Impact of dengue virus (serotype DENV-2) infection on liver of BALB/c mice: A histopathological analysis

In this research, we characterized the histopathological impact of dengue virus (serotype DENV-2) infection in livers of BALB/c mice. The mice were infected with different doses of DENV-2 via intraperitoneal injection and liver tissues were processed for histological analyses and variation was documented. In the BALB/c mouse model, typical liver tissues showed regular hepatocyte architecture, with normal endothelial cells surrounding sinusoid capillary. Based on histopathological observations, the liver sections of BALB/c mice infected by DENV-2 exhibited a loss of cell integrity, with a widening of the sinusoidal spaces. There were marked increases in the infiltration of mononuclear cells. The areas of hemorrhage and micro- and macrovesicular steatosis were noted. Necrosis and apoptosis were abundantly present. The hallmark of viral infection, i.e., cytopathic effects, included intracellular edema and vacuole formation, cumulatively led to sinusoidal and lobular collapse in the liver. The histopathological studies on autopsy specimens of fatal human DENV cases are important to shed light on tissue damage for preventive and treatment modalities, in order to manage future DENV infections. In this framework, the method present here on BALB/c mouse model may be used to study not only the effects of infections by other DENV serotypes, but also to investigate the effects of novel drugs, such as recently developed nano-formulations, and the relative recovery ability with intact immune functions of host.     

Sample preparation method for tissue based proteomic analysis of <Emphasis Type="Italic">Azolla microphylla</Emphasis>

The nitrogen fixing aquatic pteridophyte Azolla is used as biofertilizer for rice paddy. It is also used as poultry and cattle feed due to high protein content. However, its mass cultivation and exploitation is constrained due to the abiotic stress conditions it is exposed to. The system is interesting due to the presence of symbiotic nitrogen fixing cyanobacteria and its interaction with the carbon fixing host. Therefore these interactions have to be studied at the molecular level using advanced techniques. Proteomics is a technique which can be employed to reveal the mechanism of cross talk between the host and its symbiont as well as its response to abiotc stress. The primary step that contributes to successful proteomic analysis is standardization of sound protocols for protein extraction and sufficient yield to initiate proteomic studies using 2-dimensional electrophoresis. However, reports are not available on the protein extraction procedures in Azolla. Therefore in the present study we attempted to optimize protein extraction protocol in the whole plant, roots and the chloroplast of Azolla microphylla using phenol extraction, TCA-acetone and phosphate buffer methods. Our studies showed the efficacy of phenol extraction method in terms of maximum yield and resolution of proteins in Azolla.     

<Emphasis Type="Italic">Trichoderma lixii ID11D</Emphasis> seed biopriming mitigates dose dependent salt toxicity in maize

Certain number of commercial products has been developed to grow stress resistant plants for the sustainability of agriculture in current era with full of energy dependency and hunger besides global warming. Given the risk of these products on the microbial environment in the rhizosphere and food security of mankind due to the accumulated chemical pollution through the food web, organic fungal plant growth promoting agents might be used. Hence, effects of Trichoderma lixii ID11D (TXD), our local fungal isolate on Zea mays L. cv. Samada 07 as a seed biopriming agent was investigated under dose dependent NaCl stress in this study. Fungus was characterized based on ITS (internal transcribed spacer) regions via clustering approach after isolated from tea plantation area. The higher the NaCl concentration, the more effective the TXD was observed. Improved electron transport rate (ETR), maximum quantum efficiency of PS II (Fv/Fm), the effective quantum yield of PS2 (ΦPS2), photochemical quenching (qP) and decreased non-photochemical quenching (NPQ) was detected in TXD primed plants after NaCl expose. TXD seed biopriming increased the lengths, fresh and dry weights of root/shoots and decreased the lipid peroxidation (MDA) remarkably. Non-enzymatic pathway was found to be more effective than enzymatic one for seed bioprimed plants proven by higher RWC, soluble protein, proline, chlorophyll, carotenoid, and less H₂O₂ and MDA levels under each dose of NaCl. Detected phenotypic and biochemical improvements pave the way of the potential usage of the formulated fungus biopreperations as a pre-harvest agent in agriculturally important cereals in the future and going beyond lab-based level.     

Identification and comparative analysis of <Emphasis Type="Italic">Brassica juncea</Emphasis> pathogenesis-related genes in response to hormonal,biotic and abiotic stresses

Pathogenesis-related proteins (PRs) are the antimicrobial proteins which are commonly used as signatures of defense signaling pathways and systemic acquired resistance. However, in Brassica juncea most of the PR proteins have not been fully characterized and remains largely enigmatic. In this study, full-length cDNA sequences of SA (PR1, PR2, PR5) and JA (PR3, PR12 and PR13) marker genes were isolated from B. juncea and were named as BjPR proteins. BjPR proteins showed maximum identity with known PR proteins of Brassica species. Further, expression profiling of BjPR genes were investigated after hormonal, biotic and abiotic stresses. Pre-treatment with SA and JA stimulators downregulates each other signature genes suggesting an antagonistic relationship between SA and JA in B. juncea. After abscisic acid (ABA) treatment, SA signatures were downregulated while as JA signature genes were upregulated. During Erysiphe cruciferarum infection, SA- and JA-dependent BjPR genes showed distinct expression pattern both locally and systemically, thus suggesting the activation of SA- and JA-dependent signaling pathways. Further, expression of SA marker genes decreases while as JA-responsive genes increases during drought stress. Interestingly, both SA and JA signature genes were induced after salt stress. We also found that BjPR genes displayed ABA-independent gene expression pattern during abiotic stresses thus providing the evidence of SA/JA cross talk. Further, in silico analysis of the upstream regions (1.5 kb) of both SA and JA marker genes showed important cis-regulatory elements related to biotic, abiotic and hormonal stresses.     

Amino acid transporter mutants of Arabidopsis provides evidence that a non‐mycorrhizal plant acquires organic nitrogen from agricultural soil

Although organic nitrogen (N) compounds are ubiquitous in soil solutions, their potential role in plant N nutrition has been questioned. We performed a range of experiments on Arabidopsis thaliana genetically modified to enhance or reduce root uptake of amino acids. Plants lacking expression of the Lysine Histidine Transporter 1 (LHT1) displayed significantly lower contents of ¹³C and ¹⁵N label and of U‐¹³C₅,¹⁵N₂ L‐glutamine, as determined by liquid chromatography–mass spectrometry when growing in pots and supplied with dually labelled L‐glutamine compared to wild type plants and LHT1‐overexpressing plants. Slopes of regressions between accumulation of ¹³C‐labelled carbon and ¹⁵N‐labelled N were higher for LHT1‐overexpressing plants than wild type plants, while plants lacking expression of LHT1 did not display a significant regression between the two isotopes. Uptake of labelled organic N from soil tallied with that of labelled ammonium for wild type plants and LHT1‐overexpressing plants but was significantly lower for plants lacking expression of LHT1. When grown on agricultural soil plants lacking expression of LHT1 had the lowest, and plants overexpressing LHT1 the highest C/N ratios and natural δ¹⁵N abundance suggesting their dependence on different N pools. Our data show that LHT1 expression is crucial for plant uptake of organic N from soil.     

CaCO3 and MgCO3 Dissolving Halophilic Bacteria

In the current study, fifteen halophilic and halotolerant bacteria were isolated from salt-affected soil of ?anl?urfa, Turkey. The isolates were characterized by conventional and molecular techniques (16S rDNA sequence analyses) as belonging to seven different genus including Bacillus (5 isolates), Halobacillus (1 isolate), Oceanobacillus (2 isolates), Halomonas (3 isolate), Nesterenkonia (1 isolate), Chromohalobacter (2 isolates) and Jeotgalibacillus (2 isolates). According to the results obtained, the investigated bacterial strains have high salt tolerance and significant enzyme activities which can improve soil nutrient cycling and fertility. Furthermore, these bacterial strains have been investigated for their ability to dissolve common salts available in salt-affected soils. Salt dissolving experiments showed that two Chromohalobacter isolates were able to dissolve CaCO₃ and one of the Halomonas isolate was able to dissolve both CaCO₃ and MgCO₃. As these bacterial isolates can dissolve CaCO₃ and MgCO₃, the availability of Ca²⁺ and Mg²⁺ ions may increase which can enhance the removal of the excess Na⁺ in soil profile.     

A computational modeling of Raman radial breathing-like mode frequencies of fullerene encapsulated inside single-walled carbon nanotubes

Raman radial breathing-like mode (RBLM) frequencies of an infinite nanopeapods are calculated within the framework of a continuum-molecular based model. The nanotube-fullerene interaction is modeled via the Lennard-Jones interatomic potential. An analytical formulation is developed and is justified due to its good agreement with the experimental and atomistic-based results. Furthermore, we propose new relationships for the van der Waals (vdW) interaction coefficients between the atoms of this hybrid nanostructure. Numerical results are also obtained for various nanopeapods on the basis of the present formulation. The RBLM frequency upshifts are predicted for small single-walled carbon nanotubes (SWCNTs). The frequency shifts can be adequately explained by the vdW intermolecular interactions acting between the fullerene and the SWCNTs atoms. To the best of our knowledge, a simple theoretical method which can predict the Raman RBLM frequencies of the nanopeapods with high precision has not been provided hitherto. We believe that the present study is likely to fill the gap.     

Enhanced Electrocatalysis for Energy‐Efficient Hydrogen Production over CoP Catalyst with Nonelectroactive Zn as a Promoter

As a non‐toxic species, Zn fulfills a multitude of biological roles, but its promoting effect on electrocatalysis has been rarely explored. Herein, the theoretic predications and experimental investigations that nonelectroactive Zn behaves as an effective promoter for CoP‐catalyzed hydrogen evolution reaction (HER) in both acidic and alkaline media is reported. Density function theory calculations reveal that Zn doing leads to more thermal‐neutral hydrogen adsorption free energy and thus enhanced HER activity for CoP catalyst. Electrochemical tests show that a Zn_0.08Co_0.92P nanowall array on titanium mesh (Zn_0.08Co_0.92P/TM) needs overpotentials of only 39 and 67 mV to drive a geometrical catalytic current of 10 mA cm^‐2 in 0.5 m H₂SO₄ and 1.0 m KOH, respectively. This Zn_0.08Co_0.92P/TM is also superior in activity over CoP/TM for urea oxidation reaction (UOR), driving 115 mA cm^‐2 at 0.6 V in 1.0 m KOH with 0.5 m urea. The high HER and UOR activity of this bifunctional electrode enables a Zn_0.08Co_0.92P/TM‐based two‐electrode electrolyzer for energy‐saving hydrogen production, offering 10 mA cm^‐2 at a low voltage of 1.38 V with strong long‐term electrochemical stability.     

Production and partial characterization of biosurfactant produced by Streptomyces sp. R1

The present study focused on developing a wild-type actinomycete isolate as a model for a non-pathogenic filamentous producer of biosurfactants. A total of 33 actinomycetes isolates were screened and their extracellular biosurfactants production was evaluated using olive oil as the main substrate. Out of 33 isolates, 32 showed positive results in the oil spreading technique (OST). All isolates showed good emulsification activity (E₂₄) ranging from 84.1 to 95.8%. Based on OST and E₂₄ values, isolate R1 was selected for further investigation in biosurfactant production in an agitated submerged fermentation. Phenotypic and genotypic analyses tentatively identified isolate R1 as a member of the Streptomyces genus. A submerged cultivation of Streptomyces sp. R1 was carried out in a 3-L stirred-tank bioreactor. The influence of impeller tip speed on volumetric oxygen transfer coefficient (k _L a), growth, cell morphology and biosurfactant production was observed. It was found that the maximum biosurfactant production, indicated by the lowest surface tension measurement (40.5 ± 0.05 dynes/cm) was obtained at highest k _L a value (50.94 h⁻¹) regardless of agitation speed. The partially purified biosurfactant was obtained at a concentration of 7.19 g L⁻¹, characterized as a lipopeptide biosurfactant and was found to be stable over a wide range of temperature (20–121 °C), pH (2–12) and salinity [5–20% (w/v) of NaCl].