Ehd3 encodes a nuclear protein that contains two PHD-finger motifs and play crucial role as a promoter within the gene regulatory network for photoperiodic flowering in rice. Under LD conditions, Ehd3 negatively regulates transcription of the flowering repressor Ghd7, and then, repression of Ghd7 causes the promotion of Ehd1 transcription. Under SD conditions, Ehd3 upregulates the transcription of Ehd1 independently of Ghd7.