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Medicago-Sinorhizobium-Ralstonia Co-infection Reveals Legume Nodules as Pathogen Confined Infection Sites Developing Weak Defenses
- Source :
- Current Biology-CB, Current Biology-CB, Elsevier, 2020, 30 (2), pp.351-358. ⟨10.1016/j.cub.2019.11.066⟩, Current Biology-CB, 2020, 30 (2), pp.351-358. ⟨10.1016/j.cub.2019.11.066⟩
- Publication Year :
- 2020
- Publisher :
- HAL CCSD, 2020.
-
Abstract
- Summary Legumes have the capacity to develop root nodules hosting nitrogen-fixing bacteria, called rhizobia. For the plant, the benefit of the symbiosis is important in nitrogen-deprived conditions, but it requires hosting and feeding massive numbers of rhizobia. Recent studies suggest that innate immunity is reduced or suppressed within nodules [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ]; this likely maintains viable rhizobial populations. To evaluate the potential consequences and risks associated with an altered immuni`ty in the symbiotic organ, we developed a tripartite system with the model legume Medicago truncatula [ 11 , 12 ], its nodulating symbiont of the genus Sinorhizobium (syn. Ensifer) [ 13 , 14 ], and the pathogenic soil-borne bacterium Ralstonia solanacearum [ 15 , 16 , 17 , 18 ]. We show that nodules are frequent infection sites where pathogen multiplication is comparable to that in the root tips and independent of nodule ability to fix nitrogen. Transcriptomic analyses indicate that, despite the presence of the hosted rhizobia, nodules are able to develop weak defense reactions against pathogenic R. solanacearum. Nodule defense response displays specificity compared to that activated in roots. In agreement with nodule innate immunity, optimal R. solanacearum growth requires pathogen virulence factors. Finally, our data indicate that the high susceptibility of nodules is counterbalanced by the existence of a diffusion barrier preventing pathogen spreading from nodules to the rest of the plant.
- Subjects :
- 0301 basic medicine
Root nodule
cost of mutualism
[SDV]Life Sciences [q-bio]
legumes
Sinorhizobium
rhizobia
symbiotic organ
General Biochemistry, Genetics and Molecular Biology
Microbiology
Rhizobia
03 medical and health sciences
0302 clinical medicine
Symbiosis
Medicago truncatula
medicine
Plant Immunity
Plant Diseases
Ralstonia solanacearum
Medicago
biology
food and beverages
Nodule (medicine)
[SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology
biochemical phenomena, metabolism, and nutrition
biology.organism_classification
plant pathogen
[SDV.BV.AP]Life Sciences [q-bio]/Vegetal Biology/Plant breeding
030104 developmental biology
[SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology
nitrogen fixation
defense responses
medicine.symptom
General Agricultural and Biological Sciences
Root Nodules, Plant
030217 neurology & neurosurgery
Sinorhizobium meliloti
Subjects
Details
- Language :
- English
- ISSN :
- 09609822 and 18790445
- Database :
- OpenAIRE
- Journal :
- Current Biology-CB, Current Biology-CB, Elsevier, 2020, 30 (2), pp.351-358. ⟨10.1016/j.cub.2019.11.066⟩, Current Biology-CB, 2020, 30 (2), pp.351-358. ⟨10.1016/j.cub.2019.11.066⟩
- Accession number :
- edsair.doi.dedup.....64241442ac443e04c837bf1a208b2f09
- Full Text :
- https://doi.org/10.1016/j.cub.2019.11.066⟩