Abstract
Assessment of mutagenic effects and DNA damage induced by radioactive elements at molecular level is important in ecotoxicology. In the present study, the radionuclides content was determined in four crop plant species, namely Eruca sativa M., Solanum lycopersicum L. Pasidium guajava L. and Mangifera indica L. cultivated in the black sand soil. The results revealed the ability of the plants to accumulate a considerable amount of uranium and thorium in the edible portions. The absorbed radionuclide induced damages in DNA as indicated by variations in band intensities, loss of normal band and appearance of new bands in RAPD profiles compared to plants with low radionuclides content. The high level of uranium and thorium in plant tissues caused some changes in SDS-PAGE of proteins reflected by alterations in the band relative mobility and intensities, expression of new proteins and suppression of some proteins. It is concluded that high uranium and thorium content induces mutagenesis and genotoxicity in the four crop plant species. The DNA polymorphism detected by RAPD analysis and SDS-PAGE of proteins could be used as investigation tool for environmental toxicology and as a useful biomarker for the detection of genotoxicity caused by the radionuclides pollution in plants.