1. Lichen Redefined as a Symbiosis of Three

    Basidiomycete yeast was discovered in the cortex of the wolf lichen, as well as among several other species. Image credit: University of Montana Image credit: None
    Basidiomycete yeast was discovered in the cortex of the wolf lichen, as well as among several other species. Image credit: University of Montana

    Recent research from the University of Montana has challenged the longstanding textbook definition of lichen.

    Before the study was published in Science, lichen was thought to be a symbiosis of a single fungus, usually an ascomycete, and a photosynthesizing bacteria or algae. Lead author Toby Spribille analyzed different species across six continents and discovered the existence of a third essential constituent: basidiomycete yeast. The yeast cells were embedded in the lichen cortex and may provide an explanation for the variety of characteristics seen among the species.

    “Basidiomycete yeasts in the cortex of ascomycete macrolichens” has since received wide media coverage, with stories published in Science News, The Atlantic, The New York Times, and more. The research was supported by grants from the University of Montana, the Austrian Science Fund, the NASA Astrobiology Institute, the National Science Foundation, the Swedish University of Agricultural Sciences Council, and Stiftelsen Oscar och Lili Lamms Minne.