[Role of phytochrome in organ formation processes in Cucumis sativus L].

The role of phytochrome B in the organogenesis process in the apical and axillary shoot meristems during early ontogenesis stages in cucumber Cucumis sativus L. at photoperiods (day/night) 10/14, 16/8 h, and continuous light in comparison with wild type plants and phytochrome B-deficient mutant (lh-mutant) was investigated. In mutant phytochrome B, deficiency caused inhibition of initiation of leaves both in the leading shoot and off-shoots and increased the number of flower buds (IV stage of organogenesis). With continuous light, the number of off-shoots and flowers during stage IV of organogenesis in wild-type plants increased twofold in comparison with the mutant. Short-term temperature drops did not induce floral ontogenesis in mutants but increased the number of off-shoots in both experimental variants during a long photoperiod and continuous light situations. We propose that phytochrome B, by increasing the compactness of chromatin, may facilitate coordination of ontogenesis processes with changing environmental conditions.

[The effect of daily exposure to low hardening temperature on plant vital activity].

Phenomenological responses of plants to daily short-term exposure to low hardening temperature was studied under chamber and field conditions. Experiments were carried out on cucumber (Cucumis sativus L.), barley (Hordeum vulgare L.), marigolds (Tagetes L.), and petunia (Petunia x hybrida) plants. The obtained data demonstrated a similar pattern of response in all studied plant species to different variants of exposure to low hardening temperature. The main features of plant response to daily short-term exposure to low hardening temperature include: a higher rate of increase in cold tolerance (cf. two- or threefold increase relative to constant low hardening temperature) that peaked on day 5 (cf. day 2 at constant low hardening temperature) and was maintained for 2 weeks (cf. 3-4 days at constant low hardening temperature); a simultaneous increase in heat tolerance (cf. twofold relative to constant low hardening temperature) maintained over a long period (cf. only in the beginning of the exposure to constant low hardening temperature); a sharp drop in the subsequent cold tolerance after plant incubation in the dark (cf. a very low decrease in cold tolerance following the exposure to constant low hardening temperature); a combination of high cold tolerance and high photochemical activity of the photosynthetic apparatus (cf. a low non-photochemical quenching at constant low hardening temperature); and the capacity to rapidly increase cold tolerance in response to repeated short-term exposures to low hardening temperature in plants grown outdoors (cf. a gradual increase after repeated exposure to constant low hardening temperature). Possible methods underlying the plant response to daily short-term exposure to low temperature are proposed.

[Daily temperature gradients and processes of organogenesis in apical meristem of Cucumis sativus L].

We studied the influence of daily temperature gradients on organogenesis in apical and axil shoot meristems at different developmental stages in Cucumis sativus L. The level of organogenic activity of meristems was determined according to the number of leaf primordia on the main and lateral shoots, number of 2nd order shoots, and rudiments of flowers of different levels of development. At the studied ontogenetic stages (mesotrophic seedling or juvenile state), plants were grown under the controlled conditions: photoperiod 12 h, light intensity 100 Wt/m2, range of mean daily temperatures 20 ... 30 degrees C, and daily temperature gradients -20 ... +20 degrees C. After the temperature treatment, some plants were returned to the optimal, for growth and development, conditions for two weeks (aftereffect). Three types of organogenic activity of meristems in response to the influence of variable daily temperatures were described: stimulation, inhibition, or absence of effect. The phenomenon of stimulation includes two subtypes: optimization, when a maximum effect, observed at other constant temperatures, was attained under the influence of variable temperatures and maximization, when maximum values markedly exceeded those at constant temperatures. The patterns described are preserved on the whole in the aftereffect of daily temperatures.

[The effect of short-term daily temperature drops on the processes of organogenesis in Cucumis sativus L. under conditions of different photoperiods].

The effect of nightly temperature drops of different durations (2, 4, and 6 h) on the processes of apical and axillary meristem organogenesis was studied in young Cucumis sativus L. under short photoperiod (day/night, 10/14 h), long photoperiod (16/8 h), and continuous light. Nightly temperature drops for 2 h had no effect on cucumber development under all studied photoperiods; however, longer temperature drops (4-8 h) accelerated the development under long photoperiod and continuous light. Short-term exposures to low temperature under continuous light considerably increased lateral branching of cucumber plants.

[Photothermal model of plant development].

The development of plants depends on the photoperiod length, light intensity, temperature, and length of light day integral. The reaction of a plant to the day length or daily light integral can depend on both the range of studied light intensities and photoperiod. Based on the data concerning the effects of light and thermal integrals on the developmental rate of plants of different photoperiodic groups, a photothermal model of plant development was proposed. The model was used to calculate the lengths of optimal photoperiods and ranges of daily temperature gradients ensuring the highest developmental rate of some plants, such as soybean, wheat, cucumber, and barley.

[On the problem of formalization of temperature dependence of developmental rate in plants]. / K voprosu o formalizatsii temperaturnoi zavisimosti skorosti razvitiia rastenii.

Based on the data obtained in the experiments with constant and fluctuating diurnal temperatures, the temperature dependence of developmental rate was calculated for different photoperiodic groups of plants using the square equations of regression. These equations made it possible to calculate the temperature areas of maximum developmental rates of plants under different photoperiodic conditions.

[The influence of thermoperiod on cucumber growth and development]. / Vliianie termoperioda na rost i razvitie ogurtsa.

We studied the influence of gradient temperature regimes on various parameters of the formation of above-the-ground and underground organs of cucumber plants, such as rate of leaf appearance, rate of growth, duration of growth and length of leaves, and the rate of growth of above-the-ground organs and roots. The plants were grown under the controlled conditions: at different combinations of day and night temperature, illumination 100 Wt/m2, and 12 h photoperiod. The comparison of constant and fluctuating diurnal temperature regimes has shown that in the optimal area for all studied indices, the highest values were recorded at the constant daily temperature (25 degrees C for all growth indices of above-the-ground organs and 20 degrees C for growth of roots), while all gradient regimes either did not affect, or exerted inhibitory effects on the plant. The main acting fluctuating temperatures, that exerted stimulating effects, combined low hardening (15 degrees C) and optimal temperatures (25 degrees C), which was earlier described for animals. The 15/35 and 35/15 degrees C combinations were unambiguously inhibitory, since both temperatures are hardening for the cucumber. A lesser stimulating effect of the developmental rate in a plant, as compared to poikilothermic animals, could be due to a greater autonomy of plant ontogenesis because of autotrophy and, correspondingly, a greater degree of homeostasis. The mechanisms accounting for the reactions to temperature gradients are similar in different groups of ectotherms.

[Immunocorrective therapy in esophageal cancer]. / Immunokorrigiruiushchaia terapiia pri rake pishchevoda.

Additional non-specific therapy including levamisole and other drugs was tested in 20 patients with esophageal cancer. Complex (immuno- and chemoradiation) treatment brought immune response, lipid metabolism and cortisol level to normal, which in most cases, was in correlation with the clinical effect of therapy.

[Adrenal cortical function, immunological reactivity and the blood serum cholesterol level of esophageal cancer patients]. / Funktsiia kory nadpochechnikov, immunologicheskaia reaktivnost' i uroven' kholesterina syvorotki krovi u bol'nykh rakom pishchevoda.

Functional status of the adrenal cortex was studied in 80 patients (aged 31-70) suffering esophageal cancer (predominantly stage III). Blood serum showed high levels of cortisol and 11-HCS and a decrease in those of 17-HCS and 17-KS. Groups with hypo-, normo- and hypercholesterolemia were formed. Lowered blood-cholesterol levels were more frequent in cancer patients as compared to healthy subjects. Cases under study revealed decreased immunologic vigor. A peak concentration of cortisol was matched by a decrease in E-RFC level and a sharp drop in that of blood serum cholesterol. Combined chemoradiation treatment partially brought glucocorticoid and 17-KS levels to normal but did not affect cell-mediated immunity. Complex immunocorrection and chemoradiation treatment normalized hormonal function and immunologic indexes.

[Characteristics of carbohydrate-protein metabolism in rats of different ages after administration of ulcerogenic doses of aspirin]. / Osobennosti v obmene uglevodno-belkovykh soedinenii u krys razlichnogo vozrasta pri deistvii ul'tserogennykh doz aspirina.

Distinct age differences in content of carbohydrate-protein substances were found in rat gastric and pre-gastric walls, liver tissue and blood during experimental ulcer caused by acetyl salicylic acid. These results may be applied to the procedures of aspirin administration depending on age as well as they should be considered during stomach impairments followed the drug treatment using the carbohydrate-protein patterns of blood.