A genetic screen of a population of Arabidopsis thaliana lines exhibiting enhanced somatic homologous recombination yielded a mutant affected in expression of a gene encoding a caltractin-like protein (centrin). The hyperrecombinogenic phenotype could be reproduced using RNA interference (RNAi) technology. Both the original mutant and the RNAi plants exhibited a moderate UV-C sensitivity as well as a reduced efficiency of in vitro repair of UV-damaged DNA. Transcription profiling of the mutant showed that expression of components of the nucleotide excision repair (NER) pathway and of factors involved in other DNA repair processes were significantly changed. Our data suggest an indirect involvement of centrin in recombinational DNA repair via the modulation of the NER pathway. These findings thus point to a novel interconnection between an early step of NER and homologous recombination, which may play a critical role in plant DNA repair.
Copyright 2004 American Society of Plant Biologists