Plant virus infection development as affected by heavy metal stress

The work was focused on the investigation of possible dependencies between the development of viral infection in plants and the presence of high heavy metal concentrations in soil. Field experiments have been conducted in order to study the development of systemic tobacco mosaic virus (TMV) infection in Lycopersicon esculentum L. cv. Miliana plants under effect of separate salts of heavy metals Cu, Zn and Pb deposited in soil. As it is shown, simultaneous effect of viral infection and heavy metals in tenfold maximum permissible concentration leads to decrease of total chlorophyll content in experiment plants mainly due to the degradation of chlorophyll a. The reduction of chlorophyll concentration under the combined influence of both stress factors was more serious comparing to the separate effect of every single factor. Plants' treatment with toxic concentrations of lead and zinc leaded to slight delay in the development of systemic TMV infection together with more than twofold increase of virus content in plants that may be an evidence of synergism between these heavy metal's and virus' effects. Contrary, copper although decreased total chlorophyll content but showed protective properties and significantly reduced amount of virus in plants.     

Extramedullary hematopoiesis in a case of benign mixed mammary tumor in a female dog: cytological and histopathological assessment

Backgroud  

Extramedullary hematopoiesis (EMH) is defined as the presence of hematopoietic stem cells such as erythroid and myeloid lineage plus megakaryocytes in extramedullary sites like liver, spleen and lymph nodes and is usually associated with either bone marrow or hematological disorders. Mammary EMH is a rare condition either in human and veterinary medicine and can be associated with benign mixed mammary tumors, similarly to that described in this case.     

Soil-to-plant and soil-to-grain transfer of 137Cs in field-grown maize hybrids during two contrasting seasons: assessing the phenotypic variability and its genetic component

Field-grown maize hybrids were assessed for variability in ¹³⁷Cs accumulation in vegetative parts of young and mature maize shoots and grains during 2 years with contrasting climatic conditions. Trials were carried out at different sites in the Tula region of Russia, which is characterized by a highly homogenous soil classified as Luvic Chernozem according to FAO/UNESCO, and average contamination levels of about 509–564 Bq ¹³⁷Cs kg⁻¹ soil. In the first year, 19 hybrids were tested. The two hybrids with the highest and the two with the lowest ¹³⁷Cs concentration ratios (C _r) were also tested in the second year, together with another 11 hybrids. All samples were additionally assessed for their potassium content. In both investigation periods ¹³⁷Cs accumulation in vegetative shoots and grains was found to vary up to more than twofold between hybrids. However, C _r values of those hybrids that showed a relatively low ¹³⁷Cs accumulation in the first year were not necessarily low in the second year, and the ratio between the ¹³⁷Cs C _r of low- and high-accumulating hybrids was much smaller than in the year before. In both vegetative shoots and grains the variance caused by the different years was larger than the genotypic variance, thus indicating the limits of genotype selection for this trait. Significant correlations were determined between the ⁴⁰K and ¹³⁷Cs C _r values in the same tissue, but for one hybrid indications for uncoupling of the two traits were found. Average Cs/K ratios in young shoots, mature shoots and grains were 0.06, 0.05 and 0.02, respectively, indicating tissue- and stage-specific regulation of accumulation within each plant. The findings are discussed with respect to new approaches towards a better understanding of ¹³⁷Cs accumulation and its potential reduction in plants. Katharina Schneider was deceased.     

Taxonomy of leafminers of the genus Phyllonorycter Hübner (Lepidoptera, Gracillariidae) associated with ulmaceous plants (Ulmaceae)

A contribution to the taxonomy of the genus Phyllonorycter Hübner (Lepidoptera, Gracillariidae) is proposed, based on the morphological study of species developing on Ulmaceae. Species trophically associated with Ulmaceae belong to two subgenera: Phyllonorycter s. str. and a new subgenus, Juxtafera Baryshnikova, subgen. n. (type species Tinea tristrigella Hw.), both representing complex taxa. Three species-groups including species feeding on Ulmaceae as well as morphologically similar species developing on Betulaceae, Fabaceae, Salicaceae, Juglandaceae, and Rosaceae are established within the nominotypical subgenus; several species are characterized by disjunct oligophagy, consuming Ulmaceae together with plants of other families. Juxtafera subgen. n., established on the basis of the development of juxta in the male genitalia, is divided into 6 species-groups whose representatives are mainly strict oligophages, being predominantly associated with plants of three unrelated families Ulmaceae, Rosaceae, and Caprifoliaceae. Based on the comparative morphology of the male genitalia, evolutionary trends in Juxtafera are hypothesized.     

Studies on the partial characterization of extracted glycosaminoglycans from fish waste and its potentiality in modulating obesity through in-vitro and in-vivo

Glycoconjugate Journal - Glycosaminoglycans (GAGs) are bioactive polysaccharides or glycoconjugates found in the fish waste having significant health impacts. In the present study it has been...     

Yield and quality of forage maize (<i>Zea mays</i> L.) with different levels of subsurface drip irrigation and plant density

The scarcity of water in arid and semiarid regions of the world is a problem that every day increases by climate change. The subsurface drip irrigation (SDI) and changes in population density of plants are alternatives that can be used to make a sustainable use of water. Therefore, the objectives of this study were to determine the combination that allows for an increased corn performance and efficient use of water without losing the quality of forage. Three different irrigation levels were applied through a system of a SDI at three different densities of forage maize plants in an arid region. The results demonstrated that by applying different levels of water, either enough or lack of soil moisture is created, which is directly reflected in crop yield, and its determining variables such as green forage and dry matter yield, and nutritional quality. The irrigation level to a 100% of potential evapotranspiration (PET), at a density of 80000 plants/ha, increased yield of green forage to 57664 kg/ha; crude protein was 8.59%, while the rest of the quality parameters decreased. This study allowed to conclude that the irrigation level was the major factor in the response of the crop.     

Methods for preparation of recombinant cytokine proteins V. mutant analogues of human interferon-gamma with higher stability and activity

Mutant analogues of recombinant human immune interferon (IFN-gamma) with higher stability and biological activity were prepared. Depending on the analogue, protein structure modification might involve introduction of an intramonomer disulfide bond (through replacements of Glu7Cys and Ser69Cys), C-terminal shortening by 10 amino acid residues, as well as Gln133Leu substitution in truncated variant. Isolation, purification, and renaturation of the IFN-gamma analogues expressed in Escherichia coli as inclusion bodies were performed according to the scheme developed earlier for wild-type protein. The main idea of this scheme is to remove cellular impurities before recombinant protein renaturation. Folding kinetics of IFN-gamma was studied by reversed-phase HPLC. IFN-gamma and mutant proteins were characterized by their thermal stability and biological activity. Introduction of the intramolecular disulfide bond together with C-terminal shortening and replacement of C-terminal residue was shown to result in increasing the thermal stability by 19 degrees C and four times enhancement of biological activity compared with intact IFN-gamma molecule.     

Heterogeneity of the Nucleotide Sequences of the 16S rRNA Genes of the Type Strain of Desulfotomaculum kuznetsovii

Two copies of the 16S rRNA gene, rrnAand rrnB, of the type strain 17^Tof the thermophilic sulfate-reducing bacterium Desulfotomaculum kuznetsoviiwere cloned and completely sequenced. The comparison of the determined sequences revealed considerable heterogeneity (8.3%) of the two genes, rrnAand rrnB.The main differences were associated with superlong inserts located in the variable 5"- and 3"-terminal regions of the 16S rRNA genes. Comparative analysis that involved analogous genes from the phylogenetically closest representatives of the genus Desulfotomaculumshowed that disregard of the heterogeneity of the two gene copies distorts the position of the bacterium studied in the phylogenetic tree.     

Influence of a stationary magnetic field on bioelectric properties of snail neurons

Identified cells of Helix lucorum L. received 20 min exposures to 23, 120, or 200 mT stationary magnetic field (MFs). Resting potentials and input resistances were measured. Controls were instituted for temperature changes and for mechanical and other sources of artifact. Resting potentials did not change with MF exposure. Input resistances decreased significantly in normally silent cells during MF exposure, but increased significantly in spontaneously active cells. The magnitudes of changes were monotonically related to strength of the MF. Changes in excitatory postsynaptic potentials were observed during MF exposure. Elimination of perineuronal glia by proteolytic enzymes eliminated the MF effects.