Maybe involved in both the vernalization and photoperiod pathways by regulating gene expression. Binds preferentially to dimethylated histone H3 'Lys-9' (H3K9me2). Promotes flowering in non-inductive photoperiods (e.g. short days) through the maintenance of the epigenetically repressed state of MAF5 via H3K9me2 and plant homeodomain / polycomb repressive complex 2 (PHD-PRC2)-dependent H3K27me3. Self-interacts. Interacts with VIN3 and VIL1. Component of the plant homeodomain / polycomb repressive complex 2 (PHD-PRC2) large complex during prolonged cold, composed of core PRC2 components (VRN2, EZA1, FIE and MSI1), and three related PHD finger proteins (VIL1, VIL2 and VIN3) that mediates histone H3 trimethylation on 'Lys-27' (H3K27me3). Probably DNA-associated. By cold (e.g. 4 degrees Celsius). Levels follow a diurnal regulation with an accumulation during the dark period and reduced levels upon exposure to light (at protein level). Delayed flowering in short days but not in long days conditions, associated with high expression of MAF5, a floral repressor, due to a reduced H3K9me2 status of MAF5 locus.