title: Differential requirements for RAD51 in Physcomitrella patens and Arabidopsis thaliana development and DNA damage repair.
abstract: RAD51, the eukaryotic homolog of the bacterial RecA recombinase, plays a central role in homologous recombination (HR) in yeast and animals. Loss of RAD51 function causes lethality in vertebrates but not in other animals or in the flowering plant Arabidopsis thaliana, suggesting that RAD51 is vital for highly developed organisms but not for others. Here, we found that loss of RAD51 function in the moss Physcomitrella patens, a plant of less complexity, caused a significant vegetative phenotype, indicating an important function for RAD51 in this organism. Moreover, loss of RAD51 caused marked hypersensitivity to the double-strand break-inducing agent bleomycin in P. patens but not in Arabidopsis. Therefore, HR is used for somatic DNA damage repair in P. patens but not in Arabidopsis. These data imply fundamental differences in the use of recombination pathways between plants. Moreover, these data demonstrate that the importance of RAD51 for viability is independent of taxonomic position or complexity of an organism. The involvement of HR in DNA damage repair in the slowly evolving species P. patens but not in fast-evolving Arabidopsis suggests that the choice of the recombination pathway is related to the speed of evolution in plants.
authors.affiliation: Department of Plant Developmental Biology, Max-Planck-Institut für Züchtungsforschung, D-50829 Cologne, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Markmann-Mulisch
authors.forename: Edelgard
authors.initials: E
authors.lastname: Wendeler
authors.forename: Oliver
authors.initials: O
authors.lastname: Zobell
authors.forename: Gabriele
authors.initials: G
authors.lastname: Schween
authors.forename: Hans-Henning
authors.initials: HH
authors.lastname: Steinbiss
authors.forename: Bernd
authors.initials: B
authors.lastname: Reiss
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D015152:Blotting, Northern; D015139:Blotting, Southern; D019068:Bryopsida / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D004260:DNA Repair; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D051135:Rad51 Recombinase / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D010940:Plant Proteins; D051135:Rad51 Recombinase