Peptide AEDL and Glutathione Stimulates Root Development .

Reactive oxygen species (ROS) are essential molecules involved in intercellular communication, signal transduction, and metabolic processes. Abiotic stresses cause the accumulation of excess ROS in plant cells. The issue of regulating the antioxidant protection of plants using natural and synthetic compounds with antioxidant activity still remains one of the most important and relevant areas of fundamental and applied research.

ROS as Signaling Molecules to Initiate the Process of Plant Acclimatization to Abiotic Stress.

During their life cycle, plants constantly respond to environmental changes. Abiotic stressors affect the photosynthetic and respiratory processes of plants. Reactive oxygen species (ROS) are produced during aerobic metabolism and play an important role as regulatory mediators in signaling processes, activating the plant's protective response to abiotic stress and restoring "oxidation-reduction homeostasis".

Salt Tolerance Assessment in and .

Background: Salt stress is a multicomponent phenomenon; it includes many processes that directly or indirectly affect the plant. Attempts have been made to comprehensively consider the processes of salt stress in plants (variety Orenburgskaya 22) and (variety Zolotaya).

Methods: The study used methods of light and fluorescence microscopy, methods of immunofluorodetection, expression of DNA methyltransferase genes, genes of the ion transporter and superoxide dismutase families, as well as biochemical determination of total antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) reagent.

Features of the Effect of Quercetin on Different Genotypes of Wheat under Hypoxia.

Hypoxia is one of the common abiotic stresses that negatively affects the development and productivity of agricultural crops. Quercetin is used to protect plants from oxidative stress when exposed to environmental stressors. O deficiency leads to impaired development and morphometric parameters in wheat varieties Orenburgskaya 22 ( L.

Mechanisms of Antioxidant Resistance in Different Wheat Genotypes under Salt Stress and Hypoxia.

Various stressors lead to an increase in ROS and damage to plant tissues. Plants have a powerful antioxidant system (AOS), which allows them to neutralize excess ROS. We detected an intense fluorescent glow of ROS in the cells of the cap, meristem, and elongation zones in the roots of wheat (Orenburgskaya 22 variety) and (Zolotaya variety).

Molecular Mechanisms of Regulation of Root Development by Plant Peptides.

Peptides perform many functions, participating in the regulation of cell differentiation, regulating plant growth and development, and also involved in the response to stress factors and in antimicrobial defense. Peptides are an important class biomolecules for intercellular communication and in the transmission of various signals. The intercellular communication system based on the ligand-receptor bond is one of the most important molecular bases for creating complex multicellular organisms.

Elongating Effect of the Peptide AEDL on the Root of under Salinity.

The overall survival of a plant depends on the development, growth, and functioning of the roots. Root development and growth are not only genetically programmed but are constantly influenced by environmental factors, with the roots adapting to such changes. The peptide AEDL (alanine-glutamine acid-asparagine acid-leucine) at a concentration of 10 M had an elongating effect on the root cells of seedlings.

Short Peptides Induce Development of Root Hair .

Root hairs absorb soil nutrients and water, and anchor the plant in the soil. Treatment of tobacco () roots with glycine (Gly) amino acid, and glycilglycine (GlyGly) and glycilaspartic acid (GlyAsp) dipeptides (10 M concentration) significantly increased the development of root hairs. In the root, peptide accumulation was tissue-specific, with predominant localization to the root cap, meristem, elongation zone, and absorption zone.

Short Exogenous Peptides Regulate Expression of CLE, KNOX1, and GRF Family Genes in Nicotiana tabacum.

Exogenous short biologically active peptides epitalon (Ala-Glu-Asp-Gly), bronchogen (Ala-Glu-Asp-Leu), and vilon (Lys-Glu) at concentrations 10-10 M significantly influence growth, development, and differentiation of tobacco (Nicotiana tabacum) callus cultures. Epitalon and bronchogen, in particular, both increase growth of calluses and stimulate formation and growth of leaves in plant regenerants. Because the regulatory activity of the short peptides appears at low peptide concentrations, their action to some extent is like that of the activity of phytohormones, and it seems to have signaling character and epigenetic nature.

Modulation of action of wheat seedling endonucleases WEN1 and WEN2 by histones.

Wheat core histones and various subfractions of histone H1 modulate differently the action of endonucleases WEN1 and WEN2 from wheat seedlings. The character of this modulation depends on the nature of the histone and the methylation status of the substrate DNA. The modulation of enzyme action occurs at different stages of processive DNA hydrolysis and is accompanied by changes in the site specificity of the enzyme action.

Interaction of short peptides with FITC-labeled wheat histones and their complexes with deoxyribooligonucleotides.

Judging from fluorescence modulation (quenching), short peptides (Ala-Glu-Asp-Gly, Glu-Asp-Arg, Ala-Glu-Asp-Leu, Lys-Glu-Asp-Gly, Ala-Glu-Asp-Arg, and Lys-Glu-Asp-Trp) bind with FITC-labeled wheat histones H1, H2B, H3, and H4. This results from the interaction of the peptides with the N-terminal histone regions that contain respective and seemingly homologous peptide-binding motifs. Because homologous amino acid sequences in wheat core histones were not found, the peptides seem to bind with some core histone regions having specific conformational structure.

Mechanisms of catalytic action and chemical modifications of endonucleases WEN1 and WEN2 from wheat seedlings.

Hydrolysis of DNA catalyzed by wheat endonucleases WEN1 and WEN2 is pronouncedly processive. A correlation has been revealed between appearance of new products of DNA hydrolysis with different length and conformational changes in the enzymes. The first conformational conversion of the endonucleases is associated with appearance of large fragments of DNA hydrolysis with length longer than 500 bp, and the second conversion is associated with formation of oligonucleotides with length of 120-140 bp, and the third conversion is associated with formation of short oligonucleotides and mononucleotides.

Processing character of the action of wheat endonucleases WEN1 and WEN2. Kinetic parameters.

The wheat seedling endonucleases WEN1 and WEN2 dependent on Mg(2+), Ca(2+), and S-adenosyl-L-methionine (SAM) and sensitive to the substrate DNA methylation status have an expressed processing action. The enzymes hydrolyze DNA at a few subsequent stages: first, they split λ phage DNA specifically at CNG-sites (WEN1) with liberation of large fragments; second, they hydrolyze these fragments to 120-140 bp oligonucleotides that finally are hydrolyzed to very short fragments and mononucleotides. Initial stages of DNA hydrolysis may proceed in the absence of Mg(2+), but subsequent hydrolysis stages are very strongly stimulated by Mg(2+).

Site-specific binding of short peptides with DNA modulated eukaryotic endonuclease activity.

Short peptides (2-4 amino acid residues) inhibit or stimulate hydrolysis of λ phage DNA by eukaryotic endonucleases WEN1 and WEN2 depending on DNA methylation status. Peptide modulation of endonucleases activity most likely appears as a result of their binding to DNA. Peptides discriminate (recognize) not only certain DNA sequences, but also their methylation status.

Penetration of short fluorescence-labeled peptides into the nucleus in HeLa cells and in vitro specific interaction of the peptides with deoxyribooligonucleotides and DNA.

Marked fluorescence in cytoplasm, nucleus, and nucleolus was observed in HeLa cells after incubation with each of several fluorescein isothiocyanate-labeled peptides (epithalon, Ala-Glu-Asp-Gly; pinealon, Glu-Asp-Arg; testagen, Lys-Glu-Asp-Gly). This means that short biologically active peptides are able to penetrate into an animal cell and its nucleus and, in principle they may interact with various components of cytoplasm and nucleus including DNA and RNA. It was established that various initial (intact) peptides differently affect the fluorescence of the 5,6-carboxyfluorescein-labeled deoxyribooligonucleotides and DNA-ethidium bromide complexes.

CNG site-specific and methyl-sensitive endonuclease WEN1 from wheat seedlings.

Endonuclease WEN1 with apparent molecular mass about 27 kDa isolated from cytoplasmic vesicular fraction of aging coleoptiles of wheat seedlings has expressed site specificity action. This is a first detection and isolation of a site-specific endonuclease from higher eukaryotes, in general, and higher plants, in particular. The enzyme hydrolyzes deoxyribooligonucleotides of different composition on CNG (N is G, A, C, or T) sites by splitting the phosphodiester bond between C and N nucleotide residues in CNG sequence independent from neighbor nucleotide context except for CCCG.

H1 histone modulates DNA hydrolysis with WEN1 and WEN2 endonucleases from wheat coleoptiles.

We show that total H1 histone from wheat seedlings or rat liver enhances hydrolysis of lambda phage DNA with plant endonucleases WEN1 and WEN2 isolated from wheat coleoptiles. Optimal DNA/protein weight ratio in the hydrolysis reaction is 1 : 1. The action of fractions I and IV (obtained from total wheat H1 histone by electrophoresis) on DNA hydrolysis with WEN1 and WEN2 enzymes depends on the DNA methylation status.

Wheat coleoptile endonuclease Wen2 is dependent on S-adenosyl-L-methionine and sensitive to DNA methylation status.

Endonuclease WEN2 with an apparent molecular mass 21.5 kD was isolated from subcellular vesicular fraction obtained from aging apoptotic coleoptiles of 8-day-old etiolated wheat seedlings and partially characterized. Similar to wheat endonuclease WEN1 of the same origin described earlier, the WEN2 enzyme is a neutral Ca2+,Mg2+,Mn2+-dependent endonuclease.

Wheat endonuclease WEN1 dependent on S-adenosyl-L-methionine and sensitive to DNA methylation status.

Ca(2+)-, Mg(2+)-dependent wheat endonuclease WEN1 with molecular mass of about 27 kDa was isolated from coleoptyles. Methylated DNA of lambda phage grown on E. coli dam(+), dcm(+) cells was hydrolyzed by WEN1 more effectively than DNA of phage grown on dam(-), dcm(-) cells.

Effect of ethylene producer ethrel and antioxidant ionol (BHT) on the proteolytic apparatus in coleoptiles of wheat seedlings during apoptosis.

It was established that total proteolytic activity in etiolated wheat seedlings changes in ontogenesis in cycles: peaks of proteolytic activity correspond to the 3rd, 5th, and 8th days of seedling growth, respectively. The maximum of proteolytic activity preceded the maximum of nuclease activity, which may be due to activation of nucleases by proteolytic enzymes. According to inhibitory analysis the cysteine and serine proteases play the main role in apoptosis in wheat coleoptiles.

N(6)-Adenine DNA-methyltransferase in wheat seedlings.

The N(6)-adenine DNA-methyltransferase was isolated from the vacuolar vesicle fraction of wheat coleoptiles. In the presence of S-adenosyl-L-methionine the enzyme de novo methylates the first adenine residue in the TGATCA sequence in the single- or double-stranded DNA substrates but it prefers single-stranded structures. Wheat adenine DNA-methyltransferase (wadmtase) is a Mg(2+)- or Ca(2+)-dependent enzyme with a maximum activity at pH 7.

Primary structures of two ribonucleases from ginseng calluses. New members of the PR-10 family of intracellular pathogenesis-related plant proteins.

The amino acid sequences of two ribonucleases from a callus cell culture of Panax ginseng were determined. The two sequences differ at 26% of the amino acid positions. Homology was found with a large family of intracellular pathogenesis-related proteins, food allergens and tree pollen allergens from both dicotyledonous and monocotyledonous plant species.

High sequence similarity between a ribonuclease from ginseng calluses and fungus-elicited proteins from parsley indicates that intracellular pathogenesis-related proteins are ribonucleases.

A ribonuclease from a callus cell culture of Panax ginseng C.A. Mey strain R1 was isolated.