Quinone Binding Sites of Membrane Proteins as Targets for Inhibitors

Quinones are a central component of most photosynthetic and respiratory electron transfer chains. The proteins that reduce and oxidise these quinones have quinone binding sites—Q sites—that are good targets for pesticides. This paper reviews the diversity of these sites, their possible structure, and the types of compounds that act upon them.     

Pesticide Adsorption as a Function of Depth below Surface

The adsorption of atrazine and mecoprop to soil at different levels below the surface was measured and compared with values calculated from the partition coefficient—between soil organic carbon and water—and the carbon content. With soil samples from the top layers, the calculated values were in fairly good agreement with the measured values. Below the top layers, the importance of the effect of clay content on the adsorption is reflected in the difference between the measured and calculated K_d values. Calculated values can be unrealistically low resulting in overestimates of leaching. © 1997 SCI.     

Herbicidal phenylalkylureas as possible mutagens: II. Chemical basis of mutagenic activity

The herbicide monuron (N-(4-chlorophenyl)-N′, N′-dimethylurea)—a recognized carcinogen—and some of its congeners have been found also to induce back mutations in Salmonella typhimurium (Ames test), as well as micronuclei in mouse bone marrow cells and an inhibition of testicular DNA synthesis (DSI test) in mice. As both the Ames test and the DSI test correlate well with chemical carcinogenicity, urea herbicides in general might be suspected of carcinogenic activity. In order to investigate the potential carcinogenic mode of action of these substances we looked for possible activation mechanisms. The reaction sequence N-oxidation-esterification-carbonium ion formation seemed the only one able to fit the observed structure-activity relationships. Chemical synthesis of the proposed N-acetoxy compounds provided the means for testing this hypothesis. Only the N-acetoxy-, but neither the N-hydroxy- nor the unchanged parent ureas, exhibited a direct alkylating action as measured by the NBP-assay. The DSI reactivity pattern of several positional isomers could be shown to coincide with the theoretical predictions, as did the stability of the chloroisomers in aqueous solution at pH 7. Furthermore the N-acetoxy derivatives could be demonstrated to behave in the Ames test as directly acting mutagens, while the activity of the parent compounds is dependent on the metabolic activation by an S-9-liver fraction. The enhancing action of Acetyl-CoA on the S-9 mediated mutagenicity of these ureas can then be regarded as the final proof for the proposed reaction sequence.     

7‐(4,6‐Dimethoxypyrimidinyl)oxy‐ and ‐thiophthalides as novel herbicides: Part 1. CGA 279 233: a new grass‐killer for rice

A series of novel types of 7‐(4,6‐dimethoxypyrimidin‐2‐yl)oxy ‐ and ‐thio‐3‐methyl‐1 (3H)‐isobenzofuranones were discovered at Dr R Maag AG. From the thio‐isobenzofuranyl series, CGA 279 233—BSI‐proposed common name pyriftalid—was chosen for further development as a grass herbicide for use in rice. General synthetic approaches to these new phthalic acid‐derived compounds are given, with emphasis on the synthesis of pyriftalid and its physico‐chemical behaviour. © 2001 Society of Chemical Industry     

Trichoderma as a biostimulator and biocontrol agent against Fusarium in the production of cereal crops: Opportunities and possibilities

Despite technological advances in global agriculture in recent years, the problem of pathogenic fungi in the production of cereal crops continues to be an issue. Currently, the high variability of weather factors that are considered unusual for specific locations affect the growth and physiology of pathogens attacking cereal crops. One of the most common plant protection methods is the use of synthetic pesticides; however, there is growing controversy over this approach due to the build-up of pesticides in the environment and the presence of their residues in food. The purpose of this literature review is to explore the current state of knowledge regarding the potential of using Trichoderma species as a biostimulator and for the biological protection of cereal crops against pathogenic fungi. Trichoderma fungi—through mycoparasitism, antibiosis and competition for space and nutrients—help to inhibit the growth of pathogens and have a positive impact on the growth of plants, including their root system, which is considered a desirable effect during drought episodes. It has also been demonstrated that Trichoderma fungi can convert Fusarium toxins into new metabolites that can be of lower toxicity. However, the highly limited number of in vivo studies investigating the use of these fungi for biocontrol in cereal crops remains an obstacle to the commercialization of Trichoderma fungi. It appears that the determination of their effectiveness in the biocontrol of cereal crops under variable weather and climate conditions presents a considerable challenge.     

生防菌解淀粉芽胞杆菌Lx-11悬乳剂研制及其对水稻白叶枯病的防治效果评价

目前已经登记的芽胞杆菌微生物杀菌剂剂型以悬浮剂和可湿性粉剂为主，剂型相对比较单一，为进一步提高货架期和利用效率，以解淀粉芽胞杆菌Lx-11作为研究对象，筛选出纳米材料作为载体，添加各种不同功能性助剂，在高速均质机的作用下剪切、均质，研制出解淀粉芽胞杆菌Lx-11悬乳剂。解淀粉芽胞杆菌Lx-11悬乳剂配方：发酵液70%～80%，吸附载体白炭黑10%～15%，大豆油30%～50%，乳化剂Span80和Tween80复配6%～10%，分散剂脂肪醇聚氧乙烯醚羧酸钠1%～3%，防冻剂乙二醇2%～4%，增效助剂SY-6535 1.5%～2.5%。该制剂的性能指标为：活菌体含量大于8×10⁸cfu/mL，悬浮率大于85%，粘度225 mPa·s，热贮稳定性合格；各项技术指标均符合产品标准要求。田间药效试验表明：解淀粉芽胞杆菌Lx-11悬乳剂对水稻白叶枯病的防治效果显著高于其发酵液。     

The prediction of biodegradability by the use of quantitative structure–activity relationships: Correlation of biological oxygen demand with atomic charge difference

The use of quantitative structure—activity relationships for the prediction of bioaccumulation, toxicity and biodegradability is briefly surveyed. A new parameter—the difference of the modulus of atomic charge across a selected bond in a molecule—is shown to correlate extremely well with 5-day biological oxygen demand for several series of compounds; furthermore, the equations for the several series are then combined to give a single, all-embracing correlation for the quantitative prediction of biodegradability.     

The occurrence of Fusarium crown and root rot of tomato in Israel

Based upon symptomatology and the results of pathogenicity tests, it has been shown that the Fusarium crown and root rot organism of tomato — previously reported only from North America and Japan — is present in Israel.     

Damage by vertebrates to plastic irrigation pipes in Israel

Plastic irrigation pipes are damaged in Israel by vertebrates — both mammals and birds — of the following species: Aves: Piciformes, Picidae —Dendrocopos syriacus. Mammalia: Rodentia —Mus musculus, Rattus rattus alexandrinus, Nesokia indica, Spalax ehrenbergi, andHystrix indica; Carnivora: Canidae —Canis familiaris, C. aureus, andVulpes vulpes; Mustelidae —Meles meles; Viveridae —Herpestes ichneumon; Artiodactyla, Suiformes: Suidae —Sus scrofa. It is assumed that the reasons these vertebrates attack and damage the pipes are the excitement regulation mechanism; the habit of gnawing or pecking; playing; and a search for drinking water.     

Mode of action of meturine

The effect of meturine on the light processes of photosynthesis was studied.Meturine is a herbicide for weed control in potato and cotton crops. It is a N-phenyl—N-hydroxy—N′-methylurea.The experiments were carried out on isolated pea and spinach chloroplasts.When examining photosystem I, reduced DPIP was used as an electron donor, whereas methyl-viologen served as an electron acceptor. When examining photosystem II, DPIP represented the electron acceptor.The obtained experimental results have pointed to the absence of the effect of meturine upon the photoreaction I.Unlike N-phenyl—N′, N′-dimethylureas (CMU, DCMU) meturine has been a very weak inhibitor of photoreaction II.The authors explain the photoreaction II inhibition of chloroplasts from plants treated with herbicidal doses of meturine by conversion of N-phenyl—N-hydroxy—N′-methylurea into Hill reaction inhibitor(s). N-Phenyl—N′-methylurea can be one of such meturine metabolites.Meturine herbicidal action is accounted for by meturine transformation into Hill reaction inhibitor(s) in the plant tissues.     

2.0亿CFU/mL嗜硫小红卵菌HNI-1悬浮剂研发与应用

2.0亿CFU/mL嗜硫小红卵菌HNI-1悬浮剂防治对象为番茄根结线虫和番茄花叶病。番茄根结线虫防治选择番茄移栽时进行灌根处理,每季使用2～3次,用量400～600 mL/667 m²;番茄花叶病防治选择发病前或发病初期,采用喷雾方式,每季使用2～3次,用量180～240 mL/667 m²。该制剂为纯生物制剂,使用后未见药害发生;对捕食天敌、寄生天敌低毒或无影响。     

Rearing of the leopard moth,Zeuzera Pyrina L., on an improved diet

Larvae of the wood borerZeuzera pyrina L. were reared on a practical diet based on soybean — milk powder — yeast as the nutrient source, and sugar-beet pulp as a binder. This diet improved the yield of adults from neonates and increased the number of matings, compared with an agar — pear-bark diet. The larva-to-adult period on the experimental diets was 3–4 months, which is one-third the period within the tree. Mass rearing of this insect for biological control programs is discussed.     

Principles in the absorption,distribution and elimination of pharmaceuticals

The processes by which the body handles drugs and which determine the temporal profile of drug concentrations in the body can be conveniently categorized into: absorption —process of drug transport from the site of release of drug from the delivery system into the systemic blood circulation; distribution —process of reversible transport of drug molecules from the site of absorption to those tissues of the body into which the drug is able to distribute; and elimination —process of irreversible removal of drug molecules from the body. Elimination of drug from the body will occur by metabolism—chemical modification of drug, and/or excretion—physical removal of drug from the body, e.g. renal or biliary excretion. This article first discusses the composition and structure of mammalian cell membranes, as this is fundamental to understanding the relationship between a drug's physicochemical properties and its membrane transport, and as a corollary, the understanding of the processes of drug absorption, distribution and elimination. Mechanisms involved in the absorption, distribution and elimination of pharmaceuticals are then discussed through integration of mammalian physiology, biochemistry and drug physicochemical properties. Further, the effect of changes in the above processes upon drug concentration-time profiles in the body is considered.     

渭河流域气象及水文旱涝演变规律分析

降水是径流的基本来源,分析极端旱涝条件下降水与径流之间演变规律的异步性,可有效表征径流丰枯变化对人类活动的响应。基于渭河流域降水、径流资料,采用泰森多边形法计算渭河流域面降水量及12个月标准化降水指数(SPI12),对比典型频率下SPI12的空间分布特征及其对径流系数的影响;采用经验正交函数和时间序列分析法挖掘SPI12和年径流量的演变规律,对比演变规律的同步及异步变化特征。结果表明:在25%、50%、75%频率下,流域面降水量分别为582.5 mm、518.6 mm、467.5 mm。SPI12第一主成分减少趋势显著,自1991年7月开始突变,于1962-09(1962年9月,下同)—1969-07—1983-02—1985-08—1991-07—1999-12呈现湿润~正常~湿润~正常~干旱状态。渭河年径流量呈显著减少趋势,自1989年开始突变,且分别于1950—1968和1982—1993年经历湿润和正常阶段,于1970—1974、1976—1980、1994—2007年经历干旱阶段。以流域内大规模水利、水土保持措施及城市化等为代表的人类活动使流域年径流量较SPI12第一主成分突变年份提前,使二者于1970—1996年间旱涝类型不匹配,年径流量相对SPI12第一主成分呈现旱化趋势。     

补充营养对草地贪夜蛾成虫存活和繁殖的影响

草地贪夜蛾Spodoptera frugiperda（Smith）是一种远距离迁飞害虫,其成虫生存期间会取食,但是取食获得的水和糖在其交配繁殖中的作用目前并不清楚。本研究利用卵巢解剖法和行为观察法,详细研究了成虫喂食对草地贪夜蛾存活、卵巢发育和繁殖的影响。发现饥饿不喂食草地贪夜蛾成蛾存活时间短（约3 d）,卵巢发育不成熟（低于2级）、交配率低（22.00%）、几乎不产卵（5.8枚）,卵几乎不孵化（3.0%）。喂食纯水或蜂蜜水成蛾存活时间长（6~8 d）,雌蛾卵巢发育成熟（3.4~3.6级）、交配率高（61.1%~66.7%）、产卵量大（436~1281枚）、卵孵化率高（大于95%）,均显著大于不喂食成蛾。喂食对交配雌蛾的交配次数（1.1~1.7次）和未发育成熟雌蛾的交配率（18.2%~22.9%）无显著影响。喂食蜂蜜水雌蛾的存活时间（8.06 d）和产卵量（1281枚）显著大于喂食纯水（分别为6.57d和436枚）,而雄蛾存活时间、雌蛾卵巢发育等级、交配率、卵孵化率在喂食纯水和蜂蜜水之间无显著差异。本研究结果认为水是草地贪夜蛾成蛾存活和繁殖必须补充的物质,糖仅能增加雌蛾的产卵量。仅仅利用花香气味进行草地贪夜蛾的监测和防控,效果可能不理想。这些结果为草地贪夜蛾的精准监测和有效防控提供理论依据。     

用洛川黄土中碳同位素重建140万年以来古气候

在洛川黄土剖面,通过密集采样,做出从第三纪红到整个第四纪黄土地层的碳同位素分析。1δ3C曲线可与大西洋深海钻孔DSDP607的氧同位素曲线及南极氘温度详细对比。S5上有一个特别突出的负高峰,1δ3C=-16.615‰,是气候最温湿的阶段。S0、S1、S4、S8、S9的δ13C峰值在-5.85—-10.00‰之间,是一般间冰期阶段。峰值在-8.72—-6.95‰的S2、S3、S6、S7等对应的是温干的间冰期。L1、L2、L5、L6、L8、L9的1δ3C在-3.7—-2.27‰之间,是一些极冷的冰期。因此,黄土1δ3C是一个灵敏的替代性古气候指标。     

山东省聊城市棉田杂草种类和数量对棉花产量的影响

调查山东省聊城市棉田杂草种类,分析其数量对棉花产量的影响。结果表明,棉田中禾本科杂草主要有牛筋草、马唐、稗、千金子;莎草科主要有异型莎草;阔叶杂草主要有藜、鳢肠、马齿苋、反枝苋等。各科杂草都会明显降低棉花的株高、果枝数、铃数和单铃质量等产量指标,其中对成铃数的影响最大。与无草区相比,杂草混生对棉花的生长影响最大,棉花株高、果枝数、铃数、单铃质量分别降低了52.9%、65.6%、87.6%、15.5%,棉花产量降幅高达90.5%;其次为阔叶杂草生长区,棉花产量降低87.5%;禾本科、莎草科杂草对棉花的影响亦很高,棉花产量分别降低69.8%、57.7%。     

哈尔滨沙尘天气的源地分析

本文对哈尔滨2002年3月20日的沙尘暴沉积物进行了粒度分析研究。结果表明:沉积物4—8Ф的粉砂占71.18%,>4Ф的砂粒组分占21.7%,<8Ф的粘土组分仅占7.13%;粒度分布呈现三峰态特征,4.85—5.10Ф粒级组成第一主峰,1—1.25Ф粒级为第二主峰,10.25—10.5Ф粒级形成第三主峰;平均粒径Mz为5.14Ф。哈尔滨沙尘暴沉积物是迄今为止有见报道中最粗的,是不同来源沙尘远距离和近距离搬运的混合体。本文认为哈尔滨市沙尘暴的远距离沙源为内蒙古镜内沙地、科尔沁沙地、近距离沙源为松嫩平原和哈尔滨周边地区。     

Effect of diclobutrazol on the growth and sterol and photosynthetic pigment content of winter wheat

The effect of the fungicide, diclobutrazol, on the germination, growth, chloroplast pigment and sterol content of winter wheat seedlings has been studied. At 250 μEm it retards their germination and growth, producing smaller, darker green and apparently healthy young plants. This is largely due to the 2S,3S–enantiomeric component. The increased greenness is not due to a direct effect on chloroplast pigments. It inhibits sterol 14—demethylation, causing an increase in the content of 4α,14α–dimethyl sterols, and also increases the proportion of campesterol, a 24—methyl sterol, relative to that of the 24—ethyl sterols, stigmasterol and sitosterol. Both the 2R,3R– and 2S,3S–enantiomers appear to be able to cause these changes in sterol content.     

Viral sanitary status of declining grapevine Syrah clones and genetic diversity of Grapevine Rupestris stem pitting-associated virus

In order to determine the etiology of Syrah decline, virus detection was performed on 22 Syrah clones, chosen for their various levels of sensitivity to Syrah decline. All clones, including the sensitive ones, were free of 20 main grapevine viruses. In contrast, Grapevine Syrah virus-1 and Grapevine Rupestris stem pitting-associated virus (GRSPaV), were detected in 56 % and 100 % of the analysed Syrah clones respectively. This is the first report of GSyV-1 in a French vineyard. The genetic diversity of a 380 nt region within the GRSPaV coat protein gene was studied extensively in vines differing in their sensitivity to Syrah decline. Most GRSPaV variants were scattered between the four phylogenetic groups previously identified; 65 % of the sequences analysed were found to belong to the GRSPaV—group 1, 22 % to—group 2b, 10 % to—group 2a and 2 % to—group 3. Seventy percent of the 31 plants analysed harboured mixtures of genomic variants. Statistical analyses revealed no significant correlation between sensitivity and GRSPaV sequence variation. This suggests that GRSPaV is not the direct etiological agent of the Syrah decline.