PHD finger-containing protein. Interacts with BDT1, acts with other PHD proteins to associate with flowering genes and thereby suppress their transcription.
Together with AIPP3/BDT1, cooperates to form a BAH-PHD bivalent histone reader complex able to read histone H3 lysine 27 trimethylation (H3K27me3) histone marks in order to regulate transcription, especially to prevent early flowering; promotes AIPP3/BDT1 binding to H3K27me3.