Rhizobium meliloti mutants that overproduce the R. meliloti acidic calcofluor-binding exopolysaccharide
نویسندگان
چکیده
منابع مشابه
Interference between Rhizobium meliloti and Rhizobium trifolii nodulation genes: genetic basis of R. meliloti dominance.
Transfer of an IncP plasmid carrying the Rhizobium meliloti nodFE, nodG, and nodH genes to Rhizobium trifolii enabled R. trifolii to nodulate alfalfa (Medicago sativa), the normal host of R. meliloti. Using transposon Tn5-linked mutations and in vitro-constructed deletions of the R. meliloti nodFE, nodG, and nodH genes, we showed that R. meliloti nodH was required for R. trifolii to elicit both...
متن کاملNodules Initiated by Rhizobium meliloti Exopolysaccharide Mutants Lack a Discrete, Persistent Nodule Meristem.
Infection of alfalfa with Rhizobium meliloti exo mutants deficient in exopolysaccharide results in abnormal root nodules that are devoid of bacteria and fail to fix nitrogen. Here we report further characterization of these abnormal nodules. Tightly curled root hairs or shepherd's crooks were found after inoculation with Rm 1021-derived exo mutants, but curling was delayed compared with wild-ty...
متن کاملA second exopolysaccharide of Rhizobium meliloti strain SU47 that can function in root nodule invasion.
Rhizobium meliloti strain SU47 produces the calcofluor-binding exopolysaccharide, succinoglycan, that is required for alfalfa root nodule invasion. Strains derived from R. meliloti SU47 secreted an acidic exopolysaccharide, EPSb, that replaced succinoglycan in nodule invasion. EPSb, which has not formerly been identified among the Rhizobiaceae, consisted of the repeating unit 4,6-O-(1-carboxyet...
متن کاملAnalysis of Rhizobium meliloti Sym Mutants Obtained by Heat Treatment.
Deletions in the pSym megaplasmid of Rhizobium meliloti were produced at a high frequency, and their lengths varied according to incubation temperature. Morphological differentiation into large and small colonies occurred after heat treatment. Small colonies elicited pseudonodules on alfalfa roots.
متن کاملCharacterization of polysaccharides of Rhizobium meliloti exo mutants that form ineffective nodules.
Mutants of Rhizobium meliloti SU47 with defects in the production of the Calcofluor-binding expolysaccharide succinoglycan failed to gain entry into alfalfa root nodules. In order to define better the polysaccharide phenotypes of these exo mutants, we analyzed the periplasmic oligosaccharide cyclic (1-2)-beta-D-glucan and lipopolysaccharide (LPS) in representative mutants. The exoC mutant lacke...
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ژورنال
عنوان ژورنال: Journal of Bacteriology
سال: 1988
ISSN: 0021-9193,1098-5530
DOI: 10.1128/jb.170.9.4249-4256.1988