Exogenous application of β-sitosterol mediated growth and yield improvement in water-stressed wheat (Triticum aestivum) involves up-regulated antioxidant system

Journal of Plant Research - Water stress reduces crop production significantly, and climate change has further aggravated the problem mainly in arid and semi-arid regions. This was the first study...     

Interaction of Na2B12H11SH with dimyristoyl phosphatidylcholine liposomes

Previous investigations have revealed that the boron cluster compound Na₂B₁₂H₁₁SH (BSH) is very potent in causing major structural rearrangements of and leakage from phosphatidylcholine liposomes. This somewhat unexpected finding is interesting from a fundamental point of view and may also constitute the basis of future important pharmaceutical/medical applications of BSH. In order to further explore the BSH-lipid interaction, we have studied the effects caused by BSH on dimyristoyl phosphatidylcholine (DMPC) liposomes.Cryo-transmission electron microscopy showed that BSH induces aggregation, membrane rupture and increasing wall thickness of the liposomes. Differential scanning calorimetry revealed a BSH dependent shift of the gel to liquid crystalline phase transition temperature of DMPC. The zeta potential of the liposomes decreases with increasing BSH concentrations, and an apparent dissociation constant of 0.23 mM was found.BSH caused leakage of liposome-encapsulated carboxyfluorescein; leakage was higher at 23 °C (near the phase transition temperature) than at 15 °C and 37 °C. It induced lipid mixing only at very high concentrations.     

Functional Analysis of the VirSR Phosphorelay from Clostridium perfringens

Toxin production in Clostridium perfringens is controlled by the VirSR two-component signal transduction system, which comprises the VirS sensor histidine kinase and the VirR response regulator. Other studies have concentrated on the elucidation of the genes controlled by this network; there is little information regarding the phosphorelay cascade that is the hallmark of such regulatory systems. In this study, we have examined each step in this cascade, beginning with autophosphorylation of VirS, followed by phosphotransfer from VirS to VirR. We also have studied the effects of gene dosage and phosphorylation in vivo. We have used random and site-directed mutagenesis to identify residues in VirS that are important for its function and have identified a region in the putative sensory domain of VirS that appeared to be essential for function. In vitro phosphorylation studies showed that VirSc, a truncated VirS protein that lacked the N-terminal sensory domain, was capable of autophosphorylation and could subsequently act as a phosphodonor for its cognate response regulator, VirR. Conserved residues of both VirS and VirR, including the D57 residue of VirR, were shown to be essential for this process. By use of Targetron technology, we were able to introduce a single copy of virR or virR_D57N onto the chromosome of a virR mutant of C. perfringens. The results showed that in vivo, when virR was present in single copy, the production of wild-type levels of perfringolysin O was dependent on the presence of virS and an unaltered D57 residue in VirR. These results provide good evidence that phosphorylation is critical for VirR function.     

Confirmation and refinement of a QTL on BTA5 affecting milk production traits in the Fleckvieh dual purpose cattle breed

We analysed a QTL affecting milk yield (MY), milk protein yield (PY) and milk fat yield (FY) in the dual purpose cattle breed Fleckvieh on BTA5. Twenty-six microsatellite markers covering 135 cM were selected to analyse nine half-sib families containing 605 sons in a granddaughter design. We thereby assigned two new markers to the public linkage map using the CRI-MAP program. Phenotypic records were daughter yield deviations (DYD) originating from the routinely performed genetic evaluations of breeding animals. To determine the position of the QTL, three different approaches were applied: interval mapping (IM), linkage analysis by variance component analysis (LAVC), and combined linkage disequilibrium (LD) and linkage (LDL) analysis. All three methods mapped the QTL in the same marker interval ( BM2830-ETH152 ) with the greatest test-statistic value at 118, 119.33 and 119.33 cM respectively. The positive QTL allele simultaneously increases DYD in the first lactation by 272 kg milk, 7.1 kg milk protein and 7.0 kg milk fat. Although the mapping accuracy and the significance of a QTL effect increased from IM over LAVC to LDL, the confidence interval was large (13, 20 and 24 cM for FY, MY and PY respectively) for the positional cloning of the causal gene. The estimated averages of pair wise marker LD with a distance <5 cM were low (0.107) and reflect the large effective population size of the Fleckvieh subpopulation analysed. This low level of LD suggests a need for increase in marker density in following fine mapping steps.     

Development,consumption rates and reproductive biology of <Emphasis Type="Italic">Orius albidipennis</Emphasis> reared on various prey

The predatory bug Orius albidipennis (Reuter) (Hemiptera: Anthocoridae) has tremendous potential as a biological control agent, especially in its native range around the Mediterranean Basin and East Africa. The need to exploit native biological control agents is growing in importance as concerns over the introduction of non-native species continue to increase. However, little is known of the effects of different prey on development and reproduction of O. albidipennis compared with other species of Orius. Therefore, we compared the development, survival, reproductive biology, and prey consumption of O. albidipennis when fed eggs of Ephestia kuehniella Zeller, Tetranychus urticae Koch, and Trialeurodes vaporariorum (Westwood), and larvae of Gynaikothrips ficorum (Marchal), under laboratory of 26 ± 1°C, 60 ± 10% RH and 16L:8D photoperiod. Individuals were reared from the neonate stage until death on one of the four prey types. The type of prey had profound effects on all measured performance traits. The highest survival rate was recorded for nymphs that were fed on E. kuehniella eggs, while the lowest survival rate was observed for those fed on T. vaporariorum eggs. The shortest nymphal period was recorded for nymphs fed on E. kuehniella eggs, while the longest was measured for those fed on T. urticae eggs. During the nymphal period, O. albidipennis consumed significantly more eggs of T. urticae than other prey types, whereas the lowest number of consumed prey were eggs of E. kuehniella. Adult females and males consumed significantly more T. urticae eggs than other types of prey. However, Orius albidipennis females showed the highest fecundity when fed on E. kuehniella eggs, and the lowest when fed on T. vaporariorum eggs. Adult females and males that fed on G. ficorum larvae had significantly longer life spans compared with those fed other prey. Because of their relatively rapid development and high fecundity, O. albidipennis fed E. kuehniella eggs had a significantly higher net reproductive rate (R_o) and intrinsic rate of increase (r _m ) than O. albidipennis fed other prey types. Overall, eggs of E. kuehniella were the most suitable diet for nymphs and adults of O. albidipennis. Although less suitable, O. albidipennis could survive and reproduce on the other prey types, which is a favourable attribute in biological control agents. These results on the effect of different prey types on development and reproduction of O. albidipennis will also contribute to the development of mass rearing programs for biological control agents in developing countries, such as Egypt.     

1,10-Phenanthroline-dithiolate mixed ligand transition metal complexes. Synthesis, characterization and EPR spectroscopy

A series of new N₂S₂ mixed ligand transition metal complexes, where N₂ is phenanthroline and S₂ is 1,2-dithiooxalate (dto) or 1,2-dithiosquarate (dtsq), has been synthesized and characterized. IR spectra reveal that the 1,2-dithiolate ligands are coordinated via the sulfur atoms forming a N₂S₂ coordination sphere. The copper(II) complex [Cu(phen)(dto)] was studied by EPR spectroscopy as a diamagnetically diluted powder. The diamagnetic dilution resulted from doping of the copper complex into the isostructural host lattice of the nickel complex [Ni(phen)(dto)]. The electronic situation in the frontier orbitals of the copper complex calculated from the experimental data is compared to the results of EHT and DFT calculations. Furthermore, one side product, chlorobis(1,10-phenanthroline)copper(I) ethanol solvate hydrate [(phen)₂CuCl]·C₂H₅OH·H₂O, was formed by a reduction process and characterized by X-ray diffraction. In the crystal packing one-dimensional columns of dimers are formed, stabilized by significant π-π interactions.     

Synthesis of AZT analogues: 7-(3-azido-2-hydroxypropyl)-, 7-(3-amino-2-hydroxypropyl)-,7-(3-triazolyl-2-hydroxypropyl)theophylline

Nucleophilic displacement of the tosyloxy group in 7-(2-hydroxy-3-p-toluenesulfonyloxypropyl)theophylline (1) with azide anion afforded 7-(3-azido-2-hydroxypropyl)theophylline (2). Reduction of the 3-azido group in 2 with Ph3P/Py/NH4OH afforded the 3-amino derivative 4, alternatively obtained by regioselective amination of 7-(2,3-epoxypropyl)theophylline (3). Selective acetylation of 4 gave the N-acetyl derivative 5. 1,3-Dipolar cycloaddition of the azide group in 2 with N1-propargyl thymine (6) afforded the regioisomeric triazole 7.     

Expression of recombinant goldfish glutamic acid decarboxylase 65 and evidence for differential pH and PLP responsiveness compared to the human enzyme

Variability of taurine (2-aminoethane sulfonic acid) was studied as a function of size in the mussel Mytilus galloprovincialis and tissue specificity. Isometric and/or allometric relationships were established with regard to total soft mass of the mussels between 20 and 60 mm shell length. Relative amounts of taurine dropped significantly with increasing mass of whole soft tissues with an allometric coefficient value of -0.15. The inverse relationship between taurine and increasing size of mussels was confirmed for gill epithelium and labial palp (allometric coefficient values of -0.16 and -0.10, respectively), tissues that, in turn, represented isometric functions with regard to total soft mass. Although relative amounts of taurine were significantly different in digestive gland, mantle and foot, relationships with increasing size of mussels remained unchanged in these tissues. Gill area of mussels was related to soft mass with an allometric coefficient of 0.70 by 2D Image Analysis, but increased to 0.85 when introducing a third dimension, i.e. gill thickness. Results are discussed according to gill structure analysis and taurine functionality.