Vol 70, No 3 (2023)

The genus Taxus (yew) is a source of a number of high-value medicinal substances, particularly, paclitaxel (taxol)—a complex diterpenoid compound with a powerful antitumor action (trade name of Taxol®). Paclitaxel is one of the most efficient drugs in chemotherapy owing to its specific ability to suppress proliferation of tumor cells via stabilization of their microtubules. The world-wide demand for taxol is 800–1000 kg a year and these figures annually rise by 20%. The growing need for paclitaxel and its derivatives and the shortage of plant resources necessary for their production made compounds of the taxane group one of the most important objects for development of biotechnological methods of their production. Out of all the possible ways of taxol production (isolation from wild or plantation trees, total chemical synthesis or semisynthesis, use of yew cell cultures, techniques of metabolic engineering, and use of yew endophytic fungi), the most promising is industrial cultivation of Taxus spp. cell cultures. This review examines the papers dealing with investigation of secondary metabolism in dedifferentiated cells in vitro of various yew species and feasibility of industrial use of cell cultures for production of taxoids. We revealed a number of specificity of Taxus spp. Cell cultures: (1) from a cytophysiological aspect—difficult initiation of cell cultures, their low growth characteristics, specific media and culturing conditions; (2) from a phytochemical aspect—distinction from intact plants in qualitative composition and content of secondary metabolites accounted for by specificity of cell culture as a biological system; predominant formation of С14-hydroxylated rather than of С13-hydroxylated taxoids; an opportunity for elevation of the content of taxoids—including commercially valuable ones (paclitaxel and baccatin III) with the aid of different tools (elicitation, stress exposures, two-phase cultivation and some others); (3) from a biotechnological aspect—possibility of industrial cultivation of yew cell cultures; existence of several successful industries (Germany and the Republic of Korea).

Eggplant (Solanum melongena L.) is an economically important vegetable crop whose purple-colored fruits are enriched with anthocyanidins. In this work in the eggplant genome, homologues of the main known structural (CHS1, CHS2, CHI, F3H, F3´5´H, DFR, ANS, and UFGT) and regulatory (TT8, GL3, bHLH137, bHLH143, MYB1, MYB2, and MYB75) anthocyanin biosynthesis genes, as well as anthocyanidin transporter gene (GSTF12), were identified. The expression of these genes was characterized in comparison
with the content of the total anthocyanins and the color of the leaf, flower petals, and fruit peel. It was shown that the gene expression pattern corresponds to the color and the presence of anthocyanins in the tissue, and also indicates the presence of organ-specific characteristics of the regulation of transcription of genes encoding transcription factors of the MBW complex. The results of correlation analysis confirm the involvement of SmbHLH137, SmTT8, SmMYB2, and SmMYB75 genes in the regulation of the expression of structural genes in flower petals and SmGL3, SmTT8, and SmMYB1 in fruit peel.

Effects of drought on plants of Triticum aestivum L., Brоmopsis inеrmis L., Pisum sativum L., and Zea mays L. inoculated with endophytic strains of Bacillus subtilis bacteria were studied. Presowing treatment of seeds with these bacteria was found to boost plant resistance to water deficit, stimulate their growth, and suppress oxidative stress. Based on the ability of the tested strains to cause antistress effect and activate the antioxidant system, it is concluded that plant treatments with them may favor growing of agricultural crops under drought conditions.

In plants, SnRK1 (Sucrose non-fermenting-Related protein Kinase 1) is one of the major activators of catabolic processes, including autophagy, during stress responses. SnRK1 generally acts as a sensor of the energy status of the cell. Photosynthesis is by far the largest energy-supplying process in green plant cells exposed to light; thus, SnRK1 might participate in its regulation. In leaves of Arabidopsis lines with different levels of the catalytic subunit of SnRK1, KIN10, quantum yields of photosystems and of non-photochemical quenching, formation of the transthylakoid proton motive force, and contents of ATP in seedlings were compared under optimal conditions and under salinity stress. We detected specific changes in the photochemical activity of the chloroplasts that were assigned to constant activation of SnRK1 in two lines with constitutive overexpression of KIN10, both under control conditions and under salinity stress. Furthermore, the inhibition of the SnRK1 activity by means of RNA interference in Arabidopsis led to a lack of response to salinity at the level of chloroplast photochemistry.

The effect of nitrogen starvation and, for the first time, low temperature, as well as their simultaneouseffect, on the physiology and ultrastructure of cells of microalgae of the genus Lobosphaera (Chlorophyta, Trebouxiophyceae) was studied. Nitrogen deficiency in both strains led to a decrease in the content ofchlorophyll by three times and an increase in the proportion of carotenoids by two times. A decrease in thecontent of both chlorophyll and carotenoids was observed at +10°C. The simultaneous effect of two factorsresulted in a threefold decrease in the chlorophyll content in NAMSU 924/2 and a sixfold decrease inNAMSU (CALU) 1497; the proportion of carotenoids in both strains decreased by 1.5–2 times. Data onultrastructural changes in cells of microalgae of the genus Lobosphaera under the influence of stress factorshave been obtained. A similar nature of the response in both strains to stress conditions was noted. Nitrogendeficiency led to the accumulation of numerous lipid droplets in the cytoplasm of cells along the cell wall. Long-term incubation on a nitrogen-free medium led to the filling of the entire volume of cells with lipiddroplets, disassembly of the membrane system of chloroplasts, that reduction in sizeand being locatedbetween densely lying lipid droplets. At low temperatures, the number of thylakoids decreased, while theinterthylakoid space and the size of chloroplasts increased. With simultaneous exposure to nitrogen starvation and low temperature, numerous lipid droplets accumulated, the number of thylakoids decreased, the interthylakoid space and the size of the chloroplast increased, which was noted under separate exposure to stress factors. The pyrenoid in both strains did not undergo significant changes in all cases.

The genome of Stellaria media contains a gene family for hevein-like antimicrobial peptides, some of which are known to encode two peptides released from the translation product as a result of post-translational proteolysis. These peptides have been shown to inhibit the growth of bacteria and fungi, including potato pathogens Alternaria solani and Alternaria alternata. One of these genes, ProSmAMP1, was introduced into the potato genome under the control of the light-inducible promoter of Cab gene from common wheat. The resulting transgenic lines expressed ProSmAMP1 mRNA during several vegetative passages, and their resistance to early blight was assessed by several indicators of detached leaf infection, with plants having the highest expression of the transgene also showing the highest resistance.