title: Microtubule-dependent targeting of the exocyst complex is necessary for xylem development in Arabidopsis.
abstract: Cortical microtubules (MTs) play a major role in the patterning of secondary cell wall (SCW) thickenings in tracheary elements (TEs) by determining the sites of SCW deposition. The EXO70A1 subunit of the exocyst secretory vesicle tethering complex was implicated to be important for TE development via the MT interaction. We investigated the subcellular localization of several exocyst subunits in the xylem of Arabidopsis thaliana and analyzed the functional significance of exocyst-mediated trafficking in TE development. Live cell imaging of fluorescently tagged exocyst subunits in TE using confocal microscopy and protein-protein interaction assays were performed to describe the role of the exocyst and its partners in TE development. In TEs, exocyst subunits were localized to the sites of SCW deposition in an MT-dependent manner. We propose that the mechanism of exocyst targeting to MTs involves the direct interaction of exocyst subunits with the COG2 protein. We demonstrated the importance of a functional exocyst subunit EXO84b for normal TE development and showed that the deposition of SCW constituents is partially compromised, possibly as a result of the mislocalization of secondary cellulose synthase in exocyst mutants. We conclude that the exocyst complex is an important factor bridging the pattern defined by cortical MTs with localized secretion of the SCW in developing TEs.
authors: Institute of Experimental Botany, v.v.i., The Czech Academy of Sciences, 16502, Prague 6, Czech Republic.|Department of Experimental Plant Biology, Faculty of Science, Charles University in Prague, 128 44, Prague 2, Czech Republic.
authors: Nemanja
authors: N
authors: Vukašinović
authors: Center for Frontier Research, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan.|Department of Genetics, School of Life Science, SOKENDAI (Graduate University for Advanced Studies), 1111 Yata, Mishima, Shizuoka, 411-8540, Japan.
authors: Yoshihisa
authors: Y
authors: Oda
authors: Institute of Experimental Botany, v.v.i., The Czech Academy of Sciences, 16502, Prague 6, Czech Republic.
authors: Přemysl
authors: P
authors: Pejchar
authors: Institute of Experimental Botany, v.v.i., The Czech Academy of Sciences, 16502, Prague 6, Czech Republic.
authors: Lukáš
authors: L
authors: Synek
authors: Institute of Experimental Botany, v.v.i., The Czech Academy of Sciences, 16502, Prague 6, Czech Republic.
authors: Tamara
authors: T
authors: Pečenková
authors: Institute of Experimental Botany, v.v.i., The Czech Academy of Sciences, 16502, Prague 6, Czech Republic.|Department of Experimental Plant Biology, Faculty of Science, Charles University in Prague, 128 44, Prague 2, Czech Republic.
authors: Anamika
authors: A
authors: Rawat
authors: Institute of Experimental Botany, v.v.i., The Czech Academy of Sciences, 16502, Prague 6, Czech Republic.|Department of Experimental Plant Biology, Faculty of Science, Charles University in Prague, 128 44, Prague 2, Czech Republic.
authors: Juraj
authors: J
authors: Sekereš
authors: Institute of Experimental Botany, v.v.i., The Czech Academy of Sciences, 16502, Prague 6, Czech Republic.
authors: Martin
authors: M
authors: Potocký
authors: Institute of Experimental Botany, v.v.i., The Czech Academy of Sciences, 16502, Prague 6, Czech Republic.|Department of Experimental Plant Biology, Faculty of Science, Charles University in Prague, 128 44, Prague 2, Czech Republic.
authors: Viktor
authors: V
authors: Žárský
mesh_terms: D017360:Arabidopsis / Q000254:growth & development* / Q000378:metabolism* / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000378:metabolism*; D002454:Cell Differentiation; D002462:Cell Membrane / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism; D017124:Conserved Sequence; D005964:Glucosyltransferases / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism* / Q000648:ultrastructure; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D058526:Plant Vascular Bundle / Q000378:metabolism; D021122:Protein Subunits / Q000378:metabolism; D052584:Xylem / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D029681:Arabidopsis Proteins; D021122:Protein Subunits; D005964:Glucosyltransferases; C478648:cellulose synthase
keywords: conserved oligomeric Golgi (COG) complex; exocyst; microtubules; secondary cell wall; tracheary elements; xylem