Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8298751 | Biochimica et Biophysica Acta (BBA) - Bioenergetics | 2015 | 7 Pages |
Abstract
When cyanobacteria are grown under iron-limited or other oxidative stress conditions the iron stress inducible pigment-protein IsiA is synthesized in variable amounts. IsiA accumulates in aggregates inside the photosynthetic membrane that strongly dissipate chlorophyll excited state energy. In this paper we applied Stark fluorescence (SF) spectroscopy at 77Â K to IsiA aggregates to gain insight into the nature of the emitting and energy dissipating state(s). Our study shows that two emitting states are present in the system, one emitting at 684Â nm and the other emitting at about 730Â nm. The new 730Â nm state exhibits strongly reduced fluorescence (F) together with a large charge transfer character. We discuss these findings in the light of the energy dissipation mechanisms involved in the regulation of photosynthesis in plants, cyanobacteria and diatoms. Our results suggest that photosynthetic organisms have adopted common mechanisms to cope with the deleterious effects of excess light under unfavorable growth conditions.
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Authors
Md. Wahadoszamen, Sandrine D'Haene, Anjue Mane Ara, Elisabet Romero, Jan P. Dekker, Rienk van Grondelle, Rudi Berera,