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08:11
Adaptation at the Extremes of Life: Experimental Evolution with the Extremophile Archaeon Sulfolobus acidocaldarius
Published on: June 14, 2024
Do extreme environments provide a refuge from pathogens? A phylogenetic test using serpentine flax
1Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, A316 Earth and Marine Sciences Building, Santa Cruz, California 95064 USA.
American Journal of Botany
|May 31, 2011
Summary
Organisms in extreme environments may face fewer diseases. Wild flax on stressful serpentine soils showed reduced fungal rust infections, supporting the pathogen refuge hypothesis.
Area of Science:
- Ecology
- Evolutionary Biology
- Plant Pathology
Background:
- Extreme environments present physiological challenges and often support less diverse life.
- Organisms in stressful habitats may benefit from reduced antagonistic interactions, such as pathogen pressure.
Purpose of the Study:
- To investigate the pathogen refuge hypothesis in wild flax (Linum spp.) populations.
- To determine if serpentine soil stress reduces the incidence and severity of fungal rust infections.
Main Methods:
- Studied 13 wild flax species with varying degrees of serpentine soil association.
- Conducted phylogenetically explicit analyses of soil chemistry and field-measured disease levels.
- Used ancestral state reconstruction to infer the evolution of serpentine soil tolerance.
Main Results:
- Rust disease was significantly less frequent and severe in flax populations on more stressful, low-calcium serpentine soils.
- Soil calcium concentration was a key indicator of serpentine soil stress.
- Evidence suggests serpentine soil tolerance evolved multiple times within the genus.
Conclusions:
- Stressful abiotic conditions, like those on serpentine soils, can create pathogen refuges for plants.
- This refuge effect may contribute to the persistence of extremophile species.
- Reduced pathogen load can be a significant fitness benefit in extreme environments.
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