Light stress response of contrasting life stages in the coccolithophore Emiliania huxleyi
Luis Valentin-Alvarado and Suzanne Strom
Shannon Point Marine Center, Western Washington University
Research QuestionHow does life stage affect the relationship between stress and chemical signal production? .
BackgroundEmiliania huxleyi, one of the most abundant coccolithophores in our oceans, forms extensive blooms (>100,000 km2) that are often visible in satellite images. This species has a heteromorphic life cycle including a non-motile diploid phase typically bearing coccoliths and a flagellated no-calcified haploid phase. .
E. huxleyi is an important producer of dimethylsulphoniopropionate DMSP. DMSP is the precursor of dimethylsulfide (DMS), which is the most dominant, volatile, biogenic organic compound in the marine environment and is thought to participate in global climate change through the formation of sulfate and aerosols. DMSP also is a multifactorial compound; it acts as a compatible solute in cell metabolism and as a chemical signal influencing bacterial and protist behavior.
This cosmopolitan marine phytoplankton has been intensely studied in the context of biogeochemistry, cellular carbon physiology, biomineralization, and plankton ecology but little is known about the ecophysiology of the two life phases of E. huxleyi. Currently, there is no literature discussing how these two life phases respond to high light stress and few studies have examined the effect of high light on the production of DMSP. We are studying both phases of E. huxleyi trying to characterize how their respond to light-stress and whether there DMSP production differs. Differences in the physiological responses of these life cycle phases may provide evidence for each stages being adapted to a different ecological environmental. To test for this, photosynthetic response, particulate and dissolved DMSP, and chlorophyll measurements of the 2 phases of E. huxleyi under light stress.
More InformationThe methods and results of this experiment are outlined in this webpage; please email me for a copy of the full manuscript or for any additional information.