title: The unique function of the Arabidopsis circadian clock gene PRR5 in the regulation of shade avoidance response.
abstract: Shade avoidance response (S.A.R) is regulated by light and circadian clock. Circadian clock controls S.A.R by the transcriptional regulation of positive regulators of S.A.R, PIF4 and PIF5, to prevent plants from responding to 'light' of dark period. Thus, in many cases, deficits in circadian clock appear in abnormalities of hypocotyl and/or petiole elongation. Previously, interesting phenomena were reported that the triple mutants of PSEUDO RESPONSE REGULATORS9, 7 and 5, which are clock components, show longer petioles and smaller leaves under light/dark cycle than those under continuous lighting. These S.A.R-like phenotypes cannot be explained by their hyposensitivity to red light. We demonstrated detailed analyses of this mutant to reveal the leaf-specific S.A.R regulated by circadian clock. Expression analyses of S.A.R-related genes suggested that PRR5 functions as a repressor of S.A.R. Morphological analyses of leaves under different light condition revealed that PRR5 is involved in the inhibition of leaf expansion in S.A.R.
authors: Department of Biological Science; Graduate School of Science; The University of Tokyo; Tokyo, Japan.
authors: Masahide
authors: M
authors: Takase
authors: Tsuyoshi
authors: T
authors: Mizoguchi
authors: Toshiaki
authors: T
authors: Kozuka
authors: Hirokazu
authors: H
authors: Tsukaya
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D057906:Circadian Clocks / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008027:Light; D009154:Mutation; D010641:Phenotype; D018515:Plant Leaves / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism / Q000502:physiology
chemical_list: D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D014157:Transcription Factors; C459466:PIF4 protein, Arabidopsis; C497729:PIF5 protein, Arabidopsis; C523307:PRR5 protein, Arabidopsis
keywords: PRR; circadian; leaf; petiole; photomorphogenesis; phytochrome; shade avoidance