Chemical regulators of plant hormones and their applications in basic research and agriculture*

Plant hormones are small molecules that play versatile roles in regulating plant growth, development, and responses to the environment. Classic methodologies, including genetics, analytic chemistry, biochemistry, and molecular biology, have contributed to the progress in plant hormone studies. In addition, chemical regulators of plant hormone functions have been important in such studies. Today, synthetic chemicals, including plant growth regulators, are used to study and manipulate biological systems, collectively referred to as chemical biology. Here, we summarize the available chemical regulators and their contributions to plant hormone studies. We also pose questions that remain to be addressed in plant hormone studies and that might be solved with the help of chemical regulators.     

化学基因组学和化学蛋白质组学用于细胞自噬研究

化学基因组学和化学蛋白质组学作为后基因组时代的新技术,是以化学小分子为工具,对细胞的生理过程进行精确干扰,研究有机体和细胞的功能,同时也是新药开发的重要手段。本文综述了化学基因组学和化学蛋白质组学征自噬相关靶点的特异性小分子的发现,及小分子存自噬机理研究中的应用。     

魔芋葡甘露聚糖化学结构及改性研究进展

本文综述了魔芋葡甘露聚糖的理化性质、化学结构及改性的研究进展     

Chemical convergence between a guild of facultative myrmecophilous caterpillars and host plants

1. Ants exert strong selective pressure on herbivorous insects, although some caterpillars can live in symbiosis with them using chemical defensive strategies.
2. We investigated the adaptive resemblance of cuticular hydrocarbons (CHCs) in multitrophic systems involving a guild of facultative myrmecophilous caterpillar species (Lepidoptera: Lycaenidae), tending ants (Hymenoptera: Formicidae), and host plants from three families. We hypothesised that the CHCs of the caterpillars would resemble those of their host plants (chemical camouflage).
3. We analysed CHCs using gas chromatography/mass spectrometry. Morisita's similarity index (SI) was used to compare CHC profiles of caterpillar species with different types of ant associations (commensal or mutualistic), ants, and host plants.
4. We found strong convergence between caterpillars' CHCs and plants, especially for commensal species that do not provide secretion rewards for ants. Moreover, we found unexpected chemical convergence among mutualistic (trophobiotic) caterpillar species that offer caloric reward secretions to ants.
5. These results show that the studied caterpillars acquire CHCs through their diet and that they vary according to host plant species and type of ant association (commensalism or mutualism). This ‘chemical camouflage’ of myrmecophilous caterpillars may have arisen as a defensive strategy allowing coexistence with ants on plants, whereas ‘chemical conspicuousness’ may have evolved in the context of honest signalling between mutualistic partners.
6. We suggest the existence of chemical mimicry among myrmecophilous species, especially between mutualistic caterpillars. Cuticular chemical mixtures can play a key adaptive role in decreasing ant attacks and increasing caterpillar survival in multimodal sensory systems.

     

Empirical correlation between protein backbone <Superscript>15</Superscript>N and <Superscript>13</Superscript>C secondary chemical shifts and its application to nitrogen chemical shift re-referencing

The linear analysis of chemical shifts (LACS) has provided a robust method for identifying and correcting ¹³C chemical shift referencing problems in data from protein NMR spectroscopy. Unlike other approaches, LACS does not require prior knowledge of the three-dimensional structure or inference of the secondary structure of the protein. It also does not require extensive assignment of the NMR data. We report here a way of extending the LACS approach to ¹⁵N NMR data from proteins, so as to enable the detection and correction of inconsistencies in chemical shift referencing for this nucleus. The approach is based on our finding that the secondary ¹⁵N chemical shift of the backbone nitrogen atom of residue i is strongly correlated with the secondary chemical shift difference (experimental minus random coil) between the alpha and beta carbons of residue i − 1. Thus once alpha and beta ¹³C chemical shifts are available (their difference is referencing error-free), the ¹⁵N referencing can be validated, and an appropriate offset correction can be derived. This approach can be implemented prior to a structure determination and can be used to analyze potential referencing problems in database data not associated with three-dimensional structure. Application of the LACS algorithm to the current BMRB protein chemical shift database, revealed that nearly 35% of the BMRB entries have δ ¹⁵N values mis-referenced by over 0.7 ppm and over 25% of them have δ ¹H^N values mis-referenced by over 0.12 ppm. One implication of the findings reported here is that a backbone ¹⁵N chemical shift provides a better indicator of the conformation of the preceding residue than of the residue itself. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

干、湿化学法在乳糜血中的应用比较

目的探讨乳糜血对干、湿化学法检测结果的影响,以期找到一种适合于在乳糜血中应用的检测方法。方法分别用干、湿化学法检测乳糜血中总蛋白、血糖,比较两种方法检测结果差异。结果湿化学法测定结果高于乙醇处理法(P0.05),干化学法与乙醇处理法结果比较差异无显著性(P0.05)。结论在乳糜血检测中干性化学法与湿性化学法比较更接近真实值。     

Identification of new candidate drugs for lung cancer using chemical–chemical interactions,chemical–protein interactions and a K-means clustering algorithm

Lung cancer, characterized by uncontrolled cell growth in the lung tissue, is the leading cause of global cancer deaths. Until now, effective treatment of this disease is limited. Many synthetic compounds have emerged with the advancement of combinatorial chemistry. Identification of effective lung cancer candidate drug compounds among them is a great challenge. Thus, it is necessary to build effective computational methods that can assist us in selecting for potential lung cancer drug compounds. In this study, a computational method was proposed to tackle this problem. The chemical–chemical interactions and chemical–protein interactions were utilized to select candidate drug compounds that have close associations with approved lung cancer drugs and lung cancer-related genes. A permutation test and K-means clustering algorithm were employed to exclude candidate drugs with low possibilities to treat lung cancer. The final analysis suggests that the remaining drug compounds have potential anti-lung cancer activities and most of them have structural dissimilarity with approved drugs for lung cancer.     

Chemical defensive substances of soft corals and gorgonians

Despite lack of efficient physical protection in the highly competitive and hostile environment, the marine invertebrates including soft corals and gorgonians can survive, mainly relying on their chemical defensive system by a series of secondary metabolites accumulating in their bodies or releasing to their surroundings. The chemical defensive functions of these secondary metabolites were found to serve as antipredatory, antimicrobial, allelopathy and antifouling agents. Study on chemical defensive substances from corals and gorgonians is one of the most important topics in marine chemical ecology. The research results could help us to understand the chemical ecological relationships between corals and their surrounding organisms. The research strategy and methodology played an enlightening role in the discovery of bioactive natural products and the generation of new drug lead compounds from marine sources. The chemical defensive substances from soft corals and gorgonians were reviewed. This review focused on the structures of these secondary metabolites as well as their functions including antipredatory, allelopathy and antifouling activities.     

Chemical defensive substances of soft corals and gorgonians

Despite lack of efficient physical protection in the highly competitive and hostile environment, the marine invertebrates including soft corals and gorgonians can survive, mainly relying on their chemical defensive system by a series of secondary metabolites accumulating in their bodies or releasing to their surroundings. The chemical defensive functions of these secondary metabolites were found to serve as antipredatory, antimicrobial, allelopathy and antifouling agents. Study on chemical defensive substances from corals and gorgonians is one of the most important topics in marine chemical ecology. The research results could help us to understand the chemical ecological relationships between corals and their surrounding organisms. The research strategy and methodology played an enlightening role in the discovery of bioactive natural products and the generation of new drug lead compounds from marine sources. The chemical defensive substances from soft corals and gorgonians were reviewed. This review focused on the structures of these secondary metabolites as well as their functions including antipredatory, allelopathy and antifouling activities.     

Controlled environment soil‐core microcosm unit for investigating fate,migration, and transformation of chemicals in soils

The controlled environment soil‐core microcosm unit (CESMU) methods embody a collection of techniques that began with soil sampling in the field and continued throughout the laboratory investigation of chemical fate, migration, and transformation in site‐specific soils; it was a cost‐effective investigative methodology that could be used to screen chemical materials before initiating high‐cost environmental field studies. Intact soil cores were collected in the field using a hydraulically controlled probe, delivering intact soil‐cores with minimal disturbance directly into high‐density polyethylene pipe (10.3‐cm ID). The inert polyethylene pipe was an effective hydrophobic barrier that remained an integral part of the soil‐core column, obviating subsequent transfers of soil. In the laboratory, each soil column was fitted with a porous ceramic plate and a polyethylene endcap containing fittings for teflon tubing, so that a tension could be applied at the bottom of each soil column (30–35 kPa) to mimic field conditions, thus preventing the undue buildup of water within columns that otherwise would change the chemical, physical, and biological properties of the soil. The intact soil‐cores were housed in the CESMU chamber, a controlled temperature unit with sufficient capacity for maintaining constant temperature within entire soil‐cores. Synthetic rain was added twice a week by peristaltic pump at rates simulating rainfall. Leachates were collected under tension via teflon tubing into flasks in darkness and kept at soil column temperature inside CESMU until harvested for analyses. Soil columns were harvested at intervals for sectioning by depth, extraction, and soil analyses. CESMU methods are applicable to investigations of water movement, soil chemistry, solute transport/transformation, and effects on plants.     

溶剂型真空过滤干燥机的分析和设计

设计了一种用于薯芋皂甙水解物提取的溶剂型真空过滤干燥装置,该装置能极大地改善工作环境,提高溶剂油的使用效率,简化工艺流程。而且,它不仅适用于薯芋皂素的过滤干燥,还适用于颗粒较细的物料有效成分的过滤和干燥。     

匹拉米洞法、邻联甲苯胺法和联苯胺法检测林麝便隐血的比较

圈养林麝(Moschusberezovskii)长期受困于消化道类疾病,尤其是肠道炎症性疾病患病率和死亡率一直居高不下。粪便检测是评估野生动物消化系统是否存在出血情况的有效方法之一,并且在圈养林麝肠道健康状况评估及肠道炎症性疾病临床诊断等方面提供了一定的诊断依据。粪便隐血在消化道出血诊断中有广泛的临床诊断价值。基于此,本研究用新鲜的林麝血液进行稀释,来探究匹拉米洞法、邻联甲苯胺法和联苯胺法三种方法对林麝血液浓度的灵敏度范围。检测结果显示,匹拉米洞法的最低敏感性检测浓度为0.05 mg/L,敏感性范围远大于邻联甲苯胺法(0.40 mg/L)和联苯胺法(100.00 mg/L)。分别利用三种检测方法对林麝粪便潜血进行检测,比较检测结果的阳性率,结果显示,匹拉米洞法的检测效果优于其他两种方法,阳性率分别为匹拉米洞法检测法10.13%、邻联甲苯胺法检测法2.56%和联苯胺法检测法0,差异有诊断学意义(P <0.05)。而且在操作上,匹拉米洞法更加简便快捷。故在诊断林麝消化道出血时,采用匹拉米洞法进行林麝便隐血的检测更加准确便捷。     

Bioactivities,bioactive compounds and chemical constituents of mangrove plants

This review article presents the traditional and medicinal uses, and examines recent investigations on the biological activities of extracts, and chemicals identified from mangroves and mangal associates. Metabolites identified from mangrove plants are classified according to ‘chemical classes’, and some of their structures are illustrated. The article also presents some of the functions of the chemicals present and attempt to emphasize and create an awareness of the great of potential mangroves and mangal associates possess as a source of novel agrochemicals, compounds of medicinal value, and a new source of many already known biologically active compounds. This revised version was published online in July 2006 with corrections to the Cover Date.     

土壤中重金属形态分析及其环境学意义

介绍了土壤重金属的形态及各种分析方法,重点说明了土壤中重金属形态分布及影响因素;讨论了影响土壤环境中重金属形态转化的因素,重金属形态与重金属在土壤中的迁移性、可给性、活性的关系,重金属污染土壤修复与重金属形态分布的关系.形态分析在一定程度上反映自然与人为作用对土壤中重金属来源的贡献,并反映重金属的生物毒性.重金属可以因形态中某一个或几个方面不同而表现出不同的毒性和环境行为.     

Impact of sixteen chemical pesticides on conidial germination of two entomophthoralean fungi: Conidiobolus thromboides and Pandora nouryi

Effects of sixteen chemical pesticides on conidial germination of C. thromboides and P. nouryi were investigated at two concentrations (R and 0.2R, where R=the lowest manufacture's recommended concentration for field use). Of the fungicides tested, propamocarb hydrochloride did not significantly affect conidial germination of C. thromboides, but at R it completely inhibited conidial germination of P. nouryi. At 0.2R of procymidone, iprodione, haloxyfop-methyl and fenoxaprop-p-ethyl, conidia of C. thromboides had some germination after 24 h, although they entirely restricted conidial germination of the fungus at the concentration of R. Tribenuron-methyl, one herbicide, had no adverse effect on conidial germination of C. thromboides and P. nouryi after 6 h at the two concentrations, whereas the other seven herbicides were strongly antagonistic to P. nouryi, except for carfentrazone-ethyl at 0.2R.     

Chemical partitioning of Cu,Pb and Zn in the soil profile of a semi arid dry woodland

Abstract

The chemical partitioning of Cu, Pb and Zn was examined in the soil profile of the woodland system in Keoladeo National Park, India using a five-step sequential extraction procedure (SEP). Metal partitioning was assessed in the soil up to a depth of 100cm with 25-cm intervals. The amount of metals obtained from the SEP exceeded pseudototal metal levels obtained from aqua regia digestion. The SEP results showed high preferential attachment of metals with Fe—Mn hydroxides. All the three metals showed least preferences to the exchangeable pool. The attachment of metals to the OM-S phase was also less, may be because of the low organic matter in the soil. In the case of Cu, the order of the fractions in terms of metal concentrations was Fe—Mn>RES>OM-S>CA>EXC and in the case of Pb the order was Fe—Mn>OM-S>RES>CA>EXC. Zn was different from Cu and Pb in showing higher affinity towards RES phase and the order of its concentration was RES>Fe—Mn>OM-S>EXC>CA. This suggests hydrous oxides of Fe—Mn as an important binding site for Cu and Pb, whereas silicate mineral matrix (RES phase) for Zn.     

3种不同香型玫瑰精油特性的研究

依照ISO9842和保加利亚玫瑰精油标准(БДС653),对来自陕西渭南玫瑰产区栽培的3种不同类型玫瑰精油进行了分析研究。渭玫1号精油来自保加利亚的大马士革玫瑰品科“kazanlik”,渭玫2号、3号分别是来自摩洛哥的百叶玫瑰和中国苦水玫瑰。就得油率而言,1996～2000年连续5年的平均得油率以渭玫l号最高达0．42‰,不低于在保加利亚栽培的得油率。3种精油在外观、色泽上无差异,而香气差别明显。三者分别为纯甜型、清甜型和浓甜型。GC-MS对3种精油分析表明,前二种均分析出115种成分,渭玫3号精油仅得到105种组分,三者主成分类型一致。主成分香茅醇均符合ISO9842和БДС653标准。中国传统玫瑰油渭玫3号蜡质含量相对极低,仅为渭玫1号的8％。     

The Relationship Between Tobacco Yield and Time of Infection with Meloidogyne javanica

Yield of tobacco was related to the amount of infection by Meloidogyne javanica during the first month after transplanting. Six nematicidal treatments significantly reduced infection during this period and subsequently increased yield. However, during the second month after transplanting, infection in plots treated with O-ethyl S,S-dipropyl phosphorodithioate (V-C 9-104) and a mixture of 80% chlorinated C₃ hydrocarbons + 20% methyl isothioeyanate (DD + MENCS) was not significantly different from infection in untreated plots. After 3 months, root-knot indices in plots treated with V-C 9-104, DD + MENCS, O,O-diethyl O-[p-(methylsulfinyl) phenyl] phosphorothioate (B-25141), and 1,3-dichloropropene, 1,2-dichloropropane (DD) were not significantly different from those in untreated plots; reduced infection was present only in plots treated with ethylene dibromide (EDB) and 2-methyl-2 (methylthio) propionaldehyde O-(methylcarbamoyl) oxime (aldicarb). At the end of harvest (4 months after transplanting), root-knot indices in all plots were essentially equal.     

一种优化的测定过氧化氢酶活性的方法

建立了一种优化的化学发光技术测定过氧化氢酶(CAT)活性的方法,并用此法检测40只正常家兔红细胞中过氧化氢酶活性为6.421±1.43K/gHb.采用H\-2O\-2-鲁米诺发光体系,探讨了反应时间、底物浓度、样品浓度、样品保存等因素对测定的影响,得到较好的线性和重复性.