Abstract
Plants and cyanobacteria use the chlorophylls embedded in their photosystems to absorb photons and perform charge separation, the first step of converting solar energy to chemical energy. While oxygenic photosynthesis is primarily based on chlorophyll a photochemistry, which is powered by red light, a few cyanobacterial species can harness less energetic photons when growing in far-red light. Acclimatization to far-red light involves the incorporation of a small number of molecules of red-shifted chlorophyll f in the photosystems, whereas the most abundant pigment remains chlorophyll a. Due to its different energetics, chlorophyll f is expected to alter the excited-state dynamics of the photosynthetic units and, ultimately, their performances. Here we combined time-resolved fluorescence measurements on intact cells and isolated complexes to show that chlorophyll f insertion slows down the overall energy trapping in both photosystems. While this marginally affects the efficiency of photosystem I, it substantially decreases that of photosystem II. Nevertheless, we show that despite the lower energy output, the insertion of red-shifted chlorophylls in the photosystems remains advantageous in environments that are enriched in far-red light and therefore represents a viable strategy for extending the photosynthetically active spectrum in other organisms, including plants. However, careful design of the new photosynthetic units will be required to preserve their efficiency.
Original language | English |
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Pages (from-to) | 1044-1053 |
Number of pages | 10 |
Journal | Nature Plants |
Volume | 6 |
Issue number | 8 |
Early online date | 13 Jul 2020 |
DOIs | |
Publication status | Published - Aug 2020 |
Funding
We thank J. Schaefers (Vrije Universiteit Amsterdam) for helping with cell growth and pigment content determination and M. Tros for insightful discussions. This project was supported by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 675006 and by the Netherlands Organization for Scientific Research (NWO) via a Top grant to R.C., and by the EMBO long-term fellowship (EMBO ALTF 292-2017) to L.B.
Funders | Funder number |
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Marie Skłodowska-Curie | |
European Molecular Biology Organization | ALTF 292-2017 |
Horizon 2020 Framework Programme | 675006 |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek | EMBO ALTF 292-2017 |