RICARDI Martiniano Maria
O-glycosylated cell wall proteins are essential in root hair growth
SILVIA M. VELASQUEZ; MARTINIANO M. RICARDI; JAVIER GLOAZZO DOROSZ1; PAULA V. FERNANDEZ; ALEJANDRO D. NADRA; LAERCIO POL-FACHIN; JACK EGELUND; SASCHA GILLE; JESPER HARHOL; MARINA CIANCIA; HUGO VERLI; MARKUS PAULY; ANTONY BACIC; CARL ERIK OLSEN; PETER ULVSKOV; BENT LARSEN PETERSEN; CHRIS SOMERVILLE; NORBERTO D. IUSEM; JOSE M. ESTEVEZ
AMER ASSOC ADVANCEMENT SCIENCE
Año: 2011 p. 1401 - 1403
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 post-translational modification of HRGPs that is catalyzed by prolyl 4-hydroxylases (P4Hs), defines the subsequent O-glycosylation sites in EXTs (mainly arabinosylation) and AGPs (arabinogalactosylation). Here, 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.