The influence of ocean acidification on phytotransferrin-mediated iron uptake rates in phytoplankton

ended

The ability of phytoplankton to access the micronutrient iron fuels vast marine ecosystems, drives biogeochemical cycles and influences climate on a planetary scale. Recent studies in the model diatom Phaeodactylum tricornutum have revealed that high-affinity iron uptake uses a carbonate-dependent phytotransferrin which is highly sensitive to ocean acidification. This project seeks to validate and extend the hypothesis that ocean acidification negatively affects the growth of marine phytoplankton by interfering with this carbonate sensitive uptake mechanism. The influence of acidification on iron uptake rates will be characterized in a number of environmentally relevant and phylogenetically diverse strains of phytoplankton, and results will be confirmed using a combination of reverse genetics and environmental validation. The resulting chemical, biological and rate-constant data will be integrated into large-scale biogeochemical Ocean General Circulation Models, which will allow us to place these results into ecological context. This project will transfer cutting-edge molecular techniques and genomic analyses to the host institution while training the experienced researcher in key analytical and biogeochemical modeling methods. Capacity-building courses in project management and opportunities for communication are planned to further develop the future potential of the researcher. Because of the outsized role that iron-limited phytoplankton have in biogeochemical cycles and the sequestration of carbon dioxide, the multidisciplinary outputs of this action are expected to be of high impact and broad interest to a wide array of disciplines, including biogeochemists, climate modelers, policy makers and resource managers.