The late elongated hypocotyl mutation of Arabidopsis disrupts circadian rhythms and the photoperiodic control of flowering.
The dominant late elongated hypocotyl (lhy) mutation of Arabidopsis disrupted circadian clock regulation of gene expression and leaf movements and caused flowering to occur independently of photoperiod. LHY was shown to encode a MYB DNA-binding protein. In wild-type plants, the LHY mRNA showed a circadian pattern of expression with a peak around dawn but in the mutant was expressed constantly at high levels. Increased LHY expression from a transgene caused the endogenous gene to be expressed at a constant level, suggesting that LHY was part of a feedback circuit that regulated its own expression. Thus, constant expression of LHY disrupts several distinct circadian rhythms in Arabidopsis, and LHY may be closely associated with the central oscillator of the circadian clock.
Schaffer
R
R
John Innes Centre, Norwich, United Kingdom.
Ramsay
N
N
Samach
A
A
Corden
S
S
Putterill
J
J
Carré
I A
IA
Coupland
G
G
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D001483:Base Sequence; D002940:Circadian Rhythm / Q000235:genetics*; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D005799:Genes, Dominant / Q000235:genetics; D017343:Genes, Plant / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation / Q000502:physiology*; D009857:Oncogenes; D017440:Photoperiod; D018520:Plant Shoots / Q000254:growth & development; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000502:physiology; D050783:Proto-Oncogene Proteins c-ets; D012333:RNA, Messenger / Q000032:analysis; D018749:RNA, Plant; D015183:Restriction Mapping; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D019076:Transgenes
D004268:DNA-Binding Proteins; C105529:ELF3 protein, human; C113192:LHY protein, Arabidopsis; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D012333:RNA, Messenger; D018749:RNA, Plant; D014157:Transcription Factors