title: Identification of the Abundant Hydroxyproline-Rich Glycoproteins in the Root Walls of Wild-Type Arabidopsis, an ext3 Mutant Line, and Its Phenotypic Revertant.
abstract: Extensins are members of the cell wall hydroxyproline-rich glycoprotein (HRGP) superfamily that form covalently cross-linked networks in primary cell walls. A knockout mutation in EXT3 (AT1G21310), the gene coding EXTENSIN 3 (EXT3) in Arabidopsis Landsberg erecta resulted in a lethal phenotype, although about 20% of the knockout plants have an apparently normal phenotype (ANP). In this study the root cell wall HRGP components of wild-type, ANP and the ext3 mutant seedlings were characterized by peptide fractionation of trypsin digested anhydrous hydrogen fluoride deglycosylated wall residues and by sequencing using LC-MS/MS. Several HRGPs, including EXT3, were identified in the wild-type root walls but not in walls of the ANP and lethal mutant. Indeed the ANP walls and walls of mutants displaying the lethal phenotype possessed HRGPs, but the profiles suggest that changes in the amount and perhaps type may account for the corresponding phenotypes.
authors.affiliation: Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701, USA. yuc27@psu.edu.
authors.forename: Yuning
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701, USA. Boxofjacky@gmail.com.
authors.forename: Dening
authors.initials: D
authors.lastname: Ye
authors.affiliation: Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701, USA. held@ohio.edu.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Held
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA. mcannon@biochem.umass.edu.
authors.forename: Maura C
authors.initials: MC
authors.lastname: Cannon
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA. tuiray76@gmail.com.
authors.forename: Tui
authors.initials: T
authors.lastname: Ray
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA. sahap76@gmail.com.
authors.forename: Prasenjit
authors.initials: P
authors.lastname: Saha
authors.affiliation: Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701, USA. af844006@gmail.com.
authors.forename: Alexandra N
authors.initials: AN
authors.lastname: Frye
authors.affiliation: Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA. Andrew.mort@okstate.edu.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Mort
authors.affiliation: Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701, USA. kielisze@helios.phy.ohiou.edu.
authors.forename: Marcia J
authors.initials: MJ
authors.lastname: Kieliszewski
keywords: Arabidopsis root; Extensin 3; LRX; PRP4; cell wall; hydroxyproline-rich glycoprotein; proteomics