The Nuclear Factor Y subunits NF-YB2 and NF-YB3 play additive roles in the promotion of flowering by inductive long-day photoperiods in Arabidopsis.
Accumulating evidence supports a role for members of the plant Nuclear Factor Y (NF-Y) family of CCAAT-box binding transcription factors in the regulation of flowering time. In this study we have used a genetic approach to show that the homologous proteins NF-YB3 and NF-YB2 have comparable activities and play additive roles in the promotion of flowering, specifically under inductive photoperiodic conditions. We demonstrate that NF-YB2 and NF-YB3 are both essential for the normal induction of flowering by long-days and act through regulation of the expression of FLOWERING LOCUS T (FT). Using an ELISA-based in-vitro assay, we provide a novel demonstration that plant NF-YB subunits are capable of directly binding to a CCAAT-box containing region of the FLOWERING LOCUS T promoter as part of an NF-Y trimer in combination with the yeast HAP2 and HAP5 subunits. These results support an emerging model in which NF-Y complexes provide a component of the DNA target specificity for transcriptional regulators such as CONSTANS.
Kumimoto
Roderick W
RW
Mendel Biotechnology, Inc., Hayward, CA 94545, USA.
Adam
Luc
L
Hymus
Graham J
GJ
Repetti
Peter P
PP
Reuber
T Lynne
TL
Marion
Colleen M
CM
Hempel
Frederick D
FD
Ratcliffe
Oliver J
OJ
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D023081:CCAAT-Binding Factor / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004269:DNA, Bacterial; D004797:Enzyme-Linked Immunosorbent Assay; D035264:Flowers / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D005838:Genotype; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D017440:Photoperiod; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D011485:Protein Binding; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology
D029681:Arabidopsis Proteins; D023081:CCAAT-Binding Factor; D004269:DNA, Bacterial; C418905:FT protein, Arabidopsis; C524874:NF-YB1 protein, Arabidopsis; C000609478:NF-YB2 protein, Arabidopsis; C036483:T-DNA; D014157:Transcription Factors; C402244:nuclear factor Y