GEOGRAPH, LAIRICH RIGThe dictionary entry on lichen may require editing. A study published in Science last week (July 21) upends the old one alga-one fungus symbiosis idea, replacing it with one slightly more complicated: two fungi—the known ascomycete and newly discovered Basidiomycete yeasts—instead of one.
“This discovery overturns our longstanding assumptions about the best-studied symbiotic relationship on the planet,” study coauthor and Purdue mycologist M. Catherine Aime said in a press release. “These yeasts comprise a whole lineage that no one knew existed, and yet they are in a variety of lichens on every continent as a third symbiotic partner.”
University of Graz postdoc Toby Spribille initiated the study on lichen composition to figure out what explained phenotypic differences between two lichens that were composed of the same fungus and alga. That led Spribille to discover a Basidiomycete yeast in the lichens whose gene expression was responsible for the differences. “It took a long time to convince myself that I wasn’t dealing with a contamination,” Spribille said in the statement.
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