Janus-faced charge recombinations in photosystem II photoinhibition

Trends Plant Sci. 2009 Apr;14(4):200-5. doi: 10.1016/j.tplants.2009.01.009. Epub 2009 Mar 18.

Abstract

Light-induced damage of the photosynthetic apparatus in plants is an important phenomenon that primarily affects the photosystem II complex. Here, we propose a new model of photoinhibition in which charge recombination processes have a double-faced role: first, photodamage is induced by singlet oxygen, which is produced via interaction with the triplet reaction center chlorophyll ((3)P(680)) arising from the recombination of the charge-separated state between P(680) and the pheophytin electron acceptor ((3)[P(680)(+)Phe(-)]). Second, photoprotection is provided by competition between (3)[P(680)(+)Phe(-)] formation and direct recombination of the (1)[P(680)(+)Phe(-)] and P(680)(+)Q(A)(-) states. The efficiency of these two pathways is under control of the redox potential of the Phe and Q(A) electron acceptors, which is utilized during adaptation to high light conditions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Electron Transport / radiation effects
  • Energy Transfer / radiation effects
  • Models, Biological
  • Oxidation-Reduction
  • Photosynthesis / physiology*
  • Photosynthesis / radiation effects
  • Photosystem II Protein Complex / chemistry
  • Photosystem II Protein Complex / metabolism*
  • Plant Proteins / chemistry
  • Plant Proteins / metabolism*
  • Thylakoids / metabolism
  • Thylakoids / radiation effects

Substances

  • Photosystem II Protein Complex
  • Plant Proteins