Alexander P. Dmitriev

Institute of Cell Biology and Genetic Engineering · Laboratory of Molecular Plant Pathology

The role of the gasotransmitter carbon monoxide (CO) in signaling and adaptive processes in plants has been studied insufficiently. There are indirect data indicating jasmonate signaling participation in realization of CO effects, but the possible connection between carbon monoxide and jasmonate signaling during plant adaptation to salt stress rema...

Carbon monoxide (CO) is considered to be an important molecule-gasotransmitter involved in the regulation of the functional activity of plants, including in the processes of adaptation to stress factors. However, the associations of CO with other participants of signaling in the plant cells remain poorly studied. Using an inhibitory method, the rol...

The effect of donors of hydrogen sulfide (50 μM sodium hydrosulfide NaHS) and nitric oxide (500 μM sodium nitroprusside, SNP) on the salt resistance of wild type (Col-0) Arabidopsis plants (Arabidopsis thaliana L. Heynh.) and those defective in jasmonate signaling—coi1 (mutant for the gene encoding protein COI1 involved in the removal of repressor...

The influence of hemin (donor of carbon monoxide CO formed due to action of heme oxygenase) on the heat resistance of wheat plantlets and the possible participation of reactive oxygen species (ROS) as mediators in the realization of stress-protective effects of exogenous CO have been studied. The treatment of plantlets with hemin in the concentrati...

To clarify a possible role of jasmonate signaling in regulation of the state of stomata under salt stress, the effect of the treatment of Arabidopsis thaliana L. plant leaves (wild type and mutants deficient in jasmonate signaling) with sodium chloride (50–200 mM) and/or methyl jasmonate (200 μM) was studied. A 2–3-h effect of NaCl induced stomatal...

The review is devoted to the physiological functions of the main gasotransmitters (GT) in plants. The pathways for synthesis of nitric oxide, hydrogen sulphide, and carbon monoxide are characterized. Their interplay (cross-talk) with other key participants of signaling—calcium ions and reactive oxygen species—was shown. The main pathways for modifi...

A time and concentration dependence of the hydrogen sulfide donor sodium hydrosulfide (NaHS) influence on the state of stomata of Arabidopsis thaliana (Col-0) leaves, as well as the role of calcium and phospholipases in the implementation of its effects, was studied. Treatment of leaves with NaHS in the concentration range of 5–250 μM caused a decr...

Role of jasmonate signaling in the regulation of stress-protective systems in Arabidopsis under salt stress remains insufficiently studied. For its clarification, comparative studies with mutants lacking various protein components of jasmonate signaling are advisable. In this connection, effects of methyl jasmonate (MJ, 50 μM) and salt stress (NaCl...

The effects of combined treatment with an elicitor (lipopolysaccharide) and a signaling molecule (salicylic acid) on the disease resistance of wild-type (Col-0) and mutant Arabidopsis thaliana L. plants have been compared. The mutant lines used were jin1 (with impaired jasmonate signaling), npr1 (lacking expression of pathogen-dependent PR genes),...

The effects of combined treatment with an elicitor (lipopolysaccharide) and a signaling molecule (salicylic acid) on the disease resistance of wild-type (Col-0) and mutant Arabidopsis thaliana L. plants have been compared. The mutant lines used were jin1 (with impaired jasmonate signaling), npr1 (lacking expression of pathogen-dependent PR genes),...

The effect of hydrogen peroxide treatment on the salt tolerance of wild-type Arabidopsis thaliana L. plants (Col-0) and plants transformed with the bacterial salicylate hydroxylase gene (NahG) was studied. The base tolerance to salt stress caused by 200 mM of NaCl in solution culture was higher in plants with the NahG genotype in comparison with th...

Aim. The aim of the investigation was to study the effect of lipopolysaccharides (LPS) derived from saprophytic strains of Pseudomonas aeruginosa on the resistance to phytopathogenic strain of P. aeruginosa IMB 9096. The wild-type (Col-0) Arabidopsis thaliana plants, npr1 mutant, which lacks expression of PR-genes, NahG genotype plants, expressing...

To elucidate the possible role of the transcription factor (TRF) JIN1/MYC2 in implementation of stress-protective effects of abscisic acid (ABA), the effect of exogenous ABA on the state of stomata and the activity of antioxidant enzymes and proline content under salt stress conditions in Arabidopsis thaliana plants of wild type (Col-0) and jin1 mu...

The effect of NO donor sodium nitroprusside (SNP) on salt resistance of 4-week-old Arabidopsis thaliana L. wild-type Columbia-0 (Col-0) plants and jin1 mutants defective in the jasmonate signaling have been investigated. As affected by 0.5 mM, SNP salt resistance of wild-type plants rose, which was exhibited in a smaller growth inhibition and prese...

The effects of treatment with nitric oxide donor sodium nitroprusside (SNP, 0.5 mM) on salt tolerance of wild type (Col–0) Arabidopsis thaliana plants and Arabidopsis thaliana plants transformed with the bacterial salicylate hydroxylase gene (NahG) were compared. Basic salt tolerance level (200 mM NaCl) was higher in NahG transformants. Under salt...

Thirty years after the Chernobyl explosion we still lack information regarding the genetic effects of radionuclide contamination on the plant population. For example, are plants adapting to the low dose of chronic ionising irradiation and showing improved resistance to radiation damage? Are they coping with changing/increased pathogenicity of fungi...

The effects of the salt stress (200 mM NaCl) and exogenous jasmonic acid (JA) on levels of osmolytes and flavonoids in leaves of four-week-old Arabidopsis thaliana L. plants of the wild-type (WT) Columbia-0 (Col-0) and the mutant jin1 (jasmonate insensitive 1) with impaired jasmonate signaling were studied. The increase in proline content caused by...

p>Phytopathogenic fungi interrupt the macromorphogenesis of wheat (Triticum aestivum) but biotic elicitors stimulate the nonspecific tolerance, growth and development of plant stems. It is shown that oxalic acid as a biotic elicitor and donor of nitric oxide signal molecule (sodium nitroprusside) stimulate stem growth in height and last leaves leng...

The effects of exogenous jasmonic acid (JA) on antioxidant enzymes in four-week-old leaves of wild-type Arabidopsis thaliana L. (Columbia-0) and jin1 (jasmonate insensitive 1) mutant plants with defective jasmonate signaling were investigated under normal conditions and under salt stress (200 mM NaCl, 24 h). The wild-type plants responded to JA by...

Perception of signals to abiotic stressors by plant cells is accompanied by an increase in the cytosolic calcium concentration, content of reactive oxygen species (ROS) and nitrogen monoxide (NO) which execute the role of signal mediators at the activation of gene expression responsible for defense responses. Calcium ions, ROS, and NO stay in the m...

The influence of fungus Septoria tritici on winter wheat (Triticum aestivum) cultivars ‘Polis´ka 90’ and ‘Stolychna’ yield formation and plant development, as well as protective role of oxalic acid were studied in the field experiment. It was shown that treatment by oxalic acid decreases the infected square of flag leaves, ears and stems in both va...

The effects of low dose chronic radiation and heavy metals contamination on plant disease resistance, fungal and virus infections have been studied. The results obtained in 10-km Chernobyl exclusion (ChE) zone demonstrated a decrease in plant disease resistance of different wheat, rye and corn cultivars. Analysis of biochemical mechanisms underlyin...

The effects of low dose chronic radiation and heavy metals contamination on plant disease resistance, fungal and virus infections have been studied. The results obtained in 10-km Chernobyl exclusion (ChE) zone demonstrated a decrease in plant disease resistance of different wheat, rye and corn cultivars. Analysis of biochemical mechanisms underlyin...

It was established in greenhouse experiments that infection with powdery moldew (Erysiphe graminis DC. f. sp. tritici Em. Marchal) and brown rust (Puccinia triticana Erikss. & Henn.) of three wheat (Triticum aestivum L.) cultivars (Mironovskaya 808, Polesskay 70, and Kiyanka) grown from seeds, collected in the Chernobyl exclusion zone, was 1.5–2.0...

The effects of low dose chronic radiation on plant disease resistance and fungal and virus infections have been studied. The results obtained in the 10-km Chernobyl zone demonstrated a decrease in plant disease resistance and appearance of a "new" population of stem rust agents of cereal with a high frequency of more virulent clones. Radionuclide c...

The mechanism of action of β-aminobutyric acid (BABA) as an inducer of resistance to the necrotrophic fungi Botrytis spp. in three different varieties of onion (Allium cepa) is investigated. It is shown that low concentrations of BABA are capable of inducing resistance in onion to neck rot induced by Botrytis allii and that induced by B. cinerea. B...

The effects of beta-aminobutiric acid as an inductor of plant resistance was studied. The influence of BABA pretreatment on A. cepa plants of three different pathogen-resistant varieties was investigated by fluorescence microscopic methods. It was determined that BABA is able to prime the plant callose accumulation.

Cell walls of the phytopathogenic fungus, Botrytis cinerea were identified for the presence of biotic elicitors. The isolation of carbohydrates from purified mycelial cell walls of B. cinerea (CCW) and the effect of CCW on induction of disease resistance of Lycopersicon esculentum were carried out. CCW, Immunocytophyt and a fungicide, Ridomil Gold,...

The magnitude of the chitinase activity in tomato plant cells induced by elicitors is determined. It is shown that the magnitude of the enzymatic activity of cells is a function of the dimensions and concentration of the biotic elicitors.

The levels of chitinase activity induced with elicitors in tomato cells have been detected. It was shown that enzymatic activity depended on degree of polymerization and concentration of biotic elicitors.

Metabolites of a phytopathogenic fungus Botrytis cinerea Pers. were analyzed for the presence of biotic elicitors. Three groups of elicitors competent in inducing defense responses inAllium cepa cells were identified and partly purified. The recognition of the elicitor signal in onion cells was shown to elevate the concentration of reactive oxygen...

When a pathogen is perceived by a host plant, a series of defense responses can be activated. One of these are "local" defenses that occur rapidly at the site of pathogen invasion. Another are "systemic" defenses that are induced in uninoculated parts of the plant. Recently, molecular genetic studies have revealed genes that are signaling component...

Discovery of nitric oxide (NO*) as a key endogenous molecule, which regulates metabolism among very distantly related organisms, stimulated intensive research related to its multiple functions in plants. NO* exerts its cellular effects as toxic agent, metabolism regulator, second messenger during elicitation of different defense responses. It can i...

Systemic acquired resistance (SAR) to infection by Botrytis cinerea in the leaves of sunflower (Helianthus annuus L.) plants was induced following cotyledon inoculation with B. cinerea or treatment with abiotic inducers. Salicylic acid (SA), benzo-(1,2,3)-thiadiazole-7-carbothioic S-methyl ester (BTH), 2,6-dichloroisonicotinic acid (INA) or EDTA pr...

Plants are capable of recognizing the penetrating pathogens and of responding to their attack by the activation of the defense systems. Signal transduction from the receptor to the cell genome is required for this activation. Recently, signal molecules have been found, which are involved in the signal transduction triggered in response to biotic st...

Plants can recognise the penetrating pathogen and respond to the attack with an array of defense reactions. Signal transduction from receptor in plasma membrane to genome is necessary to activate these reactions. Plant cell signaling systems which take part in signal transduction were discovered and identified recently. The obtained results suggest...

The content of anthocianins was determined in Oenothera biennis plants, grown from seeds, picked on the plots with different levels of radionuclide contamination in the 30-km Chernobyl zone. It was shown that the content of anthocianins was higher in plants from Yanov area (20-40 mR/h) than in plants from Chernobyl area (0.04 mR/h). An acute gamma-...

The elicitor-induced generation of two oxygen species in tomato cell culture as well as their involvement into hypersensitive reaction was investigated. Generation of superoxide O2.- was measured by a lucigenin-related chemiluminescence. Accumulation of hydrogen peroxide H2O2 was measured by a fluorescent probe pyranin. Xylanase and chitosan were u...

The existence of a gene or genes conferring weak resistance against the fungal tomato pathogen Cladosporium fulvum, in addition to the Cf-9 resistance gene, present on the Lycopersicon pimpinellifolium Cf-9 segment introgressed into L. esculentum, was demonstrated with strains of C. fulvum lacking a functional Avr9 avirulence gene and tomato genoty...

Two defense reactions, the accumulation of phytoalexins (PA) and the production of callose, were elicited in a suspension culture of onion (Allium cepa L.) cells by the addition of chitosan or Botrytis cinerea culture filtrate to the nutrient medium. The role of Ca2+ in signal transduction following the recognition of the biogenous elicitor was inv...

Treatment of Allium cepa L. cellsuspension cultures with a biotic elicitor derived from the fungus Botrytis cinerea, resulted in phytoalexin synthesis. Two phytoalexins, 5-octylcyclopenta-1,3-dione and 5-hexyl-cyclopenta-1,3-dione, were accumulated in cultured onion cells. Removal of extracellular Ca2+ by the calcium chelator ethylene glycol bis(b-...

Treatment of Allium cepa L. cellsuspension cultures with a biotic elicitor derived from the fungus Botrytis cinerea, resulted in phytoalexin synthesis. Two phytoalexins, 5-octylcyclopenta-1,3-dione and 5-hexyl-cyclopenta-1,3-dione, were accumulated in cultured onion cells. Removal of extracellular Ca2+ by the calcium chelator ethylene glycol bis(b-...

Two new phytoalexins: 5-octyl-cyclopenta-1,3-dione and 5-hexyl-cyclopenta-1,3-dione were isolated from the bulbs of Allium cepa. Their structures were elucidated by HPLC and spectroscopic methods.

Two phytoalexins accumulated in onion bulb scales in response to inoculation with Botrytis cinerea, a non-pathogen of onions. These compounds, termed tsibulins (1d and 2d) after the Ukrainian word tsibulya for onion, were isolated by gel filtration, TLC and HPLC, and identified by spectroscopic methods as 1,3-dion-5-octyl-cyclopentane (tsibulin 1d)...

A cell-free extract from blue-green alga Anacystis nidulans contains enzymes which repair in vitro the transforming activity of gamma-irradiated Bacillus subtilis DNA. The level of restoration of the transforming activity depends on the protein concentration in the reaction mixture, the duration of incubation and on the dose of irradiation. The rep...

The effect of gamma irradiation on asynchronous and synchronous plasmodia of Physarum polycephalum was studied. Micro- and macroplasmodia were exposed to 30–225 krad during different mitotic cycle stages; subsequent protein synthesis was measured. After coalescence of asynchronous microplasmodia to multinuclear macroplasmodia radioresistance increa...

The level of inactivation of oxygen evolving photosynthesis in the blue-green alga, Anacystis nidulans was 30% in N2 at a dose of 100 krad of gamma-irradiation. These organisms irradiated in the presence of CO2 and light in anoxic conditions demonstrate an increase in radiation sensitivity with an oxygen enhancement ratio of 2.0. Neither light alon...

The photosynthetic system of the blue-green alga Anacystis nidulans was inactivated by 30% at a dose of 100 krad of gamma irradiation in N2. If the cells were irradiated in N2+2% CO2 in the light, their radiation sensitivity was increased with an oxygen enhancement ratio of 2.0. Neither light nor CO2 taken separately affected radiosensitization of...

The effects of the radiosentisizing agents iodoacetic acid (IAA) and p-chloromercuribenzoate (PCMB) on the production and repair of DNA single-strand breaks induced in unicellular blue-green alga Anacystis nidulans by ionizing radiation were studied. The number of single-strand breaks in DNA, as measured by the alkaline sucrose gradient technique,...

The radiosensitizing effect of a rifamycin derivate — dimethylbenzyldesmethylrifampicin (DMB) was compared with that of actinomycin D in unicellular blue-green alga, Anacystis nidulans. These agents are active when added after irradiation and potentiate γ-ray-induced killing in cells. Pre-irradiation treatment of cells with DMB or actinomycin D is...

The blue-green algae appear to have maintained efficient repair systems. They were sensitized to gamma-irradiation by chemical sensitizers. This work presents evidence for the influence of sensitizers on post-irradiation DNA degradation. Uracil-14C labelled A. nidulans were irradiated in the presence of solutions of various radiosensitizers. Loss o...