The presence of a gynoecium composed by carpels is a key feature of angiosperms. The carpel is often viewed as homologous to megasporophyll of gymnosperms (i.e., a leaf bearing ovules), but it is possible that its morphological nature is more complex. Carpels of angiosperms can unite to form a syncarpous gynoecium. Most syncarpous gynoecia possess a compitum, which is a region where pollen tube transmitting tracts of individual carpels unite in a way that pollen tubes can grow from one carpel to another. The presence of a compitum is a precondition for evolution of carpel dimorphism, where some carpels do not possess functional stigma or fertile ovules. Pseudomonomery is a kind of carpel dimorphism where only one carpel has a fertile ovule (or ovules). Pseudomonomerous gynoecium usually has a single symmetry plane and it is likely that regulation of its development is similar to those of monosymmetric perianth and androecium. Monomerous gynoecium consists of a single carpel. In course of evolution, syncarpous gynoecia can jump abruptly to monomerous gynoecia or undergo sterilization and gradual reduction of some carpels. There is a peculiar group of gynoecia with partial or complete loss of carpel individuality, so that it is impossible to assign an ovule (or ovules) to particular carpel. A term mixomery is proposed for this phenomenon, which is not identical to pseudomonomery.

The abundance, biomass and species composition of phototrophic picoeukaryotes (PPE, cells size less than 3 μm) were studied in Onega Bay of the White Sea in June 2015. The highest PPE abundance and biomass were registered in the 0–5 m water layer. In the bay the average (in the 0–5 m water layer) abundance and biomass varied from 0 to 36,8 ·104 cell/l and from 0 to 117 μg С/m3, respectively. The Illumina sequencing of V4 region of 18S rRNA gene revealed eight classes of PPE. Mamiellophyceae dominated both in number of reads and operational taxonomic units. The green algae Bathycoccus prasinos, Ostreococcus tauri and Micromonas pusila, as well as diatoms Skeletonema marinoi and Minidiscus trioculatus were identified to species level.

The combined effect of salts of heavy metals and schungite on the test organisms of phytoand zooplankton has been studied. The toxic effect, of both cadmium sulfate and potassium dichromate on the culture of Scenedesmus guadricauda was inactivated in the presence of schungite (100 g/l). The efficiency of photosynthesis, the number of cells, the proportion of living cells and the lifetime of the microalgal cell population increased after adding shungite to the medium (without toxicants).In addition, in acute experiments with a duration up to 96 hrs, the toxicity of potassium dichromate, copper sulfate and cadmium sulfate on crustaceans (Daphnia magna and Ceriodaphnia affinis) was determined in the presence of schungite (0.01 g/l) and without schungite. The study of the action of schungite on crustaceans showed that it protects, both Daphnia magna and Ceriodaphnia affinis, from the action of toxicants at the minimum concentration (0.01 g/l) of the five tested concentrations. At higher concentrations of schungite, Daphnia magna died. It was shown that the acute toxicity of heavy metals for two species of crustaceans decreases in the series Cu-Cd-Cr. An analysis of the obtained data showed that the shungite concentrations necessary for the inactivation of heavy metals are thousands of times higher for algae than for crustaceans. Therefore, for the use of schungite as a protector against the toxic effects of various substances, a preliminary laboratory analysis of the survival of different species of hydrobionts in a specific aquatic environment is needed.

For the first time, a study of the mycobiota of littoral sands of the cold-water White Sea was made. 24 samples were collected in July–August 2015 in Onega Bay, Kandalaksha Bay and on the Tersky coast. Culture methods were used to detect the number of colony forming units (CFU) and diversity of fungi. The number of CFUs is small, and ranges from 0 to 57 per 1 cm3. A total of 54 morphotypes were detected, of which 22 were identified to the species, 7 – not more accurately than to the genus level, and 25 were not identified, because did not form sporulation. With an abundance of more than 10% and a occurence of more than 50%, only two species are noted: Cladosorium sphaerospermum and Paradendryphiella salina. Five more species were found in more than one samles: Penicillium chrysogenum, Cadophora fastigiata, Acremonium fuci, anamorph of Pseudogymnoascus pannorum and teleomorph of Pseudeurotium hygrophilum. All other morphotypes were found in a small number in individual samples. In general, dark-colored forms predominated in the mycobiota both in diversity and in number.

Endocytosis is a complex process of absorption from the external environment and further distribution within the cell of soluble substances, macromolecules, microparticles, and etc. which occurs with the participation of vesicles formed by the cytoplasmic membrane. Endocytosis in the cells of animals and humans is actively and successfully explored. Thus, the classification of this process in animals, based only on the characteristics of the formation of primary vesicles, includes up to ten different ways of endocytosis. Modern knowledge of endocytosis in mycelial fungi is not so extensive, so its study in this group of organisms is an actual and promising direction in fundamental and applied mycology. In the present work, we investigated the effect of six different inhibitors, acting both on the assembly of actin/tubulin cytoskeletons and on the formation of different types of endocytosis, on the dynamics of endocytosis in the phytopathogenic heterobasidial fungus Rhizoctonia solani The effect of inhibitors was evaluated by microscopic analysis of the mycelial cell absorption of a fluorescent marker of endocytosis AM4-64. As a result of the study, four types of inhibitor effects on R. solani endocytosis were revealed: from complete absence of action to severe suppression of different stages of fungal endocytosis. Four of the six inhibitors, used to inhibit endocytosis in animals and humans, have a suppressing effect on the endocytosis of the heterobasidial fungus R. solani, which indicates the conservative nature of individual mechanisms of endocytosis in the examined fungus and, possibly, in mycelial fungi as a whole. Various hypotheses on the principles of the action of the studied inhibitors on the endocytosis activity of fungi are proposed.

We have carried out morphological, biochemical, as well as molecular and genetic studies of green microalgae from the Collection of cyanobacteria, algae and algal parasites of Saint-Petersburg State University (CALU), presumably belonging to the genus Parietochloris, to assess their biotechnological potential and to refine their phylogenetic position. It was found that the investigated strains have a close relationship to two genera from different classes – Lobosphaera (Trebouxiaceae) and Deasonia (Actinochloridaceae). They can be of interest as producers of valuable polyunsaturated fatty acids, especially arachidonic, linoleic, α-linolenic.

The present study contributes to the understanding of DNA compaction in cell nucleus at the nucleosomal level. The interactions between DNA and histones can be described in terms of a free energy profile, DNA binding affects key processes of cell life including replication and transcription. MM/PBSA method was used to calculate free energy profile during DNA unwrapping from histone octamer. Our results are in good agreement with experimental data published earlier. The developed approach can be applied to study the effects of post-translational modifications of histones and histone variants on nucleosome stability, which is important for understanding the mechanisms of transcriptional regulation in chromatin.

The structure of chromatin and DNA accessibility to proteins depend on the structure of DNA “linkers” entering and exiting the nucleosome. Since DNA is negatively charged, conformation of the DNA linkers, in turn, is likely affected by ionic microenvironment. Here method of fluorescence microscopy of single complexes was used to study the effect of Na+ and K+ ions on the structure of the DNA linkers. It was revealed that nucleosomes adopt one of two conformational states, and occupancy of these states is considerably changed after substitution of K+ ions by Na+. These changes are likely caused by different interaction of Na+ and K+ ions with DNA in the regions of entry and exit of DNA from the nucleosome. Cation- dependent changes in conformation of the DNA linkers can affect topological barriers in nucleosomes, structure of polynucleosome chromatin and interactions of DNA with different protein factors.

Combined effects of Semax with an aqueous solutions of lead diacetate (10–7 M) and ammonium molybdate (10–5 M) on the two-way active avoidance learning in rats in the Shuttle box have been studied. It was established that both salts of heavy metals depressed learning and memory; greater inhibition was caused by the lead diacetate. Semax inhibited the avoidance learning but counteracted the negative impact on this process on the part of both metals. Additionally, the influence of Semax on avoidance learning paradoxically increased in the presence of ammonium molybdate, which inhibited avoidance responses when injected alone. Avoidance learning in rats coexposed to the peptide and ammonium molybdate was much faster than in rats injected by Semax. Overall, the data indicate that Semax counteracts the neurotoxic effect of the salts of lead and molybdenum. As the main mechanism of the neurotoxic impact of heavy metals is oxidative stress, the positive effect of Semax could, in our opinion, serve as confirmation of the presence of antioxidant properties in the spectrum of the peptide pharmacological activity.

This work is a continuation of a series of studies on the short-term effects of UV-B radiation (12.5 kJ/m2) on plants with particular attention paid to the rapid response of the antioxidant system (measurement 24 hrs after irradiation). Free and conjugated forms of putrescine polyamines (putrescine, spermine, spermidine) and cadaverine are known to be part of the antioxidant system. In the plants Thellungiella salsuginea, Salvia officinalis L, Plantago major L., and Geum urbanum L. grown in aquatic culture under phytotron conditions, the content of free and conjugated forms of polyamins was determined 24 hrs after the treatment with UV-B. The obtained data confirm the existing hypothesis about the major role of putrescine in the protective response of plants to UV-B irradiation. An increase in the content of this polyamine was observed in the leaves of three of the four plants studied. And it was the changes in its content that determined the total increase in the level of free polyamines. It was not possible to reveal a general trend in the level of conjugated forms of spermine, spermidine and cadaverine, and only for putrescine conjugates there was a clear increase. The data obtained allow to conclude that the relative contribution of specific forms of polyamines to the protective response is determined primarily by the species of the investigated plants. It is likely that conjugated forms of polyamines can serve as a reserve for rapid recovery of the required level of endogenous free forms of polyamines.