N-deacetylation of Sinorhizobium meliloti Nod factors increases their stability in the Medicago sativa rhizosphere and decreases their biological activity.
Mol Plant Microbe Interact
; 13(1): 72-9, 2000 Jan.
Article
em En
| MEDLINE
| ID: mdl-10656587
ABSTRACT
Nod factors excreted by rhizobia are signal molecules that consist of a chitin oligomer backbone linked with a fatty acid at the nonreducing end. Modifications of the Nod factor structures influence their stability in the rhizosphere and their biological activity. To test the function of N-acetyl groups in Nod factors, NodSm-IV(C162,S) from Sinorhizobium meliloti was enzymatically N-deacetylated in vitro with purified chitin deacetylase from Colletotrichum lindemuthianum. A family of partially and completely deacetylated derivatives was produced and purified. The most abundant chemical structures identified by mass spectrometry were GlcN(C162)-GlcNAc-GlcNH2-GlcNAc(OH)(S), GlcN(C16,2)-GlcNAc-GlcNH2-GlcNH2(OH)(S), and GlcN(C162)-GlcNH2-GlcNH2-GlcNH2(OH)(S). In contrast to NodSm-IV(C162,S), the purified N-deacetylated derivatives were stable in the rhizosphere of Medicago sativa, indicating that the N-acetyl groups make the carbohydrate moiety of Nod factors accessible for glycosyl hydrolases of the host plant. The N-deacetylated derivatives displayed only a low level of activity in inducing root hair deformation. Furthermore, the N-deacetylated molecules were not able to stimulate Nod factor degradation by M. sativa roots, a response elicited by active Nod factors. These data show that N-acetyl groups of Nod factors are required for biological activity.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oligossacarídeos
/
Sinorhizobium meliloti
/
Medicago sativa
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Mol Plant Microbe Interact
Assunto da revista:
BIOLOGIA MOLECULAR
/
BOTANICA
/
MICROBIOLOGIA
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
França