Nearly half of photosynthesis on Earth occurs in the oceans, mostly by tiny phytoplankton that are invisible to the naked eye. Each day, a significant fraction of these phytoplankton cells are infected and killed by viruses. This process affects not only the abundance of these cells, but also how much carbon dioxide they remove from the atmosphere. Nutrients from the dead cells are also released, feeding other nearby microbes. Our project investigates whether some phytoplankton cells are more susceptible to viruses, and what happens to the nutrients inside the cell during and after infection.
Our project seeks to understand how host physiology affects viral infection in cyanobacteria and picoeukaryote phytoplankton, and how host and virus metabolism interact at the molecular level. We will use transcriptomics and proteomics, as well as newly developed single-cell methods, to characterize the viral infection process in multiple model systems in the lab under different physiological conditions. We will also perform field experiments to extend these lab results to complex natural communities in the Sargasso Sea. Another goal of the project is to characterize the dissolved organic matter that is released by viral infection using chromatography and mass spectrometry techniques. Finally, we are especially interested in the role of virus-encoded “host-like” genes in the infection process and in virus-host coevolution; these genes will be the focus of gene expression, metagenomics, and biochemical characterization.
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