Governing the Silencing State of Chromatin: The Roles of Polycomb Repressive Complex 1 in Arabidopsis.

Polycomb group proteins form multiple protein complexes such as Polycomb Repressive Complex (PRC) 1 and PRC2, which repress the expression of thousands of genes. PRC1 and PRC2 are essential for normal development in Arabidopsis. Recently, significant progress has been made in understanding the functions and regulatory mechanisms of PRC1. In this review, we focus on the discovery of the composition of PRC1, functions of its components, the recruitment of PRC1 to target genes and the control of PRC1 function in Arabidopsis. Perspectives on dissecting the roles of PRC1 in plant gene expression and development are also given.