Publikationsserver der Universitätsbibliothek Marburg

Titel:Genetic analysis and phenotypic characterization of three novel genes of Rhizobium tropici CIAT899 involved in symbiotic interactions with Phaseolus vulgaris
Autor:Rojas Jimenez, Keilor
Weitere Beteiligte: Werner, Dietrich (Prof. Dr.)
Veröffentlicht:2005
URI:https://archiv.ub.uni-marburg.de/diss/z2005/0119
URN: urn:nbn:de:hebis:04-z2005-01193
DOI: https://doi.org/10.17192/z2005.0119
DDC:570 Biowissenschaften, Biologie
Titel (trans.):Genetische Analyse und phänotypische Charakterisierung dreier neuartiger Gene des Bakteriums Rhizobium tropici CIAT899, die eine Rolle während der symbiontischen Wechselwirkungen des Bakteriums mit der Wirtspflanze Phaseolus vulgaris spielen
Publikationsdatum:2005-07-25
Lizenz:https://rightsstatements.org/vocab/InC-NC/1.0/

Dokument

Schlagwörter:
Gartenbohne, Intrazelluläre Symbiose, Membranlipide, Rhizobium, Rhizobium tropici, Symbiose, Rhizobium tropici

Summary:
Rhizobium tropici CIAT899 is highly tolerant to many environmental stresses and a good competitor for nodule occupancy of Phaseolus vulgaris. Random transposon mutagenesis was performed with the aim to identify novel genes of this strain involved in symbiosis and stress tolerance. The analysis of the locus disrupted by the Tn5 insertion in mutants 899-PV9 and 899-PV4 led the discovery of three novel genes required for and efficient symbiotic interaction with beans plants. The first gene (syc1) bears significant similarity to voltage-gated chloride channels. A non-polar deletion in this gene caused serious deficiencies for nodule establishment, nodulation competitiveness and N2 fixation, probably due to its reduced ability to invade plant cells and to form stable symbiosomes, as judged by electron transmission microscopy. A second gene (olsC) found downstream of the former was shown to be homologous with aspartyl/asparaginyl β-hydroxylases and involved in the modification of two species of ornithine-containing lipids, presumably by a hydroxylation. A mutant carrying a non-polar deletion in olsC was symbiotically defective, whereas over-expressed OlsC in the complemented strain was related with an acid-sensitive phenotype. The third gene (sigE) codes for a putative σE factor. Analysis performed on the mutant carrying a deletion in this gene also revealed serious deficiencies for nodule development, nodulation competitiveness and N2 fixation when inoculated on bean plants. These three different bacterial activities have not been previously reported as required for the symbiotic interaction of rhizobia with its legume host.


* Das Dokument ist im Internet frei zugänglich - Hinweise zu den Nutzungsrechten