Tomato (Lycopersicon esculentum) seeds were germinated in Peteri dishes for 7-10 days. Seedlings were transferred to pots and grown in greenhouse for two weeks. Cadmium treatments were applied with water with concentrations 0.0, 10.0, 50.0, 70.0 and 100.0 µM. Genomic DNA from tomato leaves was used for RAPD-PCR analysis using four random primers (OPB05, OPB07, OPB08 and OPB09). RAPD profiles showed great variations in banding patterns, particularly in intensity, number, thickness and mobility of the generated PCR fragments. Appearance of new PCR products may be occurred because some oligonucleotide priming sites could become accessible to primers due to changes in DNA sequence. Disappearance of some DNA fragments might be due to structural rearrangement in DNA caused by different types of DNA damage after exposure to cadmium pollution which can change the number of binding sites of Taq polymerase. Structural rearrangement may also results in an increase in the intensity and thickness of some DNA fragments. The change in the mobility of some DNA fragments might be due to Single Strand Conformational Polymorphism (SSCP) that reveals differences in electrophoretic mobility between normal and mutant single strands of DNA. These results indicated that RAPD analysis could be used as a useful biomarker assay for detection of genotoxic effects of cadmium. Cadmium pollution can cause genotoxic effects and tomato plants can be used as a bioindicator for evaluation of environmental pollution by heavy metals.
Key words: genotoxicity, Cadmium, tomato, Lycopersicon esculentum, RAPD markers
|
