Heat shock proteins (HSPs) are widely distributed among prokaryotic and eukaryotic organisms, and their function is not limited to protection from temperature exposure. HSPs are detected not only under broad-spectrum abiotic stress but also under biotic stress. They have a common universal role as chaperones to maintain the functioning of protein molecules. The review provides data indicating the participation of representatives of each HSP family in the development of plant defense responses against phytopathogens. HSPs are activated at different levels of plant protection from pathogens: both at the level of nonspecific pattern-activated and at the level of specific effector-activated immunity. Of no small importance is the interaction of HSPs with participants in cellular signaling cascade systems, exercising control over the correct and timely maturation, assembly, and, if necessary, degradation of protein molecules. Consideration of the participation of HSPs in plant immunity undoubtedly deserves the attention of specialists in the field of phytoimmunology.

It is widely believed that phthalates are xenobiotic pollutants whose prevalence in the environment is associated with their facilitated diffusion from plastic materials. Studies into the effect of synthetic phthalates on living organisms revealed their extremely negative action on the metabolism of animals and humans. The acting mechanism of these compounds is realised through a ligand-receptor pathway. Along with dioxins, polychlorinated biphenyls and similar compounds, phthalates are classified as endocrine disrupters. However, at present, sufficient evidence has been accumulated confirming the natural origin of phthalates. Thus, phthalates were de novo biosynthesised from labelled precursors in an algae culture. These compounds were detected in closed experimental systems, including cell cultures of highest plants, as well as those isolated from a number of bacterial, fungi, lowest and highest plant forms located far from the sources of technogenic pollution. The concept of phthalate biogenesis assumes the action of these compounds on living systems. Phthalates exhibit bactericidal and fungicidal action and compose allelopathic exudates, suppressing the growth of competing plant forms. Phthalates possess insecticidal and repellent properties. An analogy can be traced between the action of phthalates and endocrine disrupters of another chemical category, namely phytoestrogens, which regulate herbivorous mammal populations. A hypothesis is proposed about the biological role of endogenous plant phthalates representing secondary metabolic compounds. Exhibiting predominantly a shielding function, these compounds participate in the network of interactions between plants, animals, fungi and microorganisms. It should be noted that synthetic and endogenous phthalates are characterised by essential stereochemical differences, which can explain their different action on living organisms.

The environment is polluted with ortho-phthalic acid esters (phthalates). There is a steady and generally accepted opinion that the reason for this is human production activities. The global annual production of phthalic esters is estimated at 4.9 million tons. It is believed that part of this amount enters into the environment as a harmful industrial pollutant and has an adverse effect on the health of the human population. However, from a large number of publications it is clear that phthalates, as natural metabolites, are also produced in living nature: bacteria, algae, fungi, plants and other organisms. Dibutyl phthalate and di-2-ethylhexyl phthalate are the main ingredients among natural phthalic acid metabolites. The green cover of the planet simultaneously contains these substances many times more than their annual industrial production. The unicellate inhabitants of the oceans, soils, and other planetary spaces make a big contribution to the phthalates entering in the nature. The lifetime of phthalates in the environment is short and their long-term accumulation is impossible. The observed level of these pollutants in the environment is the result of a dynamic equilibrium process with the participation of natural biosynthesis and industrial production, on the one hand, and biota absorption and natural degradation, on the other. The proportion of biosynthesis and degradation in this equilibrium is seen to be predominant. Therefore, the recommended measures and efforts to limit the production and use of ortho-phthalic acid esters are of little use and make little sense. The observed level is supported by constant feeding from wildlife. Throughout human history, people have received and are receiving phthalates with plant foods without visible consequences. Their harmful effects on the health of the human population are exaggerated. And in the process of evolution, effective endogenous ways of detoxification have been developed.

The study of plant defence mechanisms in response to pathogens in the mid-20th century resulted in Harold Flor’s gene-for-gene interaction hypothesis, which became recognised as central to the study of phytoimmunity. According to this theory, the outcome of interactions in plant – pathogen phytopathosystems – i.e. compatibility or incompatibility – is controlled genetically in interacting organisms and determined by the presence of specific genes in both pathogen and plant: resistance genes in the plant and avirulence genes in pathogen. The latest achievements in phytoimmunology, obtained with the help of modern molecular biology and bioinformatics methods, have made a significant contribution to the classical understanding of plant immunity and provided grounds for a modern concept of phytoimmunity consisting in the “zig-zag model” developed by Jonathan Jones and Jefferey Dangl. Plant immunity is currently understood as being determined by an innate multi-layer immune system involving various structures and mechanisms of specific and non-specific immunity. Recognition by plant membrane receptors of conservative molecular patterns associated with microorganisms, as well as molecules produced during cell wall disruption by pathogen hydrolytic enzymes forms a basic non-specific immune response in the plant. Detection of pathogen effector molecules by plant intra-cellular receptors triggers a specific effector-triggered immunity, resulting in the development of the hypersensitive response, systemic resistance and immune memory of the plant. Virulence factors and pathogen attack strategies on the one hand, and mechanisms of plant immune protection on the other, are the result of one form of constant co-evolution, often termed an “evolutionary arms race”. This paper discusses the main principles of Flor's classical “gene-for-gene interaction” theory as well as the molecular-genetic processes of plant innate immunity, their mechanisms and participants in light of contemporary achievements in phytoimmunology.

Abstract Endogenous phthalates (esters of o-phthalic acid) have been revealed in plant in situ and in vitro. Phthalates reduced biofilm formation and growth of Clavibacter michiganensis ssp. sepedonicus and changed morphology of colonies. So phthalates were considered to be a part of plant defense against bacterial phytopathogens. Meanwhile, phthalates have been found in the cells of phytopathogenic bacteria. It was suggested that the physiological and biochemical role of phthalates can be much more complex and not be limited to the participation of plant organisms in the protective process.

The endogenous esters of orthophthalic acid, dibutyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP), have been first detected in bacterial pathogens of plants (Clavibacter michiganensis ssp. sepedonicus, Pectobacterium carotovorum ssp. carotovorum, Rhizobium rhizogenes, Rhizobium radiobacter) and bacterial pathogens of animal (Escherichia coli).

In this research, we investigated changes in the concentration of hydrogen peroxide in the potato plants and their cell cultures (Solanum tuberosum L.) of two varieties - Lugovskoy and Lukyanovsky - under the action of the necrotrophic bacterial phytopathogen Pectobacterium carotovorum ssp. carotovorum (Pcc) and its exometabolites (filtrate devoid of bacterial cells and thermally inactivated bacterial suspension). A biphasic accumulation of hydrogen peroxide is shown to occur in the cell cultures of the potato varieties under investigation infected with Pcc It is established that a thermally inactivated Pcc culture affects both the cell cultures and plant roots of the plants under study by causing a significant change in the generation of hydrogen peroxide in comparison with a filtrate devoid of bacterial cells. When infected with pathogens and their exometabolites, the intensity and dynamics of changes in hydrogen peroxide in the potato plants is significantly higher compared to a suspension cell culture. The intensity and dynamics of changes in the generation of hydrogen peroxide indicate the development of a systemic induced resistance in the studied potato varieties to Pcc bacteria and their exometabolites.

Федеральное государственное бюджетное учреждение науки Сибирский институт физиологии и

Аннотация.Инфицирование растений суспензией биотрофного патогена Clavibacter michiganensis ssp.michiganensis и его экзометаболитами индуцирует развитие системной устойчивости растения к последующему инфицированию некротрофом Pectobacterium carotovorum ssp.carotovorum.Устойчивость к некротрофу сохраняется у

This is the first study demonstrating that ortho-phthalic acid esters, dibutylphthalate (DBP) and di-(2-ethylhexyl)-o-phthalate (DEHP), inhibit the ability to form biofilms of the biotrophic pathogen Clavibacter michiganensis ssp. sepedonicus and Pectobacterium carotovorum ssp. carotovorum necrotroph. Inhibition of biofilm formation depends on the DBP and DEHP concentrations.

Generation of reactive oxygen species (ROS) in tobacco ( Nicotiana tabacum L.) cell cultures and potato ( Solanum tuberosum L.) of two varieties experiencing the action of bacterial pathogen Clavibacter michiganensis ssp. sepedonicus ( Cms ) was investigated. The intensity and dynamics of the changes in hydrogen peroxide concentration observed in these cultures provided evidence for the development in tobacco of the effector-activated immune responses and the induction of the same type of responses but with low intensity for resistant potato variety and the inhibition of the defense mechanisms for its susceptible variety. This is in accordance with the data concerning the dynamics of plant cell culture death as well as the results obtained earlier on the whole plants. The experiments performed had also the purpose to elucidate whether the development of the above responses on the ability of bacteria Cms to form biofilms during plant infection. It was shown that this ability of Cms is significantly inhibited upon the combined cultivation of it with the plant cells exerting the responses of the effector-activated immunity and represented by the cells of tobacco and resistant potato variety. In the case of susceptible potato variety, the process of the biofilm formation was suppressed by the plant only to a slight extent. In addition, the fact concerning the participation of heat shock proteins (HSPs) in the development of the effector-activated immune responses was revealed.

Infection of plants by suspension of biotrophic pathogen Clavibacter michiganensis ssp. michiganensis and its exometabolites induces the development of systemic resistance of plants to subsequent infection of necrotroph Pectobacterium carotovorum ssp. carotovorum. Resistance to necrotroph saved in the secondgeneration plant, which indicate the development of immune memory upon infection with biotrophs. The results indicate a synergistic effect of salicylate and jasmonate signaling pathways in the development of immune responses in the studied plant-microbe interactions.

Recent investigations in phytoimmunology have extended the classical views on plant immunity, thus providing the modern concept of phytoimmunity. According to the current vision, the protection of plant organisms against pathogen attacks is determined by functioning of multilayered immune system in combination with structures and mechanisms of specific and nonspecific innate immunity. Perception by plant membrane receptors of the conserved molecular patterns associated with microorganisms, as well as perception of molecules released from the host cell walls under the impact of pathogen hydrolytic enzymes, constitutes the basal (nonspecific) immunity of plants. Detection of pathogen effector molecules by intracellular plant receptors triggers specific immunity reactions, including the development of hypersensitive response, systemic resistance, and the immune memory. Virulence factors alongside with the strategies of pathogen attack, on the one hand, and the components of plant immune system, on the other hand, are the result of a permanent coevolution reminiscent of “an arms race and counterattacks” between the warring parties. The basic molecular–genetic aspects of specific and nonspecific immunity in plants exposed to fungal and bacterial phytopathogens are discussed in the light of modern advances in phytoimmunology.

The transgenic and non-transgenic tobacco cell cultures were analyzed for resistance to abiotic and biotic stress. The different physiological reaction of cell culture depending on T-DNA structure (or transgen structure) was observed. The cell culture transformed by disarmed Agrobacterium tumefaciense A699 with pCNL 65 nptII demonstrated the same stress-resistance as non-transgenic control cell culture. The cell culture transformed by Agrobacterium tumefaciense LBA 4400 pBiCaMV nptII + hsp101 showed a raised stress-resistance to high temperature, high KF concentration, and to the action of Clavibacter michiganensis ssp sepidonicus. Obviously, the expression of transferred arabodopsis gene hsp101 provides protection properties of transgenic cell culture under the influence of various stress factors. Moreover, that agrobacterial transformation as previous stress-factor is supposed to make a contribution to formation of transgenic cell culture cross-resistance.