DNA double-strand break repair is involved in desiccation resistance of Sinorhizobium meliloti, but is not essential for its symbiotic interaction with Medicago truncatula
In: Microbiology Microbiology, Microbiology Society, 2017, 163 (3), pp.333-342. ⟨10.1099/mic.0.000400⟩; (2017)
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Zugriff:
The soil bacterium Sinorhizobium meliloti, a nitrogen-fixing symbiont of legume plants, is exposed to numerous stress conditions in nature, some of which cause the formation of harmful DNA double-strand breaks (DSBs). In particular, the reactive oxygen species (ROS) and the reactive nitrogen species (RNS) produced during symbiosis, and the desiccation occurring in dry soils, are conditions which induce DSBs. Two major systems of DSB repair are known in S. meliloti: homologous recombination (HR) and non-homologous end-joining (NHEJ). However, their role in the resistance to ROS, RNS and desiccation has never been examined in this bacterial species, and the importance of DSB repair in the symbiotic interaction has not been properly evaluated. Here, we constructed S. meliloti strains deficient in HR (by deleting the recA gene) or in NHEJ (by deleting the four ku genes) or both. Interestingly, we observed that ku and/ or recA genes are involved in S. meliloti resistance to ROS and RNS. Nevertheless, an S. meliloti strain deficient in both HR and NHEJ was not altered in its ability to establish and maintain an efficient nitrogen-fixing symbiosis with Medicago truncatula, showing that rhizobial DSB repair is not essential for this process. This result suggests either that DSB formation in S. meliloti is efficiently prevented during symbiosis or that DSBs are not detrimental for symbiosis efficiency. In contrast, we found for the first time that both recA and ku genes are involved in S. meliloti resistance to desiccation, suggesting that DSB repair could be important for rhizobium persistence in the soil.
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DNA double-strand break repair is involved in desiccation resistance of Sinorhizobium meliloti, but is not essential for its symbiotic interaction with Medicago truncatula
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Autor/in / Beteiligte Person: | Bruand, Claude ; Dupuy, Pierre ; Sauviac, Laurent ; Gourion, Benjamin ; Laboratoire des interactions plantes micro-organismes (LIPM) ; Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA) ; Departement Sante des Plantes et Environnement of, INRA ; ANR grant 'STAYPINK' : ANR-15-CE20-0005 ; French Laboratory of Excellence project 'TULIP' : ANR-10-LABX-41, ANR-11-IDEX-0002-02 ; Contrat Jeune Scientifique from, INRA ; Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS) |
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Quelle: | Microbiology Microbiology, Microbiology Society, 2017, 163 (3), pp.333-342. ⟨10.1099/mic.0.000400⟩; (2017) |
Veröffentlichung: | HAL CCSD, 2017 |
Medientyp: | unknown |
ISSN: | 1350-0872 (print) ; 1465-2080 (print) |
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