Abstract
Kinetic curves of absorbance changes induced by far-red light (FR, 830 nm) (ΔA 830), which reflect redox transformations of PSI primary electron donor, P700, were examined in intact barley (Hordeum vulgare L.) leaves. In intact leaves, FR induced the biphasic increase in absorbance related to P700 photooxidation. Leaf treatment with methyl viologen or antimycin A suppressed the slow phase of P700 photooxidation, which was attained in such leaves within the first second of light exposure. With FR turned off, the previously increased absorbance at 830 nm dropped down to its initial level, thus reflecting P700+ reduction. In the control leaves, the kinetics of P700+ reduction consisted of three exponentially decaying components, with the corresponding half-times of 8.8 s (the slow component, with its magnitude comprising 24% of the total ΔA 830 signal), 0.73 s (the middle component, 49% of ΔA 830), and 0.092 s (the fast component, 26% of ΔA 830). The rate of the fast component of P700+ reduction, following FR irradiation of leaves, was about ten times lower than that of the noncyclic electron transfer from PSII to PSI computed from ΔA 830 relaxation after the abrupt offset of white light. The treatment of leaves with methyl viologen or antimycin A completely abolished the fast component of ΔA 830 relaxation after FR exposure. It was concluded that the fast component is determined by the operation of ferredoxin-dependent cyclic electron transport around PSI. This study represents the first report on the identification of this pathway of electron transport in vivo and the estimation of its rate.
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Abbreviations
- FR:
-
far-red
- PS:
-
photosystem
- WL:
-
white light
REFERENCES
Canaani, O. and Havaux, M., Evidence for a Biological Role in Photosynthesis for Cytochrome b-559 — a Component of Photosystem II Reaction Center, Proc. Natl. Acad. Sci. USA, 1990, vol. 87, pp. 9295–9299.
Bukhov, N.G. and Carpentier, R., Alternative Photosystem I-Driven Electron Transport Routes: Mechanisms and Functions, Photosynth. Res., 2004, vol. 82, pp. 17–33.
Fork, D.C. and Herbert, S.K., Electron Transport and Photophosphorylation by Photosystem I In Vivo in Plants and Cyanobacteria, Photosynth. Res., 1993, vol. 36, pp. 149–168.
Arnon, D.I., Tsujimoto, H.Y., and McSwain, B.D., Ferredoxin and Photosynthetic Phosphorylation, Nature, 1967, vol. 214, pp. 526–529.
Sazanov, L.A., Borrows, P., and Nixon, P., The Chloroplast Ndh Complex Mediates the Dark Reduction of the Plastoquinone Pool in Response to Heat Stress in Tobacco Leaves, FEBS Lett., 1998, vol. 429, pp. 115–118.
Shikanai, T., Endo, T., Hashimoto, T., Yamada, Y., Asada, K., and Yokota, A., Directed Disruption of the Tobacco ndhB Gene Impairs Cyclic Electron Flow around Photosystem I, Proc. Natl. Acad. Sci. USA, 1998, vol. 95, pp. 9705–9709.
Corneille, S., Cournac, L., Guedeney, G., Havaux, M., and Peltier, G., Reduction of the Plastoquinone Pool by Exogenous NADH and NADPH in Higher Plant Chloroplasts. Characterization of a NAD(P)H-Plastoquinone Oxidoreductase Activity, Biochim. Biophys. Acta, 1998, vol. 1363, pp. 59–69.
Arnon, D.I. and Chain, R.K., Regulation of Ferredoxin-Catalyzed Photosynthetic Phosphorylation, Proc. Natl. Acad. Sci. USA, 1975, vol. 72, pp. 4961–4965.
Egorova, E.A. and Bukhov, N.G., Modeling of Alternative Pathways of Electron Transport to Photosystem I in Isolated Thylakoids, Fiziol. Rast. (Moscow), 2004, vol. 51, pp. 645–650 (Russ. J. Plant Physiol., Engl. Transl., pp. 579-583).
Harbinson, J. and Hedley, C.L., The Kinetics of P700+ Reduction in Leaves: A Novel In Situ Probe of Thylakoid Functioning, Plant Cell Environ., 1989, vol. 12, pp. 357–369.
Laisk, A. and Oja, V., Range of Photosynthetic Control of Postillumination P700+ Reduction Side in Sunflower Leaves, Photosynth. Res., 1994, vol. 39, pp. 39–50.
Bukhov, N.G., Carpentier, R., and Samson, G., Heterogeneity of Photosystem I Reaction Centers in Barley Leaves as Related to the Donation from Stromal Reductants, Photosynth. Res., 2001, vol. 70, pp. 273–279.
Bukhov, N.G., Egorova, E.A., and Carpentier, R., Electron Flow to Photosystem I from Stromal Reductants In Vivo: the Size of the Pool of Stromal Reductants Controls the Rate of Electron Donation to Both Rapidly and Slowly Reducing Photosystem I Units, Planta, 2002, vol. 215, pp. 812–820.
Schreiber, U., Klughammer, C., and Neubauer, C., Measuring P700 Absorbance Changes around 830 nm with a New Type of Pulse Modulated System, Z. Naturforsch., 1988, vol. 43c, pp. 686–698.
Fujii, T., Yokoyama, E.-I., Inoue, K., and Sakurai, H., The Sites of Electron Donation of Photosystem I to Methyl Viologen, Biochim. Biophys. Acta, 1990, vol. 1015, pp. 41–48.
Kobayashi, Y., Neimanis, S., and Heber, U., Coupling Ratios H+/e = 3 yersus H+/e = 2 in Chloroplasts and Quantum Requirements of Net Oxygen Exchange during the Reduction of Nitrite, Ferricyanide and Methylviologen, Plant Cell Physiol., 1995, vol. 36, pp. 1613–1620.
Ivanov, B., Kobayashi, Y., Bukhov, N., and Heber, U., Photosystem I-Dependent Cyclic Electron Flow in Intact Spinach Chloroplasts: Occurrence, Dependence on Redox Conditions and Electron Acceptors, and Inhibition by Antimycin A, Photosynth. Res., 1998, vol. 57, pp. 67–75.
Cornic, G., Bukhov, N.G., Wiese, C., Bligny, R., and Heber, U., Flexible Coupling between Light-Dependent Electron and Vectorial Proton Transport in Illuminated Leaves of C3 Plants. Role of Photosystem I-Dependent Proton Pumping, Planta, 2000, vol. 210, pp. 468–477.
Witt, Y.T., Coupling of Quanta, Electrons, Fields, Ions and Phosphorylation in the Functional Membrane of Photosynthesis. Results by Pulse Spectrophotometric Methods, Quart. Rev. Biophys., 1971, vol. 4, pp. 365–477.
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Translated from Fiziologiya Rastenii, Vol. 52, No. 3, 2005, pp. 325–330.
Original Russian Text Copyright © 2005 by Bukhov, Egorova.
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Bukhov, N.G., Egorova, E.A. Identification of Ferredoxin-Dependent Cyclic Electron Transport around Photosystem I Using the Kinetics of Dark P700+ Reduction. Russ J Plant Physiol 52, 283–287 (2005). https://doi.org/10.1007/s11183-005-0042-5
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DOI: https://doi.org/10.1007/s11183-005-0042-5