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Cloning and functional characterization of two peptidoglycan recognition protein isoforms (PGRP-LC) in Bactrocera dorsalis (Diptera: Tephritidae)

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Journal of Integrative Agriculture 2020年第12期19卷 3025-3034页

作者： WEI Dong wang Zhe XU Hui-qian NIU jin-zhi wang jin-jun Chongqing Key Laboratory of Entomology and Pest Control Engineering College of Plant ProtectionSouthwest UniversityChongqing 400715P.R.China State Cultivation Base of Crop Stress Biology for Southern Mountainous Land Academy of Agricultural SciencesSouthwest UniversityChongqing 400715P.R.China

The innate immune system of insects is the front line of self-defense against pathogen invasion. Peptidoglycan recognition proteins (PGRPs) are important components and play key roles in insect immune systems by recognizing peptidoglycan (PGN) in bacterial cell walls. We characterized two isoforms of the PGRP-LC gene, BdPGRP-LCa and BdPGRP-LCb, from Bactrocera dorsalis (Hendel), an important fruit and vegetable pest worldwide. These two isoforms contain an open reading frames of 1 668 bp and 1 731 bp, encoding a protein of 555 and 576 amino acids, respectively. Quantitative real-time PCR results showed that both transcripts were prominently expressed in midgut and fat body of B. dorsalis adult. Inoculation of pathogens showed that both isoforms actively responded to Escherichia coli PGN. We also observed a light response to Staphylococcus aureus PGN. Upon Beauveria bassiana inoculation, the expression of BdPGRP-LCa was enhanced, but the expression of BdPGRP-LCb was suppressed. Suppression of both transcripts by RNA interference led to increased mortality of flies challenged by E. coli, indicating that the two isoforms are involved in sensing Gram-negative bacterial infections.

关键词： oriental fruit fly innate immunity PGRPs Gram-negative bacterium

Effect of Host Plants on Development,Fecundity and Enzyme Activity of Spodoptera exigua (Hübner)(Lepidoptera:Noctuidae)

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Agricultural Sciences in China 2011年第8期10卷 1232-1240页

作者： ZHANG Bin LIU Huai Helen Hull-Sanders wang jin-jun Chongqing Key Laboratory of Entomology and Pest Control Engineering Southwest UniversityChongqing 400716P.R.China Chongqing Tobacco Company China National Tobacco CorporationChongqing 400023P.R.China

The beet armyworm,Spodoptera exigua （Lepidoptera：Noctuidae）,is an economically important pest of crops worldwide,attacking plants from over 20 families including trans-continental agricultural cotton,corn and citrus *** this study,performance and subsequent enzyme activity of beet armyworm reared on host plants from five families were *** differences were found in development,fecundity and enzyme activity on different host *** rate was the highest （42.8%） on asparagus lettuce （Lactuca sativar ***） and the lowest （17.0%） on sweet pepper （Capsicum annuum）.Larval duration was the shortest on asparagus lettuce （12.0 d）,and was 43.4% longer on sweet peppers （21.2 d）.The activity of acetylcholine esterase （AChE） and carboxylesterase （CarE） in 3rd instar larvae,and soluble carbohydrate and crude protein contents in different host plants were *** activity was the highest in the larvae feeding on Chinese cabbage （Brassica rapa）,but declined by nearly 60% on maize （Zea mays） *** ratio of soluble carbohydrate content to crude protein content in host plants was found to have a positive effect on oviposition and a negative correlation with larval duration and life time （from larval to adult stages） of the insect.

关键词： beet armyworm Spodoptera exigua host plants nutrition enzyme activity

Molecular Evidences for the Biosynthesis of Pederin by Endosymbiont

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Agricultural Sciences in China 2009年第11期8卷 1339-1350页

作者： LIU Zhi-ping WU Xuan wang jin-jun HUANG Fang Key Laboratory of Entomology and Pest Control Engineering College of Plant Protection Southwest University Chongqing 400716 P.R.China Chongqing Animal Disease Control Center Chongqing 401147 P.R.China College of Medicine Shanxi Datong University Datong 037008 P.R.China

Pederin belongs to a group of antitumor compounds found in terrestrial beetles and marine sponges. It is apparently used by some members of the rove beetle Paederus as a chemical defense against predators. A recent cluster analysis of the putative pederin biosynthesis gene （ped） strongly suggests that pederin is produced by bacterial symbionts. This paper reviewed the criteria for proving symbiontic origin of bioactive metabolite, indirect and molecular evidences for pederin bacterial origin, as well as three sets ofped clusters and putative biosynthesis process of pederin.

关键词： pederin PKS/NRPS endosymbiont

Dynamic Recrystallization Behavior of Microalloyed Forged Steel

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Journal of Iron and Steel Research International 2008年第3期15卷 78-81,91页

作者： wang jin CHEN jun ZHAO Zhen RUAN Xue-yu National Die and Mold CAD Engineering Research Center Shanghai Jiao Tong University Shanghai 200030 China

The dynamic recrystallization behavior of microalloyed forged steel was investigated with a compression test in the temperature range of 1 223-1 473 K and a strain rate of 0. 01-5 s^-1. Activation energy was calculated to be 305.9 kJ/mol by regression analysis. Modeling equations were developed to represent the dynamic recrystallization volume fraction and grain size. Parameters of the modeling equations were determined as a function of the Zener-Hollomon parameter. The developed modeling equation will be combined with finite element modeling to predict microstructural change during the hot forging processing.

关键词： microalloyed forged steel dynamic recrystallization flow stress

Experimental Investigation of Wake-Induced Bypass Transition Control by Surface Roughness

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Chinese Physics Letters 2012年第10期29卷 120-124页

作者： PAN Chong wang jin-jun HE Guo-Sheng Key Laboratory of Fluid Mechanics(Ministry of Education) Beihang UniversityBeijing 100191

Surface roughness is experimentally used to control the flat-plate boundary layer bypass transition induced by an upstream convected two-dimensional(2D)circular cylinder *** is shown that the later stage of this bypass transition is successfully postponed,at the price of accelerating the earlier transition stage.A regularisation process of the hairpin vortices,which are the dominant coherent structures to promote the transition process,are observed under the influence of roughness *** scale reduction and localisation of these hairpins are achieved,which enhances the possibility of a hairpin self-annihilation ***,the cascade to large-scale structures in the later transition stage might be impeded/weakened.

关键词： process roughness Transition

Characterization of the Purified Glutathione S-transferases from Two Psocids Liposcelis bostrychophila and ***

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Agricultural Sciences in China 2010年第7期9卷 1008-1016页

作者： DOU Wei XIAO Li-sha NIU jin-zhi JIANG Hong-bo wang jin-jun Key Laboratory of Entomology and Pest Control Engineering College of Plant Protection Southwest University Chongqing 400716 P.R. China

Glutathione S-transferases（GSTs） from Liposcelis bostrychophila Badonnel and ***（Enderlein）（Psocoptera：Liposcelididae） were purified by glutathione-agarose affinity chromatography,and characterized subsequently by their Michaelis-Menten kinetics toward the artificial substrates 1-chloro-2,4-dinitrobenzene（CDNB） and reduced glutathione（GSH）,*** specific activity of the purified GST toward CDNB was 2.3-fold higher in *** than in *** the specific activities of purified enzymes varied between the two species,the purification yields were ***-PAGE revealed one band at 23 kDa for both the *** of *** exhibited higher Michaelis-Menten constants（Km） but lower maximal velocity（Vmax） values than those of *** optimum pH for CDNB conjugation of *** and *** GSTs was 7.0 and 7.5,and optimum temperature was 35 and 40°C,*** kinetics showed that cibacron blue,curcumin,bromosulfalein,ethacrynic acid,and carbosulfan had excellent inhibitory effects on GSTs in both species,but the inhibitory effects of beta-cypermethrin,fenpropathrin,tetraethylthiuram disulfide,and diethyl maleate were not significant.

关键词： GSTs purification psocids xenobiotic compounds

Adsorption and Desorption of Methiopyrsulfuron in Soils

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Pedosphere 2011年第3期21卷 380-388页

作者： WU Chun-Xian wang jin-jun ZHANG Su-Zhi ZHANG Zhong-Ming College of Plant Protection Southwest University Chongqing 400716 China Institute for the Control of Agrochemicals of Sichuan Province Chengdu 610041 China Maize Research Institute Sichuan Agricultural University Ya'an 625014 China

Methiopyrsulfuron is a new low-rate sulfonylurea herbicide for weed control in wheat; however, there is a lack of published information on its behavior in soils. In this study, methiopyrsulfuron adsorption and desorption were measured in seven soils sampled from Heilongjiang, Shandong, Jiangxi, Sichuan, Anhui, and Chongqing provinces of China using a batch equilibrium method. The Freundlich equation was used to described its adsorption and desorption. Adsorption isotherms were nonlinear with the values of Kf-ads, the Freundlich empirical constant indicative of the adsorption capacity, ranging from 0.75 to 2.46, suggesting that little of this herbicide was adsorbed by any of the seven soils. Soil pH and organic matter content (OM) were the main factors influencing adsorption; adsorption was negatively correlated with pH and positively correlated with OM. Methiopyrsulfuron desorption was hysteretic on the soils with high OM content and low pH.

关键词： Freundlich equation herbicide hysteresis organic matter pH

Influence of Organic Amendments on Adsorption, Desorption and Leaching of Methiopyrisulfuron in Soils

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Journal of Integrative Agriculture 2013年第9期12卷 1589-1597页

作者： WU Chun-xian NIE Guo ZHANG Zhong-ming wang Guang-cheng GAO Li-ming wang jin-jun College of Plant Protection Southwest University Institute of the Control of Agrochemical of Sichuan Province

Methiopyrisulfuron is a novel sulfonylurea herbicide with good activity for annual broadleaf and gramineal weeds control. Present study was to investigate the effects of organic amendments （including peat （PE）, sewage sludge （SS）, and humic acid （HA）） on adsorption, desorption and leaching of methiopyrisulfuron in soils. The batch equilibration technique was applied for adsorption-desorption experiments and the leaching was tested through soil column simulated experiments under laboratory conditions. The Freundlich model may well describe adsorption-desorption of methiopyrisulfuron on organic amendments, the natural soil, and amended soils. Organic amendments could not only greatly increase the adsorption capacity of methiopyrisulfuron, but also significantly enhance the hysteresis of desorption of methiopyrisulfuron. The correlations between Kf_ads and organic matter content of amended soils were significant, and the correlations between H and soil organic matter in amended soils with PE, SS, and HA were significant too. The results of soil column experiments indicated that organic amendments greatly decreased leaching of methiopyrisulfuron. This study suggested that PE, SS, and HA could greatly influence environmental behavior of methiopyrisulfuron in soils. Use of organic amendments might be an effective management practice for controlling potential pollution of methiopyrisulfuron to environment.

关键词： organic amendment adsorption desorption leaching methiopyrisulfuron soil

Adsorption-Desorption Characteristics of Chlorimuron-Ethyl in Soils

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Agricultural Sciences in China 2007年第11期6卷 1359-1368页

作者： ZHANG Wei wang jin-jun ZHANG Zhong-ming QIN Zhen College of Plant Protection Southwest University Chongqing 400716 P.R.China Institute of the Control of Agrochemical of Sichuan Province Chengdu 610041 P.R.China

The adsorption-desorption characteristics of chlorimuron-ethyl in soils were investigated to provide the basic data for evaluating the safety in field and the risk to water resource. The adsorption-desorption experiment was conducted by the batch equilibration and HPLC techniques; furthermore, data were analyzed with 5 mathematic models to describe the characteristics and mechanism of adsorption-desorption and translocation of the herbicide in soils. The results showed that the adsorption-desorption isotherms of chlorimuron-ethyl fitted for the Freundlich model well, and the physical reaction presents the main contribution during the adsorption-desorption process. The adsorption values （Kads-f） of chlorimuron-ethyl in 8 types of soil ranged from 0.798 to 6.891. The isotherms of 2# （Jiangxi clay） and 3# （Jiangxi sand loam） soils belong to the S-type curve, while the isotherms of another 6 type soils belong to the L-type isotherm. The results of desorption indicated that the hysteresis phenomena appeared during the desorption process, and the hysteresis coefficients （H） of the herbicides in 8 soils varied from 0.259-0.980. Furthermore, Kads-f and desorption values （Kads-f） increased with the OM （%） and the clay content increasing, while the values decreased with the soils pH increasing. The H values decreased with the OM and the clay content increasing, and increased with the soils pH increasing. It can be concluded that the low adsorption abilities of chlorimuron-ethyl in test soils and un-reversible adsorption existed in the process, which will induce the great translocation of the herbicide after application in field. It can be transported to ground or groundwater causing risk to environments. The physical and chemical properties of soils, including the OM, the clay content, and the pH of soil were the dominating factors during the adsorption-desorption.

关键词： chlorimuron-ethyl adsorption-desorption Freundlich model hysteresis physical and chemical properties of soils