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The Stoichiometry of Photosystem II to Photosystem I in Higher Plants

  • Da-Yong Fan
  • Alexander B. Hope
  • Paul J. Smith
  • Husen Jia
  • Ron J. Pace
  • Jan M. Anderson
  • Wah Soon Chow

Abstract

The stoichiometry of photosystem II to photosystem I reaction centres in spinach leaf segments was determined by two methods, each capable of monitoring both photosystems in a given sample. One method, based on the fast electrochromic (EC) signal, was applied to leaf segments, thereby avoiding potential artefacts associated with the isolation of thylakoids. Two variations of the EC method were used, either suppression of PSII activity by prior photoinactivation or suppression PSI by photo- oxidation of P700, gave the separate contribution of each photosystem to the fast EC signal. The PSII/PSI stoichiometries obtained by the EC methods ranged from 1.5 to 1.8 for spinach, and 1.5 to 1.9 for two other plant species. A second method, based on electron paramagnetic resonance (EPR), gave comparable values of 1.7–2.1 for spinach. A third method consisting of separate determination of the contents of functional PSII by oxygen yield per single turnover flash and of P700 gave a PSII/PSI stiochiometry consistent with above values. We conclude that the content of functional PSII is greater than that of PSI, and PSII/PSI reaction centre ratios considerably higher than unity in typical higher plants.

Keywords

Electrochromic signal EPR Photosystem I Photosystem II Photosystem stoichiometry 

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References

  1. Anderson JM, Chow WS, Goodchild DJ (1988) Thylakoid membrane organization in sun/shade acclimation. Aust J Plant Physiol 15:11-26.CrossRefGoogle Scholar
  2. Andersson B, Anderson JM (1980) Lateral heterogeneity in the distribution of chlorophyll-protein complexes of the thylakoid membranes of spinach chloroplasts. Biochim Biophys Acta 593:427-440.PubMedCrossRefGoogle Scholar
  3. Chow WS, Hope AB (2004) Kinetics of reactions around the cytochrome bf complex studied in intact leaf disks. Photosynth Res 81:153-163.CrossRefGoogle Scholar
  4. Chow WS, Anderson JM, Hope AB (1988) Variable stoichiometries of photosystem II to photosystem I reaction centers. Photosynth Res 17:277-281.CrossRefGoogle Scholar
  5. Chow WS, Hope AB, Anderson JM (1989) Oxygen per flash from leaf discs quantifies photosystem II. Biochim Biophys Acta 973:105-108.CrossRefGoogle Scholar
  6. Chow WS, Melis A, Anderson JM (1990) Adjustments of photosystem stoichiometry in chloroplasts improve the quantum efficiency of photosynthesis. Proc Natl Acad Sci USA 87:7502-7506.PubMedCrossRefGoogle Scholar
  7. Danielsson R, Albertsson P-Å, Mamedov F, Styring S (2004) Quantification of photosystem I and II in different parts of the thylakoid membrane from spinach. Biochim Biophys Acta 1608:53-61.PubMedCrossRefGoogle Scholar
  8. Fan DY, Hope AB, Smith PJ, Jia H, Pace RJ, Anderson JM, Chow WS (2007) The stoichiometry of the two photosystems in higher plants revisited. Biochim Biophys Acta 1767:1064-1072.PubMedCrossRefGoogle Scholar
  9. Melis A (1991) Dynamics of photosynthetic membrane composition and function. Biochim Biophys Acta 1058:87-106.CrossRefGoogle Scholar
  10. Melis A, Brown JS (1980) Stoichiometry of system I and system II reaction centers and of plastoquinone in different photosynthetic membranes. Proc Natl Acad Sci USA 77:4712-4716.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science + Business Media, B.V. 2008

Authors and Affiliations

  • Da-Yong Fan
    • 1
    • 2
  • Alexander B. Hope
    • 3
  • Paul J. Smith
    • 4
  • Husen Jia
    • 1
  • Ron J. Pace
    • 4
  • Jan M. Anderson
    • 1
  • Wah Soon Chow
    • 1
  1. 1.Photobioenergetics Group Research School of Biological SciencesThe Australian National UniversityCanberraAustralia
  2. 2.State Key Laboratory of Vegetation and Environmental ChangeInstitute of Botany, The Chinese Academy of SciencesBeijingChina
  3. 3.School of Biological SciencesFlinders UniversityAdelaideAustralia
  4. 4.Department of Chemistry, College of SciencesThe Australian National UniversityCanberraAustralia

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