天然来源农药活性氨基酸的研究进展CSCD

天然产物在新农药研究与开发中发挥着重要作用,氨基酸是其中一类重要的天然活性物质。天然来源氨基酸广泛存在于植物和微生物中,其中一些氨基酸具有显著的农药活性,包括除草、植物生长调节、杀细菌、杀真菌、杀虫、杀螨及杀线虫。本文通过对近三十年国内外文献检索,对天然来源氨基酸的结构多样性及其农药活性进行了系统综述,为新农药的研究开发提供参考。     

多种农药与次氯酸钠、高锰酸钾和高铁酸钾的反应活性

为探究4类,10种广泛使用的农药(苯氧羧酸类,芳香酸类,取代脲类和烟碱类)与3种氧化剂(次氯酸钠,高锰酸钾和高铁酸钾)的反应活性,本研究在温度(25±2)℃、pH值为8的条件下,分析10种农药分别与3种氧化剂NaClO、KMnO4、K2Fe O4在不同浓度下的反应活性,采用HPLC检测法,对比降解效能,探究氧化剂性质与有机物结构导致的反应活性的差异。实验结果表明,不同种类农药的结构性质对反应活性有重要影响,3种氧化剂的氧化降解能力有明显差异。苯氧羧酸类和芳香酸类农药结构较简单,并含有稳定的苯环或吡啶环结构,氧化降解较困难。取代脲类和烟碱类农药结构较复杂,氧化剂可攻击其不饱和官能团,反应活性较高。NaClO对取代脲类农药的降解率明显优于其他2种氧化剂,3种氧化剂对烟碱类农药的氧化降解效果依次为NaClO>KMn O4>K2Fe O4。研究多种农药与次氯酸钠、高锰酸钾和高铁酸钾的反应活性对降解去除水体中的农药残留对水环境的治理具有重要意义。     

质谱分子网络在天然产物结构研究中的应用CSCD

质谱分子网络(molecular networking)常用于新颖天然产物发现及鉴定、药物代谢及药物研发等研究。目前,分子网络能够将具有相似二级质谱的化合物连接成簇,在天然产物分析中得到了广泛的应用。本综述将简单介绍分子网络的基本概念和构建分子网络的步骤,以及从化合物的鉴定及发现;鉴定天然产物的代谢产物;天然产物化学成分的定性及定量;天然产物活性成分筛选、分离与制备;天然产物的生物合成途径五个方面对分子网络的应用进行阐述。     

重组乙酰胆碱酯酶的表达及其分子进化研究进展

乙酰胆碱酯酶(Acetylcholinesterase,AChE)是酶抑制法检测农药残留的核心试剂。但天然提取的AChE存在含量低、纯化困难、稳定性差等不足,因此,高性能的重组AChE制备成为研究学者关注的热点。文中综述了重组AChE的表达、和分子进化等方面的研究成果,并指出酶定向进化策略与表面展示技术结合是重组AChE活性改造的未来趋势。     

蔬菜中农药残留检测技术研究进展

对目前蔬菜中农药残留分析检测方法及其前处理过程以及快速检测技术作了综述。固相萃取(SPE)、超临界流体萃取(SFE)等新的萃取方法已逐渐代替了液-液萃取(LLE)等传统提取方法。色谱技术是农药残留分析中的重要手段。毛细管气相色谱(CGC)、高效液相色谱(HPLC)及其联用技术是现阶段农药残留分析中的主要检测方法。并指出了今后该领域的研究方向。     

化学蛋白质组学在天然产物分子靶标鉴定中的应用

绿色新农药的开发和利用有利于农业的可持续发展,基于天然产物进行活性先导发现及作用机制研究是重要的新农药创制策略,然而其作用靶标和作用机制难以确定,阻碍了其在新农药中的应用。因此发现化合物新靶点对于新农药创制来说是一项既重要又艰巨的任务。化学蛋白质组学作为后基因组时代的新技术,目前已经成为研究药物靶点的重要手段之一。本文对基于化学蛋白组学的化合物作用分子靶点发现方法和典型案例进行探析,介绍这些技术的主要原理、应用以及各自的优点和局限性,旨在阐述基于化学蛋白质组学发现药物作用靶标的最新方法,并为天然产物靶点及新农药创制研究提供参考。     

从植物中寻找农药活性物质

从植物中寻找农药活性物质,判明结构,使之成为创新类型农药有效母体,是创制新农药品种的重要途径之一,受到当今全世界农药界的广泛重视。本文综合性介绍植物与农药的关系,该交叉学科研究的一般程序和方法以及通过对有效母体的结构改造,构一效关系的研究,创制新农药的研究过程。     

一种降解农药和致癌物的土壤细菌

<正> 发现一种叫做缺陷假单胞菌(PD)的常见土壤细菌能够把有机磷农药对硫磷和地亚农降解成毒性较小的产物,并还能把致癌化合物苯并蒽降解成二氧化碳和水溶性产物。美国得克萨斯大学的研究人员在美国微生物学会于3月3日～7日在内华达拉斯维加斯召开的年会上介绍了这些研究结果。     

表面活性剂在农药制剂中的应用

表面活性剂所特有的物理化学性质使其在农药加工中应用十分广泛。主要起以下几种作用。 一、作稳定剂或其组分 表面活性剂对农药的多种剂型起稳定作用,特别是含水解性农药活性成分的农药制剂,     

农药对土壤微生物的生态效应

大量有关农药对土壤微生物生态效应的研究表明,虽然有些农药对土壤微生物及其活性会产生抑制或促进作用,但这种作用一般是短暂的;按推荐浓度正常使用农药通常不会影响土壤微生物的各种生化过程和活性,对土壤的物质循环和土壤肥力也没有不利影响;但大多数土壤薰蒸剂和杀真菌剂能改变土壤微生物平衡,它们对土壤微生物的作用强于杀虫剂和除草剂;长期使用农药不致使土壤微生物数量和活性发生明显变化,这应部分归功于土壤微生物对农药的降解或转化．     

Quantifying pesticide efficacy from multiple field trials

Simple corrected density indices (CDIs) have been used to measure reductions in pest density in fields. In the contemporary pesticide registration system, few comprehensive statistical frameworks are available that can integrate multiple datasets to evaluate how pesticidal effects are influenced by the products' properties such as mixing multiple active ingredients and possession of systemic ability. In this study, we provide a statistical framework for evaluating pesticide efficacy from multiple field trials and applying it to contemporary pesticides. In this framework, we extended the conventional CDI to a generalized linear mixed model (GLMM), which we applied to a dataset of the pesticide registration test in Japan (n = 758). The estimated mortality of a single active ingredient in reducing pest density is 88.0%, indicating the registered pesticide satisfies the “effective” criterion (roughly 70–95%) under the current pesticide registration system in Japan. Although systemic ability additionally reduced pest population to 55.5% of the post-treatment densities, the addition of active ingredients scarcely enhances efficacy (reducing population to 74.6%), suggesting that the pesticide design resulted in broadening the spectrum of target species rather than increasing toxicity.     

THE JUST-ABOUT-RIGHT INTENSITY SCALE: FUNCTIONAL ANALYSES AND RELATION TO HEDONICS

This study assessed the meaning of just‐about‐right (JAR) categories when used with a 5‐point intensity scale. The panelists comprised both consumer and in‐house respondents. The JAR categories have various meanings as perceived by the respondents: “prefer product,”“very good,”“I like the product,”“like it very much,”“highly favorable,”“high acceptability,”“desirable like the product,”“best for the situation” and “correct.” Thus, the JAR meanings invoke preference and acceptability. This article presents two additional analyses to help the product tested. One method of analysis divides below‐JAR deviation from the above‐JAR deviation, with standard statistical procedures applied in each data set. The second method introduces the signal‐to‐noise ratio statistic for analyzing the relation of JAR to overall liking. Both analytic methods provide new ways to look at the JAR data, especially with respect to hedonics and product improvement.     

Measuring environmental value for Natural Lawn and Garden Care practices

Background, Aims and Scope   Measuring Environmental Value for Natural Lawn and Garden Care Practices provides a life cycle assessment and impacts valuation methodology to quantify environmental (public health and ecological) and water conservation benefits from natural lawn and garden care practices in Seattle. Seattle Public Utilities (SPU) initiated this study as part of a triple-bottom-line analysis of its Natural Lawn and Garden Care program. Methods  The study uses life cycle assessment (LCA) methods, including the Carnegie-Mellon Economic Input-Output Life Cycle Assessment (EIOLCA) tool publicly available on the Internet, to inventory pollutant generation from a synthetic nutrients and pesticide approach to lawn and garden care compared against a natural/organic care approach. The study applies US Environmental Protection Agency’s TRACI (Tool for the Reduction and Assessment of Chemical and other environmental Impacts) climate change, acidification, eutrophication, and human health-criteria air pollutant stressor factors, along with the Lawrence Berkeley National Laboratory’s CalTOX risk assessment model’s human and ecosystem toxicity potentials to roll up the numerous pollutant quantities into six environmental impact categories (global warming potential, human respiratory disease potential, human toxicity potential, ecological toxicity potential, acidification potential and eutrophication potential). The study develops cost valuation estimates for each impact category to produce a dollar estimate of the environmental cost of the two archetypical lawn and garden care methods. Results  Lawns and gardens account for 25% of Seattle’s land area, so lawn and garden care methods potentially have substantial impacts on the city’s land-and water-based ecosystems. LCA methods provide an informative methodology for comparing environmental impacts from lawn and garden care practices. These methods reveal the importance of more natural lawn and garden care practices. They also show that resource extraction and manufacturing impacts of pesticides and synthetic fertilizers dominate their on site use impacts in the case of global warming, but that the reverse holds for human and ecological toxicity, and eutrophication. In addition, releases of particulates, SO_x and NO_x associated with gasoline-powered lawn mowing are nearly an order of magnitude larger than releases of these pollutants as a result of the production of pesticides and fertilizers. Discussion  The study proceeds by using available data and research to build a desktop model that characterizes and contrasts two archetypical lawn and garden care practices: (1) Petroleum-based fertilizers and pesticides, a gasoline-powered lawn mower, and substantial irrigation to maintain a traditional weed-free, always-green lawn and garden, versus (2) A backyard compost system to provide lawn and garden nutrients, supplemented moderately by purchased non-synthetic soil amendments, an electricity-powered mower, no pesticides, and drought tolerant lawn and garden species having little need for irrigation. Conclusions  The study concludes that each household converting from synthetic to natural practices produces nearly $75 in annual ongoing public health, ecological, water conservation and hazardous waste management benefits — between $16 and $21 of environmental benefits from reduced use of synthetic fertilizers and pesticides, $8 of environmental benefits for switching from gas to electricity for lawn mowing, $42 in cost savings due to reduced irrigation, and $5 or $6 from lower hazardous waste management costs. There also is a potential one time avoidance of $31 in construction costs resulting from reduced need for storm water detention and diversion capacity. Recommendations and Perspectives  This study’s estimates of environmental value would benefit from comprehensive information on direct exposure to active ingredients in insecticides during their application. Estimates of impacts are based only on volatilization and runoff of active ingredients after application. Furthermore, the study would benefit from estimates of carbon sequestration in soils promoted by natural lawn and garden care techniques, and on the upstream pollutant releases from production of synthetic versus organic fertilizers. All three of these data gaps suggest that the estimated $75 per single family residence for environmental value is probably a lower bound on benefits from natural lawn and garden care versus more traditional pesticide-and-synthetic-fertilizer-based approaches. ESS-Submission Editor: Mary Ann Curran (curran.maryann@epa.gov)     

Physio-chemical characterization of indigenous agricultural waste materials for the development of potting media

Organic residues are an important factor that directly affects fruiting tree seedlings' health at earlier stages. It provides a suitable environment for seedling growth by providing better nutrient ions, water, and aeration. However, low organic contents and high shrinkage of most organic materials mostly deteriorate ideal potting media characteristics. Low aeration, high water, and nutrients leaching decrease seedling growth and cause a significant loss of valuable resources. That is why the current study was conducted to screen out the best indigenous materials based on particle size to produce good characteristics bearing potting media. For that, eight different ingredients, i.e., “sugarcane”, “coconut coir”, “wheat straw”, “rice straw”, “corn cob”, “leaf litter”, “farmyard manure”, and “sunflower heads” were collected. Initially, all the materials were air-dried and processes as per requirement. After grinding, three particles size (fine = < 2 mm, medium = 3 mm and coarse = 5 mm) were separated by sieving. Results showed that decreasing particle size in “rice straw”, “corn cob”, “farmyard manure,” and “sunflower head” decreased leachate pH. Higher EC in leachates was negatively correlated with particle size in all potting media ingredients. Except for farmyard manure, fine particle size increases the water-holding ability of potting media ingredients. However, air-filled porosity was associated with a decrease in particle size of potting media in gradients. In conclusion, farmyard manure, “sunflower heads”, “leaf litter” and “sugarcane” should be incorporated while making a combination for potting media. More investigations are suggested by mixing different particle size ingredients to prepare potting media.     

Development,registration and commercialization of microbial pesticides for plant protection

Plant protection against pathogens, pests and weeds has been progressively reoriented from a therapeutic approach to a rational use of pesticide chemicals in which consumer health and environmental preservation prevail over any other productive or economic considerations. Microbial pesticides are being introduced in this new scenario of crop protection and currently several beneficial microorganisms are the active ingredients of a new generation of microbial pesticides or the basis for many natural products of microbial origin. The development of a microbial pesticide requires several steps addressed to its isolation in pure culture and screening by means of efficacy bioassays performed in vitro, ex vivo, in vivo, or in pilot trials under real conditions of application (field, greenhouse, post-harvest). For the commercial delivery of a microbial pesticide, the biocontrol agent must be produced at an industrial scale (fermentation), preserved for storage and formulated by means of biocompatible additives to increase survival and to improve the application and stability of the final product. Despite the relative high number of patents for biopesticides, only a few of them have materialized in a register for agricultural use. The excessive specificity in most cases and biosafety or environmental concerns in others are major limiting factors. Non-target effects may be possible in particular cases, such as displacement of beneficial microorganisms, allergenicity, toxinogencity (production of secondary metabolites toxic to plants, animals, or humans), pathogenicity (to plants or animals) by the agent itself or due to contaminants, or horizontal gene transfer of these characteristics to non-target microorganisms. However, these non-target effects should not be evaluated in an absolute manner, but relative to chemical control or the absence of any control of the target disease (for example, toxins derived from the pathogen). Consumer concerns about live microbes due to emerging food-borne diseases and bioterrorism do not help to create a socially receptive environment to microbial pesticides. The future of microbial pesticides is not only in developing new active ingredients based on microorganisms beneficial to plants, but in producing self-protected plants (so-called plant-incorporated pesticides) by transforming agronomically high-value crop plants with genes from biological control agents     

Sustainability indicators for municipalities of megacities: Integrating health,safety and environmental performance

The sustainability assessment of public sector organizations including municipalities, with a focus on the integration of health, safety, and environmental (HSE) issues in the context of sustainability performance indicators, has almost remained underexplored. Moreover, since a large number of the activities of megacities’ municipalities have directly to do with HSE issues, there seems to be a substantial gap in the study of megacities and corresponding local public administrations. The present study is aimed at developing a performance evaluation tool, supported by indicators, to monitor the HSE aspects of sustainable development in the municipalities of megacities. To put the proposed tool into practice, a set of performance evaluation indicators is proposed to be adopted in Iranian municipalities, integrated in the megacity of Tehran. The selection process was conducted by employing Delphi technique. In doing so, a 2-round questionnaire was responded by qualified experts to select the most robust indicators of HSE performance and evaluate the priority of each indicator. A total of 80 indicators were generated and grouped into 13 categories, 29 sub-categories, and 7 themes- (Health (H), Safety (S), Environment (E), Health-Safety (HS), Health-Environment (HE), Safety-Environment (SE), and Health, Safety and Environment (HSE)). Findings indicate that amongst the overall average score of the 13 categories, “Fire and emergency response” is the most important category, closely followed by “Waste”, “Transportation”, and “Natural systems” categories. Moreover, among the 7 proposed themes, the integrated “HSE theme”, nearly followed by “safety theme”, plays the most significant role in enhancing the HSE performance of sustainability in Tehran municipalities. It is concluded that in the HSE context of the megacities municipalities under scrutiny, social aspects of sustainability gain more attention in comparison with the environmental ones. Furthermore, in municipalities of megacities, the indicators related to health and safety could be considered as ‘key indicators’ and should be thus classified into independent categories so that their roles can be highlighted in the management and assessment of municipal sustainable development.     

Comparing the recovery of richness,structure, and biomass in naturally regrowing and planted reforestation

The clearing of natural vegetation for agriculture has reduced the capacity of natural systems to provide ecosystem functions. Ecological restoration can restore desirable ecosystem functions, such as creating habitat for animal conservation and carbon sequestration as woody biomass. In order to maintain these beneficial ecosystem functions, restoration projects need to mature into self‐perpetuating communities. Here we compared the ecological attributes of two types of restoration, “active” tree plantings with “passive” natural forest regeneration (“natural regrowth”) to existing remnant vegetation in a cleared agricultural landscape. Specifically, we measured differences between forest categories in factors that may predict future restoration failure or ecosystem collapse: aboveground plant biomass and biomass accrual over time (for regrowing stands), plant density and size class distributions, and diversity of functional groups based on seed dispersal and growth strategy traits. We found that natural regrowth and planted forests were similar in many ecological characteristics, including biomass accrual. Despite this, planted stands contained fewer tree recruit and shrub individuals, which may be due to limited recruitment in plantings. If this continues, these forests may be at risk of collapsing into nonforest states after mature trees senesce. Lower shrub density and richness of mid‐story trees may lead to lower structural complexity in planting plots, and alongside lower richness of fleshy‐fruited plant species may reduce animal resources and animal use of the restored stand. In our study region, natural regrowth may result in restored woodland communities with greater conservation and carbon mitigation value.     

Natural decision theory: A general formalism for the analysis of evolved characteristics

Classical Decision Theory, a mature and highly developed theory of rational choice, can be applied within evolutionary biology to the question of what traits an organism ought “rationally” to adopt, given that it wants to maximize its fitness. In this way the powerful formalism of decision theory can be brought to bear on the problem of how to predict which characters will be favored by natural selection, or to explain why certain characters have been so favored.Under some circumstances the classical theory of decision can be applied as it stands to an evolutionary problem simply by substituting an appropriate measure of biological fitness for the decision-theoretic concept of “utility”. Under other circumstances, however, it is necessary to extend the classical rules of decision in certain new directions. The result is a family of decision calculi of which the classical is only one. The name “Natural Decision Theory” is proposed for this extended class of biologically relevant decision methods.The decision tree method of diagramming an evolutionary decision situation is illustrated for the classical and three non-classical decision criteria, and is suggested as a potential means of gaining new insights into evolutionary forces.     

The genomic context of retrocopies increases their chance of functional relevancy in mammals

Described as “junk” DNA, pseudogenes are dead structures of previously active genes present in genomes. Pseudogenes are categorized into two main classes: processed pseudogenes, formed through retrotransposition, and non-processed pseudogenes, typically originated from gene decay following duplication events. The term “processed pseudogene” has changed to “retrocopy” since they are likely to evolve new functional roles and became a retrogene. Here, we surveyed 38,080 retrocopies from chimpanzee, dog, human, mouse, and rat genomes to assess their potential adaptive value. The retrocopies inserted in the same chromosome of the parental gene have higher chances of remain potentially “active” (absence of premature stop codons and frameshifts) (~26.1%), while those placed into a different chromosome have a twofold decrease chance of continuing potentially “active” (~7.52%). The genomic context of their placement seems associated with their expression. Retrocopies placed in intragenic regions and the same sense of the “host” gene have higher chances of being expressed relative to other genomic contexts. The proximity of retrocopies to their parental gene is associated with a lower decay rate, and their location likely influence their expression. Thus, despite their unclear role, retrocopies are probably involved in adaptive processes. Our results evidence natural selection acting in retrocopies.     

Modeling landscape condition for biodiversity assessment—Application in temperate North America

Conservation decisions are well supported by predictive spatial models that indicate the relative ecological condition of a given place. The intent of this 90 m pixel landscape condition model is to use nationally available spatial data from the USA, Mexico, and Canada to express assumptions regarding the relative ecological effects of land uses on terrestrial natural communities and species. This approach emphasizes and updateable and transparent design which takes advantage of empirical biodiversity data from the USA to both calibrate and validate the model. Map layers depicting infrastructure, land use, and modified vegetation were each scored for site impact and distance decay, and then combined into one map surface. Field observations from Natural Heritage Programs, each scored for relative ecological condition (in categories A = excellent to D = poor), were used to calibrate distance decay parameters. Some 90,000 observations for at-risk species, invasive plant species, and natural communities were used for model validation. Statistically significant distinctions in ecological condition among validation samples were predicted by the resultant spatial model. Variation in landscape condition was then summarized by regional U.S. Landscape Conservation Cooperatives (LCCs) in terms of areas approximating A–D condition. Montane and desert LCCs scored on average much higher in area approximating “A” and “B” landscape condition, while LCCs with more substantial agricultural and urban footprints scored overwhelmingly within the “D” range of condition. Similar analyses illustrated range-wide scoring of landscape condition for major vegetation types across temperate North America.