Effects of Cadmium Stress on DNA Polymorphism of Genome in Barley Seedlings

Cd stress on DNA polymorphism in root-tips of barley (Hordeum vulgare) seedlings was studied using random amplified polymorphic DNA(RAPD)technique, and the relationship between changes in RAPD profiles, root growth and total soluble protein level in root-tips of barley seedlings was compared in laboratory condition. The results indicated that inhibition of root growth and reduction of total soluble protein content in root tips of barley seedlings altered to various degrees in the range of 20~80 mg·L-1 Cd after 8 d. Of the 12 decamer oligonucleotide primers tested, only 5 gave specific and stable results. 5 primers gave a total of 51 RAPD bands ranging from 240 to 2344 bp in molecular size in the normal seedlings. The changes occurring in RAPD profiles of root tips following Cd treatment included loss of normal bands and appearance of new bands and variation in band intensity in comparison to that of the normal seedlings. Additionally, the effect of changes was dose-dependent. These results indicated that genomic template stability (a qualitative measure reflecting changes in RAPD profiles) was significantly affected by the above Cd concentration. Thus, DNA polymorphisms detected by RAPD analysis could be used as a useful biomarker assay for the detection of genotoxic effects of Cd pollution on plants.