title: Evidence for a role of Arabidopsis CDT1 proteins in gametophyte development and maintenance of genome integrity.
abstract: Meristems retain the ability to divide throughout the life cycle of plants, which can last for over 1000 years in some species. Furthermore, the germline is not laid down early during embryogenesis but originates from the meristematic cells relatively late during development. Thus, accurate cell cycle regulation is of utmost importance to avoid the accumulation of mutations during vegetative growth and reproduction. The Arabidopsis thaliana genome encodes two homologs of the replication licensing factor CDC10 Target1 (CDT1), and overexpression of CDT1a stimulates DNA replication. Here, we have investigated the respective functions of Arabidopsis CDT1a and CDT1b. We show that CDT1 proteins have partially redundant functions during gametophyte development and are required for the maintenance of genome integrity. Furthermore, CDT1-RNAi plants show endogenous DNA stress, are more tolerant than the wild type to DNA-damaging agents, and show constitutive induction of genes involved in DNA repair. This DNA stress response may be a direct consequence of reduced CDT1 accumulation on DNA repair or may relate to the ability of CDT1 proteins to form complexes with DNA polymerase ε, which functions in DNA replication and in DNA stress checkpoint activation. Taken together, our results provide evidence for a crucial role of Arabidopsis CDT1 proteins in genome stability.
authors: Institut de Biologie des Plantes, UMR8618 Université Paris-Sud XI, 91405 Orsay, France.
authors: Séverine
authors: S
authors: Domenichini
authors: Moussa
authors: M
authors: Benhamed
authors: Geert
authors: G
authors: De Jaeger
authors: Eveline
authors: E
authors: Van De Slijke
authors: Sophie
authors: S
authors: Blanchet
authors: Mickaël
authors: M
authors: Bourge
authors: Lieven
authors: L
authors: De Veylder
authors: Catherine
authors: C
authors: Bergounioux
authors: Cécile
authors: C
authors: Raynaud
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000196:embryology / Q000235:genetics* / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D004249:DNA Damage / Q000528:radiation effects; D004260:DNA Repair; D015536:Down-Regulation / Q000235:genetics; D062951:Endoreduplication / Q000235:genetics; D005720:Gamma Rays; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D018745:Genome, Plant / Q000235:genetics / Q000528:radiation effects; D042822:Genomic Instability / Q000235:genetics* / Q000528:radiation effects; D055993:Germ Cells, Plant / Q000166:cytology / Q000254:growth & development*; D008958:Models, Molecular; D016254:Mutagenesis, Insertional; D010641:Phenotype; D018515:Plant Leaves / Q000166:cytology / Q000196:embryology / Q000235:genetics / Q000528:radiation effects; D018517:Plant Roots / Q000166:cytology / Q000196:embryology / Q000235:genetics / Q000528:radiation effects; D030821:Plants, Genetically Modified; D011058:Pollen / Q000166:cytology / Q000196:embryology / Q000235:genetics / Q000528:radiation effects; D034622:RNA Interference; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; C493651:CDT1a protein, Arabidopsis; C493652:CDT1b protein, Arabidopsis; D018797:Cell Cycle Proteins