Dissecting the role of NtrC and RpoN in the expression of assimilatory nitrate and nitrite reductases in Bradyrhizobium diazoefficiens

Autores
López, María Florencia; Cabrera, Juan J.; Salas, Ana; Delgado, María J.; López García, Silvina Laura
Año de publicación
2017
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Bradyrhizobium diazoefficiens, a nitrogen- fixing endosymbiont of soybeans, is a model strain for studying rhizobial denitrification. This bacterium can also use nitrate as the sole nitrogen (N) source during aerobic growth by inducing an assimilatory nitrate reductase encoded by nasC located within the narK-bjgb-flp-nasC operon along with a nitrite reductase encoded by nirA at a different chromosomal locus. The global nitrogen two-component regulatory system NtrBC has been reported to coordinate the expression of key enzymes in nitrogen metabolism in several bacteria. In this study, we demonstrate that disruption of ntrC caused a growth defect in B. diazoefficiens cells in the presence of nitrate or nitrite as the sole N source and a decreased activity of the nitrate and nitrite reductase enzymes. Furthermore, the expression of narK-lacZor nirA-lacZ transcriptional fusions was significantly reduced in the ntrC mutant after incubation under nitrate assimilation conditions. AB. diazoefficiens rpoN 1/2 mutant, lacking both copies of the gene encoding the alternative sigma factor σ54, was also defective in aerobic growth with nitrate as the N source as well as in nitrate and nitrite reductase expression. These results demonstrate that the NtrC regulator is required for expression of the B. diazoefficiens nasC and nirA genes and that the sigma factor RpoN is also involved in this regulation.
Instituto de Biotecnologia y Biologia Molecular
Materia
Biología
Alternative sigma factor
Bradyrhizobium
Nitrate assimilation
Two-component-regulatory system
Nitrate reductase
Nitrite reductase
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc-sa/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/103754

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network_name_str SEDICI (UNLP)
spelling Dissecting the role of NtrC and RpoN in the expression of assimilatory nitrate and nitrite reductases in Bradyrhizobium diazoefficiensLópez, María FlorenciaCabrera, Juan J.Salas, AnaDelgado, María J.López García, Silvina LauraBiologíaAlternative sigma factorBradyrhizobiumNitrate assimilationTwo-component-regulatory systemNitrate reductaseNitrite reductaseBradyrhizobium diazoefficiens, a nitrogen- fixing endosymbiont of soybeans, is a model strain for studying rhizobial denitrification. This bacterium can also use nitrate as the sole nitrogen (N) source during aerobic growth by inducing an assimilatory nitrate reductase encoded by nasC located within the narK-bjgb-flp-nasC operon along with a nitrite reductase encoded by nirA at a different chromosomal locus. The global nitrogen two-component regulatory system NtrBC has been reported to coordinate the expression of key enzymes in nitrogen metabolism in several bacteria. In this study, we demonstrate that disruption of ntrC caused a growth defect in B. diazoefficiens cells in the presence of nitrate or nitrite as the sole N source and a decreased activity of the nitrate and nitrite reductase enzymes. Furthermore, the expression of narK-lacZor nirA-lacZ transcriptional fusions was significantly reduced in the ntrC mutant after incubation under nitrate assimilation conditions. AB. diazoefficiens rpoN 1/2 mutant, lacking both copies of the gene encoding the alternative sigma factor σ54, was also defective in aerobic growth with nitrate as the N source as well as in nitrate and nitrite reductase expression. These results demonstrate that the NtrC regulator is required for expression of the B. diazoefficiens nasC and nirA genes and that the sigma factor RpoN is also involved in this regulation.Instituto de Biotecnologia y Biologia Molecular2017info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf531-542http://sedici.unlp.edu.ar/handle/10915/103754enginfo:eu-repo/semantics/altIdentifier/issn/1572-9699info:eu-repo/semantics/altIdentifier/doi/10.1007/s10482-016-0821-3info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-03T10:54:48Zoai:sedici.unlp.edu.ar:10915/103754Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-03 10:54:49.021SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Dissecting the role of NtrC and RpoN in the expression of assimilatory nitrate and nitrite reductases in Bradyrhizobium diazoefficiens
title Dissecting the role of NtrC and RpoN in the expression of assimilatory nitrate and nitrite reductases in Bradyrhizobium diazoefficiens
spellingShingle Dissecting the role of NtrC and RpoN in the expression of assimilatory nitrate and nitrite reductases in Bradyrhizobium diazoefficiens
López, María Florencia
Biología
Alternative sigma factor
Bradyrhizobium
Nitrate assimilation
Two-component-regulatory system
Nitrate reductase
Nitrite reductase
title_short Dissecting the role of NtrC and RpoN in the expression of assimilatory nitrate and nitrite reductases in Bradyrhizobium diazoefficiens
title_full Dissecting the role of NtrC and RpoN in the expression of assimilatory nitrate and nitrite reductases in Bradyrhizobium diazoefficiens
title_fullStr Dissecting the role of NtrC and RpoN in the expression of assimilatory nitrate and nitrite reductases in Bradyrhizobium diazoefficiens
title_full_unstemmed Dissecting the role of NtrC and RpoN in the expression of assimilatory nitrate and nitrite reductases in Bradyrhizobium diazoefficiens
title_sort Dissecting the role of NtrC and RpoN in the expression of assimilatory nitrate and nitrite reductases in Bradyrhizobium diazoefficiens
dc.creator.none.fl_str_mv López, María Florencia
Cabrera, Juan J.
Salas, Ana
Delgado, María J.
López García, Silvina Laura
author López, María Florencia
author_facet López, María Florencia
Cabrera, Juan J.
Salas, Ana
Delgado, María J.
López García, Silvina Laura
author_role author
author2 Cabrera, Juan J.
Salas, Ana
Delgado, María J.
López García, Silvina Laura
author2_role author
author
author
author
dc.subject.none.fl_str_mv Biología
Alternative sigma factor
Bradyrhizobium
Nitrate assimilation
Two-component-regulatory system
Nitrate reductase
Nitrite reductase
topic Biología
Alternative sigma factor
Bradyrhizobium
Nitrate assimilation
Two-component-regulatory system
Nitrate reductase
Nitrite reductase
dc.description.none.fl_txt_mv Bradyrhizobium diazoefficiens, a nitrogen- fixing endosymbiont of soybeans, is a model strain for studying rhizobial denitrification. This bacterium can also use nitrate as the sole nitrogen (N) source during aerobic growth by inducing an assimilatory nitrate reductase encoded by nasC located within the narK-bjgb-flp-nasC operon along with a nitrite reductase encoded by nirA at a different chromosomal locus. The global nitrogen two-component regulatory system NtrBC has been reported to coordinate the expression of key enzymes in nitrogen metabolism in several bacteria. In this study, we demonstrate that disruption of ntrC caused a growth defect in B. diazoefficiens cells in the presence of nitrate or nitrite as the sole N source and a decreased activity of the nitrate and nitrite reductase enzymes. Furthermore, the expression of narK-lacZor nirA-lacZ transcriptional fusions was significantly reduced in the ntrC mutant after incubation under nitrate assimilation conditions. AB. diazoefficiens rpoN 1/2 mutant, lacking both copies of the gene encoding the alternative sigma factor σ54, was also defective in aerobic growth with nitrate as the N source as well as in nitrate and nitrite reductase expression. These results demonstrate that the NtrC regulator is required for expression of the B. diazoefficiens nasC and nirA genes and that the sigma factor RpoN is also involved in this regulation.
Instituto de Biotecnologia y Biologia Molecular
description Bradyrhizobium diazoefficiens, a nitrogen- fixing endosymbiont of soybeans, is a model strain for studying rhizobial denitrification. This bacterium can also use nitrate as the sole nitrogen (N) source during aerobic growth by inducing an assimilatory nitrate reductase encoded by nasC located within the narK-bjgb-flp-nasC operon along with a nitrite reductase encoded by nirA at a different chromosomal locus. The global nitrogen two-component regulatory system NtrBC has been reported to coordinate the expression of key enzymes in nitrogen metabolism in several bacteria. In this study, we demonstrate that disruption of ntrC caused a growth defect in B. diazoefficiens cells in the presence of nitrate or nitrite as the sole N source and a decreased activity of the nitrate and nitrite reductase enzymes. Furthermore, the expression of narK-lacZor nirA-lacZ transcriptional fusions was significantly reduced in the ntrC mutant after incubation under nitrate assimilation conditions. AB. diazoefficiens rpoN 1/2 mutant, lacking both copies of the gene encoding the alternative sigma factor σ54, was also defective in aerobic growth with nitrate as the N source as well as in nitrate and nitrite reductase expression. These results demonstrate that the NtrC regulator is required for expression of the B. diazoefficiens nasC and nirA genes and that the sigma factor RpoN is also involved in this regulation.
publishDate 2017
dc.date.none.fl_str_mv 2017
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
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info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/103754
url http://sedici.unlp.edu.ar/handle/10915/103754
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/1572-9699
info:eu-repo/semantics/altIdentifier/doi/10.1007/s10482-016-0821-3
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
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531-542
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