Fungal Kingdom Spotlight Part I: Likin’ the Lichens
The Fungal Kingdom has been a two quarter upper-division program in mycology and lichenology taught by Lalita Calabria and Paul Przybylowicz. Over winter quarter, students in this program have been doing independent projects in groups. Over the next few issues, I will delve into these fascinating projects and explore mycology as a whole at Evergreen.
On Monday March 6th, I sat down with student Jae Andersen to discuss their group’s lichenology research. Lichens are a symbiotic relationship between a fungal component and a photobiont (which are typically either macroalgae or cyanobacteria). The mycobiont, or fungal component, receives its energy from the photobiont. Some researchers hypothesize that there is a third symbiotic component to lichens: yeasts.
Yeast species have been found in lichens, and some theorize these yeasts affect how the lichen body or thallus is formed. While attempted many times over the years, a lichen thallus hasn’t been cultured in the lab in a way that resembles lichen in their natural environment. Jae Anderson worked with group members Nathan Kent and Levi Hamilton to investigate the presence of yeasts in the prairie lichen genus cladonia.
While most surveys of lichens have focused on the presence of yeasts in the cortex, or waxy membrane-like structure found in many yeasts, past surveys have found yeasts in the thallus of cladonia species. Cladonia do not have a cortex, meaning all yeasts found must be in the thallus.
Jae and their group mates originally wanted to see if there was a relationship between usnic acid, which is produced in certain lichens, and the yeast populations in cladonia. They collected the cladonia ciliata species which does not contain usnic acid, and the subvariant cladonia ciliata tenuis. To identify the mycobiont, they made initial chemical tests, then they used PCR testing with an Internal Transcribed Spacer (ITS). ITS sequences are useful for distinguishing between species in the same genus because the region is present in all samples and its sequence is different enough to identify a specific species or subvariant. Polymerase Chain Reaction (PCR), can be used to amplify, or make a large number of copies, of this region so it can be sequenced. After discovering a significant amount of their sample was the lookalike species cladonia portentosa, the study was expanded to include this species and adapted to study the species of the yeasts themselves.
PCR was also used to identify the yeast species present in the cladonia samples. The sequences of the yeasts found in the cladonia samples were of the same species of yeasts found in other cladonia species suggesting there may be cladonia-specific yeast species. This is also significant because the same species of yeasts have been found in European cladonia samples.
While this research did not wind up answering the questions initially asked, of whether usnic acid has an effect on the yeast populations, it raises other interesting questions in lichenology. Why are the same species of yeast present in lichens in entirely different continents? What role do these yeasts play in lichens and do they affect the development of the thallus? Jae intends to do further ILC research into this relationship, putting them and their group mates to the cutting edge of lichenology research. Meanwhile, they will be presenting their research from this quarter at the Northwest Scientific Association (NWSA) conference later this month.
Jae encourages other students to do upper division science at Evergreen. They gained a love for surveying through this program, something that they hadn’t had much interest in before. They also expressed appreciation to the professors of this program, as well as their group members. Jae intends to further study lichenology and has a deep interest in molecular biology.
During the course of this interview I, of course, asked the very important question: “Are lichens edible?” Apparently, there is little research into this area. My initial thoughts would be that they would be crunchy, as they spend most of the time in a very dry state, however because they have no way to store water, Jae expressed concern that all of the water in one’s mouth would be immediately soaked up into the lichen like a sponge. Lichens are more commonly used for dyeing fabrics. However, lichens grow incredibly slowly, so sustainable harvest is crucial. Would I eat a small lichen salad for science? Yes, I would. I’m joking… maybe.As always, if you have any fun and funky research coming up and would like to be featured by the Evergreen Eye on Science, feel free to contact the Cooper Point Journal at cooperpointjournal@gmail.com. The next issue will feature some more mushy (get it) science, and the Eye will see you all again in April.
