| Autor: |
Irving, Helen R., Boukli Hacene Tani, Nawal Maria, Toomre, D., Krause, Andréa, Gehring, C.A., Jabbouri, Said, Kabbara, A.A., Seidel, Kerstin, Parish, R.W., Kader, J.-C., Varki, A.A., Broughton, William John |
| Jazyk: |
angličtina |
| Rok vydání: |
1997 |
| Předmět: |
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| Zdroj: |
Biological fixation of nitrogen for ecology and sustainable agriculture: proceedings of the NATO Advanced Research Workshop "Biological Fixation of Nitrogen for Ecology and Sustainable Agriculture" pp. 37-42 |
| Popis: |
Temporal and spatial observations on the attachment of Nodfactors were made by biotinylating the reducing terminus of the lipo-chitooligosaccharides of the broad host-range Rhizobium sp. NGR234 with the fluorescent reagent 2-amino-(6-amidobiotinyl)pyridine. Complex formation between the biotinylated Nod-factors and fluorescent streptavidin allowed localisation of the binding-site. At concentrations of > 10⁻⁷ M, these fluorescently tagged moleculs bound rapidly and asymmetrically (≈ 1 min) to nodulation competent root-hairs but they did not bind to root-hairs of the nonhost Arabidopsis thaliana. Early cellular events within the root-hairs were studied by loading root-segments with the calcium indicators Fura-2 and Fluo-3. Fluorescence ratio imaging showed that addition of NodNGR factors provoked almost immediate, plateau-like increases in intra-cellular free calcium {[Ca²⁺]i} in root-hairs and epidermal cells. Confocal laser scanning microscopy (CLSM) revealed that calcium accumulation was concentrated at the tips and the sides of the responsive root-hairs. A gene encoding a lipid transfer-like protein (LPT2) was isolated from a Vigna unguiculata root-hair cDNA bank. Levels of the L TP2-transcript increased in root-hairs 24h after treatment with NGR234, or its Nod-factors. The L TP2-gene was cloned into the pMal™ expression vector and L TP2 purified by affinity chromatography. It was unable to transfer phospholipids between liposomes and mitochondria. Anti-sense analysis in which the LTP2 coding region was cloned between the 35S promoter and terminator sequences reduced nodulation when transformed into V. unguiculata. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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