Circadian control of chloroplast transcription by a nuclear-encoded timing signal

Science. 2013 Mar 15;339(6125):1316-9. doi: 10.1126/science.1230397.

Abstract

Circadian timekeeping in plants increases photosynthesis and productivity. There are circadian oscillations in the abundance of many chloroplast-encoded transcripts, but it is not known how the circadian clock regulates chloroplast transcription or the photosynthetic apparatus. We show that, in Arabidopsis, nuclear-encoded SIGMA FACTOR5 (SIG5) controls circadian rhythms of transcription of several chloroplast genes, revealing one pathway by which the nuclear-encoded circadian oscillator controls rhythms of chloroplast gene expression. We also show that SIG5 mediates the circadian gating of light input to a chloroplast-encoded gene. We have identified an evolutionarily conserved mechanism that communicates circadian timing information between organelles with distinct genetic systems and have established a new level of integration between eukaryotic circadian clocks and organelles of endosymbiotic origin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Active Transport, Cell Nucleus
  • Arabidopsis / genetics*
  • Arabidopsis / physiology*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Cell Nucleus / metabolism
  • Chloroplasts / genetics*
  • Circadian Rhythm*
  • Gene Expression Regulation, Plant*
  • Photosystem II Protein Complex / metabolism
  • Sigma Factor / genetics
  • Sigma Factor / metabolism*
  • Transcription, Genetic

Substances

  • Arabidopsis Proteins
  • Photosystem II Protein Complex
  • PsbD protein, Arabidopsis
  • Sig5 protein, Arabidopsis
  • Sigma Factor