Publications des scientifiques de l'IRD

Teulet A., Busset N., Fardoux Joël, Gully Djamel, Chaintreuil Clémence, Cartieaux Fabienne, Jauneau A., Comorge V., Okazaki S., Kaneko T., Gressent F., Nouwen Nico, Arrighi Jean-François, Koebnik Ralf, Mergaert P., Deslandes L., Giraud Eric. (2019). The rhizobial type III effector ErnA confers the ability to form nodules in legumes. Proceedings of the National Academy of Sciences of the United States of America, 116 (43), p. 21758-21768. ISSN 0027-8424.

Titre du document
The rhizobial type III effector ErnA confers the ability to form nodules in legumes
Année de publication
2019
Type de document
Article référencé dans le Web of Science WOS:000491366700061
Auteurs
Teulet A., Busset N., Fardoux Joël, Gully Djamel, Chaintreuil Clémence, Cartieaux Fabienne, Jauneau A., Comorge V., Okazaki S., Kaneko T., Gressent F., Nouwen Nico, Arrighi Jean-François, Koebnik Ralf, Mergaert P., Deslandes L., Giraud Eric
Source
Proceedings of the National Academy of Sciences of the United States of America, 2019, 116 (43), p. 21758-21768 ISSN 0027-8424
Several Bradyrhizobium species nodulate the leguminous plant Aeschynomene indica in a type III secretion system-dependent manner, independently of Nod factors. To date, the underlying molecular determinants involved in this symbiotic process remain unknown. To identify the rhizobial effectors involved in nodulation, we mutated 23 out of the 27 effector genes predicted in Bradyrhizobium strain ORS3257. The mutation of nopAO increased nodulation and nitrogenase activity, whereas mutation of 5 other effector genes led to various symbiotic defects. The nopM1 and nopP1 mutants induced a reduced number of nodules, some of which displayed large necrotic zones. The nopT and nopAB mutants induced uninfected nodules, and a mutant in a yet-undescribed effector gene lost the capacity for nodule formation. This effector gene, widely conserved among bradyrhizobia, was named ernA for "effector required for nodulation-A." Remarkably, expressing ernA in a strain unable to nodulate A. indica conferred nodulation ability. Upon its delivery by Pseudomonas fluorescens into plant cells, ErnA was specifically targeted to the nucleus, and a fluorescence resonance energy transfer-fluorescence lifetime imaging microscopy approach supports the possibility that ErnA binds nucleic acids in the plant nuclei. Ectopic expression of ernA in A. indica roots activated organogenesis of root- and nodule-like structures. Collectively, this study unravels the symbiotic functions of rhizobial type III effectors playing distinct and complementary roles in suppression of host immune functions, infection, and nodule organogenesis, and suggests that ErnA triggers organ development in plants by a mechanism that remains to be elucidated.
Plan de classement
Sciences du monde végétal [076] ; Biotechnologies [084]
Localisation
Fonds IRD [F B010077167]
Identifiant IRD
fdi:010077167
Contact