Stem Nodulation in Legumes: Diversity, Mechanisms, and Unusual Characteristics

Boivin, C.; Ndoye, Ibrahima; Molouba, Flore; Lajudie, Philippe de; Dupuy, Nicolas; Dreyfus, B

doi:10.1080/07352689709701944

Cited by 67 publications

(55 citation statements)

References 133 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The surfaces and interiors of the rice roots, which we found densely colonized by Aeschynomene-nodulating Bradyrhizobium strains, therefore appear in nature as unexpected niches, much more abundant than root and stem nodules of the aquatic legumes. Photosynthetic Bradyrhizobium strains were also directly isolated from water, thus confirming their aquatic character (9), which could result in a bacterial selective advantage in the absence of rice or legume hosts. Yanni et al (44) previously reported endophytic association between another rhizobial species, R. leguminosarum bv.…”

Section: Discussionmentioning

confidence: 77%

Photosynthetic Bradyrhizobia Are Natural Endophytes of the African Wild Rice Oryza breviligulata

Chaintreuil

Giraud

Prin

et al. 2000

Appl Environ Microbiol

Self Cite

251

139

View full text Add to dashboard Cite

We investigated the presence of endophytic rhizobia within the roots of the wetland wild rice Oryza breviligulata, which is the ancestor of the African cultivated rice Oryza glaberrima. This primitive rice species grows in the same wetland sites as Aeschynomene sensitiva, an aquatic stem-nodulated legume associated with photosynthetic strains of Bradyrhizobium. Twenty endophytic and aquatic isolates were obtained at three different sites in West Africa (Senegal and Guinea) from nodal roots of O. breviligulata and surrounding water by using A. sensitiva as a trap legume. Most endophytic and aquatic isolates were photosynthetic and belonged to the same phylogenetic Bradyrhizobium/Blastobacter subgroup as the typical photosynthetic Bradyrhizobium strains previously isolated from Aeschynomene stem nodules. Nitrogen-fixing activity, measured by acetylene reduction, was detected in rice plants inoculated with endophytic isolates. A 20% increase in the shoot growth and grain yield of O. breviligulata grown in a greenhouse was also observed upon inoculation with one endophytic strain and one Aeschynomene photosynthetic strain. The photosynthetic Bradyrhizobium sp. strain ORS278 extensively colonized the root surface, followed by intercellular, and rarely intracellular, bacterial invasion of the rice roots, which was determined with a lacZ-tagged mutant of ORS278. The discovery that photosynthetic Bradyrhizobium strains, which are usually known to induce nitrogen-fixing nodules on stems of the legume Aeschynomene, are also natural true endophytes of the primitive rice O. breviligulata could significantly enhance cultivated rice production.

show abstract

Section: Discussionmentioning

confidence: 77%

Photosynthetic Bradyrhizobia Are Natural Endophytes of the African Wild Rice Oryza breviligulata

Chaintreuil

Giraud

Prin

et al. 2000

Appl Environ Microbiol

Self Cite

251

139

View full text Add to dashboard Cite

show abstract

“…5). This strain forms nitrogen-fixing nodules on the stems of the plant Aeschynomene sensitiva, a tropical legume that grows in water logged soils 6 . In addition to a conserved arrangement of photosynthesis genes, the A. sensitiva symbiont and R. palustris each contain a bacteriophytochrome regulatory gene that is absent in other purple phototrophs.…”

Section: Phototrophymentioning

confidence: 99%

Complete genome sequence of the metabolically versatile photosynthetic bacterium Rhodopseudomonas palustris

et al. 2003

View full text Add to dashboard Cite

“…Some tropical legumes, such as Sesbania rostrata, are also nodulated on the stem by their rhizobial partners (5). Initiation of symbiosis requires a two-way signal exchange program involving plant compounds and bacterial nodulation (nod) genes (6).…”

mentioning

confidence: 99%

Plant nodulation inducers enhance horizontal gene transfer of Azorhizobium caulinodans symbiosis island

Ling

Wang

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Horizontal gene transfer (HGT) of genomic islands is a driving force of bacterial evolution. Many pathogens and symbionts use this mechanism to spread mobile genetic elements that carry genes important for interaction with their eukaryotic hosts. However, the role of the host in this process remains unclear. Here, we show that plant compounds inducing the nodulation process in the rhizobium-legume mutualistic symbiosis also enhance the transfer of symbiosis islands. We demonstrate that the symbiosis island of the Sesbania rostrata symbiont, Azorhizobium caulinodans, is an 87.6-kb integrative and conjugative element (ICE Ac ) that is able to excise, form a circular DNA, and conjugatively transfer to a specific site of gly-tRNA gene of other rhizobial genera, expanding their host range. The HGT frequency was significantly increased in the rhizosphere. An ICE Aclocated LysR-family transcriptional regulatory protein AhaR triggered the HGT process in response to plant flavonoids that induce the expression of nodulation genes through another LysR-type protein, NodD. Our study suggests that rhizobia may sense rhizosphere environments and transfer their symbiosis gene contents to other genera of rhizobia, thereby broadening rhizobial host-range specificity.horizontal gene transfer | host-range | integrative and conjugative element | naringenin | nodulation

show abstract

Stem Nodulation in Legumes: Diversity, Mechanisms, and Unusual Characteristics

Cited by 67 publications

References 133 publications

Photosynthetic Bradyrhizobia Are Natural Endophytes of the African Wild Rice Oryza breviligulata

Photosynthetic Bradyrhizobia Are Natural Endophytes of the African Wild Rice Oryza breviligulata

Complete genome sequence of the metabolically versatile photosynthetic bacterium Rhodopseudomonas palustris

Plant nodulation inducers enhance horizontal gene transfer of Azorhizobium caulinodans symbiosis island

Contact Info

Product

Resources

About