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One of the main tasks of modern plant physiology is regulation of growth and development of cultivated plants in order to optimize the productive process. The attention of the scientific community is focused on the use of natural activators and growth inhibitors. We investigated the effect of foliar treatment with 0.005% solution of gibberellic acid (GA3) and 0.025% solution of the antigibberellic preparation tebuconazole (EW-250) on morphogenesis, leaf mesostructure, the content of photosynthetic pigments, the balance of endogenous phytohormones and productivity of Capsicum annuum L., Antey variety. The vegetation experiment was carried out in the conditions of soil-sand culture in vessels with a volume of 10 L. Treatment of plants was carried out in the budding phase. Morphometric parameters were determined every 10 days. The mesostructure of the middle tier leaves was studied in the fruit formation phase, and the chlorophyll content was determined in the raw material by spectrophotometric method. Analytical determination of endogenous phytohormones – indolyl-3-acetic (IAA), gibberellic (GA3) and abscisic (ABA) acids and cytokinins – zeatin (Z), zeatin-O-glucoside (ZG), zeatinribozide (ZR), isopentenyladenine (iP) and isopentenyladenosine (iPA) were performed by high performance liquid chromatography – mass spectrometry (HPLC-MS). With GA3 treatment, plant height increased considerably, while with EW-250, it decreased. Both regulators led to an increase in the number of leaves on the plant, the leaf raw biomass, stems and roots and the dry matter of the whole plant, the area of a single leaf blade and the total area of leaves on the plant. Under the action of EW-250, the chlorophyll content in the leaves surged, while under the action of GA3 it tended to decrease or did not change at all. Both regulators thickened the chlorenchyma and boosted the volume of the columnar parenchyma cells. GA3 treatment induced a rise in the thickness of the upper and lower epidermis, and EW-250 led, on the contrary, to a decrease. It is shown that after treatment with exogenous GA3, the content of endogenous IAA and ABA decreased and GA3 in plant stems increased. Instead, EW-250 caused a decrease in the levels of GA3, IAA and ABA in the stems. Exogenous GA3 enhanced the accumulation of endogenous GA3 and IAA and inhibited ABA in the leaves. Under the action of the retardant, the level of ABA in the leaves did not change, while GA3 and IAA decreased. Treatment of plants with the studied growth regulators caused a decrease in the pool of cytokinins (CK) in stems. EW-250 showed a significant rise in the hormone content in the leaves. After spraying with GA3 solution, the level of ZG, Z and ZR grew. Under the action of the retardant, the increase in the CK pool occurred exclusively due to the iP. Growth regulators optimized the productivity of sweet pepper plants: under the action of GA3 there was an increase in the number of fruits per plant, and after the use of EW-250 there was a rise in the average weight of one fruit. The obtained results showed that anatomical-morphological and structural-functional rearrangements of sweet pepper plants under the action of exogenous gibberellic acid and EW-250 took place against the background of changes in the balance and distribution of endogenous hormones. Increased photosynthetic activity, stimulation of growth processes of some plant organs and inhibition of others enlarged biological productivity of the culture.

The review analyzes and summarizes the latest literature on the history of development and the current state of methodological approaches to the identification and quantification of phytohormones in plant tissues. Phytohormones play a key role in the regulation of physiological processes throughout the life cycle of plants – from seed germination to aging. In tissues of plants, their concentrations are very low (from 10-9 M to 10-6 M), so the development of fast, highly efficient, comprehensive, and at the same time reliable approaches to the determination of phytohormones is extremely urgent. The article gives a brief description of the main classes of phytohormones, describes their functional activity. The substantiated and checked sequence of procedures on the extraction of plant hormones, their separation from interfering substances, quantification methodology for indol-3-acetic, abscisic, gibberellic (GA3), salicylic acids and five cytokinins that combines a high-performance liquid chromatography with mass spectrometry are presented. The article describes four chromatographic methods of profiling, gives the conditions for detecting phytohormones of different classes and ionization of these substances in a mass spectrometer. The importance of phytohormones profiling in plant tissues for further applied in biotechnological approaches, in particular in metabolic engineering, for the formation of stress resistance in crops is discussed.

The review analyzes and summarizes information on the history of development and the current state of methodological approaches to the qualitative and quantitative determination of phytohormones in plant tissues. Plant hormones play an indispensable role in many physiological processes during a plant life cycle, from seed’s germination to senescence. The determination of the endogenous hormones concentration is essential for elucidating the role of a particular hormone in any physiological process. A sensitive and quick analytical method of a simultaneous quantitative estimation of the main classes of phytohormones is essential for the investigation of signaling control networks in specific developmental pathways and physiological responses. In plant tissues, phytohormones are present in very low concentrations (from 10-9 M to 10-6 M); hence, the availability of highly effective, comprehensive and reliable analytical techniques for their identification is extremely important. The article gives a brief description of the main classes of plant hormones and outlines their functional activity. The importance of methods for hormones identification in plant tissues and their use in plant physiology and agricultural practice is discussed. The study presents a valid and tested sequence of procedures for the extraction of plant hormones, a methodology for purification of the obtained extracts from interfering substances and an up-to-date method of plant hormones quantification (indole-3-acetic, abscisic, gibberellic, salicylic acids and five forms of cytokinins). The quantification method combines a high-performance liquid chromatography with a mass spectrometry. Four chromatographic methods for the sepa­ration and detection of substances in aliquots as well as ionization conditions for hormones in a mass spectrometer are described. The presented analytical technique is adapted for scientific laboratories in Ukraine.

Regulation of growth and development of cultivated plants in order to optimize the production process is one of the main objectives of modern plant physiology. Both activators and growth inhibitors are used for this purpose. The effect of foliar treatment with 0.005% solution of gibberellic acid and 0.025% solution of antigibberellic preparation of tebuconazole on the morphogenesis, leaf structure, photosynthetic pigment content, balance of phytohormones and eggplant productivity cv. Diamond variety was investigated. The treatment with the preparations was carried out in the budding phase. The vegetation experiment was laid under soil and sand culture in vessels of a ten-liter capacity. The morphometric parameters were determined every 10 days, the mesostructure was studied in the leaves of the middle tier in the phase of fruit formation, chlorophyll content was measured in the raw material by spect­rophotometric method. Analytical determination of phytohormones (indole-3-acetic acid, gibberellic, abscisic acids and cytokinins – zeatin, zeatin-O-glucoside, zeatinriboside, isopentenyladenine and isopentenyladenosine) was performed by high performance liquid chromatography. Under the action of gibberellic acid, plant height increased significantly, and it decreased after its treatment with tebuconazole. The stimulator and inhibitor increased the number of leaves per plant, the weight of the leaf dry matter, the area of the individual leaf blade and the area of leaves per plant. Both preparations increased the weight of the raw material of the stems and roots, as well as the mass of dry matter of the whole plant. Under the action of tebuconazole, the content of chlorophylls in the leaves increased, while under the action of gibberellic acid it decreased. After treatment with gibberellic acid and tebuconazole, the thickness of the leaf blade increased due to chlorenchyma thickening. In the variant with gibberellic acid, the thickness of upper and lower epidermis increased, and in the variant with tebuconazole, these parameters decreased. Both growth regulators increased the volume of cells of the columnar parenchyma. The contet of endogenous gibberellic, indole-3-acetic and abscisic acids of the stems and especially in the leaves increased with the treatment of exogenous gibberellic acid, whereas after the application of tebuconazole the gibberellic and indole-3-acetic acid content of the stems decreased significantly and practically decreased to traces. Instead, the amount of abscisic acid increased. After treatment with exogenous gibberellic acid, the pool of cytokinins in the leaves significantly decreased. The inactive isoforms of the hormone zeatin-O-glucoside and isopentenyladenosine dominated in the stems. The effect of tebuconazole decreased the pool of cytokinins in the stems and increased in the leaves. In general, due to the multidirectional action, growth regulators positively influenced the elements of eggplant productivity. More effective was the retardant – tebuconazole. Therefore, the anatomic-morphological and structural-functional rearrangements in eggplants under the effects of exogenous gibberellic acid and tebuconazole are due to changes in the balance and distribution of endogenous hormones. Increased photosynthetic activity, stimulation of growth processes of some organs of the plant and inhibition of others enlarged the biological productivity of the culture.

The review focuses on the analysis of new information concerning molecular enzymology of lipoxygenases – proteins involved in lipid peroxidation and found in animals and plants. Modern concept of structural features, catalytic characteristics and functions of lipoxygenase family enzymes as well as products of their catalytic activity in plants have been discussed and summarized. Issues of enzyme localization in plant cells and tissues, evolution and distribution of lipoxygenases, involvement in production of signaling substances involved in formation of adaptation response to abiotic and biotic stress factors and in regulation of lipoxygenase signal system activity are highlighted. Participants of the elements signaling of LOX-pathway reception and transduction into genome are considered. Special attention is given to jasmonates, metabolites of the allene oxide synthase branch of the lipoxygenase cascade, because these metabolites have high biological activity, are ubiquitously present in all plant organisms, and are involved in regulation of vitally important processes. Data concerning lipoxygenase phylogeny, possible occurrence of a common predecessor for modern isoforms of the enzyme in pro- and eukaryote have been examined. Some results of our studies that open up possibilities of using the lipoxygenase catalytic activity characteristics as biological markers in plant stress tolerance researches are given.

The characteristics of photosynthetic pigments and efficient use of light energy are analyzed fon the example of chloroplast ultrastructure of the photosynthetic apparatus of floating and submerged fronds of annual heterosporous of water fern Salvinia natans (L.) All. in ontogenesis. It is established that at the stage of intensive growth chloroplasts floating fronds had a well-developed system of thylakoid membranes with many faces and contain a lot of starch grains. Submerged fronds shaped chloroplasts are smaller with little starch in the stroma. Destructive changes in chloroplast photosynthetic membranes of both frond types are observed at the stage of sporocarp formation. Particularly, decomposition of gran tylakoiod membranes, disturbances in inter-gran connections, reduction of starch grain number in stroma were revealed. In the chloroplast stroma of floating wai numerous plastoglobules were fouond. In chloroplasts submerged fronds fewer plastoglobules education were noted. In addition, a certain portion of popu­lation hloroplastoa in both types fronds retains intact structures.The photosynthetic pigment content of floating fronds was found to exceed that of submerged two times, and at some stages of ontogenesis – three times. At the stage of sporocarp formation, the chloroplast and carotinoid content in fronds of the both types decreased. Floating fronds are characterized by an effective action of the chloroplast photosynthetic electron transport chain, and are adapted to an intensive natural lighting on a water surface. Submerged fronds affected by lighting whose intensity fits with a maximum level of natural characteristics were found to be at stress. That was confirmed by a decrease in quantum efficiency ФСІІ (ΦPSII) and increase in dissipation of excessive light energy as heat in rise of the level of nonphotochemical quenching of chloroplast fluorescence (NPQ).

The pattern of changes of lipoxygenaze activity (LOX) and cell ultrustructure of the horsetail rhizome (Equisetum arvense L.) in ontogenesis was studied. LOX activity in the rhizome of spore-bearing and vegetative shoots in ontogenesis was analyzed. Dormancy release was found to occur against the background of 9-LOX activity increase. In vegetative shoot rhizomes there was identified 9-LOX activity while generative shoot rhizomes displayed 9-LOX and 13-LOX activity. It is shown that changes in the activity of lipoxygenase consistent with the dynamics of lipid metabolizing rhizome E. arvense throughout ontogeny. In contrast to a ground stem, a differentiated rhizome of E. аrvense has no internal valecular channels and hollows. The whole space between integumentary tissue and conducting bundles is filled with large cells of the main parenchyma, which functions as storing tissue. Parenchyma cells are vacuolated and contain numerous aminoplasts filled with starch grains. Specific changes were found in the horsetail rhizome cell ultrustructure during dormancy release, viz: reduction of starch grains in aminoplasts and increase in the number of lipid drops that form typical accumulations close to the plasmolemma. In epidermis (rhyzodermis) cells and parenchyma cell surface layers located closer to the rhyzodermis numerous osmiumphylic pigment granules were identified. The are characterized by a considerable electro­nic density which determine the rhizome colour.