Organ-specific Transcription of the rrn Operon in Spinach Plastids
| Autor: | Rabah Iratni, Ludger Diederich, Hassan Harrak, Silva Lerbs-Mache, Muriel Bligny |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
DNA
Plant Transcription Genetic Operon Molecular Sequence Data Ribonuclease H Biology Polymerase Chain Reaction Biochemistry Species Specificity Gene Expression Regulation Plant Spinacia oleracea Transcription (biology) RNA Ribosomal 16S Tobacco Gene expression Transcriptional regulation Plastids rRNA Operon Plastid Promoter Regions Genetic RNA Transfer Val Molecular Biology Gene Genetics Binding Sites Base Sequence food and beverages RNA Promoter Cell Biology Cell biology DNA-Binding Proteins Plants Toxic |
| Zdroj: | Journal of Biological Chemistry. 272:13676-13682 |
| ISSN: | 0021-9258 |
| Popis: | The spinach rrn operon is used as a model system to study transcriptional regulation in higher plant photosynthetic and non-photosynthetic plastids. We performed capping experiments to determine whether P1, PC, or P2 promoters are employed for rrn transcription start sites in cotyledon and root tissues. By using a new method of analysis of capped RNA we demonstrate for the first time that 1) in both organs the rrn operon is expressed in a constitutive manner by cotranscription with the preceding tRNA(GAC)Val gene, and 2) the PC transcription start site is used only in cotyledons and leaves, i.e. we demonstrate the organ-specific usage of a plastid promoter. Both start sites, PC and that of the tRNA(GAC)Val cotranscript, lack Escherichia coli-like consensus sequences. The cotranscript is initiated 457 base pairs upstream of the tRNA(GAC)Val gene. The PC-specific DNA-binding factor, CDF2, is not detectable in root tissues confirming its regulatory role in PC-initiated rrn expression and the organ specificity of PC expression. Furthermore, our results show that rrn operon expression patterns differ in spinach and tobacco indicating species-specific transcriptional regulation of plant plastid gene expression. |
| Databáze: | OpenAIRE |
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