title: Natural diversity in daily rhythms of gene expression contributes to phenotypic variation.
abstract: Daily rhythms of gene expression provide a benefit to most organisms by ensuring that biological processes are activated at the optimal time of day. Although temporal patterns of expression control plant traits of agricultural importance, how natural genetic variation modifies these patterns during the day and how precisely these patterns influence phenotypes is poorly understood. The circadian clock regulates the timing of gene expression, and natural variation in circadian rhythms has been described, but circadian rhythms are measured in artificial continuous conditions that do not reflect the complexity of biologically relevant day/night cycles. By studying transcriptional rhythms of the evening-expressed gene gigantea (GI) at high temporal resolution and during day/night cycles, we show that natural variation in the timing of GI expression occurs mostly under long days in 77 Arabidopsis accessions. This variation is explained by natural alleles that alter light sensitivity of GI, specifically in the evening, and that act at least partly independent of circadian rhythms. Natural alleles induce precise changes in the temporal waveform of GI expression, and these changes have detectable effects on phytochrome interacting factor 4 expression and growth. Our findings provide a paradigm for how natural alleles act within day/night cycles to precisely modify temporal gene expression waveforms and cause phenotypic diversity. Such alleles could confer an advantage by adjusting the activity of temporally regulated processes without severely disrupting the circadian system.
authors.affiliation: Max Planck Institute for Plant Breeding Research, D-50829 Cologne, Germany; and.
authors.forename: Amaury
authors.initials: A
authors.lastname: de Montaigu
authors.affiliation: Max Planck Institute for Plant Breeding Research, D-50829 Cologne, Germany; and.
authors.forename: Antonis
authors.initials: A
authors.lastname: Giakountis
authors.affiliation: Department of Botany, University of Wyoming, Laramie, WY 82071.
authors.forename: Matthew
authors.initials: M
authors.lastname: Rubin
authors.affiliation: Max Planck Institute for Plant Breeding Research, D-50829 Cologne, Germany; and.
authors.forename: Réka
authors.initials: R
authors.lastname: Tóth
authors.affiliation: Max Planck Institute for Plant Breeding Research, D-50829 Cologne, Germany; and.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Cremer
authors.affiliation: Max Planck Institute for Plant Breeding Research, D-50829 Cologne, Germany; and.
authors.forename: Vladislava
authors.initials: V
authors.lastname: Sokolova
authors.affiliation: Max Planck Institute for Plant Breeding Research, D-50829 Cologne, Germany; and.
authors.forename: Aimone
authors.initials: A
authors.lastname: Porri
authors.affiliation: Max Planck Institute for Plant Breeding Research, D-50829 Cologne, Germany; and.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Reymond
authors.affiliation: Department of Botany, University of Wyoming, Laramie, WY 82071.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Weinig
authors.affiliation: Max Planck Institute for Plant Breeding Research, D-50829 Cologne, Germany; and coupland@mpipz.mpg.de.
authors.forename: George
authors.initials: G
authors.lastname: Coupland
mesh_terms: D017360:Arabidopsis / Q000502:physiology*; D002940:Circadian Rhythm; D018506:Gene Expression Regulation, Plant; D008027:Light; D015398:Signal Transduction
keywords: Arabidopsis; GIGANTEA; circadian; diurnal; rhythms