Publications des scientifiques de l'IRD

Okazaki S., Tittabutr P., Teulet A., Thouin J., Fardoux Joël, Chaintreuil Clémence, Gully Djamel, Arrighi Jean-François, Furuta N., Miwa H., Yasuda M., Nouwen Nico, Teaumroong N., Giraud Eric. (2015). Rhizobium-legume symbiosis in the absence of Nod factors : two possible scenarios with or without the T3SS. ISME Journal, 10 juillet, 11 p. ISSN 1751-7362.

Titre du document
Rhizobium-legume symbiosis in the absence of Nod factors : two possible scenarios with or without the T3SS
Année de publication
2015
Type de document
Article référencé dans le Web of Science WOS:000366667130008
Auteurs
Okazaki S., Tittabutr P., Teulet A., Thouin J., Fardoux Joël, Chaintreuil Clémence, Gully Djamel, Arrighi Jean-François, Furuta N., Miwa H., Yasuda M., Nouwen Nico, Teaumroong N., Giraud Eric
Source
ISME Journal, 2015, 10 juillet, 11 p. ISSN 1751-7362
The occurrence of alternative Nod factor (NF)-independent symbiosis between legumes and rhizobia was first demonstrated in some Aeschynomene species that are nodulated by photosynthetic bradyrhizobia lacking the canonical nodABC genes. In this study, we revealed that a large diversity of non-photosynthetic bradyrhizobia, including B. elkanii, was also able to induce nodules on the NFindependent Aeschynomene species, A. indica. Using cytological analysis of the nodules and the nitrogenase enzyme activity as markers, a gradient in the symbiotic interaction between bradyrhizobial strains and A. indica could be distinguished. This ranged from strains that induced nodules that were only infected intercellularly to rhizobial strains that formed nodules in which the host cells were invaded intracellularly and that displayed a weak nitrogenase activity. In all nonphotosynthetic bradyrhizobia, the type III secretion system (T3SS) appears required to trigger nodule organogenesis. In contrast, genome sequence analysis revealed that apart from a few exceptions, like the Bradyrhizobium ORS285 strain, photosynthetic bradyrhizobia strains lack a T3SS. Furthermore, analysis of the symbiotic properties of an ORS285 T3SS mutant revealed that the T3SS could have a positive or negative role for the interaction with NF-dependent Aeschynomene species, but that it is dispensable for the interaction with all NF-independent Aeschynomene species tested. Taken together, these data indicate that two NF-independent symbiotic processes are possible between legumes and rhizobia: one dependent on a T3SS and one using a so far unknown mechanism.
Plan de classement
Nodosités [084SYMBIO01]
Descripteurs
LEGUMINEUSE ; SYMBIOSE ; NODOSITE VEGETALE ; NODULE RACINAIRE ; GENE ; ENZYME ; NITROGENASE
Localisation
Fonds IRD [F B010065109]
Identifiant IRD
fdi:010065109
Contact