Photoinhibition of photosystem I is accelerated by dimethyldithiocarbamate, an inhibitor of superoxide dismutase, during light-chilling of spinach leaves

J Photochem Photobiol B. 2004 Jan 23;73(1-2):79-85. doi: 10.1016/j.jphotobiol.2003.09.008.

Abstract

In vivo photoinhibition of photosystem I (PS I) was investigated at chilling temperature using the leaves of the chilling-resistant spinach plant treated with an inhibitor of superoxide dismutase, diethyldithiocarbamate (DDC). When spinach leaves were treated with DDC during chilling at 4 degrees C for 12 h with a light intensity of 120 micromol m(-2) s(-1), the activity of PS I and the content of iron-sulfur centers declined to about 50% and 25% of the non-DDC-treated controls, respectively. A native green gel analysis of thylakoid membranes isolated from the DDC-treated leaves resolved a novel chlorophyll-protein complex, which was identified as the light-harvesting complex I (LHC I)-deficient PS I complex when examined by 77 K fluorescence spectroscopy and two-dimensional sodium dodecyl sulfate gel electrophoresis. The possible dissociation of LHC I as an early structural change in the PS I complex after DDC-induced photoinhibition of PS I is discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Dimethyldithiocarbamate / pharmacology*
  • Electrophoresis, Gel, Two-Dimensional
  • Enzyme Inhibitors / pharmacology*
  • Light*
  • Photosystem I Protein Complex / antagonists & inhibitors*
  • Plant Leaves / metabolism
  • Plant Leaves / radiation effects
  • Spectrometry, Fluorescence
  • Spinacia oleracea / metabolism
  • Spinacia oleracea / radiation effects*
  • Superoxide Dismutase / antagonists & inhibitors*

Substances

  • Dimethyldithiocarbamate
  • Enzyme Inhibitors
  • Photosystem I Protein Complex
  • Superoxide Dismutase