Microtubule-dependent targeting of the exocyst complex is necessary for xylem development in Arabidopsis

0475903 - ÚEB 2018 RIV US eng J - Journal Article
Vukašinović, Nemanja - Oda, Y. - Pejchar, Přemysl - Synek, Lukáš - Pečenková, Tamara - Rawat, Anamika - Sekereš, Juraj - Potocký, Martin - Žárský, Viktor
Microtubule-dependent targeting of the exocyst complex is necessary for xylem development in Arabidopsis.
New Phytologist. Roč. 213, č. 3 (2017), s. 1052-1067. ISSN 0028-646X. E-ISSN 1469-8137
R&D Projects: GA ČR(CZ) GA15-14886S
Grant - others:GA MŠk(CZ) LO1417
Institutional support: RVO:61389030
Keywords : secondary cell-wall * tracheary element differentiation * cortical microtubules * plasma-membrane * vesicle trafficking * secretory pathways * auxin transport * exocytosis * deposition * thaliana * conserved oligomeric Golgi (COG) complex * exocyst * microtubules * secondary cell wall * tracheary elements * xylem
OECD category: Cell biology
Impact factor: 7.433, year: 2017

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.
Permanent Link: http://hdl.handle.net/11104/0272487