title: Genotoxin induced mutagenesis in the model plant Physcomitrella patens.
abstract: The moss Physcomitrella patens is unique for the high frequency of homologous recombination, haploid state, and filamentous growth during early stages of the vegetative growth, which makes it an excellent model plant to study DNA damage responses. We used single cell gel electrophoresis (comet) assay to determine kinetics of response to Bleomycin induced DNA oxidative damage and single and double strand breaks in wild type and mutant lig4 Physcomitrella lines. Moreover, APT gene when inactivated by induced mutations was used as selectable marker to ascertain mutational background at nucleotide level by sequencing of the APT locus. We show that extensive repair of DSBs occurs also in the absence of the functional LIG4, whereas repair of SSBs is seriously compromised. From analysis of induced mutations we conclude that their accumulation rather than remaining lesions in DNA and blocking progression through cell cycle is incompatible with normal plant growth and development and leads to sensitive phenotype.
authors.affiliation: Institute of Experimental Botany ASCR, Na Karlovce 1, 160 00 Praha 6, Czech Republic.
authors.forename: Marcela
authors.initials: M
authors.lastname: Holá
authors.affiliation: Institute of Organic Chemistry and Biochemistry ASCR, Flemingovo nám. 2, 1600 00 Praha 6, Czech Republic.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Kozák
authors.affiliation: Institute of Experimental Botany ASCR, Na Karlovce 1, 160 00 Praha 6, Czech Republic.
authors.forename: Radka
authors.initials: R
authors.lastname: Vágnerová
authors.affiliation: Institute of Experimental Botany ASCR, Na Karlovce 1, 160 00 Praha 6, Czech Republic.
authors.forename: Karel J
authors.initials: KJ
authors.lastname: Angelis
mesh_terms: D001761:Bleomycin / Q000494:pharmacology; D019068:Bryopsida / Q000235:genetics / Q000254:growth & development*; D002453:Cell Cycle / Q000235:genetics; D004249:DNA Damage / Q000187:drug effects*; D004260:DNA Repair / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D006238:Haploidy; D059765:Homologous Recombination / Q000235:genetics; D016296:Mutagenesis / Q000235:genetics*; D009153:Mutagens / Q000494:pharmacology; D009154:Mutation; D018384:Oxidative Stress / Q000187:drug effects; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics; D059010:Single-Cell Analysis
chemical_list: D009153:Mutagens; D010940:Plant Proteins; D001761:Bleomycin