Evaluation of solar UV damage to Crepis capillaris by chromosome aberration test.
Ultraviolet (UV) radiation comprises only a small portion of the electromagnetic spectrum of solar light, but it exerts a disproportionally greater genotoxic effect on all organisms, including water plants. However, genotoxicity evaluation of solar UV is complicated because of the simultaneous actions of UVB, UVA, and photoreactivating light (PHL). The latter very effectively repairs the main type of DNA lesions, pyrimidine dimers (PD), which are induced specifically only by UV. However, other types of DNA lesions are induced by UV; they are unrepairable by PHL and present a real danger to the plant genome. To evaluate this part of DNA lesions, the frequency of chromosome aberrations (CA) was determined after solar UVB and UVB+UVA irradiation with or without PHL. Meristematic cells of Crepis capillaris were irradiated in special chambers with filters. The 4-year investigation showed that only about half of CA had been repaired with PHL. Both findings of the study, of the part of CA that remained after PHL and of the stronger genotoxicity of UVB+UVA, are discussed.
Institute of Botany, Zaliyjy Ezery 49, LT-08406 Vilnius, Lithuania. vida.ranceliene@botanika.lt
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D002869:Chromosome Aberrations; D027468:Crepis / Q000528:radiation effects*; D009152:Mutagenicity Tests; D018518:Plant Root Cap / Q000235:genetics / Q000528:radiation effects; D012639:Seeds / Q000235:genetics / Q000254:growth & development / Q000528:radiation effects; D014466:Ultraviolet Rays