Papers by Victor Bulgakov
Life
The E3 ubiquitin-protein ligase HOS1 is an important integrator of temperature information and de... more The E3 ubiquitin-protein ligase HOS1 is an important integrator of temperature information and developmental processes. HOS1 is a negative regulator of plant cold tolerance, and silencing HOS1 leads to increased cold tolerance. In the present work, we studied ROS levels in hos1Cas9 Arabidopsis thaliana plants, in which the HOS1 gene was silenced by disruption of the open reading frame via CRISPR/Cas9 technology. Confocal imaging of intracellular reactive oxygen species (ROS) showed that the hos1 mutation moderately increased levels of ROS under both low and high light (HL) conditions, but wild-type (WT) and hos1Cas9 plants exhibited similar ROS levels in the dark. Visualization of single cells did not reveal differences in the intracellular distribution of ROS between WT and hos1Cas9 plants. The hos1Cas9 plants contained a high basal level of ascorbic acid, maintained a normal balance between reduced and oxidized glutathione (GSH and GSSG), and generated a strong antioxidant defense...
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International Journal of Molecular Sciences
During Agrobacterium rhizogenes–plant interaction, the rolB gene is transferred into the plant ge... more During Agrobacterium rhizogenes–plant interaction, the rolB gene is transferred into the plant genome and is stably inherited in the plant’s offspring. Among the numerous effects of rolB on plant metabolism, including the activation of secondary metabolism, its effect on plant defense systems has not been sufficiently studied. In this work, we performed a proteomic analysis of rolB-expressing Arabidopsis thaliana plants with particular focus on defense proteins. We found a total of 77 overexpressed proteins and 64 underexpressed proteins in rolB-transformed plants using two-dimensional gel electrophoresis and MALDI mass spectrometry. In the rolB-transformed plants, we found a reduced amount of scaffold proteins RACK1A, RACK1B, and RACK1C, which are known as receptors for activated C-kinase 1. The proteomic analysis showed that rolB could suppress the plant immune system by suppressing the RNA-binding proteins GRP7, CP29B, and CP31B, which action are similar to the action of type-III...
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International Journal of Molecular Sciences
Ipomoea batatas is a vital root crop and a source of caffeoylquinic acid derivatives (CQAs) with ... more Ipomoea batatas is a vital root crop and a source of caffeoylquinic acid derivatives (CQAs) with potential health-promoting benefits. As a naturally transgenic plant, I. batatas contains cellular T-DNA (cT-DNA) sequence homologs of the Agrobacterium rhizogenes open reading frame (ORF)14, ORF17n, rooting locus (Rol)B/RolC, ORF13, and ORF18/ORF17n of unknown function. This study aimed to evaluate the effect of abiotic stresses (temperature, ultraviolet, and light) and chemical elicitors (methyl jasmonate, salicylic acid, and sodium nitroprusside) on the biosynthesis of CQAs and cT-DNA gene expression in I. batatas cell culture as a model system. Among all the applied treatments, ultraviolet irradiation, methyl jasmonate, and salicylic acid caused the maximal accumulation of secondary compounds. We also discovered that I. batatas cT-DNA genes were not expressed in cell culture, and the studied conditions weakly affected their transcriptional levels. However, the Ib-rolB/C gene expresse...
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Mathematics, 2021
The following two optimization problems on acyclic digraph analysis are solved. The first of them... more The following two optimization problems on acyclic digraph analysis are solved. The first of them consists of determining the minimum (in terms of volume) set of arcs, the removal of which from an acyclic digraph breaks all paths passing through a subset of its vertices. The second problem is to determine the smallest set of arcs, the introduction of which into an acyclic digraph turns it into a strongly connected one. The first problem was solved by reduction to the problem of the maximum flow and the minimum section. The second challenge was solved by calculating the minimum number of input arcs and determining the smallest set of input arcs in terms of the minimum arc coverage of an acyclic digraph. The solution of these problems extends to an arbitrary digraph by isolating the components of cyclic equivalence in it and the arcs between them.
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Molecules, 2021
The COVID-19 pandemic, as well as the more general global increase in viral diseases, has led res... more The COVID-19 pandemic, as well as the more general global increase in viral diseases, has led researchers to look to the plant kingdom as a potential source for antiviral compounds. Since ancient times, herbal medicines have been extensively applied in the treatment and prevention of various infectious diseases in different traditional systems. The purpose of this review is to highlight the potential antiviral activity of plant compounds as effective and reliable agents against viral infections, especially by viruses from the coronavirus group. Various antiviral mechanisms shown by crude plant extracts and plant-derived bioactive compounds are discussed. The understanding of the action mechanisms of complex plant extract and isolated plant-derived compounds will help pave the way towards the combat of this life-threatening disease. Further, molecular docking studies, in silico analyses of extracted compounds, and future prospects are included. The in vitro production of antiviral ch...
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Molecules
During our ongoing efforts to investigate biotechnological sources of caffeoylquinic acid (CQA) m... more During our ongoing efforts to investigate biotechnological sources of caffeoylquinic acid (CQA) metabolites, we discovered the plant Scorzonera radiata Fisch. (Asteraceae), which is able to produce callus cultures with high yield and extremely high stability. An actively growing callus line, designated as Sr-L1, retained the ability to produce 11 CQAs during long-term cultivation (more than 20 years). A total of 29 polyphenolic compounds were identified in the leaves and Sr-L1 callus culture of S. radiata, including CQAs, lignol derivatives, flavonoids, and dihydrostilbenes. The composition of CQAs in the Sr-L1 culture was identical to that in the S. radiata leaves. Sr-L1 calli did not produce flavonoids and dihydrostilbenes, but produced lignol derivatives, which were absent in leaves. The HPLC-UV-HRMS determination showed the presence of monoacyl derivatives of CQAs such as 5-CQA, 4-CQA, cis-5-CQA, and 5-O-p-coumaroylquinic acid in the Sr-L1 culture. Among diacyl derivatives, 3,4-...
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Applied Sciences
Exosomal nanoparticles (exosomes or nanovesicles) are biogenic membrane vesicles secreted by vari... more Exosomal nanoparticles (exosomes or nanovesicles) are biogenic membrane vesicles secreted by various cell types and represent a conservative mechanism of intercellular and interspecies communication in pro- and eukaryotic organisms. By transporting specific proteins, nucleic acids, and low molecular weight metabolites, the exosomes are involved in the regulation of developmental processes, activation of the immune system, and the development of a protective response to stress. Recently, the plant nanovesicles, due to an economical and affordable source of their production, have attracted a lot of attention in the biomedical field. Being a natural transport system, the plant exosomes represent a promising platform in biomedicine for the delivery of molecules of both endogenous and exogenous origin. This review presents current data on the biogenesis of plant exosomes and their composition, as well as mechanisms of their loading with various therapeutic compounds, which are determinin...
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Frontiers in Plant Science
It is generally accepted that plants use the complex signaling system regulated by light and absc... more It is generally accepted that plants use the complex signaling system regulated by light and abscisic acid (ABA) signaling components to optimize growth and development in different situations. The role of ABA–light interactions is evident in the coupling of stress defense reactions with seed germination and root development, maintaining of stem cell identity and stem cell specification, stem elongation and leaf development, flowering and fruit formation, senescence, and shade avoidance. All these processes are regulated jointly by the ABA–light signaling system. Although a lot of work has been devoted to ABA–light signal interactions, there is still no systematic description of central signaling components and protein modules, which jointly regulate plant development. New data have emerged to promote understanding of how ABA and light signals are integrated at the molecular level, representing an extensively growing area of research. This work is intended to fill existing gaps by u...
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International Journal of Molecular Sciences, 2021
The present study reports a green chemistry approach for the rapid and easy biological synthesis ... more The present study reports a green chemistry approach for the rapid and easy biological synthesis of silver (Ag), gold (Au), and bimetallic Ag/Au nanoparticles using the callus extract of Lithospermum erythrorhizon as a reducing and capping agent. The biosynthesized nanoparticles were characterized with ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD) analysis, and transmission electron microscopy (TEM). Our results showed the formation of crystalline metal nanostructures of both spherical and non-spherical shape. Energy dispersive X-ray (EDX) spectroscopy showed the characteristic peaks in the silver and gold regions, confirming the presence of the corresponding elements in the monometallic particles and both elements in the bimetallic particles. Fourier-transform infrared (FTIR) spectroscopy affirmed the role of polysaccharides and polyphenols of the L. erythrorhizon extract as the major reducing and capping agents for metal ions. In addition, our results showed t...
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Different LED light treatments (monochromatic royal blue - RB, blue - B, green G, yellow - Y, red... more Different LED light treatments (monochromatic royal blue - RB, blue - B, green G, yellow - Y, red - R, deep red - DR, and polychromatic cold white - CW, white - W, warm white - WW, full spectrum - FS, and the newly constructed Sun box - SB) on potato plantlets in vitro were studied. Longwave monochromatic light sources cannot be used for micropropagation of virus-free material due to producing the fragile stems and poorly developed leaves. Two LED lights (WW and FS), were excellent sources for micropropagation. . Investigation of different light brightness in SB revealed the optimum at 135 μmol/с*m2 , which activated plantlet growth, and induced green and root mass accumulation. Such illumination parameters can be usefull for shortening the time of vegetation, rapid stolonization and increase of virusfree minitubers productivity.
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We studied growth of potato plantlets of two cultivars under different constant polychromatic lig... more We studied growth of potato plantlets of two cultivars under different constant polychromatic light-emitting diodes (LEDs) and dynamic lighting with the spectrum modifications during growth. Light sources constructed by us were sunbox SB, red-green-blue RGB, and full spectrum FS, red-blue. White luminescent lamps were used as control light. Dynamic lighting was achieved by transferring groups of plantlets from one box to another. Red/green/blue portions in the light sources were (in percents): 39R/39G/22B for SB, 63R/21G/16B for RGB, 74R/8G/18B for FS, and 22R/49G/29B for control. PPFD was set at 45 μmol/m2 s. Morphometric measurements were made 14 and 28 days after planting. Plantlets developed differently from initial stages. Cultivar 'Red Scarlett' appeared to be more susceptible to different lighting than 'Innovator'. Light variations RGB and RGB-SB were the most favorable for plantlet development. This is the first report on the dynamic lighting application for ...
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Colloids and Surfaces B: Biointerfaces, 2021
Presently, multifunctional silver nanoparticles (AgNPs) show a rapid growth in various commercial... more Presently, multifunctional silver nanoparticles (AgNPs) show a rapid growth in various commercial applications, leading to increasing demand for new eco-friendly manufacturing technologies. An array of genetic engineering tools can be used to increase the yield in the production of AgNPs using various biological systems. The present study reports a green chemistry approach for the biological synthesis of AgNPs using extracts from non-transformed callus, rolC-transgenic callus and hairy roots of Panax ginseng and an evaluation of their efficacy against crop-damaging fungal pathogens. All types of ginseng cell lines promote the reduction of silver nitrate and formation of spherical AgNPs with an average diameter of 50-90 nm. Notably, hairy root extract possessed the maximal reduction potential among the studied cell lines probably due to higher secondary metabolite content. The biosynthesized nanoparticles were highly toxic against several wheat fungal pathogens including Fusarium graminearum, F. avenaceum, F. poae, and F. sporotrichioides, which are associated with fusarium head blight disease in cereals. Furthermore, the antifungal activity of nanosilver was successfully utilized for surface sterilization of infected wheat kernels without any negative effect on seed germination capability.
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Scientific Reports, 2018
The rolB plant oncogene of Agrobacterium rhizogenes perturbs many biochemical processes in transf... more The rolB plant oncogene of Agrobacterium rhizogenes perturbs many biochemical processes in transformed plant cells, thereby causing their neoplastic reprogramming. The oncogene renders the cells more tolerant to environmental stresses and herbicides and inhibits ROS elevation and programmed cell death. In the present work, we performed a proteomic analysis of Arabidopsis thaliana rolB-expressing callus line AtB-2, which represents a line with moderate expression of the oncogene. Our results show that under these conditions rolB greatly perturbs the expression of some chaperone-type proteins such as heat-shock proteins and cyclophilins. Heat-shock proteins of the DnaK subfamily were overexpressed in rolB-transformed calli, whereas the abundance of cyclophilins, members of the closely related single-domain cyclophilin family was decreased. Real-time PCR analysis of corresponding genes confirmed the reliability of proteomics data because gene expression correlated well with the express...
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Molecular Plant-Microbe Interactions®, 2008
It is known that expression of the Agrobacterium rhizogenes rolC gene in transformed plant cells ... more It is known that expression of the Agrobacterium rhizogenes rolC gene in transformed plant cells causes defense-like reactions, such as increased phytoalexin production and expression of pathogenesis-related proteins. In the present study, we examined whether this phenomenon is associated with increased production of reactive oxygen species (ROS). Single-cell assays based on confocal microscopy and fluorogenic dyes (2,7-dichlorofluorescein diacetate and dihydrorhodamine 123) showed reduced steady-state levels of ROS in rolC-expressing Rubia cordifolia cells as compared with normal cells. Paraquat, a ROS inducer, caused significant ROS elevation in normal cells but had little effect on rolC-transformed cells. Likewise, ROS elevation triggered by a light stress was suppressed in transformed cells. Our results indicate that the rolC gene acts as a ROS suppressor in unstressed cells and its expression prevents stress-induced ROS elevations. We detected a two- to threefold increase in to...
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Biotechnology Journal, 2007
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Life
Calcium-dependent protein kinases (CDPKs) regulate plant development and stress responses. Howeve... more Calcium-dependent protein kinases (CDPKs) regulate plant development and stress responses. However, the interaction of these protein kinases with the abscisic acid (ABA) stress hormone signalling system has not been studied in detail. In Arabidopsis, AtCPK1 plays an important role in the acclimation of plants to environmental stresses. Phylogenetic and molecular analyses showed that, among 50 isoforms of Glycine max (L.) Merrill CDPKs, the GmCDPK27/GmCDPK48, GmCDPK5/GmCDPK24, and GmCDPK10/GmCDPK46 paralogous pairs were the isoforms most related to AtCDPK1. We investigated the expression of the corresponding six GmCDPKs genes during treatment with cold, heat, and salt stress. Wild soybean was the most resistant to stresses, and among the three cultivars studied (Sfera, Hodgson, and Hefeng25), Sfera was close to the wild type in terms of resistance. GmCDPK5 and GmCDPK10 were the most responsive to stress treatments, especially in wild soybean, compared with cultivars. Among the studie...
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Plants
In Arabidopsis, the RING finger-containing E3 ubiquitin ligase HIGH EXPRESSION OF OSMOTICALLY RES... more In Arabidopsis, the RING finger-containing E3 ubiquitin ligase HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENES 1 (HOS1) functions as a main regulator of the cold signaling. In this study, CRISPR/Cas9-mediated targeted mutagenesis of the HOS1 gene in the first exon was performed. DNA sequencing showed that frameshift indels introduced by genome editing of HOS1 resulted in the appearance of premature stop codons, disrupting the open reading frame. Obtained hos1Cas9 mutant plants were compared with the SALK T-DNA insertion mutant, line hos1-3, in terms of their tolerance to abiotic stresses, accumulation of secondary metabolites and expression levels of genes participating in these processes. Upon exposure to cold stress, enhanced tolerance and expression of cold-responsive genes were observed in both hos1-3 and hos1Cas9 plants. The hos1 mutation caused changes in the synthesis of phytoalexins in transformed cells. The content of glucosinolates (GSLs) was down-regulated by 1.5-times, w...
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International Journal of Molecular Sciences
The important regulatory role of brassinosteroids (BRs) in the mechanisms of tolerance to multipl... more The important regulatory role of brassinosteroids (BRs) in the mechanisms of tolerance to multiple stresses is well known. Growing data indicate that the phenomenon of BR-mediated drought stress tolerance can be explained by the generation of stress memory (the process known as ‘priming’ or ‘acclimation’). In this review, we summarize the data on BR and abscisic acid (ABA) signaling to show the interconnection between the pathways in the stress memory acquisition. Starting from brassinosteroid receptors brassinosteroid insensitive 1 (BRI1) and receptor-like protein kinase BRI1-like 3 (BRL3) and propagating through BR-signaling kinases 1 and 3 (BSK1/3) → BRI1 suppressor 1 (BSU1) ―‖ brassinosteroid insensitive 2 (BIN2) pathway, BR and ABA signaling are linked through BIN2 kinase. Bioinformatics data suggest possible modules by which BRs can affect the memory to drought or cold stresses. These are the BIN2 → SNF1-related protein kinases (SnRK2s) → abscisic acid responsive elements-bind...
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International Journal of Molecular Sciences
Alkaloids attract great attention due to their valuable therapeutic properties. Stepharine, an ap... more Alkaloids attract great attention due to their valuable therapeutic properties. Stepharine, an aporphine alkaloid of Stephania glabra plants, exhibits anti-aging, anti-hypertensive, and anti-viral effects. The distribution of aporphine alkaloids in cell cultures, as well as whole plants is unknown, which hampers the development of bioengineering strategies toward enhancing their production. The spatial distribution of stepharine in cell culture models, plantlets, and mature micropropagated plants was investigated at the cellular and organ levels. Stepharine biosynthesis was found to be highly spatially and temporally regulated during plant development. We proposed that self-intoxication is the most likely reason for the failure of the induction of alkaloid biosynthesis in cell cultures. During somatic embryo development, the toxic load of alkaloids inside the cells increased. Only specialized cell sites such as vascular tissues with companion cells (VT cells), laticifers, and parenc...
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Papers by Victor Bulgakov