for help in material collection during the summer campaigns (2015-2019). We thank Experimental Ecology platform (ECOLEX) of Ecobio lab, T. Fontaine-Breton, F. Nassur and R. Bodiguel for help in plant cultivation in the phytotron, T. Fontaine-Breton and O. Lima for leaf collection for flow cytometry. The authors thank B. Robert for his help in statistical analyses and Dr. M. Bourge for his expert assistance in flow cytometry on the Platform of Cytometry, Institute of Integrative Biology of the Cell (I2BC), Gif-sur-Yvette. Finally, we would like to thank Dr Dieter Piepenburg, Editor-in-chief of Polar Biology and three reviewers (Dr Joan Vallès, Dr Teresa Garnatje and one anonymous reviewer) for their constructive comments that have fully contributed to improving our manuscript.
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SS-Y and FH conceived the ideas. FL, FH and TR collected the samples. SS-Y, NV and NT performed the flow cytometry measurement. FH cultivated the plants in the field and in the laboratory in Rennes and FH and VG collected and treated the root samples for karyology. SSY performed the chromosome counts. TR performed data analysis. SS-Y wrote the manuscript with contributions from TR, FH and NT. All the authors read and approved the manuscript. SS-Y, TR and FH revised the manuscript following comments from the Editor and three reviewers.
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Siljak-Yakovlev, S., Lamy, F., Takvorian, N. et al. Genome size and chromosome number of ten plant species from Kerguelen Islands. Polar Biol 43, 1985–1999 (2020). https://doi.org/10.1007/s00300-020-02755-7
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DOI: https://doi.org/10.1007/s00300-020-02755-7