Characterisation of Phaseolus symbionts isolated from Mediterranean soils and analysis of genetic factors related to pH tolerance

Détails

ID Serval
serval:BIB_8689F1FCF978
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Characterisation of Phaseolus symbionts isolated from Mediterranean soils and analysis of genetic factors related to pH tolerance
Périodique
Journal of Biotechnology
Auteur(s)
Priefer  U. B., Aurag  J., Boesten  B., Bouhmouch  I., Defez  R., Filali-Maltouf  A., Miklis  M., Moawad  H., Mouhsine  B., Prell  J., Schluter  A., Senatore  B.
ISSN
0168-1656 (Print)
Statut éditorial
Publié
Date de publication
2001
Volume
91
Numéro
2-3
Pages
223-236
Notes
DA - 20010921
LA - eng
PT - Journal Article
PT - Research Support, Non-U.S. Gov't
RN - 0 (DNA Transposable Elements)
RN - EC 2.6.1.19 (4-Aminobutyrate Transaminase)
SB - IM
Résumé
The ultimate objective of PhIMED, in which two European (Germany, Italy) and two Mediterranean (Morocco, Egypt) countries collaborate, is to improve the cultivation of French bean (Phaseolus vulgaris) under arid and semi-arid conditions by analysing and enhancing stress tolerance of the nitrogen fixing rhizobial microsymbionts. Rhizobial strains nodulating P. vulgaris (RP strains) isolated from areas in Morocco frequently subjected to drought were analysed for their salt and pH tolerance and their phylogenetic relationship. Strain RP163, exhibiting high nodulation efficiency and a broad pH tolerance was mutagenised by Tn5 and mutants unable to grow on extreme pH media were isolated. Some of the mutants affected in low pH tolerance were found to be mutated in genes related to cobalmin biosynthesis and in succinate dehydrogenase (sdhA). In a parallel approach, promoters and genes inducible under extreme pH values were identified in Rhizobium leguminosarum bv. viciae VF39, among them gabT, which encodes the GABA transaminase and which is induced under acidic conditions. The same gene is present and similarly regulated in RP163. The actSR gene region was cloned from VF39, sequenced and mutants generated in this region were found to be impaired in growth at low pH, but also under neutral conditions. The Agrobacterium rhizogenes 'promintron' promoter, reported to be activated in stationary phase, was found to be also strongly induced under acidic conditions in rhizobia and it is currently being characterised to construct a system allowing the expression of stress tolerance genes in bacteroids and free-living bacteria
Mots-clé
4-Aminobutyrate Transaminase/classification/DNA Transposable Elements/Gene Expression Regulation,Bacterial/Genes,Bacterial/genetics/Hydrogen-Ion Concentration/isolation & purification/Mediterranean Region/microbiology/Morocco/Mutation/Phaseolus/physiology/Promoter Regions (Genetics)/Rhizobiaceae/Soil Microbiology/Symbiosis
Pubmed
Web of science
Création de la notice
21/02/2008 11:34
Dernière modification de la notice
20/08/2019 15:45
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