Divergent physiological and molecular responses of light- and iron-limited Southern Ocean phytoplankton
It has recently been shown that Southern Ocean phytoplankton species have evolved to optimize their light-harvesting potential without increasing the high iron-requiring proteins used for photosynthesis. We measured molecular and physiological responses of phytoplankton cultures under a combination of iron and light conditions. While iron-replete cultures mostly increased biovolume, photochemical efficiency (Fv/Fm) and the relative abundance of photosystem II (PSII) and Cytochrome b6f protein compared to iron-limited cultures, light also regulated cellular chlorophyll a content and played a role in controlling PSII protein abundance. Investment of protein resources into the carbon fixing enzyme Ribulose 1,5-bisphosphate carboxylase oxygenase (Rubisco) was species-specific, but increased growth rates correlated with increased investment into Rubisco for all species. Our results suggest that Proboscia inermis uses a divergent molecular strategy to compete for nutrients, light, and CO2 in the Southern Ocean.
History
Publication title
Limnology and Oceanography LettersVolume
7Pagination
150-158ISSN
2378-2242Department/School
Institute for Marine and Antarctic StudiesPublisher
John Wiley & Sons IncPlace of publication
United StatesRights statement
© 2021 The Authors. Limnology and Oceanography Letters published by Wiley Periodicals LLC. This is an open access article under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) License, (https://creativecommons.org/licenses/by/4.0/) which permits use, distribution and reproduction in any medium, provided the original work is properly cited.Repository Status
- Open