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Registro Completo |
Biblioteca(s): |
Embrapa Agrobiologia. |
Data corrente: |
24/01/1996 |
Data da última atualização: |
24/01/1996 |
Autoria: |
UMALI-GARCIA, M. |
Título: |
Early events in the establishment of an associative symbiosis of Azospirillum brasilense sp 7 with grass roots. |
Ano de publicação: |
1978 |
Fonte/Imprenta: |
Florida: University of Florida, 1978. |
Páginas: |
103p. |
Série: |
Tese de Doutorado. |
Idioma: |
Inglês |
Notas: |
Tese de Doutorado. Orientada por: David H. Hubbell. |
Conteúdo: |
The objectives of this study were to document by light and electron microscopy the events leading to the successful establishment of an associative symbiosis of Azospirillum brasilense sp 7 with the roots of a grass host under axenic conditions and to define physiological and biochemical interactions of the association suggested by the ultrastructural studies. The association between grass roots and Azospirillum brasilense sp 7 was investigated by the Fahraeus glass slide technique for axenic plant culture. Young inoculated roots of pearl millet and guinea grass produced more mucigel, more root hairs and more lateral roots than did the uninoculated controls. Within 12 h after inoculation cells of A. brasilense sp 7 were embedded in the mucigel at the root capand along the root axis. The bacteria were also firmly adsorbed to root hairs and epidermal cells but supplementing the medium with combined nitrogen reduced the adherence to root hairs. Preincubation in root exudate enhanced ability of the bacteria to attach firmly to root surfaces. The active root exudate factor is non-dialyzable and is inactivated by protease. Examination of the grass rhizosphere by electron microscopy revealed azospirilla enclosed within a slime layer with high affinity for electron dense materials normally associated with the host root cell wall. The bacteria entered the root tissue through lysed root hairs, open spaces created by sloughing of epidermal cells and lateral root emergence, and afterward invaded the middle lamellae of ....... MenosThe objectives of this study were to document by light and electron microscopy the events leading to the successful establishment of an associative symbiosis of Azospirillum brasilense sp 7 with the roots of a grass host under axenic conditions and to define physiological and biochemical interactions of the association suggested by the ultrastructural studies. The association between grass roots and Azospirillum brasilense sp 7 was investigated by the Fahraeus glass slide technique for axenic plant culture. Young inoculated roots of pearl millet and guinea grass produced more mucigel, more root hairs and more lateral roots than did the uninoculated controls. Within 12 h after inoculation cells of A. brasilense sp 7 were embedded in the mucigel at the root capand along the root axis. The bacteria were also firmly adsorbed to root hairs and epidermal cells but supplementing the medium with combined nitrogen reduced the adherence to root hairs. Preincubation in root exudate enhanced ability of the bacteria to attach firmly to root surfaces. The active root exudate factor is non-dialyzable and is inactivated by protease. Examination of the grass rhizosphere by electron microscopy revealed azospirilla enclosed within a slime layer with high affinity for electron dense materials normally associated with the host root cell wall. The bacteria entered the root tissue through lysed root hairs, open spaces created by sloughing of epidermal cells and lateral root emergence, and afterwar... Mostrar Tudo |
Palavras-Chave: |
Methods; Root; Schizomycetos. |
Thesagro: |
Bactéria; Gramínea; Gramineae; Método; Microscopia; Raiz; Rizosfera; Simbiose. |
Thesaurus Nal: |
Azospirillum brasilense; microscopy; rhizosphere; symbiosis. |
Categoria do assunto: |
-- |
Marc: |
LEADER 02415nam a2200325 a 4500 001 1621522 005 1996-01-24 008 1978 bl uuuu m 00u1 u #d 100 1 $aUMALI-GARCIA, M. 245 $aEarly events in the establishment of an associative symbiosis of Azospirillum brasilense sp 7 with grass roots. 260 $aFlorida: University of Florida$c1978 300 $a103p. 490 $aTese de Doutorado. 500 $aTese de Doutorado. Orientada por: David H. Hubbell. 520 $aThe objectives of this study were to document by light and electron microscopy the events leading to the successful establishment of an associative symbiosis of Azospirillum brasilense sp 7 with the roots of a grass host under axenic conditions and to define physiological and biochemical interactions of the association suggested by the ultrastructural studies. The association between grass roots and Azospirillum brasilense sp 7 was investigated by the Fahraeus glass slide technique for axenic plant culture. Young inoculated roots of pearl millet and guinea grass produced more mucigel, more root hairs and more lateral roots than did the uninoculated controls. Within 12 h after inoculation cells of A. brasilense sp 7 were embedded in the mucigel at the root capand along the root axis. The bacteria were also firmly adsorbed to root hairs and epidermal cells but supplementing the medium with combined nitrogen reduced the adherence to root hairs. Preincubation in root exudate enhanced ability of the bacteria to attach firmly to root surfaces. The active root exudate factor is non-dialyzable and is inactivated by protease. Examination of the grass rhizosphere by electron microscopy revealed azospirilla enclosed within a slime layer with high affinity for electron dense materials normally associated with the host root cell wall. The bacteria entered the root tissue through lysed root hairs, open spaces created by sloughing of epidermal cells and lateral root emergence, and afterward invaded the middle lamellae of ....... 650 $aAzospirillum brasilense 650 $amicroscopy 650 $arhizosphere 650 $asymbiosis 650 $aBactéria 650 $aGramínea 650 $aGramineae 650 $aMétodo 650 $aMicroscopia 650 $aRaiz 650 $aRizosfera 650 $aSimbiose 653 $aMethods 653 $aRoot 653 $aSchizomycetos
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Registro original: |
Embrapa Agrobiologia (CNPAB) |
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8. | | ROMBKE, J.; GARCIA, M. Earthworms. In: SHIFT PROJECT ENV 52 (Manaus-AB). Soil fauna and litter decomposition in primary and secondary forests and a mixed culture system in Amazonia. Manaus: SMNK/Embrapa Amazonia Ocidental, 1999. p.152-167 Final Report 1996-1999.Tipo: Capítulo em Livro Técnico-Científico |
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