Signaling systems of plant cells. Cell signaling systems and their role in plant life
The action of elicitor preparations is due to the presence of special biologically active substances in their composition. According to modern concepts, signaling substances or elicitors are biologically active compounds of various nature, which, in very low dosages, measured in milli-, micro-, and in some cases, nanograms, cause cascades of various plant responses at the genetic, biochemical, and physiological levels. Their impact on phytopathogenic organisms is carried out by influencing the genetic apparatus of cells and changing the physiology of the plant itself, giving it greater viability, resistance to various negative environmental factors.
The relationship of plants with the outside world, as highly organized elements of ecological systems, is carried out through the perception of physical and chemical signals coming from outside and correcting all the processes of their life by influencing genetic structures, the immune and hormonal systems. The study of plant signaling systems is one of the most promising areas in modern cell and molecular biology. In recent decades, scientists have paid much attention to the study of signaling systems responsible for plant resistance to phytopathogens.
The biochemical processes occurring in plant cells are strictly coordinated by the integrity of the organism, which is complemented by their adequate responses to information flows associated with various effects of biogenic and technogenic factors. This coordination is carried out due to the work of signal chains (systems), which are woven into signal networks of cells. Signaling molecules turn on most hormones, as a rule, not penetrating inside the cell, but interacting with receptor molecules of outer cell membranes. These molecules are integral membrane proteins, the polypeptide chain of which penetrates the thickness of the membrane. A variety of molecules that initiate transmembrane signaling activate receptors at nano-concentrations (10-9-10-7 M). The activated receptor transmits a signal to intracellular targets - proteins, enzymes. In this case, their catalytic activity or the conductivity of ion channels is modulated. In response to this, a certain cellular response is formed, which, as a rule, consists in a cascade of successive biochemical reactions. In addition to protein messengers, signal transduction can also involve relatively small messenger molecules that are functionally mediators between receptors and the cellular response. An example of an intracellular messenger is salicylic acid, which is involved in the induction of stress and immune responses in plants. After switching off the signaling system, the messengers are rapidly split or (in the case of Ca cations) are pumped out through the ion channels. Thus, proteins form a kind of “molecular machine”, which, on the one hand, perceives an external signal, and on the other hand, has enzymatic or other activity modeled by this signal.
In multicellular plant organisms, signal transmission is carried out through the level of cell communication. Cells "speak" the language of chemical signals, which allows the homeostasis of a plant as an integral biological system. The genome and cell signaling systems form a complex self-organizing system or a kind of "biocomputer". The hard information carrier in it is the genome, and the signaling systems play the role of a molecular processor that performs the functions of operational control. At present, we have only the most general information about the principles of operation of this extremely complex biological entity. In many ways, the molecular mechanisms of signaling systems still remain unclear. Among the solution of many issues, it is necessary to decipher the mechanisms that determine the temporary (transient) nature of the inclusion of certain signaling systems, and at the same time, the long-term memory of their inclusion, which manifests itself, in particular, in the acquisition of systemic prolonged immunity.
There is a two-way relationship between signaling systems and the genome: on the one hand, enzymes and proteins of signaling systems are encoded in the genome, on the other hand, signaling systems are controlled by the genome, expressing some genes and suppressing others. This mechanism includes reception, transformation, multiplication, and signal transmission to the promoter regions of genes, programming of gene expression, changes in the spectrum of synthesized proteins, and the functional response of the cell, for example, induction of immunity to phytopathogens.
Various organic compounds-ligands and their complexes can act as signal molecules or elicitors that exhibit inductive activity: amino acids, oligosaccharides, polyamines, phenols, carboxylic acids and esters of higher fatty acids (arachidonic, eicosapentaenoic, oleic, jasmonic, etc.), heterocyclic and organoelement compounds, including some pesticides, etc. .
The secondary elicitors formed in plant cells under the action of biogenic and abiogenic stressors and included in the cell signaling networks include phytohormones: ethylene, abscisic, jasmonic, salicylic acids, and
also the systemin polypeptide and some other compounds that cause the expression of protective genes, the synthesis of the corresponding proteins, the formation of phytoalexins (specific substances that have an antimicrobial effect and cause the death of pathogenic organisms and affected plant cells) and, ultimately, contribute to the formation of systemic resistance in plants to negative environmental factors.
At present, seven cell signaling systems are the most studied: cycloadenylate, MAP-kinase (mitogen-activated protein-kinase), phosphatidic acid, calcium, lipoxygenase, NADPH-oxidase (superoxide synthase), NO-synthase. Scientists continue to discover new signaling systems and their biochemical participants.
In response to the attack of pathogens, plants can use various pathways for the formation of systemic resistance, which are triggered by different signaling molecules. Each of the elicitors, acting on the vital activity of a plant cell through a certain signaling pathway, through the genetic apparatus, causes a wide range of reactions, both protective (immune) and hormonal, leading to a change in the properties of the plants themselves, which allows them to withstand a whole range of stress factors. At the same time, inhibitory or synergistic interaction of various signaling pathways intertwined into signaling networks takes place in plants.
Induced resistance is similar in manifestation to genetically determined horizontal resistance, with the only difference being that its nature is determined by phenotypic changes in the genome. Nevertheless, it has a certain stability and serves as an example of phenotypic immunocorrection of plant tissue, since as a result of treatment with eliciting substances, it is not the plant genome that changes, but only its functioning associated with the level of activity of protective genes.
In a certain way, the effects arising from the treatment of plants with immunoinductors are related to gene modification, differing from it in the absence of quantitative and qualitative changes in the gene pool itself. With the artificial induction of immune responses, only phenotypic manifestations are observed, characterized by changes in the activity of the expressed genes and the nature of their functioning. However, the changes caused by the treatment of plants with phytoactivators have a certain degree of stability, which manifests itself in the induction of prolonged systemic immunity, which is maintained for 2-3 months or more, as well as in the preservation of the acquired properties by plants during 1-2 subsequent reproductions.
The nature of the action of a particular elicitor and the effects achieved are most closely dependent on the strength of the generated signal or the dosage used. These dependences, as a rule, are not linear, but sinusoidal in nature, which can serve as evidence of switching signaling pathways during their inhibitory or synergistic interactions. high severity of their adaptogenic action. On the contrary, treatment with these substances in high doses, as a rule, caused desensitization processes in plants, sharply reducing the immune status of plants and leading to an increase in plant susceptibility to diseases.
BBK 28.57 T22
Executive Editor, Corresponding Member of the Russian Academy of Sciences.I. Grechkin
Reviewers:
Doctor of Biological Sciences, Professor L.Kh. Gordon Doctor of Biological Sciences, Professor L.P. Khokhlova
Tarchevsky I.A.
Signaling systems of plant cells / I.A. Tarchevsky; [Resp. ed. A.N. Grechkin]. -
M.: Nauka, 2002. - 294 p., ill. ISBN 5-02-006411-4
The links of information chains of interaction between pathogens and plants are considered, including elicitors, elicitor receptors, G-proteins, protein kinases and protein phosphatases, transcription regulation factors, reprogramming of gene expression, and cell response. The main attention is paid to the analysis of the features of the functioning of individual signaling systems of plant cells - adenylate cyclase, MAP kinase, phosphatidate, calcium, lipoxygenase, NADPH oxidase, NO synthase and proton, their interaction and integration into a single signaling network. A classification of pathogen-induced proteins according to their functional features is proposed. Data on transgenic plants with increased resistance to pathogens are presented.
For specialists in the field of plant physiology, biochemists, biophysicists, geneticists, phytopathologists, ecologists, agrobiologists.
On the AK network
Plant Cell Signaling Systems /1.A. Tarchevsky; . - M.: Nauka, 2002. - 294 p.; il. ISBN 5-02-006411-4
The book discussed the members of signaling chains of interplay of pathogens and plant-host, namely elicitors, receptors, G-proteins, protein kinases and protein phosphatases, transcription factors reprogramming of genes expression, cell response. The main part of the book is devoted to functioning of separate cell signaling systems: adenylate cyclase, MAP kinase, phosphatidate, calcium, lipoxy-genase, NADPH-oxidase, NO-synthase, protons systems. The concept of interconnections of cell signaling systems and their integration to general cell signaling network is developing. The author has preposed the classification of pathogen-related proteins according to their function properties. The data on transgenic plants with the increased resistance to pathogens are presented.
For physiologists, biochemists, biophysicists, genetics, phytopathologists, ecologists, and agrobiologists
ISBN 5-02-006411-4
© Russian Academy of Sciences, 2002 © Nauka Publishing House
(art design), 2002
In recent years, studies of the molecular mechanisms of regulation of gene expression under the influence of changing living conditions have been rapidly developing. In plant cells, the existence of signal chains was discovered, which, with the help of special receptor proteins, in most cases located in the plasmalemma, perceive signal impulses, convert, amplify and transmit them to the cell genome, causing reprogramming of gene expression and changes in metabolism (including including cardinal) associated with the inclusion of previously "silent" and the exclusion of some active genes. The significance of cell signaling systems was demonstrated in the study of the mechanisms of action of phytohormones. The decisive role of signaling systems in the formation of an adaptation syndrome (stress) caused by the action of abiotic and biotic stressors on plants was also shown.
The lack of review papers that would analyze all the links of various signaling systems, starting with the characteristics of the perceived signals and their receptors, the transformation of signal impulses and their transmission to the nucleus, and ending with dramatic changes in the metabolism of cells and their structure, forced the author to attempt to fill this gap. with the help of the book offered to the attention of readers. It must be taken into account that the study of the information field of cells is still very far from being completed, and many details of its structure and functioning remain insufficiently illuminated. All this attracts new researchers, for whom the generalization of publications on the signaling systems of plant cells will be especially useful. Unfortunately, not all reviews
articles of an experimental nature were included in the list of references, which to a certain extent depended on the limited volume of the book and the time for its preparation. The author apologizes to colleagues whose research was not reflected in the book.
The author expresses his gratitude to his collaborators who took part in the joint study of the signaling systems of plant cells. The author is especially grateful to Professor F.G. Karimova, candidates of biological sciences V.G. Yakovleva and E.V. Asafova, A.R. Mucha-metshin and associate professor T.M. Nikolaeva for help in preparing the manuscript for publication.
This work was supported financially by the Leading Scientific School of the Russian Federation (grants 96-15-97940 and 00-15-97904) and the Russian Foundation for Basic Research (grant 01-04-48-785).
INTRODUCTION
One of the most important problems of modern biology is the deciphering of the mechanisms of response of prokaryotic and eukaryotic organisms to changes in the conditions of their existence, especially to the action of extreme factors (stress factors, or stressors) that cause a state of stress in cells.
In the process of evolution, cells have developed adaptations that allow them to perceive, transform and amplify the signals of a chemical and physical nature coming from the environment and, with the help of the genetic apparatus, respond to them, not only adapting to changing conditions, rebuilding their metabolism and structure, but also highlighting various volatile and non-volatile compounds into the extracellular space. Some of them play the role of protective substances against pathogens, while others can be considered as signaling molecules that cause a response of other cells located at a great distance from the site of action of the primary signal on plants.
We can assume that all these adaptive events occur as a result of changes in the information field of cells. Primary signals with the help of various signaling systems cause a reaction on the part of the cell genome, which manifests itself in the reprogramming of gene expression. In fact, signaling systems regulate the operation of the main receptacle of information - DNA molecules. On the other hand, they themselves are under the control of the genome.
For the first time in our country, E.S. Severin (Severin, Kochetkova, 1991) on animal objects and O.N. Kulaeva [Kulaeva et al., 1989; Kulaeva, 1990; Kulaeva et al., 1992; Kulaeva, 1995;
Burkhanova et al., 1999] - on plants.
The monograph presented to the attention of readers contains a generalization of the results of studying the effect of biotic stressors on the functioning of the signaling systems of plant cells. MAP kinase, adenylate cyclase, phosphatidate, calcium, lipoxygenase, NADPH oxidase, NO synthase, and proton signaling systems and their role in the ontogenetic development of plants and in shaping the response to changing living conditions, especially to the action of various abiotic and biotic stressors. The author decided to focus only on the last aspect of this problem - on the molecular mechanisms of plant response to the action of pathogens, especially since this response involves a number of phytohormones and elucidation of the features of the interaction of plant cell signaling systems with them attracts much attention of researchers.
The impact of biotic stressors leads to a plant response that is basically similar to the response to abiotic stressors. It is characterized by a set of non-specific reactions, which made it possible to call it an adaptation syndrome, or stress. Naturally, specific features of the response depending on the type of stressor can also be detected, however, as the measure of its impact increases, nonspecific changes come to the fore more and more [Meyerson, 1986; Tarchevsky, 1993]. The greatest attention was paid to them by N.S. Vvedensky (ideas about parabiosis), D.S. Nasonov and V.Ya. Alexandrov (ideas about paranecrosis), G. Selye - in works devoted to stress in animals, V.Ya. Aleksandrov - in studies of the molecular basis of stress.
The most significant non-specific changes in biotic stress include the following:
1. Phase in the deployment in time of the response to the action of the pathogen.
2. Increased catabolism of lipids and biopolymers.
3. An increase in the content of free radicals in tissues.
4. Acidification of the cytosol followed by activation of proton pumps, which returns the pH to its original value.
5. An increase in the content of calcium ions in the cytosol, followed by activation of calcium ATPases.
6. Exit from cells of potassium and chlorine ions.
7. Drop in membrane potential (on the plasmalemma).
8. Decreased overall intensity of biopolymer synthesis and
9. Stopping the synthesis of some proteins.
10. Increased synthesis or synthesis of absent so-called pathogen-induced protective proteins (chitinases,(3-1,3-glucanases, proteinase inhibitors, etc.).
11. Intensification of the synthesis of components that strengthen cell walls - lignin, suberin, cutin, callose, a protein rich in hydroxyproline.
12. Synthesis of antipathogenic non-volatile compounds -
phytoalexins.
13. Synthesis and isolation of volatile bactericidal and fungicidal compounds (hexenals, nonenals, terpenes and
Dr->- 14. Strengthening the synthesis and increasing the content (or according to
phenomenon) of stress phytohormones - abscisic, jasmonic, salicylic acids, ethylene, the hormone of the peptide nature of systemin.
15. Inhibition of photosynthesis.
16. Redistribution of carbon from |4 CO2, assimilated during photosynthesis, among various compounds - a decrease in the inclusion of the label in high-polymer compounds (proteins, starch) and sucrose and an increase (more often relative - as a percentage of the assimilated carbon) - in alanine, malate , aspartate (Tarchevsky, 1964).
17. Increased breathing followed by its inhibition. Activation of an alternative oxidase that changes the direction of electron transport in mitochondria.
18. Violations of the ultrastructure - a change in the fine granular structure of the nucleus, a decrease in the number of polysomes and dictyosomes, swelling of mitochondria and chloroplasts, a decrease in the number of thylakoids in chloroplasts, rearrangement of cyto-
skeleton.
19. Apoptosis (programmed death) of cells exposed to pathogens and neighboring cells.
20. The appearance of the so-called systemic nonspecific
resistance to pathogens in plant sites (for example, metameric organs) remote from the place of pathogen impact.
Many of the changes listed above are a consequence of the "switching on" by stressors of a relatively small number of nonspecific signaling systems.
As the mechanisms of plant responses to pathogens become more and more deeply studied, new nonspecific responses of plant cells are being discovered. These include previously unknown signaling pathways.
When elucidating the features of the functioning of signaling systems, it should be borne in mind that these issues are part of a more general problem of regulating the functioning of the genome. It should be noted that the universality of the structure of the main information carriers of cells of various organisms - DNA and genes - predetermines the unification of the mechanisms that serve the implementation of this information [Grechkin, Tarchevsky, 2000]. This concerns DNA replication and transcription, the structure and mechanism of action of ribosomes, as well as the mechanisms of regulation of gene expression by changing conditions of cell existence using a set of largely universal signaling systems. The links of the signaling systems are also basically unified (nature, having found the optimal structural and functional solution of a biochemical or informational problem in its time, preserves and replicates it in the process of evolution). In most cases, a wide variety of chemical signals coming from the environment are captured by the cell with the help of special "antennas" - receptor protein molecules that penetrate the cell membrane and protrude above its surfaces from the outside and inside.
her side. Several types of structure of these receptors are unified in plant and animal cells. The non-covalent interaction of the outer region of the receptor with one or another signal molecule coming from the environment surrounding the cell leads to a change in the conformation of the receptor protein, which is transmitted to the inner, cytoplasmic region. In most signaling systems, intermediary G-proteins are in contact with it - another unified (in terms of its structure and functions) link of signaling systems. G-proteins perform the functions of a signal transducer, transmitting a signal conformational impulse to the starting enzyme specific for a particular signal system. Starting enzymes of the same type of signaling system in different objects are also universal and have extended regions with the same amino acid sequence. One of the most important unified links of signaling systems are protein kinases (enzymes that transfer the terminal residue of orthophosphoric acid from ATP to certain proteins), activated by the products of starting signal reactions or their derivatives. Phosphorylated proteins by protein kinases are the next links in the signal chains. Another unified link in cell signaling systems is protein transcription regulation factors, which are one of the substrates of protein kinase reactions. The structure of these proteins is also largely unified, and structural modifications determine whether transcription regulation factors belong to one or another signaling system. Phosphorylation of transcription regulation factors causes a change in the conformation of these proteins, their activation and subsequent interaction with the promoter region of a certain gene, which leads to a change in the intensity of its expression (induction or repression), and in extreme cases, to the "switching on" of some silent genes or "switching off" active. Reprogramming of the expression of the totality of genome genes causes a change in the ratio of proteins in the cell, which is the basis of its functional response. In some cases, a chemical signal from the external environment can interact with a receptor located inside the cell - in the cytosol or yes -
Rice. 1. Scheme of interaction of external signals with cell receptors
1, 5, 6 - receptors located in the plasmalemma; 2,4 - receptors located in the cytosol; 3 - starting enzyme of the signaling system, localized in the plasmalemma; 5 - receptor activated under the influence of non-specific changes in the structure of the lipid component of the plasmalemma; SIB - signal-induced proteins; PGF - protein transcription regulation factors; i|/ - change in membrane potential
same nucleus (Fig. 1). In animal cells, such signals are, for example, steroid hormones. This information pathway has a smaller number of intermediates, and therefore it has fewer opportunities for regulation by the cell.
In our country, great attention has always been paid to the problems of phytoimmunity. A number of monographs and reviews by domestic scientists are devoted to this problem [Sukhorukov, 1952; Verderevsky, 1959; Vavilov, 1964; Gorlenko, 1968; Rubin et al., 1975; Metlitsky, 1976; Tokin, 1980;
Metlitsky et al., 1984; Metlitsky and Ozeretskovskaya, 1985; Kursanov, 1988; Ilinskaya et al., 1991; Ozeretskovskaya et al., 1993; Korableva, Platonova, 1995; Chernov et al., 1996; Tarchevsky and Chernov, 2000].
In recent years, special attention has been paid to the molecular mechanisms of phytoimmunity. It was shown that
when plants are infected, various signaling systems are activated that perceive, multiply, and transmit signals from pathogens to the genetic apparatus of cells, where protective genes are expressed, which allows plants to organize both structural and chemical protection against pathogens. Advances in this area are associated with gene cloning, deciphering their primary structure (including promoter regions), the structure of the proteins they encode, the use of activators and inhibitors of individual parts of signaling systems, as well as mutants and transgenic plants with inserted genes responsible for the synthesis of participants in the reception. , transmission and amplification of signals. In the study of plant cell signaling systems, an important role is played by the construction of transgenic plants with promoters of the genes of proteins involved in signaling systems.
Currently, the signaling systems of plant cells under biotic stress are most intensively studied at the Institute of Biochemistry. A.N. Bach RAS, Kazan Institute of Biochemistry and Biophysics RAS, Institute of Plant Physiology RAS, Pushchino Branch of the Institute of Bioorganic Chemistry RAS, Center "Bioengineering" RAS, Moscow and St. Petersburg State Universities, All-Russian Research Institute of Agricultural Biotechnology RAS, All-Russian Research Institute of Phytopathology RAS .
The problem of deciphering the molecular mechanisms of biotic stress, including the role of signaling systems in its development, has united plant physiologists and biochemists, microbiologists, geneticists, molecular biologists, and phytopathologists over the past ten years. A large number of experimental and review articles on various aspects of this problem are published (including in special journals:
"Physiological and Molecular Plant Pathology", "Molecular Plant - Microbe Interactions", "Annual Review of Plant Physiology and Pathology"). At the same time, in the domestic literature there is no generalization of works devoted to cell signaling systems, which led the author to the need to write a monograph offered to readers.
PATHOGENS AND ELICITERS
Plant diseases are caused by thousands of species of microorganisms, which can be divided into three groups: viruses (more than 40 families) and viroids; bacteria (Agrobacterium, Corynebacterium, Erwinia, Pseudomonas, Xanthomonas, Streptomyces) and
mycoplasma-like microorganisms; mushrooms (lower:
Plasmodiophoromycetes, Chitridomycetes, Oomycetes: higher: Ascomycetes, Basidi-omycetes, Deuteromycetes).
theses for protective enzymes: phenylalanine-ammonia-lyase
And anionic peroxidase. The wingless forms belonging to this subclass appeared as a result of the loss of these organs during the evolution of winged forms. The subclass includes 20 orders of insects, among which there are polyphages that do not have plant specificity, oligophages and monophages, in which the specificity of the interaction between the pathogen and the host plant is pronounced. Some insects feed on leaves (the entire leaf blade or skeletonizing the leaf), others feed on stems (including gnawing the stem from the inside), flower ovaries, fruits, and roots. Aphids and cicadas suck the juice from conducting vessels with the help of a proboscis or stylet.
Despite the measures taken to combat insects, the problem of reducing the harm they cause continues to be a topical issue. Currently, over 12% of the world's agricultural crops are lost as a result of attack by pathogenic microorganisms,
nematodes and insects.
Damage to cells leads to the degradation of their contents, such as high-polymer compounds, and the appearance of oligomeric signaling molecules. These "wreckage fragments" [Tarchevsky, 1993] reach neighboring cells and induce a protective reaction in them, including changes in gene expression and the formation of protective proteins encoded by them. Often, mechanical damage to plants is accompanied by their infection, since a wound surface opens through which pathogens penetrate into the plant. In addition, phytopathogenic microorganisms can live in the oral organs of insects. It is known, for example, that the carriers of mycoplasma infection are cicadas, in which adult forms and larvae feed on the juice of sieve vessels of plants, piercing the leaf covers with a stylet proboscis and
Rice. 2. Scheme of interaction of a pathogen cell with a host plant / - cutinase; 2 - degradation products of cuticle components (possibly
having signaling properties); 3 - (3-glucanase and other glycosylases excreted by the pathogen; 4 - elicitors - fragments of the host cell wall (CS); 5 - chitinases and other glycosylases that act destructively on the pathogen CS; 6 - elicitors - fragments of the pathogen CS; 7 - phytoalexins - inhibitors of proteinases, cutinases, glycosylases and other enzymes of the pathogen; 8 - toxic substances of the pathogen; 9 - strengthening of the host's CS due to the activation of peroxidases and increased synthesis of lignin, deposition of hydroxyproline proteins and lectins; 10 - inducers of hypersensitivity and necrosis of neighboring cells; // - cutin degradation products acting on the pathogen cell
young stems. The rose leafhopper, unlike other representatives of the leafhopper, sucks out the contents of the cells. Cicadas cause less damage to plant tissues than leaf-eating insects, however, plants can react to it in the same way as to the infection of plants associated with it.
Upon contact with plants, pathogen cells secrete various compounds that ensure their penetration into the plant, nutrition, and development (Fig. 2). Some of these compounds are toxins that pathogens secrete to weaken the host's resistance. More than 20 host-specific toxins produced by pathogenic fungi have been described so far.
Rice. 3. Phytotoxic compound from Cochlio-bolus carbonum
Bacteria and fungi also form non-selective toxins, in particular fusicoccin, erihoseten, coronatin, phase-olotoxin, syringomycin, tabtoxin.
One of the host-specific toxins released
Pyrenophora triticirepentis is a 13.2 kDa protein, others are products of secondary metabolism with a wide variety of structures - these are polyketides, terpenoids, saccharides, cyclic peptides, etc.
As a rule, the latter include peptides, the synthesis of which occurs outside the ribosomes and which contain residues of D-amino acids. For example, the host-specific toxin from Cochliobolus carbonum has a tetrapeptide ring structure (D-npo-L-ana-D-ana-L-A3JJ), where the last abbreviation is 2-amino-9,10-epoxy-8-oxo-de -canoic acid (Fig. 3). The toxin is produced in pathogen cells by toxin synthase. Resistance to this compound in maize depends on the gene encoding NADPH-dependent carbonyl reductase, which reduces the carbonyl group, resulting in
deactivation of the toxin. It turned out that in the body of the host plant, the toxin causes inhibition of histone deacetylases and, as a consequence, histone overacetylation. This suppresses the plant's defense response to pathogen infection.
Another type of compounds secreted by pathogens is called elicitors (from the English elicit - to identify, cause). The collective term "elicitor" was proposed for the first time in 1972 to designate chemical signals that appear at the sites of infection of plants by pathogenic microorganisms and has become widespread.
Elicitors play the role of primary signals and set in motion a complex network of processes of induction and regulation of phytoimmunity. This is manifested in the synthesis of protective proteins, non-volatile plant antibiotics - phytoalexins, in the isolation of anti-pathogenic volatile compounds, etc. At present, the structure of many natural elicitors has been characterized. Some of them are produced by microorganisms, others (secondary elicitors) are formed during the enzymatic cleavage of high-polymer compounds of the cuticle and polysaccharides of the cell walls of plants and microorganisms, and others are stress phytohormones, the synthesis of which in plants is induced by pathogens and abiogenic stressors. Among the most important elicitors are protein compounds excreted by pathogenic bacteria and fungi, as well as viral envelope proteins. Small (10 kDa), conservative, hydrophilic, cysteine-enriched elicitins secreted by all studied species can be considered the most studied protein elicitors.
Phytophthora and Pythium. These include, for example, cryptogein.
Elicitins cause hypersensitivity and death of infected cells, especially in plants of the genus Nicotiana. The most intensive formation of elicitins by phytophthora occurs during the growth of mi-
It was found that elicitins are capable of transporting sterols across membranes, since they have a sterol-binding site. Many pathogenic fungi are unable to synthesize sterols themselves, which explains the role of elicitins not only in the nutrition of microorganisms, but also in inducing the defense response of plants. A 42 kDa glycoprotein elicitor was isolated from Phytophthora. Its activity and binding to the plasma membrane protein receptor, the monomeric form of which is a 100 kDa protein, was provided by an oligopeptide fragment of 13 amino acid residues. A race-specific elicitor peptide consisting of 28 amino acid residues with three disulfide groups was obtained from the phytopathogenic fungus Cladosporium fulvum, and the peptide was formed from a precursor containing 63 amino acids. This avirulence factor showed structural homology to a number of small peptides, such as carboxypeptidase inhibitors and ion channel blockers, and bound to the plasma membrane receptor protein, apparently causing its modulation, dimerization, and transmission of a signal impulse to signaling systems. The larger Cladosporium fulvum pre-protein of 135 amino acids is post-translationally processed into an elicitor protein of 106 amino acids. The elicitor proteins produced by the rust fungus Uromyces vignae are two small polypeptides of 5.6 and 5.8 kDa, unlike other elicitins in properties. Among bacterial protein elicitors, harpins are the most studied.
Many phytopathogenic bacteria produce elicitor oligopeptides (their synthetic
sian analogues), corresponding to the most conservative regions of the protein - flagellin,
which is an important factor in the virulence of these bacteria. A new elicitor protein has been isolated from Erwinia amylovora, the C-region of which is homologous to the pectate lyase enzyme, which can cause the appearance of elicitor oligomeric fragments - pectin degradation products. The pathogenic bacterium Erwinia carotovora excretes the elicitor protein harpin and the enzymes pectate lyase, cellulase, polygalacturonase, and proteases that hydrolyze the polymeric components of the host plant cell walls (see Fig. 2), resulting in the formation of oligomeric elicitor molecules. Interestingly, the pectate lyase secreted by Erwinia chrysanthemi,
acquired activity as a result of extracellular processing. Some lipids and their derivatives are also
elicitors, in particular 20-carbon polyunsaturated fatty acids of some pathogens - arachidonic and eicosapentaenoic [Ilyinskaya et al., 1991; Ozeretskovskaya et al., 1993; Ozeretskovskaya, 1994; Gilyazetdinov et al., 1995; Ilyinskaya et al., 1996a, b; Ilyinskaya, Ozeretskovskaya, 1998], and their oxygenated derivatives. The review paper [Ilyinskaya et al., 1991] summarizes data on the elicitor effect of lipids (lipoproteins) produced by pathogenic fungi on plants. It turned out that it is not the protein part of lipoproteins that has the eliciting effect, but their lipid part, which is arachidonic (eicosatetraenoic) and eicosapentaenoic acids, which are not characteristic of higher plants. They caused the formation of phytoalexins, tissue necrosis, and systemic plant resistance to various pathogens. Products of lipoxygenase conversion in plant tissues of C20 fatty acids (hydroperoxy-, hydroxy-, oxo-, cyclic derivatives, leukotrienes) formed in host plant cells with the help of an enzymatic lipoxygenase complex (substrates of which can be both C,8 and C20 polyene fatty acids) had a strong influence on the defense response of plants. This is apparently due to the fact that there is no oxygen in uninfected plants.
derivatives of 20-carbon fatty acids, and their appearance as a result of infection leads to dramatic results, for example, the formation of necrosis around infected cells, which creates a barrier to the spread of pathogens throughout the plant.
There is evidence that the induction of lipoxygenase activity by a pathogen led to the formation of a plant response even in the case when the elicitor did not contain C20 fatty acids and only native C18 polyene fatty acids could be the substrate of lipoxygenase activity, and the products could be octadecanoids rather than eicosanoids. Syringolides also have eliciting properties [L et al., 1998] and cerebrosides - sphingolipid compounds. Cerebrosides A and C isolated from Magnaporthe grisea were the most active elicitors for rice plants. Cerebroside degradation products (fatty acid methyl esters, sphingoid bases, glycosyl-sphingoid bases) showed no elicitor activity.
Some elicitors are formed as a result of the action on plant tissues of hydrolases released by pathogens. The purpose of hydrolases is twofold. On the one hand, they provide nutrition for pathogens necessary for their development and reproduction, on the other hand, they loosen the mechanical barriers that prevent the penetration of pathogens into their habitats in plants.
One such barrier is the cuticle, which consists mainly of a cutin heteropolymer embedded in wax. More than 20 monomers that make up cutin have been discovered
These are saturated and unsaturated fatty acids and alcohols of various lengths, including hydroxylated and epoxidized, long-chain dicarboxylic acids, etc. In cutin, most of the primary alcohol groups participate in the formation of ether bonds, as well as some of the secondary alcohol groups that provide crosslinks between chains and branch points in the polymer. Part of another "barrier" polymer, suberin, is close in composition to cutin. Its main difference is that free fatty acids are the main component of suberic waxes, while there are very few of them in cutin. In addition, in the sub
mainly C22 and C24 fatty alcohols are present, while cutin contains C26 and C28. To overcome the surface mechanical barrier of plants, many pathogenic fungi secrete enzymes that hydrolyze cutin and some of the components of suberin. The products of the cutinase reaction were various oxygenated fatty acids and alcohols, mainly 10,16-dihydroxy-CK- and 9,10,18-trihydroxy-C|8-acids, which are signal molecules that induce the formation and release of additional amounts of cutinase, which "corrode" cutin and facilitate the penetration of the fungus into the plant. It was found that the lag period for the appearance of cutinase mRNA in the fungus after the onset of the formation of the above di- and trihydroxy acids was only 15 min, while the release of additional cutinase was twice as long. Damage to the cutinase gene in Fusarium solani greatly reduced the virulence of this fungus. Inhibition of cutinase with chemicals or antibodies prevented plant infection. The assumption that oxygenated cutin degradation products can act not only as inducers of cutinase formation in pathogens, but also as elicitors of defense reactions in the host plant [Tarchevsky, 1993], was subsequently confirmed.
After the penetration of pathogenic microorganisms through the cuticle, some of them move into the vascular bundles of plants and use the nutrients available there for their development, while others are transported into the living cells of the host. In any case, pathogens encounter yet another mechanical barrier - cell walls, consisting of various polysaccharides and proteins and in most cases reinforced with a rigid polymer - lignin [Tarchevsky, Marchenko, 1987; Tarchevsky and Marchenko, 1991]. As mentioned above, in order to overcome this barrier and ensure their development with carbohydrate and nitrogen nutrition, pathogens secrete enzymes that hydrolyze polysaccharides and cell wall proteins.
Special studies have shown that during the interaction of bacteria and tissues of the host plant, enzymes
degradation does not appear simultaneously. For example, pectylmethylesterase was also present in non-inoculated Erwinia carotovora subsp. atroseptia in the tissues of potato tubers, while polygalacturonase, pectate lyase, cellulase, protease, and xylanase activities appeared 10, 14, 16, 19, and 22 h after inoculation, respectively.
It turned out that oligosaccharide degradation products of plant cell wall polysaccharides have elicitor properties. However, active oligosaccharides can also be formed by polysaccharides that are part of the cell walls of pathogens. It is known that one of the ways to protect plants from pathogenic microorganisms is the formation after infection and release outside the plasma membrane of enzymes - chitinase and β-1,3-glucanase, which hydrolyze chitin polysaccharides and β-1,3-polyglucans of pathogen cell walls, which leads to inhibition of their growth and development. It was found that the oligosaccharide products of such hydrolysis are also active elicitors of plant defense reactions. As a result of the action of oligosaccharides, plant resistance to bacterial, fungal or viral infection increases.
Oligosaccharide elicitors, their structure, activity, receptors, their “switching on” of cell signaling systems, induction of defense gene expression, synthesis of phytoalexins, hypersensitivity reactions, and other plant responses are the subject of a number of review articles.
In the laboratory of Elbersheim, and then in a number of other laboratories, it was shown that oligoglycosides formed as a result of pathogen-induced endoglycosidase degradation of hemicelluloses and pectin substances of plants, chitin and chitosan of fungi, can play the role of biologically active substances. It has even been suggested that they be considered a new class of hormones ("oligosaccharins", as opposed to oligosaccharides that have no activity). The formation of oligosaccharides as a result of the hydrolysis of polysaccharides, and not in the course of synthesis from monosaccharides, was shown by the example
Tarchevsky I. A. Signal systems of plant cells / holes. ed. A. N. Grechkin. M. : Nauka, 2002. 294 p.
UDC 633.11(581.14:57.04)
FEATURES OF THE DISTRIBUTION OF PLANTS IN THE AGROPOPULATION OF WHEAT BY CLASSES OF VARIATIONS OF THE ELEMENTS OF HEAD PRODUCTIVITY
A. A. Goryunov, M. V. Ivleva, S. A. Stepanov
Vegetation conditions significantly affect the distribution of plants in the agropopulation of durum wheat according to the classes of variation in the number of spikelets, the number of grains of the spike and their weight. Among the varieties of Saratov breeding in the conditions of extreme agro-climatic conditions of the year, a different number of plants is characteristic: old varieties - small classes, new varieties - large classes of variation. Favorable agro-climatic conditions increase the number of plants assigned to higher classes of variation of ear productivity elements.
Key words: variety, spikelet, caryopsis, wheat.
FEATURES DISTRIBUTION OF PLANTS IN WHEAT AGROPOPULATION ON CLASSES OF THE VARIATION OF ELEMENTS EFFICIENCY OF THE EAR
A. A. Goryunov, M. V. Ivleva, S. A. Stepanov
Vegetation in agro-population-earlets. Among cultivars of the Saratov selection in the conditions of extreme year on agroclimatic conditions it is characteristic various number of plants: to age-old cultivars - the small classes, to new cultivars - the big classes of a variation. Favorable agroclimatic conditions raise the number of the plants carried to higher classes of a variation of elements of efficiency of an ear.
Key words: cultivar, spikelet, kernel, wheat.
In the morphogenesis of wheat, according to researchers (Morozova, 1983, 1986), several phases can be distinguished: 1) morphogenesis of the apical part of the germinal bud meristem, leading to the formation of a rudimentary main shoot; 2) morphogenesis of the phytomer elements of the rudimentary main shoot into the plant organs, which determines the habit of the bush. The first phase (primary organogenesis - according to Rostovtseva, 1984) determines, as it were, the matrix of the plant. As established (Rostovtseva, 1978; Morozova, 1986; Stepanov and Mostovaya, 1990; Adams, 1982), the features of the passage of the primary processes of organogenesis are reflected in the subsequent structure formation.
According to researchers (Morozova, 1986, 1988), the formation of phytomers of the vegetative zone of the rudimentary main shoot is a species-specific process, while the deployment of phytomer elements of the rudimentary main shoot into functioning plant organs is a cultivar-specific process. The process of formation of phytomers of the generative zone of the shoot is more variety-specific (Morozova, 1994).
The significance of primary morphogenetic processes is expressed most contrastingly; the establishment and formation of phytomers in the vegetative and generative zones of wheat shoots and their subsequent implementation under appropriate agro-climatic conditions in the analysis of the crop structure according to variation curves of shoot productivity elements (Morozova, 1983, 1986; Stepanov, 2009). This is preceded by a selective accounting of the distribution of plants in their agropopulation according to the classes of variation of individual productivity elements, in particular, the number of spikelets, the number of grains per spike, and the mass of grains of the spike.
Material and Method
The studies were carried out in 2007-2009. The following varieties of spring durum wheat of Saratov breeding were chosen as objects of study: Gordeiforme 432, Melyanopus 26, Melyanopus 69, Saratovskaya 40, Saratovskaya 59, Saratovskaya golden, Lyudmila, Valentina, Nick, Elizavetinskaya, Zolotaya volna, Annushka, Krassar. The main observations and records were carried out in field small-plot experiments in the fields of the near-station selection crop rotation of the Research Institute of Agriculture of the South-East and the Botanical Garden of the SSU, the repetition of experiments was 3-fold. To conduct a structural analysis of the productivity of wheat varieties, at the end of the growing season, 25 plants from each repetition were taken, which were then combined into a group and 25 plants were randomly selected from it for analysis. The number of spikelets, the number of grains in spikelets, and the mass of one grain were taken into account. Based on the data obtained,
according to the method of Z. A. Morozova (1983), the features of the distribution of plants in the agropopulation of durum wheat were divided according to the classes of variation of the elements of ear productivity. Statistical processing of the research results was carried out using the Excel Windows 2007 software package.
Results and its discussion
As our studies have shown, in the conditions of vegetation in 2007, the main number of main shoots of wheat varieties of Saratov selection in terms of the number of spikelets of an ear was in the 2nd and 3rd classes of variation. Only a small number of plants were assigned to the 1st class - 4% (Table 1).
Table 1. The number of shoots of wheat varieties of Saratov breeding by classes of variation in the number of spikelets of an ear, % (2007)
Variety Variation class
1st 2nd 3rd 4th 5th
Gordeiforme 432 0 92 8 0 0
Melanopus 26 4 76 20 0 0
Melanopus 69 4 64 32 0 0
Saratovskaya 40 7 93 0 0 0
Ancient 4 81 15 0 0
Saratovskaya 59 4 76 20 0 0
Saratov golden 0 16 80 4 0
Ludmila 8 44 48 0 0
Valentina 0 16 76 8 0
Nick 14 14 72 0 0
Elizabethan 0 24 72 4 0
Golden Wave 8 16 52 24 0
Annushka 0 20 64 16 0
Krassar 0 20 48 32 0
New 4 27 59 10 0
When analyzing varieties by groups, it was found that ancient varieties are characterized by a greater number of plants of the 2nd class of variation (81%) and a smaller number of plants of the 3rd class of variation (15%). According to the group of new varieties, it was revealed that a greater number of plants belong to the 3rd class of variation (59%), some of the plants of the 4th class of variation (10%). It has been established that in some new varieties the number of plants of the 4th class of variation is more than 10% - Krassar (32%), Golden Wave (24%), Annushka (16%), and in some varieties their number is less than 10% (Valentina,
Saratovskaya golden, Elizavetinskaya) or not observed at all - Saratovskaya 59, Lyudmila, Nick (see Table 1).
In the growing season of 2008, which was distinguished by a more favorable agro-climatic state, among the varieties of Saratov breeding, both ancient and new, a greater number of plants by the number of spikelets of an ear were assigned to the 3rd class of variation. Not a single plant, as in the previous year, was presented in the 5th variation class. It is characteristic that, in contrast to new varieties of durum wheat, a larger number of plants of the 2nd class of variation was noted in ancient varieties - 41% (Table 2).
Table 2. The number of shoots of wheat varieties of Saratov breeding by classes of variation in the number of spikelets of an ear, % (2008)
Variety Variation class
1st 2nd 3rd 4th 5th
Gordeiforme 432 12 20 60 8 0
Melanopus 26 4 36 56 4 0
Melanopus 69 4 48 48 0 0
Saratovskaya 40 4 60 28 8 0
Ancient 6 41 48 5 0
Saratovskaya 59 28 48 24 0 0
Saratov golden 0 28 64 8 0
Ludmila 8 44 48 0 0
Valentina 4 28 64 4 0
Nick 4 28 68 0 0
Elizabethan 8 36 52 4 0
Golden Wave 4 12 68 16 0
Annushka 0 28 60 12 0
Krassar 8 28 32 32 0
New 7 32 52.5 8.5 0
Among the new varieties of durum wheat, there were varieties that, like in the previous year, are characterized by the presence of part of the plants in the 4th class of variation in the number of spikelets of the ear - Krassar (32%), Golden Wave (16%), Annushka (12%) , Saratovskaya golden (8%), Valentina (4%), Elizavetinskaya (4%), i.e., the same trend was observed as in the previous year, 2007 (see Table 2).
In the conditions of the growing season of 2009, most of the wheat plants of the Saratov selection by the number of spikelets of the ear were assigned to the 4th and 3rd classes of variation: new varieties - 45 and 43%, respectively, old varieties - 30 and 51%, respectively. It is characteristic that some
The presence of a higher relative to the average value of the number of plants of the 4th class of variation is characteristic of other varieties - Annushka (76%), Valentina (64%), Nick (56%), Golden Wave (52%), Saratovskaya 40 (48%). In some varieties, plants of the 5th class of variation were noted - Golden Wave (12%), Krassar (8%), Lyudmila (8%), Gordeiforme 432 and Saratovskaya 40 - 4% (Table 3).
Table 3. The number of shoots of wheat varieties of Saratov breeding by classes of variation in the number of spikelets of an ear, % (2009)
Variety Variation class
Gordeiforme 432 4 12 52 28 4
Melanopus 26 4 36 44 16 0
Melanopus 69 0 8 64 28 0
Saratovskaya 40 0 4 44 48 4
Ancient 2 15 51 30 2
Saratovskaya 59 0 28 48 24 0
Saratov golden 4 8 72 16 0
Ludmila 0 4 56 32 8
Valentine 0 0 36 64 0
Nick 4 4 36 56 0
Elizabethan 4 12 40 44 0
Golden wave 0 4 32 52 12
Annushka 0 0 24 76 0
Krassar 0 8 40 44 8
New 1 8 43 45 3
Thus, the conducted studies have shown that the growing conditions significantly affect the distribution of plants in the agro-population according to the classes of variation in the number of spikelets of an ear. Among the varieties of Saratov breeding in the conditions of extreme agro-climatic conditions of the year, a larger number of plants is characteristic: old varieties - the 2nd class, new varieties - the 3rd class, and some of them the 4th class of variation. Under favorable agro-climatic conditions, the number of plants attributable to higher classes of variation in the number of spikelets of an ear of durum wheat increases.
In the conditions of vegetation in 2007, the number of main shoots of wheat varieties of Saratov selection by the number of grains of the ear was in the 1st and 2nd classes of variation. Only a part of the plants of some varieties were assigned to the 3rd, 4th, and 5th classes (Table 4).
Variety Variation class
1st 2nd 3rd 4th 5th
Gordeiforme 432 96 4 0 0 0
Melanopus 26 96 4 0 0 0
Melanopus 69 92 8 0 0 0
Saratovskaya 40 93 7 0 0 0
Ancient 94 6 0 0 0
Saratovskaya 59 80 20 0 0 0
Saratov golden 20 48 32 0 0
Ludmila 0 64 24 12 0
Valentine 48 36 16 0 0
Nick 28 62 10 0 0
Elizabethan 48 48 4 0 0
Golden Wave 12 32 48 4 4
Annushka 52 36 12 0 0
Krassar 88 8 4 0 0
New 42 39 17 1.5 0.5
When analyzing varieties by groups, it was found that ancient varieties are characterized by a larger number of plants of the 1st class of variation (94%) and a very small proportion of plants of the 2nd class of variation (6%). According to the group of new varieties, it was revealed that a greater number of plants of individual varieties also belong to the 1st variation class - Krassar (88%), Saratovskaya 59 (80%), Annushka (52%), Valentina (48%), Elizavetinskaya (48% ), individual varieties - to the 2nd class of variation - Lyudmila (64%), Nick (62%), Saratovskaya golden (48%), Elizavetinskaya (48%) or to the 3rd class - Golden Wave - 48% ( see Table 3). In two varieties, plants of the 4th class of variation in the number of grains of the ear were noted - Lyudmila (12%) and Zolotaya volna - 4% (see Table 4).
During the growing season of 2008, which, as noted earlier, was distinguished by more favorable agro-climatic conditions, among the varieties of Saratov breeding, both ancient and new, a greater number of plants by the number of spikelets of an ear were assigned to the 2nd and 3rd classes of variation. . However, among the ancient varieties, two varieties differed in a large relative to the average values in the number of plants of the 2nd class - Saratovskaya 40 and Melyanopus 69 - 72 and 48%, respectively. Among the new varieties, 3 varieties also differed in a large number of plants of the 2nd class relative to the average values - Saratovskaya 59 and Valentina (72%), Lyudmila - 64%.
In contrast to the previous year, among the varieties of Saratov breeding, the presence of a certain number of plants classified as the 4th class of variation in the number of grains of the ear is characteristic. This is especially characteristic of the varieties Melyanopus 26, Elizavetinskaya, Lyudmila, Gordeiforme 432, Melyanopus 69, Nick, Annushka (Table 5).
Table 5. The number of shoots of wheat varieties of Saratov breeding by classes of variation in the number of grains of the ear, % (2008)
Variety Variation class
1st 2nd 3rd 4th 5th
Gordeiforme 432 0 28 56 8 8
Melanopus 26 0 24 48 24 4
Melanopus 69 4 48 40 8 0
Saratovskaya 40 0 72 24 4 0
Ancient 1 43 42 11 3
Saratovskaya 59 20 72 8 0 0
Saratov golden 4 36 56 4 0
Ludmila 0 64 24 12 0
Valentine 0 72 28 0 0
Nick 0 32 60 8 0
Elizabethan 0 48 32 20 0
Golden Wave 12 32 48 4 4
Annushka 4 44 40 8 4
Krassar 4 40 52 4 0
New 5 49 39 6 1
During the growing season of 2009, the distribution of wheat plants of Saratov breeding varieties by the number of spikelets of an ear was different depending on the group affiliation - old or new varieties. In the group of ancient varieties, most of the plants were assigned to the 3rd and 4th classes of variation - 42.5% and 27%, respectively. In two varieties, Melyanopus 26 and Melyanopus 69, plants of the 5th class of variation were observed in the number of grains of the ear (Table 6).
Among the new varieties, most of the plants were assigned to the 3rd and 2nd classes - 50.5 and 24%, respectively (Table 6). It is characteristic that some varieties are characterized by the presence of a larger relative to the average value of the number of plants of the corresponding class: the 2nd class of variation - Saratovskaya 59 (56%), Elizavetinskaya (32%), Krassar (32%), Gordeiforme 32 (28%), Saratovskaya golden (28%); 3rd class variations - Valentina (72%), Annushka (60%), Krassar (56%), Saratovskaya 40 (52%), Nick (52%), Elizavetinskaya (52%); 4th class variation - Zo-
lota wave (36%), Annushka (32%), Saratovskaya golden and Lyudmila (20%). It is noteworthy that, in contrast to previous years, under the conditions of 2009, part of the plants of half of the varieties were in the 5th class of variation in terms of the number of grains of the ear - Lyudmila, Nick, Zolotaya volna, Annushka, Melyanopus 26 and Melyanopus 69 (see Table 6) .
Table 6. The number of shoots of wheat varieties of Saratov breeding by classes of variation in the number of grains of the ear, % (2009)
Variety Variation class
1st 2nd 3rd 4th 5th
Gordeiforme 432 12 28 28 32 0
Melanopus 26 8 22 46 20 4
Melanopus 69 12 8 44 32 4
Saratovskaya 40 4 20 52 24 0
Ancient 9 19.5 42.5 27 2
Saratovskaya 59 12 56 24 8 0
Saratov golden 4 28 48 20 0
Ludmila 0 12 52 20 16
Valentine 4 20 72 4 0
Nick 8 24 52 8 8
Elizabethan 4 32 52 12 0
Golden Wave 4 12 40 36 8
Annushka 4 0 60 32 4
Krassar 12 32 56 0 0
New 6 24 50.5 15.5 4
The conducted studies have shown that the growing conditions significantly affect the distribution of plants in the agropopulation according to the classes of variation in the number of grains of the ear. Among the varieties of Saratov breeding in the conditions of extreme agro-climatic conditions of the year, a larger number of plants is characteristic: old varieties - the 1st class, new varieties - the 1st, 2nd and 3rd classes, and some of them the 4th class of variation. Under favorable agro-climatic conditions, the number of plants attributable to higher classes of variation in the number of grains of an ear of durum wheat increases.
In the conditions of vegetation in 2007, the number of main shoots of wheat varieties of Saratov breeding according to the mass of grains of the ear was in the 1st and 2nd classes of variation (Table 7).
When analyzing varieties by groups, it was found that for some ancient varieties, the number of plants of the 1st variation class was
100% - Gordeiforme 432 and Melyanopus 26.93% - Saratovskaya 40. The ancient variety Melyanopus 69 differed significantly in this regard, which is characterized by a larger number of plants of the 2nd class - 80%. For the group of new varieties, it was revealed that some varieties are characterized by a larger number of plants of the corresponding class relative to the average value: 1st class - Golden Wave (96%), Saratovskaya 59 (80%), Krassar (76%), Annushka (68%); 2nd class - Nick (52%), Lyudmila (48%), Saratov golden (44%), Valentina and Elizavetinskaya (40%); 3rd class variations - Lyudmila (28%), Saratov golden (24%), Nick (14%), Valentina - 12%. It is noteworthy that in two varieties, Lyudmila and Valentina, plants of the 5th class of variation in the mass of grains of the ear were observed - 12 and 4%, respectively (see Table 7).
Table 7. The number of shoots of wheat varieties of Saratov breeding by classes of grain weight variation, % (2007)
Variety Variation class
1st 2nd 3rd 4th 5th
Gordeiforme 432 100 0 0 0 0
Melanopus 26 100 0 0 0 0
Melanopus 69 4 80 16 0 0
Saratovskaya 40 93 7 0 0 0
Ancient 74 22 4 0 0
Saratovskaya 59 80 16 4 0 0
Saratov golden 32 44 24 0 0
Ludmila 12 48 28 12 0
Valentina 44 40 12 4 0
Nick 28 52 14 6 0
Elizabethan 56 40 4 0 0
Golden Wave 96 4 0 0 0
Annushka 68 32 0 0 0
Krassar 76 20 4 0 0
New 55 33 9.5 2.5 0
Under the growing conditions of 2008, a different number of plants of the corresponding class of variation in the weight of grains of the ear was observed. Among the ancient varieties of Saratov breeding, a greater number of plants in this element of productivity corresponded to the 2nd class of variation - 48%, among new varieties - to the 3rd and 2nd classes of variation - 38 and 36%, respectively. A certain number of plants of the corresponding varieties are distributed in the 4th and 5th classes of variation (Table 8).
Variety Variation class
1st 2nd 3rd 4th 5th
Gordeiforme 432 12 48 32 4 4
Melanopus 26 0 32 44 12 12
Melanopus 69 16 60 20 4 0
Saratovskaya 40 24 52 12 8 4
Ancient 13 48 27 7 5
Saratovskaya 59 48 48 4 0 0
Saratov golden 4 24 64 4 4
Ludmila 12 48 28 12 0
Valentine 4 36 56 0 4
Nick 12 44 32 12 0
Elizabethan 8 36 36 20 0
Golden wave 8 28 40 20 4
Annushka 8 36 36 16 4
Krassar 4 28 48 20 0
New 12 36 38 12 2
Some Saratov varieties were distinguished by a large relative to the average value of the representation of plants of the corresponding class of variation in the mass of grains of the ear: 1st class - Saratovskaya 59 (48%), Saratovskaya 40 (24%), Melyanopus 69 (16%); 2nd class - Melyanopus 69 (60%), Saratovskaya 40 (52%), Saratovskaya 59 and Lyudmila (48% respectively), Nick (44%); 3rd class - Saratov golden (64%), Valentina (56%), Krassar (48%), Melyanopus 26 (44%); 4th class - Elizabethan, Golden Wave and Krassar (20% respectively); Variation class 5 - Melanopus 26 - 12% (see Table 8).
In the conditions of the growing season of 2009, most of the wheat plants of the varieties of Saratov breeding were assigned to the 3rd and 4th classes of variation in terms of the mass of grains of the ear. Moreover, the average values of the classes of variation of the group of ancient varieties and the group of new varieties differed significantly. In particular, the ancient varieties were distinguished by a large representation of plants of the 3rd and 4th classes of variation - 41.5 and 29.5%, respectively, the new varieties were distinguished by the predominant presence in the agropopulation of plants of the 4th and 3rd classes of variation - 44 and 26%, respectively. . Attention is drawn to a significant number of plants of the 5th class of variation in the mass of grains of the ear, which is especially characteristic of the varieties Krassar (32%), Valentina (24%), Golden Wave (20%), Saratovskaya 40-16% (Table 9) .
Variety Variation class
1st 2nd 3rd 4th 5th
Gordeiforme 432 4 16 48 32 0
Melanopus 26 4 28 38 18 12
Melanopus 69 0 8 48 40 4
Saratovskaya 40 4 20 32 28 16
Ancient 3 18 41.5 29.5 8
Saratovskaya 59 14 36 38 8 4
Saratov golden 4 8 28 52 8
Ludmila 0 0 12 80 8
Valentine 0 8 28 40 24
Nick 8 20 28 36 8
Elizabethan 0 20 24 44 12
Golden wave 0 16 32 32 20
Annushka 4 8 32 56 0
Krassar 0 8 12 48 32
New 3 14 26 44 13
As in other years, some varieties were distinguished by a large relative to the average value of the representation of plants of the corresponding class of variation in the mass of grains of the ear: 1st class - Saratovskaya 59 (14%); 2nd class - Saratovskaya 59 (36%), Melyanopus 26 (28%), Saratovskaya 40, Nick and Elizavetinskaya (respectively 20%); 3rd class variations - Gordeiforme 432 and Melyanopus 69 (48% respectively), Saratovskaya 59 (38%), Golden Wave and Annushka (32% respectively); 4th class of variation - Lyudmila (80%), Annushka (56%), Saratov golden (52%), Krassar (48%), Melyanopus 69-40% (see Table 9).
Thus, the conducted studies have shown that the distribution of plants in the agropopulation according to the classes of variation in the mass of grains of the ear is significantly affected by the growing conditions. For the majority of ancient varieties under extreme growing conditions, the number of plants of the 1st class is 93-100%, while the new varieties compare favorably with a significant representation of plants of the 2nd and 3rd classes. Under favorable growing conditions, the proportion of plants of a higher variation class increases, but the same trend persists for new varieties - a larger number of plants of higher variation classes in terms of the weight of grains of the ear compared to old varieties.
Morozova ZA Morphogenetic analysis in wheat breeding. M. : MGU, 1983. 77 p.
Morozova ZA The main patterns of wheat morphogenesis and their importance for breeding. M. : MGU, 1986. 164 p.
Morozova ZA Morphogenetic aspect of the problem of wheat productivity // Morphogenesis and productivity of plants. M. : MGU, 1994. S. 33-55.
Rostovtseva ZP Influence of plant photoperiodic reaction on the function of the apical meristem in vegetative and generative organogenesis // Light and morphogenesis of plants. M., 1978. S. 85-113.
Rostovtseva Z. P. Growth and differentiation of plant organs. M. : MGU 1984. 152 p.
Stepanov S. A., Mostovaya L. A. Evaluation of the productivity of a variety according to the primary organogenesis of a wheat shoot // Production process, its modeling and field control. Saratov: Sarat Publishing House. un-ta, 1990. S. 151-155.
Stepanov, S.A., Morphogenetic features of the implementation of the production process in spring wheat, Izv. SSU Ser., Chemistry, biology, ecology. 2009. V. 9, issue 1. pp. 50-54.
Adams M. Plant development and crop productivity // CRS Handbook Agr. productivity. 1982. Vol.1. P. 151-183.
UDC 633.11: 581.19
Yu. V. Dashtoyan, S. A. Stepanov, M. Yu. Kasatkin
Saratov State University N. G. Chernyshevsky 410012, Saratov, st. Astrakhanskaya, 83 e-mail: [email protected]
Peculiarities in the content of pigments of various groups (chlorophylls a and b, carotenoids), as well as the ratio between them in wheat leaves belonging to different shoot phytomers, were established. The minimum or maximum content of chlorophylls and carotenoids can be observed in different leaves, depending on the growing conditions of plants.
Key words: phytomer, chlorophyll, carotenoid, leaf, wheat.
STRUCTURE AND THE MAINTENANCE OF PIGMENTS OF PHOTOSYNTHESIS IN THE PLATE OF LEAVES OF WHEAT
Y. V. Dashtojan, S. A. Stepanov, M. Y. Kasatkin
Features in the maintenance of pigments of various groups (chlorophyll a and chlorophyll b, carotenoids), as well as parities between them in the leaves of wheat
Presidium of the Russian Academy of Sciences
AWARDED
A.N. Bach Prize 2002
Academician Igor Anatolyevich TARCHEVSKY
for the cycle of works "Signaling systems of plant cells"
Academician I.A. TARCHEVSKY
(Kazan Institute of Biochemistry and Biophysics KSC RAS, A.N. Bach Institute of Biochemistry RAS)
SIGNALING SYSTEMS OF PLANT CELLS
I.A. Tarchevsky has been studying the effect of abiotic and biotic stressors on plant metabolism for almost 40 years. Over the past 12 years, the greatest attention has been paid to one of the most promising areas of modern plant biochemistry and physiology—the role of cell signaling systems in the formation of a stress state. On this issue, I.A. Tarchevsky published 3 monographs: “Catabolism and stress in plants”, “Plant metabolism under stress”, and “Signaling systems of plant cells”. In 30 articles, I.A. Tarchevsky and co-authors published the results of studies of adenylate cyclase, calcium, lipoxygenase and NADPH oxidase signaling systems of plant cells. The NO-synthase signaling system is being investigated.
An analysis of the characteristics of plant catabolism under stress led to the conclusion about the signaling function of "wreckage" - oligomeric degradation products of biopolymers and "fragments" of phospholipids. The assumption made in this work about the elicitor (signal) properties of cutin degradation products was later confirmed by foreign authors.
Not only works of an experimental nature were published, but also reviews summing up the results of studies of the signaling systems of plant cells by domestic and foreign authors.
Started in the author's laboratory by A.N. Grechkin and then continued by him in an independent laboratory, studies of lipid metabolism made it possible to obtain priority results that significantly expanded the understanding of the lipoxygenase signaling cascade. The study of the effect of salicylic acid, an intermediate of the NADPH oxidase system, on protein synthesis led to the conclusion about the reason for the long-established biological activity of another compound, succinic acid. It turned out that the latter is a salicylate mimetic and its treatment of plants “turns on” signaling systems, which leads to the synthesis of salicylate-induced protective proteins and an increase in resistance to pathogens.
It was found that various exogenous stress phytohormones - jasmonic, salicylic and abscisic acids cause the induction of the synthesis of both the same proteins (which indicates the "switching on" of the same signaling pathways by these hormones) and proteins specific for each of them ( which indicates the simultaneous "on" and different signal stages).
For the first time in the world literature, I.A. Tarchevsky analyzed the functioning of all known cell signaling systems in plants and the possibilities of their mutual influence, which led to the idea that cells do not have isolated signaling systems, but a signaling network consisting of interacting systems.
A classification of pathogen-induced proteins according to their functional characteristics was proposed and a review was made of the features of the synthesis of these proteins “switched on” by various signaling systems. Some of them are participants in the signaling systems of plants, and their intensive formation enhances the perception, transformation and transmission of elicitor signals to the genetic apparatus, others limit the nutrition of pathogens, others catalyze the formation of phytoalexins, the fourth ones strengthen plant cell walls, and the fifth cause apoptosis of infected cells. The functioning of all these pathogen-induced proteins significantly limits the spread of infection throughout the plant. The sixth group of proteins can directly act on the structure and functions of pathogens, stopping or suppressing their development. Some of these proteins cause degradation of the cell wall of fungi and bacteria, others disrupt the functioning of their cell membrane by changing its permeability to ions, and others inhibit the work of the protein-synthesizing machine by blocking protein synthesis on the ribosomes of fungi and bacteria or by acting on viral RNA.
Finally, for the first time, the work on the construction of pathogen-resistant transgenic plants was summed up, and this review work was based on the above-mentioned classification of pathogen-induced defense proteins.
The study of plant cell signaling systems is not only of great theoretical importance (because they form the basis of the molecular mechanisms of stress), but also of great practical importance, since they allow the creation of effective antipathogenic drugs based on natural elicitors and intermediates of signaling systems.
Timiryazevskaya, Kostychevskaya and Sisakyanovsky lectures by I.A. Israel, India, Germany, etc.).
For studies of one of the signaling systems - lipoxygenase, I.A. Tarchevsky and Corresponding Member of the Russian Academy of Sciences A.N. Grechkin in 1999 were awarded the V.A. Engelgardt Prize of the Academy of Sciences of the Republic of Tatarstan.
In many publications of I. A. Tarchevsky, his colleagues took part as co-authors - Corresponding Member of the Russian Academy of Sciences A.N. .Chernova and candidate of biological sciences V.G. Yakovleva.
In 2001, on the initiative of I.A. Tarchevsky and with his participation as the chairman of the Organizing Committee, the International Symposium on Signaling Systems of Plant Cells was held in Moscow.
LITERATURE
1. Tarchevsky I.A. Catabolism and stress in plants. The science. M. 1993. 83 p.
2. Tarchevsky I.A. Plant metabolism under stress. Selected works. Publishing house "Feng" (Science). Kazan. 2001. 448 p.
3. Tarchevsky I.A. Signal systems of plant cells. M.: Nauka, 2002. 16.5 pp. (in the press).
4. Maksyutova N.N., Viktorova L.V., Tarchevsky I.A. The effect of ATP and c-AMP on protein synthesis in wheat grains. // Physiol. biochem. cultures. plants. 1989. V. 21. No. 6. S.582-586.
5. Grechkin A.N., Gafarova T.E., Korolev O.S., Kuramshin R.A., Tarchevsky I.A. The monooxygenase pathway of linoleic acid oxidation in pea seedlings. / In: "Biological Role of Plant Lipids". Budapest: Academy. Kiado. New York, London. Plenum. 1989. P.83-85.
6. Tarchevsky I.A., Grechkin A.N. Perspectives of search for eicosanoid analogs in plants. / In: "Biological Role of Plant Lipids". Budapest: Academy. Kiado. New York, London. Plenum. 1989. P.45-49.
7. Grechkin A.N., Kukhtina N.V., Kuramshin R.A., Safonova E.Yu., Efremov Yu.Ya., Tarchevsky I.A. Metabolization of coronary and vernolic acids in pea epicotyl homogenate. // Bioorgan. chemistry. 1990. V.16. No. 3. S. 413-418.
8. Grechkin A.N., Gafarova T.E., Tarchevsky I.A. Biosynthesis of 13-oxo-9(Z), 11(E)-tridecadienoic acid in pea leaf homogenate. / In: “Plant Lipid Biochemistry. Structure and Utilization". London. Portland Press. 1990. P. 304-306.
9. Grechkin A.N., Kuramshin R.A., Tarchevsky I.A. Minor isomer of 12-oxo-10,15-phytodienoic acid and the mechanism of natural cyclopentenones formation. / In: “Plant Lipid Biochemistry. Structure and Utilization". London. Portland Press. 1990. P.301-303.
10. Tarchevsky I.A., Kuramshin R.A., Grechkin A.N. Conversation of α-linolenate into conjugated trienes and oxotrienes by potato tuber lipoxygenase. / In: “Plant Lipid Biochemistry. Structure and Utilization". London. Portland Press. 1990. P. 298-300.
11. Grechkin A.N., Kuramshin R.A., Tarchevsky I.A. Formation of a new α-ketol by hydroperoxide dehydrase from flax seeds. // Bioorgan. chemistry. 1991. V. 17. No. 7. S. 997-998.
12. Grechkin A.N., Kuramshin R.A., Safonova E.Y., Yefremov Y.J., Latypov S.K., Ilyasov A.V., Tarchevsky I.A. Double hydroperoxidation of linolenic acid by potato tuber lipoxygenase. // Biochim. Biophys. acta. 1991. V. 1081. N 1. P. 79-84.
13. Tarchevsky I.A. Regulatory role of degradation of biopolymers and lipids. // Physiol. plants. 1992. T. 39. N 6. S. 156-164.
14. Tarchevsky I.A., Maksyutova N.N., Yakovleva V.G. Influence of salicylic acid on protein synthesis in pea seedlings. // Plant Physiology. 1996. V.43. No. 5. S. 667-670.
15. Tarchevsky I.A., Maksyutova N.N., Yakovleva V.G., Chernov V.M. Mycoplasma-induced and jasmonate-induced proteins of pea plants. // Reports of the Russian Academy of Sciences. 1996. T. 350. N 4. S. 544 - 545.
16. Chernov V.M., Chernova O.A., Tarchevsky I.A. Phenomenology of mycoplasmal infections in plants. // Physiol. plants. 1996. T. 43. N.5. S. 721 - 728.
17. Tarchevsky I.A. On the probable causes of the activating effect of succinic acid on plants. / In the book "Succinic acid in medicine, food industry, agriculture." Pushchino. 1997. S.217-219.
18. Grechkin A.N., Tarchevsky I.A. Lipoxygenase signaling system. // Physiol. plants. 1999. V. 46. No. 1. S. 132-142.
19. Karimova F.G., Korchuganova E.E., Tarchevsky I.A., Abubakirova M.R. Na+/Ca+ exchange in plant cells. // Reports of the Russian Academy of Sciences. 1999. Vol. 366. No. 6. S. 843-845.
20. Karimova F.G., Tarchevsky I.A., Mursalimova N.U., Grechkin A.N. Influence of the product of lipoxygenase metabolism -12-hydroxydodecenoic acid on the phosphorylation of plant proteins. // Physiol. plants. 1999. V.46. No. 1. pp.148-152.
21. Tarchevsky I.A. Interaction of signaling systems of plant cells "switched on" by oligosaccharides and other elicitors. // "New perspectives in the study of chitin and chitosan". Materials of the Fifth Conference. M. VNIRO Publishing House. 1999. S.105-107.
22. Tarchevsky I.A., Grechkin A.N., Karimova F.G., Korchuganova E.E., Maksyutova N.N., Mukhtarova L.Sh., Yakovleva V.G., Fazliev F.N., Yagusheva M.R., Palikh E., Khokhlova L.P. On the possibility of participation of cycloadenylate and lipoxygenase signaling systems in the adaptation of wheat plants to low temperatures. / In the book. “Frontiers of cooperation. To the 10th anniversary of the Cooperation Agreement between Kazan and Giessen Universities”. Kazan: UNIPRESS, 1999. P. 299-309.
23. Tarchevsky I.A., Maksyutova N.N., Yakovleva V.G., Grechkin A.N. Succinic acid is a salicylic acid mimetic. // Physiol. plants. 1999. V. 46. No. 1. S. 23-28.
24. Grechkin A.N., Tarchevsky I.A. Lipoxygenase signaling cascade in plants. // Scientific Tatarstan. 2000. No. 2. S. 28-31.
25. Grechkin A.N., Tarchevsky I.A. Cell signaling systems and the genome. // Bioorganic chemistry. 2000. V. 26. No. 10. S. 779-781.
26. Tarchevsky I.A. Elicitor-induced signaling systems and their interaction. // Physiol. plants. 2000. V.47. No. 2. S.321-331.
27. Tarchevsky I.A., Chernov V.M. Molecular aspects of phytoimmunity. // Mycology and phytopathology. 2000. V. 34. No. 3. S. 1-10.
28. Karimova F., Kortchouganova E., Tarchevsky I., Lagoucheva M. The oppositely directed Ca+2 and Na+ transmembrane transport in algal cells. // Protoplasma. 2000. V. 213. P. 93-98.
29. Tarchevsky I.A., Karimova F.G., Grechkin A.N. and Moukhametchina N.M. Influence of (9Z)-12-hydroxy-9-dodecenoic acid and methyl jasmonate on plant protein phosphorylation. // Biochemical Society Transactions. 2000. V. 28. N. 6. P. 872-873.
30. Tarchevsky I.A. Pathogen-induced plant proteins. // Applied microbiology and biochemistry. 2001. V. 37. No. 5. S. 1-15.
31. Tarchevsky I.A., Maksyutova N.N., Yakovleva V.G. Influence of salicylate, jasmonate and ABA on protein synthesis. // Biochemistry. 2001. T. 66. N. 1. S. 87-91.
32. Yakovleva V.G., Tarchevsky I.A., Maksyutova N.N. Influence of NO donor nitroprusside on protein synthesis in pea seedlings. // Abstracts of International Symposium "Plant Under Environmental Stress". Moscow. Publishing House of Peoples' Friendship University of Russia. 2001. P. 318-319.
33. Yakovleva V.G., Maksyutova N.N., Tarchevsky I.A., Abdullaeva A.R. Influence of donor and inhibitor of NO-synthase on protein synthesis of pea seedlings. // Abstracts of International Symposium "Signalling systems of plant cells". Moscow, Russia, 2001, June, 5-7. ONTI, Pushchino. 2001. P. 59.
BIOORGANIC CHEMISTRY, 2000, volume 26, no. 10, p. 779-781
MOLECULAR BIOLOGY -
CELL SIGNALING SYSTEMS AND THE GENOME © A. I. Grechkin#, I. A. Tarchevsky
Kazan Institute of Biochemistry and Biophysics RAS, Kazan; Institute of Biochemistry named after A.N. Bach RAS, Moscow
Predictions about the future of molecular and cellular biology before the year 2000 made by F. Crick in 1970 were quite bold. The task of studying the genome seemed gigantic and long-term, but the concentration of huge scientific and financial resources led to the rapid solution of many problems that faced molecular biology and molecular genetics 30 years ago. At that time, it was even more difficult to foresee progress in the field of cell biology. Over the past years, the line between the cellular and molecular levels of research has largely blurred. In 1970, for example, there was no idea of cellular signaling systems, which took shape quite clearly only by the mid-1980s. In this article, an attempt will be made to highlight the current state and prospects for the development of research on the signaling systems of glues - one of the most important areas of modern biology, combining biochemistry, bioorganic chemistry, molecular biology, molecular genetics, plant and microorganism physiology, human and animal physiology, medicine, pharmacology, biotechnology.
Recent studies have shown that there is a two-way relationship between signaling systems and the genome. On the one hand, enzymes and proteins of signaling systems are encoded in the genome, on the other hand, signaling systems control the genome, expressing some and suppressing other genes. Signaling molecules, as a rule, are characterized by a fast metabolic turnover and a short lifetime. Research related to signaling systems is being intensively developed, but the molecular mechanisms of signaling connections remain largely unexplained. Much remains to be done in this direction in the next two or three decades.
The general principles of operation of signaling systems are largely universal. The universality of DNA, the "main" molecule of life, determines the similarity of its maintenance mechanisms in the cells of microorganisms, plants, and animals. In recent years, the universality of the mechanism of transmission of extracellular
ny signals in the genetic apparatus of the cell. This mechanism includes reception, transformation, multiplication, and signal transmission to the promoter regions of genes, reprogramming of gene expression, changes in the spectrum of synthesized proteins, and functional response of cells, for example, in plants, increasing resistance to adverse environmental factors or immunity to pathogens. A universal participant in signaling systems is the protein kinase-phosphoprotein phosphatase block, which determines the activity of many enzymes, as well as the protein transcription regulation factor (interacting with the promoter regions of genes), which determines the change in the intensity and nature of gene expression reprogramming, which, in turn, determines the functional the cell's response to a signal.
Currently, at least seven types of signaling systems have been identified: cycloadenylate-
nay, MAP *-kinase, phosphatidate, calcium, oxylipin, superoxide synthase and NO-synthase. In the first six systems (figure, signaling pathway 1), protein signal receptors having a universal type of structure are "mounted" in the cell membrane and perceive the signal by the variable extracellular K-domain. In this case, the conformation of the protein, including its cytoplasmic C-site, changes, which leads to the activation of the associated β-protein and the transmission of the excitation impulse to the first enzyme and subsequent intermediates of the signal chain.
It is possible that some primary signals act on receptors localized in the cytoplasm and associated with the genome by signaling pathways (figure, signaling pathway 2). Interestingly, in the case of the MO signaling system, this pathway includes the enzyme G)-synthase localized in the cell membrane (figure, signaling pathway 4-3). Some physical or chemical signals can interact directly with the lipid component of the cell membrane, causing its modification, which leads to a change in the conformation of the receptor protein and includes
*MAP - mitogen activated protein, mitogen activated protein.
GRECHKIN, TARCHEVSKY
Diagram of the diversity of cell signaling pathways. Designations: 1,5,6 - receptors localized in the cell membrane; 2,4- receptors localized in the cytoplasm; 3 - IO-synthase localized in the cell membrane; 5 - receptor activated by changes in the conformation of the lipid phase of the membrane; FRT - transcription regulation factors; SIB - signal-induced proteins.
signaling system (figure, signaling pathway 5).
It is known that signal perception by cell membrane receptors leads to a rapid change in the permeability of its ion channels. Moreover, it is believed, for example, that a signal-induced change in the concentration of protons and other ions in the cytoplasm can play the role of intermediates in the signaling system, eventually inducing the synthesis of signal-dependent proteins (figure, signaling pathway 6).
The results of the functioning of signaling systems in plants can be judged by pathogen (elicitor)-induced proteins, which are divided into several groups according to the functions they perform. Some are participants in plant signaling systems, and their intensive formation ensures the expansion of signal channels, others limit the nutrition of pathogens, others catalyze the synthesis of low-molecular antibiotics - phytoalexins, and the fourth - the reactions of strengthening plant cell walls. The functioning of all these pathogen-induced proteins can significantly limit the spread of infection throughout the plant. The fifth group of proteins causes degradation of the cell walls of fungi and bacteria, the sixth disrupts the functioning of their cell membrane, changing its permeability to ions, the seventh inhibits the work of the protein synthesis machine, blocking the synthesis of proteins on the ribosomes of fungi and bacteria or acting on viral RNA.
evolutionarily younger, since their functioning uses molecular oxygen. The latter led to the fact that in addition to the most important function of transmitting information about the extracellular signal to the cell genome, another one was added, associated with the appearance of active forms of lipids (in the case of the oxylipin system), oxygen (in all three cases) and nitrogen (in the case of the NO signaling system). ). The reactions involving molecular oxygen accompanying these three systems are characterized by a very high rate, which characterizes them as "quick response systems". Many products of these systems are cytotoxic and can suppress the development of pathogens or kill them, lead to necrosis of infected and neighboring cells, thereby hindering the penetration of pathogens into the tissue.
Among the most important signaling systems is the oxylipin signaling system, which is widespread in all eukaryotic organisms. The recently introduced term "oxylipins" refers to the products of oxidative metabolism of polyene fatty acids, regardless of their structural features and chain length (C18, C20 and others). Oxylipins perform not only the function of signal mediators in the transfer of transformed information to the cell genome, but also a number of other functions. By the time of the publication of F. Crick's article, lipoxygenase enzymes and a relatively small amount of oxylipins, for example, some prostaglandins, were known. Over the past thirty years, not only has the cyclooxygenase pathway of prostaglandin biosynthesis been elucidated, but also
SIGNALING SYSTEMS OF CELLS AND THE GENOME
many new bioregulators-oxylipins. It turned out that prostanoids and other eicosanoids (metabolism products of C20-fatty acids) maintain homeostasis in mammals at the cellular and organismal levels, control many vital functions, in particular, smooth muscle contraction, blood clotting, cardiovascular, digestive and respiratory systems, inflammatory processes, allergic reactions. The first of these functions, the control of smooth muscle contractions, coincides with one of the predictions of F. Crick, who predicted the decoding of the mechanisms of muscle functioning.
One of the promising areas is the study of the oxylipin signaling system and its role in plants and non-mammals. Interest in this area is largely due to the fact that the metabolism of oxylipins in mammals and plants has more differences than similarities. Over the past thirty years there have been notable advances in the study of oxylipin signaling metabolism in plants. Some of the discovered oxylipins control the growth and development of plants, are involved in the formation of local and systemic resistance to pathogens, and in adaptation to adverse factors.
Of particular interest are the facts of the control of signaling systems by the expression of genes encoding protein intermediates of the signaling systems themselves. This control includes autocatalytic cycles or, in the case of the expression of phosphoprotein phosphatase genes, leads to the suppression of one or another signaling system. It was found that signal-induced formation of both initial protein participants of signal chains - receptors, and final ones - transcription regulation factors can occur. There are also data on elicitor-induced activation of the synthesis of protein intermediates of signaling systems, caused, for example, by the expression of genes for MAP kinase, calmodulin, various lipoxygenases, cyclooxygenase, ]HO synthase, protein kinases, etc.
The genome and signaling network of the cell form a complex self-organizing system, a kind of biocomputer. In this computer, the hard information carrier is the gene, and the signaling network plays the role of a molecular processor, performing
A. M. Egorova, I. A. Tarchevskii, and V. G. Yakovleva - 2010
A. M. Egorova, I. A. Tarchevskii, and V. G. Yakovleva - 2012
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