Photobiont Switching in a Common Lichen in Response to the UHI Effect
Photobiont switching is a mode of acclimation that lichens are thought to use in response to changing environmental conditions, where a lichen fungal mycobiont associates with a new algal photobiont. This study is the first to investigate photobiont switching in common transplanted lichens to gain insight on the impacts of the urban heat island (UHI) effect in Minnesota. DNA extractions were performed on transplanted and existing Flavoparmelia caperata lichens, which are abundant across Minnesota. Extracted DNA was sequenced, then analyzed using bioinformatics methods to determine if significant shifts in algal (Trebouxia) clades had occurred during 6 and 10 month time periods. Based on global climatic data, it was hypothesized that there would be a shift towards clade C Trebouxia in urban areas due to the UHI effect. While there were definite shifts in Trebouxia clades in the urban transplants, this shift was predominantly towards clade I, and almost no clade C Trebouxia was found in any lichen samples. Although evident in clade proportion data, the shift towards clade I was not statistically significant, nor consistent with temperature increase across Minnesota. These results suggest photobiont switching towards clade I in urban Minnesota due to the UHI effect, but further studies are needed to confirm this finding.