Martin Grube phone: +43 316 380 5655 fax: +43 316 380 9883 email: Institut für Pflanzenwissenschaften Karl-Franzens-Universität Graz Symbiosis Workgroup

Symbiont selectivity	The encounter of the appropriate partners is essential in the establishment of interspecific symbiotic associations. Compatible partners can be rare and confined to microhabitats. Two strategies can be considered in the evolution of symbiont specificity. While optimization of interaction betweens the partners can lead to increasing specificity of dependent partners, the scarcity of their symbionts can act against this evolutionary trend. Lichen associations display various levels of symbiont specificity, and they developed diverse strategies to ensure successful symbioses. We study the specificity of symbiotic associations using molecular sequence data.
Bacteria and lichens	In contrast to many fungal symbioses, which reside inside substrates or hosts, lichens expose their vegetative parts. Lichens also grow at extremely slow rates, and some of the organisms can persist for thousands of years, even under extremely harsh ecological conditions. Therefore they represent stable and diverse ecological niches for other micro-organisms. We are now able to identify and localize the diversity of lichen associated bacterial communities. So far we found biofilm-like colonization of fungal matrices by diverse bacteria, generally with a predominance of Alphaproteobacteria. (A cooperation with G. Berg, University of Technology Graz)
Surface colonization	Human activity has created a wide range of artificial niches, which are readily colonized by microorganisms. These include broad range of species, including extremotolerant organisms and also lichen symbioses. Specialized lichens can readily develop on plastic or glass surfaces exposed in rain-forest. One interesting aspect detected on such materials (and living leafs) is that germinating fungal hyphae can form extensive presymbiotic mycelia to contact algae. It is likely that these "symbiotic arenas" formed by the juvenile mycelia serve to screen the different locally available algae in search for the optimal symbiosis partner. We are now exploring other artificial surfaces for microbial colonization and the resulting effects on biocomplexity and substrates.
Evolution of fungi focusing on lichenized ascomycetes	Lichens are self-supporting exosymbioses of fungi with photoautotrophs. Lichens evolved since 600 mio years and diversified as major fungal lineages, encompassing one fifth of all fungi. More than 10% of the terrestrial surface are covered by lichens. The light-exposed and compact vegetative bodies of lichens represent the most complex  morphologies developed in the fungal kingdom and the physiological integration of the partners confers extremotolerance and longevity. We use phylogenetic trees of different genes to reveal the evolution of morphological and chemical characters in diverse lichen mycobiont lineages.
The Team:	Lucia Muggia, PostDoc. Barbara Klug: PhD student. Philipp Resl, Daniel Hofstadler, Johannes Rabensteiner: Undergraduates. Sigrun Kraker: Technician (part time)

Selected recent papers:

Boustie J, Tomasi S, Grube M 2010. Bioactive lichen metabolites: alpine habitats as an untapped source. Phytochemistry Reviews. In press.

Bjelland T, Grube M, Hoem S, Jorgensen SL, Daae FL, Thorseth IH, Øvreås, L 2010. Microbial metacommunities in the lichen–rock habitat. Environmental Microbiology Reports Article first published online : 19 AUG 2010, DOI: 10.1111/j.1758-2229.2010.00206.x

Muggia L, Gueidan C, Grube M 2010. Phylogenetic placement of some morphologically unusual members of Verrucariales. Mycologia 102: 835-846.

Ertz D, Elix J, Grube M 2010. Arthonia borbonica (Ascomycota, Arthoniales), a new species from La Réunion. Plant Ecology and Evolution 143: 222–224.

Muggia L, Zellnig, G, Rabensteiner J, Grube M 2010. Morphological and phylogenetic study of algal partners associated with the lichen-forming fungus Tephromela atra from the Mediterranean region. Symbiosis, on-line first.

Adamatzky A, Grube M 2010. Minimal cellular automaton model of inter-species interactions: phenomenology, complexity and interpretations. In: Hoekstra A, Kroc J, Sloot P (eds) Modeling of Complex Systems using Cellular Automata. in press.

Grube M, Rabensteiner J, Grube U, Muggia L 2010. Architectures of biocomplexity: lichen-dominated soil crusts and mats. In, Oren A and Seckbach J (eds) Microbial Mats. Springer, Dordrecht. in press.

Selbmann L, Zucconi L, Ruisi S, Grube M, Cardinale M, Onofri S 2010. Culturable bacteria associated with Antarctic lichens: affiliation and psychrotolerance. Polar Biol 33, 71-83.

Wornik S, Grube M 2010. Joint Dispersal Does Not Imply Maintenance of Partnerships in Lichen Symbioses. Microbial Ecology 59: 150-157.

Muggia L, Grube M 2010. Type III polyketide synthase genes in lichen fungi. Fungal Biol 114: 379-385.

Muggia L, Grube M 2010. Fungal composition of lichen thalli assessed by single strand conformation polymorphism. Lichenologist 42: 461-473.

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