Anthraquinone dyes decolorization capacity of anamorphic Bjerkandera adusta CCBAS 930 strain and its HRP-like negative mutants

Cultures of the anamorphic fungus Bjerkandera adusta CCBAS 930 decolorizing, in stationary cultures, 0.01 % solutions of carminic acid and Poly R-478, were characterised by a strong increase in the activity of the horseradish peroxidase (HRP-like) and manganese-dependent peroxidase (MnP) at a low activity of lignin peroxidase. Genotypically modified mutants of B. adusta CCBAS 930: 930-5 and 930-14, with total or partial loss of decolorization capabilities relative to anthraquinonic dyes, showed inhibition of the activity of HRP-like peroxidase and MnP. Whereas, compared to the parental strain, in the mutant cultures there was an increase in the activity of lignin peroxidase and laccase. The paper presents a discussion of the role of the studied enzymatic activities in the process of decolorization of anthraquinonic dyes by the strain B. adusta CCBAS 930.     

The high-resolution crystal structure of a parallel intermolecular DNA G-4 quadruplex/drug complex employing syn glycosyl linkages

We have determined the X-ray structure of the complex between the DNA quadruplex d(5′-GGGG-3′)₄ and daunomycin, as a potential model for studying drug–telomere interactions. The structure was solved at 1.08 Å by direct methods in space group I4. The asymmetric unit comprises a linear arrangement of one d(GGGG) strand, four daunomycin molecules, a second d(GGGG) strand facing in the opposite direction to the first, and Na and Mg cations. The crystallographic 4-fold axis generates the biological unit, which is a 12-layered structure comprising two sets of four guanine layers, with four layers each of four daunomycins stacked between the 5′ faces of the two quadruplexes. The daunomycin layers fall into two groups which are novel in their mode of self assembly. The only contacts between daunomycin molecules within any one of these layers are van der Waals interactions, however there is substantial π–π stacking between successive daunomycin layers and also with adjacent guanine layers. The structure differs significantly from all other parallel d(TGGGGT)₄ quadruplexes in that the 5′ guanine adopts the unusual syn glycosyl linkage, refuting the widespread belief that such conformations should all be anti. In contrast to the related d(TGGGGT)/daunomycin complex, there are no ligand–quadruplex groove insertion interactions.     

Raman spectroscopy analysis of lipid droplets content,distribution and saturation level in Non‐Alcoholic Fatty Liver Disease in mice

Non‐Alcoholic Fatty Liver Disease (NAFLD) is a common liver disorder, characterized by an excessive lipids deposition within the hepatic tissue. Due to the lack of clear‐cut symptoms and optimal diagnostic method, the actual prevalence of NAFLD and its pathogenesis remains unclear, especially in the early stages of progression. In the presented work confocal Raman microspectroscopy was used to investigate alterations in the chemical composition of the NAFLD‐affected liver. We have investigated two NAFLD models, representative for macrovesicular and microvesicular steatosis, induced by High Fat Diet (60 kcal %) and Low Carbohydrate High Protein Diet (LCHP), respectively. In both models we confirmed the development of NAFLD, manifested by the presence of lipid droplets (LDs), but of different sizes. Model of macrovesicular steatosis was characterized by large LDs, whereas in the microvesicular steatosis model small droplets were found. In both models, however, we observed a significant decrease in the degree of unsaturation of lipids, in comparison to the control. In addition, for both models, the impact of medical treatment with selected drugs (perindopril and nicotinic acid, respectively) was tested, indicating a significant influence of medicine not only on the occurrence and size of the droplets, but also on their composition. Inboth cases the drug treatment resulted in an increase of the degree of unsaturation of lipids forming droplets. Confocal Raman microspectroscopy was proven to be a powerful tool providing detailed insight into selected areas of hepatic tissue, following the NAFLD pathogenesis and diagnostic potential of the applied drugs.

     

Sex-dependent body mass and respiratory responses on Euschistus heros individuals resistant to imidacloprid

1. In insect-resistant populations, adaptive fitness is intimately related to the physiological responses of males and females to different stressors.
2. By using laboratory-selected imidacloprid-resistant individuals of the Neotropical brown stink bug Euschistus heros, one of the most prevalent pests in soybean fields in the Neotropical region, we evaluated whether resistance to imidacloprid (synergized by piperonyl butoxide—PBO) would differentially affect the longevity, body mass and respiratory responses of E. heros males and females.
3. We used an imidacloprid-susceptible E. heros strain (ImiSusc), whose individuals were reared under controlled and imidacloprid-free conditions for over a decade, to select the PBO-synergized imidacloprid-resistant strain (ImiPBOSel).
4. After eight generations using PBO-synergized imidacloprid, our results revealed that resistant individuals exposed only to dry residues of imidacloprid (tarsal contact) could survive at concentrations as high as 168 μg a.i./cm², which is equivalent to 40-fold the label recommendation for field applications. Furthermore, ImiPBOSel males and females exhibited higher longevity, higher body mass and elevated respiratory activity than ImiSusc individuals.
5. Altogether, the findings described here showed that imidacloprid resistance can select E. heros individuals with better metabolic capacities, which can complicate the management of this pest under field conditions.

     

Copper (II) acetate improves the quality of pear (Pyrus) DNA during extraction

Isolation of high-quality DNA from Pyrus is particularly difficult because of high endogenous levels of polysaccharides, phenolics, and other organic constituents that interfere with DNA isolation and purification. Presence of phenolic compounds caused browning of tissue and supernatant during the extraction process, despite supplementation with PVP, as suggested by standard methods. By modifying the CTAB extraction procedure of Aldrich and Cullis (1993) by including copper (II) acetate treatment, we obtained high-quality DNA. Copper (II) acetate enabled fixation and removal of tannins. The DNA yield from this procedure is high (up to 1.25 μg of DNA/mg of leaf tissue). This DNA is completely digestible with restriction endonucleases and suitable for generation of molecular markers, such as random-amplified polymorphic DNA and amplified fragment length polymorphism analyses, indicating freedom from common contaminating polyphenolic compounds.     

Parasitic microfungi of the Tatra Mountains. 3. <Emphasis Type="Italic">Spermosporina gymnadeniae</Emphasis> (Hyphomycetes): species new to Slovakia and new records from Poland

Spermosporina gymnadeniae (Hyphomycetes) on Gymnadenia sp. (Orchidaceae) collected in the Polish part of the Tatra Mts was described in 2003. The fungus was recently found at new localities in Poland and Slovakia. It was recorded on Gymnadenia conopsea s.l. and Dactylorhiza fuchsii, which are new hosts of this parasite. The fungus is described and additional illustrations are provided.     

Irradiance-driven 20-hydroxyecdysone production and morphophysiological changes in Pfaffia glomerata plants grown in vitro

Pfaffia glomerata possesses potential pharmacological and medicinal properties, mainly owing to the secondary metabolite 20-hydroxyecdysone (20E). Increasing production of biomass and 20E is important for industrial purposes. This study aimed to evaluate the influence of irradiance on plant morphology and production of 20E in P. glomerata grown in vitro. Nodal segments of accessions 22 and 43 (Ac22 and Ac43) were inoculated in culture medium containing MS salts and vitamins. Cultures were maintained at 25 ± 2 °C under a 16-h photoperiod and subjected to irradiance treatments of 65, 130, and 200 μmol m⁻² s⁻¹ by fluorescent lamps. After 30 days, growth parameters, pigment content, stomatal density, in vitro photosynthesis, metabolites content, and morphoanatomy were assessed. Notably, Ac22 plants exhibited 10-fold higher 20E production when cultivated at 200 μmol m⁻² s⁻¹ than at 65 μmol m⁻² s⁻¹, evidencing the importance of light quantity for the accumulation of this metabolite. 20E production was twice as high in Ac22 as in Ac43 plants although both accessions responded positively to higher irradiance. Growth under 200 μmol m⁻² s⁻¹ stimulated photosynthesis and consequent biomass accumulation, but lowered carotenoids and anthocyanins. Furthermore, increasing irradiance enhanced the number of palisade and spongy parenchyma cells, enhancing the overall growth of P. glomerata.

Graphical abstract

     

Parasitic microfungi of the Tatra Mountains: 5. <Emphasis Type="Italic">Plasmopara</Emphasis> representatives on the species of <Emphasis Type="Italic">Geranium</Emphasis>

A list of species and the distribution of the members of Plasmopara (Chromista, Peronosporales) on Geranium spp. in the Tatra National Park (Western Carpathians) biospheric reserve are given. Three fungal species parasitizing 3 plant species were recorded in the area. Plasmopara praetermissa is a species new to Poland and Slovakia.