TitleAn Arabidopsis photolyase mutant is hypersensitive to ultraviolet-B radiation.
Publication TypeJournal Article
Year of Publication1997
AuthorsLandry LG, Stapleton AE, Lim J, Hoffman PD, Hays JB, Walbot V, Last RL
JournalProc Natl Acad Sci U S A
Date Published1997 Jan 07
Apoenzymes, Arabidopsis, Deoxyribodipyrimidine Photo-Lyase, DNA Repair, Dose-Response Relationship, Radiation, Fungal Proteins, Membrane Glycoproteins, Mutagenesis, Mutation, Pyrimidine Dimers, Radiation Tolerance, Ultraviolet Rays

Photolyases are DNA repair enzymes that use energy from blue light to repair pyrimidine dimers. We report the isolation of an Arabidopsis thaliana mutant (uvr2-1) that is defective in photorepair of cyclobutylpyrimidine dimers (CPDs). Whereas uvr2-1 is indistinguishable from wild type in the absence of UV light, low UV-B levels inhibit growth and cause leaf necrosis. uvr2-1 is more sensitive to UV-B than wild type when placed under white light after UV-B treatment. In contrast, recovery in darkness or in light lacking photoreactivating blue light results in equal injury in uvr2-1 and wild type. The uvr2-1 mutant is unable to remove CPDs in vivo, and plant extracts lack detectable photolyase activity. This recessive mutation segregates as a single gene located near the top of chromosome 1, and is a structural gene mutation in the type II CPD photolyase PHR1. This mutant provides evidence that CPD photolyase is required for plant survival in the presence of UV-B light.

Alternate JournalProc. Natl. Acad. Sci. U.S.A.
PubMed ID8990208
PubMed Central IDPMC19334