The TIME FOR COFFEE gene maintains the amplitude and timing of Arabidopsis circadian clocks.
Plants synchronize developmental and metabolic processes with the earth's 24-h rotation through the integration of circadian rhythms and responses to light. We characterize the time for coffee (tic) mutant that disrupts circadian gating, photoperiodism, and multiple circadian rhythms, with differential effects among rhythms. TIC is distinct in physiological functions and genetic map position from other rhythm mutants and their homologous loci. Detailed rhythm analysis shows that the chlorophyll a/b-binding protein gene expression rhythm requires TIC function in the mid to late subjective night, when human activity may require coffee, in contrast to the function of EARLY-FLOWERING3 (ELF3) in the late day to early night. tic mutants misexpress genes that are thought to be critical for circadian timing, consistent with our functional analysis. Thus, we identify TIC as a regulator of the clock gene circuit. In contrast to tic and elf3 single mutants, tic elf3 double mutants are completely arrhythmic. Even the robust circadian clock of plants cannot function with defects at two different phases.
Hall
Anthony
A
Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom.
Bastow
Ruth M
RM
Davis
Seth J
SJ
Hanano
Shigeru
S
McWatters
Harriet G
HG
Hibberd
Victoria
V
Doyle
Mark R
MR
Sung
Sibum
S
Halliday
Karen J
KJ
Amasino
Richard M
RM
Millar
Andrew J
AJ
D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002874:Chromosome Mapping; D002940:Circadian Rhythm / Q000235:genetics* / Q000502:physiology; D003624:Darkness; D035264:Flowers / Q000235:genetics / Q000254:growth & development / Q000528:radiation effects; D018507:Gene Expression Regulation, Developmental / Q000528:radiation effects; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D008027:Light; D045342:Light-Harvesting Protein Complexes / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D020323:Tics; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D029681:Arabidopsis Proteins; D045342:Light-Harvesting Protein Complexes; D014157:Transcription Factors; C432430:At2g25930 protein, Arabidopsis