Stress memory in two generations of from radioactive and chemical contaminated areas after the cessation of exposure.

HYPOTHESIS

The differences in viability, root length, and pro/antioxidant features of seedlings identified in seed progeny formed in areas of radioactive and chemical contamination can persist in subsequent generations after the elimination of the stress.

MATERIALS AND METHODS

The seed mixtures of F1 generation were collected from natural populations (P plants) growing for a long time in the East Ural Radioactive Trace, the Karabash Copper Smelter zone, and background area. The seeds of F2 generation were obtained from F1 generation plants grown on experimental plots with 'clean' agricultural background; F3 generation was grown from F2 generation on the same plots. The viability of seed progeny was estimated by survival rate and root length. Pro/antioxidant features were determined spectrophotometrically by malondialdehyde content, superoxide dismutase and catalase activities, and total content of low molecular weight antioxidants in seedlings.

RESULTS AND CONCLUSIONS

The hypothesis about the persistence of effects from chronic exposure to ionizing radiation and chemical contamination in the generations' sequence of after the removal of stress was confirmed only partially. The data obtained indicated that changes in the prooxidant and antioxidant features of plants in response to low doses of ionizing radiation can persist for at least in two generations after the stress removal. In the case of long-term exposure to chemical contaminants, we observed the persistence of the effect in a succession of generations only on the morphological indicator of root length.