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Hisamatsu, Makoto; Amemura, Akinori; Harada, Tokuya; Koizumi, Kyoko; Utamura, Toshiko; Okada, Yasuyo

doi:10.5458/jag1972.31.117

Cited by 15 publications

(20 citation statements)

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“…Inner membranes prepared from the mutant did not form P-(1--*2) glucan in vitro, while wild-type inner membranes formed P-(1-->2) glucans whose most abundant species eluted from the HPLC column with a retention time that corresponded to a higher degree of polymerization than that in A. tumefaciens. This result agrees with previous reports in which P-(1--+2) glucans from A. tumefaciens and other strains of R. meliloti were compared (11,13,28). These results showed that mutant cells have some alteration in the enzyme(s) required for the synthesis of P-(1--2) glucan.…”

Section: Discussionsupporting

confidence: 83%

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A Rhizobium meliloti mutant that forms ineffective pseudonodules in alfalfa produces exopolysaccharide but fails to form beta-(1----2) glucan

Geremia¹,

Cavaignac²,

Zorreguieta³

et al. 1987

J Bacteriol

105

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A mutant of Rhizobium meliloti that elicited the formation of inactive nodules in alfalfa was found not to form beta-(1----2) glucan in vivo or in vitro. It was nonmotile because it lacks flagella. The 235-kilodalton protein which acts as an intermediate in beta-(1----2) glucan synthesis was undetectable in the mutant. These properties of the mutant are common to those of chvB mutants of Agrobacterium tumefaciens. Exopolysaccharide formation by the R. meliloti mutant was about double that by the wild type.

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Section: Discussionsupporting

confidence: 83%

“…The higher degree of polymerization of the most abundant species of R. meliloti GR4 ,B-(1--2) glucan as compared with that of Agrobacterium sp. ,B-(1-+2) glucan was previously observed with two different strains of A. tumefaciens and R. meliloti (11,13,28).…”

Section: Resultsmentioning

confidence: 99%

A Rhizobium meliloti mutant that forms ineffective pseudonodules in alfalfa produces exopolysaccharide but fails to form beta-(1----2) glucan

Geremia¹,

Cavaignac²,

Zorreguieta³

et al. 1987

J Bacteriol

105

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“…The 1H and '3C NMR spectra of this glucan fraction (Fig. 3) displayed simple patterns of resonances typical of low-MW P(1,2)-glucans already described in several species in the family Rhizobiaceae (4,9,25). The glucans neither were retained on a DEAE-Trisacryl column (at pH 7.0) nor gave any indication of noncarbohydrate substitutions in their H NMR spectra (Fig.…”

Section: Resultsmentioning

confidence: 99%

Characterization and symbiotic importance of acidic extracellular polysaccharides of Rhizobium sp. strain GRH2 isolated from acacia nodules

et al. 1993

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RIizobium sp. wild-type strain GRH2 was originally isolated from root nodules of the leguminous tree Acacia cyanophylla and has a broad host range which includes herbaceous legumes, e.g., Trifolium spp. We examined the extracellular exopolysaccharides (EPSs) produced by strain GRH2 and found three independent glycosidic structures: a high-molecular-weight acidic heteropolysaccharide which is very similar to the acidic EPS produced by Rhizobium leguminosarum biovar trifolii ANU843, a low-molecular-weight native heterooligosaccharide resembling a dimer of the repeat unit of the high-molecular-weight EPS, and low-molecular-weight neutral 13(1,2)-glucans. A TnS insertion mutant derivative of GRH2 (exo-57) Leguminous trees proliferate in arid and semiarid regions of the world which are unsuited for crop production. These leguminous trees are of increasing interest since they provide wood, fiber, gum, and food for animal and human nutrition, protect the soil from erosion, and form nitrogenfixing nodules in symbiotic association with bacteria (2,5,19,24,31,41). Recent studies revealed that leguminous trees are infected by both fast-growing rhizobia and slowly growing bradyrhizobia. Some rhizobial strains isolated from the nodules have a wide host range, even including herbaceous legumes (15,16,24,30,45). This is the case for fast-growing Rhizobium sp. strain GRH2, originally isolated from Acacia cyanophylla (24). Many reports suggest involvement of Rhizobium acidic heteropolysaccharides in infection of legume roots hairs, invasion of nodules, and nitrogen fixation (1,6,11,21,28,32,35,37) and a possible contribution to determination of the bacterial host range (13,14,20,36).Rhizobia with broad host ranges are very useful for investigations of the molecular mechanisms of symbiotic interaction. Rhizobium sp. strain NGR234 is one of the most extensively studied strains with a broad host range, which includes several tropical legumes and the nonlegume Parasponia spp. This strain shows functional and evolutionary genetic equivalence to Rhizobium meliloti (44). In contrast, studies of restriction fragment length polymorphism suggest that broad-host-range Rhizobium sp. strain GRH2 is more closely related to R. leguminosarum (30a). The aim of the present work was to evaluate the extracellular exopolysaccharide (EPS) of strain GRH2 and its role in the root nodule symbiosis between the bacterial symbiont and its leguminous hosts. We show that the EPSs produced by Rhizobium sp. strain GRH2 are very closely related to those produced by wild-type R. leguminosarum bv. tnfolii strain ANU843. * Corresponding author.In addition, a Tn5-induced Exo-mutant derivative of GRH2 which does not produce acidic heteropolysaccharides was obtained and found to be unable to induce nodules on several herbaceous legumes hosts. However, it still nodulated Acacia sp. but infected fewer host cells in the nodule. MATERIALS AND METHODSBacterial strains and genetic manipulations. Rhizobium sp. strain GRH2 was originally isolated from root nodules ofA. cya...

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“…tumefaciens, like R. meliloti, produces succinoglycan and cyclic P-(1-2)-glucan (12,24,25,26). Cangelosi et al (6) isolated …”

Section: Discussionmentioning

confidence: 99%

“…,-(1-2)-linked D-glucosyl residues (12,26,46)] is a periplasmic oligosaccharide that has also been found in the culture supernatants of some strains (2,47). Recently, acidic, modified forms have been reported (3,27,37).…”

mentioning

confidence: 99%

Characterization of polysaccharides of Rhizobium meliloti exo mutants that form ineffective nodules

1988

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Mutants of Rhizobium meliloti SU47 with defects in the production of the Calcofluor-binding exopolysaccharide 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)-p-D-glucan and lipopolysaccharide (LPS) in representative mutants. The exoC mutant lacked the glucan and had abnormal LPS which appeared to lack a substantial portion of the 0 side chain. The exoB mutant had a spectrum of LPS species which differed from those of both the wild-type parental strain and the exoC mutant. The presence of the glucan and normal LPS in the exoA, exoD, exoF, and exoH mutants eliminated defects in these carbohydrates as explanations for the nodule entry defects of these mutants. We also assayed for high-and low-molecular-weight succinoglycans. All of the exo mutants except exoD and exoH completely lacked both forms. For the Calcofluor-dim exoD mutant, the distribution of high-and low-molecular-weight forms depended on the growth medium. The haloless exoH mutant produced high-molecular-weight and only a trace of low-molecular-weight succinoglycan; the succinyl modification was missing, as was expected from the results of previous studies. The implications of these observations with regard to nodule entry are discussed.

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Cited by 15 publications

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A Rhizobium meliloti mutant that forms ineffective pseudonodules in alfalfa produces exopolysaccharide but fails to form beta-(1----2) glucan

A Rhizobium meliloti mutant that forms ineffective pseudonodules in alfalfa produces exopolysaccharide but fails to form beta-(1----2) glucan

Characterization and symbiotic importance of acidic extracellular polysaccharides of Rhizobium sp. strain GRH2 isolated from acacia nodules

Characterization of polysaccharides of Rhizobium meliloti exo mutants that form ineffective nodules

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