Effects of chronic radiation exposure on the plant populations, observed in the reference plant the Scots pine. Review

Large-scale radiation accidents at the Mayak production association and at the Chernobyl NPP caused contamination of large territories of Russia by radioactive fallouts. The increased level of mutagenesis found in plants and animals inhabiting radioactively contaminated lands raise the question about possible ecological consequences of chronic exposure to low-dose radiation. However, late effects of chronic exposure to radiation on plants and animals are still debated in scientific communities. The paper presents the basic results of long-term follow up (2003-2016) of the populations of the Scots pine inhabiting in areas with different levels and spectrum of radioactive contamination. Population of animals and plants developing under continuous radiation exposure have increased levels of mutagenesis, genome wide methylation, changes in genes expression, genetic structure of the population and temporal dynamics of cytogenetic defects. However, found genetic changes in the pine organism did not affect enzyme activity in endosperms, rates of morphologic abnormalities and rates of reproductive power. Results of the study provide evidence that the pine has high sensitivity to chronic radiation exposure. Significant genetic effects had been observed during the surveillance period, perhaps these effects will be observed for a long time. Since changes in epigenetic status and genetic structures of the edificator plant, the Scots pine is one of the environment-forming plants playing important role in forming response of the environment to radiation, these processes should be taken into account when programs on the preservation of biodiversity under chronic radiation exposure are developed.