Scientists have learned how to protect plants from heavy metal
07.12.2017

TSU biologists are studying the properties of plant steroid hormones - brassinosteroids. Researchers have found that phytohormones can prevent the accumulation of heavy metals in plants. Along with this, brassinosteroids have a complex of other unique properties: In particular, they trigger the process of light development in the dark. The scientists are using these data to create new effective and safe biotechnologies.

- Brassinosteroids are hormones that are responsible for the normal functioning of the plant's immune system, especially under adverse conditions: low temperatures, excess of moisture and drought, diseases, pesticides, and others. They are contained in plants in extremely low concentrations, so plants cannot be used as a source to produce them. For this reason, large amounts of brassinosteroids for practical use are obtained synthetically, - says Marina Efimova, associate professor of the Department of Plant Physiology and Biotechnology at TSU’s Biological Institute.

According to Marina Efimova, today more than 70 different brassinosteroids are known. And there is only one for creating biostimulators that is well-studied and used. Recently, TSU scientists have tested 10 more steroid phytohormones. They are synthesized by Academician Vladimir Khripach, the head of the Laboratory of the Chemistry of Steroids of the Institute of Bioorganic Chemistry of the National Academy of Sciences of Belarus and the invited member of TSU’s Department of Plant Physiology and Biotechnology.

In the study of new compounds, scientists test bioregulators on different cultures and find out which of their inherent properties can be used to protect plants. One of these useful characteristics is the ability of brassinosteroids to prevent the accumulation of heavy metals by plants, the presence of which makes the product toxic.

- In the course of a series of experiments with potatoes and rapeseed, the results showed that even the lowest concentration of brassinosteroids (10-12 M) provides a good protective effect for plants,- says Marina Efimova. - In particular, phytohormones protect plants from the accumulation of lead and copper. At the present time, we are finding out exactly how brassinosteroids block the flow of heavy metals into plant cells.

Along with this, phytohormones intensify the intensity of photosynthesis in conditions of insufficient illumination. They are not able to replace daylight, but they can increase the yield of plants when it is inadequate.

The data obtained were used by TSU scientists to develop priming - a new method of plant protection. This short-term treatment of seeds with a solution of brassinosteroids allows plants to secure a margin of safety for a "rainy day". But even if extreme conditions do not come, the positive effect in the form of an increase in yields will still occur. The solution can also be used to treat crops, with one milligram of bioregulator sufficient per hectare.