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Yi X.,South China Agricultural University | Wang P.,South China Agricultural University | Wang Z.,South China Agricultural University | Cai J.,South China Agricultural University | And 3 more authors.
Journal of Chemical Ecology | Year: 2014

Insects have evolved many physiological and behavioral adaptations to recognize external complex chemicals. Olfaction plays an important role in perceiving volatile chemicals, utilizing them to locate host sites, conspecifics, and enemies. Chemosensory proteins (CSPs) are present in high concentrations within the sensory sensilla of insects and are endowed with a heterogeneous range of functions. However, direct evidence for the involvement of CSPs in olfactory function is still lacking. In this study, a fluorescence-based ligand binding assay using Bdor-CSP2 illustrated its ability to bind the majority of the selected ligands of different shapes and chemical structures that are ecologically significant, host plant volatiles of Bactrocera dorsalis. RNAi-mediated silencing coupled with electrophysiological tests showed lower electrophysiological responses to (3Z)-hex-3-en-1-ol, trans-2-hexenal, 6-methylhept-5-en-2-one, and 3-methylbutyl acetate in dsBdor CSP2 treated flies compared with the untreated controls. The reduced expression of Bdor-CSP2 by RNA interference was confirmed by semi-quantitative PCR, real-time quantitative PCR and Western blot, which suggested the RNAi-treatment was responsible for the observed reduction of antennal responses in EAG recordings. These data suggest that the expression of Bdor-CSP2 is necessary for the recognition of antennal responses to some plant host volatiles by B. dorsalis. © 2014 Springer Science+Business Media New York. Source

Han R.,Central China Normal University | Han R.,Qinghai University | Zhang J.,Central China Normal University | Li S.,Central China Normal University | And 7 more authors.
Journal of Agricultural and Food Chemistry | Year: 2010

Ustilago maydis infection is a serious disease affecting corn crops worldwide. Sterol 14α-demethylase (CYP51) is one of the key enzymes of sterol biosynthesis and an effective target of antifungal drugs. To further study the interaction between CYP51 and drugs and exploit more specific 14α-demethylase inhibitor (DMI) fungicides for U. maydis, in this study homology modeling of CYP51 from U. maydis (UmCYP51) templated as the eukaryotic orthologues (the human CYP51) and screening of new DMI fungicides based on optimized expression were carried out for the first time. In addition, XF-113 and ZST-4 were screened by analyzing the spectral characteristics between the purified UmCYP51-35 and fungicides. These results provide a theoretical basis and new ideas for efficient design and development of new antifungal drugs. © 2010 American Chemical Society. Source

Gong L.,Key Laboratory of Pesticide and Chemical Biology | Gong L.,South China Agricultural University | Luo Q.,Key Laboratory of Pesticide and Chemical Biology | Luo Q.,South China Agricultural University | And 4 more authors.
Bulletin of Entomological Research | Year: 2012

Insect chemosensory proteins (CSPs) are supposed to transport hydrophobic chemicals to receptors on sensory neurons. However, CSPs are broadly expressed in various insect tissues, suggesting their involvement in the physiological processes beyond chemoreception. So, the exact physiological roles of CSPs in insects still need to be unraveled. In this study, three full-length of CSP genes from Spodoptera exigua have been cloned and characterized. The deduced amino acid sequences of SexiCSP1, SexiCSP2 and SexiCSP3 revealed open reading frames of 128, 128 and 126 amino acids, respectively, with four conserved cysteine residues. The expression patterns of the three SexiCSPs were further investigated by real-time PCR. Three SexiCSPs were expressed in antennae, heads, legs, wings, thoraxes, abdomens, testes and ovaries, with the highest expression level in female and male antennae. Furthermore, all three SexiCSPs mRNA were distributed extensively in the tested development stages with the highest expression level in pupae. RNAi-based gene silencing study resulted in a dramatic reduction of corresponding mRNA in female S. exigua after injection with dsRNA of all three SexiCSPs. Consequentially, 42.5% of mortalities, 68.3% (compare to DEPC water injected control) and 71.4% (compare to uninjected control) oviposition inhibition, and significantly effected egg hatching were observed in the female S. exigua injected with dsSexiCSP3 as compared to control treatments. On the other hand, dsSexiCSP1 and dsSexiCSP2 injected female adults did not show effects on survival and reproduction. Our study confirms the utility of RNAi approach to functional characterization of CSP genes in S. exigua and provides a starting point for further studies on female survival and reproduction in this insect. It also reveals the potential pest controlling method, as insect behavior regulation agent that disrupts the expression of chemosensory proteins. Copyright © 2012 Cambridge University Press. Source

Chen S.,Key Laboratory of Pesticide and Chemical Biology | Geng P.,Key Laboratory of Pesticide and Chemical Biology | Xiao Y.,Key Laboratory of Pesticide and Chemical Biology | Hu M.,Key Laboratory of Pesticide and Chemical Biology
Applied Microbiology and Biotechnology | Year: 2012

Using laboratory and field experiments, the ability of Streptomyces aureus HP-S-01 to eliminate β-cypermethrin (β-CP) and its metabolite 3-phenoxybenzaldehyde (3-PBA) in soils was investigated. In the laboratory, 80.5% and 73.1% of the initial dose of β-CP and 3-PBA (50 mg kg-1)was removed in sterilized soils within 10 days, respectively, while in the same period, disappearance rate of β-CP and 3-PBA in non-sterilized soils was higher and reached 87.8% and 79.3%, respectively. Furthermore, the disappearance process followed the first-order kinetics and the half-life (T 1/2)for β-CP and 3-PBA reduced by 20.3-52.9 and 133.7-186.8 days, respectively, as compared to the controls. The addition of sucrose to the soils enhanced the ability of strain HP-S-01 to eliminate β-CP and 3-PBA. Similar results were observed in the field experiments. The introduced strain HP-S-01 quickly adapted to the environment and rapidly removed β-CP and 3-PBA without any lag phases in the field experiments. Compared with the controls, 47.9% and 67.0% of applied dose of β-CP and 3-PBA was removed from the soils without extra carbon sources and 52.5% and 73.3% of β-CP and 3PBA was eliminated in soils supplemented with sucrose within 10 days, respectively. Analysis of β-CP degradation products in soil indicated that the tested strain transform β-CP to 3-PBA and a-hydroxy-3-phenoxy- benzeneacetonitrile. However, both intermediates were transient and they disappeared after 10 days. Therefore, the selected actinomyces strain HP-S-01 is suitable for the efficient and rapid bioremediation of β-CP contaminated soils. © Springer-Verlag 2011. Source

Weng Q.,Key Laboratory of Pesticide and Chemical Biology | Weng Q.,South China Agricultural University | Huang J.,Key Laboratory of Pesticide and Chemical Biology | Huang J.,South China Agricultural University | And 6 more authors.
Molecules | Year: 2012

Based on the original structure of harmine, several novel 1,2,3,4-tetrahydro-β- carboline, β-carboline and 1-substituted-β- carboline derivatives bearing a substituted carbohydrazide group at C-3 were designed and synthesized to investigate the structureactivity relationship of their analogues. All of the compounds were characterized by infrared (IR), proton and carbon nuclear magnetic resonance ( 1H-NMR, 13C-NMR), and mass spectroscopy (MS). The bioassay tests showed that N'-benzylidene-1-phenyl-β- carboline-3-carbohydrazide (C 25H 18N 4O, m.w. 390.4) (c2) and N'-(4- trifluoromethylbenzylidene)- 1-phenyl-β-carboline-3-carbohydrazide (C26H17N4OF3, m.w. 458) (d2) exhibited good inhibitory activity against dicotyledonous and monocotyledonous weeds, with EC50 values of 4.83 μM and 14.25 μM, respectively. © 2012 by the authors. Source

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