The plant nucleolus

Abstract

The majority of an actively dividing cell’s metabolic activity is devoted to ribosome biogenesis, and most traffic in and out of the nucleus is targeted to or from the nucleolus. It is therefore not surprising that the nucleolus is the most prominent and easily observable structure within the nucleus. It has been studied for more than two hundred years, and is still an active subject of research and is still generating surprising discoveries. This chapter summarizes the current state of knowledge of the nucleolus with particular reference to recent developments, and concentrating on work from plants where appropriate. Topics covered include the organization of ribosomal rDNA in nucleolar chromatin, epigenetic phenomena, nucleolar dynamics and non-conventional functions of the nucleolus, particularly in its involvement in various RNA pathways.