Stress Tolerance and Symbiotic and Phylogenic Features of Root Nodule Bacteria Associated with Medicago Species in Different Bioclimatic Regions of Tunisia
- 1 January 2011
- journal article
- Published by Japanese Society of Microbial Ecology in Microbes and Environments
- Vol. 26 (1), 36-45
- https://doi.org/10.1264/jsme2.me10138
Abstract
Thirty two rhizobial isolates were obtained from different bioclimatic regions of Tunisia using as trap plants, Medicago sativa, Medicago ciliaris, Medicago polymorpha and Medicago minima. To study their diversity and characterize them in relation to Mediterranean conditions, abiotic stress resistance, symbiotic properties and genetic diversity in terms of 16S rRNA and nodA sequences were assessed. Five isolates from M. sativa, three from M. ciliaris and three from M. minima could grow at 45°C. Only two isolates from M. sativa grew at 4% NaCl. The most stress tolerant isolates were obtained from arid soils. A phylogenetic analysis of 16S rRNA genes revealed 29 isolates to be closely related to Ensifer including one (Pl.3-9) that showed a 16S rRNA sequence similar to that of Ensifer meliloti and nodA sequence similar to that of Ensifer medicae. However, three isolates were categorized into Agrobacterium containing the nodA of Ensifer. Furthermore, these isolates developed nodules on original hosts. The results for the four isolates suggest horizontal gene transfer between the species.Keywords
This publication has 37 references indexed in Scilit:
- Nodulation of Sesbania species by Rhizobium (Agrobacterium) strain IRBG74 and other rhizobiaEnvironmental Microbiology, 2009
- Phenotypic and genotypic characteristics ofAcacia senegal(L.) Willd. root-nodulating bacteria isolated from soils in the dryland part of SenegalLetters in Applied Microbiology, 2008
- Horizontal Gene Transfer and Homologous Recombination Drive the Evolution of the Nitrogen-Fixing Symbionts of Medicago SpeciesJournal of Bacteriology, 2007
- Comparison of rhizobia that nodulate Medicago laciniata and Medicago truncatula present in a single Tunisian arid soilCanadian Journal of Microbiology, 2007
- Recombination and selection shape the molecular diversity pattern of nitrogen‐fixing Sinorhizobium sp. associated to MedicagoMolecular Ecology, 2006
- Medicago – Sinorhizobium symbiotic specificity evolution and the geographic expansion of MedicagoJournal of Evolutionary Biology, 2005
- The Symbiotic Requirements of Different Medicago Spp. Suggest the Evolution of Sinorhizobium Meliloti and S. Medicae with Hosts Differentially Adapted to Soil pHPlant and Soil, 2005
- The Composite Genome of the Legume Symbiont Sinorhizobium melilotiScience, 2001
- Horizontal gene transfer and the origin of species: lessons from bacteriaTrends in Microbiology, 2000
- The Acetylene-Ethylene Assay for N2 Fixation: Laboratory and Field EvaluationPlant Physiology, 1968