title: Gibberellin and auxin influence the diurnal transcription pattern of photoreceptor genes via CRY1a in tomato.
abstract: BACKGROUND
  Plant photoreceptors, phytochromes and cryptochromes, regulate many aspects of development and growth, such as seed germination, stem elongation, seedling de-etiolation, cotyledon opening, flower induction and circadian rhythms. There are several pieces of evidence of interaction between photoreceptors and phyto-hormones in all of these physiological processes, but little is known about molecular and genetic mechanisms underlying hormone-photoreceptor crosstalk.
  
  
  RESULTS
  In this work, we investigated the molecular effects of exogenous phyto-hormones to photoreceptor gene transcripts of tomato wt, as well as transgenic and mutant lines with altered cryptochromes, by monitoring day/night transcript oscillations. GA and auxin alter the diurnal expression level of different photoreceptor genes in tomato, especially in mutants that lack a working form of cryptochrome 1a: in those mutants the expression of some (IAA) or most (GA) photoreceptor genes is down regulated by these hormones.
  
  
  CONCLUSIONS
  Our results highlight the presence of molecular relationships among cryptochrome 1a protein, hormones, and photoreceptors' gene expression in tomato, suggesting that manipulation of cryptochromes could represent a good strategy to understand in greater depth the role of phyto-hormones in the plant photoperceptive mechanism.
authors.affiliation: Italian National Agency for New Technologues, Energy and Sustainable Economic Development (ENA), Trisaia Research Center, Rotondella, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Facella
authors.forename: Loretta
authors.initials: L
authors.lastname: Daddiego
authors.forename: Giovanni
authors.initials: G
authors.lastname: Giuliano
authors.forename: Gaetano
authors.initials: G
authors.lastname: Perrotta
mesh_terms: D002940:Circadian Rhythm / Q000235:genetics; D056931:Cryptochromes / Q000235:genetics*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D005875:Gibberellins / Q000494:pharmacology*; D007210:Indoleacetic Acids / Q000494:pharmacology*; D018551:Solanum lycopersicum / Q000235:genetics*; D009154:Mutation; D055519:Photoreceptors, Plant / Q000235:genetics*; D010937:Plant Growth Regulators / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D056931:Cryptochromes; D005875:Gibberellins; D007210:Indoleacetic Acids; D055519:Photoreceptors, Plant; D010937:Plant Growth Regulators