Том 45, № 6 (2018)

UVB radiation (290–320 nm) activates various signaling mechanisms triggering the processes of programmed cell death in plants or their protection against the damaging action of this type of radiation. In the case of high dosages of UVB radiation, the mechanisms of cell death are associated with DNA damage and oxidative stress. In the first case, activation of DNA damage checkpoints and cell cycle arrest may occur; in the second case, cytochrome c is released from mitochondria with the subsequent activation of metacaspases. According to the existing data, both mechanisms induce DNA fragmentation and other changes typical for apoptotic cells, while low-intensity UVB radiation, which is perceived by a UVR8 photoreceptor, initiates protective processes promoting plant acclimatization to sunlight.

The peculiarities of meiosis, C-heterochromatin (C-HC) distribution, and the activity of nucleolus organizer regions (NORs) of the chromosomes were studied in the Pisum sativum L. pea and Triticum compactum Host. club wheat grown from the seeds obtained in Lada space greenhouse on the board of RS ISS. It was noted that the analysis of meiosis detected no significant violations in the “space” plant cells, and the total amount of C-HC did not differ significantly from the control, despite the polymorphism of the chromosome C-banding pattern. Paracentric inversion on the chromosome 4A was found for the first time in the T. compactum, while no additional active NOR chromosomes were found.

The results of spore-pollen analysis and analysis of non-pollen palynomorphs of the Katcha zoogenic deposit, located in the Harenna Forest (Bale Mountains National Park, Ethiopia) are presented. It is revealed that bamboo monodominant communities have inhabited areas at altitudes of 2700–2800 m above sea level for at least the past 6500 years. A trend towards a decrease in bamboo communities due to climate aridization in the last 5000 years has been revealed. It is established that active human impact on these ecosystems began 1000 years ago.

Alterations in the ultrastructure of chloroplasts and the content of sugars during low-temperature hardening (5°C, 6 days) of potato plants (Solanum tuberosum L., cv. Desnitsa) and a transformed line with the desA gene of Δ12 acyl-lipid desaturase Synechocystis sp. RCC 6803 were studied. It was noted that during hardening, sugars were accumulated in the leaves of both lines, but with greater speed in the leaves of the transformants. In control plants after hardening, an increase in the total number of thylakoid membranes and in the number of plastoglobules per chloroplast were obtained accompanied by a decrease in the chloroplast cross-sectional area and starch grain area. It was found that chloroplasts of transformed plants, which were different from the control plants in the higher absolute content of membrane lipids and the amount of polyunsaturated fatty acids, corresponded to the hardened plants before cold exposure by some ultrastructural parameters. In the early period of low-temperature hardening, the transformed plants were more adaptable, according to the data on the sugar content.

The influence of odor stimulation with solutions of the amino acids L-glutamine and L-phenylalanine on the response of the cave fish Astyanax fasciatus (blind form) to the taste of agar pellets with L-glutamine and L-phenylalanine has been studied. It has been established that the odors used cause a food search behavior in fish, but do not affect the orosensory testing of the pellets. It is noted that the taste characteristics of both amino acids differ in the evaluation of the extraoral and oral taste systems, which indicates food selectivity in the blind cave fish, the food of which in its habitats is extremely monotonous. The attitude to the taste of amino acids is stable with a different smell background and a changing combination of odor and taste stimuli.

The authors analyze their own and published data on the screening pigments of the eyes of vertebrates and invertebrates and the human eye, i.e., melanosomes and ommochromes. The structure, biochemistry, and functions of these pigments in the vision of vertebrates and invertebrates as light-filtering and light-absorbing organelles are discussed.

In this review, based on published experimental and clinical data (1980‒2016), a comparative analysis of the structures and effects of Semax (peptide drug) and its analogue fragments was carried out. The effect of these oligopeptides on various body systems is examined. The multiple effects of Semax for a number of diseases have been collected for a single scheme of corrective processes. The rationale for the long-term therapeutic effects of this peptide drug is presented. A comparative analysis of the temporal dynamics of the expression of certain genes is carried out.

We identified five types of moss litter in a green moss–hypnum spruce forest during alloevolution (metamorphosis) according to the habitat: peat, peaty, reduced peaty, high-ash peaty, and reduced high-ash peaty litters. During the self-development (autoevolution) of the litter, the transformation of plant matter occurs in four stages: (1) leaf (background) stage, (2) peat- and peaty-fermentative stage (browning, destruction of the litter fall and formation of platy macroaggregates), (3) humified-fermentative stage (formation of colloidal humus plasma and granular organogenic macroaggregates), and (4) the black mold humus stage (formation of colloidal humus plasma and organo-mineral humus nutty and granular macroaggregates). It was found that peat litters undergo only the initial stages of plant substrate transformation (1 and 2). The genetic profile of peaty litter is formed by three unidirectional processes (1, 2, and 3). High-ash peaty litter undergoes all the stages of plant matter transformation. The reduced analogs of peaty and high-ash peaty litter bedding were found to bypass the transitional stage 2.