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- Voerman, Sofie E., et al.
(författare)
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Red algae acclimate to low light by modifying phycobilisome composition to maintain efficient light harvesting
- 2022
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Ingår i: BMC Biology. - : BioMed Central (BMC). - 1741-7007. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Despite a global prevalence of photosynthetic organisms in the ocean’s mesophotic zone (30–200+ m depth), the mechanisms that enable photosynthesis to proceed in this low light environment are poorly defined. Red coralline algae are the deepest known marine benthic macroalgae — here we investigated the light harvesting mechanism and mesophotic acclimatory response of the red coralline alga Lithothamnion glaciale.Results: Following initial absorption by phycourobilin and phycoerythrobilin in phycoerythrin, energy was transferred from the phycobilisome to photosystems I and II within 120 ps. This enabled delivery of 94% of excitations to reaction centres. Low light intensity, and to a lesser extent a mesophotic spectrum, caused significant acclimatory change in chromophores and biliproteins, including a 10% increase in phycoerythrin light harvesting capacity and a 20% reduction in chlorophyll-a concentration and photon requirements for photosystems I and II. The rate of energy transfer remained consistent across experimental treatments, indicating an acclimatory response that maintains energy transfer.Conclusions: Our results demonstrate that responsive light harvesting by phycobilisomes and photosystem functional acclimation are key to red algal success in the mesophotic zone.
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