Arabidopsis thylakoid formation 1 is a critical regulator for dynamics of PSII-LHCII complexes in leaf senescence and excess light

Mol Plant. 2013 Sep;6(5):1673-91. doi: 10.1093/mp/sst069. Epub 2013 May 13.


In higher plants, photosystem II (PSII) is a large pigment-protein supramolecular complex composed of the PSII core complex and the plant-specific peripheral light-harvesting complexes (LHCII). PSII-LHCII complexes are highly dynamic in their quantity and macro-organization to various environmental conditions. In this study, we reported a critical factor, the Arabidopsis Thylakoid Formation 1 (THF1) protein, which controls PSII-LHCII dynamics during dark-induced senescence and light acclimation. Loss-of-function mutations in THF1 lead to a stay-green phenotype in pathogen-infected and senescent leaves. Both LHCII and PSII core subunits are retained in dark-induced senescent leaves of thf1, indicative of the presence of PSII-LHCII complexes. Blue native (BN)-polyacrylamide gel electrophoresis (PAGE) and immunoblot analysis showed that, in dark- and high-light-treated thf1 leaves, a type of PSII-LHCII megacomplex is selectively retained while the stability of PSII-LHCII supercomplexes significantly decreased, suggesting a dual role of THF1 in dynamics of PSII-LHCII complexes. We showed further that THF1 interacts with Lhcb proteins in a pH-dependent manner and that the stay-green phenotype of thf1 relies on the presence of LHCII complexes. Taken together, the data suggest that THF1 is required for dynamics of PSII-LHCII supramolecular organization in higher plants.

Keywords: Arabidopsis.; light regulation; photosynthesis; physiology of plant growth.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / growth & development*
  • Arabidopsis / microbiology
  • Arabidopsis / radiation effects*
  • Arabidopsis / ultrastructure
  • Arabidopsis Proteins / metabolism*
  • Chlorophyll / metabolism
  • Darkness
  • Epistasis, Genetic
  • Light*
  • Light-Harvesting Protein Complexes / metabolism*
  • Membrane Proteins / metabolism*
  • Models, Biological
  • Mutation / genetics
  • Phenotype
  • Photosynthesis / radiation effects
  • Photosystem II Protein Complex / metabolism*
  • Plant Leaves / growth & development*
  • Plant Leaves / microbiology
  • Plant Leaves / radiation effects
  • Protein Binding / radiation effects
  • Protein Stability / radiation effects
  • Pseudomonas syringae / physiology
  • Pseudomonas syringae / radiation effects
  • Thylakoids / metabolism
  • Thylakoids / ultrastructure


  • Arabidopsis Proteins
  • Light-Harvesting Protein Complexes
  • Membrane Proteins
  • Photosystem II Protein Complex
  • THF1 protein, Arabidopsis
  • Chlorophyll