caa a22 4500 605518181 CHVBK 20210128100724.0 cr unu---uuuuu 210128e20151101xx s 000 0 eng 10.1007/s00572-015-0642-7 doi (NATIONALLICENCE)springer-10.1007/s00572-015-0642-7 Anatomically and morphologically unique dark septate endophytic association in the roots of the Mediterranean endemic seagrass Posidonia oceanica [Elektronische Daten] [Martin Vohník, Ondřej Borovec, Ivan Župan, David Vondrášek, Miloslav Petrtýl, Radka Sudová] Roots of terrestrial plants host a wide spectrum of soil fungi that form various parasitic, neutral and mutualistic associations. A similar trend is evident in freshwater aquatic plants and plants inhabiting salt marshes or mangroves. Marine vascular plants (seagrasses), by contrast, seem to lack specific root-fungus symbioses. We examined roots of two Mediterranean seagrasses, Posidonia oceanica and Cymodocea nodosa, in the northwestern Mediterranean Sea for fungal colonization using light and scanning and transmission electron microscopy. We found that P. oceanica, but not C. nodosa, is regularly associated with melanized septate hyphae in a manner resembling colonization by the ubiquitous dark septate endophytes (DSE) in roots of most terrestrial plants. P. oceanica roots were found to be colonized by sparse dematiaceous running hyphae as well as dense parenchymatous nets/hyphal sheaths on the root surface, intracellular melanized microsclerotia and occasionally also intra- and intercellular hyphae. The colonization was most prominent in the thick-walled hypodermis of the thinnest healthy looking roots, and the mycobiont seemed to colonize both living and dead host cells. Dark septate hyphae infrequently occurred also inside rhizodermal cells, but never colonized vascular tissues. The biological significance of this overlooked marine symbiosis remains unknown, but its morphology, extent, distribution across the NW Mediterranean Sea and absence in C. nodosa indicate an intriguing relationship between the dominant Mediterranean seagrass and its dark septate root mycobionts. Springer-Verlag Berlin Heidelberg, 2015 Marine vascular plants nationallicence Seagrasses nationallicence Dark septate endophytes nationallicence Posidonia oceanica nationallicence Cymodocea nodosa nationallicence Mediterranean Sea nationallicence Vohník Martin Department of Mycorrhizal Symbioses, Institute of Botany ASCR, Průhonice, Czech Republic aut Borovec Ondřej Department of Mycorrhizal Symbioses, Institute of Botany ASCR, Průhonice, Czech Republic aut Župan Ivan Department of Ecology, Agronomy and Aquaculture, University of Zadar, Zadar, Croatia aut Vondrášek David Department of Technical and Combat Sports and Martial Arts, Faculty of Physical Education and Sport, Charles University in Prague, Prague, Czech Republic aut Petrtýl Miloslav Department of Zoology and Fisheries, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Prague, Czech Republic aut Sudová Radka Department of Mycorrhizal Symbioses, Institute of Botany ASCR, Průhonice, Czech Republic aut Mycorrhiza Springer Berlin Heidelberg 25/8(2015-11-01), 663-672 0940-6360 25:8<663 2015 25 572 https://doi.org/10.1007/s00572-015-0642-7 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00572-015-0642-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Vohník Martin Department of Mycorrhizal Symbioses, Institute of Botany ASCR, Průhonice, Czech Republic aut NATIONALLICENCE 700 1- Borovec Ondřej Department of Mycorrhizal Symbioses, Institute of Botany ASCR, Průhonice, Czech Republic aut NATIONALLICENCE 700 1- Župan Ivan Department of Ecology, Agronomy and Aquaculture, University of Zadar, Zadar, Croatia aut NATIONALLICENCE 700 1- Vondrášek David Department of Technical and Combat Sports and Martial Arts, Faculty of Physical Education and Sport, Charles University in Prague, Prague, Czech Republic aut NATIONALLICENCE 700 1- Petrtýl Miloslav Department of Zoology and Fisheries, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Prague, Czech Republic aut NATIONALLICENCE 700 1- Sudová Radka Department of Mycorrhizal Symbioses, Institute of Botany ASCR, Průhonice, Czech Republic aut NATIONALLICENCE 773 0- Mycorrhiza Springer Berlin Heidelberg 25/8(2015-11-01), 663-672 0940-6360 25:8<663 2015 25 572