title: Proteomic Analysis of Microtubule Interacting Proteins over the Course of Xylem Tracheary Element Formation in Arabidopsis.
abstract: Plant vascular cells, or tracheary elements (TEs), rely on circumferential secondary cell wall thickenings to maintain sap flow. The patterns in which TE thickenings are organized vary according to the underlying microtubule bundles that guide wall deposition. To identify microtubule interacting proteins present at defined stages of TE differentiation, we exploited the synchronous differentiation of TEs in Arabidopsis thaliana suspension cultures. Quantitative proteomic analysis of microtubule pull-downs, using ratiometric (14)N/(15)N labeling, revealed 605 proteins exhibiting differential accumulation during TE differentiation. Microtubule interacting proteins associated with membrane trafficking, protein synthesis, DNA/RNA binding, and signal transduction peaked during secondary cell wall formation, while proteins associated with stress peaked when approaching TE cell death. In particular, CELLULOSE SYNTHASE-INTERACTING PROTEIN1, already associated with primary wall synthesis, was enriched during secondary cell wall formation. RNAi knockdown of genes encoding several of the identified proteins showed that secondary wall formation depends on the coordinated presence of microtubule interacting proteins with nonoverlapping functions: cell wall thickness, cell wall homogeneity, and the pattern and cortical location of the wall are dependent on different proteins. Altogether, proteins linking microtubules to a range of metabolic compartments vary specifically during TE differentiation and regulate different aspects of wall patterning.
authors.affiliation: John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom.
authors.forename: Paul
authors.identifier: http://orcid.org/0000-0002-5095-9397
authors.initials: P
authors.lastname: Derbyshire
authors.affiliation: Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, 901 87 Umeå, Sweden.
authors.forename: Delphine
authors.identifier: http://orcid.org/0000-0002-7320-7921
authors.initials: D
authors.lastname: Ménard
authors.affiliation: John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom.
authors.forename: Porntip
authors.identifier: http://orcid.org/0000-0002-1968-0574
authors.initials: P
authors.lastname: Green
authors.affiliation: John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom.
authors.forename: Gerhard
authors.identifier: http://orcid.org/0000-0002-9849-4875
authors.initials: G
authors.lastname: Saalbach
authors.affiliation: John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom.
authors.forename: Henrik
authors.initials: H
authors.lastname: Buschmann
authors.affiliation: John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom.
authors.forename: Clive W
authors.initials: CW
authors.lastname: Lloyd
authors.affiliation: John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, 901 87 Umeå, Sweden edouard.pesquet@umu.se.
authors.forename: Edouard
authors.identifier: http://orcid.org/0000-0002-6959-3284
authors.initials: E
authors.lastname: Pesquet
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation; D002473:Cell Wall / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D055785:Gene Knockdown Techniques; D008868:Microtubule Proteins / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism; D030821:Plants, Genetically Modified; D040901:Proteomics; D034622:RNA Interference; D015398:Signal Transduction; D052584:Xylem / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology
chemical_list: D029681:Arabidopsis Proteins; D008868:Microtubule Proteins