Investigating the gene expression of mixotrophic phytoplankton under iron-limited upwelling conditions

Mixotrophic phytoplankton may have significant impacts on ocean food web dynamics, biogeochemistry, and ecosystem stability. As global warming is expected to decrease iron bioavailability to phytoplankton, mixotrophs may have an advantage due to their potential ability to acquire iron through their prey. The goal of this proposed study is to investigate the prevalence of mixotrophic phytoplankton and their molecular physiology within upwelling zones as a function of iron status. The proposed analysis will be conducted using RNA samples taken from fresh upwelling within the California Current System, which were incubated under unamended, iron-enriched, and iron-deplete treatments. These RNA samples can be analyzed for the differential expression of mixotrophic genes between treatments and over time to decipher the potential benefits of mixotrophy in variable iron environments.