Rosenberg Institute Fall Seminar Series @ EOS Center

Chemical signaling induced by various modes of phytoplankton death
and the implications for the microbial loop

Bethanie Edwards, Assistant Professor, UC Berkeley

Abstract: Diatoms are important phytoplankton in the world oceans, contributing significantly to primary productivity and carbon export. Some species of diatoms and other eukaryotic phytoplankton produce allelopathic compounds called oxylipins when they are stressed. Oxylipins produced by diatoms have been observed to decrease copepod reproductive success and induce expression of key stress response genes, inhibit free-living bacteria, stimulate particle-associated bacteria, and stunt the growth of phytoplankton competitors. Here we will explore the impact of dinoflagellate grazing and viral infection on the production of oxylipins by diatoms and the ecological implications of the oxylipins produced.

Bio: Bethanie Edwards is a sea-going oceanographer who is interested in how marine microbes interact with one another, the chemical language that they use to do so, and the impact this has on ocean chemistry and climate. Since the industrial revolution, the ocean has absorbed ~40% of the CO2 that we’ve put into the atmosphere. This process is driven in part by microscopic phytoplankton and the bacteria, viruses, and zooplankton grazers that use them as an energy source. Dr. Edwards’ expertise is in lipidomics, which allows her to listen in on their molecular conversations and gain insight into the complex web of microbial community dynamics.