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Morphological, biological, and phylogenetic approaches were undertaken for the identification of pathogenic species F. temperatum in the Serbian population of F. subglutinans collected in the 1999-2010 period from Zea mays (3 root, 15 stalk, and 6 seed samples), Sorghum bicolor (two seed samples), Hordeum vulgare (one seed sample) and Taraxacum officinale (one seed sample). Based on interspecies mating compatibility analyses and the maximum parsimony analysis of EF-1α sequences, only two strains, originating from S. bicolor seed (MRIZP 0418 and MRIZP 0552), were identified as F. temperatum, while the remaining 26 single-spore strains were identified as F. subglutinans Group 2. In situ detached barley leaf assay and artificially stalk and ear inoculation of two maize hybrids demonstrated that both F. temperatum and F. subglutinans strains were medium and strong pathogens under laboratory and field conditions, respectively. These are the first data on the F. temperatum as seed-borne pathogens of sorghum, as well as pathogenicity of F. temperatum strains on maize. [ABSTRACT FROM AUTHOR]

The presented study shows a simple way for optimization of extrusion process, which was used for deterioration of cyanogenic glycosides - antinutritive components of linseed, with minimum damage of essential Alpha-Linolenic Acid (ALA) at the same time. Extrusion of the material was done on a laboratory single screw extruder. Content of Hydrogen cyanide (HCN) as a measurement of cyanogenic glycosides in produced co-extrudate and fatty acid composition were determined, together with basic chemical analyses, which were done in accordance with AOAC methods. Statistical analysis showed that HCN content in the product was the most dependent (P= 0.0002) on quadratic influence of moisture content of starting material. The highest HCN content (126 mg kg-1) was measured at the lowest moisture content (7%) and the lowest screw speed (240 rpm). Low moisture content caused weak volatilization of HCN along with the evaporating water, which was intensified with higher values of moisture content. However, increase in moisture content from 11.5 to 16% slightly increased the amount of present HCN, due to the lower material viscosity. Extrusion process caused some changes in fatty acid composition, but even the highest degradation of ALA did not exceed 4%. Linear and quadratic influence of moisture content on ALA reduction was significant (P< 0.05), as well as quadratic influence of screw speed. Specific attention has to be paid to selecting appropriate levels of screw speed and moisture content of the material which contains linseed, in order to achieve both detoxification of linseed and preservation of essential fatty acids. [ABSTRACT FROM AUTHOR]

Morphogenesis of two K. zeae isolates (V7486 and ZP24986) on carbon, nitrogen and sulphur solid nutritive media after 2, 10, 18 and 28 days of incubation were studied. Highly significant differences were found between the isolates in regard to the use of compounds containing these elements. On carbon sources the fungus generally developed smaller colonies of branchy, loose, creamy-brown appearance, with abundant sporulation and abnormal conidia. Sucrose and D-glucose were the best carbon sources for K. zeae because both isolates had the maximum growth, abundant to medium abundant sporulation and mostly typical conidia. K. zeae colonies on organic and inorganic nitrogen and on sulphur sources too were leathery, creased, predominantly pink. Organic nitrogen sources lead to maximum growth and abundant sporulation, whereas ammonium and nitrate compounds caused intermediary growth and medium to very poor fungus sporulation. Addition of different sulphur sources, except sodium thiosulphate and thiocarbamide, did not affect the growth and sporulation of V7486. The growth of ZP24986 depended on potassium and ammonium sulphate and sodium bisulphate. [ABSTRACT FROM AUTHOR]

An NMR-based approach to characterizing the binding kinetics of ligand molecules to biomolecules, like RNA or proteins, by ligand-detected Carr-Purcell-Meiboom-Gill (CPMG) relaxation dispersion experiments is described. A (15)N-modified preQ1 ligand is used to acquire relaxation dispersion experiments in the presence of low amounts of the Fsu class I preQ1 aptamer RNA, and increasing ligand concentrations to probe the RNA small molecule interaction. Our experimental data strongly support the conformational selection mechanism postulated. The approach gives direct access to two parameters of a ligand-receptor interaction: the off rate and the population of the small molecule-receptor complex. A detailed description of the kinetics underlying the ligand binding process is of crucial importance to fully understanding a riboswitch's function and to evaluate potential new antibiotics candidates targeting the noncoding RNA species. Ligand-detected NMR relaxation dispersion experiments represent a valuable diagnostic tool for the characterization of binding mechanisms., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Pre-queuosine or queuine (preQ1) is a guanine derivative that is involved in the biosynthetic pathway of the hypermodified tRNA nucleoside queuosine (Que). The core structure of preQ1 is represented by 7-(aminomethyl)-7-deazaguanine (preQ1 base). Here, we report the synthesis of three preQ1 base derivatives with complementary (15)N-labeling patterns, utilizing [(15)N]-KCN, [(15)N]-phthalimide, and [(15)N3]-guanidine as cost-affordable (15)N sources. Such derivatives are required to explore the binding process of the preQ1 base to RNA targets using advanced NMR spectroscopic methods. PreQ1 base specifically binds to bacterial mRNA domains and thereby regulates genes that are required for queuosine biosynthesis.