Plastoquinol as a Singlet Oxygen Scavenger in Photosystem II

  • Jerzy Kruk
  • Jolanta Gruszka
  • Achim Trebst
Conference paper

Abstract

We have found that in control Chlamydomonas reinhardtii cells, under high-light stress, the level of reduced plastoquinone considerably increases while in the presence of pyrazolate, an inhibitor of plastoquinone and tocopherol biosynthesis, the content of reduced plastoquinone quickly decreases, similarly to α-tocopherol. Photodegradation of both prenyllipids was partially reversed by diphenylamine, a singlet oxygen scavenger. It was concluded that under high-light stress plastoquinol, as well as α-tocopherol is degraded as a result of a scavenging reaction of singlet oxygen generated in photosystem II. The lack of photodegradation of α-tocopherol and of the reduced plastoquinone in the absence of the inhibitor is due to a fast turnover of both prenyllipids, i.e., their degradation is compensated by fast biosynthesis. We have also found that the level of α-tocopherol quinone, an oxidation product of α-tocopherol, increases as the α-tocopherol is consumed. The same correlation was also observed for γ-tocopherol and its quinone form.

Keywords

Photosystem II plastoquinol plastoquinone singlet oxygen tocopherol tocopherolquinone 

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References

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Copyright information

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

Authors and Affiliations

  • Jerzy Kruk
    • 1
  • Jolanta Gruszka
    • 1
  • Achim Trebst
    • 2
  1. 1.Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and BiotechnologyJagiellonian UniversityKrakówPoland
  2. 2.Plant BiochemistryRuhr-University BochumBochumGermany

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