| Abstract Detail
Unusual fungal niches Lutzoni, Francois [1], Miadlikowska, Jolanta [1], URen, Jana M. [2], Molnar, Katalin [1], Gaya, Ester [1], Arnold, A.E. [2]. The lichen microbiome and the evolution of fungi. Lichen thalli host a hyperdiversity of fungi similar to and frequently exceeding that harbored by leaves of plants. This fungal microbiota in lichens belongs to three distinct biological groups within the Pezizomycotina. First, the thallus itself is comprised of the lichen-forming mycobiont. Second, lichenicolous fungi cause visible symptoms such as the presence of reproductive structures or deformations on lichen thalli. Third, endolichenic fungi grow cryptically within the asymptomatic thallus, much like endophytic fungi within plant tissues. Endolichenic fungi are common among all major primary non-lichenized lineages of euascomycetes (Sordariomycetes, Dothideomycetes, Leotiomycetes, and Pezizomycetes) but are absent among the lichen-dominated clades (Lecanoromycetes, Arthoniomycetes, Lichinomycetes) and rare among the putative secondarily non-lichenized Eurotiomycetidae and Chaetothyriales. In contrast, the majority of lichenicolous fungi are classified within mycobiont-dominated groups (e.g., Lecanoromycetes). Therefore, endolichenic fungi are distinct both taxonomically and ecologically from the ca. 1200 species previously recognized as lichenicolous fungi, as well as the ca. 13,500 species of mycobionts that form lichen thalli. Our work suggests two fundamentally different patterns of diversification among photobiont-symbiotrophic euascomycetes: an evolutionarily ancient and canalized strategy (concentrated diversification) characterized by the lichen-mycobiont symbiosis; and a recent and evolutionarily flexible strategy (phylogenetically diffuse diversification) characterized by endolichenic and endophytic symbioses. Data suggest that endophytic diversity first evolved in lichen thalli as endolichenic fungi before switching to plant hosts as they colonized land. We will explore potential ecological roles of endolichenic fungi based on a systematic sampling of endophytic and endolichenic fungi from ten plants and ten lichens growing side by side in three sites (Arizona, Florida and North Carolina) and phylogenetic analyses.
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1 - Duke University, Department of Biology, 139 Biological Sciences Building, PO Box 90338, Durham, North Carolina, 27708, USA
2 - University of Arizona, Division of Plant Pathology and Microbiology, Dept. of Plant Sciences, 1140 E. South Campus Drive, P.O. Box 210036, Tucson, AZ, 85721, USA
Keywords:
Endolichenic fungi
endophytic fungi
lichens
fungal diversity
Fungal evolution.
Presentation Type: Symposium or Colloquium Presentation
Session: SY3
Location: Ballroom 1/Cliff Lodge - Level B
Date: Monday, July 27th, 2009
Time: 4:00 PM
Number: SY3006
Abstract ID:873 |
