1. Photosystem II core quenching in desiccated Leptolyngbya ohadii
- Author
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Yossi Paltiel, Nir Keren, Reza Ranjbar Choubeh, Leeat Bar-Eyal, Paul C. Struik, and Herbert van Amerongen
- Subjects
0301 basic medicine ,Cyanobacteria ,Time Factors ,Crop Physiology ,Photosystem II ,Photosystem II quenching ,Biophysics ,Plant Science ,010402 general chemistry ,Photosynthesis ,Photochemistry ,Photosystem I ,01 natural sciences ,Biochemistry ,03 medical and health sciences ,Image Processing, Computer-Assisted ,Desiccation ,VLAG ,Time-resolved fluorescence spectroscopy ,P700 ,biology ,Chemistry ,Photoprotection ,Temperature ,Photosystem II Protein Complex ,Cell Biology ,General Medicine ,biology.organism_classification ,PE&RC ,0104 chemical sciences ,Light intensity ,Spectrometry, Fluorescence ,030104 developmental biology ,Biofysica ,Original Article ,Phycobilisome ,EPS - Abstract
Cyanobacteria living in the harsh environment of the desert have to protect themselves against high light intensity and prevent photodamage. These cyanobacteria are in a desiccated state during the largest part of the day when both temperature and light intensity are high. In the desiccated state, their photosynthetic activity is stopped, whereas upon rehydration the ability to perform photosynthesis is regained. Earlier reports indicate that light-induced excitations in Leptolyngbya ohadii are heavily quenched in the desiccated state, because of a loss of structural order of the light-harvesting phycobilisome structures (Bar Eyal et al. in Proc Natl Acad Sci 114:9481, 2017) and via the stably oxidized primary electron donor in photosystem I, namely P700+ (Bar Eyal et al. in Biochim Biophys Acta Bioenergy 1847:1267–1273, 2015). In this study, we use picosecond fluorescence experiments to demonstrate that a third protection mechanism exists, in which the core of photosystem II is quenched independently. Electronic supplementary material The online version of this article (10.1007/s11120-019-00675-0) contains supplementary material, which is available to authorized users.
- Published
- 2020