EARLY FLOWERING 4 functions in phytochrome B-regulated seedling de-etiolation.
To define the functions of genes previously identified by expression profiling as being rapidly light induced under phytochrome (phy) control, we are investigating the seedling de-etiolation phenotypes of mutants carrying T-DNA insertional disruptions at these loci. Mutants at one such locus displayed reduced responsiveness to continuous red, but not continuous far-red light, suggesting a role in phyB signaling but not phyA signaling. Consistent with such a role, expression of this gene is induced by continuous red light in wild-type seedlings, but the level of induction is strongly reduced in phyB-null mutants. The locus encodes a novel protein that we show localizes to the nucleus, thus suggesting a function in light-regulated gene expression. Recently, this locus was identified as EARLY FLOWERING 4, a gene implicated in floral induction and regulating the expression of the gene CIRCADIAN CLOCK-ASSOCIATED 1. Together with these previous data, our findings suggest that EARLY FLOWERING 4 functions as a signaling intermediate in phy-regulated gene expression involved in promotion of seedling de-etiolation, circadian clock function, and photoperiod perception.
Khanna
Rajnish
R
Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA.
Kikis
Elise A
EA
Quail
Peter H
PH
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics*; D002940:Circadian Rhythm; D016384:Consensus Sequence; D003624:Darkness; D035264:Flowers / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D008969:Molecular Sequence Data; D010786:Photoreceptor Cells; D010834:Phytochrome / Q000502:physiology*; D051939:Phytochrome B; D012639:Seeds / Q000502:physiology*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors
D029681:Arabidopsis Proteins; C465973:ELF4 protein, Arabidopsis; C497952:PHYB protein, Arabidopsis; D014157:Transcription Factors; D010834:Phytochrome; D051939:Phytochrome B