Chromatin Structure Of Plant Genes

Abstract

Abstract Plant growth and development requires a sophisticated programme of differential expression of nuclear genes. Individual plant cells express only specific sets of genes from the plant’s full gene complement, and knowledge of the mechanisms of differential gene expression is currently an important research objective. However, a full understanding of these processes is obviously a formidable task as it has been estimated that approximately 60000 genes are expressed during the life of a tobacco plant and these genes account for less than 5% of the nuclear genome (Kamalay and Goldberg, 1980). The plant’s transcription machinery is obviously able to identify the necessary genes amongst the vast excess of other genomic DNA and to transcribe them in the desired fashion. It seems reasonable to assume that the transcription apparatus is able to recognise certain features of the chromatin structure of genes to be transcribed, and that this structure is different from that of inactive genes. A major problem is to understand the changes in chromatin structure of active and inactive genes. Unfortunately, at the present time, it is often difficult to know if the detected alterations in chromatin structure are a prerequisite for or a consequence of changes in gene activity. The aim of this review is to provide an overview of the chromatin structure of plant genes, with some emphasis on structural changes that may be correlated with changes in gene activity. An understanding of the organisation of genes in the plant nucleus is an essential part of any attempt to understand the mechanisms of differential gene expression in plants.