Identification of DNA polymorphism induced by X-ray and UV irradiation in plant cells

Angelonia protoplasts were irradiated with X-rays or UV to obtain a half su rvival rate. To evaluate the DNA damage, total genomic DNA was prepared fro m protoplasts irradiated with X-rays or UV and nonirradiated control protop lasts, respectively. An aliquot of DNA was subjected to polymerase chain re action (PCR) with a decamer arbitrary primer in the presence of radiolabele d nucleotides under annealing conditions of low stringency. Randomly amplif ied PCR products were analyzed using a denaturing polyacrylamide gel. All t he DNA bands detected by autoradiography were compared. The number of DNA b ands detected in one lane was approximately similar to 150. The results ind icate that the arbitrarily amplified PCR method is very sensitive for monit oring the DNA polymorphism caused by X-ray and UV irradiation. This novel p rocedure, designated as RI (radioisotope incorporated)-RAPD, could be appli ed to detect precise DNA polymorphism in plant cells.