Abstract
Seagrasses, a small group of submerged marine macrophytes, were reported to lack mycorrhizae, i.e., the root-fungus symbioses most terrestrial plants use for nutrient uptake. On the other hand, several authors detected fungal endophytes in seagrass leaves, shoots, rhizomes, and roots, and an anatomically and morphologically unique dark septate endophytic (DSE) association has been recently described in the roots of the Mediterranean seagrass Posidonia oceanica. Nevertheless, the global diversity of seagrass mycobionts is not well understood, and it remains unclear what fungus forms the DSE association in P. oceanica roots. We isolated and determined P. oceanica root mycobionts from 11 localities in the northwest Mediterranean Sea with documented presence of the DSE association and compared our results with recent literature. The mycobiont communities were low in diversity (only three species), were dominated by a single yet unreported marine fungal species (ca. 90 % of the total 177 isolates), and lacked common terrestrial and freshwater root mycobionts. Our phylogenetic analysis suggests that the dominating species represents a new monotypic lineage within the recently described Aigialaceae family (Pleosporales, Ascomycota), probably representing a new genus. Most of its examined colonies developed from intracellular microsclerotia occupying host hypodermis and resembling microsclerotia of terrestrial DSE fungi. Biological significance of this hitherto overlooked seagrass root mycobiont remains obscure, but its presence across the NW Mediterranean Sea and apparent root intracellular lifestyle indicate an intriguing symbiotic relationship with the dominant Mediterranean seagrass. Our microscopic observations suggest that it may form the DSE association recently described in P. oceanica roots.
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References
Hemminga MA, Duarte CM (2000) Seagrass ecology. Cambridge University Press, Cambridge
Hemminga MA, Harrison PG, van Lent F (1991) The balance of nutrient losses and gains in seagrass meadows. Mar Ecol Prog Ser 71:85–96
Fourqurean JW, Duarte CM, Kennedy H, Marba N, Holmer M et al (2012) Seagrass ecosystems as a globally significant carbon stock. Nat Geosci 5:505–509
Green EP, Short FT (2003) World atlas of seagrasses. University of California Press, Berkeley
den Hartog C (1970) Seagrasses of the world. North-Holland Publishing, Amsterdam
den Hartog C, Kuo J (2007) Taxonomy and biogeography of seagrasses. In: Larkum AWD, Orth RJ, Duarte CM (eds) Seagrasses: Biology, Ecology and Conservation. Springer, Dordrecht
Borum J, Duarte CM, Krause-Jensen D, Greve TM (2004) European seagrasses: an introduction to monitoring and management. A publication by the EU project Monitoring and Managing of European Seagrasses EVK3-CT-2000-00044. ISBN: 87-89143-21-3
Gambi MC, Barbieri F, Bianchi CN (2009) New record of the alien seagrass Halophila stipulacea (Hydrocharitaceae) in the western Mediterranean: a further clue to changing Mediterranean Sea biogeography. Mar Biodivers Rec 2:1–7
Arnaud-Haond S, Duarte CM, Diaz-Almela E, Marbá N, Sintes T et al (2012) Implications of extreme life span in clonal organisms: millenary clones in meadows of the threatened seagrass Posidonia oceanica. PLoS One 7:e30454. doi:10.1371/journal.pone.0030454
Peirano A, Bianchi NC (1995) Decline of the seagrass Posidonia oceanica in response to environmental disturbance: a simulation-like approach off Liguria (NW Mediterranean Sea). Proceedings of the 3rd European Marine Biological Symposium, Southampton
Leriche A, Pasqualini V, Boudouresque C-F, Bernard G, Bonhomme P et al (2006) Spatial, temporal and structural variations of a Posidonia oceanica seagrass meadow facing human activities. Aquat Bot 84:287–293
Stapel J, Aarts TL, van Duynhoven BHM, de Groot JD, van den Hoogen PHW, Hemminga MA (1996) Nutrient uptake by leaves and roots of the seagrass Thalassia hemprichii in the Spermonde Archipelago, Indonesia. Mar Ecol Prog Ser 134:195–206
Nielsen SL, Thingstrup I, Wigand C (1999) Apparent lack of vesicular-arbuscular mycorrhiza (VAM) in the seagrasses Zostera marina L. and Thalassia testudinum Banks ex Konig. Aquat Bot 63:261–266
Smith SE, Read DJ (2008) Mycorrhizal symbiosis. Academic Press, London
Kothamasi D, Kothamasi S, Bhattacharyya A, Kuhad RC, Babu CR (2006) Arbuscular mycorrhizae and phosphate solubilising bacteria of the rhizosphere of the mangrove ecosystem of Great Nicobar Island, India. Biol Fertil Soils 42:358–361
Welsh AK, Burke DJ, Hamerlynck EP, Hahn D (2010) Seasonal analyses of arbuscular mycorrhizae, nitrogen-fixing bacteria and growth performance of the salt marsh grass Spartina patens. Plant Soil 330:251–266
Kohout P, Sýkorová Z, Čtvrtlíková M, Rydlová J, Suda J et al (2012) Surprising spectra of root-associated fungi in submerged aquatic plants. FEMS Microbiol Ecol 80:216–235
Wilson WL (1998) Isolation of endophytes from seagrasses from Bermuda. MSc. thesis, University of New Brunswick. National Library of Canada, Ottawa
Devarajan PT, Suryanarayanan TS, Geetha V (2002) Endophytic fungi associated with the tropical seagrass Halophila ovalis (Hydrocharitaceae). Indian J Mar Sci 31:73–74
Sakayaroj J, Preedanon S, Supaphon O, Jones EBG, Phongpaichit S (2010) Phylogenetic diversity of endophyte assemblages associated with the tropical seagrass Enhalus acoroides in Thailand. Fungal Divers 42:27–45
Mata JL, Cebrián J (2013) Fungal endophytes of the seagrasses Halodule wrightii and Thalassia testudinum in the north central Gulf of Mexico. Bot Mar 56:541–545
Vohník M, Borovec O, Župan I, Vondrášek D, Petrtýl M, Sudová R (2015) Anatomically and morphologically unique dark septate endophytic association in the roots of the Mediterranean endemic seagrass Posidonia oceanica. Mycorrhiza. doi:10.1007/s00572-015-0642-7
Brundrett M (2006) Understanding the roles of multifunctional mycorrhizal and endophytic fungi. In: Schulz B, Boyle C, Sieber TN (eds) Microbial root endophytes. Springer, Berlin
Durieu de Maisonneuve C, Montagne JFC (1869) Pyrenomycetes Fr. In: Bory de Saint-Vincent J, Durieu de Maisonneuve C (eds) Exploration Scientifique de l´Algérie, Botanique
Kohlmeyer J (1963) Zwei neue Ascomyceten-Gattungen auf Posidonia-Rhizomen. Nova Hedwigia 6:5–13
Cuomo V, Vanzanella F, Fresi E, Cinelli F, Mazzella L (1985) Fungal flora of Posidonia oceanica and its ecological significance. Trans Brit Mycol Soc 84:35–40
Kohlmeyer J, Kohlmeyer E (1979) Marine mycology—the higher fungi. Academic Press, New York
Panno L, Bruno M, Voyron S, Anastasi A, Gnavi G et al (2013) Diversity, ecological role and potential biotechnological applications of marine fungi associated to the seagrass Posidonia oceanica. N Biotechnol 30:685–694
Torta L, Lo Piccolo S, Piazza G, Burruano S, Colombo P et al (2015) Lulwoana sp., a dark septate endophyte in roots of Posidonia oceanica (L.) Delile seagrass. Plant Biol 17:505–511
Usuki F, Narisawa K (2007) A mutualistic symbiosis between a dark septate endophytic fungus, Heteroconium chaetospira, and a nonmycorrhizal plant, Chinese cabbage. Mycologia 99:175–184
Tellenbach C, Sieber TN (2012) Do colonization by dark septate endophytes and elevated temperature affect pathogenicity of oomycetes? FEMS Microbiol Ecol 82:157–168
Marx DH (1969) Influence of ectotrophic mycorrhizal fungi on resistance of pine roots to pathogenic infections I. Antagonism of mycorrhizal fungi to root pathogenic fungi and soil bacteria. Phytopathology 59:153–163
Caye G, Bulard C, Meinesz A, Loques F (1992) Dominant role of seawater osmotic pressure on germination in Cymodocea nodosa. Aquat Bot 42:187–193
White TJ, Bruns TD, Lee SB, Taylor JW (1990) Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: Innis N, Gelfand D, Sninsky J, White T (eds) PCR—protocols and applications—a laboratory manual. Academic Press, New York
Gardes M, Bruns TD (1993) ITS primers with enhanced specificity for Basidiomycetes—application to the identification of mycorrhizae and rusts. Mol Ecol 2:113–118
Vilgalys R, Hester M (1990) Rapid genetic identification and mapping of enzymatically amplified ribosomal DNA from several Cryptococcus species. J Bacteriol 172:4238–4246
Vohník M, Sadowsky JJ, Kohout P, Lhotáková Z, Nestby R, Kolařík M (2012) Novel root-fungus symbiosis in Ericaceae: sheathed ericoid mycorrhiza formed by a hitherto undescribed basidiomycete with affinities to Trechisporales. PLoS One 7:e39524. doi:10.1371/journal.pone.0039524
Hall TA (1999) BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucleic Acids Sym Ser 41:95–98
Altschul SF, Madden TL, Schaffer AA, Zhang JH, Zhang Z et al (1997) Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucleic Acids Res 25:3389–3402
Liu JK, Phookamsak R, Jones EBG, Zhang Y, Ko-Ko TW et al (2011) Astrosphaeriella is polyphyletic, with species in Fissuroma gen. nov., and Neoastrosphaeriella gen. nov. Fungal Divers 51:135–154
Katoh K, Toh H (2008) Improved accuracy of multiple ncRNA alignment by incorporating structural information into a MAFFT-based framework. BMC Bioinform 9:212. doi:10.1186/1471-2105-9-212
Guindon S, Dufayard JF, Lefort V, Anisimova M, Hordijk W et al (2010) New algorithms and methods to estimate Maximum likelihood phylogenies: Assessing the performance of PhyML 3.0. Syst Biol 59:307–321
Tamura K, Peterson D, Peterson N, Stecher G, Nei M et al (2011) MEGA5: molecular evolutionary genetics analysis using maximum likelihood, evolutionary distance, and maximum parsimony methods. Mol Biol Evol 28:2731–2739
Vohník M, Mrnka L, Lukešová T, Bruzone MC, Kouhout P, Fehrer J (2013) The cultivable endophytic community of Norway spruce ectomycorrhizas from microhabitats lacking ericaceous hosts is dominated by ericoid mycorrhizal Meliniomyces variabilis. Fungal Ecol 6:281–292
Sieber TN (2002) Fungal root endophytes. In: Waisel Y, Eshel A, Kafkafi (eds) Plant roots—the hidden half, 3rd edn. Marcel Dekker, New York
Park D (1974) Accumulation of fungi by cellulose exposed in a river. Trans Br Mycol Soc 63:437–447
Newell SY, Fell JW (1982) Surface sterilization and the active mycoflora of leaves of a seagrass. Bot Mar 25:339–346
Shoemaker G, Wyllie-Echeverria S (2013) Occurrence of rhizomal endophytes in three temperate northeastpacific seagrasses. Aquat Bot 111:71–73
Suetrong S, Schoch CL, Spatafora JW, Kohlmeyer J, Volkmann-Kohlmeyer B et al (2009) Molecular systematics of the marine Dothideomycetes. Stud Mycol 64:155–173
Tomšovský M, Jankovský L (2007) DNA sequence analysis of extraordinary fruiting specimens of Fuscoporia torulosa (Phellinus torulosus) on Pyrus spp. Czech Mycol 59:91–99
Addy HD, Piercey MM, Currah RS (2005) Microfungal endophytes in roots. Can J Bot 83:1–13
Vohník M, Albrechtová J (2011) The co-occurrence and morphological continuum between ericoid mycorrhiza and dark septate endophytes in roots of six European Rhododendron species. Folia Geobot 46:373–386
Bruzone MC, Fontenla SB, Vohník M (2015) Is the prominent ericoid mycorrhizal fungus Rhizoscyphus ericae absent in the Southern Hemisphere’s Ericaceae? A case study on the diversity of root mycobionts in Gaultheria spp. from northwest Patagonia, Argentina. Mycorrhiza 25:25–40
Porras-Alfaro A, Herrera J, Sinsabaugh RL, Odenbach KJ, Lowrey T, Natvig DO (2008) Novel root fungalconsortium associated with a dominant desert grass. Appl Environ Microbiol 74:1308–1315
Knapp DG, Kovács GM, Zajta E, Groenewald JZ, Crous PW (2015) Dark septate endophytic pleosporalean genera fromsemiarid areas. Persoonia 35:87–100
Zhang Y, Fournier J, Schoch CL, Crous PW, de Gruyter J et al (2009) Multi-locus phylogeny of Pleosporales: a taxonomic, ecological and evolutionary re-evaluation. Stud Mycol 64:85–102
Vohník M, Lukančič S, Bahor E, Regvar M, Vosátka M, Vodnik D (2003) Inoculation of Rhododendron cv. Belle-Heller with two strains of Phialocephala fortinii in two different substrates. Folia Geobot 38:191–200
Lukešová T, Kohout P, Větrovský T, Vohník M (2015) The potential of dark septate endophytes to form root symbioses with ectomycorrhizal and ericoid mycorrhizal middle European forest plants. PLoS One 10:e0124752. doi:10.1371/journal.pone.012475259
Vohník M, Burdíková Z, Albrechtová J, Vosátka M (2009) Testate amoebae (Arcellinida & Euglyphida) vs. ericoid mycorrhizal and DSE fungi: a possible novel interaction in the mycorrhizosphere of ericaceous plants? Microb Ecol 57:203–214
Vohník M, Burdíková Z, Vyhnal A, Koukol O (2011) Interactions between testate amoebae and saprotrophic microfungi in a Scots pine litter microcosm. Microb Ecol 61:660–668
Acknowledgments
Financial support was provided by the Grant Agency of Charles University in Prague (GAUK 68313/PrF/B-BIO). This study is a part of the long-term research projects of the Institute of Botany ASCR (RVO 67985939) and Faculty of Science, Charles University in Prague (MŠMT LO1417). Lukáš Kalous and Miloslav Petrtýl organized a workshop on marine biology in Borak, Croatia, which substantially stimulated our research at its beginning, Kateřina Rylková and David Vondrášek helped with collection of some root samples, Ivan Župan helped with obtaining a permit for sampling in Croatia (Croatian Ministry of Environmental and Nature Protection, Klasa UP/I-612-07/13-48/48, Urbroj 517-07-1-1-1-13-2), and Symbio-m Ltd. (Lanškroun, Czech Republic) provided a portable flow box for isolation of P. oceanica root mycobionts; all these contributions are greatly acknowledged. The authors also acknowledge inspiring comments of two anonymous reviewers which helped to improve earlier versions of the manuscript.
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Vohník, M., Borovec, O. & Kolařík, M. Communities of Cultivable Root Mycobionts of the Seagrass Posidonia oceanica in the Northwest Mediterranean Sea Are Dominated by a Hitherto Undescribed Pleosporalean Dark Septate Endophyte. Microb Ecol 71, 442–451 (2016). https://doi.org/10.1007/s00248-015-0640-5
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DOI: https://doi.org/10.1007/s00248-015-0640-5