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The dynamics and distribution of endogenous cytokinins (CKs), gibberellic (GA3) and salicylic (SA) acids in wheat (Triticum aestivum L., ‘Podolyanka’) and spelt wheat (Triticum spelta L., ‘Frankenkorn’) plants was analyzed using HPLC–MS. Fourteen-day-old plants that had been exposed to short-term heat stress (+ 40 °C, 2 h) and 21-day-old plants after recovery were studied. Heat stress induced rapid changes, both specific and nonspecific, in hormone levels and distribution. The level of GA3 decreased in the shoots and roots of both winter and spelt wheat. A reduction in SA content was observed in wheat, while an increase was observed in spelt. The pool of CKs significantly increased in wheat, while in spelt—it decreased more than twofold. After recovery, an increase in GA3 content occurred in both species, but not to the levels measured in control plants. More active accumulation of GA3 was observed in the roots. The content of SA in the shoots of wheat continued to decrease, while in the roots it increased. In spelt, hormone concentration decreased, but it remained higher than in 21-day-old control plants. In shoots of both plants the pool of CKs decreased, while in wheat roots it did not change, and in spelt roots it decreased. The total CKs content in stressed wheat plants was twice as high as in spelt. In general, we established significant hormonal fluctuations, which indicate a direct involvement of endogenous cytokinins, gibberellic and salicylic acids in wheat and spelt response to heat stress. Screening of stress-resistant genotypes of cereals may benefit from quantitation of CKs, GA3, and SA.

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 content of indole-3-acetic (IAA), gibberellic (GA3), abscisic acids (ABA), and cytokinins—zeatin (Z), zeatin glucoside (ZG), zeatin riboside (ZP), isopentenyladenin (iР), and isopentenyladenosine (iРА)—was determined using the method of high-performance liquid chromatography in fern Polystichum aculeatum gametophytes at different stages of morphogenesis in vitro culture. It was shown that, at the stage of spatulate prothallium development, gametophytes contained significant amounts of GA3 and IAA, while the content of ABA and cytokinins was low. The inactive ZG and active iP were dominant. At the stage of cordiform thallus formation, the level of GA3 increased by 1.6, IAA by 2.4, and ABA by 1.7 times. The content of inactive iPA increased twice, significantly increased the level of active ZR and iP. At the development stage of sporophyte on the surface of gametophyte thallus, the levels of IAA, ABA, and GA3 decreased. The accumulation of inactive ZG and decrease in the content of active zeatin and zeatin riboside were documented. At all stages of gametophytes’ morphogenesis, GA3 was dominant, and its highest content was detected during the development of archegonia and antheridia. The pattern of gibberellic acid and zeatin riboside accumulation has shown the key role of these hormones in the regulation of growth processes and the development of reproductive structures of P. aculeatum gametophytes.

The article describes the growth and development of Salvinia natans (L.) All., a native aquatic fern found in Ukraine, collected from artificial water reservoirs in the Desnyansky district of Kyiv. Scanning electron microscopy was used to study the surface microstructure of its vegetative and reproductive organs. The success of the fern on the boundary of water and air is apparently supported by the specific microstructure of its floating leaves, the adaxial surface of which are characterised by the presence of a well-developed cuticle and sunken stomata. The stomatal density was found to be 142 per mm2, with an average stomatal pore diameter of 8.1 μm. The abaxial surface of both floating and submerged leaves was characterised by the presence of thin cell walls in the epidermis and of numerous filamentary appendages (trichomes). The structure of both the sori and the sporangia allows for an annual summer-green phenological pattern, whereby sori are produced near the bottom of the reservoir in autumn, and rise to the surface of water in spring.

Работа выполнена в рамках проекта “Скрининг лекарственных грибов — продуцентов цитокининов для создания новейших биологически активных препаратов и лекарственных средств” при поддержке НАН Украины.

The effects of exogenous phytohormones–gibberellic acid (GA3) and benzyl-aminopurine (BAP)–on the spore germination and morphogenesis of Polystichum aculeatum (L.) Roth gametophyte in vitro culture were studied. In the control, four stages of gametophyte morphogenesis were determined and their periods were established. Spore germination and protonema formation of P. aculeatum occurred according to the Vittaria-type and prothalium development according to the Aspidium-type. The spore germination percentage depended on the storage time duration. It was found that 80–95% of freshly collected spores germinated. Spore viability was within the range of 68–95% after 4–6-month storage under lab conditions and did not exceed 20% after 1.5 year of the storage period. High concentrations of exogenous GA3 (10–5 and 10–6 M) and BAP (10–5 M) significantly inhibited spore germination, whereas low concentrations (GA3 10–7–10–8 M) had an insignificant stimulating effect or did not affect germination at all (BAP 10–6, 10–7, 10–8 M). All concentrations of exogenous BAP were demonstrated to inhibit the development of P. aculeatum gametophyte at the protonema stage, which might be due to the removal of apical dominance. The inhibiting effect directly depended on BAP concentrations. The formation of abnormal thalli of the P. aculeatum gametophyte in the response to exogenous GA3 treatments occurred as a result of impairment of cell growth by elongation. A direct interrelationship between GA3 concentrations and level of morphological abnormalities and grade of thalli underdevelopment was demonstrated.

We investigated whether the priming with abscisic acid (ABA) alters the growth and the content of endogenous phytohormones in winter wheat seedlings under zinc stress. It was shown that zinc at a concentration of 228 mg/l inhibits the growth of the root system. Under these conditions, a decrease in the content of endogenous indole-3-acetic acid (IAA), zeatin, and abscisic acid (ABA) and an increase in gibberellic acid (GA3), isopentenyladenosine (iPA) and salicylic acid (SA) took place. After the adding of 10⁻⁶ M ABA to the incubation medium, the growth of seedling roots, the level of stressful hormones ABA and SA became higher. The strategy of the adaptation of wheat seedlings to zinc stress in the presence of exogenous ABA was aimed at the activation of root growth. Changes in the phytohormones balance initiate protective mechanisms and a further adaptation of plants to a high concentration of zinc, and the treatment of grains with exogenous ABA can be used to enhance the stress resistance. Досліджено вплив цинкового стресу на ріст та акумуляцію ендогенних фітогормонів у проростках озимої пшениці, зернівки якої були праймовані абсцизовою кислотою (АБК). Показано, що в результаті інкубації на розчині цинку надлишкової концентрації (228 мг/л) гальмувався ріст кореневої системи, знижувався вміст ендогенної індоліл-3-оцтової, абсцизової кислот і зеатину та збільшувалась кількість гіберелінів, ізопентеніладенозину та саліцилової кислоти. Після додавання в інкубаційне середовище 10⁻⁶ М АБК посилювався ріст коренів, вміст стресових гормонів абсцизової та саліцилової кислот зростав. Зміни у балансі фітогормонів ініціювали захисні механізми рослин до дії високої концентрації цинку, а отже, праймування зернівок екзогенною АБК може бути використане для підвищення стресостійкості. Исследовано влияние цинкового стресса на рост и аккумуляцию эндогенных фитогормонов проростками озимой пшеницы, зерновки которой были праймированы абсцизовой кислотой (АБК). Показано, что при инкубации на растворе цинка избыточной концентрации (228 мг/л) угнетался рост корней, уменьшалось количество эндогенных индолил-3-уксусной, абсцизовой кислот, зеатина и увеличивалось содержание гиббереллинов, изопентениладенозина и салициловой кислоты. После добавления в инкубационную среду 10⁻⁶ М АБК рост корней усиливался, содержание стрессовых гормонов абсцизовой и салициловой кислот возрастало. Изменения в балансе фитогормонов инициировали защитные механизмы растений к действию высоких концентраций цинка, следовательно, праймирование зерновок экзогенной АБК может быть использовано для повышения стрессоустойчивости.

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.

The leaf surface microstructure, pigments spectrum, phytohormones content, and lipids composition of halophytes with various metabolic and physiological strategies of adaptation to salinity of Polygonum maritimum L. and Euphorbia paralias L. grown under natural conditions on dunes of the Pomorie Lake (Bulgaria) are compared. P. maritimum stomata are located on the leaf both sides below the cuticle level, whereas, in E. рaralias, stomata are present only on the abaxial side, and they are surrounded with hump-shaped cuticle constructions. A high amount of carotenoids (as compared with chlorophylls) in P. maritimum leaves indicates that these pigments have a light-collecting function and could transfer an additional energy to chlorophylls. In leaves of E. paralias and P. maritimum, free abscisic acid and conjugated indole-3-acetic acid prevailed. The inactive cytokinins (cis-zeatin and zeatin-O-glucoside) dominated in E. paralias leaves, whereas P. maritimum leaves contained a significant quantity of isopentenyl-type cytokinins. The presence of a large amount of saturated fatty acids provides a decrease of membrane permeability and better resistance against soil salinity. It is concluded that the ecological strategy of halophytes involves the complex of structural and functional adaptations and determines a successful existence under salinity conditions. Проведено порівняння мікроструктури листкової поверхні, пігментного спектра, вмісту фітогормонів і складу ліпідів у галофітів з різною метаболічною і фізіологічною стратегіями адаптації до засолення Polygonum maritimum L. та Euphorbia paralias L., які зростали у природних умовах на дюнах Поморійського озера (Болгарія). У P. maritimum продихи знаходяться по обидва боки листка нижче рівня кутикули, тоді як у E. paralias — лише на абаксіальному боці й оточені складками кутикули. Значна кількість каротиноїдів (порівняно з хлорофілами) у листках P. maritimum указує на те, що ці пігменти виконують світлозбиральну функцію і можуть передавати додаткову енергію на хлорофіли. У листках E. paralias і P. maritimum переважають вільна абсцизова кислота і кон'югована індоліл-3-оцтова кислота. Неактивні цитокініни (цисзеатин і зеатин-О-глюкозид) домінують у листках E. paralias, тоді як у листках P. maritimum міститься значна кількість ізопентенільних форм цитокінінів. Наявність великої концентрації насичених жирних кислот забезпечує зменшення проникності мембран і кращу солестійкість. Зроблено висновок, що екологічна стратегія галофітів поєднує комплекс структурних та функціональних пристосувань і визначає успішне існування в умовах засолення. Проведено сравнение микроструктуры листовой поверхности, пигментного спектра, содержания фитогормонов и состава липидов у галофитов с различной метаболической и физиологической стратегиями адаптации к засолению Polygonum maritimum L. и Euphorbia paralias L., произраставших в естественных условиях на дюнах Поморийского озера (Болгария). У P. maritimum устьица находятся по обе стороны листа ниже уровня кутикулы, тогда как у E. paralias — только на абаксиальной стороне и окружены складками кутикулы. Значительное количество каротиноидов (относительно хлорофиллов) в листьях P. maritimum указывает на то, что эти пигменты выполняют светособирающую функцию и могут передавать дополнительную энергию на хлорофиллы. В листьях E. paralias и P. maritimum преобладают свободная абсцизовая кислота и конъюгированная индолил-3-уксусная кислота. Неактивные цитокинины (цис-зеатин и зеатин-О-глюкозид) доминируют в листьях E. paralias, в то время как в листьях P. maritimum содержится значительное количество изопентенильных форм цитокининов. Наличие высокой концентрации насыщенных жирных кислот обеспечивает уменьшение проницаемости мембран и улучшает солеустойчивость. Сделан вывод, что экологическая стратегия галофитов объединяет комплекс структурных и функциональных приспособлений и определяет успешное существование в условиях засоления.

Thermally stable mesoporous nanocrystalline ТiО2 with a pure anatase structure was obtained by sol–gel synthesis (in combination with hydrothermal treatment) using titanium tetrabutoxide and dibenzo-18-crown-6 as a structure-directing agent in presence of surfactant and/or La3+ ions additives. Nanocrystalline TiO2 demonstrates various textures with a well-defined spherical morphology (micro- and nanospheres), a crystallite size of no greater than 10 nm (XRD), and a narrow pore size distribution. Spherical particles of micrometer scale in the presence of La3+ ions do not form. TiO2 calcined (at 500 °C) after hydrothermal treatment (at 175 °C) has a significantly more developed porous structure as compared with TiO2 which was not treated hydrothermally. For example, specific surface area amounts 137 m2 g−1 and 69 m2 g−1, pore volume 0.98 cm3 g−1 and 0.21 cm3 g−1, pore diameter 17.5 nm and 12.5 nm respectively for samples hydrothermally treated and not treated.