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Arabidopsis UVR8 regulates ultraviolet-B signal transduction and tolerance and contains sequence similarity to human regulator of chromatin condensation 1

Author:
Kliebenstein, D.J., Lim, J.E., Landry, L.G., Last, R.L.
Source:
Plant physiology 2002 v.130 no.1 pp. 234-243
ISSN:
0032-0889
Subject:
Arabidopsis thaliana, plant proteins, recessive genes, chromosomes, chromosome mapping, open reading frames, alleles, flavonoids, messenger RNA, biosynthesis, plant morphology, ultraviolet radiation, phenylpropanoids, nucleotide sequences, chemical constituents of plants, mutation, pathogenesis-related proteins, genetic complementation, naringenin-chalcone synthase
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.
Agid:
671298