naa a22 4500 510746756 CHVBK 20180411092755.0 cr unu---uuuuu 180411e20130301xx s 000 0 eng 10.1007/s13199-013-0232-4 doi (NATIONALLICENCE)springer-10.1007/s13199-013-0232-4 Recognition mechanisms during the pre-contact state of lichens: I. Mycobiont-photobiont interactions of the mycobiont of Fulgensia bracteata [Elektronische Daten] [Joachim Meeßen, Sieglinde Ott] Lichens are an association of a photoautotrophic alga/cyanobacteria (photobiont) and a heterotrophic fungus (mycobiont) constituting the lichen thallus as a complex phenotype. Many mycobionts reproduce sexually and the ascospores are dispersed without the photobiont. For successful re-lichenization the specific photobiont must be recognized, contacted, and incorporated by the mycobiont. A so-called pre-contact stage has been postulated as the initial step of a gradual recognition process. In the present study, the effect of the specific Trebouxia photobiont, an unspecific Asterochloris photobiont and the non-lichenizing green alga Myrmecia bisecta on the development of the mycobiont Fulgensia bracteata was assessed by pre-contact assays. Three hypotheses were confirmed: (i) the pre-contact stage exists, (ii) it is characterized by morphological reactions in the development of the mycobiont, and (iii) the reactions depend on the interacting alga. Control conditions revealed a mycelial growth arrest but this effect was not observed in the presence of any of the three algae. Different algae induce distinct growth patterns with respect to hyphal length, morphological characteristics, and formation of mucilage. The specific Trebouxia photobiont had a positive impact on hyphal growth, branching frequency, and mucilage formation. These effects were less explicit with the non-specific Asterochloris photobiont. Myrmecia bisecta induced uncharacteristic growth patterns with pronounced hyphal growth and high numbers of aerial hyphae but less formation of mucilage. These results indicate that symbiont recognition mechanisms are established before physical contact. Pre-contact reactions may be an evolutionary advantage that supports the persistence of the mycobiont on newly colonized sites and improves the probability of re-lichenization. Springer Science+Business Media Dordrecht, 2013 Fulgensia bracteata nationallicence Pre-contact interaction nationallicence Biont recognition nationallicence Lichenization nationallicence Mycobiont nationallicence Photobiont nationallicence ABP : Algal binding protein nationallicence ITS rDNA : Internal transcribed spacer ribosomal DNA nationallicence MYS1 : Malt yeast extract medium with 1% sucrose nationallicence PPFD : Photosynthetic photon flux density nationallicence SD : Standard deviation nationallicence TOM : Trebouxia Organic Medium nationallicence VAM : Vesicular-arbuscular mycorrhiza nationallicence Meeßen Joachim Institute of Botany, Heinrich-Heine-University, Universitaetsstr. 1, 40225, Duesseldorf, Germany aut Ott Sieglinde Institute of Botany, Heinrich-Heine-University, Universitaetsstr. 1, 40225, Duesseldorf, Germany aut Symbiosis Springer Netherlands 59/3(2013-03-01), 121-130 0334-5114 59:3<121 2013 59 13199 https://doi.org/10.1007/s13199-013-0232-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s13199-013-0232-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Meeßen Joachim Institute of Botany, Heinrich-Heine-University, Universitaetsstr. 1, 40225, Duesseldorf, Germany aut NATIONALLICENCE 700 1- Ott Sieglinde Institute of Botany, Heinrich-Heine-University, Universitaetsstr. 1, 40225, Duesseldorf, Germany aut NATIONALLICENCE 773 0- Symbiosis Springer Netherlands 59/3(2013-03-01), 121-130 0334-5114 59:3<121 2013 59 13199 Metadata rights reserved Springer special CC-BY-NC licence nationallicence SWISSBIB 510746756 BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer