1. Harvesting far-red light
- Author
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Luca Bersanini, Roberta Croce, Martijn Tros, Gaozhong Shen, Donald A. Bryant, Ming Yang Ho, Ivo H. M. van Stokkum, Biophysics Photosynthesis/Energy, and LaserLaB - Energy
- Subjects
0106 biological sciences ,0301 basic medicine ,Photosynthetic reaction centre ,Chlorophyll ,Pigments ,Light ,Chlorophyll f ,Biophysics ,Photosynthesis ,Photosystem I ,01 natural sciences ,Biochemistry ,03 medical and health sciences ,chemistry.chemical_compound ,Excitation energy transfer ,SDG 7 - Affordable and Clean Energy ,Synechococcus ,biology ,Photosystem I Protein Complex ,Far-red ,Time-resolved fluorescence ,Cell Biology ,biology.organism_classification ,Light harvesting ,030104 developmental biology ,chemistry ,Energy Transfer ,Photosynthetically active radiation ,010606 plant biology & botany ,Protein Binding - Abstract
The heterologous expression of the far-red absorbing chlorophyll (Chl) f in organisms that do not synthesize this pigment has been suggested as a viable solution to expand the solar spectrum that drives oxygenic photosynthesis. In this study, we investigate the functional binding of Chl f to the Photosystem I (PSI) of the cyanobacterium Synechococcus 7002, which has been engineered to express the Chl f synthase gene. By optimizing growth light conditions, one-to-four Chl f pigments were found in the complexes. By using a range of spectroscopic techniques, isolated PSI trimeric complexes were investigated to determine how the insertion of Chl f affects excitation energy transfer and trapping efficiency. The results show that the Chls f are functionally connected to the reaction center of the PSI complex and their presence does not change the overall pigment organization of the complex. Chl f substitutes Chl a (but not the Chl a red forms) while maintaining efficient energy transfer within the PSI complex. At the same time, the introduction of Chl f extends the photosynthetically active radiation of the new hybrid PSI complexes up to 750 nm, which is advantageous in far-red light enriched environments. These conclusions provide insights to engineer the photosynthetic machinery of crops to include Chl f and therefore increase the light-harvesting capability of photosynthesis.
- Published
- 2020