Genome-Wide Identification and analysis of Polycomb Repressive Complexes 2 core components in three cucumber genomes

Abstract ● Polycomb Repressive Complexes 2 (PRC2) are evolutionarily conserved, high molecular weight complexes which are important gene regulators maintaining normal growth and development in plants. But, there is little research focusing on the characteristics and evolution of PRC2 components in cucumber.● We used genome-wide identification, phylogenetic analysis, available RNA-seq data to examine cucumber PRC2 components and expression pattern.● In this study, we identified 17 PRC2 core components in three cucumber lines genome, each line contains one FIE-like protein, one MSI1-like protein and two Enhancer of Zeste-like proteins. Phylogenetic analysis shows that FIE-like and MSI1-like homologous groups were evolutionary conservation. Compared with Arabidopsis, which including three enhancer of zeste-like proteins, three cucumber lines in this study only have two, furthermore, both of them were AtCLF homologous series. The results of gene expression pattern showed that FIE-like and MSI1-like genes in three cucumber lines have a conservative constitutive expression pattern and highly expression in reproductive organs and fruits, surprisingly, the two AtCLF homologous genes (EZ1 and EZ2) in three lines all have complementary expression pattern, indicating the evolutionary and functional differences of PRC2 complexes was existed between A. thaliana and cucumber.● This study provides a systematic analysis of PRC2 core components in three lines of cucumber using bioinformatics tools.