Lichenized Fungi and the Evolution of Symbiotic Organization
- Authors: Martin Grube1, Mats Wedin2
- Editors: Joseph Heitman3, Barbara J. Howlett4
-
VIEW AFFILIATIONS HIDE AFFILIATIONSAffiliations: 1: Institute of Plant Sciences, University of Graz, 8010 Graz, Austria; 2: Department of Botany, Swedish Museum of Natural History, 104 05 Stockholm, Sweden; 3: Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710; 4: School of Biosciences, The University of Melbourne, Victoria, NSW 3010, Australia
-
Received 10 May 2016 Accepted 08 July 2016 Published 16 December 2016
- Correspondence: Mats Wedin, [email protected]

-
Abstract:
Lichen symbioses comprise a fascinating relationship between algae and fungi. The lichen symbiotic lifestyle evolved early in the evolution of ascomycetes and is also known from a few basidiomycetes. The ascomycete lineages have diversified in the lichenized stage to give rise to a tremendous variety of morphologies. Their thalli are often internally complex and stratified for optimized integration of algal and fungal metabolisms. Thalli are frequently colonized by specific nonlichenized fungi and occasionally also by other lichens. Microscopy has revealed various ways these fungi interact with their hosts. Besides the morphologically recognizable diversity of the lichen mycobionts and lichenicolous (lichen-inhabiting) fungi, many other microorganisms including other fungi and bacterial communities are now detected in lichens by culture-dependent and culture-independent approaches. The application of multi-omics approaches, refined microscopic techniques, and physiological studies has added to our knowledge of lichens, not only about the taxa involved in the lichen interactions, but also about their functions.
-
Citation: Grube M, Wedin M. 2016. Lichenized Fungi and the Evolution of Symbiotic Organization. Microbiol Spectrum 4(6):FUNK-0011-2016. doi:10.1128/microbiolspec.FUNK-0011-2016.




Lichenized Fungi and the Evolution of Symbiotic Organization, Page 1 of 2
< Previous page | Next page > /docserver/preview/fulltext/microbiolspec/4/6/FUNK-0011-2016-1.gif /docserver/preview/fulltext/microbiolspec/4/6/FUNK-0011-2016-2.gif

References

Article metrics loading...
Abstract:
Lichen symbioses comprise a fascinating relationship between algae and fungi. The lichen symbiotic lifestyle evolved early in the evolution of ascomycetes and is also known from a few basidiomycetes. The ascomycete lineages have diversified in the lichenized stage to give rise to a tremendous variety of morphologies. Their thalli are often internally complex and stratified for optimized integration of algal and fungal metabolisms. Thalli are frequently colonized by specific nonlichenized fungi and occasionally also by other lichens. Microscopy has revealed various ways these fungi interact with their hosts. Besides the morphologically recognizable diversity of the lichen mycobionts and lichenicolous (lichen-inhabiting) fungi, many other microorganisms including other fungi and bacterial communities are now detected in lichens by culture-dependent and culture-independent approaches. The application of multi-omics approaches, refined microscopic techniques, and physiological studies has added to our knowledge of lichens, not only about the taxa involved in the lichen interactions, but also about their functions.

Full text loading...
Figures

Click to view
FIGURE 1
Diverse shapes of lichen thalli. (A) Coral-like fruticose (shrub-like) thallus of Cladia retipora. Photo: Birgitta Strömbäck. (B) Foliose (leaf-like) thalli of Lobaria pulmonaria and Lobarina scrobiculata covering the trunk of a Salix caprea in an old-growth spruce-dominated forest. Photo: Mats Wedin. (C) Crustose (crust-like) thallus of Acarospora fuscata growing on a siliceous rock. Photo: Martin Westberg.

Click to view
FIGURE 2
Substantial biomass of lichens. (A) Scandinavian costal lichen heath dominated by reindeer lichens (Cladonia spp.). Photo: Birgitta Strömbäck. (B) Lichen-dominated soil crust community on the Great Alvar of Öland (Sweden). Photo: Martin Westberg. (C) Abundant lichen cover dominated by Pseudocyphellaria homoeophylla in a New Zealand cool temperate rain forest. Photo: Birgitta Strömbäck.

Click to view
FIGURE 3
Vertical section through a thallus of Parmelia saxatilis, a foliose lichen. A distinct layer of green algal cells is clearly visible under the uppermost cortex; all other structures are made up by fungal hyphae. Photo: Einar Timdal.

Click to view
FIGURE 4
Vegetative dispersal in lichens. (A) Soralia formed along the thallus margins in Vulpicida pinastri. These structures produce soredia, small granules of algal cells surrounded by fungal hyphae. Photo: Einar Timdal. (B) Simple, cylindrical isidia formed on the thallus upper surface by Parmelia saxatilis. Photo: Einar Timdal.

Click to view
FIGURE 5
Optional lichenization: Schizoxylon albescens. (A) Apothecium of a saprotrophic colony on dead aspen (Populus tremula) wood. Photo: Lucia Muggia. (B) Lichenized morph on aspen bark. Note the green algal colonies around the young apothecium. Photo: Lucia Muggia.

Click to view
FIGURE 6
(A) Cephalodia visible as dark structures that include cyanobacteria, on Peltigera aphtosa. Photo: Einar Timdal. (B) Phycosymbiodemes with different morphologies: Sticta with joined photomorphs. Note green-algal foliose parts growing out from the basal cyanobacterial fruticose parts. Photo: Mats Wedin.

Click to view
FIGURE 7
Symbiotic invasion. The transition of Cladonia thallus into Diploschistes thallus by invasion of the latter. (A) Uninfected Cladonia symphycarpa thallus. Photo: Einar Timdal. (B) Cladonia thallus with clear Diploschistes infection (whitish areas) with typical Diploschistes apothecia (dark patches in the whitish areas). Photo: Einar Timdal. (C) An almost complete takeover by Diploschistes, with only small remnants of Cladonia. Photo: Martin Westberg.
Tables

Click to view
TABLE 1
Lichenized fungal species for which genome information is available (as of March 2016)
Supplemental Material
No supplementary material available for this content.