Overexpression ofGLUTAMINE DUMPER1Leads to Hypersecretion of Glutamine from Hydathodes of Arabidopsis Leaves[W]
| Autor: | Wolf B. Frommer, Uwe Ludewig, Dean F. Bushey, Harald Stransky, Guillaume Pilot, Reéjane Pratelli, Vincent P. M. Wingate |
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| Rok vydání: | 2004 |
| Předmět: |
DNA
Bacterial Guttation Molecular Sequence Data Arabidopsis Plant Science Plant Roots Gene Expression Regulation Plant Arabidopsis thaliana Amino Acid Sequence Amino Acids Research Articles chemistry.chemical_classification biology Arabidopsis Proteins Membrane Proteins Xylem Cell Biology biology.organism_classification Amino acid Hydathode Plant Leaves Glutamine Phenotype Biochemistry chemistry Multigene Family Mutation Phloem |
| Zdroj: | The Plant Cell. 16:1827-1840 |
| ISSN: | 1532-298X |
| DOI: | 10.1105/tpc.021642 |
| Popis: | Secretion is a fundamental process providing plants with the means for disposal of solutes, improvement of nutrient acquisition, and attraction of other organisms. Specific secretory organs, such as nectaries, hydathodes, and trichomes, use a combination of secretory and retrieval mechanisms, which are poorly understood at present. To study the mechanisms involved, an Arabidopsis thaliana activation tagged mutant, glutamine dumper1 (gdu1), was identified that accumulates salt crystals at the hydathodes. Chemical analysis demonstrated that, in contrast with the amino acid mixture normally present in guttation droplets, the crystals mainly contain Gln. GDU1 was cloned and found to encode a novel 17-kD protein containing a single putative transmembrane span. GDU1 is expressed in the vascular tissues and in hydathodes. Gln content is specifically increased in xylem sap and leaf apoplasm, whereas the content of several amino acids is increased in leaves and phloem sap. Selective secretion of Gln by the leaves may be explained by an enhanced release of this amino acid from cells. GDU1 study may help to shed light on the secretory mechanisms for amino acids in plants. |
| Databáze: | OpenAIRE |
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