Effects of temperature on development,survival, longevity,and fecundity of Serangium japonicum (Coleoptera: Coccinellidae), a predator of Bemisia tabaci Gennadius (Homoptera: Aleyrodidae)

In this study, we evaluated the effect of temperature on the development and reproductive biology of Serangium japonicum (Coleoptera: Coccinellidae) at seven constant temperature regimes (17, 20, 23, 26, 29, 32 and 35°C) for its effect as a predator of Bemisia tabaci (Homoptera: Aleyrodidae). Results indicated that the duration of the egg, larval and pupal stages were significantly affected by temperature. The developmental time gradually declined with the increase of temperature from 17 to 29°C, however an extension in the developmental periods was observed in the temperature range of 32 to 35°C. The survival rates of different insect stages were stable at temperatures between 20 and 32°C; however at extreme temperatures of 35°C, a sharp decrease was evident. The highest fecundity of the female (387.2 eggs per female) was recorded at 20°C. Based on these results, life tables of S. japonicum were constructed for temperatures in the range 20–35°C. The maximum reproductive rate (R ₀=279.9) occurred at 26°C. The maximum values for innate capacity for increase (r _m=0.1131) and the finite rate of increase (λ=1.1197) occurred at 29°C. The mean generation time (T) decreased with increased temperature, the longest of which was 76.0 days (at 20°C) and the shortest was 36.6 days (at 32°C). These results offer valuable insight on the importation and establishment of S. japonicum into new environments with diverse temperature regimes.     

Pyrazinamide resistance and mutations L19R,R140H,and E144K in Pyrazinamidase of Mycobacterium tuberculosis

Pyrazinamide (PZA) is an important component of first-line antituberculosis drugs activated by Mycobacterium tuberculosis pyrazinamidase (PZase) into its active form pyrazinoic acid. Mutations in the pncA gene have been recognized as the major cause of PZA resistance. We detected some novel mutations, Leucine19Arginine (L19R), Arginine140Histidine (R140H), and Glutamic acid144 Lysine (E144K), in the pncA gene of PZA-resistant isolates in our wet lab PZA drug susceptibility testing and sequencing. As the molecular mechanism of resistance of these variants has not been reported earlier, we have performed multiple analyses to unveil different mechanisms of resistance because of PZase mutations L19R, R140H, and E144K. The mutants and native PZase structures were subjected to comprehensive computational molecular dynamics (MD) simulations at 100 nanoseconds in apo and drug-bound form. Mutants and native PZase binding pocket were compared to observe the consequence of mutations on the binding pocket size. Hydrogen bonding, Gibbs free energy, and natural ligand Fe ⁺² effect were also analyzed between native and mutants. A significant variation between native and mutant PZase structure activity was observed. The native PZase protein docking score was found to be the maximum, showing strong binding affinity in comparison with mutants. MD simulations explored the effect of the variants on the biological function of PZase. Hydrogen bonding, metal ion Fe ⁺² deviation, and fluctuation also seemed to be affected because of the mutations L19R, R140H, and E144K. The variants L19R, R140H, and E144K play a significant role in PZA resistance, altering the overall activity of native PZase, including metal ion Fe ⁺² displacement and free energy. This study offers valuable evidence for better management of drug-resistant tuberculosis.     

Targeting the ROS/PI3K/AKT/HIF‐1α/HK2 axis of breast cancer cells: Combined administration of Polydatin and 2‐Deoxy‐d‐glucose

It is well established that cancer cells depend upon aerobic glycolysis to provide the energy they need to survive and proliferate. However, anti‐glycolytic agents have yielded few positive results in human patients, in part due to dose‐limiting side effects. Here, we discovered the unexpected anti‐cancer efficacy of Polydatin (PD) combined with 2‐deoxy‐D‐glucose (2‐DG), which is a compound that inhibits glycolysis. We demonstrated in two breast cell lines (MCF‐7 and 4T1) that combination treatment with PD and 2‐DG induced cell apoptosis and inhibited cell proliferation, migration and invasion. Furthermore, we determined the mechanism of PD in synergy with 2‐DG, which decreased the intracellular reactive oxygen (ROS) levels and suppressed the PI3K/AKT pathway. In addition, the combined treatment inhibited the glycolytic phenotype through reducing the expression of HK2. HK2 deletion in breast cancer cells thus improved the anti‐cancer activity of 2‐DG. The combination treatment also resulted in significant tumour regression in the absence of significant morphologic changes in the heart, liver or kidney in vivo. In summary, our study demonstrates that PD synergised with 2‐DG to enhance its anti‐cancer efficacy by inhibiting the ROS/PI3K/AKT/HIF‐1α/HK2 signalling axis, providing a potential anti‐cancer strategy.     

CD45-mediated signaling pathway is involved in Rhizoctonia bataticola lectin (RBL)-induced proliferation and Th1/Th2 cytokine secretion in human PBMC

We earlier reported the mitogenic and immunostimulatory activities of Rhizoctonia bataticola lectin (RBL), purified from phytopathogenic fungus R. bataticola in human PBMC. The lectin demonstrates specificity towards glycoproteins containing complex N-glycans. Since CD45-protein tyrosine phosphatase that abundantly expresses N-glycans is important in T-cell signaling, the study aimed to investigate the involvement of CD45 in the immunomodulatory activities of RBL. Flowcytometry and confocal microscopy studies revealed that RBL exhibited binding to PBMC and colocalized with CD45. The binding was comparable in cells expressing different CD45 isoforms-RA, -RB and -RO. CD45 blocking antibody reduced the binding and proliferation of PBMC induced by RBL. CD45-PTPase inhibitor dephostatin inhibited RBL-induced proliferation, expression of CD25 and pZAP-70. RBL-induced secretion of Th1/Th2 cytokines were significantly inhibited in presence of dephostatin. Also, dephostatin blocked phosphorylation of p38MAPK and STAT-5 that was crucial for the biological functions of RBL. The study demonstrates the involvement of CD45-mediated signaling in RBL-induced PBMC proliferation and Th1/Th2 cytokine secretion through activation of p38MAPK and STAT-5.     

Over Expression of Rice chitinase Gene in Transgenic Peanut (Arachis hypogaea L.) Improves Resistance Against Leaf Spot

A Rice chitinase-3 under enhance version of CaMV 35S was introduced into peanut (Arachis hypogaea L.) through Agrobacterium mediation. Agrobacterium tumefaciens strain LB4404 was used harboring the binary vector (pB1333-EN4-RCG3) containing the chitinase (chit) and hygromycin resistance (hpt) gene as selectable marker. Putative transgenic shoots were regenerated and grown on MS medium supplemented with 5 mg/l BAP, 1 mg/l kinetin, and 30 mg/l hygromycin. Elongated shoots were examined for the presence of the integrated rice chitinase gene along with hygromycin gene as selectable. The integration pattern of transgene in the nuclear genome of the putative transformed plants (T₀) was confirmed through Southern hybridization analysis of the genomic DNA. Survival rate of the in vitro regenerated plantlets was over 60% while healthy putatively transgenic (T₀) plants with over 42% transformation frequency were produced through Agrobacterium mediated gene transfer of the rice chitinase gene and all the plants flowered and set seed normally. T1 plants were tested for resistance against Cercospora arachidicola by infection with the microspores. Transgenic strains exhibited a higher resistance than the control (non-transgenic plants). chitinase gene expression in highly resistant transgenic strains was compared to that of a susceptible control. A good correlation was observed between chitinase activity and fungal pathogen resistance.     

Characterization of the New World monkey homologues of human poliovirus receptor CD155

In contrast to Old World monkeys, most New World monkeys (NWMs) are not susceptible to poliovirus (PV), regardless of the route of infection. We have investigated the molecular basis of restricted PV pathogenesis of NWMs with two kidney cell lines of NWMs, TMX (tamarin) and NZP-60 (marmoset), and characterized their PV receptor homologues. TMX cells were susceptible to infection by PV1 (Mahoney) and PV3 (Leon) but not by PV2 (Lansing). Binding studies to TMX cells indicated that the formation of PV/receptor complexes increased when measured first at 4 degrees C and then at 25 degrees C, whereas PV2 did not significantly bind to TMX cells at either temperature. On the other hand, NZP-60 cells were not susceptible to infection by any of the PV serotypes. However, a low amount of PV1 bound to NZP-60 cells at 4 degrees C, but there was no increase of binding at 25 degrees C. In contrast, both NWM cell lines supported genome replication and virion formation when transfected with viral RNAs of either serotype, an observation indicating that infection was blocked in receptor-virus interaction. To overcome the receptor block, we substituted 3 amino acids in the marmoset receptor (nCD155), H80Q, N85S, and P87S, found in the human PV receptor, hCD155. Cells expressing the mutant receptor (L-nCD155mt) were now susceptible to infection with PV1, which correlated with an increase in PV1-bound receptor complexes from 4 degrees C to 25 degrees C. L-nCD155mt cells were, however, still resistant to PV2 and PV3. These data show that an increase in the formation of PV/receptor complexes, when measured at 4 degrees C and at 25 degrees C, correlates with and is an indicator of successful infection at 37 degrees C, suggesting that the complex formed at 25 degrees C may be an intermediate in PV uptake.     

Toxic Effect of Cadmium on Rice as Affected by Nitrogen Fertilizer Form

A nutrient solution experiment was conducted to determine the influence of N forms on growth, oxidative stress, and Cd and N uptake in rice plants. The treatments were consisted of two Cd levels (0 and 1 μmol) and three N forms (NH₄)₂SO₄, NH₄NO₃ and Ca(NO₃)₂. The results indicated that without Cd addition in the culture solution, the N forms had no significant effect on all measured parameters, including plant growth, photosynthetic traits, malondialdehyde (MDA) concentration, superoxide dismutase (SOD) activity, and Cd and N concentration, while Cd addition in the medium resulted in significant differences in measured parameters among the three forms of N fertilizers. The least inhibition of growth was noted in (NH₄)₂SO₄-fed plants, and the largest in Ca(NO₃)₂-fed plants, when plants were exposed to Cd stress. The highest photosynthetic rate and chlorophyll content was also recorded in (NH₄)₂SO₄-fed plants. Addition of Cd caused a remarkable increase in SOD activity and MDA content in plants, and the extent of increase varied with N form, with (NH₄)₂SO₄-fed plants being smallest. In comparison with the control plants, the N concentration in roots and shoots was not significantly affected in (NH₄)₂SO₄-fed plants, but significant decrease in root N concentration was found for the NH₄NO₃ and Ca(NO₃)₂-fed plants under Cd stress. Moreover, the significant differences were also noted among the three N forms in both root and shoot Cd concentrations, with (NH₄)₂SO₄-fed plants being the lowest. The results indicated that the toxic effect of Cd on rice varied with the form of N fertilizer.     

Post-embryonic pericardial cells of <Emphasis Type="Italic">Drosophila</Emphasis> are required for overcoming toxic stress but not for cardiac function or adult development

The Drosophila heart is composed of two cell types: cardioblasts (CB) and pericardial cells (PC). Whereas CBs act to maintain rhythmic contractions, the functions of accessory PCs are not clear. The close association between these two cell types has led to speculation of a cardio-regulatory role for PCs. However, we find that viability and cardiac function are normal in larvae following post-embryonic ablation of PCs by induced cell death. Removal of PCs during the larval instars or before metamorphosis results in viable and fertile adults. Interestingly, such animals have a reduced lifespan and increased sensitivity to toxic chemicals. Thus, although PCs may have an embryonic role in cardiogenesis, they do not appear to play a part later in cardiac function as suggested. However, the role of PCs in the uptake and sequestering of toxins, their sensitivity to toxic stress and the decreased lifespan of animals without PCs indicate the importance of PCs in organismal homeostasis. D.D. is supported by a CSIR-SPM fellowship. This work was funded by the JNCASR, the Council of Scientific and Industrial Research, and the Department of Biotechnology, Government of India.     

Influence of experimental extreme water pulses on greenhouse gas emissions from soils

Climate models predict increased frequency and intensity of storm events, but it is unclear how extreme precipitation events influence the dynamics of soil fluxes for multiple greenhouse gases (GHGs). Intact soil mesocosms (0–10 cm depth) from a temperate forested watershed in the piedmont region of Maryland [two upland forest soils, and two hydric soils (i.e., wetland, creek bank)] were exposed to experimental water pulses with periods of drying, forcing soils towards extreme wet conditions under controlled temperature. Automated measurements (hourly resolution) of soil CO₂, CH₄, and N₂O fluxes were coupled with porewater chemistry analyses (i.e., pH, Eh, Fe, S, NO₃ ^?), and polymerase chain reaction–denaturing gradient gel electrophoresis to characterize changes in microbial community structure. Automated measurements quantified unexpected increases in emissions up to 245% for CO₂ (Wetland), >23,000% for CH₄ (Creek), and >110,000% for N₂O (Forest Soils) following pulse events. The Creek soil produced the highest soil CO₂ emissions, the Wetland soil produced the highest CH₄ emissions, and the Forest soils produced the highest N₂O emissions during the experiment. Using carbon dioxide equivalencies of the three GHGs, we determined the Creek soil contributed the most to a 20-year global warming potential (GWP; 30.3%). Forest soils contributed the most to the 100-year GWP (up to 53.7%) as a result of large N₂O emissions. These results provide insights on the influence of extreme wet conditions on porewater chemistry and factors controlling soil GHGs fluxes. Finally, this study addresses the need to test biogeochemical thresholds and responses of ecosystem functions to climate extremes.     

Characterization of a Novel Enterovirus Serotype and an Enterovirus EV-B93 Isolated from Acute Flaccid Paralysis Patients

Non-polio enteroviruses (NPEVs) are among the most common viruses infecting humans worldwide. Most of these infections are asymptomatic but few can lead to systemic and neurological disorders like Acute Flaccid Paralysis (AFP). Acute Flaccid Paralysis is a clinical syndrome and NPEVs have been isolated frequently from the patients suffering from AFP but little is known about their causal relationship. The objective of this study was to identify and characterize the NPEV serotypes recovered from 184 stool samples collected from AFP patients in Federally Administered Tribal Areas (FATA) in north-west of Pakistan. Overall, 44 (95.6 %) isolates were successfully typed through microneutralization assay as a member of enterovirus B species including echovirus (E)-2, E-3, E-4, E-6, E-7, E-11, E-13, E-14, E-21 and E-29 while two isolates (PAK NIH SP6545B and PAK NIH SP1202B) remained untypeable. The VP1 and capsid regions analysis characterized these viruses as EV-B93 and EV-B106. Phylogenetic analysis confirmed that PAK NIH isolates had high genetic diversity and represent distinct genotypes circulating in the country. Our findings highlight the role of NPEVs in AFP cases to be thoroughly investigated especially in high disease risk areas, with limited surveillance activities and health resources.