Host-Symbiont Specificity Expressed during Early Adsorption of Rhizobium meliloti to the Root Surface of Alfalfa.
TLDR
The differential effects of homologous and heterologous competitors indicate that initial adsorption of R. meliloti to the root surface of its host occurs in symbiont-specific as well as nonspecific modes and suggest the existence of binding sites on roots which are highly selective for the specific microsymbiont in the presence of otherheterologous bacteria even in very unfavorable symbionT-competitor concentration ratios.Abstract:
Early (4 h) adsorption of Rhizobium meliloti L5-30 in low numbers to alfalfa roots in mineral solution was examined for competition with other bacterial strains. All tested competitor strains decreased the adsorption of L5-30 by extents which depended on the strain and its concentration. The decrease of adsorption by R. meliloti competitors (all of them infective in alfalfa) was nearly complete at saturation (97 to 99% decrease). All other heterologous rhizobia and Agrobacterium tumefaciens at saturating concentrations (106 to 107 per ml) decreased adsorption of L5-30 only partially, less than 60%. The differential effects of homologous and heterologous competitors indicate that initial adsorption of R. meliloti to the root surface of its host occurs in symbiont-specific as well as nonspecific modes and suggest the existence of binding sites on roots which are highly selective for the specific microsymbiont in the presence of other heterologous bacteria even in very unfavorable (less than 10−4) symbiont-competitor concentration ratios.read more
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Attachment of bacteria to the roots of higher plants.
Dulce N. Rodríguez-Navarro,Marta Susana Dardanelli,Marta Susana Dardanelli,Marta Susana Dardanelli,José E. Ruiz-Sainz +4 more
TL;DR: Bacterial surface proteins, capsular polysaccharide and flagella appear to govern the first binding step while extracellular poly Saccharide is involved in the second step.
Journal ArticleDOI
Role of Motility and Chemotaxis in Efficiency of Nodulation by Rhizobium meliloti.
Gustavo Caetano-Anollés,L G Wall,A T De Micheli,E M Macchi,Wolfgang D. Bauer,Gabriel Favelukes +5 more
TL;DR: It appears that motility and chemotaxis are quantitatively important traits that facilitate the initial contact and adsorption of symbiotic rhizobia to the host root surface, increase the efficiency of nodule initiation, and increase the rate of infection development.
Journal ArticleDOI
Characterization of the lipopolysaccharide from a Rhizobium phaseoli mutant that is defective in infection thread development.
TL;DR: The lipopolysaccharide from a Rhizobium phaseoli mutant, CE109, was isolated and compared with that of its wild-type parent, CE3, and showed that CE109 LPS consists of only the lipid A core and is missing the antigenic O chain.
Journal ArticleDOI
The Genetic and Biochemical Basis for Nodulation of Legumes by Rhizobia
TL;DR: This review focuses on the nodulation genes of rhizobia, with particular emphasis on the concept of biological specificity of symbiosis with legume host plants.
Lectin-Enhanced Accumulation ofManganese-Limited Rhizobium leguminosarum Cells onPeaRootHairTips
TL;DR: Spot inoculation tests with rhizobia grown under various culture conditions indicated that differences in attachment between manganese- and carbon-limited R. leguminosarum cells are correlated with a significant difference in infectivity in that mangane-limited rhizobic cells, in contrast to carbon- limited rhzobia, are infective.
References
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The Infection of Clover Root Hairs by Nodule Bacteria Studied by a Simple Glass Slide Technique
TL;DR: A simple glass slide technique has been devised for the continuous microscopical observation of growth and infection of root hairs of clover seedlings which involves an aseptic cultivation of seedlings on microscope slides which are partly immersed in a mineral salts medium.
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Transient Susceptibility of Root Cells in Four Common Legumes to Nodulation by Rhizobia
TL;DR: Root cells of four common legumes were found to remain susceptible to nodulation by rhizobia for only a short period of time, suggesting the existence of a fast-acting regulatory mechanism in these hosts that prevents overnodulation.
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Cross-reactive antigens and lectin as determinants of symbiotic specificity in the Rhizobium-clover association.
F B Dazzo,D H Hubbell +1 more
TL;DR: Inhibition studies indicated that 2-deoxyglucose was the most probable haptenic determinant of the cross-reactive capsular antigen capable of binding to the root antiserum and the clover lectin.
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Adsorption of bacteria to roots as related to host specificity in the Rhizobium-clover symbiosis.
TL;DR: Results suggest that expression of host specificity in the Rhizobium-clover symbiosis involves a preferential adsorption of infective cells to clover root hairs through a 2-deoxyglucose-sensitive receptor site.
Journal ArticleDOI
Specific phases of root hair attachment in the Rhizobium trifolii-clover symbiosis.
TL;DR: The results are interpreted as a sequence of phases in attachment, beginning with specific reversible interactions between bacterial and plant surfaces (phase I attachment), followed by production of extracellular microfibrils which firmly anchor the bacterium to the root hair (phase 2 adhesion).