ThenodSGene ofRhizobium tropiciStrain CIAT899 Is Necessary for Nodulation onPhaseolus vulgarisand onLeucaena leucocephala

Waelkens, F.; Voets, Thomas; Vlassak, K.; Vanderleyden, Jozef; Rhijn, Pieternel van

doi:10.1094/mpmi-8-0147

Cited by 52 publications

(21 citation statements)

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“…NodS is an N-methyltransferase (93,94,129), while NodU and NolO control carbamoylation at C-6 and C-3 (or C-4), respectively, on the nonreducing N-acetyl-D-glucosamine (57,129,131). Inactivation of nodS in A. caulinodans, strain NGR234, and R. tropici abolishes the nodulation of L. leucocephala and P. vulgaris (158,276). Introduction of either nodS or nodU into R. fredii extends its host range to include Leucaena spp.…”

Section: Nod Enzymes and Nod Factor Synthesismentioning

confidence: 99%

Molecular Basis of Symbiotic Promiscuity

Perret

Staehelin

Broughton

2000

Microbiol Mol Biol Rev

863

630

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SUMMARY Eukaryotes often form symbioses with microorganisms. Among these, associations between plants and nitrogen-fixing bacteria are responsible for the nitrogen input into various ecological niches. Plants of many different families have evolved the capacity to develop root or stem nodules with diverse genera of soil bacteria. Of these, symbioses between legumes and rhizobia (Azorhizobium, Bradyrhizobium, Mesorhizobium, and Rhizobium) are the most important from an agricultural perspective. Nitrogen-fixing nodules arise when symbiotic rhizobia penetrate their hosts in a strictly controlled and coordinated manner. Molecular codes are exchanged between the symbionts in the rhizosphere to select compatible rhizobia from pathogens. Entry into the plant is restricted to bacteria that have the “keys” to a succession of legume “doors”. Some symbionts intimately associate with many different partners (and are thus promiscuous), while others are more selective and have a narrow host range. For historical reasons, narrow host range has been more intensively investigated than promiscuity. In our view, this has given a false impression of specificity in legume-Rhizobium associations. Rather, we suggest that restricted host ranges are limited to specific niches and represent specialization of widespread and more ancestral promiscuous symbioses. Here we analyze the molecular mechanisms governing symbiotic promiscuity in rhizobia and show that it is controlled by a number of molecular keys.

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Section: Nod Enzymes and Nod Factor Synthesismentioning

confidence: 99%

Molecular Basis of Symbiotic Promiscuity

Perret

Staehelin

Broughton

2000

Microbiol Mol Biol Rev

863

630

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“…Among bean-nodulating rhizobia, the host range varies from narrow, as is the case for Rhizobium etli strain CFN42 (13), to wide, as for example the Rhizobium tropici IIA and IIB strains CFN299 and CIAT899 (14). Wide host range in bean-nodulating rhizobia was defined as the ability to form a symbiosis with the tropical tree Leucaena leucocephala (14) requiring the R. tropici nodS gene downstream of nodC (32). In complementation analysis, the R. tropici nodS gene was shown to extend the host range of R. etli to include L. leucocephala (32).…”

Section: Common Bean (Phaseolus Vulgaris)mentioning

confidence: 99%

“…Wide host range in bean-nodulating rhizobia was defined as the ability to form a symbiosis with the tropical tree Leucaena leucocephala (14) requiring the R. tropici nodS gene downstream of nodC (32). In complementation analysis, the R. tropici nodS gene was shown to extend the host range of R. etli to include L. leucocephala (32).…”

Section: Common Bean (Phaseolus Vulgaris)mentioning

confidence: 99%

Evidence of an American Origin for Symbiosis-Related Genes in Rhizobium lusitanum

Valverde

Velázquez

Cervantés

et al. 2011

Appl Environ Microbiol

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Randomly amplified polymorphic DNA (RAPD) analysis was used to investigate the diversity of 179 bean isolates recovered from six field sites in the Arcos de Valdevez region of northwestern Portugal. The isolates were divided into 6 groups based on the fingerprint patterns that were obtained. Representatives for each group were selected for sequence analysis of 4 chromosomal DNA regions. Five of the groups were placed within Rhizobium lusitanum, and the other group was placed within R. tropici type IIA. Therefore, the collection of Portuguese bean isolates was shown to include the two species R. lusitanum and R. tropici. In plant tests, the strains P1-7, P1-1, P1-2, and P1-16 of R. lusitanum nodulated and formed nitrogen-fixing symbioses both with Phaseolus vulgaris and Leucaena leucocephala. A methyltransferase-encoding nodS gene identical with the R. tropici locus that confers wide host range was detected in the strain P1-7 as well as 24 others identified as R. lusitanum. A methyltransferase-encoding nodS gene also was detected in the remaining isolates of R. lusitanum, but in this case the locus was that identified with the narrow-host-range R. etli. Representatives of isolates with the nodS of R. etli formed effective nitrogen-fixing symbioses with P. vulgaris and did not nodulate L. leucocephala. From sequence data of nodS, the R. lusitanum genes for symbiosis were placed within those of either R. tropici or R. etli. These results would support the suggestion that R. lusitanum was the recipient of the genes for symbiosis with beans from both R. tropici and R. etli. Common bean (Phaseolus vulgaris)is an important agricultural leguminous crop that has the ability to nodulate with rhizobia from at least 20 different host plant genera (summarized in reference 1). Among bean-nodulating rhizobia, the host range varies from narrow, as is the case for Rhizobium etli strain CFN42 (13), to wide, as for example the Rhizobium tropici IIA and IIB strains CFN299 and CIAT899 (14). Wide host range in bean-nodulating rhizobia was defined as the ability to form a symbiosis with the tropical tree Leucaena leucocephala (14) requiring the R. tropici nodS gene downstream of nodC (32). In complementation analysis, the R. tropici nodS gene was shown to extend the host range of R. etli to include L. leucocephala (32).According to Graham and Ranalli (6), common bean was introduced as a curiosity from the Americas into Europe via the Iberian Peninsula during the 16th century (34), but today it is a widely cultivated crop in Spain (21) and Portugal (19). Descriptions of bean rhizobia from the Iberian Peninsula have been made with isolates that originated from soils of Spain (8,20) and Portugal (25). The majority of the isolates originating from Spain were characterized as R. etli, R. gallicum, and R. giardinii (8,20), probably imported from the Americas (4, 14, 23, 35) along with the seeds (16). However, the isolates of Portuguese origin were proposed to represent the new species R. lusitanum, having characters that are different from ...

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“…A R. tropici strain mutated in nodP lacks the symbiotic PAPS form (since its NFs are no longer sulphated) and still nodulates common bean (Laeremans et al, 1996). Since methylation of NFs is required for nodulation of bean (Waelkens et al, 1995), and is dependent on the presence of PAPS, it can be suggested that the PAPS source for NF methylation might come from the household sulphate activation system. Thus, for NF production, nodulation genes are indispensable, but at least in some strains household genes can take over their functions, possibly even in the Nod factor sulphation pathway.…”

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confidence: 99%

Functional redundancy of genes for sulphate activation enzymes in Rhizobium sp. BR816

et al. 1997

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The broad-host-range, heat-tolerant Rhizobium strain BR816 produces sulphated Nod metabolites. Two ORFs highly homologous to the Sinorhizo&ium meliloti nodPQ genes were isolated and sequenced. It was found that Rhizo&ium sp. BR816 contained two copies of these genes; one copy was localized on the symbiotic plasmid, the other on the megaplasmid. Both nodP genes were interrupted by insertion of antibiotic resistance cassettes, thus constructing a double nodPlP2 mutant strain. However, no detectable differences in Nod factor TLC profile from this mutant were observed as compared to the wild-type strain. Additionally, plant inoculation experiments did not reveal differences between the mutant strain and the wild-type. It is proposed that a third, functionally homologous locus complements mutations in the Nod factor sulphation genes. Southern blot analysis suggested that this locus contains genes necessary for the sulphation of amino acids.

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ThenodSGene ofRhizobium tropiciStrain CIAT899 Is Necessary for Nodulation onPhaseolus vulgarisand onLeucaena leucocephala

Cited by 52 publications

References 0 publications

Molecular Basis of Symbiotic Promiscuity

Molecular Basis of Symbiotic Promiscuity

Evidence of an American Origin for Symbiosis-Related Genes in Rhizobium lusitanum

Functional redundancy of genes for sulphate activation enzymes in Rhizobium sp. BR816

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