title: Multiple roles for UV RESISTANCE LOCUS8 in regulating gene expression and metabolite accumulation in Arabidopsis under solar ultraviolet radiation.
abstract: Photomorphogenic responses triggered by low fluence rates of ultraviolet B radiation (UV-B; 280-315 nm) are mediated by the UV-B photoreceptor UV RESISTANCE LOCUS8 (UVR8). Beyond our understanding of the molecular mechanisms of UV-B perception by UVR8, there is still limited information on how the UVR8 pathway functions under natural sunlight. Here, wild-type Arabidopsis (Arabidopsis thaliana) and the uvr8-2 mutant were used in an experiment outdoors where UV-A (315-400 nm) and UV-B irradiances were attenuated using plastic films. Gene expression, PYRIDOXINE BIOSYNTHESIS1 (PDX1) accumulation, and leaf metabolite signatures were analyzed. The results show that UVR8 is required for transcript accumulation of genes involved in UV protection, oxidative stress, hormone signal transduction, and defense against herbivores under solar UV. Under natural UV-A irradiance, UVR8 is likely to interact with UV-A/blue light signaling pathways to moderate UV-B-driven transcript and PDX1 accumulation. UVR8 both positively and negatively affects UV-A-regulated gene expression and metabolite accumulation but is required for the UV-B induction of phenolics. Moreover, UVR8-dependent UV-B acclimation during the early stages of plant development may enhance normal growth under long-term exposure to solar UV.
authors.affiliation: Division of Plant Biology, Department of Biosciences, University of Helsinki, FI-00014 Helsinki, Finland. luisorlando.moraless@gmail.com
authors.forename: Luis O
authors.initials: LO
authors.lastname: Morales
authors.forename: Mikael
authors.initials: M
authors.lastname: Brosché
authors.forename: Julia
authors.initials: J
authors.lastname: Vainonen
authors.forename: Gareth I
authors.initials: GI
authors.lastname: Jenkins
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Wargent
authors.forename: Nina
authors.initials: N
authors.lastname: Sipari
authors.forename: Åke
authors.initials: Å
authors.lastname: Strid
authors.forename: Anders V
authors.initials: AV
authors.lastname: Lindfors
authors.forename: Riitta
authors.initials: R
authors.lastname: Tegelberg
authors.forename: Pedro J
authors.initials: PJ
authors.lastname: Aphalo
mesh_terms: D000064:Acclimatization / Q000235:genetics; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D019759:Carbon-Nitrogen Lyases; D002734:Chlorophyll / Q000378:metabolism; D002853:Chromatography, Liquid; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000528:radiation effects; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D013058:Mass Spectrometry; D009154:Mutation; D019884:Nitrogenous Group Transferases / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D019441:Plant Epidermis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics / Q000528:radiation effects; D059467:Transcriptome / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D029681:Arabidopsis Proteins; D002868:Chromosomal Proteins, Non-Histone; C525052:Uvr8 protein, Arabidopsis; D002734:Chlorophyll; D019884:Nitrogenous Group Transferases; D019759:Carbon-Nitrogen Lyases; C505161:At2g38230 protein, Arabidopsis