Genetics and biochemistry of the Rhizobium meliloti acidic extracellular heteropolysaccharide and its role in nodulation: Annual report for the period 1 June 1986-31 May 1987
This document briefly describes studies of the genetics and biochemistry of Rhizobium meliloti exopolysaccharides and their role in alfalfa root nodule formation. Previously the author demonstrated that a large set of mutants (Exo/sup -/) of R. meliloti failed to secrete succinoglycan, an acidic exopolysaccharide of known structure. These mutations belonged to five different loci in the R. meliloti genome. All of the mutants shared the inability to enter alfalfa root nodules, providing strong correlative evidence that succinoglycan is involved in a certain phase in nodule development. In the past year, this research group characterized mutants that were previously designated ''haloless'' mutants. These mutants were thought to be unable to degrade the secreted polysaccharide into diffusible fragments that ordinarily form a halo of binding of a polysaccharide specific dye surrounding a colony of growth. The research team discovered a second acidic exopolysaccharide that is synthesized by certain mutant derivatives of our strain of R. meliloti. This polysaccharide appeared quite distinct from succinoglycan by NMR spectroscopy and appeared to replace succinoglycan in a Tn5-induced mutant called ''halo-clearing'', and in wild type strains containing a certain cosmid from the R. meliloti clone bank. 2 figs.
- Research Organization:
- Washington Univ., Seattle (USA)
- DOE Contract Number:
- FG06-86ER13532
- OSTI ID:
- 6429880
- Report Number(s):
- DOE/ER/13532-1; ON: DE87011076
- Country of Publication:
- United States
- Language:
- English
Similar Records
(Genetics and biochemistry of Rhizobium meliloti acidic extracellular heteropolysaccharide and its role in nodulation): Final technical report
Genetics and biochemistry of the Rhizobium meliloti acidic extracellular heteropolysaccharide and its role in nodulation: Annual report for the period 1 June 1987-31 May 1988
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59 BASIC BIOLOGICAL SCIENCES
ALFALFA
BACTERIA
BIOLOGICAL FUNCTIONS
CARBOHYDRATES
CELL CONSTITUENTS
CELL WALL
CHEMICAL REACTIONS
CHROMATOGRAPHY
FUNCTIONS
GENE MUTATIONS
LEGUMINOSAE
LIQUID COLUMN CHROMATOGRAPHY
MICROORGANISMS
MUTATIONS
MYCORRHIZAS
NITRIFICATION
ORGANIC COMPOUNDS
PLANTS
POLYSACCHARIDES
RHIZOBIUM
ROOTS
SACCHARIDES
SEPARATION PROCESSES
SYMBIOSIS