Pollination biology of Albizia lebbeck (L.) Benth. (Fabaceae: Mimosoideae) with reference to insect floral visitors

Indian siris, Albizia lebbeck (L.) Benth. (Fabaceae: Mimosoideae) has significant importance to human beings for its multipurpose use. Insects play a crucial role in the pollination biology of flowering plants. In the current study, we studied the pollination biology of A. lebbeck with special reference to insect floral visitors. The effectiveness of floral visitors was investigated in term of visitation frequency, visitation rate and pollen load during 2012 and 2013. In the second experiment, effect of pollinators on yield of A. lebbeck was studied in open and cage pollination experiments. Floral visitor fauna of A. lebbeck included eight-bees, two wasps, two flies, and two butterflies species. Among them, Apis dorsata, Apis florea, Amegilla cingulata, and Nomia oxybeloides had maximum abundance ranging from 349–492, 339–428, 291–342 and 235–255 numbers of individuals, respectively during two flowering seasons. A. dorsata had the highest visitation frequency (6.44 ± 0.49–8.78 ± 0.48 visits/flower/5min) followed by Amegilla cingulata (6.03 ± 0.43–7.99 ± 0.33 visits/flower/5min) and A. florea (3.61 ± 0.31–4.44 ± 0.18 visits/flower/5min). A. dorsata, N. oxybeloides, and Amegilla cingulata had the highest visitation rates (18.904 ± 1.53–11.43 ± 1.17 flower visited/min) and pollen load (15333 ± 336.22–19243 ± 648.45 pollen grains). The open pollinated flowers had significantly higher capsule weight (4.97 ± 0.21 g), seed weight (1.04 ± 0.05 g), seed numbers per pod (9.80 ± 0.34) and seed germination percentage (84.0 ± 1.78%) as compared to caged flowers. The results suggested bees especially A. dorsata, N. oxybeloides and Amegilla cingulata could be effective pollinators of A. lebbeck.     

Combined application of citric acid and 5-aminolevulinic acid improved biomass,photosynthesis and gas exchange attributes of sunflower (Helianthus annuus L.) grown on chromium contaminated soil

Abstract

Phytoremediation is an important technique to remove heavy metals from contaminated soils due to its efficiency and cost-effectiveness. The present study was conducted to assess the synergistic role of 5-aminolevulinic acid (ALA) and citric acid (CA) in improving the phyto-extraction of chromium (Cr) by sunflower. Sunflower plants were grown in soil, spiked with different concentrations of Cr (0, 5, 10, 20?mg kg^?1). Various concentrations of 5-ALA (0, 10, 20?mg L^?1) and CA (0, 2.5, 5?mM) were applied exogenously at juvenile stage. A significant decrease was observed in biomass and agronomic traits of sunflower under Cr stress alone. Further, Cr toxicity significantly decreased the plant growth, soluble proteins and photosynthetic pigments. However, exogenously applied ALA and CA significantly improved the plants’ physiological as well as agronomic attributes by lowering the production of reactive oxygen species and reducing electrolyte leakage. Moreover, Cr uptake was increased with increasing concentration of Cr in spiked soil, which was further enhanced by combined application of ALA and CA.     

MicroRNA Let‐7 targets the ecdysone signaling pathway E75 gene to control larval–pupal development in Bactrocera dorsalis

MicroRNAs (miRNAs) regulate various biological processes during insect developme nt;however, their role in larval-pupal development in oriental fruit fly, Bactrocera dorsalis (Hendel) remains unknown. In the current study, we address the biological function of a conserved miRNA, Bdo-Let-7 in the regulation of BdE75 gene, which belongs to the ecdysone signaling pathway and participates in the larval-pupal development in B. dorsalis. Using dual luciferase reporter assay in HEK293T cells we show that Bdo-Let-7 miRNA interacts with the 3' untranslated region of BdE75 gene and suppresses its expression. The Bdo-Let?7 and BdE75 are also co-expressed in the larval-pupal stages and in different tissues of B. dorsalis .In in vivo experiments, the injectio n of Bdo-Let-7 agomir and antagomir in third instar larvae down- and up-regulated the expression of BdE75、 respectively. The 20-hydroxyecdysone (20E) injection assay shows that 20E up-regulated the expression of Bdo-Let-7 on the 5th day of the larvae. Moreover, abnormal pupation and eclosion were observed after larval Bdo-Let-7 antagomir injection. Based on these results, we show that Bdo-Let-7 regulates the ecdysone signaling pathway through the exact dose of BdE75 gene, and is indispensable for normal larval-pupal development in B. dorsalis.     

Metal Ion-dependent Heavy Chain Transfer Activity of TSG-6 Mediates Assembly of the Cumulus-Oocyte Matrix

The matrix polysaccharide hyaluronan (HA) has a critical role in the expansion of the cumulus cell-oocyte complex (COC), a process that is necessary for ovulation and fertilization in most mammals. Hyaluronan is organized into a cross-linked network by the cooperative action of three proteins, inter-α-inhibitor (IαI), pentraxin-3, and TNF-stimulated gene-6 (TSG-6), driving the expansion of the COC and providing the cumulus matrix with its required viscoelastic properties. Although it is known that matrix stabilization involves the TSG-6-mediated transfer of IαI heavy chains (HCs) onto hyaluronan (to form covalent HC·HA complexes that are cross-linked by pentraxin-3) and that this occurs via the formation of covalent HC·TSG-6 intermediates, the underlying molecular mechanisms are not well understood. Here, we have determined the tertiary structure of the CUB module from human TSG-6, identifying a calcium ion-binding site and chelating glutamic acid residue that mediate the formation of HC·TSG-6. This occurs via an initial metal ion-dependent, non-covalent, interaction between TSG-6 and HCs that also requires the presence of an HC-associated magnesium ion. In addition, we have found that the well characterized hyaluronan-binding site in the TSG-6 Link module is not used for recognition during transfer of HCs onto HA. Analysis of TSG-6 mutants (with impaired transferase and/or hyaluronan-binding functions) revealed that although the TSG-6-mediated formation of HC·HA complexes is essential for the expansion of mouse COCs in vitro, the hyaluronan-binding function of TSG-6 does not play a major role in the stabilization of the murine cumulus matrix.     

From the Macro to the Micro: Gel Mapping to Differentiate between Sporozoites of Two Immunologically Distinct Strains of Eimeria maxima (Strains M6 and Guelph)

Two immunologically distinct strains of E. maxima were examined in this study: the M6 strain and the Guelph strain. The differential expression between the sporozoites of the two strains of E. maxima was determined by image analysis of 100 μg of protein from each strain separated by standard one- and conventional two-dimensional polyacrylamide gel electrophoresis. In addition to differences in both molecular weight and the electrophoretic mobility, differences in the intensity of polypeptide bands for example, GS 136.4 and M6 169 were explored. Pooled gels were prepared from each strain. A representative 2D-PAGE gel spanning a non-linear pH range of 3–10 of E. maxima strain M6 consisted of approximately 694 polypeptide spots with about 67 (9.6%) of the polypeptide spots being unique relative to the other strain. E. maxima strain GS had about 696 discernable polypeptide spots with 69 spots (9.9%) that differed from those of the M6 strain. In-depth characterization of the variable polypeptide spots; unique polypeptide spots (absence or presence) and shared polypeptide spots with modifications may lead to novel vaccine target in the form of multi-component, multi-stage, multi-immunovariant strains, multi-species subunit vaccine, and diagnostic probe for E. maxima.     

Brucellosis and Coxiella burnetii Infection in Householders and Their Animals in Secure Villages in Herat Province,Afghanistan: A Cross-Sectional Study

Background

Brucellosis and coxiellosis are known to be endemic in ruminant populations throughout Afghanistan, but information about their prevalence and factors that affect prevalence in householders and livestock under diverse husbandry systems and pastoral settings is sparse.

Methods/Principal Findings

We conducted a cross-sectional survey to investigate the seroprevalence of brucellosis and Coxiella burnetii in humans and livestock in six secure districts in Herat from 26^th December 2012–17^th January 2013. A total of 204 households with livestock were surveyed in six Kuchi and five sedentary type villages. Blood samples from 1,017 humans, 1,143 sheep, 876 goats and 344 cattle were tested for brucellosis and Q fever. About one in six households (15.7%) had at least one Brucella seropositive person, about one in eight households (12.3%) had at least one Brucella seropositive animal and about one in four (24.5%) had either seropositive animals or humans. Ninety-seven percent of households had at least one C. burnetii seropositive person and 98.5% of households had one or more C. burnetii seropositive animals. Forty- seven householders had serological evidence of exposure to both C. burnetii and Brucella and eight animals were serologically positive for both diseases. Drinking unpasteurised milk (OR 1.6), treating animals for ticks (OR 1.4), milking sheep (OR 1.4), male gender (OR 1.4) and seropositivity to Brucella (OR 4.3) were identified as risk factors for seropositivity to C. burnetii in householders. Household factors associated with households having either Brucella seropositive animals or humans were Kuchi households (OR 2.5), having ≤4 rooms in the house (OR 2.9) and not owning land (OR 2.9).

Conclusions

The results from this study provide baseline information for the planning and monitoring of future interventions against these diseases. The implementation of this study greatly improved collaboration, coordination and capability of veterinary and public health professionals from government, NGOs and donor funded projects.     

Exploring Early and Late Toxoplasma gondii Strain RH Infection by Two-Dimensional Immunoblots of Chicken Immunoglobulin G and M Profiles

Toxoplasma gondii is an intracellular apicomplexan parasite infecting warm-blooded vertebrate hosts, with only early infection stage being contained with drugs. But diagnosis differencing early and late infection was not available. In the present investigation, 2-dimensional immunobloting was used to explore early and late infections in chickens. The protein expression of T. gondii was determined by image analysis of the tachyzoites proteome separated by standard-one and conventional two-dimentional gel polyacrylamide electrophoresis (2D- PAGE). Pooled gels were prepared from tachyzoites of T. gondii. A representative gel spanning a pH range of 3-10 of the tachyzoite proteome consisted of 1306 distinct polypeptide spots. Two-dimensional electrophoresis (2-DE) combined with 2-DE immunoblotting was used to resolve and compare immunoglobulins (Igs) M & G patterns against Toxoplasma gondii strain RH (mouse virulent strain). Total tachyzoite proteins of T. gondii were separated by two-dimensional gel electrophoresis and analyzed by Western blotting for their reactivity with the 7 and 56 days post-infection (dpi) SPF chicken antisera. Different antigenic determinant patterns were detected during analysis with M and G immunoglobulins. Of the total number of polypeptide spots analyzed (1306 differentially expressed protein spots), 6.97% were identified as having shared antigenic polypeptide spots on immunoblot profiles with IgG and IgM antibodies regardless the time after infection. Furthermore, some of the immunoreactive polypeptide spots seemed to be related to the stage of infection. Interestingly, we found natural antibodies to toxoplasmic antigens, in addition to the highly conserved antigenic determinants that reacted with non-specific secondary antibody; goat anti-chicken IgG antibodies conjugated with horseradish peroxidase. In conclusion, unique reactive polypeptide spots are promising candidates for designation of molecular markers to discriminate early and late chicken infection.     

An Investigation on the Effect of Polyethylene Oxide Concentration and Particle Size in Modulating Theophylline Release from Tablet Matrices

Polyethylene oxide has been researched extensively as an alternative polymer to hydroxypropyl methylcellulose (HPMC) in controlled drug delivery due to its desirable swelling properties and its availability in a number of different viscosity grades. Previous studies on HPMC have pointed out the importance of particle size on drug release, but as of yet, no studies have investigated the effect of particle size of polyethylene oxide (polyox) on drug release. The present study explored the relationship between polymer level and particle size to sustain the drug release. Tablets produced contained theophylline as their active ingredient and consisted of different polyethylene oxide particle size fractions (20–45, 45–90, 90–180 and 180–425 μm). It was shown that matrices containing smaller particle sizes of polyox produced harder tablets than when larger polyox particles were used. The release studies showed that matrices consisting of large polyox particles showed a faster release rate than matrices made from smaller particles. Molecular weight (MW) of the polymer was a key determining step in attaining sustained release, with the high MW of polyox resulting in a delayed release profile. The results showed that the effect of particle size on drug release was more detrimental when a low concentration of polyox was used. This indicates that care must be taken when low levels of polyox with different particle size fractions are used. More robust formulations could be obtained when the concentration of polyox is high. Differential scanning calorimetry (DSC) traces showed that particle size had no major effect on the thermal behaviour of polyox particles.KEY WORDS: DSC traces, particle size, polyox, sustained release, theophylline