PS II model-based simulations of single turnover flash-induced transients of fluorescence yield monitored within the time domain of 100ns-10s 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, GYu, Chemeris, YuK, Renger, G, Rubin, AB
• Format: Journal Article
• Language: English
• Published: 01.10.2008
• Subjects: Chlorella pyrenoidosa
• 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 100ns to 10s 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 super(+; ) and super(3)Car. 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 super(+; )Q sub(A) super(-; ) 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 PSII states. We analyzed the maximum ($$ F_{\text{m}}{\text{STF}} $$) and minimum (F sub(0)) of the normalized FL yield dependence on the rate of the recombination processes (radiative and dissipative nonradiative) and of P680 super(+; ) reduction. The developed PSII 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).