Participation of Chromatin-Remodeling Proteins in the Repair of Ultraviolet-B-Damaged DNA

CAMPI M.; LUCIO D´ANDREA; EMILIANI J.; CASATI P.

PLANT PHYSIOLOGY.

AMER SOC PLANT BIOLOGISTS

Lugar: Rockville; Año: 2012 vol. 158 p. 981 - 995

0032-0889

The genome of plants is organized into chromatin, affecting the rates of transcription, DNA recombination, and repair. In thiswork, we have investigated the consequences of reduced expression of some chromatin-remodeling factors and histoneacetylation in maize (Zea mays) and Arabidopsis (Arabidopsis thaliana) in their participation in DNA repair after ultraviolet(UV)-B irradiation. Plants deficient in NFC102/NFC4 or SDG102/SDG26 showed more damaged DNA than wild-type plants;however, the Arabidopsis chc1 mutant showed similar accumulation of cyclobutane pyrimidine dimers as wild-type plants, incontrast to the increased DNA damage measured in the maize chc101 RNA interference line. In Arabidopsis, plants deficient inchromatin remodeling are also affected in the accumulation of pigments by UV-B. Plants treated with an inhibitor of histoneacetyltransferases, curcumin, previous to the UV-B treatment show deficiencies in DNA repair; in addition, the chromatinremodeling-deficient plants have altered levels of acetylated histones after the UV-B treatment, demonstrating that histoneacetylation is important during DNA repair in these two plant species. Arabidopsis mutants ham1 and ham2 also showedincreased DNA damage after UV-B, suggesting that the role of these proteins in DNA damage repair has been conservedthrough evolution. However, cyclobutane pyrimidine dimer accumulation was higher in ham1 than in ham2; suggesting thatHAM1 has a major role in DNA repair after UV-B. In summary, in this work, we have demonstrated that chromatinremodeling, and histone acetylation in particular, is important during DNA repair by UV-B, demonstrating that both geneticand epigenetic effects control DNA repair in plants.