The effects of electromagnetic field radiation of extremely low frequency on growth parameters and nucleotide substitutions in L. minor clones

Current technologies have become a source of electromagnetic pollution resulting from artificially generated electromagnetic radiation (EMR). To understand the influence of the EMR on living organisms, we investigated the long-term effects of EMR of 50 Hz frequency on duckweed (Lemna minor) clones. Experimental groups of duckweed were treated directly and indirectly by changing EMR generating magnetic flux (MF) starting from 2 mu T (0-11 weeks from the beginning of the experiment) and switching to 300 mu T (12-48 weeks) MF density during the second part of the experiment. The growth parameters (plant growth, frond area, and frond number) and the point mutations appearing at the antioxidant genes DNA sequences [ascorbate peroxidase (APx), glutathione peroxidase (GPx), and catalase (Cat)] were analyzed. The significantly enhanced number of nucleotide substitutions in DNA sequences of L. minor clones directly affected by LF EMR in comparison to indirectly affected clones was revealed at the introns of APx, GPx, and Cat genes starting from the 10th week of the experiment. The results indicate that even low-dose chronic electromagnetic radiation may contribute to the changes in growth parameters and generation of point mutations in antioxidant gene sequences, especially in the intron regions.