Arabidopsis UVR8 regulates ultraviolet-B signal transduction and tolerance and contains sequence similarity to human regulator of chromatin condensation 1.
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.
Kliebenstein
Daniel J
DJ
The Boyce Thompson Institute for Plant Research and Section of Genetics and Development, Cornell University, Ithaca, New York 14853, USA. Kliebenstein@ucdavis.edu
Lim
Jackie E
JE
Landry
Laurie G
LG
Last
Robert L
RL
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
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