Biotechnologia Acta

5-18

Authors: I. V. Kosakivska, V. A. Vasyuk

Gibberellins (GAs), a class of diterpenoid phytohormones, play an important role in regulation of plant growth and development. Among more than 130 different gibberellin molecules, only a few are bioactive. GA1, GA3, GA4, and GA7 regulate plant growth through promotion the degradation of the DELLA proteins, a family of nuclear growth repressors – negative regulator of GAs signaling. Recent studies on GAs biosynthesis, metabolism, transport, and signaling, as well as crosstalk with other phytohormones and environment have achieved great progress thanks to molecular genetics and functional genomics. Aim. In this review, we focused on the role of GAs in regulation of plant gtowth in abiotic stress conditions. Results. We represented a key information on GAs biosynthesis, signaling and functional activity; summarized current understanding of the crosstalk between GAs and auxin, cytokinin, abscisic acid and other hormones and what is the role of GAs in regulation of adaptation to drought, salinization, high and low temperature conditions, and heavy metal pollution. We emphasize that the effects of GAs depend primarily on the strength and duration of stress and the phase of ontogenesis and tolerance of the plant. By changing the intensity of biosynthesis, the pattern of the distribution and signaling of GAs, plants are able to regulate resistance to abiotic stress, increase viability and even avoid stress. The issues of using retardants – inhibitors of GAs biosynthesis to study the functional activity of hormones under abiotic stresses were discussed. Special attention was focused on the use of exogenous GAs for pre-sowing priming of seeds and foliar treatment of plants. Conclusion. Further study of the role of gibberellins in the acquisition of stress resistance would contribute to the development of biotechnology of exogenous use of the hormone to improve growth and increase plant yields under adverse environmental conditions.

28-36

Authors: N. O Volkova, M. S. Yukhta, L. V. Sokil, L. G. Chernyschenko, L. V. Stepanyuk, A. M. Goltsev

An optimal approach to the recovery of testicular tissue fragments after cryopreservation is critical for their further use in order to successful fertility restoration. Aim. The purpose of this study was to investigate the effect of bovine serum albumin (BSA) addition to the rehabilitation medium on the morphofunctional characteristics of fragments of seminiferous tubules of testes (FSTT) of immature rats after cryopreservation. Methods. The object of the study was cryopreserved by slow cooling and vitrified FSTT. Warmed samples were incubated for 30 min in Leibovitz medium supplemented with BSA at concentrations of 0, 2, 5 or 10%. After that, morphological characteristics, the activity of the metabolic and antioxidant systems were evaluated. Results. It was found that in the samples cryopreserved by slow cooling, the use of 5% BSA contributed to the increase in the safety of spermatogenic epithelium cells, in the levels of metabolic and antioxidant activities. In case of vitrified FSTT samples, it was observed that the addition of 5% BSA to the medium promoted the repair of minor tissue damage and increased metabolic activity level, but did not affect the state of the antioxidant defense system. Conclusions. The obtained data can be used to develop an effective rehabilitation medium for cryopreserved fragments of the seminiferous tubules of testes using BSA.

47-58

Authors: A. A. Muratova, A. E. Akhremchuk, L. N. Valentovich

The strain Pseudomonas brassicacearum S-1 is the basis of the biopesticide “Ecogreen”, which is used to control pathogens infecting vegetable and green spicy crops in small-scale hydroponics. Aim. The purpose of this work was to sequence and analyze the nucleotide sequence of the genome of strain P. brassicacearum S-1 (GenBank accession number CP045701). Methods. Whole-genome sequencing was performed by both MiSeq (Illuminа) and MinION (Oxford Nanopore). Analysis of the genome sequence was performed with a number of bioinformatics programs. Results. The genome of the P. brassicacearum S-1 strain comprising a single circular 6 577 561-bp chromosome with GC content of 60.8 %. Genome analysis revealed genes that constitute valuable biotechnological potential of the S-1 strain and determine synthesis of a wide range of secondary metabolites. Moreover, mobile genetic elements, prophages and short repetitive sequences were identified in the S-1 genome. Conclusions. Detected genetic determinants, which are responsible for the synthesis of practically valuable compounds, indicate a significant potential of the P. brassicacearum S-1 strain as a biocontrol agent.

67-78

Authors: B. Vijaya Geetha, K S. Shreenidhi, P. Priya Vadhana, N. Purnima, A. Rashminiza, S. Sneha

Aim. The key motive was to investigate the toxicological impact of clofibrate and phenol prescribed under human medicine, having potential in water and sediments contamination via input from sewage treatment plants as active pharmaceutical compounds discharge into the environment had kindled present harmful effects on the aquatic ecosystem. Methods. The present study was performed on the fish model, Pangasius sp.. After acclimatization period, fishes were exposed to the appropriate LC50 concentration of the tested drugs. Their toxic effects were studied in terms of oxidative stress markers, antioxidant status, and protein damage levels in the occupancies environment under the action of bioremediation source, Artemisia pallens, and further proceeded by histopathological study and cortisol level measurements. Results. The results comparison between fish maintained under the bioremediation source, when exposed to clofibrate and phenol resulted in severe oxidative stress (significant at *P<0.001, #P<0.001, respectively) with significant alterations in antioxidant enzyme activities (significant at *P<0.001, #P<0.001, respectively), histopathological changes and cortisol levels. Bioremediation with the use of Artemisia pallens alleviated both clofibrate- and phenol-induced elevation of cortisol level (significant at *P<0.05, #P<0.05, respectively), indicating pronounced effects on the cell survival via protecting against oxidative damage. Conclusion. Determination of several biomarkers, including indices of oxidative stress and cortisol levels, may serve as a convenient approach for pollution biomonitoring of aqueous environment. Artemisia pallens water extracts can be applied as an effective bioremediation agent.