title: Arabidopsis UVR8 regulates ultraviolet-B signal transduction and tolerance and contains sequence similarity to human regulator of chromatin condensation 1.
abstract: To further our understanding of how plants defend against the harmful effects of ultraviolet (UV) light, we characterized an Arabidopsis mutant hypersensitive to UV-B. This mutant, UV resistance locus 8-1 (uvr8-1), contains a single recessive mutation at the bottom of chromosome 5. Fine-scale mapping localized uvr8-1 to a 21-kb locus containing five predicted open reading frames. Sequencing of this entire region revealed that the uvr8-1 allele contains a 15-nucleotide deletion in a gene similar to the human guanine nucleotide exchange factor regulator of chromatin condensation 1. This mutation reduces the UV-B-mediated induction of flavonoids and blocks chalcone synthase mRNA and protein induction. In contrast, uvr8-1 has enhanced induction of PR1 and PR5 proteins in response to UV-B, an indication of increased UV-B injury. These results suggest that UVR8 acts in a UV-B signal transduction pathway leading to induction of flavonoid biosynthesis.
authors.affiliation: The Boyce Thompson Institute for Plant Research and Section of Genetics and Development, Cornell University, Ithaca, New York 14853, USA. Kliebenstein@ucdavis.edu
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Kliebenstein
authors.forename: Jackie E
authors.initials: JE
authors.lastname: Lim
authors.forename: Laurie G
authors.initials: LG
authors.lastname: Landry
authors.forename: Robert L
authors.initials: RL
authors.lastname: Last
mesh_terms: D000217:Acyltransferases / Q000378:metabolism; D000222:Adaptation, Physiological / Q000502:physiology; D000483:Alleles; D017360:Arabidopsis / Q000235:genetics / Q000502:physiology* / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology* / Q000528:radiation effects; D018797:Cell Cycle Proteins; D002874:Chromosome Mapping; D005419:Flavonoids / Q000096:biosynthesis; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D005816:Genetic Complementation Test; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins; D010666:Phenylpropionates / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D015398:Signal Transduction / Q000502:physiology*; D014466:Ultraviolet Rays
chemical_list: D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; D005419:Flavonoids; D020662:Guanine Nucleotide Exchange Factors; D009687:Nuclear Proteins; D010666:Phenylpropionates; C062521:RCC1 protein, human; D012333:RNA, Messenger; D000217:Acyltransferases; C020141:flavanone synthetase