Journal article

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

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

Science | AMER ASSOC ADVANCEMENT SCIENCE | Published : 2011

Abstract

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 block..

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University of Melbourne Researchers

Grants

Awarded by Agencia Nacional de Promocion Cientifica y Tecnologica (ANPCyT)


Awarded by CONICET


Awarded by Danish Agency for Science Technology and Innovation


Awarded by U.S. Department of Energy


Awarded by Villum Fonden


Funding Acknowledgements

We thank R. A. Fernandez for his assistance in confocal microscopy, S. Maldonado and S. Petrucelli for providing the access to a stereoscope, and A. Nebenfuhr for providing vectors of the ER and Golgi markers. This work was supported by grants from Agencia Nacional de Promocion Cientifica y Tecnologica (ANPCyT) (PICT2007-732 and PICT2006-983) and CONICET (PIP2812, PIP0890, and PIP0071) to A.D.N., N.D.I., and J.M.E.; from the Danish Agency for Science Technology and Innovation from the Danish Agency for Science Technology and Innovation (274-09-0082, 2101-07-0071) to J.E, P.U., and B.L.P; from the Australian Research Council to A.B.; and Conselho Nacional de Desinvolvimento Cientific e Tecnologico (CNPq) and Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) to L.F. and H.V. We thank Arabidopsis Biological Resource Center (Ohio University) for providing T-DNA lines seed lines. Thanks to K. Kobayashi and M. Otegui for critical reading of the manuscript. This work was partially supported by a grant from the U.S. Department of Energy (DOE-FG02-03ER20133) and funding from the Energy Biosciences Institute to C.S. S.M.V. performed most of the experiments. M.M.R. analyzed and performed some of the experiments and analyzed the data. J.G.D. performed some of the experiments. P.V.F and M.C. quantified Hyp in mutants and transgenic lines. S.G. and M.P. provided the XEG113-GFP data and xeg113-2 mutant. A.D.N. performed molecular modeling of P4Hs. L.F. and H.V. measured the molecular dynamics of EXT peptides. J.E. and A.B. assessed the Golgi localization of RRAs proteins. C.E.O., P.U., and B.L.P. characterized rra3 and xeg113 EXTs using ESI-MS, and P.U. and B.L.P. isolated rra1-3 RNAi and rra3 mutants. C.S. analyzed the data. N.D.I. analyzed the data and wrote the paper. J.M.E. designed research, performed most of the experiments, analyzed the data, supervised the project, and wrote the paper. The authors declare no competing financial interests.