title: Arabidopsis FH1 Formin Affects Cotyledon Pavement Cell Shape by Modulating Cytoskeleton Dynamics.
abstract: Plant cell morphogenesis involves concerted rearrangements of microtubules and actin microfilaments. We previously reported that FH1, the main Arabidopsis thaliana housekeeping Class I membrane-anchored formin, contributes to actin dynamics and microtubule stability in rhizodermis cells. Here we examine the effects of mutations affecting FH1 (At3g25500) on cell morphogenesis and above-ground organ development in seedlings, as well as on cytoskeletal organization and dynamics, using a combination of confocal and variable angle epifluorescence microscopy with a pharmacological approach. Homozygous fh1 mutants exhibited cotyledon epinasty and had larger cotyledon pavement cells with more pronounced lobes than the wild type. The pavement cell shape alterations were enhanced by expression of the fluorescent microtubule marker GFP-microtubule-associated protein 4 (MAP4). Mutant cotyledon pavement cells exhibited reduced density and increased stability of microfilament bundles, as well as enhanced dynamics of microtubules. Analogous results were also obtained upon treatments with the formin inhibitor SMIFH2 (small molecule inhibitor of formin homology 2 domains). Pavement cell shape in wild-type (wt) and fh1 plants in some situations exhibited a differential response towards anti-cytoskeletal drugs, especially the microtubule disruptor oryzalin. Our observations indicate that FH1 participates in the control of microtubule dynamics, possibly via its effects on actin, subsequently influencing cell morphogenesis and macroscopic organ development.
authors.affiliation: Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic Colombian Institute for Agricultural Research-CORPOICA-Turipana, Km 13 via Monteria, Cereté, Cordoba, Colombia Department of Cell Biology, Faculty of Science, Palacký University Olomouc, Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 586/11, CZ 783 71 Olomouc-Holice, Czech Republic.
authors.forename: Amparo
authors.initials: A
authors.lastname: Rosero
authors.affiliation: Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 135, CZ 160 00 Prague 6, Czech Republic.
authors.forename: Denisa
authors.initials: D
authors.lastname: Oulehlová
authors.affiliation: Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic.
authors.forename: Lenka
authors.initials: L
authors.lastname: Stillerová
authors.affiliation: Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic.
authors.forename: Petra
authors.initials: P
authors.lastname: Schiebertová
authors.affiliation: Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic.
authors.forename: Michal
authors.initials: M
authors.lastname: Grunt
authors.affiliation: Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 135, CZ 160 00 Prague 6, Czech Republic.
authors.forename: Viktor
authors.initials: V
authors.lastname: Žárský
authors.affiliation: Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic fatima@natur.cuni.cz.
authors.forename: Fatima
authors.initials: F
authors.lastname: Cvrčková
mesh_terms: D008841:Actin Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D000199:Actins / Q000378:metabolism; D017360:Arabidopsis / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D048430:Cell Shape / Q000187:drug effects; D002966:Clathrin / Q000378:metabolism; D018548:Cotyledon / Q000187:drug effects / Q000378:metabolism*; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism*; D005453:Fluorescence; D000080865:Formins; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D013871:Thiones / Q000494:pharmacology; D014498:Uracil / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: C417969:AFH1 protein, Arabidopsis; D000199:Actins; D029681:Arabidopsis Proteins; D015415:Biomarkers; D002966:Clathrin; D000080865:Formins; D008565:Membrane Proteins; C547376:SMIFH2 compound; D013871:Thiones; D049452:Green Fluorescent Proteins; D014498:Uracil
keywords: Arabidopsis thaliana; Confocal microscopy; Cotyledon pavement cells; Cytoskeleton; Formin; Variable angle epifluorescence microscopy