WorldWideScience

Sample records for plant defence responses

  1. Signalling network construction for modelling plant defence response.

    Directory of Open Access Journals (Sweden)

    Dragana Miljkovic

    Full Text Available Plant defence signalling response against various pathogens, including viruses, is a complex phenomenon. In resistant interaction a plant cell perceives the pathogen signal, transduces it within the cell and performs a reprogramming of the cell metabolism leading to the pathogen replication arrest. This work focuses on signalling pathways crucial for the plant defence response, i.e., the salicylic acid, jasmonic acid and ethylene signal transduction pathways, in the Arabidopsis thaliana model plant. The initial signalling network topology was constructed manually by defining the representation formalism, encoding the information from public databases and literature, and composing a pathway diagram. The manually constructed network structure consists of 175 components and 387 reactions. In order to complement the network topology with possibly missing relations, a new approach to automated information extraction from biological literature was developed. This approach, named Bio3graph, allows for automated extraction of biological relations from the literature, resulting in a set of (component1, reaction, component2 triplets and composing a graph structure which can be visualised, compared to the manually constructed topology and examined by the experts. Using a plant defence response vocabulary of components and reaction types, Bio3graph was applied to a set of 9,586 relevant full text articles, resulting in 137 newly detected reactions between the components. Finally, the manually constructed topology and the new reactions were merged to form a network structure consisting of 175 components and 524 reactions. The resulting pathway diagram of plant defence signalling represents a valuable source for further computational modelling and interpretation of omics data. The developed Bio3graph approach, implemented as an executable language processing and graph visualisation workflow, is publically available at http://ropot.ijs.si/bio3graph/and can be

  2. Priming, induction and modulation of plant defence responses by bacterial lipopolysaccharides

    DEFF Research Database (Denmark)

    Newman, Mari-Anne; Dow, J. Maxwell; Molinaro, Antonio

    2007-01-01

    Bacterial lipopolysaccharides (LPSs) have multiple roles in plant-microbe interactions. LPS contributes to the low permeability of the outer membrane, which acts as a barrier to protect bacteria from plant-derived antimicrobial substances. Conversely, perception of LPS by plant cells can lead...... to the triggering of defence responses or to the priming of the plant to respond more rapidly and/or to a greater degree to subsequent pathogen challenge. LPS from symbiotic bacteria can have quite different effects on plants to those of pathogens. Some details are emerging of the structures within LPS...... that are responsible for induction of these different plant responses. The lipid A moiety is not solely responsible for all of the effects of LPS in plants; core oligosaccharide and O-antigen components can elicit specific responses. Here, we review the effects of LPS in induction of defence-related responses...

  3. Grape marc extract acts as elicitor of plant defence responses.

    Science.gov (United States)

    Goupil, Pascale; Benouaret, Razik; Charrier, Olivia; Ter Halle, Alexandra; Richard, Claire; Eyheraguibel, Boris; Thiery, Denis; Ledoigt, Gérard

    2012-07-01

    Plant protection based on novel alternative strategies is a major concern in agriculture to sustain pest management. The marc extract of red grape cultivars reveals plant defence inducer properties. Treatment with grape marc extract efficiently induced hypersensitive reaction-like lesions with cell death evidenced by Evans Blue staining of tobacco leaves. Examination of the infiltration zone and the surrounding areas under UV light revealed the accumulation of autofluorescent compounds. Both leaf infiltration and a foliar spray of the red grape extract on tobacco leaves induced defence gene expression. The PR1 and PR2 target genes were upregulated locally and systemically in tobacco plants following grape marc extract treatment. The grape extract elicited an array of plant defence responses making this natural compound a potential phytosanitary product with a challenging issue and a rather attractive option for sustainable agriculture and environmentally friendly practices.

  4. A saponin-detoxifying enzyme mediates suppression of plant defences

    Science.gov (United States)

    Bouarab, K.; Melton, R.; Peart, J.; Baulcombe, D.; Osbourn, A.

    2002-08-01

    Plant disease resistance can be conferred by constitutive features such as structural barriers or preformed antimicrobial secondary metabolites. Additional defence mechanisms are activated in response to pathogen attack and include localized cell death (the hypersensitive response). Pathogens use different strategies to counter constitutive and induced plant defences, including degradation of preformed antimicrobial compounds and the production of molecules that suppress induced plant defences. Here we present evidence for a two-component process in which a fungal pathogen subverts the preformed antimicrobial compounds of its host and uses them to interfere with induced defence responses. Antimicrobial saponins are first hydrolysed by a fungal saponin-detoxifying enzyme. The degradation product of this hydrolysis then suppresses induced defence responses by interfering with fundamental signal transduction processes leading to disease resistance.

  5. Long-distance signalling in plant defence.

    Science.gov (United States)

    Heil, Martin; Ton, Jurriaan

    2008-06-01

    Plants use inducible defence mechanisms to fend off harmful organisms. Resistance that is induced in response to local attack is often expressed systemically, that is, in organs that are not yet damaged. In the search for translocated defence signals, biochemical studies follow the physical movement of putative signals, and grafting experiments use mutants that are impaired in the production or perception of these signals. Long-distance signals can directly activate defence or can prime for the stronger and faster induction of defence. Historically, research has focused on the vascular transport of signalling metabolites, but volatiles can play a crucial role as well. We compare the advantages and constraints of vascular and airborne signals for the plant, and discuss how they can act in synergy to achieve optimised resistance in distal plant parts.

  6. Salicylic acid-independent plant defence pathways

    NARCIS (Netherlands)

    Pieterse, C.M.J.; Loon, L.C. van

    1999-01-01

    Salicylic acid is an important signalling molecule involved in both locally and systemically induced disease resistance responses. Recent advances in our understanding of plant defence signalling have revealed that plants employ a network of signal transduction pathways, some of which are

  7. Understanding plant defence responses against herbivore attacks: an essential first step towards the development of sustainable resistance against pests.

    Science.gov (United States)

    Santamaria, M Estrella; Martínez, Manuel; Cambra, Inés; Grbic, Vojislava; Diaz, Isabel

    2013-08-01

    Plant-herbivore relationships are complex interactions encompassing elaborate networks of molecules, signals and strategies used to overcome defences developed by each other. Herbivores use multiple feeding strategies to obtain nutrients from host plants. In turn, plants respond by triggering defence mechanisms to inhibit, block or modify the metabolism of the pest. As part of these defences, herbivore-challenged plants emit volatiles to attract natural enemies and warn neighbouring plants of the imminent threat. In response, herbivores develop a variety of strategies to suppress plant-induced protection. Our understanding of the plant-herbivore interphase is limited, although recent molecular approaches have revealed the participation of a battery of genes, proteins and volatile metabolites in attack-defence processes. This review describes the intricate and dynamic defence systems governing plant-herbivore interactions by examining the diverse strategies plants employ to deny phytophagous arthropods the ability to breach newly developed mechanisms of plant resistance. A cornerstone of this understanding is the use of transgenic tools to unravel the complex networks that control these interactions.

  8. Phospholipase D and phosphatidic acid in plant defence response: from protein–protein and lipid–protein interactions to hormone signalling

    Science.gov (United States)

    Zhao, Jian

    2015-01-01

    Phospholipase Ds (PLDs) and PLD-derived phosphatidic acids (PAs) play vital roles in plant hormonal and environmental responses and various cellular dynamics. Recent studies have further expanded the functions of PLDs and PAs into plant–microbe interaction. The molecular diversities and redundant functions make PLD–PA an important signalling complex regulating lipid metabolism, cytoskeleton dynamics, vesicle trafficking, and hormonal signalling in plant defence through protein–protein and protein–lipid interactions or hormone signalling. Different PLD–PA signalling complexes and their targets have emerged as fast-growing research topics for understanding their numerous but not yet established roles in modifying pathogen perception, signal transduction, and downstream defence responses. Meanwhile, advanced lipidomics tools have allowed researchers to reveal further the mechanisms of PLD–PA signalling complexes in regulating lipid metabolism and signalling, and their impacts on jasmonic acid/oxylipins, salicylic acid, and other hormone signalling pathways that essentially mediate plant defence responses. This review attempts to summarize the progress made in spatial and temporal PLD/PA signalling as well as PLD/PA-mediated modification of plant defence. It presents an in-depth discussion on the functions and potential mechanisms of PLD–PA complexes in regulating actin filament/microtubule cytoskeleton, vesicle trafficking, and hormonal signalling, and in influencing lipid metabolism-derived metabolites as critical signalling components in plant defence responses. The discussion puts PLD–PA in a broader context in order to guide future research. PMID:25680793

  9. Phospholipase D and phosphatidic acid in plant defence response: from protein-protein and lipid-protein interactions to hormone signalling.

    Science.gov (United States)

    Zhao, Jian

    2015-04-01

    Phospholipase Ds (PLDs) and PLD-derived phosphatidic acids (PAs) play vital roles in plant hormonal and environmental responses and various cellular dynamics. Recent studies have further expanded the functions of PLDs and PAs into plant-microbe interaction. The molecular diversities and redundant functions make PLD-PA an important signalling complex regulating lipid metabolism, cytoskeleton dynamics, vesicle trafficking, and hormonal signalling in plant defence through protein-protein and protein-lipid interactions or hormone signalling. Different PLD-PA signalling complexes and their targets have emerged as fast-growing research topics for understanding their numerous but not yet established roles in modifying pathogen perception, signal transduction, and downstream defence responses. Meanwhile, advanced lipidomics tools have allowed researchers to reveal further the mechanisms of PLD-PA signalling complexes in regulating lipid metabolism and signalling, and their impacts on jasmonic acid/oxylipins, salicylic acid, and other hormone signalling pathways that essentially mediate plant defence responses. This review attempts to summarize the progress made in spatial and temporal PLD/PA signalling as well as PLD/PA-mediated modification of plant defence. It presents an in-depth discussion on the functions and potential mechanisms of PLD-PA complexes in regulating actin filament/microtubule cytoskeleton, vesicle trafficking, and hormonal signalling, and in influencing lipid metabolism-derived metabolites as critical signalling components in plant defence responses. The discussion puts PLD-PA in a broader context in order to guide future research. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  10. Antagonism between salicylic and abscisic acid reflects early host-pathogen conflict and moulds plant defence responses.

    Science.gov (United States)

    de Torres Zabala, Marta; Bennett, Mark H; Truman, William H; Grant, Murray R

    2009-08-01

    The importance of phytohormone balance is increasingly recognized as central to the outcome of plant-pathogen interactions. Recently it has been demonstrated that abscisic acid signalling pathways are utilized by the bacterial phytopathogen Pseudomonas syringae to promote pathogenesis. In this study, we examined the dynamics, inter-relationship and impact of three key acidic phytohormones, salicylic acid, abscisic acid and jasmonic acid, and the bacterial virulence factor, coronatine, during progression of P. syringae infection of Arabidopsis thaliana. We show that levels of SA and ABA, but not JA, appear to play important early roles in determining the outcome of the infection process. SA is required in order to mount a full innate immune responses, while bacterial effectors act rapidly to activate ABA biosynthesis. ABA suppresses inducible innate immune responses by down-regulating SA biosynthesis and SA-mediated defences. Mutant analyses indicated that endogenous ABA levels represent an important reservoir that is necessary for effector suppression of plant-inducible innate defence responses and SA synthesis prior to subsequent pathogen-induced increases in ABA. Enhanced susceptibility due to loss of SA-mediated basal resistance is epistatically dominant over acquired resistance due to ABA deficiency, although ABA also contributes to symptom development. We conclude that pathogen-modulated ABA signalling rapidly antagonizes SA-mediated defences. We predict that hormonal perturbations, either induced or as a result of environmental stress, have a marked impact on pathological outcomes, and we provide a mechanistic basis for understanding priming events in plant defence.

  11. Transgenerational effects alter plant defence and resistance in nature.

    Science.gov (United States)

    Colicchio, J

    2017-04-01

    Trichomes, or leaf hairs, are epidermal extensions that take a variety of forms and perform many functions in plants, including herbivore defence. In this study, I document genetically determined variation, within-generation plasticity, and a direct role of trichomes in herbivore defence for Mimulus guttatus. After establishing the relationship between trichomes and herbivory, I test for transgenerational effects of wounding on trichome density and herbivore resistance. Patterns of interannual variation in herbivore density and the high cost of plant defence makes plant-herbivore interactions a system in which transgenerational phenotypic plasticity (TPP) is apt to evolve. Here, I demonstrate that parental damage alters offspring trichome density and herbivore resistance in nature. Moreover, this response varies between populations. This is among the first studies to demonstrate that TPP contributes to variation in nature, and also suggests that selection can modify TPP in response to local conditions. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  12. 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).

  13. Salicylic acid-independent plant defence pathways

    OpenAIRE

    Pieterse, C.M.J.; Loon, L.C. van

    1999-01-01

    Salicylic acid is an important signalling molecule involved in both locally and systemically induced disease resistance responses. Recent advances in our understanding of plant defence signalling have revealed that plants employ a network of signal transduction pathways, some of which are independent of salicylic acid. Evidence is emerging that jasmonic acid and ethylene play key roles in these salicylic acid-independent pathways. Cross-talk between the salicylic acid-dependent and the salicy...

  14. Assessment of defence in depth for nuclear power plants

    International Nuclear Information System (INIS)

    2005-01-01

    Defence in depth is a comprehensive approach to safety that has been developed by nuclear power experts to ensure with high confidence that the public and the environment are protected from any hazards posed by the use of nuclear power for the generation of electricity. The concepts of defence in depth and safety culture have served the nuclear power industry well as a basic philosophy for the safe design and operation of nuclear power plants. Properly applied, defence in depth ensures that no single human error or equipment failure at one level of defence, nor even a combination of failures at more than one level of defence, propagates to jeopardize defence in depth at the subsequent level or leads to harm to the public or the environment. The importance of the concept of defence in depth is underlined in IAEA Safety Standards, in particular in the requirements set forth in the Safety Standards: Safety of Nuclear Power Plants: Design (NS-R-1) and Safety Assessment and Verification for Nuclear Power Plants (NS-G-1.2). A specific report, Defence in Depth in Nuclear Safety (INSAG-10), describes the objectives, strategy, implementation and future development in the area of defence in depth in nuclear and radiation safety. In the report Basic Safety Principles for Nuclear Power Plants (INSAG-12), defence in depth is recognized as one of the fundamental safety principles that underlie the safety of nuclear power plants. In consonance with those high level publications, this Safety Report provides more specific technical information on the implementation of this concept in the siting, design, construction and operation of nuclear power plants. It describes a method for comprehensive and balanced review of the provisions required for implementing defence in depth in existing plants. This publication is intended to provide guidance primarily for the self-assessment by plant operators of the comprehensiveness and quality of defence in depth provisions. It can be used

  15. How insects overcome two-component plant chemical defence

    DEFF Research Database (Denmark)

    Pentzold, Stefan; Zagrobelny, Mika; Rook, Frederik

    2014-01-01

    Insect herbivory is often restricted by glucosylated plant chemical defence compounds that are activated by plant β-glucosidases to release toxic aglucones upon plant tissue damage. Such two-component plant defences are widespread in the plant kingdom and examples of these classes of compounds...... are alkaloid, benzoxazinoid, cyanogenic and iridoid glucosides as well as glucosinolates and salicinoids. Conversely, many insects have evolved a diversity of counteradaptations to overcome this type of constitutive chemical defence. Here we discuss that such counter-adaptations occur at different time points......, before and during feeding as well as during digestion, and at several levels such as the insects’ feeding behaviour, physiology and metabolism. Insect adaptations frequently circumvent or counteract the activity of the plant β-glucosidases, bioactivating enzymes that are a key element in the plant’s two...

  16. Ecological trade-offs between jasmonic acid-dependent direct and indirect plant defences in tritrophic interactions.

    Science.gov (United States)

    Wei, Jianing; Wang, Lizhong; Zhao, Jiuhai; Li, Chuanyou; Ge, Feng; Kang, Le

    2011-01-01

    Recent studies on plants genetically modified in jasmonic acid (JA) signalling support the hypothesis that the jasmonate family of oxylipins plays an important role in mediating direct and indirect plant defences. However, the interaction of two modes of defence in tritrophic systems is largely unknown. In this study, we examined the preference and performance of a herbivorous leafminer (Liriomyza huidobrensis) and its parasitic wasp (Opius dissitus) on three tomato genotypes: a wild-type (WT) plant, a JA biosynthesis (spr2) mutant, and a JA-overexpression 35S::prosys plant. Their proteinase inhibitor production and volatile emission were used as direct and indirect defence factors to evaluate the responses of leafminers and parasitoids. Here, we show that although spr2 mutant plants are compromised in direct defence against the larval leafminers and in attracting parasitoids, they are less attractive to adult flies compared with WT plants. Moreover, in comparison to other genotypes, the 35S::prosys plant displays greater direct and constitutive indirect defences, but reduced success of parasitism by parasitoids. Taken together, these results suggest that there are distinguished ecological trade-offs between JA-dependent direct and indirect defences in genetically modified plants whose fitness should be assessed in tritrophic systems and under natural conditions. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).

  17. Development of a qPCR strategy to select bean genes involved in plant defence response and regulated by the Trichoderma velutinum - Rhizoctonia solani interaction

    Directory of Open Access Journals (Sweden)

    Sara Mayo

    2016-08-01

    Full Text Available Bean production is affected by a wide diversity of fungal pathogens, among them Rhizoctonia solani is one of the most important. A strategy to control bean infectious diseases, mainly those caused by fungi, is based on the use of biocontrol agents that can reduce the negative effects of plant pathogens and also can promote positive responses in the plant. Trichoderma is a fungal genus that is able to induce the expression of genes involved in plant defence response and also to promote plant growth, root development and nutrient uptake. In this article, a strategy that combines in silico analysis and real time PCR to detect additional bean defence-related genes, regulated by the presence of Trichoderma velutinum and/or R. solani has been applied. Based in this strategy, from From the 48 bean genes initially analysed, 14 were selected, and only WRKY33, CH5b and hGS showed an up-regulatory response in the presence of T. velutinum. The other genes were or not affected (OSM34 or down-regulated by the presence of this fungus. R. solani infection resulted in a down-regulation of most of the genes analyzed, except PR1, OSM34 and CNGC2 that were not affected, and the presence of both, T. velutinum and R. solani, up-regulates hGS and down-regulates all the other genes analyzed, except CH5b which was not significantly affected.As conclusion, the strategy described in the present work has been shown to be effective to detect genes involved in plant defence, which respond to the presence of a biocontrol agent or to a pathogen and also to the presence of both. The selected genes show significant homology with previously described plant defence genes and they are expressed in bean leaves of plants treated with T. velutinum and/or infected with R. solani.

  18. Inducible indirect defence of plants : from mechanisms to ecological functions

    NARCIS (Netherlands)

    Dicke, M.; Poecke, van R.M.P.; Boer, de J.G.

    2003-01-01

    Inducible defences allow plants to be phenotypically plastic. Inducible indirect defence of plants by attracting carnivorous enemies of herbivorous arthropods can vary with plant species and genotype, with herbivore species or instar and potentially with other environmental conditions. So far,

  19. Cyclic lipopeptides from Bacillus subtilis activate distinct patterns of defence responses in grapevine.

    Science.gov (United States)

    Farace, Giovanni; Fernandez, Olivier; Jacquens, Lucile; Coutte, François; Krier, François; Jacques, Philippe; Clément, Christophe; Barka, Essaid Ait; Jacquard, Cédric; Dorey, Stéphan

    2015-02-01

    Non-self-recognition of microorganisms partly relies on the perception of microbe-associated molecular patterns (MAMPs) and leads to the activation of an innate immune response. Bacillus subtilis produces three main families of cyclic lipopeptides (LPs), namely surfactins, iturins and fengycins. Although LPs are involved in induced systemic resistance (ISR) activation, little is known about defence responses induced by these molecules and their involvement in local resistance to fungi. Here, we showed that purified surfactin, mycosubtilin (iturin family) and plipastatin (fengycin family) are perceived by grapevine plant cells. Although surfactin and mycosubtilin stimulated grapevine innate immune responses, they differentially activated early signalling pathways and defence gene expression. By contrast, plipastatin perception by grapevine cells only resulted in early signalling activation. Gene expression analysis suggested that mycosubtilin activated salicylic acid (SA) and jasmonic acid (JA) signalling pathways, whereas surfactin mainly induced an SA-regulated response. Although mycosubtilin and plipastatin displayed direct antifungal activity, only surfactin and mycosubtilin treatments resulted in a local long-lasting enhanced tolerance to the necrotrophic fungus Botrytis cinerea in grapevine leaves. Moreover, challenge with specific strains overproducing surfactin and mycosubtilin led to a slightly enhanced stimulation of the defence response compared with the LP-non-producing strain of B. subtilis. Altogether, our results provide the first comprehensive view of the involvement of LPs from B. subtilis in grapevine plant defence and local resistance against the necrotrophic pathogen Bo. cinerea. Moreover, this work is the first to highlight the ability of mycosubtilin to trigger an immune response in plants. © 2014 BSPP AND JOHN WILEY & SONS LTD.

  20. 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

  1. Post-translational modification of host proteins in pathogen-triggered defence signalling in plants

    NARCIS (Netherlands)

    Stulemeijer, I.J.E.; Joosten, M.H.A.J.

    2008-01-01

    Microbial plant pathogens impose a continuous threat to global food production. Similar to animals, an innate immune system allows plants to recognize pathogens and swiftly activate defence. To activate a rapid response, receptor-mediated pathogen perception and subsequent downstream signalling

  2. The dual nature of trehalose in citrus canker disease: a virulence factor for Xanthomonas citri subsp. citri and a trigger for plant defence responses

    KAUST Repository

    Piazza, A.; Zimaro, T.; Garavaglia, B. S.; Ficarra, F. A.; Thomas, L.; Marondedze, C.; Feil, R.; Lunn, J. E.; Gehring, Christoph A; Ottado, J.; Gottig, N.

    2015-01-01

    and proteomic analyses of infected leaves showed that infection with XccΔotsA triggered only weak defence responses in the plant compared with infection with Xcc, and had less impact on the host plant's metabolism than the wild-type strain. These results

  3. Chemicals on plant surfaces as a heretofore unrecognized, but ecologically informative, class for investigations into plant defence.

    Science.gov (United States)

    LoPresti, Eric F

    2016-11-01

    Plants produce and utilize a great diversity of chemicals for a variety of physiological and ecological purposes. Many of these chemicals defend plants against herbivores, pathogens and competitors. The location of these chemicals varies within the plant, some are located entirely within plant tissues, others exist in the air- (or water-) space around plants, and still others are secreted onto plant surfaces as exudates. I argue herein that the location of a given defensive chemical has profound implications for its ecological function; specifically, I focus on the characteristics of chemical defences secreted onto plant surfaces. Drawing from a broad literature encompassing ecology, evolution, taxonomy and physiology, I found that these external chemical defences (ECDs) are common and widespread in plants and algae; hundreds of examples have been detailed, yet they are not delineated as a separate class from internal chemical defences (ICDs). I propose a novel typology for ECDs and, using existing literature, explore the ecological consequences of the hypothesized unique characteristics of ECDs. The axis of total or proportional investment in ECDs versus ICDs should be considered as one axis of investment by a plant, in the same way as quantitative versus qualitative chemical defences or induced versus constitutive defences is considered. The ease of manipulating ECDs in many plant systems presents a powerful tool to help test plant defence theory (e.g. optimal defence). The framework outlined here integrates various disciplines of botany and ecology and suggests a need for further examinations of exudates in a variety of contexts, as well as recognition of the effects of within-plant localization of defences. © 2015 Cambridge Philosophical Society.

  4. Mechanisms and ecological consequences of plant defence induction and suppression in herbivore communities

    Science.gov (United States)

    Kant, M. R.; Jonckheere, W.; Knegt, B.; Lemos, F.; Liu, J.; Schimmel, B. C. J.; Villarroel, C. A.; Ataide, L. M. S.; Dermauw, W.; Glas, J. J.; Egas, M.; Janssen, A.; Van Leeuwen, T.; Schuurink, R. C.; Sabelis, M. W.; Alba, J. M.

    2015-01-01

    Background Plants are hotbeds for parasites such as arthropod herbivores, which acquire nutrients and energy from their hosts in order to grow and reproduce. Hence plants are selected to evolve resistance, which in turn selects for herbivores that can cope with this resistance. To preserve their fitness when attacked by herbivores, plants can employ complex strategies that include reallocation of resources and the production of defensive metabolites and structures. Plant defences can be either prefabricated or be produced only upon attack. Those that are ready-made are referred to as constitutive defences. Some constitutive defences are operational at any time while others require activation. Defences produced only when herbivores are present are referred to as induced defences. These can be established via de novo biosynthesis of defensive substances or via modifications of prefabricated substances and consequently these are active only when needed. Inducibility of defence may serve to save energy and to prevent self-intoxication but also implies that there is a delay in these defences becoming operational. Induced defences can be characterized by alterations in plant morphology and molecular chemistry and are associated with a decrease in herbivore performance. These alterations are set in motion by signals generated by herbivores. Finally, a subset of induced metabolites are released into the air as volatiles and function as a beacon for foraging natural enemies searching for prey, and this is referred to as induced indirect defence. Scope The objective of this review is to evaluate (1) which strategies plants have evolved to cope with herbivores and (2) which traits herbivores have evolved that enable them to counter these defences. The primary focus is on the induction and suppression of plant defences and the review outlines how the palette of traits that determine induction/suppression of, and resistance/susceptibility of herbivores to, plant defences can

  5. Comparison of defence responses to Botrytis cinerea infection in tomato plants propagated in vitro and grown in vivo

    Directory of Open Access Journals (Sweden)

    Jacek Patykowski

    2013-12-01

    Full Text Available Defence reactions: O2 - generation, superoxide dismutase, catalase, guaiacol peroxidase and ascorbate peroxidase activities after B. cinerea infection in tomato plants propagated in vitro and grown in vivo have been compared. Infection resulted in rapid O2 - generation. Superoxide dismutase activity increase was slower than O2 - response. In plants propagated in vitro catalase and guaiacol peroxidase activities after infection were induced less strongly than in plants grown in vivo. K2HPO4 pretreatment of plants grown in vitro enhanced significantly the activities of catalase and guaiacol peroxidase after infection. Slight restriction of B. cinerea infection development in in vitro propagated plants pretreated with K2HP04 was observed.

  6. Mechanisms and ecological consequences of plant defence induction and suppression in herbivore communities.

    Science.gov (United States)

    Kant, M R; Jonckheere, W; Knegt, B; Lemos, F; Liu, J; Schimmel, B C J; Villarroel, C A; Ataide, L M S; Dermauw, W; Glas, J J; Egas, M; Janssen, A; Van Leeuwen, T; Schuurink, R C; Sabelis, M W; Alba, J M

    2015-06-01

    Plants are hotbeds for parasites such as arthropod herbivores, which acquire nutrients and energy from their hosts in order to grow and reproduce. Hence plants are selected to evolve resistance, which in turn selects for herbivores that can cope with this resistance. To preserve their fitness when attacked by herbivores, plants can employ complex strategies that include reallocation of resources and the production of defensive metabolites and structures. Plant defences can be either prefabricated or be produced only upon attack. Those that are ready-made are referred to as constitutive defences. Some constitutive defences are operational at any time while others require activation. Defences produced only when herbivores are present are referred to as induced defences. These can be established via de novo biosynthesis of defensive substances or via modifications of prefabricated substances and consequently these are active only when needed. Inducibility of defence may serve to save energy and to prevent self-intoxication but also implies that there is a delay in these defences becoming operational. Induced defences can be characterized by alterations in plant morphology and molecular chemistry and are associated with a decrease in herbivore performance. These alterations are set in motion by signals generated by herbivores. Finally, a subset of induced metabolites are released into the air as volatiles and function as a beacon for foraging natural enemies searching for prey, and this is referred to as induced indirect defence. The objective of this review is to evaluate (1) which strategies plants have evolved to cope with herbivores and (2) which traits herbivores have evolved that enable them to counter these defences. The primary focus is on the induction and suppression of plant defences and the review outlines how the palette of traits that determine induction/suppression of, and resistance/susceptibility of herbivores to, plant defences can give rise to

  7. Role of stress-related hormones in plant defence during early infection of the cyst nematode Heterodera schachtii in Arabidopsis

    Science.gov (United States)

    Kammerhofer, Nina; Radakovic, Zoran; Regis, Jully M A; Dobrev, Petre; Vankova, Radomira; Grundler, Florian M W; Siddique, Shahid; Hofmann, Julia; Wieczorek, Krzysztof

    2015-01-01

    Heterodera schachtii, a plant-parasitic cyst nematode, invades host roots and induces a specific syncytial feeding structure, from which it withdraws all required nutrients, causing severe yield losses. The system H. schachtii–Arabidopsis is an excellent research model for investigating plant defence mechanisms. Such responses are suppressed in well-established syncytia, whereas they are induced during early parasitism. However, the mechanisms by which the defence responses are modulated and the role of phytohormones are largely unknown. The aim of this study was to elucidate the role of hormone-based defence responses at the onset of nematode infection. First, concentrations of main phytohormones were quantified and the expression of several hormone-related genes was analysed using quantitative real-time (qRT)-PCR or GeneChip. Further, the effects of individual hormones were evaluated via nematode attraction and infection assays using plants with altered endogenous hormone concentrations. Our results suggest a pivotal and positive role for ethylene during nematode attraction, whereas jasmonic acid triggers early defence responses against H. schachtii. Salicylic acid seems to be a negative regulator during later syncytium and female development. We conclude that nematodes are able to impose specific changes in hormone pools, thus modulating hormone-based defence and signal transduction in strict dependence on their parasitism stage. PMID:25825039

  8. A plant EPF-type zinc-finger protein, CaPIF1, involved in defence against pathogens.

    Science.gov (United States)

    Oh, Sang-Keun; Park, Jeong Mee; Joung, Young Hee; Lee, Sanghyeob; Chung, Eunsook; Kim, Soo-Yong; Yu, Seung Hun; Choi, Doil

    2005-05-01

    SUMMARY To understand better the defence responses of plants to pathogen attack, we challenged hot pepper plants with bacterial pathogens and identified transcription factor-encoding genes whose expression patterns were altered during the subsequent hypersensitive response. One of these genes, CaPIF1 (Capsicum annuum Pathogen-Induced Factor 1), was characterized further. This gene encodes a plant-specific EPF-type protein that contains two Cys(2)/His(2) zinc fingers. CaPIF1 expression was rapidly and specifically induced when pepper plants were challenged with bacterial pathogens to which they are resistant. In contrast, challenge with a pathogen to which the plants are susceptible only generated weak CaPIF1 expression. CaPIF1 expression was also strongly induced in pepper leaves by the exogenous application of ethephon, an ethylene-releasing compound, and salicylic acid, whereas methyl jasmonate had only moderate effects. CaPIF1 localized to the nuclei of onion epidermis when expressed as a CaPIF1-smGFP fusion protein. Transgenic tobacco plants over-expressing CaPIF1 driven by the CaMV 35S promoter showed increased resistance to challenge with a tobacco-specific pathogen or non-host bacterial pathogens. These plants also showed constitutive up-regulation of multiple defence-related genes. Moreover, virus-induced silencing of the CaPIF1 orthologue in Nicotiana benthamiana enhanced susceptibility to the same host or non-host bacterial pathogens. These observations provide evidence that an EPF-type Cys(2)/His(2) zinc-finger protein plays a crucial role in the activation of the pathogen defence response in plants.

  9. Can genetically based clines in plant defence explain greater herbivory at higher latitudes?

    Science.gov (United States)

    Anstett, Daniel N; Ahern, Jeffrey R; Glinos, Julia; Nawar, Nabanita; Salminen, Juha-Pekka; Johnson, Marc T J

    2015-12-01

    Greater plant defence is predicted to evolve at lower latitudes in response to increased herbivore pressure. However, recent studies question the generality of this pattern. In this study, we tested for genetically based latitudinal clines in resistance to herbivores and underlying defence traits of Oenothera biennis. We grew plants from 137 populations from across the entire native range of O. biennis. Populations from lower latitudes showed greater resistance to multiple specialist and generalist herbivores. These patterns were associated with an increase in total phenolics at lower latitudes. A significant proportion of the phenolics were driven by the concentrations of two major ellagitannins, which exhibited opposing latitudinal clines. Our analyses suggest that these findings are unlikely to be explained by local adaptation of herbivore populations or genetic variation in phenology. Rather greater herbivory at high latitudes can be explained by latitudinal clines in the evolution of plant defences. © 2015 John Wiley & Sons Ltd/CNRS.

  10. How insects overcome two-component plant chemical defence: plant β-glucosidases as the main target for herbivore adaptation.

    Science.gov (United States)

    Pentzold, Stefan; Zagrobelny, Mika; Rook, Fred; Bak, Søren

    2014-08-01

    Insect herbivory is often restricted by glucosylated plant chemical defence compounds that are activated by plant β-glucosidases to release toxic aglucones upon plant tissue damage. Such two-component plant defences are widespread in the plant kingdom and examples of these classes of compounds are alkaloid, benzoxazinoid, cyanogenic and iridoid glucosides as well as glucosinolates and salicinoids. Conversely, many insects have evolved a diversity of counteradaptations to overcome this type of constitutive chemical defence. Here we discuss that such counter-adaptations occur at different time points, before and during feeding as well as during digestion, and at several levels such as the insects’ feeding behaviour, physiology and metabolism. Insect adaptations frequently circumvent or counteract the activity of the plant β-glucosidases, bioactivating enzymes that are a key element in the plant’s two-component chemical defence. These adaptations include host plant choice, non-disruptive feeding guilds and various physiological adaptations as well as metabolic enzymatic strategies of the insect’s digestive system. Furthermore, insect adaptations often act in combination, may exist in both generalists and specialists, and can act on different classes of defence compounds. We discuss how generalist and specialist insects appear to differ in their ability to use these different types of adaptations: in generalists, adaptations are often inducible, whereas in specialists they are often constitutive. Future studies are suggested to investigate in detail how insect adaptations act in combination to overcome plant chemical defences and to allow ecologically relevant conclusions.

  11. Expression profiling of marker genes responsive to the defence-associated phytohormones salicylic acid, jasmonic acid and ethylene in Brachypodium distachyon.

    Science.gov (United States)

    Kouzai, Yusuke; Kimura, Mamiko; Yamanaka, Yurie; Watanabe, Megumi; Matsui, Hidenori; Yamamoto, Mikihiro; Ichinose, Yuki; Toyoda, Kazuhiro; Onda, Yoshihiko; Mochida, Keiichi; Noutoshi, Yoshiteru

    2016-03-02

    Brachypodium distachyon is a promising model plants for grasses. Infections of Brachypodium by various pathogens that severely impair crop production have been reported, and the species accordingly provides an alternative platform for investigating molecular mechanisms of pathogen virulence and plant disease resistance. To date, we have a broad picture of plant immunity only in Arabidopsis and rice; therefore, Brachypodium may constitute a counterpart that displays the commonality and uniqueness of defence systems among plant species. Phytohormones play key roles in plant biotic stress responses, and hormone-responsive genes are used to qualitatively and quantitatively evaluate disease resistance responses during pathogen infection. For these purposes, defence-related phytohormone marker genes expressed at time points suitable for defence-response monitoring are needed. Information about their expression profiles over time as well as their response specificity is also helpful. However, useful marker genes are still rare in Brachypodium. We selected 34 candidates for Brachypodium marker genes on the basis of protein-sequence similarity to known marker genes used in Arabidopsis and rice. Brachypodium plants were treated with the defence-related phytohormones salicylic acid, jasmonic acid and ethylene, and their transcription levels were measured 24 and 48 h after treatment. Two genes for salicylic acid, 7 for jasmonic acid and 2 for ethylene were significantly induced at either or both time points. We then focused on 11 genes encoding pathogenesis-related (PR) 1 protein and compared their expression patterns with those of Arabidopsis and rice. Phylogenetic analysis suggested that Brachypodium contains several PR1-family genes similar to rice genes. Our expression profiling revealed that regulation patterns of some PR1 genes as well as of markers identified for defence-related phytohormones are closely related to those in rice. We propose that the Brachypodium immune

  12. Effects of fudioxonil on Botrytis cinerea and on grapevine defence response

    Directory of Open Access Journals (Sweden)

    Anne-Noëlle PETIT

    2011-05-01

    Full Text Available Normal 0 14 false false false IT ZH-TW X-NONE MicrosoftInternetExplorer4 Botrytis bunch rot of grapes is mainly controlled by applying fungicides at three crop stages: the end of flowering (BBCH 68, bunch closure (BBCH 77 and the beginning of veraison (BBCH 81. The phenylpyrroles derivative fudioxonil is among the most effective fungicides registered to control Botrytis cinerea. Its effectiveness was investigated in relation to spray timing, fungicide resistance and defence responses of grapevine. Frequencies of B. cinerea strains which were resistant to fungicides were evaluated at harvest. The frequencies of resistant phenotypes were similar in all treatments except for a class of multidrug resistant strains (MDR 1 whose frequency increased after fudioxonil applications. None of the treatments tested induced defence responses in flowers/berries after fungicide application, suggesting that fudioxonil effectiveness was not related to a stimulation of plant defence processes. The standard program of three fungicide applications provided the best control of B. cinerea  in the Champagne region in comparison with a single treatment of fudioxonil at any of the crop stages tested.

  13. Trichoderma harzianum T-78 supplementation of compost stimulates the antioxidant defence system in melon plants.

    Science.gov (United States)

    Bernal-Vicente, Agustina; Pascual, José A; Tittarelli, Fabio; Hernández, José A; Diaz-Vivancos, Pedro

    2015-08-30

    Compost is emerging as an alternative plant growing medium in efforts to achieve more sustainable agriculture. The addition of specific microorganisms such as Trichoderma harzianum to plant growth substrates increases yields and reduces plant diseases, but the mechanisms of such biostimulants and the biocontrol effects are not yet fully understood. In this work we investigated how the addition of citrus and vineyard composts, either alone or in combination with T. harzianum T-78, affects the antioxidant defence system in melon plants under nursery conditions. Compost application and/or Trichoderma inoculation modulated the antioxidant defence system in melon plants. The combination of citrus compost and Trichoderma showed a biostimulant effect that correlated with an increase in ascorbate recycling enzymes (monodehydroascorbate reductase, dehydroascorbate reductase) and peroxidase. Moreover, the inoculation of both composts with Trichoderma increased the activity of antioxidant enzymes, especially those involved in ascorbate recycling. Based on the long-established relationship between ascorbic acid and plant defence responses as well as plant growth and development, it can be suggested that ascorbate recycling activities play a major role in the protection provided by Trichoderma and its biostimulant effect and that these outcomes are linked to increases in antioxidant enzymes. We can conclude that the combination of citrus compost and T. harzianum T-78 constitutes a viable, environmentally friendly strategy for improving melon plant production. © 2014 Society of Chemical Industry.

  14. Early season herbivore differentially affects plant defence responses to subsequently colonizing herbivores and their abundance in the field

    NARCIS (Netherlands)

    Poelman, E.H.; Broekgaarden, C.; Loon, van J.J.A.; Dicke, M.

    2008-01-01

    Induction of plant defences by early season herbivores can mediate interspecific herbivore competition. We have investigated plant-mediated competition between three herbivorous insects through studies at different levels of biological integration. We have addressed (i) gene expression; (ii) insect

  15. The evolution of plant chemical defence - new roles for hydroxynitrile glucosides in Lotus japonicus

    DEFF Research Database (Denmark)

    Knudsen, Camilla

    Plants are sessile organisms well-known to produce a vast array of chemical compounds of which many are used in chemical defence against herbivores and pathogens. The biosynthesis of these plant chemical defence compounds poses a considerable risk of self-toxicity for the plant itself. Several...... on hydroxynitrile glucoside metabolism in the legume model plant Lotus japonicus. Lotus japonicus produces both cyanogenic and non-cyanogenic hydroxynitrile glucosides as chemical defence compounds. The cyanogenic glucosides linamarin and lotaustralin are stored in the cell vacuole as inactive glycosides and, upon...... function and evolution. Further, it contributes to our understanding of the formation and role of biosynthetic gene clusters in plant chemical defence. The bifurcation in hydroxynitrile glucoside biosynthesis and catabolism observed in Lotus japonicus makes it a very suitable model system to study...

  16. Plant response to butterfly eggs

    NARCIS (Netherlands)

    Griese, Eddie; Dicke, Marcel; Hilker, Monika; Fatouros, Nina E.

    2017-01-01

    Plants employ various defences killing the insect attacker in an early stage. Oviposition by cabbage white butterflies (Pieris spp.) on brassicaceous plants, including Brassica nigra, induces a hypersensitive response (HR) - like leaf necrosis promoting desiccation of eggs. To gain a deeper insight

  17. Metabolic Engineering of Chemical Defence Pathways in Plant Disease Control

    DEFF Research Database (Denmark)

    Rook, Frederik

    2016-01-01

    on each topic. The chapter reviews the some of the scientific and technical challenges in metabolic engineering and the new possibilities emerging from recent technological developments. It concludes by discussing the outlook for bioengineered chemical defences as part of crop protection strategies, also...... with antimicrobial properties for use in crop protection. It presents an overview of the metabolic engineering efforts made in the area of plant chemical defence. For in-depth information on the characteristics of a specific class of chemical defence compounds, the reader is referred to the specialized reviews...

  18. Getting prepared for future attack : induction of plant defences by herbivore egg deposition and consequences for the insect community

    NARCIS (Netherlands)

    Pashalidou, F.G.

    2015-01-01

    Plants have evolved intriguing defences against insect herbivores. Compared to constitutive Plants have evolved intriguing defences against insect herbivores. Compared to constitutive defences that are always present, plants can respond with inducible defences when they are attacked. Insect

  19. Damage-associated responses of the host contribute to defence against cyst nematodes but not root-knot nematodes

    NARCIS (Netherlands)

    Shah, Syed Jehangir; Anjam, Muhammad Shahzad; Mendy, Badou; Anwer, Muhammad Arslan; Habash, Samer S.; Lozano-Torres, Jose L.; Grundler, Florian M.W.; Siddique, Shahid

    2017-01-01

    When nematodes invade and subsequently migrate within plant roots, they generate cell wall fragments (in the form of oligogalacturonides; OGs) that can act as damage-associated molecular patterns and activate host defence responses. However, the molecular mechanisms mediating damage responses in

  20. Specificity in Mesograzer-Induced Defences in Seagrasses.

    Directory of Open Access Journals (Sweden)

    Begoña Martínez-Crego

    Full Text Available Grazing-induced plant defences that reduce palatability to herbivores are widespread in terrestrial plants and seaweeds, but they have not yet been reported in seagrasses. We investigated the ability of two seagrass species to induce defences in response to direct grazing by three associated mesograzers. Specifically, we conducted feeding-assayed induction experiments to examine how mesograzer-specific grazing impact affects seagrass induction of defences within the context of the optimal defence theory. We found that the amphipod Gammarus insensibilis and the isopod Idotea chelipes exerted a low-intensity grazing on older blades of the seagrass Cymodocea nodosa, which reflects a weak grazing impact that may explain the lack of inducible defences. The isopod Synischia hectica exerted the strongest grazing impact on C. nodosa via high-intensity feeding on young blades with a higher fitness value. This isopod grazing induced defences in C. nodosa as indicated by a consistently lower consumption of blades previously grazed for 5, 12 and 16 days. The lower consumption was maintained when offered tissues with no plant structure (agar-reconstituted food, but showing a reduced size of the previous grazing effect. This indicates that structural traits act in combination with chemical traits to reduce seagrass palatability to the isopod. Increase in total phenolics but not in C:N ratio and total nitrogen of grazed C. nodosa suggests chemical defences rather than a modified nutritional quality as primarily induced chemical traits. We detected no induction of defences in Zostera noltei, which showed the ability to replace moderate losses of young biomass to mesograzers via compensatory growth. Our study provides the first experimental evidence of induction of defences against meso-herbivory that reduce further consumption in seagrasses. It also emphasizes the relevance of grazer identity in determining the level of grazing impact triggering resistance and

  1. Life-history constraints in grassland plant species: a growth-defence trade-off is the norm

    Science.gov (United States)

    E.M. Lind; E.T. Borer; E.W. Seabloom; P.B. Adler; J.D. Bakker; D.M. Blumenthal; M. Crawley; K.F. Davies; J. Firn; D.S. Gruner; S. Harpole; Y. Hautier; H. Hillebrand; J.M.H. Knops; B.A. Melbourne; B. Mortensen; A.C. Risch; M. Schuetz; C.J. Stevens; P.D. Wragg

    2013-01-01

    Plant growth can be limited by resource acquisition and defence against consumers, leading to contrasting trade-off possibilities. The competition-defence hypothesis posits a trade-off between competitive ability and defence against enemies (e.g. herbivores and pathogens). The growth-defence hypothesis suggests that strong competitors for nutrients are also defended...

  2. Infection biology and defence responses in sorghum against Colletotrichum sublineolum

    DEFF Research Database (Denmark)

    Puttalingaiah, Basavaraju; Shetty, Nandini Prasad; Shetty, H. S.

    2009-01-01

    Aims: To investigate the infection biology of Colletotrichum sublineolum (isolate CP2126) and defence responses in leaves of resistant (SC146), intermediately resistant (SC326) and susceptible (BTx623) sorghum genotypes. Methods and Results: Infection biology and defence responses were studied...

  3. Hexanoic acid protects tomato plants against Botrytis cinerea by priming defence responses and reducing oxidative stress.

    Science.gov (United States)

    Finiti, Ivan; de la O Leyva, María; Vicedo, Begonya; Gómez-Pastor, Rocío; López-Cruz, Jaime; García-Agustín, Pilar; Real, Maria Dolores; González-Bosch, Carmen

    2014-08-01

    Treatment with the resistance priming inducer hexanoic acid (Hx) protects tomato plants from Botrytis cinerea by activating defence responses. To investigate the molecular mechanisms underlying hexanoic acid-induced resistance (Hx-IR), we compared the expression profiles of three different conditions: Botrytis-infected plants (Inf), Hx-treated plants (Hx) and Hx-treated + infected plants (Hx+Inf). The microarray analysis at 24 h post-inoculation showed that Hx and Hx+Inf plants exhibited the differential expression and priming of many Botrytis-induced genes. Interestingly, we found that the activation by Hx of other genes was not altered by the fungus at this time point. These genes may be considered to be specific targets of the Hx priming effect and may help to elucidate its mechanisms of action. It is noteworthy that, in Hx and Hx+Inf plants, there was up-regulation of proteinase inhibitor genes, DNA-binding factors, enzymes involved in plant hormone signalling and synthesis, and, remarkably, the genes involved in oxidative stress. Given the relevance of the oxidative burst occurring in plant-pathogen interactions, the effect of Hx on this process was studied in depth. We showed by specific staining that reactive oxygen species (ROS) accumulation in Hx+Inf plants was reduced and more restricted around infection sites. In addition, these plants showed higher ratios of reduced to oxidized glutathione and ascorbate, and normal levels of antioxidant activities. The results obtained indicate that Hx protects tomato plants from B. cinerea by regulating and priming Botrytis-specific and non-specific genes, preventing the harmful effects of oxidative stress produced by infection. © 2013 BSPP AND JOHN WILEY & SONS LTD.

  4. The Xanthomonas campestris type III effector XopJ targets the host cell proteasome to suppress salicylic-acid mediated plant defence.

    Directory of Open Access Journals (Sweden)

    Suayib Üstün

    Full Text Available The phytopathogenic bacterium Xanthomonas campestris pv. vesicatoria (Xcv requires type III effector proteins (T3Es for virulence. After translocation into the host cell, T3Es are thought to interact with components of host immunity to suppress defence responses. XopJ is a T3E protein from Xcv that interferes with plant immune responses; however, its host cellular target is unknown. Here we show that XopJ interacts with the proteasomal subunit RPT6 in yeast and in planta to inhibit proteasome activity. A C235A mutation within the catalytic triad of XopJ as well as a G2A exchange within the N-terminal myristoylation motif abolishes the ability of XopJ to inhibit the proteasome. Xcv ΔxopJ mutants are impaired in growth and display accelerated symptom development including tissue necrosis on susceptible pepper leaves. Application of the proteasome inhibitor MG132 restored the ability of the Xcv ΔxopJ to attenuate the development of leaf necrosis. The XopJ dependent delay of tissue degeneration correlates with reduced levels of salicylic acid (SA and changes in defence- and senescence-associated gene expression. Necrosis upon infection with Xcv ΔxopJ was greatly reduced in pepper plants with reduced expression of NPR1, a central regulator of SA responses, demonstrating the involvement of SA-signalling in the development of XopJ dependent phenotypes. Our results suggest that XopJ-mediated inhibition of the proteasome interferes with SA-dependent defence response to attenuate onset of necrosis and to alter host transcription. A central role of the proteasome in plant defence is discussed.

  5. The wheat NB-LRR gene TaRCR1 is required for host defence response to the necrotrophic fungal pathogen Rhizoctonia cerealis.

    Science.gov (United States)

    Zhu, Xiuliang; Lu, Chungui; Du, Lipu; Ye, Xingguo; Liu, Xin; Coules, Anne; Zhang, Zengyan

    2017-06-01

    The necrotrophic fungus Rhizoctonia cerealis is the major pathogen causing sharp eyespot disease in wheat (Triticum aestivum). Nucleotide-binding leucine-rich repeat (NB-LRR) proteins often mediate plant disease resistance to biotrophic pathogens. Little is known about the role of NB-LRR genes involved in wheat response to R. cerealis. In this study, a wheat NB-LRR gene, named TaRCR1, was identified in response to R. cerealis infection using Artificial Neural Network analysis based on comparative transcriptomics and its defence role was characterized. The transcriptional level of TaRCR1 was enhanced after R. cerealis inoculation and associated with the resistance level of wheat. TaRCR1 was located on wheat chromosome 3BS and encoded an NB-LRR protein that was consisting of a coiled-coil domain, an NB-ARC domain and 13 imperfect leucine-rich repeats. TaRCR1 was localized in both the cytoplasm and the nucleus. Silencing of TaRCR1 impaired wheat resistance to R. cerealis, whereas TaRCR1 overexpression significantly increased the resistance in transgenic wheat. TaRCR1 regulated certain reactive oxygen species (ROS)-scavenging and production, and defence-related genes, and peroxidase activity. Furthermore, H 2 O 2 pretreatment for 12-h elevated expression levels of TaRCR1 and the above defence-related genes, whereas treatment with a peroxidase inhibitor for 12 h reduced the resistance of TaRCR1-overexpressing transgenic plants and expression levels of these defence-related genes. Taken together, TaRCR1 positively contributes to defence response to R. cerealis through maintaining ROS homoeostasis and regulating the expression of defence-related genes. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  6. Interactive effects of above- and belowground herbivory and plant competition on plant growth and defence

    NARCIS (Netherlands)

    Jing, Y.; Raaijmakers, C.; Kostenko, O.; Kos, M.; Mulder, P.P.J.; Bezemer, T.M.

    2015-01-01

    Competition and herbivory are two major factors that can influence plant growth and plant defence. Although these two factors are often studied separately, they do not operate independently. We examined how aboveground herbivory by beet armyworm larvae (Spodoptera exigua) and belowground herbivory

  7. The octadecanoid signalling pathway in plants mediates a response to ultraviolet radiation

    International Nuclear Information System (INIS)

    Conconi, A.; Smerdon, M.J.; Howe, G.A.; Ryan, C.A.

    1996-01-01

    Many plant genes that respond to environmental and developmental changes are regulated by jasmonic acid, which is derived from linolenic acid via the octadecanoid pathway. Linolenic acid is an important fatty-acid constituent of membranes in most plant species and its intracellular levels increase in response to certain signals. Here we report that irradiation of tomato leaves with ultraviolet light induces the expression of several plant defensive genes that are normally activated through the octadecanoid pathway after wounding. The response to ultraviolet light is blocked by an inhibitor of the octadecanoid pathway and it does not occur in a tomato mutant defective in this pathway. The ultraviolet irradiation maximally induces the defence genes at levels where cyclobutane pyrimidine dimer formation, an indicator of DNA damage, is less than 0.2 dimers per gene. Our evidence indicates that this plant defence response to certain wavelengths of ultraviolet radiation requires the activation of the octadecanoid defence signalling pathway. (author)

  8. Instar-specific sensitivity of specialist Manduca sexta larvae to induced defences in their host plant Nicotiana attenuata

    NARCIS (Netherlands)

    Van Dam, N.M.; Hermenau, U.; Baldwin, I.T.

    2001-01-01

    1. The time delay associated with the activation of induced defences is thought to be a liability for this type of defence because it allows herbivores to remove biomass before the defence is fully induced. When defences are costly and plants grow with competitors, however, it may be more

  9. Strategies to increase Vitamin C in plants: from plant defence perspective to food biofortification

    Directory of Open Access Journals (Sweden)

    Vittoria eLocato

    2013-05-01

    Full Text Available Vitamin C participates in several physiological processes, among others, immune stimulation, synthesis of collagen, hormones, neurotransmitters and iron absorption. Severe deficiency leads to scurvy, whereas a limited vitamin C intake causes general symptoms, such as increased susceptibility to infections, fatigue, insomnia and weight loss. Surprisingly vitamin C deficiencies are spread in both developing and developed countries, with the latter actually trying to overcome this lack through dietary supplements and food fortification. Therefore new strategies aimed to increase vitamin C in food plants would be of interest to improve human health. Interestingly, plants are not only living bioreactors for vitamin C production in optimal growing conditions, but also they can increase their vitamin C content as consequence of stress conditions. An overview of the different approaches aimed at increasing vitamin C level in plant food is given. They include genotype selection by classical breeding, bio-engineering and changes of the agronomic conditions, on the basis of the emerging concepts that plant can enhance vitamin C synthesis as part of defence responses.

  10. Fitness consequences of indirect plant defence in the annual weed, Sinapis arvensis

    NARCIS (Netherlands)

    Gols, R.; Wagenaar, R.; Poelman, E.H.; Kruidhof, H.M.; van Loon, J.J.A.; Harvey, J.A.

    2015-01-01

    Plant traits that enhance the attraction of the natural enemies of their herbivores have been postulated to function as an 'indirect defence'. An important underlying assumption is that this enhanced attraction results in increased plant fitness due to reduced herbivory. This assumption has been

  11. Uncovering the defence responses of Eucalyptus to pests and pathogens in the genomics age.

    Science.gov (United States)

    Naidoo, Sanushka; Külheim, Carsten; Zwart, Lizahn; Mangwanda, Ronishree; Oates, Caryn N; Visser, Erik A; Wilken, Febé E; Mamni, Thandekile B; Myburg, Alexander A

    2014-09-01

    Long-lived tree species are subject to attack by various pests and pathogens during their lifetime. This problem is exacerbated by climate change, which may increase the host range for pathogens and extend the period of infestation by pests. Plant defences may involve preformed barriers or induced resistance mechanisms based on recognition of the invader, complex signalling cascades, hormone signalling, activation of transcription factors and production of pathogenesis-related (PR) proteins with direct antimicrobial or anti-insect activity. Trees have evolved some unique defence mechanisms compared with well-studied model plants, which are mostly herbaceous annuals. The genome sequence of Eucalyptus grandis W. Hill ex Maiden has recently become available and provides a resource to extend our understanding of defence in large woody perennials. This review synthesizes existing knowledge of defence mechanisms in model plants and tree species and features mechanisms that may be important for defence in Eucalyptus, such as anatomical variants and the role of chemicals and proteins. Based on the E. grandis genome sequence, we have identified putative PR proteins based on sequence identity to the previously described plant PR proteins. Putative orthologues for PR-1, PR-2, PR-4, PR-5, PR-6, PR-7, PR-8, PR-9, PR-10, PR-12, PR-14, PR-15 and PR-17 have been identified and compared with their orthologues in Populus trichocarpa Torr. & A. Gray ex Hook and Arabidopsis thaliana (L.) Heynh. The survey of PR genes in Eucalyptus provides a first step in identifying defence gene targets that may be employed for protection of the species in future. Genomic resources available for Eucalyptus are discussed and approaches for improving resistance in these hardwood trees, earmarked as a bioenergy source in future, are considered. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Parasitism by Cuscuta pentagona sequentially induces JA and SA defence pathways in tomato.

    Science.gov (United States)

    Runyon, Justin B; Mescher, Mark C; Felton, Gary W; De Moraes, Consuelo M

    2010-02-01

    While plant responses to herbivores and pathogens are well characterized, responses to attack by other plants remain largely unexplored. We measured phytohormones and C(18) fatty acids in tomato attacked by the parasitic plant Cuscuta pentagona, and used transgenic and mutant plants to explore the roles of the defence-related phytohormones salicylic acid (SA) and jasmonic acid (JA). Parasite attachment to 10-day-old tomato plants elicited few biochemical changes, but a second attachment 10 d later elicited a 60-fold increase in JA, a 30-fold increase in SA and a hypersensitive-like response (HLR). Host age also influenced the response: neither Cuscuta seedlings nor established vines elicited a HLR in 10-day-old hosts, but both did in 20-day-old hosts. Parasites grew larger on hosts deficient in SA (NahG) or insensitive to JA [jasmonic acid-insensitive1 (jai1)], suggesting that both phytohormones mediate effective defences. Moreover, amounts of JA peaked 12 h before SA, indicating that defences may be coordinated via sequential induction of these hormones. Parasitism also induced increases in free linolenic and linoleic acids and abscisic acid. These findings provide the first documentation of plant hormonal signalling induced by a parasitic plant and show that tomato responses to C. pentagona display characteristics similar to both herbivore- and pathogen-induced responses.

  13. A defence in depth approach to safety assessment of existing nuclear power plant

    International Nuclear Information System (INIS)

    Butcher, P.; Holloway, N.J.

    1998-01-01

    The safety assessment of plant built to earlier standards requires an approach to prioritisation of upgrades that is based on sound engineering and safety principles. The principles of defence in depth are universally accepted and can form the basis of a prioritisation scheme for safety issues, and hence for the upgrading required to address them. The described scheme includes criteria for acceptability and issue prioritisation that are based on the number of lines of defence and the consequences of their failure. They are thus equivalent in concept to risk criteria, but are based on deterministic principles. This scheme has been applied successfully to the RBMK plant at Ignalina in Lithuania, for which a Western-style Safety Analysis Report has recently been produced and reviewed by joint Western and Eastern teams. An extended Safety Improvement Programme (SIP2) has been developed and agreed, based on prioritisations from the defence in depth assessment. (author)

  14. The Capsicum annuum class IV chitinase ChitIV interacts with receptor-like cytoplasmic protein kinase PIK1 to accelerate PIK1-triggered cell death and defence responses

    Science.gov (United States)

    Kim, Dae Sung; Kim, Nak Hyun; Hwang, Byung Kook

    2015-01-01

    The pepper receptor-like cytoplasmic protein kinase, CaPIK1, which mediates signalling of plant cell death and defence responses was previously identified. Here, the identification of a class IV chitinase, CaChitIV, from pepper plants (Capsicum annuum), which interacts with CaPIK1 and promotes CaPIK1-triggered cell death and defence responses, is reported. CaChitIV contains a signal peptide, chitin-binding domain, and glycol hydrolase domain. CaChitIV expression was up-regulated by Xanthomonas campestris pv. vesicatoria (Xcv) infection. Notably, avirulent Xcv infection rapidly induced CaChitIV expression in pepper leaves. Bimolecular fluorescence complementation and co-immunoprecipitation revealed that CaPIK1 interacts with CaChitIV in planta, and that the CaPIK1–CaChitIV complex is localized mainly in the cytoplasm and plasma membrane. CaChitIV is also localized in the endoplasmic reticulum. Transient co-expression of CaChitIV with CaPIK1 enhanced CaPIK1-triggered cell death response and reactive oxygen species (ROS) and nitric oxide (NO) bursts. Co-silencing of both CaChitIV and CaPIK1 in pepper plants conferred enhanced susceptibility to Xcv infection, which was accompanied by a reduced induction of cell death response, ROS and NO bursts, and defence response genes. Ectopic expression of CaPIK1 in Arabidopsis enhanced basal resistance to Hyaloperonospora arabidopsidis infection. Together, the results suggest that CaChitIV positively regulates CaPIK1-triggered cell death and defence responses through its interaction with CaPIK1. PMID:25694549

  15. Variation in the effectiveness of biotic defence: the case of an opportunistic ant-plant protection mutualism.

    Science.gov (United States)

    Giusto, Bruno; Anstett, Marie-Charlotte; Dounias, Edmond; McKey, Doyle B

    2001-11-01

    Benefits to plants in facultative ant protection mutualisms are highly variable. This allows examination of the sources of this variation and the mechanisms by which ants protect plants. We studied opportunistic interactions between ants and an extrafloral nectary-bearing vine, Dioscorea praehensilis, during 3 different years. Variation in plant protection among years was striking. Several factors affected the effectiveness of the biotic defence. Stems recently emerged from the underground tuber were self-supporting, contacting no other plants and encountering few foraging ants. Stems then became lianescent, and contact with supporting plants greatly increased ant recruitment. Both species and number of ant workers influenced the effect of ants on the major herbivore, the chrysomelid beetle Lilioceris latipennis. Protective actions included limitation of oviposition (reduction in the number of eggs laid on the plant) and predation, leading to increased larval mortality. The probability of successful predation was strongly dependent on larval size. If temporarily low ant-patrolling activity allows larvae to grow beyond a critical size, their mechanical (thick integument) or chemical (plant-derived compounds in a fecal shield) defences become more effective against ants. Secondary metabolites derived from the host plant thus appear to be important for the anti-predator mechanisms of this beetle, being necessary for its survival and reproduction on a host plant that actively recruits ants as a biotic defence against herbivores.

  16. Parasitism by Cuscuta pentagona sequentially induces JA and SA defence pathways in tomato

    Science.gov (United States)

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

    2010-01-01

    While plant responses to herbivores and pathogens are well characterized, responses to attack by other plants remain largely unexplored. We measured phytohormones and C18 fatty acids in tomato attacked by the parasitic plant Cuscuta pentagona, and used transgenic and mutant plants to explore the roles of the defence-related phytohormones salicylic...

  17. A novel Meloidogyne graminicola effector, MgMO237, interacts with multiple host defence-related proteins to manipulate plant basal immunity and promote parasitism.

    Science.gov (United States)

    Chen, Jiansong; Hu, Lili; Sun, Longhua; Lin, Borong; Huang, Kun; Zhuo, Kan; Liao, Jinling

    2018-02-27

    Plant-parasitic nematodes can secrete effector proteins into the host tissue to facilitate their parasitism. In this study, we report a novel effector protein, MgMO237, from Meloidogyne graminicola, which is exclusively expressed within the dorsal oesophageal gland cell and markedly up-regulated in parasitic third-/fourth-stage juveniles of M. graminicola. Transient expression of MgMO237 in protoplasts from rice roots showed that MgMO237 was localized in the cytoplasm and nucleus of the host cells. Rice plants overexpressing MgMO237 showed an increased susceptibility to M. graminicola. In contrast, rice plants expressing RNA interference vectors targeting MgMO237 showed an increased resistance to M. graminicola. In addition, yeast two-hybrid and co-immunoprecipitation assays showed that MgMO237 interacted specifically with three rice endogenous proteins, i.e. 1,3-β-glucan synthase component (OsGSC), cysteine-rich repeat secretory protein 55 (OsCRRSP55) and pathogenesis-related BetvI family protein (OsBetvI), which are all related to host defences. Moreover, MgMO237 can suppress host defence responses, including the expression of host defence-related genes, cell wall callose deposition and the burst of reactive oxygen species. These results demonstrate that the effector MgMO237 probably promotes the parasitism of M. graminicola by interacting with multiple host defence-related proteins and suppressing plant basal immunity in the later parasitic stages of nematodes. © 2018 BSPP AND JOHN WILEY & SONS LTD.

  18. Jasmonate-deficient plants have reduced direct and indirect defences against herbivores

    NARCIS (Netherlands)

    Thaler, J.S.; Farag, M.A.; Paré, P.W.; Dicke, M.

    2002-01-01

    Plants employ a variety of defence mechanisms, some of which act directly by having a negative effect on herbivores and others that act indirectly by attracting natural enemies of herbivores. In this study we asked if a common jasmonate-signalling pathway links the regulation of direct and indirect

  19. Thrips advisor: exploiting thrips-induced defences to combat pests on crops.

    Science.gov (United States)

    Steenbergen, Merel; Abd-El-Haliem, Ahmed; Bleeker, Petra; Dicke, Marcel; Escobar-Bravo, Rocio; Cheng, Gang; Haring, Michel A; Kant, Merijn R; Kappers, Iris; Klinkhamer, Peter G L; Leiss, Kirsten A; Legarrea, Saioa; Macel, Mirka; Mouden, Sanae; Pieterse, Corné M J; Sarde, Sandeep J; Schuurink, Robert C; De Vos, Martin; Van Wees, Saskia C M; Broekgaarden, Colette

    2018-04-09

    Plants have developed diverse defence mechanisms to ward off herbivorous pests. However, agriculture still faces estimated crop yield losses ranging from 25% to 40% annually. These losses arise not only because of direct feeding damage, but also because many pests serve as vectors of plant viruses. Herbivorous thrips (Thysanoptera) are important pests of vegetable and ornamental crops worldwide, and encompass virtually all general problems of pests: they are highly polyphagous, hard to control because of their complex lifestyle, and they are vectors of destructive viruses. Currently, control management of thrips mainly relies on the use of chemical pesticides. However, thrips rapidly develop resistance to these pesticides. With the rising demand for more sustainable, safer, and healthier food production systems, we urgently need to pinpoint the gaps in knowledge of plant defences against thrips to enable the future development of novel control methods. In this review, we summarize the current, rather scarce, knowledge of thrips-induced plant responses and the role of phytohormonal signalling and chemical defences in these responses. We describe concrete opportunities for breeding resistance against pests such as thrips as a prototype approach for next-generation resistance breeding.

  20. The bile acid deoxycholate elicits defences in Arabidopsis and reduces bacterial infection.

    Science.gov (United States)

    Zarattini, Marco; Launay, Alban; Farjad, Mahsa; Wénès, Estelle; Taconnat, Ludivine; Boutet, Stéphanie; Bernacchia, Giovanni; Fagard, Mathilde

    2017-05-01

    Disease has an effect on crop yields, causing significant losses. As the worldwide demand for agricultural products increases, there is a need to pursue the development of new methods to protect crops from disease. One mechanism of plant protection is through the activation of the plant immune system. By exogenous application, 'plant activator molecules' with elicitor properties can be used to activate the plant immune system. These defence-inducing molecules represent a powerful and often environmentally friendly tool to fight pathogens. We show that the secondary bile acid deoxycholic acid (DCA) induces defence in Arabidopsis and reduces the proliferation of two bacterial phytopathogens: Erwinia amylovora and Pseudomonas syringae pv. tomato. We describe the global defence response triggered by this new plant activator in Arabidopsis at the transcriptional level. Several induced genes were selected for further analysis by quantitative reverse transcription-polymerase chain reaction. We describe the kinetics of their induction and show that abiotic stress, such as moderate drought or nitrogen limitation, does not impede DCA induction of defence. Finally, we investigate the role in the activation of defence by this bile acid of the salicylic acid biosynthesis gene SID2, of the receptor-like kinase family genes WAK1-3 and of the NADPH oxidase-encoding RbohD gene. Altogether, we show that DCA constitutes a promising molecule for plant protection which can induce complementary lines of defence, such as callose deposition, reactive oxygen species accumulation and the jasmonic acid and salicylic acid signalling pathways. © 2016 BSPP AND JOHN WILEY & SONS LTD.

  1. Plant parasitic nematode effectors target host defence and nuclear functions to establish feeding cells

    Directory of Open Access Journals (Sweden)

    Michaël eQuentin

    2013-03-01

    Full Text Available Plant parasitic nematodes are microscopic worms, the most damaging species of which have adopted a sedentary lifestyle within their hosts. These obligate endoparasites have a biotrophic relationship with plants, in which they induce the differentiation of root cells into hypertrophied, multinucleate feeding cells. Effectors synthesised in the oesophageal glands of the nematode are injected into the plant cells via the syringe-like stylet and play a key role in manipulating the host machinery. The establishment of specialized feeding cells requires these effectors to modulate many aspects of plant cell morphogenesis and physiology, including defence responses. This cell reprogramming requires changes to host nuclear processes. Some proteins encoded by parasitism genes target host nuclei. Several of these proteins were immunolocalised within feeding cell nuclei or shown to interact with host nuclear proteins. Comparative genomics and functional analyses are gradually revealing the roles of nematode effectors. We describe here these effectors and their hypothesised roles in the unique feeding behaviour of these pests.

  2. A cellular backline: specialization of host membranes for defence.

    Science.gov (United States)

    Faulkner, Christine

    2015-03-01

    In plant-pathogen interactions, the host plasma membrane serves as a defence front for pathogens that invade from the extracellular environment. As such, the lipid bilayer acts as a scaffold that targets and delivers defence responses to the site of attack. During pathogen infection, numerous changes in plasma membrane composition, organization, and structure occur. There is increasing evidence that this facilitates the execution of a variety of responses, highlighting the regulatory role membranes play in cellular responses. Membrane microdomains such as lipid rafts are hypothesized to create signalling platforms for receptor signalling in response to pathogen perception and for callose synthesis. Further, the genesis of pathogen-associated structures such as papillae and the extra-haustorial membrane necessitates polarization of membranes and membrane trafficking pathways. Unlocking the mechanisms by which this occurs will enable greater understanding of how targeted defences, some of which result in resistance, are executed. This review will survey some of the changes that occur in host membranes during pathogen attack and how these are associated with the generation of defence responses. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  3. Chemical defences against herbivores

    DEFF Research Database (Denmark)

    Pavia, Henrik; Baumgartner, Finn; Cervin, Gunnar

    2012-01-01

    This chapter focuses on the recent and emerging research involving chemical defences against herbivory in aquatic primary producers. It provides an overview of plant chemical defence theories and highlights recent research on aquatic primary producers addressing a number of aspects...... of these theories, concluding with new chemical approaches to tackle the questions and suggestions for future research directions. It explains that aquatic primary producers are a taxonomically and functionally diverse group of organisms that includes macroalgae, microalgae, and vascular plants. It also states...... that despite the fact that aquatic primary producers constitute a large and diverse group of organisms that vary in their evolutionary histories, selection for chemical defences to resist or reduce grazing are commonplace across the phylogenetic boundaries....

  4. Plasma membrane order and fluidity are diversely triggered by elicitors of plant defence.

    Science.gov (United States)

    Sandor, Roman; Der, Christophe; Grosjean, Kevin; Anca, Iulia; Noirot, Elodie; Leborgne-Castel, Nathalie; Lochman, Jan; Simon-Plas, Françoise; Gerbeau-Pissot, Patricia

    2016-09-01

    Although plants are exposed to a great number of pathogens, they usually defend themselves by triggering mechanisms able to limit disease development. Alongside signalling events common to most such incompatible interactions, modifications of plasma membrane (PM) physical properties could be new players in the cell transduction cascade. Different pairs of elicitors (cryptogein, oligogalacturonides, and flagellin) and plant cells (tobacco and Arabidopsis) were used to address the issue of possible modifications of plant PM biophysical properties induced by elicitors and their links to other events of the defence signalling cascade. We observed an increase of PM order whatever the elicitor/plant cell pair used, provided that a signalling cascade was induced. Such membrane modification is dependent on the NADPH oxidase-mediated reactive oxygen species production. Moreover, cryptogein, which is the sole elicitor able to trap sterols, is also the only one able to trigger an increase in PM fluidity. The use of cryptogein variants with altered sterol-binding properties confirms the strong correlation between sterol removal from the PM and PM fluidity enhancement. These results propose PM dynamics as a player in early signalling processes triggered by elicitors of plant defence. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  5. Evading plant defence: Infestation of poisonous milkweed fruits (Asclepiadaceae) by the fruit fly Dacus siliqualactis (Diptera: Tephritidae).

    Science.gov (United States)

    Schneider, Michael; Wunder, Cora; Reuss, Esther; Toennes, Stefan W; Mebs, Dietrich

    2017-12-01

    To cope with toxic metabolites plants use for defence, herbivorous insects employ various adaptive strategies. For oviposition, the fruit fly Dacus siliqualactis (Tephritidae) uses milkweed plants of the genus Gomphocarpus (Asclepiadaceae) by circumventing the plant's physical (gluey latex) and chemical (toxic cadenolides) defence. With its long, telescope-like ovipositor, the fly penetrates the exo- and endocarp of the fruit and places the eggs on the unripe seeds located in the centre of the fruit. Whereas most plant parts contain high concentrations of cardenolides such as gomphoside, calotropin/calacatin and gomphogenin, only the seeds exhibit low cardenolide levels. By surmounting physical barriers (fruit membranes, latex), the fly secures a safe environment and a latex-free food source of low toxicity for the developing larvae. One amino acid substitution (Q111V) at the cardenolide binding site of the fly's Na + , K + -ATPase was detected, but the significance of that substitution: reducing cardenolide sensitivity or not, is unclear. However, poisoning of the larvae by low levels of cardenolides is assumed to be prevented by non-resorption and excretion of the polar cardenolides, which cannot passively permeate the midgut membrane. This example of an insect-plant interaction demonstrates that by morphological and behavioural adaptation, a fruit fly manages to overcome even highly effective defence mechanisms of its host plant. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Early herbivore alert matters: plant-mediated effects of egg deposition on higher trophic levels benefit plant fitness

    NARCIS (Netherlands)

    Pashalidou, F.G.; Frago, E.; Griese, E.; Poelman, E.H.; Loon, van J.J.A.; Dicke, M.; Fatouros, N.E.

    2015-01-01

    Induction of plant defences, specifically in response to herbivore attack, can save costs that would otherwise be needed to maintain defences even in the absence of herbivores. However, plants may suffer considerable damage during the time required to mount these defences against an attacker. This

  7. Phenylpropanoid Defences in Nicotiana tabacum Cells: Overlapping Metabolomes Indicate Common Aspects to Priming Responses Induced by Lipopolysaccharides, Chitosan and Flagellin-22.

    Directory of Open Access Journals (Sweden)

    Msizi I Mhlongo

    Full Text Available Plants have evolved both constitutive and inducible defence strategies to cope with different biotic stimuli and stresses. Exposure of a plant to a challenging stress can lead to a primed state that allows it to launch a more rapid and stronger defence. Here we applied a metabolomic approach to study and compare the responses induced in Nicotiana tabacum cells by microbe-associated molecular pattern (MAMP molecules, namely lipopolysaccharides (LPS, chitosan (CHT and flagellin-22 (FLG22. Early response metabolites, extracted with methanol, were analysed by UHPLC-MS/MS. Using multivariate statistical tools the metabolic profiles induced by these elicitors were analysed. In the metabolic fingerprint of these agents a total of 19 cinnamic acid derivatives conjugated to quinic acids (chlorogenic acids, shikimic acid, tyramine, polyamines or glucose were found as discriminant biomarkers. In addition, treatment with the phytohormones salicylic acid (SA, methyljasmonic acid (MJ and abscisic acid (ABA resulted in differentially-induced phenylpropanoid pathway metabolites. The results indicate that the phenylpropanoid pathway is activated by these elicitors while hydroxycinnamic acid derivatives are commonly associated with the metabolic response to the MAMPs, and that the activated responses are modulated by both SA and MJ, with ABA not playing a role.

  8. The role of thionins in rice defence against root pathogens.

    Science.gov (United States)

    Ji, Hongli; Gheysen, Godelieve; Ullah, Chhana; Verbeek, Ruben; Shang, Chenjing; De Vleesschauwer, David; Höfte, Monica; Kyndt, Tina

    2015-10-01

    Thionins are antimicrobial peptides that are involved in plant defence. Here, we present an in-depth analysis of the role of rice thionin genes in defence responses against two root pathogens: the root-knot nematode Meloidogyne graminicola and the oomycete Pythium graminicola. The expression of rice thionin genes was observed to be differentially regulated by defence-related hormones, whereas all analysed genes were consistently down-regulated in M. graminicola-induced galls, at least until 7 days post-inoculation (dpi). Transgenic lines of Oryza sativa cv. Nipponbare overproducing OsTHI7 revealed decreased susceptibility to M. graminicola infection and P. graminicola colonization. Taken together, these results demonstrate the role of rice thionin genes in defence against two of the most damaging root pathogens attacking rice. © 2015 BSPP AND JOHN WILEY & SONS LTD.

  9. Arbuscular Mycorrhizal Fungi and Plant Chemical Defence: Effects of Colonisation on Aboveground and Belowground Metabolomes.

    Science.gov (United States)

    Hill, Elizabeth M; Robinson, Lynne A; Abdul-Sada, Ali; Vanbergen, Adam J; Hodge, Angela; Hartley, Sue E

    2018-02-01

    Arbuscular mycorrhizal fungal (AMF) colonisation of plant roots is one of the most ancient and widespread interactions in ecology, yet the systemic consequences for plant secondary chemistry remain unclear. We performed the first metabolomic investigation into the impact of AMF colonisation by Rhizophagus irregularis on the chemical defences, spanning above- and below-ground tissues, in its host-plant ragwort (Senecio jacobaea). We used a non-targeted metabolomics approach to profile, and where possible identify, compounds induced by AMF colonisation in both roots and shoots. Metabolomics analyses revealed that 33 compounds were significantly increased in the root tissue of AMF colonised plants, including seven blumenols, plant-derived compounds known to be associated with AMF colonisation. One of these was a novel structure conjugated with a malonyl-sugar and uronic acid moiety, hitherto an unreported combination. Such structural modifications of blumenols could be significant for their previously reported functional roles associated with the establishment and maintenance of AM colonisation. Pyrrolizidine alkaloids (PAs), key anti-herbivore defence compounds in ragwort, dominated the metabolomic profiles of root and shoot extracts. Analyses of the metabolomic profiles revealed an increase in four PAs in roots (but not shoots) of AMF colonised plants, with the potential to protect colonised plants from below-ground organisms.

  10. Polymorphism at selected defence gene analogs (DGAs) of Musa ...

    African Journals Online (AJOL)

    One of the major diseases affecting banana is Sigatoka or leaf spot disease that comprises three species, Mycosphaerella fijiensis, Mycosphaerella musicola and Mycosphaerella eumusae. Plants have a large number of defence related genes which trigger a cascade of defense responses that halt the spread of pathogens.

  11. 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

  12. Application of glycerol as a foliar spray activates the defence response and enhances disease resistance of Theobroma cacao.

    Science.gov (United States)

    Zhang, Yufan; Smith, Philip; Maximova, Siela N; Guiltinan, Mark J

    2015-01-01

    Previous work has implicated glycerol-3-phosphate (G3P) as a mobile inducer of systemic immunity in plants. We tested the hypothesis that the exogenous application of glycerol as a foliar spray might enhance the disease resistance of Theobroma cacao through the modulation of endogenous G3P levels. We found that exogenous application of glycerol to cacao leaves over a period of 4 days increased the endogenous level of G3P and decreased the level of oleic acid (18:1). Reactive oxygen species (ROS) were produced (a marker of defence activation) and the expression of many pathogenesis-related genes was induced. Notably, the effects of glycerol application on G3P and 18:1 fatty acid content, and gene expression levels, in cacao leaves were dosage dependent. A 100 mm glycerol spray application was sufficient to stimulate the defence response without causing any observable damage, and resulted in a significantly decreased lesion formation by the cacao pathogen Phytophthora capsici; however, a 500 mm glycerol treatment led to chlorosis and cell death. The effects of glycerol treatment on the level of 18:1 and ROS were constrained to the locally treated leaves without affecting distal tissues. The mechanism of the glycerol-mediated defence response in cacao and its potential use as part of a sustainable farming system are discussed. © 2014 BSPP AND JOHN WILEY & SONS LTD.

  13. Soil microbial species loss affects plant biomass and survival of an introduced bacterial strain, but not inducible plant defences.

    Science.gov (United States)

    Kurm, Viola; van der Putten, Wim H; Pineda, Ana; Hol, W H Gera

    2018-02-12

    Plant growth-promoting rhizobacteria (PGPR) strains can influence plant-insect interactions. However, little is known about the effect of changes in the soil bacterial community in general and especially the loss of rare soil microbes on these interactions. Here, the influence of rare soil microbe reduction on induced systemic resistance (ISR) in a wild ecotype of Arabidopsis thaliana against the aphid Myzus persicae was investigated. To create a gradient of microbial abundances, soil was inoculated with a serial dilution of a microbial community and responses of Arabidopsis plants that originated from the same site as the soil microbes were tested. Plant biomass, transcription of genes involved in plant defences, and insect performance were measured. In addition, the effects of the PGPR strain Pseudomonas fluorescens SS101 on plant and insect performance were tested under the influence of the various soil dilution treatments. Plant biomass showed a hump-shaped relationship with soil microbial community dilution, independent of aphid or Pseudomonas treatments. Both aphid infestation and inoculation with Pseudomonas reduced plant biomass, and led to downregulation of PR1 (salicylic acid-responsive gene) and CYP79B3 (involved in synthesis of glucosinolates). Aphid performance and gene transcription were unaffected by soil dilution. Neither the loss of rare microbial species, as caused by soil dilution, nor Pseudomonas affect the resistance of A. thaliana against M. persicae. However, both Pseudomonas survival and plant biomass respond to rare species loss. Thus, loss of rare soil microbial species can have a significant impact on both above- and below-ground organisms. © The Author(s) 2018. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. The multiple strategies of an insect herbivore to overcome plant cyanogenic glucoside defence

    DEFF Research Database (Denmark)

    Pentzold, Stefan; Zagrobelny, Mika; Roelsgaard, Pernille Sølvhøj

    2014-01-01

    Cyanogenic glucosides (CNglcs) are widespread plant defence compounds that release toxic hydrogen cyanide by plant bglucosidase activity after tissue damage. Specialised insect herbivores have evolved counter strategies and some sequester CNglcs, but the underlying mechanisms to keep CNglcs intact...... during feeding and digestion are unknown. We show that CNglc-sequestering Zygaena filipendulae larvae combine behavioural, morphological, physiological and biochemical strategies at different time points during feeding and digestion to avoid toxic hydrolysis of the CNglcs present in their Lotus food...

  15. Can Plant Defence Mechanisms Provide New Approaches for the Sustainable Control of the Two-Spotted Spider Mite Tetranychus urticae?

    Directory of Open Access Journals (Sweden)

    Blas Agut

    2018-02-01

    Full Text Available Tetranychus urticae (T. urticae Koch is a cosmopolitan, polyphagous mite which causes economic losses in both agricultural and ornamental plants. Some traits of T. urticae hamper its management, including a short life cycle, arrhenotokous parthenogenesis, its haplodiploid sex determination system, and its extraordinary ability to adapt to different hosts and environmental conditions. Currently, the use of chemical and biological control are the major control methods used against this mite. In recent years, some studies have focused on plant defence mechanisms against herbivores. Various families of plant compounds (such as flavonoids, glucosinolates, or acyl sugars have been shown to behave as acaricides. Plants can be induced upon appropriate stimuli to increase their resistance against spider mites. This knowledge, together with the understanding of mechanisms by which T. urticae detoxifies and adapts to pesticides, may complement the control of this pest. Herein, we describe plant volatile compounds (VOCs with repellent activity, and new findings about defence priming against spider mites, which interfere with the T. urticae performance. The use of VOCs and defence priming can be integrated into current management practices and reduce the damage caused by T. urticae in the field by implementing new, more sustainable crop management tools.

  16. Damage-associated responses of the host contribute to defence against cyst nematodes but not root-knot nematodes.

    Science.gov (United States)

    Shah, Syed Jehangir; Anjam, Muhammad Shahzad; Mendy, Badou; Anwer, Muhammad Arslan; Habash, Samer S; Lozano-Torres, Jose L; Grundler, Florian M W; Siddique, Shahid

    2017-12-16

    When nematodes invade and subsequently migrate within plant roots, they generate cell wall fragments (in the form of oligogalacturonides; OGs) that can act as damage-associated molecular patterns and activate host defence responses. However, the molecular mechanisms mediating damage responses in plant-nematode interactions remain unexplored. Here, we characterized the role of a group of cell wall receptor proteins in Arabidopsis, designated as polygalacturonase-inhibiting proteins (PGIPs), during infection with the cyst nematode Heterodera schachtii and the root-knot nematode Meloidogyne incognita. PGIPs are encoded by a family of two genes in Arabidopsis, and are involved in the formation of active OG elicitors. Our results show that PGIP gene expression is strongly induced in response to cyst nematode invasion of roots. Analyses of loss-of-function mutants and overexpression lines revealed that PGIP1 expression attenuates infection of host roots by cyst nematodes, but not root-knot nematodes. The PGIP1-mediated attenuation of cyst nematode infection involves the activation of plant camalexin and indole-glucosinolate pathways. These combined results provide new insights into the molecular mechanisms underlying plant damage perception and response pathways during infection by cyst and root-knot nematodes, and establishes the function of PGIP in plant resistance to cyst nematodes. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  17. The roles of plant phenolics in defence and communication during Agrobacterium and Rhizobium infection.

    Science.gov (United States)

    Bhattacharya, Amita; Sood, Priyanka; Citovsky, Vitaly

    2010-09-01

    Phenolics are aromatic benzene ring compounds with one or more hydroxyl groups produced by plants mainly for protection against stress. The functions of phenolic compounds in plant physiology and interactions with biotic and abiotic environments are difficult to overestimate. Phenolics play important roles in plant development, particularly in lignin and pigment biosynthesis. They also provide structural integrity and scaffolding support to plants. Importantly, phenolic phytoalexins, secreted by wounded or otherwise perturbed plants, repel or kill many microorganisms, and some pathogens can counteract or nullify these defences or even subvert them to their own advantage. In this review, we discuss the roles of phenolics in the interactions of plants with Agrobacterium and Rhizobium.

  18. Do induced responses mediate the ecological interactions between the specialist herbivores and phytopathogens of an alpine plant?

    Science.gov (United States)

    Röder, Gregory; Rahier, Martine; Naisbit, Russell E

    2011-05-04

    Plants are not passive victims of the myriad attackers that rely on them for nutrition. They have a suite of physical and chemical defences, and are even able to take advantage of the enemies of their enemies. These strategies are often only deployed upon attack, so may lead to indirect interactions between herbivores and phytopathogens. In this study we test for induced responses in wild populations of an alpine plant (Adenostyles alliariae) that possesses constitutive chemical defence (pyrrolizidine alkaloids) and specialist natural enemies (two species of leaf beetle, Oreina elongata and Oreina cacaliae, and the phytopathogenic rust Uromyces cacaliae). Plants were induced in the field using chemical elicitors of the jasmonic acid (JA) and salicylic acid (SA) pathways and monitored for one month under natural conditions. There was evidence for induced resistance, with lower probability and later incidence of attack by beetles in JA-induced plants and of rust infection in SA-induced plants. We also demonstrate ecological cross-effects, with reduced fungal attack following JA-induction, and a cost of SA-induction arising from increased beetle attack. As a result, there is the potential for negative indirect effects of the beetles on the rust, while in the field the positive indirect effect of the rust on the beetles appears to be over-ridden by direct effects on plant nutritional quality. Such interactions resulting from induced susceptibility and resistance must be considered if we are to exploit plant defences for crop protection using hormone elicitors or constitutive expression. More generally, the fact that induced defences are even found in species that possess constitutively-expressed chemical defence suggests that they may be ubiquitous in higher plants.

  19. Do induced responses mediate the ecological interactions between the specialist herbivores and phytopathogens of an alpine plant?

    Directory of Open Access Journals (Sweden)

    Gregory Röder

    2011-05-01

    Full Text Available Plants are not passive victims of the myriad attackers that rely on them for nutrition. They have a suite of physical and chemical defences, and are even able to take advantage of the enemies of their enemies. These strategies are often only deployed upon attack, so may lead to indirect interactions between herbivores and phytopathogens. In this study we test for induced responses in wild populations of an alpine plant (Adenostyles alliariae that possesses constitutive chemical defence (pyrrolizidine alkaloids and specialist natural enemies (two species of leaf beetle, Oreina elongata and Oreina cacaliae, and the phytopathogenic rust Uromyces cacaliae. Plants were induced in the field using chemical elicitors of the jasmonic acid (JA and salicylic acid (SA pathways and monitored for one month under natural conditions. There was evidence for induced resistance, with lower probability and later incidence of attack by beetles in JA-induced plants and of rust infection in SA-induced plants. We also demonstrate ecological cross-effects, with reduced fungal attack following JA-induction, and a cost of SA-induction arising from increased beetle attack. As a result, there is the potential for negative indirect effects of the beetles on the rust, while in the field the positive indirect effect of the rust on the beetles appears to be over-ridden by direct effects on plant nutritional quality. Such interactions resulting from induced susceptibility and resistance must be considered if we are to exploit plant defences for crop protection using hormone elicitors or constitutive expression. More generally, the fact that induced defences are even found in species that possess constitutively-expressed chemical defence suggests that they may be ubiquitous in higher plants.

  20. Effects of antimony on redox activities and antioxidant defence systems in sunflower (Helianthus annuus L. plants.

    Directory of Open Access Journals (Sweden)

    Alfonso Ortega

    Full Text Available The alterations induced by the toxicity of antimony (Sb in the roots and leaves of sunflower plants were determined. The plants were grown hydroponically with different concentrations of Sb, a heavy metal which reduces biomass production and growth. There was preferential accumulation of Sb in the tissues of the roots, with the concentrations in the leaves being much lower. The accumulation of other mineral elements was also altered, especially that of Fe and Zn. Chlorophyll content declined, as also did the photosynthetic efficiency, but the carotenoid content remained unaltered. The total content of phenolics, flavonoids, and phenylpropanoid glycosides rose, evidence of their participation in the defence response. Increases were observed in the amount of superoxide anion in both roots and leaves, and in lipid peroxidation levels, especially with the highest Sb concentration of 1.0 mM. The induced oxidative stress leads to a strong increase in the SOD, POX and APX antioxidant activities, while the GR activity was only increased in the leaves and at the 1.0 mM Sb concentration. In contrast, the DHAR activity increased considerably in both organs. The GSNOR activity increased only in roots, and the total RSNOs increased. The total amount of AsA + DHA increased in roots and remained unaltered in leaves, whereas that of GSH + GSSG decreased considerably in all cases. As a whole, these results are evidence for the development of a strong oxidative stress induced by Sb, with there being a clear imbalance in the content of the compounds that constitute the AsA/GSH cycle. 0.5 mM Sb enhances GST expression, especially in leaves. This, together with the increase that was observed in the amount of GSH, may play an important part in detoxification. This oxidative stress affects both the phenolic and the ROS/RNS metabolic processes, which seems to implicate their involvement in the plant's defence and response to the stress.

  1. Ecological mechanisms for the coevolution of mating systems and defence.

    Science.gov (United States)

    Campbell, Stuart A

    2015-02-01

    The diversity of flowering plants is evident in two seemingly unrelated aspects of life history: sexual reproduction, exemplified by the stunning variation in flower form and function, and defence, often in the form of an impressive arsenal of secondary chemistry. Researchers are beginning to appreciate that plant defence and reproduction do not evolve independently, but, instead, may have reciprocal and interactive (coevolutionary) effects on each other. Understanding the mechanisms for mating-defence interactions promises to broaden our understanding of how ecological processes can generate these two rich sources of angiosperm diversity. Here, I review current research on the role of herbivory as a driver of mating system evolution, and the role of mating systems in the evolution of defence strategies. I outline different ecological mechanisms and processes that could generate these coevolutionary patterns, and summarize theoretical and empirical support for each. I provide a conceptual framework for linking plant defence with mating system theory to better integrate these two research fields.

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

    Directory of Open Access Journals (Sweden)

    Daniel M Mutyambai

    C. sesamiae parasitic wasps indicated that these parasitoids preferred volatiles from oviposited and neighbouring landrace plants compared to those from the control plants. This effect was absent in the standard commercial hybrid we tested. There was no HIPV induction and no difference in parasitoid attraction in neighbouring and control hybrid maize plants. These results show plant-plant signalling: 'Nyamula' maize plants emitting oviposition-induced volatiles attractive to the herbivore's natural enemies can induce this indirect defence trait in conspecific neighbouring undamaged maize plants. Maize plants growing in a field may thus benefit from this indirect defence through airborne signalling which may enhance the fitness of the volatile-emitting plant by increasing predation pressure on herbivores.

  3. The dual nature of trehalose in citrus canker disease: a virulence factor for Xanthomonas citri subsp. citri and a trigger for plant defence responses

    KAUST Repository

    Piazza, A.

    2015-03-14

    Xanthomonas citri subsp. citri (Xcc) is a bacterial pathogen that causes citrus canker in susceptible Citrus spp. The Xcc genome contains genes encoding enzymes from three separate pathways of trehalose biosynthesis. Expression of genes encoding trehalose-6-phosphate synthase (otsA) and trehalose phosphatase (otsB) was highly induced during canker development, suggesting that the two-step pathway of trehalose biosynthesis via trehalose-6-phosphate has a function in pathogenesis. This pathway was eliminated from the bacterium by deletion of the otsA gene. The resulting XccΔotsA mutant produced less trehalose than the wild-type strain, was less resistant to salt and oxidative stresses, and was less able to colonize plant tissues. Gene expression and proteomic analyses of infected leaves showed that infection with XccΔotsA triggered only weak defence responses in the plant compared with infection with Xcc, and had less impact on the host plant\\'s metabolism than the wild-type strain. These results suggested that trehalose of bacterial origin, synthesized via the otsA-otsB pathway, in Xcc, plays a role in modifying the host plant\\'s metabolism to its own advantage but is also perceived by the plant as a sign of pathogen attack. Thus, trehalose biosynthesis has both positive and negative consequences for Xcc. On the one hand, it enables this bacterial pathogen to survive in the inhospitable environment of the leaf surface before infection and exploit the host plant\\'s resources after infection, but on the other hand, it is a tell-tale sign of the pathogen\\'s presence that triggers the plant to defend itself against infection. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  4. Accident management-defence in depth in Indian PHWRS

    International Nuclear Information System (INIS)

    Jagannad, V.B.L.; Reddy, V.V.; Hajela, Sameer; Bhatia, C.M.; Nair, Suma

    2015-01-01

    Defence in Depth (DiD) is the established safety principle for the design of Nuclear Power Plants (NPPs). Accident at Fukushima Dai-ichi had highlighted the importance of provisions at Level-4 and 5 of DiD. Post Fukushima accident, on-site measures have been strengthened for Indian Nuclear Power Plants. On procedural front, Accident Management Guidelines have been introduced to handle events more severe than design basis accidents. This paper elaborates enhancement of Defence in Depth provisions for Indian Nuclear Power Plants. (author)

  5. The role of web sharing, species recognition and host-plant defence in interspecific competition between two herbivorous mite species.

    Science.gov (United States)

    Sato, Yukie; Alba, Juan M; Egas, Martijn; Sabelis, Maurice W

    2016-11-01

    When competing with indigenous species, invasive species face a problem, because they typically start with a few colonizers. Evidently, some species succeeded, begging an answer to the question how they invade. Here, we investigate how the invasive spider mite Tetranychus evansi interacts with the indigenous species T. urticae when sharing the solanaceous host plant tomato: do they choose to live together or to avoid each other's colonies? Both species spin protective, silken webs on the leaf surfaces, under which they live in groups of con- and possibly heterospecifics. In Spain, T. evansi invaded the non-crop field where native Tetranychus species including T. urticae dominated. Moreover, T. evansi outcompetes T. urticae when released together on a tomato plant. However, molecular plant studies suggest that T. urticae benefits from the local down-regulation of tomato plant defences by T. evansi, whereas T. evansi suffers from the induction of these defences by T. urticae. Therefore, we hypothesize that T. evansi avoids leaves infested with T. urticae whereas T. urticae prefers leaves infested by T. evansi. Using wild-type tomato and a mutant lacking jasmonate-mediated anti-herbivore defences, we tested the hypothesis and found that T. evansi avoided sharing webs with T. urticae in favour of a web with conspecifics, whereas T. urticae more frequently chose to share webs with T. evansi than with conspecifics. Also, T. evansi shows higher aggregation on a tomato plant than T. urticae, irrespective of whether the mites occur on the plant together or not.

  6. Knowing your friends and foes--plant receptor-like kinases as initiators of symbiosis or defence.

    Science.gov (United States)

    Antolín-Llovera, Meritxell; Petutsching, Elena Kristin; Ried, Martina Katharina; Lipka, Volker; Nürnberger, Thorsten; Robatzek, Silke; Parniske, Martin

    2014-12-01

    The decision between defence and symbiosis signalling in plants involves alternative and modular plasma membrane-localized receptor complexes. A critical step in their activation is ligand-induced homo- or hetero-oligomerization of leucine-rich repeat (LRR)- and/or lysin motif (LysM) receptor-like kinases (RLKs). In defence signalling, receptor complexes form upon binding of pathogen-associated molecular patterns (PAMPs), including the bacterial flagellin-derived peptide flg22, or chitin. Similar mechanisms are likely to operate during the perception of microbial symbiont-derived (lipo)-chitooligosaccharides. The structurally related chitin-oligomer ligands chitooctaose and chitotetraose trigger defence and symbiosis signalling, respectively, and their discrimination involves closely related, if not identical, LysM-RLKs. This illustrates the demand for and the challenges imposed on decision mechanisms that ensure appropriate signal initiation. Appropriate signalling critically depends on abundance and localization of RLKs at the cell surface. This is regulated by internalization, which also provides a mechanism for the removal of activated signalling RLKs. Abundance of the malectin-like domain (MLD)-LRR-RLK Symbiosis Receptor-like Kinase (SYMRK) is additionally controlled by cleavage of its modular ectodomain, which generates a truncated and rapidly degraded RLK fragment. This review explores LRR- and LysM-mediated signalling, the involvement of MLD-LRR-RLKs in symbiosis and defence, and the role of endocytosis in RLK function. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  7. The combined use of Pochonia chlamydosporia and plant defence activators - a potential sustainable control strategy for Meloidogyne chitwoodi

    Directory of Open Access Journals (Sweden)

    Maria Clara VIEIRA DOS SANTOS

    2014-05-01

    Full Text Available Sustainable strategies are required for control of the root-knot nematode Meloidogyne chitwoodi to reduce dependence on toxic chemical pesticides. The efficacy of the nematophagous fungus Pochonia chlamydosporia in biocontrol could be enhanced by integration with control measures that reduce initial nematode infestations. The use of foliar sprays with plant defence activators can reduce the susceptibility of potato plants to M. chitwoodi. This study assessed effects of combined soil application of P. chlamydosporia with foliar sprays of benzothiadiazole (BTH or cis-jasmone on infection of potatoes by M. chitwoodi. Solanum tuberosum, cv. Désirée plants were grown in soil mixed with 5000 chlamydospores g-1 of soil, sprayed twice with BTH or cis-jasmone and inoculated with 300 M. chitwoodi second-stage juveniles. Forty-five days after inoculation, nematode reproduction, numbers of colony-forming units of the fungus g-1 of soil and g-1 of root, and egg parasitism were assessed by standard techniques. Foliar sprays of BTH or cis-jasmone combined with the fungus reduced nematode reproduction (P<0.05, LSD. The presence of the fungus slightly increased the efficacy of cis-jasmone, as the number of eggs per egg mass was less in plants treated both with cis-jasmone and the fungus than in the plants treated only with the defence activator. The proportion of parasitized eggs was greater in the cis-jasmone treatment where rhizosphere colonisation was less, suggesting that P. chlamydosporia became a poorer rhizosphere coloniser but a more efficient nematode parasite. The addition of P. chlamydosporia to soil in combination with application of inducers of plant defence could be an alternative control strategy to be used against M. chitwoodi in potato.

  8. Convergent evolution of plant and animal embryo defences by hyperstable non-digestible storage proteins.

    Science.gov (United States)

    Pasquevich, María Yanina; Dreon, Marcos Sebastián; Qiu, Jian-Wen; Mu, Huawei; Heras, Horacio

    2017-11-20

    Plants have evolved sophisticated embryo defences by kinetically-stable non-digestible storage proteins that lower the nutritional value of seeds, a strategy that have not been reported in animals. To further understand antinutritive defences in animals, we analysed PmPV1, massively accumulated in the eggs of the gastropod Pomacea maculata, focusing on how its structure and structural stability features affected its capacity to withstand passage through predator guts. The native protein withstands >50 min boiling and resists the denaturing detergent sodium dodecyl sulphate (SDS), indicating an unusually high structural stability (i.e., kinetic stability). PmPV1 is highly resistant to in vitro proteinase digestion and displays structural stability between pH 2.0-12.0 and 25-85 °C. Furthermore, PmPV1 withstands in vitro and mice digestion and is recovered unchanged in faeces, supporting an antinutritive defensive function. Subunit sequence similarities suggest a common origin and tolerance to mutations. This is the first known animal genus that, like plant seeds, lowers the nutritional value of eggs by kinetically-stable non-digestible storage proteins that survive the gut of predators unaffected. The selective pressure of the harsh gastrointestinal environment would have favoured their appearance, extending by convergent evolution the presence of plant-like hyperstable antinutritive proteins to unattended reproductive stages in animals.

  9. Partial demethylation of oligogalacturonides by pectin methyl esterase 1 is required for eliciting defence responses in wild strawberry (Fragaria vesca).

    Science.gov (United States)

    Osorio, Sonia; Castillejo, Cristina; Quesada, Miguel A; Medina-Escobar, Nieves; Brownsey, Geoff J; Suau, Rafael; Heredia, Antonio; Botella, Miguel A; Valpuesta, Victoriano

    2008-04-01

    In addition to the role of the cell wall as a physical barrier against pathogens, some of its constituents, such as pectin-derived oligogalacturonides (OGA), are essential components for elicitation of defence responses. To investigate how modifications of pectin alter defence responses, we expressed the fruit-specific Fragaria x ananassa pectin methyl esterase FaPE1 in the wild strawberry Fragaria vesca. Pectin from transgenic ripe fruits differed from the wild-type with regard to the degree and pattern of methyl esterification, as well as the average size of pectin polymers. Purified oligogalacturonides from the transgenic fruits showed a reduced degree of esterification compared to oligogalacturonides from wild-type fruits. This reduced esterification is necessary to elicit defence responses in strawberry. The transgenic F. vesca lines had constitutively activated pathogen defence responses, resulting in higher resistance to the necrotropic fungus Botrytis cinerea. Further studies in F. vesca and Nicotiana benthamiana leaves showed that the elicitation capacity of the oligogalacturonides is more specific than previously envisaged.

  10. Augmenting Plant Immune Responses and Biological Control by Microbial Determinants

    Directory of Open Access Journals (Sweden)

    Sang Moo Lee

    2015-09-01

    Full Text Available Plant have developed sophisticated defence mechanisms against microbial pathogens. The recent accumulated information allow us to understand the nature of plant immune responses followed by recognition of microbial factors/determinants through cutting-edge genomics and multi-omics techniques. However, the practical approaches to sustain plant health using enhancement of plant immunity is yet to be fully appreciated. Here, we overviewed the general concept and representative examples on the plant immunity. The fungal, bacterial, and viral determinants that was previously reported as the triggers of plant immune responses are introduced and described as the potential protocol of biological control. Specifically, the role of chitin, glucan, lipopolysaccharides/extracellular polysaccharides, microbe/pathogen-associated molecular pattern, antibiotics, mimic-phytohormones, N-acyl homoserine lactone, harpin, vitamins, and volatile organic compounds are considered. We hope that this review stimulates scientific community and farmers to broaden their knowledge on the microbial determinant-based biological control and to apply the technology on the integrated pest management program.

  11. Perception of low red:far-red ratio compromises both salicylic acid- and jasmonic acid-dependent pathogen defences in Arabidopsis.

    Science.gov (United States)

    de Wit, Mieke; Spoel, Steven H; Sanchez-Perez, Gabino F; Gommers, Charlotte M M; Pieterse, Corné M J; Voesenek, Laurentius A C J; Pierik, Ronald

    2013-07-01

    In dense stands of plants, such as agricultural monocultures, plants are exposed simultaneously to competition for light and other stresses such as pathogen infection. Here, we show that both salicylic acid (SA)-dependent and jasmonic acid (JA)-dependent disease resistance is inhibited by a simultaneously reduced red:far-red light ratio (R:FR), the early warning signal for plant competition. Conversely, SA- and JA-dependent induced defences did not affect shade-avoidance responses to low R:FR. Reduced pathogen resistance by low R:FR was accompanied by a strong reduction in the regulation of JA- and SA-responsive genes. The severe inhibition of SA-responsive transcription in low R:FR appeared to be brought about by the repression of SA-inducible kinases. Phosphorylation of the SA-responsive transcription co-activator NPR1, which is required for full induction of SA-responsive transcription, was indeed reduced and may thus play a role in the suppression of SA-mediated defences by low R:FR-mediated phytochrome inactivation. Our results indicate that foraging for light through the shade-avoidance response is prioritised over plant immune responses when plants are simultaneously challenged with competition and pathogen attack. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

  12. Plant responses to water stress

    Science.gov (United States)

    Kar, Rup Kumar

    2011-01-01

    Terrestrial plants most often encounter drought stress because of erratic rainfall which has become compounded due to present climatic changes.Responses of plants to water stress may be assigned as either injurious change or tolerance index. One of the primary and cardinal changes in response to drought stress is the generation of reactive oxygen species (ROS), which is being considered as the cause of cellular damage. However, recently a signaling role of such ROS in triggering the ROS scavenging system that may confer protection or tolerance against stress is emerging. Such scavenging system consists of antioxidant enzymes like SOD, catalase and peroxidases, and antioxidant compounds like ascorbate, reduced glutathione; a balance between ROS generation and scavenging ultimately determines the oxidative load. As revealed in case of defence against pathogen, signaling via ROS is initiated by NADPH oxidase-catalyzed superoxide generation in the apoplastic space (cell wall) followed by conversion to hydrogen peroxide by the activity of cell wall-localized SOD. Wall peroxidase may also play role in ROS generation for signaling. Hydrogen peroxide may use Ca2+ and MAPK pathway as downstream signaling cascade. Plant hormones associated with stress responses like ABA and ethylene play their role possibly via a cross talk with ROS towards stress tolerance, thus projecting a dual role of ROS under drought stress. PMID:22057331

  13. SMART DEFENCE AND DEFENCE RESOURCES MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Teodor FRUNZETI

    2012-12-01

    Full Text Available Ever since the Chicago Summit in May 2012. the Euro-Atlantic community has been imprinted, from the security and defence perspective. by me launch of a new initiative known as smart defence, a concept referring to the need to improve the way in which defence spending is made at the Alliance's level. Smart defence also has a corollary at EU's level — i.e., pooling and sharing - the two notions referring. Overall, to the same procedure and implying a crucial need for the two organizations to coordinate their efforts in this. This article approaches the conceptual meaning of smart defence, with special emphasis on its management dimension regarding the defence resources. As a consequence, it is approached in connection with Other similar concepts such as pooling and sharing', Planning, Programming, Budgeting, and Evaluation System (PPBES, and the Connected Force Initiative.

  14. Environmental Effects on Constitutive and Inducible Resin Defences of Pinus taeda

    Science.gov (United States)

    Maria L. Lombardero; Matthew P. Ayres; Peter L. Lorio; Jonathan J. Ruel

    2000-01-01

    The ecological literature abounds with studies of environmental effects on plant antiherbivore defences. While various models have been proposed (e.g. plant stress, optimal allocation, growth-differentiation balance), each has met with mixed support. One possible explanation for the mixed results is that constitutive and induced defences are differentialiy affected by...

  15. Civil defence abroad. Pt. 3: The Warsaw Pact countries

    International Nuclear Information System (INIS)

    Schirrmeister, K.G.; Hofmann, H.

    1988-01-01

    Civil defence forms part of the national defence of the G.D.R., and belongs since 1976 to the responsibility of the Defence Ministry. Civil defence service is equal to military service. Civil defence services are organised on a territorial basis and a production-oriented basis: Double concept. Construction of shelters is propagated for 30 years now, maintenance of existing buildings is an obligation since 1965. Principles (triage) of military medical service are applied, and are valid for students and post-graduate medical training. Civil defence training is required in school and industry. Civil defence expenditure is increasing, although there is little acceptance by the population. The issue presents extensive documentation. - Civil defence in the Soviet Union covers services in times of peace and of war. Defence measures are prepared and held up to date in the entire territory. The civil defence service belongs to the responsibility of the Council of Ministers, and the deputy minister of defence is the head of services. The training schedules and principles are laid down by the Central Committee of the Communist Party, the government, and local party organisations and governmental authorities. Civil defence training is a general obligation for all citizens over 8 years of age. The main goal is: Protection of the population as the production force, of the economy, and resources. (orig.) [de

  16. Defence responses of arabidopsis thaliana to infection by pseudomonas syringae are regulated by the circadian clock

    KAUST Repository

    Bhardwaj, Vaibhav

    2011-10-31

    The circadian clock allows plants to anticipate predictable daily changes in abiotic stimuli, such as light; however, whether the clock similarly allows plants to anticipate interactions with other organisms is unknown. Here we show that Arabidopsis thaliana (Arabidopsis) has circadian clock-mediated variation in resistance to the virulent bacterial pathogen Pseudomonas syringae pv. tomato DC3000 (Pst DC3000), with plants being least susceptible to infection in the subjective morning. We suggest that the increased resistance to Pst DC3000 observed in the morning in Col-0 plants results from clock-mediated modulation of pathogen associated molecular pattern (PAMP)-triggered immunity. Analysis of publicly available microarray data revealed that a large number of Arabidopsis defence-related genes showed both diurnal- and circadian-regulation, including genes involved in the perception of the PAMP flagellin which exhibit a peak in expression in the morning. Accordingly, we observed that PAMP-triggered callose deposition was significantly higher in wild-type plants inoculated with Pst DC3000 hrpA in the subjective morning than in the evening, while no such temporal difference was evident in arrhythmic plants. Our results suggest that PAMP-triggered immune responses are modulated by the circadian clock and that temporal regulation allows plants to anticipate and respond more effectively to pathogen challenges in the daytime. © 2011 Bhardwaj et al.

  17. Costs and benefits of chemical defence in the Red Alga Bonnemaisonia hamifera.

    Directory of Open Access Journals (Sweden)

    Göran M Nylund

    Full Text Available A number of studies have shown that the production of chemical defences is costly in terrestrial vascular plants. However, these studies do not necessarily reflect the costs of defence production in macroalgae, due to structural and functional differences between vascular plants and macroalgae. Using a specific culturing technique, we experimentally manipulated the defence production in the red alga Bonnemaisonia hamifera to examine if the defence is costly in terms of growth. Furthermore, we tested if the defence provides fitness benefits by reducing harmful bacterial colonisation of the alga. Costly defences should provide benefits to the producer in order to be maintained in natural populations, but such benefits through protection against harmful bacterial colonisation have rarely been documented in macroalgae. We found that algae with experimentally impaired defence production, but with an externally controlled epibacterial load, grew significantly better than algae with normal defence production. We also found that undefended algae exposed to a natural epibacterial load experienced a substantial reduction in growth and a 6-fold increase in cell bleaching, compared to controls. Thus, this study provides experimental evidence that chemical defence production in macroalgae is costly, but that the cost is outweighed by fitness benefits provided through protection against harmful bacterial colonisation.

  18. Seismic measures and defence in depth of nuclear power plant. Lessons learned from the great east Japan earthquake

    International Nuclear Information System (INIS)

    Ochiai, Kanehiro

    2011-01-01

    The Great East Japan Earthquake occurred in March 11, 2011 brought about severe accident at nuclear power plant, which gave significant lessons to nuclear experts concerned with safety measures. Concepts of defence in depth was basic philosophy to assure safety of nuclear power plant even against uncertainties exceeding design basis. This concept consisted of prevention, monitoring, and action to mitigate consequences of failures such as a series of physical barriers between the reactor core and the environment, which were called multiple safety systems, each with backup and designed to accommodate human error. As for natural disaster, depth of recognition of characteristic of natural phenomena and its effect and engineering judgment was of prime importance. Different waveforms of ground motion at Fukushima and Onagawa at the Great East Japan Earthquake showed that design ground motion should have large uncertainties. To cope with uncertainties of ground motion, robust seismic measures based on experience were such as design of static seismic intensity and rigid structure of natural period less than 0.1 sec. As for tsunami, defence in depth measures were prepared for the cooling of reactor core, spent fuel and related electric generation equipment with taking into account 1) time lag between tsunami generation and arrival, 2) tsunami affected area could be limited by coastal levee or anti-inundation measure, 3) system redundancy could be assured by different locations of equipments and 4) repair works could be done by shipment of replacement equipment from outside due to limitation of affected regional area. Success examples of Onagawa, Tokai unit 2, Fukushima Daiichi unit 6 and Fukushima Daini Nuclear Power Plants could suggest definite tsunami defence in depth measures. Containment vent system as final heat sink and emergency condenser as reactor core cooling at outage should be properly utilized for Fukushima Daiichi unit 1 Nuclear Power Plant. (T. Tanaka)

  19. Defence responses regulated by jasmonate and delayed senescence caused by ethylene receptor mutation contribute to the tolerance of petunia to Botrytis cinerea.

    Science.gov (United States)

    Wang, Hong; Liu, Gang; Li, Chunxia; Powell, Ann L T; Reid, Michael S; Zhang, Zhen; Jiang, Cai-Zhong

    2013-06-01

    Ethylene and jasmonate (JA) have powerful effects when plants are challenged by pathogens. The inducible promoter-regulated expression of the Arabidopsis ethylene receptor mutant ethylene-insensitive1-1 (etr1-1) causes ethylene insensitivity in petunia. To investigate the molecular mechanisms involved in transgenic petunia responses to Botrytis cinerea related to the ethylene and JA pathways, etr1-1-expressing petunia plants were inoculated with Botrytis cinerea. The induced expression of etr1-1 by a chemical inducer dexamethasone resulted in retarded senescence and reduced disease symptoms on detached leaves and flowers or intact plants. The extent of decreased disease symptoms correlated positively with etr1-1 expression. The JA pathway, independent of the ethylene pathway, activated petunia ethylene response factor (PhERF) expression and consequent defence-related gene expression. These results demonstrate that ethylene induced by biotic stress influences senescence, and that JA in combination with delayed senescence by etr1-1 expression alters tolerance to pathogens. © 2013 BSPP AND JOHN WILEY & SONS LTD.

  20. Role of the Regulatory Body in Implementing Defence in Depth in Nuclear Installations - Regulatory Oversight in Egypt

    Energy Technology Data Exchange (ETDEWEB)

    El-Sheikh, B. M., E-mail: badawymel@yahoo.com [Egyptian Nuclear and Radiological Regulatory Authority Cairo (Egypt)

    2014-10-15

    The fundamental objective of all nuclear safety regulatory bodies is to ensure that nuclear facilities are operated at all times in an acceptably safe manner including the safe conduct of decommissioning activities. Defence in depth is recognized as one of the fundamental safety principles that underlie the safety of nuclear power plants. Defence in depth is implemented to provide a graded protection against a wide variety of transients, incidents and accidents, including equipment failures and human errors within nuclear power plants and events initiated outside plants. The Regulator Body plays an important role in implementing defence in depth in nuclear installations in the context of a clear allocation of responsibilities with an operating organization. This role starting with setting safety objectives and by its own independent review and technical assessment of the safety justifications provided by the operating organization in addition to safety culture investigating within relevant organizations. This paper briefly reviews this role in normal operation and post accidents, and its effects on overall nuclear safety in nuclear installations with reference to Egyptian regulatory oversight. (author)

  1. Induced defences alter the strength and direction of natural selection on reproductive traits in common milkweed.

    Science.gov (United States)

    Thompson, K A; Cory, K A; Johnson, M T J

    2017-06-01

    Evolutionary biologists have long sought to understand the ecological processes that generate plant reproductive diversity. Recent evidence indicates that constitutive antiherbivore defences can alter natural selection on reproductive traits, but it is unclear whether induced defences will have the same effect and whether reduced foliar damage in defended plants is the cause of this pattern. In a factorial field experiment using common milkweed, Asclepias syriaca L., we induced plant defences using jasmonic acid (JA) and imposed foliar damage using scissors. We found that JA-induced plants experienced selection for more inflorescences that were smaller in size (fewer flowers), whereas control plants only experienced a trend towards selection for larger inflorescences (more flowers); all effects were independent of foliar damage. Our results demonstrate that induced defences can alter both the strength and direction of selection on reproductive traits, and suggest that antiherbivore defences may promote the evolution of plant reproductive diversity. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  2. Rosatom Corporation at the All-Russian civil defence training exercise

    International Nuclear Information System (INIS)

    Glukhikh, E.N.; Glazunov, A.V.; Tyurin, R.L.

    2012-01-01

    The 80th anniversary of civil defence in Russia was marked by the All-Russian civil defence exercise attended by representatives of federal executive authorities, regional and local executive authorities. During the exercise performance of the following activities was verified: introduction of increased preparedness mode for local air-defence emergency-response forces, activities of emergency-response and fire safety commissions, information collection and exchange during implementation of top-priority civil defence measures, etc. The paper describes the activities carried out during the exercise [ru

  3. NATO Defence Planning Process. Implications for defence posture

    Directory of Open Access Journals (Sweden)

    Paweł Fleischer

    2015-12-01

    Full Text Available The NATO Defence Planning Process (NDPP is the most important element affecting the Alliance's defence posture. Under the process states commit themselves to provide capabilities and forces required to fulfil NATO missions, defined in the NATO Strategic Concept. The NDPP directly affects national defence plans by harmonizing them with identified security and defence objectives as well by influencing development of the novel national defence capabilities. The emergence of new threats in the NATO environment, demands modifications in the defense planning process and establishing new goals for the Alliance. Enhancement of the NDPP should be priority during the time of unrest.

  4. Airborne signals from Trichoderma fungi stimulate iron uptake responses in roots resulting in priming of jasmonic acid-dependent defences in shoots of Arabidopsis thaliana and Solanum lycopersicum.

    Science.gov (United States)

    Martínez-Medina, Ainhoa; Van Wees, Saskia C M; Pieterse, Corné M J

    2017-11-01

    Root colonization by Trichoderma fungi can trigger induced systemic resistance (ISR). In Arabidopsis, Trichoderma-ISR relies on the transcription factor MYB72, which plays a dual role in the onset of ISR and the activation of Fe uptake responses. Volatile compounds (VCs) from rhizobacteria are important elicitors of MYB72 in Arabidopsis roots. Here, we investigated the mode of action of VCs from Trichoderma fungi in the onset of ISR and Fe uptake responses. VCs from Trichoderma asperellum and Trichoderma harzianum were applied in an in vitro split-plate system with Arabidopsis or tomato seedlings. Locally, Trichoderma-VCs triggered MYB72 expression and molecular, physiological and morphological Fe uptake mechanisms in Arabidopsis roots. In leaves, Trichoderma-VCs primed jasmonic acid-dependent defences, leading to an enhanced resistance against Botrytis cinerea. By using Arabidopsis micrografts of VCs-exposed rootstocks and non-exposed scions, we demonstrated that perception of Trichoderma-VCs by the roots leads to a systemic signal that primes shoots for enhanced defences. Trichoderma-VCs also elicited Fe deficiency responses and shoot immunity in tomato, suggesting that this phenomenon is expressed in different plant species. Our results indicate that Trichoderma-VCs trigger locally a readjustment of Fe homeostasis in roots, which links to systemic elicitation of ISR by priming of jasmonic acid-dependent defences. © 2017 John Wiley & Sons Ltd.

  5. Boosting plant defence by beneficial soil microorganisms

    NARCIS (Netherlands)

    Pozo, Maria J.; Loon, L.C. van; Pieterse, C.M.J.

    2004-01-01

    Plants in their environment face potential deleterious organisms such as fungi, bacteria, viruses, nematodes, etc. Many of them are able to cause plant diseases, responsible of important losses in crop production worldwide. But often the outcome of these interactions is not disease, since plants

  6. Systemic resistance and lipoxygenase-related defence response induced in tomato by Pseudomonas putida strain BTP1

    Directory of Open Access Journals (Sweden)

    Dommes Jacques

    2008-11-01

    Full Text Available Abstract Background Previous studies showed the ability of Pseudomonas putida strain BTP1 to promote induced systemic resistance (ISR in different host plants. Since ISR is long-lasting and not conducive for development of resistance of the targeted pathogen, this phenomenon can take part of disease control strategies. However, in spite of the numerous examples of ISR induced by PGPR in plants, only a few biochemical studies have associated the protective effect with specific host metabolic changes. Results In this study, we showed the protective effect of this bacterium in tomato against Botrytis cinerea. Following treatment by P. putida BTP1, analyses of acid-hydrolyzed leaf extracts showed an accumulation of antifungal material after pathogen infection. The fungitoxic compounds thus mainly accumulate as conjugates from which active aglycones may be liberated through the activity of hydrolytic enzymes. These results suggest that strain BTP1 can elicit systemic phytoalexin accumulation in tomato as one defence mechanism. On another hand, we have shown that key enzymes of the lipoxygenase pathway are stimulated in plants treated with the bacteria as compared with control plants. Interestingly, this stimulation is observed only after pathogen challenge in agreement with the priming concept almost invariably associated with the ISR phenomenon. Conclusion Through the demonstration of phytoalexin accumulation and LOX pathway stimulation in tomato, this work provides new insights into the diversity of defence mechanisms that are inducible by non-pathogenic bacteria in the context of ISR.

  7. Defence in Depth: Assessment of Comprehensiveness and Further Strengthening of the Concept

    Energy Technology Data Exchange (ETDEWEB)

    Misak, J., E-mail: Jozef.Misak@ujv.cz

    2014-10-15

    Full text: Defence in depth concept based on multiple levels of protection of the workers, public and the environment against radiation harm is and should remain an essential strategy for ensuring safety of nuclear power plants. This strategy should be comprehensively implemented through all stages of the plant lifetime, from the siting through construction and operation up to decommissioning. First part of the presentation will introduce a screening method developed by the IAEA as a tool facilitating the assessment of the comprehensiveness of defence in depth and will indicate further possibilities for using and updating the approach by taking into account recent lessons learned. Although it is clear that it is not possible for any industrial facility including nuclear power plants to fully eliminate the risk, further strengthening the defence in depth in particular at level 4 dealing with design extension conditions gives very high confidence in prevention and effective mitigation of severe accidents so that they are either practically eliminated or their consequences are limited in area and time. Second part of the presentation will discuss several issues associated with current efforts for strengthening the defence in depth, including the issues of practical elimination, independence and diversity of safety provisions at different levels of defence. (author)

  8. ETHYLENE RESPONSE FACTOR 96 positively regulates Arabidopsis resistance to necrotrophic pathogens by direct binding to GCC elements of jasmonate - and ethylene-responsive defence genes.

    Science.gov (United States)

    Catinot, Jérémy; Huang, Jing-Bo; Huang, Pin-Yao; Tseng, Min-Yuan; Chen, Ying-Lan; Gu, Shin-Yuan; Lo, Wan-Sheng; Wang, Long-Chi; Chen, Yet-Ran; Zimmerli, Laurent

    2015-12-01

    The ERF (ethylene responsive factor) family is composed of transcription factors (TFs) that are critical for appropriate Arabidopsis thaliana responses to biotic and abiotic stresses. Here we identified and characterized a member of the ERF TF group IX, namely ERF96, that when overexpressed enhances Arabidopsis resistance to necrotrophic pathogens such as the fungus Botrytis cinerea and the bacterium Pectobacterium carotovorum. ERF96 is jasmonate (JA) and ethylene (ET) responsive and ERF96 transcripts accumulation was abolished in JA-insensitive coi1-16 and in ET-insensitive ein2-1 mutants. Protoplast transactivation and electrophoresis mobility shift analyses revealed that ERF96 is an activator of transcription that binds to GCC elements. In addition, ERF96 mainly localized to the nucleus. Microarray analysis coupled to chromatin immunoprecipitation-PCR of Arabidopsis overexpressing ERF96 revealed that ERF96 enhances the expression of the JA/ET defence genes PDF1.2a, PR-3 and PR-4 as well as the TF ORA59 by direct binding to GCC elements present in their promoters. While ERF96-RNAi plants demonstrated wild-type resistance to necrotrophic pathogens, basal PDF1.2 expression levels were reduced in ERF96-silenced plants. This work revealed ERF96 as a key player of the ERF network that positively regulates the Arabidopsis resistance response to necrotrophic pathogens. © 2015 John Wiley & Sons Ltd.

  9. The plant cell nucleus: a true arena for the fight between plants and pathogens.

    Science.gov (United States)

    Deslandes, Laurent; Rivas, Susana

    2011-01-01

    Communication between the cytoplasm and the nucleus is a fundamental feature shared by both plant and animal cells. Cellular factors involved in the transport of macromolecules through the nuclear envelope, including nucleoporins, importins and Ran-GTP related components, are conserved among a variety of eukaryotic systems. Interestingly, mutations in these nuclear components compromise resistance signalling, illustrating the importance of nucleocytoplasmic trafficking in plant innate immunity. Indeed, spatial restriction of defence regulators by the nuclear envelope and stimulus-induced nuclear translocation constitute an important level of defence-associated gene regulation in plants. A significant number of effectors from different microbial pathogens are targeted to the plant cell nucleus. In addition, key host factors, including resistance proteins, immunity components, transcription factors and transcriptional regulators shuttle between the cytoplasm and the nucleus, and their level of nuclear accumulation determines the output of the defence response, further confirming the crucial role played by the nucleus during the interaction between plants and pathogens. Here, we discuss recent findings that situate the nucleus at the frontline of the mutual recognition between plants and invading microbes.

  10. How predictable are the behavioral responses of insects to herbivore induced changes in plants? Responses of two congeneric thrips to induced cotton plants.

    Directory of Open Access Journals (Sweden)

    Rehan Silva

    Full Text Available Changes in plants following insect attack are referred to as induced responses. These responses are widely viewed as a form of defence against further insect attack. In the current study we explore whether it is possible to make generalizations about induced plant responses given the unpredictability and variability observed in insect-plant interactions. Experiments were conducted to test for consistency in the responses of two congeneric thrips, Frankliniella schultzei Trybom and Frankliniella occidentalis Pergrande (Thysanoptera: Thripidae to cotton seedlings (Gossypium hirsutum Linneaus (Malvales: Malvaceae damaged by various insect herbivores. In dual-choice experiments that compared intact and damaged cotton seedlings, F. schultzei was attracted to seedlings damaged by Helicoverpa armigera (Hübner (Lepidoptera: Noctuidae, Tetranychus urticae (Koch (Trombidiforms: Tetranychidae, Tenebrio molitor Linnaeus (Coleoptera: Tenebrionidae, F. schultzei and F. occidentalis but not to mechanically damaged seedlings. In similar tests, F. occidentalis was attracted to undamaged cotton seedlings when simultaneously exposed to seedlings damaged by H. armigera, T. molitor or F. occidentalis. However, when exposed to F. schultzei or T. urticae damaged plants, F. occidentalis was more attracted towards damaged plants. A quantitative relationship was also apparent, F. schultzei showed increased attraction to damaged seedlings as the density of T. urticae or F. schultzei increased. In contrast, although F. occidentalis demonstrated increased attraction to plants damaged by higher densities of T. urticae, there was a negative relationship between attraction and the density of damaging conspecifics. Both species showed greater attraction to T. urticae damaged seedlings than to seedlings damaged by conspecifics. Results demonstrate that the responses of both species of thrips were context dependent, making generalizations difficult to formulate.

  11. Plant root transcriptome profiling reveals a strain-dependent response during Azospirillum-rice cooperation

    Directory of Open Access Journals (Sweden)

    Benoît eDrogue

    2014-11-01

    Full Text Available Cooperation involving Plant Growth-Promoting Rhizobacteria results in improvements of plant growth and health. While pathogenic and symbiotic interactions are known to induce transcriptional changes for genes related to plant defence and development, little is known about the impact of phytostimulating rhizobacteria on plant gene expression. This study aims at identifying genes significantly regulated in rice roots upon Azospirillum inoculation, considering possible favored interaction between a strain and its original host cultivar. Genome-wide analyses of Oryza sativa japonica cultivars Cigalon and Nipponbare were performed, by using microarrays, seven days post inoculation with A. lipoferum 4B (isolated from Cigalon or Azospirillum sp. B510 (isolated from Nipponbare and compared to the respective non-inoculated condition. A total of 7,384 genes were significantly regulated, which represent about 16 % of total rice genes. A set of 34 genes is regulated by both Azospirillum strains in both cultivars, including a gene orthologous to PR10 of Brachypodium, and these could represent plant markers of Azospirillum-rice interactions. The results highlight a strain-dependent response of rice, with 83 % of the differentially expressed genes being classified as combination-specific. Whatever the combination, most of the differentially expressed genes are involved in primary metabolism, transport, regulation of transcription and protein fate. When considering genes involved in response to stress and plant defence, it appears that strain B510, a strain displaying endophytic properties, leads to the repression of a wider set of genes than strain 4B. Individual genotypic variations could be the most important driving force of rice roots gene expression upon Azospirillum inoculation. Strain-dependent transcriptional changes observed for genes related to auxin and ethylene signalling highlight the complexity of hormone signalling networks in the Azospirillum

  12. Fungal Production and Manipulation of Plant Hormones.

    Science.gov (United States)

    Fonseca, Sandra; Radhakrishnan, Dhanya; Prasad, Kalika; Chini, Andrea

    2018-01-01

    Living organisms are part of a highly interconnected web of interactions, characterised by species nurturing, competing, parasitizing and preying on one another. Plants have evolved cooperative as well as defensive strategies to interact with neighbour organisms. Among these, the plant-fungus associations are very diverse, ranging from pathogenic to mutualistic. Our current knowledge of plant-fungus interactions suggests a sophisticated coevolution to ensure dynamic plant responses to evolving fungal mutualistic/pathogenic strategies. The plant-fungus communication relies on a rich chemical language. To manipulate the plant defence mechanisms, fungi produce and secrete several classes of biomolecules, whose modeof- action is largely unknown. Upon perception of the fungi, plants produce phytohormones and a battery of secondary metabolites that serve as defence mechanism against invaders or to promote mutualistic associations. These mutualistic chemical signals can be co-opted by pathogenic fungi for their own benefit. Among the plant molecules regulating plant-fungus interaction, phytohormones play a critical role since they modulate various aspects of plant development, defences and stress responses. Intriguingly, fungi can also produce phytohormones, although the actual role of fungalproduced phytohormones in plant-fungus interactions is poorly understood. Here, we discuss the recent advances in fungal production of phytohormone, their putative role as endogenous fungal signals and how fungi manipulate plant hormone balance to their benefits. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  13. Physcomitrella patens activates reinforcement of the cell wall, programmed cell death and accumulation of evolutionary conserved defence signals, such as salicylic acid and 12-oxo-phytodienoic acid, but not jasmonic acid, upon Botrytis cinerea infection.

    Science.gov (United States)

    Ponce De León, Inés; Schmelz, Eric A; Gaggero, Carina; Castro, Alexandra; Álvarez, Alfonso; Montesano, Marcos

    2012-10-01

    The moss Physcomitrella patens is an evolutionarily basal model system suitable for the analysis of plant defence responses activated after pathogen assault. Upon infection with the necrotroph Botrytis cinerea, several defence mechanisms are induced in P. patens, including the fortification of the plant cell wall by the incorporation of phenolic compounds and the induced expression of related genes. Botrytis cinerea infection also activates the accumulation of reactive oxygen species and cell death with hallmarks of programmed cell death in moss tissues. Salicylic acid (SA) levels also increase after fungal infection, and treatment with SA enhances transcript accumulation of the defence gene phenylalanine ammonia-lyase (PAL) in P. patens colonies. The expression levels of the genes involved in 12-oxo-phytodienoic acid (OPDA) synthesis, including lipoxygenase (LOX) and allene oxide synthase (AOS), increase in P. patens gametophytes after pathogen assault, together with a rise in free linolenic acid and OPDA concentrations. However, jasmonic acid (JA) could not be detected in healthy or infected tissues of this plant. Our results suggest that, although conserved defence signals, such as SA and OPDA, are synthesized and are probably involved in the defence response of P. patens against B. cinerea infection, JA production appears to be missing. Interestingly, P. patens responds to OPDA and methyl jasmonate by reducing moss colony growth and rhizoid length, suggesting that jasmonate perception is present in mosses. Thus, P. patens can provide clues with regard to the evolution of different defence pathways in plants, including signalling and perception of OPDA and jasmonates in nonflowering and flowering plants. © 2012 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

  14. Harnessing ant defence at fruits reduces bruchid seed predation in a symbiotic ant–plant mutualism

    Science.gov (United States)

    Pringle, Elizabeth G.

    2014-01-01

    In horizontally transmitted mutualisms, mutualists disperse separately and reassemble in each generation with partners genetically unrelated to those in the previous generation. Because of this, there should be no selection on either partner to enhance the other's reproductive output directly. In symbiotic ant–plant mutualisms, myrmecophytic plants host defensive ant colonies, and ants defend the plants from herbivores. Plants and ants disperse separately, and, although ant defence can indirectly increase plant reproduction by reducing folivory, it is unclear whether ants can also directly increase plant reproduction by defending seeds. The neotropical tree Cordia alliodora hosts colonies of Azteca pittieri ants. The trees produce domatia where ants nest at stem nodes and also at the node between the peduncle and the rachides of the infloresence. Unlike the stem domatia, these reproductive domatia senesce after the tree fruits each year. In this study, I show that the tree's resident ant colony moves into these ephemeral reproductive domatia, where they tend honeydew-producing scale insects and patrol the nearby developing fruits. The presence of ants significantly reduced pre-dispersal seed predation by Amblycerus bruchid beetles, thereby directly increasing plant reproductive output. PMID:24807259

  15. Harnessing ant defence at fruits reduces bruchid seed predation in a symbiotic ant-plant mutualism.

    Science.gov (United States)

    Pringle, Elizabeth G

    2014-06-22

    In horizontally transmitted mutualisms, mutualists disperse separately and reassemble in each generation with partners genetically unrelated to those in the previous generation. Because of this, there should be no selection on either partner to enhance the other's reproductive output directly. In symbiotic ant-plant mutualisms, myrmecophytic plants host defensive ant colonies, and ants defend the plants from herbivores. Plants and ants disperse separately, and, although ant defence can indirectly increase plant reproduction by reducing folivory, it is unclear whether ants can also directly increase plant reproduction by defending seeds. The neotropical tree Cordia alliodora hosts colonies of Azteca pittieri ants. The trees produce domatia where ants nest at stem nodes and also at the node between the peduncle and the rachides of the infloresence. Unlike the stem domatia, these reproductive domatia senesce after the tree fruits each year. In this study, I show that the tree's resident ant colony moves into these ephemeral reproductive domatia, where they tend honeydew-producing scale insects and patrol the nearby developing fruits. The presence of ants significantly reduced pre-dispersal seed predation by Amblycerus bruchid beetles, thereby directly increasing plant reproductive output.

  16. Leaf Colour as a Signal of Chemical Defence to Insect Herbivores in Wild Cabbage (Brassica oleracea.

    Directory of Open Access Journals (Sweden)

    Jonathan P Green

    Full Text Available Leaf colour has been proposed to signal levels of host defence to insect herbivores, but we lack data on herbivory, leaf colour and levels of defence for wild host populations necessary to test this hypothesis. Such a test requires measurements of leaf spectra as they would be sensed by herbivore visual systems, as well as simultaneous measurements of chemical defences and herbivore responses to leaf colour in natural host-herbivore populations. In a large-scale field survey of wild cabbage (Brassica oleracea populations, we show that variation in leaf colour and brightness, measured according to herbivore spectral sensitivities, predicts both levels of chemical defences (glucosinolates and abundance of specialist lepidopteran (Pieris rapae and hemipteran (Brevicoryne brassicae herbivores. In subsequent experiments, P. rapae larvae achieved faster growth and greater pupal mass when feeding on plants with bluer leaves, which contained lower levels of aliphatic glucosinolates. Glucosinolate-mediated effects on larval performance may thus contribute to the association between P. rapae herbivory and leaf colour observed in the field. However, preference tests found no evidence that adult butterflies selected host plants based on leaf coloration. In the field, B. brassicae abundance varied with leaf brightness but greenhouse experiments were unable to identify any effects of brightness on aphid preference or performance. Our findings suggest that although leaf colour reflects both levels of host defences and herbivore abundance in the field, the ability of herbivores to respond to colour signals may be limited, even in species where performance is correlated with leaf colour.

  17. Disruption of the ammonium transporter AMT1.1 alters basal defences generating resistance against Pseudomonas syringae and Plectosphaerella cucumerina

    Directory of Open Access Journals (Sweden)

    Victoria ePastor

    2014-05-01

    Full Text Available Disruption of the high-affinity nitrate transporter NRT2.1 activates the priming defence against Pseudomonas syringae, resulting in enhanced resistance. In this study, it is demonstrated that the high-affinity ammonium transporter AMT1.1 is a negative regulator of Arabidopsis defence responses. The T-DNA knockout mutant amt1.1 displays enhanced resistance against Plectosphaerella cucumerina and reduced susceptibility to P. syringae. The impairment of AMT1.1 induces significant metabolic changes in the absence of challenge, suggesting that amt1.1 retains constitutive defence responses. Interestingly, amt1.1 combats pathogens differently depending on the lifestyle of the pathogen. In addition, N starvation enhances the susceptibility of wild type plants and the mutant amt1.1 to P. syringae whereas it has no effect on P. cucumerina resistance. The metabolic changes of amt1.1 against P. syringae are subtler and are restricted to the phenylpropanoid pathway, which correlates with its reduced susceptibility. By contrast, the amt1.1 mutant responds by activating higher levels of camalexin and callose against P. cucumerina. In addition, amt1.1 shows altered levels of aliphatic and indolic glucosinolates and other Trp-related compounds following infection by the necrotroph. These observations indicate that AMT1.1 may play additional roles that affect N uptake and plant immune responses.

  18. Reinforcing Defence in Depth: A Practical Systemic Approach

    International Nuclear Information System (INIS)

    Watts, G.; Misak, J.

    2016-01-01

    The concept of defence in depth for ensuring nuclear safety of nuclear installations is often oversimplified and interpreted as a set of physical barriers, whose integrity is ensured by safety provisions in the form of the plant systems implemented independently at various levels of defence. However, the provisions established at each level of defence should in general terms include not only hardware components (active and passive systems), but more comprehensively, also inherent safety characteristics, safety margins, operating procedures and guidelines, quality assurance, safety culture, staff training, and many other organizational measures as parts of management of safety. Many of the above mentioned provisions belong to the category of human and organizational factors. While various hardware components are typically specific for different levels of defence, human and organizational factors may have an impact on several levels of defence. These factors are associated with large uncertainties and can result in latent weaknesses. Their implementation can negatively affect several levels of defence at the same time. The proposed paper will underline the need for a more comprehensive view of the defence in depth concept in order to provide a practical and effective tool for a systemic approach to safety. The paper will consist of two main parts. The first part will introduce a screening method developed by the IAEA as a tool for facilitating the assessment of the comprehensiveness of defence in depth. The method uses screening of safety provisions at five levels of defence to ensure integrity of the physical barriers and achievement of safety objectives at each level of defence. The second part of the paper will focus on human and organizational factors considered as provisions for reliable performance of safety functions. It will explain the significant shift in the demands on the human system between levels 3 and 4 of the defence in depth framework, and will

  19. Evidence of viscerally-mediated cold-defence thermoeffector responses in man.

    Science.gov (United States)

    Morris, Nathan B; Filingeri, Davide; Halaki, Mark; Jay, Ollie

    2017-02-15

    Visceral thermoreceptors that modify thermoregulatory responses are widely accepted in animal but not human thermoregulation models. Recently, we have provided evidence of viscerally-mediated sweating alterations in humans during exercise brought about by warm and cool fluid ingestion. In the present study, we characterize the modification of shivering and whole-body thermal sensation during cold stress following the administration of a graded thermal stimuli delivered to the stomach via fluid ingestion at 52, 37, 22 and 7°C. Despite no differences in core and skin temperature, fluid ingestion at 52°C rapidly decreased shivering and sensations of cold compared to 37°C, whereas fluid ingestion at 22 and 7°C led to equivalent increases in these responses. Warm and cold fluid ingestion independently modifies cold defence thermoeffector responses, supporting the presence of visceral thermoreceptors in humans. However, the cold-defence thermoeffector response patterns differed from previously identified hot-defence thermoeffectors. Sudomotor activity is modified by both warm and cold fluid ingestion during heat stress, independently of differences in core and skin temperatures, suggesting independent viscerally-mediated modification of thermoeffectors. The present study aimed to determine whether visceral thermoreceptors modify shivering responses to cold stress. Ten males (mean ± SD: age 27 ± 5 years; height 1.73 ± 0.06 m, weight 78.4 ± 10.7 kg) underwent whole-body cooling via a water perfusion suit at 5°C, on four occasions, to induce a steady-state shivering response, at which point two aliquots of 1.5 ml kg -1 (SML) and 3.0 ml kg -1 (LRG), separated by 20 min, of water at 7, 22, 37 or 52°C were ingested. Rectal, mean skin and mean body temperature (T b ), electromyographic activity (EMG), metabolic rate (M) and whole-body thermal sensation on a visual analogue scale (WBTS) ranging from 0 mm (very cold) to 200 mm (very hot) were all

  20. Abscisic acid deficiency increases defence responses against Myzus persicae in Arabidopsis.

    Science.gov (United States)

    Hillwig, Melissa S; Chiozza, Mariana; Casteel, Clare L; Lau, Siau Ting; Hohenstein, Jessica; Hernández, Enrique; Jander, Georg; MacIntosh, Gustavo C

    2016-02-01

    Comparison of Arabidopsis thaliana (Arabidopsis) gene expression induced by Myzus persicae (green peach aphid) feeding, aphid saliva infiltration and abscisic acid (ABA) treatment showed a significant positive correlation. In particular, ABA-regulated genes are over-represented among genes that are induced by M. persicae saliva infiltration into Arabidopsis leaves. This suggests that the induction of ABA-related gene expression could be an important component of the Arabidopsis-aphid interaction. Consistent with this hypothesis, M. persicae populations induced ABA production in wild-type plants. Furthermore, aphid populations were smaller on Arabidopsis aba1-1 mutants, which cannot synthesize ABA, and showed a significant preference for wild-type plants compared with the mutant. Total free amino acids, which play an important role in aphid nutrition, were not altered in the aba1-1 mutant line, but the levels of isoleucine (Ile) and tryptophan (Trp) were differentially affected by aphids in wild-type and mutant plants. Recently, indole glucosinolates have been shown to promote aphid resistance in Arabidopsis. In this study, 4-methoxyindol-3-ylmethylglucosinolate was more abundant in the aba1-1 mutant than in wild-type Arabidopsis, suggesting that the induction of ABA signals that decrease the accumulation of defence compounds may be beneficial for aphids. © 2015 BSPP AND JOHN WILEY & SONS LTD.

  1. Plant stress signalling: understanding and exploiting plant-plant interactions.

    Science.gov (United States)

    Pickett, J A; Rasmussen, H B; Woodcock, C M; Matthes, M; Napier, J A

    2003-02-01

    When plants are attacked by insects, volatile chemical signals can be released, not only from the damaged parts, but also systemically from other parts of the plant and this continues after cessation of feeding by the insect. These signals are perceived by olfactory sensory mechanisms in both the herbivorous insects and their parasites. Molecular structures involved can be characterized by means of electrophysiological assays, using the insect sensory system linked to chemical analysis. Evidence is mounting that such signals can also affect neighbouring intact plants, which initiate defence by the induction of further signalling systems, such as those that increase parasitoid foraging. Furthermore, insect electrophysiology can be used in the identification of plant compounds having effects on the plants themselves. It has been found recently that certain plants can release stress signals even when undamaged, and that these can cause defence responses in intact plants. These discoveries provide the basis for new crop protection strategies, that are either delivered by genetic modification of plants or by conventionally produced plants to which the signal is externally applied. Delivery can also be made by means of mixed seed strategies in which the provoking and recipient plants are grown together. Related signalling discoveries within the rhizosphere seem set to extend these approaches into new ways of controlling weeds, by exploiting the elusive potential of allelopathy, but through signalling rather than by direct physiological effects.

  2. Plant pathology: monitoring a pathogen-targeted host protein.

    Science.gov (United States)

    Ellis, Jeff; Dodds, Peter

    2003-05-13

    A plant protein RIN4 is targeted and modified by bacterial pathogens as part of the disease process. At least two host resistance proteins monitor this pathogen interference and trigger the plant's defence responses.

  3. Buckwheat trypsin inhibitor with helical hairpin structure belongs to a new family of plant defence peptides.

    Science.gov (United States)

    Oparin, Peter B; Mineev, Konstantin S; Dunaevsky, Yakov E; Arseniev, Alexander S; Belozersky, Mikhail A; Grishin, Eugene V; Egorov, Tsezi A; Vassilevski, Alexander A

    2012-08-15

    A new peptide trypsin inhibitor named BWI-2c was obtained from buckwheat (Fagopyrum esculentum) seeds by sequential affinity, ion exchange and reversed-phase chromatography. The peptide was sequenced and found to contain 41 amino acid residues, with four cysteine residues involved in two intramolecular disulfide bonds. Recombinant BWI-2c identical to the natural peptide was produced in Escherichia coli in a form of a cleavable fusion with thioredoxin. The 3D (three-dimensional) structure of the peptide in solution was determined by NMR spectroscopy, revealing two antiparallel α-helices stapled by disulfide bonds. Together with VhTI, a trypsin inhibitor from veronica (Veronica hederifolia), BWI-2c represents a new family of protease inhibitors with an unusual α-helical hairpin fold. The linker sequence between the helices represents the so-called trypsin inhibitory loop responsible for direct binding to the active site of the enzyme that cleaves BWI-2c at the functionally important residue Arg(19). The inhibition constant was determined for BWI-2c against trypsin (1.7×10(-1)0 M), and the peptide was tested on other enzymes, including those from various insect digestive systems, revealing high selectivity to trypsin-like proteases. Structural similarity shared by BWI-2c, VhTI and several other plant defence peptides leads to the acknowledgement of a new widespread family of plant peptides termed α-hairpinins.

  4. Involvement of potato (Solanum tuberosum L.) MKK6 in response to potato virus Y.

    Science.gov (United States)

    Lazar, Ana; Coll, Anna; Dobnik, David; Baebler, Spela; Bedina-Zavec, Apolonija; Zel, Jana; Gruden, Kristina

    2014-01-01

    Mitogen-activated protein kinase (MAPK) cascades have crucial roles in the regulation of plant development and in plant responses to stress. Plant recognition of pathogen-associated molecular patterns or pathogen-derived effector proteins has been shown to trigger activation of several MAPKs. This then controls defence responses, including synthesis and/or signalling of defence hormones and activation of defence related genes. The MAPK cascade genes are highly complex and interconnected, and thus the precise signalling mechanisms in specific plant-pathogen interactions are still not known. Here we investigated the MAPK signalling network involved in immune responses of potato (Solanum tuberosum L.) to Potato virus Y, an important potato pathogen worldwide. Sequence analysis was performed to identify the complete MAPK kinase (MKK) family in potato, and to identify those regulated in the hypersensitive resistance response to Potato virus Y infection. Arabidopsis has 10 MKK family members, of which we identified five in potato and tomato (Solanum lycopersicum L.), and eight in Nicotiana benthamiana. Among these, StMKK6 is the most strongly regulated gene in response to Potato virus Y. The salicylic acid treatment revealed that StMKK6 is regulated by the hormone that is in agreement with the salicylic acid-regulated domains found in the StMKK6 promoter. The involvement of StMKK6 in potato defence response was confirmed by localisation studies, where StMKK6 accumulated strongly only in Potato-virus-Y-infected plants, and predominantly in the cell nucleus. Using a yeast two-hybrid method, we identified three StMKK6 targets downstream in the MAPK cascade: StMAPK4_2, StMAPK6 and StMAPK13. These data together provide further insight into the StMKK6 signalling module and its involvement in plant defence.

  5. Integrating Studies on Plant-Pollinator and Plant-Herbivore Interactions

    NARCIS (Netherlands)

    Lucas-Barbosa, Dani

    2016-01-01

    Research on herbivore-induced plant defence and research on pollination ecology have had a long history of separation. Plant reproduction of most angiosperm species is mediated by pollinators, and the effects of herbivore-induced plant defences on pollinator behaviour have been largely neglected.

  6. Nuclear power reactors: reactor safety and military and civil defence

    International Nuclear Information System (INIS)

    Hvinden, T.

    1976-01-01

    The formation of fission products and plutonium in reactors is briefly described, followed by a short general discussion of reactor safety. The interaction of reactor safety and radioactive release considerations with military and civil defence is thereafter discussed. Reactors and other nuclear plants are factors which must be taken into account in the defence of the district around the site, and as potential targets of both conventional and guerilla attacks and sabotage, requiring special defence. The radiological hazards arising from serious damage to a power reactor by conventional weapons are briefly discussed, and the benefits of underground siting evaluated. Finally the author discusses the significance of the IAEA safeguards work as a preventive factor. (JIW)

  7. Defence in depth by 'Leittechnique' systems with graded intelligence

    International Nuclear Information System (INIS)

    Aleite, W.

    1983-01-01

    In the past, only two types of nuclear power plant instrumentation and control systems were in use in the Federal Republic of Germany (FRG): safety systems and operational systems. Present nuclear power plant 'Leittechnique' systems in the FRG have been expanded from this 'black-and-white' status to multiple-grade systems with respect to safety, qualification requirements and intelligence. The extensive experience of the past has encouraged the rule-making committees - representing all parties working in the nuclear field - to differentiate between the protection limitations and condition limitations of the reactor protection system on one hand and the information systems (including the accident monitoring and alarm system) of different safety importance on the other, assuming additional extensive application of non-safety-grade operational Leittechnique systems. These definitions of categories are in accordance with international practice and enable designers to apply 'echelons of defence', composed of equipment of all categories, in accordance with 'defence-in-depth' concepts. They also simplify the introduction of computerized equipment, especially in the lower safety categories. Status, background and reasons of the introduction, as well as typical defence-in-depth modes, of the first running Leittechnique system of this kind (in the Grafenrheinfeld nuclear power plant) and especially their different tasks in disturbance handling are described. The international situation and future developments are briefly characterized. (author)

  8. The suppression of tomato defence response genes upon potato cyst nematode infection indicates a key regulatory role of miRNAs.

    Science.gov (United States)

    Święcicka, Magdalena; Skowron, Waldemar; Cieszyński, Piotr; Dąbrowska-Bronk, Joanna; Matuszkiewicz, Mateusz; Filipecki, Marcin; Koter, Marek Daniel

    2017-04-01

    Potato cyst nematode Globodera rostochiensis is an obligate parasite of solanaceous plants, triggering metabolic and morphological changes in roots which may result in substantial crop yield losses. Previously, we used the cDNA-AFLP to study the transcriptional dynamics in nematode infected tomato roots. Now, we present the rescreening of already published, upregulated transcript-derived fragment dataset using the most current tomato transcriptome sequences. Our reanalysis allowed to add 54 novel genes to 135, already found as upregulated in tomato roots upon G. rostochiensis infection (in total - 189). We also created completely new catalogue of downregulated sequences leading to the discovery of 76 novel genes. Functional classification of candidates showed that the 'wound, stress and defence response' category was enriched in the downregulated genes. We confirmed the transcriptional dynamics of six genes by qRT-PCR. To place our results in a broader context, we compared the tomato data with Arabidopsis thaliana, revealing similar proportions of upregulated and downregulated genes as well as similar enrichment of defence related transcripts in the downregulated group. Since transcript suppression is quite common in plant-nematode interactions, we assessed the possibility of miRNA-mediated inverse correlation on several tomato sequences belonging to NB-LRR and receptor-like kinase families. The qRT-PCR of miRNAs and putative target transcripts showed an opposite expression pattern in 9 cases. These results together with in silico analyses of potential miRNA targeting to the full repertoire of tomato R-genes show that miRNA mediated gene suppression may be a key regulatory mechanism during nematode parasitism. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  9. Foliar treatments with Gaultheria procumbens essential oil induce defence responses and resistance against a fungal pathogen in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Sophie eVergnes

    2014-09-01

    Full Text Available Essential oil from Gaultheria procumbens is mainly composed of methylsalicylate (>96%, a compound which can be metabolized in plant tissues to salicylic acid, a phytohormone inducing plant immunity against microbial pathogens. The potential use of G. procumbens essential oil as a biocontrol agent was evaluated on the model plant Arabidopsis thaliana. Expression of a selection of defence genes was detected 1, 6 and 24 hours after essential oil treatment (0.1 ml/L using a high-throughput qPCR-based microfluidic technology. Control treatments included methyl jasmonate and a commercialized salicylic acid analog, benzo(1,2,3-thiadiazole-7carbothiolic acid (BTH. Strong induction of defence markers known to be regulated by the salicylic acid pathway was observed after the treatment with G. procumbens essential oil. Treatment induced the accumulation of total salicylic acid in the wild -type Arabidopsis line Col-0 and analysis of the Arabidopsis line sid2, mutated in a salicylic acid biosynthetic gene, revealed that approximately 30% of methylsalicylate sprayed on the leaves penetrated inside plant tissues and was demethylated by endogenous esterases. Induction of plant resistance by G. procumbens essential oil was tested following inoculation with a GFP-expressing strain of the Arabidopsis fungal pathogen Colletotrichum higginsianum. Flurorescence measurement of infected tissues revealed that treatments led to a strong reduction (60% of pathogen development and that the efficacy of the G. procumbens essential oil was similar to the commercial product BION®. Together, these results show that the G. procubens essential oil is a natural source of methylsalicylate which can be formulated to develop new biocontrol products.

  10. Role of stress-related hormones in plant defence during early infection of the cyst nematode Heterodera schachtii in Arabidopsis

    Czech Academy of Sciences Publication Activity Database

    Kammerhofer, N.; Radakovic, Z.; Regis, J.M.A.; Dobrev, Petre; Vaňková, Radomíra; Grundler, F.M.W.; Siddique, S.; Hofmann, J.; Wieczorek, K.

    2015-01-01

    Roč. 207, č. 3 (2015), s. 778-789 ISSN 0028-646X R&D Projects: GA MŠk LD14120 Institutional support: RVO:61389030 Keywords : defence responses * early infection * ethylene Subject RIV: ED - Physiology Impact factor: 7.210, year: 2015

  11. Plant-parasitic nematodes: towards understanding molecular players in stress responses.

    Science.gov (United States)

    Gillet, François-Xavier; Bournaud, Caroline; Antonino de Souza Júnior, Jose Dijair; Grossi-de-Sa, Maria Fatima

    2017-03-01

    Plant-parasitic nematode interactions occur within a vast molecular plant immunity network. Following initial contact with the host plant roots, plant-parasitic nematodes (PPNs) activate basal immune responses. Defence priming involves the release in the apoplast of toxic molecules derived from reactive species or secondary metabolism. In turn, PPNs must overcome the poisonous and stressful environment at the plant-nematode interface. The ability of PPNs to escape this first line of plant immunity is crucial and will determine its virulence. Nematodes trigger crucial regulatory cytoprotective mechanisms, including antioxidant and detoxification pathways. Knowledge of the upstream regulatory components that contribute to both of these pathways in PPNs remains elusive. In this review, we discuss how PPNs probably orchestrate cytoprotection to resist plant immune responses, postulating that it may be derived from ancient molecular mechanisms. The review focuses on two transcription factors, DAF-16 and SKN-1 , which are conserved in the animal kingdom and are central regulators of cell homeostasis and immune function. Both regulate the unfolding protein response and the antioxidant and detoxification pathways. DAF-16 and SKN-1 target a broad spectrum of Caenorhabditis elegans genes coding for numerous protein families present in the secretome of PPNs. Moreover, some regulatory elements of DAF-16 and SKN-1 from C. elegans have already been identified as important genes for PPN infection. DAF-16 and SKN-1 genes may play a pivotal role in PPNs during parasitism. In the context of their hub status and mode of regulation, we suggest alternative strategies for control of PPNs through RNAi approaches. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company.

  12. Probabilistic Flood Defence Assessment Tools

    Directory of Open Access Journals (Sweden)

    Slomp Robert

    2016-01-01

    Full Text Available The WTI2017 project is responsible for the development of flood defence assessment tools for the 3600 km of Dutch primary flood defences, dikes/levees, dunes and hydraulic structures. These tools are necessary, as per January 1st 2017, the new flood risk management policy for the Netherlands will be implemented. Then, the seven decades old design practice (maximum water level methodology of 1958 and two decades old safety standards (and maximum hydraulic load methodology of 1996 will formally be replaced by a more risked based approach for the national policy in flood risk management. The formal flood defence assessment is an important part of this new policy, especially for flood defence managers, since national and regional funding for reinforcement is based on this assessment. This new flood defence policy is based on a maximum allowable probability of flooding. For this, a maximum acceptable individual risk was determined at 1/100 000 per year, this is the probability of life loss of for every protected area in the Netherlands. Safety standards of flood defences were then determined based on this acceptable individual risk. The results were adjusted based on information from cost -benefit analysis, societal risk and large scale societal disruption due to the failure of critical infrastructure e.g. power stations. The resulting riskbased flood defence safety standards range from a 300 to a 100 000 year return period for failure. Two policy studies, WV21 (Safety from floods in the 21st century and VNK-2 (the National Flood Risk in 2010 provided the essential information to determine the new risk based safety standards for flood defences. The WTI2017 project will provide the safety assessment tools based on these new standards and is thus an essential element for the implementation of this policy change. A major issue to be tackled was the development of user-friendly tools, as the new assessment is to be carried out by personnel of the

  13. Host defence peptides in human burns.

    Science.gov (United States)

    Kaus, Aljoscha; Jacobsen, Frank; Sorkin, Michael; Rittig, Andrea; Voss, Bruno; Daigeler, Adrien; Sudhoff, Holger; Steinau, Hans-Ulrich; Steinstraesser, Lars

    2008-02-01

    The goal of this study was to analyse expression profiles of human epithelial host defence peptides in burned and unburned skin tissue, samples of which were obtained during debridements and snap-frozen in liquid nitrogen. Total RNA was isolated, and cDNA of epithelial host defence peptides and proteins (hCAP-18/LL-37, hBD1-hBD4, dermcidin, S100A7/psoriasin and RNAse7) was quantified by qRT-PCR. In situ hybridisation and immunohistochemical staining localised gene expression of hCAP-18/LL-37, hBD2 and hBD3 in histological sections. Most of the analysed host defence peptides and proteins showed higher mRNA levels in partial-thickness burns than in unburned tissue. In situ hybridisation revealed expression of hCAP-18/LL-37, hBD2 and hBD3 at the surface of burns that was independent of burn depth. However, the finding of higher host defence peptide gene expression rates does not correlate with the incidence of wound infection in burns. We hypothesise that the epithelial innate immune response in burns is complex.

  14. NRT/PTR transporters are essential for translocation of glucosinolate defence compounds to seeds

    DEFF Research Database (Denmark)

    Nour-Eldin, Hussam Hassan; Andersen, Tonni Grube; Burow, Meike

    2012-01-01

    glucosinolates in seeds and had more than tenfold over-accumulation in source tissues such as leaves and silique walls, indicating that both plasma membrane-localized transporters are essential for long-distance transport of glucosinolates. We propose that GTR1 and GTR2 control the loading of glucosinolates from......In plants, transport processes are important for the reallocation of defence compounds to protect tissues of high value, as demonstrated in the plant model Arabidopsis, in which the major defence compounds, glucosinolates, are translocated to seeds on maturation. The molecular basis for long...

  15. Interaction between the moss Physcomitrella patens and Phytophthora: a novel pathosystem for live-cell imaging of subcellular defence.

    Science.gov (United States)

    Overdijk, Elysa J R; DE Keijzer, Jeroen; DE Groot, Deborah; Schoina, Charikleia; Bouwmeester, Klaas; Ketelaar, Tijs; Govers, Francine

    2016-08-01

    Live-cell imaging of plant-pathogen interactions is often hampered by the tissue complexity and multicell layered nature of the host. Here, we established a novel pathosystem with the moss Physcomitrella patens as host for Phytophthora. The tip-growing protonema cells of this moss are ideal for visualizing interactions with the pathogen over time using high-resolution microscopy. We tested four Phytophthora species for their ability to infect P. patens and showed that P. sojae and P. palmivora were only rarely capable to infect P. patens. In contrast, P. infestans and P. capsici frequently and successfully penetrated moss protonemal cells, showed intracellular hyphal growth and formed sporangia. Next to these successful invasions, many penetration attempts failed. Here the pathogen was blocked by a barrier of cell wall material deposited in papilla-like structures, a defence response that is common in higher plants. Another common response is the upregulation of defence-related genes upon infection and also in moss we observed this upregulation in tissues infected with Phytophthora. For more advanced analyses of the novel pathosystem we developed a special set-up that allowed live-cell imaging of subcellular defence processes by high-resolution microscopy. With this set-up, we revealed that Phytophthora infection of moss induces repositioning of the nucleus, accumulation of cytoplasm and rearrangement of the actin cytoskeleton, but not of microtubules. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

  16. The intrinsically disordered structural platform of the plant defence hub protein RPM1-interacting protein 4 provides insights into its mode of action in the host-pathogen interface and evolution of the nitrate-induced domain protein family.

    Science.gov (United States)

    Sun, Xiaolin; Greenwood, David R; Templeton, Matthew D; Libich, David S; McGhie, Tony K; Xue, Bin; Yoon, Minsoo; Cui, Wei; Kirk, Christopher A; Jones, William T; Uversky, Vladimir N; Rikkerink, Erik H A

    2014-09-01

    Arabidopsis thaliana (At) RPM1-interacting protein 4 (RIN4), targeted by many defence-suppressing bacterial type III effectors and monitored by several resistance proteins, regulates plant immune responses to pathogen-associated molecular patterns and type III effectors. Little is known about the overall protein structure of AtRIN4, especially in its unbound form, and the relevance of structure to its diverse biological functions. AtRIN4 contains two nitrate-induced (NOI) domains and is a member of the NOI family. Using experimental and bioinformatic approaches, we demonstrate that the unbound AtRIN4 is intrinsically disordered under physiological conditions. The intrinsically disordered polypeptide chain of AtRIN4 is interspersed with molecular recognition features (MoRFs) and anchor-identified long-binding regions, potentially allowing it to undergo disorder-to-order transitions upon binding to partner(s). A poly-l-proline II structure, often responsible for protein recognition, is also identified in AtRIN4. By performing bioinformatics analyses on RIN4 homologues from different plant species and the NOI proteins from Arabidopsis, we infer the conservation of intrinsic disorder, MoRFs and long-binding regions of AtRIN4 in other plant species and the NOI family. Intrinsic disorder and MoRFs could provide RIN4 proteins with the binding promiscuity and plasticity required to act as hubs in a pivotal position within plant defence signalling cascades. © 2014 FEBS.

  17. Plant physiology meets phytopathology: plant primary metabolism and plant-pathogen interactions.

    Science.gov (United States)

    Berger, Susanne; Sinha, Alok K; Roitsch, Thomas

    2007-01-01

    Phytopathogen infection leads to changes in secondary metabolism based on the induction of defence programmes as well as to changes in primary metabolism which affect growth and development of the plant. Therefore, pathogen attack causes crop yield losses even in interactions which do not end up with disease or death of the plant. While the regulation of defence responses has been intensively studied for decades, less is known about the effects of pathogen infection on primary metabolism. Recently, interest in this research area has been growing, and aspects of photosynthesis, assimilate partitioning, and source-sink regulation in different types of plant-pathogen interactions have been investigated. Similarly, phytopathological studies take into consideration the physiological status of the infected tissues to elucidate the fine-tuned infection mechanisms. The aim of this review is to give a summary of recent advances in the mutual interrelation between primary metabolism and pathogen infection, as well as to indicate current developments in non-invasive techniques and important strategies of combining modern molecular and physiological techniques with phytopathology for future investigations.

  18. Foliar aphid feeding recruits rhizosphere bacteria and primes plant immunity against pathogenic and non-pathogenic bacteria in pepper.

    Science.gov (United States)

    Lee, Boyoung; Lee, Soohyun; Ryu, Choong-Min

    2012-07-01

    Plants modulate defence signalling networks in response to different biotic stresses. The present study evaluated the effect of a phloem-sucking aphid on plant defence mechanisms in pepper (Capsicum annuum) during subsequent pathogen attacks on leaves and rhizosphere bacteria on roots. Plants were pretreated with aphids and/or the chemical trigger benzothiadiazol (BTH) 7 d before being challenged with two pathogenic bacteria, Xanthomonas axonopodis pv. vesicatoria (Xav) as a compatible pathogen and X. axonopodis pv. glycines (Xag) as an incompatible (non-host) pathogen. Disease severity was noticeably lower in aphid- and BTH + aphid-treated plants than in controls. Although treatment with BTH or aphids alone did not affect the hypersensitive response (HR) against Xag strain 8ra, the combination treatment had a synergistic effect on the HR. The aphid population was reduced by BTH pretreatment and by combination treatment with BTH and bacterial pathogens in a synergistic manner. Analysis of the expression of the defence-related genes Capsicum annum pathogenesis-related gene 9 (CaPR9), chitinase 2 (CaCHI2), SAR8·2 and Lipoxygenase1 (CaLOX1) revealed that aphid infestation resulted in the priming of the systemic defence responses against compatible and incompatible pathogens. Conversely, pre-challenge with the compatible pathogen Xav on pepper leaves significantly reduced aphid numbers. Aphid infestation increased the population of the beneficial Bacillus subtilis GB03 but reduced that of the pathogenic Ralstonia solanacearum SL1931. The expression of defence-related genes in the root and leaf after aphid feeding indicated that the above-ground aphid infestation elicited salicylic acid and jasmonic acid signalling throughout the whole plant. The findings of this study show that aphid feeding elicits plant resistance responses and attracts beneficial bacterial populations to help the plant cope with subsequent pathogen attacks.

  19. 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

  20. Testing phenotypic trade-offs in the chemical defence strategy of Scots pine under growth-limiting field conditions.

    Science.gov (United States)

    Villari, Caterina; Faccoli, Massimo; Battisti, Andrea; Bonello, Pierluigi; Marini, Lorenzo

    2014-09-01

    Plants protect themselves from pathogens and herbivores through fine-tuned resource allocation, including trade-offs among resource investments to support constitutive and inducible defences. However, empirical research, especially concerning conifers growing under natural conditions, is still scarce. We investigated the complexity of constitutive and induced defences in a natural Scots pine (Pinus sylvestris L.) stand under growth-limiting conditions typical of alpine environments. Phenotypic trade-offs at three hierarchical levels were tested by investigating the behaviour of phenolic compounds and terpenoids of outer bark and phloem. We tested resource-derived phenotypic correlations between (i) constitutive and inducible defences vs tree ring growth, (ii) different constitutive defence metabolites and (iii) constitutive concentration and inducible variation of individual metabolites. Tree ring growth was positively correlated only with constitutive concentration of total terpenoids, and no overall phenotypic trade-offs between different constitutive defensive metabolites were found. At the lowest hierarchical level tested, i.e., at the level of relationship between constitutive and inducible variation of individual metabolites, we found that different compounds displayed different behaviours; we identified five different defensive metabolite response types, based on direction and strength of the response, regardless of tree age and growth rate. Therefore, under growth-limiting field conditions, Scots pine appears to utilize varied and complex outer bark and phloem defence chemistry, in which only part of the constitutive specialized metabolism is influenced by tree growth, and individual components do not appear to be expressed in a mutually exclusive manner in either constitutive or inducible metabolism. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Silencing of acidic pathogenesis-related PR-1 genes increases extracellular beta-(1 -> 3)-glucanase activity at the onset of tobacco defence reactions

    DEFF Research Database (Denmark)

    Riviere, M.P.; Marais, A.; Ponchet, M.

    2008-01-01

    silenced. Plants lacking extracellular PR-1s were more susceptible than wild-type plants to the oomycete Phytophthora parasitica but displayed unaffected systemic acquired resistance and developmental resistance to this pathogen. Treatment with salicylic acid up-regulates the PR-1g gene, encoding a basic...... protein of the PR-1 family, in PR-1-deficient tobacco, indicating that PR-1 expression may repress that of PR-1g. This shows that acidic PR-1s are dispensable for expression of salicylic acid-dependent acquired resistances against P. parasitica and may reveal a functional overlap in tobacco defence......The class 1 pathogenesis-related (PR) proteins are thought to be involved in plant defence responses, but their molecular functions are unknown. The function of PR-1 was investigated in tobacco by generating stable PR-1a-silenced lines in which other acidic PR-1 genes (PR-1b and PR-1c) were...

  2. Induction of host defences by Rhizobium during ineffective nodulation of pea (Pisum sativum L.) carrying symbiotically defective mutations sym40 (PsEFD), sym33 (PsIPD3/PsCYCLOPS) and sym42.

    Science.gov (United States)

    Ivanova, Kira A; Tsyganova, Anna V; Brewin, Nicholas J; Tikhonovich, Igor A; Tsyganov, Viktor E

    2015-11-01

    Rhizobia are able to establish a beneficial interaction with legumes by forming a new organ, called the symbiotic root nodule, which is a unique ecological niche for rhizobial nitrogen fixation. Rhizobial infection has many similarities with pathogenic infection and induction of defence responses accompanies both interactions, but defence responses are induced to a lesser extent during rhizobial infection. However, strong defence responses may result from incompatible interactions between legumes and rhizobia due to a mutation in either macro- or microsymbiont. The aim of this research was to analyse different plant defence reactions in response to Rhizobium infection for several pea (Pisum sativum) mutants that result in ineffective symbiosis. Pea mutants were examined by histochemical and immunocytochemical analyses, light, fluorescence and transmission electron microscopy and quantitative real-time PCR gene expression analysis. It was observed that mutations in pea symbiotic genes sym33 (PsIPD3/PsCYCLOPS encoding a transcriptional factor) and sym40 (PsEFD encoding a putative negative regulator of the cytokinin response) led to suberin depositions in ineffective nodules, and in the sym42 there were callose depositions in infection thread (IT) and host cell walls. The increase in deposition of unesterified pectin in IT walls was observed for mutants in the sym33 and sym42; for mutant in the sym42, unesterified pectin was also found around degrading bacteroids. In mutants in the genes sym33 and sym40, an increase in the expression level of a gene encoding peroxidase was observed. In the genes sym40 and sym42, an increase in the expression levels of genes encoding a marker of hypersensitive reaction and PR10 protein was demonstrated. Thus, a range of plant defence responses like suberisation, callose and unesterified pectin deposition as well as activation of defence genes can be triggered by different pea single mutations that cause perception of an otherwise

  3. The rare sugar D-allose acts as a triggering molecule of rice defence via ROS generation.

    Science.gov (United States)

    Kano, Akihito; Fukumoto, Takeshi; Ohtani, Kouhei; Yoshihara, Akihide; Ohara, Toshiaki; Tajima, Shigeyuki; Izumori, Ken; Tanaka, Keiji; Ohkouchi, Takeo; Ishida, Yutaka; Nishizawa, Yoko; Ichimura, Kazuya; Tada, Yasuomi; Gomi, Kenji; Akimitsu, Kazuya

    2013-11-01

    Only D-allose, among various rare monosaccharides tested, induced resistance to Xanthomonas oryzae pv. oryzae in susceptible rice leaves with defence responses: reactive oxygen species, lesion mimic formation, and PR-protein gene expression. These responses were suppressed by ascorbic acid or diphenylene iodonium. Transgenic rice plants overexpressing OsrbohC, encoding NADPH oxidase, were enhanced in sensitivity to D-allose. D-Allose-mediated defence responses were suppressed by the presence of a hexokinase inhibitor. 6-Deoxy-D-allose, a structural derivative of D-allose unable to be phosphorylated, did not confer resistance. Transgenic rice plants expressing Escherichia coli AlsK encoding D-allose kinase to increase D-allose 6-phosphate synthesis were more sensitive to D-allose, but E. coli AlsI encoding D-allose 6-phosphate isomerase expression to decrease D-allose 6-phosphate reduced sensitivity. A D-glucose 6-phosphate dehydrogenase-defective mutant was also less sensitive, and OsG6PDH1 complementation restored full sensitivity. These results reveal that a monosaccharide, D-allose, induces rice resistance to X. oryzae pv. oryzae by activating NADPH oxidase through the activity of D-glucose 6-phosphate dehydrogenase, initiated by hexokinase-mediated conversion of D-allose to D-allose 6-phosphate, and treatment with D-allose might prove to be useful for reducing disease development in rice.

  4. Role of Arginine decarboxylase (ADC) in Arabidopsis thaliana defence against the pathogenic bacterium Pseudomonas viridiflava.

    Science.gov (United States)

    Rossi, F R; Marina, M; Pieckenstain, F L

    2015-07-01

    Polyamine biosynthesis starts with putrescine production through the decarboxylation of arginine or ornithine. In Arabidopsis thaliana, putrescine is synthesised exclusively by arginine decarboxylase (ADC), which exists as two isoforms (ADC1 and 2) that are differentially regulated by abiotic stimuli, but their role in defence against pathogens has not been studied in depth. This work analysed the participation of ADC in Arabidopsis defence against Pseudomonas viridiflava. ADC activity and expression, polyamine levels and bacterial resistance were analysed in null mutants of each ADC isoform. In non-infected wild-type (WT) plants, ADC2 expression was much higher than ADC1. Analysis of adc mutants demonstrated that ADC2 contributes to a much higher extent than ADC1 to basal ADC activity and putrescine biosynthesis. In addition, adc2 mutants showed increased basal expression of salicylic acid- and jasmonic acid-dependent PR genes. Bacterial infection induced putrescine accumulation and ADC1 expression in WT plants, but pathogen-induced putrescine accumulation was blocked in adc1 mutants. Results suggest a specific participation of ADC1 in defence, although basal resistance was not decreased by dysfunction of either of the two ADC genes. In addition, and as opposed to WT plants, bacterial infection increased ADC2 expression and ADC activity in adc1 mutants, which could counterbalance the lack of ADC1. Results demonstrate a major contribution of ADC2 to total ADC activity and the specific induction of ADC1 in response to infection. A certain degree of functional redundancy between the two isoforms in relation to their contribution to basal resistance is also evident. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  5. Testing for the induction of anti-herbivory defences in four Portuguese macroalgae by direct and water-borne cues of grazing amphipods

    Science.gov (United States)

    Yun, Hee Young; Cruz, Joana; Treitschke, Michaela; Wahl, Martin; Molis, Markus

    2007-09-01

    Herbivory is a key factor in regulating plant biomass, thereby driving ecosystem performance. Algae have developed multiple adaptations to cope with grazers, including morphological and chemical defences. In a series of experiments we investigated whether several species of macroalgae possess anti-herbivore defences and whether these could be regulated to demand, i.e. grazing events. The potential of direct grazing on defence induction was assessed for two brown ( Dictyopteris membranacea, Fucus vesiculosus) and two red seaweeds ( Gelidium sesquipedale, Sphaerococcus coronopifolius) from São Rafael and Ria Formosa, Portugal. Bioassays conducted with live algal pieces and agar-based food containing lipophilic algal extracts were used to detect changes in palatability after exposure to amphipod attacks (=treatment phase). Fucus vesiculosus was the only species significantly reducing palatability in response to direct amphipod-attacks. This pattern was observed in live F. vesiculosus pieces and agar-based food containing a lipophilic extract, suggesting that lipophilic compounds produced during the treatment phase were responsible for the repulsion of grazers. Water-borne cues of grazed F. vesiculosus as well as non-grazing amphipods also reduced palatability of neighbouring conspecifics. However, this effect was only observed in live tissues of F. vesiculosus. This study is the first to show that amphipods, like isopods, are capable to induce anti-herbivory defences in F. vesiculosus and that a seasonally variable effectiveness of chemical defences might serve as a dynamic control in alga-herbivore interactions.

  6. Defence electro-optics: European perspective

    Science.gov (United States)

    Hartikainen, Jari

    2011-11-01

    In 2009 the United States invested in defence R&T 3,6 times and in defence research and development 6,8 times as much as all member states of the European Defence Agency (EDA) combined while the ratio in the total defence expenditure was 2,6 in the US' favour. The European lack of investments in defence research and development has a negative impact on the competitiveness of European defence industry and on the European non-dependence. In addition, the efficiency of investment is reduced due to duplication of work in different member states. The Lisbon Treaty tasks EDA to support defence technology research, and coordinate and plan joint research activities and the study of technical solutions meeting future operational needs. This paper gives an overview how EDA meets the challenge of improving the efficiency of European defence R&T investment with an emphasis on electro-optics and describes shortly the ways that governmental and industrial partners can participate in the EDA cooperation. Examples of joint R&T projects addressing electro-optics are presented.

  7. Inter-plant communication through mycorrhizal networks mediates complex adaptive behaviour in plant communities.

    Science.gov (United States)

    Gorzelak, Monika A; Asay, Amanda K; Pickles, Brian J; Simard, Suzanne W

    2015-05-15

    Adaptive behaviour of plants, including rapid changes in physiology, gene regulation and defence response, can be altered when linked to neighbouring plants by a mycorrhizal network (MN). Mechanisms underlying the behavioural changes include mycorrhizal fungal colonization by the MN or interplant communication via transfer of nutrients, defence signals or allelochemicals. We focus this review on our new findings in ectomycorrhizal ecosystems, and also review recent advances in arbuscular mycorrhizal systems. We have found that the behavioural changes in ectomycorrhizal plants depend on environmental cues, the identity of the plant neighbour and the characteristics of the MN. The hierarchical integration of this phenomenon with other biological networks at broader scales in forest ecosystems, and the consequences we have observed when it is interrupted, indicate that underground 'tree talk' is a foundational process in the complex adaptive nature of forest ecosystems. Published by Oxford University Press on behalf of the Annals of Botany Company.

  8. Extraction and quantification of "condensed tannins" as a measure of plant anti-herbivore defence? Revisiting an old problem.

    Science.gov (United States)

    Heil, Martin; Baumann, Birgit; Andary, Claude; Linsenmair, K Eduard; McKey, Doyle

    2002-11-01

    Contents of phenolic compounds in leaf extracts often serve as a measure of plant anti-herbivore defence. This method suffers from the multifunctionality of phenolics and from problems with their colorimetric quantification. Here we present further evidence for the pertinence of these problems. Contents of condensed tannins (CCT) were spectrophotometrically quantified in leaf extracts of 11 closely related mimosoid species, and Spodoptera littoralis caterpillars were reared on artificial diet containing these extracts. The relationship of CCT with caterpillar growth differed considerably among plant species, since both positive and negative correlations were detected. There was, however, a negative correlation of CCT with fungal spore germination, indicating a role of these compounds in resistance to fungi. Detailed knowledge on the structure and biological function of defensive compounds and on the overall composition of leaves is required to estimate a plant's defensive efficacy against a particular group of enemies.

  9. Aerodynamic Test Facility Requirements for Defence R&D to 2000 and Beyond.

    Science.gov (United States)

    1982-09-01

    Defence Force. Following its review of science and technology, the Australian Science and Technology Council ( ASTEC ) reported I that the present pattern...Organisation (DSTO) within the Department of Defence. Accordingly, ASTEC recommended to the Prime Minister that the Department of Defence be asked to develop...DSTO2 as well as by ASTEC 1 . An additional reason for choosing aerodynamics for early consideration in response to ASTEC’s recommendation is that wind

  10. Good and bad protons: genetic aspects of acidity stress responses in plants.

    Science.gov (United States)

    Shavrukov, Yuri; Hirai, Yoshihiko

    2016-01-01

    Physiological aspects of acidity stress in plants (synonymous with H(+) rhizotoxicity or low-pH stress) have long been a focus of research, in particular with respect to acidic soils where aluminium and H(+) rhizotoxicities often co-occur. However, toxic H(+) and Al(3+) elicit different response mechanisms in plants, and it is important to consider their effects separately. The primary aim of this review was to provide the current state of knowledge regarding the genetics of the specific reactions to low-pH stress in growing plants. A comparison of the results gleaned from quantitative trait loci analysis and global transcriptome profiling of plants in response to high proton concentrations revealed a two-stage genetic response: (i) in the short-term, proton pump H(+)-ATPases present the first barrier in root cells, allocating an excess of H(+) into either the apoplast or vacuole; the ensuing defence signaling system involves auxin, salicylic acid, and methyl jasmonate, which subsequently initiate expression of STOP and DREB transcription factors as well as chaperone ROF; (2) the long-term response includes other genes, such as alternative oxidase and type II NAD(P)H dehydrogenase, which act to detoxify dangerous reactive oxygen species in mitochondria, and help plants better manage the stress. A range of transporter genes including those for nitrate (NTR1), malate (ALMT1), and heavy metals are often up-regulated by H(+) rhizotoxicity. Expansins, cell-wall-related genes, the γ-aminobutyric acid shunt and biochemical pH-stat genes also reflect changes in cell metabolism and biochemistry in acidic conditions. However, the genetics underlying the acidity stress response of plants is complicated and only fragmentally understood. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  11. Defence in depth for electric power supplies in Indian nuclear power plants

    International Nuclear Information System (INIS)

    Gupta, S.K.; Srivasista, K.; Solanki, R.B.

    2009-01-01

    The purpose of electric power supply system in a nuclear power plant is to supply and distribute reliable electric power to safety related systems and systems important to safety in various forms, arrangements and combinations of redundancy and diversity in order to perform safety functions required during operational states and design basis events (DBE) such as shutting down the reactor, maintaining the reactor in safe shutdown state, containment isolation and reactor core cooling preventing significant release of radioactive material to the environment. Hence the design basis of electric power supply systems includes identification of DBE that require power supplies, adequacy of redundancy and diversity, environmental conditions to which electric equipment are qualified, identification of loads requiring interrupted and uninterrupted power supplies, time sequence in which emergency loads are to be supplied in case of interruption, provisions for maintaining and testing, consideration for minimum duration capability of emergency power supplies during station blackout etc. Based on operation experience, results of probability safety assessment and certain weaknesses noticed in defence in depth of electric power supply systems, several continuous design improvements have been made in Indian nuclear power plants during operating phase and life extension. Instituting various tests during initial commissioning, subsequent operation and life extension has ensured high standards of performance of electric power supplies. Some of these aspects are highlighted in this paper

  12. Cathelicidin-like helminth defence molecules (HDMs: absence of cytotoxic, anti-microbial and anti-protozoan activities imply a specific adaptation to immune modulation.

    Directory of Open Access Journals (Sweden)

    Karine Thivierge

    Full Text Available Host defence peptides (HDPs are expressed throughout the animal and plant kingdoms. They have multifunctional roles in the defence against infectious agents of mammals, possessing both bactericidal and immune-modulatory activities. We have identified a novel family of molecules secreted by helminth parasites (helminth defence molecules; HDMs that exhibit similar structural and biochemical characteristics to the HDPs. Here, we have analyzed the functional activities of four HDMs derived from Schistosoma mansoni and Fasciola hepatica and compared them to human, mouse, bovine and sheep HDPs. Unlike the mammalian HDPs the helminth-derived HDMs show no antimicrobial activity and are non-cytotoxic to mammalian cells (macrophages and red blood cells. However, both the mammalian- and helminth-derived peptides suppress the activation of macrophages by microbial stimuli and alter the response of B cells to cytokine stimulation. Therefore, we hypothesise that HDMs represent a novel family of HDPs that evolved to regulate the immune responses of their mammalian hosts by retaining potent immune modulatory properties without causing deleterious cytotoxic effects.

  13. Armed rollers: does nestling's vomit function as a defence against predators?

    Directory of Open Access Journals (Sweden)

    Deseada Parejo

    Full Text Available Chemical defences against predators are widespread in the animal kingdom although have been seldom reported in birds. Here, we investigate the possibility that the orange liquid that nestlings of an insectivorous bird, the Eurasian roller (Coracias garrulus, expel when scared at their nests acts as a chemical defence against predators. We studied the diet of nestling rollers and vomit origin, its chemical composition and deterrent effect on a mammal generalist predator. We also hypothesized that nestling rollers, as their main prey (i.e. grasshoppers do from plants, could sequester chemicals from their prey for their use. Grasshoppers, that also regurgitate when facing to a threat, store the harmful substances used by plants to defend themselves against herbivores. We found that nestling rollers only vomit after being grasped and moved. The production of vomit depended on food consumption and the vomit contained two deterrent chemicals (hydroxycinnamic and hydroxybenzoic acids stored by grasshoppers and used by plants to diminish herbivory, suggesting that they originate from the rollers' prey. Finally, we showed for the first time that the oral secretion of a vertebrate had a deterrent effect on a model predator because vomit of nestling rollers made meat distasteful to dogs. These results support the idea that the vomit of nestling rollers is a chemical defence against predators.

  14. Defence-in-depth and development of safety requirements for advanced nuclear reactors

    International Nuclear Information System (INIS)

    Carnino, A.; Gasparini, M.

    2002-01-01

    The paper addresses a general approach for the preparation of the design safety requirements using the IAEA Safety Objectives and the strategy of defence-in-depth. It proposes a general method (top-down approach) to prepare safety requirements for a given kind of reactor using the IAEA requirements for nuclear power plants as a starting point through a critical interpretation and application of the strategy of defence-in-depth. The IAEA has recently developed a general methodology for screening the defence-in-depth of nuclear power plants starting from the fundamental safety objectives as proposed in the IAEA Safety Fundamentals. This methodology may provide a useful tool for the preparation of safety requirements for the design and operation of any kind of reactor. Currently the IAEA is preparing the technical basis for the development of safety requirements for Modular High Temperature Gas Reactors, with the aim of showing the viability of the method. A draft TECDOC has been prepared and circulated among several experts for comments. This paper is largely based on the content of the draft TECDOC. (authors)

  15. RNA-Binding Proteins in Plant Immunity

    Directory of Open Access Journals (Sweden)

    Virginia Woloshen

    2011-01-01

    Full Text Available Plant defence responses against pathogen infection are crucial to plant survival. The high degree of regulation of plant immunity occurs both transcriptionally and posttranscriptionally. Once transcribed, target gene RNA must be processed prior to translation. This includes polyadenylation, 5′capping, editing, splicing, and mRNA export. RNA-binding proteins (RBPs have been implicated at each level of RNA processing. Previous research has primarily focused on structural RNA-binding proteins of yeast and mammals; however, more recent work has characterized a number of plant RBPs and revealed their roles in plant immune responses. This paper provides an update on the known functions of RBPs in plant immune response regulation. Future in-depth analysis of RBPs and other related players will unveil the sophisticated regulatory mechanisms of RNA processing during plant immune responses.

  16. Isolation and characterization of a Vitis vinifera transcription factor, VvWRKY1, and its effect on responses to fungal pathogens in transgenic tobacco plants.

    Science.gov (United States)

    Marchive, Chloé; Mzid, Rim; Deluc, Laurent; Barrieu, François; Pirrello, Julien; Gauthier, Adrien; Corio-Costet, Marie-France; Regad, Farid; Cailleteau, Bernard; Hamdi, Saïd; Lauvergeat, Virginie

    2007-01-01

    Pathogen attack represents a major problem for viticulture and for agriculture in general. At present, the use of phytochemicals is more and more restrictive, and therefore it is becoming essential to control disease by having a thorough knowledge of resistance mechanisms. The present work focused on the trans-regulatory proteins potentially involved in the control of the plant defence response, the WRKY proteins. A full-length cDNA, designated VvWRKY1, was isolated from a grape berry library (Vitis vinifera L. cv. Cabernet Sauvignon). It encodes a polypeptide of 151 amino acids whose structure is characteristic of group IIc WRKY proteins. VvWRKY1 gene expression in grape is regulated in a developmental manner in berries and leaves and by various signal molecules involved in defence such as salicylic acid, ethylene, and hydrogen peroxide. Biochemical analysis indicates that VvWRKY1 specifically interacts with the W-box in various nucleotidic contexts. Functional analysis of VvWRKY1 was performed by overexpression in tobacco, and transgenic plants exhibited reduced susceptibility to various fungi but not to viruses. These results are consistent with a possible role for VvWRKY1 in grapevine defence against fungal pathogens.

  17. Organ-specific defence strategies of pepper (Capsicum annuum L.) during early phase of water deficit.

    Science.gov (United States)

    Sziderics, Astrid Heide; Oufir, Mouhssin; Trognitz, Friederike; Kopecky, Dieter; Matusíková, Ildikó; Hausman, Jean-Francois; Wilhelm, Eva

    2010-03-01

    Drought is one of the major factors that limits crop production and reduces yield. To understand the early response of plants under nearly natural conditions, pepper plants (Capsicum annuum L.) were grown in a greenhouse and stressed by withholding water for 1 week. Plants adapted to the decreasing water content of the soil by adjustment of their osmotic potential in root tissue. As a consequence of drought, strong accumulation of raffinose, glucose, galactinol and proline was detected in the roots. In contrast, in leaves the levels of fructose, sucrose and also galactinol increased. Due to the water deficit cadaverine, putrescine, spermidine and spermine accumulated in leaves, whereas the concentration of polyamines was reduced in roots. To study the molecular basis of these responses, a combined approach of suppression subtractive hybridisation and microarray technique was performed on the same material. A total of 109 unique ESTs were detected as responsive to drought, while additional 286 ESTs were selected from the bulk of rare transcripts on the array. The metabolic profiles of stressed pepper plants are discussed with respect to the transcriptomic changes detected, while attention is given to the differences between defence strategies of roots and leaves.

  18. Do plants and animals differ in phenotypic plasticity?

    Indian Academy of Sciences (India)

    Unknown

    fits, of a plastic versus non-plastic phenotype in plants and animals. [Renee M Borges ... polyphenol oxidase and other oxidative enzymes in the defence repertoire of .... males in response to environmental stress (Cremer and. Heinze 2003).

  19. 4th International Conference in Software Engineering for Defence Applications

    CERN Document Server

    Sillitti, Alberto; Succi, Giancarlo; Messina, Angelo

    2016-01-01

    This book presents high-quality original contributions on new software engineering models, approaches, methods, and tools and their evaluation in the context of defence and security applications. In addition, important business and economic aspects are discussed, with a particular focus on cost/benefit analysis, new business models, organizational evolution, and business intelligence systems. The contents are based on presentations delivered at SEDA 2015, the 4th International Conference in Software Engineering for Defence Applications, which was held in Rome, Italy, in May 2015. This conference series represents a targeted response to the growing need for research that reports and debates the practical implications of software engineering within the defence environment and also for software performance evaluation in real settings through controlled experiments as well as case and field studies. The book will appeal to all with an interest in modeling, managing, and implementing defence-related software devel...

  20. Grapevine fatty acid hydroperoxide lyase generates actin-disrupting volatiles and promotes defence-related cell death

    Science.gov (United States)

    Wang, Hao; Claudel, Patricia; Riemann, Michael; Hause, Bettina; Hugueney, Philippe; Nick, Peter

    2018-01-01

    Abstract Fatty acid hydroperoxides can generate short-chained volatile aldehydes that may participate in plant defence. A grapevine hydroperoxide lyase (VvHPL1) clustering to the CYP74B class was functionally characterized with respect to a role in defence. In grapevine leaves, transcripts of this gene accumulated rapidly to high abundance in response to wounding. Cellular functions of VvHPL1 were investigated upon heterologous expression in tobacco BY-2 cells. A C-terminal green fluorescent protein (GFP) fusion of VvHPL1 was located in plastids. The overexpression lines were found to respond to salinity stress or the bacterial elicitor harpin by increasing cell death. This signal-dependent mortality response was mitigated either by addition of exogenous jasmonic acid or by treatment with diphenyleneiodonium (DPI), an inhibitor of NADPH oxidases. By feeding different substrates to recombinantly expressed enzyme, VvHPL1 could also be functionally classified as true 13-HPL. The cognate products generated by this 13-HPL were cis-3-hexenal and trans-2-hexenal. Using a GFP-tagged actin marker line, one of these isomeric products, cis-3-hexenal, was found specifically to elicit a rapid disintegration of actin filaments. This response was not only observed in the heterologous system (tobacco BY-2), but also in a grapevine cell strain expressing this marker, as well as in leaf discs from an actin marker grape used as a homologous system. These results are discussed in the context of a role for VvHPL1 in a lipoxygenase-dependent signalling pathway triggering cell death-related defence that bifurcates from jasmonate-dependent basal immunity. PMID:29659985

  1. Phytoplankton defence mechanisms: traits and trade-offs

    DEFF Research Database (Denmark)

    Pančić, Marina; Kiørboe, Thomas

    2018-01-01

    mechanisms in phytoplankton are diverse and include physiological (e.g. toxicity, bioluminescence), morphological (e.g. silica shell, colony formation), and behavioural (e.g. escape response) traits. However, the function of many of the proposed defence mechanisms remains elusive, and the costs and benefits...

  2. Plum pox virus capsid protein suppresses plant pathogen-associated molecular pattern (PAMP)-triggered immunity.

    Science.gov (United States)

    Nicaise, Valerie; Candresse, Thierry

    2017-08-01

    The perception of pathogen-associated molecular patterns (PAMPs) by immune receptors launches defence mechanisms referred to as PAMP-triggered immunity (PTI). Successful pathogens must suppress PTI pathways via the action of effectors to efficiently colonize their hosts. So far, plant PTI has been reported to be active against most classes of pathogens, except viruses, although this defence layer has been hypothesized recently as an active part of antiviral immunity which needs to be suppressed by viruses for infection success. Here, we report that Arabidopsis PTI genes are regulated upon infection by viruses and contribute to plant resistance to Plum pox virus (PPV). Our experiments further show that PPV suppresses two early PTI responses, the oxidative burst and marker gene expression, during Arabidopsis infection. In planta expression of PPV capsid protein (CP) was found to strongly impair these responses in Nicotiana benthamiana and Arabidopsis, revealing its PTI suppressor activity. In summary, we provide the first clear evidence that plant viruses acquired the ability to suppress PTI mechanisms via the action of effectors, highlighting a novel strategy employed by viruses to escape plant defences. © 2016 BSPP AND JOHN WILEY & SONS LTD.

  3. Genome-wide identification of potato long intergenic noncoding RNAs responsive to Pectobacterium carotovorum subspecies brasiliense infection.

    Science.gov (United States)

    Kwenda, Stanford; Birch, Paul R J; Moleleki, Lucy N

    2016-08-11

    Long noncoding RNAs (lncRNAs) represent a class of RNA molecules that are implicated in regulation of gene expression in both mammals and plants. While much progress has been made in determining the biological functions of lncRNAs in mammals, the functional roles of lncRNAs in plants are still poorly understood. Specifically, the roles of long intergenic nocoding RNAs (lincRNAs) in plant defence responses are yet to be fully explored. In this study, we used strand-specific RNA sequencing to identify 1113 lincRNAs in potato (Solanum tuberosum) from stem tissues. The lincRNAs are expressed from all 12 potato chromosomes and generally smaller in size compared to protein-coding genes. Like in other plants, most potato lincRNAs possess single exons. A time-course RNA-seq analysis between a tolerant and a susceptible potato cultivar showed that 559 lincRNAs are responsive to Pectobacterium carotovorum subsp. brasiliense challenge compared to mock-inoculated controls. Moreover, coexpression analysis revealed that 17 of these lincRNAs are highly associated with 12 potato defence-related genes. Together, these results suggest that lincRNAs have potential functional roles in potato defence responses. Furthermore, this work provides the first library of potato lincRNAs and a set of novel lincRNAs implicated in potato defences against P. carotovorum subsp. brasiliense, a member of the soft rot Enterobacteriaceae phytopathogens.

  4. Both heavy metal-amendment of soil and aphid-infestation increase Cd and Zn concentrations in phloem exudates of a metal-hyperaccumulating plant.

    Science.gov (United States)

    Stolpe, Clemens; Giehren, Franziska; Krämer, Ute; Müller, Caroline

    2017-07-01

    Plants that are able to hyperaccumulate heavy metals show increased concentrations of these metals in their leaf tissue. However, little is known about the concentrations of heavy metals and of organic defence metabolites in the phloem sap of these plants in response to either heavy metal-amendment of the soil or biotic challenges such as aphid-infestation. In this study, we investigated the effects of heavy metal-exposure and of aphid-infestation on phloem exudate composition of the metal hyperaccumulator species Arabidopsis halleri L. O'Kane & Al-Shehbaz (Brassicaceae). The concentrations of elements and of organic defence compounds, namely glucosinolates, were measured in phloem exudates of young and old (mature) leaves of plants challenged either by amendment of the soil with cadmium and zinc and/or by an infestation with the generalist aphid Myzus persicae. Metal-amendment of the soil led to increased concentrations of Cd and Zn, but also of two other elements and one indole glucosinolate, in phloem exudates. This enhanced defence in the phloem sap of heavy metal-hyperaccumulating plants can thus potentially act as effective protection against aphids, as predicted by the elemental defence hypothesis. Aphid-infestation also caused enhanced Cd and Zn concentrations in phloem exudates. This result provides first evidence that metal-hyperaccumulating plants can increase heavy metal concentrations tissue-specifically in response to an attack by phloem-sucking herbivores. Overall, the concentrations of most elements, including the heavy metals, and glucosinolates were higher in phloem exudates of young leaves than in those of old leaves. This defence distribution highlights that the optimal defence theory, which predicts more valuable tissue to be better defended, is applicable for both inorganic and organic defences. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. The Mediator subunit SFR6/MED16 controls defence gene expression mediated by salicylic acid and jasmonate responsive pathways.

    Science.gov (United States)

    Wathugala, Deepthi L; Hemsley, Piers A; Moffat, Caroline S; Cremelie, Pieter; Knight, Marc R; Knight, Heather

    2012-07-01

    • Arabidopsis SENSITIVE TO FREEZING6 (SFR6) controls cold- and drought-inducible gene expression and freezing- and osmotic-stress tolerance. Its identification as a component of the MEDIATOR transcriptional co-activator complex led us to address its involvement in other transcriptional responses. • Gene expression responses to Pseudomonas syringae, ultraviolet-C (UV-C) irradiation, salicylic acid (SA) and jasmonic acid (JA) were investigated in three sfr6 mutant alleles by quantitative real-time PCR and susceptibility to UV-C irradiation and Pseudomonas infection were assessed. • sfr6 mutants were more susceptible to both Pseudomonas syringae infection and UV-C irradiation. They exhibited correspondingly weaker PR (pathogenesis-related) gene expression than wild-type Arabidopsis following these treatments or after direct application of SA, involved in response to both UV-C and Pseudomonas infection. Other genes, however, were induced normally in the mutants by these treatments. sfr6 mutants were severely defective in expression of plant defensin genes in response to JA; ectopic expression of defensin genes was provoked in wild-type but not sfr6 by overexpression of ERF5. • SFR6/MED16 controls both SA- and JA-mediated defence gene expression and is necessary for tolerance of Pseudomonas syringae infection and UV-C irradiation. It is not, however, a universal regulator of stress gene transcription and is likely to mediate transcriptional activation of specific regulons only. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  6. Neurons of self-defence: neuronal innervation of the exocrine defence glands in stick insects.

    Science.gov (United States)

    Stolz, Konrad; von Bredow, Christoph-Rüdiger; von Bredow, Yvette M; Lakes-Harlan, Reinhard; Trenczek, Tina E; Strauß, Johannes

    2015-01-01

    Stick insects (Phasmatodea) use repellent chemical substances (allomones) for defence which are released from so-called defence glands in the prothorax. These glands differ in size between species, and are under neuronal control from the CNS. The detailed neural innervation and possible differences between species are not studied so far. Using axonal tracing, the neuronal innervation is investigated comparing four species. The aim is to document the complexity of defence gland innervation in peripheral nerves and central motoneurons in stick insects. In the species studied here, the defence gland is innervated by the intersegmental nerve complex (ISN) which is formed by three nerves from the prothoracic (T1) and suboesophageal ganglion (SOG), as well as a distinct suboesophageal nerve (Nervus anterior of the suboesophageal ganglion). In Carausius morosus and Sipyloidea sipylus, axonal tracing confirmed an innervation of the defence glands by this N. anterior SOG as well as N. anterior T1 and N. posterior SOG from the intersegmental nerve complex. In Peruphasma schultei, which has rather large defence glands, only the innervation by the N. anterior SOG was documented by axonal tracing. In the central nervous system of all species, 3-4 neuron types are identified by axonal tracing which send axons in the N. anterior SOG likely innervating the defence gland as well as adjacent muscles. These neurons are mainly suboesophageal neurons with one intersegmental neuron located in the prothoracic ganglion. The neuron types are conserved in the species studied, but the combination of neuron types is not identical. In addition, the central nervous system in S. sipylus contains one suboesophageal and one prothoracic neuron type with axons in the intersegmental nerve complex contacting the defence gland. Axonal tracing shows a very complex innervation pattern of the defence glands of Phasmatodea which contains different neurons in different nerves from two adjacent body segments

  7. Involvement of the ABC transporter BcAtrB and the laccase BcLCC2 in defence of Botrytis cinerea against the broad-spectrum antibiotic 2,4-diacetylphloroglucinol

    NARCIS (Netherlands)

    Schouten, A.; Maksimova, O.; Cuesta Arenas, Y.; Berg, van den G.; Raaijmakers, J.M.

    2008-01-01

    The genetic and biochemical basis of defence mechanisms in plant pathogenic fungi against antifungal compounds produced by antagonistic microorganisms is largely unknown. The results of this study show that both degradative and non-degradative defence mechanisms enable the plant pathogenic fungus

  8. Leaf habit does not determine the investment in both physical and chemical defences and pair-wise correlations between these defensive traits.

    Science.gov (United States)

    Moreira, X; Pearse, I S

    2017-05-01

    Plant life-history strategies associated with resource acquisition and economics (e.g. leaf habit) are thought to be fundamental determinants of the traits and mechanisms that drive herbivore pressure, resource allocation to plant defensive traits, and the simultaneous expression (positive correlations) or trade-offs (negative correlations) between these defensive traits. In particular, it is expected that evergreen species - which usually grow slower and support constant herbivore pressure in comparison with deciduous species - will exhibit higher levels of both physical and chemical defences and a higher predisposition to the simultaneous expression of physical and chemical defensive traits. Here, by using a dataset which included 56 oak species (Quercus genus), we investigated whether leaf habit of plant species governs the investment in both physical and chemical defences and pair-wise correlations between these defensive traits. Our results showed that leaf habit does not determine the production of most leaf physical and chemical defences. Although evergreen oak species had higher levels of leaf toughness and specific leaf mass (physical defences) than deciduous oak species, both traits are essentially prerequisites for evergreenness. Similarly, our results also showed that leaf habit does not determine pair-wise correlations between defensive traits because most physical and chemical defensive traits were simultaneously expressed in both evergreen and deciduous oak species. Our findings indicate that leaf habit does not substantially contribute to oak species differences in plant defence investment. © 2017 German Botanical Society and The Royal Botanical Society of the Netherlands.

  9. Radiation protection and safety in the Australian Defence Organisation (ADO)

    International Nuclear Information System (INIS)

    Jenks, G.J.; O'Donovan, E.J.B.

    1995-01-01

    Very few organisations have to address such a diverse and complex range of radiation safety matters as the Australian Defence Organisation. The Australian Defence Force and the Department of Defence (its military and civilian branches) have to comply with strict regulations in normal peace time activities. The Surgeon-General, to whom responsibility for policy in radiation protection and safety falls, has established a Defence Radiation Safety Committee, which in turn oversees four specialist subcommittees. Their tasks include recommending policy and doctrine in relation to radiation safety, overseeing the implementation of appropriate regulations, monitoring their compliance. generating the relevant documentation (particularly on procedures to be followed), developing and improving any necessary training courses, and providing sound technical advice whenever and to whomever required. The internal Defence regulations do not permit radiation doses to exceed those limits recommended by the Australian National Health and Medical Research Council and precautions are taken to ensure during normal peace time duties that these levels are not exceeded. At times of national emergency, the Surgeon-General provides guidance and advice to military commanders on the consequences of receiving dose levels that would not be permitted during normal peace time activities. The paper describes the methods adopted to implement such arrangements

  10. Testing for the induction of anti-herbivory defences in four Portuguese macroalgae by direct and water-borne cues of grazing amphipods

    OpenAIRE

    Yun, H. Y.; Cruz, J.; Treitschke, M.; Wahl, Martin; Molis, M.

    2007-01-01

    Herbivory is a key factor in regulating plant biomass, thereby driving ecosystem performance. Algae have developed multiple adaptations to cope with grazers, including morphological and chemical defences. In a series of experiments we investigated whether several species of macroalgae possess anti-herbivore defences and whether these could be regulated to demand, i.e. grazing events. The potential of direct grazing on defence induction was assessed for two brown (Dictyopteris membranacea, Fuc...

  11. Public Private Business Models for Defence Acquisition - A Multiple Case Study of Defence Acquisition Projects in the UK

    OpenAIRE

    Ekström, Thomas

    2012-01-01

    Since the ending of the Cold War, the defence sector, particularly the areas of military logistics and defence acquisition, has been undergoing a comprehensive transformation. There are several factors that explain this transformation: changes in defence and security policies for nations and organisations; reductions in defence expenditure; participation in Peace Support Operations; Lessons Learned from these operations, especially in the area of logistics; revolutionary development in the ar...

  12. Menadione Sodium Bisulphite (MSB) enhances the resistance response of tomato, leading to repel mollusc pests.

    Science.gov (United States)

    Carrillo-Perdomo, Estefanía; Jiménez-Arias, David; Aller, Ángel; Borges, Andrés A

    2016-05-01

    Snails and slugs are terrestrial gastropods representing an important biotic stress that adversely affects crop yields. These pests are typically controlled with molluscicides, which produce pollution and toxicity and further induce the evolution of resistance mechanisms, making pest management even more challenging. In our work, we have assessed the efficacy of two different plant defence activators, menadione sodium bisulphite (MSB) and 1,2,3-benzothiadiazole-7-thiocarboxylic acid S-methyl ester (BTH), as inducers of resistance mechanisms of the model plant for defence, Solanum lycopersicum, against the generalist mollusc Theba grasseti (Helicidae). The study was designed to test the feeding behaviour and choice of snails, and also to analyse the expression profile of different genes specifically involved in defence against herbivores and wounds. Our data suggest that, through the downregulation of the terpene volatile genes and the production of proteinase inhibitors, treated MSB plants may be less apparent to herbivores that use herbivore-induced plant volatiles for host location. By contrast, BTH was not effective in the treatment of the pest, probably owing to an antagonistic effect derived from the induction of both salicylic-acid-dependent and jasmonic-acid-dependent pathways. This information is crucial to determine the genetic basis of the choice of terrestrial gastropod herbivores in tomato, providing valuable insight into how the plant defence activators could control herbivore pests in plants. Our work not only reports for the first time the interaction between tomato and a mollusc pest but also presents the action of two plant defence inductors that seems to produce opposed responses by inducing resistance mechanisms through different defence pathways. © 2015 Society of Chemical Industry.

  13. Transcriptome analysis in oak uncovers a strong impact of endogenous rhythmic growth on the interaction with plant-parasitic nematodes.

    Science.gov (United States)

    Maboreke, Hazel R; Feldhahn, Lasse; Bönn, Markus; Tarkka, Mika T; Buscot, Francois; Herrmann, Sylvie; Menzel, Ralph; Ruess, Liliane

    2016-08-12

    Pedunculate oak (Quercus robur L.), an important forest tree in temperate ecosystems, displays an endogenous rhythmic growth pattern, characterized by alternating shoot and root growth flushes paralleled by oscillations in carbon allocation to below- and aboveground tissues. However, these common plant traits so far have largely been neglected as a determining factor for the outcome of plant biotic interactions. This study investigates the response of oak to migratory root-parasitic nematodes in relation to rhythmic growth, and how this plant-nematode interaction is modulated by an ectomycorrhizal symbiont. Oaks roots were inoculated with the nematode Pratylenchus penetrans solely and in combination with the fungus Piloderma croceum, and the systemic impact on oak plants was assessed by RNA transcriptomic profiles in leaves. The response of oaks to the plant-parasitic nematode was strongest during shoot flush, with a 16-fold increase in the number of differentially expressed genes as compared to root flush. Multi-layered defence mechanisms were induced at shoot flush, comprising upregulation of reactive oxygen species formation, hormone signalling (e.g. jasmonic acid synthesis), and proteins involved in the shikimate pathway. In contrast during root flush production of glycerolipids involved in signalling cascades was repressed, suggesting that P. penetrans actively suppressed host defence. With the presence of the mycorrhizal symbiont, the gene expression pattern was vice versa with a distinctly stronger effect of P. penetrans at root flush, including attenuated defence, cell and carbon metabolism, likely a response to the enhanced carbon sink strength in roots induced by the presence of both, nematode and fungus. Meanwhile at shoot flush, when nutrients are retained in aboveground tissue, oak defence reactions, such as altered photosynthesis and sugar pathways, diminished. The results highlight that gene response patterns of plants to biotic interactions, both

  14. Civil defence information for every home

    International Nuclear Information System (INIS)

    Joutsi, L.

    1995-01-01

    In Finland, the local authorities and the central government are responsible for the general planning of civil defence and for joint protection measures, while individual citizens and corporations are responsible for individual protection measures. In practice, housing companies and employers are required to carry out the statutory preparations needed for civil defence. Preparation for accidents can be improved, for instance, by awareness of correct actions in each situation. The most important individual protection measures are first aid, basic fire extinguishing skills, provision of shelter, and acquisition of a reserve stock of provisions at home. A reserve stock means that there is a sufficient supply of non-perishable foodstuffs, medication and water vessels for a couple of days' needs at home. A warning of imminent danger is usually given by sounding a general alarm signal. Even slight changes in radiation are reported immediately. Shelter should primarily be sought indoors. Instructions may be given on the radio, on TV and by means of loudspeakers. If there is a radiation risk, the thyroid may be protected against radioactive iodine by taking iodine tablets, but they should not be taken until so instructed by the authorities. (2 figs.)

  15. Biochemical response and host-pathogen relation of stalk rot fungi ...

    African Journals Online (AJOL)

    Dr. nirupma

    photosynthesis, which are the vital processes taking place inside the plant, leading to wide fluctuations in sugars (Klement ... The suspension spray was prepared by taking. 200 ml of ..... biochemical factors due to cell response that is, defence .... by Fusarium moniliforme on corn growth and cellular morphology. Plant Dis.

  16. Did fleshy fruit pulp evolve as a defence against seed loss rather ...

    Indian Academy of Sciences (India)

    dispersers. Most seed dispersal studies are ecological and examine the role of fruit pulp in promoting seed dispersal. ... Introduction. Endozoochory, the interaction between fleshy-fruited plants ... adaptations for seed defence may have led to the evolution ..... Eriksson O and Bremer B 1992 Pollination systems, dispersal.

  17. Safety improvements at Canadian nuclear power plants in the aftermath of Fukushima accident

    International Nuclear Information System (INIS)

    Rzentkowski, G.; Khouaja, H.

    2014-01-01

    This paper describes the safety review of operating nuclear power plants undertaken by the Canadian Nuclear Safety Commission in light of the March 11, 2011 accident at the Fukushima Daiichi Nuclear Power Plants (NPPs). The review confirmed that the Canadian NPPs are robust and have a strong design relying on multiple layers of defence to protect the public from credible external events. Nevertheless, in the spirit of continuous safety improvements, the review identified a number of recommendations to further strengthen reactor defence-in-depth in preventing and mitigating the consequences of beyond design basis accidents, enhance onsite and offsite emergency response, and improve the CNSC regulatory framework. Progress achieved to date, in implementing these measures, is described in this paper along with a summary of safety benefits for each level of the reactor defence-in-depth. (author)

  18. Safety improvements at Canadian nuclear power plants in the aftermath of Fukushima accident

    Energy Technology Data Exchange (ETDEWEB)

    Rzentkowski, G.; Khouaja, H. [Canadian Nuclear Safety Commission, Ottawa, ON (Canada)

    2014-07-01

    This paper describes the safety review of operating nuclear power plants undertaken by the Canadian Nuclear Safety Commission in light of the March 11, 2011 accident at the Fukushima Daiichi Nuclear Power Plants (NPPs). The review confirmed that the Canadian NPPs are robust and have a strong design relying on multiple layers of defence to protect the public from credible external events. Nevertheless, in the spirit of continuous safety improvements, the review identified a number of recommendations to further strengthen reactor defence-in-depth in preventing and mitigating the consequences of beyond design basis accidents, enhance onsite and offsite emergency response, and improve the CNSC regulatory framework. Progress achieved to date, in implementing these measures, is described in this paper along with a summary of safety benefits for each level of the reactor defence-in-depth. (author)

  19. Self-Defence as a Circumstance Precluding the Wrongfulness of the Use of Force

    Directory of Open Access Journals (Sweden)

    Cliff Farhang

    2015-07-01

    Full Text Available Roberto Ago, the International Law Commission’s second Special Rapporteur on the topic of state responsibility for internationally wrongful acts, defined self-defence as a faculté of a state to use force in response to an act of another state through which a breach of the principal obligation under Article 2(4 Charter is committed. On this basis, he then inserted a provision in Chapter V to Part One of the Draft Articles on State Responsibility expressing self-defence as a specific factual circumstance precluding the wrongfulness of the use of force which constitutes a response to state aggression. This conception of self-defence, although misunderstood from the onset, remained in the backdrop of the study of the law of state responsibility for a considerable period. It was only dismantled during the reign of the last Special Rapporteur on the topic of state responsibility, James Crawford. The last Rapporteur, at the onset, submitted that it is not the function of the Draft Articles to specify the content of the primary rules, including that referred to in Article 51 Charter. He then redefined the function of the circumstance of self-defence as that of precluding the wrongfulness of non-performance of certain obligations other than the general prohibition insofar as such non-performance is connected with the exercise of the right under Article 51 Charter.This contribution first scrutinises this paradigmatic shift and finds it to be symptomatic of the conviction on the part of Crawford that the notion of self-defence could also encompass the use of force against speculative threats of state origin as well as actual threats that emanate from individuals or groups which are disconnected from the organisation of any state. It then uses this finding as a springboard towards the examination of the controversy surrounding the notion of self-defence under international law. In that connection, it first outlines the findings of the World Court on the

  20. Bruce NGS a loss of flow analysis for effectiveness of level 2 defence-in-depth provisions

    International Nuclear Information System (INIS)

    Won, W.; Jiang, Y.; Kwee, M.; Xue, J.

    2014-01-01

    The concept of defence-in-depth is applied to CANDU (CANada Deuterium Uranium) reactor designs and operations to provide series of levels of defence to prevent accidents progressing and to provide protection for reactor and public safety. The level 2 defence-in-depth provisions are designed to detect and intercept deviation from normal operation in order to prevent anticipated operating occurrences (AOOs) from escalating to accident conditions, and to return the plant to a state of normal operations, according to the Canada Nuclear Safety Commission (CNSC) regulatory document RD-337. Historically, safety analysis has focused on the effectiveness of level 3 defence-in-depth provisions in accident conditions, and the effectiveness of level 2 defence-in-depth has not been assessed. In this study, the effectiveness of Level 2 defence-in-depth is assessed for loss of flow (LOF) events for Bruce Nuclear Generating Station (NGS) A reactors. The level 2 defence-in-depth in Bruce NGS A design is identified to be the stepback function of reactor regulating system (RRS). The behavior of RRS stepback following the initiation of loss of flow event is simulated using RFSP/TUF/RRS - em coupled code. The behavior of full system and single channel is simulated and assessed against the acceptance criteria - fitness for service of systems, structures and components (SSCs). (author)

  1. Bruce NGS a loss of flow analysis for effectiveness of level 2 defence-in-depth provisions

    Energy Technology Data Exchange (ETDEWEB)

    Won, W. [AMEC NSS, Toronto, ON (Canada); Jiang, Y.; Kwee, M.; Xue, J. [Bruce Power, Toronto, ON (Canada)

    2014-07-01

    The concept of defence-in-depth is applied to CANDU (CANada Deuterium Uranium) reactor designs and operations to provide series of levels of defence to prevent accidents progressing and to provide protection for reactor and public safety. The level 2 defence-in-depth provisions are designed to detect and intercept deviation from normal operation in order to prevent anticipated operating occurrences (AOOs) from escalating to accident conditions, and to return the plant to a state of normal operations, according to the Canada Nuclear Safety Commission (CNSC) regulatory document RD-337. Historically, safety analysis has focused on the effectiveness of level 3 defence-in-depth provisions in accident conditions, and the effectiveness of level 2 defence-in-depth has not been assessed. In this study, the effectiveness of Level 2 defence-in-depth is assessed for loss of flow (LOF) events for Bruce Nuclear Generating Station (NGS) A reactors. The level 2 defence-in-depth in Bruce NGS A design is identified to be the stepback function of reactor regulating system (RRS). The behavior of RRS stepback following the initiation of loss of flow event is simulated using RFSP/TUF/RRS{sub -}em coupled code. The behavior of full system and single channel is simulated and assessed against the acceptance criteria - fitness for service of systems, structures and components (SSCs). (author)

  2. Western European Nuclear Regulators’ Association (WENRA) Views on Defence-in-Depth for New Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Reiman, L.; Routamo, T. [STUK, Helsinki (Finland); Féron, F., E-mail: lasse.reiman@stuk.fi [ASN (France)

    2014-10-15

    WENRA published in 2010 a statement on safety objectives for new NPPs. Based on these objectives, WENRA decided to develop common positions, compiled in a booklet (available on www.wenra.org), on selected key safety issues for the design of new NPPs. One position presents WENRA’s Defence-in-Depth approach, describing WENRA’s expectation that multiple failure events and core melt accidents are considered in the original design of new nuclear power plants; another position presents expectations on the independence between different levels of Defence-in-Depth. (author)

  3. Induction of defence mechanisms in grapevine leaves by emodin- and anthraquinone-rich plant extracts and their conferred resistance to downy mildew.

    Science.gov (United States)

    Godard, Sophie; Slacanin, Ivan; Viret, Olivier; Gindro, Katia

    2009-09-01

    The ability of two plant extracts, Rheum palmatum root extract (RPRE) and Frangula alnus bark extract (FABE), to protect Vitis vinifera leaves from Plasmopara viticola infection was evaluated. These natural products are toxic to the pathogen and induce defence reactions in a susceptible cultivar of V. vinifera (V. vinifera cv. Chasselas), including stilbenic phytoalexin accumulation, enhanced peroxidase (EC 1.11.1.7) activity, and a hypersensitive reaction. Inhibition of the first stage of biotrophic hyphal development of P. Viticola by the two plant extracts was observed. HPLC-DAD-MS analysis showed that these two natural extracts contain many phenolic compounds belonging to the anthraquinone family, such as rhein, frangulin A, emodin, aloe-emodin, chrysophanol, and physcion. Emodin alone is able to impair P. viticola development and to stimulate viniferins and the accumulation of pterostilbene.

  4. Simple growth patterns can create complex trajectories for the ontogeny of constitutive chemical defences in seaweeds.

    Directory of Open Access Journals (Sweden)

    Nicholas A Paul

    Full Text Available All of the theory and most of the data on the ecology and evolution of chemical defences derive from terrestrial plants, which have considerable capacity for internal movement of resources. In contrast, most macroalgae--seaweeds--have no or very limited capacity for resource translocation, meaning that trade-offs between growth and defence, for example, should be localised rather than systemic. This may change the predictions of chemical defence theories for seaweeds. We developed a model that mimicked the simple growth pattern of the red seaweed Asparagopsis armata which is composed of repeating clusters of somatic cells and cells which contain deterrent secondary chemicals (gland cells. To do this we created a distinct growth curve for the somatic cells and another for the gland cells using empirical data. The somatic growth function was linked to the growth function for defence via differential equations modelling, which effectively generated a trade-off between growth and defence as these neighbouring cells develop. By treating growth and defence as separate functions we were also able to model a trade-off in growth of 2-3% under most circumstances. However, we found contrasting evidence for this trade-off in the empirical relationships between growth and defence, depending on the light level under which the alga was cultured. After developing a model that incorporated both branching and cell division rates, we formally demonstrated that positive correlations between growth and defence are predicted in many circumstances and also that allocation costs, if they exist, will be constrained by the intrinsic growth patterns of the seaweed. Growth patterns could therefore explain contrasting evidence for cost of constitutive chemical defence in many studies, highlighting the need to consider the fundamental biology and ontogeny of organisms when assessing the allocation theories for defence.

  5. The long-term resistance mechanisms, critical irrigation threshold and relief capacity shown by Eugenia myrtifolia plants in response to saline reclaimed water

    DEFF Research Database (Denmark)

    Acosta-Motos, José Ramón; Hernández, José Antonio; Álvarez, Sara

    2017-01-01

    water potential, the relative water content of leaves, leaf stomatal conductance, the leaf photosynthetic rate, water-use efficiency and accumulated evapotranspiration in order to limit water loss; and 4) changes in the antioxidant defence mechanisms. These different responses induced oxidative stress...... to different electric conductivities of the treatments. Based on these premises, we studied the long-term effect of three reclaimed water treatments with different saline concentrations on Eugenia myrtifolia plants. We also looked at the ability of these plants to recover when no drainage was applied. The RW...... with the highest electric conductivity (RW3, EC = 6.96 dS m(-1)) provoked a number of responses to salinity in these plants, including: 1) accumulation and extrusion of phytotoxic ions in roots; 2) a decrease in the shoot/root ratio, leaf area, number of leaves; 3) a decrease in root hydraulic conductivity, leaf...

  6. Biocontrol traits of plant growth suppressive arbuscular mycorrhizal fungi against root rot in tomato caused by Pythium aphanidermatum

    DEFF Research Database (Denmark)

    Larsen, John; Graham, James H.; Cubero, Jaime

    2012-01-01

    Arbuscular mycorrhizal (AM) fungi known to cause plant growth depressions in tomato were examined for their biocontrol effects against root rot caused by Pythium aphanidermatum. The main hypothesis was that plant growth suppressive AM fungi would elicit a defence response in the host plant reduci...

  7. Driving Danish Defence Towards Political Goals

    Science.gov (United States)

    2016-06-10

    discuss the political agreement.90 The Defence Chief of Staff is interviewed in the same paper along the same lines, where he provides an in- depth ...DRIVING DANISH DEFENCE TOWARDS POLITICAL GOALS A thesis presented to the Faculty of the U.S. Army Command and General Staff...4. TITLE AND SUBTITLE Driving Danish Defence Towards Political Goals 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6

  8. Effect of water deficiency on the cellular status and antioxidant defences in anthyllis sericea. A saharian plant

    International Nuclear Information System (INIS)

    Triki, T.; Selmi, A.

    2017-01-01

    Drought is known as an important restricting factor of plant productivity in arid and semi arid areas of the world. The intended increase of temperature in many areas will intensify this problem. In this study the effect of drought stress was studied in a Saharan plant, Anthyllissericea, by Poly-ethylene glycol (PEG-6000) in three different treatments (-0.2 MPa (control), -1.2 MPa (moderate stress) and -2.1 MPa (severe stress)) after 14 days. Nitric oxide (NO) content, Hydrogen peroxide (H/sub 2/O/sub 2/), RWC, lipid peroxidation and enzymatic antioxidant levels from the leaves were analyzed. Initially, plant growth, RWC and the water potentiel (/psi/ w) were decreased with increase of osmotic stress. Drought induces the increase of NO and hydrogen peroxide levels reaching maximum in severe stress period. MDA, proline content and soluble sugars were found to be higher under moderate and severe stress conditions. Plant employs enzymatic antioxidant system to avoid the subproduction of (ROS) resulting by drought. The analysis of CAT, APX and POD activities showed a significant increase during drought stress. Under moderate and severe stress treatments, the higher activities of H/sub 2/O/sub 2/, NO, CAT and POD showed a stronger system of antioxidant defences in the metabolic regulation during the applied stress. These results propose that A. sericea has the capacity to activate important adaptative mechanisms under dry conditions involving activation of enzymatic antioxidative defense system and higher osmoprotectants accumulation. (author)

  9. Operational Analysis on Torpedo Defence

    NARCIS (Netherlands)

    Grootendorst, H.J.; Benders, F.P.A.; Fitski, H.J.; Veldhoven, E.R. van

    2007-01-01

    Since 1998, TNO Defence, Security and Safety has performed operational analysis with the Underwater Warfare Testbed, which provides an environment for evaluation and validation of systems, concepts, and tactics. On top of this testbed the Torpedo Defence System TestBed has been built to simulate

  10. The coat protein of Alfalfa mosaic virus interacts and interferes with the transcriptional activity of the bHLH transcription factor ILR3 promoting salicylic acid-dependent defence signalling response.

    Science.gov (United States)

    Aparicio, Frederic; Pallás, Vicente

    2017-02-01

    During virus infection, specific viral component-host factor interaction elicits the transcriptional reprogramming of diverse cellular pathways. Alfalfa mosaic virus (AMV) can establish a compatible interaction in tobacco and Arabidopsis hosts. We show that the coat protein (CP) of AMV interacts directly with transcription factor (TF) ILR3 of both species. ILR3 is a basic helix-loop-helix (bHLH) family member of TFs, previously proposed to participate in diverse metabolic pathways. ILR3 has been shown to regulate NEET in Arabidopsis, a critical protein in plant development, senescence, iron metabolism and reactive oxygen species (ROS) homeostasis. We show that the AMV CP-ILR3 interaction causes a fraction of this TF to relocate from the nucleus to the nucleolus. ROS, pathogenesis-related protein 1 (PR1) mRNAs, salicylic acid (SA) and jasmonic acid (JA) contents are increased in healthy Arabidopsis loss-of-function ILR3 mutant (ilr3.2) plants, which implicates ILR3 in the regulation of plant defence responses. In AMV-infected wild-type (wt) plants, NEET expression is reduced slightly, but is induced significantly in ilr3.2 mutant plants. Furthermore, the accumulation of SA and JA is induced in Arabidopsis wt-infected plants. AMV infection in ilr3.2 plants increases JA by over 10-fold, and SA is reduced significantly, indicating an antagonist crosstalk effect. The accumulation levels of viral RNAs are decreased significantly in ilr3.2 mutants, but the virus can still systemically invade the plant. The AMV CP-ILR3 interaction may down-regulate a host factor, NEET, leading to the activation of plant hormone responses to obtain a hormonal equilibrium state, where infection remains at a level that does not affect plant viability. © 2016 BSPP AND JOHN WILEY & SONS LTD.

  11. Piloting Snapchat for Finnish Defence Forces

    OpenAIRE

    Immonen, Helena

    2016-01-01

    This thesis is about piloting Snapchat for Finnish Defence Forces. The goals for the thesis are to find out how Snapchat can be used as part of Finnish Defence Forces’ social media communication and strategy. Conscripts are the most important target group for social media communication in the Defence Forces. Young conscripts are the main target group for Snapchat. This thesis is theoretically based on organizational communication, stakeholder communication and social media communicati...

  12. The reconfiguration of the SA defence industry in the post-2015-defence review environment: prospects & challenges

    CSIR Research Space (South Africa)

    Khanyile, Moses

    2017-10-01

    Full Text Available IMPLICATIONS • Licence category (FSB) • Credit licence (NCR) • Forex Licence (SARB) Armscor & AMD Initiative: Establishment of the Defence Industry Fund (DIF) WAY FORWARD Finalisation of the Defence Industry Strategy Drafting...

  13. CSIR eNews: Defence peace safety and security

    CSIR Research Space (South Africa)

    CSIR

    2009-08-01

    Full Text Available , peace, safety and security. CSIR Defence, Peace, Safety and Security provides a national defence S&T capability: supplying knowledge, advice and solutions in defence and matters of national security....

  14. Ethylenediurea as a potential tool in evaluating ozone phytotoxicity: a review study on physiological, biochemical and morphological responses of plants.

    Science.gov (United States)

    Tiwari, Supriya

    2017-06-01

    Present-day climate change scenario has intensified the problem of continuously increasing ground-level ozone (O 3 ), which is responsible for causing deleterious effects on growth and development of plants. Studies involving use of ethylenediurea (EDU), a chemical with antiozonant properties, have given some promising results in evaluating O 3 injury in plants. The use of EDU is especially advantageous in developing countries which face a more severe problem of ground-level O 3 , and technical O 3 -induced yield loss assessment techniques like open-top chambers cannot be used. Recent studies have detected a hormetic response of EDU on plants; i.e. treatment with higher EDU concentrations may or may not show any adverse effect on plants depending upon the experimental conditions. Although the mode of action of EDU is still debated, it is confirmed that EDU remains confined in the apoplastic regions. Certain studies indicate that EDU significantly affects the electron transport chain and has positive impact on the antioxidant defence machinery of the plants. However, the mechanism of protecting the yield of plants without significantly affecting photosynthesis is still questionable. This review discusses in details the probable mode of action of EDU on the basis of available data along with the impact of EDU on physiological, biochemical, growth and yield response of plants under O 3 stress. Data regarding the effect of EDU on plant 'omics' is highly insufficient and can form an important aspect of future EDU research.

  15. European defence industry consolidation and domestic procurement bias

    DEFF Research Database (Denmark)

    Kluth, Michael Friederich

    2017-01-01

    How have European cross-border defence industrial mergers and acquisitions affected domestic procurement bias among the major EU powers? This article departs from the findings of Andrew Moravcsik more than two decades ago suggesting that major West European states had no ingrained preferences...... for defence industrial autarchy. When cross-national armament projects were derailed, this could be attributed to political efforts of national defence industrial champions favouring purely domestic projects. As former national champions join pan-European defence groups, their preferences are likely modified......-border defence industry consolidation will be analysed. Procurement bias is assessed in two industry segments characterised by pervasive consolidation....

  16. Antioxidant defences of Norway spruce bark against bark beetles and its associated blue-stain fungus

    Directory of Open Access Journals (Sweden)

    Felicijan Mateja

    2015-12-01

    Full Text Available Bark beetles and their fungal associates are integral parts of forest ecosystems, the European spruce bark beetle (Ips typographus Linnaeus, 1758 and the associated pathogenic blue stain fungus Ceratocystis polonica (SIEM. C. MOREAU, are the most devastating pests regarding Norway spruce [Picea abies (L. H. KARST.]. Bark beetles commonly inhabit weakened and felled trees as well as vital trees. They cause physiological disorders in trees by destroying a phloem and cambium or interrupt the transpiration -ow in the xylem. Conifers have a wide range of effective defence mechanisms that are based on the inner bark anatomy and physiological state of the tree. The basic function of bark defences is to protect the nutrient-and energy-rich phloem, the vital meristematic region of the vascular cambium, and the transpiration -ow in the sapwood. The main area of defence mechanisms is secondary phloem, which is physically and chemically protected by polyphenolic parenchyma (PP cells, sclerenchyma, calcium oxalate crystals and resin ducts. Conifer trunk pest resistance includes constitutive, inducible defences and acquired resistance. Both constitutive and inducible defences may deter beetle invasion, impede fungal growth and close entrance wounds. During a successful attack, systemic acquired resistance (SAR becomes effective and represents a third defence strategy. It gradually develops throughout the plant and provides a systemic change within the whole tree’s metabolism, which is maintained over a longer period of time. The broad range of defence mechanisms that contribute to the activation and utilisation of SAR, includes antioxidants and antioxidant enzymes, which are generally linked to the actions of reactive oxygen species (ROS. The presented review discusses the current knowledge on the antioxidant defence strategies of spruce inner bark against the bark beetle (Ips typographus and associated blue stain fungus (Ceratocystis polonica.

  17. Chemical defence and toxins of plants

    NARCIS (Netherlands)

    Yamane, H.; Konno, K.; Sabelis, M.; Takabayashi, J.; Sassa, T.; Oikawa, H.; Mander, L.; Lui, H.W.

    2010-01-01

    Higher plants protect themselves by producing a variety of secondary metabolites and proteins that are involved in defense against herbivores as well as microbial pathogens. Concerning microbial pathogenesis in plants, in many cases, it is known that phytotoxins that are produced by plant pathogens

  18. Defence in Depth and Ageing Management

    Energy Technology Data Exchange (ETDEWEB)

    Fabbri, S.; Vega, G.; Diluch, A.; Versaci, R., E-mail: versaci@cnea.gov.ar [Comisión Nacional de Energía Atómica, Buenos Aires (Argentina)

    2014-10-15

    Accident prevention is the first safety priority of both designers and operators. It is achieved through the use of reliable structures, components, systems and procedures in a plant operated by personnel who are committed to a strong safety culture. For future nuclear power plants, consideration of multiple failures and severe accidents will be achieved in a more systematic and complete way from the design stage. Defence in depth (DID) consists of a hierarchical deployment of different levels of equipment and procedures in order to maintain the effectiveness of physical barriers placed between radioactive materials and workers, the public or the environment, in normal operation, anticipated operational occurrences and, for some barriers, in accidents at the plant. The primary way of preventing accidents is to achieve a high quality in design, construction and operation of the plant, and thereby to ensure that deviations from normal operation are infrequent. The best way to meet these premises of effectiveness of the barriers and the Systems, Structures and Components (SSCs) is to develop an ageing management programme to prevent potential failures and accidents. In this work we will refer to the ageing management programme for Atucha I and Atucha II power plants and to the Atucha I spent fuel storage. (author)

  19. Families of returned defence force personnel: a changing landscape of challenges.

    Science.gov (United States)

    Berle, David; Steel, Zachary

    2015-08-01

    This paper aims to identify the key challenges experienced by the families of defence force personnel following deployment. We undertook a selective review of four post-deployment challenges to the families of defence force personnel: (1) changes to relationships; (2) changes to family member roles and responsibilities; (3) adjustment of children and parenting challenges; and (4) anger, family conflict and violence. Emerging issues in the area of post-deployment adjustment are also discussed. Empirical studies of post-deployment family adjustment are lacking. Each of the reviewed challenges can contribute to psychological difficulties and precipitate contact with mental health services. The challenges faced by defence force personnel when returning from deployment arise within a family context. Clinicians should thoroughly assess these factors in families following deployment, but also recognise family strengths and resilience to these challenges. © The Royal Australian and New Zealand College of Psychiatrists 2015.

  20. CSIR eNews: Defence peace safety and security

    CSIR Research Space (South Africa)

    CSIR

    2008-12-01

    Full Text Available The CSIR Defence peace safety and security research unit aims to provide a defence evaluation and research institute capability for the Department of Defence. It also serves as the 'in-house' S&T capability of key government departments and agencies...

  1. Molecular signatures in Arabidopsis thaliana in response to insect attack and bacterial infection.

    Science.gov (United States)

    Barah, Pankaj; Winge, Per; Kusnierczyk, Anna; Tran, Diem Hong; Bones, Atle M

    2013-01-01

    Under the threat of global climatic change and food shortages, it is essential to take the initiative to obtain a comprehensive understanding of common and specific defence mechanisms existing in plant systems for protection against different types of biotic invaders. We have implemented an integrated approach to analyse the overall transcriptomic reprogramming and systems-level defence responses in the model plant species Arabidopsis thaliana (A. thaliana henceforth) during insect Brevicoryne brassicae (B. brassicae henceforth) and bacterial Pseudomonas syringae pv. tomato strain DC3000 (P. syringae henceforth) attacks. The main aim of this study was to identify the attacker-specific and general defence response signatures in A. thaliana when attacked by phloem-feeding aphids or pathogenic bacteria. The obtained annotated networks of differentially expressed transcripts indicated that members of transcription factor families, such as WRKY, MYB, ERF, BHLH and bZIP, could be crucial for stress-specific defence regulation in Arabidopsis during aphid and P. syringae attack. The defence response pathways, signalling pathways and metabolic processes associated with aphid attack and P. syringae infection partially overlapped. Components of several important biosynthesis and signalling pathways, such as salicylic acid (SA), jasmonic acid (JA), ethylene (ET) and glucosinolates, were differentially affected during the two the treatments. Several stress-regulated transcription factors were known to be associated with stress-inducible microRNAs. The differentially regulated gene sets included many signature transcription factors, and our co-expression analysis showed that they were also strongly co-expressed during 69 other biotic stress experiments. Defence responses and functional networks that were unique and specific to aphid or P. syringae stresses were identified. Furthermore, our analysis revealed a probable link between biotic stress and microRNAs in Arabidopsis and

  2. Molecular signatures in Arabidopsis thaliana in response to insect attack and bacterial infection.

    Directory of Open Access Journals (Sweden)

    Pankaj Barah

    Full Text Available BACKGROUND: Under the threat of global climatic change and food shortages, it is essential to take the initiative to obtain a comprehensive understanding of common and specific defence mechanisms existing in plant systems for protection against different types of biotic invaders. We have implemented an integrated approach to analyse the overall transcriptomic reprogramming and systems-level defence responses in the model plant species Arabidopsis thaliana (A. thaliana henceforth during insect Brevicoryne brassicae (B. brassicae henceforth and bacterial Pseudomonas syringae pv. tomato strain DC3000 (P. syringae henceforth attacks. The main aim of this study was to identify the attacker-specific and general defence response signatures in A. thaliana when attacked by phloem-feeding aphids or pathogenic bacteria. RESULTS: The obtained annotated networks of differentially expressed transcripts indicated that members of transcription factor families, such as WRKY, MYB, ERF, BHLH and bZIP, could be crucial for stress-specific defence regulation in Arabidopsis during aphid and P. syringae attack. The defence response pathways, signalling pathways and metabolic processes associated with aphid attack and P. syringae infection partially overlapped. Components of several important biosynthesis and signalling pathways, such as salicylic acid (SA, jasmonic acid (JA, ethylene (ET and glucosinolates, were differentially affected during the two the treatments. Several stress-regulated transcription factors were known to be associated with stress-inducible microRNAs. The differentially regulated gene sets included many signature transcription factors, and our co-expression analysis showed that they were also strongly co-expressed during 69 other biotic stress experiments. CONCLUSIONS: Defence responses and functional networks that were unique and specific to aphid or P. syringae stresses were identified. Furthermore, our analysis revealed a probable link between

  3. Interplant communication of tomato plants through underground common mycorrhizal networks.

    Science.gov (United States)

    Song, Yuan Yuan; Zeng, Ren Sen; Xu, Jian Feng; Li, Jun; Shen, Xiang; Yihdego, Woldemariam Gebrehiwot

    2010-10-13

    Plants can defend themselves to pathogen and herbivore attack by responding to chemical signals that are emitted by attacked plants. It is well established that such signals can be transferred through the air. In theory, plants can also communicate with each other through underground common mycorrhizal networks (CMNs) that interconnect roots of multiple plants. However, until now research focused on plant-to-plant carbon nutrient movement and there is no evidence that defense signals can be exchanged through such mycorrhizal hyphal networks. Here, we show that CMNs mediate plant-plant communication between healthy plants and pathogen-infected tomato plants (Lycopersicon esculentum Mill.). After establishment of CMNs with the arbuscular mycorrhizal fungus Glomus mosseae between tomato plants, inoculation of 'donor' plants with the pathogen Alternaria solani led to increases in disease resistance and activities of the putative defensive enzymes, peroxidase, polyphenol oxidase, chitinase, β-1,3-glucanase, phenylalanine ammonia-lyase and lipoxygenase in healthy neighbouring 'receiver' plants. The uninfected 'receiver' plants also activated six defence-related genes when CMNs connected 'donor' plants challenged with A. solani. This finding indicates that CMNs may function as a plant-plant underground communication conduit whereby disease resistance and induced defence signals can be transferred between the healthy and pathogen-infected neighbouring plants, suggesting that plants can 'eavesdrop' on defence signals from the pathogen-challenged neighbours through CMNs to activate defences before being attacked themselves.

  4. New materials in defence

    International Nuclear Information System (INIS)

    Khan, Sikandar S.; Khan, Shahid A.; Butt, N.M.

    1992-01-01

    National defence is very important and always needs new such materials which have technological and socio-economic development of human society. The types of materials used by a society reflect its level of sophistication. These modern materials are basically the same conventional materials but with a greater knowledge content which include superalloys, modern polymers, engineering ceramics and the advanced composite. The production and use of new materials is playing and important role in the recent development in the defence industry. (A.B.)

  5. Defence counsel in international criminal law

    NARCIS (Netherlands)

    Temminck Tuinstra, J.P.W.

    2009-01-01

    The field of international criminal law is relatively new and rapidly developing. This dissertation examines whether international criminal courts enable defence counsel to conduct an effective defence. When the International Criminal Tribunals for the former Yugoslavia and Rwanda (the ad hoc

  6. Chemical defence and toxins of plants

    OpenAIRE

    Yamane, H.; Konno, K.; Sabelis, M.; Takabayashi, J.; Sassa, T.; Oikawa, H.; Mander, L.; Lui, H.W.

    2010-01-01

    Higher plants protect themselves by producing a variety of secondary metabolites and proteins that are involved in defense against herbivores as well as microbial pathogens. Concerning microbial pathogenesis in plants, in many cases, it is known that phytotoxins that are produced by plant pathogens play an important role in disease development causing chlorosis, necrosis, or wilting. This chapter mainly focuses on the chemical structures, distribution, and biosynthesis of defense-related natu...

  7. The South African National Defence Force

    DEFF Research Database (Denmark)

    Mandrup, Thomas

    2009-01-01

    This research paper is an evaluation of The Souch African National Defence Force´s (SANDF) involvement in Peace Support Operations.......This research paper is an evaluation of The Souch African National Defence Force´s (SANDF) involvement in Peace Support Operations....

  8. Networks and network analysis for defence and security

    CERN Document Server

    Masys, Anthony J

    2014-01-01

    Networks and Network Analysis for Defence and Security discusses relevant theoretical frameworks and applications of network analysis in support of the defence and security domains. This book details real world applications of network analysis to support defence and security. Shocks to regional, national and global systems stemming from natural hazards, acts of armed violence, terrorism and serious and organized crime have significant defence and security implications. Today, nations face an uncertain and complex security landscape in which threats impact/target the physical, social, economic

  9. A change in temperature modulates defence to yellow (stripe) rust in wheat line UC1041 independently of resistance gene Yr36.

    Science.gov (United States)

    Bryant, Ruth R M; McGrann, Graham R D; Mitchell, Alice R; Schoonbeek, Henk-Jan; Boyd, Lesley A; Uauy, Cristobal; Dorling, Steve; Ridout, Christopher J

    2014-01-08

    Rust diseases are of major importance in wheat production worldwide. With the constant evolution of new rust strains and their adaptation to higher temperatures, consistent and durable disease resistance is a key challenge. Environmental conditions affect resistance gene performance, but the basis for this is poorly understood. Here we show that a change in day temperature affects wheat resistance to Puccinia striiformis f. sp tritici (Pst), the causal agent of yellow (or stripe) rust. Using adult plants of near-isogenic lines UC1041 +/- Yr36, there was no significant difference between Pst percentage uredia coverage in plants grown at day temperatures of 18°C or 25°C in adult UC1041 + Yr36 plants. However, when plants were transferred to the lower day temperature at the time of Pst inoculation, infection increased up to two fold. Interestingly, this response was independent of Yr36, which has previously been reported as a temperature-responsive resistance gene as Pst development in adult UC1041 -Yr36 plants was similarly affected by the plants experiencing a temperature reduction. In addition, UC1041 -Yr36 plants grown at the lower temperature then transferred to the higher temperature were effectively resistant and a temperature change in either direction was shown to affect Pst development up to 8 days prior to inoculation. Results for seedlings were similar, but more variable compared to adult plants. Enhanced resistance to Pst was observed in seedlings of UC1041 and the cultivar Shamrock when transferred to the higher temperature. Resistance was not affected in seedlings of cultivar Solstice by a temperature change in either direction. Yr36 is effective at 18°C, refining the lower range of temperature at which resistance against Pst is conferred compared to previous studies. Results reveal previously uncharacterised defence temperature sensitivity in the UC1041 background which is caused by a change in temperature and independently of Yr36. This novel

  10. Transcriptomics-based analysis using RNA-Seq of the coconut (Cocos nucifera) leaf in response to yellow decline phytoplasma infection.

    Science.gov (United States)

    Nejat, Naghmeh; Cahill, David M; Vadamalai, Ganesan; Ziemann, Mark; Rookes, James; Naderali, Neda

    2015-10-01

    Invasive phytoplasmas wreak havoc on coconut palms worldwide, leading to high loss of income, food insecurity and extreme poverty of farmers in producing countries. Phytoplasmas as strictly biotrophic insect-transmitted bacterial pathogens instigate distinct changes in developmental processes and defence responses of the infected plants and manipulate plants to their own advantage; however, little is known about the cellular and molecular mechanisms underlying host-phytoplasma interactions. Further, phytoplasma-mediated transcriptional alterations in coconut palm genes have not yet been identified. This study evaluated the whole transcriptome profiles of naturally infected leaves of Cocos nucifera ecotype Malayan Red Dwarf in response to yellow decline phytoplasma from group 16SrXIV, using RNA-Seq technique. Transcriptomics-based analysis reported here identified genes involved in coconut innate immunity. The number of down-regulated genes in response to phytoplasma infection exceeded the number of genes up-regulated. Of the 39,873 differentially expressed unigenes, 21,860 unigenes were suppressed and 18,013 were induced following infection. Comparative analysis revealed that genes associated with defence signalling against biotic stimuli were significantly overexpressed in phytoplasma-infected leaves versus healthy coconut leaves. Genes involving cell rescue and defence, cellular transport, oxidative stress, hormone stimulus and metabolism, photosynthesis reduction, transcription and biosynthesis of secondary metabolites were differentially represented. Our transcriptome analysis unveiled a core set of genes associated with defence of coconut in response to phytoplasma attack, although several novel defence response candidate genes with unknown function have also been identified. This study constitutes valuable sequence resource for uncovering the resistance genes and/or susceptibility genes which can be used as genetic tools in disease resistance breeding.

  11. High CO2 Primes Plant Biotic Stress Defences through Redox-Linked Pathways.

    Science.gov (United States)

    Mhamdi, Amna; Noctor, Graham

    2016-10-01

    Industrial activities have caused tropospheric CO 2 concentrations to increase over the last two centuries, a trend that is predicted to continue for at least the next several decades. Here, we report that growth of plants in a CO 2 -enriched environment activates responses that are central to defense against pathogenic attack. Salicylic acid accumulation was triggered by high-growth CO 2 in Arabidopsis (Arabidopsis thaliana) and other plants such as bean (Phaseolus vulgaris). A detailed analysis in Arabidopsis revealed that elevated CO 2 primes multiple defense pathways, leading to increased resistance to bacterial and fungal challenge. Analysis of gene-specific mutants provided no evidence that activation of plant defense pathways by high CO 2 was caused by stomatal closure. Rather, the activation is partly linked to metabolic effects involving redox signaling. In support of this, genetic modification of redox components (glutathione contents and NADPH-generating enzymes) prevents full priming of the salicylic acid pathway and associated resistance by high CO 2 The data point to a particularly influential role for the nonphosphorylating glyceraldehyde-3-phosphate dehydrogenase, a cytosolic enzyme whose role in plants remains unclear. Our observations add new information on relationships between high CO 2 and oxidative signaling and provide novel insight into plant stress responses in conditions of increased CO 2 . © 2016 American Society of Plant Biologists. All Rights Reserved.

  12. Functional analysis of Arabidopsis immune-related MAPKs uncovers a role for MPK3 as negative regulator of inducible defences

    KAUST Repository

    Frei dit Frey, Nicolas

    2014-06-30

    Background Mitogen-activated protein kinases (MAPKs) are key regulators of immune responses in animals and plants. In Arabidopsis, perception of microbe-associated molecular patterns (MAMPs) activates the MAPKs MPK3, MPK4 and MPK6. Increasing information depicts the molecular events activated by MAMPs in plants, but the specific and cooperative contributions of the MAPKs in these signalling events are largely unclear. Results In this work, we analyse the behaviour of MPK3, MPK4 and MPK6 mutants in early and late immune responses triggered by the MAMP flg22 from bacterial flagellin. A genome-wide transcriptome analysis reveals that 36% of the flg22-upregulated genes and 68% of the flg22-downregulated genes are affected in at least one MAPK mutant. So far MPK4 was considered as a negative regulator of immunity, whereas MPK3 and MPK6 were believed to play partially redundant positive functions in defence. Our work reveals that MPK4 is required for the regulation of approximately 50% of flg22-induced genes and we identify a negative role for MPK3 in regulating defence gene expression, flg22-induced salicylic acid accumulation and disease resistance to Pseudomonas syringae. Among the MAPK-dependent genes, 27% of flg22-upregulated genes and 76% of flg22-downregulated genes require two or three MAPKs for their regulation. The flg22-induced MAPK activities are differentially regulated in MPK3 and MPK6 mutants, both in amplitude and duration, revealing a highly interdependent network. Conclusions These data reveal a new set of distinct functions for MPK3, MPK4 and MPK6 and indicate that the plant immune signalling network is choreographed through the interplay of these three interwoven MAPK pathways.

  13. Metabolomic analysis of isonitrosoacetophenone-induced perturbations in phenolic metabolism of Nicotiana tabacum cells

    CSIR Research Space (South Africa)

    Madala, NE

    2013-10-01

    Full Text Available Plants have developed biochemical and molecular responses to adapt to different stress environments. One of the characteristics of the multi-component defence response is the production of defence-related metabolites. Plant defences can be triggered...

  14. Systematic analysis of rice (Oryza sativa) metabolic responses to herbivory.

    Science.gov (United States)

    Alamgir, Kabir Md; Hojo, Yuko; Christeller, John T; Fukumoto, Kaori; Isshiki, Ryutaro; Shinya, Tomonori; Baldwin, Ian T; Galis, Ivan

    2016-02-01

    Plants defend against attack from herbivores by direct and indirect defence mechanisms mediated by the accumulation of phytoalexins and release of volatile signals, respectively. While the defensive arsenals of some plants, such as tobacco and Arabidopsis are well known, most of rice's (Oryza sativa) defence metabolites and their effectiveness against herbivores remain uncharacterized. Here, we used a non-biassed metabolomics approach to identify many novel herbivory-regulated metabolic signatures in rice. Most were up-regulated by herbivore attack while only a few were suppressed. Two of the most prominent up-regulated signatures were characterized as phenolamides (PAs), p-coumaroylputrescine and feruloylputrescine. PAs accumulated in response to attack by both chewing insects, i.e. feeding of the lawn armyworm (Spodoptera mauritia) and the rice skipper (Parnara guttata) larvae, and the attack of the sucking insect, the brown planthopper (Nilaparvata lugens, BPH). In bioassays, BPH insects feeding on 15% sugar solution containing p-coumaroylputrescine or feruloylputrescine, at concentrations similar to those elicited by heavy BPH attack in rice, had a higher mortality compared to those feeding on sugar diet alone. Our results highlight PAs as a rapidly expanding new group of plant defence metabolites that are elicited by herbivore attack, and deter herbivores in rice and other plants. © 2015 John Wiley & Sons Ltd.

  15. Herbivore benefits from vectoring plant virus through reduction of period of vulnerability to predation

    NARCIS (Netherlands)

    Belliure, B.; Janssen, A.; Sabelis, M.W.

    2008-01-01

    Herbivores can profit from vectoring plant pathogens because the induced defence of plants against pathogens sometimes interferes with the induced defence of plants against herbivores. Plants can also defend themselves indirectly by the action of the natural enemies of the herbivores. It is unknown

  16. Tritrophic interactions in wild and cultivated brassicaceous plant species

    NARCIS (Netherlands)

    Gols, R.

    2008-01-01

    Plants have evolved a range of defence traits that prevent or reduce attack by insect herbivores. Direct defence traits hamper or reduce the performance and behaviour of the herbivores, whereas indirect defence promote the efficiency of natural enemies to attack the herbivores. Here, I focused on

  17. Pareto Efficient Solutions of Attack-Defence Trees

    DEFF Research Database (Denmark)

    Aslanyan, Zaruhi; Nielson, Flemming

    2015-01-01

    Attack-defence trees are a promising approach for representing threat scenarios and possible countermeasures in a concise and intuitive manner. An attack-defence tree describes the interaction between an attacker and a defender, and is evaluated by assigning parameters to the nodes, such as proba......Attack-defence trees are a promising approach for representing threat scenarios and possible countermeasures in a concise and intuitive manner. An attack-defence tree describes the interaction between an attacker and a defender, and is evaluated by assigning parameters to the nodes......, such as probability or cost of attacks and defences. In case of multiple parameters most analytical methods optimise one parameter at a time, e.g., minimise cost or maximise probability of an attack. Such methods may lead to sub-optimal solutions when optimising conflicting parameters, e.g., minimising cost while...... maximising probability. In order to tackle this challenge, we devise automated techniques that optimise all parameters at once. Moreover, in the case of conflicting parameters our techniques compute the set of all optimal solutions, defined in terms of Pareto efficiency. The developments are carried out...

  18. Reinforcement of Defence-in-Depth: Modification Practice After the Fukushima Nuclear Accident

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.; Tang, H.; Mao, Q., E-mail: wangyuhong@cgnpc.com.cn [China Nuclear Power Design Co., Ltd Xia Meilin, Futian District, Shenzhen, Guangdong Province (China)

    2014-10-15

    The Fukushima Daiichi nuclear accident revealed the importance and demand for further reinforcement of defence in- depth. CGN (China General Nuclear Power Group) has made a complete safety assessment on CPR1000 nuclear power plants under construction in China. Dozens of modifications have been implemented based on the assessment findings and lessons learned from Fukushima nuclear accident, taking into account of PSA (Probabilistic Safety Analysis) and comparison analysis of the latest regulations and standards. These modifications help to enhance nuclear safety significantly for nuclear power plants under construction in China, and provide helpful modification guidance for nuclear power plants in operation of the same type. (author)

  19. Revealing the importance of meristems and roots for the development of hypersensitive responses and full foliar resistance to Phytophthora infestans in the resistant potato cultivar Sarpo Mira

    DEFF Research Database (Denmark)

    Orlowska, Elzbieta Zofia; Basile, Alessio; Kandzia, Izabela

    2012-01-01

    The defence responses of potato against Phytophthora infestans were studied using the highly resistant Sarpo Mira cultivar. The effects of plant integrity, meristems, and roots on the hypersensitive response (HR), plant resistance, and the regulation of PR genes were analysed. Sarpo Mira shoots a...

  20. 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.

  1. Evolution of host innate defence: insights from Caenorhabditis elegans and primitive invertebrates.

    Science.gov (United States)

    Irazoqui, Javier E; Urbach, Jonathan M; Ausubel, Frederick M

    2010-01-01

    The genetically tractable model organism Caenorhabditis elegans was first used to model bacterial virulence in vivo a decade ago. Since then, great strides have been made in identifying the host response pathways that are involved in its defence against infection. Strikingly, C. elegans seems to detect, and respond to, infection without the involvement of its homologue of Toll-like receptors, in contrast to the well-established role for these proteins in innate immunity in mammals. What, therefore, do we know about host defence mechanisms in C. elegans and what can they tell us about innate immunity in higher organisms?

  2. Evolution of host innate defence: insights from C. elegans and primitive invertebrates

    Science.gov (United States)

    Irazoqui, Javier E.; Urbach, Jonathan M.; Ausubel, Frederick M.

    2010-01-01

    Preface The genetically tractable model organism Caenorhabditis elegans was first used to model bacterial virulence in vivo a decade ago. Since then, great strides have been made in the identification of host response pathways that are involved in the defence against infection. Strikingly, C. elegans seems to detect and respond to infection without the involvement of its Toll-like receptor homologue, in contrast to the well-established role for these proteins in innate immunity in mammals. What, therefore, do we know about host defence mechanisms in C. elegans, and what can they tell us about innate immunity in higher organisms? PMID:20029447

  3. Potato type I and II proteinase inhibitors: modulating plant physiology and host resistance.

    Science.gov (United States)

    Turra, David; Lorito, Matteo

    2011-08-01

    Serine protease inhibitors (PIs) are a large and complex group of plant proteins. Members of the potato type I (Pin1) and II (Pin2) proteinase inhibitor families are among the first and most extensively characterized plant PIs. Many insects and phytopathogenic microorganisms use intracellular and extracellular serine proteases playing important roles in pathogenesis. Plants, however, are able to fight these pathogens through the activation of an intricate defence system that leads to the accumulation of various PIs, including Pin1 and Pin2. Several transgenic plants over-expressing members of the Pin1 and Pin2 families have been obtained in the last twenty years and their enhanced defensive capabilities demonstrated against insects, fungi and bacteria. Furthermore, Pin1 and Pin2 genetically engineered plants showed altered regulation of different plant physiological processes (e.g., dehydratation response, programmed cell death, plant growth, trichome density and branching), supporting an endogenous role in various plant species in addition to the well established defensive one. This review summarizes the current knowledge about Pin1 and Pin2 structure, the role of these proteins in plant defence and physiology, and their potential exploitation in biotechnology.

  4. Conversion policy principles of defence factory

    International Nuclear Information System (INIS)

    Fedik, I.I.; Deniskin, V.P.; Stepanov, V.S.

    1997-01-01

    1.Research Production Association 'LUCH' (RPA 'LUCH') have worked at atomic industry for 51 years. Now it is one of the leading scientific production centers of Russia Ministry of Atomic Energy. Not long ago it was a complex of Scientific Research Institute, experimental plant and Obyedenennaya Expedicia at the Semipalatinsk test site (now it is the Institute of Atomic Energy NNC RK). Basic directions of the complex activity are defence tasks. These tasks are to develop structure and technology of producing fuel assemblies for NRE (nuclear rocket engine) reactors. Also the tasks include testing the fuel assemblies at IWG-1, RWD and RA reactors. Also the tasks include structure and technology development, production and testing electric generating channels for nuclear thermal emission converters of nuclear energy into electric one (space board power engineering), power metal optics for powerful lasers, high temperature gas reactors. 2.Main directions of RPA 'LUCH' conversion were determined on the basis of possibilities for developing main achievements in defence technology directions.These directions are high temperature materials and constructions (carbides, refractory metals, measurements, optics, uranium compound, beryllium, molybdenum) 3.At present at RPA 'LUCH' there have been created experimental and industrial productions making temperature sensors for Atomic Electric Power Stations (AEPS). Also these manufactures release commercial products. They produce technological equipment of carbide-silicon for electronic industry as well as parts or X-ray tubes, vermiculite parts for cable driving of AEP stations (high temperature, fireproof ones) of thermal and electrical accumulators. Thus, a scientific-production center is being created. Core of it is a scientific engineers group and development directions, generated from orders of defence department, as well as new foreign technologies (along with investments).The example of the said above can be development of a

  5. Plant-pathogen interactions: what microarray tells about it?

    Science.gov (United States)

    Lodha, T D; Basak, J

    2012-01-01

    Plant defense responses are mediated by elementary regulatory proteins that affect expression of thousands of genes. Over the last decade, microarray technology has played a key role in deciphering the underlying networks of gene regulation in plants that lead to a wide variety of defence responses. Microarray is an important tool to quantify and profile the expression of thousands of genes simultaneously, with two main aims: (1) gene discovery and (2) global expression profiling. Several microarray technologies are currently in use; most include a glass slide platform with spotted cDNA or oligonucleotides. Till date, microarray technology has been used in the identification of regulatory genes, end-point defence genes, to understand the signal transduction processes underlying disease resistance and its intimate links to other physiological pathways. Microarray technology can be used for in-depth, simultaneous profiling of host/pathogen genes as the disease progresses from infection to resistance/susceptibility at different developmental stages of the host, which can be done in different environments, for clearer understanding of the processes involved. A thorough knowledge of plant disease resistance using successful combination of microarray and other high throughput techniques, as well as biochemical, genetic, and cell biological experiments is needed for practical application to secure and stabilize yield of many crop plants. This review starts with a brief introduction to microarray technology, followed by the basics of plant-pathogen interaction, the use of DNA microarrays over the last decade to unravel the mysteries of plant-pathogen interaction, and ends with the future prospects of this technology.

  6. Time-dependent reliability analysis of flood defences

    International Nuclear Information System (INIS)

    Buijs, F.A.; Hall, J.W.; Sayers, P.B.; Gelder, P.H.A.J.M. van

    2009-01-01

    This paper describes the underlying theory and a practical process for establishing time-dependent reliability models for components in a realistic and complex flood defence system. Though time-dependent reliability models have been applied frequently in, for example, the offshore, structural safety and nuclear industry, application in the safety-critical field of flood defence has to date been limited. The modelling methodology involves identifying relevant variables and processes, characterisation of those processes in appropriate mathematical terms, numerical implementation, parameter estimation and prediction. A combination of stochastic, hierarchical and parametric processes is employed. The approach is demonstrated for selected deterioration mechanisms in the context of a flood defence system. The paper demonstrates that this structured methodology enables the definition of credible statistical models for time-dependence of flood defences in data scarce situations. In the application of those models one of the main findings is that the time variability in the deterioration process tends to be governed the time-dependence of one or a small number of critical attributes. It is demonstrated how the need for further data collection depends upon the relevance of the time-dependence in the performance of the flood defence system.

  7. The use of plants to protect plants and food against fungal pathogens

    African Journals Online (AJOL)

    Background: Plant fungal pathogens play a crucial role in the profitability, quality and quantity of plant production. These phytopathogens are persistent in avoiding plant defences causing diseases and quality losses around the world that amount to billions of US dollars annually. To control the scourge of plant fungal ...

  8. Effects of silicon treatment and inoculation with Fusarium oxysporum f. sp. vasinfectum on cellular defences in root tissues of two cotton cultivars.

    Science.gov (United States)

    Whan, Jennifer A; Dann, Elizabeth K; Aitken, Elizabeth A B

    2016-08-01

    Silicon has been shown to enhance the resistance of plants to fungal and bacterial pathogens. Here, the effect of potassium silicate was assessed on two cotton (Gossypium hirsutum) cultivars subsequently inoculated with Fusarium oxysporum f. sp. vasinfectum (Fov). Sicot 189 is moderately resistant whilst Sicot F-1 is the second most resistant commercial cultivar presently available in Australia. Transmission and light microscopy were used to compare cellular modifications in root cells after these different treatments. The accumulation of phenolic compounds and lignin was measured. Cellular alterations including the deposition of electron-dense material, degradation of fungal hyphae and occlusion of endodermal cells were more rapidly induced and more intense in endodermal and vascular regions of Sicot F-1 plants supplied with potassium silicate followed by inoculation with Fov than in similarly treated Sicot 189 plants or in silicate-treated plants of either cultivar not inoculated with Fov. Significantly more phenolic compounds were present at 7 d post-infection (dpi) in root extracts of Sicot F-1 plants treated with potassium silicate followed by inoculation with Fov compared with plants from all other treatments. The lignin concentration at 3 dpi in root material from Sicot F-1 treated with potassium silicate and inoculated with Fov was significantly higher than that from water-treated and inoculated plants. This study demonstrates that silicon treatment can affect cellular defence responses in cotton roots subsequently inoculated with Fov, particularly in Sicot F-1, a cultivar with greater inherent resistance to this pathogen. This suggests that silicon may interact with or initiate defence pathways faster in this cultivar than in the less resistant cultivar. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Modelling joint air defence doctrinal issues with a LinkZA-based integration of two C2 simulators – a case study

    CSIR Research Space (South Africa)

    Nel, JJ

    2007-07-01

    Full Text Available This paper describes the integration between two command and control simulators in order to clarify doctrinal issues surrounding Joint Air Defence using as example the uncertainty of roles and responsibilities between the Air Defence Cell...

  10. Pathogenesis and host defence against Mucorales: the role of cytokines and interaction with antifungal drugs.

    Science.gov (United States)

    Roilides, Emmanuel; Antachopoulos, Charalampos; Simitsopoulou, Maria

    2014-12-01

    Innate immune response, including macrophages, neutrophils and dendritic cells and their respective receptors, plays an important role in host defences against Mucorales with differential activity against specific fungal species, while adaptive immunity is not the first line of defence. A number of endogenous and exogenous factors, such as cytokines and growth factors as well as certain antifungal agents have been found that they influence innate immune response to these organisms. Used alone or especially in combination have been shown to exert antifungal effects against Mucorales species. These findings suggest novel ways of adjunctive therapy for patients with invasive mucormycosis. © 2014 Blackwell Verlag GmbH.

  11. Shaping Baltic States Defence Strategy: Host Nation Support

    Directory of Open Access Journals (Sweden)

    Otzulis Valdis

    2017-12-01

    Full Text Available The presence of NATO troops in the Baltic states has increased in the last years due to changing international environment, increased level of potential risks and threats, and necessity to enhance deterrence in the region. As a result of NATO’s Wales and Warsaw summits decisions, Estonia, Latvia, and Lithuania are entitled to host a battalion size battle group. The article aims at investigating how host nation support (HNS can contribute to the national defence and, additionally, to the self-defence capabilities of the Baltic states. The concept of HNS is present in the national defence concepts of all three countries. However, its active application and utilization started in the last two years. The article argues that more intensive incorporation of an HNS system in national defence policies serve the capability development in fields like national military logistics, infrastructure, and civil-military cooperation. Those capabilities can serve as an extension of the national defence.

  12. A bacterial cysteine protease effector protein interferes with photosynthesis to suppress plant innate immune responses.

    Science.gov (United States)

    Rodríguez-Herva, José J; González-Melendi, Pablo; Cuartas-Lanza, Raquel; Antúnez-Lamas, María; Río-Alvarez, Isabel; Li, Ziduo; López-Torrejón, Gema; Díaz, Isabel; Del Pozo, Juan C; Chakravarthy, Suma; Collmer, Alan; Rodríguez-Palenzuela, Pablo; López-Solanilla, Emilia

    2012-05-01

    The bacterial pathogen Pseudomonas syringae pv tomato DC3000 suppresses plant innate immunity with effector proteins injected by a type III secretion system (T3SS). The cysteine protease effector HopN1, which reduces the ability of DC3000 to elicit programmed cell death in non-host tobacco, was found to also suppress the production of defence-associated reactive oxygen species (ROS) and callose when delivered by Pseudomonas fluorescens heterologously expressing a P. syringae T3SS. Purified His(6) -tagged HopN1 was used to identify tomato PsbQ, a member of the oxygen evolving complex of photosystem II (PSII), as an interacting protein. HopN1 localized to chloroplasts and both degraded PsbQ and inhibited PSII activity in chloroplast preparations, whereas a HopN1(D299A) non-catalytic mutant lost these abilities. Gene silencing of NtPsbQ in tobacco compromised ROS production and programmed cell death by DC3000. Our data reveal PsbQ as a contributor to plant immunity responses and a target for pathogen suppression. © 2012 Blackwell Publishing Ltd.

  13. Integrating nitric oxide into salicylic acid and jasmonic acid/ethylene plant defense pathways

    DEFF Research Database (Denmark)

    Mur, Luis A J; Prats, Elena; Pierre, Sandra

    2013-01-01

    to be tailored to particular biotic stresses. Nitric oxide (NO) has emerged as a major signal influencing resistance mediated by both signalling pathways but no attempt has been made to integrate NO into established SA/JA/ET interactions. NO has been shown to act as an inducer or suppressor of signalling along......Plant defence against pests and pathogens is known to be conferred by either salicylic acid (SA) or jasmonic acid (JA)/ethylene (ET) pathways, depending on infection or herbivore-grazing strategy. It is well attested that SA and JA/ET pathways are mutually antagonistic allowing defence responses...

  14. Interactions between nutritional approaches and defences against microbial diseases in small ruminants.

    Science.gov (United States)

    Caroprese, M; Giannenas, I; Fthenakis, G C

    2015-12-14

    Objective of this review is to discuss the role of small ruminant diet in the defence of these animals against microbial diseases, in relation to different experimental approaches and various stressors acting on animals. The effects of various diets in immune reactions and animal defences are presented. Also, effects in relation to the species studied and the type of stressors acting on animals are discussed. Evidence is provided about the significance of the diet in enhancing immune responses of small ruminants during specific conditions, e.g., around parturition, during lactation, as well as in growing lambs or kids. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Pareto Efficient Solution of Attack-Defence Trees

    NARCIS (Netherlands)

    Aslanyan, Zaruhi; Nielson, Flemming

    Attack-defence trees are a promising approach for representing threat scenarios and possible countermeasures in a concise and intuitive manner. An attack-defence tree describes the interaction between an attacker and a defender, and is evaluated by assigning parameters to the nodes, such as

  16. The structure of a purple acid phosphatase involved in plant growth and pathogen defence exhibits a novel immunoglobulin-like fold

    Directory of Open Access Journals (Sweden)

    Svetlana Vladimirovna Antonyuk

    2014-03-01

    Full Text Available Phosphatases function in the production, transport and recycling of inorganic phosphorus, which is crucial for cellular metabolism and bioenergetics, as well as in bacterial killing, since they are able to generate reactive oxygen species via Fenton chemistry. Diphosphonucleotide phosphatase/phosphodiesterase (PPD1, a glycoprotein plant purple acid phosphatase (PAP from yellow lupin seeds, contains a bimetallic Fe–Mn catalytic site which is most active at acidic pH. Unlike other plant PAPs, PPD1 cleaves the pyrophosphate bond in diphosphonucleotides and the phosphodiester bond in various phosphodiesters. The homohexameric organization of PPD1, as revealed by a 1.65 Å resolution crystal structure and confirmed by solution X-ray scattering, is unique among plant PAPs, for which only homodimers have previously been reported. A phosphate anion is bound in a bidentate fashion at the active site, bridging the Fe and Mn atoms in a binding mode similar to that previously reported for sweet potato PAP, which suggests that common features occur in their catalytic mechanisms. The N-terminal domain of PPD1 has an unexpected and unique fibronectin type III-like fold that is absent in other plant PAPs. Here, the in vitro DNA-cleavage activity of PPD1 is demonstrated and it is proposed that the fibronectin III-like domain, which `overhangs' the active site, is involved in DNA selectivity, binding and activation. The degradation of DNA by PPD1 implies a role for PPD1 in plant growth and repair and in pathogen defence.

  17. The long road of antimissile defence

    International Nuclear Information System (INIS)

    Gere, Francois

    2001-01-01

    The author proposes a discussion of the elaboration of the National Missile Defence (NMD) by the new US administration in 2001. He first reports the evolution of this concept which resulted in 1999 with the National Missile Defence Act, produced by a commission chaired by Rumsfeld and aimed at the assessment of the threat of ballistic missiles in the world. Before that, in the 1960, the USA already tried to protect themselves by designing two type of missiles: long range interceptors (Nike Zeus), and short range missiles (Sprint). Later, Reagan launched the Strategic Defence Initiative (SDI). By the end of Cold War, the SDI was downgraded into smaller programmes. In a second part, the author discusses some elements of the NMD content: definition of objectives over 20 years, technical and strategic obstacles, definition of Rogue States. In a third part, he proposes an overview of the relationships between antimissile defence and nuclear deterrence, notably through the ABM Treaty, and with problem raised by Arms of Mass Destruction (AMD). In the last part, he comments reactions (mainly opposition) of different countries (Russia, China, European countries and particularly Germany), and proposes some possible true motivations for the creation of the NMD

  18. KYPO – A Platform for Cyber Defence Exercises

    OpenAIRE

    Čeleda Pavel; Čegan Jakub; Vykopal Jan; Tovarňák Daniel

    2015-01-01

    Correct and timely responses to cyber attacks are crucial for the effective implementation of cyber defence strategies and policies. The number of threats and ingenuity of attackers is ever growing, as is the need for more advanced detection tools, techniques and skilled cyber security professionals. KYPO – Cyber Exercise & Research Platform is focused on modelling and simulating complex computer systems and networks in a virtualized and separated environment. The platform enables realist...

  19. A proteomic approach to studying plant response to crenate broomrape (Orobanche crenata) in pea (Pisum sativum).

    Science.gov (United States)

    Angeles Castillejo, M; Amiour, Nardjis; Dumas-Gaudot, Eliane; Rubiales, Diego; Jorrín, Jesús V

    2004-06-01

    Crenate broomrape (Orobanche crenata) is a parasitic plant that threatens legume production in Mediterranean areas. Pea (Pisum sativum) is severely affected, and only moderate levels of genetic resistance have so far been identified. In the present work we selected the most resistant accession available (Ps 624) and compared it with a susceptible (Messire) cultivar. Experiments were performed by using pot and Petri dish bioassays, showing little differences in the percentage of broomrape seed germination induced by both genotypes, but a significant hamper in the number of successfully installed tubercles and their developmental stage in the Ps 624 compared to Messire. The protein profile of healthy and infected P. sativum root tissue were analysed by two-dimensional electrophoresis. Approximately 500 individual protein spots could be detected on silver stained gels. At least 22 different protein spots differentiated control, non-infected, Messire and Ps 624 accessions. Some of them were identified by MALDI-TOF mass spectrometry and database searching as cysteine proteinase, beta-1,3-glucanase, endochitinase, profucosidase, and ABA-responsive protein. Both qualitative and quantitative differences have been found among infected and non-infected root extracts. Thus, in the infected susceptible Messire genotype 34 spots were decreased, one increased and three newly detected, while in Ps 624, 15 spots were increased, three decreased and one newly detected. In response to the inoculation, proteins that correspond to enzymes of the carbohydrate metabolism (fructokinase, fructose-bisphosphate aldolase), nitrogen metabolism (ferredoxin-NADP reductase) and mitochondrial electronic chain transport (alternative oxidase 2) decreased in the susceptible check, while proteins that correspond to enzymes of the nitrogen assimilation pathway (glutamine synthetase) or typical pathogen defence, PR proteins, including beta-1,3-glucanase and peroxidases, increased in Ps 624. Results are

  20. Three lines of defence model and the role of internal audit activities as the response to the global economic crisis

    Science.gov (United States)

    Dragičević Radičević, T.; Stojanović Trivanović, M.; Stanojević, Lj

    2017-05-01

    The existing framework of corporate governance has shown a number of weaknesses, and the result was a new economic crisis at the global level. The main problems were identified as: increased risk of investors, non-transparency of information, conflict of interest between corporation subjects. European Institute of Internal Auditors in response to the strengthening the trust in information, shareholders activism, better communication, which all will lead to the reduction of risks and restore investors confidence, proposed the Model Three Lines of Defence, where the key role has internal audit.

  1. THE SMART DEFENCE CONCEPT - A NEW APPROACH OF COMMON DEFENCE WITHIN NATO

    Directory of Open Access Journals (Sweden)

    Liviu IONIȚĂ

    2012-12-01

    Full Text Available The Smart Defence concept was introduced in the NATO policy in a time when the Alliance is confronted with new challenges generated by the global economic crisis, a lack of balance in the participation of the member states in the financing of common operations, threats coming from states that do not adhere to nuclear non-proliferation treaties, as well as the emergence of new state actors at the global level. By implementing the Smart Defence concept, the Alliance intends to adapt its own means of generating critical capabilities in accordance with the pooling and sharing paradigm, implemented with the European Union, an initiative that might lead to stronger cooperation between the two organisms and to a more efficient use of shared capabilities.

  2. How Strong Is Europeanisation, Really? The Danish Defence Administration and the Opt-Out from the European Security and Defence Policy

    DEFF Research Database (Denmark)

    Olsen, Gorm Rye

    2011-01-01

    The article questions how strong Europeanisation is as an explanation of administrative changes in EU member states. Denmark has an opt-out from the European cooperation on defence, and, therefore, its defence administration represents a critical or a less likely case to test the Europeanisation...... thesis. The article shows that in spite of the opt-out, the administrative structures and the policy processes in the Ministry of Foreign Affairs (MFA) have adapted to the common foreign and security policy (CFSP) and the European security and defence policy (ESDP). Surprisingly, the administrative...... structures and the decision-making processes in the Ministry of Defence (MoD) have also adapted to the ESDP. The latter example emphasises the strength of top-down Europeanisation as a possible explanation of domestic administrative changes in member states. It is argued that Europeanisation per se...

  3. Plant response to biotic stress: Is there a common epigenetic response during plant-pathogenic and symbiotic interactions?

    Science.gov (United States)

    Zogli, Prince; Libault, Marc

    2017-10-01

    Plants constantly interact with pathogenic and symbiotic microorganisms. Recent studies have revealed several regulatory mechanisms controlling these interactions. Among them, the plant defense system is activated not only in response to pathogenic, but also in response to symbiotic microbes. Interestingly, shortly after symbiotic microbial recognition, the plant defense system is suppressed to promote plant infection by symbionts. Research studies have demonstrated the influence of the plant epigenome in modulating both pathogenic and symbiotic plant-microbe interactions, thereby influencing plant survival, adaptation and evolution of the plant response to microbial infections. It is however unclear if plant pathogenic and symbiotic responses share similar epigenomic profiles or if epigenomic changes differentially regulate plant-microbe symbiosis and pathogenesis. In this mini-review, we provide an update of the current knowledge of epigenomic control on plant immune responses and symbiosis, with a special attention being paid to knowledge gap and potential strategies to fill-in the missing links. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Responses of plants to air pollution

    National Research Council Canada - National Science Library

    Mudd, J. Brian; Kozlowski, T. T

    1975-01-01

    .... KOZLOWSKI Pollution, 1975 ELROY L. RICE. Allelopathy, (Eds.). Fire and Ecosystems, 1974 (Eds.). Responses of Plants to Air Responses of Plants to Air PollutionRESPONSES OF PLANTS TO AIR POLLUTION E...

  5. The mirror has two faces: dissociative identity disorder and the defence of pathological criminal incapacity--a South African criminal law perspective.

    Science.gov (United States)

    Stevens, Philip

    2013-03-01

    Dissociative identity disorder poses numerous medico legal issues whenever the insanity defence emerges. Within the context of the South African criminal law, the impact of dissociative identity disorder on criminal responsibility has only been addressed very briefly in one decided case. Various questions arise as to the impact that the distinctive diagnostic features of dissociative identity disorder could possibly have on the defence of pathological criminal incapacity, or better known as the insanity defence, within the ambit of the South African criminal law. In this contribution the author reflects on the mental disorder known as dissociative identity disorder or multiple personality disorder, against the backdrop of the defence of pathological criminal incapacity. Reflections are also provided pertaining to the various medico legal issues at stake whenever this defence has to be adjudicated upon.

  6. Implementation of accident management programmes in nuclear power plants

    International Nuclear Information System (INIS)

    2004-01-01

    According to the generally established defence in depth concept in nuclear safety, consideration in plant operation is also given to highly improbable severe plant conditions that were not explicitly addressed in the original design of currently operating nuclear power plants (NPPs). Defence in depth is achieved primarily by means of four successive barriers which prevent the release of radioactive material (fuel matrix, cladding, primary coolant boundary and containment), and these barriers are primarily protected by three levels of design measures: prevention of abnormal operation and failures (level 1), control of abnormal operation and detection of failures (level 2) and control of accidents within the design basis (level 3). If these first three levels fail to ensure the structural integrity of the core, e.g. due to beyond the design basis multiple failures, or due to extremely unlikely initiating events, additional efforts are made at level 4 to further reduce the risks. The objective at the fourth level is to ensure that both the likelihood of an accident entailing significant core damage (severe accident) and the magnitude of radioactive releases following a severe accident are kept as low as reasonably achievable. Finally, level 5 includes off-site emergency response measures, with the objective of mitigating the radiological consequences of significant releases of radioactive material. The implementation of the emergency response is usually dependent upon the type and magnitude of the accident. Good co-ordination between the operator and the responding organizations is needed to ensure the appropriate response. Accident management is one of the key components of effective defence in depth. In accordance with defence in depth, each design level should be protected individually, independently of other levels. This report focuses on the fourth level of defence in depth, including the transitions from the third level and into the fifth level. It describes

  7. Trichoderma spp.: a biocontrol agent for sustainable management of plant diseases

    International Nuclear Information System (INIS)

    Naher, L.; Ismail, A.

    2014-01-01

    Trichoderma spp. are mainly asexual fungi that are present in all types of agricultural soils and also in decaying wood. The antagonistic activity of Trichoderma species showed that it is parasitic on many soil-borne and foliage pathogens. The fungus is also a decomposer of cellulosic waste materials. Recent discoveries show that the fungi not only act as biocontrol agents, but also stimulate plant resistance, and plant growth and development resulting in an increase in crop production. The biocontrol activity involving mycoparasitism, antibiotics and competition for nutrients, also induces defence responses or systemic resistance responses in plants. These responses are an important part of Trichoderma in biocontrol program. Currently, Trichoderma spp., is being used to control plant diseases in sustainable diseases management systems. This paper reviews the published information on Trichoderma spp., and its biocontrol activity in sustainable disease management programs. (author)

  8. Modelling the effect of environmental factors on resource allocation in mixed plants systems

    Science.gov (United States)

    Gayler, Sebastian; Priesack, Eckart

    2010-05-01

    In most cases, growth of plants is determined by competition against neighbours for the local resources light, water and nutrients and by defending against herbivores and pathogens. Consequently, it is important for a plant to grow fast without neglecting defence. However, plant internal substrates and energy required to support maintenance, growth and defence are limited and the total demand for these processes cannot be met in most cases. Therefore, allocation of carbohydrates to growth related primary metabolism or to defence related secondary metabolism can be seen as a trade-off between the demand of plants for being competitive against neighbours and for being more resistant against pathogens. A modelling approach is presented which can be used to simulate competition for light, water and nutrients between plant individuals in mixed canopies. The balance of resource allocation between growth processes and synthesis of secondary compounds is modelled by a concept originating from different plant defence hypothesis. The model is used to analyse the impact of environmental factors such as soil water and nitrogen availability, planting density and atmospheric concentration of CO2 on growth of plant individuals within mixed canopies and variations in concentration of carbon-based secondary metabolites in plant tissues.

  9. Impact of antimissile defence on nuclear strategies in Asia

    International Nuclear Information System (INIS)

    Delory, Stephane

    2015-01-01

    As antimissile defence has become a mean to compensate the limitations of nuclear deterrence in Asia, notably within the frame of the US-North Korea relationship, but has also influence on the relationships between countries which do not possess an actual operational antimissile defence like Pakistan and India, the author proposes an assessment of the consequences antimissile defence may have on deterrence logics in Asia. He also notices that various issues must be taken into account: arsenal sizes, the slow rate of ballistic modernisation processes, the weaknesses of C4ISR systems and advanced alarm systems. He recalls the peculiarities of antimissile defence, and then addresses the cases of North Korea, India and Pakistan, and China. For each country, he analyses and discusses the influence of a choice or of the existence of an antimissile defence on the nuclear strategy and doctrine, but also on the posture of other countries like the USA

  10. Shifting from priming of salicylic acid- to jasmonic acid-regulated defences by Trichoderma protects tomato against the root knot nematode Meloidogyne incognita.

    Science.gov (United States)

    Martínez-Medina, Ainhoa; Fernandez, Ivan; Lok, Gerrit B; Pozo, María J; Pieterse, Corné M J; Van Wees, Saskia C M

    2017-02-01

    Beneficial root endophytes such as Trichoderma spp. can reduce infections by parasitic nematodes through triggering host defences. Little is currently known about the complex hormone signalling underlying the induction of resistance. In this study, we investigated whether Trichoderma modulates the hormone signalling network in the host to induce resistance to nematodes. We investigated the role and the timing of the jasmonic acid (JA)- and salicylic acid (SA)-regulated defensive pathways in Trichoderma-induced resistance to the root knot nematode Meloidogyne incognita. A split-root system of tomato (Solanum lycopersicum) was used to study local and systemic induced defences by analysing nematode performance, defence gene expression, responsiveness to exogenous hormone application, and dependence on SA and JA signalling of Trichoderma-induced resistance. Root colonization by Trichoderma impeded nematode performance both locally and systemically at multiple stages of the parasitism, that is, invasion, galling and reproduction. First, Trichoderma primed SA-regulated defences, which limited nematode root invasion. Then, Trichoderma enhanced JA-regulated defences, thereby antagonizing the deregulation of JA-dependent immunity by the nematodes, which compromised galling and fecundity. Our results show that Trichoderma primes SA- and JA-dependent defences in roots, and that the priming of responsiveness to these hormones upon nematode attack is plastic and adaptive to the parasitism stage. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  11. 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.

  12. Proteomic analysis of Arabidopsis thaliana (L.) Heynh responses to a generalist sucking pest (Myzus persicae Sulzer).

    Science.gov (United States)

    Truong, D-H; Bauwens, J; Delaplace, P; Mazzucchelli, G; Lognay, G; Francis, F

    2015-11-01

    Herbivorous insects can cause severe cellular changes to plant foliage following infestations, depending on feeding behaviour. Here, a proteomic study was conducted to investigate the influence of green peach aphid (Myzus persicae Sulzer) as a polyphagous pest on the defence response of Arabidopsis thaliana (L.) Heynh after aphid colony establishment on the host plant (3 days). Analysis of about 574 protein spots on 2-DE gels revealed 31 differentially expressed protein spots. Twenty out of these 31 differential proteins were selected for analysis by mass spectrometry. In 12 of the 20 analysed spots, we identified seven and nine proteins using MALDI-TOF-MS and LC-ESI-MS/MS, respectively. Of the analysed spots, 25% contain two proteins. Different metabolic pathways were modulated in Arabidopsis leaves according to aphid feeding: most corresponded to carbohydrate, amino acid and energy metabolism, photosynthesis, defence response and translation. This paper has established a survey of early alterations induced in the proteome of Arabidopsis by M. persicae aphids. It provides valuable insights into the complex responses of plants to biological stress, particularly for herbivorous insects with sucking feeding behaviour. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  13. Probiotics: beneficial factors of the defence system.

    Science.gov (United States)

    Antoine, Jean Michel

    2010-08-01

    Probiotics, defined as living micro-organisms that provide a health benefit to the host when ingested in adequate amounts, have been used traditionally as food components to help the body to recover from diarrhoea. They are commonly ingested as part of fermented foods, mostly in fresh fermented dairy products. They can interact with the host through different components of the gut defence systems. There is mounting clinical evidence that some probiotics, but not all, help the defence of the host as demonstrated by either a shorter duration of infections or a decrease in the host's susceptibility to pathogens. Different components of the gut barrier can be involved in the strengthening of the body's defences: the gut microbiota, the gut epithelial barrier and the immune system. Many studies have been conducted in normal free-living subjects or in subjects during common infections like the common cold and show that some probiotic-containing foods can improve the functioning of or strengthen the body's defence. Specific probiotic foods can be included in the usual balanced diet of consumers to help them to better cope with the daily challenges of their environment.

  14. How to Reinforce the “Defence-in-Depth” in NPP by Taking into Account Natural Hazards?

    Energy Technology Data Exchange (ETDEWEB)

    Lavarenne, C.; Herviou, K.; Picot, C.; Dupuy, P., E-mail: caroline.lavarenne@irsn.fr, E-mail: karine.herviou@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Pôle Sûreté Nucléaire, Fontenay aux Roses (France)

    2014-10-15

    The “defence-in-depth” (DiD) principle is the fundamental safety principle for the design and operation of nuclear power plants. This principle aims to prevent as far as possible initiating events and managing their consequences if preventive provisions failed. It has to be applied to the protection against hazards so as to limit their likelihood and/or their consequences by the implementation of prevention, control and mitigation provisions in NPPs consistently with provisions for internal events. So far, the protection of nuclear power plants against external hazards follows a “load-cases” approach, which differs from the approach used for internal events. In 2011, the Fukushima accident showed that, for a beyond design hazard or a combination of hazards not considered at the design stage, all levels of defence may be swept away simultaneously and may lead to a disaster. Natural hazards can therefore be considered as a potential common cause of failure affecting at the same time all levels of the “defence-in-depth”. In France, the definition and the implementation of a post-Fukushima “Hardened Safety Core” for operating NPPs should compensate for some weaknesses in the current approach and improve significantly the robustness of the installations against natural hazards. For future reactors, a new approach based on the definition of two domains, “design basis” and “design extension” for natural hazards, is examined in order to fulfil ambitious general plant safety objectives. It turns out that safety assessments related to natural hazards raise some challenges and difficulties, especially to characterize events with very low frequencies in a context of limited data, to define combinations of hazards (eventually with internal events) and to consider events that go beyond the design basis. For these issues, international guidance and discussions may be fruitful. (author)

  15. From Defence To Development

    International Development Research Centre (IDRC) Digital Library (Canada)

    From this perspective, high defence expenditure has been compared to dismantling ...... availability exceed evaporative demand and a state of permanent drought ...... In October 1993, South African authorities seized a container on a plot near ...

  16. S-Nitrosoglutathione is a component of wound- and salicylic acid-induced systemic responses in Arabidopsis thaliana.

    Science.gov (United States)

    Espunya, M Carme; De Michele, Roberto; Gómez-Cadenas, Aurelio; Martínez, M Carmen

    2012-05-01

    S-Nitrosoglutathione (GSNO) is a bioactive, stable, and mobile reservoir of nitric oxide (NO), and an important player in defence responses to herbivory and pathogen attack in plants. It has been demonstrated previously that GSNO reductase (GSNOR) is the main enzyme responsible for the in vivo control of intracellular levels of GSNO. In this study, the role of S-nitrosothiols, in particular of GSNO, in systemic defence responses in Arabidopsis thaliana was investigated further. It was shown that GSNO levels increased rapidly and uniformly in injured Arabidopsis leaves, whereas in systemic leaves GSNO was first detected in vascular tissues and later spread over the parenchyma, suggesting that GSNO is involved in the transmission of the wound mobile signal through the vascular tissue. Moreover, GSNO accumulation was required to activate the jasmonic acid (JA)-dependent wound responses, whereas the alternative JA-independent wound-signalling pathway did not involve GSNO. Furthermore, extending previous work on the role of GSNOR in pathogenesis, it was shown that GSNO acts synergistically with salicylic acid in systemic acquired resistance activation. In conclusion, GSNOR appears to be a key regulator of systemic defence responses, in both wounding and pathogenesis.

  17. Methodology to detect gaps in a soccer defence

    DEFF Research Database (Denmark)

    Knudsen, Nikolas Sten; Andersen, Thomas Bull

    2015-01-01

    The purpose of the present study was to create a methodology which can provide information about gaps in an opposing team’s defence. To illustrate the methodology, a defence was tracked during a game in the danish Superliga using ZXY radio tracking and analysed using the methodology. Results show...

  18. Diverse opportunities in defence

    Science.gov (United States)

    Brown, Gareth

    2016-08-01

    Working at the UK's defence laboratory gives Gareth Brown the ability to apply his physics and mathematics knowledge to real-world applications - and not necessarily in the ways you might expect. This article is Crown copyright

  19. Defence responses of arabidopsis thaliana to infection by pseudomonas syringae are regulated by the circadian clock

    KAUST Repository

    Bhardwaj, Vaibhav; Meier, Stuart; Petersen, Lindsay N.; Ingle, Robert A.; Roden, Laura C.

    2011-01-01

    of Arabidopsis defence-related genes showed both diurnal- and circadian-regulation, including genes involved in the perception of the PAMP flagellin which exhibit a peak in expression in the morning. Accordingly, we observed that PAMP-triggered callose deposition

  20. The Defence Medical Library Service and military medicine.

    Science.gov (United States)

    Walker, S B

    2005-01-01

    The Defence Medical Library Service (DMLS) supports the clinical practice and career development of military health professionals across the world. Clinical governance and the need for medical knowledge to be evidence-based means the DMLS has a central role to play in support of defence medicine. The DMLS is important for enabling health professionals to make sense of the evidence-based pyramid and the hierarchy of medical knowledge. The Royal Centre for Defence Medicine (RCDM) in Birmingham is recognised as an international centre of excellence. The information, knowledge and research requirements of the RCDM will provide opportunities for the DMLS to support and engage with the academic community.

  1. Plant Responses to Nanoparticle Stress

    Directory of Open Access Journals (Sweden)

    Zahed Hossain

    2015-11-01

    Full Text Available With the rapid advancement in nanotechnology, release of nanoscale materials into the environment is inevitable. Such contamination may negatively influence the functioning of the ecosystems. Many manufactured nanoparticles (NPs contain heavy metals, which can cause soil and water contamination. Proteomic techniques have contributed substantially in understanding the molecular mechanisms of plant responses against various stresses by providing a link between gene expression and cell metabolism. As the coding regions of genome are responsible for plant adaptation to adverse conditions, protein signatures provide insights into the phytotoxicity of NPs at proteome level. This review summarizes the recent contributions of plant proteomic research to elaborate the complex molecular pathways of plant response to NPs stress.

  2. Genetic responses induced in olive roots upon colonization by the biocontrol endophytic bacterium Pseudomonas fluorescens PICF7.

    Directory of Open Access Journals (Sweden)

    Elisabetta Schilirò

    Full Text Available Knowledge on the genetic basis underlying interactions between beneficial bacteria and woody plants is still very limited, and totally absent in the case of olive. We aimed to elucidate genetic responses taking place during the colonization of olive roots by the native endophyte Pseudomonas fluorescens PICF7, an effective biocontrol agent against Verticillium wilt of olive. Roots of olive plants grown under non-gnotobiotic conditions were collected at different time points after PICF7 inoculation. A Suppression Subtractive Hybridization cDNA library enriched in induced genes was generated. Quantitative real time PCR (qRT-PCR analysis validated the induction of selected olive genes. Computational analysis of 445 olive ESTs showed that plant defence and response to different stresses represented nearly 45% of genes induced in PICF7-colonized olive roots. Moreover, quantitative real-time PCR (qRT-PCR analysis confirmed induction of lipoxygenase, phenylpropanoid, terpenoids and plant hormones biosynthesis transcripts. Different classes of transcription factors (i.e., bHLH, WRKYs, GRAS1 were also induced. This work highlights for the first time the ability of an endophytic Pseudomonas spp. strain to mount a wide array of defence responses in an economically-relevant woody crop such as olive, helping to explain its biocontrol activity.

  3. Evolutionary responses of native plant species to invasive plants : a review

    OpenAIRE

    Oduor, Ayub M. O.

    2013-01-01

    Strong competition from invasive plant species often leads to declines in abundances and may,in certain cases, cause localized extinctions of native plant species. Nevertheless, studies have shown that certain populations of native plant species can co-exist with invasive plant species, suggesting the possibility of adaptive evolutionary responses of those populations to the invasive plants. Empirical inference of evolutionary responses of the native plant species to invasive plants has invol...

  4. Safety and security aspects in design of digital safety I and C in nuclear power plants

    International Nuclear Information System (INIS)

    Ding, Yongjian; Waedt, Karl

    2016-01-01

    The paper describes a safety objective oriented systematic design approach of digital (computerized) safety I and C in modern nuclear power plants which considers the plant safety requirements as well as cybersecurity needs. The defence in depth philosophy is applied by using different defence lines in the I and C architecture and protection zones in the plant IT environment.

  5. Safety and security aspects in design of digital safety I and C in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Yongjian [University of Applied Sciences Magdeburg-Stendal, Magdeburg (Germany). Inst. of Electrical Engineering; Waedt, Karl [Areva GmbH, Erlangen (Germany). PEAS-G

    2016-05-15

    The paper describes a safety objective oriented systematic design approach of digital (computerized) safety I and C in modern nuclear power plants which considers the plant safety requirements as well as cybersecurity needs. The defence in depth philosophy is applied by using different defence lines in the I and C architecture and protection zones in the plant IT environment.

  6. Evolutionary responses of native plant species to invasive plants: a review.

    Science.gov (United States)

    Oduor, Ayub M O

    2013-12-01

    Strong competition from invasive plant species often leads to declines in abundances and may, in certain cases, cause localized extinctions of native plant species. Nevertheless, studies have shown that certain populations of native plant species can co-exist with invasive plant species,suggesting the possibility of adaptive evolutionary responses of those populations to the invasive plants. Empirical inference of evolutionary responses of the native plant species to invasive plants has involved experiments comparing two conspecific groups of native plants for differences in expression of growth/reproductive traits: populations that have experienced competition from the invasive plant species (i.e. experienced natives) versus populations with no known history of interactions with the invasive plant species (i.e. naıve natives). Here, I employ a meta-analysis to obtain a general pattern of inferred evolutionary responses of native plant species from 53 such studies. In general, the experienced natives had significantly higher growth/reproductive performances than naıve natives, when grown with or without competition from invasive plants.While the current results indicate that certain populations of native plant species could potentially adapt evolutionarily to invasive plant species, the ecological and evolutionary mechanisms that probably underlie such evolutionary responses remain unexplored and should be the focus of future studies.

  7. EST sequencing and gene expression profiling of defence-related genes from Persea americana infected with Phytophthora cinnamomi

    Directory of Open Access Journals (Sweden)

    Mahomed Waheed

    2011-11-01

    Full Text Available Abstract Background Avocado (Persea americana belongs to the Lauraceae family and is an important commercial fruit crop in over 50 countries. The most serious pathogen affecting avocado production is Phytophthora cinnamomi which causes Phytophthora root rot (PRR. Root pathogens such as P. cinnamomi and their interactions with hosts are poorly understood and despite the importance of both the avocado crop and the effect Phytophthora has on its cultivation, there is a lack of molecular knowledge underpinning our understanding of defence strategies against the pathogen. In order to initiate a better understanding of host-specific defence we have generated EST data using 454 pyrosequencing and profiled nine defence-related genes from Pc-infected avocado roots. Results 2.0 Mb of data was generated consisting of ~10,000 reads on a single lane of the GS FLX platform. Using the Newbler assembler 371 contigs were assembled, of which 367 are novel for Persea americana. Genes were classified according to Gene Ontology terms. In addition to identifying root-specific ESTs we were also able to identify and quantify the expression of nine defence-related genes that were differentially regulated in response to P. cinnamomi. Genes such as metallothionein, thaumatin and the pathogenesis related PsemI, mlo and profilin were found to be differentially regulated. Conclusions This is the first study in elucidating the avocado root transcriptome as well as identifying defence responses of avocado roots to the root pathogen P. cinnamomi. Our data is currently the only EST data that has been generated for avocado rootstocks, and the ESTs identified in this study have already been useful in identifying defence-related genes as well as providing gene information for other studies looking at processes such as ROS regulation as well as hypoxia in avocado roots. Our EST data will aid in the elucidation of the avocado transcriptome and identification of markers for improved

  8. Defence in depth in nuclear safety

    International Nuclear Information System (INIS)

    Jayakumar, J.S.

    2016-01-01

    Nuclear energy is clean and can prevent global warming and hence it has a lot of importance in the current world. In order for the safe and reliable operation of the NPP, a defence in depth concept has been practised, so that even one level of protection fails the subsequent one will contain the hazardous situation. Various levels, both from consideration of the physical barriers and implementation are described in this paper. Three major accidents happened in nuclear reactors are analysed from the defence in depth concept and shortcomings are discussed. (author)

  9. Differential modulation of plant immune responses by diverse members of the Pseudomonas savastanoi pv. savastanoi HopAF type III effector family.

    Science.gov (United States)

    Castañeda-Ojeda, M Pilar; López-Solanilla, Emilia; Ramos, Cayo

    2017-06-01

    The Pseudomonas savastanoi pv. savastanoi NCPPB 3335 type III secretion system (T3SS) effector repertoire includes 33 candidates, seven of which translocate into host cells and interfere with plant defences. The present study was performed to investigate the co-existence of both plasmid- and chromosomal-encoded members of the HopAF effector family, HopAF1-1 and HopAF1-2, respectively, in the genome of NCPPB 3335. Here, we show that the HopAF1 paralogues are widely distributed in the Pseudomonas syringae complex, where HopAF1-1 is most similar to the homologues encoded by other P. syringae pathovars infecting woody hosts that belong to phylogroups 1 and 3. We show that the expression of both HopAF1-1 and HopAF-2 is transcriptionally dependent on HrpL and demonstrate their delivery into Nicotiana tabacum leaves. Although the heterologous delivery of either HopAF1-1 or HopAF1-2 significantly suppressed the production of defence-associated reactive oxygen species levels, only HopAF1-2 reduced the levels of callose deposition. Moreover, the expression of HopAF1-2 by functionally effectorless P. syringae pv. tomato DC3000D28E completely inhibited the hypersensitive response in tobacco and significantly increased the competitiveness of the strain in Nicotiana benthamiana. Despite their functional differences, subcellular localization studies reveal that green fluorescent protein (GFP) fusions to either HopAF1-1 or HopAF1-2 are targeted to the plasma membrane when they are expressed in plant cells, a process that is completely dependent on the integrity of their N-myristoylation motif. Our results further support the notion that highly similar T3SS effectors might differentially interact with diverse plant targets, even when they co-localize in the same cell compartment. © 2016 BSPP AND JOHN WILEY & SONS LTD.

  10. EU Defence Industry Integration between Spillover and High Politics

    DEFF Research Database (Denmark)

    Kluth, Michael Friederich

    on an intergovernmental base. In the past 10 years, however, the defence industries of the major EU powers have instigated a move from cross national collaboration to cross national consolidation. Cross border mergers and acquisitions has been carried out and pressures for regulatory mainstreaming is mounting....... This raises the question: are we witnessing an incursion of spillover mechanisms into the ‘High Politics' domain of the defence industry? What are the drivers eroding the ‘High Politics' character of defence industry integration? Are market forces at play? Does it reflect pressures for institutional...

  11. Leaf biochemical responses and fruit oil quality parameters in olive plants subjected to airborne metal pollution.

    Science.gov (United States)

    Fourati, Radhia; Scopa, Antonio; Ben Ahmed, Chedlia; Ben Abdallah, Ferjani; Terzano, Roberto; Gattullo, Concetta Eliana; Allegretta, Ignazio; Galgano, Fernanda; Caruso, Marisa Carmela; Sofo, Adriano

    2017-02-01

    This study was carried out in two olive orchards (Olea europaea L., cv. Chemlali) located in a polluted area near a fertilizers factory and in a control unpolluted site, managed with similar cultivation techniques. The aim was to investigate the physiological and biochemical responses of polluted plants (PP), exposed to atmospheric metal contamination (Cd, Cu, Fe, Mn, Ni and Pb) as compared to control plants (CP). Leaves, roots and fruits of PP showed a depression of their non-enzymatic and enzymatic antioxidant defences and a disruption of their hormonal homeostasis. The anomalous physiological status of PP was also demonstrated by the lower values of pigments in leaves and fruits, as compared to CP. Atmospheric metals negatively affected olive oil chemical and sensory quality. However, despite metal deposition on fruit surfaces, the accumulation of potentially toxic metals in olive oil was negligible. Considering that olive oil is an important food product worldwide and that many productive olive orchards are exposed to several sources of pollution, this work could contribute to clarify the effects of atmospheric metal pollution on olive oil quality and its potential toxicity for humans. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Collective defence portfolios of ant hosts shift with social parasite pressure.

    Science.gov (United States)

    Jongepier, Evelien; Kleeberg, Isabelle; Job, Sylwester; Foitzik, Susanne

    2014-09-22

    Host defences become increasingly costly as parasites breach successive lines of defence. Because selection favours hosts that successfully resist parasitism at the lowest possible cost, escalating coevolutionary arms races are likely to drive host defence portfolios towards ever more expensive strategies. We investigated the interplay between host defence portfolios and social parasite pressure by comparing 17 populations of two Temnothorax ant species. When successful, collective aggression not only prevents parasitation but also spares host colonies the cost of searching for and moving to a new nest site. However, once parasites breach the host's nest defence, host colonies should resort to flight as the more beneficial resistance strategy. We show that under low parasite pressure, host colonies more likely responded to an intruding Protomognathus americanus slavemaker with collective aggression, which prevented the slavemaker from escaping and potentially recruiting nest-mates. However, as parasite pressure increased, ant colonies of both host species became more likely to flee rather than to fight. We conclude that host defence portfolios shift consistently with social parasite pressure, which is in accordance with the degeneration of frontline defences and the evolution of subsequent anti-parasite strategies often invoked in hosts of brood parasites. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  13. Successive Evolutions of the Defence in Depth Concept

    Energy Technology Data Exchange (ETDEWEB)

    Poulat, B., E-mail: B.Poulat@iaea.org [International Atomic Energy Agency (IAEA), Department of Nuclear Safety and Security, Wagramer Strasse 5, P.O. Box 100, 1400 Vienna (Austria)

    2014-10-15

    Following Fukushima Daiichi accident, the Defence-in-depth concept, which is usually defined as a combination of a number of consecutive and independent levels of protection that would have to fail before harmful effects could be caused, has been confirmed as an essential element to be applied in the design of a nuclear facility to protect people and the environment. However, and although the implementation of the defence in depth concept had been required for long, the Fukushima Daiichi accident and the “stress tests” conducted in different countries have revealed deficiencies in its implementation. Consequently within the review of the IAEA safety requirements requested by Member states, it was important to check whether this concept was appropriately defined in order to be properly understood and fully implemented by vendors and operating organizations. By screening the successive definitions of the defence in depth principle and concept, this paper emphasizes the few issues which have been gradually clarified and enhanced to ensure effectiveness of the defence in depth as expressed from its original statement. (author)

  14. High CO2 Primes Plant Biotic Stress Defences through Redox-Linked Pathways1[OPEN

    Science.gov (United States)

    2016-01-01

    Industrial activities have caused tropospheric CO2 concentrations to increase over the last two centuries, a trend that is predicted to continue for at least the next several decades. Here, we report that growth of plants in a CO2-enriched environment activates responses that are central to defense against pathogenic attack. Salicylic acid accumulation was triggered by high-growth CO2 in Arabidopsis (Arabidopsis thaliana) and other plants such as bean (Phaseolus vulgaris). A detailed analysis in Arabidopsis revealed that elevated CO2 primes multiple defense pathways, leading to increased resistance to bacterial and fungal challenge. Analysis of gene-specific mutants provided no evidence that activation of plant defense pathways by high CO2 was caused by stomatal closure. Rather, the activation is partly linked to metabolic effects involving redox signaling. In support of this, genetic modification of redox components (glutathione contents and NADPH-generating enzymes) prevents full priming of the salicylic acid pathway and associated resistance by high CO2. The data point to a particularly influential role for the nonphosphorylating glyceraldehyde-3-phosphate dehydrogenase, a cytosolic enzyme whose role in plants remains unclear. Our observations add new information on relationships between high CO2 and oxidative signaling and provide novel insight into plant stress responses in conditions of increased CO2. PMID:27578552

  15. The correlated evolution of antipredator defences and brain size in mammals.

    Science.gov (United States)

    Stankowich, Theodore; Romero, Ashly N

    2017-01-11

    Mammals that possess elaborate antipredator defences such as body armour, spines and quills are usually well protected, intermediate in size, primarily insectivorous and live in simple open environments. The benefits of such defences seem clear and may relax selection on maintaining cognitive abilities that aid in vigilance and predator recognition, and their bearers may accrue extensive production and maintenance costs. Here, in this comparative phylogenetic analysis of measurements of encephalization quotient and morphological defence scores of 647 mammal species representing nearly every order, we found that as lineages evolve stronger defences, they suffer a correlated reduction in encephalization. The only exceptions were those that live in trees-a complex three-dimensional world probably requiring greater cognitive abilities. At the proximate level, because brain tissue is extremely energetically expensive to build, mammals may be trading off spending more on elaborate defences and saving by building less powerful brains. At the ultimate level, having greater defences may also reduce the need for advanced cognitive abilities for constant assessment of environmental predation risk, especially in simple open environments. © 2017 The Author(s).

  16. The correlated evolution of antipredator defences and brain size in mammals

    Science.gov (United States)

    Romero, Ashly N.

    2017-01-01

    Mammals that possess elaborate antipredator defences such as body armour, spines and quills are usually well protected, intermediate in size, primarily insectivorous and live in simple open environments. The benefits of such defences seem clear and may relax selection on maintaining cognitive abilities that aid in vigilance and predator recognition, and their bearers may accrue extensive production and maintenance costs. Here, in this comparative phylogenetic analysis of measurements of encephalization quotient and morphological defence scores of 647 mammal species representing nearly every order, we found that as lineages evolve stronger defences, they suffer a correlated reduction in encephalization. The only exceptions were those that live in trees—a complex three-dimensional world probably requiring greater cognitive abilities. At the proximate level, because brain tissue is extremely energetically expensive to build, mammals may be trading off spending more on elaborate defences and saving by building less powerful brains. At the ultimate level, having greater defences may also reduce the need for advanced cognitive abilities for constant assessment of environmental predation risk, especially in simple open environments. PMID:28077771

  17. Ecophysiological response to seasonal variations in water availability in the arborescent, endemic plant Vellozia gigantea.

    Science.gov (United States)

    Morales, Melanie; Garcia, Queila S; Munné-Bosch, Sergi

    2015-03-01

    The physiological response of plants growing in their natural habitat is strongly determined by seasonal variations in environmental conditions and the interaction of abiotic and biotic stresses. Here, leaf water and nutrient contents, changes in cellular redox state and endogenous levels of stress-related phytohormones (abscisic acid (ABA), salicylic acid and jasmonates) were examined during the rainy and dry season in Vellozia gigantea, an endemic species growing at high elevations in the rupestrian fields of the Espinhaço Range in Brazil. Enhanced stomatal closure and increased ABA levels during the dry season were associated with an efficient control of leaf water content. Moreover, reductions in 12-oxo-phytodienoic acid (OPDA) levels during the dry season were observed, while levels of other jasmonates, such as jasmonic acid and jasmonoyl-isoleucine, were not affected. Changes in ABA and OPDA levels correlated with endogenous concentrations of iron and silicon, hydrogen peroxide, and vitamin E, thus indicating complex interactions between water and nutrient contents, changes in cellular redox state and endogenous hormone concentrations. Results also suggested crosstalk between activation of mechanisms for drought stress tolerance (as mediated by ABA) and biotic stress resistance (mediated by jasmonates), in which vitamin E levels may serve as a control point. It is concluded that, aside from a tight ABA-associated regulation of stomatal closure during the dry season, crosstalk between activation of abiotic and biotic defences, and nutrient accumulation in leaves may be important modulators of plant stress responses in plants growing in their natural habitat. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Novel perspectives for the engineering of abiotic stress tolerance in plants.

    Science.gov (United States)

    Cabello, Julieta V; Lodeyro, Anabella F; Zurbriggen, Matias D

    2014-04-01

    Adverse environmental conditions pose serious limitations to agricultural production. Classical biotechnological approaches towards increasing abiotic stress tolerance focus on boosting plant endogenous defence mechanisms. However, overexpression of regulatory elements or effectors is usually accompanied by growth handicap and yield penalties due to crosstalk between developmental and stress-response networks. Herein we offer an overview on novel strategies with the potential to overcome these limitations based on the engineering of regulatory systems involved in the fine-tuning of the plant response to environmental hardships, including post-translational modifications, small RNAs, epigenetic control of gene expression and hormonal networks. The development and application of plant synthetic biology tools and approaches will add new functionalities and perspectives to genetic engineering programs for enhancing abiotic stress tolerance. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Dopamine is a key regulator in the signalling pathway underlying predator-induced defences in Daphnia

    Science.gov (United States)

    Weiss, Linda C.; Leese, Florian; Laforsch, Christian; Tollrian, Ralph

    2015-01-01

    The waterflea Daphnia is a model to investigate the genetic basis of phenotypic plasticity resulting from one differentially expressed genome. Daphnia develops adaptive phenotypes (e.g. morphological defences) thwarting predators, based on chemical predator cue perception. To understand the genomic basis of phenotypic plasticity, the description of the precedent cellular and neuronal mechanisms is fundamental. However, key regulators remain unknown. All neuronal and endocrine stimulants were able to modulate but not induce defences, indicating a pathway of interlinked steps. A candidate able to link neuronal with endocrine responses is the multi-functional amine dopamine. We here tested its involvement in trait formation in Daphnia pulex and Daphnia longicephala using an induction assay composed of predator cues combined with dopaminergic and cholinergic stimulants. The mere application of both stimulants was sufficient to induce morphological defences. We determined dopamine localization in cells found in close association with the defensive trait. These cells serve as centres controlling divergent morphologies. As a mitogen and sclerotization agent, we anticipate that dopamine is involved in proliferation and structural formation of morphological defences. Furthermore, dopamine pathways appear to be interconnected with endocrine pathways, and control juvenile hormone and ecdysone levels. In conclusion, dopamine is suggested as a key regulator of phenotypic plasticity. PMID:26423840

  20. Physiological and Biochemical Responses of Saltmarsh Plant Spartina alterniflora to Long-term Wave Exposure

    Science.gov (United States)

    Zhou, W.

    2017-12-01

    In recent years, ecosystem-based flood defence, i.e., eco-shoreline or living shoreline, that is more sustainable and cost-effective than conventional coastal engineering structures has been brought into large-scale practice. Numerous laboratory experiments have been performed to explore the wave-attenuation effects of saltmarsh plants that are widely used in eco-shoreline, and yet no study has ever been conducted on the physiological and biochemical responses of saltmarsh plants to long-term wave exposure, presumably due to the constraint that traditional wave generator fails to provide long-term stable wave conditions necessary for physiological experiments. In this study, a long-term shallow water wave environment simulator using crank-yoke mechanism was built in the laboratory to address this gap. Experiments using the wave simulator were conducted for 8 weeks in a greenhouse and the temperature was maintained at 24-30°C. 5‰ artificial sea water was filled in the test tank, and the water was changed every week. After being acclimatized, nine S. alterniflora individual plants (initial height 30 cm) were planted in each of the three streamlined cuboid containers (12cm×12cm×20cm), which were partially submerged in a test tank, and undertook horizontal sinusoidal motion imposed by the crank-yoke mechanism to mimic plants exposed to shallow water waves. The substrate filled in the containers were soils collected from the Yellow River Delta, so were the S. alterniflora plants. A realistic stem density of 400 stems/m2 was tested, which corresponded to a grid spacing of 5.0 cm. Shallow water waves with six wave heights (H: 0.041, 0.055, 0.069, 0.033, 0.044 and 0.056m), one plants submerged depth (0.1m) and two wave periods (2s and 3s) were simulated in the experiments. A no wave condition was also tested as control. Key physiological and biochemical parameters, such as stem length, peroxidase activity, catalase, superoxide dismutase, ascorbate peroxidase, etc

  1. How to address patients' defences: a pilot study of the accuracy of defence interpretations and alliance.

    Science.gov (United States)

    Junod, Olivier; de Roten, Yves; Martinez, Elena; Drapeau, Martin; Despland, Jean-Nicolas

    2005-12-01

    This pilot study examined the accuracy of therapist defence interpretations (TAD) in high-alliance patients (N = 7) and low-alliance patients (N = 8). TAD accuracy was assessed in the two subgroups by comparing for each case the patient's most frequent defensive level with the most frequent defensive level addressed by the therapist when making defence interpretations. Results show that in high-alliance patient-therapist dyads, the therapists tend to address accurate or higher (more mature) defensive level than patients most frequent level. On the other hand, the therapists address lower (more immature) defensive level in low-alliance dyads. These results are discussed along with possible ways to better assess TAD accuracy.

  2. Quantitative Verification and Synthesis of Attack-Defence Scenarios Conference

    NARCIS (Netherlands)

    Aslanyan, Zaruhi; Nielson, Flemming; Parker, David

    Attack-defence trees are a powerful technique for formally evaluating attack-defence scenarios. They represent in an intuitive, graphical way the interaction between an attacker and a defender who compete in order to achieve conflicting objectives. We propose a novel framework for the formal

  3. Elevated O3 enhances the attraction of whitefly-infested tomato plants to Encarsia formosa

    Science.gov (United States)

    Cui, Hongying; Su, Jianwei; Wei, Jianing; Hu, Yongjian; Ge, Feng

    2014-01-01

    We experimentally examined the effects of elevated O3 and whitefly herbivory on tomato volatiles, feeding and oviposition preferences of whiteflies and behavioural responses of Encarsia formosa to these emissions on two tomato genotypes, a wild-type (Wt) and a jasmonic acid (JA) defence-enhanced genotype (JA-OE, 35S). The O3 level and whitefly herbivory significantly increased the total amount of volatile organic compounds (VOCs), monoterpenes, green leaf volatiles (GLVs), and aldehyde volatiles produced by tomato plants. The 35S plants released higher amount of total VOCs and monoterpene volatiles than Wt plants under O3+herbivory treatments. The feeding and oviposition bioassays showed that control plants were preferred by adult whiteflies whereas the 35S plants were not preferred by whiteflies. In the Y-tube tests, O3+herbivory treatment genotypes were preferred by adult E. Formosa. The 35S plants were preferred by adult E. formosa under O3, herbivory and O3+herbivory treatments. Our results demonstrated that elevated O3 and whitefly herbivory significantly increased tomato volatiles, which attracted E. formosa and reduced whitefly feeding. The 35S plants had a higher resistance to B. tabaci than Wt plant. Such changes suggest that the direct and indirect defences of resistant genotypes, such as 35S, could strengthen as the atmospheric O3 concentration increases. PMID:24939561

  4. Conditions for the lawful exercise of the right of self-defence in international law

    Directory of Open Access Journals (Sweden)

    Upeniece V.

    2018-01-01

    Full Text Available The Charter of the United Nations wasthought to establish a normative order, maintain international peace and security. According to the Article 51 of the Charter of the United Nations “Nothing in the present Charter shall impair the inherent right of individual or collective self-defence if an armed attack occurs”[1]. However the Article 51 doesnot propose a legal definition of the conduct which is considered as an armed attack or the commencement of such an attack. It does not propose strict criterions for the use of force for self-defence. As a result different interpretations of this norm have been arising and continuing to change in response to new situations and threats.

  5. Computed Tomography Technology: Development and Applications for Defence

    International Nuclear Information System (INIS)

    Baheti, G. L.; Saxena, Nisheet; Tripathi, D. K.; Songara, K. C.; Meghwal, L. R.; Meena, V. L.

    2008-01-01

    Computed Tomography(CT) has revolutionized the field of Non-Destructive Testing and Evaluation (NDT and E). Tomography for industrial applications warrants design and development of customized solutions catering to specific visualization requirements. Present paper highlights Tomography Technology Solutions implemented at Defence Laboratory, Jodhpur (DLJ). Details on the technological developments carried out and their utilization for various Defence applications has been covered.

  6. Transgenic expression of a functional fragment of harpin protein Hpa1 in wheat induces the phloem-based defence against English grain aphid

    Science.gov (United States)

    Fu, Maoqiang; Xu, Manyu; Zhang, Chunling

    2014-01-01

    The harpin protein Hpa1 has multiple beneficial effects in plants, promoting plant growth and development, increasing crop yield, and inducing resistance to pathogens and insect pests. For these effects, the 10–40 residue fragment (Hpa110–42) isolated from the Hpa1 sequence is 1.3- to 7.5-fold more effective than the full-length protein. Here it is reported that the expression of Hpa110–42 under the direction of an insect-induced promoter induces the phloem-based defence to English grain aphid, a dominant species of wheat aphids. The expression of Hpa110–42 was found to compromise the colonization preference of aphids on the plant and further inhibit aphid reproduction in leaf colonies. In Hpa110–42-expressing wheat lines, moreover, aphid feeding from the phloem was repressed in correlation with the phloem-based defence. This defensive mechanism was shown as enhanced expression of wheat genes encoding phloem lectin proteins (PP2-A1 and PP2-A2) and β-1,3-glucan synthase-like enzymes (GSL2, GSL10, and GSL12). Both PP2-A and β-1,3-glucan formed high molecular mass polymers to block phloem sieve plate pores and therefore impede aphid feeding from the phloem. However, the phloem-based defence was impaired by treating plants with ethylene signalling inhibitors, suggesting the requirement for the ethylene signalling pathway. In addition, if Hpa110–42-expressing plants were subjected to attack by a small number of aphids, they newly acquired agriculturally beneficial characters, such as enhanced vegetative growth and increased tiller numbers and grain output values. These results suggest that the defensive and developmental roles of Hpa110–42 can be integrated into the germplasm of this agriculturally significant crop. PMID:24676030

  7. TNO and CBRN defence

    NARCIS (Netherlands)

    2015-01-01

    Within the Defence, Safety & Security branch of TNO a dedicated department focuses on Chemical, Biological, Radiological and Nuclear (CBRN) Protection. This is a world class research department consisting of about 50 people and a High Tox laboratory that is the only facility in The Netherlands that

  8. Safety principles for nuclear power plants

    International Nuclear Information System (INIS)

    Vuorinen, A.

    1993-01-01

    The role and purpose of safety principles for nuclear power plants are discussed. A brief information is presented on safety objectives as given in the INSAG documents. The possible linkage is discussed between the two mentioned elements of nuclear safety and safety culture. Safety culture is a rather new concept and there is more than one interpretation of the definition given by INSAG. The defence in depth is defined by INSAG as a fundamental principle of safety technology of nuclear power. Discussed is the overall strategy for safety measures, and features of nuclear power plants provided by the defence-in-depth concept. (Z.S.) 7 refs

  9. Flavonoid Functions in Plants and Their Interactions with Other Organisms

    Directory of Open Access Journals (Sweden)

    Ulrike Mathesius

    2018-04-01

    Full Text Available Flavonoids are structurally diverse secondary metabolites in plants, with a multitude of functions. These span from functions in regulating plant development, pigmentation, and UV protection, to an array of roles in defence and signalling between plants and microorganisms. Because of their prevalence in the human diet, many flavonoids constitute important components of medicinal plants and are used in the control of inflammation and cancer prevention. Advances in the elucidation of flavonoid biosynthesis and its regulation have led to an increasing number of studies aimed at engineering the flavonoid pathway for enhancing nutritional value and plant defences against pathogens and herbivores, as well as modifying the feeding value of pastures. Many future opportunities await for the exploitation of this colourful pathway in crops, pastures, and medicinal plants.

  10. Identification of distinct quantitative trait loci associated with defence against the closely related aphids Acyrthosiphon pisum and A. kondoi in Medicago truncatula

    KAUST Repository

    Guo, Su-Min

    2012-03-21

    Aphids are a major family of plant insect pests. Medicago truncatula and Acyrthosiphon pisum (pea aphid, PA) are model species with a suite of resources available to help dissect the mechanism underlying plant-aphid interactions. A previous study focused on monogenic and relatively strong resistance in M. truncatula to PA and other aphid species. In this study a moderate resistance to PA was characterized in detail in the M. truncatula line A17 and compared with the highly susceptible line A20 and the more resistant line Jester. The results show that PA resistance in A17 involves both antibiosis and tolerance, and that resistance is phloem based. Quantitative trait locus (QTL) analysis using a recombinant inbred line (RIL) population (n=114) from a cross between A17 and A20 revealed that one locus, which co-segregated with AIN (Acyrthosiphon-induced necrosis) on chromosome 3, is responsible for the reduction of aphid biomass (indicator of antibiosis) for both PA and bluegreen aphid (BGA, A. kondoi), albeit to a lesser degree for PA than BGA. Interestingly, two independent loci on chromosomes 5 and 3 were identified for the plant biomass reduction (indicator of plant tolerance) by PA and BGA, respectively, demonstrating that the plant\\'s tolerance response to these two closely related aphid species is distinct. Together with previously identified major resistant (R) genes, the QTLs identified in this study are powerful tools to understand fully the spectrum of plant defence against sap-sucking insects and provide opportunities for breeders to generate effective and sustainable strategies for aphid control. 2012 The Author.

  11. Expression profiles of defence related cDNAs in oil palm (Elaeis guineensis Jacq.) inoculated with mycorrhizae and Trichoderma harzianum Rifai T32.

    Science.gov (United States)

    Tan, Yung-Chie; Wong, Mui-Yun; Ho, Chai-Ling

    2015-11-01

    Basal stem rot is one of the major diseases of oil palm (Elaies guineensis Jacq.) caused by pathogenic Ganoderma species. Trichoderma and mycorrhizae were proposed to be able to reduce the disease severity. However, their roles in improving oil palm defence system by possibly inducing defence-related genes in the host are not well characterized. To better understand that, transcript profiles of eleven putative defence-related cDNAs in the roots of oil palm inoculated with Trichoderma harzianum T32 and mycorrhizae at different time points were studied. Transcripts encoding putative Bowman-Birk protease inhibitor (EgBBI2) and defensin (EgDFS) increased more than 2 fold in mycorrhizae-treated roots at 6 weeks post inoculation (wpi) compared to those in controls. Transcripts encoding putative dehydrin (EgDHN), glycine-rich RNA binding protein (EgGRRBP), isoflavone reductase (EgIFR), type 2 ribosome inactivating protein (EgT2RIP), and EgDFS increased in the oil palm roots treated with T. harzianum at 6 and/or 12 wpi compared to those in the controls. Some of these genes were also expressed in oil palm roots treated with Ganoderma boninense. This study provides an insight of some defence-related genes induced by Trichoderma and mycorrhizae, and their roles as potential agents to boost the plant defence system. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  12. Transcriptional analysis and histochemistry reveal that hypersensitive cell death and H2O2 have crucial roles in the resistance of tea plant (Camellia sinensis (L.) O. Kuntze) to anthracnose.

    Science.gov (United States)

    Wang, Yuchun; Hao, Xinyuan; Lu, Qinhua; Wang, Lu; Qian, Wenjun; Li, Nana; Ding, Changqing; Wang, Xinchao; Yang, Yajun

    2018-01-01

    Anthracnose causes severe losses of tea production in China. Although genes and biological processes involved in anthracnose resistance have been reported in other plants, the molecular response to anthracnose in tea plant is unknown. We used the susceptible tea cultivar Longjing 43 and the resistant cultivar Zhongcha 108 as materials and compared transcriptome changes in the leaves of both cultivars following Colletotrichum fructicola inoculation. In all, 9015 and 8624 genes were differentially expressed between the resistant and susceptible cultivars and their controls (0 h), respectively. In both cultivars, the differentially expressed genes (DEGs) were enriched in 215 pathways, including responses to sugar metabolism, phytohormones, reactive oxygen species (ROS), biotic stimuli and signalling, transmembrane transporter activity, protease activity and signalling receptor activity, but DEG expression levels were higher in Zhongcha 108 than in Longjing 43. Moreover, functional enrichment analysis of the DEGs showed that hydrogen peroxide (H 2 O 2 ) metabolism, cell death, secondary metabolism, and carbohydrate metabolism are involved in the defence of Zhongcha 108, and 88 key genes were identified. Protein-protein interaction (PPI) network demonstrated that putative mitogen-activated protein kinase (MAPK) cascades are activated by resistance (R) genes and mediate downstream defence responses. Histochemical analysis subsequently validated the strong hypersensitive response (HR) and H 2 O 2 accumulation that occurred around the hyphal infection sites in Zhongcha 108. Overall, our results indicate that the HR and H 2 O 2 are critical mechanisms in tea plant defence against anthracnose and may be activated by R genes via MAPK cascades.

  13. Drought-induced trans-generational tradeoff between stress tolerance and defence: consequences for range limits?

    Science.gov (United States)

    Alsdurf, Jacob D; Ripley, Tayler J; Matzner, Steven L; Siemens, David H

    2013-01-01

    Areas just across species range boundaries are often stressful, but even with ample genetic variation within and among range-margin populations, adaptation towards stress tolerance across range boundaries often does not occur. Adaptive trans-generational plasticity should allow organisms to circumvent these problems for temporary range expansion; however, range boundaries often persist. To investigate this dilemma, we drought stressed a parent generation of Boechera stricta (A.Gray) A. Löve & D. Löve, a perennial wild relative of Arabidopsis, representing genetic variation within and among several low-elevation range margin populations. Boechera stricta is restricted to higher, moister elevations in temperate regions where generalist herbivores are often less common. Previous reports indicate a negative genetic correlation (genetic tradeoff) between chemical defence allocation and abiotic stress tolerance that may prevent the simultaneous evolution of defence and drought tolerance that would be needed for range expansion. In growth chamber experiments, the genetic tradeoff became undetectable among offspring sib-families whose parents had been drought treated, suggesting that the stress-induced trans-generational plasticity may circumvent the genetic tradeoff and thus enable range expansion. However, the trans-generational effects also included a conflict between plastic responses (environmental tradeoff); offspring whose parents were drought treated were more drought tolerant, but had lower levels of glucosinolate toxins that function in defence against generalist herbivores. We suggest that either the genetic or environmental tradeoff between defence allocation and stress tolerance has the potential to contribute to range limit development in upland mustards.

  14. 43. and 44. annual meeting of the Civil Defence Commission of the Federal Ministry of the Interior. Proceedings

    International Nuclear Information System (INIS)

    1997-01-01

    Changes in the conditions governing international safety call for a re-orientation in civil defence policy. The 23 papers presented to the meetings address aspects such as external hazards, including illicit trafficking with nuclear materials, novel risks emanating from the population growth rates, the international refugee problem, environmental issues, and new approaches in civil defence policy also encompassing emergency preparedness under the responsibility of the Laender. Futher topics discussed are proposals for improvement of first-aid medical care, or new approaches in concepts for risk identification and management as well as preventive action. (DG) [de

  15. Radiation protection in civil defence

    International Nuclear Information System (INIS)

    Ahlborn, K.

    The brochure contains the information given to the participants of an advanced training course in civil defence, on the subject of radiation protection. The course was held by teachers of Bundesverband fuer den Selbstschutz (BVS). (orig.) [de

  16. Oxidative defence reactions in sunflower roots induced by methyl-jasmonate and methyl-salicylate and their relation with calcium signalling.

    Science.gov (United States)

    Garrido, Inmaculada; Espinosa, Francisco; Alvarez-Tinaut, M Carmen

    2009-10-01

    Ca(2+) plays a critical role as second messenger in the signal-response coupling of plant defence responses, and methyl-jasmonate and methyl-salicylate are important components of signal transduction cascades activating plant defences. When intact axenic non-induced seedling roots of sunflower were treated with different Ca(2+) concentrations up to 1 mM, there was no significant increase in O(2)(*-) generation or DMAB-MBTH peroxidase (extracellular, ECPOX) activities in the apoplast, probably because these roots had enough Ca(2+) in their exo- and endocellular reservoirs. Both activities were strongly inhibited by the RBOH-NADPH oxidase inhibitor DPI and by the Ca(2+) surrogate antagonist La(3+), but the voltage-dependent Ca(2+) channel blocker verapamil was only inhibitory at concentrations higher than those active on animal L-type Ca(2+) channels. Concentrations >5 mM EGTA (chelating Ca(2+) in the apoplast) and Li(+) (inhibiting PI cycle dependent endogenous Ca(2+) fluxes) also inhibited both activities. W7, inhibitor of binding of Ca-CaM to its target protein, enhanced both activities, but the inactive analogue W5 showed a similar effect. Our data suggest that Ca(2+) from exocellular and, to a lesser extent, from endocellular stores is involved in oxidative activities, and that RBOH-NADPH oxidase is the main system supporting them. Ca(2+) activation of the PM cytosolic side of RBOH-NADPH oxidase is probably the key to Ca(2+) involvement in these processes. Roots induced by MeJA or MeSA showed significant enhancement of both oxidative activities, as corresponding to the oxidative burst evoked by the two phytohormones in the root apoplast. But while ECPOX activity showed a response to the effectors similar to that described above for non-induced roots, O(2)(*-) generation activity in the apoplast of induced roots was insensitive to EGTA, verapamil and Li(+), the inhibitors of exogenous and endogenous Ca(2+) fluxes; only DPI and La(3+) were inhibitory. As

  17. Characterisation of the legume SERK-NIK gene superfamily including splice variants: Implications for development and defence

    Directory of Open Access Journals (Sweden)

    Rose Ray J

    2011-03-01

    Full Text Available Abstract Background SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE (SERK genes are part of the regulation of diverse signalling events in plants. Current evidence shows SERK proteins function both in developmental and defence signalling pathways, which occur in response to both peptide and steroid ligands. SERKs are generally present as small gene families in plants, with five SERK genes in Arabidopsis. Knowledge gained primarily through work on Arabidopsis SERKs indicates that these proteins probably interact with a wide range of other receptor kinases and form a fundamental part of many essential signalling pathways. The SERK1 gene of the model legume, Medicago truncatula functions in somatic and zygotic embryogenesis, and during many phases of plant development, including nodule and lateral root formation. However, other SERK genes in M. truncatula and other legumes are largely unidentified and their functions unknown. Results To aid the understanding of signalling pathways in M. truncatula, we have identified and annotated the SERK genes in this species. Using degenerate PCR and database mining, eight more SERK-like genes have been identified and these have been shown to be expressed. The amplification and sequencing of several different PCR products from one of these genes is consistent with the presence of splice variants. Four of the eight additional genes identified are upregulated in cultured leaf tissue grown on embryogenic medium. The sequence information obtained from M. truncatula was used to identify SERK family genes in the recently sequenced soybean (Glycine max genome. Conclusions A total of nine SERK or SERK-like genes have been identified in M. truncatula and potentially 17 in soybean. Five M. truncatula SERK genes arose from duplication events not evident in soybean and Lotus. The presence of splice variants has not been previously reported in a SERK gene. Upregulation of four newly identified SERK genes (in addition to the

  18. Regulation of disease-responsive genes mediated by epigenetic factors: interaction of Arabidopsis-Pseudomonas.

    Science.gov (United States)

    De-La-Peña, Clelia; Rangel-Cano, Alicia; Alvarez-Venegas, Raúl

    2012-05-01

    Genes in eukaryotic organisms function within the context of chromatin, and the mechanisms that modulate the structure of chromatin are defined as epigenetic. In Arabidopsis, pathogen infection induces the expression of at least one histone deacetylase, suggesting that histone acetylation/deacetylation has an important role in the pathogenic response in plants. How/whether histone methylation affects gene response to pathogen infection is unknown. To gain a better understanding of the epigenetic mechanisms regulating the interaction between Pseudomonas syringae and Arabidopsis thaliana, we analysed three different Arabidopsis ash1-related (absent, small or homeotic discs 1) mutants. We found that the loss of function of ASHH2 and ASHR1 resulted in faster hypersensitive responses (HRs) to both mutant (hrpA) and pathogenic (DC3000) strains of P. syringae, whereas control (Col-0) and ashr3 mutants appeared to be more resistant to the infection after 2 days. Furthermore, we showed that, in the ashr3 background, the PR1 gene (PATHOGENESIS-RELATED GENE 1) displayed the highest expression levels on infection with DC3000, correlating with increased resistance against this pathogen. Our results show that, in both the ashr1 and ashh2 backgrounds, the histone H3 lysine 4 dimethylation (H3K4me2) levels decreased at the promoter region of PR1 on infection with the DC3000 strain, suggesting that an epigenetically regulated PR1 expression is involved in the plant defence. Our results suggest that histone methylation in response to pathogen infection may be a critical component in the signalling and defence processes occurring between plants and microbes. © 2011 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2011 BSPP AND BLACKWELL PUBLISHING LTD.

  19. The failing firm defence: merger policy and entry

    OpenAIRE

    Mason, Robin; Weeds, Helen

    2003-01-01

    This Paper considers the 'failing firm defence'. Under this principle, found in most antitrust jurisdictions, a merger that would otherwise be blocked due to its adverse effect on competition is permitted when the firm to be acquired is a failing firm, and an alternative, less detrimental merger is unavailable. Competition authorities have shown considerable reluctance to accept the failing firm defence, and it has been successfully used in just a handful of cases. The Paper considers the def...

  20. Independently recruited oxidases from the glucose-methanol-choline oxidoreductase family enabled chemical defences in leaf beetle larvae (subtribe Chrysomelina) to evolve

    Science.gov (United States)

    Rahfeld, Peter; Kirsch, Roy; Kugel, Susann; Wielsch, Natalie; Stock, Magdalena; Groth, Marco; Boland, Wilhelm; Burse, Antje

    2014-01-01

    Larvae of the leaf beetle subtribe Chrysomelina sensu stricto repel their enemies by displaying glandular secretions that contain defensive compounds. These repellents can be produced either de novo (iridoids) or by using plant-derived precursors (e.g. salicylaldehyde). The autonomous production of iridoids, as in Phaedon cochleariae, is the ancestral chrysomeline chemical defence and predates the evolution of salicylaldehyde-based defence. Both biosynthesis strategies include an oxidative step of an alcohol intermediate. In salicylaldehyde-producing species, this step is catalysed by salicyl alcohol oxidases (SAOs) of the glucose-methanol-choline (GMC) oxidoreductase superfamily, but the enzyme oxidizing the iridoid precursor is unknown. Here, we show by in vitro as well as in vivo experiments that P. cochleariae also uses an oxidase from the GMC superfamily for defensive purposes. However, our phylogenetic analysis of chrysomeline GMC oxidoreductases revealed that the oxidase of the iridoid pathway originated from a GMC clade different from that of the SAOs. Thus, the evolution of a host-independent chemical defence followed by a shift to a host-dependent chemical defence in chrysomeline beetles coincided with the utilization of genes from different GMC subfamilies. These findings illustrate the importance of the GMC multi-gene family for adaptive processes in plant–insect interactions. PMID:24943369

  1. Fallout: the defence, industrial and technological benefits of nuclear deterrence

    International Nuclear Information System (INIS)

    Tertrais, Bruno

    2015-01-01

    In the current climate of budgetary restrictions, it is fair to question the weight of military nuclear defence spending. Upon examination, however, nuclear deterrence has numerous military, industrial, and technological benefits. It is, in fact, totally intertwined with the other elements of our defence system. (author)

  2. Interdepartmental Cooperation in Defence Issues and Strategic Intelligence

    Directory of Open Access Journals (Sweden)

    Nebojsa Nikolic

    2016-05-01

    Full Text Available The motivation for this paper comes from one successfully conducted empirical research about motivation of potential candidates to serve in the active reserve as a kind of military service which is recently introduced in the Serbian Army. The research team was faced with a set of problems related to the deadlines, resources and mandate issues. A solution was found in agile interdepartmental cooperation. Firstly, we started with identification of missing resources and mandates of our research team. Then, we investigated where we could find the missing issues. After that, we established lines for cooperation with other departments in the MoD. The clarity of interdepartmental communication and concretisation of demands and expectations were crucial for success. In the end we realized the full potential of interdepartmental cooperation and started to think about that phenomenon in the wider context of defence and security issues. We found some other examples of interdepartmental cooperation in earlier efforts of the defence sector reform, as well as some results in other armies. The paper presents strengths and opportunities of interdepartmental cooperation through temporary engaged working groups in the specific defence sector environment, as well as potential obstacles. In a wider aspect, interdepartmental cooperation in defence and security issues becomes more and more important because of new security challenges we are facing today.

  3. Defence in Depth - Applied to the Nuclear System

    Energy Technology Data Exchange (ETDEWEB)

    Weightman, M., E-mail: mike_weightman@hotmail.com

    2014-10-15

    Full text: Normally, the Defence in Depth concept is applied to the technical barriers that provide protection to the public and workers from nuclear accidents. This allows designers, operators and regulators to challenge (along with using other design principles such as independence, redundancy, diversity, single point failure, etc) the technical systems provided to see whether more needs to be done to provide adequate defence in depth to ensure risks are reduced so far as is reasonably practical. Post Fukushima, much thought has gone into reconsidering whether the effectiveness of the defence in depth concept can be enhanced by, for example, rebalancing the attention between prevention and mitigation or enhancing the independence of protective measures such as providing extremely robust standalone emergency cooling capability. This presentation argues that Fukushima teaches us a more fundamental lesson - that the defence in depth concept (along with other design principles') should be applied to the nuclear system to see whether more should be done to enhance the institutional barriers in any particular nuclear system. These barriers are at three main levels: industry, regulators and stakeholders each with sub-barriers. It reinforces the need for industry and regulators to be independent, open and transparent so that the nuclear system can work effectively. Examples are given where the application of the model identifies areas for improvement in existing systems. (author)

  4. Post-secretory fate of host defence components in mucus.

    Science.gov (United States)

    Salathe, Matthias; Forteza, Rosanna; Conner, Gregory E

    2002-01-01

    Airway mucus is a complex mixture of secretory products that provide a multifaceted defence against infection. Among many antimicrobial substances, mucus contains a peroxidase identical to milk lactoperoxidase (LPO) that is produced by goblet cells and submucosal glands. Airway secretions contain the substrates for LPO, namely thiocyanate and hydrogen peroxide, at concentrations sufficient for production of the biocidal compound hypothiocyanite, a fact confirmed by us in vitro. In vivo, inhibition of airway LPO in sheep significantly inhibits bacterial clearance, suggesting that the LPO system is a major contributor to host defences. Since secretory products including LPO are believed to be steadily removed by mucociliary clearance, their amount and availability on the surface is thought to be controlled solely by secretion. In contrast to this paradigm, new data suggest that LPO and other substances are retained at the ciliary border of the airway epithelium by binding to surface-associated hyaluronan, thereby providing an apical, fully active enzyme pool. Thus, hyaluronan, secreted from submucosal gland cells, plays a previously unrecognized pivotal role in mucosal host defence by retaining LPO and possibly other substances important for first line host defence at the apical surface 'ready for use' and protected from ciliary clearance.

  5. Impact of plant domestication on rhizosphere microbiome assembly and functions

    NARCIS (Netherlands)

    Perez Jaramillo, Juan Esteban; Mendes, Rodrigo; Raaijmakers, Jos

    2016-01-01

    The rhizosphere microbiome is pivotal for plant health and growth, providing defence against pests and diseases, facilitating nutrient acquisition and helping plants to withstand abiotic stresses. Plants can actively recruit members of the soil microbial community for positive feedbacks, but the

  6. Biological responses to current UV-B radiation in Arctic regions

    DEFF Research Database (Denmark)

    Albert, Kristian Rost; Mikkelsen, Teis Nørgaard; Ro-Poulsen, H.

    2008-01-01

    on high-arctic vegetation. They supplement previous investigations from the Arctic focussing on other variables like growth etc., which have reported no or minor plant responses to UV-B, and clearly indicates that UV-B radiation is an important factor affecting plant life at high-arctic Zackenberg......Depletion of the ozone layer and the consequent increase in solar ultraviolet-B radiation (UV-B) may impact living conditions for arctic plants significantly. In order to evaluate how the prevailing UV-B fluxes affect the heath ecosystem at Zackenberg (74°30'N, 20°30'W) and other high......-arctic regions, manipulation experiments with various set-ups have been performed. Activation of plant defence mechanisms by production of UV-B absorbing compounds was significant in ambient UV-B in comparison to a filter treatment reducing the UV-B radiation. Despite the UV-B screening response, ambient UV...

  7. 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...

  8. Two Theobroma cacao genotypes with contrasting pathogen tolerance show aberrant transcriptional and ROS responses after salicylic acid treatment.

    Science.gov (United States)

    Fister, Andrew S; O'Neil, Shawn T; Shi, Zi; Zhang, Yufan; Tyler, Brett M; Guiltinan, Mark J; Maximova, Siela N

    2015-10-01

    Understanding the genetic basis of pathogen susceptibility in various crop plants is crucial to increasing the stability of food, feed, and fuel production. Varietal differences in defence responses provide insights into the mechanisms of resistance and are a key resource for plant breeders. To explore the role of salicylic acid in the regulation of defence in cacao, we demonstrated that SA treatment decreased susceptibility to a pod rot pathogen, Phytophthora tropicalis in two genotypes, Scavina 6 and Imperial College Selection 1, which differ in their resistance to several agriculturally important pathogens. Transient overexpression of TcNPR1, a major transcriptional regulator of the SA-dependent plant immune system, also increased pathogen tolerance in cacao leaves. To explore further the genetic basis of resistance in cacao, we used microarrays to measure gene expression profiles after salicylic acid (SA) treatment in these two cacao genotypes. The two genotypes displayed distinct transcriptional responses to SA. Unexpectedly, the expression profile of the susceptible genotype ICS1 included a larger number of pathogenesis-related genes that were induced by SA at 24h after treatment, whereas genes encoding many chloroplast and mitochondrial proteins implicated in reactive oxygen species production were up-regulated in the resistant genotype, Sca6. Sca6 accumulated significantly more superoxide at 24h after treatment of leaves with SA. These experiments revealed critical insights regarding the molecular differences between cacao varieties, which will allow a better understanding of defence mechanisms to help guide breeding programmes. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  9. Internal emergency organization in the Beznau nuclear power plant

    International Nuclear Information System (INIS)

    Wenger, H.

    1989-01-01

    The successful mastering of every emergency situation is based on the strict adherence to frequently reviewed emergency instruction and practice on simulators. This is the primary duty of all plant employees. In addition, executive bodies are necessary. The highest authority in the emergency organization is the emergency staff. Under the leadership of the plant manager, this staff consists of all department heads and several specialists. Outside normal working hours, it can be expected of the emergency staff that it is fully functional within, at most, one hour. Until the emergency staff can take over, the on-duty engineer leads emergency procedures. Several other different teams are responsible to the emergency staff. There are five emergency teams: off-duty plant employees; fire fighters; radiation defence; first-aid; plant guards. Then there is the technical support center (TSC). The responsibilities of the TSC are: giving technical advise to the emergency staff; working out different options for fighting the emergency; checking up on special methods; communication with the reactor manufacturer for additional support. 1 fig

  10. Plants cultivation in controlled containments

    International Nuclear Information System (INIS)

    2000-01-01

    The plants cultivation in controlled containments permits to the - Departement d'Ecophysiologie Vegetale et de Microbiologie (DVEM) - of the CEA to lead several topics of research. The works of DVEM which are based on the molecular labelling, technique adapted to plants, contribute to understand the plant - soil relationships and the plant growth process. In addition, the staff of DVEM study the impact of pollutant heavy metals, existing in the soil, on plants and the plant stress induced by oxygen, light, ionizing radiations,... and defence mechanisms of plants (F. M.)

  11. United Kingdom's defence procurement: a period of smart enlightenment or halting culture

    OpenAIRE

    O Callaghan, D. M.

    2001-01-01

    The aim of this thesis is to map predominant cultures and examine their compatibility with the Smart Procurement Initiative. An initiative that was identified in the Strategic Defence Review to address the limitations of UK's defence procurement process that had previously failed to deliver defence equipment to cost, time and specification. The introduction reviews those factors, which influenced procurement since World War 11. The background to UK's current procurement process...

  12. Cathelicidin host defence peptide augments clearance of pulmonary Pseudomonas aeruginosa infection by its influence on neutrophil function in vivo.

    Directory of Open Access Journals (Sweden)

    Paula E Beaumont

    Full Text Available Cathelicidins are multifunctional cationic host-defence peptides (CHDP; also known as antimicrobial peptides and an important component of innate host defence against infection. In addition to microbicidal potential, these peptides have properties with the capacity to modulate inflammation and immunity. However, the extent to which such properties play a significant role during infection in vivo has remained unclear. A murine model of acute P. aeruginosa lung infection was utilised, demonstrating cathelicidin-mediated enhancement of bacterial clearance in vivo. The delivery of exogenous synthetic human cathelicidin LL-37 was found to enhance a protective pro-inflammatory response to infection, effectively promoting bacterial clearance from the lung in the absence of direct microbicidal activity, with an enhanced early neutrophil response that required both infection and peptide exposure and was independent of native cathelicidin production. Furthermore, although cathelicidin-deficient mice had an intact early cellular inflammatory response, later phase neutrophil response to infection was absent in these animals, with significantly impaired clearance of P. aeruginosa. These findings demonstrate the importance of the modulatory properties of cathelicidins in pulmonary infection in vivo and highlight a key role for cathelicidins in the induction of protective pulmonary neutrophil responses, specific to the infectious milieu. In additional to their physiological roles, CHDP have been proposed as future antimicrobial therapeutics. Elucidating and utilising the modulatory properties of cathelicidins has the potential to inform the development of synthetic peptide analogues and novel therapeutic approaches based on enhancing innate host defence against infection with or without direct microbicidal targeting of pathogens.

  13. Considerations on Defence Thinking in Post-1994 South Africa with ...

    African Journals Online (AJOL)

    ... analyse and discuss the new comprehensive guidelines for defence force design in the Draft Defence Review 2012 and reflects on some of the most important policy implications for the SANDF in this regard – specifically given the demands placed on the SANDF in the field of post-conflict reconstruction and development.

  14. Improvement interventions: To what extent are they manifestations of social defences?

    Directory of Open Access Journals (Sweden)

    Jeremias J. de Klerk

    2012-02-01

    Research purpose: The aim is to provide an explanation to the lure behind interventions and to contribute to building a theory on plausible systems psychodynamic drivers and mechanisms of recurrent change interventions. Motivation for the study: This study provides insights into social defences in ways that did not receive much attention previously; specifically how defence mechanisms act as drivers for new change and improvement interventions. Research design, approach and method: A literature study, consisting of a literature review and a phenomenological analysis. The study was conducted from the systems psychodynamic approach. Main findings: Improvement interventions often represent defences that serve to contain anxieties or maintain fantasies. Four specific themes emerged: interventions defend the perception of being in control, they maintain the fantasy that one is busy with worthy actions to overcome challenges, they are defences against boredom or contain anxieties about incompetence, and they maintain the fantasy of being heroic leaders. Practical/managerial implications: The findings can assist leaders to understand their own defences in order to avoid embarking on non-essential interventions. This can free up much time, energy and effort to spend on other priorities, assisting organisations to achieve better results. Contribution/value-add: The study refutes the notion that improvement interventions are always rational coping mechanisms and highlights the role of improvement interventions as defences to reduce anxiety, even though they may contribute little to organisational survival in real terms.

  15. Operational Analysis on Torpedo Defence

    NARCIS (Netherlands)

    Grootendordt, H.J.; Benders, F.P.A.; Fitski, H.J.; Veldhoven, E.R. van

    2008-01-01

    Surface vessels and submarines must be able to defend themselves against a torpedo attack. Self-defence can be approached as a modular concept. The first module involves 'Detection, Classification and Localisation (DCL)'. DCL triggers the second module: the 'evaluator'. This module starts the last

  16. Evaluating arguments during instigations of defence motivation and accuracy motivation.

    Science.gov (United States)

    Liu, Cheng-Hong

    2017-05-01

    When people evaluate the strength of an argument, their motivations are likely to influence the evaluation. However, few studies have specifically investigated the influences of motivational factors on argument evaluation. This study examined the effects of defence and accuracy motivations on argument evaluation. According to the compatibility between the advocated positions of arguments and participants' prior beliefs and the objective strength of arguments, participants evaluated four types of arguments: compatible-strong, compatible-weak, incompatible-strong, and incompatible-weak arguments. Experiment 1 revealed that participants possessing a high defence motivation rated compatible-weak arguments as stronger and incompatible-strong ones as weaker than participants possessing a low defence motivation. However, the strength ratings between the high and low defence groups regarding both compatible-strong and incompatible-weak arguments were similar. Experiment 2 revealed that when participants possessed a high accuracy motivation, they rated compatible-weak arguments as weaker and incompatible-strong ones as stronger than when they possessed a low accuracy motivation. However, participants' ratings on both compatible-strong and incompatible-weak arguments were similar when comparing high and low accuracy conditions. The results suggest that defence and accuracy motivations are two major motives influencing argument evaluation. However, they primarily influence the evaluation results for compatible-weak and incompatible-strong arguments, but not for compatible-strong and incompatible-weak arguments. © 2016 The British Psychological Society.

  17. Transgenic expression of a functional fragment of harpin protein Hpa1 in wheat induces the phloem-based defence against English grain aphid.

    Science.gov (United States)

    Fu, Maoqiang; Xu, Manyu; Zhou, Ting; Wang, Defu; Tian, Shan; Han, Liping; Dong, Hansong; Zhang, Chunling

    2014-04-01

    The harpin protein Hpa1 has multiple beneficial effects in plants, promoting plant growth and development, increasing crop yield, and inducing resistance to pathogens and insect pests. For these effects, the 10-40 residue fragment (Hpa1₁₀₋₄₂) isolated from the Hpa1 sequence is 1.3- to 7.5-fold more effective than the full-length protein. Here it is reported that the expression of Hpa1₁₀₋₄₂ under the direction of an insect-induced promoter induces the phloem-based defence to English grain aphid, a dominant species of wheat aphids. The expression of Hpa1₁₀₋₄₂ was found to compromise the colonization preference of aphids on the plant and further inhibit aphid reproduction in leaf colonies. In Hpa1₁₀₋₄₂-expressing wheat lines, moreover, aphid feeding from the phloem was repressed in correlation with the phloem-based defence. This defensive mechanism was shown as enhanced expression of wheat genes encoding phloem lectin proteins (PP2-A1 and PP2-A2) and β-1,3-glucan synthase-like enzymes (GSL2, GSL10, and GSL12). Both PP2-A and β-1,3-glucan formed high molecular mass polymers to block phloem sieve plate pores and therefore impede aphid feeding from the phloem. However, the phloem-based defence was impaired by treating plants with ethylene signalling inhibitors, suggesting the requirement for the ethylene signalling pathway. In addition, if Hpa1₁₀₋₄₂-expressing plants were subjected to attack by a small number of aphids, they newly acquired agriculturally beneficial characters, such as enhanced vegetative growth and increased tiller numbers and grain output values. These results suggest that the defensive and developmental roles of Hpa1₁₀₋₄₂ can be integrated into the germplasm of this agriculturally significant crop.

  18. Defence White Paper 2013

    Science.gov (United States)

    2013-01-01

    nurtured, particularly in Australia’s highly competitive labour market. The Government recognises that Defence’s approach to its people must be... satisfaction , increase attraction and retention, improve cost-effectiveness and support the contemporary Total Force employment model. Defence White...improve job satisfaction and thereby increase attraction and retention in areas of critical skill. Recruiting 10.13 To ensure that we have the high

  19. Plant Insecticidal Toxins in Ecological Networks

    Directory of Open Access Journals (Sweden)

    Sébastien Ibanez

    2012-04-01

    Full Text Available Plant secondary metabolites play a key role in plant-insect interactions, whether constitutive or induced, C- or N-based. Anti-herbivore defences against insects can act as repellents, deterrents, growth inhibitors or cause direct mortality. In turn, insects have evolved a variety of strategies to act against plant toxins, e.g., avoidance, excretion, sequestration and degradation of the toxin, eventually leading to a co-evolutionary arms race between insects and plants and to co-diversification. Anti-herbivore defences also negatively impact mutualistic partners, possibly leading to an ecological cost of toxin production. However, in other cases toxins can also be used by plants involved in mutualistic interactions to exclude inadequate partners and to modify the cost/benefit ratio of mutualism to their advantage. When considering the whole community, toxins have an effect at many trophic levels. Aposematic insects sequester toxins to defend themselves against predators. Depending on the ecological context, toxins can either increase insects’ vulnerability to parasitoids and entomopathogens or protect them, eventually leading to self-medication. We conclude that studying the community-level impacts of plant toxins can provide new insights into the synthesis between community and evolutionary ecology.

  20. Plant insecticidal toxins in ecological networks.

    Science.gov (United States)

    Ibanez, Sébastien; Gallet, Christiane; Després, Laurence

    2012-04-01

    Plant secondary metabolites play a key role in plant-insect interactions, whether constitutive or induced, C- or N-based. Anti-herbivore defences against insects can act as repellents, deterrents, growth inhibitors or cause direct mortality. In turn, insects have evolved a variety of strategies to act against plant toxins, e.g., avoidance, excretion, sequestration and degradation of the toxin, eventually leading to a co-evolutionary arms race between insects and plants and to co-diversification. Anti-herbivore defences also negatively impact mutualistic partners, possibly leading to an ecological cost of toxin production. However, in other cases toxins can also be used by plants involved in mutualistic interactions to exclude inadequate partners and to modify the cost/benefit ratio of mutualism to their advantage. When considering the whole community, toxins have an effect at many trophic levels. Aposematic insects sequester toxins to defend themselves against predators. Depending on the ecological context, toxins can either increase insects' vulnerability to parasitoids and entomopathogens or protect them, eventually leading to self-medication. We conclude that studying the community-level impacts of plant toxins can provide new insights into the synthesis between community and evolutionary ecology.

  1. A plant's perspective of extremes: terrestrial plant responses to changing climatic variability.

    Science.gov (United States)

    Reyer, Christopher P O; Leuzinger, Sebastian; Rammig, Anja; Wolf, Annett; Bartholomeus, Ruud P; Bonfante, Antonello; de Lorenzi, Francesca; Dury, Marie; Gloning, Philipp; Abou Jaoudé, Renée; Klein, Tamir; Kuster, Thomas M; Martins, Monica; Niedrist, Georg; Riccardi, Maria; Wohlfahrt, Georg; de Angelis, Paolo; de Dato, Giovanbattista; François, Louis; Menzel, Annette; Pereira, Marízia

    2013-01-01

    We review observational, experimental, and model results on how plants respond to extreme climatic conditions induced by changing climatic variability. Distinguishing between impacts of changing mean climatic conditions and changing climatic variability on terrestrial ecosystems is generally underrated in current studies. The goals of our review are thus (1) to identify plant processes that are vulnerable to changes in the variability of climatic variables rather than to changes in their mean, and (2) to depict/evaluate available study designs to quantify responses of plants to changing climatic variability. We find that phenology is largely affected by changing mean climate but also that impacts of climatic variability are much less studied, although potentially damaging. We note that plant water relations seem to be very vulnerable to extremes driven by changes in temperature and precipitation and that heat-waves and flooding have stronger impacts on physiological processes than changing mean climate. Moreover, interacting phenological and physiological processes are likely to further complicate plant responses to changing climatic variability. Phenological and physiological processes and their interactions culminate in even more sophisticated responses to changing mean climate and climatic variability at the species and community level. Generally, observational studies are well suited to study plant responses to changing mean climate, but less suitable to gain a mechanistic understanding of plant responses to climatic variability. Experiments seem best suited to simulate extreme events. In models, temporal resolution and model structure are crucial to capture plant responses to changing climatic variability. We highlight that a combination of experimental, observational, and/or modeling studies have the potential to overcome important caveats of the respective individual approaches. © 2012 Blackwell Publishing Ltd.

  2. WRKY transcription factors in plant responses to stresses.

    Science.gov (United States)

    Jiang, Jingjing; Ma, Shenghui; Ye, Nenghui; Jiang, Ming; Cao, Jiashu; Zhang, Jianhua

    2017-02-01

    The WRKY gene family is among the largest families of transcription factors (TFs) in higher plants. By regulating the plant hormone signal transduction pathway, these TFs play critical roles in some plant processes in response to biotic and abiotic stress. Various bodies of research have demonstrated the important biological functions of WRKY TFs in plant response to different kinds of biotic and abiotic stresses and working mechanisms. However, very little summarization has been done to review their research progress. Not just important TFs function in plant response to biotic and abiotic stresses, WRKY also participates in carbohydrate synthesis, senescence, development, and secondary metabolites synthesis. WRKY proteins can bind to W-box (TGACC (A/T)) in the promoter of its target genes and activate or repress the expression of downstream genes to regulate their stress response. Moreover, WRKY proteins can interact with other TFs to regulate plant defensive responses. In the present review, we focus on the structural characteristics of WRKY TFs and the research progress on their functions in plant responses to a variety of stresses. © 2016 Institute of Botany, Chinese Academy of Sciences.

  3. The role of strategic missile defence in the global architecture de ballistic non proliferation

    International Nuclear Information System (INIS)

    Hautecouverture, Benjamin

    2007-01-01

    Whereas some think that missile defence is a proliferation agent by nature and therefore undermines the already fragile regime of ballistic non proliferation, some others think that missile defence could underpin the non proliferation regime. The author thus discusses these issues and both points of view by commenting the ambiguous discursive relationships between missile defence and arms control, and by highlighting the various roles and missions given to missile defence, notably in treaties (like the ABM treaty) and postures adopted by concerned countries

  4. Game theory and plant ecology.

    Science.gov (United States)

    McNickle, Gordon G; Dybzinski, Ray

    2013-04-01

    The fixed and plastic traits possessed by a plant, which may be collectively thought of as its strategy, are commonly modelled as density-independent adaptations to its environment. However, plant strategies may also represent density- or frequency-dependent adaptations to the strategies used by neighbours. Game theory provides the tools to characterise such density- and frequency-dependent interactions. Here, we review the contributions of game theory to plant ecology. After briefly reviewing game theory from the perspective of plant ecology, we divide our review into three sections. First, game theoretical models of allocation to shoots and roots often predict investment in those organs beyond what would be optimal in the absence of competition. Second, game theoretical models of enemy defence suggest that an individual's investment in defence is not only a means of reducing its own tissue damage but also a means of deflecting enemies onto competitors. Finally, game theoretical models of trade with mutualistic partners suggest that the optimal trade may reflect competition for access to mutualistic partners among plants. In short, our review provides an accessible entrance to game theory that will help plant ecologists enrich their research with its worldview and existing predictions. © 2013 Blackwell Publishing Ltd/CNRS.

  5. Induction of oxidative stress related responses in Arabidopsis thaliana after uranium exposure

    International Nuclear Information System (INIS)

    Vanhoudt, N.

    2009-01-01

    Uranium contamination in the environment has resulted from releases linked with nuclear fuel cycle activities and from industries extracting and processing materials containing naturally occurring radionuclides (for example phosphate industry). Uranium toxicity effects are predominantly studied on man and animal species, but little information is available for plants. If phytomanagement of uranium contaminated soils is considered, biological effects on the vegetation have to be investigated. Information on the contamination impact can also be used for risk assessment and derivation of clean-up standards. Plants can experience oxidative stress when they are exposed to environmental stress situations (for example exposure to heavy metals). Reactive oxygen species (ROS) are produced in both stressed and unstressed cells potentially leading to cellular damage. Consequently, plants have developed an antioxidative defence system comprising ROS-scavenging enzymes (e.g. SOD (superoxide dismutase), CAT (catalase) and metabolites (e.g. ascorbate, glutathione). Previous results showed that uranium exposure can cause an imbalance between the oxidative and antioxidative capacities of the plant cells. The present study aimed to analyse biological effects induced in Arabidopsis thaliana after bioaccumulation of uranium and to define possible dose-effect relationships. Subtle effects on the antioxidative defence system (enzymes, metabolites viewed as early responses for individual disturbances (growth, nutrient profile) were analysed

  6. Slow food: insect prey and chitin induce phytohormone accumulation and gene expression in carnivorous Nepenthes plants.

    Science.gov (United States)

    Yilamujiang, Ayufu; Reichelt, Michael; Mithöfer, Axel

    2016-08-01

    Carnivorous Nepenthes plants use modified leaves forming pitfall traps to capture and digest prey, mainly insects, for additional nutrient supply. These traps, so called pitchers, contain a plant-derived fluid composed of many hydrolytic enzymes and defence-related proteins. In this study, the prey-induced induction of corresponding genes of those proteins and a role for phytohormones in this process was analysed. Tissue from insect prey-fed, chitin- and phytohormone-challenged pitchers was harvested and analysed for selected gene expressions by a quantitative PCR technique. Phytohormone levels were determined by LC-MS/MS. Nepenthesin proteolytic activities were measured in the digestive fluid using a fluorescence substrate. Insect prey in the pitchers induced the accumulation of phytohormones such as jasmonates as well as the transcription of studied genes encoding a chitinase 3 and a protease (nepenthesin I), whereas a defence-related protein (PR-1) gene was not induced. Treatment with chitin as a component of the insects' exoskeleton triggered the accumulation of jasmonates, the expression of nepenthesin I and chitinase 3 genes similar to jasmonic acid treatment, and induced protease activity in the fluid. All detectable responses were slowly induced. The results suggest that upon insect prey catch a sequence of signals is initiated: (1) insect-derived chitin, (2) jasmonate as endogenous phytohormone signal, (3) the induction of digestive gene expression and (4) protein expression. This resembles a similar hierarchy of events as described from plant pathogen/herbivore interactions, supporting the idea that carnivory evolved from plant defences. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Molecular effects of resistance elicitors from biological origin and their potential for crop protection

    Directory of Open Access Journals (Sweden)

    Lea eWiesel

    2014-11-01

    Full Text Available Plants contain a sophisticated innate immune network to prevent pathogenic microbes from gaining access to nutrients and from colonising internal structures. The first layer of inducible response is governed by the plant following the perception of microbe- or modified plant-derived molecules. As the perception of these molecules results in a plant response that can provide efficient resistance towards non-adapted pathogens they can also be described as ‘defence elicitors’. In compatible plant/microbe interactions, adapted microorganisms have means to avoid or disable this resistance response and promote virulence. However, this requires a detailed spatial and temporal response from the invading pathogens. In agricultural practice, treating plants with isolated defence elicitors in the absence of pathogens can promote plant resistance by uncoupling defence activation from the effects of pathogen virulence determinants. The plant responses to plant, bacterial, oomycete or fungal-derived elicitors are not, in all cases, universal and need elucidating prior to the application in agriculture. This review provides an overview of currently known elicitors of biological rather than synthetic origin and places their activity into a molecular context.

  8. Quantitative Verification and Synthesis of Attack-Defence Scenarios

    DEFF Research Database (Denmark)

    Aslanyan, Zaruhi; Nielson, Flemming; Parker, David

    2016-01-01

    analysis of quantitative properties of complex attack-defence scenarios, using an extension of attack-defence trees which models temporal ordering of actions and allows explicit dependencies in the strategies adopted by attackers and defenders. We adopt a game-theoretic approach, translating attack...... which guarantee or optimise some quantitative property, such as the probability of a successful attack, the expected cost incurred, or some multi-objective trade-off between the two. We implement our approach, building upon the PRISM-games model checker, and apply it to a case study of an RFID goods...

  9. Parental risk management in relation to offspring defence: bad news for kids.

    Science.gov (United States)

    Mahr, Katharina; Riegler, Georg; Hoi, Herbert

    2015-01-07

    Do parents defend their offspring whenever necessary, and do self-sacrificing parents really exist? Studies recognized that parent defence is dynamic, mainly depending on the threat predators pose. In this context, parental risk management should consider the threat to themselves and to their offspring. Consequently, the observed defence should be a composite of both risk components. Surprisingly, no study so far has determined the influence of these two threat components on parental decision rules. In a field experiment, we investigated parental risk taking in relation to the threat posed to themselves and their offspring. To disentangle the two threat components, we examined defence behaviours of parent blue tits Cyanistes caeruleus towards three different predators and during different nestling developmental stages. Nest defence strategies in terms of alarm call intensity and nearest predator approach differed between the three predators. Defence intensity was only partly explained by threat level. Most importantly, parental risk management varied in relation to their own, but not offspring risk. Parent defence investment was independent of nestling risk when parents followed a high-risk strategy. However, parents considered nestling as well as parental risk when following a low-risk strategy. Our findings could have general implications for the economy of risk management and decision-making strategies in living beings, including humans. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  10. Review of Defence Plans in Europe: Current Status, Strengths and Opportunities

    DEFF Research Database (Denmark)

    De Boeck, Steven; Van Hertem, Dirk; Das, Kaushik

    2016-01-01

    interconnected, a contingency in one area can affect the whole power system and possibly lead to a wide area black out. Therefore adequate defence plans need to be designed and in place to handle these situations. This paper starts with an overview of the terminology used in defence plans. Subsequently...... the current status of defence plans in Europe and the preferred sequence of actions to mitigate contingencies, is given based on a survey conducted among several European TSOs. Furthermore his paper gives an overview of how the ongoing changes with renewables, phasor measurement units (PMUs), power flow...

  11. Salicylic Acid Is Involved in the Basal Resistance of Tomato Plants to Citrus Exocortis Viroid and Tomato Spotted Wilt Virus.

    Science.gov (United States)

    López-Gresa, M Pilar; Lisón, Purificación; Yenush, Lynne; Conejero, Vicente; Rodrigo, Ismael; Bellés, José María

    2016-01-01

    Tomato plants expressing the NahG transgene, which prevents accumulation of endogenous salicylic acid (SA), were used to study the importance of the SA signalling pathway in basal defence against Citrus Exocortis Viroid (CEVd) or Tomato Spotted Wilt Virus (TSWV). The lack of SA accumulation in the CEVd- or TSWV-infected NahG tomato plants led to an early and dramatic disease phenotype, as compared to that observed in the corresponding parental Money Maker. Addition of acibenzolar-S-methyl, a benzothiadiazole (BTH), which activates the systemic acquired resistance pathway downstream of SA signalling, improves resistance of NahG tomato plants to CEVd and TSWV. CEVd and TSWV inoculation induced the accumulation of the hydroxycinnamic amides p-coumaroyltyramine, feruloyltyramine, caffeoylputrescine, and feruloylputrescine, and the defence related proteins PR1 and P23 in NahG plants earlier and with more intensity than in Money Maker plants, indicating that SA is not essential for the induction of these plant defence metabolites and proteins. In addition, NahG plants produced very high levels of ethylene upon CEVd or TSWV infection when compared with infected Money Maker plants, indicating that the absence of SA produced additional effects on other metabolic pathways. This is the first report to show that SA is an important component of basal resistance of tomato plants to both CEVd and TSWV, indicating that SA-dependent defence mechanisms play a key role in limiting the severity of symptoms in CEVd- and TSWV-infected NahG tomato plants.

  12. Saltmarsh plant responses to eutrophication.

    Science.gov (United States)

    Johnson, David Samuel; Warren, R Scott; Deegan, Linda A; Mozdzer, Thomas J

    2016-12-01

    In saltmarsh plant communities, bottom-up pressure from nutrient enrichment is predicted to increase productivity, alter community structure, decrease biodiversity, and alter ecosystem functioning. Previous work supporting these predictions has been based largely on short-term, plot-level (e.g., 1-300 m 2 ) studies, which may miss landscape-level phenomena that drive ecosystem-level responses. We implemented an ecosystem-scale, nine-year nutrient experiment to examine how saltmarsh plants respond to simulated conditions of coastal eutrophication. Our study differed from previous saltmarsh enrichment studies in that we applied realistic concentrations of nitrate (70-100 μM NO 3 - ), the most common form of coastal nutrient enrichment, via tidal water at the ecosystem scale (~60,000 m 2 creeksheds). Our enrichments added a total of 1,700 kg N·creek -1 ·yr -1 , which increased N loading 10-fold vs. reference creeks (low-marsh, 171 g N·m -2 ·yr -1 ; high-marsh, 19 g N·m -2 ·yr -1 ). Nutrients increased the shoot mass and height of low marsh, tall Spartina alterniflora; however, declines in stem density resulted in no consistent increase in aboveground biomass. High-marsh plants S. patens and stunted S. alterniflora did not respond consistently to enrichment. Nutrient enrichment did not shift community structure, contrary to the prediction of nutrient-driven dominance of S. alterniflora and Distichlis spicata over S. patens. Our mild responses may differ from the results of previous studies for a number of reasons. First, the limited response of the high marsh may be explained by loading rates orders of magnitude lower than previous work. Low loading rates in the high marsh reflect infrequent inundation, arguing that inundation patterns must be considered when predicting responses to estuarine eutrophication. Additionally, we applied nitrate instead of the typically used ammonium, which is energetically favored over nitrate for plant uptake. Thus, the

  13. Phenylphenalenones protect banana plants from infection by Mycosphaerella fijiensis and are deactivated by metabolic conversion.

    Science.gov (United States)

    Hidalgo, William; Chandran, Jima N; Menezes, Riya C; Otálvaro, Felipe; Schneider, Bernd

    2016-03-01

    Phenylphenalenones, polycyclic aromatic natural products from some monocotyledonous plants, are known as phytoalexins in banana (Musa spp.). In this study, (1) H nuclear magnetic resonance (NMR)-based metabolomics along with liquid chromatography and mass spectrometry were used to explore the chemical responses of the susceptible 'Williams' and the resistant 'Khai Thong Ruang' Musa varieties to the ascomycete fungus Mycosphaerella fijiensis, the agent of the black leaf Sigatoka disease. Principal component analysis discriminated strongly between infected and non-infected plant tissue, mainly because of specialized metabolism induced in response to the fungus. Phenylphenalenones are among the major induced compounds, and the resistance level of the plants was correlated with the progress of the disease. However, a virulent strain of M. fijiensis was able to overcome plant resistance by converting phenylphenalenones to sulfate conjugates. Here, we report the first metabolic detoxification of fungitoxic phenylphenalenones to evade the chemical defence of Musa plants. © 2015 John Wiley & Sons Ltd.

  14. A laws of war review of contemporary land-based missile defence ...

    African Journals Online (AJOL)

    Automated precise guided missile defence has been around for some years, and is a modern-day mechanism used frequently since 2011 to defend against rocket attacks penetrating national airspace. Israel's automated Iron Dome Missile Defence System has intercepted over 1 000 rockets during two recent military ...

  15. Contamination assessment of a coastal lagoon (Ria de Aveiro, Portugal) using defence and damage biochemical indicators in gill of Liza aurata - An integrated biomarker approach

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, M. [CESAM and Department of Biology, University of Aveiro, 3810-193 Aveiro (Portugal)], E-mail: migueloliveira@ua.pt; Maria, V.L. [CIMA and Faculty of Marine and Environmental Sciences, University of Algarve, Campus Gambelas, 8005-139 Faro (Portugal); Ahmad, I. [CESAM and Department of Biology, University of Aveiro, 3810-193 Aveiro (Portugal); Serafim, A.; Bebianno, M.J. [CIMA and Faculty of Marine and Environmental Sciences, University of Algarve, Campus Gambelas, 8005-139 Faro (Portugal); Pacheco, M.; Santos, M.A. [CESAM and Department of Biology, University of Aveiro, 3810-193 Aveiro (Portugal)

    2009-03-15

    Fish gill importance in toxicants uptake, bioconcentration and excretion allied to meagre knowledge on branchial damage/protection responses substantiate this study. Five critical sites in Ria de Aveiro (Portugal) were assessed in comparison with a reference site (Torreira), focusing on Liza aurata gill antioxidant defences versus damage (oxidative and genetic). Only in Barra fish displayed damage (lipid peroxidation) though no differences were found in antioxidants. In all other sites, except Rio, antioxidant alterations were found. Thus, fish from Gafanha, Laranjo and Vagos showed higher total glutathione, glutathione peroxidase and catalase. Higher glutathione reductase and glutathione S-transferase activity was also found in the first and the last sites, respectively. In Laranjo, metallothionein levels were higher though lower in Gafanha and Vagos. In general, damage was not accompanied by defences weakening confirming that predicting damage based on antioxidants depletion is not straightforward. The integrated biomarker response index ranked sites as: Gafanha > Barra > Laranjo > Vagos > Rio > Torreira. - The integration of antioxidant defence and damage responses in fish, using gill as a key organ, can improve the aquatic contamination assessment.

  16. Sharka: how do plants respond to Plum pox virus infection?

    Science.gov (United States)

    Clemente-Moreno, María J; Hernández, José A; Diaz-Vivancos, Pedro

    2015-01-01

    Plum pox virus (PPV), the causal agent of sharka disease, is one of the most studied plant viruses, and major advances in detection techniques, genome characterization and organization, gene expression, transmission, and the description of candidate genes involved in PPV resistance have been described. However, information concerning the plant response to PPV infection is very scarce. In this review, we provide an updated summary of the research carried out to date in order to elucidate how plants cope with PPV infection and their response at different levels, including the physiological, biochemical, proteomic, and genetic levels. Knowledge about how plants respond to PPV infection can contribute to the development of new strategies to cope with this disease. Due to the fact that PPV induces an oxidative stress in plants, the bio-fortification of the antioxidative defences, by classical or biotechnological approaches, would be a useful tool to cope with PPV infection. Nevertheless, there are still some gaps in knowledge related to PPV-plant interaction that remain to be filled, such as the effect of PPV on the hormonal profile of the plant or on the plant metabolome. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  17. Plant responses to insect egg deposition

    NARCIS (Netherlands)

    Hilker, M.; Fatouros, N.E.

    2015-01-01

    Plants can respond to insect egg deposition and thus resist attack by herbivorous insects from the beginning of the attack, egg deposition. We review ecological effects of plant responses to insect eggs and differentiate between egg-induced plant defenses that directly harm the eggs and indirect

  18. The Kassel concept for river flood defence

    Energy Technology Data Exchange (ETDEWEB)

    Toensmann, F. [Kassel Univ. (Germany). Dept. of Hydraulic and Water-Resources Engineering

    2000-07-01

    Following an introduction referring to the history, the regulation of ''interference and compensation'' and the ''sustainable development'' as the foundation of future-oriented flood defence concepts are dealt with. The position of science and technology with respect to the employed planning methods: Models for the determination of spatial and temporal distribution of maximum precipitation, river basin models, methods for water level computation, benefit/cost analysis and environmental assessment are described and evaluated. Thereafter the Kassel Concept for River Flood Defence is presented. The basic principle is a mosaic of de-central, semi-central and central measures with reference to the specific project which are economically eligible and environment-compatible. (orig.)

  19. Defence in front of challenges related to climate disruption

    International Nuclear Information System (INIS)

    Alex, Bastien

    2015-03-01

    As the Pentagon already noticed a relationship between security and climate change in a report published more than ten years ago, climate change is now considered as a threat multiplier, and is therefore a major stake for industrial, institutional and military actors of defence. The author first describes the relationship between national security and climatic security, how risks related to global warming have also an actual potential of destabilisation. He describes how this issue is increasingly addressed by defence actors, notably with a strategic approach initiated by the USA, a still holding back France, discussions about the impact of operational capabilities, and a trend for a carbon print decrease for the defence sector. In the next part, the author examines whether policies of adaptation to climate change could involve threats, evokes the development of geo-engineering, and briefly outlines that a failed adaptation could increase vulnerability

  20. Plant-phytopathogen interactions: bacterial responses to environmental and plant stimuli.

    Science.gov (United States)

    Leonard, Simon; Hommais, Florence; Nasser, William; Reverchon, Sylvie

    2017-05-01

    Plant pathogenic bacteria attack numerous agricultural crops, causing devastating effects on plant productivity and yield. They survive in diverse environments, both in plants, as pathogens, and also outside their hosts as saprophytes. Hence, they are confronted with numerous changing environmental parameters. During infection, plant pathogens have to deal with stressful conditions, such as acidic, oxidative and osmotic stresses; anaerobiosis; plant defenses; and contact with antimicrobial compounds. These adverse conditions can reduce bacterial survival and compromise disease initiation and propagation. Successful bacterial plant pathogens must detect potential hosts and also coordinate their possibly conflicting programs for survival and virulence. Consequently, these bacteria have a strong and finely tuned capacity for sensing and responding to environmental and plant stimuli. This review summarizes our current knowledge of the signals and genetic circuits that affect survival and virulence factor expression in three important and well-studied plant pathogenic bacteria with wide host ranges and the capacity for long-term environmental survival. These are: Ralstonia solanacerarum, a vascular pathogen that causes wilt disease; Agrobacterium tumefaciens, a biotrophic tumorigenic pathogen responsible for crown gall disease and Dickeya, a brute force apoplastic pathogen responsible for soft-rot disease. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  1. The Complexity of Bioactive Natural Products in Plants

    DEFF Research Database (Denmark)

    Frisch, Tina

    Plants produce a diverse range of bioactive natural products promoting their fitness. These specialized metabolites may serve as chemical defence against herbivores and pathogens and may inhibit the growth and development of competing species. Hydroxynitrile glucosides and glucosinolates are two...... classes of defence compounds, which have diverging properties, but also share common biosynthetic features. Hydroxynitrile glucosides are produced in species across the plant kingdom, whereas glucosinolates are found almost exclusively within the Brassicales, which generally does not contain...... hydroxynitrile glucosides. This division has raised questions regarding possible evolutionary relationships between the biosynthetic pathways. The very rare co-occurrence of hydroxynitrile glucosides and glucosinolates found in Alliaria petiolata (garlic mustard, løgkarse) and Carica papaya (papaya) makes...

  2. The European Security and Defence Policy

    DEFF Research Database (Denmark)

    Adler-Nissen, Rebecca

    2009-01-01

    The European Security and Defence Policy (ESDP), which is the operational military and civilian dimension of the Common Foreign and Security Policy (CFSP), is today one of the most dynamic areas of the European Union. However, it is only recently that the EU has acquired explicit military decision....... The Union is thus gradually emerging as an important player on the international scene, with a strategic vision, as well as diplomatic, civilian and military crisis-management instruments that complement the existing economic, commercial, humanitarian and development policies on which the EU has hitherto...... built its reputation as a ‘soft power'. Despite its rapid development, many still regard the EU as weak and ineffi cient when it comes to security and defence policy. Moreover, the EU struggles with internal divisions and has a strained relationship with NATO. Nonetheless, there are good reasons...

  3. Guidelines for nuclear plant response to an earthquake

    International Nuclear Information System (INIS)

    1989-12-01

    Guidelines have been developed to assist nuclear plant personnel in the preparation of earthquake response procedures for nuclear power plants. The objectives of the earthquake response procedures are to determine (1) the immediate effects of an earthquake on the physical condition of the nuclear power plant, (2) if shutdown of the plant is appropriate based on the observed damage to the plant or because the OBE has been exceeded, and (3) the readiness of the plant to resume operation following shutdown due to an earthquake. Readiness of a nuclear power plant to restart is determined on the basis of visual inspections of nuclear plant equipment and structures, and the successful completion of surveillance tests which demonstrate that the limiting conditions for operation as defined in the plant Technical Specifications are met. The guidelines are based on information obtained from a review of earthquake response procedures from numerous US and foreign nuclear power plants, interviews with nuclear plant operations personnel, and a review of reports of damage to industrial equipment and structures in actual earthquakes. 7 refs., 4 figs., 4 tabs

  4. An evaluation of the defence in depth concept in the light of the Three Mile Island accident

    International Nuclear Information System (INIS)

    Fuchs, H.; Gibbs, K.P.

    1981-01-01

    One of the fundamental bases of reactor safety has been the 'defence in depth' concept. Valuable lessons for plants outside the USA can be learned by studying both the strengths and weaknesses of all the various lines of defence in the light of the TMI findings. These lessons can be summarized as follows: Quality: lack of quality led to the initiation of the event through frequent trips, one of which eventually led to the sticking open of the PORV. It also led to wrong diagnosis of the fault. Multiple failures during the many hours the incident lasted distracted the operator and made a careful diagnosis of its causes and progress impossible. Reactor protection system: the Babcock and Wilcox PWR, with its once-through steam generators (OTSG), responds more rapidly than other LWRs to some operating transients. This does not necessarily result in a less safe system provided that the reactor protection system is designed with the fast response in mind, e.g. by providing anticipatory trips. This emphasizes the importance of a systems approach to design rather than too much reliance on codes and standards, which may not recognize important plant differences. Safety systems: For similar reasons the low water content of the OTSG could have been compensated for by a higher reliability in the emergency feed system. In US practice the operator plays an important role in aligning safety systems, whereas in Europe there is more extensive automation. The latter system leads to an analysis of a wider spectrum of faults to ensure that the automatics respond correctly in all circumstances. Containment: The TMI incident showed that the containment can be very valuable for situations where far more core damage and hydrogen production occurs than is predicted for design basis accidents. Continuing containment integrity depends on core cooling and on the correct operation or isolation of many other systems, whose role in such accidents has not always been recognized

  5. Plant Protein Inhibitors of Enzymes: Their Role in Animal Nutrition and Plant Defence.

    Science.gov (United States)

    Richardson, Michael

    1981-01-01

    Current information and research related to plant protein inhibitors of enzymes are reviewed, including potential uses of the inhibitors for medical treatment and for breeding plant varieties with greater resistance to insects. (DC)

  6. Phosphorylation and proteome dynamics in pathogen-resistant tomato plants

    NARCIS (Netherlands)

    Stulemeijer, I.J.E.

    2008-01-01

    Microbial plant pathogens impose a continuous threat on global food production. Similar to disease resistance in mammals, an innate immune system allows plants to recognise pathogens and swiftly activate defence. For the work described in this thesis, the interaction between tomato and the

  7. Emergency response training with the BNL plant analyzer

    International Nuclear Information System (INIS)

    Cheng, H.S.; Guppy, J.G.; Mallen, A.N.; Wulff, W.

    1987-01-01

    Presented is the experience in the use of the BNL Plant Analyzer for NRC emergency response training to simulated accidents in a BWR. The unique features of the BNL Plant Analyzer that are important for the emergency response training are summarized. A closed-loop simulation of all the key systems of a power plant in question was found essential to the realism of the emergency drills conducted at NRC. The faster than real-time simulation speeds afforded by the BNL Plant Analyzer have demonstrated its usefulness for the timely conduct of the emergency response training

  8. The cytoskeleton in cell-autonomous immunity: structural determinants of host defence

    Science.gov (United States)

    Mostowy, Serge; Shenoy, Avinash R.

    2016-01-01

    Host cells use antimicrobial proteins, pathogen-restrictive compartmentalization and cell death in their defence against intracellular pathogens. Recent work has revealed that four components of the cytoskeleton — actin, microtubules, intermediate filaments and septins, which are well known for their roles in cell division, shape and movement — have important functions in innate immunity and cellular self-defence. Investigations using cellular and animal models have shown that these cytoskeletal proteins are crucial for sensing bacteria and for mobilizing effector mechanisms to eliminate them. In this Review, we highlight the emerging roles of the cytoskeleton as a structural determinant of cell-autonomous host defence. PMID:26292640

  9. Wound-induced proteinase inhibitor in Salix viminalis and its association with defence against insects

    Energy Technology Data Exchange (ETDEWEB)

    Saarikoski, P. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Genetics

    1997-09-01

    For successful traditional breeding, the plant material has to be screened for genetic variation for the desired traits. By screening Salix clones for wound-induced proteinase inhibitor (PI) activity and ethylene evolution, it was possible to identify variation for both characters among the Salix clones tested. However, no correlation was observed with insect and pathogen resistance. Since there was no simple relationship between wound-induced ethylene production, accumulation of PI and pest resistance, a more systematic investigation of Salix PIs was begun. A gene (swin1.1) encoding a 21 kDa trypsin inhibitor with characteristics of Kunitz-type of PI was sequenced. The trypsin inhibitor encoded by the isolated swin1.1 gene was shown to be functional in vitro and exhibit specificity for trypsin. It is therefore likely that this PI is involved in the plant defence in Salix, since many insects have trypsin as their major digestive protease. In further support of this view, in bio-tests with poplar the mortality of the first instar larvae (Lymantria dispar) was significantly increased, both after application of the trypsin inhibitor encoded by swin1.1 directly on poplar leaves and after feeding the larvae with transgenic poplar over-expressing the swin1.1 gene. In Salix, the swin1.1 gene was shown to be induced by mechanical wounding, insect feeding and by treatment with the signalling substances salicylic and jasmonic acid. The locally wound-induced response (mechanical and insect) was greater than the systemic response. Other swin1 gene family members were also differentially expressed after the inductive treatment. 187 refs., 3 figs., 2 tabs.

  10. the role of the south african national defence force in policing

    African Journals Online (AJOL)

    mosesm

    the history and socioeconomic realities of our society. For ... White Paper on National Defence for the Republic of South Africa of 19962 and ... Reading the 1998 Defence Review,5 it was clearly assumed, without any ... year regarding the crime situation in South Africa. ..... approaches need to be augmented by the SANDF.

  11. Ionising radiation safety training in the Australian Defence Organisation (ADO)

    International Nuclear Information System (INIS)

    Jenks, G.J.; O'Donovan, E.J.B.; Wood, W.B.

    1998-01-01

    Training personnel in ionising radiation safety within the Australian Defence Organisation (ADO) requires addressing some unique features of an organisation employing both military and civilian personnel. Activities may include those of a civil nature (such as industrial and medical radiography), specific military requirements (for training and emergency response) and scientific research and development. Some personnel may be assigned to full-time duties associated with radiation. However, most are designated as radiation protection officers as a secondary duty. A further complication is that most military personnel are subjected to postings at regular intervals. The ADO's Directorate of Defence Occupational Health and Safety has established an Ionising Radiation Safety Subcommittee to monitor not only the adequacy of the internal Ionising Radiation Safety Manual but also the training requirements. A Training Course, responding to these requirements, has been developed to emphasize, basic radiation theory and protection, operation of radiation monitors available in the ADO, an understanding of the Ionising Radiation Safety Manual, day-to-day radiation safety in units and establishments, and appropriate responses to radiation accidents and emergencies. In addition, students are briefed on a limited number of peripheral topics and participate in some site visits. Currently, two Courses are held annually, each with about twenty students. Most of the material is presented by ADO personnel with external contractor support. The three Courses held to date have proved successful, both for the students and the ADO generally. To seek national accreditation of the course through the Australian National Training Authority, as a first step, competency standards have been proposed. (authors)

  12. Introducing 'The Diverse Nature of Defence Healthcare' university module for DMS personnel.

    Science.gov (United States)

    Carter, Chris; Blake, L

    2015-12-01

    Over the past 10 years the UK Defence Medical Services has deployed healthcare personnel to a variety of operational areas in support of UK Operations. The unique nature of every operational deployment, in conjunction with the wide variety of roles which healthcare staff undertake, necessitates bespoke educational preparation of the military healthcare force. This paper explores the creation and development of one of the four modules which comprise the BSc (Hons) in Defence Health Care studies, entitled 'The Diverse Nature of Defence Healthcare'. It demonstrates the unique contribution that the Defence School of Healthcare Education makes towards Generation and Preparation of the Force for deployment. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  13. Transgeneration memory of stress in plants.

    Science.gov (United States)

    Molinier, Jean; Ries, Gerhard; Zipfel, Cyril; Hohn, Barbara

    2006-08-31

    Owing to their sessile nature, plants are constantly exposed to a multitude of environmental stresses to which they react with a battery of responses. The result is plant tolerance to conditions such as excessive or inadequate light, water, salt and temperature, and resistance to pathogens. Not only is plant physiology known to change under abiotic or biotic stress, but changes in the genome have also been identified. However, it was not determined whether plants from successive generations of the original, stressed plants inherited the capacity for genomic change. Here we show that in Arabidopsis thaliana plants treated with short-wavelength radiation (ultraviolet-C) or flagellin (an elicitor of plant defences), somatic homologous recombination of a transgenic reporter is increased in the treated population and these increased levels of homologous recombination persist in the subsequent, untreated generations. The epigenetic trait of enhanced homologous recombination could be transmitted through both the maternal and the paternal crossing partner, and proved to be dominant. The increase of the hyper-recombination state in generations subsequent to the treated generation was independent of the presence of the transgenic allele (the recombination substrate under consideration) in the treated plant. We conclude that environmental factors lead to increased genomic flexibility even in successive, untreated generations, and may increase the potential for adaptation.

  14. The Fukushima Daiichi Nuclear Power Plant Accident: OECD/NEA Nuclear Safety Response and Lessons Learnt

    International Nuclear Information System (INIS)

    2013-01-01

    Following the March 2011 accident at the Fukushima Daiichi nuclear power plant, all NEA member countries took early action to ensure and confirm the continued safety of their nuclear power plants and the protection of the public. After these preliminary safety reviews, all countries with nuclear facilities carried out comprehensive safety reviews, often referred to as 'stress tests', which reassessed safety margins of nuclear facilities with a primary focus on challenges related to conditions experienced at the Fukushima Daiichi nuclear power plant, for example extreme external events and the loss of safety functions, or capabilities to cope with severe accidents. As appropriate, improvements are being made to safety and emergency response systems to ensure that nuclear power plants are capable of withstanding events that lead to loss of electrical power and/or cooling capability. In the weeks following the accident, the NEA immediately began establishing expert groups in the nuclear safety and radiological protection areas, as well as contributing to information exchange with the Japanese authorities and other international organisations. It promptly provided a forum for high-level decision makers and regulators within the G8-G20 frameworks. The NEA actions taken at the international level in response to the accident have been carried out primarily by the three NEA standing technical committees concerned with nuclear and radiation safety issues - the Committee on Nuclear Regulatory Activities (CNRA), the Committee on the Safety of Nuclear Installations (CSNI) and the Committee on Radiation Protection and Public Health (CRPPH) - under the leadership of the CNRA. More than two years following the accident, the NEA continues to assist the Japanese authorities in dealing with their nuclear safety and recovery efforts as well as to facilitate international co-operation on nuclear safety and radiological protection matters. It is strongly supporting the establishment of

  15. Defence-in-depth concept for the EU-ABWR

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, Hiroshi; Fuchs, Steffen; Takada, Toshiaki; Kataoka, Kazuyoshi [Toshiba International Limited (Japan)

    2013-07-01

    The current defence-in-depth (DiD) concept has been established by the Reactor Harmonization Working Group (RHWG) of Western European Nuclear Regulators Association (WENRA). Principally the DiD concept was already part of the very early power reactor designs. However, additional considerations have been done in order to take plant conditions into account which are beyond the original design basis. The most recent advancements have been done based on major lessons learned from the Fukushima Dai-Ichi accident. Especially for new nuclear reactors it has to be demonstrated that DiD aspects have been considered in their design. Currently Toshiba is adapting its Advanced Boiling Water Reactor (ABWR) for the European market, at first in Finland. This presentation aims to describe how the new DiD concept has been applied to achieve the safety goals for a modern reactor type and to ensure a design that can be licensed in Western Europe. (orig.)

  16. Elucidating the interaction between light competition and herbivore feeding patterns using functional-structural plant modelling.

    Science.gov (United States)

    de Vries, Jorad; Poelman, Erik H; Anten, Niels; Evers, Jochem B

    2018-01-24

    Plants usually compete with neighbouring plants for resources such as light as well as defend themselves against herbivorous insects. This requires investment of limiting resources, resulting in optimal resource distribution patterns and trade-offs between growth- and defence-related traits. A plant's competitive success is determined by the spatial distribution of its resources in the canopy. The spatial distribution of herbivory in the canopy in turn differs between herbivore species as the level of herbivore specialization determines their response to the distribution of resources and defences in the canopy. Here, we investigated to what extent competition for light affects plant susceptibility to herbivores with different feeding preferences. To quantify interactions between herbivory and competition, we developed and evaluated a 3-D spatially explicit functional-structural plant model for Brassica nigra that mechanistically simulates competition in a dynamic light environment, and also explicitly models leaf area removal by herbivores with different feeding preferences. With this novel approach, we can quantitatively explore the extent to which herbivore feeding location and light competition interact in their effect on plant performance. Our results indicate that there is indeed a strong interaction between levels of plant-plant competition and herbivore feeding preference. When plants did not compete, herbivory had relatively small effects irrespective of feeding preference. Conversely, when plants competed, herbivores with a preference for young leaves had a strong negative effect on the competitiveness and subsequent performance of the plant, whereas herbivores with a preference for old leaves did not. Our study predicts how plant susceptibility to herbivory depends on the composition of the herbivore community and the level of plant competition, and highlights the importance of considering the full range of dynamics in plant-plant-herbivore interactions

  17. The Cooperative Ballistic Missile Defence Game

    NARCIS (Netherlands)

    Evers, L.; Barros, A.I.; Monsuur, H.

    2013-01-01

    The increasing proliferation of ballistic missiles and weapons of mass destruction poses new risks worldwide. For a threatened nation and given the characteristics of this threat a layered ballistic missile defence system strategy appears to be the preferred solution. However, such a strategy

  18. Civil defence and disaster control services

    International Nuclear Information System (INIS)

    Kolb, P.W.

    1986-01-01

    Today's systems of civil defence and disaster control services are the result of a long process of development, which is outlined for the Federal Republic of Germany. The present organisational and legal systems are explained, together with the institutions concerned. (DG) [de

  19. Salicylic Acid Is Involved in the Basal Resistance of Tomato Plants to Citrus Exocortis Viroid and Tomato Spotted Wilt Virus.

    Directory of Open Access Journals (Sweden)

    M Pilar López-Gresa

    Full Text Available Tomato plants expressing the NahG transgene, which prevents accumulation of endogenous salicylic acid (SA, were used to study the importance of the SA signalling pathway in basal defence against Citrus Exocortis Viroid (CEVd or Tomato Spotted Wilt Virus (TSWV. The lack of SA accumulation in the CEVd- or TSWV-infected NahG tomato plants led to an early and dramatic disease phenotype, as compared to that observed in the corresponding parental Money Maker. Addition of acibenzolar-S-methyl, a benzothiadiazole (BTH, which activates the systemic acquired resistance pathway downstream of SA signalling, improves resistance of NahG tomato plants to CEVd and TSWV. CEVd and TSWV inoculation induced the accumulation of the hydroxycinnamic amides p-coumaroyltyramine, feruloyltyramine, caffeoylputrescine, and feruloylputrescine, and the defence related proteins PR1 and P23 in NahG plants earlier and with more intensity than in Money Maker plants, indicating that SA is not essential for the induction of these plant defence metabolites and proteins. In addition, NahG plants produced very high levels of ethylene upon CEVd or TSWV infection when compared with infected Money Maker plants, indicating that the absence of SA produced additional effects on other metabolic pathways. This is the first report to show that SA is an important component of basal resistance of tomato plants to both CEVd and TSWV, indicating that SA-dependent defence mechanisms play a key role in limiting the severity of symptoms in CEVd- and TSWV-infected NahG tomato plants.

  20. Provoking misunderstanding: a comment on Black's defence of value-free sociology.

    Science.gov (United States)

    Hammersley, Martyn

    2014-09-01

    This paper is a response to a recent article dealing with the concept of value-free sociology by Donald Black. It argues that while a defence of Weber's position on the role of values in sociological research is necessary and important, what is offered by Black is counter-productive in important respects. This is because it encourages some of the misunderstandings that it is aimed at remedying and, even more importantly, offers a simplistic discussion of what are complex issues. © London School of Economics and Political Science 2014.

  1. Defence-in-depth strategy of fire protection and its relevance after final shutdown (by the example of Germany)

    Energy Technology Data Exchange (ETDEWEB)

    Beesen, Michael; Ernst, Benjamin; Fischer, Guenter [TUeV SUeD Industrie Service GmbH (Germany)

    2015-12-15

    Nuclear power plants (NPP) are protected against internal and external fires by a fire protection defence-in-depth concept including the following precautionary measures: operational, structural and equipment related fire protection measures as well as manual fire fighting. The fire protection measures are designed in consideration of fires to be expected (from fire loads permanently and temporarily present together with potential ignition sources) in order to prevent a violation of both the protection goals of public law and the nuclear protection goals / radiological safety objectives in case of internal and external fires. The aspect ''What is the future significance of the fire protection defence-in-depth concept?'' needs to be considered with regard to the situation following the final shutdown. From our point of view as a TSO (technical safety organization) both the non-nuclear protection goals (e.g. prevent occurrence of a fire; ensure escape and rescue of humans) as well as the nuclear ones have to be ensured after final shutdown of a nuclear plant. The protection goals of public law will almost completely remain after the plant has stopped commercial operation while the nuclear safety objectives will be stepwise reduced in consideration of the decommissioning status until the end of the nuclear supervision. Nevertheless, the fire protection concept must clearly specify those fire protection measures that are necessary to ensure the plants' safety. The situation on site regularly needs to be under examination to check if the fire protection concept covers all conditions to be considered and if the existing fire protection measures are sufficient or if an adaption is necessary.

  2. H(2 enhances arabidopsis salt tolerance by manipulating ZAT10/12-mediated antioxidant defence and controlling sodium exclusion.

    Directory of Open Access Journals (Sweden)

    Yanjie Xie

    Full Text Available BACKGROUND: The metabolism of hydrogen gas (H(2 in bacteria and algae has been extensively studied for the interesting of developing H(2-based fuel. Recently, H(2 is recognized as a therapeutic antioxidant and activates several signalling pathways in clinical trials. However, underlying physiological roles and mechanisms of H(2 in plants as well as its signalling cascade remain unknown. METHODOLOGY/PRINCIPAL FINDINGS: In this report, histochemical, molecular, immunological and genetic approaches were applied to characterize the participation of H(2 in enhancing Arabidopsis salt tolerance. An increase of endogenous H(2 release was observed 6 hr after exposure to 150 mM NaCl. Arabidopsis pretreated with 50% H(2-saturated liquid medium, mimicking the induction of endogenous H(2 release when subsequently exposed to NaCl, effectively decreased salinity-induced growth inhibition. Further results showed that H(2 pretreatment modulated genes/proteins of zinc-finger transcription factor ZAT10/12 and related antioxidant defence enzymes, thus significantly counteracting the NaCl-induced reactive oxygen species (ROS overproduction and lipid peroxidation. Additionally, H(2 pretreatment maintained ion homeostasis by regulating the antiporters and H(+ pump responsible for Na(+ exclusion (in particular and compartmentation. Genetic evidence suggested that SOS1 and cAPX1 might be the target genes of H(2 signalling. CONCLUSIONS: Overall, our findings indicate that H(2 acts as a novel and cytoprotective regulator in coupling ZAT10/12-mediated antioxidant defence and maintenance of ion homeostasis in the improvement of Arabidopsis salt tolerance.

  3. Plants having modified response to ethylene

    Science.gov (United States)

    Meyerowitz, E.M.; Chang, C.; Bleecker, A.B.

    1997-11-18

    The invention includes transformed plants having at least one cell transformed with a modified ETR nucleic acid. Such plants have a phenotype characterized by a decrease in the response of at least one transformed plant cell to ethylene as compared to a plant not containing the transformed plant cell. Tissue and/or temporal specificity for expression of the modified ETR nucleic acid is controlled by selecting appropriate expression regulation sequences to target the location and/or time of expression of the transformed nucleic acid. The plants are made by transforming at least one plant cell with an appropriate modified ETR nucleic acid, regenerating plants from one or more of the transformed plant cells and selecting at least one plant having the desired phenotype. 31 figs.

  4. Defence and security applications of quantum cascade lasers

    Science.gov (United States)

    Grasso, Robert J.

    2016-09-01

    Quantum Cascade Lasers (QCL) have seen tremendous recent application in the realm of Defence and Security. And, in many instances replacing traditional solid state lasers as the source of choice for Countermeasures, Remote Sensing, In-situ Sensing, Through-Barrier Sensing, and many others. Following their development and demonstration in the early 1990's, QCL's reached some maturity and specific defence and security application prior to 2005; with much initial development fostered by DARPA initiatives in the US, dstl, MoD, and EOARD funding initiatives in the UK, and University level R&D such as those by Prof Manijeh Razeghi at Northwestern University [1], and Prof Ted Masselink at Humboldt University [2]. As QCL's provide direct mid-IR laser output for electrical input, they demonstrate high quantum efficiency compared with diode pumped solid state lasers with optical parametric oscillators (OPOs) to generate mid-Infrared output. One particular advantage of QCL's is their very broad operational bandwidth, extending from the terahertz to the near-infrared spectral regions. Defence and Security areas benefiting from QCL's include: Countermeasures, Remote Sensing, Through-the-Wall Sensing, and Explosive Detection. All information used to construct this paper obtained from open sources.

  5. PM2.5, oxidant defence and cardiorespiratory health: a review.

    Science.gov (United States)

    Weichenthal, Scott A; Godri-Pollitt, Krystal; Villeneuve, Paul J

    2013-05-04

    Airborne fine particle mass concentrations (PM2.5) are used for ambient air quality management worldwide based in part on known cardiorespiratory health effects. While oxidative stress is generally thought to be an important mechanism in determining these effects, relatively few studies have specifically examined how oxidant defence may impact susceptibility to particulate air pollution. Here we review studies that explore the impact of polymorphisms in anti-oxidant related genes or anti-oxidant supplementation on PM2.5-induced cardiorespiratory outcomes in an effort to summarize existing evidence related to oxidative stress defence and the health effects of PM2.5. Recent studies of PM-oxidative burden were also examined. In total, nine studies were identified and reviewed and existing evidence generally suggests that oxidant defence may modify the impact of PM2.5 exposure on various health outcomes, particularly heart rate variability (a measure of autonomic function) which was the most common outcome examined in the studies reviewed. Few studies examined interactions between PM2.5 and oxidant defence for respiratory outcomes, and in general studies focused primarily on acute health effects. Therefore, further evaluation of the potential modifying role of oxidant defence in PM2.5-induced health effects is required, particularly for chronic outcomes. Similarly, while an exposure metric that captures the ability of PM2.5 to cause oxidative stress may offer advantages over traditional mass concentration measurements, little epidemiological evidence is currently available to evaluate the potential benefits of such an approach. Therefore, further evaluation is required to determine how this metric may be incorporated in ambient air quality management.

  6. Defence Output Measures: An Economics Perspective

    Science.gov (United States)

    2011-11-01

    positive or negative impact of defence spending on growth and there is evidence supporting both impacts! The divergent results reflect the need for a...It also protects national interests, including independence and ‘appropriate sovereignty’ (e.g. protecting a nation’s interests in a globalised

  7. The Immune System and Bodily Defence

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 2. The Immune System and Bodily Defence How Do Parasites and the Immune System Choose their Dances? Vineeta Bal Satyajit Rath. Series Article Volume 2 Issue 2 February 1997 pp 17-24 ...

  8. The Immune System and Bodily Defence

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 9. The Immune System and Bodily Defence How Does the Immune System Recognize Everything Under the Sun? Vineeta Bal Satyajit Rath. Series Article Volume 2 Issue 9 September 1997 pp 6-10 ...

  9. Genetic and epigenetic control of plant heat responses

    Directory of Open Access Journals (Sweden)

    Junzhong eLiu

    2015-04-01

    Full Text Available Plants have evolved sophisticated genetic and epigenetic regulatory systems to respond quickly to unfavorable environmental conditions such as heat, cold, drought, and pathogen infections. In particular, heat greatly affects plant growth and development, immunity and circadian rhythm, and poses a serious threat to the global food supply. According to temperatures exposing, heat can be usually classified as warm ambient temperature (about 22-27℃, high temperature (27-30℃ and extremely high temperature (37-42℃, also known as heat stress for the model plant Arabidopsis thaliana. The genetic mechanisms of plant responses to heat have been well studied, mainly focusing on elevated ambient temperature-mediated morphological acclimation and acceleration of flowering, modulation of plant immunity and circadian clock by high temperatures, and thermotolerance to heat stress. Recently, great progress has been achieved on epigenetic regulation of heat responses, including DNA methylation, histone modifications, histone variants, ATP-dependent chromatin remodeling, histone chaperones, small RNAs, long non-coding RNAs and other undefined epigenetic mechanisms. These epigenetic modifications regulate the expression of heat-responsive genes and function to prevent heat-related damage. This review focuses on recent progresses regarding the genetic and epigenetic control of heat responses in plants, and pays more attention to the role of the major epigenetic mechanisms in plant heat responses. Further research perspectives are also discussed.

  10. Defense-in-depth for common cause failure of nuclear power plant safety system software

    International Nuclear Information System (INIS)

    Tian Lu

    2012-01-01

    This paper briefly describes the development of digital I and C system in nuclear power plant, and analyses the viewpoints of NRC and other nuclear safety authorities on Software Common Cause Failure (SWCCF). In view of the SWCCF issue introduced by the digitized platform adopted in nuclear power plant safety system, this paper illustrated a diversified defence strategy for computer software and hardware. A diversified defence-in-depth solution is provided for digital safety system of nuclear power plant. Meanwhile, analysis on problems may be faced during application of nuclear safety license are analyzed, and direction of future nuclear safety I and C system development are put forward. (author)

  11. Defence Industrial Policies and Their Impact on Acquisition Outcomes: A Comparative Analysis of the United Kingdom and Australia

    Science.gov (United States)

    2012-09-01

    average costs for firms in that industry but nonetheless support a positive (or non- negative ) level of profit. Defence industrial policies & their...prompted by increasing pressure on defence budgets; consolidation of the UK defence industry; “ globalisation ” of UK defence companies & threat of exit

  12. Physiological, structural and molecular traits activated in strawberry plants after inoculation with the plant growth-promoting bacterium Azospirillum brasilense REC3.

    Science.gov (United States)

    Guerrero-Molina, M F; Lovaisa, N C; Salazar, S M; Martínez-Zamora, M G; Díaz-Ricci, J C; Pedraza, R O

    2015-05-01

    The plant growth-promoting strain REC3 of Azospirillum brasilense, isolated from strawberry roots, prompts growth promotion and systemic protection against anthracnose disease in this crop. Hence, we hypothesised that A. brasilense REC3 can induce different physiological, structural and molecular responses in strawberry plants. Therefore, the aim of this work was to study these traits activated in Azospirillum-colonised strawberry plants, which have not been assessed until now. Healthy, in vitro micropropagated plants were root-inoculated with REC3 under hydroponic conditions; root and leaf tissues were sampled at different times, and oxidative burst, phenolic compound content, malondialdehyde (MDA) concentration, callose deposition, cell wall fortification and gene expression were evaluated. Azospirillum inoculation enhanced levels of soluble phenolic compounds after 12 h post-inoculation (hpi), while amounts of cell wall bound phenolics were similar in inoculated and control plants. Other early responses activated by REC3 (at 24 hpi) were a decline of lipid peroxidation and up-regulation of strawberry genes involved in defence (FaPR1), bacterial recognition (FaFLS2) and H₂O₂ depuration (FaCAT and FaAPXc). The last may explain the apparent absence of oxidative burst in leaves after bacterial inoculation. Also, REC3 inoculation induced delayed structural responses such as callose deposition and cell wall fortification (at 72 hpi). Results showed that A. brasilense REC3 is capable of exerting beneficial effects on strawberry plants, reinforcing their physiological and cellular characteristics, which in turns contribute to improve plant performance. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  13. Crowd-out of defence and health spending: is Israel different from other industrialised nations?

    Science.gov (United States)

    Reeves, Aaron; Stuckler, David

    2013-04-22

    Does high defence spending limit the growth of public health investment? Using comparative data from 31 OECD countries between 1980 and 2010, we find little evidence that defence crowds out public health spending. Whether measured in terms of long-term levels or short-term changes, per capita defence and health spending positively and significantly correlate. To investigate the possibility that countries with high security needs such as Israel exhibit differing patterns, we also compare crowd-out among countries experiencing violent conflicts as well as current high military-spending countries. We observed a greater positive correlation between changes in health and defence spending among conflict-countries (r = 0.65, p military spending countries, Israel's politicians reduced defence spending while increasing health expenditure during its recent recession. These analyses reveal that while Israel's politicians have chronically underinvested in public health, there are modest steps being taken to rectify the country's unique and avoidable crowding out of public health from its high military spending.

  14. "New Sport" in the street: self-defence, security and space in belle epoque Paris.

    Science.gov (United States)

    Freundschuh, Aaron

    2006-01-01

    Near the turn of the twentieth century, traditional self-defence methods (for example, jiu-jitsu) were revamped into a more accessible and practical set of techniques and tactics for everyday use in urban public space. Framed as a "new sport" with broad public utility, early urban self-defence developed against the backdrop of heightening fears of violent crime and a burgeoning politics of security, as well as tensions provoked by the increasingly common appearance of unchaperoned, middle-class women in public. Self-defence masters pitched their innovations in an inclusive rhetoric, always with separate lessons for men and women and their respective spaces of risk. This article places modern self-defence practices in tension with historical transformations in the urban landscape, arguing that urban self-defence posited a certain subjective relation to the city that tapped simultaneously into the desire for empowerment, fantasies of criminal danger and a law-and-order tone that shaded into urban vigilantism.

  15. Phyllosticta musarum Infection-Induced Defences Suppress Anthracnose Disease Caused by Colletotrichum musae in Banana Fruits cv 'Embul'.

    Science.gov (United States)

    Abayasekara, C L; Adikaram, N K B; Wanigasekara, U W N P; Bandara, B M R

    2013-03-01

    Anthracnose development by Colletotrichum musae was observed to be significantly less in the fruits of the banana cultivar 'Embul' (Mysore, AAB) infected with Phyllosticta musarum than in fruits without such infections. Anthracnose disease originates from quiescent C. musae infections in the immature fruit. P. musarum incites minute, scattered spots, referred to as freckles, in the superficial tissues of immature banana peel which do not expand during maturation or ripening. P. musarum does not appear to have a direct suppressive effect on C. musae as conidia of C. musae germinate on both freckled and non-freckled fruit forming quiescent infections. Our investigations have shown that P. musarum infection induced several defence responses in fruit including the accumulation of five phytoalexins, upregulation of chitinase and β-1,3-glucanase, phenylalanine ammonia lyase (PAL) activity and cell wall lignification. (1)H and (13)C NMR spectral data of one purified phytoalexin compared closely with 4'-hydroxyanigorufone. Some of the P. musarum-induced defences that retained during ripening, restrict C. musae development at the ripe stage. This paper examines the potential of P. musarum-induced defences, in the control of anthracnose, the most destructive postharvest disease in banana.

  16. Civil Defence Commission at the Federal German Ministry of the Interior

    International Nuclear Information System (INIS)

    1987-01-01

    The work of the Civil Defence Commission comprises also interdisciplinary questions of civil defence and disaster relief. The lectures are concerned with the causes and effects of radioactivity, medical practice in the event of disaster, toxicology and pathology, including even psychology in disaster as well as risk management and dosimetry. The subjects chemical accidents and disaster relief are marginally dealt with. (DG) [de

  17. Interactions between the jasmonic and salicylic acid pathway modulate the plant metabolome and affect herbivores of different feeding types.

    Science.gov (United States)

    Schweiger, R; Heise, A-M; Persicke, M; Müller, C

    2014-07-01

    The phytohormones jasmonic acid (JA) and salicylic acid (SA) mediate induced plant defences and the corresponding pathways interact in a complex manner as has been shown on the transcript and proteine level. Downstream, metabolic changes are important for plant-herbivore interactions. This study investigated metabolic changes in leaf tissue and phloem exudates of Plantago lanceolata after single and combined JA and SA applications as well as consequences on chewing-biting (Heliothis virescens) and piercing-sucking (Myzus persicae) herbivores. Targeted metabolite profiling and untargeted metabolic fingerprinting uncovered different categories of plant metabolites, which were influenced in a specific manner, indicating points of divergence, convergence, positive crosstalk and pronounced mutual antagonism between the signaling pathways. Phytohormone-specific decreases of primary metabolite pool sizes in the phloem exudates may indicate shifts in sink-source relations, resource allocation, nutrient uptake or photosynthesis. Survival of both herbivore species was significantly reduced by JA and SA treatments. However, the combined application of JA and SA attenuated the negative effects at least against H. virescens suggesting that mutual antagonism between the JA and SA pathway may be responsible. Pathway interactions provide a great regulatory potential for the plant that allows triggering of appropriate defences when attacked by different antagonist species. © 2013 John Wiley & Sons Ltd.

  18. Assessment of pleiotropic transcriptome perturbations in Arabidopsis engineered for indirect insect defence.

    Science.gov (United States)

    Houshyani, Benyamin; van der Krol, Alexander R; Bino, Raoul J; Bouwmeester, Harro J

    2014-06-19

    Molecular characterization is an essential step of risk/safety assessment of genetically modified (GM) crops. Holistic approaches for molecular characterization using omics platforms can be used to confirm the intended impact of the genetic engineering, but can also reveal the unintended changes at the omics level as a first assessment of potential risks. The potential of omics platforms for risk assessment of GM crops has rarely been used for this purpose because of the lack of a consensus reference and statistical methods to judge the significance or importance of the pleiotropic changes in GM plants. Here we propose a meta data analysis approach to the analysis of GM plants, by measuring the transcriptome distance to untransformed wild-types. In the statistical analysis of the transcriptome distance between GM and wild-type plants, values are compared with naturally occurring transcriptome distances in non-GM counterparts obtained from a database. Using this approach we show that the pleiotropic effect of genes involved in indirect insect defence traits is substantially equivalent to the variation in gene expression occurring naturally in Arabidopsis. Transcriptome distance is a useful screening method to obtain insight in the pleiotropic effects of genetic modification.

  19. De Nederlandse missile defence capaciteit: Strategisch onmisbaar

    NARCIS (Netherlands)

    Weimar, P.W.L.

    2013-01-01

    Surface based air & missile defence behelst enerzijds de verdediging tegen conventionele luchtdreigingen, zoals vliegtuigen, helikopters en onbemande vliegtuigen (luchtverdediging). Aan de andere kant houdt het de verdediging tegen ballistische raketten en kruisraketten in (raketverdediging). De

  20. Ionising radiation safety training in the Australian defence organisation (ADO)

    International Nuclear Information System (INIS)

    Jenks, G.J.; O'Donovan, E.J.B.; Wood, W.B.

    1996-01-01

    Full text: Training personnel in ionising radiation safety within the Australian Defence Organisation (ADO) requires addressing some unique features of an organisation employing both military and civilian personnel. Activities may include those of a civil nature (such as industrial and medical radiography), specific military requirements (for training and emergency response) and scientific research and development. Some personnel may be assigned to full-time duties associated with radiation, while others may be designated as radiation protection officers in remote units with few duties to perform in this role. A further complication is that most military personnel are subjected to postings at regular intervals. The ADO's Directorate of Defence Occupational Health and Safety has established an Ionising Radiation Safety Subcommittee to monitor not only the adequacy of the internal Ionising Radiation Safety Manual but also the training requirements. A training course, responding to these requirements, has been developed to emphasise: basic radiation theory and protection; operation of radiation monitors available in the ADO; an understanding of the Safety Manual; day-to-day radiation safety in units and establishments; and appropriate responses to radiation accidents and emergencies. In addition, students are briefed on a limited number of peripheral topics and participate in some site visits. Currently, two Courses are held annually, each with about twenty students. Most of the material is presented by ADO personnel with external contractor support. The three Courses held to date have proved sufficiently successful, both for the students and the ADO generally, to seek national accreditation through the Australian National Training Authority and, as a first step, competency standards have been identified

  1. 2015 Status Report on Major Defence Equipment Procurements

    Directory of Open Access Journals (Sweden)

    David Perry

    2015-12-01

    Full Text Available Federal elections may be good for democracy, but the campaigns — particularly the lengthy one recently held in Canada — can be crippling for plans to better arm our military. Just before the election was called, there were public signs of important progress being made in what has long been a frustratingly slow and bureaucratically complex procurement process. But then the campaign left the Department of National Defence and other federal departments unable to secure approvals from either a defence minister or the Treasury Board, until the election ended and the new prime minister appointed the current cabinet. There had already been upheaval prior to that: In the first seven months of 2015, the three senior leaders at the Canadian Forces and the Defence Department (including the minister had been replaced, along with many other people critical to the procurement process. In addition, there had been changes in the Public Works Department and the Defence Procurement Strategy Secretariat. Frustrating and disappointing delays have long been a matter of course in Canada’s defence procurement process. In 2014/15, the number of ministerial or Treasury Board approvals to allow projects to proceed was half of that in 2009/10. Yet the demand for approvals has not abated. In addition to the turnover of key figures involved in the procurement and approval process, delays have come from a number of major steps added to the process, making an already lengthy and complex system even more so. To be sure, these steps were added in the pursuit of improved financial management and project management, with the aim of addressing longstanding problems. But it will take years to see if those objectives have been realized. An irony here is that the budget for military procurement has increased. Between 2004 and 2009, the Defence Department’s procurement budget nearly doubled. But the funding was never matched by the capacity to manage it. In 2003, the Material

  2. Agrobacterium tumefaciens responses to plant-derived signaling molecules

    Science.gov (United States)

    Subramoni, Sujatha; Nathoo, Naeem; Klimov, Eugene; Yuan, Ze-Chun

    2014-01-01

    As a special phytopathogen, Agrobacterium tumefaciens infects a wide range of plant hosts and causes plant tumors also known as crown galls. The complexity of Agrobacterium–plant interaction has been studied for several decades. Agrobacterium pathogenicity is largely attributed to its evolved capabilities of precise recognition and response to plant-derived chemical signals. Agrobacterium perceives plant-derived signals to activate its virulence genes, which are responsible for transferring and integrating its Transferred DNA (T-DNA) from its Tumor-inducing (Ti) plasmid into the plant nucleus. The expression of T-DNA in plant hosts leads to the production of a large amount of indole-3-acetic acid (IAA), cytokinin (CK), and opines. IAA and CK stimulate plant growth, resulting in tumor formation. Agrobacterium utilizes opines as nutrient sources as well as signals in order to activate its quorum sensing (QS) to further promote virulence and opine metabolism. Intriguingly, Agrobacterium also recognizes plant-derived signals including γ-amino butyric acid and salicylic acid (SA) to activate quorum quenching that reduces the level of QS signals, thereby avoiding the elicitation of plant defense and preserving energy. In addition, Agrobacterium hijacks plant-derived signals including SA, IAA, and ethylene to down-regulate its virulence genes located on the Ti plasmid. Moreover, certain metabolites from corn (Zea mays) also inhibit the expression of Agrobacterium virulence genes. Here we outline the responses of Agrobacterium to major plant-derived signals that impact Agrobacterium–plant interactions. PMID:25071805

  3. Agrobacterium tumefaciens responses to plant-derived signaling molecules

    Directory of Open Access Journals (Sweden)

    Sujatha eSubramoni

    2014-07-01

    Full Text Available As a special phytopathogen, Agrobacterium tumefaciens infects a wide range of plant hosts and causes plant tumors also known as crown galls. The complexity of Agrobacterium-plant interaction has been studied for several decades. Agrobacterium pathogenicity is largely attributed to its evolved capabilities of precise recognition and response to plant-derived chemical signals. Agrobacterium perceives plant-derived signals to activate its virulence genes, which are responsible for transferring and integrating its T-DNA (Transferred DNA from its Tumour-inducing (Ti plasmid into the plant nucleus. The expression of T-DNA in plant hosts leads to the production of a large amount of indole-3-acetic acid (IAA, cytokinin (CK and opines. IAA and CK stimulate plant growth, resulting in tumor formation. Agrobacterium utilizes opines as nutrient sources as well as signals in order to activate its quorum sensing (QS to further promote virulence and opine metabolism. Intriguingly, Agrobacterium also recognizes plant-derived signals including -amino butyric acid (GABA and salicylic acid (SA to activate quorum quenching that reduces the level of QS signals, thereby avoiding the elicitation of plant defense and preserving energy. In addition, Agrobacterium hijacks plant-derived signals including SA, IAA, and ethylene (ET to down-regulate its virulence genes located on the Ti plasmid. Moreover, certain metabolites from corn (Zea mays also inhibit the expression of Agrobacterium virulence genes. Here we outline the responses of Agrobacterium to major plant-derived signals that impact Agrobacterium-plant interactions.

  4. Elucidating the interaction between light competition and herbivore feeding patterns using functional–structural plant modelling

    Science.gov (United States)

    de Vries, Jorad; Poelman, Erik H; Anten, Niels; Evers, Jochem B

    2018-01-01

    Abstract Background and Aims Plants usually compete with neighbouring plants for resources such as light as well as defend themselves against herbivorous insects. This requires investment of limiting resources, resulting in optimal resource distribution patterns and trade-offs between growth- and defence-related traits. A plant’s competitive success is determined by the spatial distribution of its resources in the canopy. The spatial distribution of herbivory in the canopy in turn differs between herbivore species as the level of herbivore specialization determines their response to the distribution of resources and defences in the canopy. Here, we investigated to what extent competition for light affects plant susceptibility to herbivores with different feeding preferences. Methods To quantify interactions between herbivory and competition, we developed and evaluated a 3-D spatially explicit functional–structural plant model for Brassica nigra that mechanistically simulates competition in a dynamic light environment, and also explicitly models leaf area removal by herbivores with different feeding preferences. With this novel approach, we can quantitatively explore the extent to which herbivore feeding location and light competition interact in their effect on plant performance. Key Results Our results indicate that there is indeed a strong interaction between levels of plant–plant competition and herbivore feeding preference. When plants did not compete, herbivory had relatively small effects irrespective of feeding preference. Conversely, when plants competed, herbivores with a preference for young leaves had a strong negative effect on the competitiveness and subsequent performance of the plant, whereas herbivores with a preference for old leaves did not. Conclusions Our study predicts how plant susceptibility to herbivory depends on the composition of the herbivore community and the level of plant competition, and highlights the importance of considering

  5. Necessity, private defence and the killing of Mary.

    Science.gov (United States)

    Rogers, J

    2001-07-01

    This article examines the reasons used by the Court of Appeal in Re A (Children) to authorise and justify an operation which would inevitably kill the weaker of a pair of conjoined twins in order to offer the stronger twin a good chance of a long and happy life. The crux of the judgment was that a utilitarian theory of necessity could justify this operation. This article seeks to define the criminal law defences at issue in the case and to argue that utilitarian necessity is such a dangerous doctrine that it should never be employed if there is any other defence which can be made to serve the same purpose--as there was in the present case.

  6. A SNARE-protein has opposing functions in penetration resistance and defence signalling pathways

    DEFF Research Database (Denmark)

    Zhang, Ziguo; Feechan, Angela; Pedersen, Carsten

    2007-01-01

    Penetration resistance is often the first line of defence against fungal pathogens. Subsequently induced defences are mediated by the programmed cell death (PCD) reaction pathway and the salicylic acid (SA), jasmonic acid (JA) and ethylene (ET) signalling pathways. We previously demonstrated...

  7. Reduction of seismic response in breeder plants

    International Nuclear Information System (INIS)

    Tajirian, F.F.; Somes, N.F.; Todeschini, R.A.

    1984-01-01

    Thin-walled vessels to be used in the Nuclear Steam Supply Systems (NSSS) of future LMFBR's will be more sensitive to seismic excitation than their equivalents used in conventional LWR plants. Optimization studies of building arrangement have indicated that embedment of future plants may be one feasible strategy for reducing seismic response. This paper presents the results of a three-dimensional soil-structure interaction analysis using the computer program SASSI. Two types of embedded buildings are considered: full embedment of the nuclear island, and embedment of the reactor cavity alone. A comparison, between the response of the embedded structure with that of a plant supported on the surface, indicates that the seismic response at the reactor vessel support ledge can be lowered by embedment of either the entire nuclear island or the reactor cavity alone. This reduction is larger when the plant is embedded in a softer site due to the increased effect of soil-structure interaction

  8. Can biomass responses to warming at plant to ecosystem levels be predicted by leaf-level responses?

    Science.gov (United States)

    Xia, J.; Shao, J.; Zhou, X.; Yan, W.; Lu, M.

    2015-12-01

    Global warming has the profound impacts on terrestrial C processes from leaf to ecosystem scales, potentially feeding back to climate dynamics. Although numerous studies had investigated the effects of warming on C processes from leaf to plant and ecosystem levels, how leaf-level responses to warming scale up to biomass responses at plant, population, and community levels are largely unknown. In this study, we compiled a dataset from 468 papers at 300 experimental sites and synthesized the warming effects on leaf-level parameters, and plant, population and ecosystem biomass. Our results showed that responses of plant biomass to warming mainly resulted from the changed leaf area rather than the altered photosynthetic capacity. The response of ecosystem biomass to warming was weaker than those of leaf area and plant biomass. However, the scaling functions from responses of leaf area to plant biomass to warming were different in diverse forest types, but functions were similar in non-forested biomes. In addition, it is challenging to scale the biomass responses from plant up to ecosystem. These results indicated that leaf area might be the appropriate index for plant biomass response to warming, and the interspecific competition might hamper the scaling of the warming effects on plant and ecosystem levels, suggesting that the acclimation capacity of plant community should be incorporated into land surface models to improve the prediction of climate-C cycle feedback.

  9. Anosognosia as motivated unawareness: the 'defence' hypothesis revisited.

    Science.gov (United States)

    Turnbull, Oliver H; Fotopoulou, Aikaterini; Solms, Mark

    2014-12-01

    Anosognosia for hemiplegia has seen a century of almost continuous research, yet a definitive understanding of its mechanism remains elusive. Essentially, anosognosic patients hold quasi-delusional beliefs about their paralysed limbs, in spite of all the contrary evidence, repeated questioning, and logical argument. We review a range of findings suggesting that emotion and motivation play an important role in anosognosia. We conclude that anosognosia involves (amongst other things) a process of psychological defence. This conclusion stems from a wide variety of clinical and experimental investigations, including data on implicit awareness of deficit, fluctuations in awareness over time, and dramatic effects upon awareness of psychological interventions such as psychotherapy, reframing of the emotional consequences of the paralysis, and first versus third person perspectival manipulations. In addition, we review and refute the (eight) arguments historically raised against the 'defence' hypothesis, including the claim that a defence-based account cannot explain the lateralised nature of the disorder. We argue that damage to a well-established right-lateralised emotion regulation system, with links to psychological processes that appear to underpin allocentric spatial cognition, plays a key role in anosognosia (at least in some patients). We conclude with a discussion of implications for clinical practice. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. The Immune System and Bodily Defence

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 6. The Immune System and Bodily Defence How Does the Immune System Organize Itself so as to Connect Target Recognition to Expected Functions? Vineeta Bal Satyajit Rath. Series Article Volume 2 Issue 6 June 1997 pp 25-38 ...

  11. Plant responses to variable timing of aboveground clipping and belowground herbivory depend on plant age

    NARCIS (Netherlands)

    Wang, Minggang; Bezemer, T. Martijn; van der Putten, W.H.; Brinkman, Pella; Biere, Arjen

    2017-01-01

    Aims Plants use different types of responses such as tolerance and induced defense to mitigate the effects of herbivores. The direction and magnitude of both these plant responses can vary with plant age. However, most studies have focused on aboveground herbivory, whereas important feeding occurs

  12. The genetic architecture of defence as resistance to and tolerance of bacterial infection in Drosophila melanogaster.

    Science.gov (United States)

    Howick, Virginia M; Lazzaro, Brian P

    2017-03-01

    Defence against pathogenic infection can take two forms: resistance and tolerance. Resistance is the ability of the host to limit a pathogen burden, whereas tolerance is the ability to limit the negative consequences of infection at a given level of infection intensity. Evolutionarily, a tolerance strategy that is independent of resistance could allow the host to avoid mounting a costly immune response and, theoretically, to avoid a co-evolutionary arms race between pathogen virulence and host resistance. Biomedically, understanding the mechanisms of tolerance and how they relate to resistance could potentially yield treatment strategies that focus on health improvement instead of pathogen elimination. To understand the impact of tolerance on host defence and identify genetic variants that determine host tolerance, we defined genetic variation in tolerance as the residual deviation from a binomial regression of fitness under infection against infection intensity. We then performed a genomewide association study to map the genetic basis of variation in resistance to and tolerance of infection by the bacterium Providencia rettgeri. We found a positive genetic correlation between resistance and tolerance, and we demonstrated that the level of resistance is highly predictive of tolerance. We identified 30 loci that predict tolerance, many of which are in genes involved in the regulation of immunity and metabolism. We used RNAi to confirm that a subset of mapped genes have a role in defence, including putative wound repair genes grainy head and debris buster. Our results indicate that tolerance is not an independent strategy from resistance, but that defence arises from a collection of physiological processes intertwined with canonical immunity and resistance. © 2017 John Wiley & Sons Ltd.

  13. On-line acquisition of plant related and environmental parameters (plant monitoring) in gerbera: determining plant responses

    NARCIS (Netherlands)

    Baas, R.; Slootweg, G.

    2004-01-01

    For on-line plant monitoring equipment to be functional in commercial glasshouse horticulture, relations between sensor readings and plant responses on both the short (days) and long term (weeks) are required. For this reason, systems were installed to monitor rockwool grown gerbera plants on a

  14. Plant hydraulic diversity buffers forest ecosystem responses to drought

    Science.gov (United States)

    Anderegg, W.; Konings, A. G.; Trugman, A. T.; Pacala, S. W.; Yu, K.; Sulman, B. N.; Sperry, J.; Bowling, D. R.

    2017-12-01

    Drought impacts carbon, water, and energy cycles in forests and may pose a fundamental threat to forests in future climates. Plant hydraulic transport of water is central to tree drought responses, including curtailing of water loss and the risk of mortality during drought. The effect of biodiversity on ecosystem function has typically been examined in grasslands, yet the diversity of plant hydraulic strategies may influence forests' response to drought. In a combined analysis of eddy covariance measurements, remote-sensing data of plant water content variation, model simulations, and plant hydraulic trait data, we test the degree to which plant water stress schemes influence the carbon cycle and how hydraulic diversity within and across ecosystems affects large-scale drought responses. We find that current plant functional types are not well-suited to capture hydraulic variation and that higher hydraulic diversity buffers ecosystem variation during drought. Our results demonstrate that tree functional diversity, particularly hydraulic diversity, may be critical to simulate in plant functional types in current land surface model projections of future vegetation's response to climate extremes.

  15. Friends or foes? Emerging insights from fungal interactions with plants.

    Science.gov (United States)

    Zeilinger, Susanne; Gupta, Vijai K; Dahms, Tanya E S; Silva, Roberto N; Singh, Harikesh B; Upadhyay, Ram S; Gomes, Eriston Vieira; Tsui, Clement Kin-Ming; Nayak S, Chandra

    2016-03-01

    Fungi interact with plants in various ways, with each interaction giving rise to different alterations in both partners. While fungal pathogens have detrimental effects on plant physiology, mutualistic fungi augment host defence responses to pathogens and/or improve plant nutrient uptake. Tropic growth towards plant roots or stomata, mediated by chemical and topographical signals, has been described for several fungi, with evidence of species-specific signals and sensing mechanisms. Fungal partners secrete bioactive molecules such as small peptide effectors, enzymes and secondary metabolites which facilitate colonization and contribute to both symbiotic and pathogenic relationships. There has been tremendous advancement in fungal molecular biology, omics sciences and microscopy in recent years, opening up new possibilities for the identification of key molecular mechanisms in plant-fungal interactions, the power of which is often borne out in their combination. Our fragmentary knowledge on the interactions between plants and fungi must be made whole to understand the potential of fungi in preventing plant diseases, improving plant productivity and understanding ecosystem stability. Here, we review innovative methods and the associated new insights into plant-fungal interactions. © FEMS 2015.

  16. Energetic consequences of an inducible morphological defence in crucian carp.

    Science.gov (United States)

    Pettersson, Lars B; Brönmark, Christer

    1999-10-01

    Crucian carp (Carassius carassius) increases in body depth in response to chemical cues from piscivores and the deeper body constitutes a morphological defence against gape-limited piscivores. In the field, deep-bodied individuals suffer a density-dependent cost when competing with shallow-bodied conspecifics. Here, we use hydrodynamic theory and swimming respirometry to investigate the proposed mechanism underlying this effect, high drag caused by the deep-bodied morphology. Our study confirms that drag is higher for deep-bodied crucian carp, both in terms of estimated theoretical drag and power curve steepness. However, deep-bodied fish swimming at the velocity associated with minimum cost of transport, U mc , did not experience higher costs of transport than shallow-bodied fish. Deep-bodied crucian carp had significantly lower standard metabolic rates, i.e. metabolic rates at rest, and also lower U mc , and the resulting costs of transport were similar for the two morphs. Nevertheless, when deep-bodied individuals deviate from U mc , e.g. when increasing foraging effort under competition, their steeper power curves will cause substantial energy costs relative to shallow-bodied conspecifics. Furthermore, there is evidence that reductions in standard metabolic rate incur costs in terms of lower stress tolerance, reduced growth rate, and life history changes. Thus, this work provides links between hydrodynamics, a cost-reducing mechanism, and a density-dependent fitness cost associated with an inducible defence.

  17. Arabidopsis redox status in response to caterpillar herbivory

    Directory of Open Access Journals (Sweden)

    Jamuna ePaudel

    2013-05-01

    Full Text Available Plant responses to insect herbivory are regulated through complex, hormone-mediated interactions. Some caterpillar species have evolved strategies to manipulate this system by inducing specific pathways that suppress plant defense responses. Effectors in the labial saliva (LS secretions of Spodoptera exigua caterpillars are believed to induce the salicylic acid (SA pathway to interfere with the jasmonic acid (JA defense pathway; however, the mechanism underlying this subversion is unknown. Since Noctuid caterpillar LS contains enzymes that may affect cellular redox balance, this study investigated rapid changes in cellular redox metabolites within 45 min after herbivory. Caterpillar LS is involved in suppressing the increase in oxidative stress that was observed in plants fed upon by caterpillars with impaired LS secretions. To further understand the link between cellular redox balance and plant defense responses, marker genes of SA, JA and ethylene (ET pathways were compared in wildtype, the glutathione-compromised pad2-1 mutant and the tga2/5/6 triple mutant plants. AtPR1 and AtPDF1.2 showed LS-dependent expression that was alleviated in the pad2-1 and tga2/5/6 triple mutants. In comparison, the ET-dependent genes ERF1 expression showed LS-associated changes in both wildtype and pad2-1 mutant plants and the ORA 59 marker AtHEL had increased expression in response to herbivory, but a LS-dependent difference was not noted. These data support the model that there are SA/NPR1-, glutathione-dependent and ET-, glutathione-independent mechanisms leading to LS-associated suppression of plant induced defences.

  18. Proteomic analysis of grapevine resistance induced by Trichoderma harzianum T39 reveals specific defence pathways activated against downy mildew

    Science.gov (United States)

    Perazzolli, Michele

    2012-01-01

    Downy mildew is caused by the oomycete Plasmopara viticola and is one of the most serious diseases of grapevine. The beneficial microorganism Trichoderma harzianum T39 (T39) has previously been shown to induce plant-mediated resistance and to reduce the severity of downy mildew in susceptible grapevines. In order to better understand the cellular processes associated with T39-induced resistance, the proteomic and histochemical changes activated by T39 in grapevine were investigated before and 1 day after P. viticola inoculation. A comprehensive proteomic analysis of T39-induced resistance in grapevine was performed using an eight-plex iTRAQ protocol, resulting in the identification and quantification of a total of 800 proteins. Most of the proteins directly affected by T39 were found to be involved in signal transduction, indicating activation of a complete microbial recognition machinery. Moreover, T39-induced resistance was associated with rapid accumulation of reactive oxygen species and callose at infection sites, as well as changes in abundance of proteins involved in response to stress and redox balance, indicating an active defence response to downy mildew. On the other hand, proteins affected by P. viticola in control plants mainly decreased in abundance, possibly reflecting the establishment of a compatible interaction. Finally, the high-throughput iTRAQ protocol allowed de novo peptide sequencing, which will be used to improve annotation of the Vitis vinifera cv. Pinot Noir proteome. PMID:23105132

  19. Physiological response of soybean genotypes to plant density

    NARCIS (Netherlands)

    Gan, Y; Stulen, [No Value; van Keulen, H; Kuiper, PJC

    2002-01-01

    Response of soybean (Glycine max (L.) Merr.) to plant density has occupied a segment of agronomic research for most of the century. Genotype differences have been noted especially in response to planting date, lodging problems and water limitation. There is limited information on the physiological

  20. Salicylic and jasmonic acid pathways are necessary for defence against Dickeya solani as revealed by a novel method for Blackleg disease screening of in vitro grown potato.

    Science.gov (United States)

    Burra, D D; Mühlenbock, P; Andreasson, E

    2015-09-01

    Potato is major crop ensuring food security in Europe, and blackleg disease is increasingly causing losses in yield and during storage. Recently, one blackleg pathogen, Dickeya solani has been shown to be spreading in Northern Europe that causes aggressive disease development. Currently, identification of tolerant commercial potato varieties has been unsuccessful; this is confounded by the complicated etiology of the disease and a strong environmental influence on disease development. There is currently a lack of efficient testing systems. Here, we describe a system for quantification of blackleg symptoms on shoots of sterile in vitro potato plants, which saves time and space compared to greenhouse and existing field assays. We found no evidence for differences in infection between the described in vitro-based screening method and existing greenhouse assays. This system facilitates efficient screening of blackleg disease response of potato plants independent of other microorganisms and variable environmental conditions. We therefore used the in vitro screening method to increase understanding of plant mechanisms involved in blackleg disease development by analysing disease response of hormone- related (salicylic and jasmonic acid) transgenic potato plants. We show that both jasmonic (JA) and salicylic (SA) acid pathways regulate tolerance to blackleg disease in potato, a result unlike previous findings in Arabidopsis defence response to necrotrophic bacteria. We confirm this by showing induction of a SA marker, pathogenesis-related protein 1 (StPR1), and a JA marker, lipoxygenase (StLOX), in Dickeya solani infected in vitro potato plants. We also observed that tubers of transgenic potato plants were more susceptible to soft rot compared to wild type, suggesting a role for SA and JA pathways in general tolerance to Dickeya. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  1. The correlated evolution of antipredator defences and brain size in mammals

    OpenAIRE

    Stankowich, Theodore; Romero, Ashly N.

    2017-01-01

    Mammals that possess elaborate antipredator defences such as body armour, spines and quills are usually well protected, intermediate in size, primarily insectivorous and live in simple open environments. The benefits of such defences seem clear and may relax selection on maintaining cognitive abilities that aid in vigilance and predator recognition, and their bearers may accrue extensive production and maintenance costs. Here, in this comparative phylogenetic analysis of measurements of encep...

  2. Beyond Predation: The Zoophytophagous Predator Macrolophus pygmaeus Induces Tomato Resistance against Spider Mites.

    Directory of Open Access Journals (Sweden)

    Maria L Pappas

    Full Text Available Many predatory insects that prey on herbivores also feed on the plant, but it is unknown whether plants affect the performance of herbivores by responding to this phytophagy with defence induction. We investigate whether the prior presence of the omnivorous predator Macrolophus pygmaeus (Rambur on tomato plants affects plant resistance against two different herbivore species. Besides plant-mediated effects of M. pygmaeus on herbivore performance, we examined whether a plant defence trait that is known to be inducible by herbivory, proteinase inhibitors (PI, may also be activated in response to the interactions of this predator with the tomato plant. We show that exposing tomato plants to the omnivorous predator M. pygmaeus reduced performance of a subsequently infesting herbivore, the two-spotted spider mite Tetranychus urticae Koch, but not of the greenhouse whitefly Trialeurodes vaporariorum (Westwood. The spider-mite infested tomato plants experience a lower herbivore load, i.e., number of eggs deposited and individuals present, when previously exposed to the zoophytophagous predator. This effect is not restricted to the exposed leaf and persists on exposed plants for at least two weeks after the removal of the predators. The decreased performance of spider mites as a result of prior exposure of the plant to M. pygmaeus is accompanied by a locally and systemically increased accumulation of transcripts and activity of proteinase inhibitors that are known to be involved in plant defence. Our results demonstrate that zoophytophagous predators can induce plant defence responses and reduce herbivore performance. Hence, the suppression of populations of certain herbivores via consumption may be strengthened by the induction of plant defences by zoophytophagous predators.

  3. Assessment methodology for air defence control systems

    CSIR Research Space (South Africa)

    Oosthuizen, R

    2013-09-01

    Full Text Available In Command and Control, humans have to make sense of the situation to support decision making on the required action. Development of an Air Defence Control system through a Systems Engineering process starts with assessment of existing systems...

  4. Phyllosticta musarum Infection-Induced Defences Suppress Anthracnose Disease Caused by Colletotrichum musae in Banana Fruits cv ‘Embul’

    Science.gov (United States)

    Abayasekara, C. L.; Adikaram, N. K. B.; Wanigasekara, U. W. N. P.; Bandara, B. M. R.

    2013-01-01

    Anthracnose development by Colletotrichum musae was observed to be significantly less in the fruits of the banana cultivar ‘Embul’ (Mysore, AAB) infected with Phyllosticta musarum than in fruits without such infections. Anthracnose disease originates from quiescent C. musae infections in the immature fruit. P. musarum incites minute, scattered spots, referred to as freckles, in the superficial tissues of immature banana peel which do not expand during maturation or ripening. P. musarum does not appear to have a direct suppressive effect on C. musae as conidia of C. musae germinate on both freckled and non-freckled fruit forming quiescent infections. Our investigations have shown that P. musarum infection induced several defence responses in fruit including the accumulation of five phytoalexins, upregulation of chitinase and β-1,3-glucanase, phenylalanine ammonia lyase (PAL) activity and cell wall lignification. 1H and 13C NMR spectral data of one purified phytoalexin compared closely with 4′-hydroxyanigorufone. Some of the P. musarum-induced defences that retained during ripening, restrict C. musae development at the ripe stage. This paper examines the potential of P. musarum-induced defences, in the control of anthracnose, the most destructive postharvest disease in banana. PMID:25288931

  5. Defence in Depth by Design for the Advanced GIII NPP in China

    Energy Technology Data Exchange (ETDEWEB)

    Liu, S.; Zhang, Y.; Zhang, X., E-mail: liusongtao.npic@gmail.com [Science and Technology on Reactor System Design Technology Laboratory Chengdu, Sichuan (China)

    2014-10-15

    This paper describes the design of the advanced nuclear power plant ACP1000 in China that keeps the principle of defence in depth. To enhance the safety of the new generation NPPs, passive and active engineering safety features are used. The reactor will be kept safe under design basis accidents by using active engineering safety features, such as the medium and low pressure safety injection systems, and the emergency feedwater system. Under beyond DBAs, the passive safety systems will be actuated to keep removing residual heat for more than 72 hours, and to keep the core melt retained and cooled in the vessel. After the Fukushima nuclear accident, there are six main design enhancements in ACP1000 to meet the demands of the China authorities. (author)

  6. Crosstalk between autophagy and inflammatory signalling pathways: balancing defence and homeostasis.

    Science.gov (United States)

    Cadwell, Ken

    2016-11-01

    Autophagy has broad functions in immunity, ranging from cell-autonomous defence to coordination of complex multicellular immune responses. The successful resolution of infection and avoidance of autoimmunity necessitates efficient and timely communication between autophagy and pathways that sense the immune environment. The recent literature indicates that a variety of immune mediators induce or repress autophagy. It is also becoming increasingly clear that immune signalling cascades are subject to regulation by autophagy, and that a return to homeostasis following a robust immune response is critically dependent on this pathway. Importantly, examples of non-canonical forms of autophagy in mediating immunity are pervasive. In this article, the progress in elucidating mechanisms of crosstalk between autophagy and inflammatory signalling cascades is reviewed. Improved mechanistic understanding of the autophagy machinery offers hope for treating infectious and inflammatory diseases.

  7. Employing modern power plant simulators in nuclear power plants

    International Nuclear Information System (INIS)

    Niedorf, V.; Storm, J.

    2005-01-01

    At the present state of the art, modern power plant simulators are characterized by new qualitative features, thus enabling operators to use them far beyond the traditional field of training. In its first part, this contribution presents an overview of the requirements to be met by simulators for multivalent uses. In part two, a survey of the uses and perspectives of simulation technology in power plants is presented on the basis of experience accumulated by Rheinmetall Defence Electronics (RDE).Modern simulators are shown to have applications by far exceeding traditional training areas. Modular client - sever systems on standard computers allow inexpensive uses to be designed at several levels, thus minimizing maintenance cost. Complex development and running time environments, like the SEMS developed by RDE, have made power plant simulators the workhorses of power plant engineers in all power plant areas. (orig.)

  8. Early perception of stink bug damage in developing seeds of field-grown soybean induces chemical defences and reduces bug attack.

    Science.gov (United States)

    Giacometti, Romina; Barneto, Jesica; Barriga, Lucia G; Sardoy, Pedro M; Balestrasse, Karina; Andrade, Andrea M; Pagano, Eduardo A; Alemano, Sergio G; Zavala, Jorge A

    2016-08-01

    Southern green stink bugs (Nezara viridula L.) invade field-grown soybean crops, where they feed on developing seeds and inject phytotoxic saliva, which causes yield reduction. Although leaf responses to herbivory are well studied, no information is available about the regulation of defences in seeds. This study demonstrated that mitogen-activated protein kinases MPK3, MPK4 and MPK6 are expressed and activated in developing seeds of field-grown soybean and regulate a defensive response after stink bug damage. Although 10-20 min after stink bug feeding on seeds induced the expression of MPK3, MPK6 and MPK4, only MPK6 was phosphorylated after damage. Herbivory induced an early peak of jasmonic acid (JA) accumulation and ethylene (ET) emission after 3 h in developing seeds, whereas salicylic acid (SA) was also induced early, and at increasing levels up to 72 h after damage. Damaged seeds upregulated defensive genes typically modulated by JA/ET or SA, which in turn reduced the activity of digestive enzymes in the gut of stink bugs. Induced seeds were less preferred by stink bugs. This study shows that stink bug damage induces seed defences, which is perceived early by MPKs that may activate defence metabolic pathways in developing seeds of field-grown soybean. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  9. Does responsiveness to arbuscular mycorrhizas depend on plant invasive status?

    Science.gov (United States)

    1. Some posit invasive alien plants are less dependent on mycorrhizal associations than native plants, and thus weak mycorrhizal responsiveness may be a general mechanism of plant invasion. 2. Here, we tested whether mycorrhizal responsiveness varies by plant invasive status while controlling for ph...

  10. Phosphorylation and proteome dynamics in pathogen-resistant tomato plants

    OpenAIRE

    Stulemeijer, I.J.E.

    2008-01-01

    Microbial plant pathogens impose a continuous threat on global food production. Similar to disease resistance in mammals, an innate immune system allows plants to recognise pathogens and swiftly activate defence. For the work described in this thesis, the interaction between tomato and the extracellular fungal pathogen Cladosporium fulvum serves as a model system to study host resistance and susceptibility in plant-pathogen interactions. Resistance to C. fulvum in tomato plants follows the ge...

  11. Nelson Mandela's defence: A psychological capital documentary analysis

    Directory of Open Access Journals (Sweden)

    Rene van Wyk

    2014-11-01

    Full Text Available This qualitative documentary analysis examines Nelson Mandela�s defence statement at the Rivonia Trial, Pretoria Supreme Court, on 20 April 1964. The defence document is analysed through the psychological capital lens, depicting themes that support the constructs of hope, efficacy, resilience and optimism. Psychological capital characteristics played a major role in the initial non-violent policies of negotiation. The inevitable establishment of Umkhonto we Sizwe followed, as a result of the increased restrictions and unwillingness of government to negotiate and collaborate. Mandela showed a determined spirit to unite the country. The discussion gives insight into Mandela�s authentic psychological capital leadership under difficult political and personal circumstances. Some implications are indicated in adopting Mandela�s psychological characteristics for personal reform.

  12. NATO Guide for Judgement-Based Operational Analysis in Defence Decision Making : Executive Leaflet

    NARCIS (Netherlands)

    Wijnmalen, D.J.D.; et al

    2012-01-01

    Judgment plays an important role in all Operational Analysis (OA). NATO practitioners have determined that approaches in OA that are based on human judgement are increasingly critical to defence decision making. The purpose of the NATO Guide for Judgement-Based OA in Defence Decision Making is to

  13. Computational intelligence methods for the efficient reliability analysis of complex flood defence structures

    NARCIS (Netherlands)

    Kingston, Greer B.; Rajabali Nejad, Mohammadreza; Gouldby, Ben P.; van Gelder, Pieter H.A.J.M.

    2011-01-01

    With the continual rise of sea levels and deterioration of flood defence structures over time, it is no longer appropriate to define a design level of flood protection, but rather, it is necessary to estimate the reliability of flood defences under varying and uncertain conditions. For complex

  14. Exogenous ascorbic acid improves defence responses of sunflower (Helianthus annuus) exposed to multiple stresses.

    Science.gov (United States)

    Kaya, Armagan

    2017-09-01

    Ascorbic acid is an important antioxidant that plays role both on growth and development and also stress response of the plant. The purpose of this study was to determine the effect of ascorbate on physiological and biochemical changes of sunflower that was exposed to multiple stresses. Chlorophyll and carotenoid contents decreased and glutathione, ascorbate and malondialdehyde contents as well as antioxidant enzyme activities increased for sunflower plant that was exposed to 50 mM NaCl and pendimethalin at different concentrations. These changes were found to be more significant in groups simultaneously exposed to both stress factors. While malondialdehyde content decreased, chlorophyll, carotenoid, ascorbate, glutathione contents and antioxidant enzyme activities increased in plants treated exogenously with ascorbate, compared to the untreated samples. According to the findings of our study; compared to individual stress, the effect of stress is more pronounced in sunflower exposed to multiple stresses, and treatment with exogenous ascorbate reduces the negative effects of stress.

  15. The Effectiveness, Costs and Coastal Protection Benefits of Natural and Nature-Based Defences.

    Science.gov (United States)

    Narayan, Siddharth; Beck, Michael W; Reguero, Borja G; Losada, Iñigo J; van Wesenbeeck, Bregje; Pontee, Nigel; Sanchirico, James N; Ingram, Jane Carter; Lange, Glenn-Marie; Burks-Copes, Kelly A

    2016-01-01

    There is great interest in the restoration and conservation of coastal habitats for protection from flooding and erosion. This is evidenced by the growing number of analyses and reviews of the effectiveness of habitats as natural defences and increasing funding world-wide for nature-based defences-i.e. restoration projects aimed at coastal protection; yet, there is no synthetic information on what kinds of projects are effective and cost effective for this purpose. This paper addresses two issues critical for designing restoration projects for coastal protection: (i) a synthesis of the costs and benefits of projects designed for coastal protection (nature-based defences) and (ii) analyses of the effectiveness of coastal habitats (natural defences) in reducing wave heights and the biophysical parameters that influence this effectiveness. We (i) analyse data from sixty-nine field measurements in coastal habitats globally and examine measures of effectiveness of mangroves, salt-marshes, coral reefs and seagrass/kelp beds for wave height reduction; (ii) synthesise the costs and coastal protection benefits of fifty-two nature-based defence projects and; (iii) estimate the benefits of each restoration project by combining information on restoration costs with data from nearby field measurements. The analyses of field measurements show that coastal habitats have significant potential for reducing wave heights that varies by habitat and site. In general, coral reefs and salt-marshes have the highest overall potential. Habitat effectiveness is influenced by: a) the ratios of wave height-to-water depth and habitat width-to-wavelength in coral reefs; and b) the ratio of vegetation height-to-water depth in salt-marshes. The comparison of costs of nature-based defence projects and engineering structures show that salt-marshes and mangroves can be two to five times cheaper than a submerged breakwater for wave heights up to half a metre and, within their limits, become more cost

  16. The Effectiveness, Costs and Coastal Protection Benefits of Natural and Nature-Based Defences.

    Directory of Open Access Journals (Sweden)

    Siddharth Narayan

    Full Text Available There is great interest in the restoration and conservation of coastal habitats for protection from flooding and erosion. This is evidenced by the growing number of analyses and reviews of the effectiveness of habitats as natural defences and increasing funding world-wide for nature-based defences-i.e. restoration projects aimed at coastal protection; yet, there is no synthetic information on what kinds of projects are effective and cost effective for this purpose. This paper addresses two issues critical for designing restoration projects for coastal protection: (i a synthesis of the costs and benefits of projects designed for coastal protection (nature-based defences and (ii analyses of the effectiveness of coastal habitats (natural defences in reducing wave heights and the biophysical parameters that influence this effectiveness. We (i analyse data from sixty-nine field measurements in coastal habitats globally and examine measures of effectiveness of mangroves, salt-marshes, coral reefs and seagrass/kelp beds for wave height reduction; (ii synthesise the costs and coastal protection benefits of fifty-two nature-based defence projects and; (iii estimate the benefits of each restoration project by combining information on restoration costs with data from nearby field measurements. The analyses of field measurements show that coastal habitats have significant potential for reducing wave heights that varies by habitat and site. In general, coral reefs and salt-marshes have the highest overall potential. Habitat effectiveness is influenced by: a the ratios of wave height-to-water depth and habitat width-to-wavelength in coral reefs; and b the ratio of vegetation height-to-water depth in salt-marshes. The comparison of costs of nature-based defence projects and engineering structures show that salt-marshes and mangroves can be two to five times cheaper than a submerged breakwater for wave heights up to half a metre and, within their limits, become

  17. Communal range defence in primates as a public goods dilemma.

    Science.gov (United States)

    Willems, Erik P; Arseneau, T Jean M; Schleuning, Xenia; van Schaik, Carel P

    2015-12-05

    Classic socio-ecological theory holds that the occurrence of aggressive range defence is primarily driven by ecological incentives, most notably by the economic defendability of an area or the resources it contains. While this ecological cost-benefit framework has great explanatory power in solitary or pair-living species, comparative work on group-living primates has always found economic defendability to be a necessary, but not sufficient condition to account for the distribution of effective range defence across the taxon. This mismatch between theory and observation has recently been ascribed to a collective action problem among group members in, what is more informatively viewed as, a public goods dilemma: mounting effective defence of a communal range against intrusions by outgroup conspecifics. We here further develop this framework, and report on analyses at three levels of biological organization: across species, across populations within a single lineage and across groups and individuals within a single population. We find that communal range defence in primates very rarely involves collective action sensu stricto and that it is best interpreted as the outcome of opportunistic and strategic individual-level decisions. Whether the public good of a defended communal range is produced by solitary, joint or collective action is thus the outcome of the interplay between the unique characteristics of each individual, local and current socio-ecological conditions, and fundamental life-history traits of the species. © 2015 The Author(s).

  18. 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.

  19. In-plant considerations for optimal offsite response to reactor accidents

    International Nuclear Information System (INIS)

    Burke, R.P.; Heising, C.D.; Aldrich, D.C.

    1982-11-01

    Offsite response decision-making methods based on in-plant conditions are developed for use during severe reactor-accident situations. Dose projections are used to eliminate all LWR plant systems except the reactor core and the spent-fuel storage pool from consideration for immediate offsite emergency response during accident situations. A simple plant information-management scheme is developed for use in offsite response decision-making. Detailed consequence calculations performed with the CRAC2 model are used to determine the appropriate timing of offsite-response implementation for a range of PWR accidents involving the reactor core. In-plant decision criteria for offsite-response implementation are defined. The definition of decision criteria is based on consideration of core-accident physical processes, in-plant accident monitoring information, and results of consequence calculations performed to determine the effectiveness of various public-protective measures. The benefits and negative aspects of the proposed response-implementation criteria are detailed

  20. Defence nuclear waste disposal in Russia. International perspective

    International Nuclear Information System (INIS)

    Stenhouse, M.J.; Kirko, V.I.

    1998-01-01

    Significant amounts of liquid and solid radioactive waste have been generated in Russia during the production of nuclear weapons, and there is an urgent need to find suitable ways to manage these wastes in a way that protects both the current population and future generations. This book contains contributions from pure and applied scientists and other representatives from Europe, North America, and Russia, who are, or have been, actively involved in the field of radioactive waste management and disposal. First-hand experience of specific problems associated with defence-related wastes in the USA and the Russian Federation is presented, and current plans are described for the disposal of solid wastes arising from civilian nuclear power production programmes in other countries, including Belgium, Bulgaria, Canada, Germany and the UK. The book provides a good insight into ongoing research at local and national level within Russia, devoted to the safe disposal of defence-related radioactive waste. It also demonstrates how existing expertise and technology from civilian nuclear waste management programmes can be applied to solving the problems created by nuclear defence programmes. Contributions address methods of immobilisation, site selection methodology, site characterisation techniques and data interpretation, the key elements of safety/performance assessments of planned deep (geological) repositories for radioactive waste, and radionuclide transport modelling. Concerns associated with certain specific nuclear waste disposal concepts and repository sites are also presented. refs

  1. Establishment of chronic hepatitis C virus infection: Translational evasion of oxidative defence

    Science.gov (United States)

    Chan, Shiu-Wan

    2014-01-01

    Hepatitis C virus (HCV) causes a clinically important disease affecting 3% of the world population. HCV is a single-stranded, positive-sense RNA virus belonging to the genus Hepacivirus within the Flaviviridae family. The virus establishes a chronic infection in the face of an active host oxidative defence, thus adaptation to oxidative stress is key to virus survival. Being a small RNA virus with a limited genomic capacity, we speculate that HCV deploys a different strategy to evade host oxidative defence. Instead of counteracting oxidative stress, it utilizes oxidative stress to facilitate its own survival. Translation is the first step in the replication of a plus strand RNA virus so it would make sense if the virus can exploit the host oxidative defence in facilitating this very first step. This is particularly true when HCV utilizes an internal ribosome entry site element in translation, which is distinctive from that of cap-dependent translation of the vast majority of cellular genes, thus allowing selective translation of genes under conditions when global protein synthesis is compromised. Indeed, we were the first to show that HCV translation was stimulated by an important pro-oxidant-hydrogen peroxide in hepatocytes, suggesting that HCV is able to adapt to and utilize the host anti-viral response to facilitate its own translation thus allowing the virus to thrive under oxidative stress condition to establish chronicity. Understanding how HCV translation is regulated under oxidative stress condition will advance our knowledge on how HCV establishes chronicity. As chronicity is the initiator step in disease progression this will eventually lead to a better understanding of pathogenicity, which is particularly relevant to the development of anti-virals and improved treatments of HCV patients using anti-oxidants. PMID:24659872

  2. Establishment of chronic hepatitis C virus infection: translational evasion of oxidative defence.

    Science.gov (United States)

    Chan, Shiu-Wan

    2014-03-21

    Hepatitis C virus (HCV) causes a clinically important disease affecting 3% of the world population. HCV is a single-stranded, positive-sense RNA virus belonging to the genus Hepacivirus within the Flaviviridae family. The virus establishes a chronic infection in the face of an active host oxidative defence, thus adaptation to oxidative stress is key to virus survival. Being a small RNA virus with a limited genomic capacity, we speculate that HCV deploys a different strategy to evade host oxidative defence. Instead of counteracting oxidative stress, it utilizes oxidative stress to facilitate its own survival. Translation is the first step in the replication of a plus strand RNA virus so it would make sense if the virus can exploit the host oxidative defence in facilitating this very first step. This is particularly true when HCV utilizes an internal ribosome entry site element in translation, which is distinctive from that of cap-dependent translation of the vast majority of cellular genes, thus allowing selective translation of genes under conditions when global protein synthesis is compromised. Indeed, we were the first to show that HCV translation was stimulated by an important pro-oxidant-hydrogen peroxide in hepatocytes, suggesting that HCV is able to adapt to and utilize the host anti-viral response to facilitate its own translation thus allowing the virus to thrive under oxidative stress condition to establish chronicity. Understanding how HCV translation is regulated under oxidative stress condition will advance our knowledge on how HCV establishes chronicity. As chronicity is the initiator step in disease progression this will eventually lead to a better understanding of pathogenicity, which is particularly relevant to the development of anti-virals and improved treatments of HCV patients using anti-oxidants.

  3. Higher Plants in Space: Microgravity Perception, Response, and Adaptation

    Science.gov (United States)

    Zheng, Hui Qiong; Han, Fei; Le, Jie

    2015-11-01

    Microgravity is a major abiotic stress in space. Its effects on plants may depend on the duration of exposure. We focused on two different phases of microgravity responses in space. When higher plants are exposed to short-term (seconds to hours) microgravity, such as on board parabolic flights and sounding rockets, their cells usually exhibit abiotic stress responses. For example, Ca 2+-, lipid-, and pH-signaling are rapidly enhanced, then the production of reactive oxygen species and other radicals increase dramatically along with changes in metabolism and auxin signaling. Under long-term (days to months) microgravity exposure, plants acclimatize to the stress by changing their metabolism and oxidative response and by enhancing other tropic responses. We conclude by suggesting that a systematic analysis of regulatory networks at the molecular level of higher plants is needed to understand the molecular signals in the distinct phases of the microgravity response and adaptation.

  4. Defence Chemistry Modulation by Light and Temperature Shifts and the Resulting Effects on Associated Epibacteria of Fucus vesiculosus

    Science.gov (United States)

    Saha, Mahasweta; Rempt, Martin; Stratil, Stephanie B.; Wahl, Martin; Pohnert, Georg; Weinberger, Florian

    2014-01-01

    The goals of this study were (1) to investigate whether Fucus vesiculosus regulates the production of its antifouling defence chemicals against epibacteria in response to light limitation and temperature shifts and (2) to investigate if different surface concentrations of defence compounds shape epibacterial communities. F. vesiculosus was incubated in indoor mesocosms at five different temperature conditions (5 to 25°C) and in outdoor mesocosms under six differently reduced sunlight conditions (0 to 100%), respectively. Algal surface concentrations of previously identified antifouling compounds - dimethylsulphopropionate (DMSP), fucoxanthin and proline – were determined and the bacterial community composition was characterized by in-depth sequencing of the 16S-rRNA gene. Altogether, the effect of different treatment levels upon defence compound concentrations was limited. Under all conditions DMSP alone appeared to be sufficiently concentrated to warrant for at least a partial inhibitory action against epibiotic bacteria of F. vesiculosus. In contrast, proline and fucoxanthin rarely reached the necessary concentration ranges for self-contained inhibition. Nonetheless, in both experiments along with the direct influence of temperature and light, all three compounds apparently affected the overall bacterial community composition associated with F. vesiculosus since tendencies for insensitivity towards all three compounds were observed among bacterial taxa that typically dominate those communities. Given that the concentrations of at least one of the compounds (in most cases DMSP) were always high enough to inhibit bacterial settlement, we conclude that the capacity of F. vesiculosus for such defence will hardly be compromised by shading or warming to temperatures up to 25°C. PMID:25360717

  5. Defence chemistry modulation by light and temperature shifts and the resulting effects on associated epibacteria of Fucus vesiculosus.

    Science.gov (United States)

    Saha, Mahasweta; Rempt, Martin; Stratil, Stephanie B; Wahl, Martin; Pohnert, Georg; Weinberger, Florian

    2014-01-01

    The goals of this study were (1) to investigate whether Fucus vesiculosus regulates the production of its antifouling defence chemicals against epibacteria in response to light limitation and temperature shifts and (2) to investigate if different surface concentrations of defence compounds shape epibacterial communities. F. vesiculosus was incubated in indoor mesocosms at five different temperature conditions (5 to 25°C) and in outdoor mesocosms under six differently reduced sunlight conditions (0 to 100%), respectively. Algal surface concentrations of previously identified antifouling compounds--dimethylsulphopropionate (DMSP), fucoxanthin and proline--were determined and the bacterial community composition was characterized by in-depth sequencing of the 16S-rRNA gene. Altogether, the effect of different treatment levels upon defence compound concentrations was limited. Under all conditions DMSP alone appeared to be sufficiently concentrated to warrant for at least a partial inhibitory action against epibiotic bacteria of F. vesiculosus. In contrast, proline and fucoxanthin rarely reached the necessary concentration ranges for self-contained inhibition. Nonetheless, in both experiments along with the direct influence of temperature and light, all three compounds apparently affected the overall bacterial community composition associated with F. vesiculosus since tendencies for insensitivity towards all three compounds were observed among bacterial taxa that typically dominate those communities. Given that the concentrations of at least one of the compounds (in most cases DMSP) were always high enough to inhibit bacterial settlement, we conclude that the capacity of F. vesiculosus for such defence will hardly be compromised by shading or warming to temperatures up to 25°C.

  6. Defence chemistry modulation by light and temperature shifts and the resulting effects on associated epibacteria of Fucus vesiculosus.

    Directory of Open Access Journals (Sweden)

    Mahasweta Saha

    Full Text Available The goals of this study were (1 to investigate whether Fucus vesiculosus regulates the production of its antifouling defence chemicals against epibacteria in response to light limitation and temperature shifts and (2 to investigate if different surface concentrations of defence compounds shape epibacterial communities. F. vesiculosus was incubated in indoor mesocosms at five different temperature conditions (5 to 25°C and in outdoor mesocosms under six differently reduced sunlight conditions (0 to 100%, respectively. Algal surface concentrations of previously identified antifouling compounds--dimethylsulphopropionate (DMSP, fucoxanthin and proline--were determined and the bacterial community composition was characterized by in-depth sequencing of the 16S-rRNA gene. Altogether, the effect of different treatment levels upon defence compound concentrations was limited. Under all conditions DMSP alone appeared to be sufficiently concentrated to warrant for at least a partial inhibitory action against epibiotic bacteria of F. vesiculosus. In contrast, proline and fucoxanthin rarely reached the necessary concentration ranges for self-contained inhibition. Nonetheless, in both experiments along with the direct influence of temperature and light, all three compounds apparently affected the overall bacterial community composition associated with F. vesiculosus since tendencies for insensitivity towards all three compounds were observed among bacterial taxa that typically dominate those communities. Given that the concentrations of at least one of the compounds (in most cases DMSP were always high enough to inhibit bacterial settlement, we conclude that the capacity of F. vesiculosus for such defence will hardly be compromised by shading or warming to temperatures up to 25°C.

  7. Rapid and dynamic subcellular reorganization following mechanical stimulation of Arabidopsis epidermal cells mimics responses to fungal and oomycete attack

    Directory of Open Access Journals (Sweden)

    Takemoto Daigo

    2008-06-01

    Full Text Available Abstract Background Plant cells respond to the presence of potential fungal or oomycete pathogens by mounting a basal defence response that involves aggregation of cytoplasm, reorganization of cytoskeletal, endomembrane and other cell components and development of cell wall appositions beneath the infection site. This response is induced by non-adapted, avirulent and virulent pathogens alike, and in the majority of cases achieves penetration resistance against the microorganism on the plant surface. To explore the nature of signals that trigger this subcellular response and to determine the timing of its induction, we have monitored the reorganization of GFP-tagged actin, microtubules, endoplasmic reticulum (ER and peroxisomes in Arabidopsis plants – after touching the epidermal surface with a microneedle. Results Within 3 to 5 minutes of touching the surface of Arabidopsis cotyledon epidermal cells with fine glass or tungsten needles, actin microfilaments, ER and peroxisomes began to accumulate beneath the point of contact with the needle. Formation of a dense patch of actin was followed by focusing of actin cables on the site of contact. Touching the cell surface induced localized depolymerization of microtubules to form a microtubule-depleted zone surrounding a dense patch of GFP-tubulin beneath the needle tip. The concentration of actin, GFP-tubulin, ER and peroxisomes remained focused on the contact site as the needle moved across the cell surface and quickly dispersed when the needle was removed. Conclusion Our results show that plant cells can detect the gentle pressure of a microneedle on the epidermal cell surface and respond by reorganizing subcellular components in a manner similar to that induced during attack by potential fungal or oomycete pathogens. The results of our study indicate that during plant-pathogen interactions, the basal defence response may be induced by the plant's perception of the physical force exerted by the

  8. Plant Nucleolar Stress Response, a New Face in the NAC-Dependent Cellular Stress Responses

    Directory of Open Access Journals (Sweden)

    Iwai Ohbayashi

    2018-01-01

    Full Text Available The nucleolus is the most prominent nuclear domain, where the core processes of ribosome biogenesis occur vigorously. All these processes are finely orchestrated by many nucleolar factors to build precisely ribosome particles. In animal cells, perturbations of ribosome biogenesis, mostly accompanied by structural disorders of the nucleolus, cause a kind of cellular stress to induce cell cycle arrest, senescence, or apoptosis, which is called nucleolar stress response. The best-characterized pathway of this stress response involves p53 and MDM2 as key players. p53 is a crucial transcription factor that functions in response to not only nucleolar stress but also other cellular stresses such as DNA damage stress. These cellular stresses release p53 from the inhibition by MDM2, an E3 ubiquitin ligase targeting p53, in various ways, which leads to p53-dependent activation of a set of genes. In plants, genetic impairments of ribosome biogenesis factors or ribosome components have been shown to cause characteristic phenotypes, including a narrow and pointed leaf shape, implying a common signaling pathway connecting ribosomal perturbations and certain aspects of growth and development. Unlike animals, however, plants have neither p53 nor MDM2 family proteins. Then the question arises whether plant cells have a nucleolar stress response pathway. In recent years, it has been reported that several members of the plant-specific transcription factor family NAC play critical roles in the pathways responsive to various cellular stresses. In this mini review, we outline the plant cellular stress response pathways involving NAC transcription factors with reference to the p53-MDM2-dependent pathways of animal cells, and discuss the possible involvement of a plant-unique, NAC-mediated pathway in the nucleolar stress response in plants.

  9. Plant Nucleolar Stress Response, a New Face in the NAC-Dependent Cellular Stress Responses.

    Science.gov (United States)

    Ohbayashi, Iwai; Sugiyama, Munetaka

    2017-01-01

    The nucleolus is the most prominent nuclear domain, where the core processes of ribosome biogenesis occur vigorously. All these processes are finely orchestrated by many nucleolar factors to build precisely ribosome particles. In animal cells, perturbations of ribosome biogenesis, mostly accompanied by structural disorders of the nucleolus, cause a kind of cellular stress to induce cell cycle arrest, senescence, or apoptosis, which is called nucleolar stress response. The best-characterized pathway of this stress response involves p53 and MDM2 as key players. p53 is a crucial transcription factor that functions in response to not only nucleolar stress but also other cellular stresses such as DNA damage stress. These cellular stresses release p53 from the inhibition by MDM2, an E3 ubiquitin ligase targeting p53, in various ways, which leads to p53-dependent activation of a set of genes. In plants, genetic impairments of ribosome biogenesis factors or ribosome components have been shown to cause characteristic phenotypes, including a narrow and pointed leaf shape, implying a common signaling pathway connecting ribosomal perturbations and certain aspects of growth and development. Unlike animals, however, plants have neither p53 nor MDM2 family proteins. Then the question arises whether plant cells have a nucleolar stress response pathway. In recent years, it has been reported that several members of the plant-specific transcription factor family NAC play critical roles in the pathways responsive to various cellular stresses. In this mini review, we outline the plant cellular stress response pathways involving NAC transcription factors with reference to the p53-MDM2-dependent pathways of animal cells, and discuss the possible involvement of a plant-unique, NAC-mediated pathway in the nucleolar stress response in plants.

  10. Audit of annual medical appraisal and revalidation activity across the UK Defence Medical Services 2013-2014.

    Science.gov (United States)

    Morris, Louisa E; Withnall, Rdj

    2017-02-01

    To provide the first annual audit of Defence Medical Services (DMS) medical appraisal and revalidation activity. A questionnaire-based survey of appraisal and revalidation activity within the 2013-2014 appraisal year (1 April 2013 - 1 March 2014) across the Royal Navy (RN), Army, Royal Air Force (RAF) and Ministry of Defence (MOD) and Defence Postgraduate Medical Deanery (DPMD) Designated Bodies (DBs). Mandatory annual medical appraisal of all DMS doctors was introduced in 2002. The General Medical Council (GMC) introduced licences to practise in November 2011. Revalidation went live in December 2012. In the 2013-2014 appraisal year, there were 1379 DMS doctors. The Responsible Officers (ROs) of the RN, Army, RAF, MOD and Defence Postgraduate Medical Deanery (DPMD) provide appraisal and revalidation services for doctors within their DBs. In the 2013-2014 appraisal year, 82% of DMS doctors completed an annual appraisal. ROs provided positive revalidation recommendations for 90% of DMS doctors without the need for additional supporting information. Additional supporting evidence was required for 10% of DMS trained doctors, but ultimately 100% of DMS doctors due revalidation in the 2013-2014 appraisal year received a positive recommendation. To assist DMS compliance with GMC quality assurance requirements, HQ Surgeon General now maintains a central database of appraisal and revalidation data across the five DMS DBs. Appropriately targeted appraiser training and 'revalidation ready top-up' training should be provided to ensure the demand for military appraisers is met, and that DMS appraisers appropriately maintain their skills. MOD now maintains a central live database for ongoing appraisal and revalidation monitoring. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  11. The association between self-image and defence mechanisms in a group of adolescent patients receiving psychiatric treatment.

    Science.gov (United States)

    Treger, Bartosz; Matusiak, Feliks; Pilecki, Maciej; Rogoż, Monika

    2015-01-01

    The aim of the study was to explore the relationship between various areas of self-image and defence mechanisms in adolescents. The study included a division into groups according to whether or not they were receiving psychiatric treatment. Data were obtained from two groups: a clinical group (30 persons), consisting of adolescent patients of the Adolescent Inpatient Ward of the Child and Adolescent Psychiatry Clinic and a control group (40 persons), adolescents attending upper secondary school. The Defence Style Questionnaire DSQ-40 and the Offer Self Image Questionnaire were used in the study. Results showed no differences, in the maturity levels of the defence mechanisms, between the two groups. Subjects from the clinical group had a significantly lower self-image of themselves than subjects from the control group.. In both groups, the use of mature defence mechanisms was accompanied by a positive self-image, while the use of less mature defence mechanisms was associated with a lower self-image. Comparison of the groups revealed different relationships between the aspects of self-image and used defence mechanisms, in particular the mechanism of projection. Number of significant correlations was greater in the clinical group. In the context of lower self-image, the study revealed the importance of such defence mechanisms as projection, acting out, somatization or schizoid fantasies. The obtained results seem to confirm a hypothesis that the assessment of the maturity of defence mechanisms in the period of adolescence is less clear and clinically useful.

  12. Implementation of Defence in Depth at Nuclear Power Plants. Lessons Learnt from the Fukushima Daiichi Accident

    International Nuclear Information System (INIS)

    Lachaume, Jean-Luc; Miller, Douglass; Rzentkowski, Greg; Lahtinen, Nina; Valtonen, Keijo; Foucher, Laurent; Harikumar, Shri S.; Yamada, Tomoho; Sharafutdinov, Rashet; Kuznetsov, Mark; Carlsson, Lennart; Hanberg, Jan; Theiss, Klaus; Holahan, Gary; Williams, Donna; Nuenighoff, Kay; Wattelle, Emmanuel; Lazo, Edward; White, Andrew; Reig, Javier; Salgado, Nancy; Weightman, Mike

    2016-01-01

    Defence in depth (DiD) is a concept that has been used for many years alongside tools to optimise nuclear safety in reactor design, assessment and regulation. The 2011 Fukushima Daiichi nuclear power plant accident raised many questions and gave unique insight into nuclear safety issues, including DiD. In June 2013, the NEA held a Joint Workshop on Challenges and Enhancements to DiD in Light of the Fukushima Daiichi Accident (NEA, 2014), organised by the NEA Committee on the Safety of Nuclear Installations (CSNI) and the NEA Committee on Nuclear Regulatory Activities (CNRA). It was noted at the time that further work would be beneficial to enhance nuclear safety worldwide, especially with regard to the implementation of DiD. Accordingly, a senior-level task group (STG) was set up to produce a regulatory guidance booklet that would assist member countries in the use of DiD, taking into account lessons learnt from the 2011 accident. This regulatory guidance booklet builds on the work of this NEA workshop, of the International Atomic Energy Agency (IAEA), the Western European Nuclear Regulators Association (WENRA) and of other members of the STG. It uses as its basis the International Nuclear Safety Advisory Group's Defence in Depth in Nuclear Safety study (INSAG-10) (IAEA, 1996). The booklet provides insights into the implementation of DiD by regulators and emergency management authorities after the Fukushima Daiichi accident, aiming to enhance global harmonisation by providing guidance on: - the background to the DiD concept; - the need for independent effectiveness among the safety provisions for the various DiD levels, to the extent practicable; - the need for greater attention to reinforce prevention and mitigation at the various levels; - the vital importance of ensuring that common cause and common mode failures, especially external events acting in combination, do not lead to breaches of safety provisions at several DiD levels, taking note of the

  13. Drought and flooding have distinct effects on herbivore-induced responses and resistance in Solanum dulcamara.

    Science.gov (United States)

    Nguyen, Duy; D'Agostino, Nunzio; Tytgat, Tom O G; Sun, Pulu; Lortzing, Tobias; Visser, Eric J W; Cristescu, Simona M; Steppuhn, Anke; Mariani, Celestina; van Dam, Nicole M; Rieu, Ivo

    2016-07-01

    In the field, biotic and abiotic stresses frequently co-occur. As a consequence, common molecular signalling pathways governing adaptive responses to individual stresses can interact, resulting in compromised phenotypes. How plant signalling pathways interact under combined stresses is poorly understood. To assess this, we studied the consequence of drought and soil flooding on resistance of Solanum dulcamara to Spodoptera exigua and their effects on hormonal and transcriptomic profiles. The results showed that S. exigua larvae performed less well on drought-stressed plants than on well-watered and flooded plants. Both drought and insect feeding increased abscisic acid and jasmonic acid (JA) levels, whereas flooding did not induce JA accumulation. RNA sequencing analyses corroborated this pattern: drought and herbivory induced many biological processes that were repressed by flooding. When applied in combination, drought and herbivory had an additive effect on specific processes involved in secondary metabolism and defence responses, including protease inhibitor activity. In conclusion, drought and flooding have distinct effects on herbivore-induced responses and resistance. Especially, the interaction between abscisic acid and JA signalling may be important to optimize plant responses to combined drought and insect herbivory, making drought-stressed plants more resistant to insects than well-watered and flooded plants. © 2016 John Wiley & Sons Ltd.

  14. Variation in maternal solitary bee nest defence related to nest state

    OpenAIRE

    Peterson , Jason H.; Hoffmeister , Thomas S.; Roitberg , Bernard D.

    2016-01-01

    International audience; AbstractParental protection of offspring is found in numerous animal species. Protection provides offspring with a greater chance of surviving to be able to reproduce, while at the same time, often posing a cost to the parent. Therefore, the net value of defence for the parent can vary depending on the developmental stage of the offspring and their ability to defend themselves. For example, in commonly studied organisms (e.g. birds), defence level increases over time u...

  15. The role of chloroplasts in plant pathology.

    Science.gov (United States)

    Sowden, Robert G; Watson, Samuel J; Jarvis, Paul

    2018-04-13

    Plants have evolved complex tolerance systems to survive abiotic and biotic stresses. Central to these programmes is a sophisticated conversation of signals between the chloroplast and the nucleus. In this review, we examine the antagonism between abiotic stress tolerance (AST) and immunity: we propose that to generate immunogenic signals, plants must disable AST systems, in particular those that manage reactive oxygen species (ROS), while the pathogen seeks to reactivate or enhance those systems to achieve virulence. By boosting host systems of AST, pathogens trick the plant into suppressing chloroplast immunogenic signals and steer the host into making an inappropriate immune response. Pathogens disrupt chloroplast function, both transcriptionally-by secreting effectors that alter host gene expression by interacting with defence-related kinase cascades, with transcription factors, or with promoters themselves-and post-transcriptionally, by delivering effectors that enter the chloroplast or alter the localization of host proteins to change chloroplast activities. These mechanisms reconfigure the chloroplast proteome and chloroplast-originating immunogenic signals in order to promote infection. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  16. From Defence to Development: Redirecting Military Resources in ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Book cover From Defence to Development: Redirecting Military Resources in ... of the IDRC-funded project "Militarization and the Ecology of Southern Africa." ... Congratulations to the first cohort of Women in Climate Change Science Fellows!

  17. Radiation accidents and defence of population

    International Nuclear Information System (INIS)

    Memmedov, A.M.

    2002-01-01

    Full text: Development of nuclear physics, the fundamental and the applied researches in the field of radioactive insured wide possibility for application of radionuclides and ionizing radiation source in the different fields of national economy. Application of radionuclides in chemical, metallurgical, food industry, in agriculture and etc. Fields provide a large economic profit. It's hard to apprise significance of ionizing radiation source using in medicine for diagnostics and treatment of different disease. Nuclear power engineering and nuclear industry are developing intensively. At same time nuclear power, ionizing radiation sources incur potential treat for surroundings and health of population. As even that stage of protective measure development: there is no possibility of that happening of radiation accidents. A radiation accident qualifies as loss of ionizing radiation sources direction, which provoked by disrepair equipment, natural calamity or other causes which could bring to unplanned irradiation of population or radioactive pollution of surroundings. At present some following typical cases connected with radiation accident have been chosen: Contentious using or keeping of ionizing radiation source with breach of established requires; Loss, theft of ionizing radiation sources or radiation plants, instruments; Leaving the sources of ionizing radiation in the holes; Refusal radiation technic exploited in industry, medicine, SRI and etc; Disrepair in nuclear transport means of conveyance; Crashes and accidents at NPP and at other enterprises of nuclear industry. The radiation accidents according to character, degree and scales have been divided into two groups: Radiation accidents not connected with NPP; Accidents in the nuclear engineering and industry; The radiation accidents not connected with NPP according their consequence divide into 5 groups; accidents which do not come to irradiation of personal, persons from population (more PN-permissible norm

  18. Methyl salicylate production in tomato affects biotic interactions.

    Science.gov (United States)

    Ament, Kai; Krasikov, Vladimir; Allmann, Silke; Rep, Martijn; Takken, Frank L W; Schuurink, Robert C

    2010-04-01

    The role of methyl salicylate (MeSA) production was studied in indirect and direct defence responses of tomato (Solanum lycopersicum) to the spider mite Tetranychus urticae and the root-invading fungus Fusarium oxysporum f. sp. lycopersici, respectively. To this end, we silenced the tomato gene encoding salicylic acid methyl transferase (SAMT). Silencing of SAMT led to a major reduction in SAMT expression and MeSA emission upon herbivory by spider mites, without affecting the induced emission of other volatiles (terpenoids). The predatory mite Phytoseiulus persimilis, which preys on T. urticae, could not discriminate between infested and non-infested SAMT-silenced lines, as it could for wild-type tomato plants. Moreover, when given the choice between infested SAMT-silenced and infested wild-type plants, they preferred the latter. These findings are supportive of a major role for MeSA in this indirect defence response of tomato. SAMT-silenced tomato plants were less susceptible to a virulent strain of F. oxysporum f. sp. lycopersici, indicating that the direct defense responses in the roots are also affected in these plants. Our studies show that the conversion of SA to MeSA can affect both direct and indirect plant defence responses.

  19. Modelling the effects of a CBRN defence system using a Bayesian Belief Model

    NARCIS (Netherlands)

    Phillipson, F.; Bastings, I.C.L.; Vink, N.

    2015-01-01

    In this paper a Bayes model to quantify the effects of a passive CBRN defence system is presented. The model gives insight in the way of the mutual influence of all the elements of passive CBRN defence, by the use of detailed scenario analysis, sensitivity analysis and root cause analysis. This can

  20. Design of reactor containment systems for nuclear power plants. Safety guide

    International Nuclear Information System (INIS)

    2008-01-01

    This Safety Guide was prepared under the IAEA programme for safety standards for nuclear power plants. It is a revision of the Safety Guide on Design of the Reactor Containment Systems in Nuclear Power Plants (Safety Series No. 50-Sg-D1) issued in 1985 and supplements the Safety Requirements publication on Safety of Nuclear Power Plants: Design. The present Safety Guide was prepared on the basis of a systematic review of the relevant publications, including the Safety of Nuclear Power Plants: Design, the Safety fundamentals publication on The Safety of Nuclear Installations, Safety Guides, INSAG Reports, a Technical Report and other publications covering the safety of nuclear power plants. 1.2. The confinement of radioactive material in a nuclear plant, including the control of discharges and the minimization of releases, is a fundamental safety function to be ensured in normal operational modes, for anticipated operational occurrences, in design basis accidents and, to the extent practicable, in selected beyond design basis accidents. In accordance with the concept of defence in depth, this fundamental safety function is achieved by means of several barriers and levels of defence. In most designs, the third and fourth levels of defence are achieved mainly by means of a strong structure enveloping the nuclear reactor. This structure is called the 'containment structure' or simply the 'containment'. This definition also applies to double wall containments. 1.3. The containment structure also protects the reactor against external events and provides radiation shielding in operational states and accident conditions. The containment structure and its associated systems with the functions of isolation, energy management, and control of radionuclides and combustible gases are referred to as the containment systems

  1. Design of reactor containment systems for nuclear power plants. Safety guide

    International Nuclear Information System (INIS)

    2004-01-01

    This Safety Guide was prepared under the IAEA programme for safety standards for nuclear power plants. It is a revision of the Safety Guide on Design of the Reactor Containment Systems in Nuclear Power Plants (Safety Series No. 50-Sg-D1) issued in 1985 and supplements the Safety Requirements publication on Safety of Nuclear Power Plants: Design. The present Safety Guide was prepared on the basis of a systematic review of the relevant publications, including the Safety of Nuclear Power Plants: Design, the Safety fundamentals publication on The Safety of Nuclear Installations, Safety Guides, INSAG Reports, a Technical Report and other publications covering the safety of nuclear power plants. 1.2. The confinement of radioactive material in a nuclear plant, including the control of discharges and the minimization of releases, is a fundamental safety function to be ensured in normal operational modes, for anticipated operational occurrences, in design basis accidents and, to the extent practicable, in selected beyond design basis accidents. In accordance with the concept of defence in depth, this fundamental safety function is achieved by means of several barriers and levels of defence. In most designs, the third and fourth levels of defence are achieved mainly by means of a strong structure enveloping the nuclear reactor. This structure is called the 'containment structure' or simply the 'containment'. This definition also applies to double wall containments. 1.3. The containment structure also protects the reactor against external events and provides radiation shielding in operational states and accident conditions. The containment structure and its associated systems with the functions of isolation, energy management, and control of radionuclides and combustible gases are referred to as the containment systems

  2. Preconscious defence analysis, memory and structural change.

    Science.gov (United States)

    Ross, John Munder

    2003-02-01

    Beginning with the ways in which the use of the couch lends 'depth to the surface' (Erikson, 1954), I explore the topography of the inter- and intrasubjective psychoanalytic situation and process. I suggest that defences are not by definition unconscious but rather can be observed operating at conscious and preconscious levels, particularly under these conditions. A focus on preconscious disavowal provides a window on what has become unconscious repression. As a result of eliciting and then verbalising the operation of such defences with regard to anxieties in the here-and-now transference, declarative memories of increasingly specific childhood fantasies and events begin to hold sway over unmanageable procedural remnants from the analysand's past. With this may even come the possibility of neuronal regeneration, the more generalisable enhancement of declarative and symbolic functions and the sense of identity with which these are associated. Herein may lie one enduring therapeutic effect of the 'talking cure' - putting feelings into words - as one among a variety of psychotherapeutic modalities.

  3. Male Rock Sparrow (Petronia petronia) Nest Defence Correlates with Female Ornament Size

    DEFF Research Database (Denmark)

    Griggio, Matteo; Matessi, Giuliano; Pilastro, Andrea

    2003-01-01

    We investigated the relationship between male nest defence and female breast patch size in an alpine population of rock sparrow (Petronia petronia) in northern Italy. We presented a mounted weasel (Mustela nivalis), a common nest predator, to 28 pairs breeding in nest boxes, with 12-13-d-old nest......We investigated the relationship between male nest defence and female breast patch size in an alpine population of rock sparrow (Petronia petronia) in northern Italy. We presented a mounted weasel (Mustela nivalis), a common nest predator, to 28 pairs breeding in nest boxes, with 12-13-d...... defence factor was significantly related only to female breast patch size. We argue that male rock sparrows apparently make parental investment decisions according to their mate's quality, and examine possible alternative hypotheses....

  4. Defence activation in strawberry and pine- Epigenetic changes in treated plants

    OpenAIRE

    Komajda, Ludwika

    2016-01-01

    Strawberry plants (Fragaria x ananassa) and Scots pine (Pinus sylvestris) represent species, withinagriculture and forestry respectively, that are traditionally protected by utilization of pesticidesincluding neurotoxic insecticides. More environmentally friendly protection strategies are thereforehighly desirable. Treating plants with specific metabolites naturally occurring in their tissues might alterepigenetic mechanisms, which in turn may strengthen plants self-defense against diseases a...

  5. Tree immunity: growing old without antibodies.

    Science.gov (United States)

    Tobias, Peri A; Guest, David I

    2014-06-01

    Perennial plants need to cope with changing environments and pathogens over their lifespan. Infections are compartmentalised by localised physiological responses, and multiple apical meristems enable repair and regrowth, but genes are another crucial component in the perception and response to pathogens. In this opinion article we suggest that the mechanism for dynamic pathogen-specific recognition in long-lived plants could be explained by extending our current understanding of plant defence genes. We propose that, in addition to physiological responses, tree defence uses a three-pronged genomic approach involving: (i) gene numbers, (ii) genomic architecture, and (iii) mutation loads accumulated over long lifespans. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Agroecology: Implications for plant response to climate change

    Science.gov (United States)

    Agricultural ecosystems (agroecosystems) represent the balance between the physiological responses of plants and plant canopies and the energy exchanges. Rising temperature and increasing CO2 coupled with an increase in variability of precipitation will create a complex set of interactions on plant ...

  7. Are bacteriophage defence and virulence two sides of the same coin in Campylobacter jejuni?

    NARCIS (Netherlands)

    R.P.L. Louwen (Rogier); P. van Baarlen (Peter)

    2013-01-01

    textabstractThe continuous battle for survival in the environment has led to the development or acquisition of sophisticated defence systems in bacteria. These defence systems have contributed to the survival of the bacterial species in the environment for millions of years. Some systems appear to

  8. Responses and damages during long-term continuous irradiation in plants

    International Nuclear Information System (INIS)

    Watanabe, Yoshito

    2011-01-01

    Effects of long-term continuous irradiation are relevant to studies in radiation ecotoxicology. To investigate plants biological responses to continuous irradiation, we performed metabolome and transcriptome analysis in a model plant, arabidopsis. Comprehensive analysis of primary metabolites using capillary electrophoresis mass spectrometry revealed extensive metabolic changes at early onset of growth inhibition in plants exposed to gamma rays at the dose rate of 20 Gy/day. The changes included elevated levels of B vitamins and second metabolites, commonly responsive to many abiotic and biotic stresses. Responses at early onset of growth inhibition were also observed in the transcriptome analysis using microarray, which showed up-regulation of 55 genes in plants exposed to gamma rays at 20 Gy/day. Although about a half of the up-regulated genes were also responsive just after acute irradiation, the other half was responsive only during long-term continuous irradiation. Database analyses showed that the specifically up-regulated genes to long-term continuous irradiation included genes relating to general stress responses and protein metabolism. The results of these analyses appear to reflect plants responses to progressive radiation damages, from radiation-specific responses, which repair primary DNA damage, to more general stress responses, which maintain homoeostasis against secondary damages. (author)

  9. South Africa's Defence Industrial Participation in Perspective

    African Journals Online (AJOL)

    jvdyk

    2014-03-31

    Mar 31, 2014 ... product and improved the economy through the retention of some ... and maintaining a defence industrial base (DIB) in those countries ... by the Department of Trade and Industry (dti) that focuses primarily ... work share on the purchased equipment (co-production), ..... These upgrades are now an integral.

  10. Production of trichodiene by Trichoderma harzianum alters the perception of this biocontrol strain by plants and antagonized fungi.

    Science.gov (United States)

    Malmierca, Mónica G; McCormick, Susan P; Cardoza, Rosa E; Alexander, Nancy J; Monte, Enrique; Gutiérrez, Santiago

    2015-08-01

    Trichothecenes are phytotoxic sesquiterpenic mycotoxins that can act as virulence factors in plant diseases. Harzianum A (HA) is a non-phytotoxic trichothecene produced by Trichoderma arundinaceum. The first step in HA biosynthesis is the conversion of farnesyl diphosphate to trichodiene (TD), a volatile organic compound (VOC), catalysed by a sesquiterpene synthase encoded by the tri5 gene. Expression of tri5 in the biocontrol strain Trichoderma harzianum CECT 2413 resulted in production of TD in parallel with a reduction of ergosterol biosynthesis and an unexpected increase in the level of squalene. Transformants expressing tri5 displayed low chitinase activity and induced expression of Botrytis cinerea BOT genes, although their total antagonistic potential against phytopathogenic fungi was not reduced. VOCs released by the tri5-transformant induced expression of tomato defence genes related to salicylic acid (SA), and TD itself strongly induced the expression of SA-responsive genes and reduced the development of lateral roots. Together, these results suggest that TD acts as a signalling VOC in the interactions of Trichoderma with plants and other microorganisms by modulating the perception of this fungus to a given environment. Moreover, the TD ability to induce systemic defences indicates that complex trichothecene structures may not be necessary for inducing such responses. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  11. 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.

  12. Status of services, overexposure and QAC in TLD PMS to defence

    International Nuclear Information System (INIS)

    Rathore, A.S.; Gupta, D.K.; Samaria, H.C.; Chouhan, R.L.; Mishra, M.; Goyal, J.K.; Gautam, M.; Kalla, R.

    2008-01-01

    Individual monitoring has always played an important role in radiological protection. There is continuous development in the field of dosimetry systems and many changes have taken place in last many years. The use of radiation for peaceful purposes is increasing with advancement of technological growth in the country. Thermo luminescence dosimeters (TLDs) have emerged as one of the best alternatives for personal monitoring. Defence sector has nearly 2100 persons, who are working in various Military Hospitals, Military Colleges, DRDO Labs, Defence Ordinance factories and many others CPMFs like CISF, BSF, who are likely to receive radiation doses. Defence Laboratory, Jodhpur is providing the TLD personal monitoring service since Jan 1999 as per the guideline by B.A.R.C. to all the institutions mentioned above. This paper brings out salient features of this service in terms of facility available, procedures fulfilling the requirement of accreditation, over exposure reported, quality measures adopted and quality assurance results conducted by BARC, utility and suggestions for such type of services. (author)

  13. Phyllosticta musarum Infection-Induced Defences Suppress Anthracnose Disease Caused by Colletotrichum musae in Banana Fruits cv ‘Embul’

    Directory of Open Access Journals (Sweden)

    C. L. Abayasekara

    2013-03-01

    Full Text Available Anthracnose development by Colletotrichum musae was observed to be significantly less in the fruits of the banana cultivar ‘Embul’ (Mysore, AAB infected with Phyllosticta musarum than in fruits without such infections. Anthracnose disease originates from quiescent C. musae infections in the immature fruit. P. musarum incites minute, scattered spots, referred to as freckles, in the superficial tissues of immature banana peel which do not expand during maturation or ripening. P. musarum does not appear to have a direct suppressive effect on C. musae as conidia of C. musae germinate on both freckled and non-freckled fruit forming quiescent infections. Our investigations have shown that P. musarum infection induced several defence responses in fruit including the accumulation of five phytoalexins, upregulation of chitinase and β-1,3-glucanase, phenylalanine ammonia lyase (PAL activity and cell wall lignification. ¹H and ¹³C NMR spectral data of one purified phytoalexin compared closely with 4′-hydroxyanigorufone. Some of the P. musarum-induced defences that retained during ripening, restrict C. musae development at the ripe stage. This paper examines the potential of P. musarum-induced defences, in the control of anthracnose, the most destructive postharvest disease in banana.

  14. Plant Responses to Pathogen Attack: Small RNAs in Focus.

    Science.gov (United States)

    Islam, Waqar; Noman, Ali; Qasim, Muhammad; Wang, Liande

    2018-02-08

    Small RNAs (sRNA) are a significant group of gene expression regulators for multiple biological processes in eukaryotes. In plants, many sRNA silencing pathways produce extensive array of sRNAs with specialized roles. The evidence on record advocates for the functions of sRNAs during plant microbe interactions. Host sRNAs are reckoned as mandatory elements of plant defense. sRNAs involved in plant defense processes via different pathways include both short interfering RNA (siRNA) and microRNA (miRNA) that actively regulate immunity in response to pathogenic attack via tackling pathogen-associated molecular patterns (PAMPs) and other effectors. In response to pathogen attack, plants protect themselves with the help of sRNA-dependent immune systems. That sRNA-mediated plant defense responses play a role during infections is an established fact. However, the regulations of several sRNAs still need extensive research. In this review, we discussed the topical advancements and findings relevant to pathogen attack and plant defense mediated by sRNAs. We attempted to point out diverse sRNAs as key defenders in plant systems. It is hoped that sRNAs would be exploited as a mainstream player to achieve food security by tackling different plant diseases.

  15. NATO Guide for Judgement-Based Operational Analysis in Defence Decision Making : Client-Oriented Volume

    NARCIS (Netherlands)

    Wijnmalen, D.J.D.; et al

    2012-01-01

    Judgment plays an important role in all Operational Analysis (OA). NATO practitioners have determined that approaches in OA that are based on human judgement are increasingly critical to defence decision making. The purpose of the NATO Guide for Judgement-Based OA in Defence Decision Making is to

  16. Interactions of Salmonella with animals and plants

    Directory of Open Access Journals (Sweden)

    Agnès eWiedemann

    2015-01-01

    Full Text Available Salmonella enterica species is a Gram negative bacterium, which is responsible for a wide range of food- and water-borne diseases in both humans and animals, thereby posing a major threat to public health. Recently, there has been an increasing number of reports, linking Salmonella contaminated raw vegetables and fruit with food poisoning. Many studies have shown that an essential feature of the pathogenicity of Salmonella is its capacity to cross a number of barriers requiring invasion of a large variety of cells and that the extent of internalization may be influenced by numerous factors. However, it is poorly understood how Salmonella successfully infects hosts as diversified as animals or plants. The aim of this review is to describe the different stages required for Salmonella interaction with its hosts: (i attachment to host surfaces; (ii entry processes; (iii, multiplication; (iv suppression of host defence mechanisms ; and to point out similarities and differences between animal and plant infections.

  17. CNS Orientations, Safety Objectives and Implementation of the Defence in Depth Concept

    Energy Technology Data Exchange (ETDEWEB)

    Lacoste, A.C., E-mail: Andre-Claude.LACOSTE@asn.fr [Autorité de Sureté Nucléaire, Montrouge (France)

    2014-10-15

    Full text: The 6th Review Meeting of the Convention on Nuclear Safety (CNS) is convened in Vienna next year for two weeks from Monday March 24{sup th} to Friday April 4{sup th} 2014. The consequences and the lessons learnt from the accident that occurred at the Fukushima Daiichi nuclear power plant will be a major issue. The 2nd Extraordinary Meeting of the CNS in August 2012 was totally devoted to the Fukushima Daiichi accident. One of its main conclusions was Conclusion 17 included in the summary report which says: ''Nuclear power plants should be designed, constructed and operated with the objectives of preventing accidents and, should an accident occur, mitigating its effects and avoiding off-site contamination. The Contracting Parties also noted that regulatory authorities should ensure that these objectives are applied in order to identify and implement appropriate safety improvements at existing plants''. The wording of the sentences of Conclusion 17 dedicated, the first one to new built reactors, the second one to existing plants, can be improved and clarified. But obviously the issue of the off-site consequences of an accident is fundamental. So the in-depth question comes: what can and should be done to achieve these safety objectives? And in particular how to improve the definition and then the implementation of the Defence in Depth Concept? From my point of view, this is clearly the main issue of this Conference. (author)

  18. People's Front in Defence of Land, San Salvador Atenco: A testimony

    OpenAIRE

    Martha Pérez Pineda

    2011-01-01

    Martha Pérez Pineda gives her statement of the Peoples Front in Defence of the Land (The Peoples Front in Defence of Land (Frente del Pueblo en Defensa de la Tierra, FPDT) was formed in 2002, by residents of San Salvador Atenco, to resist their forced displacement by the federal government of Mexico and Estado de Mexico. The government planned to displace them to make way for the new Mexico City Airport. The people of San Salvador Atenco refused and battled, the most common fights were disput...

  19. Unravelling how plants benefit from ROS and NO reactions, while resisting oxidative stress.

    Science.gov (United States)

    Considine, Michael J; Sandalio, Luisa Maria; Foyer, Christine Helen

    2015-09-01

    Reactive oxygen species (ROS) and reactive nitrogen species (RNS), such as nitric oxide (NO), play crucial roles in the signal transduction pathways that regulate plant growth, development and defence responses, providing a nexus of reduction/oxidation (redox) control that impacts on nearly every aspect of plant biology. Here we summarize current knowledge and concepts that lay the foundations of a new vision for ROS/RNS functions – particularly through signalling hubs – for the next decade. Plants have mastered the art of redox control using ROS and RNS as secondary messengers to regulate a diverse range of protein functions through redox-based, post-translational modifications that act as regulators of molecular master-switches. Much current focus concerns the impact of this regulation on local and systemic signalling pathways, as well as understanding how such reactive molecules can be effectively used in the control of plant growth and stress responses. The spectre of oxidative stress still overshadows much of our current philosophy and understanding of ROS and RNS functions. While many questions remain to be addressed – for example regarding inter-organellar regulation and communication, the control of hypoxia and how ROS/RNS signalling is used in plant cells, not only to trigger acclimation responses but also to create molecular memories of stress – it is clear that ROS and RNS function as vital signals of living cells.

  20. Potassium and calcium application ameliorates growth and oxidative homeostasis in salt-stressed indian mustard (brassica juncea) plants

    International Nuclear Information System (INIS)

    Yousuf, P. Y.; Ahmad, A.; Hemant, M.; Ganie, A. H.; Iqbal, M.; Aref, I. M.

    2015-01-01

    The effect of potassium (K) and calcium (Ca) on growth and antioxidant defence system of salt-stressed Indian mustard plants was studied. Twenty-day-old Indian mustard plants grown hydroponically in Hoagland growth medium were randomly divided into five groups. To served as control and did not receive any additional K or Ca (except that present in Hoagland solution), T1 received 150 mM NaCl, T2 was given an additional doze of 6 mM K, T3 was given 5.6 mM Ca as additional doze, while as T4 received a combination of 150 mM NaCl + 6 mM K + 5.6 mM Ca. The response of the plants was studied ten days after treatment. Salt stress inhibited growth parameters including biomass, chlorophyll content, protein content and NR activity. Membrane damage was induced by the salt treatment with a concurrent increase in antioxidant defence system and proline content. Individual application of K and Ca mitigated the negative influence of the stress with the maximum alleviating potential exhibited by the combined application of these nutrients. Results obtained on real time expression of genes encoding enzymatic antioxidants (SOD, APX, CAT and GR), NR and proline supported our findings with biochemical assays. We conclude from the study that maintaining high K and Ca levels may serve as an effective means for regulating the growth and productivity of Indian mustard plants under saline conditions. (author)

  1. Transcription Factor Functional Protein-Protein Interactions in Plant Defense Responses

    Directory of Open Access Journals (Sweden)

    Murilo S. Alves

    2014-03-01

    Full Text Available Responses to biotic stress in plants lead to dramatic reprogramming of gene expression, favoring stress responses at the expense of normal cellular functions. Transcription factors are master regulators of gene expression at the transcriptional level, and controlling the activity of these factors alters the transcriptome of the plant, leading to metabolic and phenotypic changes in response to stress. The functional analysis of interactions between transcription factors and other proteins is very important for elucidating the role of these transcriptional regulators in different signaling cascades. In this review, we present an overview of protein-protein interactions for the six major families of transcription factors involved in plant defense: basic leucine zipper containing domain proteins (bZIP, amino-acid sequence WRKYGQK (WRKY, myelocytomatosis related proteins (MYC, myeloblastosis related proteins (MYB, APETALA2/ ETHYLENE-RESPONSIVE ELEMENT BINDING FACTORS (AP2/EREBP and no apical meristem (NAM, Arabidopsis transcription activation factor (ATAF, and cup-shaped cotyledon (CUC (NAC. We describe the interaction partners of these transcription factors as molecular responses during pathogen attack and the key components of signal transduction pathways that take place during plant defense responses. These interactions determine the activation or repression of response pathways and are crucial to understanding the regulatory networks that modulate plant defense responses.

  2. Experience with RTD response time testing in nuclear power plants

    International Nuclear Information System (INIS)

    Hashemian, H.M.; Kerlin, T.W.

    1985-01-01

    The reactor coolant temperatures in pressurized water reactors are measured with platinum resistance temperature detectors (RTDs). The information furnished by these RTDs is used for plant protection as well as control. As a part of the plant protection system, the RTDs must respond to temperature changes in a timely fashion. The RTD response time requirements are different for the various plant types. These requirements are specified in the plant technical specifications in terms of an RTd time constant. The current time constant requirements for nuclear plant RTDs varies from 0.5 seconds to 13.0 seconds depending on the type of the plant. Therefore, different types of RTDs are used in different plants to achieve the required time constants. In addition, in-situ response time tests are periodically performed on protective system RTDs to ensure that the in-service time constants are within acceptable limits as the plant is operating. The periodic testing is important because response time degradation may occur while the RTD ages in the process. Recent response time tests in operating plants revealed unacceptable time constants for several protection system RTDs. As a result, these plants had to be shut down to resolve the problem which in one case was due to improper installation and in another case was because of degradation of a thermal compound used in the thermowell

  3. Omnivore-herbivore interactions: thrips and whiteflies compete via the shared host plant.

    Science.gov (United States)

    Pappas, Maria L; Tavlaki, Georgia; Triantafyllou, Anneta; Broufas, George

    2018-03-05

    Phytophagy is a common feature among pure herbivorous insects and omnivores that utilise both plant and prey as food resources; nevertheless, experimental evidence for factors affecting their interactions is restricted to intraguild predation and predator-mediated competition. We herein focused on plant-mediated effects that could result from plant defence activation or quality alteration and compared the performance of an omnivore, the western flower thrips Frankliniella occidentalis, and a pure herbivore, the greenhouse whitefly Trialeurodes vaporariorum, on cucumber plants previously infested with either species. Furthermore, we recorded their behavioural responses when given a choice among infested and clean plants. Whiteflies laid less eggs on plants previously exposed to thrips but more on whitefly-infested plants. Thrips survival was negatively affected on whitefly-infested than on thrips-infested or clean plants. Notably, whiteflies developed significantly faster on plants infested with conspecifics. In accordance, whiteflies avoided thrips-infested plants and preferred whitefly-infested over clean plants. Thrips showed no preference for either infested or clean plants. Our study is a first report on the role of plant-mediated effects in shaping omnivore-herbivore interactions. Considering the factors driving such interactions we will likely better understand the ecology of the more complex relationships among plants and pest organisms.

  4. The arms race between heliconiine butterflies and Passiflora plants - new insights on an ancient subject

    DEFF Research Database (Denmark)

    Pinheiro de Castro, Érika Cristina; Zagrobelny, Mika; Cardoso, Márcio Z.

    2018-01-01

    , are morphological defences reported in this plant genus. Moreover, Passiflora plants are well protected chemically, not only by cyanogenic glucosides, but also by other compounds such as alkaloids, flavonoids, saponins, tannins and phenolics. Heliconiines can synthesize cyanogenic glucosides themselves...

  5. Plant responses to multiple herbivory

    NARCIS (Netherlands)

    Li, Yehua

    2016-01-01

    This thesis explores whether aphid-infestation interferes with the plant response to chewing herbivores and whether this impacts performance and behaviour of individual chewing insect herbivores and their natural enemies, as well as the entire insect community. I investigated this using three

  6. The Audit of Explosives Storage and Transport Within the Australian Defence Force

    Science.gov (United States)

    1994-08-01

    Headquarters Australian Defence Force Australian Ordnance Council THE AUDIT OF EXPLOSIVES STORAGE AND TRANSPORT WITHIN THE AUSTRALIAN DEFENCE FORCE...control number. 1. REPORT DATE AUG 1994 2. REPORT TYPE 3. DATES COVERED 00-00-1994 to 00-00-1994 4. TITLE AND SUBTITLE The Audit of Explosives...8-98) Prescribed by ANSI Std Z39-18 THE AUDIT OF EXPLOSIVES STORAGE AND TRANSPORT WITHIN THE AUSTRALIAN DFFENCE FORCE - by R.W. Johnson and M.J

  7. How do plants manage to survive on toxic spoil-mining sites? Physiological and structural properties of plants on substrates with high As and Hg contents

    OpenAIRE

    Kovářová, Monika

    2010-01-01

    The heavy metals contamination of environment represents a worldwide problem lately. Heavy metals cause harmful effects not only to plants, but also to other organisms. Throught their acumulation in plant biomass, heavy metals enter a food chain and could negatively influence the human health. The impact of heavy metals on plants and their defence mechanisms against toxicity of heavy metals have been in focus of plant physiology and ecology research for decades. Importance of this topic arise...

  8. South Africa's Defence Industrial Participation in Perspective

    African Journals Online (AJOL)

    jvdyk

    2014-03-31

    Mar 31, 2014 ... product and improved the economy through the retention of some 58 000 jobs. ... and maintaining a defence industrial base (DIB) in those countries that have the ... by the Department of Trade and Industry (dti) that focuses primarily on civil industry ... work share on the purchased equipment (co-production), ...

  9. Nuclear Belief Systems and Individual Policy-Makers: Duncan Sandys, Unmanned Weaponry, and the Impossibility of Defence

    OpenAIRE

    Betts, Lewis

    2014-01-01

    This thesis attempts to explore the influence that Duncan Sandys' experiences of the Second World War had on his policy preferences, and policy-making, in relation to British defence policy during his years in government. This is a significant period in British nuclear policy which began with thermonuclear weaponry being placed ostentatiously at the centre of British defence planning in the 1957 Defence White Paper, and ended with the British acquiring the latest American nuclear weapon techn...

  10. Resistance of red clover (Trifolium pratense) to the root parasitic plant Orobanche minor is activated by salicylate but not by jasmonate.

    Science.gov (United States)

    Kusumoto, Dai; Goldwasser, Yaakov; Xie, Xiaonan; Yoneyama, Kaori; Takeuchi, Yasutomo; Yoneyama, Koichi

    2007-09-01

    Obligate root holoparasites of the genus Orobanche attack dicotyledonous crops and cause severe losses in many parts of the world. Chemical induction of plant defence systems such as systemic acquired resistance was proposed to be an available strategy to control the root parasite, but the detailed mechanisms involved have not been clarified. The aim of this study was to elucidate the effects of salicylic acid (SA), jasmonic acid (JA) and their analogues on resistance of red clover to Orobanche parasitism. Roots of red clover grown in plastic chambers were applied with SA, S-methyl benzo[1,2,3]thiadiazole-7-carbothioate (BTH), methyl jasmonate (MeJA) and n-propyl dihydrojasmonate (PDJ), and then were inoculated with O. minor seeds. Attachments of the parasite were observed after 5 weeks. SA and BTH, inducers of SA-mediated defences, significantly reduced the number of established parasites by more than 75 %. By contrast, MeJA and PDJ, inducers of JA-mediated defences, did not affect parasitism. The reduction in the number of established parasites by SA and BTH was due to the inhibited elongation of O. minor radicles and the activation of defence responses in the host root including lignification of the endodermis. These results suggest that SA-induced resistance, but not JA-induced resistance, is effective in inhibiting Orobanche parasitism and that the resistance is expressed by the host root both externally and internally.

  11. A Plant's Response to Gravity as a Wave Guide Phenomenon

    Science.gov (United States)

    Wagner, Orvin

    1997-11-01

    Plant experimental data provides a unifying wave theory (W-wave theory) for the growth and development of plants. A plant's response to gravity is an important aspect of this theory. It appears that a plant part is tuned to the angle with which it initially grew with respect to the gravitational field and changes produce correction responses. This is true because the velocity of W-waves (whose standing waves determine plant structure) within plant tissue is found to be different in different directions (angle a) with respect to the gravitational field. I found that there are preferred values of a, namely integral multiples of near 5 degrees for some plants. Conifers apparently are more sensitive to the gravitational field than deciduous trees, in the cases studied, so their structure is determined in more detail by the gravitational field. A plant's response to gravity appears to be a fundamental phenomenon and may provide a new model for gravity that can be experimentally verified in the laboratory. Along these same lines accelerometers placed in plant tissue indicate that plants produce gravity related forces that facilitate sap flow. See the

  12. CSIR eNews: Defence peace safety and security

    CSIR Research Space (South Africa)

    CSIR

    2008-03-01

    Full Text Available At the CSIR, science and technology (S&T) is hard at work for a peaceful, safe and prosperous South Africa. The organisation has developed strong S&T capabilities through its associations with key players in defence, safety and security...

  13. CSIR eNews: Defence, peace, safety and security

    CSIR Research Space (South Africa)

    CSIR

    2007-12-01

    Full Text Available At the CSIR, science and technology (S&T) is hard at work for a peaceful, safe and prosperous South Africa. The organisation has developed strong S&T capabilities through its associations with key players in defence, safety and security...

  14. Stage-Related Defense Response Induction in Tomato Plants by Nesidiocoris tenuis

    Science.gov (United States)

    Naselli, Mario; Urbaneja, Alberto; Siscaro, Gaetano; Jaques, Josep A.; Zappalà, Lucia; Flors, Víctor; Pérez-Hedo, Meritxell

    2016-01-01

    The beneficial effects of direct predation by zoophytophagous biological control agents (BCAs), such as the mirid bug Nesidiocoris tenuis, are well-known. However, the benefits of zoophytophagous BCAs’ relation with host plants, via induction of plant defensive responses, have not been investigated until recently. To date, only the females of certain zoophytophagous BCAs have been demonstrated to induce defensive plant responses in tomato plants. The aim of this work was to determine whether nymphs, adult females, and adult males of N. tenuis are able to induce defense responses in tomato plants. Compared to undamaged tomato plants (i.e., not exposed to the mirid), plants on which young or mature nymphs, or adult males or females of N. tenuis fed and developed were less attractive to the whitefly Bemisia tabaci, but were more attractive to the parasitoid Encarsia formosa. Female-exposed plants were more repellent to B. tabaci and more attractive to E. formosa than were male-exposed plants. When comparing young- and mature-nymph-exposed plants, the same level of repellence was obtained for B. tabaci, but mature-nymph-exposed plants were more attractive to E. formosa. The repellent effect is attributed to the signaling pathway of abscisic acid, which is upregulated in N. tenuis-exposed plants, whereas the parasitoid attraction was attributed to the activation of the jasmonic acid signaling pathway. Our results demonstrate that all motile stages of N. tenuis can trigger defensive responses in tomato plants, although these responses may be slightly different depending on the stage considered. PMID:27472328

  15. Quality audit in design

    International Nuclear Information System (INIS)

    Horton, G.T.

    1976-01-01

    The subject is discussed under the headings: introduction (explanation of firm's responsibility to design and procure naval nuclear reactor plant for the Ministry of Defence, whose quality assurance requirements are laid down in Defence Standards); principles of quality audit; audit procedure. (U.K.)

  16. Distinct roles of jasmonates and aldehydes in plant-defense responses.

    Directory of Open Access Journals (Sweden)

    E Wassim Chehab

    Full Text Available BACKGROUND: Many inducible plant-defense responses are activated by jasmonates (JAs, C(6-aldehydes, and their corresponding derivatives, produced by the two main competing branches of the oxylipin pathway, the allene oxide synthase (AOS and hydroperoxide lyase (HPL branches, respectively. In addition to competition for substrates, these branch-pathway-derived metabolites have substantial overlap in regulation of gene expression. Past experiments to define the role of C(6-aldehydes in plant defense responses were biased towards the exogenous application of the synthetic metabolites or the use of genetic manipulation of HPL expression levels in plant genotypes with intact ability to produce the competing AOS-derived metabolites. To uncouple the roles of the C(6-aldehydes and jasmonates in mediating direct and indirect plant-defense responses, we generated Arabidopsis genotypes lacking either one or both of these metabolites. These genotypes were subsequently challenged with a phloem-feeding insect (aphids: Myzus persicae, an insect herbivore (leafminers: Liriomyza trifolii, and two different necrotrophic fungal pathogens (Botrytis cinerea and Alternaria brassicicola. We also characterized the volatiles emitted by these plants upon aphid infestation or mechanical wounding and identified hexenyl acetate as the predominant compound in these volatile blends. Subsequently, we examined the signaling role of this compound in attracting the parasitoid wasp (Aphidius colemani, a natural enemy of aphids. PRINCIPAL FINDINGS: This study conclusively establishes that jasmonates and C(6-aldehydes play distinct roles in plant defense responses. The jasmonates are indispensable metabolites in mediating the activation of direct plant-defense responses, whereas the C(6-aldehyes are not. On the other hand, hexenyl acetate, an acetylated C(6-aldehyde, is the predominant wound-inducible volatile signal that mediates indirect defense responses by directing tritrophic

  17. The effect of co-infestation by conspecific and heterospecific aphids on the feeding behaviour of Nasonovia ribisnigri on resistant and susceptible lettuce cultivars

    NARCIS (Netherlands)

    Broeke, ten Cindy J.M.; Dicke, Marcel; Loon, van Joop J.A.

    2017-01-01

    Aphid saliva can suppress the blocking of sieve elements, a reaction that plants employ to inhibit aphid feeding, but aphid saliva can also elicit plant defence responses. Such plant responses might affect interactions between different aphid species and intraspecifically, e.g. among different

  18. SOYBEAN AND CASEIN HYDROLYSATES INDUCE GRAPEVINE IMMUNE RESPONSES AND RESISTANCE AGAINST PLASMOPARA VITICOLA

    Directory of Open Access Journals (Sweden)

    Nihed eLachhab

    2014-12-01

    Full Text Available Plasmopara viticola, the causal agent of grapevine downy mildew, is one of the most devastating grape pathogen in Europe and North America. Although phytochemicals are used to control pathogen infections, the appearance of resistant strains and the concern for possible adverse effects on environment and human health are increasing the search for alternative strategies. In the present investigation, we successfully tested two protein hydrolysates from soybean (soy and casein (cas to trigger grapevine resistance against P. viticola. On Vitis vinifera cv. Marselan plants, the application of soy and cas reduced the infected leaf surface by 76 and 63%, as compared to the control, respectively. Since both hydrolysates might trigger the plant immunity, we investigated their ability to elicit grapevine defence responses. On grapevine cell suspensions, a different free cytosolic calcium signature was recorded for each hydrolysate, whereas a similar transient phosphorylation of two MAP kinases of 45 and 49 kDa was observed. These signalling events were followed by transcriptome reprogramming, including the up-regulation of defence genes encoding pathogenesis-related (PR proteins and the stilbene synthase enzyme responsible for the biosynthesis of resveratrol, the main grapevine phytoalexin. Liquid chromatography analyses confirmed the production of resveratrol and its dimer metabolites, δ- and ε-viniferins. Overall, soy effects were more pronounced as compared to the cas one. Both hydrolysates proved to act as elicitors to enhance grapevine immunity against pathogen attack.

  19. Costs and limits of dosage response to predation risk: to what extent can tadpoles invest in anti-predator morphology?

    Science.gov (United States)

    Teplitsky, Céline; Plénet, Sandrine; Joly, Pierre

    2005-09-01

    Inducible defences have long been considered as a polyphenism opposing defended and undefended morphs. However, in nature, preys are exposed to various levels of predation risk and scale their investment in defence to actual predation risk. Still, among the traits that are involved in the defence, some are specific to one predator type while others act as a more generalised defence. The existence of defence costs could prevent an individual investing in all these traits simultaneously. In this study, we investigate the impact of an increasing level of predator density (stickleback, Gasterosteus aculeatus) on the expression of morphological inducible defences in tadpoles of Rana dalmatina. In this species, investment in tail length and tail muscle is a stickleback-specific response while increased tail fin depth is a more general defence. As expected, we found a relationship between investment in defence and level of risk through the responses of tail fin depth and tail length. We also found an exponential increase of defence cost, notably expressed by convex decrease of growth and developmental rates. We found a relative independence of investment in the different traits that compose the defence, revealing a high potential for fine tuning the expression of defended phenotypes with respect to local ecological conditions.

  20. On-line acquisition of plant related and environmental parameters (plant monitoring) in gerbera: determining plant responses

    OpenAIRE

    Baas, R.; Slootweg, G.

    2004-01-01

    For on-line plant monitoring equipment to be functional in commercial glasshouse horticulture, relations between sensor readings and plant responses on both the short (days) and long term (weeks) are required. For this reason, systems were installed to monitor rockwool grown gerbera plants on a minute-to-minute basis from July 2002 until April 2003. Data collected included, amongst others, crop transpiration from lysimeter data (2 m2), canopy temperature using infrared sensors, rockwool water...

  1. The role of lipopolysaccharide and peptidoglycan, two glycosylated bacterial microbe-associated molecular patterns (MAMPs), in plant innate immunity

    DEFF Research Database (Denmark)

    Erbs, Gitte; Newman, Mari-Anne

    2012-01-01

    innate immune system through the action of pattern recognition receptors (PRRs). A greater insight into the mechanisms of MAMP recognition and the description of PRRs for different microbial glycoconjugates will have considerable impact on the improvement of plant health and disease resistance. Here...... to as ‘innate immunity’. Innate immunity is the first line of defence against invading microorganisms in vertebrates and the only line of defence in invertebrates and plants. Bacterial glycoconjugates, such as lipopolysaccharides (LPSs) from the outer membrane of Gram-negative bacteria and peptidoglycan (PGN......) from the cell walls of both Gram-positive and Gram-negative bacteria, have been found to act as elicitors of plant innate immunity. These conserved, indispensable, microbe-specific molecules are also referred to as ‘microbe-associated molecular patterns’ (MAMPs). MAMPs are recognized by the plant...

  2. Probabilistic Design of Coastal Flood Defences in Vietnam

    NARCIS (Netherlands)

    Mai Van, C.

    2010-01-01

    This study further develops the method of probabilistic design and to address a knowledge gap in its application regarding safety and reliability, risk assessment and risk evaluation to the fields of flood defences. The thesis discusses: - a generic probabilistic design framework for assessing flood

  3. Diving bradycardia: a mechanism of defence against hypoxic damage.

    Science.gov (United States)

    Alboni, Paolo; Alboni, Marco; Gianfranchi, Lorella

    2011-06-01

    A feature of all air-breathing vertebrates, diving bradycardia is triggered by apnoea and accentuated by immersion of the face or whole body in cold water. Very little is known about the afferents of diving bradycardia, whereas the efferent part of the reflex circuit is constituted by the cardiac vagal fibres. Diving bradycardia is associated with vasoconstriction of selected vascular beds and a reduction in cardiac output. The diving response appears to be more pronounced in mammals than in birds. In humans, the bradycardic response to diving varies greatly from person to person; the reduction in heart rate generally ranges from 15 to 40%, but a small proportion of healthy individuals can develop bradycardia below 20 beats/min. During prolonged dives, bradycardia becomes more pronounced because of activation of the peripheral chemoreceptors by a reduction in the arterial partial pressure of oxygen (O2), responsible for slowing of heart rate. The vasoconstriction is associated with a redistribution of the blood flow, which saves O2 for the O2-sensitive organs, such as the heart and brain. The results of several investigations carried out both in animals and in humans show that the diving response has an O2-conserving effect, both during exercise and at rest, thus lengthening the time to the onset of serious hypoxic damage. The diving response can therefore be regarded as an important defence mechanism for the organism.

  4. Integration of Renewable Generation in Power System Defence Plans

    DEFF Research Database (Denmark)

    Das, Kaushik

    Increasing levels of penetration of wind power and other renewable generations in European power systems pose challenges to power system security. The power system operators are continuously challenged especially when generations from renewables are high thereby reducing online capacity of conven......Increasing levels of penetration of wind power and other renewable generations in European power systems pose challenges to power system security. The power system operators are continuously challenged especially when generations from renewables are high thereby reducing online capacity......, one of them being the North East area with high share of wind power generation.The aim of this study is to investigate how renewable generations like wind power can contribute to the power system defence plans. This PhD project “Integration of Renewable Generation in Power System Defence Plans...

  5. High levels of cyclic-di-GMP in plant-associated Pseudomonas correlate with evasion of plant immunity.

    Science.gov (United States)

    Pfeilmeier, Sebastian; Saur, Isabel Marie-Luise; Rathjen, John Paul; Zipfel, Cyril; Malone, Jacob George

    2016-05-01

    The plant innate immune system employs plasma membrane-localized receptors that specifically perceive pathogen/microbe-associated molecular patterns (PAMPs/MAMPs). This induces a defence response called pattern-triggered immunity (PTI) to fend off pathogen attack. Commensal bacteria are also exposed to potential immune recognition and must employ strategies to evade and/or suppress PTI to successfully colonize the plant. During plant infection, the flagellum has an ambiguous role, acting as both a virulence factor and also as a potent immunogen as a result of the recognition of its main building block, flagellin, by the plant pattern recognition receptors (PRRs), including FLAGELLIN SENSING2 (FLS2). Therefore, strict control of flagella synthesis is especially important for plant-associated bacteria. Here, we show that cyclic-di-GMP [bis-(3'-5')-cyclic di-guanosine monophosphate], a central regulator of bacterial lifestyle, is involved in the evasion of PTI. Elevated cyclic-di-GMP levels in the pathogen Pseudomonas syringae pv. tomato (Pto) DC3000, the opportunist P. aeruginosa PAO1 and the commensal P. protegens Pf-5 inhibit flagellin synthesis and help the bacteria to evade FLS2-mediated signalling in Nicotiana benthamiana and Arabidopsis thaliana. Despite this, high cellular cyclic-di-GMP concentrations were shown to drastically reduce the virulence of Pto DC3000 during plant infection. We propose that this is a result of reduced flagellar motility and/or additional pleiotropic effects of cyclic-di-GMP signalling on bacterial behaviour. © 2015 THE AUTHORS MOLECULAR PLANT PATHOLOGY PUBLISHED BY BRITISH SOCIETY FOR PLANT PATHOLOGY AND JOHN WILEY & SONS LTD.

  6. A Primer on Recent Canadian Defence Budgeting Trends and Implications

    Directory of Open Access Journals (Sweden)

    David Perry

    2015-04-01

    Full Text Available Faced with a dangerous world, the federal government has made recapitalizing and updating Canada’s armed forces a priority. Unfortunately, fiscal pressures obliged the government to deviate from its Canada First Defence Strategy, cutting staff and delaying military hardware acquisitions. However, the introduction this year of the Defence Procurement Strategy should allow Ottawa to use improved approaches to buy equipment that would otherwise have been purchased already under the DND’s opaque capital expenditure system. At present, DND capital funds are mostly subject to accrual accounting. Capital costs are charged against the defence budget as annual amortization expenses over equipment lifecycles. While this enables multiple capital projects to go ahead simultaneously, not all of the money covering capital costs is treated this way. Traditional A-Base Vote 5 expenses are still charged to the budget the year the expenditure is made — and the DND consistently underspends the Vote 5 funds available by as much as 28 percent. Since 2007/8, an estimated $6.42 billion wasn’t used as intended. While some of this can be carried forward, there are limits. Leftover funds exceeding them are returned to the Treasury and are thereby lost. It’s up to the DND to make up losses out of future funding. Just as bad, the accrual method doesn’t fully account for inflation, so when schedules slip, project purchasing power diminishes by hundreds of millions of dollars. Ambitious initiatives like the Joint Support Ship and (likely the Canadian Surface Combatant end up taking hits to reflect harsh budgetary realities; the capabilities of Canada’s soldiers suffer. This policy brief draws on research and confidential interviews to highlight the pressing need for reform in Canadian defence procurement.

  7. Dynamic Frequency Response of Wind Power Plants

    DEFF Research Database (Denmark)

    Altin, Müfit

    according to their grid codes. In these scenarios particularly with high wind power penetration cases, conventional power plants (CPPs) such as old thermal power plants are planned to be replaced with wind power plants (WPPs). Consequently, the power system stability will be affected and the control...... to maintain sustainable and reliable operation of the power system for these targets, transmission system operators (TSOs) have revised the grid code requirements. Also, the TSOs are planning the future development of the power system with various wind penetration scenarios to integrate more wind power...... capability of WPPs would be investigated. The objective of this project is to analyze and identify the power system requirements for the synchronizing power support and inertial response control of WPPs in high wind power penetration scenarios. The dynamic frequency response of WPPs is realized...

  8. Plant responses to metal toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Briat, J.F. [Montpellier-2 Univ., 34 (France). Biochimie et physiologie moleculaire des plantes, CNRS, URA 2133; Lebrun, M. [Montpellier-2 Univ., 34 (France). Biochimie et physiologie vegetale appliquee

    1999-01-01

    Increased metal concentration in the soils, up to toxic levels, is becoming an important environmental problem. Safety rule evolution will require solutions in order to cope with food safety rules, and to freeze metal leakage from heavily metal-poisoned soils, such as those from industrial fallows. In this context, plants could serve to develop bio-assays in order to promote new standards, more realistic than the mass of a given metal per kg of soil, that does not consider the metal bio-disponibility. Plants could also be used for phyto-extraction and/or phyto-stabilization. To reach these objectives, a genetic approach could be useful to generate metal-tolerant plants with enough biomass. In this work is more particularly studied the plant responses to metal toxicity. Metal toxicity for living organisms involves oxidative and /or genotoxic mechanisms. Plant protection against metal toxicity occurs, at least in part, through control of root metal uptake and of long distance metal transport. Inside cells, proteins such as ferritins and metallothioneins, and glutathione-derived peptides named phyto-chelatins, participate in excess metal storage and detoxification. Low molecular weight organic molecules, mainly organic acids and amino acids and their derivatives, also play an important role in plant metal homeostasis. When these systems are overloaded, oxidative stress defense mechanisms are activated. Molecular and cellular knowledge of these processes will be necessary to improve plant metal resistance. Occurrence of naturally tolerant plants which hyper accumulate metals provides helpful tools for this research. (authors) 130 refs.

  9. Ionic signaling in plant responses to gravity and touch

    Science.gov (United States)

    Fasano, Jeremiah M.; Massa, Gioia D.; Gilroy, Simon

    2002-01-01

    Touch and gravity are two of the many stimuli that plants must integrate to generate an appropriate growth response. Due to the mechanical nature of both of these signals, shared signal transduction elements could well form the basis of the cross-talk between these two sensory systems. However, touch stimulation must elicit signaling events across the plasma membrane whereas gravity sensing is thought to represent transformation of an internal force, amyloplast sedimentation, to signal transduction events. In addition, factors such as turgor pressure and presence of the cell wall may also place unique constraints on these plant mechanosensory systems. Even so, the candidate signal transduction elements in both plant touch and gravity sensing, changes in Ca2+, pH and membrane potential, do mirror the known ionic basis of signaling in animal mechanosensory cells. Distinct spatial and temporal signatures of Ca2+ ions may encode information about the different mechanosignaling stimuli. Signals such as Ca2+ waves or action potentials may also rapidly transfer information perceived in one cell throughout a tissue or organ leading to the systemic reactions characteristic of plant touch and gravity responses. Longer-term growth responses are likely sustained via changes in gene expression and asymmetries in compounds such as inositol-1,4,5-triphosphate (IP3) and calmodulin. Thus, it seems likely that plant mechanoperception involves both spatial and temporal encoding of information at all levels, from the cell to the whole plant. Defining this patterning will be a critical step towards understanding how plants integrate information from multiple mechanical stimuli to an appropriate growth response.

  10. Ventral medullary neurones excited from the hypothalamic and mid-brain defence areas.

    Science.gov (United States)

    Hilton, S M; Smith, P R

    1984-07-01

    In cats anaesthetised with chloralose, the ventral medulla was explored in and around the strip previously identified as the location of the efferent pathway from the hypothalamic and mid-brain defence areas to the spinal cord, in a search for neurones excited by electrical stimulation of the defence areas. Such units were found mostly in the caudal part of this strip, at a depth of not more than 500 microns from the surface. Nearly all were located in the ventral part of nucleus paragigantocellularis lateralis (PGL) at the level of the rostral pole of the inferior olive. There was evidence of temporal and spatial facilitation, indicating a convergent excitatory input from the defence areas onto neurones in PGL. This is consistent with earlier evidence of a synaptic relay in the efferent pathway at this site. When the pathway is blocked at this site, arterial blood pressure falls profoundly, so activity in these neurones may be essential for the normal level of sympathetic nerve activity.

  11. Radiation Protection and Civil defence Department

    International Nuclear Information System (INIS)

    Gomaa, M.A.; Elshinawy, R.M.K.; Abdelfattah, A.T.

    1991-01-01

    This conference involves subjects of radiation protection, programming of civil defence, on the implementation of 1990 ICRP recommendation, thermoluminescence properties of bone equivalent calcium phosphate ceramics, potassium body burdens in occupational users of egyptian nuclear research centre, transport of radionuclides in fresh water stream, water treatment process for nuclear reactor, research activities related to internal contamination and bioassay and experience and environmental radiation monitoring in inshass. it contains of figures and tables

  12. The Man-in-the-Middle Defence

    Science.gov (United States)

    Anderson, Ross; Bond, Mike

    Eliminating middlemen from security protocols helps less than one would think. EMV electronic payments, for example, can be made fairer by adding an electronic attorney - a middleman which mediates access to a customer’s card. We compare middlemen in crypto protocols and APIs with those in the real world, and show that a man-in-the-middle defence is helpful in many circumstances. We suggest that the middleman has been unfairly demonised.

  13. Interactions between plant hormones and heavy metals responses.

    Science.gov (United States)

    Bücker-Neto, Lauro; Paiva, Ana Luiza Sobral; Machado, Ronei Dorneles; Arenhart, Rafael Augusto; Margis-Pinheiro, Marcia

    2017-01-01

    Heavy metals are natural non-biodegradable constituents of the Earth's crust that accumulate and persist indefinitely in the ecosystem as a result of human activities. Since the industrial revolution, the concentration of cadmium, arsenic, lead, mercury and zinc, amongst others, have increasingly contaminated soil and water resources, leading to significant yield losses in plants. These issues have become an important concern of scientific interest. Understanding the molecular and physiological responses of plants to heavy metal stress is critical in order to maximize their productivity. Recent research has extended our view of how plant hormones can regulate and integrate growth responses to various environmental cues in order to sustain life. In the present review we discuss current knowledge about the role of the plant growth hormones abscisic acid, auxin, brassinosteroid and ethylene in signaling pathways, defense mechanisms and alleviation of heavy metal toxicity.

  14. Native plant community response to alien plant invasion and removal

    Directory of Open Access Journals (Sweden)

    Jara ANDREU

    2011-01-01

    Full Text Available Given the potential ecological impacts of invasive species, removal of alien plants has become an important management challenge and a high priority for environmental managers. To consider that a removal effort has been successful requires both, the effective elimination of alien plants and the restoration of the native plant community back to its historical composition and function. We present a conceptual framework based on observational and experimental data that compares invaded, non-invaded and removal sites to quantify invaders’ impacts and native plant recover after their removal. We also conduct a meta-analysis to quantitatively evaluate the impacts of plant invaders and the consequences of their removal on the native plant community, across a variety of ecosystems around the world. Our results that invasion by alien plants is responsible for a local decline in native species richness and abundance. Our analysis also provides evidence that after removal, the native vegetation has the potential to recover to a pre-invasion target state. Our review reveal that observational and experimental approaches are rarely used in concert, and that reference sites are scarcely employed to assess native species recovery after removal. However, we believe that comparing invaded, non-invaded and removal sites offer the opportunity to obtain scientific information with relevance for management.

  15. An alternatively spliced heat shock transcription factor, OsHSFA2dI, functions in the heat stress-induced unfolded protein response in rice.

    Science.gov (United States)

    Cheng, Q; Zhou, Y; Liu, Z; Zhang, L; Song, G; Guo, Z; Wang, W; Qu, X; Zhu, Y; Yang, D

    2015-03-01

    As sessile organisms, plants have evolved a wide range of defence pathways to cope with environmental stress such as heat shock. However, the molecular mechanism of these defence pathways remains unclear in rice. In this study, we found that OsHSFA2d, a heat shock transcriptional factor, encodes two main splice variant proteins, OsHSFA2dI and OsHSFA2dII in rice. Under normal conditions, OsHSFA2dII is the dominant but transcriptionally inactive spliced form. However, when the plant suffers heat stress, OsHSFA2d is alternatively spliced into a transcriptionally active form, OsHSFA2dI, which participates in the heat stress response (HSR). Further study found that this alternative splicing was induced by heat shock rather than photoperiod. We found that OsHSFA2dI is localised to the nucleus, whereas OsHSFA2dII is localised to the nucleus and cytoplasm. Moreover, expression of the unfolded protein response (UNFOLDED PROTEIN RESPONSE) sensors, OsIRE1, OsbZIP39/OsbZIP60 and the UNFOLDED PROTEIN RESPONSE marker OsBiP1, was up-regulated. Interestingly, OsbZIP50 was also alternatively spliced under heat stress, indicating that UNFOLDED PROTEIN RESPONSE signalling pathways were activated by heat stress to re-establish cellular protein homeostasis. We further demonstrated that OsHSFA2dI participated in the unfolded protein response by regulating expression of OsBiP1. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  16. Plant defences against ants provide a pathway to social parasitism in butterflies

    DEFF Research Database (Denmark)

    Patricelli, Dario; Barbero, Francesca; Occhipinti, Andrea

    2015-01-01

    , which in turn may benefit infested Origanum plants by relieving their roots of further damage. Our results suggest a new pathway, whereby social parasites can detect successive resources by employing plant volatiles to simultaneously select their initial plant food and a suitable sequential host....... the exploitation of sequential hosts by the phytophagous-predaceous butterfly Maculinea arion, whose larvae initially feed on Origanum vulgare flowerheads before switching to parasitize Myrmica ant colonies for their main period of growth. Gravid female butterflies were attracted to Origanum plants that emitted...

  17. The Strategic Failure of UK Defence Reform and What Still Needs to Be Done

    Science.gov (United States)

    2016-04-04

    from the previous Labour Government, see HM Government, “Defence Secretary Balances MoD Budget,” https://www.gov.uk/government/news/defence-secretary...conceptualize the different levels of strategy required in a modern environment, inclusive of grand strategy...Learning Under Fire: Military Change in Wartime. Lecture to selected JAWS students , Norfolk, VA, March 2015. HM Government. A Strong Britain in an Age

  18. Security Policy at Road’s End? The Roles of Sweden and Finland in the Nordic-Baltic Defence Cooperation Process

    Directory of Open Access Journals (Sweden)

    Winnerstig Mike

    2014-12-01

    Full Text Available The article addresses a number of questions related to Nordic and to an extent also Nordic-Baltic defence cooperation. First of all, how far has Nordic and Nordic-Baltic defence cooperation come today? Secondly, what are the differences in the approaches of Sweden and Finland when it comes to defence cooperation, especially regarding NATO, in the Nordic-Baltic area? As a first analytical result, it is apparent that the rhetorical standing of the Nordic and Nordic-Baltic defence cooperation process is greater than its real achievements, especially in terms of defence integration. Secondly, it seems also to be clear that the defence and security policy debates of Sweden and Finland are quite different. Some problems identified in the debates within the two countries, respectively, are very similar although the suggested solutions vary very remarkably. Regarding the key issue of NATO membership, the developments of the last few years suggest that the Swedish political establishment, as well as the general public, might be closer to a substantial discussion of NATO membership than their Finnish equivalents.

  19. Chemical sensing of plant stress at the ecosystem scale

    Directory of Open Access Journals (Sweden)

    T. Karl

    2008-09-01

    Full Text Available Significant ecosystem-scale emissions of methylsalicylate (MeSA, a semivolatile plant hormone thought to act as the mobile signal for systemic acquired resistance (SAR, were observed in an agroforest. Our measurements show that plant internal defence mechanisms can be activated in response to temperature stress and are modulated by water availability on large scales. Highest MeSA fluxes (up to 0.25 mg/m2/h were observed after plants experienced ambient night-time temperatures of ~7.5°C followed by a large daytime temperature increase (e.g. up to 22°C. Under these conditions estimated night-time leaf temperatures were as low as ~4.6°C, likely inducing a response to prevent chilling injury. Our observations imply that plant hormones can be a significant component of ecosystem scale volatile organic compound (VOC fluxes (e.g. as high as the total monoterpene (MT flux and therefore contribute to the missing VOC budget. If generalized to other ecosystems and different types of stresses these findings suggest that semivolatile plant hormones have been overlooked by investigations of the impact of biogenic VOCs on aerosol formation events in forested regions. Our observations show that the presence of MeSA in canopy air serves as an early chemical warning signal indicating ecosystem-scale stresses before visible damage becomes apparent. As a chemical metric, ecosystem emission measurements of MeSA in ambient air could therefore support field studies investigating factors that adversely affect plant growth.

  20. Defence in depth perspectives

    International Nuclear Information System (INIS)

    Veneau, Tania; Ferrier, Agnes; Barbaud, Jean

    2017-01-01

    complex technical solutions. The independence between DiD levels should not be an absolute design principle but risk analysis should be used to identify the areas where this would be necessary. For instance, devoting equipments/systems to a single level (without possibility of sharing them with other levels) could negatively impact the overall plant safety: it might complexify the facility and affect operator reliability (even if the operators are trained to face accidental situations, they are more familiar with normal system operation on a daily basis). The paper presents first how the concept of DiD evolved over time, the link with the barriers notion, the current consensus on DiD definitions obtained despite some differences observed between standards (eg. IAEA and WENRA definitions), and discusses the subjects identified above, before raising perspectives on how to achieve a sufficient independence of DiD levels. They are based on a minimum level of redundancy, on physical separation, on diversity (even though they are not systematically recommended), but also on strengthening the robustness of defence lines. In practice, DiD concept should be implemented in a manner that ensures that each level is effective in meeting its specific objective. (author)