<i>Rhizobium meliloti</i> exopolysaccharide mutants elicit feedback regulation of nodule formation in alfalfa

Nodule formation by wild-type Rhizobium meliloti is strongly suppressed in younger parts of alfalfa (Medicago sativum L.) root systems as a feedback response to development of the first nodules (G Caetano-Anolles, WD Bauer [1988] Planta 175: 546-557). Mutants of R. meliloti deficient in exopolysacch...

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Detalles Bibliográficos
Autores principales: Caetano Anollés, Gustavo, Lagares, Antonio, Bauer, Wolfgang D.
Formato: Articulo
Lenguaje:Inglés
Publicado: 1990
Materias:
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/123085
Aporte de:
id I19-R120-10915-123085
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Biología
Mutant
Inoculation
Wild type
Magnoliopsida
Medicago
Rhizobiaceae
Rhizobium
Bacteria
Biology
Microbiology
spellingShingle Biología
Mutant
Inoculation
Wild type
Magnoliopsida
Medicago
Rhizobiaceae
Rhizobium
Bacteria
Biology
Microbiology
Caetano Anollés, Gustavo
Lagares, Antonio
Bauer, Wolfgang D.
<i>Rhizobium meliloti</i> exopolysaccharide mutants elicit feedback regulation of nodule formation in alfalfa
topic_facet Biología
Mutant
Inoculation
Wild type
Magnoliopsida
Medicago
Rhizobiaceae
Rhizobium
Bacteria
Biology
Microbiology
description Nodule formation by wild-type Rhizobium meliloti is strongly suppressed in younger parts of alfalfa (Medicago sativum L.) root systems as a feedback response to development of the first nodules (G Caetano-Anolles, WD Bauer [1988] Planta 175: 546-557). Mutants of R. meliloti deficient in exopolysaccharide synthesis can induce the formation of organized nodular structures (pseudonodules) on alfalfa roots but are defective in their ability to invade and multiply within host tissues. The formation of empty pseudonodules by exo mutants was found to elicit a feedback suppression of nodule formation similar to that elicited by the wild-type bacteria. Inoculation of an exo mutant onto one side of a split-root system 24 hours before inoculation of the second side with wild-type cells suppressed wild-type nodule formation on the second side in proportion to the extent of pseudonodule formation by the exo mutants. The formation of pseudonodules is thus sufficient to elicit systemic feedback control of nodulation in the host root system: infection thread development and internal proliferation of the bacteria are not required for elicitation of feedback. Pseudonodule formation by the exo mutants was found to be strongly suppressed in split-root systems by prior inoculation on the opposite side with the wild type. Thus, feedback control elicited by the wild-type inhibits Rhizobium-induced redifferentiation of host root cells.
format Articulo
Articulo
author Caetano Anollés, Gustavo
Lagares, Antonio
Bauer, Wolfgang D.
author_facet Caetano Anollés, Gustavo
Lagares, Antonio
Bauer, Wolfgang D.
author_sort Caetano Anollés, Gustavo
title <i>Rhizobium meliloti</i> exopolysaccharide mutants elicit feedback regulation of nodule formation in alfalfa
title_short <i>Rhizobium meliloti</i> exopolysaccharide mutants elicit feedback regulation of nodule formation in alfalfa
title_full <i>Rhizobium meliloti</i> exopolysaccharide mutants elicit feedback regulation of nodule formation in alfalfa
title_fullStr <i>Rhizobium meliloti</i> exopolysaccharide mutants elicit feedback regulation of nodule formation in alfalfa
title_full_unstemmed <i>Rhizobium meliloti</i> exopolysaccharide mutants elicit feedback regulation of nodule formation in alfalfa
title_sort <i>rhizobium meliloti</i> exopolysaccharide mutants elicit feedback regulation of nodule formation in alfalfa
publishDate 1990
url http://sedici.unlp.edu.ar/handle/10915/123085
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AT lagaresantonio irhizobiummelilotiiexopolysaccharidemutantselicitfeedbackregulationofnoduleformationinalfalfa
AT bauerwolfgangd irhizobiummelilotiiexopolysaccharidemutantselicitfeedbackregulationofnoduleformationinalfalfa
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