We studied the production of xyloglucanase enzymes of leguminous roots in the presence of Rhizobium and arbuscularmycorrhizal (AM) fungi. The AM fungus Glomus mosseae and Sinorhizobium meliloti GR4 for alfalfa, Rhizobium leguminosarum bv. viceae Rlv 13 for pea, R. leguminosarum bv. trifolii 2152 for clover, R. tropici CIAT 899 for bean and Mesorrhizobium mediterraneum USDA 3392 for chickpea. Th...

Rhizobium leguminosarum bv. trifolii SRDI565 (syn. N8-J) is an aerobic, motile, Gram-negative, non-spore-forming rod. SRDI565 was isolated from a nodule recovered from the roots of the annual clover Trifolium subterraneum subsp. subterraneum grown in the greenhouse and inoculated with soil collected from New South Wales, Australia. SRDI565 has a broad host range for nodulation within the clover...

An interrelationship between introduced and indigenous rhizobia focused on their competitiveness in nodulation was evaluated in a soil pot experiment. Clover seeds were inoculated by six different gradual concentrations of inoculum of two effective Rhizobium leguminosarum bv. trifolii isolates (inoculation strains 1/2 and 14/2). At the beginning of flowering, clover plants were removed from the...

other Rhizobium species. Most of these plasmids encoding for fixation and nodulation properties are non-self transmissible. Plasmid profiles were determined for 24 strains of R. trifolii. All the strains harboured at least three plasmids and as many as eight were present in some strains. Southern hybridization with cloned R. meliloti nifgenes was used to identify indigenous Nif plasmids. Each s...

The adhesion of rhizobia to surfaces of clover roots was examined by an indirect plate-counting assay and phase-contrast microscopy. The number of Rhizobium trifolii cells attached to clover root segments increased in approximately linear fashion during the first hour of incubation, but did not change appreciably thereafter. The addition of 30 mM-2-deoxy-D-glucose, which effectively inhibits bi...

Sciences, University of East Anglia, Norwich NR4 7TJ, UK 2 School of Biological Analysis of the nodulation characteristics of transposon-induced mutants of Rhizobium leguminosarum bv. viciae revealed that nodO and the closely-linked rhi genes contribute t o nodulation of peas (Pisum sativum) and the vetch Vicia hirsuta. Although mutation of nodO alone had no significant effect on nodulation of ...

Carboxymethyl cellulase and polygalacturonase activities were evaluated in wild-type strains from different taxonomic groups of rhizobia which nodulate a specific range of legume hosts that do not normally overlap (R. meliloti, R. loti, R. leguminosarum biovar trifolii, R. leguminosarum biovar phaseoli, R. leguminosarum biovar viceae, and Bradyrhizobium japonicum). To detect these enzymatic act...

The Rhizobium leguminosarum h o s t-range (Sym) plasmid, pJB5JI, is a 130 Mdal conjugative plasmid which carries the genes for host-specificity (i.e., for peas) and some of the genes for ni trogen-fixation. We have t ransferred plasmid pJB5JI into different species of Rhizobium and examined the symbiotic propert ies of the result ing transconjugants. The donor strain R. leguminosarum 6015 (pJB5...

Virtanen and Laine (1937) were the first to suggest the existence of an aspartic acid decarboxylase in Rhizobium trifolii, by the isolation of beta-alanine from a 47-day fermentation mash containing aspartic acid. Shive and Macow (1946), working with hydroxyaspartic acid as a competitive analogue for aspartic acid in the metabolism of Escherichia coli, found that the addition of this compound t...