A galacturonic acid-containing xyloglucan is involved in Arabidopsis root hair tip growth.
Plant Cell
; 24(11): 4511-24, 2012 Nov.
Article
en En
| MEDLINE
| ID: mdl-23175743
ABSTRACT
Root hairs provide a model system to study plant cell growth, yet little is known about the polysaccharide compositions of their walls or the role of these polysaccharides in wall expansion. We report that Arabidopsis thaliana root hair walls contain a previously unidentified xyloglucan that is composed of both neutral and galacturonic acid-containing subunits, the latter containing the ß-D-galactosyluronic acid-(1â2)-α-D-xylosyl-(1â and/or α-L-fucosyl-(1â2)-ß-D-galactosyluronic acid-(1â2)-α-D-xylosyl-(1â) side chains. Arabidopsis mutants lacking root hairs have no acidic xyloglucan. A loss-of-function mutation in At1g63450, a root hair-specific gene encoding a family GT47 glycosyltransferase, results in the synthesis of xyloglucan that lacks galacturonic acid. The root hairs of this mutant are shorter than those of the wild type. This mutant phenotype and the absence of galacturonic acid in the root xyloglucan are complemented by At1g63450. The leaf and stem cell walls of wild-type Arabidopsis contain no acidic xyloglucan. However, overexpression of At1g63450 led to the synthesis of galacturonic acid-containing xyloglucan in these tissues. We propose that At1g63450 encodes XYLOGLUCAN-SPECIFIC GALACTURONOSYLTRANSFERASE1, which catalyzes the formation of the galactosyluronic acid-(1â2)-α-D-xylopyranosyl linkage and that the acidic xyloglucan is present only in root hair cell walls. The role of the acidic xyloglucan in root hair tip growth is discussed.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Xilanos
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Arabidopsis
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Raíces de Plantas
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Regulación de la Expresión Génica de las Plantas
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Proteínas de Arabidopsis
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Glucanos
Idioma:
En
Revista:
Plant Cell
Asunto de la revista:
BOTANICA
Año:
2012
Tipo del documento:
Article
País de afiliación:
Estados Unidos