title: UV radiation reduces epidermal cell expansion in Arabidopsis thaliana leaves without altering cellular microtubule organization.
abstract: Upon chronic UV treatment pavement cell expansion in Arabidopsis leaves is reduced, implying alterations in symplastic and apoplastic properties of the epidermal cells. In this study, the effect of UV radiation on microtubule patterning is analysed, as microtubules are thought to serve as guiding rails for the cellulose synthase complexes depositing cellulose microfibrils. Together with hemicelluloses, these microfibrils are regarded as the load-bearing components of the cell wall. Leaves of transgenic plants with fluorescently tagged microtubules (GFP-TUA6) were as responsive to UV as wild type plants. Despite the UV-induced reduction in cell elongation, confocal microscopy revealed that cellular microtubule arrangements were seemingly not affected by the UV treatments. This indicates an unaltered deposition of cellulose microfibrils in the presence of UV radiation. Therefore, we surmise that the reduction in cell expansion in UV-treated leaves is most probably due to changes in cell wall loosening and/or turgor pressure.
authors.affiliation: Department of Biology, Plant Growth and Development, University of Antwerp, Antwerpen, Belgium.
authors.forename: Eveline
authors.initials: E
authors.lastname: Jacques
authors.forename: Kathleen
authors.initials: K
authors.lastname: Hectors
authors.forename: Yves
authors.initials: Y
authors.lastname: Guisez
authors.forename: Els
authors.initials: E
authors.lastname: Prinsen
authors.forename: Marcel A K
authors.initials: MA
authors.lastname: Jansen
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Verbelen
authors.forename: Kris
authors.initials: K
authors.lastname: Vissenberg
mesh_terms: D017360:Arabidopsis / Q000166:cytology* / Q000378:metabolism / Q000528:radiation effects*; D029681:Arabidopsis Proteins / Q000378:metabolism; D049109:Cell Proliferation / Q000528:radiation effects; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism* / Q000528:radiation effects*; D019441:Plant Epidermis / Q000166:cytology* / Q000378:metabolism / Q000528:radiation effects; D018515:Plant Leaves / Q000166:cytology* / Q000378:metabolism / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D029681:Arabidopsis Proteins; D049452:Green Fluorescent Proteins