BackgroundConserved polycomb repressive complex 2 (PRC2) mediates H3K27me3 to direct transcriptional repression and has a key role in cell fate determination and cell differentiation in both animals and plants. PRC2 subunits have undergone independent multiplication and functional divergence in higher plants. However, relevant information is still absent in gymnosperms.ResultsTo launch gymnosperm PRC2 research, we identified and cloned the PRC2 core component genes in the conifer model speciesPicea abies, including oneEsc/FIEhomologPaFIE, twop55/MSIhomologsPaMSI1aand PaMSI1b, twoE(z)homologsPaKMT6A2andPaKMT6A4, aSu(z)12homologPaEMF2and aPaEMF2-likefragment. Phylogenetic and protein domain analyses were conducted. TheEsc/FIEhomologs were highly conserved in the land plant, except the monocots. The other gymnospermous PRC2 subunits underwent independent evolution with angiospermous species to different extents. The relative transcript levels of these genes were measured in endosperm and zygotic and somatic embryos at different developmental stages. The obtained results proposed the involvement ofPaMSI1bandPaKMT6A4in embryogenesis andPaKMT6A2andPaEMF2in the transition from embryos to seedlings. ThePaEMF2-likefragment was predominantly expressed in the endosperm but not in the embryo. In addition, immunohistochemistry assay showed that H3K27me3 deposits were generally enriched at meristem regions during seed development inP. abies.ConclusionsThis study reports the first characterization of the PRC2 core component genes in the coniferous speciesP. abies. Our work may enable a deeper understanding of the cell reprogramming process during seed and embryo development and may guide further research on embryonic potential and development in conifers.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12870-023-04359-9.