Structural organization of chloroplast of tomato plants <Emphasis Type="Italic">Solanum lycopersicum</Emphasis> transformed by Fe-containing superoxide dismutase

In this work we analyzed the results of the transformation of tomato plants Solanum lycopersicum by gene FeSOD1 from Arabidopsis thaliana, equipped with the signal sequence for targeting into chloroplasts. PCR analysis showed that the gene was integrated into the genome of several tomato plants that underwent transformation followed by selection in the kanamycin-containing medium. Two lines, provisionally denoted as nos. 6 and 8, were selected from the independent transformants. Line 6 was characterized by a reduced growth rate and altered leaves and line 8, by normal growth and leaves typical for control plants. Both lines showed a significant increase in SOD activity. In line 8 the increase in SOD activity was accompanied by an increase of ascorbate peroxidase activity, and in line 6 this effect was not present. Electron microscopic analysis of parenchymal and guard cells of both lines was performed, with an emphasis on the ultrastructural organization of chloroplasts. It is shown that the chloroplasts of the two transgenic lines differ in the number and size of starch grains and deposited plastoglobules as well as in the organization of lamellae and grana. Taken together, the results indicate that the expression of the introduced gene FeSOD1 has a significant effect on metabolic processes in the plastids. The findings are discussed in relation to the hypothesis about the importance of low concentrations of ROS for the integration of structure and function of chloroplasts.     

Role of extracellular DNA oxidative modification in radiation induced bystander effects in human endotheliocytes

The development of the bystander effect induced by low doses of irradiation in human umbilical vein endothelial cells (HUVECs) depends on extracellular DNA (ecDNA) signaling pathway. We found that the changes in the levels of ROS and NO production by human endothelial cells are components of the radiation induced bystander effect that can be registered at a low dose. We exposed HUVECs to X-ray radiation and studied effects of ecDNA(R) isolated from the culture media conditioned by the short-term incubation of irradiated cells on intact HUVECs. Effects of ecDNA(R) produced by irradiated cells on ROS and NO production in non-irradiated HUVECs are similar to bystander effect. These effects at least partially depend on TLR9 signaling. We compared the production of the nitric oxide and the ROS in human endothelial cells that were (1) irradiated at a low dose; (2) exposed to the ecDNA(R) extracted from the media conditioned by irradiated cells; and (3) exposed to human DNA oxidized in vitro. We found that the cellular responses to all three stimuli described above are essentially similar. We conclude that irradiation-related oxidation of the ecDNA is an important component of the ecDNA-mediated bystander effect.     

Resistance of winter wheat varieties to tan spot in the North Caucasus region of Russia

Tan spot caused by Pyrenophora tritici-repentis (Died.) Drechsler, in recent years, occupies an increasingly large area on the territory of Russia. Due to the wide distribution and economic significance of this disease, the search for resistant plants to the pathogen is relevant. This paper presents the results of a field assessment for 2017–2019 of 34 regionally distributed winter wheat varieties of Russian selection for resistance to P. tritici-repentis in the North Caucasus region of Russia. Field resistance - the development of the disease up to 30% against the background of artificial infection for three years was shown by 20.5% of the studied varieties. Wheat varieties were assessed for resistance to isolates of tan spot identified as races 1, 3, and 4 in the greenhouse at the seedling stage. The number of resistant accessions for each race was different and ranged from 12 to 20. The 12 varieties showed resistance to race 1, 14 varieties to race 3, 20 varieties to race 4. This research showed that the resistance to tan spot of studied varieties was race-specific. A functional allele of the susceptibility gene Tsn1 to P. tritici-repentis isolates, producing the toxin Ptr ToxA, was diagnosed by PCR method. Of the analyzed 34 varieties, 13 had a dominant allele of the Tsn1 (Tsn1⁺), and 21 had a recessive allele in the tsn1tsn1 homozygous state. All Tsn1⁺ varieties, and most varieties with recessive alleles tsn1tsn1, were susceptible to tan spot in the field. Varieties Dolya, Gurt, Lebed and Sila, which showed field resistance, had the tsn1tsn1 genotype. The expected reaction of varieties with different allelic composition of the Tsn1 gene to inoculation with the isolate of race 1, according to the generally accepted model of “gene-to-gene” interaction, did not coincide with that observed in reality, which confirms the results obtained by other authors. Research results demonstrate the effect of weather conditions on the susceptibility of wheat varieties to tan spot. In years with higher humidity and higher average air temperatures, the susceptibility response to the disease was observed in more varieties than in drier years. The studies show that the main part (79.5%) of winter wheat varieties of Russian selection widely zoned in the North Caucasus region of Russia are susceptible to P. tritici-repentis. Varieties that have been resistant to the pathogen in the adult phase in the field for three years and to the pathogen races in which the recessive allele of the tsn1 gene has been identified may be of interest as sources of resistance for developing new disease-resistant varieties.     

Diversity of integrase-hydrolyzing IgGs and IgMs from sera of HIV-infected patients

It was previously shown that small fractions of IgGs and IgMs from the sera of AIDS patients specifically hydrolyze only HIV integrase (IN) but not many other tested proteins. Here we present evidence showing that these IgGs and IgMs are extreme catalytically heterogeneous. Affinity chromatography on IN-Sepharose using elution of IgGs (or IgMs) with different concentration of NaCl and acidic buffer separated catalytic antibodies (ABs) into many AB subfractions demonstrating different values of K _m for IN and k _cat. Nonfractionated IgGs and IgMs possess serine-, thiol-, acidiclike, and metal-dependent proteolytic activity. Metal-dependent activity of abzymes increases in the presence of ions of different metals. In contrast to canonical proteases having one pH optimum, initial nonfractionated IgGs and IgMs demonstrate several optima at pH from 3 to 10. The data obtained show that IN-hydrolyzing polyclonal IgG and IgM of HIV-infected patients are cocktails of anti-IN ABs with different structure of the active centers possessing various affinity to IN, pH optima, and relative rates of the specific substrate hydrolysis.     

Interaction of Na,K-ATPase with modifying ATP analogs and chloromethylphosphonic acid

The interaction of synthetic ATP analogs, containing active groups in the triphosphate moiety and in the 8-position of the nucleotide molecule, with highly purified Na, K-ATPase from the medullar layer of porcine kidney was studied. It was found that 11 out of 17 ATP analogs studied irreversibly inhibit the ATPase activity of the enzyme. The pH optimum of the enzyme inactivation by adenosine-5'-(beta-chloroethylphosphate) and adenosine-5'-(p-fluorosulfonylphenylphosphate) beside the pronounced protective effect of ATP suggests possible covalent blocking of histidine and dicarboxylic amino acid residues in the enzyme active center. The irreversible inhibition of the enzyme by "oxo-ATP" containing aldehyde groups in the modified ribose residue in the presence of sodium borohydride suggests a possible presence of the lysine residue epsilon-amino group in the ATP binding site of the enzyme. Na, K-ATPase was found to possess an inorganic phosphate binding site, which is specifically blocked by chloromethylphosphonic acid. the accessibility of this site for modification depends on ATP, NA+ and K+.     

Isolation and characterization of polymorphic microsatellite markers for the endangered Korean freshwater fish Hemibarbus mylodon

Korean barbel, Hemibarbus mylodon, is an endangered freshwater species endemic to Korea. In order to undertake a conservation program for this species in Korea, it is essential to evaluate its genetic diversity and population structure. For this purpose, we developed 10 polymorphic microsatellite markers and examined their allelic variation using a total of 60 wild individuals collected from three different localities. The number of alleles per locus ranged from three to 26. The expected and observed heterozygosities per locus ranged from 0.19 to 0.94 and from 0.20 to 0.98, respectively. Significant departures from Hardy–Weinberg equilibrium expectations occurred in four loci. These markers will be useful for the assessment of genetic diversity for this species.     

内源性NO在LPS和TNFα诱导离体兔肺动脉反应性变化中 …

目的：探讨脂多糖（Ｌｉｐｏｐｏｌｙｓａｃｃｈａｒｉｄｅ,ＬＰＳ）和肿瘤坏死因子α（ｔｕｍｏｒ ｎｅｃｒｏｓｉｓ ｆａｃｔｏｒ ａｌｐｈａ,ＴＮＦα）所致离体肺动脉反应性张力变化与肺动脉源性一氧化氮（ｎｉｔｒｉｃ ｏｘｉｅ,ＮＯ）的关系。方法：离体兔肺动脉环用ＬＰＳ＋ＴＮＦα、ＬＰＳ或深剂孵育２ｈ和６ｈ,检测肺动脉对乙酰胆碱（ＡＣｈ）、硝普钠（ＳＮＰ）和苯肾上腺素（ＰＥ）的累积剂量反应,以及一氧化氮     

Application of the bridgehead fragments for the design of conformationally restricted melatonin analogues

Conformationally constrained analogues of the hormone melatonin with a side chain incorporated into the bicyclic bridgehead core were synthesized based on the homology modeling and molecular docking studies performed for the MT₂ melatonin receptor. The methoxy-indole derivative fused with exo-N-acetamino-substituted bicyclo[2.2.2]octane was found to possess nanomolar MT₂ receptor affinity.