| Plant growth and development require the coordinate regulation of gene expression beginning with the fertilized egg and continuing throughout the life of the organism. The ribosome is a complex organelle that has the central role of translating the genetic code and therefore mediates the flow of information for plant growth and development through the production of proteins that carry out the genetic instructions. In order to investigate some of the molecular aspects of gene expression in the garden pea a cDNA (PsG-F) was used to determine the nucleotide sequence, structure, expression and functional significance of a ribosomal protein gene (rp L9) believed to be involved in the growth and development of the plant.;The nucleotide sequence of the rp L9 gene was obtained from two genomic clones isolated using the cDNA, PsG-F, as a probe. Truncations of a 1261 bp region ;Northern blot analysis indicates gene transcription is abundant in rapidly growing shoot and root tissues, low in maturing internodes and absent in expanded leaves. Histochemical localization of GUS in transgenic plants has demonstrated that gene activity is most intense in tissues undergoing rapid cell division such as the lateral and apical meristems of roots, the developing vascular tissue of stem and rapidly expanding axillary buds of shoots.;The computational characterization of the promoter sequence indicates that significant nucleotide homologies exist with other plant ribosomal protein genes. Consensus sequences for 6 cis-acting motifs have been derived from these computations. It is proposed that a regulatory pathway for the transcription of ribosomal protein genes may converge on these motifs, effecting their coordinate expression in the dividing cells of the developing plant. |
