IRONBIND · The influence of ocean acidification on phytotransferrin-mediated iron uptake rates in phytoplankton
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2019-06-01 → 2020-05-31
- EU contribution
- €87,403
- Participants
- 1
- Scheme
- MSCA-IF-EF-ST
Lines connect the coordinator with its partners.
Results in brief
The influence of ocean acidification on phytotransferrin-mediated iron uptake rates in phytoplankton
The goal of Project IRONBIND is to determine whether elevated concentrations of atmospheric carbon dioxide (CO2) negatively affect the growth of marine phytoplankton by interfering with a key iron acquisition mechanism. This mechanism, phytotransferrin-mediated iron binding, requires high concentrations of carbonate ion to bind dilute concentrations of iron. At the sea surface, dissolved carbonate is inversely proportional to atmospheric CO2, thus as global CO2 concentration rises from the combustion of fossil fuels, seawater carbonate concentration decreases, potentially interfering with the ability of phytoplankton to bind and internalize iron. This interference may be critical in oceanic regions where low concentrations of iron already limit phytoplankton growth. Phytoplankton in these ‘iron limited’ regions support highly productive fisheries and marine ecosystems and function as a critical sink for planetary CO2. Changes to the ability of phytoplankton to acquire iron would likely lead to a decrease in productivity and reduce carbon drawdown rates. Phytotransferrin was first described in 2018, and phytotransferrin-encoding gene sequences can be found in most major phytoplankton groups. However, the phytotransferrin mechanism has only been characterized in a model organism, and iron-carbonate co-limitation has never been documented in the environment. To fill these knowledge gaps, project IRONBIND set out to answer three fundamental questions: How widespread is the phytotransferrin mechanism? Can the effect of carbonate on iron uptake be measured in the environment? And if there is an effect, what are the ramifications for climate change and the global carbon cycle?
Data: CORDIS, © European Union
Project objective
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.
Original text from CORDIS.
Participants
- ALFRED-WEGENER-INSTITUT HELMHOLTZ-ZENTRUM FUR POLAR- UND MEERESFORSCHUNG · BremerhavenCoordinatorGermany
Links
Data: CORDIS, © European Union