Characterization of plants expressing the human ß1,4-galactosyltrasferase gene.
Plant Physiol Biochem
; 92: 39-47, 2015 Jul.
Article
em En
| MEDLINE
| ID: mdl-25900423
ABSTRACT
Modification of the plant N-glycosylation pathway towards human type structures is an important strategy to implement plants as expression systems for therapeutic proteins. Nevertheless, relatively little is known about the overall impact of non-plant glycosylation enzymes in stable transformed plants. Here, we analyzed transgenic lines (Nicotiana benthamiana and Arabidopsis thaliana) that stably express a modified version of human ß1,4-galactosyltransferase ((ST)GalT). While some transgenic plants grew normally, other lines exhibited a severe phenotype associated with stunted growth and developmental retardation. The severity of the phenotype correlated with both increased (ST)GalT mRNA and protein levels but no differences were observed between N-glycosylation profiles of plants with and without the phenotype. In contrast to non-transgenic plants, all (ST)GalT expressing plants synthesized significant amounts of incompletely processed (largely depleted of core fucose) N-glycans with up to 40% terminally galactosylated structures. While transgenic plants showed no differences in nucleotide sugar composition and cell wall monosaccharide content, alterations in the reactivity of cell wall carbohydrate epitopes associated with arabinogalactan-proteins and pectic homogalacturonan were detected in (ST)GalT expressing plants. Notably, plants with phenotypic alterations showed increased levels of hydrogen peroxide, most probably a consequence of hypersensitive reactions. Our data demonstrate that unfavorable phenotypical modifications may occur upon stable in planta expression of non-native glycosyltransferases. Such important issues need to be taken into consideration in respect to stable glycan engineering in plants.
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MEDLINE
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Fenótipo
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Polissacarídeos
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Nicotiana
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Plantas Geneticamente Modificadas
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N-Acetil-Lactosamina Sintase
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Arabidopsis
Idioma:
En
Revista:
Plant Physiol Biochem
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Áustria