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Symbiont-specific responses to environmental cues in a threesome lichen symbiosis
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  • Jasmin Almer,
  • Philipp Resl,
  • Hörður Gudmundsson,
  • Denis Warshan,
  • Olafur Andresson,
  • Silke Werth
Jasmin Almer
Ludwig-Maximilians-Universitat Munchen

Corresponding Author:[email protected]

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Philipp Resl
University of Graz
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Hörður Gudmundsson
University of Iceland
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Denis Warshan
University of Iceland
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Olafur Andresson
Haskoli Islands
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Silke Werth
Ludwig-Maximilians-Universitat Munchen
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Photosymbiodemes are a special case of lichen symbiosis where one lichenized fungus engages in symbiosis with two different photosynthetic partners, a cyanobacterium and a green alga, to develop two distinctly looking photomorphs. We investigated differential gene expression in photosymbiodemes of the lichen Peltigera britannica at different temperatures representing mild and putatively stressful conditions and compared gene expression of thallus sectors containing cyanobacterial photobionts with thallus sectors with both green algal and cyanobacterial photobionts. Firstly, because of known ecological differences between photomorphs, we investigated symbiont-specific responses in gene expression to temperature increases. Secondly, we quantified photobiont-mediated differences in fungal gene expression. High temperatures expectedly led to an upregulation of genes involved in heat shock responses in all organisms in whole transcriptome data. As expected, the expression of genes involved in photosynthesis was increased in both photobiont types at 15 and 25 °C. The green algae exhibited thermal stress responses mainly at 25 °C, the fungus and the cyanobacteria already at 15 °C, demonstrating symbiont-specific responses to environmental cues and symbiont-specific ecological optima. Furthermore, photobiont-mediated differences in fungal gene expression could be identified, with upregulation of distinct biological processes in the different morphs, showing that interaction with specific symbiosis partners profoundly impacts fungal gene expression.
03 Aug 2022Submitted to Molecular Ecology
04 Aug 2022Submission Checks Completed
04 Aug 2022Assigned to Editor
03 Oct 2022Reviewer(s) Assigned
01 Nov 2022Review(s) Completed, Editorial Evaluation Pending
02 Nov 2022Editorial Decision: Revise Minor
01 Dec 2022Review(s) Completed, Editorial Evaluation Pending
01 Dec 20221st Revision Received
05 Dec 2022Editorial Decision: Accept
07 Dec 2022Published in Molecular Ecology. 10.1111/mec.16814