We report different roles of three PRC2 components, KMT6, P55 and SIN3 played in distribution of genome-wide H3K27 tri-methylation of Pyricularia oryzae. Polycomb repressive complex 2 (PRC2), which is composed of Ezh(Kmt6), Su(z)12, Esc(Eed) and accessory subunits RbAp48/Nurf55(P55), catalyzes the methylation of histone H3 at lysine 27. Loss of P55 caused severe global defects in the normal distribution of H3K27me3 and transcriptional reprogramming on the H3K27me3-occupied genes. Furthermore, we found that the Sin3 histone deacetylase complex was required to sustain H3K27me3 occupancy and stably maintain gene repression by directly interacting with P55. Overall design: Examination of H3K27 tri-methylation of different PRC2 components of Pyricularia oryzae. Two biological replicates were performed.