title: Accumulation of N-acetylglucosamine oligomers in the plant cell wall affects plant architecture in a dose-dependent and conditional manner.
abstract: To study the effect of short N-acetylglucosamine (GlcNAc) oligosaccharides on the physiology of plants, N-ACETYLGLUCOSAMINYLTRANSFERASE (NodC) of Azorhizobium caulinodans was expressed in Arabidopsis (Arabidopsis thaliana). The corresponding enzyme catalyzes the polymerization of GlcNAc and, accordingly, β-1,4-GlcNAc oligomers accumulated in the plant. A phenotype characterized by difficulties in developing an inflorescence stem was visible when plants were grown for several weeks under short-day conditions before transfer to long-day conditions. In addition, a positive correlation between the oligomer concentration and the penetrance of the phenotype was demonstrated. Although NodC overexpression lines produced less cell wall compared with wild-type plants under nonpermissive conditions, no indications were found for changes in the amount of the major cell wall polymers. The effect on the cell wall was reflected at the transcriptome level. In addition to genes encoding cell wall-modifying enzymes, a whole set of genes encoding membrane-coupled receptor-like kinases were differentially expressed upon GlcNAc accumulation, many of which encoded proteins with an extracellular Domain of Unknown Function26. Although stress-related genes were also differentially expressed, the observed response differed from that of a classical chitin response. This is in line with the fact that the produced chitin oligomers were too small to activate the chitin receptor-mediated signal cascade. Based on our observations, we propose a model in which the oligosaccharides modify the architecture of the cell wall by acting as competitors in carbohydrate-carbohydrate or carbohydrate-protein interactions, thereby affecting noncovalent interactions in the cell wall or at the interface between the cell wall and the plasma membrane.
authors.affiliation: Department of Plant Systems Biology, Flanders Institute for Biotechnology, 9052 Ghent, Belgium.
authors.forename: Bartel
authors.initials: B
authors.lastname: Vanholme
authors.forename: Ruben
authors.initials: R
authors.lastname: Vanholme
authors.forename: Halbay
authors.initials: H
authors.lastname: Turumtay
authors.forename: Geert
authors.initials: G
authors.lastname: Goeminne
authors.forename: Igor
authors.initials: I
authors.lastname: Cesarino
authors.forename: Florence
authors.initials: F
authors.lastname: Goubet
authors.forename: Kris
authors.initials: K
authors.lastname: Morreel
authors.forename: Jorge
authors.initials: J
authors.lastname: Rencoret
authors.forename: Vincent
authors.initials: V
authors.lastname: Bulone
authors.forename: Cortwa
authors.initials: C
authors.lastname: Hooijmaijers
authors.forename: Riet
authors.initials: R
authors.lastname: De Rycke
authors.forename: Godelieve
authors.initials: G
authors.lastname: Gheysen
authors.forename: John
authors.initials: J
authors.lastname: Ralph
authors.forename: Marc
authors.initials: M
authors.lastname: De Block
authors.forename: Frank
authors.initials: F
authors.lastname: Meulewaeter
authors.forename: Wout
authors.initials: W
authors.lastname: Boerjan
mesh_terms: D000117:Acetylglucosamine / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D017360:Arabidopsis / Q000033:anatomy & histology* / Q000166:cytology* / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism*; D002686:Chitin / Q000378:metabolism; D002688:Chitinases / Q000378:metabolism; D015536:Down-Regulation / Q000235:genetics; D004721:Endoplasmic Reticulum / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D008031:Lignin / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D017351:N-Acetylglucosaminyltransferases / Q000378:metabolism; D018384:Oxidative Stress; D019683:Penetrance; D010641:Phenotype; D059828:Plant Cells / Q000378:metabolism*; D018547:Plant Stems / Q000166:cytology / Q000235:genetics / Q000648:ultrastructure; D030821:Plants, Genetically Modified; D013314:Stress, Mechanical; D059467:Transcriptome / Q000235:genetics; D015854:Up-Regulation / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D001426:Bacterial Proteins; D002686:Chitin; D008031:Lignin; D017351:N-Acetylglucosaminyltransferases; C060771:NodC protein, Rhizobiales; D002688:Chitinases; D000117:Acetylglucosamine