THE CONTRIBUTION OF THE ORGANS OF THE BARLEY SEEDLING TO THE FORMATION OF THE RESPONSE TO THE ACTION OF THE MICROWAVE STRESSOR
The whole plant may exhibit organospecificity in response to the influence of stress factors. Knowledge of the role of leaves and roots of a seedling in the formation of a response to the action of a stressor will improve understanding of the relationships between individual organs in an intact plant. The fatty acid profile is particularly interesting in this regard, since fatty acids perform many important physiological and biochemical functions in the plant (and not only) world. The purpose of the research: to establish the role of aboveground and underground organs of barley seedlings in the formation of a response to the action of a microwave stressor by changing the fatty acid profile. One of the main grain forage crops, spring barley of the Simon variety, was chosen as the object of research. The combination of treatment modes included the following options: control, without treatment; electromagnetic microwave irradiation of dry seeds with a power of 0.70 kW, a frequency of 2.45 GHz, with an exposure of 10 seconds. From all anatomical parts of the seedlings obtained after microwave treatment, they were extracted with a mixture of chloroform and n-hexane, in which the content of fatty acids was determined by gas chromatography. The total number of identified fatty acids reaches 20, of which only 17 names were registered on the control variants of leaves and roots. All identified LC contain from 14 to 26 carbon atoms, i.e. they belong to medium-chain, long-chain and very long-chain fatty acids. In the leaves of microwave-treated seedlings, in comparison with native samples, de novo synthesis of tricocylic and eicosenic acids occurs, and part of linoleic acid undergoes isomerization. In the roots of microwave-treated seedlings, myristooleic, aceterucic and linoleic acid isomer are synthesized de novo. Palmitic acid occupies more than 40% of all identified LC in native leaves, as well as native microwave-treated roots. In the leaves of experimental seedlings, there is a sharp, more than 2-fold decrease in the amount of palmitic acid, almost as much hexacosanoic acid is contained. There is a significant organospecificity for individual fatty acids. Thus, the amount of а-linolenic acid in the leaves of experimental plants increases by 19.63% relative to the control, and in the roots, on the contrary, decreases by 2.84 times. The differences found between the responses of leaves and roots are explained by the different metabolic activity and the different contribution of these anatomical organs of the seedling to the physiological and biochemical processes of growth and development. Due to the transformation of the fatty acid profile of seedlings, the negative effect of the stressor - the electromagnetic field of the microwave - is compensated.