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Background: Microalgae are able to produce a significant amount of biologically significant substances. In connection with the growing popularity of microalgae, it is important to develop effective methods for storing cultures and creating strain banks. This will not only meet the needs of science and biotechnology for viable and sustainable crops, but will also solve the problem of biodiversity conservation. Objectives: study the effect of salt stress and cooling regimes on the pigment composition of microalgae Dunaliella salina cells in order to increase their safety after freezing-thawing. Materials and methods: The objects of the study were the unicellular green microalgae D. salina. Cultivation was carried out according to the standard method on nutrient media with different amounts of NaCl and trace elements. Adaptation to low temperatures was carried out by exposure of samples in the dark at temperature 4°C for 24 hours. Freezing was performed by placing 1 ml of the cell suspension in a 1.8 ml polypropylene cryogenic vial (Nunc, Sigma-Aldrich), cooled at a rate of 1 deg/min using a Mr. Frosty with following regimes: to -10°С, -40°С, -40°С followed by immersion to liquid nitrogen or direct immersion to liquid nitrogen (-196°С). Thawing was carried out in a water bath (37°С) with continuous shaking for 1–2 min. Microscopic examinations were carried out on an LSM-510 Meta laser scanning microscope (Carl Zeiss, Germany) upon excitation by a diode laser with a wavelength of 405 nm and 573 nm using a Nile Red stain. Results: It has been established that the formation of intracellular lipid globules and the synthesis of carotenoids in D. salina cells contribute to an increase in the concentration and number of motile cells after freezing-thawing. It has been shown that during rapid cooling, adaptive mechanisms do not have time to turn on in cells, and complete destruction of carotene-containing lipid globules occurs. Conclusions: Cryopreservation of D. salina cells should be carried out at a rate of 1 deg/min to -40°C, followed by immersion in liquid nitrogen and a mandatory stage of precultivation at 4°C for 24 hours. This approach allows the cells to adapt to a decrease in temperature, which contributes to the best result after freezing-thawing.

Purpose. To analyze the current state of agricultural crop improvement using gene editing technologies. Results. The current state of plant breeding using gene editing technologies is analyzed. To date, genome editing has been applied to a wide range of crops, including wheat, barley, maize, legumes, soybean, rapeseed, tomato, chicory, various vegetable crops, fruit trees, forest trees and algae. The practical application of these technologies is illustrated by the example of genes associated with ensuring tolerance to high and low temperatures. Examples of commercialized geneedited plants are given. Conclusions. By contributing to increased yields, improved resistance to diseases and pests, and biofortification of food crops, gene editing technology undoubtedly has great prospects and is definitely already the technology for creating improved varieties of agricultural crops. [ABSTRACT FROM AUTHOR]

The article provides an analytical solution to the three-dimensional coupled problem of thermoelasticity for a composite whose structure and possible defects are given by trigonometric polynomials. Parameters of the temperature field arising as a result of defects in its structure are used in the diagnosis of defects in its structure. This is of great importance and practical value for non-destructive testing tasks. An expedient way of finding temperature values as a function of time and geometric coordinates is also the solution of inverse problems of thermoelasticity, i.e. determination of the temperature field based on the field of temperature stresses. The economy of this method lies in the fact that its application makes complex experimental studies of technical objects cheaper and eliminates the need to create computational and analytical methods that accompany these studies. [ABSTRACT FROM AUTHOR]

We investigated nucleic acid content in plants with different types of ecological strategies. Special features in character of RNA content changes were shown after short time temperature stresses. After heat stress level of RNA in patient Rumex patientia × R. tianshanicus and ruderale with C-4 pathway of photosynthesis Amaranthus caudatus seedlings became lower and in ruderale Brassica campestris seedlings with C-3 pathway of photosynthesis became higher. After short time cold stress content of RNA in all analyzed plants became higher. Content of RNA in violent Festuca pratensis seedlings after temperature stresses was practically stable. Lowest balance RNA/DNA was in patient Rumex patientia × R. tianshanicus seedlings. Ruderale Amaranthus caudatus seedlings had highest balance RNA/DNA.