Abstract

Lichen-forming fungi establish stable symbioses with green algae or cyanobacteria. Many species have broad distributions, both in geographic and ecological space, making them ideal subjects to study organism-environment interactions. However, little is known about the specific mechanisms that contribute to environmental adaptation in lichen-forming fungi. The circadian clock provides a well-described mechanism that contributes to regional adaptation across a variety of species, including fungi. Here, we identify the putative circadian clock components in phylogenetically divergent lichen-forming fungi. The core circadian genes (frq, wc-1, wc-2, frh) are present across the Fungi, including 31 lichen-forming species, and their evolutionary trajectories mirror overall fungal evolution. Comparative analyses of the clock genes indicate conserved domain architecture among lichen- and non-lichen-forming taxa. We used RT-qPCR to examine the core circadian loop of two unrelated lichen-forming fungi, Umbilicaria pustulata (Lecanoromycetes) and Dermatocarpon miniatum (Eurotiomycetes), to determine that the putative frq gene is activated in a light-dependent manner similar to the model fungus Neurospora crassa. Together, these results demonstrate that lichen-forming fungi retain functional light-responsive mechanisms, including a functioning circadian clock. Our findings provide a stepping stone into investigating the circadian clock in the lichen symbiosis, e.g. its role in adaptation, and in synchronizing the symbiotic interaction.

Published in

Scientific Reports
2022, Volume: 12, number: 1, article number: 15884
Publisher: NATURE PORTFOLIO

SLU Authors

• Merges, Dominik

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    
  • Senckenberg Biodiversitat and Klima- Forschungszentrum (BiK-F)

UKÄ Subject classification

Evolutionary Biology
Ecology


Publication identifier

DOI: https://doi.org/10.1038/s41598-022-19646-y

Permanent link to this page (URI)

https://res.slu.se/id/publ/123010