Medicago-Sinorhizobium-Ralstonia: A Model System to Investigate Pathogen-Triggered Inhibition of Nodulation
How plants deal with beneficial and pathogenic microorganisms and how they can tolerate beneficial ones and face pathogens at the same time are questions that remain puzzling to plant biologists. Legume plants are good models to explore those issues, as their interactions with nitrogen-fixing bacter...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
The American Phytopathological Society
2021-06-01
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| Series: | Molecular Plant-Microbe Interactions |
| Online Access: | https://doi.org/10.1094/MPMI-11-20-0319-SC |
| Summary: | How plants deal with beneficial and pathogenic microorganisms and how they can tolerate beneficial ones and face pathogens at the same time are questions that remain puzzling to plant biologists. Legume plants are good models to explore those issues, as their interactions with nitrogen-fixing bacteria called rhizobia results in a drastic and easy-to-follow phenotype of nodulation. Intriguingly, despite massive and chronic infection, legume defense reactions are essentially suppressed during the whole symbiotic process, raising a question about a potential negative effect of plant immune responses on the establishment of nodulation. In the present study, we used the model legume, Medicago truncatula, coinoculated with mutualistic and phytopathogenic bacteria, Sinorhizobium medicae and Ralstonia solanacearum, respectively. We show that the presence of R. solanacearum drastically inhibits the nodulation process. The type III secretion system of R. solanacearum, which is important for the inhibition of pathogen-associated molecular pattern–triggered immunity (PTI), strongly contributes to inhibit nodulation. Thus, our results question the negative effect of PTI on nodulation. By including a pathogenic bacterium in the interaction system, our study provides a new angle to address the influence of the biotic environment on the nodulation process. |
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| ISSN: | 0894-0282 1943-7706 |