Nuclear organization in plants.

Plant nuclei, like animal nuclei, are highly organized organelles, and much evidence is now accumulating that their organization is central to their function. Many plant nuclei are amenable to detailed structural analysis because of their large size, and the economic importance of plants as crops makes it important to understand the functional organization of plant nuclei, in particular gene expression. Problems such as gene silencing will probably require an understanding of nuclear organization for their solution. Several identifiable domains are now known in the nucleus, including the nucleolus, coiled and other nuclear bodies, and interchromatin granule clusters, but much of their function remains obscure. The nucleolus may be regarded as a giant transcription and transcript-processing domain. The steps of ribosome biogenesis are organized within it spatially as well as temporally. It may also provide a useful model for other nuclear transcription domains.