What is RNA polymerase V?

RNA polymerase V , previously known as RNA polymerase IVb, is a multisubunit plant specific RNA polymerase. It is required for normal function and biogenesis of small interfering RNA. Together withRNA polymerase IV , Pol V is involved in an siRNA-dependent epigenetic pathway known as RNA-directed DNA methylation , which establishes and maintains heterochromatic silencing in plants.