On the origin of the `35‐μs kinetics' of P680<sup>+⋅</sup> reduction in photosystem II with an intact water oxidising complex

Christen, G.; Reifarth, F.; Ренгер, Г.

doi:10.1016/s0014-5793(98)00552-3

Cited by 59 publications

(58 citation statements)

References 31 publications

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“…Recent studies with isolated LHC II revealed that in the time domain of 1-100 µs the fluorescence yield only depends on formation of 3 Car and its decay with a characteristic 3 µs kinetics under aerobic conditions (27,48,49). Accordingly, after correction for these 3 µs kinetics, the fluorescence rise reflects the kinetics of P680 +• reduction by Y Z whereas the P680 +• Q A -• recombination is "invisible".…”

Section: Methodsmentioning

confidence: 99%

P680^+•Reduction Kinetics and Redox Transition Probability of the Water Oxidizing Complex as a Function of pH and H/D Isotope Exchange in Spinach Thylakoids

1999

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The rise of fluorescence as an indicator for P680(+)* reduction by YZ and the period-four oscillation of oxygen yield induced by a train of saturating flashes were measured in dark-adapted thylakoids as a function of pH in the absence of exogenous electron acceptors. The results reveal that: (i) the average amplitude of the nanosecond kinetics and the average of the maximum fluorescence attained at 100 micros after the flash in the acidic range decrease with decreasing pH; (ii) the oxygen yield exhibits a pronounced period-four oscillation at pH 6.5 and higher damping at both pH 5.0 and pH 8.0; (iii) the probability of misses in the Si-state transitions of the water oxidizing complex is affected characteristically when exchangeable protons are replaced by deuterons [at pH <6.5, the ratio alpha(D)/alpha(H) is larger than 1 whereas at pH >7.0 values of <1 are observed]. The results are discussed within the framework of a combined mechanism for P680(+)* reduction where the nanosecond kinetics reflect an electron transfer coupled with a "rocket-type" proton shift within a hydrogen bridge from YZ to a nearby basic group, X [Eckert, H.-J., and Renger, G. (1988) FEBS Lett. 236, 425-431], and subsequent relaxations within a network of hydrogen bonds. It is concluded that in the acidic region the hydrogen bond between YZ and X (most likely His 190 of polypeptide D1) is interrupted either by direct protonation of X or by conformational changes due to acid-induced Ca2+ release. This gives rise to a decreased P680(+)* reduction by nanosecond kinetics and an increase of dissipative P680(+)* recombination at low pH. A different mechanism is responsible for the almost invariant amplitude of nanosecond kinetics and increase of alpha in the alkaline region.

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Section: Methodsmentioning

confidence: 99%

P680^+•Reduction Kinetics and Redox Transition Probability of the Water Oxidizing Complex as a Function of pH and H/D Isotope Exchange in Spinach Thylakoids

1999

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“…At about 45 µs after the actinic flash, a maximum level symbolized by F m -(45 µs) is reached. At saturating intensity of the actinic laser flash, the ratio of F m (45 µs)/F 0 is about 2.7, which is typical for the flash-induced increase of the relative fluorescence quantum yield (14,28). It is slightly lower (by about 20%) than values reported recently for the F m /F 0 ratio of 3.2 measured at a delay of 100 µs (14,28) because at 45 µs the slow rise components with lifetimes of the order of 30 µs are not completed.…”

Section: Flash-induced Fluorescence Changes In Thylakoidsmentioning

confidence: 97%

“…The extent of a 3 is gathered from the difference ∆Φ( 3 Car) shown in Figure 3. The contribution of the 35 µs kinetics of P680 •+ reduction by Y Z due to relaxation processes (11,14,16,28) is comparatively small and can be neglected in the time domain of e5 µs.…”

Section: Changes Of Relative Fluorescence Yield In Dark-adapted Thylamentioning

confidence: 99%

Time-Resolved Monitoring of Flash-Induced Changes of Fluorescence Quantum Yield and Decay of Delayed Light Emission in Oxygen-Evolving Photosynthetic Organisms

2000

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The present contribution describes a new experimental setup that permits time-resolved monitoring of the rise kinetics of the relative fluorescence yield, Phi(rel)(t), and simultaneously of the decay of delayed light emission, L(t), induced by strong actinic laser flashes. The results obtained by excitation of dark-adapted samples with a train of eight flashes reveal (a) in suspensions of spinach thylakoids, Phi(rel)(t) exhibits a typical period four oscillation that is characteristic for a dependence on the redox states S(i)() of the water oxidizing complex (WOC), (b) the relative extent of the unresolved "instantaneous" rise to the level (100 ns) at 100 ns and the maximum values of Phi(rel)(t) attained at about 45 s after each actinic flash, (45 s) synchronously oscillate and exhibit the largest values at flash nos. 1 and 5 and minima after flash nos. 2 and 3, (c) opposite effects are observed for the normalized extent of the rise kinetics in the 100 ns to 5 s time domain of relative fluorescence yield, Phi(rel)(5 s) - Phi(rel)(100 ns), i.e., both parameters attain minimum and maximum values after the first/fifth and second/third flash, respectively, and (d) analogous features for the "fast" and "slow" ns-kinetics of the fluorescence rise were observed in suspensions of Chlamydomas reinhardtii cells. A slight phase shift by one flash is ascribed to physiological differences. The applicability of this noninvasive technique to study reactions of photosystem II, especially the reduction kinetics of P680(*)(+) and their dependence on the redox state S(i)() of the WOC, is discussed.

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“…On the contrary, DF has components that decay in very different time domains: in the nanoseconds (Christen et al 2000), microseconds (Jursinic and Govindjee 1977;Jursinic et al 1978;Wong et al 1978;Christen et al 1998;Mimuro et al 2007;Buchta et al 2008), milliseconds (Hipkins and Barber 1974;Barber and Neumann 1974;Zaharieva and Goltsev 2003;Goltsev et al 2005;Buchta et al 2007), seconds Hideg et al 1991;Katsumata et al 2008), and even in the hour time range (Hideg et al 1990).…”

Section: Origin Of Delayed Fluorescencementioning

confidence: 99%

Delayed fluorescence in photosynthesis

et al. 2009

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Photosynthesis is a very efficient photochemical process. Nevertheless, plants emit some of the absorbed energy as light quanta. This luminescence is emitted, predominantly, by excited chlorophyll a molecules in the light-harvesting antenna, associated with Photosystem II (PS II) reaction centers. The emission that occurs before the utilization of the excitation energy in the primary photochemical reaction is called prompt fluorescence. Light emission can also be observed from repopulated excited chlorophylls as a result of recombination of the charge pairs. In this case, some time-dependent redox reactions occur before the excitation of the chlorophyll. This delays the light emission and provides the name for this phenomenon-delayed fluorescence (DF), or delayed light emission (DLE). The DF intensity is a decreasing polyphasic function of the time after illumination, which reflects the kinetics of electron transport reactions both on the (electron) donor and the (electron) acceptor sides of PS II. Two main experimental approaches are used for DF measurements: (a) recording of the DF decay in the dark after a single turnover flash or after continuous light excitation and (b) recording of the DF intensity during light adaptation of the photosynthesizing samples (induction curves), following a period of darkness. In this paper we review historical data on DF research and recent advances in the understanding of the relation between the delayed fluorescence and specific reactions in PS II. An experimental method for simultaneous recording of the induction transients of prompt and delayed chlorophyll fluorescence and decay curves of DF in the millisecond time domain is discussed.

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On the origin of the `35‐μs kinetics' of P680^+⋅ reduction in photosystem II with an intact water oxidising complex

Cited by 59 publications

References 31 publications

P680^+•Reduction Kinetics and Redox Transition Probability of the Water Oxidizing Complex as a Function of pH and H/D Isotope Exchange in Spinach Thylakoids

P680^+•Reduction Kinetics and Redox Transition Probability of the Water Oxidizing Complex as a Function of pH and H/D Isotope Exchange in Spinach Thylakoids

Time-Resolved Monitoring of Flash-Induced Changes of Fluorescence Quantum Yield and Decay of Delayed Light Emission in Oxygen-Evolving Photosynthetic Organisms

Delayed fluorescence in photosynthesis

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On the origin of the `35‐μs kinetics' of P680+⋅ reduction in photosystem II with an intact water oxidising complex

Cited by 59 publications

References 31 publications

P680+•Reduction Kinetics and Redox Transition Probability of the Water Oxidizing Complex as a Function of pH and H/D Isotope Exchange in Spinach Thylakoids

P680+•Reduction Kinetics and Redox Transition Probability of the Water Oxidizing Complex as a Function of pH and H/D Isotope Exchange in Spinach Thylakoids

Time-Resolved Monitoring of Flash-Induced Changes of Fluorescence Quantum Yield and Decay of Delayed Light Emission in Oxygen-Evolving Photosynthetic Organisms

Delayed fluorescence in photosynthesis

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Product

Resources

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On the origin of the `35‐μs kinetics' of P680^+⋅ reduction in photosystem II with an intact water oxidising complex

P680^+•Reduction Kinetics and Redox Transition Probability of the Water Oxidizing Complex as a Function of pH and H/D Isotope Exchange in Spinach Thylakoids

P680^+•Reduction Kinetics and Redox Transition Probability of the Water Oxidizing Complex as a Function of pH and H/D Isotope Exchange in Spinach Thylakoids