DNA Damage and Repair in Higher Plants

Abstract

Various investigations into the repair processes in higher plants have provided evidence for the presence of photoreactivation, excision repair of pyrimidine dimers, repair synthesis, rejoining of single-strand DNA breaks, and liberation of alkylated guanines from the DNA of plants. This chapter reviews the principle mechanisms of DNA damage and repair in higher plants and their relation to chromosome and genic mutation induction by radiation and chemicals. The repair of double-strand breaks induced in plant DNA by fast neutrons has not yet been found. The first data on the possibility of caffeine and ethylenediaminetetraacetic acid (EDTA) inhibition of such repair processes as dimer excision, DNA strand break rejoining, and repair replication have been obtained. There are not yet enough data to subdivide the dark repair processes in plants on the basis of the enzymes involved. However, even the preliminary findings show the occurrence in plants of very rapid, rapid, and prolonged repairs that differ from each other. The possibility of the inhibition of excision of pyrimidine dimers from DNA in plant cells by EDTA points to an essential difference of these nucleases from bacterial endonucleases.