Journal Article

O-Glycosylated Cell Wall Proteins Are Essential in Root Hair Growth

Verli, Hugo, Egelund, Jack, Somerville, Chris, Bacic, Antony, Ulvskov, Peter, Iusem, Norberto D., Dorosz, Javier Gloazzo, Olsen, Carl Erik, Harholt, Jesper, Ciancia, Marina, Fernandez, Paula V., Pauly, Markus, Gille, Sascha, Ricardi, Martiniano M., Pol-Fachin, Laercio, Estevez, Jose M., Nadra, Alejandro D., Velasquez, Silvia M., Petersen, Bent Larsen

2011

Overview

Root hairs are single cells that develop by tip growth and are specialized in the absorption of nutrients. Their cell walls are composed of polysaccharides and hydroxyproline-rich glycoproteins (HRGPs) that include extensins (EXTs) and arabinogalactan-proteins (AGPs). Proline hydroxylation, an early posttranslational modification of HRGPs that is catalyzed by prolyl 4-hydroxylases (P4Hs), defines the subsequent O-glycosylation sites in EXTs (which are mainly arabinosylated) and AGPs (which are mainly arabinogalactosylated). We explored the biological function of P4Hs, arabinosyltransferases, and EXTs in root hair cell growth. Biochemical inhibition or genetic disruption resulted in the blockage of polarized growth in root hairs and reduced arabinosylation of EXTs. Our results demonstrate that correct O-glycosylation on EXTs is essential for cell-wall self-assembly and, hence, root hair elongation in Arabidopsis thaliana.

• Publisher: American Association for the Advancement of Science,The American Association for the Advancement of Science
• Subject: absorption / Arabidopsis - genetics / Arabidopsis - growth & development / Arabidopsis - metabolism / Arabidopsis Proteins - chemistry / Arabidopsis Proteins - genetics / Arabidopsis Proteins - metabolism / Arabidopsis thaliana / Arabinose - metabolism / Biochemistry / Biological and medical sciences / Blockage / Carbohydrate Conformation / Cell growth / Cell Wall - metabolism / Cell walls / Elongation / Enzymes / Fundamental and applied biological sciences. Psychology / Gene Expression Regulation, Plant / Genes, Plant / Genetics / Glycoproteins / Glycoproteins - chemistry / Glycoproteins - metabolism / Glycosylation / Glycosyltransferases - genetics / Glycosyltransferases - metabolism / Hair / Hair cells / Hydroxylation / Hydroxyproline - metabolism / Models, Biological / Mutation / nutrients / Pentosyltransferases - chemistry / Pentosyltransferases - metabolism / Phenotype / Phenotypes / Plant cells / Plant physiology and development / Plant Proteins - chemistry / Plant Proteins - metabolism / Plant Roots - cytology / Plant Roots - growth & development / Plant Roots - metabolism / Plants / Polysaccharides / Polysaccharides - chemistry / post-translational modification / Procollagen-Proline Dioxygenase - genetics / Procollagen-Proline Dioxygenase - metabolism / Proline - metabolism / Protein Conformation / Protein Processing, Post-Translational / Protein Structure, Secondary / Root hairs / Roots / Saccharides / Self assembly / structural proteins / Walls