Photoprotection in higher plants: The putative quenching site is conserved in all outer light-harvesting complexes of Photosystem II

M. Mozzo, F. Passarini, R. Bassi, H. van Amerongen, R. Croce

Research output: Contribution to journalArticleAcademicpeer-review

72 Citations (Scopus)

Abstract

In bright sunlight, the amount of energy harvested by plants exceeds the electron transport capacity of Photosystem II in the chloroplasts. The excess energy can lead to severe damage of the photosynthetic apparatus and to avoid this, part of the energy is thermally dissipated via a mechanism called non-photochemical quenching (NPQ). It has been found that LHCII, the major antenna complex of Photosystem II, is involved in this mechanism and it was proposed that its quenching site is formed by the cluster of strongly interacting pigments: chlorophylls 611 and 612 and lutein 620. In the present work we have investigated the interactions between the pigments in this cluster not only for LHCII, but also for the homologous minor antenna complexes CP24, CP26 and CP29. Use was made of wild-type and mutated reconstituted complexes that were analyzed with (low-temperature) absorption and circular-dichroism spectroscopy as well as by biochemical methods. The pigments show strong interactions that lead to highly specific spectroscopic properties that appear to be identical for LHCII, CP26 and CP29. The interactions are similar but not identical for CP24. It is concluded that if the 611/612/620 domain is responsible for the quenching in LHCII, then all these antenna complexes are prepared to act as a quencher. This can explain the finding that none of the Lhcb complexes seems to be strictly required for NPQ while, in the absence of all of them, NPQ is abolished.
Original languageEnglish
Pages (from-to)1263-1267
JournalBiochimica et Biophysica Acta. B, Bioenergetics
Volume1777
Issue number10
DOIs
Publication statusPublished - 2008

Keywords

  • antenna protein cp26
  • energy-dissipation
  • chlorophyll-a
  • mutation analysis
  • green plants
  • lhcii
  • mechanism
  • binding
  • xanthophylls
  • identification

Fingerprint Dive into the research topics of 'Photoprotection in higher plants: The putative quenching site is conserved in all outer light-harvesting complexes of Photosystem II'. Together they form a unique fingerprint.

  • Cite this