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Sample records for plant volatiles regulate

  1. Molecular plant volatile communication.

    Science.gov (United States)

    Holopainen, Jarmo K; Blande, James D

    2012-01-01

    Plants produce a wide array of volatile organic compounds (VOCs) which have multiple functions as internal plant hormones (e.g., ethylene, methyl jasmonate and methyl salicylate), in communication with conspecific and heterospecific plants and in communication with organisms of second (herbivores and pollinators) and third (enemies of herbivores) trophic levels. Species specific VOCs normally repel polyphagous herbivores and those specialised on other plant species, but may attract specialist herbivores and their natural enemies, which use VOCs as host location cues. Attraction of predators and parasitoids by VOCs is considered an evolved indirect defence, whereby plants are able to indirectly reduce biotic stress caused by damaging herbivores. In this chapter we review these interactions where VOCs are known to play a crucial role. We then discuss the importance of volatile communication in self and nonself detection. VOCs are suggested to appear in soil ecosystems where distinction of own roots from neighbours roots is essential to optimise root growth, but limited evidence of above-ground plant self-recognition is available.

  2. Influence of growth regulators on distribution of trichomes and the production of volatiles in micropropagated plants of Plectranthus ornatus

    Directory of Open Access Journals (Sweden)

    Helna C. Passinho-Soares

    Full Text Available ABSTRACT The profile of volatile organic compounds, the glandular and non-glandular trichomes of Plectranthus ornatus, obtained by in vitro cultivation, was evaluated in plants grown in Murashide and Skoog medium supplemented with benylaminopurine at 4.5, 9.0, and 18.0 µM + naphthaleneacetic acid at 5.37 µM, kinetin at 4.7, 9.3 and 18.5 µM + naphthaleneacetic acid (5.37 µM or Murashide and Skoog 0 medium (as a control. Scanning Electron Microscopy was performed on samples of the third leaf node of the 90 days old plants obtained from treatment with 4.5 or 9.0 µM benylaminopurine, and 4.7 or 9.3 µM kinetin. Headspace Solid Phase Micro-Extraction of the 30, 60 and 90 days old in vitro plants permitted to determinate by GC/MS the composition comprised of 62 compounds. The data were analyzed using Principal Component Analysis and Hierarchical Clustering Analysis and, the major constituents of these oils after treatment and aging were monoterpenes and sesquiterpenes. Morphoanatomical analysis of trichomes, by Scanning Electron Microscopy, enabled the identification of non-glandular trichomes and four types of glandular trichomes, which comprised capitate and peltate glandular trichomes that were distributed on both sides of the leaf. We observed that the regulators influenced qualitative and quantitative profiles of the volatile organic compounds and the number and distribution of hairs on the leaf surface.

  3. Chirospecific analysis of plant volatiles

    International Nuclear Information System (INIS)

    Tkachev, A V

    2007-01-01

    Characteristic features of the analysis of plant volatiles by enantioselective gas (gas-liquid) chromatography and gas chromatography/mass spectrometry are discussed. The most recent advances in the design of enantioselective stationary phases are surveyed. Examples of the preparation of the most efficient phases based on modified cyclodextrins are given. Current knowledge on the successful analytical resolution of different types of plant volatiles (aliphatic and aromatic compounds and mono-, sesqui- and diterpene derivatives) into optical antipodes is systematically described. Chiral stationary phases used for these purposes, temperature conditions and enantiomer separation factors are summarised. Examples of the enantiomeric resolution of fragrance compounds and components of plant extracts, wines and essential oils are given.

  4. Chirospecific analysis of plant volatiles

    Energy Technology Data Exchange (ETDEWEB)

    Tkachev, A V [N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2007-10-31

    Characteristic features of the analysis of plant volatiles by enantioselective gas (gas-liquid) chromatography and gas chromatography/mass spectrometry are discussed. The most recent advances in the design of enantioselective stationary phases are surveyed. Examples of the preparation of the most efficient phases based on modified cyclodextrins are given. Current knowledge on the successful analytical resolution of different types of plant volatiles (aliphatic and aromatic compounds and mono-, sesqui- and diterpene derivatives) into optical antipodes is systematically described. Chiral stationary phases used for these purposes, temperature conditions and enantiomer separation factors are summarised. Examples of the enantiomeric resolution of fragrance compounds and components of plant extracts, wines and essential oils are given.

  5. Herbivore-induced blueberry volatiles and intra-plant signaling.

    Science.gov (United States)

    Rodriguez-Saona, Cesar R

    2011-12-18

    Herbivore-induced plant volatiles (HIPVs) are commonly emitted from plants after herbivore attack. These HIPVs are mainly regulated by the defensive plant hormone jasmonic acid (JA) and its volatile derivative methyl jasmonate (MeJA). Over the past 3 decades researchers have documented that HIPVs can repel or attract herbivores, attract the natural enemies of herbivores, and in some cases they can induce or prime plant defenses prior to herbivore attack. In a recent paper, I reported that feeding by gypsy moth caterpillars, exogenous MeJA application, and mechanical damage induce the emissions of volatiles from blueberry plants, albeit differently. In addition, blueberry branches respond to HIPVs emitted from neighboring branches of the same plant by increasing the levels of JA and resistance to herbivores (i.e., direct plant defenses), and by priming volatile emissions (i.e., indirect plant defenses). Similar findings have been reported recently for sagebrush, poplar, and lima beans. Here, I describe a push-pull method for collecting blueberry volatiles induced by herbivore (gypsy moth) feeding, exogenous MeJA application, and mechanical damage. The volatile collection unit consists of a 4 L volatile collection chamber, a 2-piece guillotine, an air delivery system that purifies incoming air, and a vacuum system connected to a trap filled with Super-Q adsorbent to collect volatiles. Volatiles collected in Super-Q traps are eluted with dichloromethane and then separated and quantified using Gas Chromatography (GC). This volatile collection method was used in my study to investigate the volatile response of undamaged branches to exposure to volatiles from herbivore-damaged branches within blueberry plants. These methods are described here. Briefly, undamaged blueberry branches are exposed to HIPVs from neighboring branches within the same plant. Using the same techniques described above, volatiles emitted from branches after exposure to HIPVs are collected and

  6. Volatile communication in plant-aphid interactions.

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    de Vos, Martin; Jander, Georg

    2010-08-01

    Volatile communication plays an important role in mediating the interactions between plants, aphids, and other organisms in the environment. In response to aphid infestation, many plants initiate indirect defenses through the release of volatiles that attract ladybugs, parasitoid wasps, and other aphid-consuming predators. Aphid-induced volatile release in the model plant Arabidopsis thaliana requires the jasmonate signaling pathway. Volatile release is also induced by infection with aphid-transmitted viruses. Consistent with mathematical models of optimal transmission, viruses that are acquired rapidly by aphids induce volatile release to attract migratory aphids, but discourage long-term aphid feeding. Although the ecology of these interactions is well-studied, further research is needed to identify the molecular basis of aphid-induced and virus-induced changes in plant volatile release. Copyright 2010 Elsevier Ltd. All rights reserved.

  7. Volatilization of iodine from soils and plants

    International Nuclear Information System (INIS)

    Wildung, R.E.; Cataldo, D.A.; Garland, T.R.

    1985-04-01

    Elevated levels of 129 I, a long-lived fission product, are present in the environment as a result of nuclear weapons testing and fuel reprocessing. To aid in understanding the anomalous behavior of this element, relative to natural I ( 127 I), in the vicinity of nuclear fuel reprocessing plants, preliminary laboratory-growth chamber studies were undertaken to examine the possible formation of volatile inorganic and organic I species in soil and plant systems. Inorganic 129 I added to soil was volatilized from both the soil and plant during plant growth, at average ratios of 2 x 10 -3 %/day soil and 9 x 10 -3 %/day foliage, respectively. Volatilization rates from soil were an order of magnitude less in the absence of growing roots. Less than 2% of soil or plant volatiles was subsequently retained by plant canopies. Volatile I, chemically characterized by selective sorption methods, consisted principally of alkyl iodides formed by both soil and plant processes. However, plants and soils containing actively growing roots produced a larger fraction of volatile inorganic I than soil alone. 14 refs., 1 fig., 3 tabs

  8. Volatile chemical interaction between undamaged plants

    OpenAIRE

    Glinwood, Robert

    2010-01-01

    This chapter discusses whether plant chemical communication is a mechanism by which plant genetic diversity can affect the natural enemies of herbivores. Plant genetic diversity influences natural enemies, and these insects use volatile chemical cues to locate suitable habitats. However, the importance of chemical communication for these interactions has not been considered. In this chapter, the latest research on chemical communication between undamaged plants is reviewed. ...

  9. Three odorant binding proteins may regulate the behavioural response of Chrysopa pallens to plant volatiles and the aphid alarm pheromone (E)-β-farnesene.

    Science.gov (United States)

    Li, Z-Q; Zhang, S; Cai, X-M; Luo, J-Y; Dong, S-L; Cui, J-J; Chen, Z-M

    2017-06-01

    Artificial Chrysopa pallens release is a well-known method for suppressing aphids, but it is difficult to establish lacewing populations in the field. Understanding the functions of C. pallens odorant-binding proteins (CpalOBPs) and behavioural responses of C. pallens to plant volatiles and aphid alarm pheromone (E)-ß-farnesene has important implications for population establishment after lacewing release. Based on our previous study, five antennae-enriched CpalOBPs were selected. Sequence alignment and phylogenetic analysis revealed that these five CpalOBPs were Classic OBPs and separated into different clades. Of them, CpalOBP10 clustered in the same clade with aphid OBP7, which mediates the perception of green leaf volatiles and (E)-ß-farnesene. Ligand-binding assays showed 31 compounds, including plant-derived compounds, pest-induced volatiles and (E)-ß-farnesene, had high binding affinities for at least one of these five CpalOBPs. Of the 31 compounds, the pest-induced volatiles (Z)-3-hexenyl hexanoate and 2-hexyl-1-decanol, used in host location by the black bean aphid, elicited significant attractive behavioural responses from C. pallens. Conversely, (E)-ß-farnesene elicited strongly repellent behavioural responses. It is conceivable that C. pallens utilizes plant-derived compounds, pest-induced volatiles and (E)-ß-farnesene as foraging cues. Our studies provide new insights into the interrelationships amongst C. pallens, its prey and the host plants. Compounds that elicited significant behavioural responses from C. pallens were also identified. © 2017 The Royal Entomological Society.

  10. Synergism in the effect of prior jasmonic acid application on herbivore-induced volatile emission by Lima bean plants: transcription of a monoterpene synthase gene and volatile emission

    NARCIS (Netherlands)

    Menzel, T.R.; Weldegergis, B.T.; David, A.; Boland, W.; Gols, R.; Loon, van J.J.A.; Dicke, M.

    2014-01-01

    Jasmonic acid (JA) plays a central role in induced plant defence e.g. by regulating the biosynthesis of herbivore-induced plant volatiles that mediate the attraction of natural enemies of herbivores. Moreover, exogenous application of JA can be used to elicit plant defence responses similar to those

  11. Noctuidae-induced plant volatiles: current situation and prospects

    Directory of Open Access Journals (Sweden)

    Vanusa Rodrigues Horas

    2014-01-01

    Full Text Available Noctuids are phytophagous lepidopterans with some species causing significant damage to agriculture. The host plants, in turn, have developed defense mechanisms to cope with them, for instance chemical defenses. In this study we review the literature on plant volatiles induced by noctuids, and discuss the methodologies used to induce the production of volatiles that are usually employed in plant defense mechanisms. Future prospects involving this line of research in pest control are also discussed.

  12. Release of volatile mercury from vascular plants

    Science.gov (United States)

    Siegel, S. M.; Puerner, N. J.; Speitel, T. W.

    1974-01-01

    Volatile, organic solvent soluble mercury has been found in leaves and seeds of several angiosperms. Leaves of garlic vine, avocado, and haole-koa release mercury in volatile form rapidly at room temperature. In garlic vine, the most active release is temperature dependent, but does not parallel the vapor-pressure temperature relationship for mercury. Mercury can be trapped in nitric-perchloric acid digestion fluid, or n-hexane, but is lost from the hexane unless the acid mixture is present. Seeds of haole-koa also contain extractable mercury but volatility declines in the series n-hexane (90%), methanol (50%), water (10%). This suggests that reduced volatility may accompany solvolysis in the more polar media.

  13. Atmospheric transformation of plant volatiles disrupts host plant finding

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    Li, Tao; Blande, James D.; Holopainen, Jarmo K.

    2016-09-01

    Plant-emitted volatile organic compounds (VOCs) play important roles in plant-insect interactions. Atmospheric pollutants such as ozone (O3) can react with VOCs and affect the dynamics and fidelity of these interactions. However, the effects of atmospheric degradation of plant VOCs on plant-insect interactions remains understudied. We used a system comprising Brassica oleracea subsp. capitata (cabbage) and the specialist herbivore Plutella xylostella to test whether O3-triggered VOC degradation disturbs larval host orientation, and to investigate the underlying mechanisms. Larvae oriented towards both constitutive and larva-induced cabbage VOC blends, the latter being the more attractive. Such behaviour was, however, dramatically reduced in O3-polluted environments. Mechanistically, O3 rapidly degraded VOCs with the magnitude of degradation increasing with O3 levels. Furthermore, we used Teflon filters to collect VOCs and their reaction products, which were used as odour sources in behavioural tests. Larvae avoided filters exposed to O3-transformed VOCs and spent less time searching on them compared to filters exposed to original VOCs, which suggests that some degradation products may have repellent properties. Our study clearly demonstrates that oxidizing pollutants in the atmosphere can interfere with insect host location, and highlights the need to address their broader impacts when evaluating the ecological significance of VOC-mediated interactions.

  14. How common is within-plant signaling via volatiles?

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    Li, Tao; Blande, James D

    2017-08-03

    Many plants respond to herbivory by releasing a complex blend of volatiles that may differ from that emitted by intact counterparts. These herbivore-induced plant volatiles (HIPV) mediate many interactions among plants and their community members, including alerting undamaged leaves of the attacked or neighboring plants to impending danger. It has been postulated that HIPVs evolved for within-plant signaling and that other organisms subsequently evolved to use them. However, only 7 studies have reported HIPV-mediated within-plant signaling, most conducted in the laboratory or greenhouse. This leaves open the ecological relevance and evolutionary underpinning of the phenomenon. We recently observed within-plant signaling in hybrid aspen under laboratory and field conditions. Greenhouse experiments showed that HIPVs mediated the process. While our study adds an aspen hybrid to the list of plants in which within-plant signaling has been demonstrated, we lack understanding of how common the process is and whether plants obtain fitness benefits.

  15. Beyond the network of plants volatile organic compounds

    OpenAIRE

    Vivaldo, Gianna; Masi, Elisa; Taiti, Cosimo; Caldarelli, Guido; Mancuso, Stefano

    2017-01-01

    Plants emission of volatile organic compounds (VOCs) is involved in a wide class of ecological functions, as VOCs play a crucial role in plants interactions with biotic and abiotic factors. Accordingly, they vary widely across species and underpin differences in ecological strategy. In this paper, VOCs spontaneously emitted by 109 plant species (belonging to 56 different families) have been qualitatively and quantitatively analysed in order to classify plants species. By using bipartite netwo...

  16. Slow Release of Plant Volatiles Using Sol-Gel Dispensers.

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    Bian, L; Sun, X L; Cai, X M; Chen, Z M

    2014-12-01

    The black citrus aphid, also known as the tea aphid, (Toxoptera aurantii Boyer) attacks economically important crops, including tea (Camellia sinensis (L.) O. Kuntze). In the current study, silica sol-gel formulations were screened to find one that could carry and release C. sinensis plant volatiles to lure black citrus aphids in a greenhouse. The common plant volatile trans-2-hexen-1-al was used as a model molecule to screen for suitable sol-gel formulations. A zNose (Electronic Sensor Technology, Newbury Park, CA) transportable gas chromatograph was used to continuously monitor the volatile emissions. A sol-gel formulation containing tetramethyl orthosilicate and methyltrimethoxysilane in an 8:2 (vol:vol) ratio was selected to develop a slow-release dispenser. The half-life of trans-2-hexen-1-al in the sol-gel dispenser increased slightly with the volume of this compound in the dispenser. Ten different volatiles were tested in the sol-gel dispenser. Alcohols of 6-10 carbons had the longest half-lives (3.01-3.77 d), while esters of 6-12 carbons had the shortest (1.53-2.28 d). Release of these volatiles from the dispensers could not be detected by the zNose after 16 d (cis-3-hexenyl acetate) to 26 d (3,7-dimethylocta-1,6-dien-3-ol). In greenhouse experiments, trans-2-hexen-1-al and cis-3-hexen-1-ol released from the sol-gel dispensers attracted aphids for ≍17 d, and release of these volatiles could not be detected by the zNose after ≍24 d. The sol-gel dispensers performed adequately for the slow release of plant volatiles to trap aphids in the greenhouse. © 2014 Entomological Society of America.

  17. Metabolic engineering of volatile isoprenoids in plants and microbes.

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    Vickers, Claudia E; Bongers, Mareike; Liu, Qing; Delatte, Thierry; Bouwmeester, Harro

    2014-08-01

    The chemical properties and diversity of volatile isoprenoids lends them to a broad variety of biological roles. It also lends them to a host of biotechnological applications, both by taking advantage of their natural functions and by using them as industrial chemicals/chemical feedstocks. Natural functions include roles as insect attractants and repellents, abiotic stress protectants in pathogen defense, etc. Industrial applications include use as pharmaceuticals, flavours, fragrances, fuels, fuel additives, etc. Here we will examine the ways in which researchers have so far found to exploit volatile isoprenoids using biotechnology. Production and/or modification of volatiles using metabolic engineering in both plants and microorganisms are reviewed, including engineering through both mevalonate and methylerythritol diphosphate pathways. Recent advances are illustrated using several case studies (herbivores and bodyguards, isoprene, and monoterpene production in microbes). Systems and synthetic biology tools with particular utility for metabolic engineering are also reviewed. Finally, we discuss the practical realities of various applications in modern biotechnology, explore possible future applications, and examine the challenges of moving these technologies forward so that they can deliver tangible benefits. While this review focuses on volatile isoprenoids, many of the engineering approaches described here are also applicable to non-isoprenoid volatiles and to non-volatile isoprenoids. © 2014 John Wiley & Sons Ltd.

  18. Recent Advances in the Emission and Functions of Plant Vegetative Volatiles

    Directory of Open Access Journals (Sweden)

    Fang Dong

    2016-01-01

    Full Text Available Plants synthesize and emit a large variety of volatile organic compounds, which possess extremely important ecological functions. In most case, most plant volatiles are liquids, rather than gases, at room temperature. Some volatiles are emitted “on demand” when plants, especially vegetative parts, are exposed to abiotic or biotic stress. In this review, we summarize some of the highlights of plant vegetative volatile emission and functions research published during the past few years.

  19. Simple plant-based design strategies for volatile organic pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Narayanan, M.; Erickson, L.E.; Davis, L.C.

    1999-12-31

    Vegetation which enhances in-situ biodegradation of organic compounds can play a key role in the bioremediation of such contaminants in polluted soils and groundwater. Plants may act directly on some contaminants by degrading them, but their main effect is to enhance microbial populations in the thizosphere. Microbially mediated transformations are thus indirectly facilitated by root exudates which nourish the indigenous microorganisms. Plants may also be viewed as a solar driven pump-and-treat system which can contain a plume and reduce the spread of contaminated water. Laboratory investigations carried out in a growth chamber with alfalfa plants provide evidence for the (microbially mediated) biodegradation of organic compounds such as toluene, phenol and TCE. Alfalfa plants tolerate concentrations of these organics in contaminated water up to 100 mg/L. They facilitate transfer of the contaminants from the saturated to the vadose zone. For volatile organic compounds such as TCE, vegetation provides a controlled release of compounds and hence assures dilution of the TCE evapotranspired into the atmosphere from contaminated soils. Using a range of calculated plausible scenarios, it is shown that intermedia transfer caused by volatilization associated with plants is most unlikely to lead to exceedance of standards for gas phase contamination, for most volatile contaminants. Possible action level exceedances might occur with highly toxic substances including vinyl chloride and carbon tetrachloride, if they re present in ground water at levels above kilogram amounts in a single plume of a few hectares, and released by vigorously growing plants under hot dry conditions. Information needed for the calculation and design of plant-based bioremediation systems for typical sites is discussed in this paper.

  20. Oil price volatility, financial regulation and energy policy

    International Nuclear Information System (INIS)

    Chevalier, J.M.

    2010-01-01

    In October of 2009, the French Ministry of Economy asked the author to chair a work group on oil price volatility. The report resulting from that work was submitted to the minister on February 9, 2010. Based on the report, this article focuses on three major elements: (i) the operation of the oil market, with interacting physical basics and financial basics (ii) financial market regulation, more specifically commodities-derived product markets and current work in that area and (iii) the lessons one can draw from that exercise in terms of energy policy. Significant projects have been initiated on global, European and national levels. (author)

  1. Perception of volatiles produced by UVC-irradiated plants alters the response to viral infection in naïve neighboring plants.

    Science.gov (United States)

    Yao, Youli; Danna, Cristian H; Ausubel, Frederick M; Kovalchuk, Igor

    2012-07-01

    Interplant communication of stress via volatile signals is a well-known phenomenon. It has been shown that plants undergoing stress caused by pathogenic bacteria or insects generate volatile signals that elicit defense response in neighboring naïve plants. Similarly, we have recently shown that naïve plants sharing the same gaseous environment with UVC-exposed plants exhibit similar changes in genome instability as UVC-exposed plants. We found that methyl salicylate (MeSA) and methyl jasmonate (MeJA) serve as volatile signals communicating genome instability (as measured by an increase in the homologous recombination frequency). UVC-exposed plants produce high levels of MeSA and MeJA, a response that is missing in an npr1 mutant. Concomitantly, npr1 mutants are impaired in communicating the signal leading to genome instability, presumably because this mutant does not develop new necrotic lesion after UVC irradiation as observed in wt plants. To analyze the potential biological significance of such plant-plant communication, we have now determined whether bystander plants that receive volatile signals from UVC-irradiated plants, become more resistant to UVC irradiation or infection with oilseed rape mosaic virus (ORMV). Specifically, we analyzed the number of UVC-elicited necrotic lesions, the level of anthocyanin pigments, and the mRNA levels corresponding to ORMV coat protein and the NPR1-regulated pathogenesis-related protein PR1 in the irradiated or virus-infected bystander plants that have been previously exposed to volatiles produced by UVC-irradiated plants. These experiments showed that the bystander plants responded similarly to control plants following UVC irradiation. Interestingly, however, the bystander plants appeared to be more susceptible to ORMV infection, even though PR1 mRNA levels in systemic tissue were significantly higher than in the control plants, which indicates that bystander plants could be primed to strongly respond to bacterial

  2. Volatile chemical cues guide host location and host selection by parasitic plants

    Science.gov (United States)

    Justin B. Runyon; Mark C. Mescher; Consuelo M. De Moraes

    2006-01-01

    The importance of plant volatiles in mediating interactions between plant species is much debated. Here, we demonstrate that the parasitic plant Cuscuta pentagona (dodder) uses volatile cues for host location. Cuscuta pentagona seedlings exhibit directed growth toward nearby tomato plants (Lycopersicon esculentum...

  3. Plant volatiles in extreme terrestrial and marine environments.

    Science.gov (United States)

    Rinnan, Riikka; Steinke, Michael; McGenity, Terry; Loreto, Francesco

    2014-08-01

    This review summarizes the current understanding on plant and algal volatile organic compound (VOC) production and emission in extreme environments, where temperature, water availability, salinity or other environmental factors pose stress on vegetation. Here, the extreme environments include terrestrial systems, such as arctic tundra, deserts, CO₂ springs and wetlands, and marine systems such as sea ice, tidal rock pools and hypersaline environments, with mangroves and salt marshes at the land-sea interface. The emission potentials at fixed temperature and light level or actual emission rates for phototrophs in extreme environments are frequently higher than for organisms from less stressful environments. For example, plants from the arctic tundra appear to have higher emission potentials for isoprenoids than temperate species, and hypersaline marine habitats contribute to global dimethyl sulphide (DMS) emissions in significant amounts. DMS emissions are more widespread than previously considered, for example, in salt marshes and some desert plants. The reason for widespread VOC, especially isoprenoid, emissions from different extreme environments deserves further attention, as these compounds may have important roles in stress resistance and adaptation to extremes. Climate warming is likely to significantly increase VOC emissions from extreme environments both by direct effects on VOC production and volatility, and indirectly by altering the composition of the vegetation. © 2014 John Wiley & Sons Ltd.

  4. PLANT VOLATILES. Biosynthesis of monoterpene scent compounds in roses.

    Science.gov (United States)

    Magnard, Jean-Louis; Roccia, Aymeric; Caissard, Jean-Claude; Vergne, Philippe; Sun, Pulu; Hecquet, Romain; Dubois, Annick; Hibrand-Saint Oyant, Laurence; Jullien, Frédéric; Nicolè, Florence; Raymond, Olivier; Huguet, Stéphanie; Baltenweck, Raymonde; Meyer, Sophie; Claudel, Patricia; Jeauffre, Julien; Rohmer, Michel; Foucher, Fabrice; Hugueney, Philippe; Bendahmane, Mohammed; Baudino, Sylvie

    2015-07-03

    The scent of roses (Rosa x hybrida) is composed of hundreds of volatile molecules. Monoterpenes represent up to 70% percent of the scent content in some cultivars, such as the Papa Meilland rose. Monoterpene biosynthesis in plants relies on plastid-localized terpene synthases. Combining transcriptomic and genetic approaches, we show that the Nudix hydrolase RhNUDX1, localized in the cytoplasm, is part of a pathway for the biosynthesis of free monoterpene alcohols that contribute to fragrance in roses. The RhNUDX1 protein shows geranyl diphosphate diphosphohydrolase activity in vitro and supports geraniol biosynthesis in planta. Copyright © 2015, American Association for the Advancement of Science.

  5. A method for the solvent extraction of low-boiling-point plant volatiles.

    Science.gov (United States)

    Xu, Ning; Gruber, Margaret; Westcott, Neil; Soroka, Julie; Parkin, Isobel; Hegedus, Dwayne

    2005-01-01

    A new method has been developed for the extraction of volatiles from plant materials and tested on seedling tissue and mature leaves of Arabidopsis thaliana, pine needles and commercial mixtures of plant volatiles. Volatiles were extracted with n-pentane and then subjected to quick distillation at a moderate temperature. Under these conditions, compounds such as pigments, waxes and non-volatile compounds remained undistilled, while short-chain volatile compounds were distilled into a receiving flask using a high-efficiency condenser. Removal of the n-pentane and concentration of the volatiles in the receiving flask was carried out using a Vigreux column condenser prior to GC-MS. The method is ideal for the rapid extraction of low-boiling-point volatiles from small amounts of plant material, such as is required when conducting metabolic profiling or defining biological properties of volatile components from large numbers of mutant lines.

  6. Non-Host Plant Volatiles Disrupt Sex Pheromone Communication in a Specialist Herbivore

    OpenAIRE

    Wang, Fumin; Deng, Jianyu; Schal, Coby; Lou, Yonggen; Zhou, Guoxin; Ye, Bingbing; Yin, Xiaohui; Xu, Zhihong; Shen, Lize

    2016-01-01

    The ecological effects of plant volatiles on herbivores are manifold. Little is known, however, about the impacts of non-host plant volatiles on intersexual pheromonal communication in specialist herbivores. We tested the effects of several prominent constitutive terpenoids released by conifers and Eucalyptus trees on electrophysiological and behavioral responses of an oligophagous species, Plutella xylostella, which feeds on Brassicaceae. The non-host plant volatile terpenoids adversely affe...

  7. The impact of induced plant volatiles on lant-arthropod interactions

    NARCIS (Netherlands)

    Alba, J.M.; Bleeker, P.M.; Glas, J.J.; Schimmel, B.C.J.; van Wijk, M.; Sabelis, M.W.; Schuurink, R.C.; Kant, M.R.; Smagghe, G.; Diaz, I.

    2012-01-01

    Plants release volatile organic compounds from their vegetative tissues into their environment during most of their life cycle. The functions of these volatiles are diverse and not always known but some of these volatiles repel foraging herbivores while others, in turn, attract them and are feeding

  8. An Indirect Defence Trait Mediated through Egg-Induced Maize Volatiles from Neighbouring Plants.

    Directory of Open Access Journals (Sweden)

    Daniel M Mutyambai

    Full Text Available Attack of plants by herbivorous arthropods may result in considerable changes to the plant's chemical phenotype with respect to emission of herbivore-induced plant volatiles (HIPVs. These HIPVs have been shown to act as repellents to the attacking insects as well as attractants for the insects antagonistic to these herbivores. Plants can also respond to HIPV signals from other plants that warn them of impending attack. Recent investigations have shown that certain maize varieties are able to emit volatiles following stemborer egg deposition. These volatiles attract the herbivore's parasitoids and directly deter further oviposition. However, it was not known whether these oviposition-induced maize (Zea mays, L. volatiles can mediate chemical phenotypic changes in neighbouring unattacked maize plants. Therefore, this study sought to investigate the effect of oviposition-induced maize volatiles on intact neighbouring maize plants in 'Nyamula', a landrace known to respond to oviposition, and a standard commercial hybrid, HB515, that did not. Headspace volatile samples were collected from maize plants exposed to Chilo partellus (Swinhoe (Lepidoptera: Crambidae egg deposition and unoviposited neighbouring plants as well as from control plants kept away from the volatile emitting ones. Behavioural bioassays were carried out in a four-arm olfactometer using egg (Trichogramma bournieri Pintureau & Babault (Hymenoptera: Trichogrammatidae and larval (Cotesia sesamiae Cameron (Hymenoptera: Braconidae parasitoids. Coupled Gas Chromatography-Mass Spectrometry (GC-MS was used for volatile analysis. For the 'Nyamula' landrace, GC-MS analysis revealed HIPV production not only in the oviposited plants but also in neighbouring plants not exposed to insect eggs. Higher amounts of EAG-active biogenic volatiles such as (E-4,8-dimethyl-1,3,7-nonatriene were emitted from these plants compared to control plants. Subsequent behavioural assays with female T. bournieri and

  9. Public regulation of nuclear plants

    International Nuclear Information System (INIS)

    Burtheret, M.; Cormis, de

    1980-01-01

    The construction and operation of nuclear plants are subject to a complex system of governmental administration. The authors list the various governmental authorisations and rules applicable to these plants. In the first part, they describe the national regulations which relate specifically to nuclear plants, and emphasize the provisions which are intended to ensure the safety of the installations and the protection of the public against ionizing radiation. However, while the safety of nuclear plants is a major concern of the authorities, other interests are also protected. This is accomplished by various laws or regulations which apply to nuclear plants as well as other industrial installations. The duties which these texts, and the administrative practice based thereon, impose on Electricite de France are covered in the second part [fr

  10. Monitoring of volatile and non-volatile urban air genotoxins using bacteria, human cells and plants.

    Science.gov (United States)

    Ceretti, E; Zani, C; Zerbini, I; Viola, G; Moretti, M; Villarini, M; Dominici, L; Monarca, S; Feretti, D

    2015-02-01

    Urban air contains many mutagenic pollutants. This research aimed to investigate the presence of mutagens in the air by short-term mutagenicity tests using bacteria, human cells and plants. Inflorescences of Tradescantia were exposed to air in situ for 6h, once a month from January to May, to monitor volatile compounds and micronuclei frequency was computed. On the same days PM10 was collected continuously for 24h. Half of each filter was extracted with organic solvents and studied by means of the Ames test, using Salmonella typhimurium TA98 and TA100 strains, and the comet assay on human leukocytes. A quarter of each filter was extracted with distilled water in which Tradescantia was exposed. PM10 concentration was particularly high in the winter season (> 50 μg/m(3)). In situ exposure of inflorescences to urban air induced a significant increase in micronuclei frequency at all the sites considered, but only in January (p bacteria, human cells and plants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Equipment Leaks of Volatile Organic Compounds From Onshore Natural Gas Processing Plants for Which Construction, Reconstruction, or Modification Commenced After January 20, 1984, and on or Before August 23, 2011: New Source Performance Standards (NSPS)

    Science.gov (United States)

    Learn about the NSPS regulation for equipment leaks of Volatile Organic Compounds (VOC) from onshore natural gas processing plants by reading the rule summary, rule history, federal register citations, and the code of federal regulations

  12. Reactive trace gas emissions from stressed plants: a poorly characterized major source of atmospheric volatiles

    Science.gov (United States)

    Niinemets, Ülo

    2017-04-01

    Vegetation constitutes the greatest source of reactive volatile organic compounds in the atmosphere. The current emission estimates primarily rely on constitutive emissions that are present only in some plant species. However, all plant species can be induced to emit reactive volatiles by different abiotic and biotic stresses, but the stress-dependent emissions have been largely neglected in emission measurements and models. This presentation provides an overview of systematic screening of stress-dependent volatile emissions from a broad range of structurally and physiologically divergent plant species from temperate to tropical ecosystems. Ozone, heat, drought and wounding stress were the abiotic stresses considered in the screening, while biotic stress included herbivory, chemical elicitors simulating herbivory and fungal infections. The data suggest that any moderate to severe stress leads to significant emissions of a rich blend of volatiles, including methanol, green leaf volatiles (the lipoxygenase pathway volatiles, dominated by C6 aldehydes, alcohols and derivatives), different mono- and sesquiterpenes and benzenoids. The release of volatiles occurs in stress severity-dependent manner, although the emission responses are often non-linear with more severe stresses resulting in disproportionately greater emissions. Stress volatile release is induced in both non-constitutive and constitutive volatile emitters, whereas the rate of constitutive volatile emissions in constitutive emitters is often reduced under environmental and biotic stresses. Given that plants in natural conditions often experience stress, this analysis suggests that global volatile emissions have been significantly underestimated. Furthermore, in globally changing hotter climates, the frequency and severity of both abiotic and biotic stresses is expected to increase. Thus, the stress-induced volatile emissions are predicted to play a dominant role in plant-atmosphere interactions in near

  13. Herbivore-induced plant volatiles and tritrophic interactions across spatial scales

    NARCIS (Netherlands)

    Aartsma, Y.S.Y.; Bianchi, F.J.J.A.; Werf, van der W.; Poelman, E.H.; Dicke, M.

    2017-01-01

    Herbivore-induced plant volatiles (HIPVs) are an important cue used in herbivore location by carnivorous arthropods such as parasitoids. The effects of plant volatiles on parasitoids have been well characterised at small spatial scales, but little research has been done on their effects at larger

  14. 40 CFR 180.1080 - Plant volatiles and pheromone; exemptions from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Plant volatiles and pheromone... RESIDUES IN FOOD Exemptions From Tolerances § 180.1080 Plant volatiles and pheromone; exemptions from the... pheromone Z-2-isopropenyl-1-methylcyclobutaneethanol; Z-3,3-dimethyl-Δ1,β-cyclohexaneethanol; Z-3,3-dimethyl...

  15. Promotion of plant growth by Pseudomonas fluorescens strain SS101 via novel volatile organic compounds

    NARCIS (Netherlands)

    Park, Yong-Soon; Dutta, Swarnalee; Ann, Mina; Raaijmakers, Jos M.; Park, Kyungseok

    2015-01-01

    Abstract Volatile organic compounds (VOCs) from plant growth-promoting rhizobacteria (PGPR) play key roles in modulating plant growth and induced systemic resistance (ISR) to pathogens. Despite their significance, the physiological functions of the specific VOCs produced by Pseudomonas fluorescens

  16. Nocturnal herbivore-induced plant volatiles attract the generalist predatory earwig Doru luteipes Scudder

    Science.gov (United States)

    Naranjo-Guevara, Natalia; Peñaflor, Maria Fernanda G. V.; Cabezas-Guerrero, Milton F.; Bento, José Maurício S.

    2017-10-01

    Numerous studies have demonstrated that entomophagous arthropods use herbivore-induced plant volatile (HIPV) blends to search for their prey or host. However, no study has yet focused on the response of nocturnal predators to volatile blends emitted by prey damaged plants. We investigated the olfactory behavioral responses of the night-active generalist predatory earwig Doru luteipes Scudder (Dermaptera: Forficulidae) to diurnal and nocturnal volatile blends emitted by maize plants ( Zea mays) attacked by either a stem borer ( Diatraea saccharalis) or a leaf-chewing caterpillar ( Spodoptera frugiperda), both suitable lepidopteran prey. Additionally, we examined whether the earwig preferred odors emitted from short- or long-term damaged maize. We first determined the earwig diel foraging rhythm and confirmed that D. luteipes is a nocturnal predator. Olfactometer assays showed that during the day, although the earwigs were walking actively, they did not discriminate the volatiles of undamaged maize plants from those of herbivore damaged maize plants. In contrast, at night, earwigs preferred volatiles emitted by maize plants attacked by D. saccharalis or S. frugiperda over undamaged plants and short- over long-term damaged maize. Our GC-MS analysis revealed that short-term damaged nocturnal plant volatile blends were comprised mainly of fatty acid derivatives (i.e., green leaf volatiles), while the long-term damaged plant volatile blend contained mostly terpenoids. We also observed distinct volatile blend composition emitted by maize damaged by the different caterpillars. Our results showed that D. luteipes innately uses nocturnal herbivore-induced plant volatiles to search for prey. Moreover, the attraction of the earwig to short-term damaged plants is likely mediated by fatty acid derivatives.

  17. Volatile-Mediated within-Plant Signaling in Hybrid Aspen: Required for Systemic Responses.

    Science.gov (United States)

    Li, Tao; Blande, James D

    2017-04-01

    Plant volatiles play crucial roles in signaling between plants and their associated community members, but their role in within-plant signaling remains largely unexplored, particularly under field conditions. Using a system comprising the hybrid aspen (Populus tremula x tremuloides) and the specialized herbivorous leaf beetle (Phratora laticollis) and, combining field, greenhouse and laboratory experiments, we examined whether local damage triggered systemic responses in undamaged branches that lack vascular connection to the damaged branches, and to what extent this was caused by airborne volatile signals versus internal signals. An experiment tracing dye through the vasculature of saplings revealed no downward movement of the dye from upper to lower branches, suggesting a lack of vascular connectivity among branches. However, we found under both field and laboratory conditions that herbivore feeding on upper branches elicited volatile emissions by undamaged lower branches. Greenhouse experiments manipulating air contact between damaged and undamaged branches showed that systemic induction of volatiles was almost eliminated when air contact was interrupted. Our findings clearly demonstrate that herbivore-induced volatiles overcome vascular constraints and mediate within-plant signaling. Further, we found that volatile signaling led to induction of different classes of volatiles under field and environment controlled conditions, with a weaker response observed in the field. This difference not only reflects the dose- and time-dependent nature of volatile signaling, but also points out that future studies should focus more on field observations to better understand the ecological role of volatile-mediated within-plant signaling.

  18. Redox regulation of plant development.

    Science.gov (United States)

    Considine, Michael J; Foyer, Christine H

    2014-09-20

    We provide a conceptual framework for the interactions between the cellular redox signaling hub and the phytohormone signaling network that controls plant growth and development to maximize plant productivity under stress-free situations, while limiting growth and altering development on exposure to stress. Enhanced cellular oxidation plays a key role in the regulation of plant growth and stress responses. Oxidative signals or cycles of oxidation and reduction are crucial for the alleviation of dormancy and quiescence, activating the cell cycle and triggering genetic and epigenetic control that underpin growth and differentiation responses to changing environmental conditions. The redox signaling hub interfaces directly with the phytohormone network in the synergistic control of growth and its modulation in response to environmental stress, but a few components have been identified. Accumulating evidence points to a complex interplay of phytohormone and redox controls that operate at multiple levels. For simplicity, we focus here on redox-dependent processes that control root growth and development and bud burst. The multiple roles of reactive oxygen species in the control of plant growth and development have been identified, but increasing emphasis should now be placed on the functions of redox-regulated proteins, along with the central roles of reductants such as NAD(P)H, thioredoxins, glutathione, glutaredoxins, peroxiredoxins, ascorbate, and reduced ferredoxin in the regulation of the genetic and epigenetic factors that modulate the growth and vigor of crop plants, particularly within an agricultural context.

  19. Trophic complexity and the adaptive value of damage-induced plant volatiles.

    Directory of Open Access Journals (Sweden)

    Ian Kaplan

    Full Text Available Indirect plant defenses are those facilitating the action of carnivores in ridding plants of their herbivorous consumers, as opposed to directly poisoning or repelling them. Of the numerous and diverse indirect defensive strategies employed by plants, inducible volatile production has garnered the most fascination among plant-insect ecologists. These volatile chemicals are emitted in response to feeding by herbivorous arthropods and serve to guide predators and parasitic wasps to their prey. Implicit in virtually all discussions of plant volatile-carnivore interactions is the premise that plants "call for help" to bodyguards that serve to boost plant fitness by limiting herbivore damage. This, by necessity, assumes a three-trophic level food chain where carnivores benefit plants, a theoretical framework that is conceptually tractable and convenient, but poorly depicts the complexity of food-web dynamics occurring in real communities. Recent work suggests that hyperparasitoids, top consumers acting from the fourth trophic level, exploit the same plant volatile cues used by third trophic level carnivores. Further, hyperparasitoids shift their foraging preferences, specifically cueing in to the odor profile of a plant being damaged by a parasitized herbivore that contains their host compared with damage from an unparasitized herbivore. If this outcome is broadly representative of plant-insect food webs at large, it suggests that damage-induced volatiles may not always be beneficial to plants with major implications for the evolution of anti-herbivore defense and manipulating plant traits to improve biological control in agricultural crops.

  20. 27 CFR 18.40 - Qualification to alternate volatile fruit-flavor concentrate plant and bonded wine cellar.

    Science.gov (United States)

    2010-04-01

    ... volatile fruit-flavor concentrate plant and bonded wine cellar. 18.40 Section 18.40 Alcohol, Tobacco... Qualification to alternate volatile fruit-flavor concentrate plant and bonded wine cellar. A proprietor of a volatile fruit-flavor concentrate plant operating a contiguous bonded wine cellar may alternate the use of...

  1. Enhanced Iron and Selenium Uptake in Plants by Volatile Emissions of Bacillus amyloliquefaciens (BF06

    Directory of Open Access Journals (Sweden)

    Jianfei Wang

    2017-01-01

    Full Text Available Volatile organic compounds (VOCs released by plant growth-promoting rhizobacteria (PGPR are involved in promoting growth and triggering systemic resistance (ISR in plants. Importantly, the release of VOCs by some PGPR strains confers improved plant uptake of nutrient elements from the soil. However, the underlying mechanisms of VOCs-regulated nutrient acquisition remain elusive. In this study, VOCs were extracted and identified from Bacillus amyloliquefaciens (strain BF06 using gas chromatography–mass spectrometry (GC–MS. BF06 VOCs exposure significantly promoted the growth and photosynthesis of Arabidopsis plants. To explore how microbial VOCs stimulate growth in plants, gene expression profiles of Arabidopsis seedlings exposed to BF06 VOCs were examined using transcriptomic analyses. In screening differentially expressed genes (DEGs, most upregulated DEGs were found to be related to amino acid transport, iron (Fe uptake and homeostasis, and sulfate transport. Furthermore, BF06 VOCs significantly enhanced Fe absorption in plants under Fe-limited conditions. However, when nitric oxide (NO synthesis was inhibited, BF06 VOCs exposure could not substantially augment Fe acquisition in plants under alkaline stress, indicating that VOCs-mediated plant uptake of Fe was required for induction of root NO accumulation. In addition, BF06 VOCs exposure led to a marked increase in some genes encoding for sulfate transporters, and further increased Se accumulation in plants. Intriguingly, BF06 VOCs exposure failed to increase Se uptake in sultr1;2 mutants, which may indicate that high-level transcription of these sulfate transporters induced by BF06 VOCs was essential for enhancing Se absorption by plants. Taken together, our results demonstrated the potential of VOCs released by this strain BF06 to increase Fe and Se uptake in plants.

  2. Emission index for evaluation of volatile organic compounds emitted from tomato plants in greenhouses

    NARCIS (Netherlands)

    Takayama, K.; Jansen, R.M.C.; Henten, van E.J.; Verstappen, F.W.A.; Bouwmeester, H.J.; Nishina, H.

    2012-01-01

    Measurement of volatile organic compounds (VOCs) emitted by plants allows us to monitor plant health status without touching the plant. To bring this technique a step further towards a practical plant diagnosis technique for greenhouse crop production, we have defined a numerical index named

  3. Fusarium oxysporum volatiles enhance plant growth via affecting auxin transport and signaling

    Directory of Open Access Journals (Sweden)

    Vasileios eBitas

    2015-11-01

    Full Text Available Volatile organic compounds (VOCs have well-documented roles in plant-plant communication and directing animal behavior. In this study, we examine the less understood roles of VOCs in plant-fungal relationships. Phylogenetically and ecologically diverse strains of Fusarium oxysporum, a fungal species complex that often resides in the rhizosphere of assorted plants, produce volatile compounds that augment shoot and root growth of Arabidopsis thaliana and tobacco. Growth responses of A. thaliana hormone signaling mutants and expression patterns of a GUS reporter gene under the auxin-responsive DR5 promoter supported the involvement of auxin signaling in F. oxysporum volatile-mediated growth enhancement. In addition, 1-naphthylthalamic acid, an inhibitor of auxin efflux, negated F. oxysporum volatile-mediated growth enhancement in both plants. Comparison of the profiles of volatile compounds produced by F. oxysporum strains that differentially affected plant growth suggests that the relative compositions of both growth inhibitory and stimulatory compounds may determine the degree of plant growth enhancement. Volatile-mediated signaling between fungi and plants may represent a potentially conserved, yet mostly overlooked, mechanism underpinning plant-fungus interactions and fungal niche adaption.

  4. Non-Host Plant Volatiles Disrupt Sex Pheromone Communication in a Specialist Herbivore

    Science.gov (United States)

    Wang, Fumin; Deng, Jianyu; Schal, Coby; Lou, Yonggen; Zhou, Guoxin; Ye, Bingbing; Yin, Xiaohui; Xu, Zhihong; Shen, Lize

    2016-01-01

    The ecological effects of plant volatiles on herbivores are manifold. Little is known, however, about the impacts of non-host plant volatiles on intersexual pheromonal communication in specialist herbivores. We tested the effects of several prominent constitutive terpenoids released by conifers and Eucalyptus trees on electrophysiological and behavioral responses of an oligophagous species, Plutella xylostella, which feeds on Brassicaceae. The non-host plant volatile terpenoids adversely affected the calling behavior (pheromone emission) of adult females, and the orientation responses of adult males to sex pheromone were also significantly inhibited by these terpenoids in a wind tunnel and in the field. We suggest that disruption of both pheromone emission and orientation to sex pheromone may explain, at least in part, an observed reduction in herbivore attack in polyculture compared with monoculture plantings. We also propose that mating disruption of both male and female moths with non-host plant volatiles may be a promising alternative pest management strategy. PMID:27585907

  5. Non-Host Plant Volatiles Disrupt Sex Pheromone Communication in a Specialist Herbivore.

    Science.gov (United States)

    Wang, Fumin; Deng, Jianyu; Schal, Coby; Lou, Yonggen; Zhou, Guoxin; Ye, Bingbing; Yin, Xiaohui; Xu, Zhihong; Shen, Lize

    2016-09-02

    The ecological effects of plant volatiles on herbivores are manifold. Little is known, however, about the impacts of non-host plant volatiles on intersexual pheromonal communication in specialist herbivores. We tested the effects of several prominent constitutive terpenoids released by conifers and Eucalyptus trees on electrophysiological and behavioral responses of an oligophagous species, Plutella xylostella, which feeds on Brassicaceae. The non-host plant volatile terpenoids adversely affected the calling behavior (pheromone emission) of adult females, and the orientation responses of adult males to sex pheromone were also significantly inhibited by these terpenoids in a wind tunnel and in the field. We suggest that disruption of both pheromone emission and orientation to sex pheromone may explain, at least in part, an observed reduction in herbivore attack in polyculture compared with monoculture plantings. We also propose that mating disruption of both male and female moths with non-host plant volatiles may be a promising alternative pest management strategy.

  6. Attraction of Phytoseiulus persimilis (Acari: Phytoseiidae) towards volatiles from various Tetranychus urticae-infested plant species.

    Science.gov (United States)

    van den Boom, C E M; van Beek, T A; Dicke, M

    2002-12-01

    Plants infested with the spider mite Tetranychus urticae Koch, may indirectly defend themselves by releasing volatiles that attract the predatory mite Phytoseiulus persimilis Athias-Henriot. Several plants from different plant families that varied in the level of spider mite acceptance were tested in an olfactometer. The predatory mites were significantly attracted to the spider mite-infested leaves of all test plant species. No differences in attractiveness of the infested plant leaves were found for predatory mites reared on spider mites on the different test plants or on lima bean. Thus, experience with the spider mite-induced plant volatiles did not affect the predatory mites. Jasmonic acid was applied to ginkgo leaves to induce a mimic of a spider mite-induced volatile blend, because the spider mites did not survive when incubated on ginkgo. The volatile blend induced in ginkgo by jasmonic acid was slightly attractive to predatory mites. Plants with a high degree of direct defence were thought to invest less in indirect defence than plants with a low degree of direct defence. However, plants that had a strong direct defence such as ginkgo and sweet pepper, did emit induced volatiles that attracted the predatory mite. This indicates that a combination of direct and indirect defence is to some extent compatible in plant species.

  7. Olfactory antennal responses of the black vine weevil (Otiorhynchus sulcatus) to plant volatiles

    NARCIS (Netherlands)

    Tol, van R.W.H.M.; Visser, J.H.

    2002-01-01

    Electroantennograms (EAGs) were recorded from the vine weevil, Otiorhynchus sulcatus F. (Coleoptera: Curculionidae) to a broad range of volatile plant compounds. The response profile is restricted to a small number of volatiles that evoke substantial EAGs. Large EAG responses were particularly found

  8. Volatile-mediated suppression of plant pathogens is related to soil properties and microbial community composition

    NARCIS (Netherlands)

    Van Agtmaal, M.; Straathof, A.L.; Termorshuizen, Aad J; Lievens, Bart; Hoffland, Ellis; De Boer, W.

    2018-01-01

    There is increasing evidence that the soil microbial community produces a suite of volatile organic compounds that suppress plant pathogens. However, it remains unknown which soil properties and management practices influence volatile-mediated pathogen suppression. The aim of this study was to

  9. Volatile-mediated suppression of plant pathogens is related to soil properties and microbial community composition

    NARCIS (Netherlands)

    Agtmaal, van Maaike; Straathof, Angela L.; Termorshuizen, Aad; Lievens, Bart; Hoffland, Ellis; Boer, de Wietse

    2018-01-01

    There is increasing evidence that the soil microbial community produces a suite of volatile organic compounds that suppress plant pathogens. However, it remains unknown which soil properties and management practices influence volatile-mediated pathogen suppression. The aim of this study was to

  10. Effects of airborne volatile organic compounds on plants

    International Nuclear Information System (INIS)

    Cape, J.N.

    2003-01-01

    Possible adverse effects of VOCs on vegetation in urban areas cannot be rejected. - Routine measurements of volatile organic compounds (VOCs) in air have shown that average concentrations are very much smaller than those used in laboratory experiments designed to study the effects of VOCs on plants. However, maximum hourly concentrations of some VOCs can be 100 times larger than the average, even in rural air. Experimental studies have rarely extended for longer than a few days, so there is little information on potential long-term effects of exposure to small concentrations. This review considers the available evidence for long-term effects, based on laboratory and field data. Previous reviews of the literature from Germany and the USA are cited, prior to an assessment of the effects of individual VOCs. Although hydrocarbons from vehicle exhausts have been implicated in the observed effects on roadside vegetation, the evidence suggests that it is the nitrogen oxides in the exhaust gases that are mostly responsible. There is evidence that aromatic hydrocarbons can be metabolised in plants, although the fate of the metabolites is not known. There is a large literature on the effects of ethylene, because of its role as a plant hormone. Effects have been reported in the field, in response to industrial emissions, and dose-response experiments over several weeks in laboratory studies have clearly identified the potential for effects at ambient concentrations. The main responses are morphological (e.g. epinasty), which may be reversible, and on the development of flowers and fruit. Effects on seed production may be positive or negative, depending on the exposure concentration. Chlorinated hydrocarbons have been identified as potentially harmful to vegetation, but only one long-term experiment has studied dose-response relationships. As for ethylene, the most sensitive indication of effect was on seed production, although long-term accumulation of trichloroacetic acid in

  11. Volatility

    Directory of Open Access Journals (Sweden)

    María Sánchez

    2016-11-01

    Full Text Available The action consists of moving with small kicks a tin of cola refresh -without Brand-from a point of the city up to other one. During the path I avoid bollards, the slope differences between sidewalks, pedestrians, parked motorcycles, etc. Volatility wants to say exactly that the money is getting lost. That the money is losing by gentlemen and by ladies who are neither financial sharks, nor big businessmen… or similarly, but ingenuous people, as you or as me, who walk down the street.

  12. De novo biosynthesis of volatiles induced by insect herbivory in cotton plants

    International Nuclear Information System (INIS)

    Pare, P.W.; Tumlinson, J.H.

    1997-01-01

    In response to insect feeding on the leaves, cotton (Gossypium hirsutum L.) plants release elevated levels of volatiles, which can serve as a chemical signal that attracts natural enemies of the herbivore to the damaged plant. Pulse-labeling experiments with [13C]CO2 demonstrated that many of the volatiles released, including the acyclic terpenes (E,E)-alpha-farnesene, (E)-beta-farnesene, (E)-beta-ocimene, linalool,(E)-4,8-dimethyl-1,3,7-nonatriene, and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetrane, as well as the shikimate pathway product indole, are biosynthesized de novo following insect damage. However, other volatile constituents, including several cyclic terpenes, butyrates, and green leaf volatiles of the lipoxygenase pathway are released from storage or synthesized from stored intermediates. Analysis of volatiles from artificially damaged plants, with and without beet armyworm (Spodoptera exigua Hubner) oral secretions exogenously applied to the leaves, as well as volatiles from beet armyworm-damaged and -undamaged control plants, demonstrated that the application of caterpillar oral secretions increased both the production and release of several volatiles that are synthesized de novo in response to insect feeding. These results establish that the plant plays an active and dynamic role in mediating the interaction between herbivores and natural enemies of herbivores

  13. Volatile Semiochemical Mediated Plant Defense in Cereals: A Novel Strategy for Crop Protection

    Directory of Open Access Journals (Sweden)

    Amanuel Tamiru

    2017-09-01

    Full Text Available Plants have evolved highly intriguing ways of defending themselves against insect attacks, including through emission of defense volatiles. These volatiles serve the plant’s defense by directly repelling phytophagous insects and/or indirectly through attracting natural enemies antagonistic to the herbivores. Several laboratory studies established the potential of improving plant resistance against insect attacks by manipulating the plant-derived volatile semiochemicals emissions. Yet, more efforts need to be conducted to translate the promising laboratory studies to fight economically-important crop pests under real field conditions. This is needed to address an increasing demand for alternative pest control options driven by ecological and environmental costs associated with the use of broad-spectrum insecticides. The practical examples discussed in this review paper demonstrate the real prospect of exploiting an inducible and constitutive plant volatile semiochemicals for developing novel and ecologically-sustainable pest management strategies to protect cereal crops from damaging insect pests.

  14. Interference of plant volatiles on pheromone receptor neurons of male Grapholita molesta (Lepidoptera: Tortricidae).

    Science.gov (United States)

    Ammagarahalli, Byrappa; Gemeno, César

    2015-10-01

    In moths, sex pheromone components are detected by pheromone-specific olfactory receptor neurons (ph-ORNs) housed in sensilla trichodea in the male antennae. In Grapholita molesta, ph-ORNs are highly sensitive and specific to the individual sex pheromone components, and thus help in the detection and discrimination of the unique conspecific pheromone blend. Plant odors interspersed with a sub-optimal pheromone dose are reported to increase male moth attraction. To determine if the behavioral synergism of pheromone and plant odors starts at the ph-ORN level, single sensillum recordings were performed on Z8-12:Ac and E8-12:Ac ph-ORNs (Z-ORNs and E-ORNs, respectively) stimulated with pheromone-plant volatile mixtures. First, biologically meaningful plant-volatile doses were determined by recording the response of plant-specific ORNs housed in sensilla auricillica and trichodea to several plant odorants. This exploration provided a first glance at plant ORNs in this species. Then, using these plant volatile doses, we found that the spontaneous activity of ph-ORNs was not affected by the stimulation with plant volatiles, but that a binary mixture of sex pheromone and plant odorants resulted in a small (about 15%), dose-independent, but statistically significant, reduction in the spike frequency of Z-ORNs with respect to stimulation with Z8-12:Ac alone. The response of E-ORNs to a combination of E8-12:Ac and plant volatiles was not different from E8-12:Ac alone. We argue that the small inhibition of Z-ORNs caused by physiologically realistic plant volatile doses is probably not fully responsible for the observed behavioral synergism of pheromone and plant odors. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Powdery mildew suppresses herbivore-induced plant volatiles and interferes with parasitoid attraction in Brassica rapa

    Science.gov (United States)

    The co-occurrence of different antagonists on a plant can greatly affect infochemicals with ecological consequences for higher trophic levels. Here we investigated how the presence of a plant pathogen, the powdery mildew Erysiphe cruciferarum, on Brassica rapa affects 1) plant volatiles emitted in r...

  16. The herbivore-induced plant volatile methyl salicylate negatively affects attraction of the parasitoid Diadegma semiclausum

    NARCIS (Netherlands)

    Snoeren, T.A.L.; Mumm, R.; Poelman, E.H.; Yang, Y.; Pichersky, E.; Dicke, M.

    2010-01-01

    The indirect defense mechanisms of plants comprise the production of herbivore-induced plant volatiles that can attract natural enemies of plant attackers. One of the often emitted compounds after herbivory is methyl salicylate (MeSA). Here, we studied the importance of this caterpillar-induced

  17. Methyl salicylate, a soybean aphid-induced plant volatile attractive to the predator Coccinella septempunctata.

    Science.gov (United States)

    Zhu, Junwei; Park, Kye-Chung

    2005-08-01

    Induced volatiles provide a signal to foraging predatory insects about the location of their prey. In Iowa, early in the growing season of soybean, Glycine max, many predacious seven-spotted lady beetles, Coccinella septempunctata, were observed on plants with heavy infestations of soybean aphid, Aphis glycines. We studied whether the attraction of this beetle is caused by the release of specific volatile compounds of soybean plants infested by aphids. Volatile compounds emitted by soybean plants infested by aphids were compared with those of undamaged, uninfested, and artificially damaged plants. Gas chromatography-mass spectrometry analyses revealed consistent differences in the profiles of volatile compounds between aphid-infested soybean plants and undamaged ones. Significantly more methyl salicylate was released from infested plants at both the V1 and V2 plant growth stages. However, release patterns of two other induced plant volatiles, (D)-limonene and (E,E)-alpha-farnesene, differed between the two plant growth stages. Gas chromatographic-electroantennographic detection of volatile extracts from infested soybean plants showed that methyl salicylate elicited significant electrophysiological responses in C. septempunctata. In field tests, traps baited with methyl salicylate were highly attractive to adult C. septempunctata, whereas 2-phenylethanol was most attractive to the lacewing Chrysoperla carnea and syrphid flies. Another common lady beetle, the multicolored Asian lady beetle, Harmonia axyridis, showed no preference for the compounds. These results indicate that C. septempunctata may use methyl salicylate as the olfactory cue for prey location. We also tested the attractiveness of some selected soybean volatiles to alate soybean aphids in the field, and results showed that traps baited with benzaldehyde caught significantly higher numbers of aphids.

  18. Identification of octanal as plant growth inhibitory volatile compound released from Heracleum sosnowskyi fruit.

    Science.gov (United States)

    Mishyna, Maryia; Laman, Nikolai; Prokhorov, Valery; Maninang, John Solomon; Fujii, Yoshiharu

    2015-05-01

    Heracleum sosnowskyi Manden of the Apiaceae family is a malignant invasive plant in Eastern Europe, Belarus and Russia. The species is known for its prolific seed production, which has been linked to the plant's invasive success. The fruit also has a strong aroma, but the contribution of the fruit's volatile constituent to out-compete neighboring plants has not been fully established. In this study, fruit volatiles of H. sosnowskyi and conspecifics (i.e. H. asperum, H. lescovii, H. dissectum, H. hirtum) were identified by headspace gas chromatography-mass spectrometry (HS-GC-MS). Octyl acetate, octanol, octanal, hexyl isobutyrate, and hexyl-2-methyl butyrate were found to be the principal volatiles. Using authentic standards, the growth-inhibitory property of the individual compounds was assayed by the novel Cotton swab method. Assay results with lettuce (Lactuca sativa) showed that octanal strongly inhibited seed germination and radicle elongation of seedlings. The results suggest that octanal may be the main contributor to the allelopathic activity of H. sosnowksyi fruits. Furthermore, the mixture of fruit volatiles from the invasive H. sosnowskyi more strongly delayed lettuce seedling elongation than the volatiles from fruits of the non-invasive H. asperum, H. lescovii, H. dissectum and H. hirtum. Thus, the present study is the first to demonstrate the possible involvement of fruit volatiles of Heracleum species in plant-plant interaction.

  19. Volatile oils from the plant and hairy root cultures of Ageratum conyzoides L.

    Science.gov (United States)

    Abdelkader, Mohamed Salaheldin A; Lockwood, George B

    2011-05-01

    Two lines of hairy root culture of Ageratum conyzoides L. induced by Agrobacterium rhizogenes ATCC 15834 were established under either complete darkness or 16 h light/8 h dark photoperiod conditions. The volatile oil yields from aerial parts and roots of the parent plant, the hairy root culture photoperiod line and the hairy root culture dark line were 0.2%, 0.08%, 0.03% and 0.02%, (w/w), respectively. The compositions of the volatiles from the hairy roots, plant roots and aerial parts were analysed by GC and GC-MS. The main components of the volatiles from the hairy root cultures were β-farnesene, precocene I and β-caryophyllene, in different amounts, depending on light conditions and also on the age of cultures. Precocene I, β-farnesene, precocene II and β-caryophyllene were the main constituents of the volatile oils from the parent plant roots, whereas precocene I, germacrene D, β-caryophyllene and precocene II were the main constituents of the aerial parts of the parent plant. Growth and time-course studies of volatile constituents of the two hairy root lines were compared. Qualitative and quantitative differences were found between the volatile oils from the roots of the parent plant and those from the hairy roots.

  20. Biochar application reduce ammonia volatilization in a soil-plant system: A closed chamber experiment

    Science.gov (United States)

    Mandal, Sanchita; Donner, Erica; Smith, Euan; Lombi, Enzo

    2017-04-01

    Ammonia (NH3) volatilization is considered as one of the major mechanisms responsible for the loss of nitrogen (N) from soil-plant systems worldwide. About 10-30% of N can be lost as NH3 volatilization, which constitutes a significant economic loss. In recent years carbon-based materials such as biochar have created a great research interest because of their ability to increase soil fertility by reducing nutrient loss and pollutants bioavailability in soil. Most of the studies so far have investigated how biochar addition can reduce NH3 volatilization from soils but less information is available for soil-plant systems. In this research, wheat plants (Triticum aestivum, variety: Calingiri) were grown in a calcareous soil (pH 8, calcarosol) inside a closed chamber system to assess both ammonia volatilization and plant N uptake. In this specialized glass chamber air was passed through an inlet where the flow rate was maintained using an air pump (3.5 L min-1). The air outlet was passed through a sulphuric acid trap which was used to capture the volatilized NH3 from the chamber. Plants were watered using the inlet to maintain 50% field capacity throughout the incubation. Two different biochar samples were used in this study: a poultry manure biochar (PM-BC) and a green waste compost biochar (GW-BC) produced at 250 ˚C. Five different application rates were tested (0, 0.5, 1, 1.5, and 2%). The soil was mixed with biochar samples, water, N, P, K, Ca, Mg, and S for one week before sowing. After one week of germination, plants were transferred to the chamber for further three weeks incubation for NH3 volatilization measurement. The study identified that biochar application reduced the NH3 volatilization and increase the plant biomass. Biochar application at 0.5 and 2% decreased the NH3 volatilization by 36 and 48% respectively. The N uptake of the plants also increased from 2.9 to 28% at 0.5 and 2% application rates respectively. The dry biomass of the plant also increased

  1. Induced release of a plant-defense volatile 'deceptively' attracts insect vectors to plants infected with a bacterial pathogen.

    Directory of Open Access Journals (Sweden)

    Rajinder S Mann

    Full Text Available Transmission of plant pathogens by insect vectors is a complex biological process involving interactions between the plant, insect, and pathogen. Pathogen-induced plant responses can include changes in volatile and nonvolatile secondary metabolites as well as major plant nutrients. Experiments were conducted to understand how a plant pathogenic bacterium, Candidatus Liberibacter asiaticus (Las, affects host preference behavior of its psyllid (Diaphorina citri Kuwayama vector. D. citri were attracted to volatiles from pathogen-infected plants more than to those from non-infected counterparts. Las-infected plants were more attractive to D. citri adults than non-infected plants initially; however after feeding, psyllids subsequently dispersed to non-infected rather than infected plants as their preferred settling point. Experiments with Las-infected and non-infected plants under complete darkness yielded similar results to those recorded under light. The behavior of psyllids in response to infected versus non-infected plants was not influenced by whether or not they were carriers of the pathogen. Quantification of volatile release from non-infected and infected plants supported the hypothesis that odorants mediate psyllid preference. Significantly more methyl salicylate, yet less methyl anthranilate and D-limonene, was released by infected than non-infected plants. Methyl salicylate was attractive to psyllids, while methyl anthranilate did not affect their behavior. Feeding on citrus by D. citri adults also induced release of methyl salicylate, suggesting that it may be a cue revealing location of conspecifics on host plants. Infected plants were characterized by lower levels of nitrogen, phosphorus, sulfur, zinc, and iron, as well as, higher levels of potassium and boron than non-infected plants. Collectively, our results suggest that host selection behavior of D. citri may be modified by bacterial infection of plants, which alters release of

  2. Herbivore-induced plant volatiles and tritrophic interactions across spatial scales.

    Science.gov (United States)

    Aartsma, Yavanna; Bianchi, Felix J J A; van der Werf, Wopke; Poelman, Erik H; Dicke, Marcel

    2017-12-01

    Herbivore-induced plant volatiles (HIPVs) are an important cue used in herbivore location by carnivorous arthropods such as parasitoids. The effects of plant volatiles on parasitoids have been well characterised at small spatial scales, but little research has been done on their effects at larger spatial scales. The spatial matrix of volatiles ('volatile mosaic') within which parasitoids locate their hosts is dynamic and heterogeneous. It is shaped by the spatial pattern of HIPV-emitting plants, the concentration, chemical composition and breakdown of the emitted HIPV blends, and by environmental factors such as wind, turbulence and vegetation that affect transport and mixing of odour plumes. The volatile mosaic may be exploited differentially by different parasitoid species, in relation to species traits such as sensory ability to perceive volatiles and the physical ability to move towards the source. Understanding how HIPVs influence parasitoids at larger spatial scales is crucial for our understanding of tritrophic interactions and sustainable pest management in agriculture. However, there is a large gap in our knowledge on how volatiles influence the process of host location by parasitoids at the landscape scale. Future studies should bridge the gap between the chemical and behavioural ecology of tritrophic interactions and landscape ecology. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  3. An air transfer experiment confirms the role of volatile cues in communication between plants.

    Science.gov (United States)

    Karban, Richard; Shiojiri, Kaori; Ishizaki, Satomi

    2010-09-01

    Previous studies reported that sagebrush plants near experimentally clipped neighbors experienced less herbivory than did plants near unclipped neighbors. Blocking air flow with plastic bags made this effect undetectable. However, some scientists remained skeptical about the possibility of volatile communication between plants since the existence and identity of a cue that operates in nature have never been demonstrated. We conducted an air transfer experiment that collected air from the headspace of an experimentally clipped donor plant and delivered it to the headspace of an unclipped assay plant. We found that assay plants treated with air from clipped donors were less likely to be damaged by naturally occurring herbivores in a field experiment. This simple air transfer experiment fulfills the most critical of Koch's postulates and provides more definitive evidence for volatile communication between plants. It also provides an inexpensive experimental protocol that can be used to screen plants for interplant communication in the field.

  4. Metabolic engineering of volatile isoprenoids in plants and microbes

    NARCIS (Netherlands)

    Vickers, C.; Bongers, M.; Liu, Q.; Delatte, T.L.; Bouwmeester, H.J.

    2014-01-01

    The chemical properties and diversity of volatile isoprenoids lends them to a broad variety of biological roles. It also lends them to a host of biotechnological applications, both by taking advantage of their natural functions and by using them as industrial chemicals/chemical feedstocks. Natural

  5. Plant-specific volatile organic compound emission rates from young and mature leaves of Mediterranean vegetation

    Science.gov (United States)

    Bracho-Nunez, Araceli; Welter, Saskia; Staudt, Michael; Kesselmeier, Jürgen

    2011-08-01

    The seasonality of vegetation, i.e., developmental stages and phenological processes, affects the emission of volatile organic compounds (VOCs). Despite the potential significance, the contributions of seasonality to VOC emission quality and quantity are not well understood and are therefore often ignored in emission simulations. We investigated the VOC emission patterns of young and mature leaves of several Mediterranean plant species in relation to their physiological and developmental changes during the growing period and estimated Es. Foliar emissions of isoprenoids and oxygenated VOCs like methanol and acetone were measured online by means of a proton transfer reaction mass spectrometer (PTR-MS) and offline with gas chromatography coupled with a mass spectrometer and flame ionization detector. The results suggest that VOC emission is a developmentally regulated process and that quantitative and qualitative variability is plant species specific. Leaf ontogeny clearly influenced both the VOC Es and the relative importance of different VOCs. Methanol was the major compound contributing to the sum of target VOC emissions in young leaves (11.8 ± 10.4 μg g-1 h-1), while its contribution was minor in mature leaves (4.1 ± 4.1 μg g-1 h-1). Several plant species showed a decrease or complete subsidence of monoterpene, sesquiterpene, and acetone emissions upon maturity, perhaps indicating a potential response to the higher defense demands of young emerging leaves.

  6. Complexity of plant volatile-mediated interactions beyond the third trophic level

    NARCIS (Netherlands)

    Poelman, E.H.; Kos, M.

    2016-01-01

    Food chains of plant-associated communities typically reach beyond three trophic levels. The predators and parasitoids in the third trophic level are under attack by top predators or parasitised by hyperparasitoids. These higher trophic level organisms respond to plant volatiles in search of their

  7. Dynamic chemical communication between plants and bacteria through airborne signals: induced resistance by bacterial volatiles.

    Science.gov (United States)

    Farag, Mohamed A; Zhang, Huiming; Ryu, Choong-Min

    2013-07-01

    Certain plant growth-promoting rhizobacteria (PGPR) elicit induced systemic resistance (ISR) and plant growth promotion in the absence of physical contact with plants via volatile organic compound (VOC) emissions. In this article, we review the recent progess made by research into the interactions between PGPR VOCs and plants, focusing on VOC emission by PGPR strains in plants. Particular attention is given to the mechanisms by which these bacterial VOCs elicit ISR. We provide an overview of recent progress in the elucidation of PGPR VOC interactions from studies utilizing transcriptome, metabolome, and proteome analyses. By monitoring defense gene expression patterns, performing 2-dimensional electrophoresis, and studying defense signaling null mutants, salicylic acid and ethylene have been found to be key players in plant signaling pathways involved in the ISR response. Bacterial VOCs also confer induced systemic tolerance to abiotic stresses, such as drought and heavy metals. A review of current analytical approaches for PGPR volatile profiling is also provided with needed future developments emphasized. To assess potential utilization of PGPR VOCs for crop plants, volatile suspensions have been applied to pepper and cucumber roots and found to be effective at protecting plants against plant pathogens and insect pests in the field. Taken together, these studies provide further insight into the biological and ecological potential of PGPR VOCs for enhancing plant self-immunity and/or adaptation to biotic and abiotic stresses in modern agriculture.

  8. The herbivore-induced plant volatile methyl salicylate negatively affects attraction of the parasitoid Diadegma semiclausum.

    Science.gov (United States)

    Snoeren, Tjeerd A L; Mumm, Roland; Poelman, Erik H; Yang, Yue; Pichersky, Eran; Dicke, Marcel

    2010-05-01

    The indirect defense mechanisms of plants comprise the production of herbivore-induced plant volatiles that can attract natural enemies of plant attackers. One of the often emitted compounds after herbivory is methyl salicylate (MeSA). Here, we studied the importance of this caterpillar-induced compound in the attraction of the parasitoid wasp Diadegma semiclausum by using a mutant Arabidopsis line. Pieris rapae infested AtBSMT1-KO mutant Arabidopsis plants, compromised in the biosynthesis of MeSA, were more attractive to parasitoids than infested wild-type plants. This suggests that the presence of MeSA has negative effects on parasitoid host-finding behavior when exposed to wild-type production of herbivore-induced Arabidopsis volatiles. Furthermore, in line with this, we recorded a positive correlation between MeSA dose and repellence of D. semiclausum when supplementing the headspace of caterpillar-infested AtBSMT1-KO plants with synthetic MeSA.

  9. Variation among volatile profiles induced by Botrytis cinerea infection of tomato plants

    OpenAIRE

    Jansen, R.M.C.

    2007-01-01

    Botrytis blight caused by the fungus Botrytis cinerea is probably the most common disease of greenhouse-grown crops like tomato. Botrytis blight in tomato plants is mainly detected by visual inspection or destructive biochemical and molecular determinations. These methods are time consuming and not suitable for large sample sizes. In contrast we propose a fast and non-destructive detection method for plant diagnosis using volatiles as an early indicator of plant diseases. This report presents...

  10. Phytoseiulus persimilis response to herbivore-induced plant volatiles as a function of mite-days.

    Science.gov (United States)

    Nachappa, Punya; Margolies, David C; Nechols, James R; Loughin, Thomas

    2006-01-01

    The predatory mite, Phytoseiulus persimilis (Acari: Phytoseiidae), uses plant volatiles (i.e., airborne chemicals) triggered by feeding of their herbivorous prey, Tetranychus urticae (Acari: Tetranychidae), to help locate prey patches. The olfactory response of P. persimilis to prey-infested plants varies in direct relation to the population growth pattern of T. urticae on the plant; P. persimilis responds to plants until the spider mite population feeding on a plant collapses, after which infested plants do not attract predators. It has been suggested that this represents an early enemy-free period for T. urticae before the next generation of females is produced. We hypothesize that the mechanism behind the diminished response of predators is due to extensive leaf damage caused by T. urticae feeding, which reduces the production of volatiles irrespective of the collapse of T. urticae population on the plant. To test this hypothesis we investigated how the response of P. persimilis to prey-infested plants is affected by: 1) initial density of T. urticae, 2) duration of infestation, and 3) corresponding leaf damage due to T. urticae feeding. Specifically, we assessed the response of P. persimilis to plants infested with two T. urticae densities (20 or 40 per plant) after 2, 4, 6, 8, 10, 12 or 14 days. We also measured leaf damage on these plants. We found that predator response to T. urticae-infested plants can be quantified as a function of mite-days, which is a cumulative measure of the standing adult female mite population sampled and summed over time. That is, response to volatiles increased with increasing numbers of T. urticae per plant or with the length of time plant was infested by T. urticae, at least as long at the leaves were green. Predatory mites were significantly attracted to plants that were infested for 2 days with only 20 spider mites. This suggests that the enemy-free period might only provide a limited window of opportunity for T. urticae

  11. How common is within-plant signalling via volatiles?

    DEFF Research Database (Denmark)

    Li, Tao; Blande, James D.

    2017-01-01

    or neighbouring plants to impending danger. It has been postulated that HIPVs evolved for within-plant signalling and that other organisms subsequently evolved to use them. However, only seven studies have reported HIPV-mediated within-plant signalling, most conducted in the laboratory or greenhouse. This leaves...... open the ecological relevance and evolutionary underpinning of the phenomenon. We recently observed within-plant signalling in hybrid aspen under laboratory and field conditions. Greenhouse experiments showed that HIPVs mediated the process. While our study adds an aspen hybrid to the list of plants...... in which within-plant signalling has been demonstrated, we lack understanding of how common the process is and whether plants obtain fitness benefits....

  12. The Salicylic Acid-Mediated Release of Plant Volatiles Affects the Host Choice of Bemisia tabaci

    Directory of Open Access Journals (Sweden)

    Xiaobin Shi

    2016-06-01

    Full Text Available The whitefly Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae causes serious crop losses worldwide by transmitting viruses. We have previously shown that salicylic acid (SA-related plant defenses directly affect whiteflies. In this study, we applied exogenous SA to tomato plants in order to investigate the interaction between SA-induced plant volatiles and nonviruliferous B. tabaci B and Q or B- and Q-carrying tomato yellow leaf curl virus (TYLCV. The results showed that exogenous SA caused plants to repel nonviruliferous whiteflies, but the effect was reduced when the SA concentration was low and when the whiteflies were viruliferous. Exogenous SA increased the number and quantity of plant volatiles—especially the quantity of methyl salicylate and δ-limonene. In Y-tube olfactometer assays, methyl salicylate and δ-limonene repelled the whiteflies, but the repellency was reduced for viruliferous Q. We suggest that the release of plant volatiles as mediated by SA affects the interaction between whiteflies, plants, and viruses. Further studies are needed to determine why viruliferous Q is less sensitive than nonviruliferous Q to repellent plant volatiles.

  13. [Effects of azadirachtin on rice plant volatiles induced by Nilaparvata lugens].

    Science.gov (United States)

    Lu, Hai-Yan; Liu, Fang; Zhu, Shu-De; Zhang, Qing

    2010-01-01

    With the method of solid phase microextraction (SPME), a total of twenty-five volatiles were collected from rice plants induced by Nilaparvata lugens, and after applying azadirachtin fourteen of them were qualitatively identified by gas chromatography coupled by mass spectrometry (GC-MS), mainly of nine kinds of sesquiterpenes. Comparing with healthy rice plants, the plants attacked by N. lugens had more kinds of volatiles, including limonene, linalool, methyl salicylate, unknown 6, unknown 7, zingiberene, nerolidol, and hexadecane. Applying azadirachtin did not result in the production of new kind volatiles, but affected the relative concentrations of the volatiles induced by N. lugens. The proportions of limonene, linalool, methyl salicylate, unknown 6, zingiberene, and hexadecane changed obviously with the concentration of applied azadirachtin, while those of methyl salicylate, unknown 6, unknown 7, zingiberene, and nerolidol changed significantly with the days after azadirachtin application. Azadirachtin concentration, rice variety, and N. lugens density had significant interactions on the relative concentrations of all test N. lugens-induced volatiles.

  14. Regulating nutrient allocation in plants

    Science.gov (United States)

    Udvardi, Michael; Yang, Jiading; Worley, Eric

    2014-12-09

    The invention provides coding and promoter sequences for a VS-1 and AP-2 gene, which affects the developmental process of senescence in plants. Vectors, transgenic plants, seeds, and host cells comprising heterologous VS-1 and AP-2 genes are also provided. Additionally provided are methods of altering nutrient allocation and composition in a plant using the VS-1 and AP-2 genes.

  15. Prey and non-prey arthropods sharing a host plant : Effects on induced volatile emission and predator attraction

    NARCIS (Netherlands)

    de Boer, Jetske G.; Hordijk, Cornelis A.; Posthumus, Maarten A.; Dicke, Marcel

    It is well established that plants infested with a single herbivore species can attract specific natural enemies through the emission of herbivore-induced volatiles. However, it is less clear what happens when plants are simultaneously attacked by more than one species. We analyzed volatile

  16. Innate responses of the predatory mite Phytoseiulus persimilis to a herbivore-induced plant volatile

    NARCIS (Netherlands)

    Sznajder, B.; Sabelis, M.W.; Egas, M.

    2011-01-01

    The responses of the predatory mite P. persimilis to herbivore-induced plant volatiles are at least partly genetically determined. Thus, there is potential for the evolution of this behaviour by natural selection. We tested whether distinct predator genotypes with contrasting responses to a specific

  17. Genetic engineering of plant volatile terpenoids: effects on a herbivore, a predator and a parasitoid

    NARCIS (Netherlands)

    Kos, M.; Houshyani, B.; Overeem, A.J.; Bouwmeester, H.J.; Weldegergis, B.T.; van Loon, J.J.A.; Dicke, M.; Vet, L.E.M.

    2013-01-01

    BACKGROUND: Most insect-resistant transgenic crops employ toxins to control pests. A novel approach is to enhance the effectiveness of natural enemies by genetic engineering of the biosynthesis of volatile organic compounds (VOCs). Before the commercialisation of such transgenic plants can be

  18. A model Apparatus for Isolation of Volatile Oils from Various Plant Materials

    Directory of Open Access Journals (Sweden)

    Mahdi T. AI-Kaisey

    2018-02-01

    The present paper givas a detailed description of apparatus which were sutable for isola.tion the lighter and tile heavier u.('-m water volatile oils fronl differenet plant materials. Meanwhile tbe purity of tile concentrates were ex lrined by g-aS liquid chromato graphy( GLe.

  19. Birds exploit herbivore-induced plant volatiles to locate herbivorous prey

    NARCIS (Netherlands)

    Amo, L.; Jansen, J.J.; Dam, van N.M.; Dicke, M.; Visser, M.E.

    2013-01-01

    Arthropod herbivory induces plant volatiles that can be used by natural enemies of the herbivores to find their prey. This has been studied mainly for arthropods that prey upon or parasitise herbivorous arthropods but rarely for insectivorous birds, one of the main groups of predators of herbivorous

  20. Determining the vapour pressures of plant volatiles from gas chromatographic retention data

    Czech Academy of Sciences Publication Activity Database

    Hoskovec, Michal; Grygarová, D.; Cvačka, Josef; Streinz, Ludvík; Zima, J.; Verevkin, S. P.; Koutek, Bohumír

    2005-01-01

    Roč. 1083, - (2005), s. 161-172 ISSN 0021-9673 Institutional research plan: CEZ:AV0Z4055905 Keywords : vapour pressure * thermodinamic parameters * plant volatiles Subject RIV: CC - Organic Chemistry Impact factor: 3.096, year: 2005

  1. Aboveground endophyte affects root volatile emission and host plant selection of a belowground insect.

    Science.gov (United States)

    Rostás, Michael; Cripps, Michael G; Silcock, Patrick

    2015-02-01

    Plants emit specific blends of volatile organic compounds (VOCs) that serve as multitrophic, multifunctional signals. Fungi colonizing aboveground (AG) or belowground (BG) plant structures can modify VOC patterns, thereby altering the information content for AG insects. Whether AG microbes affect the emission of root volatiles and thus influence soil insect behaviour is unknown. The endophytic fungus Neotyphodium uncinatum colonizes the aerial parts of the grass hybrid Festuca pratensis × Lolium perenne and is responsible for the presence of insect-toxic loline alkaloids in shoots and roots. We investigated whether endophyte symbiosis had an effect on the volatile emission of grass roots and if the root herbivore Costelytra zealandica was able to recognize endophyte-infected plants by olfaction. In BG olfactometer assays, larvae of C. zealandica were more strongly attracted to roots of uninfected than endophyte-harbouring grasses. Combined gas chromatography-mass spectrometry and proton transfer reaction-mass spectrometry revealed that endophyte-infected roots emitted less VOCs and more CO2. Our results demonstrate that symbiotic fungi in plants may influence soil insect distribution by changing their behaviour towards root volatiles. The well-known defensive mutualism between grasses and Neotyphodium endophytes could thus go beyond bioactive alkaloids and also confer protection by being chemically less apparent for soil herbivores.

  2. Pesticide volatilization from soil and plant surfaces: Measurements at different scales versus model predictions

    Energy Technology Data Exchange (ETDEWEB)

    Wolters, A.

    2003-07-01

    Simulation of pesticide volatilization from plant and soil surfaces as an integral component of pesticide fate models is of utmost importance, especially as part of the PEC (predicted environmental concentrations) models used in the registration procedures for pesticides. Experimentally determined volatilization rates at different scales were compared to model predictions to improve recent approaches included in European registration models. To assess the influence of crucial factors affecting volatilization under well-defined conditions, a laboratory chamber was set-up and validated. Aerodynamic conditions were adjusted to fulfill the requirements of the German guideline on assessing pesticide volatilization for registration purposes. At the semi-field scale, volatilization rates were determined in a wind-tunnel study after soil surface application of pesticides to gleyic cambisol. The following descending order of cumulative volatilization was observed: chlorpyrifos > parathion-methyl > terbuthylazine > fenpropimorph. Parameterization of the models PEARL (pesticide emission assessment at regional and local scales) and PELMO (pesticide leaching model) was performed to mirror the experimental boundary conditions. (orig.)

  3. Herbivore-specific, density-dependent induction of plant volatiles: honest or "cry wolf" signals?

    Directory of Open Access Journals (Sweden)

    Kaori Shiojiri

    Full Text Available Plants release volatile chemicals upon attack by herbivorous arthropods. They do so commonly in a dose-dependent manner: the more herbivores, the more volatiles released. The volatiles attract predatory arthropods and the amount determines the probability of predator response. We show that seedlings of a cabbage variety (Brassica oleracea var. capitata, cv Shikidori also show such a response to the density of cabbage white (Pieris rapae larvae and attract more (naive parasitoids (Cotesia glomerata when there are more herbivores on the plant. However, when attacked by diamondback moth (Plutella xylostella larvae, seedlings of the same variety (cv Shikidori release volatiles, the total amount of which is high and constant and thus independent of caterpillar density, and naive parasitoids (Cotesia vestalis of diamondback moth larvae fail to discriminate herbivore-rich from herbivore-poor plants. In contrast, seedlings of another cabbage variety of B. oleracea (var. acephala: kale respond in a dose-dependent manner to the density of diamondback moth larvae and attract more parasitoids when there are more herbivores. Assuming these responses of the cabbage cultivars reflect behaviour of at least some genotypes of wild plants, we provide arguments why the behaviour of kale (B. oleracea var acephala is best interpreted as an honest signaling strategy and that of cabbage cv Shikidori (B. oleracea var capitata as a "cry wolf" signaling strategy, implying a conflict of interest between the plant and the enemies of its herbivores: the plant profits from being visited by the herbivore's enemies, but the latter would be better off by visiting other plants with more herbivores. If so, evolutionary theory on alarm signaling predicts consequences of major interest to students of plant protection, tritrophic systems and communication alike.

  4. Quantitative patterns between plant volatile emissions induced by biotic stresses and the degree of damage

    Directory of Open Access Journals (Sweden)

    Ülo eNiinemets

    2013-07-01

    Full Text Available Plants have to cope with a plethora of biotic stresses such as herbivory and pathogen attacks throughout their life cycle. The biotic stresses typically trigger rapid emissions of volatile products of lipoxygenase pathway (LOX products, various C6 aldehydes, alcohols and derivatives, also called green leaf volatiles associated with oxidative burst. Further a variety of defense pathways is activated, leading to induction of synthesis and emission of a complex blend of volatiles, often including methyl salicylate, indole, mono-, homo- and sesquiterpenes. The airborne volatiles are involved in systemic responses leading to elicitation of emissions from non-damaged plant parts. For several abiotic stresses, it has been demonstrated that volatile emissions are quantitatively related to the stress dose. The biotic impacts under natural conditions vary in severity from mild to severe, but it is unclear whether volatile emissions also scale with the severity of biotic stresses in a dose-dependent manner. Furthermore, biotic impacts are typically recurrent, but it is poorly understood how direct stress-triggered and systemic emission responses are silenced during periods intervening sequential stress events. Here we review the information on induced emissions elicited in response to biotic attacks, and argue that biotic stress severity vs. emission rate relationships should follow principally the same dose-response relationships as previously demonstrated for several abiotic stresses. Analysis of several case studies investigating the elicitation of emissions in response to chewing herbivores, aphids, rust fungi, powdery mildew and Botrytis, suggests that induced emissions do respond to stress severity in dose-dependent manner. Bi-phasic emission kinetics of several induced volatiles have been demonstrated in these experiments, suggesting that next to immediate stress-triggered emissions, biotic stress elicited emissions typically have a secondary

  5. Fungal endophytes – the hidden inducers of volatile terpene biosynthesis in tomato plants

    DEFF Research Database (Denmark)

    Ntana, Fani; Jensen, Birgit; Jørgensen, Hans Jørgen Lyngs

    mycorrhizal spores in the Indian Thar desert, colonizes the root cortex of a wide range of plants, enhancing plant growth and modulating plant specialized metabolism. The effect of S. indica colonization on the metabolism of the host can be potentially used in improving plant defence against pathogens...... and herbivores. Tomato (Solanum lycopersicum) is an important crop, often challenged by fungal pathogens and insect pests. The wide variety of secondary metabolites produced by the plant, and especially terpenes, play a crucial role in plant defence, helping in repelling possible enemies. This project is focused....... indica-inoculated and S. indica-free tomato plants. Preliminary data suggest that fungal colonization results in increased production of specific volatile terpenes. A transcriptome analysis on fungus-associated and fungus-free plant tissues is currently ongoing to elucidate in depth the mechanisms...

  6. An overview of plant volatile metabolomics, sample treatment and reporting considerations with emphasis on mechanical damage and biological control of weeds.

    Science.gov (United States)

    Beck, John J; Smith, Lincoln; Baig, Nausheena

    2014-01-01

    The technology for the collection and analysis of plant-emitted volatiles for understanding chemical cues of plant-plant, plant-insect or plant-microbe interactions has increased over the years. Consequently, the in situ collection, analysis and identification of volatiles are considered integral to elucidation of complex plant communications. Due to the complexity and range of emissions the conditions for consistent emission of volatiles are difficult to standardise. To discuss: evaluation of emitted volatile metabolites as a means of screening potential target- and non-target weeds/plants for insect biological control agents; plant volatile metabolomics to analyse resultant data; importance of considering volatiles from damaged plants; and use of a database for reporting experimental conditions and results. Recent literature relating to plant volatiles and plant volatile metabolomics are summarised to provide a basic understanding of how metabolomics can be applied to the study of plant volatiles. An overview of plant secondary metabolites, plant volatile metabolomics, analysis of plant volatile metabolomics data and the subsequent input into a database, the roles of plant volatiles, volatile emission as a function of treatment, and the application of plant volatile metabolomics to biological control of invasive weeds. It is recommended that in addition to a non-damaged treatment, plants be damaged prior to collecting volatiles to provide the greatest diversity of odours. For the model system provided, optimal volatile emission occurred when the leaf was punctured with a needle. Results stored in a database should include basic environmental conditions or treatments. Copyright © 2013 John Wiley & Sons, Ltd.

  7. Volatile science? Metabolic engineering of terpenoids in plants

    NARCIS (Netherlands)

    Aharoni, A.; Jongsma, M.A.; Bouwmeester, H.J.

    2005-01-01

    Terpenoids are important for plant survival and also possess biological properties that are beneficial to humans. Here, we describe the state of the art in terpenoid metabolic engineering, showing that significant progress has been made over the past few years. Subcellular targeting of enzymes has

  8. Volatile compounds emitted by diverse phytopathogenic microorganisms promote plant growth and flowering through cytokinin action

    Czech Academy of Sciences Publication Activity Database

    Sanchez-Lopez, A.; Baslam, M.; De Diego, N.; Jose Munoz, F.; Bahaji, A.; Almagro, G.; Ricarte-Bermejo, A.; Garcia-Gomez, P.; Li, J.; Humplík, J.F.; Novák, Ondřej; Spíchal, L.; Doležal, Karel; Baroja-Fernandez, E.; Pozueta-Romero, J.

    2016-01-01

    Roč. 39, č. 12 (2016), s. 2592-2608 ISSN 0140-7791 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : exceptionally high-levels * tandem mass-spectrometry * arabidopsis-thaliana * nitric-oxide * bacterial volatiles * floral transition * anthocyanin biosynthesis * transgenic arabidopsis * liquid-chromatography * organic-compounds * cytokinin * flowering * growth promotion * microbial volatile compounds * photoregulation * photosynthesis * plant-microbe interaction * starch Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.173, year: 2016

  9. Volatile communication between plants that affects herbivory: a meta-analysis.

    Science.gov (United States)

    Karban, Richard; Yang, Louie H; Edwards, Kyle F

    2014-01-01

    Volatile communication between plants causing enhanced defence has been controversial. Early studies were not replicated, and influential reviews questioned the validity of the phenomenon. We collected 48 well-replicated studies and found overall support for the hypothesis that resistance increased for individuals with damaged neighbours. Laboratory or greenhouse studies and those conducted on agricultural crops showed stronger induced resistance than field studies on undomesticated species, presumably because other variation had been reduced. A cumulative analysis revealed that early, non-replicated studies were more variable and showed less evidence for communication. Effects of habitat and plant growth form were undetectable. In most cases, the mechanisms of resistance and alternative hypotheses were not considered. There was no indication that some response variables were more likely to produce large effects. These results indicate that plants of diverse taxonomic affinities and ecological conditions become more resistant to herbivores when exposed to volatiles from damaged neighbours. © 2013 John Wiley & Sons Ltd/CNRS.

  10. Volatile compounds from beneficial or pathogenic bacteria differentially regulate root exudation, transcription of iron transporters, and defense signaling pathways in Sorghum bicolor.

    Science.gov (United States)

    Hernández-Calderón, Erasto; Aviles-Garcia, Maria Elizabeth; Castulo-Rubio, Diana Yazmín; Macías-Rodríguez, Lourdes; Ramírez, Vicente Montejano; Santoyo, Gustavo; López-Bucio, José; Valencia-Cantero, Eduardo

    2018-02-01

    Our results show that Sorghum bicolor is able to recognize bacteria through its volatile compounds and differentially respond to beneficial or pathogens via eliciting nutritional or defense adaptive traits. Plants establish beneficial, harmful, or neutral relationships with bacteria. Plant growth promoting rhizobacteria (PGPR) emit volatile compounds (VCs), which may act as molecular cues influencing plant development, nutrition, and/or defense. In this study, we compared the effects of VCs produced by bacteria with different lifestyles, including Arthrobacter agilis UMCV2, Bacillus methylotrophicus M4-96, Sinorhizobium meliloti 1021, the plant pathogen Pseudomonas aeruginosa PAO1, and the commensal rhizobacterium Bacillus sp. L2-64, on S. bicolor. We show that VCs from all tested bacteria, except Bacillus sp. L2-64, increased biomass and chlorophyll content, and improved root architecture, but notheworthy A. agilis induced the release of attractant molecules, whereas P. aeruginosa activated the exudation of growth inhibitory compounds by roots. An analysis of the expression of iron-transporters SbIRT1, SbIRT2, SbYS1, and SbYS2 and genes related to plant defense pathways COI1 and PR-1 indicated that beneficial, pathogenic, and commensal bacteria could up-regulate iron transporters, whereas only beneficial and pathogenic species could induce a defense response. These results show how S. bicolor could recognize bacteria through their volatiles profiles and highlight that PGPR or pathogens can elicit nutritional or defensive traits in plants.

  11. Volatile isoprenoids as defense compounds during abiotic stress in tropical plants

    Science.gov (United States)

    Jardine, K.

    2015-12-01

    Emissions of volatile isoprenoids from tropical forests play central roles in atmospheric processes by fueling atmospheric chemistry resulting in modified aerosol and cloud lifecycles and their associated feedbacks with the terrestrial biosphere. However, the identities of tropical isoprenoids, their biological and environmental controls, and functions within plants and ecosystems remain highly uncertain. As part of the DOE ARM program's GoAmazon 2014/15 campaign, extensive field and laboratory observations of volatile isoprenoids are being conducted in the central Amazon. Here we report the results of our completed and ongoing activities at the ZF2 forest reserve in the central Amazon. Among the results of the research are the suprisingly high abundance of light-dependent volatile isoprenoid emissions across abundant tree genera in the Amazon in both primary and secondary forests, the discovery of highly reactive monoterpene emissions from Amazon trees, and evidence for the importance of volatile isoprenoids in protecting photosynthesis during oxidative stress under elevated temperatures including energy consumption and direct antioxidant functions and a tight connection betwen volatile isoprenoid emissions, photorespiration, and CO2 recycling within leaves. The results highlight the need to model allocation of carbon to isoprenoids during elevated temperature stress in the tropics.

  12. Prey and Non-prey Arthropods Sharing a Host Plant: Effects on Induced Volatile Emission and Predator Attraction

    Science.gov (United States)

    Hordijk, Cornelis A.; Posthumus, Maarten A.; Dicke, Marcel

    2008-01-01

    It is well established that plants infested with a single herbivore species can attract specific natural enemies through the emission of herbivore-induced volatiles. However, it is less clear what happens when plants are simultaneously attacked by more than one species. We analyzed volatile emissions of lima bean and cucumber plants upon multi-species herbivory by spider mites (Tetranychus urticae) and caterpillars (Spodoptera exigua) in comparison to single-species herbivory. Upon herbivory by single or multiple species, lima bean and cucumber plants emitted volatile blends that comprised mostly the same compounds. To detect additive, synergistic, or antagonistic effects, we compared the multi-species herbivory volatile blend with the sum of the volatile blends induced by each of the herbivore species feeding alone. In lima bean, the majority of compounds were more strongly induced by multi-species herbivory than expected based on the sum of volatile emissions by each of the herbivores separately, potentially caused by synergistic effects. In contrast, in cucumber, two compounds were suppressed by multi-species herbivory, suggesting the potential for antagonistic effects. We also studied the behavioral responses of the predatory mite Phytoseiulus persimilis, a specialized natural enemy of spider mites. Olfactometer experiments showed that P. persimilis preferred volatiles induced by multi-species herbivory to volatiles induced by S. exigua alone or by prey mites alone. We conclude that both lima bean and cucumber plants effectively attract predatory mites upon multi-species herbivory, but the underlying mechanisms appear different between these species. PMID:18185960

  13. Volatile Constituents of Different Plant Parts and Populations of Malabaila aurea Boiss. from Montenegro

    Directory of Open Access Journals (Sweden)

    Ivan Vučković

    2014-03-01

    Full Text Available The volatile constituents of different plant parts and populations of Malabaila aurea Boiss. from Montenegro were obtained by simultaneous distillation-extraction and analyzed by GC-FID and GC-MS. A total of 12 samples were examined and 45 compounds were identified. The volatile content of different M. aurea populations was very similar, while the volatile fractions obtained from different plant parts showed significant qualitative and quantitative differences. The most abundant compounds found in stems & leaves were apiole (51.0-56.3%, myristicin (16.3-25.4%, and falcarinol (4.1-10.7%. The roots showed the same major components, but with different relative abundances: 30.9-49.1% of apiole, 12.9-34.7% of falcarinol, and 9.9-31.1% of myristicin. The volatile constituents of fruits & flowers were remarkably different, containing up to 71.2-80.5% octyl butyrate, 11.4-18.0% octanol, and 2.7-6.8% octyl hexanoate. The results were discussed as possible indication of relatedness of Malabaila aurea and Pastinacasativa (parsnip .

  14. Analysis of volatile organic compound from Elaeis guineensis inflorescences planted on different soil types in Malaysia

    Science.gov (United States)

    Muhamad Fahmi, M. H.; Ahmad Bukhary, A. K.; Norma, H.; Idris, A. B.

    2016-11-01

    The main attractant compound for Eleidobius kamerunicus to male spikelet Elaeis guineensis (oil palm) were determined by analyzing volatile organic compound extracted from E. guineenses inflorescences planted on different soil types namely peat soil, clay soil and sandy soil. Anthesizing male oil palm inflorescences were randomly choosen from palm aged between 4-5 years old age. Extraction of the volatiles from the oil palm inflorescences were performed by Accelerated Solvent Extraction method (ASE). The extracted volatile compound were determined by using gas chromatography-mass spectrometry. Out of ten identified compound, estragole was found to be a major compound in sandy soil (37.49%), clay soil (30.71%) and peat soil (27.79%). Other compound such as 9,12-octadecadieonic acid and n-hexadecanoic acid were found as major compound in peat soil (27.18%) and (7.45%); sandy soil (14.15 %) and (9.31%); and clay soil (30.23%) and (4.99%). This study shows that estragole was the predominant volatile compound detected in oil palm inflorescences with highly concentrated in palm planted in sandy soil type.

  15. Diaphorina citri Induces Huanglongbing-Infected Citrus Plant Volatiles to Repel and Reduce the Performance of Propylaea japonica.

    Science.gov (United States)

    Lin, Yongwen; Lin, Sheng; Akutse, Komivi S; Hussain, Mubasher; Wang, Liande

    2016-01-01

    Transmission of plant pathogens through insect vectors is a complex biological process involving interactions between the host plants, insects, and pathogens. Simultaneous impact of the insect damage and pathogenic bacteria in infected host plants induce volatiles that modify not only the behavior of its insect vector but also of their natural enemies, such as parasitoid wasps. Therefore, it is essential to understand how insects such as the predator ladybird beetle responds to volatiles emitted from a host plant and how the disease transmission alters the interactions between predators, vector, pathogens, and plants. In this study, we investigated the response of Propylaea japonica to volatiles from citrus plants damaged by Diaphorina citri and Candidatus Liberibacter asiaticus through olfactometer bioassays. Synthetic chemical blends were also used to determine the active compounds in the plant volatile. The results showed that volatiles emitted by healthy plants attracted more P. japonica than other treatments, due to the presence of high quantities of D-limonene and beta-ocimene, and the lack of methyl salicylate. When using synthetic chemicals in the olfactory tests, we found that D-limonene attracted P. japonica while methyl salicylate repelled the predator. However, beta-ocimene attracted the insects at lower concentrations but repelled them at higher concentrations. These results indicate that P. japonica could not efficiently search for its host by using volatile cues emitted from psyllids- and Las bacteria-infected citrus plants.

  16. Uptake of toluene and ethylbenzene by plants: removal of volatile indoor air contaminants.

    Science.gov (United States)

    Sriprapat, Wararat; Suksabye, Parinda; Areephak, Sirintip; Klantup, Polawat; Waraha, Atcharaphan; Sawattan, Anuchit; Thiravetyan, Paitip

    2014-04-01

    Air borne uptake of toluene and ethylbenzene by twelve plant species was examined. Of the twelve plant species examined, the highest toluene removal was found in Sansevieria trifasciata, while the ethylbenzene removal from air was with Chlorophytum comosum. Toluene and ethylbenzene can penetrate the plant׳s cuticle. However, the removal rates do not appear to be correlated with numbers of stomata per plant. It was found that wax of S. trifasciata and Sansevieria hyacinthoides had greater absorption of toluene and ethylbenzene, and it contained high hexadecanoic acid. Hexadecanoic acid might be involved in toluene and ethylbenzene adsorption by cuticles wax of plants. Chlorophyll fluorescence analysis or the potential quantum yield of PSII (Fv/Fm) in toluene exposed plants showed no significant differences between the control and the treated plants, whereas plants exposed to ethylbenzene showed significant differences or those parameters, specifically in Dracaena deremensis (Lemon lime), Dracaena sanderiana, Kalanchoe blossfeldiana, and Cordyline fruticosa. The Fv/Fm ratio can give insight into the ability of plants to tolerate (indoor) air pollution by volatile organic chemicals (VOC). This index can be used for identification of suitable plants for treating/sequestering VOCs in contaminated air. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Response of Sitophilus granarius L. to fumigant toxicity of some plant volatile oils

    Directory of Open Access Journals (Sweden)

    Ali F. Hamza

    2016-01-01

    Full Text Available One-week-old adults of Sitophilus granarius (L. reared on wheat were subjected to pure plant volatile oils of Thuja, Eucalyptus and Peppermint. Volatile oil of Thuja was extracted from unripe fruits of Thuja orientalis plant by water distillation. The objective of the current study was to determine the fumigant toxicity of these volatile oils against adults of S. granarius. The fumigant toxicity of the volatile oils was tested against 1week old adults of S. granarius at 28±2 °C and 65±5% RH in darkness. The mortality of adults was tested at different concentrations ranging from 20 to 100 μl of Thuja, 10–30 μl of Eucalyptus and 3–15 μl of Peppermint at different exposure times (24, 48 and 72 h. The results demonstrated that the mortality increased with increases in concentration and exposure periods. The percent mortality of S. granarius reached 91.2, 95.0 and 91.2% when 1-w-old adult exposed to higher concentration of Thuja, Eucalyptus and Peppermint oils, respectively, comparing to 0% in the control after 24 h. After 72 h the percent mortality was 100% at the higher concentration of the three volatile oils. LC50 and LC90 were determined for each volatile oil and each exposure period. Data probit analysis demonstrated that concentrations of 70.71 μl Thuja, 16.95 μl Eucalyptus and 10.48 μl Peppermint, recorded 50% mortality after 24 h, however it reached 90% when concentrations increased to 104.04 μl Thuja, 25.48 μl Eucalyptus and 15.92 μl Peppermint after the same period. LC50 and LC90 values were decreased by increasing the exposure periods. These results showed that the three volatile oils could be applicable to the management of populations of S. granarius (L..

  18. Volatilization from borosilicate glass melts of simulated Savannah River Plant waste

    International Nuclear Information System (INIS)

    Wilds, G.W.

    1979-01-01

    Laboratory scale studies determined the rates at which the semivolatile components sodium, boron, lithium, cesium, and ruthenium volatilized from borosilicate glass melts that contained simulated Savannah River Plant waste sludge. Sodium and boric oxides volatilize as the thermally stable compound sodium metaborate, and accounted for approx. 90% of the semivolatiles that evolved. The amounts of semivolatiles that evolved increased linearly with the logarithm of the sodium content of the glass-forming mixture. Cesium volatility was slightly suppressed when titanium dioxide was added to the melt, but was unaffected when cesium was added to the melt as a cesium-loaded zeolite rather than as a cesium carbonate solution. Volatility of ruthenium was not suppressed when the glass melt was blanketed with a nonoxidizing atmosphere. Trace quantities of mercury were removed from vapor streams by adsorption onto a silver-exchanged zeolite. A bed containing silver in the ionic state removed more than 99.9% of the mercury and had a high chemisorption capacity. Beds of lead-, copper-, and copper sulfide-exchanged zeolite-X and also an unexchanged zeolite-X were tested. None of these latter beds had high removal efficiency and high chemisorption capacity

  19. Volatilization from borosilicate glass melts of simulated Savannah River Plant waste

    International Nuclear Information System (INIS)

    Wilds, G.W.

    1978-01-01

    Laboratory scale studies determined the rates at which the semivolatile components sodium, boron, lithium, cesium, and ruthenium volatilized from borosilicate glass melts that contained simulated Savannah River Plant waste sludge. Sodium and boric oxides volatilize as the thermally stable compound sodium metaborate, and accounted for approx. 90% of the semivolatiles that evolved. The amounts of semivolatiles that evolved increased linearly with the logarithm of the sodium content of the glass-forming mixture. Cesium volatility was slightly suppressed when titanium dioxide was added to the melt, but was unaffected when cesium was added to the melt as a cesium-loaded zeolite rather than as a cesium carbonate solution. Volatility of ruthenium was not suppressed when the glass melt was blanketed with a nonoxidizing atmosphere. Trace quantities of mercury were removed from vapor streams by adsorption onto a silver-exchanged zeolite. A bed containing silver in the ionic state removed more than 99.9% of the mercury and had a high chemisorption capacity. Beds of lead-, copper-, and copper sulfide-exchanged zeolite-X and also an unexchanged zeolite-X were tested. None of these latter beds had high removal efficiency and high chemisorption capacity

  20. Tritrophic Interactions Mediated by Herbivore-Induced Plant Volatiles: Mechanisms, Ecological Relevance, and Application Potential.

    Science.gov (United States)

    Turlings, Ted C J; Erb, Matthias

    2018-01-07

    Tritrophic interactions between plants, herbivores, and their natural enemies are an integral part of all terrestrial ecosystems. Herbivore-induced plant volatiles (HIPVs) play a key role in these interactions, as they can attract predators and parasitoids to herbivore-attacked plants. Thirty years after this discovery, the ecological importance of the phenomena is widely recognized. However, the primary function of HIPVs is still subject to much debate, as is the possibility of using these plant-produced cues in crop protection. In this review, we summarize the current knowledge on the role of HIPVs in tritrophic interactions from an ecological as well as a mechanistic perspective. This overview focuses on the main gaps in our knowledge of tritrophic interactions, and we argue that filling these gaps will greatly facilitate efforts to exploit HIPVs for pest control.

  1. Can ornamental potted plants remove volatile organic compounds from indoor air? - a review

    DEFF Research Database (Denmark)

    Dela Cruz, Majbrit; Christensen, Jan H.; Thomsen, Jane Dyrhauge

    2014-01-01

    Volatile organic compounds (VOCs) are found in indoor air, and many of these can affect human health (e.g. formaldehyde and benzene are carcinogenic). Plants affect the levels of VOCs in indoor environments, thus they represent a potential green solution for improving indoor air quality that at t...... concentration. For instance, an increase in light intensity has in some studies been shown to lead to an increase in removal of a pollutant. Studies conducted in real-life settings such as offices and homes are few and show mixed results....... that plant induced removal of VOCs is a combination of direct (e.g. absorption) and indirect (e.g. biotransformation by microorganisms) mechanisms. They also demonstrate that plants' rate of reducing the level of VOCs is influenced by a number of factors such as plant species, light intensity and VOC...

  2. Global volatile profile of virgin olive oils flavoured by aromatic/medicinal plants.

    Science.gov (United States)

    Perestrelo, R; Silva, C; Silva, P; Câmara, J S

    2017-07-15

    The global volatile profile of commercial virgin olive oils and flavoured olive oils with aromatic/medicinal plants, was established using liquid-liquid microextraction (LLME) and headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-quadrupole mass spectrometry (GC-qMS). More than 60 volatile organic compounds (VOCs belonging to different groups were identified using both methods. Olive oils volatile profile was slightly influenced by maceration process, which occurred at room temperature (20±2°C) for 15days. The predominant differences were observed in terpenoids group, since some of them were only identified in the flavoured olive oils, while others showed an increase with the maceration process. VOCs mass transfer from plants to olive oils could explain the observed results. Principal components analysis (PCA) applied to LLME/GC-qMS data allowed to distinguish the olive oils. The flavoured oils would increase the use of olive oil among consumers as consequence of the improvement of its aromatic profile and healthy properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Non-pathogenic rhizobacteria interfere with the attraction of parasitoids to aphid-induced plant volatiles via jasmonic acid signalling.

    Science.gov (United States)

    Pineda, Ana; Soler, Roxina; Weldegergis, Berhane T; Shimwela, Mpoki M; VAN Loon, Joop J A; Dicke, Marcel

    2013-02-01

    Beneficial soil-borne microbes, such as mycorrhizal fungi or rhizobacteria, can affect the interactions of plants with aboveground insects at several trophic levels. While the mechanisms of interactions with herbivorous insects, that is, the second trophic level, are starting to be understood, it remains unknown how plants mediate the interactions between soil microbes and carnivorous insects, that is, the third trophic level. Using Arabidopsis thaliana Col-0 and the aphid Myzus persicae, we evaluate here the underlying mechanisms involved in the plant-mediated interaction between the non-pathogenic rhizobacterium Pseudomonas fluorescens and the parasitoid Diaeretiella rapae, by combining ecological, chemical and molecular approaches. Rhizobacterial colonization modifies the composition of the blend of herbivore-induced plant volatiles. The volatile blend from rhizobacteria-treated aphid-infested plants is less attractive to an aphid parasitoid, in terms of both olfactory preference behaviour and oviposition, than the volatile blend from aphid-infested plants without rhizobacteria. Importantly, the effect of rhizobacteria on both the emission of herbivore-induced volatiles and parasitoid response to aphid-infested plants is lost in an Arabidopsis mutant (aos/dde2-2) that is impaired in jasmonic acid production. By modifying the blend of herbivore-induced plant volatiles that depend on the jasmonic acid-signalling pathway, root-colonizing microbes interfere with the attraction of parasitoids of leaf herbivores. © 2012 Blackwell Publishing Ltd.

  4. Effect of plant growth regulators on callus induction and plant ...

    African Journals Online (AJOL)

    The present study was conducted to investigate the effects of different concentrations and combinations of growth regulators on callus induction and plant regeneration of potato (Solanum tuberosum L.) cultivar Diamant. The tuber segments were used as explants and cultured on Murashige and Skoog (MS) medium ...

  5. CONTEXT MATTERS: THE IMPORTANCE OF MARKET CHARACTERISTICS IN THE VOLATILITY OF FEEDSTOCK COSTS FOR BIOGAS PLANTS.

    Science.gov (United States)

    Mertens, A; Van Meensel, J; Mondelaers, K; Buysse, J

    2015-01-01

    Recently, biogas plant managers in Flanders face increased financial uncertainty. Between 2011 and 2012, 20% of the Flemish biogas plants went bankrupt. Difficulties in obtaining feedstock at stable and affordable prices is one reason why the biogas sector struggles. In literature, contracting is often proposed as a way to decrease the volatility of the feedstock costs. However, these studies generally do not consider the context in which the biogas plant manager needs to buy the feedstock. Yet, this context could be of specific importance when biogas plant managers are in competition with other users of the same biomass type. Silage maize is an example of such a feedstock, as it is both used by dairy farmers and biogas plant managers. Using a combination of qualitative research and agent-based modelling, we investigated the effect of specific characteristics of the silage maize market on the acquisition of local silage maize by biogas plant managers. This paper details the institutional arrangements of the silage maize market in Flanders and the results of a scenario analysis, simulating three different scenarios. As shown by the results, the time of entry into the market, as well as the different institutional arrangements used by the biogas plant managers as opposed to dairy farmers could explain the difficulties in obtaining a stable supply of local silage maize by biogas plants. Our findings can help to develop mitigation strategies addressing these difficulties.

  6. Measurement of volatile plant compounds in field ambient air by thermal desorption-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Cai, Xiao-Ming; Xu, Xiu-Xiu; Bian, Lei; Luo, Zong-Xiu; Chen, Zong-Mao

    2015-12-01

    Determination of volatile plant compounds in field ambient air is important to understand chemical communication between plants and insects and will aid the development of semiochemicals from plants for pest control. In this study, a thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) method was developed to measure ultra-trace levels of volatile plant compounds in field ambient air. The desorption parameters of TD, including sorbent tube material, tube desorption temperature, desorption time, and cold trap temperature, were selected and optimized. In GC-MS analysis, the selected ion monitoring mode was used for enhanced sensitivity and selectivity. This method was sufficiently sensitive to detect part-per-trillion levels of volatile plant compounds in field ambient air. Laboratory and field evaluation revealed that the method presented high precision and accuracy. Field studies indicated that the background odor of tea plantations contained some common volatile plant compounds, such as (Z)-3-hexenol, methyl salicylate, and (E)-ocimene, at concentrations ranging from 1 to 3400 ng m(-3). In addition, the background odor in summer was more abundant in quality and quantity than in autumn. Relative to previous methods, the TD-GC-MS method is more sensitive, permitting accurate qualitative and quantitative measurements of volatile plant compounds in field ambient air.

  7. Regulating plant physiology with organic electronics.

    Science.gov (United States)

    Poxson, David J; Karady, Michal; Gabrielsson, Roger; Alkattan, Aziz Y; Gustavsson, Anna; Doyle, Siamsa M; Robert, Stéphanie; Ljung, Karin; Grebe, Markus; Simon, Daniel T; Berggren, Magnus

    2017-05-02

    The organic electronic ion pump (OEIP) provides flow-free and accurate delivery of small signaling compounds at high spatiotemporal resolution. To date, the application of OEIPs has been limited to delivery of nonaromatic molecules to mammalian systems, particularly for neuroscience applications. However, many long-standing questions in plant biology remain unanswered due to a lack of technology that precisely delivers plant hormones, based on cyclic alkanes or aromatic structures, to regulate plant physiology. Here, we report the employment of OEIPs for the delivery of the plant hormone auxin to induce differential concentration gradients and modulate plant physiology. We fabricated OEIP devices based on a synthesized dendritic polyelectrolyte that enables electrophoretic transport of aromatic substances. Delivery of auxin to transgenic Arabidopsis thaliana seedlings in vivo was monitored in real time via dynamic fluorescent auxin-response reporters and induced physiological responses in roots. Our results provide a starting point for technologies enabling direct, rapid, and dynamic electronic interaction with the biochemical regulation systems of plants.

  8. Tracing the link between plant volatile organic compound emissions and CO2 fluxes and by stable isotopes

    Science.gov (United States)

    Werner, Christiane; Wegener, Frederik; Jardine, Kolby

    2015-04-01

    The vegetation exerts a large influence on the atmosphere through the emission of volatile organic compounds (VOCs) and the emission and uptake of the greenhouse gas CO2. Despite the enormous importance, processes controlling plant carbon allocation into primary and secondary metabolism, such as photosynthetic carbon uptake, respiratory CO2 emission and VOC synthesis, remains unclear. Moreover, vegetation-atmosphere CO2 exchange is associated with a large isotopic imprint due to photosynthetic carbon isotope discrimination and 13C-fractionation during respiratory CO2 release1. The latter has been proposed to be related to carbon partitioning in the metabolic branching points of the respiratory pathways and secondary metabolism, which are linked via a number of interfaces including the central metabolite pyruvate. Notably, it is a known substrate in a large array of secondary pathways leading to the biosynthesis of many volatile organic compounds (VOCs), such as volatile isoprenoids, oxygenated VOCs, aromatics, fatty acid oxidation products, which can be emitted by plants. Here we investigate the linkage between VOC emissions, CO2 fluxes and associated isotope effects based on simultaneous real-time measurements of stable carbon isotope composition of branch respired CO2 (CRDS) and VOC fluxes (PTR-MS). We utilized positionally specific 13C-labeled pyruvate branch feeding experiments in the mediterranean shrub (Halimium halimifolium) to trace the partitioning of C1, C2, and C3 carbon atoms of pyruvate into VOCs versus CO2 emissions in the light and in the dark. In the light, we found high emission rates of a large array of VOC including volatile isoprenoids, oxygenated VOCs, green leaf volatiles, aromatics, sulfides, and nitrogen containing VOCs. These observations suggest that in the light, H. halimifolium dedicates a high carbon flux through secondary biosynthetic pathways including the pyruvate dehydrogenase bypass, mevalonic acid, MEP/DOXP, shikimic acid, and

  9. Plant pathogen-induced volatiles attract parasitoids to increase parasitism of an insect vector

    Directory of Open Access Journals (Sweden)

    Xavier eMartini

    2014-05-01

    Full Text Available Interactions between plant pathogens and arthropods have been predominantly studied through the prism of herbivorous arthropods. Currently, little is known about the effect of plant pathogens on the third trophic level. This question is particularly interesting in cases where pathogens manipulate host phenotype to increase vector attraction and presumably increase their own proliferation. Indeed, a predator or a parasitoid of a vector may take advantage of this manipulated phenotype to increase its foraging performance. We explored the case of a bacterial pathogen, Candidatus Liberibacter asiaticus (Las, which modifies the odors released by its host plant (citrus trees to attract its vector, the psyllid Diaphorina citri. We found that the specialist parasitoid of D. citri, Tamarixia radiata, was attracted more toward Las-infected than uninfected plants. We demonstrated that this attractiveness was due to the release of methyl salicylate. Parasitization of D. citri nymphs on Las-infected plants was higher than on uninfected controls. Also, parasitization was higher on uninfected plants baited with methyl salicylate than on non-baited controls. This is the first report of a parasitoid ‘eavesdropping’ on a plant volatile induced by bacterial pathogen infection, which also increases effectiveness of host seeking behavior of its herbivorous vector.

  10. Volatile Profiling of Aromatic Traditional Medicinal Plant, Polygonum minus in Different Tissues and Its Biological Activities

    Directory of Open Access Journals (Sweden)

    Rafidah Ahmad

    2014-11-01

    Full Text Available The aim of this research was to identify the volatile metabolites produced in different organs (leaves, stem and roots of Polygonum minus, an important essential oil producing crop in Malaysia. Two methods of extraction have been applied: Solid Phase Microextraction (SPME and hydrodistillation coupled with Gas Chromatography-Mass Spectrometry (GC-MS. Approximately, 77 metabolites have been identified and aliphatic compounds contribute significantly towards the aroma and flavour of this plant. Two main aliphatic compounds: decanal and dodecanal were found to be the major contributor. Terpenoid metabolites were identified abundantly in leaves but not in the stem and root of this plant. Further studies on antioxidant, total phenolic content, anticholinesterase and antimicrobial activities were determined in the essential oil and five different extracts. The plant showed the highest DPPH radical scavenging activity in polar (ethanol extract for all the tissues tested. For anti-acetylcholinesterase activity, leaf in aqueous extract and methanol extract showed the best acetylcholinesterase inhibitory activities. However, in microbial activity, the non-polar extracts (n-hexane showed high antimicrobial activity against Methicillin-resistant Staphylococcus aureus (MRSA compared to polar extracts. This study could provide the first step in the phytochemical profiles of volatile compounds and explore the additional value of pharmacology properties of this essential oil producing crop Polygonum minus.

  11. Biological relevance of volatile organic compounds emitted during the pathogenic interactions between apple plants and Erwinia amylovora.

    Science.gov (United States)

    Cellini, Antonio; Buriani, Giampaolo; Rocchi, Lorenzo; Rondelli, Elena; Savioli, Stefano; Rodriguez Estrada, Maria T; Cristescu, Simona M; Costa, Guglielmo; Spinelli, Francesco

    2018-01-01

    Volatile organic compounds emitted during the infection of apple (Malus pumila var. domestica) plants by Erwinia amylovora or Pseudomonas syringae pv. syringae were studied by gas chromatography-mass spectrometry and proton transfer reaction-mass spectrometry, and used to treat uninfected plants. Infected plants showed a disease-specific emission of volatile organic compounds, including several bio-active compounds, such as hexenal isomers and 2,3-butanediol. Leaf growth promotion and a higher resistance to the pathogen, expressed as a lower bacterial growth and migration in plant tissues, were detected in plants exposed to volatile compounds from E. amylovora-infected plants. Transcriptional analysis revealed the activation of salicylic acid synthesis and signal transduction in healthy plants exposed to volatiles produced by E. amylovora-infected neighbour plants. In contrast, in the same plants, salicylic acid-dependent responses were repressed after infection, whereas oxylipin metabolism was activated. These results clarify some metabolic and ecological aspects of the pathogenic adaptation of E. amylovora to its host. © 2016 BSPP AND JOHN WILEY & SONS LTD.

  12. Identification of Systemic Acquired Resistance–Related Volatile Organic Compounds and their Role in Plant Immunity

    OpenAIRE

    Bichlmeier, Marlies

    2017-01-01

    Systemic acquired resistance (SAR) is an inducible immune response that depends on ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1), which is essential for SAR signalling. In contrast to SAR, local resistance remains intact in Arabidopsis (Arabidopsis thaliana) eds1-2 mutant plants in response to Pseudomonas syringae delivering the effector protein AvrRpm1. I utilized the SAR-specific phenotype of the eds1-2 mutant to identify volatile organic compounds (VOCs) related to SAR. To this end, SAR was indu...

  13. The Herbivore-Induced Plant Volatiles Methyl Salicylate and Menthol Positively affect Growth and Pathogenicity of Entomopathogenic Fungi

    Science.gov (United States)

    Lin, Yongwen; Qasim, Muhammad; Hussain, Mubasher; Akutse, Komivi Senyo; Avery, Pasco Bruce; Dash, Chandra Kanta; Wang, Liande

    2017-01-01

    Some herbivore-induced-plant volatiles (HIPVs) compounds are vital for the functioning of an ecosystem, by triggering multi-trophic interactions for natural enemies, plants and herbivores. However, the effect of these chemicals, which play a crucial role in regulating the multi-trophic interactions between plant-herbivore-entomopathogenic fungi, is still unknown. To fill this scientific gap, we therefore investigated how these chemicals influence the entomopathogenic fungi growth and efficacy. In this study, Lipaphis erysimi induced Arabidopsis thaliana HIPVs were collected using headspace system and detected with GC-MS, and then analyzed the effects of these HIPVs chemicals on Lecanicillium lecanii strain V3450. We found that the HIPVs menthol and methyl salicylate at 1 and 10 nmol·ml-1 improved many performance aspects of the fungus, such as germination, sporulation, appressorial formation as well as its pathogenicity and virulence. These findings are not only important for understanding the multi-trophic interactions in an ecosystem, but also would contribute for developing new and easier procedures for conidial mass production as well as improve the pathogenicity and virulence of entomopathogenic fungi in biological pest management strategies.

  14. Plant nutrient transporter regulation in arbuscular mycorrhizas

    DEFF Research Database (Denmark)

    Burleigh, Stephen; Bechmann, I.E.

    2002-01-01

    of nutrition. Their down-regulation in mycorrhizal roots, therefore, would be predicted as a result of symbiotic function. A variety of studies on Pi- Zn- and ammonium- or nitrate-transporter genes from two plant species indirectly support this model. For example, one study showed that the expression...... of the high-affinity Pi-transporter MtPT2 within mycorrhizal roots of Medicago truncatula was inversely correlated with the concentration of P within the shoots, which suggested that P supply from the fungus influenced this gene's expression. However, there is some evidence that these plant nutrient...

  15. Leaf level emissions of volatile organic compounds (VOC) from some Amazonian and Mediterranean plants

    Science.gov (United States)

    Bracho-Nunez, A.; Knothe, , N. M.; Welter, S.; Staudt, M.; Costa, W. R.; Liberato, M. A. R.; Piedade, M. T. F.; Kesselmeier, J.

    2013-09-01

    Emission inventories defining regional and global biogenic volatile organic compounds (VOC) emission strengths are needed to determine the impact of VOC on atmospheric chemistry (oxidative capacity) and physics (secondary organic aerosol formation and effects). The aim of this work was to contribute with measurements of tree species from the poorly described tropical vegetation in direct comparison with the quite well-investigated, highly heterogeneous emissions from Mediterranean vegetation. VOC emission from sixteen plant species from the Mediterranean area were compared with twelve plant species from different environments of the Amazon basin by an emission screening at leaf level using branch enclosures. Analysis of the volatile organics was performed online by a proton-transfer-reaction mass spectrometer (PTR-MS) and offline by collection on adsorbent tubes and subsequent gas chromatographic analysis. Isoprene was the most dominant compound emitted followed by monoterpenes, methanol and acetone. The average loss rates of VOC carbon in relation to the net CO2 assimilation were found below 4% and indicating normal unstressed plant behavior. Most of the Mediterranean species emitted a large variety of monoterpenes, whereas only five tropical species were identified as monoterpene emitters exhibiting a quite conservative emission pattern (α-pinene plants showed additional emissions of sesquiterpenes. In the case of Amazonian plants no sesquiterpenes were detected. However, missing of sesquiterpenes may also be due to a lack of sensitivity of the measuring systems. Furthermore, our screening activities cover only 1% of tree species of such tropical areas as estimated based on recent biodiversity reports. Methanol emissions, an indicator of growth, were found to be common in most of the tropical and Mediterranean species. A few species from both ecosystems showed acetone emissions. The observed heterogeneous emissions, including reactive VOC species which are not

  16. Leaf level emissions of volatile organic compounds (VOC from some Amazonian and Mediterranean plants

    Directory of Open Access Journals (Sweden)

    A. Bracho-Nunez

    2013-09-01

    Full Text Available Emission inventories defining regional and global biogenic volatile organic compounds (VOC emission strengths are needed to determine the impact of VOC on atmospheric chemistry (oxidative capacity and physics (secondary organic aerosol formation and effects. The aim of this work was to contribute with measurements of tree species from the poorly described tropical vegetation in direct comparison with the quite well-investigated, highly heterogeneous emissions from Mediterranean vegetation. VOC emission from sixteen plant species from the Mediterranean area were compared with twelve plant species from different environments of the Amazon basin by an emission screening at leaf level using branch enclosures. Analysis of the volatile organics was performed online by a proton-transfer-reaction mass spectrometer (PTR-MS and offline by collection on adsorbent tubes and subsequent gas chromatographic analysis. Isoprene was the most dominant compound emitted followed by monoterpenes, methanol and acetone. The average loss rates of VOC carbon in relation to the net CO2 assimilation were found below 4% and indicating normal unstressed plant behavior. Most of the Mediterranean species emitted a large variety of monoterpenes, whereas only five tropical species were identified as monoterpene emitters exhibiting a quite conservative emission pattern (α-pinene < limonene < sabinene < ß-pinene. Mediterranean plants showed additional emissions of sesquiterpenes. In the case of Amazonian plants no sesquiterpenes were detected. However, missing of sesquiterpenes may also be due to a lack of sensitivity of the measuring systems. Furthermore, our screening activities cover only 1% of tree species of such tropical areas as estimated based on recent biodiversity reports. Methanol emissions, an indicator of growth, were found to be common in most of the tropical and Mediterranean species. A few species from both ecosystems showed acetone emissions. The observed

  17. A portion of plant airborne communication is endorsed by uptake and metabolism of volatile organic compounds.

    Science.gov (United States)

    Matsui, Kenji

    2016-08-01

    Plants have the ability to sense volatile organic compounds (VOCs) so as to efficiently adapt to their environment. The mechanisms underlying such plant 'olfactory' systems are largely unknown. Here I would like to propose that the metabolism of VOCs in plant tissues is one of the mechanisms by which plants sense VOCs. During the gas-exchange that is essential for photosynthesis, VOCs in the atmosphere are taken into the intercellular spaces of leaves. Each VOC is partitioned between the gas phase (intercellular space) and liquid phase (cell wall) at a certain ratio determined by Henry's law. The VOCs in the cell wall diffuse through the plasma membrane to the cytosol depending on their oil/water partition coefficients. Plants detoxify some VOCs, especially those that are oxidized, through glycosylation, glutathionylation, and reduction. These metabolic processes lower the concentration of VOCs in the cytosol, which facilitates further cytosolic uptake. As a result, vigorous metabolism of VOCs in the cytosol can lead to a substantial accumulation of VOC metabolites and the depletion of glutathione or NADPH. One such metabolite (a VOC glycoside) is known to mount a direct defense against herbivores, whilst deprivation of glutathione and NADPH can fortify plants with responses similar to the oxidative stress response. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Herbivore-induced plant volatiles accurately predict history of coexistence, diet breadth, and feeding mode of herbivores.

    NARCIS (Netherlands)

    Danner, H.; Desurmont, G.A.; Cristescu, S.M.; Dam, N.M. van

    2017-01-01

    Herbivore-induced plant volatiles (HIPVs) serve as specific cues to higher trophic levels. Novel, exotic herbivores entering native foodwebs may disrupt the infochemical network as a result of changes in HIPV profiles. Here, we analysed HIPV blends of native Brassica rapa plants infested with one of

  19. Identification of volatiles that are used in discrimination between plants infested with prey or nonprey herbivores by a predatory mite

    NARCIS (Netherlands)

    Boer, de J.G.; Posthumus, M.A.; Dicke, M.

    2004-01-01

    Carnivorous arthropods can use herbivore-induced plant volatiles to locate their herbivorous prey. In the field, carnivores are confronted with information from plants infested with herbivores that may differ in their suitability as prey. Discrimination by the predatory mite Phytoseiulus persimilis

  20. Regulation of meiotic gene expression in plants

    Directory of Open Access Journals (Sweden)

    Adele eZhou

    2014-08-01

    Full Text Available With the recent advances in genomics and sequencing technologies, databases of transcriptomes representing many cellular processes have been built. Meiotic transcriptomes in plants have been studied in Arabidopsis thaliana, rice (Oryza sativa, wheat (Triticum aestivum, petunia (Petunia hybrida, sunflower (Helianthus annuus, and maize (Zea mays. Studies in all organisms, but particularly in plants, indicate that a very large number of genes are expressed during meiosis, though relatively few of them seem to be required for the completion of meiosis. In this review, we focus on gene expression at the RNA level and analyze the meiotic transcriptome datasets and explore expression patterns of known meiotic genes to elucidate how gene expression could be regulated during meiosis. We also discuss mechanisms, such as chromatin organization and non-coding RNAs, that might be involved in the regulation of meiotic transcription patterns.

  1. Induced Release of a Plant-Defense Volatile ‘Deceptively’ Attracts Insect Vectors to Plants Infected with a Bacterial Pathogen

    Science.gov (United States)

    Mann, Rajinder S.; Ali, Jared G.; Hermann, Sara L.; Tiwari, Siddharth; Pelz-Stelinski, Kirsten S.; Alborn, Hans T.; Stelinski, Lukasz L.

    2012-01-01

    Transmission of plant pathogens by insect vectors is a complex biological process involving interactions between the plant, insect, and pathogen. Pathogen-induced plant responses can include changes in volatile and nonvolatile secondary metabolites as well as major plant nutrients. Experiments were conducted to understand how a plant pathogenic bacterium, Candidatus Liberibacter asiaticus (Las), affects host preference behavior of its psyllid (Diaphorina citri Kuwayama) vector. D. citri were attracted to volatiles from pathogen-infected plants more than to those from non-infected counterparts. Las-infected plants were more attractive to D. citri adults than non-infected plants initially; however after feeding, psyllids subsequently dispersed to non-infected rather than infected plants as their preferred settling point. Experiments with Las-infected and non-infected plants under complete darkness yielded similar results to those recorded under light. The behavior of psyllids in response to infected versus non-infected plants was not influenced by whether or not they were carriers of the pathogen. Quantification of volatile release from non-infected and infected plants supported the hypothesis that odorants mediate psyllid preference. Significantly more methyl salicylate, yet less methyl anthranilate and D-limonene, was released by infected than non-infected plants. Methyl salicylate was attractive to psyllids, while methyl anthranilate did not affect their behavior. Feeding on citrus by D. citri adults also induced release of methyl salicylate, suggesting that it may be a cue revealing location of conspecifics on host plants. Infected plants were characterized by lower levels of nitrogen, phosphorus, sulfur, zinc, and iron, as well as, higher levels of potassium and boron than non-infected plants. Collectively, our results suggest that host selection behavior of D. citri may be modified by bacterial infection of plants, which alters release of specific headspace

  2. Remarkable preservation of terpenoids and record of volatile signalling in plant-animal interactions from Miocene amber.

    Science.gov (United States)

    Dutta, Suryendu; Mehrotra, Rakesh C; Paul, Swagata; Tiwari, R P; Bhattacharya, Sharmila; Srivastava, Gaurav; Ralte, V Z; Zoramthara, C

    2017-09-08

    Plants produce and release a large array of volatile organic compounds that play many ecological functions. These volatile plant metabolites serve as pollinator attractants, herbivore and pathogen repellents and protect plants from abiotic stresses. To date, the geological evolution of these organic compounds remains unknown. The preservation potential of these metabolites in the fossil record is very poor due to their low boiling points. Here we report a series of volatile sesquiterpenoids, including δ-elemene, α-copaene, β-elemene, β-caryophyllene, α-humulene, germacrene D, δ-cadiene and spathunenol, from early Miocene (~17 million year) amber from eastern India. The survival of these unaltered bioterpenoids can be attributed to the existence of extraordinary taphonomic conditions conducive to the preservation of volatile biomolecules through deep time. Furthermore, the occurrence of these volatiles in the early Miocene amber suggests that the plants from this period had evolved metabolic pathways to synthesize these organic molecules to play an active role in forest ecology, especially in plant-animal interactions.

  3. The lipoxygenase metabolic pathway in plants: potential for industrial production of natural green leaf volatiles

    Directory of Open Access Journals (Sweden)

    Gigot, C.

    2010-01-01

    Full Text Available Lipoxygenase enzymatic pathway is a widely studied mechanism in the plant kingdom. Combined actions of three enzymes: lipase, lipoxygenase (LOX and hydroperoxide lyase (HPL convert lipidic substrates such as C18:2 and C18:3 fatty acids into short chain volatiles. These reactions, triggered by cell membrane disruptions, produce compounds known as Green Leaf Volatiles (GLVs which are C6 or C9-aldehydes and alcohols. These GLVs are commonly used as flavors to confer a fresh green odor of vegetable to food products. Therefore, competitive biocatalytic productions have been developed to meet the high demand in these natural flavors. Vegetable oils, chosen for their lipidic acid profile, are converted by soybean LOX and plant HPL into natural GLVs. However this second step of the bioconversion presents low yield due to the HPL instability and the inhibition by its substrate. This paper will shortly describe the different enzymes involved in this bioconversion with regards to their chemical and enzymatic properties. Biotechnological techniques to enhance their production potentialities will be discussed along with their implication in a complete bioprocess, from the lipid substrate to the corresponding aldehydic or alcoholic flavors.

  4. "Volatile Constituents of Amedicinal Plant of Iran , Echium Amoenim Fisch. and C.A. Mey "

    Directory of Open Access Journals (Sweden)

    Nasrolah Ghassemi

    2003-07-01

    Full Text Available Echium amoenum Fisch. & C.A. Mey. (Boraginaceae is an endemic Iranian plant, that its dry violet–blue petals has long been used in traditional medicine of Iran. The chemical composition of the volatile fraction of the dried petals of this plant which was isolated by steam distillation extraction with pentane (in yield of 0.05% was examined by GC-MS. The constituents were identified by their mass spectra and Kovats’ indices. The major components except aliphatic alkanes which belong to sesquiterpenes were: δ-cadinene (24.25%, viridiflorol (4.9%, α-muurolene (4.52%, ledene (3.8%, α-calacorene (3.04%, and γ-cadinene (2.9%.

  5. Host Plant Volatiles and the Sexual Reproduction of the Potato Aphid, Macrosiphum euphorbiae

    Directory of Open Access Journals (Sweden)

    Jessica Hurley

    2014-10-01

    Full Text Available In late summer, heteroecious aphids, such as the potato aphid, Macrosiphum euphorbiae, move from their secondary summer host plants to primary host plants, where the sexual oviparae mate and lay diapausing eggs. We tested the hypothesis that volatiles of the primary host, Rosa rugosa, would attract the gynoparae, the parthenogenetic alate morph that produce oviparae, as well as the alate males foraging for suitable mates. In wind tunnel assays, both gynoparae and males oriented towards and reached rose cuttings significantly more often than other odour sources, including potato, a major secondary host. The response of males was as high to rose cuttings alone as to potato with a calling virgin oviparous female. These findings are discussed within the seasonal ecology of host alternating aphids.

  6. The Ratio between Field Attractive and Background Volatiles Encodes Host-Plant Recognition in a Specialist Moth.

    Science.gov (United States)

    Knudsen, Geir K; Norli, Hans R; Tasin, Marco

    2017-01-01

    Volatiles emitted by plants convey an array of information through different trophic levels. Animals such as host-seeking herbivores encounter plumes with filaments from both host and non-host plants. While studies showed a behavioral effect of non-host plants on herbivore host location, less information is available on how a searching insect herbivore perceives and flies upwind to a host-plant odor plume within a background of non-host volatiles. We hypothesized here that herbivorous insects in search of a host-plant can discriminate plumes of host and non-host plants and that the taxonomic relatedness of the non-host have an effect on finding the host. We also predicted that the ratio between certain plant volatiles is cognized as host-plant recognition cue by a receiver herbivorous insect. To verify these hypotheses we measured the wind tunnel response of the moth Argyresthia conjugella to the host plant rowan, to non-host plants taxonomically related (Rosaceae, apple and pear) or unrelated to the host (Pinaceae, spruce) and to binary combination of host and non-host plants. Volatiles were collected from all plant combinations and delivered to the test insect via an ultrasonic sprayer as an artificial plume. While the response to the rowan as a plant was not affected by the addition of any of the non-host plants, the attraction to the corresponding sprayed headspace decreased when pear or apple but not spruce were added to rowan. A similar result was measured toward the odor exiting a jar where freshly cut plant material of apple or pear or spruce was intermixed with rowan. Dose-response gas-chromatography coupled to electroantennography revealed the presence of seven field attractive and seven background non-attractive antennally active compounds. Although the abundance of field attractive and of some background volatiles decreased in all dual combinations in comparison with rowan alone, an increased amount of the background compounds (3E)-4,8-Dimethyl-1

  7. The Ratio between Field Attractive and Background Volatiles Encodes Host-Plant Recognition in a Specialist Moth

    Directory of Open Access Journals (Sweden)

    Geir K. Knudsen

    2017-12-01

    Full Text Available Volatiles emitted by plants convey an array of information through different trophic levels. Animals such as host-seeking herbivores encounter plumes with filaments from both host and non-host plants. While studies showed a behavioral effect of non-host plants on herbivore host location, less information is available on how a searching insect herbivore perceives and flies upwind to a host-plant odor plume within a background of non-host volatiles. We hypothesized here that herbivorous insects in search of a host-plant can discriminate plumes of host and non-host plants and that the taxonomic relatedness of the non-host have an effect on finding the host. We also predicted that the ratio between certain plant volatiles is cognized as host-plant recognition cue by a receiver herbivorous insect. To verify these hypotheses we measured the wind tunnel response of the moth Argyresthia conjugella to the host plant rowan, to non-host plants taxonomically related (Rosaceae, apple and pear or unrelated to the host (Pinaceae, spruce and to binary combination of host and non-host plants. Volatiles were collected from all plant combinations and delivered to the test insect via an ultrasonic sprayer as an artificial plume. While the response to the rowan as a plant was not affected by the addition of any of the non-host plants, the attraction to the corresponding sprayed headspace decreased when pear or apple but not spruce were added to rowan. A similar result was measured toward the odor exiting a jar where freshly cut plant material of apple or pear or spruce was intermixed with rowan. Dose-response gas-chromatography coupled to electroantennography revealed the presence of seven field attractive and seven background non-attractive antennally active compounds. Although the abundance of field attractive and of some background volatiles decreased in all dual combinations in comparison with rowan alone, an increased amount of the background compounds (3E-4

  8. Optimal Regulation of Virtual Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Dall Anese, Emiliano; Guggilam, Swaroop S.; Simonetto, Andrea; Chen, Yu Christine; Dhople, Sairaj V.

    2018-03-01

    This paper develops a real-time algorithmic framework for aggregations of distributed energy resources (DERs) in distribution networks to provide regulation services in response to transmission-level requests. Leveraging online primal-dual-type methods for time-varying optimization problems and suitable linearizations of the nonlinear AC power-flow equations, we believe this work establishes the system-theoretic foundation to realize the vision of distribution-level virtual power plants. The optimization framework controls the output powers of dispatchable DERs such that, in aggregate, they respond to automatic-generation-control and/or regulation-services commands. This is achieved while concurrently regulating voltages within the feeder and maximizing customers' and utility's performance objectives. Convergence and tracking capabilities are analytically established under suitable modeling assumptions. Simulations are provided to validate the proposed approach.

  9. Extraction and GC determination of volatile aroma compounds from extracts of three plant species of the Apiaceae family

    Science.gov (United States)

    Stan, M.; Soran, M. L.; Varodi, C.; Lung, I.; Copolovici, L.; MǎruÅ£oiu, C.

    2013-11-01

    Parsley (Petroselinum crispum), dill (Anethum graveolens) and celery (Apium graveolens), three aromatic plants belonging to the Apiaceae (Umbelliferae) botanical family, were selected as sources of essential or volatile oils. Essential oils are composed of a large diversity of volatile aroma compounds. Plant-derived essential oils and extracts have long been used as natural agents in food preservation, pharmaceuticals and medicinal therapies. In the present study, the plant extracts from leaves of parsley, dill and celery, were obtained by maceration, ultrasound-assisted extraction and microwave-assisted extraction. All extractions were performed at 30°C, using different solvents (ethanol, diethyl ether, n-hexane) and solvent mixtures (1:1, v/v). The most effective solvent system for the extraction of volatile aroma compounds was diethyl ether - n-hexane (1:1, v/v). Extraction efficiency and determination of aroma volatiles were performed by GC-FID and GC-MS, respectively. The major volatile compounds present in plant extracts were myristicin, α-phellandrene, β-phellandrene, 1,3,8-p-menthatriene, apiol, dill ether and allyl phenoxyacetate.

  10. Health monitoring of plants by their emitted volatiles: A temporary increase in the concentration of nethyl salicylate after pathogen inoculation of tomato plants at greenhouse scale

    NARCIS (Netherlands)

    Jansen, R.M.C.; Hofstee, J.W.; Verstappen, F.W.A.; Bouwmeester, H.J.; Posthumus, M.A.; Henten, van E.J.

    2011-01-01

    This paper describes a method to alert growers of the presence of a pathogen infection in their greenhouse based on the detection of pathogen-induced emissions of volatile organic compounds (VOCs) from plants. Greenhouse-grown plants were inoculated with spores of a fungus to learn more about this

  11. Effect of plant age on fresh rhizome yield and volatile oil composition of Acorus calamus linn

    International Nuclear Information System (INIS)

    Osman, M.A.; Bahl, J.R.; Darokar, M. P.; Garg, S.N.; Lal, R.K.; Khanuja, S.P.S.

    2008-01-01

    The effect of plant age on growth, yield and oil content and composition of sweet flag (Acorus calamus) was studied in four populations at four different ages, raised at CIMAP experimental research Farm, India. The plant age had significant effect on total fresh yield and leaves and rhizomes fresh weights. These parameters showed increasing trend with advancement of harvesting age up to 6 years, and age increase to more than 15 years resulted in their decrease . Significantly highest number of shoots per square meter was recorded in more than 15 year old crop, and the lowest number was recorded in the 6 year old crop. The highest oil yield of rhizomes was obtained from the six year old plants. Shoot length, rhizome leaf ratio (R/L) and oil yield of leaves did not show significant differences with the age of the plant. However, 6 year old plants recorded the highest average shoot length, and the three year old plants gave the highest oil yield of leaves. The total fresh yield showed a highly significant positive correlation with rhizomes fresh weight (r = 0.999), leaves fresh weight (r=0.994) and with rhizome: leaf ratio (r = 0.998). Highly significant positive correlations (r = 0.999) were also obtained between rhizomes oil content and rhizomes oil yield and between leaves oil content and leaves oil yield. β-asarone was the most dominant constituent in the oils of both leaves and rhizomes , constituting an average of 84.2% in the leaves and 88.9% in the rhizomes oil. The study indicated that the oil content of fresh rhizomes and leaves is the main contributor to their oil yields, and selection for high oil content will be effective. The constituents of the volatile oil remained the same irrespective of the plant age.(Author)

  12. Redox regulation of plant stem cell fate.

    Science.gov (United States)

    Zeng, Jian; Dong, Zhicheng; Wu, Haijun; Tian, Zhaoxia; Zhao, Zhong

    2017-10-02

    Despite the importance of stem cells in plant and animal development, the common mechanisms of stem cell maintenance in both systems have remained elusive. Recently, the importance of hydrogen peroxide (H 2 O 2 ) signaling in priming stem cell differentiation has been extensively studied in animals. Here, we show that different forms of reactive oxygen species (ROS) have antagonistic roles in plant stem cell regulation, which were established by distinct spatiotemporal patterns of ROS-metabolizing enzymes. The superoxide anion (O2·-) is markedly enriched in stem cells to activate WUSCHEL and maintain stemness, whereas H 2 O 2 is more abundant in the differentiating peripheral zone to promote stem cell differentiation. Moreover, H 2 O 2 negatively regulates O2·- biosynthesis in stem cells, and increasing H 2 O 2 levels or scavenging O2·- leads to the termination of stem cells. Our results provide a mechanistic framework for ROS-mediated control of plant stem cell fate and demonstrate that the balance between O2·- and H 2 O 2 is key to stem cell maintenance and differentiation. © 2017 The Authors.

  13. Mediator: A key regulator of plant development.

    Science.gov (United States)

    Buendía-Monreal, Manuel; Gillmor, C Stewart

    2016-11-01

    Mediator is a multiprotein complex that regulates transcription at the level of RNA pol II assembly, as well as through regulation of chromatin architecture, RNA processing and recruitment of epigenetic marks. Though its modular structure is conserved in eukaryotes, its subunit composition has diverged during evolution and varies in response to environmental and tissue-specific inputs, suggesting different functions for each subunit and/or Mediator conformation. In animals, Mediator has been implicated in the control of differentiation and morphogenesis through modulation of numerous signaling pathways. In plants, studies have revealed roles for Mediator in regulation of cell division, cell fate and organogenesis, as well as developmental timing and hormone responses. We begin this review with an overview of biochemical mechanisms of yeast and animal Mediator that are likely to be conserved in all eukaryotes, as well as a brief discussion of the role of Mediator in animal development. We then present a comprehensive review of studies of the role of Mediator in plant development. Finally, we point to important questions for future research on the role of Mediator as a master coordinator of development. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. GC-MS Analysis of the Volatile Constituents in the Leaves of 14 Compositae Plants

    Directory of Open Access Journals (Sweden)

    Yiguang Wang

    2018-01-01

    Full Text Available The green organs, especially the leaves, of many Compositae plants possess characteristic aromas. To exploit the utility value of these germplasm resources, the constituents, mainly volatile compounds, in the leaves of 14 scented plant materials were qualitatively and quantitatively compared via gas chromatography-mass spectrometry (GC-MS. A total of 213 constituents were detected and tentatively identified in the leaf extracts, and terpenoids (especially monoterpene and sesquiterpene derivatives, accounting for 40.45–90.38% of the total compounds, were the main components. The quantitative results revealed diverse concentrations and compositions of the chemical constituents between species. Principal component analysis (PCA showed that different groups of these Compositae plants were characterized by main components of α-thujone, germacrene D, eucalyptol, β-caryophyllene, and camphor, for example. On the other hand, cluster memberships corresponding to the molecular phylogenetic framework, were found by hierarchical cluster analysis (HCA based on the terpenoid composition of the tested species. These results provide a phytochemical foundation for the use of these scented Compositae plants, and for the further study of the chemotaxonomy and differential metabolism of Compositae species.

  15. Plant volatile aldehydes as natural insecticides against stored-product beetles.

    Science.gov (United States)

    Hubert, Jan; Münzbergová, Zuzana; Santino, Angelo

    2008-01-01

    Infestation by stored-product pests causes serious losses in food and feed commodities. Among possible strategies against these pests, which aim to reduce the use of synthetic insecticides, including fumigants, natural insecticides produced by plants represent one of the most promising approaches for their ecochemical control. Three six-carbon and nine-carbon aldehydes, natural plant volatiles produced by the plant lipoxygenase pathway, were tested for their insecticidal activity against five species of stored-product beetles in feeding, fumigation and combined bioassays. The compounds (2E,6Z)-nonadienal, (2E)-nonenal and (2E)-hexenal were incorporated into feeding discs in feeding bioassays or evaporated from filter paper in closed glass chambers in fumigation tests. Beetle sensitivity to aldehydes differed according to the different treatments. The highest activity was obtained by (2E)-hexenal in fumigation tests, with the LC(50) ranging from 4 to 26 mg L(-1), while (2E, 6Z)-nonadienal was the most effective in feeding tests, giving LD(50)s ranging from 0.44 to 2.76 mg g(-1) when applied to feeding discs. Fumigation tests in the presence of wheat grains confirmed that (2E)-hexenal was the most effective compound, with a calculated LC(99) ranging from 33 to 166 mg L(-1). The results of both feeding and fumigation tests indicated that natural plant aldehydes are potential candidates to control stored-product beetles.

  16. 76 FR 9079 - Revision of Distilled Spirits Plant Regulations

    Science.gov (United States)

    2011-02-16

    ... materials. This term does not apply to wine and beer, which generally are products of fermentation alone... category, TTB should create category-specific regulations, similar to the regulations for vinegar plants and alcohol fuel plants. TTB Response: TTB notes that vinegar plants and alcohol fuel plants differ...

  17. Disruption of Vector Host Preference with Plant Volatiles May Reduce Spread of Insect-Transmitted Plant Pathogens.

    Science.gov (United States)

    Martini, Xavier; Willett, Denis S; Kuhns, Emily H; Stelinski, Lukasz L

    2016-05-01

    Plant pathogens can manipulate the odor of their host; the odor of an infected plant is often attractive to the plant pathogen vector. It has been suggested that this odor-mediated manipulation attracts vectors and may contribute to spread of disease; however, this requires further broad demonstration among vector-pathogen systems. In addition, disruption of this indirect chemical communication between the pathogen and the vector has not been attempted. We present a model that demonstrates how a phytophathogen (Candidatus Liberibacter asiaticus) can increase its spread by indirectly manipulating the behavior of its vector (Asian citrus psyllid, Diaphorina citri Kuwayama). The model indicates that when vectors are attracted to pathogen-infected hosts, the proportion of infected vectors increases, as well as, the proportion of infected hosts. Additionally, the peak of infected host populations occurs earlier as compared with controls. These changes in disease dynamics were more important during scenarios with higher vector mortality. Subsequently, we conducted a series of experiments to disrupt the behavior of the Asian citrus psyllid. To do so, we exposed the vector to methyl salicylate, the major compound released following host infection with the pathogen. We observed that during exposure or after pre-exposure to methyl salicylate, the host preference can be altered; indeed, the Asian citrus psyllids were unable to select infected hosts over uninfected counterparts. We suggest mechanisms to explain these interactions and potential applications of disrupting herbivore host preference with plant volatiles for sustainable management of insect vectors.

  18. HORMONAL REGULATION OF SELENIUM ACCUMULATION BY PLANTS

    Directory of Open Access Journals (Sweden)

    N. A. Golubkina

    2015-01-01

    Full Text Available Hormonal regulation is considered to be a unique mechanism controlling growth and development of living organism. The review discusses the correlations between pant hormonal status of non-accumulators and hyper-accumulators of Se with the accumulation levels of this microelement. The phenomenon of stimulation and redistribution of selenium as a result of phytohormone treatment, the peculiarities of phytohormones effect among different species and cultivars, and influence of plant sexualization on selenium accumulation are described in article. Data of hormonal regulation of selenium level for spinach, garlic, perennial onion, Brassica chinenesis and Valeriana officialis are presented in the review.

  19. Apple proliferation phytoplasma influences the pattern of plant volatiles emitted depending on pathogen virulence

    Directory of Open Access Journals (Sweden)

    Margit eRid

    2016-01-01

    Full Text Available Apple proliferation (AP and pear decline (PD are the most severe diseases in pome fruit growing areas. AP-infected trees show typical symptoms such as witches’ broom, enlarged stipules, tasteless and dwarf fruits. PD-infected pears show a progressive weakening, reduced terminal growth, smaller fruits and die within weeks (quick decline or years (slow decline. The diseases are caused by the cell-wall lacking bacteria Candidatus Phytoplasma mali (AP phytoplasma and Ca. P. pyri (PD phytoplasma, respectively. In previous studies it has been shown that AP-infected apple trees emitted higher amounts of the sesquiterpene β-caryophyllene, an attractant of the insect vector Cacopsylla picta (Hemiptera: Psyllidae, thereby facilitating the dispersal of AP phytoplasma. In the present study, volatile organic compounds (VOCs occurring in the headspace of plants infected with Ca. P. mali strains causing different severity of symptoms in apple plants were collected, analyzed and identified. Headspace samples from healthy and AP-infected model plant tobacco (Nicotiana occidentalis and apple (Malus domestica as well as from healthy and PD-infected pear (Pyrus communis were investigated via thermodesorption and GC-MS analysis. Significantly higher concentrations of ethyl benzoate were produced in all phytoplasma-infected plants compared to healthy ones and an as yet unidentified sesquiterpene differed between the odor bouquets of healthy and by Ca. P. mali infected tobacco plants. Additionally, statistically significant higher amounts of both compounds were measured in the headspace of plants infected by the virulent AP strain. In apple, significantly higher concentrations of ethyl benzoate and methyl salicylate were observed for trees infected with strains of Ca. P. mali. Ethyl benzoate was also detected in the headspace of pear trees infected with Ca. P. pyri.

  20. Incentive regulation of nuclear power plants by state regulators

    International Nuclear Information System (INIS)

    Martin, R.L.; Baker, K.; Olson, J.

    1991-02-01

    The Nuclear Regulatory Commission (NRC) monitors incentive programs established by state regulators in order to obtain current information and to consider the potential safety effects of the incentive programs as applied to nuclear units. The current report is an update of NUREG/CR-5509, Incentive Regulation of Nuclear Power Plants by State Public Utility Commissions, published in December 1989. The information in this report was obtained from interviews conducted with each state regulator and each utility with a minimum entitlement of 10%. The agreements, orders, and settlements from which each incentive program was implemented were reviewed as required. The interviews and supporting documentation form the basis for the individual state reports describing the structure and financial impact of each incentive program. The programs currently in effect represent the adoption of an existing nuclear performance incentive program proposal and one new program. In addition, since 1989 a number of nuclear units have been included in one existing program; while one program was discontinued and another one concluded. 6 refs., 27 tabs

  1. Development and Application of a Fast Chromatography Technique for Analysis of Biogenic Volatile Organic Compounds in Plant Emissions

    Science.gov (United States)

    Jones, C. E.; Kato, S.; Nakashima, Y.; Yamazakii, S.; Kajii, Y. J.

    2011-12-01

    Biogenic volatile organic compounds (BVOCs) emitted from vegetation constitute the largest fraction (>90 %) of total global non-methane VOC supplied to the atmosphere, yet the chemical complexity of these emissions means that achieving comprehensive measurements of BVOCs, and in particular the less volatile terpenes, is not straightforward. As such, there is still significant uncertainty associated with the contribution of BVOCs to the tropospheric oxidation budget, and to atmospheric secondary organic aerosol (SOA) formation. The rate of BVOC emission from vegetation is regulated by environmental conditions such as light intensity and temperature, and thus can be highly variable, necessitating high time-resolution BVOC measurements. In addition, the numerous monoterpene and sesquiterpene isomers, which are indistinguishable by some analytical techniques, have greatly varying lifetimes with respect to atmospheric oxidants, and as such quantification of each individual isomer is fundamental to achieving a comprehensive characterisation of the impact of BVOCs upon the atmospheric oxidation capacity. However, established measurement techniques for these trace gases typically offer a trade-off between sample frequency and the level of speciation; detailed information regarding chemical composition may be obtained, but with reduced time resolution, or vice versa. We have developed a Fast-GC-FID technique for quantification of a range of monoterpene, sesquiterpene and oxygenated C10 BVOC isomers, which retains the separation capability of conventional gas chromatography, yet offers considerably improved sample frequency. Development of this system is ongoing, but currently a 20 m x 0.18 mm i.d resistively heated metal column is employed to achieve chromatographic separation of thirteen C10-C15 BVOCs, within a total cycle time of ~15 minutes. We present the instrument specifications and analytical capability, together with the first application of this Fast-GC technique

  2. Chemical diversity of microbial volatiles and their potential for plant growth and productivity

    Directory of Open Access Journals (Sweden)

    CHIDANANDA NAGAMANGALA KANCHISWAMY

    2015-03-01

    Full Text Available Microbial volatile organic compounds (MVOCs are produced by a wide array of microorganisms ranging from bacteria to fungi. A growing body of evidence indicates that MVOCs are ecofriendly and can be exploited as a cost-effective sustainable strategy for use in agricultural practice as agents that enhance plant growth, productivity and disease resistance. As naturally occurring chemicals, MVOCs have potential as possible alternatives to harmful pesticides, fungicides and bactericides as well as genetic modification. Recent studies performed under open field conditions demonstrate that efficiently adopting MVOCs may contribute to sustainable crop protection and production. We review here the chemical diversity of MVOCs and their potential physiological effects on crops and analyze potential and actual limitations for MVOC use as a sustainable strategy for improving productivity and reducing pesticide use.

  3. Volatile Organic Compound (VOC) Air Monitoring Program design for the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Frank, L.

    1991-01-01

    The Waste Isolation Pilot Plant (WIPP) Volatile Organic Compound (VOC) Monitoring Program has been developed as part of the Department of Energy's (DOE's) No-Migration Variance petition submitted to the Environmental Protection Agency (EPA). The program is designed to demonstrate that there will be no migration of hazardous chemicals past the unit boundary in concentrations which exceed any health-based standards. The monitoring program will use EPA compendium Method TO-14. Both air and carbon sorption media samples will be collected as part of the program. Eleven separate monitoring sites have been selected where both 24-hour integrated and 1-hour grab samples will be collected and analyzed for five target compounds. The bin-scale experimental test rooms will be configured with a gas collection manifold and an activated carbon sorption bed to remove VOCs before they can be emitted into the WIPP underground atmosphere. 10 refs., 4 figs., 7 tabs

  4. Floral Volatiles in Parasitic Plants of the Orobanchaceae. Ecological and Taxonomic Implications

    Directory of Open Access Journals (Sweden)

    Peter eTóth

    2016-03-01

    Full Text Available The holoparasitic broomrapes, Orobanche spp. and Phelipanche spp. (Orobanchaceae, are root parasites that completely depend on a host plant for survival and reproduction. There is considerable controversy on the taxonomy of this biologically and agronomically important family. Flowers of over 25 parasitic Orobanchaceae and a number of close, parasitic and non-parasitic, relatives emitted a complex blend of volatile organic compounds (VOCs, consisting of over 130 VOCs per species. Floral VOC blend-based phylogeny supported the known taxonomy in internal taxonomic grouping of genus and eliminated the uncertainty in some taxonomical groups. Moreover, phylogenetic analysis suggested separation of the broomrapes into two main groups parasitizing annual and perennial hosts, and for the annual hosts, into weedy and non-weedy broomrapes. We conclude that floral VOCs are a significant tool in species identification and possibly even in defining new species and can help to improve controversial taxonomy in the Orobanchaceae.

  5. Floral Volatiles in Parasitic Plants of the Orobanchaceae. Ecological and Taxonomic Implications

    Science.gov (United States)

    Tóth, Peter; Undas, Anna K.; Verstappen, Francel; Bouwmeester, Harro

    2016-01-01

    The holoparasitic broomrapes, Orobanche spp. and Phelipanche spp. (Orobanchaceae), are root parasites that completely depend on a host plant for survival and reproduction. There is considerable controversy on the taxonomy of this biologically and agronomically important family. Flowers of over 25 parasitic Orobanchaceae and a number of close, parasitic and non-parasitic, relatives emitted a complex blend of volatile organic compounds (VOCs), consisting of over 130 VOCs per species. Floral VOC blend-based phylogeny supported the known taxonomy in internal taxonomic grouping of genus and eliminated the uncertainty in some taxonomical groups. Moreover, phylogenetic analysis suggested separation of the broomrapes into two main groups parasitizing annual and perennial hosts, and for the annual hosts, into weedy and non-weedy broomrapes. We conclude that floral VOCs are a significant tool in species identification and possibly even in defining new species and can help to improve controversial taxonomy in the Orobanchaceae. PMID:27014329

  6. Innate responses of the predatory mite Phytoseiulus persimilis to a herbivore-induced plant volatile.

    Science.gov (United States)

    Sznajder, B; Sabelis, M W; Egas, M

    2011-06-01

    The responses of the predatory mite P. persimilis to herbivore-induced plant volatiles are at least partly genetically determined. Thus, there is potential for the evolution of this behaviour by natural selection. We tested whether distinct predator genotypes with contrasting responses to a specific herbivore-induced plant volatile, i.e. methyl salicylate (MeSa), could be found in a base population collected in the field (Sicily). To this end, we imposed purifying selection on individuals within iso-female lines of P. persimilis such that the lines were propagated only via the individual that showed either a preference or avoidance of MeSa. The responses of the lines were characterized as the mean proportion of individuals choosing MeSa when given a choice between MeSa and clean air. Significant variation in predator responses was detected among iso-female lines, thus confirming the presence of a genetic component for this behaviour. Nevertheless, we did not find a significant difference in the response to MeSa between the lines that were selected to avoid MeSa and the lines selected to prefer MeSa. Instead, in the course of selection the lines selected to avoid MeSa shifted their mean response towards a preference for MeSa. An inverse, albeit weaker, shift was detected for the lines selected to prefer MeSa. We discuss the factors that may have caused the apparent lack of a response to selection within iso-female line in this study and propose experimental approaches that address them.

  7. Ozone Differentially Affects Perception of Plant Volatiles in Western Honey Bees.

    Science.gov (United States)

    Dötterl, Stefan; Vater, Marina; Rupp, Thomas; Held, Andreas

    2016-06-01

    Floral scents play a key role in mediating plant-pollinator interactions. Volatile organic compounds (VOCs) emitted by flowers are used by flower visitors as olfactory cues to locate flowers, both from a distance and at close range. More recently it has been demonstrated that reactive molecules such as ozone can modify or degrade VOCs, and this may impair the communication between plants and their pollinators. However, it is not known whether such reactive molecules also may affect the olfactory system of pollinators, and thus not only influence signal transmission but perception of the signal. In this study, we used electroantennographic measurements to determine the effect of increased levels of ozone on antennal responses in western honey bees (Apis mellifera L.). Linalool and 2-phenylethanol, both known to be involved in location of flowers by the bees, and (Z)-3-hexenyl acetate, a widespread green leaf volatile also detected by bees, were used. The results showed that ozone affected antennal responses to the different substances differently. Ozone decreased antennal responses to (Z)-3-hexenyl acetate, whereas responses to linalool and 2-phenylethanol were not influenced by ozone. Overall, the study does not provide evidence that pollination by honey bees is impaired by damage in the olfactory system of the bees caused by increased levels of ozone, at least when linalool and 2-phenylethanol are the attractive signals. However, the results also suggest that ozone can change the overall perception of an odor blend. This might have negative effects in pollination systems and other organismic interactions mediated by specific ratios of compounds.

  8. Ethylene and 1-MCP regulate major volatile biosynthetic pathways in apple fruit.

    Science.gov (United States)

    Yang, Xiaotang; Song, Jun; Du, Lina; Forney, Charles; Campbell-Palmer, Leslie; Fillmore, Sherry; Wismer, Paul; Zhang, Zhaoqi

    2016-03-01

    The effects of ethylene and 1-methylcyclopropene (1-MCP) on apple fruit volatile biosynthesis and gene expression were investigated. Statistical analysis identified 17 genes that changed significantly in response to ethylene and 1-MCP treatments. Genes encoding branched-chain amino acid aminotransferase (BCAT), aromatic amino acid aminotransferase (ArAT) and amino acid decarboxylases (AADC) were up-regulated during ripening and further enhanced by ethylene treatment. Genes related to fatty acid synthesis and metabolism, including acyl-carrier-proteins (ACPs), malonyl-CoA:ACP transacylase (MCAT), acyl-ACP-desaturase (ACPD), lipoxygenase (LOX), hydroperoxide lyase (HPL), alcohol dehydrogenase (ADH), pyruvate decarboxylase (PDC2), β-oxidation, acyl-CoA synthetase (ACS), enoyl-CoA hydratase (ECHD), acyl-CoA dehydrogenase (ACAD), and alcohol acyltransferases (AATs) also increased during ripening and in response to ethylene treatment. Allene oxide synthase (AOS), alcohol dehydrogenase 1 (ADH1), 3-ketoacyl-CoA thiolase and branched-chain amino acid aminotransferase 2 (BCAT2) decreased in ethylene-treated fruit. Treatment with 1-MCP and ethylene generally produced opposite effects on related genes, which provides evidence that regulation of these genes is ethylene dependent. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  9. Volatile amines treatment: Corrosion rates and Atucha I nuclear power plant experience

    International Nuclear Information System (INIS)

    Iglesias, Alberto M.; Jimenez Rebagliati, Raul; Raffo Calderon, Maria C.; Manzi, Ricardo

    2000-01-01

    Steam generators water treatment with volatile amines in place of ammonia is usual today. This option seems an acceptable alternative to the generalize use of ammonia-sodium phosphate and has advantages when copper alloys are present. There are several amines that can work as corrosion inhibitor but the most useful for plant applications are: morpholine, ethanolamine and cyclohexylamine. In this work, are present the obtained results of corrosion rates measurements by electrochemical methods. The hydrothermal conditions of our experiences were similar to that of the Atucha I nuclear power plant (CNA I). pH, conductivity and dissolved oxygen measures were correlated with corrosion rates of the CNA I materials as carbon steel and admiralty brass. The faradaic impedance spectroscopy techniques allows a more detailed interpretation of corrosion rates process. Morpholine and ammonia behavior can be evaluated under power plant operations conditions with the accumulated experience of CNA I. Results are present throughout material release and his effects over heat transfer parameters. (author)

  10. Distribution of volatile liquid hydrocarbons in the vicinity of power/desalination plants in Kuwait

    International Nuclear Information System (INIS)

    Saeed, T.; Khordagui, H; AI-Bloushi, A.

    1999-01-01

    Volatile liquid hydrocarbons (VLHs) represent some 40% of crude oil and are considered to be the most toxic compounds of petroleum other than the carcinogenic polycyclic aromatic hydrocarbons. The distribution of these compounds in Kuwait's coastal waters in the vicinity and at the inlets of power plants was assessed. About 200 samples were collected from selected sampling stations over the four seasons. The VLHs in the samples were concentrated using Grob's closed-loop technique and analysed by GC using FID and confirmed by GC/MS. The results showed that VLHs were ubiquitous in the coastal water of Kuwait. The detected levels (ranged from 307 to 7882 ng/l in Kuwait Bay and from 331 to 5017 ng/l in the south) were comparable to the levels found in other parts of the world and were not alarming. However, the spotty higher levels encountered gave reason for some concern. Benzenoids (originating from petroleum) predominated, representing roughly 70% of the total VLHs. The levels were relatively low at the intake of the power plant located in the Kuwait Bay (annual average 677 ng/l) while higher levels (annual average 3006 ng/l) were encountered at the intake of the plant located at the south of oil the loading terminals and refineries. (author)

  11. Assessment of volatile organic compound removal by indoor plants-a novel experimental setup

    DEFF Research Database (Denmark)

    Dela Cruz, Majbrit; Müller, Renate; Svensmark, Bo

    2014-01-01

    plants which allows for an improved real-life simulation. Parameters such as relative humidity, air exchange rate and VOC concentration are controlled and can be varied to simulate different real-life settings. For example, toluene diffusion through a needle gave concentrations in the range of 0......Indoor plants can remove volatile organic compounds (VOCs) from the air. The majority of knowledge comes from laboratory studies where results cannot directly be transferred to real-life settings. The aim of this study was to develop an experimental test system to assess VOC removal by indoor.......10-2.35 μg/L with deviations from theoretical values of 3.2-10.5 %. Overall, the system proved to be functional for the assessment of VOC removal by indoor plants with Hedera helix reaching a toluene removal rate of up to 66.5 μg/m2/h. The mode of toluene exposure (semi-dynamic or dynamic) had a significant...

  12. Targeted Genome Regulation and Editing in Plants

    KAUST Repository

    Piatek, Agnieszka

    2016-03-01

    The ability to precisely regulate gene expression patterns and to modify genome sequence in a site-specific manner holds much promise in determining gene function and linking genotype to phenotype. DNA-binding modules have been harnessed to generate customizable and programmable chimeric proteins capable of binding to site-specific DNA sequences and regulating the genome and epigenome. Modular DNA-binding domains from zinc fingers (ZFs) and transcriptional activator-like effectors (TALEs) are amenable to engineering to bind any DNA target sequence of interest. Deciphering the code of TALE repeat binding to DNA has helped to engineer customizable TALE proteins capable of binding to any sequence of interest. Therefore TALE repeats provide a rich resource for bioengineering applications. However, the TALE system is limited by the requirement to re-engineer one or two proteins for each new target sequence. Recently, the clustered regularly interspaced palindromic repeats (CRISPR)/ CRISPR associated 9 (Cas9) has been used as a versatile genome editing tool. This machinery has been also repurposed for targeted transcriptional regulation. Due to the facile engineering, simplicity and precision, the CRISPR/Cas9 system is poised to revolutionize the functional genomics studies across diverse eukaryotic species. In this dissertation I employed transcription activator-like effectors and CRISPR/Cas9 systems for targeted genome regulation and editing and my achievements include: 1) I deciphered and extended the DNA-binding code of Ralstonia TAL effectors providing new opportunities for bioengineering of customizable proteins; 2) I repurposed the CRISPR/Cas9 system for site-specific regulation of genes in plant genome; 3) I harnessed the power of CRISPR/Cas9 gene editing tool to study the function of the serine/arginine-rich (SR) proteins.

  13. Exposure of Lima bean leaves to volatiles from herbivore-induced conspecific plants results in emission of carnivore attractants: active or passive process?

    NARCIS (Netherlands)

    Choh, Y.; Shimoda, T.; Ozawa, R.; Dicke, M.; Takabayashi, J.

    2004-01-01

    There is increasing evidence that volatiles emitted by herbivore-damaged plants can cause responses in downwind undamaged neighboring plants, such as the attraction of carnivorous enemies of herbivores. One of the open questions is whether this involves an active (production of volatiles) or passive

  14. Response of predatory mites to a herbivore-induced plant volatile: genetic variation for context-dependent behaviour.

    Science.gov (United States)

    Sznajder, Beata; Sabelis, Maurice W; Egas, Martijn

    2010-07-01

    Plants infested with herbivores release specific volatile compounds that are known to recruit natural enemies. The response of natural enemies to these volatiles may be either learned or genetically determined. We asked whether there is genetic variation in the response of the predatory mite Phytoseiulus persimilis to methyl salicylate (MeSa). MeSa is a volatile compound consistently produced by plants being attacked by the two-spotted spider mite, the prey of P. persimilis. We predicted that predators express genetically determined responses during long-distance migration where previously learned associations may have less value. Additionally, we asked whether these responses depend on odors from uninfested plants as a background to MeSa. To infer a genetic basis, we analyzed the variation in response to MeSa among iso-female lines of P. persimilis by using choice-tests that involved either (1) MeSa presented as a single compound or (2) MeSa with background-odor from uninfested lima bean plants. These tests were conducted for starved and satiated predators, i.e., two physiological states, one that approximates migration and another that mimics local patch exploration. We found variation among iso-female lines in the responses to MeSa, thus showing genetic variation for this behavior. The variation was more pronounced in the starved predators, thus indicating that P. persimilis relies on innate preferences when migrating. Background volatiles of uninfested plants changed the predators' responses to MeSa in a manner that depended on physiological state and iso-female line. Thus, it is possible to select for context-dependent behavioral responses of natural enemies to plant volatiles.

  15. Isolation and identification of volatile kairomone that affects acarine predator-prey interactions: involvement of host plant in its production.

    NARCIS (Netherlands)

    Dicke, M.; Beek, van T.A.; Posthumus, M.A.; Dom, Ben N.; Bokhoven, van H.; Groot, de Ae.

    1990-01-01

    A volatile kairomone emitted from lima bean plants (Phaseolus lunatus) infested with the spider miteTetranychus urticae, was collected on Tenax-TA and analyzed with GC-MS. Two components were identified as the methylene monoterpene (3E)-4,8-dimethyl-1,3,7-nonatriene and the methylene sesquiterpene

  16. Lima bean leaves exposed to herbivore-induced conspecific plant volatiles attract herbivores in addition to carnivores

    NARCIS (Netherlands)

    Horiuchi, J.I.; Arimura, G.I.; Ozawa, R.; Shimoda, T.; Dicke, M.; Takabayashi, J.; Nishioka, T.

    2003-01-01

    We tested the response of the herbivorous mite Tetranychus urticae to uninfested lima bean leaves exposed to herbivore-induced conspecific plant volatiles by using a Y-tube olfactometer. First, we confirmed that exposed uninfested leaves next to infested leaves were more attractive to carnivorous

  17. Volatile induction of infected and neighbouring uninfected plants potentially influence attraction/repellence of a cereal herbivore

    Science.gov (United States)

    Plant infection by pathogens can induce volatile organic compounds (VOCs). We infected ‘McNeal’ wheat and ‘Harrington’ barley with a Fusarium spp. blend (graminearum, avenaceum, and culmorum). Both cereals had highest VOC induction 14 d after pathogen introduction, significantly slightly lower induc...

  18. Herbivory induces systemic production of plant volatiles that attract predators of the herbivore: extraction of endogenous elicitor.

    NARCIS (Netherlands)

    Dicke, M.; Baarlen, van P.; Wessels, R.; Dijkman, H.

    1993-01-01

    It was previously shown that in response to infestation by spider mites (Tetranychus urticae), lima bean plants produce a volatile herbivoreinduced synomone that attracts phytoseiid mites (Phytoseiulus persimilis) that are predators of the spider mites. The production of predator-attracting

  19. Experience with methyl salicylate affects behavioural responses of a predatory mite to blends of herbivore-induced plant volatiles

    NARCIS (Netherlands)

    Boer, de J.G.; Dicke, M.

    2004-01-01

    Many natural enemies of herbivorous arthropods use herbivore-induced plant volatiles to locate their prey. These foraging cues consist of mixtures of compounds that show a considerable variation within and among plantherbivore combinations, a situation that favours a flexible approach in the

  20. Hydrologic regulation of plant rooting depth.

    Science.gov (United States)

    Fan, Ying; Miguez-Macho, Gonzalo; Jobbágy, Esteban G; Jackson, Robert B; Otero-Casal, Carlos

    2017-10-03

    Plant rooting depth affects ecosystem resilience to environmental stress such as drought. Deep roots connect deep soil/groundwater to the atmosphere, thus influencing the hydrologic cycle and climate. Deep roots enhance bedrock weathering, thus regulating the long-term carbon cycle. However, we know little about how deep roots go and why. Here, we present a global synthesis of 2,200 root observations of >1,000 species along biotic (life form, genus) and abiotic (precipitation, soil, drainage) gradients. Results reveal strong sensitivities of rooting depth to local soil water profiles determined by precipitation infiltration depth from the top (reflecting climate and soil), and groundwater table depth from below (reflecting topography-driven land drainage). In well-drained uplands, rooting depth follows infiltration depth; in waterlogged lowlands, roots stay shallow, avoiding oxygen stress below the water table; in between, high productivity and drought can send roots many meters down to the groundwater capillary fringe. This framework explains the contrasting rooting depths observed under the same climate for the same species but at distinct topographic positions. We assess the global significance of these hydrologic mechanisms by estimating root water-uptake depths using an inverse model, based on observed productivity and atmosphere, at 30″ (∼1-km) global grids to capture the topography critical to soil hydrology. The resulting patterns of plant rooting depth bear a strong topographic and hydrologic signature at landscape to global scales. They underscore a fundamental plant-water feedback pathway that may be critical to understanding plant-mediated global change.

  1. Hydrologic regulation of plant rooting depth

    Science.gov (United States)

    Fan, Ying; Miguez-Macho, Gonzalo; Jobbágy, Esteban G.; Jackson, Robert B.; Otero-Casal, Carlos

    2017-10-01

    Plant rooting depth affects ecosystem resilience to environmental stress such as drought. Deep roots connect deep soil/groundwater to the atmosphere, thus influencing the hydrologic cycle and climate. Deep roots enhance bedrock weathering, thus regulating the long-term carbon cycle. However, we know little about how deep roots go and why. Here, we present a global synthesis of 2,200 root observations of >1,000 species along biotic (life form, genus) and abiotic (precipitation, soil, drainage) gradients. Results reveal strong sensitivities of rooting depth to local soil water profiles determined by precipitation infiltration depth from the top (reflecting climate and soil), and groundwater table depth from below (reflecting topography-driven land drainage). In well-drained uplands, rooting depth follows infiltration depth; in waterlogged lowlands, roots stay shallow, avoiding oxygen stress below the water table; in between, high productivity and drought can send roots many meters down to the groundwater capillary fringe. This framework explains the contrasting rooting depths observed under the same climate for the same species but at distinct topographic positions. We assess the global significance of these hydrologic mechanisms by estimating root water-uptake depths using an inverse model, based on observed productivity and atmosphere, at 30″ (˜1-km) global grids to capture the topography critical to soil hydrology. The resulting patterns of plant rooting depth bear a strong topographic and hydrologic signature at landscape to global scales. They underscore a fundamental plant-water feedback pathway that may be critical to understanding plant-mediated global change.

  2. An olfactory receptor from Apolygus lucorum (Meyer-Dur) mainly tuned to volatiles from flowering host plants.

    Science.gov (United States)

    Yan, Shu-Wei; Zhang, Jin; Liu, Yang; Li, Guo-Qing; Wang, Gui-Rong

    2015-08-01

    Apolygus lucorum (Meyer-Dür) (Hemiptera: Miridae) is one of the most serious agricultural pests, feeding on a wide range of cultivated plants, including cotton, cereals and vegetables in the north of China. This insect can frequently switch between habitats and host plants over seasons and prefer plants in bloom. A. lucorum relies heavily on olfaction to locate its host plants finely discriminating different plant volatiles in the environment. Despite its economical importance, research on the olfactory system of this species has been so far very limited. In this study, we have identified and characterized an olfactory receptor which is sensitively tuned to (Z)-3-Hexenyl acetate and several flowering compounds. Besides being present in the bouquet of some flowers, these compounds are produced by plants that have suffered attacks and are supposed to act as chemical messengers between plants. This OR may play an important role in the selection of host plants. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Electroantennogram Responses to Plant Volatiles Associated with Fenvalerate Resistance in the Diamondback Moth, Plutella xylostella (Lepidoptera: Plutellidae).

    Science.gov (United States)

    Houjun, Tian; Lin, Shuo; Chen, Yong; Chen, Yixin; Zhao, Jianwei; Gu, Xiaojun; Wei, Hui

    2018-05-28

    The diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae), is the main destructive insect pest of brassica vegetables around the world, and has developed resistance to numerous insecticides. Although host plant volatiles are important in pest control, the mechanism of low-level insecticide resistance in P. xylostella due to plant volatiles has not been examined. Here, electroantennograms (EAGs) were used to compare the responses of adult male and female DBMs of a susceptible strain (S-strain) and a derived resistant strain, Fen-R-strain (6.52-fold more resistant than the S-strain), to different concentrations of nine plant volatiles. We found significantly different relative EAG responses between S-strain and Fen-R-strain males to different concentrations of methyl jasmonate, methyl salicylate, and octanal. The relative EAG responses of S-strain and Fen-R-strain females to different concentrations of β-myrcene, methyl jasmonate, methyl salicylate, and allyl isothiocyanate were significantly different. Fen-R-strain females showed lower EAG responses to most of the tested plant volatiles (at concentrations of 1:10) than males, except for allyl isothiocyanate. A larger difference in relative EAG response to α-farnesene and β-myrcene was found between S-strain and Fen-R-strain females than between males of the two strains. A larger difference in relative EAG response to octanal, nonanal, and octan-1-ol was found between S-strain and Fen-R-strain males than between females of the two strains. These results illustrate the relationship between the function of plant volatiles and resistance in an insect pest species, and provide a scientific basis for resistance evolutionary theory in pest management research.

  4. Parasitic Wasps Can Reduce Mortality of Teosinte Plants Infested With Fall Armyworm: Support for a Defensive Function of Herbivore-Induced Plant Volatiles

    Directory of Open Access Journals (Sweden)

    Elvira S. de Lange

    2018-05-01

    Full Text Available Many parasitic wasps use volatiles emitted by plants under herbivore attack to find their hosts. It has therefore been proposed that these inducible plant volatiles serve an indirect defense function by recruiting parasitoids and other natural enemies. This suggested function remains controversial because there is little evidence that, in terms of fitness, plants benefit from the actions of natural enemies, particularly parasitoids, which do not immediately kill their hosts. We aimed to address this controversy in a semi-natural field experiment in Mexico, where we used large screen tents to evaluate how parasitoids can affect plant performance. The tritrophic study system comprised teosinte (Zea spp., the ancestor of maize, Spodoptera frugiperda Smith (Lepidoptera: Noctuidae and Campoletis sonorensis Cameron (Hymenoptera: Ichneumonidae, which have a long evolutionary history together. In tents without parasitoids, S. frugiperda larvae inflicted severe damage to the plants, whereas in the presence of parasitoid wasps, leaf damage was reduced by as much as 80%. Parasitoids also mitigated herbivore-mediated mortality among young teosinte plants. Although these findings will not resolve the long-standing debate on the adaptive function of herbivore-induced plant volatiles (HIPVs, they do present strong support for the hypothesis that plants can benefit from the presence of parasitoid natural enemies of their herbivores.

  5. Novel bioassay demonstrates attraction of the white potato cyst nematode Globodera pallida (Stone) to non-volatile and volatile host plant cues.

    Science.gov (United States)

    Farnier, Kevin; Bengtsson, Marie; Becher, Paul G; Witzell, Johanna; Witzgall, Peter; Manduríc, Sanja

    2012-06-01

    Potato cyst nematodes (PCNs) are a major pest of solanaceous crops such as potatoes, tomatoes, and eggplants and have been widely studied over the last 30 years, with the majority of earlier studies focusing on the identification of natural hatching factors. As a novel approach, we focused instead on chemicals involved in nematode orientation towards its host plant. A new dual choice sand bioassay was designed to study nematode responses to potato root exudates (PRE). This bioassay, conducted together with a traditional hatching bioassay, showed that biologically active compounds that induce both hatching and attraction of PCNs can be collected by water extraction of incised potato roots. Furthermore, our results demonstrated that PCN also were attracted by potato root volatiles. Further work is needed to fully understand how PCNs use host plant chemical cues to orientate towards hosts. Nevertheless, the simple attraction assay used in this study provides an important tool for the identification of host-emitted attractants.

  6. High Level of Nitrogen Makes Tomato Plants Releasing Less Volatiles and Attracting More Bemisia tabaci (Hemiptera: Aleyrodidae)

    Science.gov (United States)

    Islam, Md. Nazrul; Hasanuzzaman, Abu Tayeb Mohammad; Zhang, Zhan-Feng; Zhang, Yi; Liu, Tong-Xian

    2017-01-01

    Tomato (Solanum lycopersicum) production is seriously hampered by the infestation of the sweetpotato whitefly, Bemisia tabaci MEAM 1 (Middle East-Asia Minor 1). The infestation behavior of the whiteflies could be affected by the quantity of plant released volatile organic compounds (VOCs) related to nitrogen concentrations of the plant. In this study, we determined the infestation behavior of B. tabaci to the tomato plants that produced different levels of VOCs after application of different levels of nitrogen with a wind tunnel and an olfactometer. We also analyzed the VOCs released from nitrogen-treated tomato plants using solid phase microextraction and gas chromatography-mass spectrometry. The results revealed that the production of eight VOCs (β-pinene, (+)-4-carene, α-terpinene, p-cymene, β-phellandrene, α-copaene, β-caryophyllene, and α-humulene) was reduced after the plants were treated with high levels of nitrogen. However, more whiteflies were attracted to the tomato plants treated with high levels of nitrogen than to the plants treated with normal or below normal levels of nitrogen. These results clearly indicated that nitrogen can change the quality and quantity of tomato plant volatile chemicals, which play important roles in B. tabaci host plant selection. PMID:28408917

  7. Molecular regulation of plant cell wall extensibility

    Science.gov (United States)

    Cosgrove, D. J.

    1998-01-01

    Gravity responses in plants often involve spatial and temporal changes in cell growth, which is regulated primarily by controlling the ability of the cell wall to extend. The wall is thought to be a cellulose-hemicellulose network embedded in a hydrated matrix of complex polysaccharides and a small amount of structural protein. The wall extends by a form of polymer creep, which is mediated by expansins, a novel group of wall-loosening proteins. Expansins were discovered during a molecular dissection of the "acid growth" behavior of cell walls. Expansin alters the rheology of plant walls in profound ways, yet its molecular mechanism of action is still uncertain. It lacks detectable hydrolytic activity against the major components of the wall, but it is able to disrupt noncovalent adhesion between wall polysaccharides. The discovery of a second family of expansins (beta-expansins) sheds light on the biological role of a major group of pollen allergens and implies that expansins have evolved for diverse developmental functions. Finally, the contribution of other processes to wall extensibility is briefly summarized.

  8. Systemic resistance induced by volatile organic compounds emitted by plant growth-promoting fungi in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Hushna Ara Naznin

    Full Text Available Volatile organic compounds (VOC were extracted and identified from plant growth-promoting fungi (PGPF, Phoma sp., Cladosporium sp. and Ampelomyces sp., using gas chromatography-mass spectrometry (GC-MS. Among the three VOC extracted, two VOC blends (emitted from Ampelomyces sp. and Cladosporium sp. significantly reduced disease severity in Arabidopsis plants against Pseudomonas syringae pv. tomato DC3000 (Pst. Subsequently, m-cresol and methyl benzoate (MeBA were identified as major active volatile compounds from Ampelomyces sp. and Cladosporium sp., respectively, and found to elicit induced systemic resistance (ISR against the pathogen. Molecular signaling for disease suppression by the VOC were investigated by treating different mutants and transgenic Arabidopsis plants impaired in salicylic acid (SA or Jasmonic acid (JA/ethylene (ET signaling pathways with m-cresol and MeBA followed by challenge inoculation with Pst. Results show that the level of protection was significantly lower when JA/ET-impaired mutants were treated with MeBA, and in SA-, and JA/ET-disrupted mutants after m-cresol treatment, indicating the involvement of these signal transduction pathways in the ISR primed by the volatiles. Analysis of defense-related genes by real-time qRT-PCR showed that both the SA-and JA-signaling pathways combine in the m-cresol signaling of ISR, whereas MeBA is mainly involved in the JA-signaling pathway with partial recruitment of SA-signals. The ET-signaling pathway was not employed in ISR by the volatiles. Therefore, this study identified two novel volatile components capable of eliciting ISR that may be promising candidates in biological control strategy to protect plants from diseases.

  9. Volatile profiling reveals intracellular metabolic changes in Aspergillus parasiticus: veA regulates branched chain amino acid and ethanol metabolism

    Directory of Open Access Journals (Sweden)

    Roze Ludmila V

    2010-08-01

    Full Text Available Abstract Background Filamentous fungi in the genus Aspergillus produce a variety of natural products, including aflatoxin, the most potent naturally occurring carcinogen known. Aflatoxin biosynthesis, one of the most highly characterized secondary metabolic pathways, offers a model system to study secondary metabolism in eukaryotes. To control or customize biosynthesis of natural products we must understand how secondary metabolism integrates into the overall cellular metabolic network. By applying a metabolomics approach we analyzed volatile compounds synthesized by Aspergillus parasiticus in an attempt to define the association of secondary metabolism with other metabolic and cellular processes. Results Volatile compounds were examined using solid phase microextraction - gas chromatography/mass spectrometry. In the wild type strain Aspergillus parasiticus SU-1, the largest group of volatiles included compounds derived from catabolism of branched chain amino acids (leucine, isoleucine, and valine; we also identified alcohols, esters, aldehydes, and lipid-derived volatiles. The number and quantity of the volatiles produced depended on media composition, time of incubation, and light-dark status. A block in aflatoxin biosynthesis or disruption of the global regulator veA affected the volatile profile. In addition to its multiple functions in secondary metabolism and development, VeA negatively regulated catabolism of branched chain amino acids and synthesis of ethanol at the transcriptional level thus playing a role in controlling carbon flow within the cell. Finally, we demonstrated that volatiles generated by a veA disruption mutant are part of the complex regulatory machinery that mediates the effects of VeA on asexual conidiation and sclerotia formation. Conclusions 1 Volatile profiling provides a rapid, effective, and powerful approach to identify changes in intracellular metabolic networks in filamentous fungi. 2 VeA coordinates the

  10. On the use of plant emitted volatile organic compounds for atmospheric chemistry simulation experiments

    Science.gov (United States)

    Kiendler-Scharr, A.; Hohaus, T.; Yu, Z.; Tillmann, R.; Kuhn, U.; Andres, S.; Kaminski, M.; Wegener, R.; Novelli, A.; Fuchs, H.; Wahner, A.

    2015-12-01

    Biogenic volatile organic compounds (BVOC) contribute to about 90% of the emitted VOC globally with isoprene being one of the most abundant BVOC (Guenther 2002). Intensive efforts in studying and understanding the impact of BVOC on atmospheric chemistry were undertaken in the recent years. However many uncertainties remain, e.g. field studies have shown that in wooded areas measured OH reactivity can often not be explained by measured BVOC and their oxidation products (e.g. Noelscher et al. 2012). This discrepancy may be explained by either a lack of understanding of BVOC sources or insufficient understanding of BVOC oxidation mechanisms. Plants emit a complex VOC mixture containing likely many compounds which have not yet been measured or identified (Goldstein and Galbally 2007). A lack of understanding BVOC sources limits bottom-up estimates of secondary products of BVOC oxidation such as SOA. Similarly, the widespread oversimplification of atmospheric chemistry in simulation experiments, using single compound or simple BVOC mixtures to study atmospheric chemistry processes limit our ability to assess air quality and climate impacts of BVOC. We will present applications of the new extension PLUS (PLant chamber Unit for Simulation) to our atmosphere simulation chamber SAPHIR. PLUS is used to produce representative BVOC mixtures from direct plant emissions. We will report on the performance and characterization of the newly developed chamber. As an exemplary application, trees typical of a Boreal forest environment were used to compare OH reactivity as directly measured by LIF to the OH reactivity calculated from BVOC measured by GC-MS and PTRMS. The comparison was performed for both, primary emissions of trees without any influence of oxidizing agents and using different oxidation schemes. For the monoterpene emitters investigated here, we show that discrepancies between measured and calculated total OH reactivity increase with increasing degree of oxidation

  11. Volatile compounds from leaves of the African spider plant (Gynandropsis gynandra) with bioactivity against spider mite (Tetranychus urticae)

    DEFF Research Database (Denmark)

    Nyalala, Samuel Odeyo; Petersen, Mikael Agerlin; Grout, Brian William Wilson

    2013-01-01

    Previous studies have demonstrated that Gynandropsis gynandra emits acetonitrile as a foliar volatile from intact plants and isolated leaves, and that this compound is an effective spider mite repellent. This study has used gas chromatography–mass spectrometry to investigate volatile compounds...... emitted from homogenised G. gynandra leaves to evaluate their tissue acetonitrile content and to look for other compounds that might be exploited for the management of spider mites. Acetonitrile was absent from the homogenised tissues of five lines of G. gynandra, studied over two seasons. Thirteen...... volatile compounds were emitted by G. gynandra at significantly higher levels than mite-susceptible pot roses, including isothiocyanates, aldehydes, esters, alcohols and terpenes. Six representative compounds were selected to assess bioactivity. Spider mite populations were completely inactive after a 2¿h...

  12. Plant strengtheners enhance parasitoid attraction to herbivore-damaged cotton via qualitative and quantitative changes in induced volatiles.

    Science.gov (United States)

    Sobhy, Islam S; Erb, Matthias; Turlings, Ted C J

    2015-05-01

    Herbivore-damaged plants release a blend of volatile organic compounds (VOCs) that differs from undamaged plants. These induced changes are known to attract the natural enemies of the herbivores and therefore are expected to be important determinants of the effectiveness of biological control in agriculture. One way of boosting this phenomenon is the application of plant strengtheners, which has been shown to enhance parasitoid attraction in maize. It is unclear whether this is also the case for other important crops. The plant strengtheners BTH [benzo (1,2,3) thiadiazole-7-carbothioic acid S-methyl ester] and laminarin were applied to cotton plants, and the effects on volatile releases and the attraction of three hymenopteran parasitoids, Cotesia marginiventris, Campoletis sonorensis and Microplitis rufiventris, were studied. After treated and untreated plants were induced by real or simulated caterpillar feeding, it was found that BTH treatment increased the attraction of the parasitoids, whereas laminarin had no significant effect. BTH treatment selectively increased the release of two homoterpenes and reduced the emission of indole, the latter of which had been shown to interfere with parasitoid attraction in earlier studies. Canonical variate analyses of the data show that the parasitoid responses were dependent on the quality rather than the quantity of volatile emission in this tritrophic interaction. Overall, these results strengthen the emerging paradigm that induction of plant defences with chemical elicitors such as BTH could provide a sustainable and environmentally friendly strategy for biological control of pests by enhancing the attractiveness of cultivated plants to natural enemies of insect herbivores. © 2014 Society of Chemical Industry.

  13. The effect of plant growth regulators, explants and cultivars on ...

    African Journals Online (AJOL)

    To achieve the best explants and media for spinach tissue culture, the effects of two different plant growth regulators, two explants and cultivars on adventitious shoot regeneration were tested. The Analysis of Variance (ANOVA) showed that the effects of plant growth regulators on spinach tissue culture were significant; ...

  14. Attraction of Cerambycid Beetles to Their Aggregation-Sex Pheromones Is Influenced by Volatiles From Host Plants of Their Larvae.

    Science.gov (United States)

    Wong, J C H; Zou, Y; Millar, J G; Hanks, L M

    2017-06-01

    Here, we describe a field experiment that tested for attraction of cerambycid beetles to odors from angiosperm hosts, and whether plant volatiles also serve to enhance attraction of beetles to their aggregation-sex pheromones. Traps were baited with a blend of synthesized chemicals that are common pheromone components of species in the subfamilies Cerambycinae and Lamiinae. The source of plant volatiles was chipped wood from trees of three angiosperm species, as well as from one nonhost, gymnosperm species. Bioassays were conducted in wooded areas of east-central Illinois. Traps were baited with the pheromone blend alone, the blend + wood chips from one tree species, wood chips alone, or a solvent control lure. Seven species of cerambycids were significantly attracted to the pheromone blend, with or without wood chips. In two cases, wood chips from angiosperms appeared to enhance attraction to pheromones, whereas they inhibited attraction in another three cases. Pine chips did not strongly influence attraction of any species. Overall, our results suggest that host plant volatiles from wood chips may improve trap catch with synthesized pheromones for some cerambycid species, but the effect is not general, necessitating case-by-case testing to determine how individual target species are affected. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Identification of plant defence regulators through transcriptional ...

    Indian Academy of Sciences (India)

    2015-02-04

    Feb 4, 2015 ... defence-related genes also supports constitutive activation of defence in cdd1. We screened T-DNA ..... identified through this work as novel plant defence regu- ... to drought stress than untransformed plants (Lee et al. 2012).

  16. Priming by Hexanoic acid induce activation of mevalonic and linolenic pathways and promotes the emission of plant volatiles.

    Directory of Open Access Journals (Sweden)

    Eugenio eLlorens

    2016-04-01

    Full Text Available Hexanoic acid is a short natural monocarboxylic acid present in some fruits and plants. Previous studies reported that soil drench application of this acid induces effective resistance in tomato plants against Botrytis cinerea and Pseudomonas syringae and in citrus against Alternaria alternata and Xanthomonas citri. In this work, we performed an in deep study of the metabolic changes produced in citrus by the application of hexanoic acid in response to the challenge pathogen Alternaria alternata, focusing on the response of the plant. Moreover, we used 13C labeled hexanoic to analyze its behavior inside the plants. Finally, we studied the volatile emission of the treated plants after the challenge inoculation. Drench application of 13C labeled hexanoic demonstrated that this molecule stays in the roots and is not mobilized to the leaves, suggesting long distance induction of resistance. Moreover, the study of the metabolic profile showed an alteration of more than two hundred molecules differentially induced by the application of the compound and the inoculation with the fungus. Bioinformatics analysis of data showed that most of these altered molecules could be related with the mevalonic and linolenic pathways suggesting the implication of these pathways in the induced resistance mediated by hexanoic acid. Finally, the application of this compound showed an enhancement of the emission of 17 volatile metabolites. Taken together, this study indicates that after the application of hexanoic acid this compound remains in the roots, provoking molecular changes that may trigger the defensive response in the rest of the plant mediated by changes in the mevalonic and linolenic pathways and enhancing the emission of volatile compounds, suggesting for the first time the implication of mevalonic pathway in response to hexanoic application.

  17. Safety regulation KTA 3901: Communication systems for nuclear power plants

    International Nuclear Information System (INIS)

    1981-01-01

    The regulation applies to communication systems in stationary nuclear power plants with at least one power plant unit, i.e. alarm systems, staff locator systems, communicators, and systems for external communication. The regulation determines the type and extent of staff communication systems as well as the demands to be made on layout, installation, operating systems, and testing of communication systems for nuclear power plants. (orig./HP) [de

  18. Plant Responses to Abiotic Stress Regulated by Histone Deacetylases

    Directory of Open Access Journals (Sweden)

    Ming Luo

    2017-12-01

    Full Text Available In eukaryotic cells, histone acetylation and deacetylation play an important role in the regulation of gene expression. Histone acetylation levels are modulated by histone acetyltransferases and histone deacetylases (HDACs. Recent studies indicate that HDACs play essential roles in the regulation of gene expression in plant response to environmental stress. In this review, we discussed the recent advance regarding the plant HDACs and their functions in the regulation of abiotic stress responses. The role of HDACs in autophagy was also discussed.

  19. Different bioassays for investigating orientation responses of the banana weevil, Cosmopolites sordidus, show additive effects of host plant volatiles and a synthetic male-produced aggregation pheromone

    NARCIS (Netherlands)

    Tinzaara, W.; Dicke, M.; Huis, van A.; Loon, van J.A.; Gold, C.S.

    2003-01-01

    Three different bioassay methods to investigate the orientation behaviour of the banana weevil, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae), to host plant volatiles and a synthetic pheromone (cosmolure+) were compared. A locomotion compensator was used to separately record walking

  20. The European wool-carder bee (Anthidium manicatum) eavesdrops on plant volatile organic compounds (VOCs) during trichome collection.

    Science.gov (United States)

    Graham, Kelsey K; Brown, Steve; Clarke, Stephanie; Röse, Ursula S R; Starks, Philip T

    2017-11-01

    The plant-pollinator relationship is generally considered mutualistic. This relationship is less clear, however, when pollinators also cause tissue damage. Some Megachilidae bees collect plant material for nests from the plants they pollinate. In this study, we examined the relationship between Anthidium manicatum, the European wool-carder bee, and the source of its preferred nesting material - Stachys byzantina, lamb's ear. Female A. manicatum use their mandibles to trim trichomes from plants for nesting material (a behaviour dubbed "carding"). Using volatile organic compound (VOC) headspace analysis and behavioural observations, we explored (a) how carding effects S. byzantina and (b) how A. manicatum may choose specific S. byzantina plants. We found that removal of trichomes leads to a dissimilar VOC bouquet compared to intact leaves, with a significant increase in VOC detection following damage. A. manicatum also visit S. byzantina plants with trichomes removed at a greater frequency compared to plants with trichomes intact. Our data suggest that A. manicatum eavesdrop on VOCs produced by damaged plants, leading to more carding damage for individual plants due to increased detectability by A. manicatum. Accordingly, visitation by A. manicatum to S. byzantina may incur both a benefit (pollination) and cost (tissue damage) to the plant. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. A genetically-based latitudinal cline in the emission of herbivore-induced plant volatile organic compounds.

    Science.gov (United States)

    Wason, Elizabeth L; Agrawal, Anurag A; Hunter, Mark D

    2013-08-01

    The existence of predictable latitudinal variation in plant defense against herbivores remains controversial. A prevailing view holds that higher levels of plant defense evolve at low latitudes compared to high latitudes as an adaptive plant response to higher herbivore pressure on low-latitude plants. To date, this prediction has not been examined with respect to volatile organic compounds (VOCs) that many plants emit, often thus attracting the natural enemies of herbivores. Here, we compared genetically-based constitutive and herbivore-induced aboveground vegetative VOC emissions from plants originating across a gradient of more than 10° of latitude (>1,500 km). We collected headspace VOCs from Asclepias syriaca (common milkweed) originating from 20 populations across its natural range and grown in a common garden near the range center. Feeding by specialist Danaus plexippus (monarch) larvae induced VOCs, and field environmental conditions (temperature, light, and humidity) also influenced emissions. Monarch damage increased plant VOC concentrations and altered VOC blends. We found that genetically-based induced VOC emissions varied with the latitude of plant population origin, although the pattern followed the reverse of that predicted-induced VOC concentration increased with increasing latitude. This pattern appeared to be driven by a greater induction of sesquiterpenoids at higher latitudes. In contrast, constitutive VOC emission did not vary systematically with latitude, and the induction of green leafy volatiles declined with latitude. Our results do not support the prevailing view that plant defense is greater at lower than at higher latitudes. That the pattern holds only for herbivore-induced VOC emission, and not constitutive emission, suggests that latitudinal variation in VOCs is not a simple adaptive response to climatic factors.

  2. Biotechnological aspects of cytoskeletal regulation in plants.

    Science.gov (United States)

    Komis, George; Luptovciak, Ivan; Doskocilova, Anna; Samaj, Jozef

    2015-11-01

    The cytoskeleton is a protein-based intracellular superstructure that evolved early after the appearance of bacterial prokaryotes. Eventually cytoskeletal proteins and their macromolecular assemblies were established in eukaryotes and assumed critical roles in cell movements, intracellular organization, cell division and cell differentiation. In biomedicine the small-molecules targeting cytoskeletal elements are in the frontline of anticancer research with plant-derived cytoskeletal drugs such as Vinca alkaloids and toxoids, being routinely used in the clinical practice. Moreover, plants are also major material, food and energy resources for human activities ranging from agriculture, textile industry, carpentry, energy production and new material development to name some few. Most of these inheritable traits are associated with cell wall synthesis and chemical modification during primary and secondary plant growth and inevitably are associated with the dynamics, organization and interactions of the plant cytoskeleton. Taking into account the vast intracellular spread of microtubules and actin microfilaments the cytoskeleton collectively assumed central roles in plant growth and development, in determining the physical stance of plants against the forces of nature and becoming a battleground between pathogenic invaders and the defense mechanisms of plant cells. This review aims to address the role of the plant cytoskeleton in manageable features of plants including cellulose biosynthesis with implications in wood and fiber properties, in biofuel production and the contribution of plant cytoskeletal elements in plant defense responses against pathogens or detrimental environmental conditions. Ultimately the present work surveys the potential of cytoskeletal proteins as platforms of plant genetic engineering, nominating certain cytoskeletal proteins as vectors of favorable traits in crops and other economically important plants. Copyright © 2015 Elsevier Inc. All

  3. Genetic variation in jasmonic acid- and spider mite-induced plant volatile emission of cucumber accessions and attraction of the predator Phytoseiulus persimilis.

    Science.gov (United States)

    Kappers, Iris F; Verstappen, Francel W A; Luckerhoff, Ludo L P; Bouwmeester, Harro J; Dicke, Marcel

    2010-05-01

    Cucumber plants (Cucumis sativus L.) respond to spider-mite (Tetranychus urticae) damage with the release of specific volatiles that are exploited by predatory mites, the natural enemies of the spider mites, to locate their prey. The production of volatiles also can be induced by exposing plants to the plant hormone jasmonic acid. We analyzed volatile emissions from 15 cucumber accessions upon herbivory by spider mites and upon exposure to jasmonic acid using gas chromatography-mass spectrometry. Upon induction, cucumber plants emitted over 24 different compounds, and the blend of induced volatiles consisted predominantly of terpenoids. The total amount of volatiles was higher in plants treated with jasmonic acid than in those infested with spider mites, with (E)-4,8-dimethyl-1,3,7-nonatriene, (E,E)-alpha-farnesene, and (E)-beta-ocimene as the most abundant compounds in all accessions in both treatments. Significant variation among the accessions was found for the 24 major volatile compounds. The accessions differed strongly in total amount of volatiles emitted, and displayed very different odor profiles. Principal component analysis performed on the relative quantities of particular compounds within the blend revealed clusters of highly correlated volatiles, which is suggestive of common metabolic pathways. A number of cucumber accessions also were tested for their attractiveness to Phytoseiulus persimilis, a specialist predator of spider mites. Differences in the attraction of predatory mites by the various accessions correlated to differences in the individual chemical profiles of these accessions. The presence of genetic variation in induced plant volatile emission in cucumber shows that it is possible to breed for cucumber varieties that are more attractive to predatory mites and other biological control agents.

  4. 78 FR 41866 - Restructuring of Regulations on the Importation of Plants for Planting

    Science.gov (United States)

    2013-07-12

    ... DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection Service 7 CFR Parts 319 and 340 [Docket No. APHIS-2008-0011] RIN 0579-AD75 Restructuring of Regulations on the Importation of Plants for Planting AGENCY: Animal and Plant Health Inspection Service, USDA. ACTION: Proposed rule; reopening of...

  5. Cost regulation on the inspection of plants requiring supervision

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    According to annexes I to VI of this regulation, TUeVs (technical control authorities) (2nd sentence of para. 1 of sect. 24 c of the trade law) collect fees for inspections ordered by the authorities for the following plants and installations: 1. steam boiler plants, 2. pressure vessels, high-pressure gas vessels, feeders, 3. lifts, 4. acetylene plants, 5. plants for the storage, racking and transport of combustile liquids, 6. electrical installations on hazardous location. (orig.) [de

  6. Genetic variation in plant volatile emission does not result in differential attraction of natural enemies in the field.

    Science.gov (United States)

    Wason, Elizabeth L; Hunter, Mark D

    2014-02-01

    Volatile organic chemical (VOC) emission by plants may serve as an adaptive plant defense by attracting the natural enemies of herbivores. For plant VOC emission to evolve as an adaptive defense, plants must show genetic variability for the trait. To date, such variability has been investigated primarily in agricultural systems, yet relatively little is known about genetic variation in VOCs emitted by natural populations of native plants. Here, we investigate intraspecific variation in constitutive and herbivore-induced plant VOC emission using the native common milkweed plant (Asclepias syriaca) and its monarch caterpillar herbivore (Danaus plexippus) in complementary field and common garden greenhouse experiments. In addition, we used a common garden field experiment to gauge natural enemy attraction to milkweed VOCs induced by monarch damage. We found evidence of genetic variation in the total constitutive and induced concentrations of VOCs and the composition of VOC blends emitted by milkweed plants. However, all milkweed genotypes responded similarly to induction by monarchs in terms of their relative change in VOC concentration and blend. Natural enemies attacked decoy caterpillars more frequently on damaged than on undamaged milkweed, and natural enemy visitation was associated with higher total VOC concentrations and with VOC blend. Thus, we present evidence that induced VOCs emitted by milkweed may function as a defense against herbivores. However, plant genotypes were equally attractive to natural enemies. Although milkweed genotypes diverge phenotypically in their VOC concentrations and blends, they converge into similar phenotypes with regard to magnitude of induction and enemy attraction.

  7. Occurrence and removal of volatile organic compounds (VOC) relative to water treatment plants in Malaysia

    International Nuclear Information System (INIS)

    Soh Shiau Chian

    2005-01-01

    A solid phase micro extraction technique with determination analysis by gas chromatography and mass spectrometry detector (SPME-GC-MSD) to determine 54 volatile organic compounds (VOC) in drinking water was successfully developed. The optimal conditions lead to mean recoveries of 85 % with the relative standard deviation below 13 %. Limit of detection was ranged from 0.005 μg/ l to 1.121 μg/ l for all VOC. Upon consideration of the complete procedure from sample preparation to instrumental determination, the expanded uncertainty for all VOC under study was in the range of 1.056 to 2.952 μg/ l. The optimised SPME-GC-MSD method was used to determine distributions and occurence of VOC in drinking water for Peninsular Malaysia for one year and a specific study carried out in Semenyih Catchment and Semenyih River Water Treatment Plant. Results from the monitoring programme showed that concentration of VOC ranged from undetectable to 190.9 μg/ l. Chloroform has the highest concentration and was detected in all drinking water samples. Apart from trihalomethanes (THM), other abundant compounds detected were 1,2-dibromoethane, cis and trans-1,3-dichloropropene, 1,2,3-trichloropropane and benzene. This indicated the presence of VOC in drinking water and thus is required to be frequently monitored in order to ensure and maintain drinking water quality. Based on exposure risks assessment, results from this study showed that total cancer risks was the greatest for benzene, followed by 1,2-dibromo-3-chloropropane, 1,2-dibromomethane, chloroform and dichlorobromomethane. Nevertheless, after considering the frequency of detection factor and alteration of cancer risks that has been done, chloroform contributed the highest cancer risks among other VOC compounds. On a specific study in Semenyih Catchment, the declination of water quality in Semenyih River between 1990 and 2004 to a perturbing stage was due to urbanisation process and industrial growth. Apart from raw water

  8. Characterization of biosynthetic pathways for the production of the volatile homoterpenes DMNT and TMTT in Zea mays

    Science.gov (United States)

    Plant volatiles not only have multiple defense functions against herbivores, fungi, and bacteria, but also have been implicated in signaling within the plant and toward other organisms. Elucidating the function of individual plant volatiles will require more knowledge of their biosynthesis and regul...

  9. Regulation of Water in Plant Cells

    Science.gov (United States)

    Kowles, Richard V.

    2010-01-01

    Cell water relationships are important topics to be included in cell biology courses. Differences exist in the control of water relationships in plant cells relative to control in animal cells. One important reason for these differences is that turgor pressure is a consideration in plant cells. Diffusion and osmosis are the underlying factors…

  10. Identification of plant defence regulators through transcriptional ...

    Indian Academy of Sciences (India)

    ... of 4- week-old soil grown plants of Col-0 and T-DNA insertion mutant line of At2g19810 (SALK_151571). ... repeated at least twice with similar results (hpi – hours post inoculation). .... work of systemic acquired resistance in plants.

  11. Screening and identification of phytotoxic volatile compounds in medicinal plants and characterizations of a selected compound, eucarvone.

    Science.gov (United States)

    Sunohara, Yukari; Baba, Yohei; Matsuyama, Shigeru; Fujimura, Kaori; Matsumoto, Hiroshi

    2015-07-01

    Screening and identification of phytotoxic volatile compounds were performed using 71 medicinal plant species to find new natural compounds, and the characterization of the promising compound was investigated to understand the mode of action. The volatile compounds from Asarum sieboldii Miq. showed the strongest inhibitory effect on the hypocotyl growth of lettuce seedlings (Lactuca sativa L.cv. Great Lakes 366), followed by those from Schizonepeta tenuifolia Briquet and Zanthoxylum piperitum (L.) DC.. Gas chromatography-mass spectrometry (GC/MS) identified four volatile compounds, α-pinene (2,6,6-trimethylbicyclo[3.1.1]hept-2-ene), β-pinene (6,6-dimethyl-2-methylenebicyclo[3.1.1]heptane), 3-carene (3,7,7-trimethylbicyclo[4.1.0]hept-3-ene), and eucarvone (2,6,6-trimethy-2,4-cycloheptadien-1-one), from A. sieboldii, and three volatile compounds, limonene (1-methyl-4-(1-methylethenyl)-cyclohexene), menthone (5-methyl-2-(propan-2-yl)cyclohexan-1-one), and pulegone (5-methyl-2-propan-2-ylidenecyclohexan-1-one), from S. tenuifolia. Among these volatile compounds, eucarvone, menthone, and pulegone exhibited strong inhibitory effects on both the root and shoot growth of lettuce seedlings. Eucarvone-induced growth inhibition was species-selective. Cell death, the generation of reactive oxygen species (ROS), and lipid peroxidation were induced in susceptible finger millet seedlings by eucarvone treatment, whereas this compound (≤158 μM) did not cause the increase of lipid peroxidation and ROS production in tolerant maize. The results of the present study show that eucarvone can have strong phytotoxic activity, which may be due to ROS overproduction and subsequent oxidative damage in finger millet seedlings.

  12. Chemical Compositions of Achillea sivasica: Different Plant Part Volatiles, Enantiomers and Fatty Acids

    Directory of Open Access Journals (Sweden)

    Gülmira Özek

    2018-03-01

    Full Text Available In the present work, Microsteam distillation - Solid phase microextraction (MSD-SPME and hydrodistillation (HD techniques were applied to obtain volatiles from Achillea sivasica, an endemic species from Turkey. GC-FID and GC/MS analysis revealed that 1,8-cineole (22.1% and a -pinene (9.3% were the main constituents of the hydrodistilled flower volatiles. (Z- b -Farnesene (23.9%, decanoic acid (10.1%, b- eudesmol (8.0%, tricosane (7.3% and hexadecanoic acid (7.2% were the main volatiles obtained from flowers by MSD-SPME. The leaf volatiles obtained by HD contained camphor (9.0%, b -pinene (6.9%, 1,8-cineole (6.7%, a -pinene (6.7% and a -bisabolol (6.6% as the main constituents while the leaf volatiles obtained by MSD-SPME technique were rich in (E-geranyl acetone (10.5%, (E- b -ionone (10.3%, camphor (10.2%, 1,8-cineole (9.6%, longiverbenone (7.9%, b -eudesmol (7.5%, isopropyl myristate (6.7% and epi- a -bisabolol (6.4%. The root volatiles were rich in longiverbenone (14.1%, (E-geranyl acetone (9.3%, nonanol (12.1% and decanol (12.5%. The enantiomeric distribution of the major volatile constituents was analyzed by using different b -cyclodextrin chiral columns. (1R-(+- a -Pinene, (1S-(-- b -pinene, (4R-(+-limonene, (1R,3S,5R-(--trans-pinocarveol, (1S,2R,4S-(--borneol, (2S-(-- a -bisabolol were detected as dominant enantiomers. The lipids extracted from the flower and leaf with Folch method and methylated with BF 3 reagent contained common acids: linolenic, linoleic, hexadecanoic acids. Oleic and stearic acids were detected particularly in high amount in the flower lipids

  13. New evidence for a multi-functional role of herbivore-induced plant volatiles in defense against herbivores.

    Science.gov (United States)

    Rodriguez-Saona, Cesar R; Frost, Christopher J

    2010-01-01

    A diverse, often species-specific, array of herbivore-induced plant volatiles (HIPVs) are commonly emitted from plants after herbivore attack. Although research in the last 3 decades indicates a multi-functional role of these HIPVs, the evolutionary rationale underpinning HIPV emissions remains an open question. Many studies have documented that HIPVs can attract natural enemies, and some studies indicate that neighboring plants may eavesdrop their undamaged neighbors and induce or prime their own defenses prior to herbivore attack. Both of these ecological roles for HIPVs are risky strategies for the emitting plant. In a recent paper, we reported that most branches within a blueberry bush share limited vascular connectivity, which restricts the systemic movement of internal signals. Blueberry branches circumvent this limitation by responding to HIPVs emitted from neighboring branches of the same plant: exposure to HIPVs increases levels of defensive signaling hormones, changes their defensive status, and makes undamaged branches more resistant to herbivores. Similar findings have been reported recently for sagebrush, poplar and lima beans, where intra-plant communication played a role in activating or priming defenses against herbivores. Thus, there is increasing evidence that intra-plant communication occurs in a wide range of taxonomically unrelated plant species. While the degree to which this phenomenon increases a plant's fitness remains to be determined in most cases, we here argue that within-plant signaling provides more adaptive benefit for HIPV emissions than does between-plant signaling or attraction of predators. That is, the emission of HIPVs might have evolved primarily to protect undamaged parts of the plant against potential enemies, and neighboring plants and predators of herbivores later co-opted such HIPV signals for their own benefit.

  14. Environmental conditions regulate the impact of plants on cloud formation.

    Science.gov (United States)

    Zhao, D F; Buchholz, A; Tillmann, R; Kleist, E; Wu, C; Rubach, F; Kiendler-Scharr, A; Rudich, Y; Wildt, J; Mentel, Th F

    2017-02-20

    The terrestrial vegetation emits large amounts of volatile organic compounds (VOC) into the atmosphere, which on oxidation produce secondary organic aerosol (SOA). By acting as cloud condensation nuclei (CCN), SOA influences cloud formation and climate. In a warming climate, changes in environmental factors can cause stresses to plants, inducing changes of the emitted VOC. These can modify particle size and composition. Here we report how induced emissions eventually affect CCN activity of SOA, a key parameter in cloud formation. For boreal forest tree species, insect infestation by aphids causes additional VOC emissions which modifies SOA composition thus hygroscopicity and CCN activity. Moderate heat increases the total amount of constitutive VOC, which has a minor effect on hygroscopicity, but affects CCN activity by increasing the particles' size. The coupling of plant stresses, VOC composition and CCN activity points to an important impact of induced plant emissions on cloud formation and climate.

  15. [Genetic regulation of plant shoot stem cells].

    Science.gov (United States)

    Al'bert, E V; Ezhova, T A

    2013-02-01

    This article describes the main features of plant stem cells and summarizes the results of studies of the genetic control of stem cell maintenance in the apical meristem of the shoot. It is demonstrated that the WUS-CLV gene system plays a key role in the maintenance of shoot apical stem cells and the formation of adventitious buds and somatic embryos. Unconventional concepts of plant stem cells are considered.

  16. Attractiveness of Host Plant Volatile Extracts to the Asian Citrus Psyllid, Diaphorina citri, is Reduced by Terpenoids from the Non-Host Cashew.

    Science.gov (United States)

    Fancelli, Marilene; Borges, Miguel; Laumann, Raul A; Pickett, John A; Birkett, Michael A; Blassioli-Moraes, Maria C

    2018-04-01

    Diaphorina citri is a vector of the bacterial causative agent of Huanglongbing (HLB = Citrus greening), a severe disease affecting citrus crops. As there is no known control for HLB, manipulating insect behaviour through deployment of semiochemicals offers a promising opportunity for protecting citrus crops. The behavioural responses of D. citri to plant volatiles, and the identity of these plant volatiles were investigated. Volatiles were collected from host plants Murraya paniculata, Citrus sinensis, C. reshni, C. limettioides, Poncirus trifoliata, and from non-host plants Psidium guajava, Mangifera indica, Anacardium occidentale. In behavioural assays, female D. citri spent more time in the arms containing volatiles from either M. paniculata or C. sinensis compared to the control arms. When D. citri was exposed to volatiles collected from A. occidentale, they preferred the control arm. Volatiles emitted from the other studied plants did not influence the foraging behaviour of D. citri. Chemical analyses of volatile extracts from C. sinensis, M. paniculata, and A. occidentale revealed the presence of the terpenoids (E)-4,8-dimethylnona-1,3,7-triene (DMNT) and (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene (TMTT) in higher amounts in A. occidentale. In further behavioural bioassays, female D. citri spent less time in arms containing a synthetic blend of DMNT and TMTT compared to the control arms. Female D. citri also spent less time in arms containing the synthetic blend in combination with volatile extracts from either M. paniculata or C. sinensis compared to the control arms. Results suggest that higher release of the two terpenoids by A. occidentale make this species unattractive to D. citri, and that the terpenoids could be used in reducing colonisation of citrus plants and therefore HLB infection.

  17. PTR-MS analysis of reference and plant-emitted volatile organic compounds

    Science.gov (United States)

    Maleknia, Simin D.; Bell, Tina L.; Adams, Mark A.

    2007-05-01

    Proton transfer reaction-mass spectrometry (PTR-MS) was applied to the analysis of a series of volatile organic compounds (VOCs) that emit from various plants. These include a group of alcohols (methanol, ethanol and butanol), carbonyl-containing compounds (acetic acid, acetone and benzaldehyde), isoprene, acetonitrile, tetrahydrofuran (THF), pyrazine, toluene and xylene and a series of terpenes (p-cymene, camphene, 2-carene, limonene, [beta]-myrcene, [alpha]-pinene, [beta]-pinene, [gamma]-tepinene and terpinolene) and oxygen-containing terpenes (1,8-cineole and linalool). These mass spectral data were compared to an electron ionization (EI) database identifying that not all PTR-MS fragments were common to EI. PTR-MS studies of these reference compounds were utilized to identify VOCs emitted from Eucalyptus grandis leaf at a temperature range of 30-100 °C. In addition to protonated molecules (M + H)+, abundant proton-bound dimers or trimers were detected for alcohols, acetone, acetonitrile and THF. Abundant fragment ions attributed to the loss of water from these proton-bound clusters were also observed. The stability of butyl (C4H9+ m/z 57) and acetyl (CH3CO+ m/z 43) fragment ions directed the proton-transfer reactions of butanol and acetic acid. Abundant (M + H)+ ions were detected for pyrazine, THF, toluene and xylene, as well as for all terpenes except those containing oxygen. For linalool and 1,8-cineole, the loss of water generated an abundant fragment ion at m/z 137. PTR-MS fragmentation patterns for terpenes were proposed for m/z 81 (C6H9+), 93 (C7H9+), 95 (C7H11+), 107 (C8H11+), 109 (C8H13+), 119 (C9H11+), 121 (C9H13+) and 137 (loss of water for oxygen-containing terpenes; C10H17+). The relative abundances of (M + H)+ and fragments for all terpenes (except linalool) were dependent on the drift tube voltage and the optimum voltage for detection of molecular ions was different for various terpenes.

  18. Effect of plant growth regulators, explants type and efficient plantlet ...

    African Journals Online (AJOL)

    use

    2011-12-05

    Dec 5, 2011 ... Plant Pathology, Tissue Culture and Biotechnology Laboratory, Department of Botany,. University of ... variability in response to growth regulators. In vitro rooting ..... an adult tree Wrightia tomentosa through enhanced axillary.

  19. Effects of Plant Growth Regulators and Photoperiod on In

    African Journals Online (AJOL)

    Shahin

    using the combination of two plant growth regulators and same photoperiod. Key words: Tissue culture, ... they can be stored and transplanted directly into the field without an acclimatization ..... SAS user's guide. cary, NC: Statistical Analysis ...

  20. Exogenous application of plant growth regulators increased the total ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-02

    Nov 2, 2009 ... the exogenous application of flavonoids reports plant growth regulation ... method used for extraction and quantification of endogenous gibberellins was ... 365 nm) while separation was done on a C18 reverse-phase HPLC.

  1. Regulation of abiotic and biotic stress responses by plant hormones

    DEFF Research Database (Denmark)

    Grosskinsky, Dominik Kilian; van der Graaff, Eric; Roitsch, Thomas Georg

    2016-01-01

    Plant hormones (phytohormones) are signal molecules produced within the plant, and occur in very low concentrations. In the present chapter, the current knowledge on the regulation of biotic and biotic stress responses by plant hormones is summarized with special focus on the novel insights...... into the complex hormonal crosstalk of classical growth stimulating plant hormones within the naturally occurring biotic and abiotic multistress environment of higher plants. The MAPK- and phytohormone-cascades which comprise a multitude of single molecules on different signalling levels, as well as interactions...

  2. Degradation of pheromone and plant volatile components by a same odorant-degrading enzyme in the cotton leafworm, Spodoptera littoralis.

    Directory of Open Access Journals (Sweden)

    Nicolas Durand

    Full Text Available Odorant-Degrading Enzymes (ODEs are supposed to be involved in the signal inactivation step within the olfactory sensilla of insects by quickly removing odorant molecules from the vicinity of the olfactory receptors. Only three ODEs have been both identified at the molecular level and functionally characterized: two were specialized in the degradation of pheromone compounds and the last one was shown to degrade a plant odorant.Previous work has shown that the antennae of the cotton leafworm Spodoptera littoralis, a worldwide pest of agricultural crops, express numerous candidate ODEs. We focused on an esterase overexpressed in males antennae, namely SlCXE7. We studied its expression patterns and tested its catalytic properties towards three odorants, i.e. the two female sex pheromone components and a green leaf volatile emitted by host plants.SlCXE7 expression was concomitant during development with male responsiveness to odorants and during adult scotophase with the period of male most active sexual behaviour. Furthermore, SlCXE7 transcription could be induced by male exposure to the main pheromone component, suggesting a role of Pheromone-Degrading Enzyme. Interestingly, recombinant SlCXE7 was able to efficiently hydrolyze the pheromone compounds but also the plant volatile, with a higher affinity for the pheromone than for the plant compound. In male antennae, SlCXE7 expression was associated with both long and short sensilla, tuned to sex pheromones or plant odours, respectively. Our results thus suggested that a same ODE could have a dual function depending of it sensillar localisation. Within the pheromone-sensitive sensilla, SlCXE7 may play a role in pheromone signal termination and in reduction of odorant background noise, whereas it could be involved in plant odorant inactivation within the short sensilla.

  3. The pollution characteristics of odor, volatile organochlorinated compounds and polycyclic aromatic hydrocarbons emitted from plastic waste recycling plants.

    Science.gov (United States)

    Tsai, Chung-Jung; Chen, Mei-Lien; Chang, Keng-Fu; Chang, Fu-Kuei; Mao, I-Fang

    2009-02-01

    Plastic waste treatment trends toward recycling in many countries; however, the melting process in the facilities which adopt material recycling method for treating plastic waste may emit toxicants and cause sensory annoyance. The objectives of this study were to analyze the pollution characteristics of the emissions from the plastic waste recycling plants, particularly in harmful volatile organochlorinated compounds, polycyclic aromatic hydrocarbons (PAHs), odor levels and critical odorants. Ten large recycling plants were selected for analysis of odor concentration (OC), volatile organic compounds (VOCs) and PAHs inside and outside the plants using olfactometry, gas chromatography-mass spectrometry and high performance liquid chromatography-fluorescence detector, respectively. The olfactometric results showed that the melting processes used for treating polyethylene/polypropylene (PE/PP) and polyvinyl chloride (PVC) plastic waste significantly produced malodor, and the odor levels at downwind boundaries were 100-229 OC, which all exceeded Taiwan's EPA standard of 50 OC. Toluene, ethylbenzene, 4-methyl-2-pentanone, methyl methacrylate and acrolein accounted for most odors compared to numerous VOCs. Sixteen organochlorinated compounds were measured in the ambient air emitted from the PVC plastic waste recycling plant and total concentrations were 245-553 microg m(-3); most were vinyl chloride, chloroform and trichloroethylene. Concentrations of PAHs inside the PE/PP plant were 8.97-252.16 ng m(-3), in which the maximum level were 20-fold higher than the levels detected from boundaries. Most of these recycling plants simply used filter to treat the melting fumes, and this could not efficiently eliminate the gaseous compounds and malodor. Improved exhaust air pollution control were strongly recommended in these industries.

  4. Responses of the Asian citrus psyllid to volatiles emitted by the flushing shoots of its rutaceous host plants.

    Science.gov (United States)

    Patt, J M; Sétamou, M

    2010-04-01

    Diaphorina citri Kuwayama (Hemiptera: Psyllidae) carries Candidatus liberibacter spp., the putative causal agents of Huanglongbing. D. citri reproduces and develops only on the flushing shoots of its rutaceous host plants. Here we examined whether D. citri is attracted to host plant odors and a mixture of synthetic terpenes. Tests conducted in a vertically oriented Y-tube olfactometer showed that both males and females preferentially entered the Y-tube arm containing the odor from the young shoots of Murraya paniculata (L.) Jack and Citrus limon L. Burm. f. cultivar Eureka. Only males exhibited a preference for the odor of C. sinensis L., whereas the odor of C. x paradisi MacFadyen cultivar Rio Red was not attractive to both sexes. The volatiles emitted by young shoots of grapefruit cultivar Rio Red, Meyer lemon (Citrus x limon L. Burm.f.), and M. paniculata were analyzed by gas chromatograph-mass spectrometry. The samples were comprised of monoterpenes, monoterpene esters, and sesquiterpenes. The number of compounds present varied from 2 to 17, whereas the total amount of sample collected over 6 h ranged from 5.6 to 119.8 ng. The quantitatively dominant constituents were (E)-beta-ocimene, linalool, linalyl acetate, and beta-caryophyllene. The attractiveness of a mixture of synthetic terpenes, modeled on the volatiles collected from M. paniculata, was evaluated in screened cages in a no-choice test. At three observation intervals, significantly more individuals were trapped on white targets scented with the mixture than on unscented targets. These results indicate the feasibility of developing D. citri attractants patterned on actual host plant volatiles.

  5. Effect of plant growth regulators on regeneration of the endangered ...

    African Journals Online (AJOL)

    Development of an efficient in vitro regeneration protocol of Calligonum comosum is important and that has achieved to protect the endangered multipurpose medicinally important desert plant in the Kingdom of Bahrain. Nodal segments were used as explants source and the effect of various plant growth regulators (PGRs) ...

  6. The effect of plant growth regulators, explants and cultivars on ...

    African Journals Online (AJOL)

    ONOS

    2010-07-05

    Jul 5, 2010 ... The effect of plant growth regulators, explants and cultivars on spinach (Spinacia oleracea L.) tissue culture. Taha Roodbar Shojaei1*, Vahid Salari2, Darioush Ramazan3, Mahdi Ehyaei1, Javad. Gharechahi4 and Roya Motallebi Chaleshtori5. 1Department of Agronomy and Plant Breeding, College of ...

  7. Symbiotic regulation of plant growth, development and reproduction

    Science.gov (United States)

    Russell J. Rodriguez; D. Carl Freeman; E. Durant McArthur; Yong Ok Kim; Regina S. Redman

    2009-01-01

    The growth and development of rice (Oryzae sativa) seedlings was shown to be regulated epigenetically by a fungal endophyte. In contrast to un-inoculated (nonsymbiotic) plants, endophyte colonized (symbiotic) plants preferentially allocated resources into root growth until root hairs were well established. During that time symbiotic roots expanded at...

  8. GABA signalling modulates plant growth by directly regulating the activity of plant-specific anion transporters.

    Science.gov (United States)

    Ramesh, Sunita A; Tyerman, Stephen D; Xu, Bo; Bose, Jayakumar; Kaur, Satwinder; Conn, Vanessa; Domingos, Patricia; Ullah, Sana; Wege, Stefanie; Shabala, Sergey; Feijó, José A; Ryan, Peter R; Gilliham, Matthew; Gillham, Matthew

    2015-07-29

    The non-protein amino acid, gamma-aminobutyric acid (GABA) rapidly accumulates in plant tissues in response to biotic and abiotic stress, and regulates plant growth. Until now it was not known whether GABA exerts its effects in plants through the regulation of carbon metabolism or via an unidentified signalling pathway. Here, we demonstrate that anion flux through plant aluminium-activated malate transporter (ALMT) proteins is activated by anions and negatively regulated by GABA. Site-directed mutagenesis of selected amino acids within ALMT proteins abolishes GABA efficacy but does not alter other transport properties. GABA modulation of ALMT activity results in altered root growth and altered root tolerance to alkaline pH, acid pH and aluminium ions. We propose that GABA exerts its multiple physiological effects in plants via ALMT, including the regulation of pollen tube and root growth, and that GABA can finally be considered a legitimate signalling molecule in both the plant and animal kingdoms.

  9. Hydrodistillation-adsorption method for the isolation of water-soluble, non-soluble and high volatile compounds from plant materials.

    Science.gov (United States)

    Mastelić, J; Jerković, I; Blazević, I; Radonić, A; Krstulović, L

    2008-08-15

    Proposed method of hydrodistillation-adsorption (HDA) on activated carbon and hydrodistillation (HD) with solvent trap were compared for the isolation of water-soluble, non-soluble and high volatile compounds, such as acids, monoterpenes, isothiocyanates and others from carob (Certonia siliqua L.), rosemary (Rosmarinus officinalis L.) and rocket (Eruca sativa L.). Isolated volatiles were analyzed by GC and GC/MS. The main advantages of HDA method over ubiquitous HD method were higher yields of volatile compounds and their simultaneous separation in three fractions that enabled more detail analyses. This method is particularly suitable for the isolation and analysis of the plant volatiles with high amounts of water-soluble compounds. In distinction from previously published adsorption of remaining volatile compounds from distillation water on activated carbon, this method offers simultaneous hydrodistillation and adsorption in the same apparatus.

  10. Effect of plant growth regulators on callus induction and plant ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-03

    Jun 3, 2009 ... toum state and later spread to other part of the country ..... Effect of different concentrations of IBA and MS salt strength on rooting percentage, ... study for tissue culture of potato can get enough callus and plant regeneration efficiency to perform transgenic operation. Moreover, as the potentiality of shoot ...

  11. Mathematical Modelling of Supercritical CO2 Extraction of Volatile Oils from Aromatic Plants

    Czech Academy of Sciences Publication Activity Database

    Grosso, C.; Coelho, J.P.; Pessoa, F.L.P.; Fareleira, J.M.N.A.; Barroso, J.G.; Urieta, J.S.; Palavra, A.F.; Sovová, Helena

    2010-01-01

    Roč. 65, č. 11 (2010), s. 3579-3590 ISSN 0009-2509 Institutional research plan: CEZ:AV0Z40720504 Keywords : supercritical fluid extraction * modelling * volatile oils Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.379, year: 2010

  12. Extraction of Volatile Oil from Aromatic Plants with Supercritical Carbon Dioxide: Experiments and Modeling

    Czech Academy of Sciences Publication Activity Database

    Coelho, J.P.; Cristino, A.F.; Matos, P.G.; Rauter, A.P.; Nobre, B.P.; Mendes, R.L.; Barroso, J.G.; Mainar, A.; Urieta, J.S.; Fareleira, J.M.N.A.; Sovová, Helena; Palavra, A.F.

    2012-01-01

    Roč. 17, č. 9 (2012), s. 10550-10573 ISSN 1420-3049 Grant - others:FST(PT) SFRH/BPD/42004/2007; FST(PT) SFRH/BD/48596/2008 Institutional support: RVO:67985858 Keywords : essential oils * volatile iols * supercritical fluids Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.428, year: 2012

  13. Emission of climate relevant volatile organochlorines by plants occurring in temperate forests

    Czech Academy of Sciences Publication Activity Database

    Forczek, Sándor; Laturnus, F.; Doležalová, Jana; Holík, Josef; Wimmer, Zdeněk

    2015-01-01

    Roč. 61, č. 3 (2015), s. 103-108 ISSN 1214-1178 R&D Projects: GA ČR GA13-11101S Institutional support: RVO:61389030 Keywords : volatile chlorinated hydrocarbons * biodegradation * Sphagnum moss Subject RIV: EF - Botanics Impact factor: 1.039, year: 2015

  14. Chloride – a precursor in the formation of volatile organochlorines by forest plants?

    Czech Academy of Sciences Publication Activity Database

    Laturnus, F.; Matucha, Miroslav

    2008-01-01

    Roč. 99, č. 1 (2008), s. 119-125 ISSN 0265-931X R&D Projects: GA ČR GA526/05/0636 Institutional research plan: CEZ:AV0Z50380511 Keywords : 36Chloride * Volatile Organochlorines * VOCl Subject RIV: DF - Soil Science Impact factor: 1.114, year: 2008

  15. 78 FR 79636 - Restructuring of Regulations on the Importation of Plants for Planting

    Science.gov (United States)

    2013-12-31

    ... in Washington, DC, this 20th day of December 2013. Kevin Shea, Administrator, Animal and Plant Health... DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection Service 7 CFR Parts 319 and 340 [Docket No. APHIS-2008-0011] RIN 0579-AD75 Restructuring of Regulations on the Importation of Plants for...

  16. Regulations and guides for nuclear power plants

    International Nuclear Information System (INIS)

    1984-01-01

    The purpose of the present Guide is to provide information, guidance and recommendations to assist the regulatory body of a Member State in establishing its own regulations and guides. It discusses the purpose, the method and procedure of establishment, and the content and legal status of these documents, and it explains how to use the Codes of Practice and Safety Guides issued by the IAEA under the Nuclear Safety Standards (NUSS) programme. Certain aspects of how to use other international standards and appropriate regulations and guides from other countries are discussed

  17. Environmental Growth Conditions of Trichoderma spp. Affects Indole Acetic Acid Derivatives, Volatile Organic Compounds, and Plant Growth Promotion

    Science.gov (United States)

    Nieto-Jacobo, Maria F.; Steyaert, Johanna M.; Salazar-Badillo, Fatima B.; Nguyen, Dianne Vi; Rostás, Michael; Braithwaite, Mark; De Souza, Jorge T.; Jimenez-Bremont, Juan F.; Ohkura, Mana; Stewart, Alison

    2017-01-01

    Trichoderma species are soil-borne filamentous fungi widely utilized for their many plant health benefits, such as conferring improved growth, disease resistance and abiotic stress tolerance to their hosts. Many Trichoderma species are able to produce the auxin phytohormone indole-3-acetic acid (IAA), and its production has been suggested to promote root growth. Here we show that the production of IAA is strain dependent and diverse external stimuli are associated with its production. In in vitro assays, Arabidopsis primary root length was negatively affected by the interaction with some Trichoderma strains. In soil experiments, a continuum effect on plant growth was shown and this was also strain dependent. In plate assays, some strains of Trichoderma spp. inhibited the expression of the auxin reporter gene DR5 in Arabidopsis primary roots but not secondary roots. When Trichoderma spp. and A. thaliana were physically separated, enhancement of both shoot and root biomass, increased root production and chlorophyll content were observed, which strongly suggested that volatile production by the fungus influenced the parameters analyzed. Trichoderma strains T. virens Gv29.8, T. atroviride IMI206040, T. sp. “atroviride B” LU132, and T. asperellum LU1370 were demonstrated to promote plant growth through volatile production. However, contrasting differences were observed with LU1370 which had a negative effect on plant growth in soil but a positive effect in plate assays. Altogether our results suggest that the mechanisms and molecules involved in plant growth promotion by Trichoderma spp. are multivariable and are affected by the environmental conditions. PMID:28232840

  18. Genetic analysis of plant endophytic Pseudomonas putida BP25 and chemo-profiling of its antimicrobial volatile organic compounds.

    Science.gov (United States)

    Sheoran, Neelam; Valiya Nadakkakath, Agisha; Munjal, Vibhuti; Kundu, Aditi; Subaharan, Kesavan; Venugopal, Vibina; Rajamma, Suseelabhai; Eapen, Santhosh J; Kumar, Aundy

    2015-04-01

    Black pepper associated bacterium BP25 was isolated from root endosphere of apparently healthy cultivar Panniyur-5 that protected black pepper against Phytophthora capsici and Radopholus similis - the major production constraints. The bacterium was characterized and mechanisms of its antagonistic action against major pathogens are elucidated. The polyphasic phenotypic analysis revealed its identity as Pseudomonas putida. Multi locus sequence typing revealed that the bacterium shared gene sequences with several other isolates representing diverse habitats. Tissue localization assays exploiting green fluorescence protein expression clearly indicated that PpBP25 endophytically colonized not only its host plant - black pepper, but also other distantly related plants such as ginger and arabidopsis. PpBP25 colonies could be enumerated from internal tissues of plants four weeks post inoculation indicated its stable establishment and persistence in the plant system. The bacterium inhibited broad range of pathogens such as Phytophthora capsici, Pythium myriotylum, Giberella moniliformis, Rhizoctonia solani, Athelia rolfsii, Colletotrichum gloeosporioides and plant parasitic nematode, Radopholus similis by its volatile substances. GC/MS based chemical profiling revealed presence of Heneicosane; Tetratetracontane; Pyrrolo [1,2-a] pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl); Tetracosyl heptafluorobutyrate; 1-3-Eicosene, (E)-; 1-Heneicosanol; Octadecyl trifluoroacetate and 1-Pentadecene in PpBP25 metabolite. Dynamic head space GC/MS analysis of airborne volatiles indicated the presence of aromatic compounds such as 1-Undecene;Disulfide dimethyl; Pyrazine, methyl-Pyrazine, 2,5-dimethyl-; Isoamyl alcohol; Pyrazine, methyl-; Dimethyl trisulfide, etc. The work paved way for profiling of broad spectrum antimicrobial VOCs in endophytic PpBP25 for crop protection. Copyright © 2015 Elsevier GmbH. All rights reserved.

  19. Determination of volatile organic compounds from biowaste and co-fermentation biogas plants by single-sorbent adsorption.

    Science.gov (United States)

    Salazar Gómez, J I; Lohmann, H; Krassowski, J

    2016-06-01

    Characterisation of biogases is normally dedicated to the online monitoring of the major components methane and carbon dioxide and, to a lesser extent, to the determination of ammonia and hydrogen sulphide. For the case of Volatile Organic Compounds (VOCs), much less attention is usually paid, since such compounds are normally removed during gas conditioning and with exception of sulphur compounds and siloxanes represent a rather low risk to conventional downstream devices but could be a hindrance for fuel cells. However, there is very little information in the literature about the type of substances found in biogases generated from biowaste or co-fermentation plants and their concentration fluctuations. The main aim of this study was to provide information about the time dependencies of the VOCs in three biogas plants spread out through Germany from autumn until summer, which have different process control, in order to assess their potential as biofuels. Additionally, this study was an attempt to establish a correlation between the nature of the substrates used in the biogas plants and the composition of the VOCs present in the gas phase. Significant time-dependent variations in concentration were observed for most VOCs but only small changes in composition were observed. In general, terpenes and ketones appeared as the predominant VOCs in biogas. Although for substances such as esters, sulphur-organic compounds and siloxanes the average concentrations observed were rather low, they exhibited significant concentration peaks. The second biogas plant which operates with dry fermentation was found to contain the highest levels of VOCs. The amount of total volatile organic compounds (TVOCs) for the first, second and third biogas plants ranged from 35 to 259 mg Nm(-3), 291-1731 mg Nm(-3) and 84-528 mg Nm(-3), respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Study of the removal difference in indoor particulate matter and volatile organic compounds through the application of plants

    Directory of Open Access Journals (Sweden)

    Seung-Han Hong

    2017-02-01

    Full Text Available This study was conducted to evaluate the ability of plants to purify indoor air by observing the effective reduction rate among pollutant types of particulate matter (PM and volatile organic compounds (VOCs. PM and four types of VOCs were measured in a new building that is less than three years old and under three different conditions: before applying the plant, after applying the plant, and a room without a plant. The removal rate of each pollutant type due to the plant was also compared and analyzed. In the case of indoor PM, the removal effect was negligible because of outdoor influence. However, 9% of benzene, 75% of ethylbenzene, 72% of xylene, 75% of styrene, 50% of formaldehyde, 36% of acetaldehyde, 35% of acrolein with acetone, and 85% of toluene were reduced. The purification of indoor air by natural ventilation is meaningless because the ambient PM concentration has recently been high. However, contamination by gaseous materials such as VOCs can effectively be removed through the application of plants.

  1. Role of volatiles emitted by host and non-host plants in the foraging behaviour of Dentichasmias busseolae, a pupal parasitoid of the spotted stemborer Chilo partellus

    NARCIS (Netherlands)

    Gohole, L.S.; Overholt, W.A.; Khan, Z.R.; Vet, L.E.M.

    2003-01-01

    The role of volatiles from stemborer host and non-host plants in the host-finding process of Dentichasmias busseolae Heinrich (Hymenoptera: Ichneumonidae) a pupal parasitoid of Chilo partellus (Swinhoe) (Lepidoptera: Crambidae) was studied. The non-host plant, molasses grass (Melinis minutiflora

  2. Novel synthetic compounds enhance the attractiveness of host-plant volatiles: An opportunity to boost detection and monitoring of Asian citrus psyllid?

    Science.gov (United States)

    In the absence of pheromone attractants, host-plant volatiles offer the most likely means of improving capture levels of Asian citrus psyllid (ACP) with sticky cards and other types of visual traps. However, developing scent lures that can compete with the attractiveness of actual host-plants, espe...

  3. Predatory Mite Attraction to Herbivore-induced Plant Odors is not a Consequence of Attraction to Individual Herbivore-induced Plant Volatiles

    Science.gov (United States)

    De Bruijn, Paulien J. A.; Sabelis, Maurice W.

    2008-01-01

    Predatory mites locate herbivorous mites, their prey, by the aid of herbivore-induced plant volatiles (HIPV). These HIPV differ with plant and/or herbivore species, and it is not well understood how predators cope with this variation. We hypothesized that predators are attracted to specific compounds in HIPV, and that they can identify these compounds in odor mixtures not previously experienced. To test this, we assessed the olfactory response of Phytoseiulus persimilis, a predatory mite that preys on the highly polyphagous herbivore Tetranychus urticae. The responses of the predatory mite to a dilution series of each of 30 structurally different compounds were tested. They mites responded to most of these compounds, but usually in an aversive way. Individual HIPV were no more attractive (or less repellent) than out-group compounds, i.e., volatiles not induced in plants fed upon by spider-mites. Only three samples were significantly attractive to the mites: octan-1-ol, not involved in indirect defense, and cis-3-hexen-1-ol and methyl salicylate, which are both induced by herbivory, but not specific for the herbivore that infests the plant. Attraction to individual compounds was low compared to the full HIPV blend from Lima bean. These results indicate that individual HIPV have no a priori meaning to the mites. Hence, there is no reason why they could profit from an ability to identify individual compounds in odor mixtures. Subsequent experiments confirmed that naive predatory mites do not prefer tomato HIPV, which included the attractive compound methyl salicylate, over the odor of an uninfested bean. However, upon associating each of these odors with food over a period of 15 min, both are preferred. The memory to this association wanes within 24 hr. We conclude that P. persimilis possesses a limited ability to identify individual spider mite-induced plant volatiles in odor mixtures. We suggest that predatory mites instead learn to respond to prey

  4. Circadian regulation of hormone signaling and plant physiology.

    Science.gov (United States)

    Atamian, Hagop S; Harmer, Stacey L

    2016-08-01

    The survival and reproduction of plants depend on their ability to cope with a wide range of daily and seasonal environmental fluctuations during their life cycle. Phytohormones are plant growth regulators that are involved in almost every aspect of growth and development as well as plant adaptation to myriad abiotic and biotic conditions. The circadian clock, an endogenous and cell-autonomous biological timekeeper that produces rhythmic outputs with close to 24-h rhythms, provides an adaptive advantage by synchronizing plant physiological and metabolic processes to the external environment. The circadian clock regulates phytohormone biosynthesis and signaling pathways to generate daily rhythms in hormone activity that fine-tune a range of plant processes, enhancing adaptation to local conditions. This review explores our current understanding of the interplay between the circadian clock and hormone signaling pathways.

  5. Chemical Growth Regulators for Guayule Plants

    Science.gov (United States)

    Dastoor, M. N.; Schubert, W. W.; Petersen, G. R.

    1982-01-01

    Test Tubes containing Guayule - tissue cultures were used in experiments to test effects of chemical-growth regulators. The shoots grew in response to addition of 2-(3,4-dichlorophenoxy)-triethylamine (triethylamine (TEA) derivative) to agar medium. Preliminary results indicate that a class of compounds that promotes growth in soil may also promote growth in a culture medium. Further experiments are needed to define the effect of the TEA derivative.

  6. Data from: Compatible and incompatible pathogen-plant interactions differentially affect plant volatile emissions and the attraction of parasitoid wasps

    NARCIS (Netherlands)

    Ponzio, C.A.M.; Weldegergis, B.T.; Dicke, M.; Gols, R.

    2016-01-01

    The three data sheets show the data for the three types of comparisons that were made: (1) wasp choice when offered acaterpillar infested plant and a caterpillar + pathogen infected plant (2) wasp choice when offered a healthy plant against a singleattacker infected/infected plant and (3) wasp

  7. Evolution of allosteric regulation in chorismate mutases from early plants

    Energy Technology Data Exchange (ETDEWEB)

    Kroll, Kourtney; Holland, Cynthia K.; Starks, Courtney M.; Jez, Joseph M.

    2017-09-28

    Plants, fungi, and bacteria synthesize the aromatic amino acids: l-phenylalanine, l-tyrosine, and l-tryptophan. Chorismate mutase catalyzes the branch point reaction of phenylalanine and tyrosine biosynthesis to generate prephenate. In Arabidopsis thaliana, there are two plastid-localized chorismate mutases that are allosterically regulated (AtCM1 and AtCM3) and one cytosolic isoform (AtCM2) that is unregulated. Previous analysis of plant chorismate mutases suggested that the enzymes from early plants (i.e. bryophytes/moss, lycophytes, and basal angiosperms) formed a clade distinct from the isoforms found in flowering plants; however, no biochemical information on these enzymes is available. To understand the evolution of allosteric regulation in plant chorismate mutases, we analyzed a basal lineage of plant enzymes homologous to AtCM1 based on sequence similarity. The chorismate mutases from the moss/bryophyte Physcomitrella patens (PpCM1 and PpCM2), the lycophyte Selaginella moellendorffii (SmCM), and the basal angiosperm Amborella trichopoda (AmtCM1 and AmtCM2) were characterized biochemically. Tryptophan was a positive effector for each of the five enzymes examined. Histidine was a weak positive effector for PpCM1 and AmtCM1. Neither tyrosine nor phenylalanine altered the activity of SmCM; however, tyrosine was a negative regulator of the other four enzymes. Phenylalanine down-regulates both moss enzymes and AmtCM2. The 2.0 Å X-ray crystal structure of PpCM1 in complex with the tryptophan identified the allosteric effector site and reveals structural differences between the R- (more active) and T-state (less active) forms of plant chorismate mutases. Molecular insight into the basal plant chorismate mutases guides our understanding of the evolution of allosteric regulation in these enzymes.

  8. Methylobacterium-plant interaction genes regulated by plant exudate and quorum sensing molecules

    Directory of Open Access Journals (Sweden)

    Manuella Nóbrega Dourado

    2013-12-01

    Full Text Available Bacteria from the genus Methylobacterium interact symbiotically (endophytically and epiphytically with different plant species. These interactions can promote plant growth or induce systemic resistance, increasing plant fitness. The plant colonization is guided by molecular communication between bacteria-bacteria and bacteria-plants, where the bacteria recognize specific exuded compounds by other bacteria (e.g. homoserine molecules and/or by the plant roots (e.g. flavonoids, ethanol and methanol, respectively. In this context, the aim of this study was to evaluate the effect of quorum sensing molecules (N-acyl-homoserine lactones and plant exudates (including ethanol in the expression of a series of bacterial genes involved in Methylobacterium-plant interaction. The selected genes are related to bacterial metabolism (mxaF, adaptation to stressful environment (crtI, phoU and sss, to interactions with plant metabolism compounds (acdS and pathogenicity (patatin and phoU. Under in vitro conditions, our results showed the differential expression of some important genes related to metabolism, stress and pathogenesis, thereby AHL molecules up-regulate all tested genes, except phoU, while plant exudates induce only mxaF gene expression. In the presence of plant exudates there is a lower bacterial density (due the endophytic and epiphytic colonization, which produce less AHL, leading to down regulation of genes when compared to the control. Therefore, bacterial density, more than plant exudate, influences the expression of genes related to plant-bacteria interaction.

  9. Two Volatile Organic Compounds Trigger Plant Self-Defense against a Bacterial Pathogen and a Sucking Insect in Cucumber under Open Field Conditions

    Directory of Open Access Journals (Sweden)

    Choong-Min Ryu

    2013-05-01

    Full Text Available Systemic acquired resistance (SAR is a plant self-defense mechanism against a broad-range of pathogens and insect pests. Among chemical SAR triggers, plant and bacterial volatiles are promising candidates for use in pest management, as these volatiles are highly effective, inexpensive, and can be employed at relatively low concentrations compared with agrochemicals. However, such volatiles have some drawbacks, including the high evaporation rate of these compounds after application in the open field, their negative effects on plant growth, and their inconsistent levels of effectiveness. Here, we demonstrate the effectiveness of volatile organic compound (VOC-mediated induced resistance against both the bacterial angular leaf spot pathogen, Pseudononas syringae pv. lachrymans, and the sucking insect aphid, Myzus persicae, in the open field. Using the VOCs 3-pentanol and 2-butanone where fruit yields increased gave unexpectedly, a significant increase in the number of ladybird beetles, Coccinella septempunctata, a natural enemy of aphids. The defense-related gene CsLOX was induced by VOC treatment, indicating that triggering the oxylipin pathway in response to the emission of green leaf volatiles can recruit the natural enemy of aphids. These results demonstrate that VOCs may help prevent plant disease and insect damage by eliciting induced resistance, even in open fields.

  10. Occupational hygiene in terms of volatile organic compounds (VOCs) and bioaerosols at two solid waste management plants in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Lehtinen, Jenni, E-mail: jenni.k.lehtinen@jyu.fi [University of Jyväskylä, Department of Biological and Environmental Science, P.O. Box 35, 40014 Jyväskylä (Finland); Tolvanen, Outi; Nivukoski, Ulla; Veijanen, Anja; Hänninen, Kari [University of Jyväskylä, Department of Biological and Environmental Science, P.O. Box 35, 40014 Jyväskylä (Finland)

    2013-04-15

    Highlights: ► Odorous VOCs: acetic acid, 2,3-butanedione, ethyl acetate, alpha-pinene and limonene. ► VOC concentrations did not exceed occupational exposure limit concentrations. ► 2,3-Butanedione as the health effecting compound is discussed. ► Endotoxin concentrations may cause health problems in waste treatment. - Abstract: Factors affecting occupational hygiene were measured at the solid waste transferring plant at Hyvinkää and at the optic separation plant in Hämeenlinna. Measurements consisted of volatile organic compounds (VOCs) and bioaerosols including microbes, dust and endotoxins. The most abundant compounds in both of the plants were aliphatic and aromatic hydrocarbons, esters of carboxylic acids, ketones and terpenes. In terms of odour generation, the most important emissions were acetic acid, 2,3-butanedione, ethyl acetate, alpha-pinene and limonene due to their low threshold odour concentrations. At the optic waste separation plant, limonene occurred at the highest concentration of all single compounds of identified VOCs. The concentration of any single volatile organic compound did not exceed the occupational exposure limit (OEL) concentration. However, 2,3-butanedione as a health risk compound is discussed based on recent scientific findings linking it to lung disease. Microbe and dust concentrations were low at the waste transferring plant. Only endotoxin concentrations may cause health problems; the average concentration inside the plant was 425 EU/m{sup 3} which clearly exceeded the threshold value of 90 EU/m{sup 3}. In the wheel loader cabin the endotoxin concentrations were below 1 EU/m{sup 3}. High microbial and endotoxin concentrations were measured in the processing hall at the optic waste separation plant. The average concentration of endotoxins was found to be 10,980 EU/m{sup 3}, a concentration which may cause health risks. Concentrations of viable fungi were quite high in few measurements in the control room. The most

  11. Occupational hygiene in terms of volatile organic compounds (VOCs) and bioaerosols at two solid waste management plants in Finland

    International Nuclear Information System (INIS)

    Lehtinen, Jenni; Tolvanen, Outi; Nivukoski, Ulla; Veijanen, Anja; Hänninen, Kari

    2013-01-01

    Highlights: ► Odorous VOCs: acetic acid, 2,3-butanedione, ethyl acetate, alpha-pinene and limonene. ► VOC concentrations did not exceed occupational exposure limit concentrations. ► 2,3-Butanedione as the health effecting compound is discussed. ► Endotoxin concentrations may cause health problems in waste treatment. - Abstract: Factors affecting occupational hygiene were measured at the solid waste transferring plant at Hyvinkää and at the optic separation plant in Hämeenlinna. Measurements consisted of volatile organic compounds (VOCs) and bioaerosols including microbes, dust and endotoxins. The most abundant compounds in both of the plants were aliphatic and aromatic hydrocarbons, esters of carboxylic acids, ketones and terpenes. In terms of odour generation, the most important emissions were acetic acid, 2,3-butanedione, ethyl acetate, alpha-pinene and limonene due to their low threshold odour concentrations. At the optic waste separation plant, limonene occurred at the highest concentration of all single compounds of identified VOCs. The concentration of any single volatile organic compound did not exceed the occupational exposure limit (OEL) concentration. However, 2,3-butanedione as a health risk compound is discussed based on recent scientific findings linking it to lung disease. Microbe and dust concentrations were low at the waste transferring plant. Only endotoxin concentrations may cause health problems; the average concentration inside the plant was 425 EU/m 3 which clearly exceeded the threshold value of 90 EU/m 3 . In the wheel loader cabin the endotoxin concentrations were below 1 EU/m 3 . High microbial and endotoxin concentrations were measured in the processing hall at the optic waste separation plant. The average concentration of endotoxins was found to be 10,980 EU/m 3 , a concentration which may cause health risks. Concentrations of viable fungi were quite high in few measurements in the control room. The most problematic factor was

  12. Cellular growth in plants requires regulation of cell wall biochemistry.

    Science.gov (United States)

    Chebli, Youssef; Geitmann, Anja

    2017-02-01

    Cell and organ morphogenesis in plants are regulated by the chemical structure and mechanical properties of the extracellular matrix, the cell wall. The two primary load bearing components in the plant cell wall, the pectin matrix and the cellulose/xyloglucan network, are constantly remodelled to generate the morphological changes required during plant development. This remodelling is regulated by a plethora of loosening and stiffening agents such as pectin methyl-esterases, calcium ions, expansins, and glucanases. The tight spatio-temporal regulation of the activities of these agents is a sine qua non condition for proper morphogenesis at cell and tissue levels. The pectin matrix and the cellulose-xyloglucan network operate in concert and their behaviour is mutually dependent on their chemical, structural and mechanical modifications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Carbon Catabolite Repression Regulates the Production of the Unique Volatile Sodorifen of Serratia plymuthica 4Rx13

    Directory of Open Access Journals (Sweden)

    Nancy Magnus

    2017-12-01

    Full Text Available Microorganisms are capable of synthesizing a plethora of secondary metabolites including the long-overlooked volatile organic compounds. Little knowledge has been accumulated regarding the regulation of the biosynthesis of such mVOCs. The emission of the unique compound sodorifen of Serratia plymuthica isolates was significantly reduced in minimal medium with glucose, while succinate elevated sodorifen release. The hypothesis of carbon catabolite repression (CCR acting as a major control entity on the synthesis of mVOCs was proven by genetic evidence. Central components of the typical CCR of Gram-negative bacteria such as the adenylate cyclase (CYA, the cAMP binding receptor protein (CRP, and the catabolite responsive element (CRE were removed by insertional mutagenesis. CYA, CRP, CRE1 mutants revealed a lower sodorifen release. Moreover, the emission potential of other S. plymuthica isolates was also evaluated.

  14. The influence of volatile semiochemicals from stink bug eggs and oviposition-damaged plants on the foraging behaviour of the egg parasitoid Telenomus podisi.

    Science.gov (United States)

    Michereff, M F F; Borges, M; Aquino, M F S; Laumann, R A; Mendes Gomes, A C M; Blassioli-Moraes, M C

    2016-10-01

    During host selection, physical and chemical stimuli provide important cues that modify search behaviours of natural enemies. We evaluated the influence of volatiles released by eggs and egg extracts of the stink bug Euschistus heros and by soybean plants treated with the eggs and egg extracts on Telenomus podisi foraging behaviour. Responses to volatiles were evaluated in Y-tube olfactometers after exposure to (1) one egg cluster for 24 h; (2) plants with eggs laid by the stink bug, tested at 24, 48, and 72 h after treatment; (3) plants with eggs laid artificially, tested at 24, 48, and 72 h after treatment; and (4) plants treated with acetone or hexane extracts of eggs. Telenomus podisi was attracted to volatiles emitted by one egg cluster and to acetone extracts of one egg cluster, but not to air or acetone controls. There were no responses to odours of plants treated with eggs or egg extracts. Analysis of acetone extracts of egg clusters by gas chromatography revealed the major components were saturated and unsaturated fatty acids, including hexadecanoic acid, linoleic acid, and (Z)-9-octadecenoic acid. Our results suggest that one egg cluster and the acetone extract of one egg cluster contain volatile compounds that can modify T. podisi foraging behaviour, and that the amounts of these compounds, probably together with some minor compounds, are important for host recognition by T. podisi. Also, the oviposition damage or egg extracts on the plant did not elicit indirect defences that attracted Telenomus podisi.

  15. VUV and soft x-ray ionization of a plant volatile: Vanillin (C8H8O3)

    Science.gov (United States)

    Betancourt, A. Moreno; Coutinho, L. H.; Bernini, R. B.; de Moura, C. E. V.; Rocha, A. B.; de Souza, G. G. B.

    2016-03-01

    Plant volatiles are emitted by plants in response to several forms of stress, including interaction with energetic photons. In the present work, we discuss the interaction of extreme UV and soft X-ray photons with a plant volatile, vanillin. The single and double (multiple) ionization of the vanillin molecule have been studied for the first time using time-of-flight mass spectrometry and VUV and soft X-ray photons (synchrotron radiation, at 12.0 eV, 21.2 eV, 130 eV, 310 eV, 531 eV, and 550 eV). At 12.0 and 21.2 eV, only singly charged species are observed and the parent ion, C8H8O3+, is the dominant species. Energy differences for some selected fragments were calculated theoretically in this energy region. At 130 eV, direct double and triple ionization of the valence electrons may occur. The fragmentation increases and CHO+ becomes one of the main cations in the mass spectrum. The molecular ion is still the dominant species, but other fragments, such as C6H5O+, begin to present similar intensities. At 310 eV, C 1s electrons may be ionized and Auger processes give rise to dissociative doubly ionized cations. Ionization around the O 1s edge has been studied both at the 531 eV resonance and above the ionization edge. Resonant and normal Auger processes play a significant role in each case and a large fragmentation of the molecule is observed at both photon energies, with intense fragments such as CHO+ and CH3+ being clearly observed. A near edge X-ray absorption fine structure spectrum of the vanillin molecule was obtained around the O 1s ionization threshold. In addition, the fragmentation of vanillin has also been studied using a fast beam of electrons (800 eV), for the sake of comparison.

  16. VUV and soft x-ray ionization of a plant volatile: Vanillin (C8H8O3)

    International Nuclear Information System (INIS)

    Betancourt, A. Moreno; Moura, C. E. V. de; Rocha, A. B.; Souza, G. G. B. de; Coutinho, L. H.; Bernini, R. B.

    2016-01-01

    Plant volatiles are emitted by plants in response to several forms of stress, including interaction with energetic photons. In the present work, we discuss the interaction of extreme UV and soft X-ray photons with a plant volatile, vanillin. The single and double (multiple) ionization of the vanillin molecule have been studied for the first time using time-of-flight mass spectrometry and VUV and soft X-ray photons (synchrotron radiation, at 12.0 eV, 21.2 eV, 130 eV, 310 eV, 531 eV, and 550 eV). At 12.0 and 21.2 eV, only singly charged species are observed and the parent ion, C 8 H 8 O 3 + , is the dominant species. Energy differences for some selected fragments were calculated theoretically in this energy region. At 130 eV, direct double and triple ionization of the valence electrons may occur. The fragmentation increases and CHO + becomes one of the main cations in the mass spectrum. The molecular ion is still the dominant species, but other fragments, such as C 6 H 5 O + , begin to present similar intensities. At 310 eV, C 1s electrons may be ionized and Auger processes give rise to dissociative doubly ionized cations. Ionization around the O 1s edge has been studied both at the 531 eV resonance and above the ionization edge. Resonant and normal Auger processes play a significant role in each case and a large fragmentation of the molecule is observed at both photon energies, with intense fragments such as CHO + and CH 3 + being clearly observed. A near edge X-ray absorption fine structure spectrum of the vanillin molecule was obtained around the O 1s ionization threshold. In addition, the fragmentation of vanillin has also been studied using a fast beam of electrons (800 eV), for the sake of comparison.

  17. The Active Jasmonate JA-Ile Regulates a Specific Subset of Plant Jasmonate-Mediated Resistance to Herbivores in Nature

    Directory of Open Access Journals (Sweden)

    Meredith C. Schuman

    2018-06-01

    Full Text Available The jasmonate hormones are essential regulators of plant defense against herbivores and include several dozen derivatives of the oxylipin jasmonic acid (JA. Among these, the conjugate jasmonoyl isoleucine (JA-Ile has been shown to interact directly with the jasmonate co-receptor complex to regulate responses to jasmonate signaling. However, functional studies indicate that some aspects of jasmonate-mediated defense are not regulated by JA-Ile. Thus, it is not clear whether JA-Ile is best characterized as the master jasmonate regulator of defense, or if it regulates more specific aspects. We investigated possible functions of JA-Ile in anti-herbivore resistance of the wild tobacco Nicotiana attenuata, a model system for plant-herbivore interactions. We first analyzed the soluble and volatile secondary metabolomes of irJAR4xirJAR6, asLOX3, and WT plants, as well as an RNAi line targeting the jasmonate co-receptor CORONATINE INSENSITIVE 1 (irCOI1, following a standardized herbivory treatment. irJAR4xirJAR6 were the most similar to WT plants, having a ca. 60% overlap in differentially regulated metabolites with either asLOX3 or irCOI1. In contrast, while at least 25 volatiles differed between irCOI1 or asLOX3 and WT plants, there were few or no differences in herbivore-induced volatile emission between irJAR4xirJAR6 and WT plants, in glasshouse- or field-collected samples. We then measured the susceptibility of jasmonate-deficient vs. JA-Ile-deficient plants in nature, in comparison to wild-type (WT controls, and found that JA-Ile-deficient plants (irJAR4xirJAR6 are much better defended even than a mildly jasmonate-deficient line (asLOX3. The differences among lines could be attributed to differences in damage from specific herbivores, which appeared to prefer either one or the other jasmonate-deficient phenotype. We further investigated the elicitation of one herbivore-induced volatile known to be jasmonate-regulated and to mediate resistance to

  18. Ozone exposure triggers the emission of herbivore-induced plant volatiles, but does not disturb tritrophic signalling

    Energy Technology Data Exchange (ETDEWEB)

    Vuorinen, Terhi; Nerg, Anne-Marja; Holopainen, Jarmo K

    2004-09-01

    We evaluated the similarities between ozone-induced and mite-induced emission of volatile organic compounds (VOCs) from lima beans, and tested the response of the natural enemies of herbivores to these emissions using trophic system of two-spotted spider mites and predatory mites. The acute ozone-exposure and spider mite-infestation induced the emission of two homoterpenes, (E)-4,8-dimethyl-1,3,7-nonatriene and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene, and (Z)-3-hexenyl acetate. Only plants with spider mite-infestation emitted the monoterpene (E)-{beta}-ocimene. Predatory mites were equally attracted to ozone-exposed and unexposed plants, but discriminated between spider mite-infested and uninfested plants, when both were exposed to ozone. The similarities between ozone and herbivore-induced VOCs suggest that plant defence against phytotoxic ozone and the production of VOCs for attraction of the natural enemies of herbivores may have adaptive coevolution. However, the expected elevated ozone concentrations in future may not disturb tritrophic signalling, unless herbivore-induced VOCs are lost in the process of aerosol formation.

  19. Ozone exposure triggers the emission of herbivore-induced plant volatiles, but does not disturb tritrophic signalling

    International Nuclear Information System (INIS)

    Vuorinen, Terhi; Nerg, Anne-Marja; Holopainen, Jarmo K.

    2004-01-01

    We evaluated the similarities between ozone-induced and mite-induced emission of volatile organic compounds (VOCs) from lima beans, and tested the response of the natural enemies of herbivores to these emissions using trophic system of two-spotted spider mites and predatory mites. The acute ozone-exposure and spider mite-infestation induced the emission of two homoterpenes, (E)-4,8-dimethyl-1,3,7-nonatriene and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene, and (Z)-3-hexenyl acetate. Only plants with spider mite-infestation emitted the monoterpene (E)-β-ocimene. Predatory mites were equally attracted to ozone-exposed and unexposed plants, but discriminated between spider mite-infested and uninfested plants, when both were exposed to ozone. The similarities between ozone and herbivore-induced VOCs suggest that plant defence against phytotoxic ozone and the production of VOCs for attraction of the natural enemies of herbivores may have adaptive coevolution. However, the expected elevated ozone concentrations in future may not disturb tritrophic signalling, unless herbivore-induced VOCs are lost in the process of aerosol formation

  20. Modeling and monitoring cyclic and linear volatile methylsiloxanes in a wastewater treatment plant using constant water level sequencing batch reactors

    Energy Technology Data Exchange (ETDEWEB)

    Wang, De-Gao, E-mail: degaowang@dlmu.edu.cn; Du, Juan; Pei, Wei; Liu, Yongjun; Guo, Mingxing

    2015-04-15

    The fate of cyclic and linear volatile methylsiloxanes (VMSs) was evaluated in a wastewater treatment plant (WWTP) using constant water level sequencing batch reactors from Dalian, China. Influent, effluent, and sewage sludge samples were collected for seven consecutive days. The mean concentrations of cyclic VMSs (cVMSs) in influent and effluent samples are 1.05 μg L{sup −1} and 0.343 μg L{sup −1}; the total removal efficiency of VMSs is > 60%. Linear VMS (lVMS) concentration is under the quantification limitation in aquatic samples but is found in sludge samples with a value of 90 μg kg{sup −1}. High solid-water partition coefficients result in high VMS concentrations in sludge with the mean value of 5030 μg kg{sup −1}. No significant differences of the daily mass flows are found when comparing the concentration during the weekend and during working days. The estimated mass load of total cVMSs is 194 mg d{sup −1} 1000 inhabitants{sup −1} derived for the population. A mass balance model of the WWTP was developed and derived to simulate the fate of cVMSs. The removal by sorption on sludge increases, and the volatilization decreases with increasing hydrophobicity and decreasing volatility for cVMSs. Sensitivity analysis shows that the total suspended solid concentration in the effluent, mixed liquor suspended solid concentration, the sewage sludge flow rate, and the influent flow rate are the most influential parameters on the mass distribution of cVMSs in this WWTP. - Highlights: • A mass balance model for siloxanes was developed in sequencing batch reactor. • Total suspended solid in effluent has the most influence on removal efficiency. • Enhancement of suspended solid removal reduces the release to aquatic environment.

  1. Analysis of carbon emission regulations in supply chains with volatile demand.

    Science.gov (United States)

    2014-07-01

    This study analyzes an inventory control problem of a company in stochastic demand environment under carbon emissions : regulations. In particular, a continuous review inventory model with multiple suppliers is investigated under carbon taxing and ca...

  2. Auxin-BR Interaction Regulates Plant Growth and Development

    Science.gov (United States)

    Tian, Huiyu; Lv, Bingsheng; Ding, Tingting; Bai, Mingyi; Ding, Zhaojun

    2018-01-01

    Plants develop a high flexibility to alter growth, development, and metabolism to adapt to the ever-changing environments. Multiple signaling pathways are involved in these processes and the molecular pathways to transduce various developmental signals are not linear but are interconnected by a complex network and even feedback mutually to achieve the final outcome. This review will focus on two important plant hormones, auxin and brassinosteroid (BR), based on the most recent progresses about these two hormone regulated plant growth and development in Arabidopsis, and highlight the cross-talks between these two phytohormones. PMID:29403511

  3. The biogenic volatile organic compounds emission inventory in France: application to plant ecosystems in the Berre-Marseilles area (France).

    Science.gov (United States)

    Simon, Valérie; Dumergues, Laurent; Ponche, Jean-Luc; Torres, Liberto

    2006-12-15

    An inventory describing the fluxes of volatile organic compounds (VOCs), isoprene and monoterpenes, and other VOCs (OVOCs) from the biosphere to the atmosphere, has been constructed within the framework of the ESCOMPTE project (fiEld experimentS to COnstrain Models of atmospheric Pollution and Transport of Emissions). The area concerned, located around Berre-Marseilles, is a Mediterranean region frequently subject to high ozone concentrations. The inventory has been developed using a fine scale land use database for the year 1999, forest composition statistics, emission potentials from individual plant species, biomass distribution, temperature and light intensity. The seasonal variations in emission potentials and biomass were also taken into account. Hourly meteorological data for 1999 were calculated from ALADIN data and these were used to predict the hourly isoprene, monoterpene and OVOC fluxes for the area on a 1 kmx1 km spatial grid. Estimates of annual biogenic isoprene, monoterpene and OVOC fluxes for the reference year 1999 were 20.6, 38.9 and 13.3 kt, respectively, Quercus pubescens, Quercus ilex, Pinus halepensis and garrigue vegetation are the dominant emitting species of the area. VOC emissions from vegetation in this region contribute approximately 94% to the NMVOC (non-methane volatile organic compounds) of natural origin and are of the same order of magnitude as NMVOC emissions from anthropogenic sources. These results complete the global ESCOMPTE database needed to make an efficient strategy for tropospheric ozone reduction policy.

  4. 40 CFR 180.1127 - Biochemical pesticide plant floral volatile attractant compounds: cinnamaldehyde, cinnamyl...

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions..., chinese cabbage, cowpeas, cucurbitis (cucumbers, squash, pumpkin), egg plant, endive (escarole...

  5. Priming of cowpea volatile emissions with defense inducers enhances the plant's attractiveness to parasitoids when attacked by caterpillars.

    Science.gov (United States)

    Sobhy, Islam S; Bruce, Toby Ja; Turlings, Ted Cj

    2018-04-01

    The manipulation of herbivore-induced volatile organic compounds (HI-VOCs) via the application of the inducers benzo(1,2,3)thiadiazole-7-carbothioic acid S-methyl ester (BTH) and laminarin (β-1,3-glucan) is known to enhance the attractiveness of caterpillar-damaged cotton and maize plants to parasitoids. To test if this is also the case for legumes, we treated cowpea (Vigna unguiculata var. unguiculata) with these inducers and studied the effects on HI-VOC emissions and the attraction of three generalist endoparasitoids. After the inducers had been applied and the plants subjected to either real or mimicked herbivory by Spodoptera littoralis caterpillars, females of the parasitoids Campoletis sonorensis and Microplitis rufiventris showed a strong preference for BTH-treated plants, whereas Cotesia females were strongly attracted to both BTH- and laminarin-treated plants with real or mimicked herbivory. Treated plants emitted more of certain HI-VOCs, but considerably less indole and linalool and less of several sesquiterpenes. Multivariate data analysis revealed that enhanced wasp attraction after treatment was correlated with high relative concentrations of nonanal, α-pinene, (E)-β-ocimene and (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), and with low relative concentrations of indole, (S)-linalool and (E)-β-farnesene. Inducer treatments had no significant effect on leaf consumption by the caterpillars. Our findings confirm that treating cowpea plants with inducers can enhance their attractiveness to biological control agents. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  6. Anti-cyclic regulation of the Ukrainian economy under current conditions of the international markets volatility

    Directory of Open Access Journals (Sweden)

    Volodymyr Satsyk

    2009-04-01

    Full Text Available In the article there are considered the theoretical and methodological basis of anti-cyclic regulation of the countries’ economy under conditions of the world economy globalization. It suggests the analysis of practices of implementing of anti-cyclic policy in highly developed states, its defining features and directions under current global financial and economic crisis. There has been researched a practical toolkit of economic cycles diagnostics and cyclic fluctuations of total business activity in Ukraine based on this study. There are suggested recommendations concerning the formation of the effective mechanism of anti-cyclic regulation of the Ukrainian economy.

  7. Application of Volatile Antifungal Plant Essential Oils for Controlling Pepper Fruit Anthracnose by Colletotrichum gloeosporioides

    Directory of Open Access Journals (Sweden)

    Jeum Kyu Hong

    2015-09-01

    Full Text Available Anthracnose caused by Colletotrichum gloeosporioides has been destructive during pepper fruit production in outdoor fields in Korea. In vitro antifungal activities of 15 different plant essential oils or its components were evaluated during conidial germination and mycelial growth of C. gloeosporioides. In vitro conidial germination was most drastically inhibited by vapour treatments with carvacrol, cinnamon oil, trans-cinnamaldehyde, citral, p-cymene and linalool. Inhibition of the mycelial growth by indirect vapour treatment with essential oils was also demonstrated compared with untreated control. Carvacrol, cinnamon oil, trans-cinnamaldehyde, citral and eugenol were among the most inhibitory plant essential oils by the indirect antifungal efficacies. Plant protection efficacies of the plant essential oils were demonstrated by reduced lesion diameter on the C. gloeosporioides-inoculated immature green pepper fruits compared to the inoculated control fruits without any plant essential oil treatment. In planta test showed that all plant essential oils tested in this study demonstrated plant protection efficacies against pepper fruit anthracnose with similar levels. Thus, application of different plant essential oils can be used for eco-friendly disease management of anthracnose during pepper fruit production.

  8. Application of Volatile Antifungal Plant Essential Oils for Controlling Pepper Fruit Anthracnose by Colletotrichum gloeosporioides.

    Science.gov (United States)

    Hong, Jeum Kyu; Yang, Hye Ji; Jung, Heesoo; Yoon, Dong June; Sang, Mee Kyung; Jeun, Yong-Chull

    2015-09-01

    Anthracnose caused by Colletotrichum gloeosporioides has been destructive during pepper fruit production in outdoor fields in Korea. In vitro antifungal activities of 15 different plant essential oils or its components were evaluated during conidial germination and mycelial growth of C. gloeosporioides. In vitro conidial germination was most drastically inhibited by vapour treatments with carvacrol, cinnamon oil, trans-cinnamaldehyde, citral, p-cymene and linalool. Inhibition of the mycelial growth by indirect vapour treatment with essential oils was also demonstrated compared with untreated control. Carvacrol, cinnamon oil, trans-cinnamaldehyde, citral and eugenol were among the most inhibitory plant essential oils by the indirect antifungal efficacies. Plant protection efficacies of the plant essential oils were demonstrated by reduced lesion diameter on the C. gloeosporioides-inoculated immature green pepper fruits compared to the inoculated control fruits without any plant essential oil treatment. In planta test showed that all plant essential oils tested in this study demonstrated plant protection efficacies against pepper fruit anthracnose with similar levels. Thus, application of different plant essential oils can be used for eco-friendly disease management of anthracnose during pepper fruit production.

  9. UV-B radiation affects plant volatile emissions and shade avoidance responses

    NARCIS (Netherlands)

    Gankema, P.

    2015-01-01

    Plants detect and integrate an assortment of signals from their environment, and use these signals to maximise their performance by adjusting their growth and development as well as their secondary metabolite production. In this thesis, we investigated how plants integrate visual and olfactory

  10. Volatile fragrances associated with flowers mediate the host plant alternation of a polyphagous mirid bug

    Science.gov (United States)

    Apolygus lucorum (Meyer-Dür) (Hemiptera: Miridae) is an important insect pest of cotton, fruit trees and other crops in China, and exhibits a particularly broad host range. Adult A. lucorum greatly prefers host plants at the flowering stage, and their populations track flowering plants both spatiall...

  11. Occupational health risk assessment of volatile organic compounds emitted from the coke production unit of a steel plant.

    Science.gov (United States)

    Dehghani, Fateme; Omidi, Fariborz; Heravizadeh, Omidreza; Barati Chamgordani, Saied; Gharibi, Vahid; Sotoudeh Manesh, Akbar

    2018-03-27

    In this study, cancer and non-cancer risks of exposure to volatile organic compounds in the coke production unit of a steel plant were evaluated. To determine individual exposure to benzene, toluene, xylene and ethylbenzene, personal samples were taken from the breathing zone of workers according to National Institute for Occupational Safety and Health (NIOSH) method 1501. Cancer and non-cancer risk assessment was performed, using US Environmental Protection Agency (US EPA) methods. Samples analysis showed that the concentration of benzene in the energy and biochemistry and the benzol refinement sections was higher than occupational exposure limits. The cancer risk for benzene in all sections was significantly higher than allowable limit; the non-cancer risk for benzene in all sections and toluene in the benzol refinement section was also higher than 1.0. In conclusion, the current control measures are not sufficient and should be improved for efficient control of occupational exposures.

  12. Voltage regulator placement in radial distribution system using plant ...

    African Journals Online (AJOL)

    user

    location and number along with tap setting of the voltage regulators that ... can be fixed or switched type; they are considered integer multiple of a capacitor unit ..... By simulating the growth process of plant phototropism, a probability model ..... He is referee for IEE Proceedings - Generation Transmission and Distribution and ...

  13. A specialist root herbivore reduces plant resistance and uses an induced plant volatile to aggregate in a density dependent manner

    Science.gov (United States)

    1. Leaf-herbivore attack often triggers induced resistance in plants. However, certain specialist herbivores can also take advantage of the induced metabolic changes. In some cases, they even manipulate plant resistance, leading to a phenomenon called induced susceptibility. Compared to above-ground...

  14. Inhibition of predator attraction to kairomones by non-host plant volatiles for herbivores: a bypass-trophic signal.

    Directory of Open Access Journals (Sweden)

    Qing-He Zhang

    2010-06-01

    Full Text Available Insect predators and parasitoids exploit attractive chemical signals from lower trophic levels as kairomones to locate their herbivore prey and hosts. We hypothesized that specific chemical cues from prey non-hosts and non-habitats, which are not part of the trophic chain, are also recognized by predators and would inhibit attraction to the host/prey kairomone signals. To test our hypothesis, we studied the olfactory physiology and behavior of a predaceous beetle, Thanasimus formicarius (L. (Coleoptera: Cleridae, in relation to specific angiosperm plant volatiles, which are non-host volatiles (NHV for its conifer-feeding bark beetle prey.Olfactory detection in the clerid was confirmed by gas chromatography coupled to electroantennographic detection (GC-EAD for a subset of NHV components. Among NHV, we identified two strongly antennally active molecules, 3-octanol and 1-octen-3-ol. We tested the potential inhibition of the combination of these two NHV on the walking and flight responses of the clerid to known kairomonal attractants such as synthetic mixtures of bark beetle (Ips spp. aggregation pheromone components (cis-verbenol, ipsdienol, and E-myrcenol combined with conifer (Picea and Pinus spp. monoterpenes (alpha-pinene, terpinolene, and Delta(3-carene. There was a strong inhibitory effect, both in the laboratory (effect size d = -3.2, walking bioassay and in the field (d = -1.0, flight trapping. This is the first report of combining antennal detection (GC-EAD and behavioral responses to identify semiochemical molecules that bypass the trophic system, signaling habitat information rather than food related information.Our results, along with recent reports on hymenopteran parasitoids and coleopteran predators, suggest that some NHV chemicals for herbivores are part of specific behavioral signals for the higher trophic level and not part of a background noise. Such bypass-trophic signals could be of general importance for third trophic level

  15. Nematicidal effect of volatile organic compounds (VOCs on the plant-parasitic nematode Meloidogyne javanica

    Directory of Open Access Journals (Sweden)

    Mauricio Batista Fialho

    2012-06-01

    Full Text Available Previous studies have demonstrated that volatile organic compounds (VOCs, produced by the yeast Saccharomyces cerevisiae, were able to inhibit the development of phytopathogenic fungi. In this context, the nematicidal potential of the synthetic mixture of VOCs, constituted of alcohols and esters, was evaluated for the control of the root-knot nematode Meloidogyne javanica, which causes losses to crops of high economic value. The fumigation of substrate containing second-stage juveniles with VOCs exhibited nematicidal effect higher than 30% for the lowest concentration tested (33.3 µL g-1 substrate, whereas at 66.6 and 133.3 µL g-1 substrate, the nematode mortality was 100%. The present results stimulate other studies on VOCs for nematode management.

  16. Boron transport in plants: co-ordinated regulation of transporters

    Science.gov (United States)

    Miwa, Kyoko; Fujiwara, Toru

    2010-01-01

    Background The essentiality of boron (B) for plant growth was established >85 years ago. In the last decade, it has been revealed that one of the physiological roles of B is cross-linking the pectic polysaccharide rhamnogalacturonan II in primary cell walls. Borate cross-linking of pectic networks serves both for physical strength of cell walls and for cell adhesion. On the other hand, high concentrations of B are toxic to plant growth. To avoid deficiency and toxicity problems, it is important for plants to maintain their tissue B concentrations within an optimum range by regulating transport processes. Boron transport was long believed to be a passive, unregulated process, but the identification of B transporters has suggested that plants sense and respond to the B conditions and regulate transporters to maintain B homeostasis. Scope Transporters responsible for efficient B uptake by roots, xylem loading and B distribution among leaves have been described. These transporters are required under B limitation for efficient acquisition and utilization of B. Transporters important for tolerating high B levels in the environment have also been identified, and these transporters export B from roots back to the soil. Two types of transporters are involved in these processes: NIPs (nodulin-26-like intrinsic proteins), boric acid channels, and BORs, B exporters. It is demonstrated that the expression of genes encoding these transporters is finely regulated in response to B availability in the environment to ensure tissue B homeostasis. Furthermore, plants tolerant to stress produced by low B or high B in the environment can be generated through altered expression of these transporters. Conclusions The identification of the first B transporter led to the discovery that B transport was a process mediated not only by passive diffusion but also by transporters whose activity was regulated in response to B conditions. Now it is evident that plants sense internal and external B

  17. Promoter-Based Integration in Plant Defense Regulation

    DEFF Research Database (Denmark)

    Li, Baohua; Gaudinier, Allison; Tang, Michelle

    2014-01-01

    A key unanswered question in plant biology is how a plant regulates metabolism to maximize performance across an array of biotic and abiotic environmental stresses. In this study, we addressed the potential breadth of transcriptional regulation that can alter accumulation of the defensive...... glucosinolate metabolites in Arabidopsis (Arabidopsis thaliana). A systematic yeast one-hybrid study was used to identify hundreds of unique potential regulatory interactions with a nearly complete complement of 21 promoters for the aliphatic glucosinolate pathway. Conducting high-throughput phenotypic...... validation, we showed that >75% of tested transcription factor (TF) mutants significantly altered the accumulation of the defensive glucosinolates. These glucosinolate phenotypes were conditional upon the environment and tissue type, suggesting that these TFs may allow the plant to tune its defenses...

  18. Jasmonate-responsive transcription factors regulating plant secondary metabolism.

    Science.gov (United States)

    Zhou, Meiliang; Memelink, Johan

    2016-01-01

    Plants produce a large variety of secondary metabolites including alkaloids, glucosinolates, terpenoids and phenylpropanoids. These compounds play key roles in plant-environment interactions and many of them have pharmacological activity in humans. Jasmonates (JAs) are plant hormones which induce biosynthesis of many secondary metabolites. JAs-responsive transcription factors (TFs) that regulate the JAs-induced accumulation of secondary metabolites belong to different families including AP2/ERF, bHLH, MYB and WRKY. Here, we give an overview of the types and functions of TFs that have been identified in JAs-induced secondary metabolite biosynthesis, and highlight their similarities and differences in regulating various biosynthetic pathways. We review major recent developments regarding JAs-responsive TFs mediating secondary metabolite biosynthesis, and provide suggestions for further studies. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Valuing a gas-fired power plant: A comparison of ordinary linear models, regime-switching approaches, and models with stochastic volatility

    International Nuclear Information System (INIS)

    Heydari, Somayeh; Siddiqui, Afzal

    2010-01-01

    Energy prices are often highly volatile with unexpected spikes. Capturing these sudden spikes may lead to more informed decision-making in energy investments, such as valuing gas-fired power plants, than ignoring them. In this paper, non-linear regime-switching models and models with mean-reverting stochastic volatility are compared with ordinary linear models. The study is performed using UK electricity and natural gas daily spot prices and suggests that with the aim of valuing a gas-fired power plant with and without operational flexibility, non-linear models with stochastic volatility, specifically for logarithms of electricity prices, provide better out-of-sample forecasts than both linear models and regime-switching models.

  20. Assessment of solid phase microfiber extraction fibers for the monitoring of volatile organoarsinicals emitted from a plant-soil system.

    Science.gov (United States)

    Ruppert, L; Lin, Z-Q; Dixon, R P; Johnson, K A

    2013-11-15

    Phytoremediation, the use of plants and microbes to clean up inorganic and organic pollutants, has shown great promise as an inexpensive and feasible form of remediation. More recently, studies have shown that some plants have an amazing capacity to volatilize contaminants and can be an effective remediation strategy if the chemicals released are non-toxic. Arsenic contamination and remediation has drawn great attention in the scientific community. However, its toxicity also varies depending on its form. We evaluated, optimized, and then utilized a solid phase microfiber extraction (SPME) head space sampling technique to characterize the organoarsinical emissions from rabbitfoot grass (Polypogon monspeliensis) in arsenic treated soils to determine if the potentially more toxic organic forms of arsenic (AsH3, AsH2CH3, AsH(CH3)2, and As(CH3)3) were being emitted from the plant-soil system. The SPME fiber that proved best fitted for this application was the DVB/CAR/PDMS fiber with a 45 min sampling period. We did detect and confirm the emissions of dimethylchloroarsine (AsCl(CH3)2) and pentamethylarsine (As(CH3)5). However, it was determined that the more toxic organic forms of arsenic were not released during phytovolatilization. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Chemometrics and chromatographic fingerprints to classify plant food supplements according to the content of regulated plants.

    Science.gov (United States)

    Deconinck, E; Sokeng Djiogo, C A; Courselle, P

    2017-09-05

    Plant food supplements are gaining popularity, resulting in a broader spectrum of available products and an increased consumption. Next to the problem of adulteration of these products with synthetic drugs the presence of regulated or toxic plants is an important issue, especially when the products are purchased from irregular sources. This paper focusses on this problem by using specific chromatographic fingerprints for five targeted plants and chemometric classification techniques in order to extract the important information from the fingerprints and determine the presence of the targeted plants in plant food supplements in an objective way. Two approaches were followed: (1) a multiclass model, (2) 2-class model for each of the targeted plants separately. For both approaches good classification models were obtained, especially when using SIMCA and PLS-DA. For each model, misclassification rates for the external test set of maximum one sample could be obtained. The models were applied to five real samples resulting in the identification of the correct plants, confirmed by mass spectrometry. Therefore chromatographic fingerprinting combined with chemometric modelling can be considered interesting to make a more objective decision on whether a regulated plant is present in a plant food supplement or not, especially when no mass spectrometry equipment is available. The results suggest also that the use of a battery of 2-class models to screen for several plants is the approach to be preferred. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. ADP1 Affects Plant Architecture by Regulating Local Auxin Biosynthesis

    Science.gov (United States)

    Li, Shibai; Qin, Genji; Novák, Ondřej; Pěnčík, Aleš; Ljung, Karin; Aoyama, Takashi; Liu, Jingjing; Murphy, Angus; Gu, Hongya; Tsuge, Tomohiko; Qu, Li-Jia

    2014-01-01

    Plant architecture is one of the key factors that affect plant survival and productivity. Plant body structure is established through the iterative initiation and outgrowth of lateral organs, which are derived from the shoot apical meristem and root apical meristem, after embryogenesis. Here we report that ADP1, a putative MATE (multidrug and toxic compound extrusion) transporter, plays an essential role in regulating lateral organ outgrowth, and thus in maintaining normal architecture of Arabidopsis. Elevated expression levels of ADP1 resulted in accelerated plant growth rate, and increased the numbers of axillary branches and flowers. Our molecular and genetic evidence demonstrated that the phenotypes of plants over-expressing ADP1 were caused by reduction of local auxin levels in the meristematic regions. We further discovered that this reduction was probably due to decreased levels of auxin biosynthesis in the local meristematic regions based on the measured reduction in IAA levels and the gene expression data. Simultaneous inactivation of ADP1 and its three closest homologs led to growth retardation, relative reduction of lateral organ number and slightly elevated auxin level. Our results indicated that ADP1-mediated regulation of the local auxin level in meristematic regions is an essential determinant for plant architecture maintenance by restraining the outgrowth of lateral organs. PMID:24391508

  3. Symbiotic regulation of plant growth, development and reproduction

    Science.gov (United States)

    Rodriguez, R.J.; Freeman, D. Carl; McArthur, E.D.; Kim, Y.-O.; Redman, R.S.

    2009-01-01

    The growth and development of rice (Oryzae sativa) seedlings was shown to be regulated epigenetically by a fungal endophyte. In contrast to un-inoculated (nonsymbiotic) plants, endophyte colonized (symbiotic) plants preferentially allocated resources into root growth until root hairs were well established. During that time symbiotic roots expanded at five times the rate observed in nonsymbiotic plants. Endophytes also influenced sexual reproduction of mature big sagebrush (Artemisia tridentata) plants. Two spatially distinct big sagebrush subspecies and their hybrids were symbiotic with unique fungal endophytes, despite being separated by only 380 m distance and 60 m elevation. A double reciprocal transplant experiment of parental and hybrid plants, and soils across the hybrid zone showed that fungal endophytes interact with the soils and different plant genotypes to confer enhanced plant reproduction in soil native to the endophyte and reduced reproduction in soil alien to the endophyte. Moreover, the most prevalent endophyte of the hybrid zone reduced the fitness of both parental subspecies. Because these endophytes are passed to the next generation of plants on seed coats, this interaction provides a selective advantage, habitat specificity, and the means of restricting gene flow, thereby making the hybrid zone stable, narrow and potentially leading to speciation. ?? 2009 Landes Bioscience.

  4. The Importance of the Circadian Clock in Regulating Plant Metabolism

    Directory of Open Access Journals (Sweden)

    Jin A Kim

    2017-12-01

    Full Text Available Carbohydrates are the primary energy source for plant development. Plants synthesize sucrose in source organs and transport them to sink organs during plant growth. This metabolism is sensitive to environmental changes in light quantity, quality, and photoperiod. In the daytime, the synthesis of sucrose and starch accumulates, and starch is degraded at nighttime. The circadian clock genes provide plants with information on the daily environmental changes and directly control many developmental processes, which are related to the path of primary metabolites throughout the life cycle. The circadian clock mechanism and processes of metabolism controlled by the circadian rhythm were studied in the model plant Arabidopsis and in the crops potato and rice. However, the translation of molecular mechanisms obtained from studies of model plants to crop plants is still difficult. Crop plants have specific organs such as edible seed and tuber that increase the size or accumulate valuable metabolites by harvestable metabolic components. Human consumers are interested in the regulation and promotion of these agriculturally significant crops. Circadian clock manipulation may suggest various strategies for the increased productivity of food crops through using environmental signal or overcoming environmental stress.

  5. A Conserved Cytochrome P450 Evolved in Seed Plants Regulates Flower Maturation.

    Science.gov (United States)

    Liu, Zhenhua; Boachon, Benoît; Lugan, Raphaël; Tavares, Raquel; Erhardt, Mathieu; Mutterer, Jérôme; Demais, Valérie; Pateyron, Stéphanie; Brunaud, Véronique; Ohnishi, Toshiyuki; Pencik, Ales; Achard, Patrick; Gong, Fan; Hedden, Peter; Werck-Reichhart, Danièle; Renault, Hugues

    2015-12-07

    Global inspection of plant genomes identifies genes maintained in low copies across taxa and under strong purifying selection, which are likely to have essential functions. Based on this rationale, we investigated the function of the low-duplicated CYP715 cytochrome P450 gene family that appeared early in seed plants and evolved under strong negative selection. Arabidopsis CYP715A1 showed a restricted tissue-specific expression in the tapetum of flower buds and in the anther filaments upon anthesis. cyp715a1 insertion lines showed a strong defect in petal development, and transient alteration of pollen intine deposition. Comparative expression analysis revealed the downregulated expression of genes involved in pollen development, cell wall biogenesis, hormone homeostasis, and floral sesquiterpene biosynthesis, especially TPS21 and several key genes regulating floral development such as MYB21, MYB24, and MYC2. Accordingly, floral sesquiterpene emission was suppressed in the cyp715a1 mutants. Flower hormone profiling, in addition, indicated a modification of gibberellin homeostasis and a strong disturbance of the turnover of jasmonic acid derivatives. Petal growth was partially restored by the active gibberellin GA3 or the functional analog of jasmonoyl-isoleucine, coronatine. CYP715 appears to function as a key regulator of flower maturation, synchronizing petal expansion and volatile emission. It is thus expected to be an important determinant of flower-insect interaction. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

  6. Induction of stress volatiles and changes in essential oil content and composition upon microwave exposure in the aromatic plant Ocimum basilicum

    Energy Technology Data Exchange (ETDEWEB)

    Lung, Ildikó [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, Cluj-Napoca 400293 (Romania); Soran, Maria-Loredana, E-mail: loredana.soran@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, Cluj-Napoca 400293 (Romania); Opriş, Ocsana; Truşcă, Mihail Radu Cătălin [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, Cluj-Napoca 400293 (Romania); Niinemets, Ülo [Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, 1 Kreutzwaldi Street, Tartu 51014 (Estonia); Copolovici, Lucian [Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, 1 Kreutzwaldi Street, Tartu 51014 (Estonia); Institute of Technical and Natural Sciences Research-Development of “Aurel Vlaicu” University, 2 Elena Drăgoi Street, Arad 310330 (Romania)

    2016-11-01

    Exposure to sustained low intensity microwaves can constitute a stress for the plants, but its effects on plant secondary chemistry are poorly known. We studied the influence of GSM and WLAN-frequency microwaves on emissions of volatile organic compounds and content of essential oil in the aromatic plant Ocimum basilicum L. hypothesizing that microwave exposure leads to enhanced emissions of stress volatiles and overall greater investment in secondary compounds. Compared to the control plants, microwave irradiation led to decreased emissions of β-pinene, α-phellandrene, bornyl acetate, β-myrcene, α-caryophyllene and benzaldehyde, but increased emissions of eucalyptol, estragole, caryophyllene oxide, and α-bergamotene. The highest increase in emission, 21 times greater compared to control, was observed for caryophyllene oxide. The irradiation resulted in increases in the essential oil content, except for the content of phytol which decreased by 41% in the case of GSM-frequency, and 82% in the case of WLAN-frequency microwave irradiation. The strongest increase in response to WLAN irradiation, > 17 times greater, was observed for hexadecane and octane contents. Comparisons of volatile compositions by multivariate analyses demonstrated a clear separation of different irradiance treatments, and according to the changes in the volatile emissions, the WLAN-frequency irradiation represented a more severe stress than the GSM-frequency irradiation. Overall, these results demonstrating important modifications in the emission rates, essential oil content and composition indicate that microwave irradiation influences the quality of herbage of this economically important spice plant. - Highlights: • Microwave irradiation represents a stress for the plants. • Microwave exposure leads to enhanced emissions of stress volatiles. • O. basilicum irradiation with microwaves increases the essential oil content. • Microwave pollution can constitute a threat to the

  7. Induction of stress volatiles and changes in essential oil content and composition upon microwave exposure in the aromatic plant Ocimum basilicum

    International Nuclear Information System (INIS)

    Lung, Ildikó; Soran, Maria-Loredana; Opriş, Ocsana; Truşcă, Mihail Radu Cătălin; Niinemets, Ülo; Copolovici, Lucian

    2016-01-01

    Exposure to sustained low intensity microwaves can constitute a stress for the plants, but its effects on plant secondary chemistry are poorly known. We studied the influence of GSM and WLAN-frequency microwaves on emissions of volatile organic compounds and content of essential oil in the aromatic plant Ocimum basilicum L. hypothesizing that microwave exposure leads to enhanced emissions of stress volatiles and overall greater investment in secondary compounds. Compared to the control plants, microwave irradiation led to decreased emissions of β-pinene, α-phellandrene, bornyl acetate, β-myrcene, α-caryophyllene and benzaldehyde, but increased emissions of eucalyptol, estragole, caryophyllene oxide, and α-bergamotene. The highest increase in emission, 21 times greater compared to control, was observed for caryophyllene oxide. The irradiation resulted in increases in the essential oil content, except for the content of phytol which decreased by 41% in the case of GSM-frequency, and 82% in the case of WLAN-frequency microwave irradiation. The strongest increase in response to WLAN irradiation, > 17 times greater, was observed for hexadecane and octane contents. Comparisons of volatile compositions by multivariate analyses demonstrated a clear separation of different irradiance treatments, and according to the changes in the volatile emissions, the WLAN-frequency irradiation represented a more severe stress than the GSM-frequency irradiation. Overall, these results demonstrating important modifications in the emission rates, essential oil content and composition indicate that microwave irradiation influences the quality of herbage of this economically important spice plant. - Highlights: • Microwave irradiation represents a stress for the plants. • Microwave exposure leads to enhanced emissions of stress volatiles. • O. basilicum irradiation with microwaves increases the essential oil content. • Microwave pollution can constitute a threat to the

  8. Health monitoring of plants by their emitted volatiles: A model to predict the effect of Botrytis cinerea on the concentration of volatiles in a large-scale greenhouse

    NARCIS (Netherlands)

    Jansen, R.M.C.; Hofstee, J.W.; Wildt, J.; Vanthoor, B.H.E.; Verstappen, F.W.A.; Takayama, K.; Bouwmeester, H.J.; Henten, van E.J.

    2010-01-01

    This paper describes a model to calculate the concentrations of (Z)-3-hexenol, a-pinene, a-terpinene, ß-caryophyllene, and methyl salicylate in a greenhouse on the basis of their source and sink behaviour. The model was used to determine whether these volatile organic compounds (VOCs) can be used to

  9. Understanding the Posttranscriptional Regulation of Plant Responses to Abiotic Stress

    KAUST Repository

    AlShareef, Sahar A.

    2017-06-01

    Constitutive and alternative splicing of pre-mRNAs from multiexonic genes controls the diversity of the proteome; these precisely regulated processes also fine-tune responses to cues related to growth, development, and biotic and abiotic stresses. Recent work showed that AS is pervasive across plant species, with more than 60% of intron-containing genes producing different isoforms. Mammalian cell-based assays have discovered various AS small-molecule inhibitors that perturb splicing and thereby provide invaluable tools for use as chemical probes to uncover the molecular underpinnings of splicing regulation and as potential anticancer compounds. Here, I show that the macrolide Pladienolide B (PB) and herboxidiene (GEX1A) inhibits both constitutive and alternative splicing, mimics an abiotic stress signal, and activates the abscisic acid (ABA) pathway in plants. Moreover, PB and GEX1A activate genome-wide transcriptional patterns involved in abiotic stress responses in plants. PB and GEX1A treatment triggered the ABA signaling pathway, activated ABA-inducible promoters, and led to stomatal closure. Interestingly, PB and GEX1A elicited similar cellular changes, including alterations in the patterns of transcription and splicing, suggesting that these compounds might target the same spliceosome complex in plant cells. This work establishes PB and GEX1A as potent splicing inhibitors in plants that can be used to probe the assembly, dynamics, and molecular functions of the spliceosome and to study the interplay between splicing stress and abiotic stresses, as well as having potential biotechnological applications.

  10. Arctic emissions of biogenic volatile organic compounds – from plants, litter and soils

    DEFF Research Database (Denmark)

    Svendsen, Sarah Hagel

    -terpenoid BVOCs were dominating the emission profile from the soils and the magnitude of the soil emissions depended greatly on the soil water content and temperature. A warmer arctic climate will likely alter the composition of plant species, cause a thawing of permafrost soil and change soil characteristics...... in adsorbent cartridges and analyzed using gas chromatography–mass spectrometry. Ecosystem BVOC emissions were highly dominated by terpenoids but the composition of terpenoids differed between different plant species. Litter emissions were less dominated by terpenoids than the ecosystem emissions, however...... they still constituted approximately 50 % of the total emissions. I suggested that the litter emissions derived both from microbial soil processes and from stores inside the litter tissue and that the relative importance of these two sources were plant species specific. Furthermore, emissions of non...

  11. Auxin and plant morphogenesis - a model of regulation

    Directory of Open Access Journals (Sweden)

    Stefan Zajączkowski

    2015-01-01

    Full Text Available In the presented model cells of the plant body form a spatial medium in which three-dimensional morphogenic waves of auxin are propagated. Points in the same phase of oscillation form isophasic surfaces and the vectors of wave propagation form a three-dimensional vector field. The vectors in the case of local inhomogeneities of the medium deviate from organ polarity, providing positional information recognized by cells. Models of functioning of such a supracellular oscillatory system in regulation of tissue differentiation, tropic responses and plant form are discussed.

  12. Gas pressure reduction and regulation plants: Acoustic impact

    International Nuclear Information System (INIS)

    Ferrero, G.; Torello, P.

    1992-01-01

    The paper analyses the impacts of the Italian Decree of 1st March, 1991, regarding 'Maximum limits of sound exposition in premises and outside environment' on gas distribution companies. In particular it deals with how Italgas, concerning gas reduction and regulation plants, has done its best to meet some provisions of this decree. In particular, the following subjects are dealt with: intervention time, reclamation plans, measurements, destination classes of territory, estimates of environmental impact, etc. Finally, an example of a structural intervention for the reclamation of an existing plant is given

  13. 7 CFR 330.200 - Movement of plant pests regulated; permits required.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Movement of plant pests regulated; permits required... AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE FEDERAL PLANT PEST REGULATIONS; GENERAL; PLANT PESTS; SOIL, STONE, AND QUARRY PRODUCTS; GARBAGE Movement of Plant Pests § 330.200 Movement of...

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

    Science.gov (United States)

    Jiang, Kai; Asami, Tadao

    2018-04-20

    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.

  15. Detection of regulated herbs and plants in plant food supplements and traditional medicines using infrared spectroscopy.

    Science.gov (United States)

    Deconinck, E; Djiogo, C A Sokeng; Bothy, J L; Courselle, P

    2017-08-05

    The identification of a specific toxic or regulated plant in herbal preparations or plant food supplements is a real challenge, since they are often powdered, mixed with other herbal or synthetic powders and compressed into tablets or capsules. The classical identification approaches based on micro- and macroscopy are therefore not possible anymore. In this paper infrared spectroscopy, combined with attenuated total reflectance was evaluated for the screening of plant based preparations for nine specific plants (five regulated and four common plants for herbal supplements). IR and NIR spectra were recorded for a series of self-made triturations of the targeted plants. After pretreatment of the spectral data chemometric classification techniques were applied to both data sets (IR and NIR) separately and the combination of both. The results show that the screening of herbal preparations or plant food supplements for specific plants, using infrared spectroscopy, is feasible. The best model was obtained with the Mid-IR data, using SIMCA as modelling technique. During validation of the model, using an external test set, 21 of 25 were correctly classified and six of the nine targeted plants showed no misclassifications for the selected test set. For the other three a success rate of 50% was obtained. Mid-IR combined with SIMCA can therefore be applied as a first step in the screening of unknown samples, before applying more sophisticated fingerprint approaches or identification tests described in several national and international pharmacopoeia. As a proof of concept five real suspicious samples were successfully screened for the targeted regulated plants. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Fooling the harlequin bug (Hemiptera: Pentatomidae) using synthetic volatiles to alter host plant choice

    Science.gov (United States)

    Harlequin bug, Murgantia histrionica (Hahn) (Hemiptera: Pentatomidae), is a widespread invasive pest that feeds on a variety of brassicaceous crops and other plants. To understand olfactory cues which mediate host-finding, and possible utility in pest management, we deployed aggregation pheromone (m...

  17. Changes in volatile production during an infection of tomato plants by Botrytis cinerea

    NARCIS (Netherlands)

    Jansen, R.M.C.; Miebach, M.; Kleist, E.; Henten, van E.J.; Wildt, J.

    2006-01-01

    Botrytis blight caused by the fungus Botrytis cinerea is probably the most common disease of greenhouse-grown crops like tomato. Botrytis blight in tomato plants is mainly detected by visual inspection or destructive biochemical and molecular determinations. These methods are time consuming and not

  18. Variation among volatile profiles induced by Botrytis cinerea infection of tomato plants

    NARCIS (Netherlands)

    Jansen, R.M.C.

    2007-01-01

    Botrytis blight caused by the fungus Botrytis cinerea is probably the most common disease of greenhouse-grown crops like tomato. Botrytis blight in tomato plants is mainly detected by visual inspection or destructive biochemical and molecular determinations. These methods are time consuming and not

  19. Not-from-concentrate pilot plant ‘Wonderful’ cultivar pomegranate juice changes: Volatiles

    Science.gov (United States)

    Pilot plant ultrafiltration was used to mimic the dominant U.S. commercial pomegranate juice extraction method (hydraulic pressing whole fruit), to deliver a not-from-concentrate (NFC) juice that was high-temperature short-time pasteurized and stored at 4 and 25 °C. Recovered were 46 compounds, of ...

  20. Red:far-red light conditions affect the emission of volatile organic compounds from barley (Hordeum vulgare), leading to altered biomass allocation in neighbouring plants.

    Science.gov (United States)

    Kegge, Wouter; Ninkovic, Velemir; Glinwood, Robert; Welschen, Rob A M; Voesenek, Laurentius A C J; Pierik, Ronald

    2015-05-01

    Volatile organic compounds (VOCs) play various roles in plant-plant interactions, and constitutively produced VOCs might act as a cue to sense neighbouring plants. Previous studies have shown that VOCs emitted from the barley (Hordeum vulgare) cultivar 'Alva' cause changes in biomass allocation in plants of the cultivar 'Kara'. Other studies have shown that shading and the low red:far-red (R:FR) conditions that prevail at high plant densities can reduce the quantity and alter the composition of the VOCs emitted by Arabidopsis thaliana, but whether this affects plant-plant signalling remains unknown. This study therefore examines the effects of far-red light enrichment on VOC emissions and plant-plant signalling between 'Alva' and 'Kara'. The proximity of neighbouring plants was mimicked by supplemental far-red light treatment of VOC emitter plants of barley grown in growth chambers. Volatiles emitted by 'Alva' under control and far-red light-enriched conditions were analysed using gas chromatography-mass spectrometry (GC-MS). 'Kara' plants were exposed to the VOC blend emitted by the 'Alva' plants that were subjected to either of the light treatments. Dry matter partitioning, leaf area, stem and total root length were determined for 'Kara' plants exposed to 'Alva' VOCs, and also for 'Alva' plants exposed to either control or far-red-enriched light treatments. Total VOC emissions by 'Alva' were reduced under low R:FR conditions compared with control light conditions, although individual volatile compounds were found to be either suppressed, induced or not affected by R:FR. The altered composition of the VOC blend emitted by 'Alva' plants exposed to low R:FR was found to affect carbon allocation in receiver plants of 'Kara'. The results indicate that changes in R:FR light conditions influence the emissions of VOCs in barley, and that these altered emissions affect VOC-mediated plant-plant interactions. © The Author 2015. Published by Oxford University Press on

  1. Differential responses of onion and garlic against plant growth regulators

    International Nuclear Information System (INIS)

    Oozunidou, G.; Asif, M.; Giannakuola, A.; Iliass, A.

    2011-01-01

    The effects of Gibberellic acid-GA3, Prohexadione-Calcium, and Ethephon pre-harvest application on yield, biomass production, photosynthetic function, lipid peroxidation and quality characteristics of onion (Allium cepa L.) and garlic (Allium sativum L.) plants were investigated. Shoot length and biomass of onion and garlic, expressed either in fresh or dry weight, increased significantly under GA3, while a progressive decrease under Prohex-Ca and Ethephon occurred. Higher MDA (lipid peroxidation) values were recorded after Prohex-Ca and Ethephon supply on onion and garlic plants; it seems that GA3 treatment prevents lipid peroxidation as measured with the help of the TBARS method. Plants treated with Prohex-Ca and Ethephon revealed higher peroxidase activity compared to control and GA3 treated plants. Considering the results of MDA content and peroxidase activities it can be assumed that GA3 treated plants are slightly protected from the natural course of oxidative stress, which occurs during ageing as observed for control samples. The fluctuations of chlorophyll fluorescence parameters represent a general decline in chloroplasts function after plant growth regulators exposure, whereas in combination to the suppressed chlorophyll content, structural malformations of photo systems may also occur. The production of ascorbic acid, glucose and fructose content seems to be enhanced under GA3 in both species, while their values were depressed under Prohex-Ca and Ethephon. Overall, only GA3 supply leads to a vigorous onion and garlic growth and yield. (author)

  2. Metabolic regulation of the plant hormone indole-3-acetic acid

    Energy Technology Data Exchange (ETDEWEB)

    Jerry D. Cohen

    2009-11-01

    The phytohormone indole-3-acetic acid (IAA, auxin) is important for many aspects of plant growth, development and responses to the environment yet the routes to is biosynthesis and mechanisms for regulation of IAA levels remain important research questions. A critical issue concerning the biosynthesis if IAA in plants is that redundant pathways for IAA biosynthesis exist in plants. We showed that these redundant pathways and their relative contribution to net IAA production are under both developmental and environmental control. We worked on three fundamental problems related to how plants get their IAA: 1) An in vitro biochemical approach was used to define the tryptophan dependent pathway to IAA using maize endosperm, where relatively large amounts of IAA are produced over a short developmental period. Both a stable isotope dilution and a protein MS approach were used to identify intermediates and enzymes in the reactions. 2) We developed an in vitro system for analysis of tryptophan-independent IAA biosynthesis in maize seedlings and we used a metabolite profiling approach to isolate intermediates in this reaction. 3) Arabidopsis contains a small family of genes that encode potential indolepyruvate decarboxylase enzymes. We cloned these genes and studied plants that are mutant in these genes and that over-express each member in the family in terms of the level and route of IAA biosynthesis. Together, these allowed further development of a comprehensive picture of the pathways and regulatory components that are involved in IAA homeostasis in higher plants.

  3. Plant species richness regulates soil respiration through changes in productivity.

    Science.gov (United States)

    Dias, André Tavares Corrêa; van Ruijven, Jasper; Berendse, Frank

    2010-07-01

    Soil respiration is an important pathway of the C cycle. However, it is still poorly understood how changes in plant community diversity can affect this ecosystem process. Here we used a long-term experiment consisting of a gradient of grassland plant species richness to test for effects of diversity on soil respiration. We hypothesized that plant diversity could affect soil respiration in two ways. On the one hand, more diverse plant communities have been shown to promote plant productivity, which could increase soil respiration. On the other hand, the nutrient concentration in the biomass produced has been shown to decrease with diversity, which could counteract the production-induced increase in soil respiration. Our results clearly show that soil respiration increased with species richness. Detailed analysis revealed that this effect was not due to differences in species composition. In general, soil respiration in mixtures was higher than would be expected from the monocultures. Path analysis revealed that species richness predominantly regulates soil respiration through changes in productivity. No evidence supporting the hypothesized negative effect of lower N concentration on soil respiration was found. We conclude that shifts in productivity are the main mechanism by which changes in plant diversity may affect soil respiration.

  4. The ERECTA gene regulates plant transpiration efficiency in Arabidopsis.

    Science.gov (United States)

    Masle, Josette; Gilmore, Scott R; Farquhar, Graham D

    2005-08-11

    Assimilation of carbon by plants incurs water costs. In the many parts of the world where water is in short supply, plant transpiration efficiency, the ratio of carbon fixation to water loss, is critical to plant survival, crop yield and vegetation dynamics. When challenged by variations in their environment, plants often seem to coordinate photosynthesis and transpiration, but significant genetic variation in transpiration efficiency has been identified both between and within species. This has allowed plant breeders to develop effective selection programmes for the improved transpiration efficiency of crops, after it was demonstrated that carbon isotopic discrimination, Delta, of plant matter was a reliable and sensitive marker negatively related to variation in transpiration efficiency. However, little is known of the genetic controls of transpiration efficiency. Here we report the isolation of a gene that regulates transpiration efficiency, ERECTA. We show that ERECTA, a putative leucine-rich repeat receptor-like kinase (LRR-RLK) known for its effects on inflorescence development, is a major contributor to a locus for Delta on Arabidopsis chromosome 2. Mechanisms include, but are not limited to, effects on stomatal density, epidermal cell expansion, mesophyll cell proliferation and cell-cell contact.

  5. Nonvolatile, semivolatile, or volatile: redefining volatile for volatile organic compounds.

    Science.gov (United States)

    Võ, Uyên-Uyén T; Morris, Michael P

    2014-06-01

    Although widely used in air quality regulatory frameworks, the term "volatile organic compound" (VOC) is poorly defined. Numerous standardized tests are currently used in regulations to determine VOC content (and thus volatility), but in many cases the tests do not agree with each other, nor do they always accurately represent actual evaporation rates under ambient conditions. The parameters (time, temperature, reference material, column polarity, etc.) used in the definitions and the associated test methods were created without a significant evaluation of volatilization characteristics in real world settings. Not only do these differences lead to varying VOC content results, but occasionally they conflict with one another. An ambient evaporation study of selected compounds and a few formulated products was conducted and the results were compared to several current VOC test methodologies: SCAQMD Method 313 (M313), ASTM Standard Test Method E 1868-10 (E1868), and US. EPA Reference Method 24 (M24). The ambient evaporation study showed a definite distinction between nonvolatile, semivolatile, and volatile compounds. Some low vapor pressure (LVP) solvents, currently considered exempt as VOCs by some methods, volatilize at ambient conditions nearly as rapidly as the traditional high-volatility solvents they are meant to replace. Conversely, bio-based and heavy hydrocarbons did not readily volatilize, though they often are calculated as VOCs in some traditional test methods. The study suggests that regulatory standards should be reevaluated to more accurately reflect real-world emission from the use of VOC containing products. The definition of VOC in current test methods may lead to regulations that exclude otherwise viable alternatives or allow substitutions of chemicals that may limit the environmental benefits sought in the regulation. A study was conducted to examine volatility of several compounds and a few formulated products under several current VOC test

  6. Domestic Regulation for Periodic Safety Review of Nuclear Power Plants

    International Nuclear Information System (INIS)

    Kim, Daesik; Ahn, Seunghoon; Auh, Geunsun; Lee, Jonghyeok

    2015-01-01

    The so-called Periodic Safety Review (PSR) has been carried out such safety assessment throughout its life, on a periodic basis. In January 2001, the Atomic Energy Act and related regulations were amended to adopt the PSR institutional scheme from IAEA Nuclear Safety Guide 50-SG-O12. At that time the safety assessment was made to review the plant safety on 10 safety factors, such as aging management and emergency planning, where the safety factor indicates the important aspects of safety of an operating NPP to be addressed in the PSR. According to this legislation, the domestic utility, the KHNP has conducted the PSR for the operating NPP of 10 years coming up from operating license date, starting since May 2000. Some revisions in the PSR rule were made to include the additional safety factors last year. This paper introduces the current status of the PSR review and regulation, in particular new safety factors and updated technical regulation. Comprehensive safety assessment for Korea Nuclear Power Plants have performed a reflecting design and procedure changes and considering the latest technology every 10 years. This paper also examined the PSR system changes in Korea. As of July 2015, reviews for PSR of 18 units have been completed, with 229 nuclear safety improvement items. And implementation have been completed for 165 of them. PSR system has been confirmed that it has contributed to improvement of plant safety. In addition, this paper examined the PSR system change in Korea

  7. The central regulation of plant physiology by adenylates.

    Science.gov (United States)

    Geigenberger, Peter; Riewe, David; Fernie, Alisdair R

    2010-02-01

    There have been many recent developments concerning the metabolic, transport and signalling functions of adenylates in plants, suggesting new roles for these compounds as central regulators of plant physiology. For example, altering the expression levels of enzymes involved in the equilibration, salvaging, synthesis and transport of adenylates leads to perturbations in storage, growth and stress responses, implying a role for adenylates as important signals. Furthermore, sensing of the internal energy status involves SNF1-related kinases, which control the expression and phosphorylation of key metabolic enzymes. ATP also acts as an apoplastic signalling molecule to control cell growth and pathogen responses. These new results could shed light on the emerging question of whether energy homeostasis in plant cells differs from mechanisms found in microbes and mammals. Copyright 2009 Elsevier Ltd. All rights reserved.

  8. Sulfur availability regulates plant growth via glucose-TOR signaling.

    Science.gov (United States)

    Dong, Yihan; Silbermann, Marleen; Speiser, Anna; Forieri, Ilaria; Linster, Eric; Poschet, Gernot; Allboje Samami, Arman; Wanatabe, Mutsumi; Sticht, Carsten; Teleman, Aurelio A; Deragon, Jean-Marc; Saito, Kazuki; Hell, Rüdiger; Wirtz, Markus

    2017-10-27

    Growth of eukaryotic cells is regulated by the target of rapamycin (TOR). The strongest activator of TOR in metazoa is amino acid availability. The established transducers of amino acid sensing to TOR in metazoa are absent in plants. Hence, a fundamental question is how amino acid sensing is achieved in photo-autotrophic organisms. Here we demonstrate that the plant Arabidopsis does not sense the sulfur-containing amino acid cysteine itself, but its biosynthetic precursors. We identify the kinase GCN2 as a sensor of the carbon/nitrogen precursor availability, whereas limitation of the sulfur precursor is transduced to TOR by downregulation of glucose metabolism. The downregulated TOR activity caused decreased translation, lowered meristematic activity, and elevated autophagy. Our results uncover a plant-specific adaptation of TOR function. In concert with GCN2, TOR allows photo-autotrophic eukaryotes to coordinate the fluxes of carbon, nitrogen, and sulfur for efficient cysteine biosynthesis under varying external nutrient supply.

  9. Ammonia volatilization from a paddy field following applications of urea: rice plants are both an absorber and an emitter for atmospheric ammonia.

    Science.gov (United States)

    Hayashi, Kentaro; Nishimura, Seiichi; Yagi, Kazuyuki

    2008-02-15

    Ammonia (NH(3)) volatilization from a paddy field following applications of urea was measured. Two lysimeters of Gray Lowland soil with a pH (H(2)O) of 5.7 were used for the experiment. Urea was applied at a rate of 50 kg N ha(-1) by incorporation as the basal fertilization (BF) and at rates of 30 and 10 kg N ha(-1) by top-dressing as the first (SF1) and second (SF2) supplemental fertilizations, respectively. Two wind tunnels per lysimeter were installed just after BF; one was transplanted with rice plants (PR plot), and the other was without rice plants (NR plot). Weak volatilization was observed at the PR plots after BF. By contrast, strong volatilization was observed at the PR plots after SF1 with a maximum flux of 150 g N ha(-1) h(-1); however, almost no volatilization was observed after SF2. The NH(3) volatilization loss accounted for 2.1%, 20.9%, 0.5%, and 8.2% of the applied urea at each application, BF, SF1, SF2, and the total application, respectively, for which only the net fluxes as volatilization were accumulated. The NH(3) volatilization fluxes from the paddy water surface (F(vol)) at the NR plots were estimated using a film model for its verification. After confirmation of good correlation, the film model was applied to estimate F(vol) at the PR plots. The NH(3) exchange fluxes by rice plants (F(ric)) were obtained by subtracting F(vol) from the observed net NH(3) flux. The derived F(ric) showed that the rice plants emitted NH(3) remarkably just after SF1 when a relatively high rate of urea was applied, although they absorbed atmospheric NH(3) in the other periods. In conclusion, rice plants are essentially an absorber of atmospheric NH(3); however, they turn into an emitter of NH(3) under excess nutrition of ammoniacal nitrogen.

  10. The Tree Drought Emission MONitor (Tree DEMON, an innovative system for assessing biogenic volatile organic compounds emission from plants

    Directory of Open Access Journals (Sweden)

    Marvin Lüpke

    2017-03-01

    Full Text Available Abstract Background Biogenic volatile organic compounds (BVOC emitted by plants play an important role for ecological and physiological processes, for example as response to stressors. These emitted compounds are involved in chemical processes within the atmosphere and contribute to the formation of aerosols and ozone. Direct measurement of BVOC emissions requires a specialized sample system in order to obtain repeatable and comparable results. These systems need to be constructed carefully since BVOC measurements may be disturbed by several side effects, e.g., due to wrong material selection and lacking system stability. Results In order to assess BVOC emission rates, a four plant chamber system was constructed, implemented and throughout evaluated by synthetic tests and in two case studies on 3-year-old sweet chestnut seedlings. Synthetic system test showed a stable sampling with good repeatability and low memory effects. The first case study demonstrated the capability of the system to screen multiple trees within a few days and revealed three different emission patterns of sweet chestnut trees. The second case study comprised an application of drought stress on two seedlings compared to two in parallel assessed seedlings of a control. Here, a clear reduction of BVOC emissions during drought stress was observed. Conclusion The developed system allows assessing BVOC as well as CO2 and water vapor gas exchange of four tree specimens automatically and in parallel with repeatable results. A canopy volume of 30 l can be investigated, which constitutes in case of tree seedlings the whole canopy. Longer lasting experiments of e.g., 1–3 weeks can be performed easily without any significant plant interference.

  11. Temperature dependencies of Henry's law constants and octanol/water partition coefficients for key plant volatile monoterpenoids.

    Science.gov (United States)

    Copolovici, Lucian O; Niinemets, Ulo

    2005-12-01

    To model the emission dynamics and changes in fractional composition of monoterpenoids from plant leaves, temperature dependencies of equilibrium coefficients must be known. Henry's law constants (H(pc), Pa m3 mol(-1) and octanol/water partition coefficients (K(OW), mol mol(-1)) were determined for 10 important plant monoterpenes at physiological temperature ranges (25-50 degrees C for H(pc) and 20-50 degrees C for K(OW)). A standard EPICS procedure was established to determine H(pc) and a shake flask method was used for the measurements of K(OW). The enthalpy of volatilization (deltaH(vol)) varied from 18.0 to 44.3 kJ mol(-1) among the monoterpenes, corresponding to a range of temperature-dependent increase in H(pc) between 1.3- and 1.8-fold per 10 degrees C rise in temperature. The enthalpy of water-octanol phase change varied from -11.0 to -23.8 kJ mol(-1), corresponding to a decrease of K(OW) between 1.15- and 1.32-fold per 10 degrees C increase in temperature. Correlations among physico-chemical characteristics of a wide range of monoterpenes were analyzed to seek the ways of derivation of H(pc) and K(OW) values from other monoterpene physico-chemical characteristics. H(pc) was strongly correlated with monoterpene saturated vapor pressure (P(v)), and for lipophilic monoterpenes, deltaH(vol) scaled positively with the enthalpy of vaporization that characterizes the temperature dependence of P(v) Thus, P(v) versus temperature relations may be employed to derive the temperature relations of H(pc) for these monoterpenes. These data collectively indicate that monoterpene differences in H(pc) and K(OW) temperature relations can importantly modify monoterpene emissions from and deposition on plant leaves.

  12. The exploitation of volatile oil

    Institute of Scientific and Technical Information of China (English)

    MENG Teng; ZHANG Da; TENG Xiangjin; LINing; HAO Zaibin

    2007-01-01

    Rose is a kind of favorite ornamental plant. This article briefly introduced the cultivation and the use of rose around the world both in ancient time and nowadays. Today, volatile oil becomes the mainstream of the rose industry. People pay attention to the effect of volatile oil; meanwhile, they speed up their research on extracting volatile oil and the ingredients.

  13. Fresh, dried or smoked? repellent properties of volatiles emitted from ethnomedicinal plant leaves against malaria and yellow fever vectors in Ethiopia

    Directory of Open Access Journals (Sweden)

    Dube Fitsum

    2011-12-01

    Full Text Available Abstract Background In the search for plant-based mosquito repellents, volatile emanations were investigated from five plant species, Corymbia citriodora, Ocimum suave, Ocimum lamiifolium, Olea europaea and Ostostegia integrifolia, traditionally used in Ethiopia as protection against mosquitoes. Methods The behaviour of two mosquitoes, the malaria vector Anopheles arabiensis and the arbovirus vector Aedes aegypti, was assessed towards volatiles collected from the headspace of fresh and dried leaves, and the smoke from burning the dried leaves in a two-choice landing bioassay and in the background of human odour. Results Volatile extracts from the smoke of burning dried leaves were found to be more repellent than those from fresh leaves, which in turn were more repellent to mosquitoes than volatiles from dried leaves. Of all smoke and fresh volatile extracts, those from Co. citriodora (52-76% and Oc. suave (58-68% were found to be the most repellent, Os. integrifolia (29-56% to be intermediate while Ol. europaea (23-40% and Os. integrifolia (19-37% were the least repellent. One volatile present in each of the fresh leaf extracts of Co. citriodora, Oc. suave and Os. integrifolia was ß-ocimene. The levels of ß-ocimene reflected the mosquito repellent activity of these three fresh leaf extracts. Female host-seeking mosquitoes responded dose-dependently to ß-ocimene, both physiologically and behaviourally, with a maximal behavioural repulsion at 14% ß-ocimene. ß-ocimene (14% repels mosquitoes in our 6-minute landing assays comparable to the synthetic insect repellent N,N-diethyl-m-toluamide (10% DEET. Conclusions Volatiles in the smoke of burning as well as fresh leaves of Co. citriodora and Oc. suave have significant repellent properties against host seeking An. arabiensis and Ae. aegypti mosquitoes. ß-ocimene, present in the fresh leaf headspace of Co. citriodora, Oc. suave and Os. integrifolia, is a significantly effective volatile mosquito

  14. A Background of a Volatile Plant Compound Alters Neural and Behavioral Responses to the Sex Pheromone Blend in a Moth.

    Science.gov (United States)

    Dupuy, Fabienne; Rouyar, Angéla; Deisig, Nina; Bourgeois, Thomas; Limousin, Denis; Wycke, Marie-Anne; Anton, Sylvia; Renou, Michel

    2017-01-01

    Recognition of intra-specific olfactory signals within a complex environment of plant-related volatiles is crucial for reproduction in male moths. Sex pheromone information is detected by specific olfactory receptor neurons (Phe-ORNs), highly abundant on the male antenna. The information is then transmitted to the pheromone processing macroglomerular complex (MGC) within the primary olfactory center, the antennal lobe, where it is processed by local interneurons and projection neurons. Ultimately a behavioral response, orientation toward the pheromone source, is elicited. Volatile plant compounds (VPCs) are detected by other functional types of olfactory receptor neurons (ORNs) projecting in another area of the antennal lobe. However, Phe-ORNs also respond to some VPCs. Female-produced sex pheromones are emitted within a rich environment of VPCs, some of which have been shown to interfere with the detection and processing of sex pheromone information. As interference between the different odor sources might depend on the spatial and temporal features of the two types of stimuli, we investigated here behavioral and neuronal responses to a brief sex pheromone blend pulse in a VPC background as compared to a control background in the male noctuid moth Agrotis ipsilon . We observed male orientation behavior in a wind tunnel and recorded responses of Phe-ORNs and MGC neurons to a brief sex pheromone pulse within a background of individual VPCs. We also recorded the global input signal to the MGC using in vivo calcium imaging with the same stimulation protocol. We found that VPCs eliciting a response in Phe-ORNs and MGC neurons masked responses to the pheromone and decreased the contrast between background odor and the sex pheromone at both levels, whereas α-pinene did not interfere with first order processing. The calcium signal produced in response to a VPC background was tonic, lasting longer than the VPC stimulus duration, and masked entirely the pheromone response

  15. Graphene quantum dots as enhanced plant growth regulators: effects on coriander and garlic plants.

    Science.gov (United States)

    Chakravarty, Disha; Erande, Manisha B; Late, Dattatray J

    2015-10-01

    We report investigations on the use of graphene quantum dots for growth enhancement in coriander (Coriandrum sativam L.) and garlic (Allium sativum) plants. The as-received seeds of coriander and garlic were treated with 0.2 mg mL(-1) of graphene quantum dots for 3 h before planting. Graphene quantum dots enhanced the growth rate in coriander and garlic plants, including leaves, roots, shoots, flowers and fruits, when the seeds were treated with graphene quantum dots. Our investigations open up the opportunity to use graphene quantum dots as plant growth regulators that can be used in a variety of other food plants for high yield. © 2015 Society of Chemical Industry.

  16. Ligand Receptor-Mediated Regulation of Growth in Plants.

    Science.gov (United States)

    Haruta, Miyoshi; Sussman, Michael R

    2017-01-01

    Growth and development of multicellular organisms are coordinately regulated by various signaling pathways involving the communication of inter- and intracellular components. To form the appropriate body patterns, cellular growth and development are modulated by either stimulating or inhibiting these pathways. Hormones and second messengers help to mediate the initiation and/or interaction of the various signaling pathways in all complex multicellular eukaryotes. In plants, hormones include small organic molecules, as well as larger peptides and small proteins, which, as in animals, act as ligands and interact with receptor proteins to trigger rapid biochemical changes and induce the intracellular transcriptional and long-term physiological responses. During the past two decades, the availability of genetic and genomic resources in the model plant species, Arabidopsis thaliana, has greatly helped in the discovery of plant hormone receptors and the components of signal transduction pathways and mechanisms used by these immobile but highly complex organisms. Recently, it has been shown that two of the most important plant hormones, auxin and abscisic acid (ABA), act through signaling pathways that have not yet been recognized in animals. For example, auxins stimulate cell elongation by bringing negatively acting transcriptional repressor proteins to the proteasome to be degraded, thus unleashing the gene expression program required for increasing cell size. The "dormancy" inducing hormone, ABA, binds to soluble receptor proteins and inhibits a specific class of protein phosphatases (PP2C), which activates phosphorylation signaling leading to transcriptional changes needed for the desiccation of the seeds prior to entering dormancy. While these two hormone receptors have no known animal counterparts, there are also many similarities between animal and plant signaling pathways. For example, in plants, the largest single gene family in the genome is the protein kinase

  17. ROS-related redox regulation and signaling in plants.

    Science.gov (United States)

    Noctor, Graham; Reichheld, Jean-Philippe; Foyer, Christine H

    2017-07-18

    As sessile oxygenic organisms with a plastic developmental programme, plants are uniquely positioned to exploit reactive oxygen species (ROS) as powerful signals. Plants harbor numerous ROS-generating pathways, and these oxidants and related redox-active compounds have become tightly embedded into plant function and development during the course of evolution. One dominant view of ROS-removing systems sees them as beneficial antioxidants battling to keep damaging ROS below dangerous levels. However, it is now established that ROS are a necessary part of subcellular and intercellular communication in plants and that some of their signaling functions require ROS-metabolizing systems. For these reasons, it is suggested that "ROS processing systems" would be a more accurate term than "antioxidative systems" to describe cellular components that are most likely to interact with ROS and, in doing so, transmit oxidative signals. Within this framework, our update provides an overview of the complexity and compartmentation of ROS production and removal. We place particular emphasis on the importance of ROS-interacting systems such as the complex cellular thiol network in the redox regulation of phytohormone signaling pathways that are crucial for plant development and defense against external threats. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Food plant toxicants and safety: risk assessment and regulation of inherent toxicants in plant foods.

    NARCIS (Netherlands)

    Essers, A.J.; Alink, G.M.; Speijers, G.J.A.; Alexander, J.; Bouwmeister, P.J.; Brandt, van den P.A.; Ciere, S.; Gry, J.; Herrman, J.; Kuiper, H.A.; Mortby, E.; Renwickn, A.G.

    1998-01-01

    The ADI as a tool for risk management and regulation of food additives and pesticide residues is not readily applicable to inherent food plant toxicants: The margin between actual intake and potentially toxic levels is often small; application of the default uncertainty factors used to derive ADI

  19. Regulating Intracellular Calcium in Plants: From Molecular Genetics to Physiology

    International Nuclear Information System (INIS)

    Sze, Heven

    2008-01-01

    To grow, develop, adapt, and reproduce, plants have evolved mechanisms to regulate the uptake, translocation and sorting of calcium ions into different cells and subcellular compartments. Yet how plants accomplish this remarkable feat is still poorly understood. The spatial and temporal changes in intracellular (Ca2+) during growth and during responses to hormonal and environmental stimuli indicate that Ca2+ influx and efflux transporters are diverse and tightly regulated in plants. The specific goals were to determine the biological roles of multiple Ca pumps (ECAs) in the model plant Arabidopsis thaliana. We had pioneered the use of K616 yeast strain to functionally express plant Ca pumps, and demonstrated two distinct types of Ca pumps in plants (Sze et al., 2000. Annu Rev Plant Biol. 51,433). ACA2 represented one type that was auto-inhibited by the N-terminal region and stimulated by calmodulin. ECA1 represented another type that was not sensitive to calmodulin and phylogenetically distinct from ACAs. The goal to determine the biological roles of multiple ECA-type Ca pumps in Arabidopsis has been accomplished. Although we demonstrated ECA1 was a Ca pump by functional expression in yeast, the in vivo roles of ECAs was unclear. A few highlights are described. ECA1 and/or ECA4 are Ca/Mn pumps localized to the ER and are highly expressed in all cell types. Using homozygous T-DNA insertional mutants of eca1, we demonstrated that the ER-bound ECA1 supports growth and confers tolerance of plants growing on medium low in Ca or containing toxic levels of Mn. This is the first genetic study to determine the in vivo function of a Ca pump in plants. A phylogenetically distinct ECA3 is also a Ca/Mn pump that is localized to endosome, such as post-Golgi compartments. Although it is expressed at lower levels than ECA1, eca3 mutants are impaired in Ca-dependent root growth and in pollen tube elongation. Increased secretion of wall proteins in mutants suggests that Ca and Mn

  20. Regulation of phosphate starvation responses in higher plants.

    Science.gov (United States)

    Yang, Xiao Juan; Finnegan, Patrick M

    2010-04-01

    Phosphorus (P) is often a limiting mineral nutrient for plant growth. Many soils worldwide are deficient in soluble inorganic phosphate (P(i)), the form of P most readily absorbed and utilized by plants. A network of elaborate developmental and biochemical adaptations has evolved in plants to enhance P(i) acquisition and avoid starvation. Controlling the deployment of adaptations used by plants to avoid P(i) starvation requires a sophisticated sensing and regulatory system that can integrate external and internal information regarding P(i) availability. In this review, the current knowledge of the regulatory mechanisms that control P(i) starvation responses and the local and long-distance signals that may trigger P(i) starvation responses are discussed. Uncharacterized mutants that have P(i)-related phenotypes and their potential to give us additional insights into regulatory pathways and P(i) starvation-induced signalling are also highlighted and assessed. An impressive list of factors that regulate P(i) starvation responses is now available, as is a good deal of knowledge regarding the local and long-distance signals that allow a plant to sense and respond to P(i) availability. However, we are only beginning to understand how these factors and signals are integrated with one another in a regulatory web able to control the range of responses demonstrated by plants grown in low P(i) environments. Much more knowledge is needed in this agronomically important area before real gains can be made in improving P(i) acquisition in crop plants.

  1. Emission of volatile organic compounds from petunia flowers is facilitated by an ABC transporter.

    Science.gov (United States)

    Adebesin, Funmilayo; Widhalm, Joshua R; Boachon, Benoît; Lefèvre, François; Pierman, Baptiste; Lynch, Joseph H; Alam, Iftekhar; Junqueira, Bruna; Benke, Ryan; Ray, Shaunak; Porter, Justin A; Yanagisawa, Makoto; Wetzstein, Hazel Y; Morgan, John A; Boutry, Marc; Schuurink, Robert C; Dudareva, Natalia

    2017-06-30

    Plants synthesize a diversity of volatile molecules that are important for reproduction and defense, serve as practical products for humans, and influence atmospheric chemistry and climate. Despite progress in deciphering plant volatile biosynthesis, their release from the cell has been poorly understood. The default assumption has been that volatiles passively diffuse out of cells. By characterization of a Petunia hybrida adenosine triphosphate-binding cassette (ABC) transporter, PhABCG1, we demonstrate that passage of volatiles across the plasma membrane relies on active transport. PhABCG1 down-regulation by RNA interference results in decreased emission of volatiles, which accumulate to toxic levels in the plasma membrane. This study provides direct proof of a biologically mediated mechanism of volatile emission. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  2. Reduction in health risk induced by semi-volatile organic compounds and metals in a drinking water treatment plant

    International Nuclear Information System (INIS)

    Zhao, F.; Yin, J.; Zhang, X. X.; Chen, Y.; Zhang, Y.; Wu, B.; Li, M.

    2015-01-01

    This study investigated health risk reduction in a drinking water treatment plant of Nanjing City (China) based on chemical detection of 22 semi-volatile organic compounds (SVOCs) and 24 metallic elements in source water and drinking water during 2009–2011. Chemical analysis showed that 15 SVOCs and 9 metals were present in the water. Health risk assessment revealed that hazard quotient of each pollutant and hazard index (HI) of all the detectable pollutants were below 1.00, indicating that the chemicals posed negligible non-carcinogenic risk to local residents. Benzo(a)pyrene may induce carcinogenic risk since its risk index via both oral and dermal exposure exceeded the safety level (1.00E-6), but other SVOCs induced no carcinogenic risk. Total HI of the SVOCs was 1.08E-3 for the source water and 1.56E-3 for the drinking water, suggesting that the used conventional treatment processes (coagulation/sedimentation, sand filtration and chlorine disinfection) cannot effectively reduce the non-carcinogenic risk. The source water had higher carcinogenic risk than the drinking water, but risk index of the drinking water still exceeded 1.00E-6. This study might serve as a basis for health risk assessment of drinking water and also as a benchmark for the authorities to reduce health risk arising from trace-level hazardous pollutants.

  3. Plant essential oils and allied volatile fractions as multifunctional additives in meat and fish-based food products: a review.

    Science.gov (United States)

    Patel, Seema

    2015-01-01

    Essential oils are concentrated aromatic volatile compounds derived from botanicals by distillation or mechanical pressing. They play multiple, crucial roles as antioxidants, food pathogen inhibitors, shelf-life enhancers, texture promoters, organoleptic agents and toxicity-reducing agents. For their versatility, they appear promising as food preservatives. Several research findings in recent times have validated their potential as functional ingredients in meat and fish processing. Among the assortment of bioactive compounds in the essential oils, p-cymene, thymol, eugenol, carvacrol, isothiocyanate, cinnamaldehyde, cuminaldehyde, linalool, 1,8-cineol, α-pinene, α-terpineol, γ-terpinene, citral and methyl chavicol are most familiar. These terpenes (monoterpenes and sesquiterpenes) and phenolics (alcohols, esters, aldehydes and ketones) have been extracted from culinary herbs such as oregano, rosemary, basil, coriander, cumin, cinnamon, mint, sage and lavender as well as from trees such as myrtle, fir and eucalyptus. This review presents essential oils as alternatives to conventional chemical additives. Their synergistic actions with modified air packaging, irradiation, edible films, bacteriocins and plant byproducts are discussed. The decisive roles of metabolic engineering, microwave technology and metabolomics in quality and quantity augmentation of essential oil are briefly mooted. The limitations encountered and strategies to overcome them have been illuminated to pave way for their enhanced popularisation. The literature has been mined from scientific databases such as Pubmed, Pubchem, Scopus and SciFinder.

  4. Implementation of passive samplers for monitoring volatile organic compounds in ground water at the Kansas City Plant

    International Nuclear Information System (INIS)

    Gardner, F.G.; Korte, N.E.; Wilson-Nichols, M.J.; Baker, J.L.; Ramm, S.G.

    1998-06-01

    Passive sampling for monitoring volatile organic compounds (VOCs) has been suggested as a possible replacement to the traditional bailer method used at the Department of Energy Kansas City Plant (KCP) for routine groundwater monitoring. To compare methods, groundwater samples were collected from 19 KCP wells with VOC concentrations ranging from non-detectable to > 100,000 microg/L. Analysis of the data was conducted using means and medians of multiple measurements of TCE, 1,2-DCE, 1,1-DCE and VC. All 95% confidence intervals of these VOCs overlap, providing evidence that the two methods are similar. The study also suggests that elimination of purging and decontamination of sampling equipment reduces the labor required to sample by approximately 32%. Also, because the passive method generates no waste water, there are no associated disposal costs. The results suggest evidence to continue studies and efforts to replace traditional bailer methods with passive sampling at KCP based on cost and the similarity of the methods

  5. Red:far-red light conditions affect the emission of volatile organic compounds from barley (Hordeum vulgare), leading to altered biomass allocation in neighbouring plants

    Science.gov (United States)

    Kegge, Wouter; Ninkovic, Velemir; Glinwood, Robert; Welschen, Rob A. M.; Voesenek, Laurentius A. C. J.; Pierik, Ronald

    2015-01-01

    Background and Aims Volatile organic compounds (VOCs) play various roles in plant–plant interactions, and constitutively produced VOCs might act as a cue to sense neighbouring plants. Previous studies have shown that VOCs emitted from the barley (Hordeum vulgare) cultivar ‘Alva’ cause changes in biomass allocation in plants of the cultivar ‘Kara’. Other studies have shown that shading and the low red:far-red (R:FR) conditions that prevail at high plant densities can reduce the quantity and alter the composition of the VOCs emitted by Arabidopsis thaliana, but whether this affects plant–plant signalling remains unknown. This study therefore examines the effects of far-red light enrichment on VOC emissions and plant–plant signalling between ‘Alva’ and ‘Kara’. Methods The proximity of neighbouring plants was mimicked by supplemental far-red light treatment of VOC emitter plants of barley grown in growth chambers. Volatiles emitted by ‘Alva’ under control and far-red light-enriched conditions were analysed using gas chromatography–mass spectrometry (GC-MS). ‘Kara’ plants were exposed to the VOC blend emitted by the ‘Alva’ plants that were subjected to either of the light treatments. Dry matter partitioning, leaf area, stem and total root length were determined for ‘Kara’ plants exposed to ‘Alva’ VOCs, and also for ‘Alva’ plants exposed to either control or far-red-enriched light treatments. Key Results Total VOC emissions by ‘Alva’ were reduced under low R:FR conditions compared with control light conditions, although individual volatile compounds were found to be either suppressed, induced or not affected by R:FR. The altered composition of the VOC blend emitted by ‘Alva’ plants exposed to low R:FR was found to affect carbon allocation in receiver plants of ‘Kara’. Conclusions The results indicate that changes in R:FR light conditions influence the emissions of VOCs in barley, and that these altered emissions

  6. Regulation and function of DNA methylation in plants and animals

    KAUST Repository

    He, Xinjian

    2011-02-15

    DNA methylation is an important epigenetic mark involved in diverse biological processes. In plants, DNA methylation can be established through the RNA-directed DNA methylation pathway, an RNA interference pathway for transcriptional gene silencing (TGS), which requires 24-nt small interfering RNAs. In mammals, de novo DNA methylation occurs primarily at two developmental stages: during early embryogenesis and during gametogenesis. While it is not clear whether establishment of DNA methylation patterns in mammals involves RNA interference in general, de novo DNA methylation and suppression of transposons in germ cells require 24-32-nt piwi-interacting small RNAs. DNA methylation status is dynamically regulated by DNA methylation and demethylation reactions. In plants, active DNA demethylation relies on the repressor of silencing 1 family of bifunctional DNA glycosylases, which remove the 5-methylcytosine base and then cleave the DNA backbone at the abasic site, initiating a base excision repair (BER) pathway. In animals, multiple mechanisms of active DNA demethylation have been proposed, including a deaminase- and DNA glycosylase-initiated BER pathway. New information concerning the effects of various histone modifications on the establishment and maintenance of DNA methylation has broadened our understanding of the regulation of DNA methylation. The function of DNA methylation in plants and animals is also discussed in this review. © 2011 IBCB, SIBS, CAS All rights reserved.

  7. Occupational exposure to gases, polycyclic aromatic hydrocarbons and volatile organic compounds in biomass-fired power plants.

    Science.gov (United States)

    Jumpponen, M; Rönkkömäki, H; Pasanen, P; Laitinen, J

    2013-01-01

    The combustion of fuels produces air pollutants in the form of gases, organic compounds, and particulate matter. However, although the environmental aspect of these agents has been examined, workers' exposure to them is still a neglected issue. The purpose of this study was to measure maintenance and ash removal workers' multiple exposures to gases, volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) during their work tasks in biomass-fired power plants. Our hygienic measurements revealed that carbon monoxide, nitric oxide, ammonia and sulfur dioxide were the most common gases that the workers were exposed to during their tasks. Their average concentrations were 0.45 ppm, 0.06 ppm, 0.11 ppm and 0.42 ppm, respectively. Phenanthrene and naphthalene were the most prominent PAHs. At the same sampling points, the most commonly found VOCs were aromatic and aliphatic hydrocarbons and turpentines. The calculated total PAH concentrations were less than 7% of benzo[a]pyrene's eight-hour occupational exposure limit, and the total VOC concentrations were below the Finnish reference value for the normal industrial level in all measured work tasks. The most evident health effect caused by multiple exposures to gases was upper respiratory track irritation, followed by the disruption of oxygen transport, and finally central nervous system disorders. We recommend powered air respirators with ABEK+P3 cartridges and carbon monoxide gas detectors as the minimum requirement for those working inside biomass-fired power plant boilers, and compressed air breathing apparatus as the best form of protection. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Crop growth, light utilization and yield of relay intercropped cotton as affected by plant density and a plant growth regulator

    NARCIS (Netherlands)

    Mao, L.; Zhang, L.; Zhao, X.; Liu, S.; Werf, van der W.; Zhang, S.; Spiertz, J.H.J.; Li, Z.

    2014-01-01

    Modern cotton cultivation requires high plant densities and compact plants. Here we study planting density and growth regulator effects on plant structure and production of cotton when the cotton is grown in a relay intercrop with wheat, a cultivation system that is widespread in China. Field

  9. Effects of different plant growth regulators on blueberry fruit quality

    Science.gov (United States)

    Zhang, X. C.; Zhu, Y. Q.; Wang, Y. N.; Luo, C.; Wang, X.

    2017-08-01

    In order to understand the effects of different plant growth regulators (PGRs) on blueberry fruit growth, various concentrations of Abscisic acid (ABA), Methyl jasmonate (MJ), Brassinolide (BR), Melatonin (MT) were sprayed on blueberry cv. ‘Brigita’ fruits. The results showed that all the PGRs put into effect on improving the quality of blueberry fruit. Comparing with the control plants no PGR spraying,300 mg/L of MT treatment promoted effectively accumulation of the soluble sugar. ABA 20mg/L treatment in-creased effectively accumulation of anthocyanin, and significantly decreased titratable acid content. The treatment of MJ 10mg/L improved significantly the soluble solid content. The effect of the four PGRs treatments on appearance did not show obvious difference.

  10. Regulation of the NADPH Oxidase RBOHD During Plant Immunity.

    Science.gov (United States)

    Kadota, Yasuhiro; Shirasu, Ken; Zipfel, Cyril

    2015-08-01

    Pathogen recognition induces the production of reactive oxygen species (ROS) by NADPH oxidases in both plants and animals. ROS have direct antimicrobial properties, but also serve as signaling molecules to activate further immune outputs. However, ROS production has to be tightly controlled to avoid detrimental effects on host cells, but yet must be produced in the right amount, at the right place and at the right time upon pathogen perception. Plant NADPH oxidases belong to the respiratory burst oxidase homolog (RBOH) family, which contains 10 members in the model plant Arabidopsis thaliana. The perception of pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs) leads to a rapid, specific and strong production of ROS, which is dependent on RBOHD. RBOHD is mainly controlled by Ca(2+) via direct binding to EF-hand motifs and phosphorylation by Ca(2+)-dependent protein kinases. Recent studies have, however, revealed a critical role for a Ca(2+)-independent regulation of RBOHD. The plasma membrane-associated cytoplasmic kinase BIK1 (BOTRYTIS-INDUCED KINASE1), which is a direct substrate of the PRR complex, directly interacts with and phosphorylates RBOHD upon PAMP perception. Impairment of these phosphorylation events completely abolishes the function of RBOHD in immunity. These results suggest that RBOHD activity is tightly controlled by multilayered regulations. In this review, we summarize recent advances in our understanding of the regulatory mechanisms controlling RBOHD activation. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  11. Antenna-predominant and male-biased CSP19 of Sesamia inferens is able to bind the female sex pheromones and host plant volatiles.

    Science.gov (United States)

    Zhang, Ya-Nan; Ye, Zhan-Feng; Yang, Ke; Dong, Shuang-Lin

    2014-02-25

    Insect chemosensory proteins (CSPs) are proposed to capture and transport hydrophobic chemicals across the sensillum lymph to olfactory receptors (ORs), but this has not been clarified in moths. In this study, we built on our previously reported segment sequence work and cloned the full length CSP19 gene (SinfCSP19) from the antennae of Sesamia inferens by using rapid amplification of cDNA ends. Quantitative real time-PCR (qPCR) assays indicated that the gene was expressed in a unique profile, i.e. predominant in antennae and significantly higher in male than in female. To explore the function, recombinant SinfCSP19 was expressed in Escherichia coli cells and purified by Ni-ion affinity chromatography. Binding affinities of the recombinant SinfCSP19 with 39 plant volatiles, 3 sex pheromone components and 10 pheromone analogs were measured using fluorescent competitive binding assays. The results showed that 6 plant volatiles displayed high binding affinities to SinfCSP19 (Ki = 2.12-8.75 μM), and more interesting, the 3 sex pheromone components and analogs showed even higher binding to SinfCSP19 (Ki = 0.49-1.78 μM). Those results suggest that SinfCSP19 plays a role in reception of female sex pheromones of S. inferens and host plant volatiles. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Effects of volatiles from Maruca vitrata larvae and caterpillar-infested flowers of their host plant Vigna unguiculata on the foraging behavior of the parasitoid Apanteles taragamae.

    Science.gov (United States)

    Dannon, Elie A; Tamò, Manuele; Van Huis, Arnold; Dicke, Marcel

    2010-10-01

    The parasitoid wasp Apanteles taragamae is a promising candidate for the biological control of the legume pod borer Maruca vitrata, which recently has been introduced into Benin. The effects of volatiles from cowpea and peabush flowers and Maruca vitrata larvae on host selection behavior of the parasitoid Apanteles taragamae were investigated under laboratory conditions by using a Y-tube olfactometer. Naïve and oviposition-experienced female wasps were given a choice between several odor sources that included (1) uninfested, (2) Maruca vitrata-infested, and (3) mechanically damaged cowpea flowers, as well as (4) stem portions of peabush plants carrying leaves and flowers, (5) healthy M. vitrata larvae, and moribund (6), and live (7) virus-infected M. vitrata larvae. Responses of naïve and oviposition-experienced female wasps did not differ for any of the odor source combinations. Wasps were significantly attracted to floral volatiles produced by cowpea flowers that had been infested with M. vitrata larvae and from which the larvae had been removed. Apanteles taragamae females also were attracted to Maruca vitrata-infested flowers after removal of both the larvae and their feces. Female wasps discriminated between volatiles from previously infested flowers and mechanically damaged flowers. Uninfested cowpea flowers attracted only oviposition-experienced wasps that had received a rewarding experience (i.e. the parasitization of two M. vitrata larvae feeding on cowpea flowers) before the olfactometer test. Wasps also were attracted to uninfested leaves and flowers of peabush. Moreover, they were also attracted to healthy and live virus-infected M. vitrata larvae, but not when the latter were moribund. Our data show that, similarly to what has been extensively been reported for foliar volatiles, flowers of plants also emit parasitoid-attracting volatiles in response to being infested with an herbivore.

  13. Demonstration of risk-based approaches to nuclear plant regulation

    International Nuclear Information System (INIS)

    Rahn, F.J.; Sursock, J.P.; Darling, S.S.; Oddo, J.M.

    1993-01-01

    This paper describes generic technical support EPRI is providing to the nuclear power industry relative to its recent initiatives in the area of risk-based regulations (RBR). A risk-based regulatory approach uses probabilistic risk assessment (PRA), or similar techniques, to allocate safety resources commensurate with the risk posed by nuclear plant operations. This approach will reduce O ampersand M costs, and also improve nuclear plant safety. In order to enhance industry, Nuclear Regulatory Commission (NRC) and public confidence in RBR, three things need to be shown: (1) manpower/resource savings are significant for both NRC and industry; (2) the process is doable in a reasonable amount of time; and (3) the process, if uniformly applied, results in demonstrably cheaper power and safer plants. In 1992, EPRI performed a qualitative study of the key RBR issues contributing to high O ampersand M costs. The results are given on Table 1. This study is being followed up by an in-depth quantitative cost/benefit study to focus technical work on producing guidelines/procedures for licensing submittals to NRC. The guidelines/procedures necessarily will be developed from successful demonstration projects such as the Fitzpatrick pilot plant study proposed by the New York Power Authority and other generic applications. This paper presents three examples: two motor operated valve projects performed by QUADREX Energy Services Corporation working with utilities in responding to NRC Generic Letter 89-10, and a third project working with Yankee Atomic Electric Company on service water systems at a plant in its service system. These demonstration projects aim to show the following: (1) the relative ease of putting together a technical case based on RBR concepts; (2) clarity in differentiating the various risk trade-offs, and in communicating overall reductions in risk with NRC; and (3) improved prioritization of NRC directives

  14. Modules of co-regulated metabolites in turmeric (Curcuma longa) rhizome suggest the existence of biosynthetic modules in plant specialized metabolism.

    Science.gov (United States)

    Xie, Zhengzhi; Ma, Xiaoqiang; Gang, David R

    2009-01-01

    Turmeric is an excellent example of a plant that produces large numbers of metabolites from diverse metabolic pathways or networks. It is hypothesized that these metabolic pathways or networks contain biosynthetic modules, which lead to the formation of metabolite modules-groups of metabolites whose production is co-regulated and biosynthetically linked. To test whether such co-regulated metabolite modules do exist in this plant, metabolic profiling analysis was performed on turmeric rhizome samples that were collected from 16 different growth and development treatments, which had significant impacts on the levels of 249 volatile and non-volatile metabolites that were detected. Importantly, one of the many co-regulated metabolite modules that were indeed readily detected in this analysis contained the three major curcuminoids, whereas many other structurally related diarylheptanoids belonged to separate metabolite modules, as did groups of terpenoids. The existence of these co-regulated metabolite modules supported the hypothesis that the 3-methoxyl groups on the aromatic rings of the curcuminoids are formed before the formation of the heptanoid backbone during the biosynthesis of curcumin and also suggested the involvement of multiple polyketide synthases with different substrate selectivities in the formation of the array of diarylheptanoids detected in turmeric. Similar conclusions about terpenoid biosynthesis could also be made. Thus, discovery and analysis of metabolite modules can be a powerful predictive tool in efforts to understand metabolism in plants.

  15. Plant elicitor peptides are conserved signals regulating direct and indirect antiherbivore defense

    OpenAIRE

    Huffaker, Alisa; Pearce, Gregory; Veyrat, Nathalie; Erb, Matthias; Turlings, Ted C. J.; Sartor, Ryan; Shen, Zhouxin; Briggs, Steven P.; Vaughan, Martha M.; Alborn, Hans T.; Teal, Peter E. A.; Schmelz, Eric A.

    2013-01-01

    Insect-induced defenses occur in nearly all plants and are regulated by conserved signaling pathways. As the first described plant peptide signal, systemin regulates antiherbivore defenses in the Solanaceae, but in other plant families, peptides with analogous activity have remained elusive. In the current study, we demonstrate that a member of the maize (Zea mays) plant elicitor peptide (Pep) family, ZmPep3, regulates responses against herbivores. Consistent with being a signal, expression o...

  16. Navigating the transcriptional roadmap regulating plant secondary cell wall deposition

    Directory of Open Access Journals (Sweden)

    Steven Grant Hussey

    2013-08-01

    Full Text Available The current status of lignocellulosic biomass as an invaluable resource in industry, agriculture and health has spurred increased interest in understanding the transcriptional regulation of secondary cell wall (SCW biosynthesis. The last decade of research has revealed an extensive network of NAC, MYB and other families of transcription factors regulating Arabidopsis SCW biosynthesis, and numerous studies have explored SCW-related transcription factors in other dicots and monocots. Whilst the general structure of the Arabidopsis network has been a topic of several reviews, they have not comprehensively represented the detailed protein-DNA and protein-protein interactions described in the literature, and an understanding of network dynamics and functionality has not yet been achieved for SCW formation. Furthermore the methodologies employed in studies of SCW transcriptional regulation have not received much attention, especially in the case of non-model organisms. In this review, we have reconstructed the most exhaustive literature-based network representations to date of SCW transcriptional regulation in Arabidopsis. We include a manipulable Cytoscape representation of the Arabidopsis SCW transcriptional network to aid in future studies, along with a list of supporting literature for each documented interaction. Amongst other topics, we discuss the various components of the network, its evolutionary conservation in plants, putative modules and dynamic mechanisms that may influence network function, and the approaches that have been employed in network inference. Future research should aim to better understand network function and its response to dynamic perturbations, whilst the development and application of genome-wide approaches such as ChIP-seq and systems genetics are in progress for the study of SCW transcriptional regulation in non-model organisms.

  17. The interaction between strigolactones and other plant hormones in the regulation of plant development

    Directory of Open Access Journals (Sweden)

    Xi eCheng

    2013-06-01

    Full Text Available Plant hormones are small molecules derived from various metabolic pathways and are important regulators of plant development. The most recently discovered phytohormone class comprises the carotenoid-derived strigolactones (SLs. For a long time these compounds were only known to be secreted into the rhizosphere where they act as signalling compounds, but now we know they are also active as endogenous plant hormones and they have been in the spotlight ever since. The initial discovery that SLs are involved in the inhibition of axillary bud outgrowth, initiated a multitude of other studies showing that SLs also play a role in defining root architecture, secondary growth, hypocotyl elongation and seed germination, mostly in interaction with other hormones. Their coordinated action enables the plant to respond in an appropriate manner to environmental factors such as temperature, shading, day length and nutrient availability. Here, we will review the current knowledge on the crosstalk between SLs and other plant hormones – such as auxin, cytokinin, abscisic acid, ethylene and gibberellins - during different physiological processes. We will furthermore take a bird’s eye view of how this hormonal crosstalk enables plants to respond to their ever changing environments.

  18. Plant volatile eliciting FACs in lepidopteran caterpillars, fruit flies and crickets: a convergent evolution or phylogenetic inheritance?

    Directory of Open Access Journals (Sweden)

    Naoko eYoshinaga

    2014-04-01

    Full Text Available Fatty acid amino acid conjugates (FACs, first identified in lepidopteran caterpillar spit as elicitors of plant volatile emission, also have been reported as major components in gut tracts of Drosophila melanogaster and cricket Teleogryllus taiwanemma. The profile of FAC analogs in these two insects was similar to that of tobacco hornworm Manduca sexta, showing glutamic acid conjugates predominantly over glutamine conjugates. The physiological function of FACs is presumably to enhance nitrogen assimilation in Spodoptera litura larvae, but in other insects it is totally unknown. Whether these insects share a common synthetic mechanism of FACs is also unclear. In this study, the biosynthesis of FACs was examined in vitro in five lepidopteran species (M. sexta, Cephonodes hylas, silkworm, S. litura, and Mythimna separata, fruit fly larvae and T. taiwanemma. The fresh midgut tissues of all of the tested insects showed the ability to synthesize glutamine conjugates in vitro when incubated with glutamine and sodium linolenate. Such direct conjugation was also observed for glutamic acid conjugates in all the insects but the product amount was very small and did not reflect the in vivo FAC patterns in each species. In fruit fly larvae, the predominance of glutamic acid conjugates could be explained by a shortage of substrate glutamine in midgut tissues, and in M. sexta, a rapid hydrolysis of glutamine conjugates has been reported. In crickets, we found an additional unique biosynthetic pathway for glutamic acid conjugates. T. taiwanemma converted glutamine conjugates to glutamic acid conjugates by deaminating the side chain of the glutamine moiety. Considering these findings together with previous results, a possibility that FACs in these insects are results of convergent evolution can not be ruled out, but it is more likely that the ancestral insects had the glutamine conjugates and crickets and other insects developed glutamic acid conjugates in a

  19. Regulating the regulators: responses of four plant growth regulators during clonal propagation of Lachenalia montana

    Czech Academy of Sciences Publication Activity Database

    Aremu, A.O.; Plačková, Lenka; Masondo, N.A.; Amoo, S.O.; Moyo, M.; Novák, Ondřej; Doležal, Karel; Van Staden, J.

    2017-01-01

    Roč. 82, č. 2 (2017), s. 305-315 ISSN 0167-6903 R&D Projects: GA MŠk LK21306; GA MŠk(CZ) LO1204; GA ČR GA14-34792S Institutional support: RVO:61389030 Keywords : adventitious bud formation * zeatin-type cytokinins * in-vitro * cv ronina * endogenous cytokinin * biological -activity * bulb production * south-africa * biotechnology * organogenesis * Asparagaceae * Floriculture * Phytohormones * Physiological disorders * meta-Topolin * Ornamentals Subject RIV: EF - Botanics OBOR OECD: Plant sciences, botany Impact factor: 2.646, year: 2016

  20. the role of plant growth regulators in morphogenesis

    Directory of Open Access Journals (Sweden)

    A. Mujib

    2018-01-01

    Full Text Available Althaea officinalis L. (marshmallow belonging to the Malvaceae family, is an important plant that contains a variety of important phytocompounds including asparagine, pectin, flavonoids, polyphenolic acid, and scopoletin. The yield of these compounds can be improved using biotechnological methods that allow for a steady and continuous regeneration of plant material. To the best of our knowledge, thus far, the In vitro clonal multiplication of marshmallow has not been attempted on a large scale. Therefore, in this study, we developed callus induction and multiple shoot regeneration protocols from explants. All the explants, i.e., roots, nodes, and leaves, evoked compact white or yellow calli in a medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D, which grew vigorously. The callus induction frequency was the highest (62.1% from stem nodes, followed by leaves (39.1% and roots (27.5%. The differential behavior of explants in response to various plant growth regulators (PGRs was studied. The calli from leaves and roots were noted to be non-organogenic/embryogenic in media containing different PGR concentrations and have been described in this communication. The stem nodes used were cultured on MS media amended with different concentrations of benzyl-amino-purine (BAP: 0.5, 1.0, and 2.0 mg/l. Multiple shoots were formed at variable numbers, the maximum being in a medium supplemented with 1.0 mg/l of BAP. The induced shoots were rooted in IBA-, NAA-, and IAA-amended media, where IBA at 0.5 mg/l induced a maximum number of roots (8.8 roots/shoot. The regenerated plants were transferred to plastic pots, filled with soilrite and soil (1 : 1, and finally, transferred to outdoor conditions.

  1. Volatility Discovery

    DEFF Research Database (Denmark)

    Dias, Gustavo Fruet; Scherrer, Cristina; Papailias, Fotis

    The price discovery literature investigates how homogenous securities traded on different markets incorporate information into prices. We take this literature one step further and investigate how these markets contribute to stochastic volatility (volatility discovery). We formally show...... that the realized measures from homogenous securities share a fractional stochastic trend, which is a combination of the price and volatility discovery measures. Furthermore, we show that volatility discovery is associated with the way that market participants process information arrival (market sensitivity......). Finally, we compute volatility discovery for 30 actively traded stocks in the U.S. and report that Nyse and Arca dominate Nasdaq....

  2. Maize yield and quality in response to plant density and application of a novel plant growth regulator

    NARCIS (Netherlands)

    Zhang, Q.; Zhang, L.; Evers, J.B.; Werf, van der W.; Zhang, W.; Duan, L.

    2014-01-01

    Farmers in China have gradually increased plant density in maize to achieve higher yields, but this has increased risk of lodging due to taller and weaker stems at higher plant densities. Plant growth regulators can be used to reduce lodging risk. In this study, for the first time, the performance

  3. Heat shock and plant leachates regulate seed germination of the endangered carnivorous plant Drosophyllum lusitanicum

    Directory of Open Access Journals (Sweden)

    S. Gómez-González

    2018-01-01

    Full Text Available In fire-prone ecosystems, many plant species have specialized mechanisms of seed dormancy that ensure a successful recruitment after fire. A well-documented mechanism is the germination stimulated by fire-related cues, such as heat shock and smoke. However, less is known about the role of inhibitory germination signals (e.g. allelopathy in regulating post-fire recruitment. Plant leachates derived from the unburned vegetation can enforce dormancy by means of allelopathic compounds, acting as a signal of unfavourable (highly competitive niche for germination in pyrophyte species. Here, we assessed the separate effects of heat shock and plant leachates on seed germination of Drosophyllum lusitanicum, an endangered carnivorous plant endemic to Mediterranean fire-prone heathlands. We performed a germination experiment in which seeds were subjected to three treatments: (1 5 min at 100 °C, (2 watering with plant leachate, and (3 control. Germination rate and seed viability was determined after 63 days. Heat shock stimulated seed germination in D. lusitanicum while plant leachates had inhibitory germination effects without reducing seed viability. Thus, both positive and negative signals could be involved in its successful post-fire recruitment. Fire would break seed dormancy and stimulate seed germination of D. lusitanicum through high temperatures, but also by eliminating allelochemical compounds from the soil. These results help to understand the population dynamics patterns found for D. lusitanicum in natural populations, and highlight the role of fire in the ecology and conservation of this endangered species. Seed dormancy imposed by plant-derived leachates as an adaptive mechanism should be considered more in fire ecology theory.

  4. Gaseous diffusion plant transition from DOE to external regulation

    International Nuclear Information System (INIS)

    Dann, R.K.; Crites, T.R.; Rahm-Crites, L.K.

    1997-01-01

    After many years of operation as government-owned/contractor-operated facilities, large portions of the gaseous diffusion plants (GDPs) at Portsmouth, Ohio, and Paducah, Kentucky, were leased to the United States Enrichment Corporation (USEC). These facilities are now certified by the U.S. Nuclear Regulatory Commission (NRC) and subject to oversight by the Occupational Safety and Health Administration (OSHA). The transition from DOE to NRC regulation was more difficult than expected. The original commitment was to achieve NRC certification in October 1995; however, considerably more time was required and transition-related costs escalated. The Oak Ridge Operations Office originally estimated the cost of transition at $60 million; $240 million has been spent to date. The DOE's experience in transitioning the GDPs to USEC operation with NRC oversight provides valuable lessons (both positive and negative) that could be applied to future transitions

  5. Probabilistic risk assessment in nuclear power plant regulation

    Energy Technology Data Exchange (ETDEWEB)

    Wall, J B

    1980-09-01

    A specific program is recommended to utilize more effectively probabilistic risk assessment in nuclear power plant regulation. It is based upon the engineering insights from the Reactor Safety Study (WASH-1400) and some follow-on risk assessment research by USNRC. The Three Mile Island accident is briefly discussed from a risk viewpoint to illustrate a weakness in current practice. The development of a probabilistic safety goal is recommended with some suggestions on underlying principles. Some ongoing work on risk perception and the draft probabilistic safety goal being reviewed on Canada is described. Some suggestions are offered on further risk assessment research. Finally, some recent U.S. Nuclear Regulatory Commission actions are described.

  6. Incentive regulation of investor-owned nuclear power plants by public utility regulators

    International Nuclear Information System (INIS)

    McKinney, M.D.; Elliot, D.B.

    1993-01-01

    The US Nuclear Regulatory Commission (NRC) periodically surveys the Federal Energy Regulatory Commission (FERC) and state regulatory commissions that regulate utility owners of nuclear power plants. The NRC is interested in identifying states that have established economic or performance incentive programs applicable to nuclear power plants, including states with new programs, how the programs are being implemented, and in determining the financial impact of the programs on the utilities. The NRC interest stems from the fact that such programs have the potential to adversely affect the safety of nuclear power plants. The information in this report was obtained from interviews conducted with each state regulatory agency that administers an incentive program and each utility that owns at least 10% of an affected nuclear power plant. The agreements, orders, and settlements that form the basis for each incentive program were reviewed as required. The interviews and supporting documentation form the basis for the individual state reports describing the structure and financial impact of each incentive program

  7. Abandoned floodplain plant communities along a regulated dryland river

    Science.gov (United States)

    Reynolds, L. V.; Shafroth, Patrick B.; House, P. K.

    2014-01-01

    Rivers and their floodplains worldwide have changed dramatically over the last century because of regulation by dams, flow diversions and channel stabilization. Floodplains no longer inundated by river flows following dam-induced flood reduction comprise large areas of bottomland habitat, but the effects of abandonment on plant communities are not well understood. Using a hydraulic flow model, geomorphic mapping and field surveys, we addressed the following questions along the Bill Williams River, Arizona: (i) What per cent of the bottomland do abandoned floodplains comprise? and (ii) Are abandoned floodplains quantitatively different from adjacent xeric and riparian surfaces in terms of vegetation composition and surface sediment? We found that nearly 70% of active channel and floodplain area was abandoned following dam installation. Abandoned floodplains along the Bill Williams River tend to be similar to each other yet distinct from neighbouring habitats: they have been altered physically from their historic state, leading to distinct combinations of surface sediments, hydrology and plant communities. Abandoned floodplains may transition to xeric communities over time but are likely to retain some riparian qualities as long as there is access to relatively shallow ground water. With expected increases in water demand and drying climatic conditions in many regions, these surfaces and associated vegetation will continue to be extensive in riparian landscapes worldwide

  8. A quantitative and dynamic model for plant stem cell regulation.

    Directory of Open Access Journals (Sweden)

    Florian Geier

    Full Text Available Plants maintain pools of totipotent stem cells throughout their entire life. These stem cells are embedded within specialized tissues called meristems, which form the growing points of the organism. The shoot apical meristem of the reference plant Arabidopsis thaliana is subdivided into several distinct domains, which execute diverse biological functions, such as tissue organization, cell-proliferation and differentiation. The number of cells required for growth and organ formation changes over the course of a plants life, while the structure of the meristem remains remarkably constant. Thus, regulatory systems must be in place, which allow for an adaptation of cell proliferation within the shoot apical meristem, while maintaining the organization at the tissue level. To advance our understanding of this dynamic tissue behavior, we measured domain sizes as well as cell division rates of the shoot apical meristem under various environmental conditions, which cause adaptations in meristem size. Based on our results we developed a mathematical model to explain the observed changes by a cell pool size dependent regulation of cell proliferation and differentiation, which is able to correctly predict CLV3 and WUS over-expression phenotypes. While the model shows stem cell homeostasis under constant growth conditions, it predicts a variation in stem cell number under changing conditions. Consistent with our experimental data this behavior is correlated with variations in cell proliferation. Therefore, we investigate different signaling mechanisms, which could stabilize stem cell number despite variations in cell proliferation. Our results shed light onto the dynamic constraints of stem cell pool maintenance in the shoot apical meristem of Arabidopsis in different environmental conditions and developmental states.

  9. Tomato Infection by Whitefly-Transmitted Circulative and Non-Circulative Viruses Induce Contrasting Changes in Plant Volatiles and Vector Behaviour.

    Science.gov (United States)

    Fereres, Alberto; Peñaflor, Maria Fernanda G V; Favaro, Carla F; Azevedo, Kamila E X; Landi, Carolina H; Maluta, Nathalie K P; Bento, José Mauricio S; Lopes, Joao R S

    2016-08-11

    Virus infection frequently modifies plant phenotypes, leading to changes in behaviour and performance of their insect vectors in a way that transmission is enhanced, although this may not always be the case. Here, we investigated Bemisia tabaci response to tomato plants infected by Tomato chlorosis virus (ToCV), a non-circulative-transmitted crinivirus, and Tomato severe rugose virus (ToSRV), a circulative-transmitted begomovirus. Moreover, we examined the role of visual and olfactory cues in host plant selection by both viruliferous and non-viruliferous B. tabaci. Visual cues alone were assessed as targets for whitefly landing by placing leaves underneath a Plexiglas plate. A dual-choice arena was used to assess whitefly response to virus-infected and mock-inoculated tomato leaves under light and dark conditions. Thereafter, we tested the whitefly response to volatiles using an active air-flow Y-tube olfactometer, and chemically characterized the blends using gas chromatography coupled to mass spectrometry. Visual stimuli tests showed that whiteflies, irrespective of their infectious status, always preferred to land on virus-infected rather than on mock-inoculated leaves. Furthermore, whiteflies had no preference for either virus-infected or mock-inoculated leaves under dark conditions, but preferred virus-infected leaves in the presence of light. ToSRV-infection promoted a sharp decline in the concentration of some tomato volatiles, while an increase in the emission of some terpenes after ToCV infection was found. ToSRV-viruliferous whiteflies preferred volatiles emitted from mock-inoculated plants, a conducive behaviour to enhance virus spread, while volatiles from ToCV-infected plants were avoided by non-viruliferous whiteflies, a behaviour that is likely detrimental to the secondary spread of the virus. In conclusion, the circulative persistent begomovirus, ToSRV, seems to have evolved together with its vector B. tabaci to optimise its own spread. However

  10. Tomato Infection by Whitefly-Transmitted Circulative and Non-Circulative Viruses Induce Contrasting Changes in Plant Volatiles and Vector Behaviour

    Directory of Open Access Journals (Sweden)

    Alberto Fereres

    2016-08-01

    Full Text Available Virus infection frequently modifies plant phenotypes, leading to changes in behaviour and performance of their insect vectors in a way that transmission is enhanced, although this may not always be the case. Here, we investigated Bemisia tabaci response to tomato plants infected by Tomato chlorosis virus (ToCV, a non-circulative-transmitted crinivirus, and Tomato severe rugose virus (ToSRV, a circulative-transmitted begomovirus. Moreover, we examined the role of visual and olfactory cues in host plant selection by both viruliferous and non-viruliferous B. tabaci. Visual cues alone were assessed as targets for whitefly landing by placing leaves underneath a Plexiglas plate. A dual-choice arena was used to assess whitefly response to virus-infected and mock-inoculated tomato leaves under light and dark conditions. Thereafter, we tested the whitefly response to volatiles using an active air-flow Y-tube olfactometer, and chemically characterized the blends using gas chromatography coupled to mass spectrometry. Visual stimuli tests showed that whiteflies, irrespective of their infectious status, always preferred to land on virus-infected rather than on mock-inoculated leaves. Furthermore, whiteflies had no preference for either virus-infected or mock-inoculated leaves under dark conditions, but preferred virus-infected leaves in the presence of light. ToSRV-infection promoted a sharp decline in the concentration of some tomato volatiles, while an increase in the emission of some terpenes after ToCV infection was found. ToSRV-viruliferous whiteflies preferred volatiles emitted from mock-inoculated plants, a conducive behaviour to enhance virus spread, while volatiles from ToCV-infected plants were avoided by non-viruliferous whiteflies, a behaviour that is likely detrimental to the secondary spread of the virus. In conclusion, the circulative persistent begomovirus, ToSRV, seems to have evolved together with its vector B. tabaci to optimise its own

  11. Cytokinins as key regulators in plant–microbe–insect interactions: connecting plant growth and defence

    NARCIS (Netherlands)

    Giron, D.; Frago, E.; Glevarec, G.; Pieterse, C.M.J.; Dicke, M.

    2013-01-01

    1. Plant hormones play important roles in regulating plant growth and defence by mediating developmental processes and signalling networks involved in plant responses to a wide range of parasitic and mutualistic biotic interactions. 2. Plants are known to rapidly respond to pathogen and herbivore

  12. Food plant toxicants and safety - Risk assessment and regulation of inherent toxicants in plant foods

    DEFF Research Database (Denmark)

    Essers, A.J.A.; Alink, G.M.; Speijers, G.J.A.

    1998-01-01

    The ADI as a tool for risk management and regulation of food additives and pesticide residues is not readily applicable to inherent food plant toxicants: The margin between actual intake and potentially toxic levels is often small; application of the default uncertainty factors used to derive ADI...... values, particularly when extrapolating from animal data, would prohibit the utilisation of the food, which may have an overall beneficial health effect. Levels of inherent toxicants are difficult to control; their complete removal is not always wanted, due to their function for the plant or for human...... health. The health impact of the inherent toxicant is often modified by factors in the food, e.g. the bioavailability from the matrix and interaction with other inherent constituents. Risk-benefit analysis should be made for different consumption scenarios, without the use of uncertainty factors. Crucial...

  13. The effects of selenate and sulphate supply on the accumulation and volatilization of Se by cabbage, kohlrabi and alfalfa plants grown hydroponically

    Directory of Open Access Journals (Sweden)

    R. HAJIBOLAND

    2008-12-01

    Full Text Available The effect of Selenium (Se supplementation at five levels of 0 (control, 5, 10, 15, 20 ìM in plants supplied with one of four concentrations of sulphur (S including 0.05, 0.25, 0.5 and 1.0 mM was investigated in two varieties of Brassica oleracea (cabbage and kohlrabi and alfalfa (Medicago sativa L. in a hydroponic experiment. In severely S deficient plants (0.05 mM, Se acted as a toxic element, alfalfa was the most susceptible plant that died at this treatment. However, in plants supplied with near adequate (0.5 mM or adequate (1.0 mM S, Se acted as a growth promoting element. The most pronounced stimulation of growth was observed in cabbage and the lowest in alfalfa. Increasing S concentration in the medium, reduced Se uptake and transport. In contrast, S uptake and transport increased in response to Se addition. Se volatilization was higher in alfalfa than cabbage and kohlrabi when expressed on unit shoot dry weight or leaf area basis, but not when expressed per plant. Results suggested that Se supplementation of plants supplied with adequate S, not only had beneficial effects on plants growth but also can have application in enrichment of livestock fodder and human food.;

  14. Virtual volatility

    Science.gov (United States)

    Silva, A. Christian; Prange, Richard E.

    2007-03-01

    We introduce the concept of virtual volatility. This simple but new measure shows how to quantify the uncertainty in the forecast of the drift component of a random walk. The virtual volatility also is a useful tool in understanding the stochastic process for a given portfolio. In particular, and as an example, we were able to identify mean reversion effect in our portfolio. Finally, we briefly discuss the potential practical effect of the virtual volatility on an investor asset allocation strategy.

  15. Iodine volatility

    International Nuclear Information System (INIS)

    Beahm, E.C.; Shockley, W.E.

    1984-01-01

    The ultimate aim of this program is to couple experimental aqueous iodine volatilities to a fission product release model. Iodine partition coefficients, for inorganic iodine, have been measured during hydrolysis and radiolysis. The hydrolysis experiments have illustrated the importance of reaction time on iodine volatility. However, radiolysis effects can override hydrolysis in determining iodine volatility. In addition, silver metal in radiolysis samples can react to form silver iodide accompanied by a decrease in iodine volatility. Experimental data are now being coupled to an iodine transport and release model that was developed in the Federal Republic of Germany

  16. Identification of Host-Plant Volatiles and Characterization of Two Novel General Odorant-Binding Proteins from the Legume Pod Borer, Maruca vitrata Fabricius (Lepidoptera: Crambidae.

    Directory of Open Access Journals (Sweden)

    Jing Zhou

    Full Text Available Chemoreception is a key feature in selection of host plant by phytophagous insects, and odorant-binding proteins (OBPs are involved in chemical communication of both insects and vertebrates. The legume pod borer, Maruca vitrata Fabricius (Lepidoptera: Crambidae is one of the key pest species of cowpea and widely distributed throughout tropical and subtropical regions, causing up to 80% of yield loss. In this study, we investigated the electrophysiological responses of female M. vitrata to floral volatiles from V. unguiculata. Seventeen electroantennogram-active compounds were identified from floral volatiles of V. unguiculata by coupled gas chromatography-electroantennography (GC-EAD and gas chromatography-mass spectrometry (GC-MS. Then, we cloned two novel full-length GOBP genes (MvitGOBP1 and MvitGOBP2 from the antennae of M. vitrata using reverse transcription PCR. Protein sequence analysis indicated that they shared high sequence similarity with other Pyralididae insect GOBPs and had the typical six-cysteine signature. Real-time PCR analysis indicated that MvitGOBP1-2 mRNA was highly expressed in the antennae of female adult with several thousands-fold difference compare to other tissue. Next, the recombinant MvitGOBP1-2 was expressed in Escherichia coli and purified using Ni ion affinity chromatography. Fluorescence binding assays demonstrated that MvitGOBP1-2 had different binding affinities with 17 volatile odorant molecules including butanoic acid butyl ester, limonene, 4-ethylpropiophenone, 1H-indol-4-ol, butanoic acid octyl ester and 2-methyl-3-phenylpropanal. In the field trapping experiment, these six floral volatiles could effectively attract female moths and showed significant difference compared with the blank lure. These results suggested that MvitGOBPs and the seventeen floral volatiles are likely to function in the olfactory behavior response of female moths, which may have played crucial roles in the selection of oviposition

  17. Lifetime Management in Non-US-Technology Nuclear Power Plants using US Regulations

    International Nuclear Information System (INIS)

    Cornelius Steenkamp, J.; Encabo Espartero, J.; Garcia Iglesias, R.

    2013-01-01

    In July 2009 the Spanish Nuclear Regulator (CSN) issued a Safety Instruction (IS-22) for the development of Lifetime Management in the Nuclear Power Plants within Spain. The context of this Safety Instruction is based on the American Regulations 10CFR54, NUREG1800/1801 and the technical guide NEI95-10. All these regulations are aimed at US-Technology Nuclear Power Plants. Lifetime Management of Nuclear Power Plants with a plant design different from US technologies can most certainly be developed with the mentioned US regulations. The successful development of Lifetime Management in these cases depends on the adaptation of the different requirements of the regulations. Challenges resulting from the adaptation process can be resolved by taking into consideration the plant design of the plant in question.

  18. Regulation and diversity of plant polysaccharide utilisation in fungi

    NARCIS (Netherlands)

    Battaglia, E.

    2011-01-01

    Filamentous fungi obtain their nutrients by degrading dead or living plant material. Plant material consists of different cell wall and storage polysaccharides. Due to the complex structure and the variety of plant polysaccharides, filamentous fungi secrete a wide range of plant polysaccharide

  19. Plant Growth Regulators as Potential Tools in Aquatic Plant Management: Efficacy and Persistence in Small-Scale Tests

    Science.gov (United States)

    1994-01-01

    gratefully acknowledge the support of the Waterways Experi- ment Station and Drs. Howard Westerdahl and Kurt Getsinger as this research was being conducted...E. Westerdahl , eds., Plant Growth Regulator Society of America, San Antonio, TX, 127-45. Anderson, L. W. J., and Dechoretz, N. (1988). "Bensulfuron...Vegetation Management. J. E. Kaufman and H. E. Westerdahl , eds., Plant Growth Regulator Society of America, San Antonio, TX, 155-86. Herbicide Handbook

  20. Regulation of sucrose metabolism in higher plants: localization and regulation of activity of key enzymes

    Science.gov (United States)

    Winter, H.; Huber, S. C.; Brown, C. S. (Principal Investigator)

    2000-01-01

    Sucrose (Suc) plays a central role in plant growth and development. It is a major end product of photosynthesis and functions as a primary transport sugar and in some cases as a direct or indirect regulator of gene expression. Research during the last 2 decades has identified the pathways involved and which enzymes contribute to the control of flux. Availability of metabolites for Suc synthesis and 'demand' for products of sucrose degradation are important factors, but this review specifically focuses on the biosynthetic enzyme sucrose-phosphate synthase (SPS), and the degradative enzymes, sucrose synthase (SuSy), and the invertases. Recent progress has included the cloning of genes encoding these enzymes and the elucidation of posttranslational regulatory mechanisms. Protein phosphorylation is emerging as an important mechanism controlling SPS activity in response to various environmental and endogenous signals. In terms of Suc degradation, invertase-catalyzed hydrolysis generally has been associated with cell expansion, whereas SuSy-catalyzed metabolism has been linked with biosynthetic processes (e.g., cell wall or storage products). Recent results indicate that SuSy may be localized in multiple cellular compartments: (1) as a soluble enzyme in the cytosol (as traditionally assumed); (2) associated with the plasma membrane; and (3) associated with the actin cytoskeleton. Phosphorylation of SuSy has been shown to occur and may be one of the factors controlling localization of the enzyme. The purpose of this review is to summarize some of the recent developments relating to regulation of activity and localization of key enzymes involved in sucrose metabolism in plants.

  1. Effects of plant growth regulators on callus, shoot and root formation ...

    African Journals Online (AJOL)

    Root and stem explants of fluted pumpkin were cultured in medium containing different types and concentrations of plant growth regulators (PGRs). The explants were observed for callus, root and shoot formation parameters after four months. Differences among explants, plant growth regulators and their interaction were ...

  2. Utilization of γ-irradiation technique on plant mutation breeding and plant growth regulation in Tokyo Metropolitan Isotope Research Center

    International Nuclear Information System (INIS)

    Suda, Hirokatsu

    1997-01-01

    During about 30-years, we have developed γ-irradiation technique and breeding back pruning method for the study of mutation breeding of ornamental plants. As a result, we have made a wide variety of new mutant lines in chrysanthemum, narcissus, begonia rex, begonia iron cross, winter daphne, zelkova, sweet-scented oleander, abelia, kobus, and have obtained 7 plant patents. By the use of γ-irradiation to plant mutation breeding, we often observed that plants irradiated by low dose of γ-rays showed superior or inferior growth than the of non-irradiated plants. Now, we established the irradiation conditions of γ-rays for mutation breeding and growth of regulation in narcissus, tulip, Enkianthus perulatus Schneid., komatsuna, moyashi, african violet. In most cases, irradiation dose rate is suggested to be a more important factor to induce plant growth regulators than irradiation dose. (author)

  3. Comparative Digital Gene Expression Analysis of the Arabidopsis Response to Volatiles Emitted by Bacillus amyloliquefaciens.

    Directory of Open Access Journals (Sweden)

    Hai-Ting Hao

    Full Text Available Some plant growth-promoting rhizobacteria (PGPR regulated plant growth and elicited plant basal immunity by volatiles. The response mechanism to the Bacillus amyloliquefaciens volatiles in plant has not been well studied. We conducted global gene expression profiling in Arabidopsis after treatment with Bacillus amyloliquefaciens FZB42 volatiles by Illumina Digital Gene Expression (DGE profiling of different growth stages (seedling and mature and tissues (leaves and roots. Compared with the control, 1,507 and 820 differentially expressed genes (DEGs were identified in leaves and roots at the seedling stage, respectively, while 1,512 and 367 DEGs were identified in leaves and roots at the mature stage. Seventeen genes with different regulatory patterns were validated using quantitative RT-PCR. Numerous DEGs were enriched for plant hormones, cell wall modifications, and protection against stress situations, which suggests that volatiles have effects on plant growth and immunity. Moreover, analyzes of transcriptome difference in tissues and growth stage using DGE profiling showed that the plant response might be tissue-specific and/or growth stage-specific. Thus, genes encoding flavonoid biosynthesis were downregulated in leaves and upregulated in roots, thereby indicating tissue-specific responses to volatiles. Genes related to photosynthesis were downregulated at the seedling stage and upregulated at the mature stage, respectively, thereby suggesting growth period-specific responses. In addition, the emission of bacterial volatiles significantly induced killing of cells of other organism pathway with up-regulated genes in leaves and the other three pathways (defense response to nematode, cell morphogenesis involved in differentiation and trichoblast differentiation with up-regulated genes were significantly enriched in roots. Interestingly, some important alterations in the expression of growth-related genes, metabolic pathways, defense response

  4. E-β-ocimene, a volatile brood pheromone involved in social regulation in the honey bee colony (Apis mellifera.

    Directory of Open Access Journals (Sweden)

    Alban Maisonnasse

    Full Text Available BACKGROUND: In honey bee colony, the brood is able to manipulate and chemically control the workers in order to sustain their own development. A brood ester pheromone produced primarily by old larvae (4 and 5 days old larvae was first identified as acting as a contact pheromone with specific effects on nurses in the colony. More recently a new volatile brood pheromone has been identified: E-β-ocimene, which partially inhibits ovary development in workers. METHODOLOGY AND PRINCIPAL FINDING: Our analysis of E-β-ocimene production revealed that young brood (newly hatched to 3 days old produce the highest quantity of E-β-ocimene relative to their body weight. By testing the potential action of this molecule as a non-specific larval signal, due to its high volatility in the colony, we demonstrated that in the presence of E-β-ocimene nest workers start to forage earlier in life, as seen in the presence of real brood. CONCLUSIONS/SIGNIFICANCE: In this way, young larvae are able to assign precedence to the task of foraging by workers in order to increase food stores for their own development. Thus, in the complexity of honey bee chemical communication, E-β-ocimene, a pheromone of young larvae, provides the brood with the means to express their nutritional needs to the workers.

  5. Possible effects of regulating hydroponic water temperature on plant ...

    African Journals Online (AJOL)

    Yomi

    2010-12-29

    Dec 29, 2010 ... temperature on plant growth, accumulation of nutrients and other metabolites ... Padda and Picha, 2008), a defensive mechanism em- ployed by plants ..... and flower development will vary depending on the growth stage of ...

  6. Volatile, anthocyanidin, quality and sensory changes in rabbiteye blueberry from whole fruit through pilot plant juice processing.

    Science.gov (United States)

    Beaulieu, John C; Stein-Chisholm, Rebecca E; Lloyd, Steven W; Bett-Garber, Karen L; Grimm, Casey C; Watson, Michael A; Lea, Jeanne M

    2017-01-01

    High antioxidant content and keen marketing have increased blueberry demand and increased local production which in turn mandates new uses for abundant harvests. Pilot scale processes were employed to investigate the anthocyanidin profiles, qualitative volatile compositions, and sensorial attributes in not-from-concentrate (NFC) 'Tifblue' rabbiteye blueberry juices. Processing prior to pasteurization generally resulted in increased L * and hue angle color, while a * , b * , and C * decreased. After 4 months pasteurized storage, non-clarified juice (NCP) lost 73.8% of total volatiles compared with 70.9% in clarified juice (CJP). There was a total anthocyanidin decrease of 84.5% and 85.5% after 4 months storage in NCP and CJP, respectively. Storage itself resulted in only 14.2% and 7.2% anthocyanidin loss after pasteurization in NCP and CJP. Storage significantly affected nine flavor properties in juices; however, there were no significant differences in the blueberry, strawberry, purple grape, floral, sweet aroma, or sweet tastes between processed and stored juices. NFC pasteurized blueberry juices maintained desirable flavors even though highly significant volatile and anthocyanidin losses occurred through processing. Maintenance of color and flavor indicate that NFC juices could have an advantage over more abusive methods often used in commercial juice operations. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  7. Regulation and accumulation of secondary metabolites in plant ...

    African Journals Online (AJOL)

    Therefore a deeper insight in mutualistic symbiosis is of great importance for biological applications: (1) the plant/microbial co-culture system in vitro may be perfectly useful to guide the cultivation of medicinal plants for obtaining high level of bioactive compounds; (2) manipulating plant released signal molecules and ...

  8. NaJAZh Regulates a Subset of Defense Responses against Herbivores and Spontaneous Leaf Necrosis in Nicotiana attenuata Plants[C][W][OA

    Science.gov (United States)

    Oh, Youngjoo; Baldwin, Ian T.; Gális, Ivan

    2012-01-01

    The JASMONATE ZIM DOMAIN (JAZ) proteins function as negative regulators of jasmonic acid signaling in plants. We cloned 12 JAZ genes from native tobacco (Nicotiana attenuata), including nine novel JAZs in tobacco, and examined their expression in plants that had leaves elicited by wounding or simulated herbivory. Most JAZ genes showed strong expression in the elicited leaves, but NaJAZg was mainly expressed in roots. Another novel herbivory-elicited gene, NaJAZh, was analyzed in detail. RNA interference suppression of this gene in inverted-repeat (ir)JAZh plants deregulated a specific branch of jasmonic acid-dependent direct and indirect defenses: irJAZh plants showed greater trypsin protease inhibitor activity, 17-hydroxygeranyllinalool diterpene glycosides accumulation, and emission of volatile organic compounds from leaves. Silencing of NaJAZh also revealed a novel cross talk in JAZ-regulated secondary metabolism, as irJAZh plants had significantly reduced nicotine levels. In addition, irJAZh spontaneously developed leaf necrosis during the transition to flowering. Because the lesions closely correlated with the elevated expression of programmed cell death genes and the accumulations of salicylic acid and hydrogen peroxide in the leaves, we propose a novel role of the NaJAZh protein as a repressor of necrosis and/or programmed cell death during plant development. PMID:22496510

  9. Unstable volatility

    DEFF Research Database (Denmark)

    Casas, Isabel; Gijbels, Irène

    2012-01-01

    The objective of this paper is to introduce the break-preserving local linear (BPLL) estimator for the estimation of unstable volatility functions for independent and asymptotically independent processes. Breaks in the structure of the conditional mean and/or the volatility functions are common...... in Finance. Nonparametric estimators are well suited for these events due to the flexibility of their functional form and their good asymptotic properties. However, the local polynomial kernel estimators are not consistent at points where the volatility function has a break. The estimator presented...

  10. Chasing volatility

    DEFF Research Database (Denmark)

    Caporin, Massimiliano; Rossi, Eduardo; Santucci de Magistris, Paolo

    The realized volatility of financial returns is characterized by persistence and occurrence of unpreditable large increments. To capture those features, we introduce the Multiplicative Error Model with jumps (MEM-J). When a jump component is included in the multiplicative specification, the condi......The realized volatility of financial returns is characterized by persistence and occurrence of unpreditable large increments. To capture those features, we introduce the Multiplicative Error Model with jumps (MEM-J). When a jump component is included in the multiplicative specification...... estimate alternative specifications of the model using a set of daily bipower measures for 7 stock indexes and 16 individual NYSE stocks. The estimates of the jump component confirm that the probability of jumps dramatically increases during the financial crisis. Compared to other realized volatility...... models, the introduction of the jump component provides a sensible improvement in the fit, as well as for in-sample and out-of-sample volatility tail forecasts....

  11. Emissions of biogenic volatile organic compounds and subsequent photochemical production of secondary organic aerosol in mesocosm studies of temperate and tropical plant species

    Science.gov (United States)

    Wyche, K. P.; Ryan, A. C.; Hewitt, C. N.; Alfarra, M. R.; McFiggans, G.; Carr, T.; Monks, P. S.; Smallbone, K. L.; Capes, G.; Hamilton, J. F.; Pugh, T. A. M.; MacKenzie, A. R.

    2014-12-01

    Silver birch (Betula pendula) and three Southeast Asian tropical plant species (Ficus cyathistipula, Ficus benjamina and Caryota millis) from the pantropical fig and palm genera were grown in a purpose-built and environment-controlled whole-tree chamber. The volatile organic compounds emitted from these trees were characterised and fed into a linked photochemical reaction chamber where they underwent photo-oxidation under a range of controlled conditions (relative humidity or RH ~65-89%, volatile organic compound-to-NOx or VOC / NOx ~3-9 and NOx ~2 ppbV). Both the gas phase and the aerosol phase of the reaction chamber were monitored in detail using a comprehensive suite of on-line and off-line chemical and physical measurement techniques. Silver birch was found to be a high monoterpene and sesquiterpene but low isoprene emitter, and its emissions were observed to produce measurable amounts of secondary organic aerosol (SOA) via both nucleation and condensation onto pre-existing seed aerosol (YSOA 26-39%). In contrast, all three tropical species were found to be high isoprene emitters with trace emissions of monoterpenes and sesquiterpenes. In tropical plant experiments without seed aerosol there was no measurable SOA nucleation, but aerosol mass was shown to increase when seed aerosol was present. Although principally isoprene emitting, the aerosol mass produced from tropical fig was mostly consistent (i.e. in 78 out of 120 aerosol mass calculations using plausible parameter sets of various precursor specific yields) with condensation of photo-oxidation products of the minor volatile organic compounds (VOCs) co-emitted; no significant aerosol yield from condensation of isoprene oxidation products was required in the interpretations of the experimental results. This finding is in line with previous reports of organic aerosol loadings consistent with production from minor biogenic VOCs co-emitted with isoprene in principally isoprene-emitting landscapes in Southeast

  12. Plant species richness regulates soil respiration through changes in productivity.

    NARCIS (Netherlands)

    Tavares Correa Dias, A.; van Ruijven, J.; Berendse, F.

    2010-01-01

    Soil respiration is an important pathway of the C cycle. However, it is still poorly understood how changes in plant community diversity can affect this ecosystem process. Here we used a long-term experiment consisting of a gradient of grassland plant species richness to test for effects of

  13. Plant species richness regulates soil respiration through changes in productivity

    NARCIS (Netherlands)

    Dias, A.A.; Ruijven, van J.; Berendse, F.

    2010-01-01

    Soil respiration is an important pathway of the C cycle. However, it is still poorly understood how changes in plant community diversity can affect this ecosystem process. Here we used a long-term experiment consisting of a gradient of grassland plant species richness to test for effects of

  14. Regulation of the adaptation to zinc deficiency in plants

    NARCIS (Netherlands)

    Assuncao, A.G.L.; Schat, H.; Aarts, M.G.

    2010-01-01

    The molecular mechanisms by which plants sense their micronutrient status, and adapt to their environment in order to ensure a sufficient micronutrient supply, are poorly understood. Zinc is an essential micronutrient for all living organisms. When facing a shortage in zinc supply, plants adapt by

  15. Possible effects of regulating hydroponic water temperature on plant ...

    African Journals Online (AJOL)

    Water temperature can affect many physiological processes during plant growth and development. Temperatures below or above optimum levels may influence plant metabolic activities positively or negatively. This may include accumulation of different metabolites such as phenolic compounds, reactive oxygen species ...

  16. Thidiazuron: A multi-dimensional plant growth regulator | Guo ...

    African Journals Online (AJOL)

    Thidiazuron (TDZ) has gained a considerable attention during past decades due to its efficient role in plant cell and tissue culture. Wide array of physiological responses were observed in response to TDZapplication in different plant species. TDZ has shown both auxin and cytokinin like effects, although, chemically, it is ...

  17. Tissue-Specific Floral Transcriptome Analysis of the Sexually Deceptive Orchid Chiloglottis trapeziformis Provides Insights into the Biosynthesis and Regulation of Its Unique UV-B Dependent Floral Volatile, Chiloglottone 1

    Directory of Open Access Journals (Sweden)

    Darren C. J. Wong

    2017-07-01

    Full Text Available The Australian sexually deceptive orchid, Chiloglottis trapeziformis, employs a unique UV-B-dependent floral volatile, chiloglottone 1, for specific male wasp pollinator attraction. Chiloglottone 1 and related variants (2,5-dialkylcyclohexane-1,3-diones, represent a unique class of specialized metabolites presumed to be the product of cyclization between two fatty acid (FA precursors. However, the genes involved in the biosynthesis of precursors, intermediates, and transcriptional regulation remains to be discovered. Chiloglottone 1 production occurs in the aggregation of calli (callus on the labellum under continuous UV-B light. Therefore, deep sequencing, transcriptome assembly, and differential expression (DE analysis were performed across different tissue types and UV-B treatments. Transcripts expressed in the callus and labellum (∼23,000 transcripts were highly specialized and enriched for a diversity of known and novel metabolic pathways. DE analysis between chiloglottone-emitting callus versus the remainder of the labellum showed strong coordinated induction of entire FA biosynthesis and β-oxidation pathways including genes encoding Ketoacyl-ACP Synthase, Acyl-CoA Oxidase, and Multifunctional Protein. Phylogenetic analysis revealed potential gene duplicates with tissue-specific differential regulation including two Acyl-ACP Thioesterase B and a Ketoacyl-ACP Synthase genes. UV-B treatment induced the activation of UVR8-mediated signaling and large-scale transcriptome changes in both tissues, however, neither FA biosynthesis/β-oxidation nor other lipid metabolic pathways showed clear indications of concerted DE. Gene co-expression network analysis identified three callus-specific modules enriched with various lipid metabolism categories. These networks also highlight promising candidates involved in the cyclization of chiloglottone 1 intermediates (e.g., Bet v I and dimeric α,β barrel proteins and orchestrating regulation of precursor

  18. Volatility in energy prices

    International Nuclear Information System (INIS)

    Duffie, D.

    1999-01-01

    This chapter with 58 references reviews the modelling and empirical behaviour of volatility in energy prices. Constant volatility and stochastic volatility are discussed. Markovian models of stochastic volatility are described and the different classes of Markovian stochastic volatility model are examined including auto-regressive volatility, option implied and forecasted volatility, Garch volatility, Egarch volatility, multivariate Garch volatility, and stochastic volatility and dynamic hedging policies. Other volatility models and option hedging are considered. The performance of several stochastic volatility models as applied to heating oil, light oil, natural gas, electricity and light crude oil are compared

  19. STUDY ON USING A TRICKLE-BED BIOREACTOR FOR REDUCING VOLATILE ORGANIC COMPOUNDS IN WASTEWATER TREATMENT PLANT OPERATED BY PKN ORLEN S.A.

    Directory of Open Access Journals (Sweden)

    Arkadiusz Kamiński

    2017-08-01

    Full Text Available The results of studies conducted by Ekoinwentyka sp. z o.o. concerning the possibility of using a trickle-bed bioreactor for reducing of volatile organic compounds (VOCs emitted by PKN ORLEN S.A. wastewater treatment plant were presented and discussed. During the one-month trial, inlet and outlet concentrations of VOCs, H2S and NH3 were analysed and the efficiency of bio-purification process was determined on their basis. The obtained results confirmed the effectiveness of the applied technology under the given conditions, simultaneously demonstrating the validity of conducting further technological analysis to derive the design assumptions of the bioreactor on the industrial scale.

  20. Thidiazuron: A multi-dimensional plant growth regulator

    African Journals Online (AJOL)

    Jane

    2011-08-17

    Aug 17, 2011 ... recently, the morpho-regulatory potential of the chemical has led to its application in ..... The structure of TDZ is totally different from naturally occurring ..... some researches on plant melatonin and serotonin focused on their ...

  1. Effect of plant growth regulators and nitrogenous compounds on ...

    African Journals Online (AJOL)

    PROF HORSFALL

    ABSTRACT: The seed germination of Capsicum frutescens L. was investigated through various ... The seeds were subjected to the following treatments namely ... The pre-soaking in plant ..... sowing treatments on seedling emergence and.

  2. State regulation and power plant productivity: background and recommendations

    International Nuclear Information System (INIS)

    1980-09-01

    This report was prepared by representatives of several state regulatory agencies. It is a guide to some of the activities currently under way in state agencies to promote increased availability of electrical generating power plants. Standard measures of plant performance are defined and the nature of data bases that report such measures is discussed. It includes reviews of current state, federal, and industry programs to enhance power plant productivity and provides detailed outlines of programs in effect in California, Illinois, Michigan, New York, North Carolina, Ohio, and Texas. A number of actions are presented that could be adopted by state regulatory agencies, depending on local conditions. They include: develop a commission position or policy statement to encourage productivity improvements by utilities; coordinate state efforts with ongoing industry and government programs to improve the acquisition of power plant performance data and the maintenance of quality information systems; acquire the capability to perform independent analyses of power plant productivity; direct the establishment of productivity improvement programs, including explicit performance objectives for both existing and planned power plants, and a performance program; establish a program of incentives to motivate productivity improvement activities; and participate in ongoing efforts at all levels and initiate new actions to promote productivity improvements

  3. A Non-Targeted Approach Unravels the Volatile Network in Peach Fruit

    Science.gov (United States)

    Sánchez, Gerardo; Besada, Cristina; Badenes, María Luisa; Monforte, Antonio José; Granell, Antonio

    2012-01-01

    Volatile compounds represent an important part of the plant metabolome and are of particular agronomic and biological interest due to their contribution to fruit aroma and flavor and therefore to fruit quality. By using a non-targeted approach based on HS-SPME-GC-MS, the volatile-compound complement of peach fruit was described. A total of 110 volatile compounds (including alcohols, ketones, aldehydes, esters, lactones, carboxylic acids, phenolics and terpenoids) were identified and quantified in peach fruit samples from different genetic backgrounds, locations, maturity stages and physiological responses. By using a combination of hierarchical cluster analysis and metabolomic correlation network analysis we found that previously known peach fruit volatiles are clustered according to their chemical nature or known biosynthetic pathways. Moreover, novel volatiles that had not yet been described in peach were identified and assigned to co-regulated groups. In addition, our analyses showed that most of the co-regulated groups showed good intergroup correlations that are therefore consistent with the existence of a higher level of regulation orchestrating volatile production under different conditions and/or developmental stages. In addition, this volatile network of interactions provides the ground information for future biochemical studies as well as a useful route map for breeding or biotechnological purposes. PMID:22761719

  4. Effect of plant growth regulators on production of alpha-linolenic ...

    Indian Academy of Sciences (India)

    Sujana Kokkiligadda

    2017-10-05

    Oct 5, 2017 ... MS received 13 October 2016; revised 22 March 2017; accepted 30 May 2017; ... Plant growth regulators; microalgae; Chlorella pyrenoidosa; alpha-linolenic acid. 1. ... the growth period by flocculation method [9] using alum.

  5. Understanding the Posttranscriptional Regulation of Plant Responses to Abiotic Stress

    KAUST Repository

    Alshareef, Sahar

    2017-01-01

    Constitutive and alternative splicing of pre-mRNAs from multiexonic genes controls the diversity of the proteome; these precisely regulated processes also fine-tune responses to cues related to growth, development, and biotic and abiotic stresses

  6. Stochastic volatility of volatility in continuous time

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole; Veraart, Almut

    This paper introduces the concept of stochastic volatility of volatility in continuous time and, hence, extends standard stochastic volatility (SV) models to allow for an additional source of randomness associated with greater variability in the data. We discuss how stochastic volatility...... of volatility can be defined both non-parametrically, where we link it to the quadratic variation of the stochastic variance process, and parametrically, where we propose two new SV models which allow for stochastic volatility of volatility. In addition, we show that volatility of volatility can be estimated...

  7. Plant host finding by parasitic plants: a new perspective on plant to plant communication.

    Science.gov (United States)

    Mescher, Mark C; Runyon, Justin B; De Moraes, Consuelo M

    2006-11-01

    Plants release airborne chemicals that can convey ecologically relevant information to other organisms. These plant volatiles are known to mediate a large array of, often complex, interactions between plants and insects. It has been suggested that plant volatiles may have similar importance in mediating interactions among plant species, but there are few well-documented examples of plant-to-plant communication via volatiles, and the ecological significance of such interactions has been much debated. To date, nearly all studies of volatile-mediated interactions among plant species have focused on the reception of herbivore-induced volatiles by neighboring plants. We recently documented volatile effects in another system, demonstrating that the parasitic plant Cuscuta pentagona uses volatile cues to locate its hosts. This finding may broaden the discussion regarding plant-to-plant communication, and suggests that new classes of volatile-meditated interactions among plant species await discovery.

  8. Function and regulation of plant major intrinsic proteins

    DEFF Research Database (Denmark)

    Popovic, Milan

    ;1 in Arabidopsis. That led to the discovery that tip4;1 is gametophytic lethal- gene essential for normal seed set. ICP-MS analyses of the elemental composition of tip4;1 heterozygous T-DNA insert mutant plants and 35S::TIP4;1 over-expression plants indicate that AtTIP4;1 has a role in arsenic distribution...... inorganic forms of arsenic in the environment, can be taken up by plants and thus enter the food chain. Once inside the root cells, As(V) is reduced to As(III) which is then extruded to the soil solution or bound to phytochelatins (PCs) and transported to the vacuole in an effort to accomplish...... detoxification. Plant Noduline 26-like Intrinsic Proteins (NIPs) can channel As(III) and consequently influence the detoxification process. The role of the Tonoplast Intrinsic Proteins (TIPs) in As(III) detoxification remains to be clarified, yet TIPs could have an impact on As(III) accumulation in plant cell...

  9. GDSL LIPASE1 Modulates Plant Immunity through Feedback Regulation of Ethylene Signaling1[W

    Science.gov (United States)

    Kim, Hye Gi; Kwon, Sun Jae; Jang, Young Jin; Nam, Myung Hee; Chung, Joo Hee; Na, Yun-Cheol; Guo, Hongwei; Park, Ohkmae K.

    2013-01-01

    Ethylene is a key signal in the regulation of plant defense responses. It is required for the expression and function of GDSL LIPASE1 (GLIP1) in Arabidopsis (Arabidopsis thaliana), which plays an important role in plant immunity. Here, we explore molecular mechanisms underlying the relationship between GLIP1 and ethylene signaling by an epistatic analysis of ethylene response mutants and GLIP1-overexpressing (35S:GLIP1) plants. We show that GLIP1 expression is regulated by ethylene signaling components and, further, that GLIP1 expression or application of petiole exudates from 35S:GLIP1 plants affects ethylene signaling both positively and negatively, leading to ETHYLENE RESPONSE FACTOR1 activation and ETHYLENE INSENSITIVE3 (EIN3) down-regulation, respectively. Additionally, 35S:GLIP1 plants or their exudates increase the expression of the salicylic acid biosynthesis gene SALICYLIC ACID INDUCTION-DEFICIENT2, known to be inhibited by EIN3 and EIN3-LIKE1. These results suggest that GLIP1 regulates plant immunity through positive and negative feedback regulation of ethylene signaling, and this is mediated by its activity to accumulate a systemic signal(s) in the phloem. We propose a model explaining how GLIP1 regulates the fine-tuning of ethylene signaling and ethylene-salicylic acid cross talk. PMID:24170202

  10. Methods for growth regulation of greenhouse produced ornamental pot- and bedding plants – a current review

    Directory of Open Access Journals (Sweden)

    Bergstrand Karl-Johan I.

    2017-06-01

    Full Text Available Chemical plant growth regulators (PGRs are used in the production of ornamental potted and bedding plants. Growth control is needed for maximizing production per unit area, reducing transportation costs and to obtain a desired visual quality. However, the use of PGRs is associated with toxicity risks to humans and the environment. In many countries the availability of PGRs is restricted as few substances are registered for use. A number of alternative methods have been suggested. The methods include genetic methods (breeding and crop cultivation practices such as fertigation, temperature and light management. A lot of research into “alternative” growth regulation was performed during the 1980-1990s, revealing several possible ways of using different climatic factors to optimize plant growth with respect to plant height. In recent years, the interest in climatic growth regulation has been resurrected, not least due to the coming phase-out of the plant growth regulator chlormequat chloride (CCC. Today, authorities in many countries are aiming towards reducing the use of agrochemicals. At the same time, there is a strong demand from consumers for products produced without chemicals. This article provides a broad overview of available methods for non-chemical growth control. It is concluded that a combination of plant breeding and management of temperature, fertigation and light management has the potential of replacing chemical growth regulators in the commercial production of ornamental pot- and bedding plants.

  11. Plant Mediator complex and its critical functions in transcription regulation.

    Science.gov (United States)

    Yang, Yan; Li, Ling; Qu, Li-Jia

    2016-02-01

    The Mediator complex is an important component of the eukaryotic transcriptional machinery. As an essential link between transcription factors and RNA polymerase II, the Mediator complex transduces diverse signals to genes involved in different pathways. The plant Mediator complex was recently purified and comprises conserved and specific subunits. It functions in concert with transcription factors to modulate various responses. In this review, we summarize the recent advances in understanding the plant Mediator complex and its diverse roles in plant growth, development, defense, non-coding RNA production, response to abiotic stresses, flowering, genomic stability and metabolic homeostasis. In addition, the transcription factors interacting with the Mediator complex are also highlighted. © 2015 Institute of Botany, Chinese Academy of Sciences.

  12. THE USE OF CHEMICALS AS PLANT REGULATORS. AGRICULTURAL CHEMICALS TECHNOLOGY, NUMBER 8.

    Science.gov (United States)

    Ohio State Univ., Columbus. Center for Vocational and Technical Education.

    ONE OF A SERIES DESIGNED TO ASSIST TEACHERS IN PREPARING POST-SECONDARY STUDENTS FOR AGRICULTURAL CHEMICAL OCCUPATIONS, THIS MODULE IS SPECIFICALLY CONCERNED WITH CHEMICALS AS PLANT REGULATORS. IT WAS DEVELOPED BY A NATIONAL TASK FORCE ON THE BASIS OF DATA FROM STATE STUDIES. SECTIONS INCLUDE -- (1) CHEMICALS AS MODIFIERS OF PLANT GROWTH, (2)…

  13. Administrative procedures for regulating construction and operation of nuclear power plants

    International Nuclear Information System (INIS)

    Cochaud, J.P.

    1981-01-01

    This article first explains that nuclear power plants in France are governed by a complex system of regulations within the framework of different laws concerning, in particular, protection of the environment, public health and workers. It then examines the administrative procedures and the licensing regime for nuclear power plants. (NEA) [fr

  14. The effect of plant growth regulators on optimization of tissue culture ...

    African Journals Online (AJOL)

    Mature seeds of four upland rice cultivars namely Kusan, Lamsan, Selasi and Siam were assessed for callus induction and plant regeneration on different concentrations and combinations of plant growth regulators, incorporated into MS (Murashige and Skoog) basal medium. Callus induction frequency was significantly ...

  15. Regulation of polyamine synthesis in plants. Final progress report, July 1, 1991--December 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Malmberg, R.L.

    1995-07-01

    This research focused on unusual post-translational modifications occuring in a arginine decarboxylase cDNA clone in oats. A novel regulatory mechanism for polyamines was explored and an attempt was made to characterize it. A plant ornithine decarboxylase cDNA was identified in Arabidopsis. Further work remains on the mechanisms of polyamine regulation and function in plants.

  16. The effect of plant growth regulators on callus initiation in wormwood ...

    African Journals Online (AJOL)

    Studies were carried out in the Biotechnology laboratory of Plant Science Department of Ahmadu Bello University Zaria, Nigeria to study the effect of some plant growth regulators on the in vitro initiation of callus using the leaves of Chiyong variety of Artemisia annua. The explants were sterilized and incubated on Murashige ...

  17. The complexity of nitrogen metabolism and nitrogen-regulated gene expression in plant pathogenic fungi

    NARCIS (Netherlands)

    Bolton, M.D.; Thomma, B.P.H.J.

    2008-01-01

    Plant pathogens secrete effector molecules that contribute to the establishment of disease in their plant hosts. The identification of cellular cues that regulate effector gene expression is an important aspect of understanding the infection process. Nutritional status in the cell has been

  18. Information Integration and Communication in Plant Growth Regulation.

    Science.gov (United States)

    Chaiwanon, Juthamas; Wang, Wenfei; Zhu, Jia-Ying; Oh, Eunkyoo; Wang, Zhi-Yong

    2016-03-10

    Plants are equipped with the capacity to respond to a large number of diverse signals, both internal ones and those emanating from the environment, that are critical to their survival and adaption as sessile organisms. These signals need to be integrated through highly structured intracellular networks to ensure coherent cellular responses, and in addition, spatiotemporal actions of hormones and peptides both orchestrate local cell differentiation and coordinate growth and physiology over long distances. Further, signal interactions and signaling outputs vary significantly with developmental context. This review discusses our current understanding of the integrated intracellular and intercellular signaling networks that control plant growth. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Regulating power provided by an industrial virtual power plant

    NARCIS (Netherlands)

    Roossien, B.; Kamphuis, I.G.; Doss, A.

    2012-01-01

    The use of renewable energy sources for the transition towards a sustainable electricity system imposes a number of new challenges for the grid, one of them being the balancing of variable output supply and demand. The flexibility of production and consumption in Virtual Power Plants can be used

  20. Structure, function and regulation of plant photosystem I

    NARCIS (Netherlands)

    Jensen, Poul Erik; Bassi, Roberto; Boekema, Egbert J.; Dekker, Jan P.; Jansson, Stefan; Leister, Dario; Robinson, Colin; Scheller, Henrik Vibe

    Photosystem I (PSI) is a multisubunit protein complex located in the thylakoid membranes of green plants and algae, where it initiates one of the first steps of solar energy conversion by light-driven electron transport. In this review, we discuss recent progress on several topics related to the

  1. Structure, function and regulation of plant photosystem I

    NARCIS (Netherlands)

    Jensen, P.E.; Bassi, R.; Boekema, E.J.; Dekker, J.P.; Jansson, S.; Leister, D.; Robinson, C.; Scheller, H.V.

    2007-01-01

    Photosystem I (PSI) is a multisubunit protein complex located in the thylakoid membranes of green plants and algae, where it initiates one of the first steps of solar energy conversion by light-driven electron transport. In this review, we discuss recent progress on several topics related to the

  2. Effects of plant growth regulators on callus induction from Cananga ...

    African Journals Online (AJOL)

    The Cananga odorata callus was initiated from petals of the C. odorata flowers on MS medium and B5 vitamins containing 30 g/L sugar and 3 g/L agar. The medium was also supplemented with different concentrations of 1-naphtalene acetic acid (NAA), and combinations of NAA with 6-benzylaminpurine (BAP) as the plant ...

  3. Influence of plant growth regulators on development and ...

    African Journals Online (AJOL)

    Therefore propagation of the plant material by cell cultures and the extraction of potential pharmaceutical active compounds are of great interest. Calli were established on different media from roots and shoots of seedlings and softness and colour of the tissue were compared. Optimum growth of callus cultures was ...

  4. Influence of plant growth regulators on somatic embryos induction ...

    African Journals Online (AJOL)

    TANOH

    2013-04-17

    Theobroma cacao L.) using Thidiazuron. In vitro Cell Dev. Biol. 34:293-299. Michaux-Ferrière N, Carron MP (1989). Histology of early somatic embryogenesis in Hevea brasiliensis. The importance of timing of subculturing. Plant Cell Tiss ...

  5. Insecticide resistance may enhance the response to a host-plant volatile kairomone for the codling moth, Cydia pomonella (L.)

    Science.gov (United States)

    Sauphanor, Benoît; Franck, Pierre; Lasnier, Thérèse; Toubon, Jean-François; Beslay, Dominique; Boivin, Thomas; Bouvier, Jean-Charles; Renou, Michel

    2007-06-01

    The behavioral and electroantennographic responses of Cydia pomonella (L.) to the ripe pear volatile ethyl (2 E,4 Z)-2,4-decadienoate (Et- E, Z-DD), were compared in insecticide-susceptible and -resistant populations originating from southern France. A dose-response relationship to this kairomonal attractant was established for antennal activity and did not reveal differences between susceptible and resistant strains. Conversely, males of the laboratory strains expressing metabolic [cytochrome P450-dependent mixed-function oxidases (mfo)] or physiological (kdr-type mutation of the sodium-channel gene) resistance mechanisms exhibited a significantly higher response to Et- E, Z-DD than those of the susceptible strain in a wind tunnel experiment. No response of the females to this kairomone could be obtained in our wind-tunnel conditions. In apple orchards, mfo-resistant male moths were captured at significantly higher rates in kairomone-baited traps than in traps baited with the sex pheromone of C. pomonella. Such a differential phenomenon was not verified for the kdr-resistant insects, which exhibited a similar response to both the sex pheromone and the kairomonal attractant in apple orchards. Considering the widespread distribution of metabolic resistance in European populations of C. pomonella and the enhanced behavioral response to Et- E, Z-DD in resistant moths, the development of control measures based on this kairomonal compound would be of great interest for the management of insecticide resistance in this species.

  6. The Process of Legal Drafting Regulation in the Development of the Nuclear Power Plant in Indonesia

    OpenAIRE

    Mardha, Amil

    2009-01-01

    THE PROCESS OF LEGAL DRAFTING REGULATION IN THE DEVELOPMENT OF THE NUCLEAR POWER PLANT IN INDONESIA. In Indonesia, the process of legal drafting to establish the regulation is based on the Act No. 10 Year 2004 on the Establishment of Legislation. The process shall comply with the constitutional and institutional requirements of national political and legal system. In drafting the development of the regulation of nuclear energy, BAPETEN has been involving some other agencies or other related g...

  7. Biogenic volatile organic compound and respiratory CO2 emissions after 13C-labeling: online tracing of C translocation dynamics in poplar plants.

    Science.gov (United States)

    Ghirardo, Andrea; Gutknecht, Jessica; Zimmer, Ina; Brüggemann, Nicolas; Schnitzler, Jörg-Peter

    2011-02-28

    Globally plants are the primary sink of atmospheric CO(2), but are also the major contributor of a large spectrum of atmospheric reactive hydrocarbons such as terpenes (e.g. isoprene) and other biogenic volatile organic compounds (BVOC). The prediction of plant carbon (C) uptake and atmospheric oxidation capacity are crucial to define the trajectory and consequences of global environmental changes. To achieve this, the biosynthesis of BVOC and the dynamics of C allocation and translocation in both plants and ecosystems are important. We combined tunable diode laser absorption spectrometry (TDLAS) and proton transfer reaction mass spectrometry (PTR-MS) for studying isoprene biosynthesis and following C fluxes within grey poplar (Populus x canescens) saplings. This was achieved by feeding either (13)CO(2) to leaves or (13)C-glucose to shoots via xylem uptake. The translocation of (13)CO(2) from the source to other plant parts could be traced by (13)C-labeled isoprene and respiratory (13)CO(2) emission. In intact plants, assimilated (13)CO(2) was rapidly translocated via the phloem to the roots within 1 hour, with an average phloem transport velocity of 20.3±2.5 cm h(-1). (13)C label was stored in the roots and partially reallocated to the plants' apical part one day after labeling, particularly in the absence of photosynthesis. The daily C loss as BVOC ranged between 1.6% in mature leaves and 7.0% in young leaves. Non-isoprene BVOC accounted under light conditions for half of the BVOC C loss in young leaves and one-third in mature leaves. The C loss as isoprene originated mainly (76-78%) from recently fixed CO(2), to a minor extent from xylem-transported sugars (7-11%) and from photosynthetic intermediates with slower turnover rates (8-11%). We quantified the plants' C loss as respiratory CO(2) and BVOC emissions, allowing in tandem with metabolic analysis to deepen our understanding of ecosystem C flux.

  8. Emission and profile characteristic of volatile organic compounds emitted from coke production, iron smelt, heating station and power plant in Liaoning Province, China.

    Science.gov (United States)

    Shi, Jianwu; Deng, Hao; Bai, Zhipeng; Kong, Shaofei; Wang, Xiuyan; Hao, Jiming; Han, Xinyu; Ning, Ping

    2015-05-15

    107 kinds of C₂-C₁₂ volatile organic compound (VOC) mass concentrations and profiles for four types of coal-fired stationary sources in Liaoning Province were studied by a dilution sampling system and GC-MS analysis method, which are of significant importance with regard to VOC emissions in northeast of China. The results showed that there were some differences among these VOC source profiles. The total mass concentrations of analyzed 107 VOC species varied from 10,917 to 19,652 μg m(-3). Halogenated hydrocarbons exhibited higher mass percentages for the VOC source profiles of iron smelt (48.8%) and coke production plant (37.7%). Aromatic hydrocarbons were the most abundant in heating station plant (69.1%). Ketones, alcohols and acetates held 45.0% of total VOCs in thermal power plant. For non-methane hydrocarbons (NMHCs), which are demanded for photochemical assessment in the USA, toluene and n-hexane were the most abundant species in the iron smelt, coke production and thermal power plant, with the mass percentages of 64.8%, 52.7% and 38.6%, respectively. Trimethylbenzene, n-propylbenzene and o,m-ethyltoluene approximately accounted for 70.0% in heating station plant. NMHCs emitted from coke production, iron smelt, heating station and power plant listed above presented different chemical reactivities. The average OH loss rate of NMHCs from heating station, was 4 to 5.6 times higher than that of NMHCs from iron smelt, coke production and power plant, which implies that VOCs emitted from heating station in northeast of China should be controlled firstly to avoid photochemical ozone pollution and protect human health. There are significant variations in the ratios of benzene/toluene and m, p-xylene/ethylbenzene of these coal-fired source profiles. The representativeness of the coal-fired sources studied and the VOC samples collected should be more closely examined. The accuracy of VOC source profiles related to coal-fired processes is highly dependent on

  9. VUV and soft x-ray ionization of a plant volatile: Vanillin (C{sub 8}H{sub 8}O{sub 3})

    Energy Technology Data Exchange (ETDEWEB)

    Betancourt, A. Moreno; Moura, C. E. V. de; Rocha, A. B.; Souza, G. G. B. de, E-mail: rafael.bernini@ifrj.edu.br, E-mail: gerson@iq.ufrj.br [Instituto de Química, Universidade Federal do Rio de Janeiro (UFRJ) 21949-900 Rio de Janeiro–RJ (Brazil); Coutinho, L. H. [Instituto de Física, Universidade Federal do Rio de Janeiro (UFRJ) 21941-972 Rio de Janeiro–RJ (Brazil); Bernini, R. B., E-mail: rafael.bernini@ifrj.edu.br, E-mail: gerson@iq.ufrj.br [Instituto Federal de Ciência e Tecnologia do Rio de Janeiro (IFRJ), 25050-100 Duque de Caxias–RJ (Brazil)

    2016-03-21

    Plant volatiles are emitted by plants in response to several forms of stress, including interaction with energetic photons. In the present work, we discuss the interaction of extreme UV and soft X-ray photons with a plant volatile, vanillin. The single and double (multiple) ionization of the vanillin molecule have been studied for the first time using time-of-flight mass spectrometry and VUV and soft X-ray photons (synchrotron radiation, at 12.0 eV, 21.2 eV, 130 eV, 310 eV, 531 eV, and 550 eV). At 12.0 and 21.2 eV, only singly charged species are observed and the parent ion, C{sub 8}H{sub 8}O{sub 3}{sup +}, is the dominant species. Energy differences for some selected fragments were calculated theoretically in this energy region. At 130 eV, direct double and triple ionization of the valence electrons may occur. The fragmentation increases and CHO{sup +} becomes one of the main cations in the mass spectrum. The molecular ion is still the dominant species, but other fragments, such as C{sub 6}H{sub 5}O{sup +}, begin to present similar intensities. At 310 eV, C 1s electrons may be ionized and Auger processes give rise to dissociative doubly ionized cations. Ionization around the O 1s edge has been studied both at the 531 eV resonance and above the ionization edge. Resonant and normal Auger processes play a significant role in each case and a large fragmentation of the molecule is observed at both photon energies, with intense fragments such as CHO{sup +} and CH{sub 3}{sup +} being clearly observed. A near edge X-ray absorption fine structure spectrum of the vanillin molecule was obtained around the O 1s ionization threshold. In addition, the fragmentation of vanillin has also been studied using a fast beam of electrons (800 eV), for the sake of comparison.

  10. Differential Response of a Local Population of Entomopathogenic Nematodes to Non-Native Herbivore Induced Plant Volatiles (HIPV) in the Laboratory and Field.

    Science.gov (United States)

    Rivera, Monique J; Rodriguez-Saona, Cesar; Alborn, Hans T; Koppenhöfer, Albrecht M

    2016-12-01

    Recent work has shown the potential for enhanced efficacy of entomopathogenic nematodes (EPN) through their attraction to herbivore induced plant volatiles. However, there has been little investigation into the utilization of these attractants in systems other than in those in which they were identified. We compared (E)-β-caryophyllene and pregeijerene in the highbush blueberry (Vaccinium corymbosum) agroecosystem in their ability to enhance the attraction of EPN to and efficacy against the system's herbivore, oriental beetle (Anomala orientalis). The relative attractiveness of (E)-β-caryophyllene and pregeijerene to a local isolate of the EPN species Steinernema glaseri was tested in a six-arm olfactometer in the laboratory to gather baseline values of attraction to the chemicals alone in sand substrate before field tests. A similar arrangement was used in a V. corymbosum field by placing six cages with assigned treatments and insect larvae with and without compound into the soil around the base of 10 plants. The cages were removed after 72 h, and insect baits were retrieved and assessed for EPN infection. The lab results indicate that in sand alone (E)-β-caryophyllene is significantly more attractive than pregeijerene to the local S. glaseri isolate Conversely, there was no difference in attractiveness in the field study, but rather, native S. glaseri were more attracted to cages with G. mellonella larvae, no larvae, and cages with the blank control and G. mellonella larvae.

  11. Environmental regulations and plant exit: A logit analysis based on established panel data

    Energy Technology Data Exchange (ETDEWEB)

    Bioern, E; Golombek, R; Raknerud, A

    1995-12-01

    This publication uses a model to study the relationship between environmental regulations and plant exit. It has the main characteristics of a multinomial qualitative response model of the logit type, but also has elements of a Markov chain model. The model uses Norwegian panel data for establishments in three manufacturing sectors with high shares of units which have been under strict environmental regulations. In two of the sectors, the exit probability of non-regulated establishments is about three times higher than for regulated ones. It is also found that the probability of changing regulation status from non-regulated to regulated depends significantly on economic factors. In particular, establishments with weak profitability are the most likely to become subject to environmental regulation. 12 refs., 2 figs., 6 tabs.

  12. Overview of OVATE FAMILY PROTEINS, a novel class of plant-specific growth regulators

    Directory of Open Access Journals (Sweden)

    Shucai eWang

    2016-03-01

    Full Text Available OVATE FAMILY PROTEINS (OFPs are a class of proteins with a conserved OVATE domain. OVATE protein was first identified in tomato as a key regulator of fruit shape. OFPs are plant-specific proteins that are widely distributed in the plant kingdom including mosses and lycophytes. Transcriptional activity analysis of Arabidopsis OFPs (AtOFPs in protoplasts suggests that they act as transcription repressors. Functional characterization of OFPs from different plant species including Arabidopsis, rice, tomato, pepper and banana suggests that OFPs regulate multiple aspects of plant growth and development, which is likely achieved by interacting with different types of transcription factors including the KNOX and BELL classes, and/or directly regulating the expression of target genes such as Gibberellin 20 oxidase (GA20ox. Here, we examine how OVATE was originally identified, summarize recent progress in elucidation of the roles of OFPs in regulating plant growth and development, and describe possible mechanisms underpinning this regulation. Finally, we review potential new research directions that could shed additional light on the functional biology of OFPs in plants.

  13. The 5th Symposium on Post-Transcriptional Regulation of Plant Gene Expression (PTRoPGE)

    Energy Technology Data Exchange (ETDEWEB)

    Karen S. Browning; Marie Petrocek; Bonnie Bartel

    2006-06-01

    The 5th Symposium on Post-Transcriptional Regulation of Plant Gene Expression (PTRoPGE) will be held June 8-12, 2005 at the University of Texas at Austin. Exciting new and ongoing discoveries show significant regulation of gene expression occurs after transcription. These post-transcriptional control events in plants range from subtle regulation of transcribed genes and phosphorylation, to the processes of gene regulation through small RNAs. This meeting will focus on the regulatory role of RNA, from transcription, through translation and finally degradation. The cross-disciplinary design of this meeting is necessary to encourage interactions between researchers that have a common interest in post-transcriptional gene expression in plants. By bringing together a diverse group of plant molecular biologist and biochemists at all careers stages from across the world, this meeting will bring about more rapid progress in understanding how plant genomes work and how genes are finely regulated by post-transcriptional processes to ultimately regulate cells.

  14. Non-pathogenic rhizobacteria interfere with the attraction of parasitoids to aphid-induced plant volatiles via jasmonic acid signalling.

    NARCIS (Netherlands)

    Pineda, A.; Soler Gamborena, R.; Weldegergis, B.T.; Shimwela, M.M.; Loon, van J.J.A.; Dicke, M.

    2013-01-01

    Beneficial soil-borne microbes, such as mycorrhizal fungi or rhizobacteria, can affect the interactions of plants with aboveground insects at several trophic levels. While the mechanisms of interactions with herbivorous insects, that is, the second trophic level, are starting to be understood, it

  15. Innate responses of the parasitoids Cotesia glomerata and C. rubecula (Hymenoptera: Braconidae) to volatiles from different plant-herbivore complexes.

    NARCIS (Netherlands)

    Geervliet, J.B.F.; Vet, L.E.M.; Dicke, M.

    1996-01-01

    To determine and compare innate preferences of the parasitoid species Cotesia glomerata and C. rubecula for different plant-herbivore complexes, long-range (1-m) foraging behavior was studied in dual-choice experiments in a wind tunnel. In this study we tested the hypothesis that naive females of

  16. Sexual polyploidization in plants--cytological mechanisms and molecular regulation.

    Science.gov (United States)

    De Storme, Nico; Geelen, Danny

    2013-05-01

    In the plant kingdom, events of whole genome duplication or polyploidization are generally believed to occur via alterations of the sexual reproduction process. Thereby, diploid pollen and eggs are formed that contain the somatic number of chromosomes rather than the gametophytic number. By participating in fertilization, these so-called 2n gametes generate polyploid offspring and therefore constitute the basis for the establishment of polyploidy in plants. In addition, diplogamete formation, through meiotic restitution, is an essential component of apomixis and also serves as an important mechanism for the restoration of F1 hybrid fertility. Characterization of the cytological mechanisms and molecular factors underlying 2n gamete formation is therefore not only relevant for basic plant biology and evolution, but may also provide valuable cues for agricultural and biotechnological applications (e.g. reverse breeding, clonal seeds). Recent data have provided novel insights into the process of 2n pollen and egg formation and have revealed multiple means to the same end. Here, we summarize the cytological mechanisms and molecular regulatory networks underlying 2n gamete formation, and outline important mitotic and meiotic processes involved in the ectopic induction of sexual polyploidization. © 2013 Ghent University. New Phytologist © 2013 New Phytologist Trust.

  17. Hydrologic Regulation of Plant Rooting Depth and Vice Versa

    Science.gov (United States)

    Fan, Y.; Miguez-Macho, G.

    2017-12-01

    How deep plant roots go and why may hold the answer to several questions regarding the co-evolution of terrestrial life and its environment. In this talk we explore how plant rooting depth responds to the hydrologic plumbing system in the soil/regolith/bedrocks, and vice versa. Through analyzing 2200 root observations of >1000 species along biotic (life form, genus) and abiotic (precipitation, soil, drainage) gradients, we found strong sensitivities of rooting depth to local soil water profiles determined by precipitation infiltration depth from the top (reflecting climate and soil), and groundwater table depth from below (reflecting topography-driven land drainage). In well-drained uplands, rooting depth follows infiltration depth; in waterlogged lowlands, roots stay shallow avoiding oxygen stress below the water table; in between, high productivity and drought can send roots many meters down to groundwater capillary fringe. We explore the global significance of this framework using an inverse model, and the implications to the coevolution of deep roots and the CZ in the Early-Mid Devonian when plants colonized the upland environments.

  18. Down-regulation of tissue N:P ratios in terrestrial plants by elevated CO2.

    Science.gov (United States)

    Deng, Qi; Hui, Dafeng; Luo, Yiqi; Elser, James; Wang, Ying-ping; Loladze, Irakli; Zhang, Quanfa; Dennis, Sam

    2015-12-01

    Increasing atmospheric CO2 concentrations generally alter element stoichiometry in plants. However, a comprehensive evaluation of the elevated CO2 impact on plant nitrogen: phosphorus (N:P) ratios and the underlying mechanism has not been conducted. We synthesized the results from 112 previously published studies using meta-analysis to evaluate the effects of elevated CO2 on the N:P ratio of terrestrial plants and to explore the underlying mechanism based on plant growth and soil P dynamics. Our results show that terrestrial plants grown under elevated CO2 had lower N:P ratios in both above- and belowground biomass across different ecosystem types. The response ratio for plant N:P was negatively correlated with the response ratio for plant growth in croplands and grasslands, and showed a stronger relationship for P than for N. In addition, the CO2-induced down-regulation of plant N:P was accompanied by 19.3% and 4.2% increases in soil phosphatase activity and labile P, respectively, and a 10.1% decrease in total soil P. Our results show that down-regulation of plant N:P under elevated CO2 corresponds with accelerated soil P cycling. These findings should be useful for better understanding of terrestrial plant stoichiometry in response to elevated CO2 and of the underlying mechanisms affecting nutrient dynamics under climate change.

  19. Have U.S. power plants become less technically efficient? The impact of carbon emission regulation

    International Nuclear Information System (INIS)

    Zhou, Yishu; Huang, Ling

    2016-01-01

    We estimate directional distance functions to measure the impact of carbon emission regulation, the Regional Greenhouse Gas Initiative (RGGI) in particular, on U.S. power plants' technical efficiency. The model shows that the average technical efficiency scores for coal and natural gas plants are 88.70% and 83.14% respectively, indicating a very technically efficient industry. We find no evidence of technical efficiency changes due to the RGGI regime in the RGGI area. In the same area, relatively less efficient coal plants exited the market and slightly more efficient natural gas plants entered, compared to the incumbent plants. In addition, some evidence of a spillover effect is found. Using a counterfactual analysis, the RGGI regulation leads to a 1.48% decline in the average technical efficiency for coal plants within neighboring states of RGGI during 2009–2013. - Highlights: • RGGI does not lead to a change in the technical efficiency of RGGI power plants. • Less efficient coal plants exit. • Entering natural gas plants are more efficient. • RGGI has a spillover effect on neighboring coal plants.

  20. [Research advance in nitrogen metabolism of plant and its environmental regulation].

    Science.gov (United States)

    Xu, Zhenzhu; Zhou, Guangsheng

    2004-03-01

    Nitrogen metabolism is not only one of the basic processes of plant physiology, but also one of the important parts of global chemical cycle. Plant nitrogen assimilation directly takes part in the synthesis and conversion of amino acid through the reduction of nitrate. During this stage, some key enzymes, e.g., nitrate reductase (NR), glutamine synthetase (GS), glutamate dehydrogenase (GDH), glutamine synthase (GOGAT), aspargine synthetase (AS), and asparate aminotransferase (AspAT) participate these processes. The protein is assimilated in plant cell through amino acid, and becomes a part of plant organism through modifying, classifying, transporting and storing processes, etc. The nitrogen metabolism is associated with carbonic metabolism through key enzyme regulations and the conversion of products, which consists of basic life process. Among these amino acids in plant cell, glutamic acid (Glu), glutamine (Gln), aspartic acid (Asp) and asparagines (Asn), etc., play a key role, which regulates their conversion each other and their contents in the plant cell through regulating formation and activity of those key enzymes. Environmental factors also affect the conversion and recycle of the key amino acids through regulating gene expression of the key enzymes and their activities. Nitrate and light intensity positively regulate the gene transcription of NR, but ammonium ions and Glu, Gln do the negative way. Water deficit is a very serious constraint on N2 fixation rate and soybean (Glycine max Merr.) grain yield, in which, ureide accumulation and degradation under water deficit appear to be the key issues of feedback mechanism on nitrogen fixation. Water stress decreases NR activity, but increases proteinase activity, and thus, they regulate plant nitrogen metabolism, although there are some different effects among species and cultivars. Water stress also decreases plant tissue protein content, ratio of protein and amino acid, and reduces the absorption of amino

  1. Design of the robust synchronous generator stator voltage regulator based on the interval plant model

    Directory of Open Access Journals (Sweden)

    Stojić Đorđe

    2013-01-01

    Full Text Available In this paper a novel method for the stator voltage regulator of a synchronous generator based on the interval plant mode, is presented. Namely, it is shown in the literature that, in order to design a controller for the first-order compensator, the limited number of interval plants needs to be examined. Consequently, the intervals of the plant model parameter variations used to calculate the four extreme interval plants required for the sequential PI controller design are determined. The controller is designed using frequency-domain-based techniques, while its robust performance is examined using simulation tests.

  2. Regulation of galactan synthase expression to modify galactan content in plants

    Science.gov (United States)

    None

    2017-08-22

    The disclosure provides methods of engineering plants to modulate galactan content. Specifically, the disclosure provides methods for engineering a plant to increase the galactan content in a plant tissue by inducing expression of beta-1,4-galactan synthase (GALS), modulated by a heterologous promoter. Further disclosed are the methods of modulating expression level of GALS under the regulation of a transcription factor, as well as overexpression of UDP-galactose epimerse in the same plant tissue. Tissue specific promoters and transcription factors can be used in the methods are also provided.

  3. Baseline levels of bioaerosols and volatile organic compounds around a municipal waste incinerator prior to the construction of a mechanical-biological treatment plant

    International Nuclear Information System (INIS)

    Vilavert, Lolita; Nadal, Marti; Inza, Isabel; Figueras, Maria J.; Domingo, Jose L.

    2009-01-01

    New waste management programs are currently aimed at developing alternative treatment technologies such as mechanical-biological treatment (MBT) and composting plants. However, there is still a high uncertainty concerning the chemical and microbiological risks for human health, not only for workers of these facilities, but also for the population living in the neighborhood. A new MBT plant is planned to be constructed adjacently to a municipal solid waste incinerator (MSWI) in Tarragona (Catalonia, Spain). In order to evaluate its potential impact and to differentiate the impacts of MSWI from those of the MBT when the latter is operative, a pre-operational survey was initiated by determining the concentrations of 20 volatile organic compounds (VOCs) and bioaerosols (total bacteria, Gram-negative bacteria, fungi and Aspergillus fumigatus) in airborne samples around the MSWI. The results indicated that the current concentrations of bioaerosols (ranges: 382-3882, 18-790, 44-926, and 3 for fungi at 25 deg. C, fungi at 37 deg. C, total bacteria, and Gram-negative bacteria, respectively) and VOCs (ranging from 0.9 to 121.2 μg/m 3 ) are very low in comparison to reported levels in indoor and outdoor air in composting and MBT plants, as well in urban and industrial zones. With the exception of total bacteria, no correlations were observed between the environmental concentrations of biological agents and the direction/distance from the facility. However, total bacteria presented significantly higher levels downwind. Moreover, a non-significant increase of VOCs was detected in sites closer to the incinerator, which means that the MSWI could have a very minor impact on the surrounding environment.

  4. A Pilot Study of the Effectiveness of Indoor Plants for Removal of Volatile Organic Compounds in Indoor Air in a Seven-Story Office Building

    Energy Technology Data Exchange (ETDEWEB)

    Apte, Michael G.; Apte, Joshua S.

    2010-04-27

    the building. The plants used in the rooftop greenhouse and on the floors were made up of a number of species selected for the following functions: daytime metabolic carbon dioxide (CO{sub 2}) absorption, nighttime metabolic CO{sub 2} absorption, and volatile organic compound (VOC) and inorganic gas absorption/removal for air cleaning. The building contains a reported 910 indoor plants. Daytime metabolic species reported by the PBC include Areca Palm, Oxycardium, Rubber Plant, and Ficus alii totaling 188 plants (21%). The single nighttime metabolic species is the Sansevieria with a total of 28 plants (3%). The 'air cleaning' plant species reported by the PBC include the Money Plant, Aglaonema, Dracaena Warneckii, Bamboo Palm, and Raphis Palm with a total of 694 plants (76%). The plants in the greenhouse (Areca Palm, Rubber Plant, Ficus alii, Bamboo Palm, and Raphis Palm) numbering 161 (18%) of those in the building are grown hydroponically, with the room air blown by fan across the plant root zones. The plants on the building floors are grown in pots and are located on floors 1-6. We conducted a one-day monitoring session in the PBC on January 1, 2010. The date of the study was based on availability of the measurement equipment that the researchers had shipped from Lawrence Berkeley National Lab in the U.S.A. The study date was not optimal because a large proportion of the regular building occupants were not present being New Year's Day. An estimated 40 people were present in the building all day during January 1. This being said, the building systems were in normal operations, including the air handlers and other HVAC components. The study was focused primarily on measurements in the Greenhouse and 3rd and 5th floor environments as well as rooftop outdoors. Measurements included a set of volatile organic compounds (VOCs) and aldehydes, with a more limited set of observations of indoor and outdoor particulate and carbon dioxide concentrations

  5. Investment, regulation, and uncertainty: managing new plant breeding techniques.

    Science.gov (United States)

    Smyth, Stuart J; McDonald, Jillian; Falck-Zepeda, Jose

    2014-01-01

    As with any technological innovation, time refines the technology, improving upon the original version of the innovative product. The initial GM crops had single traits for either herbicide tolerance or insect resistance. Current varieties have both of these traits stacked together and in many cases other abiotic and biotic traits have also been stacked. This innovation requires investment. While this is relatively straight forward, certain conditions need to exist such that investments can be facilitated. The principle requirement for investment is that regulatory frameworks render consistent and timely decisions. If the certainty of regulatory outcomes weakens, the potential for changes in investment patterns increases.   This article provides a summary background to the leading plant breeding technologies that are either currently being used to develop new crop varieties or are in the pipeline to be applied to plant breeding within the next few years. Challenges for existing regulatory systems are highlighted. Utilizing an option value approach from investment literature, an assessment of uncertainty regarding the regulatory approval for these varying techniques is undertaken. This research highlights which technology development options have the greatest degree of uncertainty and hence, which ones might be expected to see an investment decline.

  6. REGULATION OF CHLOROPHY LL DEGRADATION IN PLANT TISSUES

    Directory of Open Access Journals (Sweden)

    Syvash O. O.

    2017-06-01

    Full Text Available The purpose of the review was to analyze the basic biochemical processes leading to the chlorophyll degradation and ways to control this process in plant product storage. First of all, this is a complex of enzymatic reactions starting with the hydrolysis of chlorophyll with the formation of acyclic diterpene phytol and water-soluble chlorophyllide. An alternative primary reaction is the removal of magnesium from the chlorophyll tetrapyrrole ring to form pheophytin with the participation of Mg2+-dechelatase and/or low-molecular Mg2+-dechelating substances. The chlorophyll breakdown can also be caused by free radicals formed in the peroxidase-catalyzed reaction of Н2О2 with phenolic compounds or fatty acids. The unstable product of chlorophyll peroxidation, C132 –hydroxychlorophyll a decomposes to colorless low-molecular compounds. Expression of the genes of chlorophyll catabolism enzymes is controlled by phytohormones. Methods for controlling the pigment decomposition during storage of plant products are associated with the use of activators and inhibitors of chlorophyll decomposition. The best known inductor of the synthesis of catabolic enzymes is ethylene, widely used to accelerate fruit ripening. Gibberellins, cytokinins and nitric oxide, on the contrary, slow down the loss of chlorophyll.

  7. Distinguishing the drivers of trends in land carbon fluxes and plant volatile emissions over the past three decades

    Science.gov (United States)

    Yue, X.; Unger, N.; Zheng, Y.

    2015-08-01

    The terrestrial biosphere has experienced dramatic changes in recent decades. Estimates of historical trends in land carbon fluxes remain uncertain because long-term observations are limited on the global scale. Here, we use the Yale Interactive terrestrial Biosphere (YIBs) model to estimate decadal trends in land carbon fluxes and emissions of biogenic volatile organic compounds (BVOCs) and to identify the key drivers for these changes during 1982-2011. Driven with hourly meteorology from WFDEI (WATCH Forcing Data methodology applied to ERA-Interim data), the model simulates an increasing trend of 297 Tg C a-2 in gross primary productivity (GPP) and 185 Tg C a-2 in the net primary productivity (NPP). CO2 fertilization is the main driver for the flux changes in forest ecosystems, while meteorology dominates the changes in grasslands and shrublands. Warming boosts summer GPP and NPP at high latitudes, while drought dampens carbon uptake in tropical regions. North of 30° N, increasing temperatures induce a substantial extension of 0.22 day a-1 for the growing season; however, this phenological change alone does not promote regional carbon uptake and BVOC emissions. Nevertheless, increases of LAI at peak season accounts for ~ 25 % of the trends in GPP and isoprene emissions at the northern lands. The net land sink shows statistically insignificant increases of only 3 Tg C a-2 globally because of simultaneous increases in soil respiration. In contrast, driven with alternative meteorology from MERRA (Modern Era-Retrospective Analysis), the model predicts significant increases of 59 Tg C a-2 in the land sink due to strengthened uptake in the Amazon. Global BVOC emissions are calculated using two schemes. With the photosynthesis-dependent scheme, the model predicts increases of 0.4 Tg C a-2 in isoprene emissions, which are mainly attributed to warming trends because CO2 fertilization and inhibition effects offset each other. Using the MEGAN (Model of Emissions of Gases

  8. Distinguishing the drivers of trends in land carbon fluxes and plant volatile emissions over the past 3 decades

    Science.gov (United States)

    Yue, X.; Unger, N.; Zheng, Y.

    2015-10-01

    The terrestrial biosphere has experienced dramatic changes in recent decades. Estimates of historical trends in land carbon fluxes remain uncertain because long-term observations are limited on the global scale. Here, we use the Yale Interactive terrestrial Biosphere (YIBs) model to estimate decadal trends in land carbon fluxes and emissions of biogenic volatile organic compounds (BVOCs) and to identify the key drivers for these changes during 1982-2011. Driven by hourly meteorology from WFDEI (WATCH forcing data methodology applied to ERA-Interim data), the model simulates an increasing trend of 297 Tg C a-2 in gross primary productivity (GPP) and 185 Tg C a-2 in the net primary productivity (NPP). CO2 fertilization is the main driver for the flux changes in forest ecosystems, while meteorology dominates the changes in grasslands and shrublands. Warming boosts summer GPP and NPP at high latitudes, while drought dampens carbon uptake in tropical regions. North of 30° N, increasing temperatures induce a substantial extension of 0.22 day a-1 for the growing season; however, this phenological change alone does not promote regional carbon uptake and BVOC emissions. Nevertheless, increases of leaf area index at peak season accounts for ~ 25 % of the trends in GPP and isoprene emissions at the northern lands. The net land sink shows statistically insignificant increases of only 3 Tg C a-2 globally because of simultaneous increases in soil respiration. Global BVOC emissions are calculated using two schemes. With the photosynthesis-dependent scheme, the model predicts increases of 0.4 Tg C a-2 in isoprene emissions, which are mainly attributed to warming trends because CO2 fertilization and inhibition effects offset each other. Using the MEGAN (Model of Emissions of Gases and Aerosols from Nature) scheme, the YIBs model simulates global reductions of 1.1 Tg C a-2 in isoprene and 0.04 Tg C a-2 in monoterpene emissions in response to the CO2 inhibition effects. Land use

  9. Ethylene sensitivity and relative air humidity regulate root hydraulic properties in tomato plants.

    Science.gov (United States)

    Calvo-Polanco, Monica; Ibort, Pablo; Molina, Sonia; Ruiz-Lozano, Juan Manuel; Zamarreño, Angel María; García-Mina, Jose María; Aroca, Ricardo

    2017-11-01

    The effect of ethylene and its precursor ACC on root hydraulic properties, including aquaporin expression and abundance, is modulated by relative air humidity and plant sensitivity to ethylene. Relative air humidity (RH) is a main factor contributing to water balance in plants. Ethylene (ET) is known to be involved in the regulation of root water uptake and stomatal opening although its role on plant water balance under different RH is not very well understood. We studied, at the physiological, hormonal and molecular levels (aquaporins expression, abundance and phosphorylation state), the plant responses to exogenous 1-aminocyclopropane-1-carboxylic acid (ACC; precursor of ET) and 2-aminoisobutyric acid (AIB; inhibitor of ET biosynthesis), after 24 h of application to the roots of tomato wild type (WT) plants and its ET-insensitive never ripe (nr) mutant, at two RH levels: regular (50%) and close to saturation RH. Highest RH induced an increase of root hydraulic conductivity (Lp o ) of non-treated WT plants, and the opposite effect in nr mutants. The treatment with ACC reduced Lp o in WT plants at low RH and in nr plants at high RH. The application of AIB increased Lp o only in nr plants at high RH. In untreated plants, the RH treatment changed the abundance and phosphorylation of aquaporins that affected differently both genotypes according to their ET sensitivity. We show that RH is critical in regulating root hydraulic properties, and that Lp o is affected by the plant sensitivity to ET, and possibly to ACC, by regulating aquaporins expression and their phosphorylation status. These results incorporate the relationship between RH and ET in the response of Lp o to environmental changes.

  10. Influence of Plant Growth Regulators (PGRs and Planting Method on Growth and Yield in Oil Pumpkin (Cucurbita pepo var. styriaca

    Directory of Open Access Journals (Sweden)

    Shirzad SURE

    2012-05-01

    Full Text Available The effect of plant growth regulators IBA (indole butyric acid, GA3 (gibberellin and ethylene (as ethephon in two methods of planting was investigated (each method was considered as a separate experiment on morphological characters and yield of medicinal pumpkin. The experiments were carried out in a factorial trial based on completely randomized block design, with four replicates. The treatments were combined with priming and spraying with the above PGRs. The first seed priming with control (water, IBA 100 ppm, GA3 25 ppm and ethephon 200 ppm, and when seedling developed to 4 leaf stage sprayed there with control (water, IBA 100 ppm, GA3 25 ppm and ethephon 200 ppm for three times. In both planting methods, there were all of these treatments. The result showed that PGRs and planting method had significant effects on vegetative, flowering and yield characteristics including: leaf area %DM plant, number of male and female flowers per plant, number of fruit/plant, fruits fresh weight, seeds length and width, number of seed per fruit, seed yield, % seeds oil and oil yield. Hence spraying with GA3 25 ppm in four leaf stage at trellis method could be a suitable treatment for enhancing growth and yield of medicinal pumpkin.

  11. No time for candy: passionfruit (Passiflora edulis) plants down-regulate damage-induced extra floral nectar production in response to light signals of competition.

    Science.gov (United States)

    Izaguirre, Miriam M; Mazza, Carlos A; Astigueta, María S; Ciarla, Ana M; Ballaré, Carlos L

    2013-09-01

    Plant fitness is often defined by the combined effects of herbivory and competition, and plants must strike a delicate balance between their ability to capture limiting resources and defend against herbivore attack. Many plants use indirect defenses, such as volatile compounds and extra floral nectaries (EFN), to attract canopy arthropods that are natural enemies of herbivorous organisms. While recent evidence suggests that upon perception of low red to far-red (R:FR) ratios, which signal the proximity of competitors, plants down-regulate resource allocation to direct chemical defenses, it is unknown if a similar phytochrome-mediated response occurs for indirect defenses. We evaluated the interactive effects of R:FR ratio and simulated herbivory on nectar production by EFNs of passion fruit (Passiflora edulis f. flavicarpa). The activity of petiolar EFNs dramatically increased in response to simulated herbivory and hormonal treatment with methyl jasmonate (MeJA). Low R:FR ratios, which induced a classic "shade-avoidance" repertoire of increased stem elongation in P. edulis, strongly suppressed the EFN response triggered by simulated herbivory or MeJA application. Strikingly, the EFN response to wounding and light quality was localized to the branches that received the treatments. In vines like P. edulis, a local response would allow the plants to precisely adjust their light harvesting and defense phenotypes to the local conditions encountered by individual branches when foraging for resources in patchy canopies. Consistent with the emerging paradigm that phytochrome regulation of jasmonate signaling is a central modulator of adaptive phenotypic plasticity, our results demonstrate that light quality is a strong regulator of indirect defenses.

  12. Fennel (Foeniculum vulgare Mill. subsp. piperitum) florets, a traditional culinary spice in Italy: evaluation of phenolics and volatiles in local populations, and comparison with the composition of other plant parts.

    Science.gov (United States)

    Ferioli, Federico; Giambanelli, Elisa; D'Antuono, L Filippo

    2017-12-01

    Wild fennel (Foeniculum vulgare Mill. subsp. piperitum) florets are used as a typical spice in central and southern Italy. Although fennel (Foeniculum vulgare Mill.), belonging to the Apiaceae (syn. Umbelliferae) family, is a well-known vegetable and aromatic plant, whose main phytochemical compounds have been extensively analysed and investigated as flavouring agents and for their putative health promoting functions, its florets have not been specifically considered up to now. Therefore, the volatile and phenolic composition of florets from an Italian wild fennel crop was determined at different developmental stages, and compared to that of leaves and fruits. Moreover, florets of nine Italian wild fennel populations of different geographical origin from northern-central Italy were also analysed. The total phenolic amount increased from leaves to florets, reaching its highest value in early florets, at 58 012 mg kg -1 of dry matter (DM), then constantly decreased in fruits. In florets of wild populations, phenolics ranged from 6666 to 43 368 mg kg -1 DM. The total amount of volatile compounds was more than twice higher in florets (21 449 mg kg -1 DM) than in leaves (10 470 mg kg -1 DM), reaching its highest value in fruits (50 533 mg kg -1 DM). Estragole and trans-anethole were the main compounds of the volatile fraction. Total volatiles ranged from 24 367 to 60 468 mg kg -1 DM in florets of local populations. Significant changes in the total amount and profile of both phenolic and volatile compounds occurred during plant development. The consistent increase of estragole at later developmental stages supported the claim of different sensory properties of florets and fruits. Geographical origin significantly affected phenolic and volatile composition of wild fennel florets. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  13. Use of a plant-derived enzyme template for the production of the green-note volatile hexanal.

    Science.gov (United States)

    Schade, Frank; Thompson, John E; Legge, Raymond L

    2003-11-05

    Hexanal is a key organoleptic element of green-note that is found in both fragrances and flavors. We report a novel process for the production of hexanal using immobilized enzyme templates extracted from different plant sources in combination with hollow-fiber ultrafiltration for in situ separation. Enzyme templates, known to be responsible for the synthesis of hexanal from linoleic acid (18:2), were isolated from naturally enriched tissues including carnation petals, strawberry and tomato leaves. These templates were immobilized in an alginate matrix and used as a biocatalyst in a packed-bed bioreactor. Continuous product recovery was achieved using a hollow-fiber ultrafiltration unit. The effects of pH, reaction temperature, and substrate and enzyme concentrations were studied and their effects on hexanal generation identified and optimized. Utilizing optimized conditions, hexanal production 112-fold higher than endogenous steady-state levels in a corresponding amount of plant tissue could be achieved over a 30-minute period. Based on the reactor studies, product inhibition also appears to be an important factor for bioreactor-based hexanal production. Copyright 2003 Wiley Periodicals, Inc.

  14. Synthesis Of 2- (1- Naphthyl) Ethanoic Acid ( Plant Growth Regulator ) From Coal Tar And Its Application

    International Nuclear Information System (INIS)

    Khin Mooh Theint; Tin Myint Htwe

    2011-12-01

    Plant growth regulators, which are commonly called as plant hormones, naturally produced non-nutrient chemical compounds involved in growth and development. Among the various kinds of plant growth regulators, 2- (1- Naphthyl ) ethanoic acid especially encourages the root development of the plant. In this work, NAA was successfuly synthesized from naphthalene which was extracted from coal tar. The purity of naphthalene, -Chloromethyl naphthalene, -Naphthyl acetonitrile, - Naphthyl acetic acid or 2 - ( 1-Naphthyl ) ethanoic acid were also confirmed by Thin Layer Chromatography, and by spectroscopy methods. The yield percent of NAA based on naphthalene was found to be 2.1%. The yield percent of naphthaleneFrom coal tar is found to be 4.09%. The effect of NAA on root development was also studied in different concentrations of soy bean (Glycine max)and cow pea (Vigna catjang walp).

  15. Principal component analysis (PCA of volatile terpene compounds dataset emitted by genetically modified sweet orange fruits and juices in which a D-limonene synthase was either up- or down-regulated vs. empty vector controls

    Directory of Open Access Journals (Sweden)

    Ana Rodríguez

    2016-12-01

    Full Text Available We have categorized the dataset from content and emission of terpene volatiles of peel and juice in both Navelina and Pineapple sweet orange cultivars in which D-limonene was either up- (S, down-regulated (AS or non-altered (EV; control (“Impact of D-limonene synthase up- or down-regulation on sweet orange fruit and juice odor perception”(A. Rodríguez, J.E. Peris, A. Redondo, T. Shimada, E. Costell, I. Carbonell, C. Rojas, L. Peña, (2016 [1]. Data from volatile identification and quantification by HS-SPME and GC–MS were classified by Principal Component Analysis (PCA individually or as chemical groups. AS juice was characterized by the higher influence of the oxygen fraction, and S juice by the major influence of ethyl esters. S juices emitted less linalool compared to AS and EV juices.

  16. The cofiring problem of a power plant under policy regulations

    International Nuclear Information System (INIS)

    Kangas, Hanna-Liisa; Lintunen, Jussi; Uusivuori, Jussi

    2009-01-01

    Cofiring of fossil and renewable fuels can contribute to reaching tightening climate and renewable energy goals. The increase in biomass share in cofiring decreases the use of fossil fuel and increases renewable energy production. We study how energy and climate policies promote that increase. First, we present and solve an electricity producer's profit-maximization problem with detailed technical description of cofiring. We then study the effectiveness of policy instruments (e.g. feed-in laws and emission trading) on biomass utilization in cofiring. The study offers a novel approach to explore the cofiring problem, because of the endogenous fuel choice combined with the policy analysis. We study two different power plants that are located in two different European electricity market areas. Our analysis shows that both feed-in tariff and feed-in premium can have unexpected weaknesses, when they are introduced together with emission trading. Therefore decision-makers should be well informed and cautious when introducing these policies. (author)

  17. Impact of botanical pesticides derived from Melia azedarach and Azadirachta indica plants on the emission of volatiles that attract parasitoids of the diamondback moth to cabbage plants

    NARCIS (Netherlands)

    Charleston, D.S.; Gols, R.; Hordijk, C.A.; Kfir, R.; Vet, L.E.M.; Dicke, M.

    2006-01-01

    Herbivorous and carnivorous arthropods use chemical information from plants during foraging. Aqueous leaf extracts from the syringa tree Melia azedarach and commercial formulations from the neem tree Azadirachta indica, Neemix 4.5®, were investigated for their impact on the flight response of two

  18. Evaluation of three analytical techniques used to determine high levels of volatile organic compounds in type IV sludge from Rocky Flats Plant

    International Nuclear Information System (INIS)

    Parish, K.J.; Applegate, D.V.; Tsai, Y.

    1996-01-01

    Before disposal, radioactive sludge (Type IV) from Rocky Flats Plant (RFP) must be evaluated for volatile organic compound (VOC) content. The Type IV sludge consists of organic solvents, degreasers, cutting oils, and transuranic (TRU) waste mixed with calcium silicate (MicroCel E reg-sign) and Oil Dri reg-sign to form a grease or paste-like material. For laboratory testing, a simulated Type IV RFP sludge (nonradioactive) was prepared at Argonne National Laboratory-East. This sludge has a composition similar to that expected from field samples. On the basis of historical information, a typical Type IV sludge is expected to contain approximately 1-10 percent of three target VOCs. The objective of this work is to evaluate three proposed methods for the determination of high levels of these three VOCs in Type IV sludge. The three methods are (1) static headspace gas analysis, (2) methanol extraction, and (3) ethylene glycol extraction. All three methods employ gas chromatography/mass spectrometry (GC/MS). They were evaluated regarding general method performance criteria, ease of operation, and amounts of secondary mixed waste generated

  19. Silicon Regulates Potential Genes Involved in Major Physiological Processes in Plants to Combat Stress

    Directory of Open Access Journals (Sweden)

    Abinaya Manivannan

    2017-08-01

    Full Text Available Silicon (Si, the quasi-essential element occurs as the second most abundant element in the earth's crust. Biological importance of Si in plant kingdom has become inevitable particularly under stressed environment. In general, plants are classified as high, medium, and low silicon accumulators based on the ability of roots to absorb Si. The uptake of Si directly influence the positive effects attributed to the plant but Si supplementation proves to mitigate stress and recover plant growth even in low accumulating plants like tomato. The application of Si in soil as well as soil-less cultivation systems have resulted in the enhancement of quantitative and qualitative traits of plants even under stressed environment. Silicon possesses several mechanisms to regulate the physiological, biochemical, and antioxidant metabolism in plants to combat abiotic and biotic stresses. Nevertheless, very few reports are available on the aspect of Si-mediated molecular regulation of genes with potential role in stress tolerance. The recent advancements in the era of genomics and transcriptomics have opened an avenue for the determination of molecular rationale associated with the Si amendment to the stress alleviation in plants. Therefore, the present endeavor has attempted to describe the recent discoveries related to the regulation of vital genes involved in photosynthesis, transcription regulation, defense, water transport, polyamine synthesis, and housekeeping genes during abiotic and biotic stress alleviation by Si. Furthermore, an overview of Si-mediated modulation of multiple genes involved in stress response pathways such as phenylpropanoid pathway, jasmonic acid pathway, ABA-dependent or independent regulatory pathway have been discussed in this review.

  20. Model and simulation of the hydraulic turbine speed regulator of the Atucha I nuclear power plant

    International Nuclear Information System (INIS)

    Copparoni, G.; Etchepareborda, A.; Urrutia, G.

    1992-01-01

    The hydraulics turbines of Atucha I Nuclear Power Plant takes advantage of condenser cooling water level difference between the plant and the river to recover about 2,5 MW e. It also supplies emergency power until diesel generators start up. Speed regulation is needed due to the transients that during this process occur. The purpose is to minimize the diesels start up time, and to avoid overshoots on the internal grid frequency. The hydraulic turbine, its speed regulator and the electric system associated with this transient have been modeled. The models and some simulation results are presented in this work. (author)

  1. Phosphorylation-dependent regulation of plant chromatin and chromatin-associated proteins

    KAUST Repository

    Bigeard, Jean; Rayapuram, Naganand; Pflieger, Delphine; Hirt, Heribert

    2014-01-01

    In eukaryotes, most of the DNA is located in the nucleus where it is organized with histone proteins in a higher order structure as chromatin. Chromatin and chromatin-associated proteins contribute to DNA-related processes such as replication and transcription as well as epigenetic regulation. Protein functions are often regulated by PTMs among which phosphorylation is one of the most abundant PTM. Phosphorylation of proteins affects important properties, such as enzyme activity, protein stability, or subcellular localization. We here describe the main specificities of protein phosphorylation in plants and review the current knowledge on phosphorylation-dependent regulation of plant chromatin and chromatin-associated proteins. We also outline some future challenges to further elucidate protein phosphorylation and chromatin regulation.

  2. Plasma Membrane H(+)-ATPase Regulation in the Center of Plant Physiology.

    Science.gov (United States)

    Falhof, Janus; Pedersen, Jesper Torbøl; Fuglsang, Anja Thoe; Palmgren, Michael

    2016-03-07

    The plasma membrane (PM) H(+)-ATPase is an important ion pump in the plant cell membrane. By extruding protons from the cell and generating a membrane potential, this pump energizes the PM, which is a prerequisite for growth. Modification of the autoinhibitory terminal domains activates PM H(+)-ATPase activity, and on this basis it has been hypothesized that these regulatory termini are targets for physiological factors that activate or inhibit proton pumping. In this review, we focus on the posttranslational regulation of the PM H(+)-ATPase and place regulation of the pump in an evolutionary and physiological context. The emerging picture is that multiple signals regulating plant growth interfere with the posttranslational regulation of the PM H(+)-ATPase. Copyright © 2016 The Author. Published by Elsevier Inc. All rights reserved.

  3. Phosphorylation-dependent regulation of plant chromatin and chromatin-associated proteins

    KAUST Repository

    Bigeard, Jean

    2014-07-10

    In eukaryotes, most of the DNA is located in the nucleus where it is organized with histone proteins in a higher order structure as chromatin. Chromatin and chromatin-associated proteins contribute to DNA-related processes such as replication and transcription as well as epigenetic regulation. Protein functions are often regulated by PTMs among which phosphorylation is one of the most abundant PTM. Phosphorylation of proteins affects important properties, such as enzyme activity, protein stability, or subcellular localization. We here describe the main specificities of protein phosphorylation in plants and review the current knowledge on phosphorylation-dependent regulation of plant chromatin and chromatin-associated proteins. We also outline some future challenges to further elucidate protein phosphorylation and chromatin regulation.

  4. Effects of plant growth regulators in heliconia ‘Red Opal’

    Directory of Open Access Journals (Sweden)

    Ana Cecilia Ribeiro de Castro

    2016-12-01

    Full Text Available The objective of this study was to evaluate growth regulators with purpose of reducing the size of heliconia ‘Red Opal’ potted plants. The experiment was carried out in randomized block design with five treatments (trinexapac-ethyl and paclobutrazol at rates of 37.5 and 75.0 mg of active ingredient per pot and control without growth regulator and five replicates. The treatments were applied 40 days after planting the rhizomes in pots filled with soil. Thirty and 150 days after the growth regulator application, plant height, number of leaves and shoots, petioles length and leaf area were evaluated. One year after planting the rhizomes in pots the number of inflorescence and leaves (leaves, sheathing leaf bases and inflorescences and rhizomes (rhizomes and roots dry mass were determined. Trinexapac-ethyl had no differences compared to the control in any of the variables evaluated. Paclobutrazol proved effective in reducing plant height, leaf area and petiole length and increase in number of leaves and shoots but the effect was temporary. Also, it did not affect the inflorescences production and leaves and rhizomes dry mass. Paclobutrazol is efficient to promote height reduction and to increase the number of shoots in heliconia ‘Red Opal’ potted plants without affect the inflorescence formation but its effects is temporary.

  5. Plant phospholipase C family: Regulation and functional role in lipid signaling.

    Science.gov (United States)

    Singh, Amarjeet; Bhatnagar, Nikita; Pandey, Amita; Pandey, Girdhar K

    2015-08-01

    Phospholipase C (PLC), a major membrane phospholipid hydrolyzing enzyme generates signaling messengers such as diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3) in animals, and their phosphorylated forms such as phosphatidic acid (PA) and inositol hexakisphosphate (IP6) are thought to regulate various cellular processes in plants. Based on substrate specificity, plant PLC family is sub-divided into phosphatidylinositol-PLC (PI-PLC) and phosphatidylcholine-PLC (PC-PLC) groups. The activity of plant PLCs is regulated by various factors and the major ones include, Ca(2+) concentration, phospholipid substrate, post-translational modifications and interacting proteins. Most of the PLC members have been localized at the plasma membrane, suited for their function of membrane lipid hydrolysis. Several PLC members have been implicated in various cellular processes and signaling networks, triggered in response to a number of environmental cues and developmental events in different plant species, which makes them potential candidates for genetically engineering the crop plants for stress tolerance and enhancing the crop productivity. In this review article, we are focusing mainly on the plant PLC signaling and regulation, potential cellular and physiological role in different abiotic and biotic stresses, nutrient deficiency, growth and development. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Nitrate Protects Cucumber Plants Against Fusarium oxysporum by Regulating Citrate Exudation.

    Science.gov (United States)

    Wang, Min; Sun, Yuming; Gu, Zechen; Wang, Ruirui; Sun, Guomei; Zhu, Chen; Guo, Shiwei; Shen, Qirong

    2016-09-01

    Fusarium wilt causes severe yield losses in cash crops. Nitrogen plays a critical role in the management of plant disease; however, the regulating mechanism is poorly understood. Using biochemical, physiological, bioinformatic and transcriptome approaches, we analyzed how nitrogen forms regulate the interactions between cucumber plants and Fusarium oxysporum f. sp. cucumerinum (FOC). Nitrate significantly suppressed Fusarium wilt compared with ammonium in both pot and hydroponic experiments. Fewer FOC colonized the roots and stems under nitrate compared with ammonium supply. Cucumber grown with nitrate accumulated less fusaric acid (FA) after FOC infection and exhibited increased tolerance to chemical FA by decreasing FA absorption and transportation in shoots. A lower citrate concentration was observed in nitrate-grown cucumbers, which was associated with lower MATE (multidrug and toxin compound extrusion) family gene and citrate synthase (CS) gene expression, as well as lower CS activity. Citrate enhanced FOC spore germination and infection, and increased disease incidence and the FOC population in ammonium-treated plants. Our study provides evidence that nitrate protects cucumber plants against F. oxysporum by decreasing root citrate exudation and FOC infection. Citrate exudation is essential for regulating disease development of Fusarium wilt in cucumber plants. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  7. Life in the dark: Roots and how they regulate plant-soil interactions

    Science.gov (United States)

    Wu, Y.; Chou, C.; Peruzzo, L.; Riley, W. J.; Hao, Z.; Petrov, P.; Newman, G. A.; Versteeg, R.; Blancaflor, E.; Ma, X.; Dafflon, B.; Brodie, E.; Hubbard, S. S.

    2017-12-01

    Roots play a key role in regulating interactions between soil and plants, an important biosphere process critical for soil development and health, global food security, carbon sequestration, and the cycling of elements (water, carbon, nutrients, and environmental contaminants). However, their underground location has hindered studies of plant roots and the role they play in regulating plant-soil interactions. Technological limitations for root phenotyping and the lack of an integrated approach capable of linking root development, its environmental adaptation/modification with subsequent impact on plant health and productivity are major challenges faced by scientists as they seek to understand the plant's hidden half. To overcome these challenges, we combine novel experimental methods with numerical simulations, and conduct controlled studies to explore the dynamic growth of crop roots. We ask how roots adapt to and change the soil environment and their subsequent impacts on plant health and productivity. Specifically, our efforts are focused on (1) developing novel geophysical approaches for non-invasive plant root and rhizosphere characterization; (2) correlating root developments with key canopy traits indicative of plant health and productivity; (3) developing numerical algorithms for novel geophysical root signal processing; (4) establishing plant growth models to explore root-soil interactions and above and below ground traits co-variabilities; and (5) exploring how root development modifies rhizosphere physical, hydrological, and geochemical environments for adaptation and survival. Our preliminary results highlight the potential of using electro-geophysical methods to quantifying key rhizosphere traits, the capability of the ecosys model for mechanistic plant growth simulation and traits correlation exploration, and the combination of multi-physics and numerical approach for a systematic understanding of root growth dynamics, impacts on soil physicochemical

  8. Jasmonic Acid Is a Key Regulator of Spider Mite-Induced Volatile Terpenoid and Methyl Salicylate Emission in Tomato1[w

    Science.gov (United States)

    Ament, Kai; Kant, Merijn R.; Sabelis, Maurice W.; Haring, Michel A.; Schuurink, Robert C.

    2004-01-01

    The tomato (Lycopersicon esculentum) mutant def-1, which is deficient in induced jasmonic acid (JA) accumulation upon wounding or herbivory, was used to study the role of JA in the direct and indirect defense responses to phytophagous mites (Tetranychus urticae). In contrast to earlier reports, spider mites laid as many eggs and caused as much damage on def-1 as on wild-type plants, even though def-1 lacked induction of proteinase inhibitor activity. However, the hatching-rate of eggs on def-1 was significantly higher, suggesting that JA-dependent direct defenses enhanced egg mortality or increased the time needed for embryonic development. As to gene expression, def-1 had lower levels of JA-related transcripts but higher levels of salicylic acid (SA) related transcripts after 1 d of spider mite infestation. Furthermore, the indirect defense response was absent in def-1, since the five typical spider mite-induced tomato-volatiles (methyl salicylate [MeSA], 4,8,12-trimethyltrideca-1,3,7,11-tetraene [TMTT], linalool, trans-nerolidol, and trans-β-ocimene) were not induced and the predatory mite Phytoseiulus persimilis did not discriminate between infested and uninfested def-1 tomatoes as it did with wild-type tomatoes. Similarly, the expression of the MeSA biosynthetic gene salicylic acid methyltransferase (SAMT) was induced by spider mites in wild type but not in def-1. Exogenous application of JA to def-1 induced the accumulation of SAMT and putative geranylgeranyl diphosphate synthase transcripts and restored MeSA- and TMTT-emission upon herbivory. JA is therefore necessary to induce the enzymatic conversion of SA into MeSA. We conclude that JA is essential for establishing the spider mite-induced indirect defense response in tomato. PMID:15310835

  9. The Effects of a Plant Growth Regulator, Leaf Removal, Bagging, and Harvest Time on the Lipoxygenase Activity and Fatty Acid Composition of Pinot Noir Grapevines

    International Nuclear Information System (INIS)

    Ju, Y.; Zeng, J.; Zhu, M.; Lv, X.; Wang, T.; Zhang, Z.; Li, H.; Fang, Y.

    2016-01-01

    Green leaf volatiles (GLVs) are an important source of grape aromas, and lipoxygenase is a key enzyme involved in the formation of green leaf volatile substances. In addition, fatty acids are the main substrates that compose GLVs and are the main precursor compound utilized in the formation of grape aromas, which are an important index of grape quality. We examined the effects of a plant growth regulator, leaf removal, bagging, and harvest time on the lipoxygenase (LOX) activity, and the fatty acid composition of grapevines were studied. The following four experimental treatments were conducted using Pinot Noir (Vitis vinifera L.) grapevines to study the following variables: treatment with a plant growth regulator, leaf removal, fruit bagging, and harvest time. We obtained the following results. (1) 16 types of fatty acids were detected in the grape skins. The unsaturated fatty acid content consisted mainly of linoleic acid, oleic acid and palmitoleic acid; however, no linolenic acid was detected. In addition, the saturated fatty acid content consisted primarily of palmitic acid, stearic acid, behenic acid and arachidic acid. (2) Abscisic acid (ABA), methyl jasmonate (MeJA), light intensity, and harvest time appeared to effect LOX activity. (3) According to a principal component analysis (PCA) of the four treatments and the fatty acid content of the skins, ABA (concentration of 1000 mg/L), MeJA (concentrations of 100 meu mol/L, 400 meu mol/L and 800 meu mol/L) and early harvest treatment were responsible for the changes in fatty acid content. These results could be helpful in vineyard management and in improving the quality of grapes. (author)

  10. Application of titration methods for measuring the contents of ammonium nitrogen and volatile fatty acids in agricultural biogas plants.

    Science.gov (United States)

    Piątek, Michał; Lisowski, Aleksander; Lisowska, Barbara

    2017-12-20

    The aim of our research was to assess a relatively new method of estimating ammonium nitrogen concentration in anaerobic digestion of plant substrates. We analysed our own data, received from the anaerobic digestion of maize silage (PM), as well as data published by Purser et al. (2014) who measured energy crops and slurry (ECS), and food waste (FW). In our study, the process was monitored for VFA content that was determined by gas chromatography, and for the content of ammonium nitrogen determined using the HACH LANGE LCK 303 cuvette test. We created polynomial regression models that bind the content of ammonium nitrogen with the volume of H 2 SO 4 used to titrate the sample from initial pH to pH 5. To estimate parameters of model, the PM dataset was used. The obtained models were positively validated using ECS and FW datasets. Our results confirmed the effectiveness of the Purser et al. method with an average absolute error of less than 223mgl -1 of the VFA concentration, which was approximately 20-times less than the level that caused inhibition. In conclusion, we can affirm the suitability of using titration methods to assess the ammonium nitrogen content of bioreactors with a stable composition. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Volatile fatty acids production in ruminants and the role of ...

    African Journals Online (AJOL)

    Yomi

    organic volatile fatty acids (VFAs) and microbial protein then become available to the host. .... BE, Drewes LR (2003). Molecular features, regulation and ... Dynamics of ruminal volatile fatty acids in black and white bulls before and after feeding ...

  12. Proposed Regulation of Fuels and Fuel Additives: Federal Volatility Control Program in the Denver-Boulder-Greeley-Ft. Collins-Loveland, Colorado, 1997 8-Hour Ozone Nonattainment Area

    Science.gov (United States)

    This notice proposes establishing an applicable standard of 7.8 pounds (psi) Reid vapor pressure under the federal volatility control program, in the Denver-Boulder-Greeley-Ft. Collins-Loveland, Colorado, 1997 8-hour ozone nonattainment area.

  13. Leaf Volatile Compounds and Associated Gene Expression during Short-Term Nitrogen Deficient Treatments in Cucumis Seedlings

    Directory of Open Access Journals (Sweden)

    Jie Deng

    2016-11-01

    Full Text Available Nitrogen (N is an important macronutrient for plant growth and development, but the regulatory mechanism of volatile compounds in response to N deficiency is not well understood, especially in cucumber, which consumes excessive N during growth. In this study, the major volatile compounds from cucumber leaves subjected to N deficiency were analyzed by GC-MS. A total of 24 volatile components were identified including 15 aldehydes, two ketones, two alkenes, and five other volatile compounds in 9930 leaves. Principal component analysis using volatile compounds from cucumber leaves provided good separation between N-sufficient and N-deficient treatments. The main volatiles in cucumber leaves were found to be C6 and C9 aldehydes, especially (E-2-hexanal and (E,Z-2,6-nonadienal. (E-2-hexanal belonged to the C6 aldehyde and was the most abundant compound, whereas (E,Z-2,6-nonadienal was the chief component of C9 aldehydes. During N-deficient treatment, short-chain volatile content was significantly improved at 5 day, other volatiles displayed significant reduction or no significantly changes in all sampling points. Improvement of short-chain volatiles was confirmed in the six other inbred lines at 5 day after N-deficient treatments. The expression analysis of 12 cucumber LOX genes and two HPL genes revealed that CsLOX19, CsLOX20, and CsLOX22 had common up-regulated expression patterns in response to N-deficient stress in most inbred lines; meanwhile, most sample points of CsHPL1 also had significant up-regulated expression patterns. This research focused on the relationship between volatiles in cucumber and different nitrogen environments to provide valuable insight into the effect of cultivation and management of the quality of cucumber and contributes to further research on volatile metabolism in cucumber.

  14. Oligosaccharins, brassinolides, and jasmonates: nontraditional regulators of plant growth, development, and gene expression.

    Science.gov (United States)

    Creelman, R A; Mullet, J E

    1997-07-01

    Each of the nontraditional plant hormones reviewed in this article, oligosaccharins, brassinolides, and JA, can exert major effects on plant growth and development. However, in many cases, the mechanisms by which these compounds are involved in the endogenous regulation of morphogenesis remain to be established. Nevertheless, the use of mutant or transgenic plants with altered levels or perception of these hormones is leading to phenomenal increases in our understanding of the roles they play in the life cycle of plants. It is likely that in the future, novel modulators of plant growth and development will be identified; some will perhaps be related to the peptide encoded by ENOD40 (Van de Sande et al., 1996), which modifies the action of auxin.

  15. Incentive regulation of nuclear power plants by state Public Utility Commissions

    International Nuclear Information System (INIS)

    Martin, R.L.; Olson, J.; Hendrickson, P.

    1989-12-01

    Economic performance incentives established by state Public Utility Commissions (PUCs) currently are applicable to the construction or operation of approximately 73 nuclear power reactors owned by 27 utilities with investment greater than 10% in 18 states. The NRC staff monitors development of the incentives and periodically provides an updated report on all nuclear plant incentives to its headquarters and regional offices. The staff maintains contact with the PUCs and the utilities responsible for implementing the incentives in order to obtain the updated information and to consider potential safety effects of the incentives. This report on incentive regulation of nuclear power plants by state PUCs presents the NRC staff's concerns on potential safety effects of economic performance incentives. It also includes a plant-by-plant survey that describes the mechanics of each incentive and discusses the financial effects of the incentive on the utility-owner(s) of the plant

  16. Incentive regulation of nuclear power plants by state public utility commissions

    International Nuclear Information System (INIS)

    Petersen, J.C.

    1987-12-01

    This report on incentive regulation of nuclear power plants by state public utility commissions (PUCs). Economic performance incentives established by state PUCs are applicable to the construction or operation of about 45 nuclear power reactors owned by 30 utilities in 17 states. The NRC staff monitors development of the incentives and periodically provides an updated report on all nuclear plant incentives to its regional offices. The staff maintains contact with the PUCs and the utilities responsible for implementing the incentives in order to obtain the updated information and to consider potential safety effects of the incentives. This report presents the NRC staff's concerns on potential safety effects of economic performance incentives. It also includes a plant-by-plant survey that describes the mechanics of each incentive and discusses the financial effects of the incentive on the utility-owner(s) of the plant

  17. Pricing Volatility Referenced Assets

    Directory of Open Access Journals (Sweden)

    Alan De Genaro Dario

    2006-12-01

    Full Text Available Volatility swaps are contingent claims on future realized volatility. Variance swaps are similar instruments on future realized variance, the square of future realized volatility. Unlike a plain vanilla option, whose volatility exposure is contaminated by its asset price dependence, volatility and variance swaps provide a pure exposure to volatility alone. This article discusses the risk-neutral valuation of volatility and variance swaps based on the framework outlined in the Heston (1993 stochastic volatility model. Additionally, the Heston (1993 model is calibrated for foreign currency options traded at BMF and its parameters are used to price swaps on volatility and variance of the BRL / USD exchange rate.

  18. Harmonization of nuclear and radiation safety regulations for nuclear power plants with reference levels of Western European Nuclear Regulators Association (WENRA)

    International Nuclear Information System (INIS)

    Bojchuk, V.S.; Mikolajchuk, O.A.; Gromov, G.V.; Dibach, O.M.; Godovanyuk, G.M.; Nosovs'kij, A.V.

    2014-01-01

    Self-evaluation of the Ukrainian regulations on nuclear and radiation safety that apply to nuclear power plants for compliance with the reference levels of the Western European Nuclear Regulators Association (WENRA) is presented. Proposals on improvement of the regulations upon self-evaluation are provided

  19. 78 FR 24633 - Restructuring of Regulations on the Importation of Plants for Planting

    Science.gov (United States)

    2013-04-25

    ...) capable of propagation, including a tree, a tissue culture, a plantlet culture, pollen, a shrub, a vine, a... sterile cultures of orchid plants) from any country or locality except Canada may be imported into the... including Africa, Australia, Brazil, Bulgaria, Japan and adjacent islands, Korea, New Zealand, Oceania, the...

  20. Plant natriuretic peptides: Systemic regulators of plant homeostasis and defense that can affect cardiomyoblasts

    KAUST Repository

    Gehring, Christoph A.

    2010-09-01

    Immunologic evidence has suggested the presence of biologically active natriuretic peptide (NPs) hormones in plants because antiatrial NP antibodies affinity purify biologically active plant NPs (PNP). In the model plant, an Arabidopsis thaliana PNP (AtPNP-A) has been identified and characterized. AtPNP-A belongs to a novel class of molecules that share some similarity with the cell wall loosening expansins but do not contain the carbohydrate-binding wall anchor thus suggesting that PNPs and atrial natriuretic peptides are heterologs. AtPNP-A acts systemically, and this is consistent with its localization in the apoplastic extracellular space and the conductive tissue. Furthermore, AtPNP-A signals via the second messenger cyclic guanosine 3′,5′-monophosphate and modulates ion and water transport and homeostasis. It also plays a critical role in host defense against pathogens. AtPNP-A can be classified as novel paracrine plant hormone because it is secreted into the apoplastic space in response to stress and can enhance its own expression. Interestingly, purified recombinant PNP induces apo-ptosis in a dose-dependent manner and was most effective on cardiac myoblast cell lines. Because PNP is mimicking the effect of ANP in some instances, PNP may prove to provide useful leads for development of novel therapeutic NPs. Copyright © 2013 by The American Federation for Medical Research.

  1. Plant natriuretic peptides: Systemic regulators of plant homeostasis and defense that can affect cardiomyoblasts

    KAUST Repository

    Gehring, Christoph A; Irving, Helen R.

    2010-01-01

    Immunologic evidence has suggested the presence of biologically active natriuretic peptide (NPs) hormones in plants because antiatrial NP antibodies affinity purify biologically active plant NPs (PNP). In the model plant, an Arabidopsis thaliana PNP (AtPNP-A) has been identified and characterized. AtPNP-A belongs to a novel class of molecules that share some similarity with the cell wall loosening expansins but do not contain the carbohydrate-binding wall anchor thus suggesting that PNPs and atrial natriuretic peptides are heterologs. AtPNP-A acts systemically, and this is consistent with its localization in the apoplastic extracellular space and the conductive tissue. Furthermore, AtPNP-A signals via the second messenger cyclic guanosine 3′,5′-monophosphate and modulates ion and water transport and homeostasis. It also plays a critical role in host defense against pathogens. AtPNP-A can be classified as novel paracrine plant hormone because it is secreted into the apoplastic space in response to stress and can enhance its own expression. Interestingly, purified recombinant PNP induces apo-ptosis in a dose-dependent manner and was most effective on cardiac myoblast cell lines. Because PNP is mimicking the effect of ANP in some instances, PNP may prove to provide useful leads for development of novel therapeutic NPs. Copyright © 2013 by The American Federation for Medical Research.

  2. Effect of increased regulation on capital costs and manual labor requirements of nuclear power plants

    International Nuclear Information System (INIS)

    Paik, S.; Schriver, W.R.

    1981-01-01

    An attempt is made to explain the impact of increasing governmental regulation on capital costs and labor requirements for constructing light water reactor (LWR) electric power plants. The principal factors contributing to these increases are: (1) market conditions and (2) increased regulation. General market conditions include additional costs attributable to price inflation of equipment, material, labor, and the increased cost of money. The central objective of this work is to estimate the impact of increasing regulation on plant costs and, conversely, on output. To do this it is necessary to isolate two opposing sets of forces which have been in operation during the period of major regulatory expansion: learning based upon plant design experience and economies of scale with increasing size (generating capacity) of newer plants. Conceptual models are specified to capture the independent effects of increasing regulation, learning, and economies of scale. Empirical results were obtained by estimating the models on data collected from industry experience during the 1967-1980 period. 23 refs

  3. The effect of plant growth regulators and their interaction with electric current on winter wheat development

    Czech Academy of Sciences Publication Activity Database

    Biesaga-Koscielniak, J.; Koscielniak, J.; Filek, M.; Marcinska, I.; Krekule, Jan; Macháčková, Ivana; Kubon, M.

    2010-01-01

    Roč. 32, č. 5 (2010), s. 987-995 ISSN 0137-5881 Institutional research plan: CEZ:AV0Z50380511 Keywords : In vitro culture * Plant growth regulators * Electric current Subject RIV: EF - Botanics Impact factor: 1.344, year: 2010

  4. Genetic activity of plant growth regulators, cartolin and benzilandenin, under ionizing radiation

    International Nuclear Information System (INIS)

    Vilenskij, E.P.

    1987-01-01

    Protective effects of a new cytokinin-type growth regulator cartolin (CRT) are established on a genetic test system of waxy-changes in pollen barley grains under acute irradiation of growing plants. It is shown that the CRT effect is similar to that of synthetic cytokinin benziladenin

  5. Improvement of Salt Tolerance in Trigonella foenum-graecum L. var. PEB by Plant Growth Regulators

    Directory of Open Access Journals (Sweden)

    Anjali Ratnakar

    2014-05-01

    Full Text Available The crop yield is reduced under saline conditions and this hampers agricultural productivity. The incorporation of plant growth regulators (PGRs during presoaking treatments in many crops has improved seed performance under saline conditions. In order to study the ameliorative effect of plant growth regulators, experiments were conducted to study the variation in organic constituents in the leaves of Trigonella foenum-graecum L. var.PEB, where the seeds were primed with different plant growth regulators and grown under NaCl salinity. After a pre-soaking treatment of six hours in 20 mg L-1 solutions of gibberllic acid (GA3, 6-furfuryladenine (Kinetin and benzyl adenine (BA, the seeds were allowed to germinate and grow for forty-five days under saline conditions. On the analysis of mature leaves, it was observed that chlorophyll a and b, total chlorophyll and protein showed an increase in PGR-treated plants compared to the untreated set. The accumulation of the stress metabolite such as proline and sugars, which increase under saline conditions, showed a significant decrease in the plants pretreated with PGRs.

  6. Plant Host Finding by Parasitic Plants: A New Perspective on Plant to Plant Communication

    OpenAIRE

    Mescher, Mark C; Runyon, Justin B; De Moraes, Consuelo M

    2006-01-01

    Plants release airborne chemicals that can convey ecologically relevant information to other organisms. These plant volatiles are known to mediate a large array of, often complex, interactions between plants and insects. It has been suggested that plant volatiles may have similar importance in mediating interactions among plant species, but there are few well-documented examples of plant-to-plant communication via volatiles, and the ecological significance of such interactions has been much d...

  7. Power variation and frequency regulation. Adaptation of PWR plant possibilities to the network needs

    International Nuclear Information System (INIS)

    Baboulin, J.P.; Burger, M.

    1980-01-01

    When the PWR are an important part of the power installed on a network, and that will be the case of the EDF network in the coming years, the participation of those plants to the power regulating becomes a necessity for the operating staff. This load regulating includes: daily variations of high amplitude; a permanent frequency - power regulating. The first part of the communication shows the network exploitation principles, and the resulting power variations concerning the existing nuclear power plants. Such transients are leading to stresses on fuel. The second part of the communication reports about the test program engaged by EDF in collaboration with the CEA and FRAMATOME, in order to study the fuel behaviour in real power conditions and power cycles, and that, just to the operational burn up of this fuel. (author)

  8. Interaction of a plant pseudo-response regulator with a calmodulin-like protein

    Energy Technology Data Exchange (ETDEWEB)

    Perochon, Alexandre; Dieterle, Stefan; Pouzet, Cecile; Aldon, Didier; Galaud, Jean-Philippe [UMR 5546 CNRS/Universite Toulouse 3, Pole de Biotechnologie vegetale, BP 42617 Auzeville, 31326 Castanet-Tolosan cedex (France); Ranty, Benoit, E-mail: ranty@scsv.ups-tlse.fr [UMR 5546 CNRS/Universite Toulouse 3, Pole de Biotechnologie vegetale, BP 42617 Auzeville, 31326 Castanet-Tolosan cedex (France)

    2010-08-06

    Research highlights: {yields} The pseudo-response regulator PRR2 specifically binds CML9, a calmodulin-like protein {yields} The interaction is confirmed in plant cell nuclei {yields} The interaction requires an intact PRR2 protein. -- Abstract: Calmodulin (CaM) plays a crucial role in the regulation of diverse cellular processes by modulating the activities of numerous target proteins. Plants possess an extended CaM family including numerous CaM-like proteins (CMLs), most of which appear to be unique to plants. We previously demonstrated a role for CML9 in abiotic stress tolerance and seed germination in Arabidopsis thaliana. We report here the isolation of PRR2, a pseudo-response regulator as a CML9 interacting protein by screening an expression library prepared from Arabidopsis seedlings with CML9 as bait in a yeast two-hybrid system. PRR2 is similar to the response regulators of the two-component system, but lacks the invariant residue required for phosphorylation by which response regulators switch their output response, suggesting the existence of alternative regulatory mechanisms. PRR2 was found to bind CML9 and closely related CMLs but not a canonical CaM. Mapping analyses indicate that an almost complete form of PRR2 is required for interaction with CML9, suggesting a recognition mode different from the classical CaM-target peptide complex. PRR2 contains several features that are typical of transcription factors, including a GARP DNA recognition domain, a Pro-rich region and a Golden C-terminal box. PRR2 and CML9 as fusion proteins with fluorescent tags co-localized in the nucleus of plant cells, and their interaction in the nuclear compartment was validated in planta by using a fluorophore-tagged protein interaction assay. These findings suggest that binding of PRR2 to CML9 may be an important mechanism to modulate the physiological role of this transcription factor in plants.

  9. Interaction of a plant pseudo-response regulator with a calmodulin-like protein

    International Nuclear Information System (INIS)

    Perochon, Alexandre; Dieterle, Stefan; Pouzet, Cecile; Aldon, Didier; Galaud, Jean-Philippe; Ranty, Benoit

    2010-01-01

    Research highlights: → The pseudo-response regulator PRR2 specifically binds CML9, a calmodulin-like protein → The interaction is confirmed in plant cell nuclei → The interaction requires an intact PRR2 protein. -- Abstract: Calmodulin (CaM) plays a crucial role in the regulation of diverse cellular processes by modulating the activities of numerous target proteins. Plants possess an extended CaM family including numerous CaM-like proteins (CMLs), most of which appear to be unique to plants. We previously demonstrated a role for CML9 in abiotic stress tolerance and seed germination in Arabidopsis thaliana. We report here the isolation of PRR2, a pseudo-response regulator as a CML9 interacting protein by screening an expression library prepared from Arabidopsis seedlings with CML9 as bait in a yeast two-hybrid system. PRR2 is similar to the response regulators of the two-component system, but lacks the invariant residue required for phosphorylation by which response regulators switch their output response, suggesting the existence of alternative regulatory mechanisms. PRR2 was found to bind CML9 and closely related CMLs but not a canonical CaM. Mapping analyses indicate that an almost complete form of PRR2 is required for interaction with CML9, suggesting a recognition mode different from the classical CaM-target peptide complex. PRR2 contains several features that are typical of transcription factors, including a GARP DNA recognition domain, a Pro-rich region and a Golden C-terminal box. PRR2 and CML9 as fusion proteins with fluorescent tags co-localized in the nucleus of plant cells, and their interaction in the nuclear compartment was validated in planta by using a fluorophore-tagged protein interaction assay. These findings suggest that binding of PRR2 to CML9 may be an important mechanism to modulate the physiological role of this transcription factor in plants.

  10. New Source Review and coal plant efficiency gains: How new and forthcoming air regulations affect outcomes

    International Nuclear Information System (INIS)

    Adair, Sarah K.; Hoppock, David C.; Monast, Jonas J.

    2014-01-01

    Forthcoming carbon dioxide (CO 2 ) regulations for existing power plants in the United States have heightened interest in thermal efficiency gains for coal-fired power plants. Plant modifications to improve thermal efficiency can trigger New Source Review (NSR), a Clean Air Act requirement to adopt of state-of-the-art pollution controls. This article explores whether existing coal plants would likely face additional pollution control requirements if they undertake modifications that trigger NSR. Despite emissions controls that are or will be installed under the Mercury and Air Toxics Standards (MATS) and Clean Air Interstate Rule (CAIR) or its replacement, 80% of coal units (76% of capacity) that are expected to remain in operation are not projected to meet the minimum NSR requirements for at least one pollutant: nitrogen oxides or sulfur dioxide. This is an important consideration for the U.S. Environmental Protection Agency and state policymakers as they determine the extent to which CO 2 regulation will rely on unit-by-unit thermal efficiency gains versus potential flexible compliance strategies such as averaging, trading, energy efficiency, and renewable energy. NSR would likely delay and add cost to thermal efficiency projects at a majority of coal units, including projects undertaken to comply with forthcoming CO 2 regulation. - Highlights: • We explore the status of the U.S. coal-fired fleet relative to New Source Review (NSR) requirements. • Modifications to improve thermal efficiency can trigger NSR. • Thermal efficiency gains may also be an important strategy for forthcoming CO 2 regulation. • 80% Of non-retiring coal-fired units are projected not to meet minimum NSR requirements. • NSR is an important consideration for the design of CO 2 regulations for existing plants

  11. Regulating the ethylene response of a plant by modulation of F-box proteins

    Science.gov (United States)

    Guo, Hongwei [Beijing, CN; Ecker, Joseph R [Carlsbad, CA

    2014-01-07

    The relationship between F-box proteins and proteins invovled in the ethylene response in plants is described. In particular, F-box proteins may bind to proteins involved in the ethylene response and target them for degradation by the ubiquitin/proteasome pathway. The transcription factor EIN3 is a key transcription factor mediating ethylne-regulated gene expression and morphological responses. EIN3 is degraded through a ubiquitin/proteasome pathway mediated by F-box proteins EBF1 and EBF2. The link between F-box proteins and the ethylene response is a key step in modulating or regulating the response of a plant to ethylene. Described herein are transgenic plants having an altered sensitivity to ethylene, and methods for making transgenic plant haing an althered sensitivity to ethylene by modulating the level of activity of F-box proteins. Methods of altering the ethylene response in a plant by modulating the activity or expression of an F-box protein are described. Also described are methods of identifying compounds that modulate the ethylene response in plants by modulating the level of F-box protein expression or activity.

  12. Exogenous application of the plant signalers methyl jasmonate and salicylic acid induces changes in volatile emissions from citrus foliage and influences the aggregation behavior of Asian citrus psyllid (Diaphorina citri, vector of Huanglongbing.

    Directory of Open Access Journals (Sweden)

    Joseph M Patt

    Full Text Available Huanglongbing, also known as citrus greening, is a destructive disease that threatens citrus production worldwide. It is putatively caused by the phloem-limited bacterium Candidatus Liberibacter asiaticus (Las. Currently, the disease is untreatable and efforts focus on intensive insecticide use to control the vector, Asian citrus psyllid (Diaphorina citri. Emerging psyllid resistance to multiple insecticides has generated investigations into the use of exogenously applied signaling compounds to enhance citrus resistance to D. citri and Las. In the present study, we examined whether foliar applications of methyl jasmonate (MJ, a volatile signaling compound associated with the induced systemic resistance pathway, and salicylic acid, a constituent of the systemic acquired resistance pathway, would elicit the emission of defense-related volatiles in citrus foliage, and what effect this might have on the host-plant searching behavior of D. citri. Comparisons were made of volatiles emitted from growing shoots of uninfected and Las-infected 'Valencia' sweet orange (Citrus sinensis trees over two consecutive sampling days. A settling behavioral assay was used to compare psyllid attraction to MJ-treated vs. Tween-treated citrus sprigs. All three main effects, Las infection status, plant signaler application, and sampling day, influenced the proportions of individual volatile compounds emitted in different treatment groups. MJ- and SA-treated trees had higher emission rates than Tween-treated trees. Methyl salicylate (MeSA and β-caryophyllene were present in higher proportions in the volatiles collected from Las-infected + trees. On the other hand, Las-infected + MJ-treated trees emitted lower proportions of MeSA than did Las-infected + Tween-treated trees. Because MeSA is a key D. citri attractant, this result suggests that MJ application could suppress MeSA emission from Las-infected trees, an approach that could be used to discourage psyllid

  13. Exogenous application of the plant signalers methyl jasmonate and salicylic acid induces changes in volatile emissions from citrus foliage and influences the aggregation behavior of Asian citrus psyllid (Diaphorina citri), vector of Huanglongbing.

    Science.gov (United States)

    Patt, Joseph M; Robbins, Paul S; Niedz, Randy; McCollum, Greg; Alessandro, Rocco

    2018-01-01

    Huanglongbing, also known as citrus greening, is a destructive disease that threatens citrus production worldwide. It is putatively caused by the phloem-limited bacterium Candidatus Liberibacter asiaticus (Las). Currently, the disease is untreatable and efforts focus on intensive insecticide use to control the vector, Asian citrus psyllid (Diaphorina citri). Emerging psyllid resistance to multiple insecticides has generated investigations into the use of exogenously applied signaling compounds to enhance citrus resistance to D. citri and Las. In the present study, we examined whether foliar applications of methyl jasmonate (MJ), a volatile signaling compound associated with the induced systemic resistance pathway, and salicylic acid, a constituent of the systemic acquired resistance pathway, would elicit the emission of defense-related volatiles in citrus foliage, and what effect this might have on the host-plant searching behavior of D. citri. Comparisons were made of volatiles emitted from growing shoots of uninfected and Las-infected 'Valencia' sweet orange (Citrus sinensis) trees over two consecutive sampling days. A settling behavioral assay was used to compare psyllid attraction to MJ-treated vs. Tween-treated citrus sprigs. All three main effects, Las infection status, plant signaler application, and sampling day, influenced the proportions of individual volatile compounds emitted in different treatment groups. MJ- and SA-treated trees had higher emission rates than Tween-treated trees. Methyl salicylate (MeSA) and β-caryophyllene were present in higher proportions in the volatiles collected from Las-infected + trees. On the other hand, Las-infected + MJ-treated trees emitted lower proportions of MeSA than did Las-infected + Tween-treated trees. Because MeSA is a key D. citri attractant, this result suggests that MJ application could suppress MeSA emission from Las-infected trees, an approach that could be used to discourage psyllid colonization during

  14. Exogenous application of the plant signalers methyl jasmonate and salicylic acid induces changes in volatile emissions from citrus foliage and influences the aggregation behavior of Asian citrus psyllid (Diaphorina citri), vector of Huanglongbing

    Science.gov (United States)

    Robbins, Paul S.; Niedz, Randy; McCollum, Greg; Alessandro, Rocco

    2018-01-01

    Huanglongbing, also known as citrus greening, is a destructive disease that threatens citrus production worldwide. It is putatively caused by the phloem-limited bacterium Candidatus Liberibacter asiaticus (Las). Currently, the disease is untreatable and efforts focus on intensive insecticide use to control the vector, Asian citrus psyllid (Diaphorina citri). Emerging psyllid resistance to multiple insecticides has generated investigations into the use of exogenously applied signaling compounds to enhance citrus resistance to D. citri and Las. In the present study, we examined whether foliar applications of methyl jasmonate (MJ), a volatile signaling compound associated with the induced systemic resistance pathway, and salicylic acid, a constituent of the systemic acquired resistance pathway, would elicit the emission of defense-related volatiles in citrus foliage, and what effect this might have on the host-plant searching behavior of D. citri. Comparisons were made of volatiles emitted from growing shoots of uninfected and Las-infected ‘Valencia’ sweet orange (Citrus sinensis) trees over two consecutive sampling days. A settling behavioral assay was used to compare psyllid attraction to MJ-treated vs. Tween-treated citrus sprigs. All three main effects, Las infection status, plant signaler application, and sampling day, influenced the proportions of individual volatile compounds emitted in different treatment groups. MJ- and SA-treated trees had higher emission rates than Tween-treated trees. Methyl salicylate (MeSA) and β-caryophyllene were present in higher proportions in the volatiles collected from Las-infected + trees. On the other hand, Las-infected + MJ-treated trees emitted lower proportions of MeSA than did Las-infected + Tween-treated trees. Because MeSA is a key D. citri attractant, this result suggests that MJ application could suppress MeSA emission from Las-infected trees, an approach that could be used to discourage psyllid colonization during

  15. Future carbon regulations and current investments in alternative coal-fired power plant technologies

    International Nuclear Information System (INIS)

    Sekar, Ram C.; Parsons, John E.; Herzog, Howard J.; Jacoby, Henry D.

    2007-01-01

    We analyze how uncertain future US carbon regulations shape the current choice of the type of power plant to build. Our focus is on two coal-fired technologies, pulverized coal (PC) and integrated coal gasification combined cycle technology (IGCC). The PC technology is cheapest-assuming there is no need to control carbon emissions. The IGCC technology may be cheaper if carbon must be captured. Since power plants last many years and future regulations are uncertain, a US electric utility faces a standard decision under uncertainty. A company will confront the range of possible outcomes, assigning its best estimate of the probability of each scenario, averaging the results and determining the power plant technology with the lowest possible cost inclusive of expected future carbon related costs, whether those costs be in the form of emissions charges paid or capital expenditures for retrofitting to capture carbon. If the company assigns high probability to no regulation or to less stringent regulation of carbon, then it makes sense for it to build the PC plant. But if it assigns sufficient probability to scenarios with more stringent regulation, then the IGCC technology is warranted. We provide some useful benchmarks for possible future regulation and show how these relate back to the relative costs of the two technologies and the optimal technology choice. Few of the policy proposals widely referenced in the public discussion warrant the choice of the IGCC technology. Instead, the PC technology remains the least costly. However, recent carbon prices in the European Emissions Trading System are higher than these benchmarks. If it is any guide to possible future penalties for emissions in the US, then current investment in the IGCC technology is warranted. Of course, other factors need to be factored into the decision as well

  16. [Effects of sulphur compounds on the volatile characteristics of heavy metals in fly ash from the MSW and sewage sludge co-combustion plant during the disposal process with higher temperature].

    Science.gov (United States)

    Liu, Jing-Yong; Sun, Shui-Yu

    2012-11-01

    Fly ash sample was collected from a MSW co-combustion with sewage sludge plant and the volatilization of heavy metals Pb, Cd, Cu and Zn was investigated before and after the water washing of fly ash, meanwhile, the influence of adding different sulphur compounds (S, NaS, Na2 SO3, Na2 SO4) on the volatilization of heavy metals was studied. The results showed that the contents of Zn, Pb and Mn were high, the Ni content was low and the Cd content reached 29.4 mg x kg(1). The contents of Pb, Cu, Zn increased, while that of Cd reduced in the fly ash after water washing. TG-DTG curves of fly ash showed highest weight loss in ranges of 579-732 degrees C and 949-1 200 degrees C, with 690 degrees C and 1 154 degrees C as the inflection point temperatures. The volatilization of different heavy metals showed great difference in the volatilization rate, following the order of Pb > Cd > Zn > Cu, in which the volatilization rate of Pb was more than 80% and that of Cu was less than 30%. After water washing, the volatilization of different heavy metals showed great difference in the volatilization rate, with the order of Zn > Pb > Cd > Cu, in which the volatilization rate of Zn was more than 20%. With the pretreatment of adding Na2 SO3 and Na2 SO4, the evaporation rates of heavy metals (Cu, Pb, Zn, Cd) were significantly decreased. After adding S, the evaporation rate of Zn was reduced, whereas the addition of Na2S reduced the evaporation rates of Cd and Zn. The evaporation rates of the four heavy metals were all reduced after adding Na2S in the washed fly ash. The evaporation rates of Cu and Zn were reduced with addition of S and Na2SO3 and the evaporation rate of Cd was reduced by adding the four sulfides. The results can provide a basis for the harmless disposal and maximized resource utilization and recycling of fly ash.

  17. Evolutionary history and stress regulation of the lectin superfamily in higher plants

    Directory of Open Access Journals (Sweden)

    Ramachandran Srinivasan

    2010-03-01

    Full Text Available Abstract Background Lectins are a class of carbohydrate-binding proteins. They play roles in various biological processes. However, little is known about their evolutionary history and their functions in plant stress regulation. The availability of full genome sequences from various plant species makes it possible to perform a whole-genome exploration for further understanding their biological functions. Results Higher plant genomes encode large numbers of lectin proteins. Based on their domain structures and phylogenetic analyses, a new classification system has been proposed. In this system, 12 different families have been classified and four of them consist of recently identified plant lectin members. Further analyses show that some of lectin families exhibit species-specific expansion and rapid birth-and-death evolution. Tandem and segmental duplications have been regarded as the major mechanisms to drive lectin expansion although retrogenes also significantly contributed to the birth of new lectin genes in soybean and rice. Evidence shows that lectin genes have been involved in biotic/abiotic stress regulations and tandem/segmental duplications may be regarded as drivers for plants to adapt various environmental stresses through duplication followed by expression divergence. Each member of this gene superfamily may play specialized roles in a specific stress condition and function as a regulator of various environmental factors such as cold, drought and high salinity as well as biotic stresses. Conclusions Our studies provide a new outline of the plant lectin gene superfamily and advance the understanding of plant lectin genes in lineage-specific expansion and their functions in biotic/abiotic stress-related developmental processes.

  18. Isolation and biological activity of a new plant growth regulator of Vicia faba L

    International Nuclear Information System (INIS)

    Sembdner, G.; Dathe, W.; Bergner, C.; Roensch, H.

    1983-01-01

    Jasmonic acid was identified as a plant growth inhibitor of the pericarp of Vicia faba by means of gas-liquid chromatography, high resolution mass spectrometry as well as 1 H and 13 C NMR. The highest level of jasmonic acid was reached during intensive pericarp growth. Jasmonic acid is a plant growth inhibitor possessing a relative activity in the wheat seedling bioassay of 1-2.5 % compared to ABA (=100%). Contrary to ABA, jasmonic acid does not cause retardation of leaf emergence. In the dwarf rice gibberellin bioassay relative low concentrations of jasmonic acid inhibit both autonomous and GA 3 -stimulated growth. Jasmonic acid does not influence seed germination of Amaranthus caudatus. The possible physiological role of jasmonic acid in the Vicia pericarp and the distribution in plants of this new plant growth regulator type are discussed. (author)

  19. New Trend in Crop Production – Application of Plant Natural Multicomponent Growth Regulators with Bioprotective Effect

    Directory of Open Access Journals (Sweden)

    S.P. Ponomarenko

    2013-09-01

    Full Text Available With the help of the Dot-blot hybridization the difference in steps of homology between mRNA of control plants and small regulatory si/mi RNA isolated from second-generation plantlets of wheat, corn, soybeans, sugar beets, chickpea, etc. cultivated from the seeds of plants infected and processed by new polycomponent plant growth regulators Regoplant® and Stimpo® in the first generation was found. It is proved that this difference is related to a partial reprogramming of the cell genome under the influence of biostimulators on growing plants with infected backgrounds that turns out in induction of low-molecular si/miRNA with antipathogenic and antiparasitic properties, which are the components of the immune system of a living organism.

  20. Isolation and biological activity of a new plant growth regulator of Vicia faba L

    Energy Technology Data Exchange (ETDEWEB)

    Sembdner, G.; Dathe, W.; Bergner, C.; Roensch, H. (Akademie der Wissenschaften der DDR, Halle/Saale. Inst. fuer Biochemie der Pflanzen)

    1983-01-01

    Jasmonic acid was identified as a plant growth inhibitor of the pericarp of Vicia faba by means of gas-liquid chromatography, high resolution mass spectrometry as well as /sup 1/H and /sup 13/C NMR. The highest level of jasmonic acid was reached during intensive pericarp growth. Jasmonic acid is a plant growth inhibitor possessing a relative activity in the wheat seedling bioassay of 1-2.5 % compared to ABA (=100%). Contrary to ABA, jasmonic acid does not cause retardation of leaf emergence. In the dwarf rice gibberellin bioassay relative low concentrations of jasmonic acid inhibit both autonomous and GA/sub 3/-stimulated growth. Jasmonic acid does not influence seed germination of Amaranthus caudatus. The possible physiological role of jasmonic acid in the Vicia pericarp and the distribution in plants of this new plant growth regulator type are discussed.

  1. The Establishment of Regulation for Supporting the Development of the First Nuclear Power Plant in Indonesia

    International Nuclear Information System (INIS)

    Mardha, Amil

    2011-01-01

    To support construction and operation of the first Nuclear Power Plant (NPP), Government of Indonesia through BAPETEN as a national authority in nuclear energy usage has pushed ahead in enhancing the development of regulatory system. BAPETEN is currently focusing its activities to the development of regulations in the form of Chairman Decree, the development of licensing and inspection system, and manpower for NPP regulators. The process of the establishment of national legislation is based on the Act No.10 Year 2004 on The establishment of legislation. The process of legal drafting to establish or to revise a regulation for controlling of the use of nuclear energy shall comply with the constitutional and institutional requirements of national political and legal system. In drafting the regulation of nuclear safety of NPP, BAPETEN has been involving some other agencies or other related government agencies, and also stakeholders such as utility, academic institutions, and publics. In general, in the process of legal drafting, international publications or other country regulations can be a reference. Present paper deals with the legal basis of regulation, the establishment of legislation in Indonesia, the process in legal drafting regulations of NPP, and the current status of NPP regulations. (author)

  2. Apoplastic and intracellular plant sugars regulate developmental transitions in witches' broom disease of cacao.

    Science.gov (United States)

    Barau, Joan; Grandis, Adriana; Carvalho, Vinicius Miessler de Andrade; Teixeira, Gleidson Silva; Zaparoli, Gustavo Henrique Alcalá; do Rio, Maria Carolina Scatolin; Rincones, Johana; Buckeridge, Marcos Silveira; Pereira, Gonçalo Amarante Guimarães

    2015-03-01

    Witches' broom disease (WBD) of cacao differs from other typical hemibiotrophic plant diseases by its unusually long biotrophic phase. Plant carbon sources have been proposed to regulate WBD developmental transitions; however, nothing is known about their availability at the plant-fungus interface, the apoplastic fluid of cacao. Data are provided supporting a role for the dynamics of soluble carbon in the apoplastic fluid in prompting the end of the biotrophic phase of infection. Carbon depletion and the consequent fungal sensing of starvation were identified as key signalling factors at the apoplast. MpNEP2, a fungal effector of host necrosis, was found to be up-regulated in an autophagic-like response to carbon starvation in vitro. In addition, the in vivo artificial manipulation of carbon availability in the apoplastic fluid considerably modulated both its expression and plant necrosis rate. Strikingly, infected cacao tissues accumulated intracellular hexoses, and showed stunted photosynthesis and the up-regulation of senescence markers immediately prior to the transition to the necrotrophic phase. These opposite findings of carbon depletion and accumulation in different host cell compartments are discussed within the frame of WBD development. A model is suggested to explain phase transition as a synergic outcome of fungal-related factors released upon sensing of extracellular carbon starvation, and an early senescence of infected tissues probably triggered by intracellular sugar accumulation. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  3. Mono- and Digalactosyldiacylglycerol Lipids Function Nonredundantly to Regulate Systemic Acquired Resistance in Plants

    Directory of Open Access Journals (Sweden)

    Qing-ming Gao

    2014-12-01

    Full Text Available Summary: The plant galactolipids monogalactosyldiacylglycerol (MGDG and digalactosyldiacylglycerol (DGDG have been linked to the anti-inflammatory and cancer benefits of a green leafy vegetable diet in humans due to their ability to regulate the levels of free radicals like nitric oxide (NO. Here, we show that DGDG contributes to plant NO as well as salicylic acid biosynthesis and is required for the induction of systemic acquired resistance (SAR. In contrast, MGDG regulates the biosynthesis of the SAR signals azelaic acid (AzA and glycerol-3-phosphate (G3P that function downstream of NO. Interestingly, DGDG is also required for AzA-induced SAR, but MGDG is not. Notably, transgenic expression of a bacterial glucosyltransferase is unable to restore SAR in dgd1 plants even though it does rescue their morphological and fatty acid phenotypes. These results suggest that MGDG and DGDG are required at distinct steps and function exclusively in their individual roles during the induction of SAR. : The galactolipids monogalactosyldiacylglycerol (MGDG and digalactosyldiacylglycerol (DGDG constitute ∼80% of total membrane lipids in plants. Gao et al. now show that these galactolipids function nonredundantly to regulate systemic acquired resistance (SAR. Furthermore, they show that the terminal galactose on the α-galactose-β-galactose head group of DGDG is critical for SAR.

  4. Spatial Regulation of Root Growth: Placing the Plant TOR Pathway in a Developmental Perspective

    Science.gov (United States)

    Barrada, Adam; Montané, Marie-Hélène; Robaglia, Christophe; Menand, Benoît

    2015-01-01

    Plant cells contain specialized structures, such as a cell wall and a large vacuole, which play a major role in cell growth. Roots follow an organized pattern of development, making them the organs of choice for studying the spatio-temporal regulation of cell proliferation and growth in plants. During root growth, cells originate from the initials surrounding the quiescent center, proliferate in the division zone of the meristem, and then increase in length in the elongation zone, reaching their final size and differentiation stage in the mature zone. Phytohormones, especially auxins and cytokinins, control the dynamic balance between cell division and differentiation and therefore organ size. Plant growth is also regulated by metabolites and nutrients, such as the sugars produced by photosynthesis or nitrate assimilated from the soil. Recent literature has shown that the conserved eukaryotic TOR (target of rapamycin) kinase pathway plays an important role in orchestrating plant growth. We will summarize how the regulation of cell proliferation and cell expansion by phytohormones are at the heart of root growth and then discuss recent data indicating that the TOR pathway integrates hormonal and nutritive signals to orchestrate root growth. PMID:26295391

  5. Prioritizing plant defence over growth through WRKY regulation facilitates infestation by non-target herbivores

    Science.gov (United States)

    Li, Ran; Zhang, Jin; Li, Jiancai; Zhou, Guoxin; Wang, Qi; Bian, Wenbo; Erb, Matthias; Lou, Yonggen

    2015-01-01

    Plants generally respond to herbivore attack by increasing resistance and decreasing growth. This prioritization is achieved through the regulation of phytohormonal signaling networks. However, it remains unknown how this prioritization affects resistance against non-target herbivores. In this study, we identify WRKY70 as a specific herbivore-induced, mitogen-activated protein kinase-regulated rice transcription factor that physically interacts with W-box motifs and prioritizes defence over growth by positively regulating jasmonic acid (JA) and negatively regulating gibberellin (GA) biosynthesis upon attack by the chewing herbivore Chilo suppressalis. WRKY70-dependent JA biosynthesis is required for proteinase inhibitor activation and resistance against C. suppressalis. In contrast, WRKY70 induction increases plant susceptibility against the rice brown planthopper Nilaparvata lugens. Experiments with GA-deficient rice lines identify WRKY70-dependent GA signaling as the causal factor in N. lugens susceptibility. Our study shows that prioritizing defence over growth leads to a significant resistance trade-off with important implications for the evolution and agricultural exploitation of plant immunity. DOI: http://dx.doi.org/10.7554/eLife.04805.001 PMID:26083713

  6. Diversity and regulation of plant Ca2+ pumps: insights from expression in yeast

    Science.gov (United States)

    Sze, H.; Liang, F.; Hwang, I.; Curran, A. C.; Harper, J. F.; Evans, M. L. (Principal Investigator)

    2000-01-01

    The spatial and temporal regulation of calcium concentration in plant cells depends on the coordinate activities of channels and active transporters located on different organelles and membranes. Several Ca2+ pumps have been identified and characterized by functional expression of plant genes in a yeast mutant (K616). This expression system has opened the way to a genetic and biochemical characterization of the regulatory and catalytic features of diverse Ca2+ pumps. Plant Ca(2+)-ATPases fall into two major types: AtECA1 represents one of four or more members of the type IIA (ER-type) Ca(2+)-ATPases in Arabidopsis, and AtACA2 is one of seven or more members of the type IIB (PM-type) Ca(2+)-ATPases that are regulated by a novel amino terminal domain. Type IIB pumps are widely distributed on membranes, including the PM (plasma membrane), vacuole, and ER (endoplasmic reticulum). The regulatory domain serves multiple functions, including autoinhibition, calmodulin binding, and sites for modification by phosphorylation. This domain, however, is considerably diverse among several type IIB ATPases, suggesting that the pumps are differentially regulated. Understanding of Ca2+ transporters at the molecular level is providing insights into their roles in signaling networks and in regulating fundamental processes of cell biology.

  7. Cyt toxin expression reveals an inverse regulation of insect and plant virulence factors of Dickeya dadantii.

    Science.gov (United States)

    Costechareyre, Denis; Dridi, Bedis; Rahbé, Yvan; Condemine, Guy

    2010-12-01

    The plant pathogenic bacteria Dickeya dadantii is also a pathogen of the pea aphid Acyrthosiphon pisum. The genome of the bacteria contains four cyt genes, encoding homologues of Bacillus thuringiensis Cyt toxins, which are involved in its pathogenicity to insects. We show here that these genes are transcribed as an operon, and we determined the conditions necessary for their expression. Their expression is induced at high temperature and at an osmolarity equivalent to that found in the plant phloem sap. The regulators of cyt genes have also been identified: their expression is repressed by H-NS and VfmE and activated by PecS. These genes are already known to regulate plant virulence factors, but in an opposite way. When tested in a virulence assay by ingestion, the pecS mutant was almost non-pathogenic while hns and vfmE mutants behaved in the same way as the wild-type strain. Mutants of other regulators of plant virulence, GacA, OmpR and PhoP, that do not control Cyt toxin production, also showed reduced pathogenicity. In an assay by injection of bacteria, the gacA strain was less pathogenic but, surprisingly, the pecS mutant was slightly more virulent. These results show that Cyt toxins are not the only virulence factors required to kill aphids, and that these factors act at different stages of the infection. Moreover, their production is controlled by general virulence regulators known for their role in plant virulence. This integration could indicate that virulence towards insects is a normal mode of life for D. dadantii. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

  8. GDP-D-mannose epimerase regulates male gametophyte development, plant growth and leaf senescence in Arabidopsis.

    Science.gov (United States)

    Qi, Tiancong; Liu, Zhipeng; Fan, Meng; Chen, Yan; Tian, Haixia; Wu, Dewei; Gao, Hua; Ren, Chunmei; Song, Susheng; Xie, Daoxin

    2017-09-04

    Plant GDP-D-mannose epimerase (GME) converts GDP-D-mannose to GDP-L-galactose, a precursor of both L-ascorbate (vitamin C) and cell wall polysaccharides. However, the genetic functions of GME in Arabidopsis are unclear. In this study, we found that mutations in Arabidopsis GME affect pollen germination, pollen tube elongation, and transmission and development of the male gametophyte through analysis of the heterozygous GME/gme plants and the homozygous gme plants. Arabidopsis gme mutants also exhibit severe growth defects and early leaf senescence. Surprisingly, the defects in male gametophyte in the gme plants are not restored by L-ascorbate, boric acid or GDP-L-galactose, though boric acid rescues the growth defects of the mutants, indicating that GME may regulate male gametophyte development independent of L-ascorbate and GDP-L-galactose. These results reveal key roles for Arabidopsis GME in reproductive development, vegetative growth and leaf senescence, and suggest that GME regulates plant growth and controls male gametophyte development in different manners.

  9. Regulation of Plant Microprocessor Function in Shaping microRNA Landscape

    Directory of Open Access Journals (Sweden)

    Jakub Dolata

    2018-06-01

    Full Text Available MicroRNAs are small molecules (∼21 nucleotides long that are key regulators of gene expression. They originate from long stem–loop RNAs as a product of cleavage by a protein complex called Microprocessor. The core components of the plant Microprocessor are the RNase type III enzyme Dicer-Like 1 (DCL1, the zinc finger protein Serrate (SE, and the double-stranded RNA binding protein Hyponastic Leaves 1 (HYL1. Microprocessor assembly and its processing of microRNA precursors have been reported to occur in discrete nuclear bodies called Dicing bodies. The accessibility of and modifications to Microprocessor components affect microRNA levels and may have dramatic consequences in plant development. Currently, numerous lines of evidence indicate that plant Microprocessor activity is tightly regulated. The cellular localization of HYL1 is dependent on a specific KETCH1 importin, and the E3 ubiquitin ligase COP1 indirectly protects HYL1 from degradation in a light-dependent manner. Furthermore, proper localization of HYL1 in Dicing bodies is regulated by MOS2. On the other hand, the Dicing body localization of DCL1 is regulated by NOT2b, which also interacts with SE in the nucleus. Post-translational modifications are substantial factors that contribute to protein functional diversity and provide a fine-tuning system for the regulation of protein activity. The phosphorylation status of HYL1 is crucial for its activity/stability and is a result of the interplay between kinases (MPK3 and SnRK2 and phosphatases (CPL1 and PP4. Additionally, MPK3 and SnRK2 are known to phosphorylate SE. Several other proteins (e.g., TGH, CDF2, SIC, and RCF3 that interact with Microprocessor have been found to influence its RNA-binding and processing activities. In this minireview, recent findings on the various modes of Microprocessor activity regulation are discussed.

  10. Development and Validation of a SPME-GC-MS Method for In situ Passive Sampling of Root Volatiles from Glasshouse-Grown Broccoli Plants Undergoing Below-Ground Herbivory by Larvae of Cabbage Root Fly, Delia radicum L.

    Science.gov (United States)

    Deasy, William; Shepherd, Tom; Alexander, Colin J; Birch, A Nicholas E; Evans, K Andrew

    2016-11-01

    Research on plant root chemical ecology has benefited greatly from recent developments in analytical chemistry. Numerous reports document techniques for sampling root volatiles, although only a limited number describe in situ collection. To demonstrate a new method for non-invasive in situ passive sampling using solid phase micro extraction (SPME), from the immediate vicinity of growing roots. SPME fibres inserted into polyfluorotetrafluoroethylene (PTFE) sampling tubes located in situ which were either perforated, covered with stainless steel mesh or with microporous PTFE tubing, were used for non-invasive sub-surface sampling of root volatiles from glasshouse-grown broccoli. Sampling methods were compared with above surface headspace collection using Tenax TA. The roots were either mechanically damaged or infested with Delia radicum larvae. Principal component analysis (PCA) was used to investigate the effect of damage on the composition of volatiles released by broccoli roots. Analyses by gas chromatography-mass spectrometry (GC-MS) with SPME and automated thermal desorption (ATD) confirmed that sulphur compounds, showing characteristic temporal emission patterns, were the principal volatiles released by roots following insect larval damage. Use of SPME with in situ perforated PTFE sampling tubes was the most robust method for out-of-lab sampling. This study describes a new method for non-invasive passive sampling of volatiles in situ from intact and insect damaged roots using SPME. The method is highly suitable for remote sampling and has potential for wide application in chemical ecology/root/soil research. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  11. Using natural and synthetic growth regulators of plants in industrial mycology and malting

    Directory of Open Access Journals (Sweden)

    O. V. Kuznetcova

    2010-07-01

    Full Text Available Data on the expansion of the use the plants growth regulators in different areas are presented. The positive impact of the growth stimulators on the development of the Pleurotus ostreatus mycelium’s on agar nutrient media during surface cultivation is shown. The results for growth regulators stimulating effect on the fungus biosynthetic activity in submerged cultures are obtained. The possibility of using fumar and heteroauxin for malting is considered. The decline of malting time and increase of amylolytic activity of the malt are recorded.

  12. Regulation for the decommissioning of nuclear power plants in U.S.A

    International Nuclear Information System (INIS)

    Oishi, Yuichi

    2001-01-01

    Since beginning of operation in nuclear reactor for practical power generation for the first one in Japan in 1966, the rector already passed more than 30 years are found and some investigations on its abolition method and its countermeasure accompanied with its permanent operation finishing of the reactor for future have been progressed by government and the relative organizations. The Japan Engineering and Inspection Corporation, under trust of the Ministry of Economy and Industry, has carried out some surveys on abolition measure regulation in the world. On the regulation in U.S.A. as a part of the surveys, abstract of the survey results performed before 1999 was introduced. Items in the survey were regulation system, definition and configuration of the abolition measure, legal procedures on the measure, and the last radiation survey and evaluating method. In U.S.A., as contents on legal procedure and document to be proposed are in detail and concretely regulated, the abolition measure activity can be progressed in standard according to the legal regulation, difference between every plants is thought to be very small. And, in spite of being regulated in details, participation of regulation agency on the procedures is less than that under operation, and there are some exempted items automatically. This is to say, it is a method to be processed under check of the abolition measure activity by NRC through its notice, inspection and approval, under agreeing with desires of applicants. (G.K.)

  13. Translation regulation in plants: an interesting past, an exciting present and a promising future.

    Science.gov (United States)

    Merchante, Catharina; Stepanova, Anna N; Alonso, Jose M

    2017-05-01

    Changes in gene expression are at the core of most biological processes, from cell differentiation to organ development, including the adaptation of the whole organism to the ever-changing environment. Although the central role of transcriptional regulation is solidly established and the general mechanisms involved in this type of regulation are relatively well understood, it is clear that regulation at a translational level also plays an essential role in modulating gene expression. Despite the large number of examples illustrating the critical role played by translational regulation in determining the expression levels of a gene, our understanding of the molecular mechanisms behind such types of regulation has been slow to emerge. With the recent development of high-throughput approaches to map and quantify different critical parameters affecting translation, such as RNA structure, protein-RNA interactions and ribosome occupancy at the genome level, a renewed enthusiasm toward studying translation regulation is warranted. The use of these new powerful technologies in well-established and uncharacterized translation-dependent processes holds the promise to decipher the likely complex and diverse, but also fascinating, mechanisms behind the regulation of translation. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  14. Regulating specific organic substances and heavy metals in industrial wastewater discharged to municipal wastewater treatment plants

    DEFF Research Database (Denmark)

    Grüttner, Henrik; Munk, L.; Pedersen, F.

    1994-01-01

    Due to the extension of wastewater treatment plants to nutrient removal and the development towards reuse of sludge m agriculture, new guidelines for regulating industrial discharges m Denmark were needed. The paper describes how a concept for regulating the discharge of specific organic substances...... substances, present knowledge of fate and effects in biological treatment plants is too scarce to underpin the setting of general standards. Therefore, it has been decided to base the developed priority system on the data used in the EEC-system for classification of hazardous chemicals. This includes ready...... degradability, defined by the OECD-test, bio-sorption and bio-accumulation, defined by the octanol/water distribution coefficient and toxic effects on water organisms. Several potential effects of seven heavy metals have been evaluated, and the most critical effects were found to be the quality criteria...

  15. New opportunities for the regulation of secondary metabolism in plants: focus on microRNAs.

    Science.gov (United States)

    Bulgakov, Victor P; Avramenko, Tatiana V

    2015-09-01

    Plant cell cultures are of particular interest in industrial applications as a source of biologically active substances. It is difficult, however, to achieve stable production of secondary metabolites for many plant cell cultures using classical techniques. Novel approaches should be developed for removal of the inhibitor blocks that prevent pathway activation and shift the regulatory balance to the activation of entire biosynthetic pathways. MicroRNAs (miRNAs) are small RNAs that play important regulatory roles in various biological processes. Only recently miRNAs have been demonstrated as active in secondary metabolism regulation. In this work, we summarize recent data on the emerging approaches based on regulation of secondary metabolism by miRNAs.

  16. Regulation and Turnover of Nitric Oxide by Phytoglobins in Plant Cell Responses

    DEFF Research Database (Denmark)

    Igamberdiev, Abir U; Hebelstrup, Kim; Stasolla, Claudio

    2016-01-01

    The involvement of phytoglobins in the metabolism of nitric oxide (NO) and reactive nitrogen species (RNS) produced during stress, plant growth, and development is discussed. The action of phytoglobin expression upon NO leads to the maintenance of redox status, minimization of the damage from...... to the mobility of both NO and phytohormones, plants developed strategies to regulate specific cell hormonal actions to permit differentiation during development and to respond to stress. Phytoglobins are the agents responsible for differential cellular responses to hormones that use NO as a signal transduction...... reactive oxygen and nitrogen species in the cytoplasm of the cell, and regulation of hormonal and stress responses. NO scavenging is achieved via phytoglobins, and it can also involve S-nitrosoglutathione reductase and a direct interaction of NO with superoxide anion followed by detoxification of formed...

  17. Plant GSK3 proteins regulate xylem cell differentiation downstream of TDIF-TDR signalling

    Science.gov (United States)

    Kondo, Yuki; Ito, Tasuku; Nakagami, Hirofumi; Hirakawa, Yuki; Saito, Masato; Tamaki, Takayuki; Shirasu, Ken; Fukuda, Hiroo

    2014-03-01

    During plant radial growth typically seen in trees, procambial and cambial cells act as meristematic cells in the vascular system to self-proliferate and differentiate into xylem cells. These two processes are regulated by a signalling pathway composed of a peptide ligand and its receptor; tracheary element differentiation inhibitory factor (TDIF) and TDIF RECEPTOR (TDR). Here we show that glycogen synthase kinase 3 proteins (GSK3s) are crucial downstream components of the TDIF signalling pathway suppressing xylem differentiation from procambial cells. TDR interacts with GSK3s at the plasma membrane and activates GSK3s in a TDIF-dependent fashion. Consistently, a specific inhibitor of plant GSK3s strongly induces xylem cell differentiation through BRI1-EMS SUPPRESSOR 1 (BES1), a well-known target transcription factor of GSK3s. Our findings provide insight into the regulation of cell fate determination in meristem maintenance.

  18. Increasing Hermaphrodite Flowers using Plant Growth Regulators in Andromonoecious Jatropha curcas

    Directory of Open Access Journals (Sweden)

    DASUMIATI

    2014-09-01

    Full Text Available Jatropha curcas (JC is a crop with potential for use in biodiesel. Production of biodiesel requires plant seed as raw material, so the viability of JC for use in biodiesel will dependent greatly on the plant's production of flowers. Generally, this plant is monoecious, meaning it has both male and female flowers. However, very rarely JC plants may be andromonoecious. Andromonoecious specimens of JC produce hermaphrodite and male flowers in the same plant. The number of hermaphrodite flowers per inflorescence is generally low compared to the number of male flowers. The aim of this study was to increase the proportion of hermaphrodite flowers by using plant growth regulators (PGRs in andromonoecious JC. Our experiment was conducted in Randomized Block Design (RBD with 9 treatments, namely kinetin, GA3, and IAA with concentrations of 0 ppm as a control, 50 and 100 ppm of each PGRs. The treatments were applied to stem cuttings from each plant and repeated 4 times. PGRs were applied by spraying the leaves within the buds of each plant. Applications took place weekly beginning when the plants entered flower initiating phase, until inflorescence produced. Observations were conducted during the treatment period (10 weeks. Results showed that plants treated with IAA, GA3, and kinetin at 50 and 100 ppm produced increased inflorescence per plant. The increases measured were 155.4 and 92.9% of (IAA, 120.4 and 151% (GA3, 96.6 and 51.7% (kinetin respectively. In addition, we found that application and GA3 at concentrations of 50 and 100 ppm, and kinetin at 50 ppm, increased the number of hermaphrodite flowers per inflorescence by 50%, and increased the number of hermaphrodite flowers per plant by 275.6 and 183.1% (IAA, 219.5 and 254.1% (GA3, 162.9 and 103.1% (kinetin respectively. As would be expected, the number of fruit per plant increased in those specimens treated with IAA, GA3, and kinetin at 50 and 100 ppm. The increases measured were 301.7 and 167

  19. Plant regeneration of non-toxic Jatropha curcas—impacts of plant growth regulators, source and type of explants

    KAUST Repository

    Kumar, Nitish

    2011-01-28

    Jatropha curcas is an oil bearing species with multiple uses and considerable economic potential as a biofuel plant, however, oil and deoiled cake are toxic. A non-toxic variety of J. curcas is reported from Mexico. The present investigation explores the effects of different plant growth regulators (PGRs) viz. 6-benzyl aminopurine (BAP) or thidiazuron (TDZ) individually and in combination with indole-3-butyric acid (IBA), on regeneration from in vitro and field-grown mature leaf explants, in vitro and glasshouse-grown seedlings cotyledonary leaf explants of non-toxic J. curcas. In all the tested parameters maximum regeneration efficiency (81.07%) and the number of shoot buds per explants (20.17) was observed on 9.08 μM TDZ containing Murashige and Skoog’s (MS) medium from in vitro cotyledonary leaf explants. The regenerated shoot buds were transferred to MS medium containing 10 μM kinetin (Kn), 4.5 μM BAP and 5.5 μM α-naphthaleneacetic acid (NAA) for shoot proliferation. The proliferated shoots could be elongated on MS medium supplemented with 2.25 μM BAP and 8.5 μM IAA. Rooting was achieved when the basal cut end of elongated shoots were dipped in half strength MS liquid medium containing different concentrations and combinations of IBA, IAA and NAA for four days followed by transfer to growth regulators free half strength MS medium supplemented 0.25 mg/l activated charcoal. The rooted plants could be established in soil with more than 90% survival rate.

  20. Plant regeneration of non-toxic Jatropha curcas—impacts of plant growth regulators, source and type of explants

    KAUST Repository

    Kumar, Nitish; Vijay Anand, K. G.; Reddy, Muppala P.

    2011-01-01

    Jatropha curcas is an oil bearing species with multiple uses and considerable economic potential as a biofuel plant, however, oil and deoiled cake are toxic. A non-toxic variety of J. curcas is reported from Mexico. The present investigation explores the effects of different plant growth regulators (PGRs) viz. 6-benzyl aminopurine (BAP) or thidiazuron (TDZ) individually and in combination with indole-3-butyric acid (IBA), on regeneration from in vitro and field-grown mature leaf explants, in vitro and glasshouse-grown seedlings cotyledonary leaf explants of non-toxic J. curcas. In all the tested parameters maximum regeneration efficiency (81.07%) and the number of shoot buds per explants (20.17) was observed on 9.08 μM TDZ containing Murashige and Skoog’s (MS) medium from in vitro cotyledonary leaf explants. The regenerated shoot buds were transferred to MS medium containing 10 μM kinetin (Kn), 4.5 μM BAP and 5.5 μM α-naphthaleneacetic acid (NAA) for shoot proliferation. The proliferated shoots could be elongated on MS medium supplemented with 2.25 μM BAP and 8.5 μM IAA. Rooting was achieved when the basal cut end of elongated shoots were dipped in half strength MS liquid medium containing different concentrations and combinations of IBA, IAA and NAA for four days followed by transfer to growth regulators free half strength MS medium supplemented 0.25 mg/l activated charcoal. The rooted plants could be established in soil with more than 90% survival rate.

  1. Genetic analysis of pathway regulation for enhancing branched-chain amino acid biosynthesis in plants

    KAUST Repository

    Chen, Hao

    2010-08-01

    The branched-chain amino acids (BCAAs) valine, leucine and isoleucine are essential amino acids that play critical roles in animal growth and development. Animals cannot synthesize these amino acids and must obtain them from their diet. Plants are the ultimate source of these essential nutrients, and they synthesize BCAAs through a conserved pathway that is inhibited by its end products. This feedback inhibition has prevented scientists from engineering plants that accumulate high levels of BCAAs by simply over-expressing the respective biosynthetic genes. To identify components critical for this feedback regulation, we performed a genetic screen for Arabidopsis mutants that exhibit enhanced resistance to BCAAs. Multiple dominant allelic mutations in the VALINE-TOLERANT 1 (VAT1) gene were identified that conferred plant resistance to valine inhibition. Map-based cloning revealed that VAT1 encodes a regulatory subunit of acetohydroxy acid synthase (AHAS), the first committed enzyme in the BCAA biosynthesis pathway. The VAT1 gene is highly expressed in young, rapidly growing tissues. When reconstituted with the catalytic subunit in vitro, the vat1 mutant-containing AHAS holoenzyme exhibits increased resistance to valine. Importantly, transgenic plants expressing the mutated vat1 gene exhibit valine tolerance and accumulate higher levels of BCAAs. Our studies not only uncovered regulatory characteristics of plant AHAS, but also identified a method to enhance BCAA accumulation in crop plants that will significantly enhance the nutritional value of food and feed. © 2010 Blackwell Publishing Ltd.

  2. Fuzzy logic and its possibility using in automation of small-scale hydroelectric power plants regulation

    International Nuclear Information System (INIS)

    Puskajler, J.

    2004-01-01

    The paper explains how can computer understand and process inaccurate (indefinite) information. It is processing of terms like e.g. 'around in the middle of month' or 'not too big'. Fuzzy logic, fuzzy sets, operations with them, fuzzy rules and using of linguistics variables are explained. The possibilities of application of fuzzy systems in automation of regulation of small-scale hydro power plants are discussed. (author)

  3. The Use of Plant Growth Regulators to Improve the Traffic Tolerance and Repair of Overseeded Bermudagrass

    OpenAIRE

    Marshall, Christopher Scott

    2007-01-01

    An active football season during the fall acclimation period tests the traffic tolerance of bermudagrass. Exogenous applications of synthetic cytokinins or cytokinin-enhancing plant growth regulators (PGRs), such as trinexapac-ethyl, may improve the traffic tolerance of "Patriot" and "Tifsport" hybrid berudagrasses (Cynodon dactylon var. dactylon x Cynodon transvaalensis). This study was designed to mimic the agronomic practices and traffic stresses experienced at Virginia Tech's Worsham Fiel...

  4. USE OF PLANT EXTRACTS AS REGULATORS OF QUALITY OF MOMORDIKA FRUIT (MOMORDICA CHARANTIA L.

    Directory of Open Access Journals (Sweden)

    O. A. Gribova

    2016-01-01

    Full Text Available Momordica (Momordica charantia L. is unconventional crop of the Cucurbitaceae family for the central regions of the Russian. Fruits of this crop have anti-inflammatory and immunomodulatory effect. The influence of promising growth regulators from plants on the qualitative composition of fruits momordika has been studied. The positive effect of leaf extract yakon as phytoregulator on productivity increasing and fruit quality of momordika is shown.

  5. Effects of reduced-risk pesticides and plant growth regulators on rove beetle (Coleoptera: Staphylinidae) adults.

    Science.gov (United States)

    Echegaray, Erik R; Cloyd, Raymond A

    2012-12-01

    In many regions, pest management of greenhouse crops relies on the use of biological control agents; however, pesticides are also widely used, especially when dealing with multiple arthropod pests and attempting to maintain high esthetic standards. As such, there is interest in using biological control agents in conjunction with chemical control. However, the prospects of combining natural enemies and pesticides are not well known in many systems. The rove beetle, Atheta coriaria (Kraatz), is a biological control agent mainly used against fungus gnats (Bradysia spp.). This study evaluated the effects of reduced-risk pesticides and plant growth regulators on A. coriaria adult survival, development, and prey consumption under laboratory conditions. Rove beetle survival was consistently higher when adults were released 24 h after rather than before applying pesticides. The pesticides acetamiprid, lambda-cyhalothrin, and cyfluthrin were harmful to rove beetle adults, whereas Beauveria bassiana (Balsamo) Vuillemin, azadirachtin, and organic oils (cinnamon oils, rosemary oil, thyme oil, and clove oil) were nontoxic to A. coriaria adults. Similarly, the plant growth regulators acymidol, paclobutrazol, and uniconazole were not harmful to rove beetle adults. In addition, B. bassiana, azadirachtin, kinoprene, organic oils, and the plant growth regulators did not negatively affect A. coriaria development. However, B. bassiana did negatively affect adult prey consumption. This study demonstrated that A. coriaria may not be used when applying the pesticides, acetamiprid, lambda-cyhalothrin, and cyfluthrin, whereas organic oils, B. bassiana, azadirachtin, and the plant growth regulators evaluated may be used in conjunction with A. coriaria adults. As such, these compounds may be used in combination with A. coriaria in greenhouse production systems.

  6. Regulation of Water Balance of the Plant from the Different Geo-Environmental Locations

    OpenAIRE

    Astghik R. Sukiasyan

    2016-01-01

    Under the drought stress condition, the plants would grow slower. Temperature is one of the most important abiotic factors which suppress the germination processes. However, the processes of transpiration are regulated directly by the cell water, which followed to an increase in volume of vacuoles. During stretching under the influence of water pressure, the cell goes into the state of turgor. In our experiments, lines of the semi-dental sweet maize of Armenian population from various zones o...

  7. Global SUMO proteome responses guide gene regulation, mRNA biogenesis, and plant stress responses

    Directory of Open Access Journals (Sweden)

    Magdalena eMazur

    2012-09-01

    Full Text Available Small-ubiquitin-like MOdifier (SUMO is a key regulator of abiotic stress, disease resistance and development in plants. The identification of >350 plant SUMO targets has revealed many processes modulated by SUMO and potential consequences of SUMO on its targets. Importantly, highly related proteins are SUMO-modified in plants, yeast, and metazoans. Overlapping SUMO targets include heat-shock proteins, transcription regulators, histones, histone-modifying enzymes, proteins involved in DNA damage repair, but also proteins involved in mRNA biogenesis and nucleo-cytoplasmic transport. Proteomics studies indicate key roles for SUMO in gene repression by controlling histone (deacetylation activity at genomic loci. The responsible heavily sumoylated transcriptional repressor complexes are recruited by EAR (Ethylene-responsive element binding factor [ERF]-associated Amphiphilic Repression-motif containing transcription factors in plants. These transcription factors are not necessarily themselves a SUMO target. Conversely, SUMO acetylation prevents binding of downstream partners by preventing binding of SIMs (SUMO-interaction peptide motifs presents in these partners, while SUMO acetylation has emerged as mechanism to recruit specifically bromodomains; bromodomain are generally linked with gene activation. These findings strengthen the idea of a bidirectional sumo-/acetylation switch in gene regulation. Quantitative proteomics has highlighted that global sumoylation provides a dynamic response to protein damage involving SUMO chain-mediated protein degradation, but also SUMO E3 ligase-dependent transcription of HSP (Heat-shock protein genes. With these insights in SUMO function and novel technical advancements, we can now study SUMO dynamics in responses to (abiotic stress in plants.

  8. An international comparison of commercial nuclear power plant staffing regulations and practice, 1980--1990

    International Nuclear Information System (INIS)

    Melber, B.; Hauth, J.; Terrill, E.; Berk, B.; Gore, B.

    1994-03-01

    In this report an international review of regulatory and industry practices is provided in the area of nuclear power plant staffing during the 1980s in Canada, France, Germany, Japan, Sweden, and the United Kingdom. The objective of this review is to highlight trends in staffing regulatory approaches, industry practices, and issues of concern in other countries that have potential relevance to nuclear power plant staffing issues in the United States. The decade of the 1980s was marked by a great deal of growth in nuclear power operations internationally; however, growth of nuclear power is not expected to continue in the 1990s except in France and Japan. A continuum of regulatory approaches to staffing was identified, ranging from prescribed regulations that are applied to all licensees (Germany is most similar to the United States in this regard), to indirect staffing regulations where the regulatory authority oversees plant operating practices that are agreed to in the plant operating license (most notably, France and the United Kingdom). Most of the changes observed in staffing regulations and practices in the early 1980s were made in response to the accident at the Three Mile Island Unit 2 nuclear power plant (TMI) in 1979. These changes included the widespread issuance of new operator and licensing requirements and the establishment of national training centers. After the post-TMI changes were implemented, a period of relative stability followed. Changes in the latter half of the 1980s have focused on continuing improvements and additions to training curricula and methods, most notably increased reliance on simulator training

  9. Apoplastic and intracellular plant sugars regulate developmental transitions in witches’ broom disease of cacao

    Science.gov (United States)

    Barau, Joan; Grandis, Adriana; Carvalho, Vinicius Miessler de Andrade; Teixeira, Gleidson Silva; Zaparoli, Gustavo Henrique Alcalá; do Rio, Maria Carolina Scatolin; Rincones, Johana; Buckeridge, Marcos Silveira; Pereira, Gonçalo Amarante Guimarães

    2015-01-01

    Witches’ broom disease (WBD) of cacao differs from other typical hemibiotrophic plant diseases by its unusually long biotrophic phase. Plant carbon sources have been proposed to regulate WBD developmental transitions; however, nothing is known about their availability at the plant–fungus interface, the apoplastic fluid of cacao. Data are provided supporting a role for the dynamics of soluble carbon in the apoplastic fluid in prompting the end of the biotrophic phase of infection. Carbon depletion and the consequent fungal sensing of starvation were identified as key signalling factors at the apoplast. MpNEP2, a fungal effector of host necrosis, was found to be up-regulated in an autophagic-like response to carbon starvation in vitro. In addition, the in vivo artificial manipulation of carbon availability in the apoplastic fluid considerably modulated both its expression and plant necrosis rate. Strikingly, infected cacao tissues accumulated intracellular hexoses, and showed stunted photosynthesis and the up-regulation of senescence markers immediately prior to the transition to the necrotrophic phase. These opposite findings of carbon depletion and accumulation in different host cell compartments are discussed within the frame of WBD development. A model is suggested to explain phase transition as a synergic outcome of fungal-related factors released upon sensing of extracellular carbon starvation, and an early senescence of infected tissues probably triggered by intracellular sugar accumulation. PMID:25540440

  10. Role of plant growth regulators on oil yield and biodiesel production of linseed (linum usitatissimum l)

    International Nuclear Information System (INIS)

    Faizanullah, A.; Bano, A.; Nosheen, A.

    2010-01-01

    A field experiment was conducted to compare the effect of plant growth regulators (PGRs) viz. kinetin (K), chlorocholine chloride (CCC) and salicylic acid (SA) on seed yield, oil content and oil quality of Linseed (Linum usitatissimum L) cv. Chandni with a new perspective to biodiesel production. The growth regulators (10-6M) were applied as seed soaking for 10 h prior to cultivation. Kinetin significantly increased the number of capsules/plant, seed number/capsule, 1000 seed weight and total seed yield (kg/h). The growth regulators increased the seed oil content maximum being in kinetin and CCC treatments. Kinetin and CCC significantly decreased the oil acid value, free fatty acid content (% oleic acid) and increased the pH of oil. Nevertheless, SA significantly decreased the oil specific gravity and did not alter the pH. Only kinetin significantly increased the oil iodine value. The oil extracted from seeds of kinetin and CCC treated plants showed maximum conversion (% w/w) to methyl esters/biodiesel after transesterification. It can be inferred that PGRs can be utilized successfully for improving the biodiesel yield of linseed. (author)

  11. The Arabidopsis synaptotagmin SYTA regulates the cell-to-cell movement of diverse plant viruses

    Directory of Open Access Journals (Sweden)

    Asako eUchiyama

    2014-11-01

    Full Text Available Synaptotagmins are a large gene family in animals that have been extensively characterized due to their role as calcium sensors to regulate synaptic vesicle exocytosis and endocytosis in neurons, and dense core vesicle exocytosis for hormone secretion from neuroendocrine cells. Thought to be exclusive to animals, synaptotagmins have recently been characterized in Arabidopsis thaliana, in which they comprise a five gene family. Using infectivity and leaf-based functional assays, we have shown that Arabidopsis SYTA regulates endocytosis and marks an endosomal vesicle recycling pathway to regulate movement protein-mediated trafficking of the Begomovirus Cabbage leaf curl virus (CaLCuV and the Tobamovirus Tobacco mosaic virus (TMV through plasmodesmata (Lewis and Lazarowitz, 2010. To determine whether SYTA has a central role in regulating the cell-to-cell trafficking of a wider range of diverse plant viruses, we extended our studies here to examine the role of SYTA in the cell-to-cell movement of additional plant viruses that employ different modes of movement, namely the Potyvirus Turnip mosaic virus (TuMV, the Caulimovirus Cauliflower mosaic virus (CaMV and the Tobamovirus Turnip vein clearing virus (TVCV, which in contrast to TMV does efficiently infect Arabidopsis. We found that both TuMV and TVCV systemic infection, and the cell-to-cell trafficking of the their movement proteins, were delayed in the Arabidopsis Col-0 syta-1 knockdown mutant. In contrast, CaMV systemic infection was not inhibited in syta-1. Our studies show that SYTA is a key regulator of plant virus intercellular movement, being necessary for the ability of diverse cell-to-cell movement proteins encoded by Begomoviruses (CaLCuV MP, Tobamoviruses (TVCV and TMV 30K protein and Potyviruses (TuMV P3N-PIPO to alter PD and thereby mediate virus cell-to-cell spread.

  12. Possible Power Estimation of Down-Regulated Offshore Wind Power Plants

    DEFF Research Database (Denmark)

    Gögmen, Tuhfe

    The penetration of offshore wind power is continuously increasing in the Northern European grids. To assure safety in the operation of the power system, wind power plants are required to provide ancillary services, including reserve power attained through down-regulating the wind farm from its...... power plant. The developed procedure, the PossPOW algorithm, can also be used in the wind farm control as it yields a real-time wind farm power curve. The modern wind turbines have a possible power signal at the turbine level and the current state of the art is to aggregate those signals to achieve...... the wind farm scale production capacity. However the summation of these individual signals is simply an over-estimation for the wind power plant, due to reduced wake losses during curtailment. The determination of the possible power with the PossPOW algorithm works as follows: firstly the second...

  13. Role of a Transcriptional Regulator in Programmed Cell Death and Plant Development

    Energy Technology Data Exchange (ETDEWEB)

    Julie M. Stone

    2008-09-13

    The long-term goal of this research is to understand the role(s) and molecular mechanisms of programmed cell death (PCD) in the controlling plant growth, development and responses to biotic and abiotic stress. We developed a genetic selection scheme to identify A. thaliana FB1-resistant (fbr) mutants as a way to find genes involved in PCD (Stone et al., 2000; Stone et al., 2005; Khan and Stone, 2008). The disrupted gene in fbr6 (AtSPL14) responsible for the FB1-insensitivity and plant architecture phenotypes encodes a plant-specific SBP DNA-binding domain transcriptional regulator (Stone et al., 2005; Liang et al., 2008). This research plan is designed to fill gaps in the knowledge about the role of SPL14 in plant growth and development. The work is being guided by three objectives aimed at determining the pathways in which SPL14 functions to modulate PCD and/or plant development: (1) determine how SPL14 functions in plant development, (2) identify target genes that are directly regulated by SPL14, and (3) identify SPL14 modifications and interacting proteins. We made significant progress during the funding period. Briefly, some major accomplishments are highlighted below: (1) To identify potential AtSPL14 target genes, we identified a consensus DNA binding site for the AtSPL14 SBP DNA-binding domain using systematic evolution of ligands by exponential selection (SELEX) and site-directed mutagenesis (Liang et al., 2008). This consensus binding site was used to analyze Affymetrix microarray gene expression data obtained from wild-type and fbr6 mutant plants to find possible AtSPL14-regulated genes. These candidate AtSPL14-regulated genes are providing new information on the molecular mechanisms linking plant PCD and plant development through modulation of the 26S proteasome. (2) Transgenic plants expressing epitope-tagged versions of AtSPL14 are being used to confirm the AtSPL14 targets (by ChIP-PCR) and further dissect the molecular interactions (Nazarenus, Liang

  14. Sensitivity of root-knot nematodes to gamma irradiation, salinity and plant growth regulator, cycocel

    Energy Technology Data Exchange (ETDEWEB)

    Sweelam, M E [Econ. Entomology Dept., Fac. Agric. Menoufia University Shebin El-Kom, (Egypt)

    1995-10-01

    The experiment was carried out at the experimental station of the faculty of agriculture, Menoufia Univ. To determine the sensitivity of root-knot nematode, Meloidogyne Javanica infecting tomato plants exposed to different doses of gamma irradiation 0,20,40,60,80 Gy, salinity levels 0. 1000, 2000, 4000 ppm and the plant growth regulator cycocel 0,200 ppm. Treated seeds were planted clay pots and salinity levels and cycocel concentrations were applied. Fresh weights and nematode populations were computed 3 months after application. Results indicated that 20 Gy, 1000 ppm salinity and cycocel gave the highest fresh weight of shoots and roots. The developmental stages and egg-laying females of nematode decreased by the increasing of irradiation dose and salinity levels. Root-knot galls decreased with 40 and 60 Gy, while significant increase was observed with 0 and 80 Gy, salinity levels decreased root galls. Cycocel decreased nematode population, egg-lying females and root-knot galls.

  15. Sensitivity of root-knot nematodes to gamma irradiation, salinity and plant growth regulator, cycocel

    International Nuclear Information System (INIS)

    Sweelam, M.E.

    1995-01-01

    The experiment was carried out at the experimental station of the faculty of agriculture, Menoufia Univ. To determine the sensitivity of root-knot nematode, Meloidogyne Javanica infecting tomato plants exposed to different doses of gamma irradiation 0,20,40,60,80 Gy, salinity levels 0. 1000, 2000, 4000 ppm and the plant growth regulator cycocel 0,200 ppm. Treated seeds were planted clay pots and salinity levels and cycocel concentrations were applied. Fresh weights and nematode populations were computed 3 months after application. Results indicated that 20 Gy, 1000 ppm salinity and cycocel gave the highest fresh weight of shoots and roots. The developmental stages and egg-laying females of nematode decreased by the increasing of irradiation dose and salinity levels. Root-knot galls decreased with 40 and 60 Gy, while significant increase was observed with 0 and 80 Gy, salinity levels decreased root galls. Cycocel decreased nematode population, egg-lying females and root-knot galls

  16. Endogenous Lunar Volatiles

    Science.gov (United States)

    McCubbin, F. M.; Liu, Y.; Barnes, J. J.; Boyce, J. W.; Day, J. M. D.; Elardo, S. M.; Hui, H.; Magna, T.; Ni, P.; Tartese, R.; hide

    2017-01-01

    The chapter will begin with an introduction that defines magmatic volatiles (e.g., H, F, Cl, S) versus geochemical volatiles (e.g., K, Rb, Zn). We will discuss our approach of understanding both types of volatiles in lunar samples and lay the ground work for how we will determine the overall volatile budget of the Moon. We will then discuss the importance of endogenous volatiles in shaping the "Newer Views of the Moon", specifically how endogenous volatiles feed forward into processes such as the origin of the Moon, magmatic differentiation, volcanism, and secondary processes during surface and crustal interactions. After the introduction, we will include a re-view/synthesis on the current state of 1) apatite compositions (volatile abundances and isotopic compositions); 2) nominally anhydrous mineral phases (moderately to highly volatile); 3) volatile (moderately to highly volatile) abundances in and isotopic compositions of lunar pyroclastic glass beads; 4) volatile (moderately to highly volatile) abundances in and isotopic compositions of lunar basalts; 5) volatile (moderately to highly volatile) abundances in and isotopic compositions of melt inclusions; and finally 6) experimental constraints on mineral-melt partitioning of moderately to highly volatile elements under lunar conditions. We anticipate that each section will summarize results since 2007 and focus on new results published since the 2015 Am Min review paper on lunar volatiles [9]. The next section will discuss how to use sample abundances of volatiles to understand the source region and potential caveats in estimating source abundances of volatiles. The following section will include our best estimates of volatile abundances and isotopic compositions (where permitted by available data) for each volatile element of interest in a number of important lunar reservoirs, including the crust, mantle, KREEP, and bulk Moon. The final section of the chapter will focus upon future work, outstanding questions

  17. Aux/IAA Gene Family in Plants: Molecular Structure, Regulation, and Function

    Directory of Open Access Journals (Sweden)

    Jie Luo

    2018-01-01

    Full Text Available Auxin plays a crucial role in the diverse cellular and developmental responses of plants across their lifespan. Plants can quickly sense and respond to changes in auxin levels, and these responses involve several major classes of auxin-responsive genes, including the Auxin/Indole-3-Acetic Acid (Aux/IAA family, the auxin response factor (ARF family, small auxin upregulated RNA (SAUR, and the auxin-responsive Gretchen Hagen3 (GH3 family. Aux/IAA proteins are short-lived nuclear proteins comprising several highly conserved domains that are encoded by the auxin early response gene family. These proteins have specific domains that interact with ARFs and inhibit the transcription of genes activated by ARFs. Molecular studies have revealed that Aux/IAA family members can form diverse dimers with ARFs to regulate genes in various ways. Functional analyses of Aux/IAA family members have indicated that they have various roles in plant development, such as root development, shoot growth, and fruit ripening. In this review, recently discovered details regarding the molecular characteristics, regulation, and protein–protein interactions of the Aux/IAA proteins are discussed. These details provide new insights into the molecular basis of the Aux/IAA protein functions in plant developmental processes.

  18. Governmental organization for the regulation of nuclear power plants. A code of practice

    International Nuclear Information System (INIS)

    1978-01-01

    This Code of Practice recommends requirements for a regulatory body responsible for regulating the siting, construction, commissioning, operation and decommissioning of nuclear power plants for safety. It forms part of the Agency's programme, referred to as the NUSS programme, for establishing Codes of Practice and Safety Guides relating to land-based stationary thermal neutron power plants. This Code has been prepared to provide recommendations for Member States embarking on a nuclear power programme and covers: (1) Establishing and maintaining a regulatory body to which is assigned the responsibility for authorizing the siting, construction, commissioning, operation and decommissioning of nuclear power plants after appropriate review and assessment (2) Organizing for and conducting the review and assessment of the safety of nuclear power plants (3) Conducting the necessary regulatory inspections and taking necessary enforcement actions during all stages of the licensing process in order to ensure that the limits and conditions of the licences are being complied with by the applicants/licensees and their contractors (4) Establishing regulations and criteria for nuclear-related health, safety and environmental protection