High light tolerance comparisons between five strains of coccolithophore Emiliania huxleyi

Emiliania huxleyi is a species of coccolithophore, an abundant and diverse group of phytoplankton. E. huxleyi are able to thrive in most of the world’s oceans despite environmental variability. The ability to bloom across wide environmental gradients indicates either broad tolerance to variable conditions or high intraspecific genetic diversity. In previous studies, high light exposure has negatively affected photosynthetic efficiency (Fv/Fm) in E. huxleyi. Our study expands on past research by comparing Fv/Fm across five strains of E. huxleyi isolated from different environments. Strains were exposed to varying levels of natural sunlight, then allowed to recover in low light intensities. Both the Fv/Fm decrease in response to high light exposure and its subsequent recovery varied with strain. This indicates that intraspecific variability in E. huxleyi light tolerance plays a role in promoting the cosmopolitan distribution of the species. This gives rise to further research questions involving what causes light tolerance in phytoplankton, and how this may reveal why E. huxleyi is able to tolerate the variable conditions of the ocean.

Presentation Preference: Poster

Primary Presenter: Mackenzie Frey, University of Delaware (mfrey@udel.edu)

Authors:

Mackenzie Frey, University of Delaware  (mfrey@udel.edu)

Suzanne Strom, Western Washington University  (stroms@wwu.edu)

Kerri Fredrickson, Western Washington University  (frederk@wwu.edu)