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...
| Published in: | Limnology and Oceanography Letters |
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| Main Authors: | , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
John Wiley & Sons Inc
2022
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| Subjects: | |
| Online Access: | https://eprints.utas.edu.au/46419/ https://eprints.utas.edu.au/46419/2/148180%20-%20Divergent%20physiological%20and%20molecular%20responses%20of%20light.pdf |
| Summary: | 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. |
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