title: UVR8 in Arabidopsis thaliana regulates multiple aspects of cellular differentiation during leaf development in response to ultraviolet B radiation.
abstract: Responses specific to ultraviolet B (UV-B) wavelengths are still poorly understood, both in terms of initial signalling and effects on morphogenesis. Arabidopsis thaliana UV RESISTANCE LOCUS8 (UVR8) is the only known UV-B specific signalling component, but the role of UVR8 in leaf morphogenesis is unknown. The regulatory effects of UVR8 on leaf morphogenesis at a range of supplementary UV-B doses were characterized, revealing both UVR8-dependent and independent responses to UV irradiation. Inhibition of epidermal cell division in response to UV-B is largely independent of UVR8. However, overall leaf growth under UV-B irradiation in wild-type plants is enhanced compared with a uvr8 mutant because of a UVR8-dependent compensatory increase of cell area in wild-type plants. UVR8 was also required for the regulation of endopolyploidy in response to UV-B, and the uvr8 mutant also has a lower density of stomata than the wild type in the presence of UV-B, indicating that UVR8 has a regulatory role in other developmental events. Our findings show that, in addition to regulating UV-protective gene expression responses, UVR8 is involved in controlling aspects of leaf growth and morphogenesis. This work extends our understanding of how UV-B response is orchestrated at the whole-plant level.
authors.affiliation: Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK.
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Wargent
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich, NR4 7UH, UK.
authors.forename: Vasilis C
authors.initials: VC
authors.lastname: Gegas
authors.affiliation: Faculty of Biomedical and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.
authors.forename: Gareth I
authors.initials: GI
authors.lastname: Jenkins
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich, NR4 7UH, UK.
authors.forename: John H
authors.initials: JH
authors.lastname: Doonan
authors.affiliation: Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK.
authors.forename: Nigel D
authors.initials: ND
authors.lastname: Paul
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000254:growth & development* / Q000528:radiation effects*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D002454:Cell Differentiation / Q000528:radiation effects*; D049109:Cell Proliferation / Q000528:radiation effects; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D008954:Models, Biological; D009024:Morphogenesis / Q000528:radiation effects; D019441:Plant Epidermis / Q000166:cytology / Q000528:radiation effects; D018515:Plant Leaves / Q000166:cytology* / Q000254:growth & development* / Q000528:radiation effects; D054046:Plant Stomata / Q000166:cytology / Q000528:radiation effects; D011123:Polyploidy; D014466:Ultraviolet Rays
chemical_list: D029681:Arabidopsis Proteins; D002868:Chromosomal Proteins, Non-Histone; C525052:Uvr8 protein, Arabidopsis