Lichen fungi have low cyanobiont selectivity in maritime Antarctica

The cyanobionts of lichens and free-living Nostoc strains from Livingston Island (maritime Antarctica) were examined to determine both the cyanobiont specificity of lichens and the spatial distribution of Nostoc strains under extreme environmental conditions. We collected five different lichen speci...

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Bibliographic Details
Published in:New Phytologist
Main Authors: Wirtz, Nora, Lumbsch, H. Thorsten, Green, T.G. Allan, Türk, Roman, Pintado, Ana, Sancho, Leopoldo G., Schroeter, Burkhard
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2010
Subjects:
lichens
Nostoc
cyanobacteria
maritime Antarctica
symbiont specificity
tRNALeu intron
Antarctic
Livingston Island
The Antarctic
Antarc*
Antarctica
Online Access:https://hdl.handle.net/10289/4090
https://doi.org/10.1046/j.1469-8137.2003.00859.x
Description
Summary:The cyanobionts of lichens and free-living Nostoc strains from Livingston Island (maritime Antarctica) were examined to determine both the cyanobiont specificity of lichens and the spatial distribution of Nostoc strains under extreme environmental conditions. We collected five different lichen species with cyanobacteria as primary or secondary photobiont (Massalongia carnosa, Leptogium puberulum, Psoroma cinnamomeum, Placopsis parellina and Placopsis contortuplicata) and free-living cyanobacteria from different sample sites and analysed them using the tRNALeu (UAA) intron as a genetic marker to identify the cyanobacterial strains. Our results showed that the same Nostoc strain was shared by all five lichen species and that an additional strain was present in two of the lichens. Both Nostoc strains associated with lichen fungi also occurred free-living in their surrounding. Bi- and tri-partite lichens were not different in their cyanobiont selectivity. Contrary to studies on different lichen species in temperate regions, the Antarctic lichen species here did not use species-specific cyanobionts; this could be because of a selection pressure in this extreme environment. Limiting factors under these ecological conditions favor more versatile mycobionts. This results in selection against photobiont specificity, a selection pressure that may be more important for lichen distribution than the effect of cold temperatures on metabolism.

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