PS II model-based simulations of single turnover flash-induced transients of fluorescence yield monitored within the time domain of 100 ns-10 s on dark-adapted Chlorella pyrenoidosa cells

• Published in: Photosynthesis research Vol. 98; no. 1-3; pp. 105 - 119
• Main Authors: Belyaeva, N. E, Schmitt, F.-J, Steffen, R, Paschenko, V. Z, Riznichenko, G. Yu, Chemeris, Yu. K, Renger, G, Rubin, A. B
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 01.10.2008; Springer Netherlands; Springer Nature B.V
• Subjects: Adaptation, Physiological; Biochemistry; Biomedical and Life Sciences; Chlorella - physiology; Computer Simulation; Darkness; Fluorescence; Life Sciences; Models, Biological; Nanotechnology; Photosynthesis; Photosystem II Protein Complex - metabolism; Plant Genetics and Genomics; Plant Physiology; Plant Sciences; Regular Paper; Time Factors; Single turnover flash; Electron transfer; Dissipative energy losses; Photosystem II; Fluorescence yield; Model simulation
• ISSN: 0166-8595; 1573-5079
• DOI: 10.1007/s11120-008-9374-2

The set up described in Steffen et al. (Biochemistry 40:173-180, 2001) was used to monitor in the time domain from 100 ns to 10 s single turnover flash-induced transients of the normalized fluorescence yield (SFITFY) on dark-adapted cells of the thermophilic algae Chlorella pyrenoidosa Chick. Perfect data fit was achieved within the framework of a previously proposed model for the PS II reaction pattern (Lebedeva et al., Biophysics 47:968-980, 2002; Belyaeva et al., Biophysics 51:860-872, 2006) after its modification by taking into account nonradiative decay processes including nonphotochemical quenching due to time-dependent populations of P680⁺[round bullet, filled] and ³Car. On the basis of data reported in the literature, a consistent set of rate constants was obtained for electron transfer at the donor and acceptor sides of PS II, pH in lumen and stroma, the initial redox state of plastoquinone pool and the rate of plastoquinone oxidation. The evaluation of the rate constant values of dissipative processes due to quenching by carotenoid triplets in antennae and P680⁺[round bullet, filled]QA ⁻[round bullet, filled] recombination as well as the initial state populations after excitation with a single laser flash are close to that outlined in (Steffen et al., Biochemistry 44:3123-3133, 2005a). The simulations based on the model of the PS II reaction pattern provide information on the time courses of population probabilities of different PS II states. We analyzed the maximum ( [graphic removed] ) and minimum (F ₀) of the normalized FL yield dependence on the rate of the recombination processes (radiative and dissipative nonradiative) and of P680⁺[round bullet, filled] reduction. The developed PS II model provides a basis for theoretical comparative analyses of time-dependent fluorescence signals, observed at different photosynthetic samples under various conditions (e.g. presence of herbicides, other stress conditions, excitation with actinic pulses of different intensity, and duration).