Epigenetic factors of the effect of UV-C and X-ray presowing seeds radiation exposure in Matricaria chamomilla L. genotypes

In a series of experiments using both X-ray and UV-C radiation exposure a parallel study of several pharmacological characteristics of the Matricaria chamomilla L. genotype group was carried out. The data concerning the changes in the productivity of pharmacological raw materials and stimulation of the synthesis of low molecular weight antioxidants as markers of secondary metabolism induction have been published earlier. In this study, the data on the relationship between the stimulation of the synthesis of secondary metabolites under different types of irradiation and the epigenetic changes in the plant organism are presented. It was shown that DNA methylation was switched to the de novo mode in plants of all studied genotypes of M. chamomilla under both types of irradiation. That indicates changes in the epigenetic program of the plant organism. Comparison of the epigenetic pattern between control and irradiated samples, based on the difference in DNA methylation patterns in terms of a statistical indicator, shows that there is no unambiguous relationship between the epigenetic changes and increasing yield of antioxidant synthesis. This is additional evidence of the diversity of metabolic rearrangements and adaptive strategies of the plant organism under radiation exposure even within one species.