Manganese transport is essential for N2 -fixation by Rhizobium leguminosarum in bacteroids from galegoid but not phaseoloid nodules.
Environ Microbiol
; 19(7): 2715-2726, 2017 07.
Article
en En
| MEDLINE
| ID: mdl-28447383
ABSTRACT
Rhizobium leguminosarum has two high-affinity Mn2+ transport systems encoded by sitABCD and mntH. In symbiosis, sitABCD and mntH were expressed throughout nodules and also strongly induced in Mn2+ -limited cultures of free-living cells. Growth of a sitA mntH double mutant was severely reduced under Mn2+ limitation and sitA and mntH single mutants were more sensitive to oxidative stress. The double sitA mntH mutant of R. leguminosarum was unable to fix nitrogen (Fix- ) with legumes belonging to the galegoid clade (Pisum sativum, Vicia faba and Vicia hirsuta). The presence of infection thread-like structures and sparsely-packed plant cells in nodules suggest that bacteroid development was blocked, either at a late stage of infection thread progression or during bacteroid-release. In contrast, a double sitA mntH mutant was Fix+ on common bean (Phaseoli vulgaris), a member of the phaseoloid clade of legumes, indicating a host-specific symbiotic requirement for Mn2+ transport.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Rhizobium leguminosarum
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Pisum sativum
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Fabaceae
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Manganeso
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Fijación del Nitrógeno
Idioma:
En
Año:
2017
Tipo del documento:
Article