Dun Wang

Characterization of Helicoverpa armigera nucleopolyhedrovirus orf33 that encodes a novel budded virion derived protein, BV-e31

Summary.Homologues of Helicoverpa armigera nucleopolyhedrovirus (HearSNPV) orf33 are found in all 22 completely sequenced members of the lepidopteran nucleopolyhedroviruses and granuloviruses, but so far their functions are unknown. In this report, we describe the characterization of HearSNPV orf33 (ha33). Northern blot analysis showed a single transcript of ha33 of approximately 0.7 kb was transcribed beginning at 3 h post-infection in infected Helicoverpa zea cells (HzAM1) and the gene product could be detected as early as 6 h post-infection by western blot analysis using a rabbit derived polyclonal antibody, suggesting it was an early gene. Western blot analysis also demonstrated the ha33 protein in infected cells was a 31 kDa protein, larger than the theoretical size of 28.4 kDa, and located in the envelope fraction of budded virions (BVs). The results suggested that HearSNPV ha33 gene is a functional gene that encodes a novel structural protein of baculovirus BVs, BV-e31.

NUTRITIONAL VALUE OF THE FIELD CRICKET (GRYLLUS TESTACEUS WALKER)

Abstract The chemical composition and the nutritional quality of protein, fatty acids and chitin of adult field cricket Gryllus testaceus Walker were investigated. The adult insect contained: crude protein 58.3 %; fat 10.3 %, chitin 8.7 % and ash 2.96 % on dry matter basis respectively. The essential amino acid profile compared well with FAO/WHO recommended pattern except for cysteine and methionine. The fatty acid analysis showed unsaturated acid of the field cricket to be present in high quantities, and the total percentage of oleic acid, linolic acid and linolenic acid was 77.51%. The chitin content of the insect was 8.7% with a better quality than the commercial chitin that was prepared from shells of shrimp and crab. Therefore the chemical composition of the field cricket indicates the insect to be a good supplement to nutrition for food and feed, even a raw material for medicine.

Cantharidin Impedes Activity of Glutathione S-Transferase in the Midgut of Helicoverpa armigera Hübner

Previous investigations have implicated glutathione S-transferases (GSTs) as one of the major reasons for insecticide resistance. Therefore, effectiveness of new candidate compounds depends on their ability to inhibit GSTs to prevent metabolic detoxification by insects. Cantharidin, a terpenoid compound of insect origin, has been developed as a bio-pesticide in China, and proves highly toxic to a wide range of insects, especially lepidopteran. In the present study, we test cantharidin as a model compound for its toxicity, effects on the mRNA transcription of a model Helicoverpa armigera glutathione S-transferase gene (HaGST) and also for its putative inhibitory effect on the catalytic activity of GSTs, both in vivo and in vitro in Helicoverpa armigera, employing molecular and biochemical methods. Bioassay results showed that cantharidin was highly toxic to H. armigera. Real-time qPCR showed down-regulation of the HaGST at the mRNA transcript ranging from 2.5 to 12.5 folds while biochemical assays showed in vivo inhibition of GSTs in midgut and in vitro inhibition of rHaGST. Binding of cantharidin to HaGST was rationalized by homology and molecular docking simulations using a model GST (1PN9) as a template structure. Molecular docking simulations also confirmed accurate docking of the cantharidin molecule to the active site of HaGST impeding its catalytic activity.

Rubisco Activase Is Also a Multiple Responder to Abiotic Stresses in Rice

Ribulose-1,5-bisphosphate carboxylase/oxygenase activase (RCA) is a nuclear gene that encodes a chloroplast protein that plays an important role in photosynthesis. Some reports have indicated that it may play a role in acclimation to different abiotic stresses. In this paper, we analyzed the stress-responsive elements in the 2.0 kb 5’-upstream regions of the RCA gene promoter and the primary, secondary and tertiary structure of the protein. We identified some cis-elements of multiple stress-related components in the RCA promoter. Amino acid and evolution analyses showed that the RCA protein had conserved regions between different species; however, the size and type varied. The secondary structures, binding sites and tertiary structures of the RCA proteins were also different. This might reflect the differences in the transcription and translation levels of the two RCA isoforms during adaptation to different abiotic stresses. Although both the transcription and translation levels of RCA isoforms in the rice leaves increased under various stresses, the large isoform was increased more significantly in the chloroplast stroma and thylakoid. It can be concluded that RCA, especially RCAL, is also a multiple responder to abiotic stresses in rice, which provides new insights into RCA functions.

Lethal and sublethal effects of cantharidin on the life history traits and population parameters of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)

BACKGROUND The cotton bollworm, Helicoverpa armigera (Hübner), is a serious and cosmopolitan pest of many economic crops. Its control has not been adequate owing to its resistance to many groups of insecticides. Toxicity of cantharidin on armyworm and diamondback moth has already been reported. However, its toxicity on H. armigera has not been investigated previously. In this study, lethal and sublethal effects of cantharidin on H. armigera under laboratory conditions are reported. RESULTS Results showed gross abnormalities in the population parameters of H. armigera, ranging from larvae to adults. Reduction in larval weight and wing malformation were observed in the cantharidin-treated population cohort, and higher mortality at the larval, pupal and adult stages was observed in cantharidin-treated H. armigera compared with the control. Moreover, almost 5 times less fecundity was recorded in the treated population cohort. Fertility was also severely affected, and reduction in all population parameters was observed. CONCLUSION Cantharidin caused larval mortality and other serious abnormalities in H. armigera population parameters, and therefore may have positive implications for pest management decision-making process. More interestingly, the experiment revealed that cantharidin in sublethal dose mimicked insect growth regulator insecticides. Furthermore, cantharidin could be used as a precursor compound for the synthesis of new analogues and compounds to replace ineffective older compounds.

Relationship between Rubisco activase isoform levels and photosynthetic rate in different leaf positions of rice plant.

To investigate into the relationship between two Rubisco activase (RCA) isoforms and photosynthetic rate, a set of enzyme-linked immunosorbent assay (ELISA) were developed for accurate quantification of two RCA polypeptides based on two specific monoclonal antibodies against different RCA isoforms. The results showed that content of RCA small isoform (RCAS) was 5-fold more than that of RCA large isoform (RCAL) content in all leaves and the RCAL/RCAS ratio reached maximum in the leaf with the highest photosynthetic rate. Although the difference in two RCA polypeptides accumulation in leaves was caused by different transcript level of two isoforms, the decrease of RCAL/RCAS ratio during leaf aging was not attributed to transcriptional regulation. The leaves with higher photosynthetic capacity exhibited higher RCAL/RCAS ratio and the decrease in photosynthetic rate and Rubisco activation state highly correlated with the decline of RCAL/RCAS ratio during leaf aging. Our results suggest that there is a posttranscriptional mechanism regulating the RCAL/RCAS ratio, which may play as a regulator modulating photosynthetic capacity during leaf aging in rice plant.

Up-regulation of cyclic electron flow and down-regulation of linear electron flow in antisense- rca mutant rice

To investigate how excess excitation energy is dissipated in a ribulose-1,5-bisphospate carboxylase/oxygenase activase antisense transgenic rice with net photosynthetic rate (PN) half of that of wild type parent, we measured the response curve of PN to intercellular CO2 concentration (Ci), electron transport rate (ETR), quantum yield of open photosystem 2 (PS2) reaction centres under irradiation (Fv′/Fm′), efficiency of total PS2 centres (ΦPS2), photochemical (qP) and non-photochemical quenching (NPQ), post-irradiation transient increase in chlorophyll (Chl) fluorescence (PITICF), and P700+ re-reduction. Carboxylation efficiency dependence on Ci, ETR at saturation irradiance, and Fv′/Fm′, ΦPS2, and qP under the irradiation were significantly lower in the mutant. However, NPQ, energy-dependent quenching (qE), PITICF, and P700+ re-reduction were significantly higher in the mutant. Hence the mutant down-regulates linear ETR and stimulates cyclic electron flow around PS1, which may generate the ΔpH to support NPQ and qE for dissipation of excess excitation energy.

Characterization of a late expression gene, Open reading frame 128 of Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus

Summary.Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (HearSNPV) is a single embedded NPV pathogenic to the bollworm, which is a major agricultural pest in many areas around the world. Ha128 homologues have been identified in all completely sequenced lepidopteran NPV’s, but no homologue has been found in a granulovirus (GV) and it is thus considered as a lepidopteran NPV-specific gene. In the HearSNPV-C1 genome Ha128 is located between 120,252 and 121,052 bp and encodes a putative protein of 266 amino acid residues with a predicted molecular weight of 30.5 kDa. Ha128 transcripts in HearSNPV-infected HzAM1 cells could be detected from 24 to 120 h post-infection (p.i.) by Northern blot. The Ha128 protein was detected at 24 h p.i. and remained detectable until 120 h p.i. by western blot using an anti-GST-Ha128 antiserum. The expression of Ha128 was inhibited in the presence of Ara-C, an inhibitor of viral DNA synthesis. These results together indicated that Ha128 was a late gene. The product of Ha128 was found to have an Mr of about 31 kDa, in agreement with the predicted molecular weight. Immunoflorescence using anti-GST-Ha128 serum showed that Ha128 was located in cytoplasm. GST pull-down and co-immunoprecipitation showed that at least two potential host proteins interacted with Ha128. In conclusion, Ha128 is a late protein localized in the cytoplasm of infected cells that may interact with host proteins.

Changes and clinical significance of serum vaspin levels in patients with type 2 diabetes.

We investigated serum visceral adipose tissue-derived serpin (vaspin) levels in patients with normal glucose regulation and recently diagnosed type 2 diabetes (T2DM) and explored the association between vaspin and body mass index, age, gender, glucose, lipid metabolism, and insulin sensitivity. Fasting serum vaspin levels in 66 patients with T2DM and 48 normal subjects were detected using enzyme-linked immunosorbent assay. We found that serum vaspin levels in the DM group were 0.65 ± 0.13 mg/L in non-obese patients and 1.13 ± 0.25 mg/L in obese patients. Serum vaspin levels in the control group were 0.38 ± 0.18 mg/L in non-obese patients and 0.95 ± 0.11 mg/L in obese patients. Average serum vaspin levels were significantly higher in obese patients than in non-obese patients in both the DM group and control group. In the DM group, the serum vaspin level was 0.76 ± 0.22 mg/L in males and 0.92 ± 0.35 mg/L in females. In the control group, the serum vaspin level was 0.48 ± 0.14 mg/L in males and 1.05 ± 0.21 mg/L in females. Association analysis showed that serum vaspin levels were significantly associated with body mass index, waist-to-rip ratio (WHR), fat percentage, triglyceride, fasting plasma insulin, and insulin sensitivity index. Stepwise multiple regression analysis showed that gender, insulin sensitivity index, and WHR were the most significant independent factors affecting vaspin. Therefore, serum vaspin levels were significantly elevated in obese people and were independently associated with WHR, gender, and index sensitivity index.

Anticancer activity of Bombyx batryticatus ethanol extract against the human tumor cell line HeLa

Anticancer activity of Bombyx batryticatus ethanol extract (BBE) against HeLa cells was studied using cell viability, DNA fragmentation, real-time polymerase chain reaction, and Western blot analyses. The BBE inhibited the growth and induced apoptosis of HeLa cells. The MTT assay indicated that the BBE induced cytotoxicity in HeLa cells in a time- and concentration-dependent manner. When HeLa cells were treated for 48 h, the 50% inhibitory concentration (IC₅₀) value for the BBE was 1.564 mg/mL. The microscopy results showed that HeLa cells were severely distorted and showed slow growth; some cells became round in shape when treated with 5 mg/mL BBE for 24 h. The DNA ladder results revealed excessive DNA fragmentation in HeLa cells treated with 7 mg/mL BBE for 36 h. The proapoptotic activity of the BBE was attributed to its ability to modulate the expression of Bcl-2 and Bax genes. The mRNA and protein expression levels of Bax were remarkably higher whereas those of Bcl-2 were lower than those in the control cells; this led to an increased Bax/Bcl-2 ratio in cells treated with the BBE for 36 h. The results suggest that the BBE might play an important role in tumor growth suppression by inducing apoptosis in human cervical cancer cells via the regulation of the Bcl-2- and Bax-mediated apoptotic pathways.