Tomato plants overexpressing cryptochrome 2 reveal altered expression of energy and stress-related gene products in response to diurnal cues

Plant Cell Environ. 2012 May;35(5):994-1012. doi: 10.1111/j.1365-3040.2011.02467.x. Epub 2011 Dec 14.


In order to sense and respond to the fluctuating light conditions, higher plants possess several families of photoreceptors, such as phytochromes (PHYs), cryptochromes (CRYs) and phototropins. CRYs are responsible for photomorphogenesis and play a role in circadian, developmental and adaptive growth regulation of plants. In tomato (Solanum lycopersicum), CRY2 controls vegetative development, flowering time, fruit antioxidant content as well as the diurnal transcription of several other photoreceptor genes. We applied large-scale molecular approaches to identify altered transcripts and proteins in tomato wild-type (WT) versus a CRY2 overexpressing transgenic genotype, under a diurnal rhythm. Our results showed that tomato CRY2 profoundly affects both gene and protein expression in response to daily light cycle. Particularly altered molecular pathways are related to biotic/abiotic stress, photosynthesis, including components of the light and dark reactions and of starch and sucrose biosynthesis, as well as to secondary metabolism, such as phenylpropanoid, phenolic and flavonoid/anthocyanin biosynthesis pathways. One of the most interesting results is the coordinated up-regulation, in the transgenic genotype, of a consistent number of transcripts and proteins involved in photorespiration and photosynthesis. It is conceivable that light modulates the energetic metabolism of tomato through a fine CRY2-mediated transcriptional control.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Respiration
  • Chloroplasts / genetics
  • Circadian Rhythm*
  • Cryptochromes / genetics*
  • Cryptochromes / metabolism
  • Down-Regulation / genetics
  • Down-Regulation / radiation effects
  • Electrophoresis, Gel, Two-Dimensional
  • Gene Expression Profiling
  • Gene Expression Regulation, Plant / genetics*
  • Gene Expression Regulation, Plant / radiation effects
  • Light
  • Lycopersicon esculentum / genetics*
  • Lycopersicon esculentum / physiology
  • Lycopersicon esculentum / radiation effects
  • Mitochondria / genetics
  • Oligonucleotide Array Sequence Analysis
  • Peroxisomes / genetics
  • Plant Proteins / genetics
  • Plants, Genetically Modified
  • Proteomics
  • RNA, Plant / genetics
  • Signal Transduction
  • Stress, Physiological / genetics*
  • Stress, Physiological / radiation effects
  • Up-Regulation / genetics
  • Up-Regulation / radiation effects


  • Cryptochromes
  • Plant Proteins
  • RNA, Plant