摘要：
Acremonium implicatum is an endophytic fungus with biocontrol potential against Meloidogyne incognita based on its opportunistic egg-parasitic, hatching inhibition, and toxic properties. To understand its mode of plant endophytism and opportunistic egg parasitism, GFP-tagged A. implicatum was constructed by PEG-mediated protoplast transformation. By laser scanning confocal microscopy (LSCM), we evaluated the endophytism and opportunistic egg parasitism of a stable gfp transformant (Acr-1). Acr-1 could colonize epidermal tissue, cortical tissue, and xylem of roots and form a mutualistic symbiosis with tomato host plants. LSCM of Acr-1 infecting M. incognita eggs revealed that hyphae penetrated the shell and grew inside eggs to form trophic hyphae. A large number of hyphae enveloped parasitized eggs. In addition, the egg shell integrity was destroyed by fungal penetration. The percentage of egg parasitism was 33.8 %. There were no marked differences between the wild type and mutant in nematode second-stage juvenile mortality and egg hatching and in fungal control efficiency in a pot experiment. In conclusion, gfp-transformation did not change the nematicidal activity of A. implicatum and is a tool to examine the mode of plant endophytism and opportunistic egg parasitism of A. implicatum.
摘要：
The nematophagous fungus Pochonia chlamydosporia, which belongs to the family Clavicipitaceae (Ascomycota: Pezizomycotina: Sordariomycetes: Hypocreales), is a promising biological control agent for root-knot and cyst nematodes. Its biocontrol effect has been confirmed by pot and field trials. The genome sequence of the fungus was completed recently; therefore, genome-wide functional analyses will identify its infection-associated genes. Gene knockout techniques are useful molecular tools to study gene functions. However, cultures of P. chlamydosporia are resistant to high levels of a range of fungal inhibitors, which makes the gene knockout technique difficult in this fungus. Fortunately, we found that the wild P. chlamydosporia strain PC-170 could not grow on medium containing 150 mu g ml(-1) G418 sulfate, representing a new selectable marker for P. chlamydosporia. The neomycin-resistance gene (neo), which was amplified from the plasmid pKOV21, conferred G418-resistance on the fungus; therefore, it was chosen as the marker gene. We subsequently developed a gene knockout system for P. chlamydosporia using split-marker homologous recombination cassettes with resistance selection and protoplast transformation. The split-marker cassettes were developed using fusion PCR, and involved only two rounds of PCR. The final products comprised two linear constructs. Each construct contained a flanking region of the target gene and two thirds of the neo gene. Alkaline serine protease and chitinase were confirmed to be produced by P. chlamydosporia during infection of nematode eggs and could participate in lysis of the eggshell of nematode eggs. Here, we knocked out one chitinase gene, VFPPC_01099, and two protease genes (VFPPC_10088, VFPPC_06535). We obtained approximately 100 suspected mutants after each transformation. After screening by PCR, the average rate of gene knockout was 13%: 11% (VFPPC_01099), 13% (VFPPC_10088) and 15% (VFPPC_06535). This efficient and convenient technique will accelerate functional genomic studies in P. chlamydosporia. (C) 2014 Elsevier GmbH. All rights reserved.
摘要：
A methacrylate monolith was prepared inside a fused silica capillary column by microwave irradiation using an ionic liquid (1-hexyl-3-methylimidazolium tetrafluoroborate) as the porogenic solvent. Baseline separation of the model analytes, including thiourea, benzene, toluene, ethylbenzene and propylbenzene, was achieved by capillary liquid chromatography, with the lowest theoretical plate height of 26.83 μm for benzene. In addition, we also investigated the effects of the acetonitrile content in the mobile phase, flow rate on retention time, resolution and total porosity. The morphology of methacrylate monolith was studied by scanning electron microscopy.
作者机构：
[赵廷昌; 杨玉文] Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China;[高必达] College of Bio-safety Science and Technology, Hunan Agricultural University, Changsha, 410128, China;[王静] Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China;[周训军] Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China, College of Bio-safety Science and Technology, Hunan Agricultural University, Changsha, 410128, China
通讯机构：
[Zhao, T.] I;Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
摘要：
A novel method to quickly prepare molecularly imprinted polymer (MIP) monolithic fibres is developed using microwave irradiation. The well-known water-compatibility problem of MIP is overcome by liquid-liquid-solid microextraction (LLSME). The atrazine (ATR) MIP fibre was obtained after silica was etched away with a controlled length of 1 cm, and subsequently characterized by scanning electron microscopy. Main factors affecting the selective extraction, including extraction time, desorption time, extraction and desorption solvents, were investigated for LLSME procedures in detail. The selectivity was also evaluated using the ATR template molecule and its structurally related compounds, including 2-amino-4-methoxy-6-methyl-1,3,5- triazine, terbuthylazine, ametryn and metribuzin pesticides. The extraction ratio of target pesticides in ATR-imprinted polymeric monolithic fibre was increased to more than 10 times than that in non-imprinted polymeric monolithic fibre. The resultant fibres coupled by HPLC were successfully applied to detect ATR and its analogue pesticides with recoveries in the range of 68.3-92.6%. In addition, the LLSME technique was proved to be effective in extracting spiked TRI, ATR, AME and TER in lake water. This method provided a satisfactory solution for the simple, rapid, selective and sensitive pre-treatment of trace herbicides in various aqueous samples. The results demonstrate that the proposed technique could solve the water compatibility problem when the MIP monolithic fibre was exposed directly to a non-polar solvent above the aqueous solution.
期刊：
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY,2014年62(49):11924-11932 ISSN：0021-8561
通讯作者：
Chen, Li
作者机构：
[Guan, Di; Chen, Li] Chinese Acad Sci, Inst Zool, State Key Lab Integrated Management Pest Insects, Beijing 100101, Peoples R China.;[Guan, Di; Liao, Xiao-Lan] Hunan Agr Univ, Coll Plant Protect, Changsha 410128, Hunan, Peoples R China.;[Wang, Lei; Lu, Yong-Yue] South China Agr Univ, Red Imported Fire Ant Res Ctr, Guangzhou 510642, Guangdong, Peoples R China.
通讯机构：
[Chen, Li] C;Chinese Acad Sci, Inst Zool, State Key Lab Integrated Management Pest Insects, Beijing 100101, Peoples R China.
摘要：
A characteristic behavior in ants is to move rapidly to emission sources of alarm pheromones. The addition of ant alarm pheromones to bait is expected to enhance its attractiveness. To search for candidate compounds for bait enhancement in fire ant control, 13 related alkylpyrazine analogues in addition to synthetic alarm pheromone component were evaluated for electroantennogram (EAG) and behavioral activities in Solenopsis invicta. Most compounds elicited dose-dependent EAG and behavioral responses. There exists a correlation between the EAG and behavioral responses. Among the 14 tested alkylpyrazines, three compounds, 2-ethyl-3,6(5)-dimethyl pyrazine (1), 2,3,5-trimethylpyrazine (7), and 2,3-diethyl-5-methylpyrazine (12), elicited significant alarm responses at a dose range of 0.1-1000 ng. Further bait discovery bioassay with the three most active alkylpyrazines demonstrated that food bait accompanied by sample-treated filter paper disk attracted significantly more fire ant workers in the first 15 min period. EAG and behavioral bioassays with pure pheromone isomers accumulated by semi-preparative high-performance liquid chromatography demonstrated that 2-ethyl-3,6-dimethylpyrazine was significantly more active than 2-ethyl-3,5-dimethylpyrazine.
摘要：
Reed lignocellulose was subjected to a steam explosion pretreatment to obtain a high conversion rate of sugar after subsequent enzymatic hydrolysis using a commercial cellulase mixture. Under conditions of differing temperature (200 °C, 220 °C and 240 °C) and residence time (2, 5, and 8 min), the effect of the pretreatment on the sugar yield from enzymatic hydrolysis was studied. The highest respective reducing sugar and glucose yields were 36.14% and 15.35% after 60-h enzymatic hydrolysis of reed straw that had been pretreated with a steam explosion at 220 °C for 5 min. Fourier transform infrared spectrophotometry (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used in this study to comprehensively investigate the steam explosion-induced changes in the organizational structure and morphological properties of reed straw to analyze the reason for the increased sugar yield from enzymatic hydrolysis after the steam explosion.
摘要：
This paper reports a novel colorimetric sensor for pymetrozine based on p-aminobenzenesulfonic acid functionalized silver nanoparticles (p-ABSA-modified Ag NPs), which were characterized by IR spectroscopy, ultraviolet-visible spectroscopy (UV-vis), and transmission electron microscopy (TEM). The newly synthesized p-ABSA-modified Ag NPs are yellow in color due to the intense surface plasmon absorption band centered at 400nm. In the presence of pymetrozine, the yellow p-ABSA-modified Ag NPs solution turns to dark green, with a dramatic surface plasmon absorption band centered at 660nm. Moreover, high selectivity for pymetrozine was approved by the comparative experiments with an absorption ratio of A660/A400 more than 0.7. This highly sensitive sensor allows a direct and rapid quantitative assay of pymetrozine with a colorimetric limited detection concentration of 0.01mg/L.
作者机构：
[刘双清; 孟锐; 李晓刚; 朱锐; 柏连阳] College of Biosafety Science and Technology, Hunan Agricultural University, Changsha 410128, China;[蒋金芝] School of Chemistry and Chemical Engineering, Central South University, Changsha 410128, China;[柏连阳] Hunan University of Humanities, Loudi 417000, China
通讯机构：
[Li, X.-G.] C;College of Biosafety Science and Technology, Hunan Agricultural University, China
