Two Hydroxyproline Galactosyltransferases, GALT5 and GALT2, Function in Arabinogalactan-Protein Glycosylation, Growth and Development in Arabidopsis
Autor: | Emily Poirier, Kirk Emch, Wuda Wang, Taylor DeBrosse, Lu Tian, Siyi Ma, Debarati Basu, Allan M. Showalter, Eric D Soukup |
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Rok vydání: | 2015 |
Předmět: |
0106 biological sciences
Glycosylation Mutant Arabidopsis lcsh:Medicine Flowers Root hair Galactans Plant Roots 01 natural sciences Pichia Cell wall 03 medical and health sciences Mucoproteins Gene Expression Regulation Plant Arabidopsis thaliana lcsh:Science Plant Proteins 030304 developmental biology Arabinogalactan protein Genetics 0303 health sciences Multidisciplinary biology Arabidopsis Proteins lcsh:R Wild type Galactose Gene Expression Regulation Developmental Galactosyltransferases Plants Genetically Modified biology.organism_classification Cell biology Adenosine Diphosphate Plant Leaves Hydroxyproline Phenotype Mutation lcsh:Q Heterologous expression Research Article 010606 plant biology & botany |
Zdroj: | PLoS ONE, Vol 10, Iss 5, p e0125624 (2015) PLoS ONE |
ISSN: | 1932-6203 |
DOI: | 10.1371/journal.pone.0125624 |
Popis: | Hydroxyproline-O-galactosyltransferase (GALT) initiates O-glycosylation of arabinogalactan-proteins (AGPs). We previously characterized GALT2 (At4g21060), and now report on functional characterization of GALT5 (At1g74800). GALT5 was identified using heterologous expression in Pichia and an in vitro GALT assay. Product characterization showed GALT5 specifically adds galactose to hydroxyproline in AGP protein backbones. Functions of GALT2 and GALT5 were elucidated by phenotypic analysis of single and double mutant plants. Allelic galt5 and galt2 mutants, and particularly galt2 galt5 double mutants, demonstrated lower GALT activities and reductions in β-Yariv-precipitated AGPs compared to wild type. Mutant plants showed pleiotropic growth and development phenotypes (defects in root hair growth, root elongation, pollen tube growth, flowering time, leaf development, silique length, and inflorescence growth), which were most severe in the double mutants. Conditional mutant phenotypes were also observed, including salt-hypersensitive root growth and root tip swelling as well as reduced inhibition of pollen tube growth and root growth in response to β-Yariv reagent. These mutants also phenocopy mutants for an AGP, SOS5, and two cell wall receptor-like kinases, FEI1 and FEI2, which exist in a genetic signaling pathway. In summary, GALT5 and GALT2 function as redundant GALTs that control AGP O-glycosylation, which is essential for normal growth and development. |
Databáze: | OpenAIRE |
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