title: The REVEILLE Clock Genes Inhibit Growth of Juvenile and Adult Plants by Control of Cell Size.
abstract: The circadian clock is a complex regulatory network that enhances plant growth and fitness in a constantly changing environment. In Arabidopsis (Arabidopsis thaliana), the clock is composed of numerous regulatory feedback loops in whichREVEILLE8(RVE8) and its homologsRVE4andRVE6act in a partially redundant manner to promote clock pace. Here, we report that the remaining members of theRVE8clade,RVE3andRVE5, play only minor roles in the regulation of clock function. However, we find that RVE8 clade proteins have unexpected functions in the modulation of light input to the clock and the control of plant growth at multiple stages of development. In seedlings, these proteins repress hypocotyl elongation in a daylength- and sucrose-dependent manner. Strikingly, adultrve4 6 8andrve3 4 5 6 8mutants are much larger than wild-type plants, with both increased leaf area and biomass. This size phenotype is associated with a faster growth rate and larger cell size and is not simply due to a delay in the transition to flowering. Gene expression and epistasis analysis reveal that the growth phenotypes ofrvemutants are due to the misregulation ofPHYTOCHROME INTERACTING FACTOR4(PIF4) andPIF5expression. Our results show that even small changes inPIFgene expression caused by the perturbation of clock gene function can have large effects on the growth of adult plants.
authors.affiliation: Department of Plant Biology, College of Biological Sciences, University of California, Davis, California 95616.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Gray
authors.affiliation: Department of Plant Biology, College of Biological Sciences, University of California, Davis, California 95616.
authors.forename: Akiva
authors.identifier: 0000-0002-7078-0132
authors.initials: A
authors.lastname: Shalit-Kaneh
authors.affiliation: Department of Plant Biology, College of Biological Sciences, University of California, Davis, California 95616.
authors.forename: Dalena Nhu
authors.initials: DN
authors.lastname: Chu
authors.affiliation: Department of Plant Biology, College of Biological Sciences, University of California, Davis, California 95616.
authors.forename: Polly Yingshan
authors.identifier: 0000-0001-7071-5798
authors.initials: PY
authors.lastname: Hsu
authors.affiliation: Department of Plant Biology, College of Biological Sciences, University of California, Davis, California 95616 slharmer@ucdavis.edu.
authors.forename: Stacey L
authors.identifier: 0000-0001-6813-6682
authors.initials: SL
authors.lastname: Harmer
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000145:classification / Q000235:genetics*; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics; D018533:Biomass; D048429:Cell Size; D057906:Circadian Clocks / Q000235:genetics; D004843:Epistasis, Genetic / Q000187:drug effects; D018507:Gene Expression Regulation, Developmental / Q000528:radiation effects; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D018546:Hypocotyl / Q000235:genetics / Q000254:growth & development; D008027:Light; D005810:Multigene Family; D009154:Mutation; D010802:Phylogeny; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development; D020133:Reverse Transcriptase Polymerase Chain Reaction; D036226:Seedlings / Q000235:genetics / Q000254:growth & development; D015398:Signal Transduction / Q000235:genetics / Q000528:radiation effects; D013395:Sucrose / Q000378:metabolism / Q000494:pharmacology; D014157:Transcription Factors / Q000145:classification / Q000235:genetics*
chemical_list: D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D013395:Sucrose; D014157:Transcription Factors; C459466:PIF4 protein, Arabidopsis; C497729:PIF5 protein, Arabidopsis; C559753:REVEILLE 8, protein Arabidopsis