| identification and cloning of the bacterial nodulation specificity gene in the sinorhizobium meliloti--medicago laciniata symbiosis. | medicago laciniata (cut-leaf medic) is an annual medic that is highly nodulation specific, nodulating only with a restricted range of sinorhizobium meliloti. e.g., strain 102l4, but not with most strains that nodulate medicago sativa (alfalfa), e.g., strains rcr2011 and rm41. our aim was to identify and clone the s. meliloti 102l4 gene implicated in the specific nodulation of m. laciniata and to characterize the adjacent nodulation (nod) region. an 11-kb ecori dna fragment from s. meliloti 102l4 ... | 2002 | 12455608 |
| screening of some indigenous qatari medicinal plants for antimicrobial activity. | aqueous, ethanol and butanol crude extracts of the aerial parts of ten plants exhibited variable degrees of antimicrobial activity against four bacterial and two fungal species. aqueous extracts had low antimicrobial activity against e.coli, p.aeruginosa, b. cerreus, s.aureus, c.albicans and a.flavus. avicennia marina (am) aqueous extract exhibited a moderate antifungal activity. ethanol and butanol crude extracts exhibited an improved antimicrobial activity. however, butanol exhibited a superio ... | 2002 | 12458480 |
| nitrogen-fixing sinorhizobia with medicago laciniata constitute a novel biovar (bv. medicaginis) of s. meliloti. | sixty-eight new rhizobial isolates were obtained from root-nodules of medicago laciniata and from mediterranean soils in tunisia and france. all of them were identified as sinorhizobium meliloti on the basis of pcr-rflp analyses of 16s rdna and the intergenic spacer sequence between 16s and 23s rdnas. dna/dna hybridization, phenotypic characterization and 16s rrna gene sequencing led to the conclusion that they belong the same taxon. all new isolates shared the ability to nodulate and fix nitrog ... | 2006 | 16413160 |
| horizontal gene transfer and homologous recombination drive the evolution of the nitrogen-fixing symbionts of medicago species. | using nitrogen-fixing sinorhizobium species that interact with medicago plants as a model system, we aimed at clarifying how sex has shaped the diversity of bacteria associated with the genus medicago on the interspecific and intraspecific scales. to gain insights into the diversification of these symbionts, we inferred a topology that includes the different specificity groups which interact with medicago species, based on sequences of the nodulation gene cluster. furthermore, 126 bacterial isol ... | 2007 | 17496100 |
| comparison of rhizobia that nodulate medicago laciniata and medicago truncatula present in a single tunisian arid soil. | the rhizobia present in a single arid region tunisian soil that nodulate medicago laciniata and medicago truncatula were compared. all isolates, 40 from each host, were sinorhizobium meliloti based on 16s rrna polymerase chain reaction restriction fragment length polymorphism (pcr-rflp) patterns and subsequent confirmation by sequence analysis of the 16s rrna genes in four representatives from each host species. there was no apparent relationship between medicago host species of isolation and th ... | 2007 | 17496977 |
| quantitative and molecular genetic variation in sympatric populations of medicago laciniata and m. truncatula (fabaceae): relationships with eco-geographical factors. | medicago laciniata is restricted to south of the mediterranean basin and it extends in tunisia from the inferior semi-arid to saharan stages, whereas m. truncatula is a widespread species in such areas. the genetic variability in four tunisian sympatric populations of m. laciniata and m. truncatula was analysed using 19 quantitative traits and 20 microsatellites. we investigated the amplification transferability of 52 microsatellites developed in m. truncatula to m. laciniata. results indicate t ... | 2007 | 17669230 |
| chromosomal and symbiotic relationships of rhizobia nodulating medicago truncatula and m. laciniata. | multilocus sequence typing (mlst) is a sequence-based method used to characterize bacterial genomes. this method was used to examine the genetic structure of medicago-nodulating rhizobia at the amra site, which is located in an arid region of tunisia. here the annual medics medicago laciniata and m. truncatula are part of the natural flora. the goal of this study was to identify whether distinct chromosomal groups of rhizobia nodulate m. laciniata because of its restricted requirement for specif ... | 2007 | 17921275 |
| morphological and microsatellite diversity associated with ecological factors in natural populations of medicago laciniata mill. (fabaceae). | genetic variability in 10 natural tunisian populations of medicago laciniata were analysed using 19 quantitative traits and 12 polymorphic microsatellite loci. a large degree of genetic variability within-populations and among-populations was detected for both quantitative characters and molecular markers. high genetic differentiation among populations for quantitative traits was seen, with q(st) = 0.47, and f(st) = 0.47 for microsatellite markers. several quantitative traits displayed no statis ... | 2008 | 19147909 |
| ensifer meliloti bv. lancerottense establishes nitrogen-fixing symbiosis with lotus endemic to the canary islands and shows distinctive symbiotic genotypes and host range. | eleven strains were isolated from root nodules of lotus endemic to the canary islands and they belonged to the genus ensifer, a genus never previously described as a symbiont of lotus. according to their 16s rrna and atpd gene sequences, two isolates represented minority genotypes that could belong to previously undescribed ensifer species, but most of the isolates were classified within the species ensifer meliloti. these isolates nodulated lotus lancerottensis, lotus corniculatus and lotus jap ... | 2009 | 19477097 |
| symbiotic diversity of ensifer meliloti strains recovered from various legume species in tunisia. | ensifer meliloti (formerly sinorhizobium meliloti) was first considered as a specific microsymbiont of medicago, melilotus and trigonella. however, strains of e. meliloti were recovered from root nodules of various legume species and their symbiotic status still remains unclear. here, we further investigate the specificity of these strains. a collection of 47 e. meliloti strains isolated in tunisia from root nodules of medicago truncatula, medicago sativa, medicago ciliaris, medicago laciniata, ... | 2009 | 19665858 |
| specificity in legume-rhizobia symbioses. | most species in the leguminosae (legume family) can fix atmospheric nitrogen (n₂) via symbiotic bacteria (rhizobia) in root nodules. here, the literature on legume-rhizobia symbioses in field soils was reviewed and genotypically characterised rhizobia related to the taxonomy of the legumes from which they were isolated. the leguminosae was divided into three sub-families, the caesalpinioideae, mimosoideae and papilionoideae. bradyrhizobium spp. were the exclusive rhizobial symbionts of species i ... | 2017 | 28346361 |