Plastid signals that affect photomorphogenesis in Arabidopsis thaliana are dependent on GENOMES UNCOUPLED 1 and cryptochrome 1

New Phytol. 2009;182(2):367-79. doi: 10.1111/j.1469-8137.2008.02729.x. Epub 2009 Jan 6.


When plastids experience dysfunction they emit signals that help coordinate nuclear gene expression with their functional state. One of these signals can remodel a light-signaling network that regulates the expression of nuclear genes that encode particular antenna proteins of photosystem II. These findings led us to test whether plastid signals might impact other light-regulated processes. Photomorphogenesis was monitored in genomes uncoupled 1 (gun1), cryptochrome 1 (cry1), and long hypocotyl 5 (hy5), which have defects in light and plastid signaling, by growing Arabidopsis thaliana seedlings under various light conditions and either treating or not treating them with antibiotics that induce chloroplast dysfunction and trigger plastid signaling. It was found that plastid signals that depend on GUN1 can affect cotyledon opening and expansion, anthocyanin biosynthesis, and hypocotyl elongation. We also found that plastid signals that depend on CRY1 can regulate cotyledon expansion and development. Our findings suggest that plastid signals triggered by plastid dysfunction can broadly affect photomorphogenesis and that plastid and light signaling can promote or antagonize each other, depending on the responses studied. These data suggest that GUN1 and cry 1 help to integrate chloroplast function with photomorphogenesis.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Anthocyanins / biosynthesis
  • Arabidopsis / genetics*
  • Arabidopsis / physiology
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism
  • Basic-Leucine Zipper Transcription Factors / genetics
  • Basic-Leucine Zipper Transcription Factors / metabolism
  • Chloroplasts / genetics*
  • Chloroplasts / metabolism
  • Cotyledon / genetics*
  • Cotyledon / growth & development
  • Cotyledon / metabolism
  • Cryptochromes
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / metabolism
  • Flavoproteins / genetics*
  • Flavoproteins / metabolism
  • Gene Expression Regulation, Plant*
  • Genes, Plant*
  • Hypocotyl / growth & development
  • Light
  • Morphogenesis
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Photosynthesis / genetics
  • Photosystem II Protein Complex / genetics
  • Photosystem II Protein Complex / metabolism
  • Plant Epidermis / ultrastructure
  • Plastids / genetics
  • Plastids / metabolism
  • Seedlings / metabolism
  • Signal Transduction


  • Anthocyanins
  • Arabidopsis Proteins
  • Basic-Leucine Zipper Transcription Factors
  • CRY1 protein, Arabidopsis
  • Cryptochromes
  • DNA-Binding Proteins
  • Flavoproteins
  • GUN1 protein, Arabidopsis
  • HY5 protein, Arabidopsis
  • Nuclear Proteins
  • Photosystem II Protein Complex