Asia Simbaevna Ansabayeva

The article considers the possibility of foliar application of amino acids (proline, methionine and lysine) for the regulation of metabolism and the formation of stress resistance in plants contaminated with heavy metals (cadmium). In the green pot experiment, stress was created due to the introduction of Cd(NO3)2 into the soil at a dose of 10 mg·kg–1, which corresponds to 5 permissible concentration (SanPiN 1.2.3685-21). In an experiment with «Nur» barley, the effect of these amino acids on biomass, the content of total and protein nitrogen in leaves, the content of pigments and their ratios (Cl a, Cl b, carotenoids, Cl a / Cl b) were studied. Foliar treatment of plants with amino acids in the absence of stressful conditions was accompanied by a significant increase in aboveground biomass. The use of proline, methionine and lysine in conditions of high Cd concentrations in the soil had a positive effect on barley biomass and ear formation. All plants treated with proline and lysine showed an increase in the content of all pigments (Cl a, Cl b, carotenoids) compared with the control. Methionine had a positive effect on the chlorophyll content precisely under stress, whereas in the absence of stress, the pigment content in the plant decreased. In the Cd-contaminated variants, there was a decrease in the content of both total and protein nitrogen in barley, which indicated a violation of metabolic processes in the plant under stress. Foliar treatment with amino acids during the tillering phase is accompanied by an increase in nitrogen content both under stress and without it.