Repression of the L-asparaginase gene during nodule development in Lupinus angustifolius
| Autor: | Paul H. S. Reynolds, Kevin J. F. Farnden, Éva Vincze, Janice M. Reeves, Erwin Lamping |
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| Rok vydání: | 1994 |
| Předmět: |
DNA
Plant Inverted repeat Molecular Sequence Data Plant Science Genes Plant Plant Roots Gene Expression Regulation Plant Nitrogen Fixation Gene expression Genetics Asparaginase RNA Messenger Asparagine Binding site Promoter Regions Genetic Symbiosis Gene Regulation of gene expression Binding Sites Plants Medicinal Base Sequence biology Binding protein Fabaceae General Medicine biology.organism_classification DNA-Binding Proteins Lupinus angustifolius Biochemistry RNA Plant Enzyme Repression Agronomy and Crop Science Rhizobium |
| Zdroj: | Plant Molecular Biology. 26:303-311 |
| ISSN: | 1573-5028 0167-4412 |
| DOI: | 10.1007/bf00039541 |
| Popis: | Upon the establishment of an effective nitrogen-fixing symbiosis in amide-transporting plants the enzymatic activity and transcript levels of L-asparaginase are dramatically decreased. This decrease in L-asparaginase activity is essential for the correct functioning of the Rhizobium-legume symbiosis in lupin in which asparagine, synthesized from recently fixed nitrogen, is exported to aerial parts of the plant for use in growth and development. Concomitant with this decrease in L-asparaginase transcript a DNA-binding protein was detected in the nodules. This binding protein was not detectable in ineffective nodules, in nodules treated with nitrate, or in root tips, mature roots, developing flowers or developing seeds. The DNA-binding activity was shown to interact with a 59 bp sequence proximal to the transcription start site. Within this sequence a CTAAAAT direct repeat and a ACTGT/TGTCA incomplete inverted repeat were implicated in the binding of protein to the DNA by DNase I protection experiments. Competitive binding studies with synthesized binding sites were consistent with the CTAAAAT/TGTCA sequence pair proximal to the transcription start site having the highest affinity for the DNA-binding protein. We postulate that this DNA-binding protein is associated with repression of L-asparaginase gene expression in mature lupin root nodules. |
| Databáze: | OpenAIRE |
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