title: Xyloglucan Deficiency Disrupts Microtubule Stability and Cellulose Biosynthesis in Arabidopsis, Altering Cell Growth and Morphogenesis.
abstract: Xyloglucan constitutes most of the hemicellulose in eudicot primary cell walls and functions in cell wall structure and mechanics. Although Arabidopsis (Arabidopsis thaliana) xxt1 xxt2 mutants lacking detectable xyloglucan are viable, they display growth defects that are suggestive of alterations in wall integrity. To probe the mechanisms underlying these defects, we analyzed cellulose arrangement, microtubule patterning and dynamics, microtubule- and wall-integrity-related gene expression, and cellulose biosynthesis in xxt1 xxt2 plants. We found that cellulose is highly aligned in xxt1 xxt2 cell walls, that its three-dimensional distribution is altered, and that microtubule patterning and stability are aberrant in etiolated xxt1 xxt2 hypocotyls. We also found that the expression levels of microtubule-associated genes, such as MAP70-5 and CLASP, and receptor genes, such as HERK1 and WAK1, were changed in xxt1 xxt2 plants and that cellulose synthase motility is reduced in xxt1 xxt2 cells, corresponding with a reduction in cellulose content. Our results indicate that loss of xyloglucan affects both the stability of the microtubule cytoskeleton and the production and patterning of cellulose in primary cell walls. These findings establish, to our knowledge, new links between wall integrity, cytoskeletal dynamics, and wall synthesis in the regulation of plant morphogenesis.
authors.affiliation: Center for Lignocellulose Structure and Formation (C.X., T.Z., Y.Z., D.J.C., C.T.A.) and Department of Biology (C.X., T.Z., D.J.C., C.T.A.), The Pennsylvania State University, University Park, Pennsylvania 16802.
authors.forename: Chaowen
authors.initials: C
authors.lastname: Xiao
authors.affiliation: Center for Lignocellulose Structure and Formation (C.X., T.Z., Y.Z., D.J.C., C.T.A.) and Department of Biology (C.X., T.Z., D.J.C., C.T.A.), The Pennsylvania State University, University Park, Pennsylvania 16802.
authors.forename: Tian
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Center for Lignocellulose Structure and Formation (C.X., T.Z., Y.Z., D.J.C., C.T.A.) and Department of Biology (C.X., T.Z., D.J.C., C.T.A.), The Pennsylvania State University, University Park, Pennsylvania 16802.
authors.forename: Yunzhen
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: Center for Lignocellulose Structure and Formation (C.X., T.Z., Y.Z., D.J.C., C.T.A.) and Department of Biology (C.X., T.Z., D.J.C., C.T.A.), The Pennsylvania State University, University Park, Pennsylvania 16802.
authors.forename: Daniel J
authors.identifier: http://orcid.org/0000-0002-4020-5786
authors.initials: DJ
authors.lastname: Cosgrove
authors.affiliation: Center for Lignocellulose Structure and Formation (C.X., T.Z., Y.Z., D.J.C., C.T.A.) and Department of Biology (C.X., T.Z., D.J.C., C.T.A.), The Pennsylvania State University, University Park, Pennsylvania 16802 cta3@psu.edu.
authors.forename: Charles T
authors.identifier: http://orcid.org/0000-0001-7481-3571
authors.initials: CT
authors.lastname: Anderson
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism; D002482:Cellulose / Q000096:biosynthesis* / Q000378:metabolism / Q000648:ultrastructure; D004136:Dinitrobenzenes / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant; D005936:Glucans / Q000235:genetics / Q000378:metabolism*; D018546:Hypocotyl / Q000235:genetics / Q000378:metabolism; D020894:Microfibrils / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D009154:Mutation; D059828:Plant Cells / Q000187:drug effects / Q000378:metabolism; D018547:Plant Stems / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified; D011312:Pressure; D036226:Seedlings / Q000235:genetics / Q000378:metabolism; D013424:Sulfanilamides / Q000494:pharmacology; D014990:Xylans / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D004136:Dinitrobenzenes; D005936:Glucans; D013424:Sulfanilamides; D014990:Xylans; C029353:xyloglucan; C012465:oryzalin; D002482:Cellulose