The Stimulation of Spore Germination in Agaricus bisporus by Living Mycelium

The stimulation of the germination of Agaricus bisporus sporesby mycelium of the same species has been shown to be due toa volatile metabolite, diffusing into the culture medium andinto the atmosphere. A wide range of other fungi has been foundto affect A. bisporus spores in a similar manner. There wasno evidence . that the stimulant was carbon dioxide. A seven-carbonolefin, isolated from air, which had been passed through culturesof A. bisporus mycelium and dried with phosphorus pentoxide,showed germination-stimulating activity but may have been producedby the action of this drying agent on some other metabolitefrom the mycelium. Volatile materials reported by other workersfrom A. bisporus mycelium and from Saccharomyces cereviseaewere tested and, of these, iso-valeric acid and iso-amyl alcoholwere found to stimulate spore germination of A. bisporus     

Studies on the Growth in Culture of Plant Cells: XI. THE INFLUENCE OF SHAKING RATE ON THE GROWTH OF SUSPENSION CULTUEES

The influence of shaking rates (expressed as revolutions permin) on orbital shaking platforms (1 in (2.54 cm) diam. rotarymotion) on the growth of cell suspension cultures of Acer pseudoplatanusL. and Atropa belladonna cultivar lutea Döll are described.By following cell growth and respiration and the levels of oxygenand carbon dioxide in the media during the progress of incubationit is concluded that the reduction of growth at sub-optimalshaking rates is not due to oxygen deficiency or toxic accumulationof carbon dioxide. The growth of the Atropa cell suspensionin ‘closed systems’ has been studied by the developmentof modified culture vessels and evidence obtained that the reducedgrowth in the systems is due to the formation by the culturesof an unidentified volatile growth inhibitor and not to eitheroxygen depletion or toxic accumulation of either carbon dioxideor ethylene. It is suggested that the reduced growth in ‘opensystems’ cultures at sub-optimal shaking speeds is eitherdue to retention of this volatile inhibitor or to restrictionof nutrient uptake by the existence of a stationary liquid-phaseboundary to the cells.     

B型烟粉虱对三种寄主植物及其挥发物的行为反应

利用Y型嗅觉仪,测定了B型烟粉虱Bemisia tabaci（Gennadius）雌虫对3种寄主植物、挥发物提取液、挥发物标样以及寄主植物挥发物模拟样的行为反应,并比较鉴定寄主植物挥发物的组分和含量,以期明确植物挥发物在B型烟粉虱寄主定向行为中的作用。结果表明：1）番茄植株和甘蓝植株及其相应的挥发物提取物对烟粉虱雌成虫均具有显著的引诱作用,而辣椒植株和挥发物提取物的引诱作用不明显;3种寄主植物和挥发物提取物分别两两之间比较时,烟粉虱的选择行为均极显著地表现为番茄 > 甘蓝 > 辣椒。2）番茄、甘蓝和辣椒具有不同的挥发物化学图谱,且挥发物组分的相对百分含量差异很大;番茄挥发物总量远远大于甘蓝和辣椒;从组分来看,番茄挥发物中主要为萜烯类（89.8%）,甘蓝挥发物中主要为烷烃类（53.0%）。3）8种寄主植物挥发物标样（10-¹～10^-6 μL/μL）中,除1,8-桉树脑始终对烟粉虱具有引诱作用外,丁子香酚、苎烯、里那醇和月桂烯则是分别在10^-4～10^-6,10^-1～10^-4,10^-1～10^-4和10^-1～10^-4μL/μL时,才具有引诱作用;α-蒎烯、顺-3-已烯-1醇则在高浓度下（10^-1和10^-2 μL/μL）对烟粉虱具有排斥作用,低浓度下对烟粉虱没有任何影响;正十二烷在任何浓度下对烟粉虱均没有任何作用。4）在辣椒上分别喷施番茄挥发物模拟样和甘蓝挥发物模拟样,均显著增加对烟粉虱的引诱作用,而在番茄上喷施辣椒挥发物模拟样则无明显增效作用。综合分析认为,挥发性物质在B型烟粉虱对不同寄主植物的选择偏好时具有重要的行为导向作用。     

大豆蚜嗅觉在选择寄主植物中的作用

大豆蚜 Aphis hlycines 有翅和无翅孤雌生殖蚜为其寄主植物大豆叶和鼠李叶气味所引诱,而非寄主植物棉花叶和黄瓜叶气味处于中性,丝瓜叶和南瓜叶气味具有明显的排斥作用。非寄主植物气味可以遮蔽寄主植物气味的引诱作用。大豆蚜触角感受器对植物气味具有嗅觉生理反应,对一些化合物的最小感觉阈值达10-5至10-6体积比浓度,表明大豆蚜触角上存在识别植物气味的嗅觉受体细胞。由此证明,嗅觉在大豆蚜选择寄主植物过程中起重要作用。     

虫害诱导的水稻挥发物对褐飞虱的驱避作用

水稻叶片在遭受害虫的危害时,释放一些特异性的挥发性物质。这些挥发性信息物质在调节植物、植食性昆虫及其天敌的相互关系中有重要作用。利用“Y”型嗅觉仪研究了褐飞虱对虫害诱导的11种水稻挥发物（浓度为2 Μl 化合物溶解在100 Μl丙酮溶液中）的行为反应。结果表明,(E)-2-己烯醛、(E)-2-己烯-1-醇、-2-庚醇和水杨酸甲酯等4种化合物对褐飞虱成虫有显著的驱避作用,而(Z)-3-己烯-1-醇、-2-庚酮、柠檬烯、罗勒烯、芳樟醇、-β-子丁香烯和橙花叔醇等7种物质对褐飞虱成虫的选择行为无显著影响。浓度梯度的实验表明,浓度(不同体积的待测化合物用100 Μl丙酮稀释)较低的(E)-2-己烯醛（0.5 Μl、1 Μl）和芳樟醇（05 Μl、1 Μl、5 Μl）对褐飞虱成虫的选择行为无显著影响,而较高浓度的(E)-2-己烯醛（5 Μl、10 Μl）和芳樟醇（10 Μl）对褐飞虱成虫均有明显的驱避作用。     

棉铃虫雌蛾对小麦花挥发性气味的触角电位反应

测定了棉铃虫Helicoverpa armigera处女雌蛾和交配雌蛾对小麦花中单一或多个挥发性物质的EAG反应。在单组分或多组分的测定中,棉铃虫处女蛾和交配蛾在P=0.05水平上并不存在显著性差异,但在混合的绿叶气味物质中加入含量为1×10^-5～5×10^-5（体积比）的正庚醛时,交配蛾对混合物的触角电位反应显著高于处女蛾的反应（P<0.05）。     

Flower and Volatile Oil Ontogeny in Boronia megastigma

The volatile oils of flowers of Boronia megastigma Nees. areimportant commercially but little has been published regardingtheir localization or the dynamics of their synthesis. In thisstudy we examined the histochemistry, anatomy and volatile oilcomposition of the floral organs of plants from a native populationby SEM. Lysigenous glands occurred in all organs except the stigma andandroecium and were associated with the presence of - and ß-pineneand limonene in tissue extracts. These compounds increased inconcentration throughout fruit development. Petals, stamens,staminodes and stigmas were glandular and contained phenolicdeposits, a dense cytoplasm and prominent intercellular spaces.Extracts of these tissues contained dodecanol, ß-iononeand dodecyl acetate, the concentrations of which were greatestat the time of stigma receptivity. The location and timing oftheir synthesis together with their biological activity suggeststhat these volatile oils may have a role in pollination.Copyright1995, 1999 Academic Press Boronia megastigma Nees., Rutaceae, essential oils, volatile oils, reproductive biology, -pinene, ß-pinene, limonene, ß-ionone, dodecyl acetate, heptadecene     

Communication by scent in some Callitrichidae (Primates) - An interdisciplinary approach

In the South American primate, Saguinus fuscicollis, complexscent marks consisting mainly of the secretions of specializedcircumgenital skin glands and some urine communicate the identityof the species, subspecies and individual, its gender, hormonalcondition and social status. The volatile constituents of thesemarks are squalene and a series of butyric acids, comprising96% (by weight) of the mark, and also a large number of as yetunidentified highly volatile compounds. Monitoring of the relativeconcentrations of squalene and the butyrate esters in the scentmarks of male Saguinus f. fuscicollis and Saguinus f. illigeridemonstrates that the two subspecies show consistent differencesin their concentration profiles. The profiles of individualpurebred males closely resemble those of the appropriate subspecieswhile those of hybrids do not. Moreover, the concentration profilesof individual purebred males and hybrids are remarkably constantover long periods of time. Behavioral studies suggest that specificratios of these compounds may be involved in encoding subspeciesspecificity. However, synergists from the highly volatile compoundsappear to be necessary for complete encoding of the message.     

Chemical Interactions in the Cactus-Microorganism-Drosophila Model System of the Sonoran Desert

The Cactus-Microorganism-Drosophila Model System of the SonoranDesert represents an excellent paradigm of the role of chemistryin plant-animal interactions. In this system, four species ofendemic Drosophila feed and reproduce in necrotic tissue offive species of columnar cacti. Studies over the past 35 yrhave characterized a myriad of interactions between the threemajor components of the model system. The cacti contain a varietyof allelochemicals which are primarily responsible for the highlyspecific pattern of host plant utilization exhibited by thedesert Drosophila. Plant chemistry, through its effect on themicrobially produced volatile patterns, is further involvedin host specificity because the flies use the volatile patternto cue in on necroses in the appropriate species of cactus.The metabolic activities of microorganisms (bacteria and yeasts)living in the necrosis can affect the substrate chemistry inboth positive and negative ways (i.e., acting to increase orto decrease the toxicity of the substrate). Finally, cactuschemistry may affect drosophilid mating behavior since larvalrearing substrate has been shown to influence adult hydrocarbonepicuticular composition. In D. mojavensis, adult hydrocarbonprofile has been implicated as a determinant of mate choiceleading to premating isolation between geographically isolatedpopulations that use chemically different cactus substrates.Current research is focused on the evolution and regulationof genes whose products (cytochrome P450 enzymes) are involvedin the specific insect-host plant relationships which existbetween the Drosophila species and the cactus species. There are many reasons why investigators choose to focus theirresearch efforts on what are referred to as "model systems."Typically included among these would be the idea that modelsystems are easier to study because they are less complex thanother scientific situations. At the same time, model systemsshould be representative of more complex, natural systems sothat information that is obtained from their study is broadlyapplicable. For almost a century, the fruit fly, Drosophilamelanogaster, has served as a model organism for the study ofgenetics. As a genetic paradigm, Drosophila is more tractableto scientific investigation than most organisms and has providedimportant insights into a wide variety of human maladies fromalcohol abuse to neurological brain disorders (Bellen, 1998).Similarly, the interrelationships of the columnar cacti andthe cactophilic Drosophila species of the Sonoran Desert have,for the past 35 yr, provided an excellent model system withwhich to study relevant questions in evolution, ecological genetics,and chemical ecology. The intent of this article is to brieflyreview and characterize the chemical interactions between theplants (cacti) and animals (Drosophila) of this model system,and, in addition, provide some thoughts on possible future directionsfor integrative approaches in this research area.     

A New Histochemical Method for Localization of the Site of Monoterpene Phenol Accumulation in Plant Secretory Structures

A new method is reported for the histochemical localizationof monoterpene phenols in essential oil secretory structures.The method was adapted from a spot test originally devised forin vitro detection of phenolic compounds in organic analyses.Plant subjects were the Lamiaceae species Thymus vulgaris L.,Oreganum vulgare L. and Mentha x piperita L., which accumulateessential oil in glandular trichomes. A reagent consisting of4-nitrosophenol in conc. H₂SO₄was applied to sample leaves ofeach species. A positive test for phenol was indicated by theproduction of coloured indophenols. Using this method, monoterpenephenols were identified in the trichomes of T. vulgaris(thymol)and O. vulgare(carvacrol), indicated by colour changes to redand green respectively. No phenol was detected in trichomesof M. x piperita. Results were confirmed by GC-MS analysis ofleaf volatile extracts from each species, and in vitro testswith thymol and carvacrol. The method could be used in fieldsurveys for rapid identification of potential medicinal plantsand bioactive compounds. Copyright 2001 Annals of Botany Company Histochemistry, secretory structures, glandular trichomes, Lamiaceae, Thymus vulgaris, Oreganum vulgare, Mentha x piperita, essential oil, aromatic monoterpenes     

Differential effects of volatile and intravenous anesthetics on the activity of human TASK-1

Volatile anesthetics have been shown to activate various two-pore (2P) domain K⁺ (K_2P) channels such as TASK-1 and TREK-1 (TWIK-related acid-sensitive K⁺ channel), and mice deficient in these channels are resistant to halothane-induced anesthesia. Here, we investigated whether K_2P channels were also potentially important targets of intravenous anesthetics. Whole cell patch-clamp techniques were used to determine the effects of the commonly used intravenous anesthetics etomidate and propofol on the acid-sensitive K⁺ current in rat ventricular myocytes (which strongly express TASK-1) and selected human K_2P channels expressed in Xenopus laevis oocytes. In myocytes, etomidate decreased both inward rectifier K⁺ (K_ir) current (I_K1) and acid-sensitive outward K⁺ current at positive potentials, suggesting that this drug may inhibit TASK channels. Indeed, in addition to inhibiting guinea pig Kir2.1 expressed in oocytes, etomidate inhibited human TASK-1 (and TASK-3) in a concentration-dependent fashion. Propofol had no effect on human TASK-1 (or TASK-3) expressed in oocytes. Moreover, we showed that, similar to the known effect of halothane, sevoflurane and the purified R-(–)- and S-(+)-enantiomers of isoflurane, without stereoselectivity, activated human TASK-1. We conclude that intravenous and volatile anesthetics have dissimilar effects on K_2P channels. Human TASK-1 (and TASK-3) are insensitive to propofol but are inhibited by supraclinical concentrations of etomidate. In contrast, stimulatory effects of sevoflurane and enantiomeric isoflurane on human TASK-1 can be observed at clinically relevant concentrations. volatile anesthetics; etomidate; propofol; ion channels     

The Diatom Genus Tabellaria: I. Taxonomy and Morphology

A morphological study of natural populations of Tabellaria infresh water suggested that there were two fundamentally differenttypes of growth (and therefore frustule structure) in the genus,and this has been confirmed by means of unialgal clone cultures.The existence of these different types of growth forms the basisfor a revision of the genus. A diagnosis of T. quadriseptatanov. spec, is given, the specific limits of T. fenestrata andT. flocculosa are redefined, and the occurrence of T. binalisin Britain is reported for the first time.     

Acid Metabolism and Respiration in Succulent Compositae: III. Further Experiments with Kleinia radicans Haw

Evidence has been obtained that starving leaves of Kleinia radicansin the summer condition produce a volatile substance, whichreacts with potassium permanganate, and which accumulates andpoisons the leaves when they are enclosed, as in a Dixon respirometer.A microrespirometer has been designed for use with continuousair-currents. Using this, the course of oxygen intake by leavesin darkness resembles that of CO₂ output (previous results)and shows an initial phase of diurnal fluctuation of O₂ intake.Humidity has also some effect, for an early increase in O₂ intakeoccurs under dry conditions.     

Low light reflectance may explain the attraction of birds to defoliated trees

Plants use volatile organic compounds to attract invertebratepredators and parasitoids of their herbivore pests. Recently,it has been suggested that plants, either through visual orolfactory cues, may also "cry for help" from vertebrate predatorssuch as birds. We show that in a laboratory choice test, passerinebirds (Parus major and Cyanistes caeruleus) were attracted tothe intact branches of trees (Betula pendula) suffering fromfoliar damage caused by herbivore larvae (Epirrita autumnata)in nontest branches. Species, age, or sex of the experimentalbird or lighting (ultraviolet [UV] or non-UV) did not affectthe preference. However, the birds made a clear choice betweenthe treatments when the trees came from a forest patch receivingmore sunlight, whereas no obvious choice was observed when thetrees came from a shadier forest patch. Results of the choicetest were supported by the spectral reflectance of tree leaves.In the sunnier forest patch, control trees reflected more visiblelight than the herbivore trees, whereas no such difference wasfound in the shadier forest patch trees. We suggest that avianpredators use their vision within visible wavelengths to findinsect-rich plants even when they do not see the prey itemsor damaged leaves.     

棉蚜和七星瓢虫对紫茎泽兰挥发物的行为反应及挥发物化学成分初步分析

田间调查 发现紫茎泽兰Eupatorium adenophorum Spreng上有一定数量的棉蚜Aphis gossypii寄生。从棉蚜是否可为紫茎泽兰的生物防治提供新思路的角度出发,研究了紫茎泽兰挥发性气味物质的化学组成及其对棉蚜和七星瓢虫Coccinella septempunctata行为的影响。棉蚜选择性试验结果表明：紫茎泽兰饲养的棉蚜对紫茎泽兰的趋向率为62.5%,对棉花的趋向率为37.5%。棉花饲养的棉蚜对紫茎泽兰的趋向率为30%,对棉花的趋向率为70%。在七星瓢虫对感染蚜虫植株的选择性实验中,七星瓢虫对感染蚜虫的紫茎泽兰植株气味趋向率为29.2%,对感染蚜虫的棉花植株气味趋向率为70.8%;七星瓢虫对除去植株的两种蚜虫气味选择率没有显著差异,对取食紫茎泽兰的蚜虫气味选择率为46.7%,对取食棉花植株的蚜虫气味选择率为53.3%。通过GC-MC分析了紫茎泽兰挥发性化学物质的组分及相对含量,其主要挥发物的成分是α-蒎烯、莰烯、β-蒎烯、2-蒈烯和α-水芹烯等。     

The Accumulation of Volatile Oils in Whole Plants and Cell Cultures of Tarragon (Artemisia dracunculus)

Two important factors thought to be involved in determiningproduct yields in plant cell cultures are the genotype of theexplant material and the level of cell and/or tissue differentiationexhibited. Cell culture of A. dracunculus is reported for thefirst time and the accumulation of volatile oils in differentgenotypes and at various levels of differentiation are examined.The quantity and quality of oils accumulated varied markedlybetween plants of different types and with the level of anatomicaldifferentiation, both in planta and in vitro. The phenylpropene,allylanisole, the major component of commercial tarragon oil,is reported for the first time in disorganized cultures. Key words: Artemisia dracunculus, tarragon, tissue culture, essential oil, phenylpropenes, allylanisole     

Physiological Growth Attributes of Saccharum Clones and their Progenies

Characters obtained by growth analysis techniques were studiedin seven sugar-cane clones and their seedling progenies froma ratton crop 139 days after virgin harvest. Significant differences in progeny means for R_wand E_Awere mainlyaccounted for by differences in L. Four select clones had amean R_w and mean E_A which, when adjusted to allow for theirsuperior L, were significantly greater than average (P< 0.05).This illustrated that for selection to be effective from theprogenies, segregants with improved L and better leaf-area dependencemust be isolated. The estimates obtained of both L and E_A wereeffective in predicting final weight of cane. Variance componentsindicated especially large ‘male X female’ interactionin progeny means. Some evidence was obtained to suggest thatleaf-area ration is a character which could be used in selectingsmall plots for weight.     

The use of gut fluorescence to estimate grazing by oceanic salps

The fluorometric measurement of chlorophyll and its degradationproducts in the guts of salps has been used as a means of calculatingin situ grazing rates. Salps are particularly suitable for thismethod because they are non-selective filter-feeders large enoughto be individually collected by divers. Analysis of the pigmentin the gut has shown that chlorophyll degradation products canbe used as tracers to estimate in situ ingestion. Filteringrates are calcuLated from the amount of pigment, the gut clearancetime and the concentration of pigment in the water. For Pegeaconfoederata and Salpa maxima, gut-pigment rates are comparedwith rates measured in laboratory particle-clearance experiments.Salpa cylindrica has proved impossible to maintain in the laboratoryand the gut-pigment results are the first feeding data for thisspecies. Filtering rates for all species examined are high,on the order of liters per hour. Variability in the amount ofpigment found in S. cylindrica suggests this species, unlikethe others, may feed sporadically. The gut-pigment method permitsmeasurements of filtration and ingestion by herbivores on analmost instantaneous basis and can be a useful tool for assessinggrazing impact in field situations.     

STEROLS OF CHLORELLA. I. THE NATURALLY OCCURRING STEROLS OF CHLORELLA VULGARIS, C. ELLIPSOIDEA, AND C. SACCHAROPHILA

The characteristics of the sterols naturally occurring in threespecies of Chlorella were examined. The algae were grown heterotrophicallyon glucose. Sterols were extracted and isolated from the lipidfraction and were characterized by means of chemical and physicaltests. Chlorella vulgaris contained three sterols. Only the principalone, chondrillasterol, was identified. Chondrillasterol hasbeen isolated previously from the genus Scenedesmus. Chlorella ellipsoidea and Chlorella saccharophila were foundto contain sterols with ß-oriented alkyl groups atC-24 in contrast to the -oriented groups commonly found in higherplants. Poriferasterol was identified as the principal sterolof both algae. Clionasterol and 22-dihydrobrassicasterol wereidentified as the two secondary sterols present. None of thesesterols have previously been reported to occur in plants. Theisolation of 22-dihydrobrassicasterol has not been previouslyreported from any natural source. ¹Scientific Article A1153, Contribution No. 3623 of the Universityof Maryland Agricultural Experiment Station. ²This work has been supported in part by a grant from the NationalAeronautics and Space Administration.