[The effect of medium-wave UV-radiation on the photosynthetic apparatus and the productivity of higher plants]. / O deistvii srednevolnovoi UF-radiatsii na fotosinteticheskii apparat i produktsionnyi protsess vysshikh rastenii.

In laboratory and field experiments, the effect of medium-wave (290-320 nm) UV-radiation (UV-B) on the build-up of photosynthetic pigments, growth and productivity of higher plants was investigated. It was found that UV-B of 5-9 W/m2 in intensity applied daily (at a daily dose of 15-20 kJ/m2) or singly (at a daily dose of 24 or 36 kJ/m2) inhibited the formation of chloroplast pigments. The pattern and magnitude of changes depended on the plant species and leaf age. The degree of photosynthetic changes and plant resistance to UV-radiation were closely correlated. In field experiments (daily irradiation with 0.6 W/m2 at a dose of 12-13 kJ/m2/day), UV-B suppressed the growth and yield of cotton and soybean plants. This exposure modified chloroplasts of soybean plants and inhibited their growth to a greater extent than that of cotton plants. The factors responsible for the species-related specificity of UV-B resistance of higher plants are discussed and approaches to its evaluation based on the pigment apparatus of photosynthesis are described.

[Tactile sensitivity as a part of the kinesthetic system (a comparative clinico-physiological approach)]. / Taktil'naia chuvstvitel'nost' kak chast' kinesteticheskoi sistemy (sravnitel'nyi kliniko-fiziologicheskii podkhod).

In experiments on healthy children as well as on children with inborn and postamputation stumps of the forearm, studies have been made of the relationship between the level of tactile sensitivity in the skin of the forearm and the level of its muscular motor activity; these studies were performed using focused ultrasound in children at the age of 7, 10 and 14 years. It was found that with the increase in motor activity of the forearm, irrespectively of the age, tactile thresholds decrease. The success of prosthetic appliance depends on the ratio between skin tactile sensitivity and motor activity of the forearm. The lowest thresholds were found in 10-year children and in a zone innervated by the median skin nerve of the forearm.

[Study of the effect of specific translation inhibitors on formation of native forms of chlorophyll in pigment-protein-lipid complexes of pea chloroplasts]. / Izuchenie deistviia spetsificheskikh ingibitorov transliatsii na obrazovanie nativnykh form khlorofilla v pigment-belkovo-lipidykh kompleksakh khloroplastov gorokha.

The effect of specific inhibitors of translation in chloroplasts (chloramphenicol) and in cytoplasm (cycloheximide) on the formation of pigment-protein-lipid complexes of photosynthetic membranes, on the chlorophyll state in chloroplasts and isolated membrane complexes had been studied. It is proved that the inhibition of translation blocks chlorophyll incorporation only into the complexes of reaction centres of photosystems without any change of the light-harvesting complex. The action of inhibitors leads to the disappearance of long-wave native forms of pigment in the complexes of reaction centres, which are characteristic for them. But the action of inhibitors does not effect the formation of non-specific short-wave forms which are present in all types of membrane complexes. Chloramphenicol proved to be more active in such processes than cycloheximide. On the basis of the data on localization of biosynthesis of polypeptide components of plastid membranes we suppose that during biogenesis of the photosynthetic apparatus the conditions for self-assembly of non-specific native forms of chlorophyll in light-harvesting complexes are made as the result of polymerazation of the main membrane polypeptides which are synthesized in the cytoplasms. Minor polypeptides of plastid (photosystems 1 and 2) and cytoplasmic (photosystem 1) orgin are necessary for self-assembly of the dense units of pigment in reaction centre complexes.

[Effects of organic solvent vapors on the protochlorophyllic complex from etiolated leaves. Conditions for reversible and irreversible destruction]. / Deistvie parov organicheskikh rastvoritelei na protokhlorofillovyi kompleks étiolirovannykh list'ev. Usloviia obratimogo in neobratimogo povrezhdeniia.

The spectral properties and the ability of etyolated leaves pigments treated with organic solvent vapours (OS) for phototransformations were studied by measuring low temperature fluorescence spectra (-196 degrees C). Under the effects of OS the fluorescence at 655 nm was gradually decreased and that at 630--640 nm was increased. The effects of OS depended on the partial pressure of OS. The ability of the pigments for phototransformations was decreased with an increase in fluorescence at 630 nm. The emission maximum of fluorescence of the pigment formed in the light was shifted by 10--18 nm towards the shortwave region. Partial reversibility of the destroying effects of diethyl ester was found. A removal of the ester vapours resulted in a relative increase of fluorescence in the etyolated leaves at 640--645 nm and a decrease of the amount of "photo-inactive" pigment. The maximum of fluorescence of the pigment formed in the light was shifted towards the long-wave region (approximately 5 nm) as compared to the leaves irradiated in the presence of the ester. Partial functional reconstitution indicates that at least part of the pigment molecules are able to form a protochlorophyllide (protochlorophyll) -- protein complex, similar to the native one.