title: Ultraviolet-B radiation stimulates downward leaf curling in Arabidopsis thaliana.
abstract: Plants are very well adapted to growth in ultraviolet-B (UV-B) containing light. In Arabidopsis thaliana, many of these adaptations are mediated by the UV-B receptor UV resistance locus 8 (UVR8). Using small amounts of supplementary UV-B light, we observed changes in the shape of rosette leaf blades. Wild type plants show more pronounced epinasty of the blade edges, while this is not the case in uvr8 mutant plants. The UVR8 effect thus mimics the effect of phytochrome (phy) B in red light. In addition, a meta-analysis of transcriptome data indicates that the UVR8 and phyB signaling pathways have over 70% of gene regulation in common. Moreover, in low levels of supplementary UV-B light, mutant analysis revealed that phyB signaling is necessary for epinasty of the blade edges. Analysis of auxin levels and the auxin signal reporter DR5::GUS suggest that the epinasty relies on altered auxin distribution, keeping auxin at the leaf blade edges in the presence of UV-B. Together, our results suggest a co-action of phyB and UVR8 signaling, with auxin as a downstream factor.
authors.affiliation: Department of Information Technology, IMinds, Faculty of Sciences, Ghent University, B-9000 Ghent, Belgium. Electronic address: carolina.fierro@intec.ugent.be.
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: Fierro
authors.affiliation: Department of Biology, Ghent University, KL Ledeganckstraat 35, B-9000 Ghent, Belgium. Electronic address: Olivier.Leroux@ugent.be.
authors.forename: Olivier
authors.initials: O
authors.lastname: Leroux
authors.affiliation: Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium; Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium. Electronic address: barbara.deconinck@biw.vib-kuleuven.be.
authors.forename: Barbara
authors.initials: B
authors.lastname: De Coninck
authors.affiliation: Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium; Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium. Electronic address: bruno.cammue@biw.vib-kuleuven.be.
authors.forename: Bruno P A
authors.initials: BP
authors.lastname: Cammue
authors.affiliation: Department of Information Technology, IMinds, Faculty of Sciences, Ghent University, B-9000 Ghent, Belgium; Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium; Department of Plant Biotechnology and Bioinformatics, Faculty of Sciences, Ghent University, B-9000 Ghent, Belgium. Electronic address: kathleen.marchal@intec.ugent.be.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Marchal
authors.affiliation: Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium. Electronic address: els.prinsen@uantwerpen.be.
authors.forename: Els
authors.initials: E
authors.lastname: Prinsen
authors.affiliation: Laboratory of Functional Plant Biology, Department of Physiology, Ghent University, KL Ledeganckstraat 35, B-9000 Ghent, Belgium. Electronic address: Dominique.VanDerStraeten@ugent.be.
authors.forename: Dominique
authors.initials: D
authors.lastname: Van Der Straeten
authors.affiliation: Laboratory of Functional Plant Biology, Department of Physiology, Ghent University, KL Ledeganckstraat 35, B-9000 Ghent, Belgium. Electronic address: Filip.Vandenbussche@ugent.be.
authors.forename: Filip
authors.initials: F
authors.lastname: Vandenbussche
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D056426:Genetic Loci; D051939:Phytochrome B / Q000235:genetics / Q000378:metabolism*; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism*; D014466:Ultraviolet Rays
chemical_list: D029681:Arabidopsis Proteins; D002868:Chromosomal Proteins, Non-Histone; C497952:PHYB protein, Arabidopsis; C525052:Uvr8 protein, Arabidopsis; D051939:Phytochrome B
keywords: Arabidopsis; Auxin; Phototropin; Phytochrome; UV-B; UVR8; phyB