Abstract
We employed single cell gel electrophoresis to analyze the kinetics of DNA repair in nuclei isolated from tobacco plants exposed to ethyl methanesulfonate (EMS), N-ethyl-N-nitrosourea (ENU) and γ-radiation. DNA repair was measured as the reduction of the tail moment values as a function of time after the mutagen treatment ended. DNA damage in leaf nuclei of EMS- or ENU-treated tobacco plants persisted over a 72 h recovery period. However, a reduction of the SCGE tail moment values in nuclei isolated from leaves was observed over a 4-week period of recovery. Newly emerged leaves expressed a lower level of DNA damage due to more efficient repair and/or dilution of initial DNA lesions during cell division. After 24 h recovery, leaf nuclei from cells exposed to 20 or 40 Gy of γ-radiation expressed complete DNA repair. These data indicate that DNA lesions induced by alkylating agents are not readily repaired and persist beyond 4 weeks. Enzymes necessary to repair γ-induced DNA lesions are fully functional in non-replicating leaf cells and single and double strand breaks are rapidly repaired. (C) 2000 Elsevier Science B.V.
Original language | English (US) |
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Pages (from-to) | 1-9 |
Number of pages | 9 |
Journal | Mutation Research - Genetic Toxicology and Environmental Mutagenesis |
Volume | 470 |
Issue number | 1 |
DOIs | |
State | Published - Oct 10 2000 |
Externally published | Yes |
Keywords
- Comet assay
- EMS
- ENU
- Ethyl methanesulfonate
- N-ethyl-N-nitrosourea
- Nicotiana tabacum var. xanthi
- SCGE
- Single cell gel electrophoresis
- γ-radiation
ASJC Scopus subject areas
- Genetics
- Health, Toxicology and Mutagenesis