EXOGENOUS LIGNIN ENHANCES THE RESISTANCE OF LEMNA MINOR L. AQUATIC PLANTS TO COPPER STRESS

Currently, there is a growing interest in preparations made from lignin, due to their various useful properties. These include biodegradability, biocompatibility, harmlessness, and a wide range of biological activities. For the first time, the fundamental possibility of using exogenous lignin to protect aquatic plant organisms from the negative effects of copper ions has been demonstrated in this work. Lignin from ledum (Ledum palustre L.) was tested as a chemoprotective agent. Presents the results of a study on the biological activity of isolated lignin on a laboratory culture of duckweed (Lemna minor L.) under the influence of a copper stress factor. During the experiments, we established the values of biomarkers for plant well-being (growth rate, level of damage, frond area, content of malondialdehyde and chlorophyll) and found that water-soluble lignin from ledum was not toxic to plant organisms. Preliminary cultivation of plants in aqueous lignin-containing media increased the total frond area, had a positive effect on growth rate, and reduced the level of damage to duckweed in copper-containing aqueous media. It was concluded that pre-treating duckweed with water-soluble lignin would increase the plant's resistance to copper stress. The data obtained confirm the opinion about the adaptive and protective properties of lignin under the influence of stress factors of various nature.