Kavulych Y. Content of phenolic compounds in wheat (Triticum aestivum L.) and buckwheat (Fagopyrum esculentum Moench.) plants under salicylic acid and cadmium ions.

The thesis deals with the study of the role of external salicilyc acid in wheat Triticum aestivum L. and buckwheat Fagopyrum esculentum Moench. plants under toxic effects of cadmium chloride. The aim of the investigation was to determine the morphometric parameters, changes of the photosynthesis and changes of antioxidant protection, which was accompanied by a change in the content of phenolic compounds and enzymes involved in protection against the action of cadmium chloride. As a result of the research we found, that salicylic acid positively influenced the initial stages of plant growth, stimulating the seed germination. Determined the negative influence of cadmium ions on the content of photosynthetic pigments, decrease growth parameters of buckwheat and wheat plants. Cadmium as one of the most toxic metals has negative affects on photosynthesis, change the structure and the functioning of chlorophyll molecules. Salicylic acid can mitigate the toxic effects of heavy metal ions, has positive affect on the structure and functioning of photosynthetic pigments and increase morphometric parameters under stress conditions. The increase of phenolic compounds in plant tissue of 14- and 21-day-old plants against the background of inhibition of growth by cadmium ions indicates their prooxidant role. Reducing the concentration of phenols in the roots and shoots of plants and increasing the content of anthocyanins due to preincubation of salicylic acid indicates that they are one of the components of the adaptive response of plants to stress by cadmium. The results of lignification process shown differences in the accumulation of lignin in the different part in plant, also this process depends on the conditions of growth and plant species. Salicylic acid induced process of lignification, because salicylic acid is phenolic compound. The positive results will allowto use salicylic acid as an efficient and cheap way to treat plants under conditions of environmental heavy metals pollution.Salicylic acid has positiveeffect on morphometric parameters, stabilized the photosynthesis and normalized the content of phenolic compounds due the work of enzymes under conditions of cadmium stress. It is necessary to indicate the specific nature the response of plants to the stress protective role of salicylate for the toxic effects of cadmium. We studied buckwheat and wheatplants. The obtained results show positive effect of salicylate for both plants species. The concentration of salicylic acid (0,05mM) has positive influenced for photosynthesis, also did not cause significant changes in the pool of phenolic compounds. Therefore, for future research, we recommend use this concentration of salicylic acid, but at the same time,take into account the specificity of the species.