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Sample records for triggers defense responses

  1. Peptidoglycan from fermentation by-product triggers defense responses in grapevine.

    Directory of Open Access Journals (Sweden)

    Yang Chen

    Full Text Available Plants are constantly under attack from a variety of microorganisms, and rely on a series of complex detection and response systems to protect themselves from infection. Here, we found that a by-product of glutamate fermentation triggered defense responses in grapevine, increasing the expression of defense response genes in cultured cells, foliar chitinase activity, and resistance to infection by downy mildew in leaf explants. To identify the molecule that triggered this innate immunity, we fractionated and purified candidates extracted from Corynebacterium glutamicum, a bacterium used in the production of amino acids by fermentation. Using hydrolysis by lysozyme, a silkworm larva plasma detection system, and gel filtration analysis, we identified peptidoglycan as inducing the defense responses. Peptidoglycans of Escherichia coli, Bacillus subtilis, and Staphylococcus aureus also generated similar defensive responses.

  2. The novel elicitor AsES triggers a defense response against Botrytis cinerea in Arabidopsis thaliana.

    Science.gov (United States)

    Hael-Conrad, V; Abou-Mansour, E; Díaz-Ricci, J-C; Métraux, J-P; Serrano, M

    2015-12-01

    AsES (Acremonium strictum Elicitor and Subtilisin) is a novel extracellular elicitor protein produced by the avirulent isolate SS71 of the opportunist strawberry fungal pathogen A. strictum. Here we describe the activity of AsES in the plant-pathogen system Arabidopsis thaliana-Botrytis cinerea. We show that AsES renders A. thaliana plants resistant to the necrotrophic pathogen B. cinerea, both locally and systemically and the defense response observed is dose-dependent. Systemic, but not local resistance is dependent on the length of exposure to AsES. The germination of the spores in vitro was not inhibited by AsES, implying that protection to B. cinerea is due to the induction of the plant defenses. These results were further supported by the findings that AsES differentially affects mutants impaired in the response to salicylic acid, jasmonic acid and ethylene, suggesting that AsES triggers the defense response through these three signaling pathways. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  3. Purification and characterization of a novel hypersensitive response-inducing elicitor from Magnaporthe oryzae that triggers defense response in rice.

    Directory of Open Access Journals (Sweden)

    Mingjia Chen

    Full Text Available BACKGROUND: Magnaporthe oryzae, the rice blast fungus, might secrete certain proteins related to plant-fungal pathogen interactions. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we report the purification, characterization, and gene cloning of a novel hypersensitive response-inducing protein elicitor (MoHrip1 secreted by M. oryzae. The protein fraction was purified and identified by de novo sequencing, and the sequence matched the genomic sequence of a putative protein from M. oryzae strain 70-15 (GenBank accession No. XP_366602.1. The elicitor-encoding gene mohrip1 was isolated; it consisted of a 429 bp cDNA, which encodes a polypeptide of 142 amino acids with a molecular weight of 14.322 kDa and a pI of 4.53. The deduced protein, MoHrip1, was expressed in E. coli. And the expression protein collected from bacterium also forms necrotic lesions in tobacco. MoHrip1 could induce the early events of the defense response, including hydrogen peroxide production, callose deposition, and alkalization of the extracellular medium, in tobacco. Moreover, MoHrip1-treated rice seedlings possessed significantly enhanced systemic resistance to M. oryzae compared to the control seedlings. The real-time PCR results indicated that the expression of some pathogenesis-related genes and genes involved in signal transduction could also be induced by MoHrip1. CONCLUSION/SIGNIFICANCE: The results demonstrate that MoHrip1 triggers defense responses in rice and could be used for controlling rice blast disease.

  4. Zinc triggers signaling mechanisms and defense responses promoting resistance to Alternaria brassicicola in Arabidopsis thaliana.

    Science.gov (United States)

    Martos, Soledad; Gallego, Berta; Cabot, Catalina; Llugany, Mercè; Barceló, Juan; Poschenrieder, Charlotte

    2016-08-01

    According to the elemental defense hypothesis the accumulation of trace elements by plants may substitute for organic defenses, while the joint effects hypothesis proposes that trace elements and organic defenses can have additive or synergistic effects against pathogens or herbivores. To evaluate these hypotheses the response of the pathosystem Alternaria brassicicola-Arabidopsis thaliana to control (2μM) and surplus (12μM) Zn was evaluated using the camalexin deficient mutant pad3-1 and mtp1-1, a mutant with impaired Zn vacuolar storage, along with the corresponding wildtypes. In vitro, a 50% inhibition of fungal growth was achieved by 440μM Zn. A. thaliana leaves could accumulate equivalent concentrations without harm. In fact, surplus Zn enhanced the resistance of A. thaliana to fungal attack in Columbia (Col-0), Wassilewskija (WS), and mtp1-1. However, surplus Zn was unable to protect pad3-1 demonstrating that Zn cannot substitute for camalexin, the main organic defense in A. thaliana. High, non phytotoxic leaf Zn concentrations enhanced the resistance to A. brassicicola of A. thaliana genotypes able to produce camalexin. This was mainly due to Zn-induced enhancement of the JA/ETH signaling pathway leading to enhanced PAD3 expression. These results support the joint effects hypothesis and highlight the importance of adequate Zn supply for reinforced pathogen resistance. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  5. Activation of neuronal defense mechanisms in response to pathogenic factors triggering induction of amyloidosis in Alzheimer's disease.

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    Maltsev, Alexander V; Santockyte, Rasa; Bystryak, Simon; Galzitskaya, Oxana V

    2014-01-01

    We present a new model for etiology of Alzheimer's disease (AD) which postulates early involvement of specialized neuroprotective mechanisms in the pathology of AD. These neuroprotective mechanisms work in concert to regulate metabolic homeostasis in healthy neuronal cells, but contribute to the distinctive cytopathic phenotype of neuronal degeneration in AD. According to this model, two molecular/genetic hallmarks of AD, amyloid-β (Aβ) deposition and tau hyperphosphorylation, are associated with neuronal mechanisms for dissipating thermal energy associated with high levels of protein synthesis in highly temperature-sensitive neuronal cells. Development of effective methods of AD treatment will require a better understanding of how this neuronal defense system is activated in response to cytopathological triggers in sporadic AD. The cause and effect link between synthesis and processing of amyloid-β protein precursor (AβPP) and the AD terminal phenotype of neurofibrillary tangles and neuron loss involve the formation of Aβ peptides that accumulate as oligomers, cannot be controlled by neurons, and are toxic to the surrounding neuronal membranes. We analyze experimental and clinical studies that have investigated the correlation between phosphorylation of some transport proteins and increased synthesis of proteins in neurons. We also review the evidence related to the possibility that protein hyperphosphorylation may be a byproduct of energetic imbalances in AD cells associated with high levels of protein synthesis, and that activation of defense systems, through which energy-rich molecules are eliminated from the site of protein synthesis and are sequestered to the peripheral neuronal areas, may bring about some of the distinctive morphological features of AD.

  6. Current understanding of pattern-triggered immunity and hormone-mediated defense in rice (Oryza sativa) in response to Magnaporthe oryzae infection.

    Science.gov (United States)

    Nasir, Fahad; Tian, Lei; Chang, Chunling; Li, Xiujun; Gao, Yingzhi; Tran, Lam-Son Phan; Tian, Chunjie

    2017-11-02

    Plant pathogens represent a huge threat to world food security, affecting both crop production and quality. Although significant progress has been made in improving plant immunity by expressing key, defense-related genes and proteins from different species in transgenic crops, a challenge remains for molecular breeders and biotechnologists to successfully engineer elite, transgenic crop varieties with improved resistance against critical plant pathogens. Upon pathogen attack, including infection of rice (Oryza sativa) by Magnaporthe oryzae, host plants initiate a complex defense response at molecular, biochemical and physiological levels. Plants perceive the presence of pathogens by detecting microbe-associated molecular patterns via pattern recognition receptors, and initiate a first line of innate immunity, the so-called pattern-triggered immunity (PTI). This results in a series of downstream defense responses, including the production of hormones, which collectively function to fend off pathogen attacks. A variety of studies have demonstrated that many genes are involved in the defense response of rice to M. oryzae. In this review, the current understanding of mechanisms that improve rice defense response to M. oryzae will be discussed, with special focus on PTI and the phytohormones ethylene, jasmonic acid, salicylic acid, and abscisic acid; as well as on the mediation of defense signaling mechanisms by PTI and these hormones. Potential target genes that may serve as promising candidates for improving rice immunity against M. oryzae will also be discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Constitutively active Arabidopsis MAP Kinase 3 triggers defense responses involving salicylic acid and SUMM2 resistance protein

    KAUST Repository

    Genot, Baptiste

    2017-04-12

    Mitogen-activated protein kinases (MAPKs) are important regulators of plant immunity. Most of the knowledge about the function of these pathways is derived from loss-of-function approaches. Using a gain-of-function approach, we investigated the responses controlled by a constitutively active (CA) MPK3 in Arabidopsis thaliana. CA-MPK3 plants are dwarfed and display a massive de-repression of defense genes associated with spontaneous cell death as well as accumulation of reactive oxygen species (ROS), phytoalexins and the stress-related hormones ethylene and salicylic acid (SA). Remarkably CA-MPK3/sid2 and CA-MPK3/ein2-50 lines which are impaired in SA synthesis and ethylene signaling, respectively, retain most of the CA-MPK3-associated phenotypes, indicating that constitutive activity of MPK3 can bypass SA and ethylene signaling to activate defense responses. A comparative analysis of the molecular phenotypes of CA-MPK3 and mpk4 autoimmunity suggested convergence between the MPK3 and MPK4-guarding modules. In support of this model, CA-MPK3 crosses with summ1 and summ2, two known suppressors of mpk4, resulted in a partial reversion of the CA-MPK3 phenotypes. Overall, our data unravel a novel mechanism by which the MAPK signaling network contributes to a robust defense response system.

  8. Nutritional and pathogenic fungi associated with the pine engraver beetle trigger comparable defenses in Scots pine.

    Science.gov (United States)

    Villari, Caterina; Battisti, Andrea; Chakraborty, Sourav; Michelozzi, Marco; Bonello, Pierluigi; Faccoli, Massimo

    2012-07-01

    Conifer bark beetles are often associated with fungal complexes whose components have different ecological roles. Some associated species are nutritionally obligate fungi, serving as nourishment to the larvae, whereas others are pathogenic blue-stain fungi known to be involved in the interaction with host defenses. In this study we characterized the local and systemic defense responses of Scots pine (Pinus sylvestris L.) against Ophiostoma brunneo-ciliatum Math. (a blue-stain pathogen) and Hyalorhinocladiella macrospora (Franke-Grosm.) Harr. (a nutritional fungus). These fungi are the principal associates of the pine engraver beetle, Ips acuminatus (Gyll.). Host responses were studied following inoculation with the fungi, singly and as a fungal complex, and by identifying and quantifying terpenoids, phenolic compounds and lignin. Although the length of the necrotic lesions differed between control (wound) and fungal treatments, only two compounds (pinosylvin monomethyl ether and (+)-α-pinene) were significantly affected by the presence of the fungi, indicating that Scots pine has a generic, rather than specific, induced response. The fact that both nutritional and blue-stain fungi triggered comparable induced defense responses suggests that even a non-pathogenic fungus may participate in exhausting host plant defenses, indirectly assisting in the beetle establishment process. Our findings contribute to the further development of current theory on the role of associated fungal complexes in bark beetle ecology.

  9. Sexual Responsivity and Ego Defenses

    Science.gov (United States)

    Schill, Thomas; Bekker, Demoyne

    1976-01-01

    The present study sought to determine whether high- and low-sexual responders on a double-entendre word association test differed in defensive preference on Gleser and Ihilevich's Defense Mechanism Inventory. (Author)

  10. GroEL from the endosymbiont Buchnera aphidicola betrays the aphid by triggering plant defense

    Science.gov (United States)

    Chaudhary, Ritu; Atamian, Hagop S.; Shen, Zhouxin; Briggs, Steven P.; Kaloshian, Isgouhi

    2014-01-01

    Aphids are sap-feeding plant pests and harbor the endosymbiont Buchnera aphidicola, which is essential for their fecundity and survival. During plant penetration and feeding, aphids secrete saliva that contains proteins predicted to alter plant defenses and metabolism. Plants recognize microbe-associated molecular patterns and induce pattern-triggered immunity (PTI). No aphid-associated molecular pattern has yet been identified. By mass spectrometry, we identified in saliva from potato aphids (Macrosiphum euphorbiae) 105 proteins, some of which originated from Buchnera, including the chaperonin GroEL. Because GroEL is a widely conserved bacterial protein with an essential function, we tested its role in PTI. Applying or infiltrating GroEL onto Arabidopsis (Arabidopsis thaliana) leaves induced oxidative burst and expression of PTI early marker genes. These GroEL-induced defense responses required the known coreceptor BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED RECEPTOR KINASE 1. In addition, in transgenic Arabidopsis plants, inducible expression of groEL activated PTI marker gene expression. Moreover, Arabidopsis plants expressing groEL displayed reduced fecundity of the green peach aphid (Myzus persicae), indicating enhanced resistance against aphids. Furthermore, delivery of GroEL into tomato (Solanum lycopersicum) or Arabidopsis through Pseudomonas fluorescens, engineered to express the type III secretion system, also reduced potato aphid and green peach aphid fecundity, respectively. Collectively our data indicate that GroEL is a molecular pattern that triggers PTI. PMID:24927572

  11. TRIGGER

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    Roberta Arcidiacono

    2013-01-01

    Trigger Studies Group (TSG) The Trigger Studies Group has just concluded its third 2013 workshop, where all POGs presented the improvements to the physics object reconstruction, and all PAGs have shown their plans for Trigger development aimed at the 2015 High Level Trigger (HLT) menu. The Strategy for Trigger Evolution And Monitoring (STEAM) group is responsible for Trigger menu development, path timing, Trigger performance studies coordination, HLT offline DQM as well as HLT release, menu and conditions validation – this last task in collaboration with PdmV (Physics Data and Monte Carlo Validation group). In the last months the group has delivered several HLT rate estimates and comparisons, using the available data and Monte Carlo samples. The studies were presented at the Trigger workshops in September and December, and STEAM has contacted POGs and PAGs to understand the origin of the discrepancies observed between 8 TeV data and Monte Carlo simulations. The most recent results show what the...

  12. Identification of a novel small cysteine-rich protein in the fraction from the biocontrol Fusarium oxysporum strain CS-20 that mitigates Fusarium wilt symptoms and triggers defense responses in tomato

    Directory of Open Access Journals (Sweden)

    Larisa A. Shcherbakova

    2016-01-01

    Full Text Available The biocontrol effect of the nonpathogenic F. oxysporum strain CS-20 against the tomato wilt pathogen F. oxysporum f. sp. lycopersici (FOL has been previously reported to be primarily plant-mediated. This study shows that CS-20 produces proteins, which elicit defense responses in tomato plants. Three protein-containing fractions were isolated from CS-20 biomass using size exclusion chromatography. Exposure of seedling roots to one of these fractions prior to inoculation with pathogenic FOL strains significantly reduced wilt severity. This fraction initiated an ion exchange response in cultured tomato cells resulting in a reversible alteration of extracellular pH; increased tomato chitinase activity, and induced systemic resistance by enhancing PR-1 expression in tomato leaves. Two other protein fractions were inactive in seedling protection. The main polypeptide (designated CS20EP, which was specifically present in the defense-inducing fraction and was not detected in inactive protein fractions, was identified. The nucleotide sequence encoding this protein was determined, and its complete amino acid sequence was deduced from direct Edman degradation (25 N-terminal amino acid residues and DNA sequencing. The CS20EP was found to be a small basic cysteine-rich protein with a pI of 9.87 and 23.43% of hydrophobic amino acid residues. BLAST search in the NCBI database showed that the protein is new; however, it displays 48% sequence similarity with a hypothetical protein FGSG_10784 from F. graminearum strain PH-1. The contribution of CS20EP to elicitation of tomato defense responses resulting in wilt mitigating is discussed.

  13. TRIGGER

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    R. Arcidiacono

    2013-01-01

      In 2013 the Trigger Studies Group (TSG) has been restructured in three sub-groups: STEAM, for the development of new HLT menus and monitoring their performance; STORM, for the development of HLT tools, code and actual configurations; and FOG, responsible for the online operations of the High Level Trigger. The Strategy for Trigger Evolution And Monitoring (STEAM) group is responsible for Trigger Menu development, path timing, trigger performance studies coordination, HLT offline DQM as well as HLT release, menu and conditions validation – in collaboration and with the technical support of the PdmV group. Since the end of proton-proton data taking, the group has started preparing for 2015 data taking, with collisions at 13 TeV and 25 ns bunch spacing. The reliability of the extrapolation to higher energy is being evaluated comparing the trigger rates on 7 and 8 TeV Monte Carlo samples with the data taken in the past two years. The effect of 25 ns bunch spacing is being studied on the d...

  14. TRIGGER

    CERN Multimedia

    J. Alimena

    2013-01-01

    Trigger Strategy Group The Strategy for Trigger Evolution And Monitoring (STEAM) group is responsible for the development of future High-Level Trigger menus, as well as of its DQM and validation, in collaboration and with the technical support of the PdmV group. Taking into account the beam energy and luminosity expected in 2015, a rough estimate of the trigger rates indicates a factor four increase with respect to 2012 conditions. Assuming that a factor two can be tolerated thanks to the increase in offline storage and processing capabilities, a toy menu has been developed using the new OpenHLT workflow to estimate the transverse energy/momentum thresholds that would halve the current trigger rates. The CPU time needed to run the HLT has been compared between data taken with 25 ns and 50 ns bunch spacing, for equivalent pile-up: no significant difference was observed on the global time per event distribution at the only available data point, corresponding to a pile-up of about 10 interactions. Using th...

  15. Helicoverpa zea gut-associated bacteria indirectly induce defenses in tomato by triggering a salivary elicitor(s).

    Science.gov (United States)

    Wang, Jie; Peiffer, Michelle; Hoover, Kelli; Rosa, Cristina; Zeng, Rensen; Felton, Gary W

    2017-05-01

    Insect gut-associated microbes modulating plant defenses have been observed in beetles and piercing-sucking insects, but the role of caterpillar-associated bacteria in regulating plant induced defenses has not been adequately examined. We identified bacteria from the regurgitant of field-collected Helicoverpa zea larvae using 16S ribosomal RNA (rRNA) gene sequencing and matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry. A combination of biochemical, molecular, and confocal electron microscopy methods were used to determine the role of caterpillar-associated bacteria in mediating defenses in Solanum lycopersicum (tomato). Laboratory-reared H. zea inoculated with one of the bacteria identified in field-collected H. zea, Enterobacter ludwigii, induced expression of the tomato defense-related enzyme polyphenol oxidase and genes regulated by jasmonic acid (JA), whereas the salicylic acid (SA)-responsive pathogenesis-related gene was suppressed. Additionally, saliva and its main component glucose oxidase from inoculated caterpillars played an important role in elevating tomato anti-herbivore defenses. However, there were only low detectable amounts of regurgitant or bacteria on H. zea-damaged tomato leaves. Our results suggest that H. zea gut-associated bacteria indirectly mediate plant-insect interactions by triggering salivary elicitors. These findings provide a proof of concept that introducing gut bacteria to a herbivore may provide a novel approach to pest management through indirect induction of plant resistance. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  16. Mp10 and Mp42 from the aphid species Myzus persicae trigger plant defenses in Nicotiana benthamiana through different activities.

    Science.gov (United States)

    Rodriguez, Patricia A; Stam, Remco; Warbroek, Tim; Bos, Jorunn I B

    2014-01-01

    Aphids are phloem-feeding insects that, like other plant parasites, deliver effectors inside their host to manipulate host responses. The Myzus persicae (green peach aphid) candidate effectors Mp10 and Mp42 were previously found to reduce aphid fecundity upon intracellular transient overexpression in Nicotiana benthamiana. We performed functional analyses of these proteins to investigate whether they activate defenses through similar activities. We employed a range of functional characterization experiments based on intracellular transient overexpression in N. benthamiana to determine the subcellular localization of Mp10 and Mp42 and investigate their role in activating plant defense signaling. Mp10 and Mp42 showed distinct subcellular localization in planta, suggesting that they target different host compartments. Also, Mp10 reduced the levels of Agrobacterium-mediated overexpression of proteins. This reduction was not due to an effect on Agrobacterium viability. Transient overexpression of Mp10 but not Mp42 activated jasmonic acid and salicylic acid signaling pathways and decreased susceptibility to the hemibiotrophic plant pathogen Phytophthora capsici. We found that two candidate effectors from the broad-host-range aphid M. persicae can trigger aphid defenses through different mechanisms. Importantly, we found that some (candidate) effectors such as Mp10 interfere with Agrobacterium-based overexpression assays, an important tool to study effector activity and function.

  17. The endochitinase VDECH from Verticillium dahliae inhibits spore germination and activates plant defense responses

    Science.gov (United States)

    Chitinases function in the digestion of chitin molecules, which are present principally in insects and fungi. In plants, chitinase genes play important roles in defense, and their expression can be triggered in response to both biotic and abiotic stresses. In this study, we cloned and characterized ...

  18. Interleukin-6 mediates host defense responses induced by abdominal surgery

    NARCIS (Netherlands)

    Wortel, C. H.; van Deventer, S. J.; Aarden, L. A.; Lygidakis, N. J.; Büller, H. R.; Hoek, F. J.; Horikx, J.; ten Cate, J. W.

    1993-01-01

    Cytokines have been implicated as pivotal mediators of the host defense reaction. In patients undergoing surgery we investigated the relationship between such mediators and postoperative host defense responses. Tumor necrosis factor (TNF) was determined with an immunoradiometric assay, interleukin

  19. Mental imagery affects subsequent automatic defense responses

    Directory of Open Access Journals (Sweden)

    Muriel A Hagenaars

    2015-06-01

    Full Text Available Automatic defense responses promote survival and appropriate action under threat. They have also been associated with the development of threat-related psychiatric syndromes. Targeting such automatic responses during threat may be useful in populations with frequent threat exposure. Here, two experiments explored whether mental imagery as a pre-trauma manipulation could influence fear bradycardia (a core characteristic of freezing during subsequent analogue trauma (affective picture viewing. Image-based interventions have proven successful in the treatment of threat-related disorders, and are easily applicable. In Experiment 1 43 healthy participants were randomly assigned to an imagery script condition. Participants executed a passive viewing task with blocks of neutral, pleasant and unpleasant pictures after listening to an auditory script that was either related (with a positive or a negative outcome or unrelated to the unpleasant pictures from the passive viewing task. Heart rate was assessed during script listening and during passive viewing. Imagining negative related scripts resulted in greater bradycardia (neutral-unpleasant contrast than imagining positive scripts, especially unrelated. This effect was replicated in Experiment 2 (N = 51, again in the neutral-unpleasant contrast. An extra no-script condition showed that bradycardia was not induced by the negative related script, but rather that a positive script attenuated bradycardia. These preliminary results might indicate reduced vigilance after unrelated positive events. Future research should replicate these findings using a larger sample. Either way, the findings show that highly automatic defense behavior can be influenced by relatively simple mental imagery manipulations.

  20. TRIGGER

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    Wesley Smith

    Level-1 Trigger Hardware and Software The hardware of the trigger components has been mostly finished. The ECAL Endcap Trigger Concentrator Cards (TCC) are in production while Barrel TCC firmware has been upgraded, and the Trigger Primitives can now be stored by the Data Concentrator Card for readout by the DAQ. The Regional Calorimeter Trigger (RCT) system is complete, and the timing is being finalized. All 502 HCAL trigger links to RCT run without error. The HCAL muon trigger timing has been equalized with DT, RPC, CSC and ECAL. The hardware and firmware for the Global Calorimeter Trigger (GCT) jet triggers are being commissioned and data from these triggers is available for readout. The GCT energy sums from rings of trigger towers around the beam pipe beam have been changed to include two rings from both sides. The firmware for Drift Tube Track Finder, Barrel Sorter and Wedge Sorter has been upgraded, and the synchronization of the DT trigger is satisfactory. The CSC local trigger has operated flawlessly u...

  1. TRIGGER

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    Wesley Smith

    Level-1 Trigger Hardware and Software The trigger synchronization procedures for running with cosmic muons and operating with the LHC were reviewed during the May electronics week. Firmware maintenance issues were also reviewed. Link tests between the new ECAL endcap trigger concentrator cards (TCC48) and the Regional Calorimeter Trigger have been performed. Firmware for the energy sum triggers and an upgraded tau trigger of the Global Calorimeter Triggers has been developed and is under test. The optical fiber receiver boards for the Track-Finder trigger theta links of the DT chambers are now all installed. The RPC trigger is being made more robust by additional chamber and cable shielding and also by firmware upgrades. For the CSC’s the front-end and trigger motherboard firmware have been updated. New RPC patterns and DT/CSC lookup tables taking into account phi asymmetries in the magnetic field configuration are under study. The motherboard for the new pipeline synchronizer of the Global Trigg...

  2. TRIGGER

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    W. Smith

    2012-01-01

      Level-1 Trigger The Level-1 Trigger group is ready to deploy improvements to the L1 Trigger algorithms for 2012. These include new high-PT patterns for the RPC endcap, an improved CSC PT assignment, a new PT-matching algorithm for the Global Muon Trigger, and new calibrations for ECAL, HCAL, and the Regional Calorimeter Trigger. These should improve the efficiency, rate, and stability of the L1 Trigger. The L1 Trigger group also is migrating the online systems to SLC5. To make the data transfer from the Global Calorimeter Trigger to the Global Trigger more reliable and also to allow checking the data integrity online, a new optical link system has been developed by the GCT and GT groups and successfully tested at the CMS electronics integration facility in building 904. This new system is now undergoing further tests at Point 5 before being deployed for data-taking this year. New L1 trigger menus have recently been studied and proposed by Emmanuelle Perez and the L1 Detector Performance Group...

  3. TRIGGER

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    W. Smith

    At the March meeting, the CMS trigger group reported on progress in production, tests in the Electronics Integration Center (EIC) in Prevessin 904, progress on trigger installation in the underground counting room at point 5, USC55, the program of trigger pattern tests and vertical slice tests and planning for the Global Runs starting this summer. The trigger group is engaged in the final stages of production testing, systems integration, and software and firmware development. Most systems are delivering final tested electronics to CERN. The installation in USC55 is underway and integration testing is in full swing. A program of orderly connection and checkout with subsystems and central systems has been developed. This program includes a series of vertical subsystem slice tests providing validation of a portion of each subsystem from front-end electronics through the trigger and DAQ to data captured and stored. After full checkout, trigger subsystems will be then operated in the CMS Global Runs. Continuous...

  4. TRIGGER

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    by Wesley Smith

    2010-01-01

    Level-1 Trigger Hardware and Software The overall status of the L1 trigger has been excellent and the running efficiency has been high during physics fills. The timing is good to about 1%. The fine-tuning of the time synchronization of muon triggers is ongoing and will be completed after more than 10 nb-1 of data have been recorded. The CSC trigger primitive and RPC trigger timing have been refined. A new configuration for the CSC Track Finder featured modified beam halo cuts and improved ghost cancellation logic. More direct control was provided for the DT opto-receivers. New RPC Cosmic Trigger (RBC/TTU) trigger algorithms were enabled for collision runs. There is further work planned during the next technical stop to investigate a few of the links from the ECAL to the Regional Calorimeter Trigger (RCT). New firmware and a new configuration to handle trigger rate spikes in the ECAL barrel are also being tested. A board newly developed by the tracker group (ReTRI) has been installed and activated to block re...

  5. TRIGGER

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    Wesley Smith

    Level-1 Trigger Hardware and Software The production of the trigger hardware is now basically finished, and in time for the turn-on of the LHC. The last boards produced are the Trigger Concentrator Cards for the ECAL Endcaps (TCC-EE). After the recent installation of the four EE Dees, the TCC-EE prototypes were used for their commissioning. Production boards are arriving and are being tested continuously, with the last ones expected in November. The Regional Calorimeter Trigger hardware is fully integrated after installation of the last EE cables. Pattern tests from the HCAL up to the GCT have been performed successfully. The HCAL triggers are fully operational, including the connection of the HCAL-outer and forward-HCAL (HO/HF) technical triggers to the Global Trigger. The HCAL Trigger and Readout (HTR) board firmware has been updated to permit recording of the tower “feature bit” in the data. The Global Calorimeter Trigger hardware is installed, but some firmware developments are still n...

  6. TRIGGER

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    W. Smith

    2010-01-01

    Level-1 Trigger Hardware and Software The Level-1 Trigger hardware has performed well during both the recent proton-proton and heavy ion running. Efforts were made to improve the visibility and handling of alarms and warnings. The tracker ReTRI boards that prevent fixed frequencies of Level-1 Triggers are now configured through the Trigger Supervisor. The Global Calorimeter Trigger (GCT) team has introduced a buffer cleanup procedure at stops and a reset of the QPLL during configuring to ensure recalibration in case of a switch from the LHC clock to the local clock. A device to test the cables between the Regional Calorimeter Trigger and the GCT has been manufactured. A wrong charge bit was fixed in the CSC Trigger. The ECAL group is improving crystal masking and spike suppression in the trigger primitives. New firmware for the Drift Tube Track Finder (DTTF) sorters was developed to improve fake track tagging and sorting. Zero suppression was implemented in the DT Sector Collector readout. The track finder b...

  7. TRIGGER

    CERN Multimedia

    Wesley Smith

    Trigger Hardware The status of the trigger components was presented during the September CMS Week and Annual Review and at the monthly trigger meetings in October and November. Procedures for cold and warm starts (e.g. refreshing of trigger parameters stored in registers) of the trigger subsystems have been studied. Reviews of parts of the Global Calorimeter Trigger (GCT) and the Global Trigger (GT) have taken place in October and November. The CERN group summarized the status of the Trigger Timing and Control (TTC) system. All TTC crates and boards are installed in the underground counting room, USC55. The central clock system will be upgraded in December (after the Global Run at the end of November GREN) to the new RF2TTC LHC machine interface timing module. Migration of subsystem's TTC PCs to SLC4/ XDAQ 3.12 is being prepared. Work is on going to unify the access to Local Timing Control (LTC) and TTC CMS interface module (TTCci) via SOAP (Simple Object Access Protocol, a lightweight XML-based messaging ...

  8. TRIGGER

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    W. Smith from contributions of C. Leonidopoulos

    2010-01-01

    Level-1 Trigger Hardware and Software Since nearly all of the Level-1 (L1) Trigger hardware at Point 5 has been commissioned, activities during the past months focused on the fine-tuning of synchronization, particularly for the ECAL and the CSC systems, on firmware upgrades and on improving trigger operation and monitoring. Periodic resynchronizations or hard resets and a shortened luminosity section interval of 23 seconds were implemented. For the DT sector collectors, an automatic power-off was installed in case of high temperatures, and the monitoring capabilities of the opto-receivers and the mini-crates were enhanced. The DTTF and the CSCTF now have improved memory lookup tables. The HCAL trigger primitive logic implemented a new algorithm providing better stability of the energy measurement in the presence of any phase misalignment. For the Global Calorimeter Trigger, additional Source Cards have been manufactured and tested. Testing of the new tau, missing ET and missing HT algorithms is underw...

  9. In Silico Identification of Mimicking Molecules as Defense Inducers Triggering Jasmonic Acid Mediated Immunity against Alternaria Blight Disease in Brassica Species

    Directory of Open Access Journals (Sweden)

    Dinesh Pandey

    2017-04-01

    Full Text Available Alternaria brassicae and Alternaria brassicicola are two major phytopathogenic fungi which cause Alternaria blight, a recalcitrant disease on Brassica crops throughout the world, which is highly destructive and responsible for significant yield losses. Since no resistant source is available against Alternaria blight, therefore, efforts have been made in the present study to identify defense inducer molecules which can induce jasmonic acid (JA mediated defense against the disease. It is believed that JA triggered defense response will prevent necrotrophic mode of colonization of Alternaria brassicae fungus. The JA receptor, COI1 is one of the potential targets for triggering JA mediated immunity through interaction with JA signal. In the present study, few mimicking compounds more efficient than naturally occurring JA in terms of interaction with COI1 were identified through virtual screening and molecular dynamics simulation studies. A high quality structural model of COI1 was developed using the protein sequence of Brassica rapa. This was followed by virtual screening of 767 analogs of JA from ZINC database for interaction with COI1. Two analogs viz. ZINC27640214 and ZINC43772052 showed more binding affinity with COI1 as compared to naturally occurring JA. Molecular dynamics simulation of COI1 and COI1-JA complex, as well as best screened interacting structural analogs of JA with COI1 was done for 50 ns to validate the stability of system. It was found that ZINC27640214 possesses efficient, stable, and good cell permeability properties. Based on the obtained results and its physicochemical properties, it is capable of mimicking JA signaling and may be used as defense inducers for triggering JA mediated resistance against Alternaria blight, only after further validation through field trials.

  10. Can Hospital Form Trigger Fear Response?

    Science.gov (United States)

    Pati, Debajyoti; O'Boyle, Michael; Hou, Jiancheng; Nanda, Upali; Ghamari, Hessam

    2016-04-01

    To examine whether exposure to curve versus sharp contours in the built healthcare setting produces systematic and identifiable patterns of amygdala activation and behavioral response in healthy adults. Recent studies in cognitive neuroscience suggest that humans prefer objects with a curved contour compared with objects that have pointed features and a sharp-angled contour. An implicit perception of threat represented by sharp objects, in humans, was hypothesized to explain this bias. The study adopted a within-subject experimental design, where 36 subjects (representing three age-groups and both sexes) were exposed to a randomized order of 312 real-life images (objects, interiors, exteriors, landscape, and a set of control images). Amygdala activation was simultaneously captured using functional magnetic resonance imaging technology. Subjects' preference (like/dislike) data were also collected while in the scanner. Data were collected in 2013. In case of images depicting landscape and healthcare objects, brain scans show significant higher amygdala activation associated with sharp contours. However, in relation to images depicting hospital interiors and exterior envelops, brain scans show significant higher amygdala activation associated with curve contours. These activations pertain to exposure during the precognitive stages of the subjects' perception. Hospital forms do have systematic impact on fear response during precognitive stages of human perception. Whether this first impression colors the subsequent experience of an actual patient with real illness or injury is unknown. © The Author(s) 2016.

  11. TRIGGER

    CERN Multimedia

    W. Smith

    Level-1 Trigger Hardware and Software The trigger system has been constantly in use in cosmic and commissioning data taking periods. During CRAFT running it delivered 300 million muon and calorimeter triggers to CMS. It has performed stably and reliably. During the abort gaps it has also provided laser and other calibration triggers. Timing issues, namely synchronization and latency issues, have been solved. About half of the Trigger Concentrator Cards for the ECAL Endcap (TCC-EE) are installed, and the firmware is being worked on. The production of the other half has started. The HCAL Trigger and Readout (HTR) card firmware has been updated, and new features such as fast parallel zero-suppression have been included. Repairs of drift tube (DT) trigger mini-crates, optical links and receivers of sector collectors are under way and have been completed on YB0. New firmware for the optical receivers of the theta links to the drift tube track finder is being installed. In parallel, tests with new eta track finde...

  12. TRIGGER

    CERN Multimedia

    R. Carlin with contributions from D. Acosta

    2012-01-01

    Level-1 Trigger Data-taking continues at cruising speed, with high availability of all components of the Level-1 trigger. We have operated the trigger up to a luminosity of 7.6E33, where we approached 100 kHz using the 7E33 prescale column.  Recently, the pause without triggers in case of an automatic "RESYNC" signal (the "settle" and "recover" time) was reduced in order to minimise the overall dead-time. This may become very important when the LHC comes back with higher energy and luminosity after LS1. We are also preparing for data-taking in the proton-lead run in early 2013. The CASTOR detector will make its comeback into CMS and triggering capabilities are being prepared for this. Steps to be taken include improved cooperation with the TOTEM trigger system and using the LHC clock during the injection and ramp phases of LHC. Studies are being finalised that will have a bearing on the Trigger Technical Design Report (TDR), which is to be rea...

  13. TRIGGER

    CERN Multimedia

    Wesley Smith

    Level-1 Trigger Hardware and Software The final parts of the Level-1 trigger hardware are now being put in place. For the ECAL endcaps, more than half of the Trigger Concentrator Cards for the ECAL Endcap (TCC-EE) are now available at CERN, such that one complete endcap can be covered. The Global Trigger now correctly handles ECAL calibration sequences, without being influenced by backpressure. The Regional Calorimeter Trigger (RCT) hardware is complete and working in USC55. Intra-crate tests of all 18 RCT crates and the Global Calorimeter Trigger (GCT) are regularly taking place. Pattern tests have successfully captured data from HCAL through RCT to the GCT Source Cards. HB/HE trigger data are being compared with emulator results to track down the very few remaining hardware problems. The treatment of hot and dead cells, including their recording in the database, has been defined. For the GCT, excellent agreement between the emulator and data has been achieved for jets and HF ET sums. There is still som...

  14. TRIGGER

    CERN Multimedia

    W. Smith

    At the December meeting, the CMS trigger group reported on progress in production, tests in the Electronics Integration Center (EIC) in Prevessin 904, progress on trigger installation in the underground counting room at point 5, USC55, and results from the Magnet Test and Cosmic Challenge (MTCC) phase II. The trigger group is engaged in the final stages of production testing, systems integration, and software and firmware development. Most systems are delivering final tested electronics to CERN. The installation in USC55 is underway and moving towards integration testing. A program of orderly connection and checkout with subsystems and central systems has been developed. This program includes a series of vertical subsystem slice tests providing validation of a portion of each subsystem from front-end electronics through the trigger and DAQ to data captured and stored. This is combined with operations and testing without beam that will continue until startup. The plans for start-up, pilot and early running tri...

  15. TRIGGER

    CERN Multimedia

    W. Smith, from contributions of D. Acosta

    2012-01-01

      The L1 Trigger group deployed several major improvements this year. Compared to 2011, the single-muon trigger rate has been reduced by a factor of 2 and the η coverage has been restored to 2.4, with high efficiency. During the current technical stop, a higher jet seed threshold will be applied in the Global Calorimeter Trigger in order to significantly reduce the strong pile-up dependence of the HT and multi-jet triggers. The currently deployed L1 menu, with the “6E33” prescales, has a total rate of less than 100 kHz and operates with detector readout dead time of less than 3% for luminosities up to 6.5 × 1033 cm–2s–1. Further prescale sets have been created for 7 and 8 × 1033 cm–2s–1 luminosities. The L1 DPG is evaluating the performance of the Trigger for upcoming conferences and publication. Progress on the Trigger upgrade was reviewed during the May Upgrade Week. We are investigating scenarios for stagin...

  16. TRIGGER

    CERN Multimedia

    Wesley Smith

    2011-01-01

    Level-1 Trigger Hardware and Software New Forward Scintillating Counters (FSC) for rapidity gap measurements have been installed and integrated into the Trigger recently. For the Global Muon Trigger, tuning of quality criteria has led to improvements in muon trigger efficiencies. Several subsystems have started campaigns to increase spares by recovering boards or producing new ones. The barrel muon sector collector test system has been reactivated, new η track finder boards are in production, and φ track finder boards are under revision. In the CSC track finder, an η asymmetry problem has been corrected. New pT look-up tables have also improved efficiency. RPC patterns were changed from four out of six coincident layers to three out of six in the barrel, which led to a significant increase in efficiency. A new PAC firmware to trigger on heavy stable charged particles allows looking for chamber hit coincidences in two consecutive bunch-crossings. The redesign of the L1 Trigger Emulator...

  17. TRIGGER

    CERN Multimedia

    W. Smith from contributions of C. Leonidopoulos, I. Mikulec, J. Varela and C. Wulz.

    Level-1 Trigger Hardware and Software Over the past few months, the Level-1 trigger has successfully recorded data with cosmic rays over long continuous stretches as well as LHC splash events, beam halo, and collision events. The L1 trigger hardware, firmware, synchronization, performance and readiness for beam operation were reviewed in October. All L1 trigger hardware is now installed at Point 5, and most of it is completely commissioned. While the barrel ECAL Trigger Concentrator Cards are fully operational, the recently delivered endcap ECAL TCC system is still being commissioned. For most systems there is a sufficient number of spares available, but for a few systems additional reserve modules are needed. It was decided to increase the overall L1 latency by three bunch crossings to increase the safety margin for trigger timing adjustments. In order for CMS to continue data taking during LHC frequency ramps, the clock distribution tree needs to be reset. The procedures for this have been tested. A repl...

  18. TRIGGER

    CERN Multimedia

    W. Smith

    Level-1 Trigger Hardware and Software The road map for the final commissioning of the level-1 trigger system has been set. The software for the trigger subsystems is being upgraded to run under CERN Scientific Linux 4 (SLC4). There is also a new release for the Trigger Supervisor (TS 1.4), which implies upgrade work by the subsystems. As reported by the CERN group, a campaign to tidy the Trigger Timing and Control (TTC) racks has begun. The machine interface was upgraded by installing the new RF2TTC module, which receives RF signals from LHC Point 4. Two Beam Synchronous Timing (BST) signals, one for each beam, can now be received in CMS. The machine group will define the exact format of the information content shortly. The margin on the locking range of the CMS QPLL is planned for study for different subsystems in the next Global Runs, using a function generator. The TTC software has been successfully tested on SLC4. Some TTC subsystems have already been upgraded to SLC4. The TTCci Trigger Supervisor ...

  19. Piriformospora indica root colonization triggers local and systemic root responses and inhibits secondary colonization of distal roots.

    Directory of Open Access Journals (Sweden)

    Lorenzo Pedrotti

    Full Text Available Piriformosporaindica is a basidiomycete fungus colonizing roots of a wide range of higher plants, including crop plants and the model plant Arabidopsis thaliana. Previous studies have shown that P. indica improves growth, and enhances systemic pathogen resistance in leaves of host plants. To investigate systemic effects within the root system, we established a hydroponic split-root cultivation system for Arabidopsis. Using quantitative real-time PCR, we show that initial P. indica colonization triggers a local, transient response of several defense-related transcripts, of which some were also induced in shoots and in distal, non-colonized roots of the same plant. Systemic effects on distal roots included the inhibition of secondary P. indica colonization. Faster and stronger induction of defense-related transcripts during secondary inoculation revealed that a P. indica pretreatment triggers root-wide priming of defense responses, which could cause the observed reduction of secondary colonization levels. Secondary P. indica colonization also induced defense responses in distant, already colonized parts of the root. Endophytic fungi therefore trigger a spatially specific response in directly colonized and in systemic root tissues of host plants.

  20. Piriformospora indica root colonization triggers local and systemic root responses and inhibits secondary colonization of distal roots.

    Science.gov (United States)

    Pedrotti, Lorenzo; Mueller, Martin J; Waller, Frank

    2013-01-01

    Piriformosporaindica is a basidiomycete fungus colonizing roots of a wide range of higher plants, including crop plants and the model plant Arabidopsis thaliana. Previous studies have shown that P. indica improves growth, and enhances systemic pathogen resistance in leaves of host plants. To investigate systemic effects within the root system, we established a hydroponic split-root cultivation system for Arabidopsis. Using quantitative real-time PCR, we show that initial P. indica colonization triggers a local, transient response of several defense-related transcripts, of which some were also induced in shoots and in distal, non-colonized roots of the same plant. Systemic effects on distal roots included the inhibition of secondary P. indica colonization. Faster and stronger induction of defense-related transcripts during secondary inoculation revealed that a P. indica pretreatment triggers root-wide priming of defense responses, which could cause the observed reduction of secondary colonization levels. Secondary P. indica colonization also induced defense responses in distant, already colonized parts of the root. Endophytic fungi therefore trigger a spatially specific response in directly colonized and in systemic root tissues of host plants.

  1. TRIGGER

    CERN Multimedia

    W. Smith

    2011-01-01

    Level-1 Trigger Hardware and Software Overall the L1 trigger hardware has been running very smoothly during the last months of proton running. Modifications for the heavy-ion run have been made where necessary. The maximal design rate of 100 kHz can be sustained without problems. All L1 latencies have been rechecked. The recently installed Forward Scintillating Counters (FSC) are being used in the heavy ion run. The ZDC scintillators have been dismantled, but the calorimeter itself remains. We now send the L1 accept signal and other control signals to TOTEM. Trigger cables from TOTEM to CMS will be installed during the Christmas shutdown, so that the TOTEM data can be fully integrated within the CMS readout. New beam gas triggers have been developed, since the BSC-based trigger is no longer usable at high luminosities. In particular, a special BPTX signal is used after a quiet period with no collisions. There is an ongoing campaign to provide enough spare modules for the different subsystems. For example...

  2. TRIGGER

    CERN Multimedia

    by Wesley Smith

    2011-01-01

    Level-1 Trigger Hardware and Software After the winter shutdown minor hardware problems in several subsystems appeared and were corrected. A reassessment of the overall latency has been made. In the TTC system shorter cables between TTCci and TTCex have been installed, which saved one bunch crossing, but which may have required an adjustment of the RPC timing. In order to tackle Pixel out-of-syncs without influencing other subsystems, a special hardware/firmware re-sync protocol has been introduced in the Global Trigger. The link between the Global Calorimeter Trigger and the Global Trigger with the new optical Global Trigger Interface and optical receiver daughterboards has been successfully tested in the Electronics Integration Centre in building 904. New firmware in the GCT now allows a setting to remove the HF towers from energy sums. The HF sleeves have been replaced, which should lead to reduced rates of anomalous signals, which may allow their inclusion after this is validated. For ECAL, improvements i...

  3. Nest defense- Grassland bird responses to snakes

    Science.gov (United States)

    Ellison, Kevin S.; Ribic, Christine

    2012-01-01

    Predation is the primary source of nest mortality for most passerines; thus, behaviors to reduce the impacts of predation are frequently quantified to study learning, adaptation, and coevolution among predator and prey species. Video surveillance of nests has made it possible to examine real-time parental nest defense. During 1999-2009, we used video camera systems to monitor 518 nests of grassland birds. We reviewed video of 48 visits by snakes to 34 nests; 37 of these visits resulted in predation of active nests. When adult birds encountered snakes at the nest (n = 33 visits), 76% of the encounters resulted in a form of nest defense (nonaggressive or aggressive); in 47% of the encounters, birds physically struck snakes. When defending nests, most birds pecked at the snakes; Eastern Meadowlarks (Sturnella magna) and Bobolinks (Dolichonyx oryzivorus) pecked most frequently in anyone encounter. Also, two Eastern Meadowlarks ran around snakes, frequently with wings spread, and three Bobolinks struck at snakes from the air. Nest defense rarely appeared to alter snake behavior; the contents of seven nests defended aggressively and two nests defended nonaggressively were partially depredated, whereas the contents of six nests defended each way were consumed completely. One fledgling was produced at each of three nests that had been aggressively defended. During aggressive defense, one snake appeared to be driven away and one was wounded. Our findings should be a useful starting point for further research. For example, future researchers may be able to determine whether the behavioral variation we observed in nest defense reflects species differences, anatomic or phylogenetic constraints, or individual differences related to a bird's prior experience. There appears to be much potential for studying nest defense behavior using video recording of both real and simulated encounters. 

  4. Phosphoinositide-signaling is one component of a robust plant defense response.

    Directory of Open Access Journals (Sweden)

    Imara Yasmin Perera

    2014-06-01

    Full Text Available The phosphoinositide pathway and inositol-1,4,5-triphosphate (InsP3 have been implicated in plant responses to many abiotic stresses; however, their role in response to biotic stress is not well characterized. In the current study, we show that both basal defense and systemic acquired resistance responses are affected in transgenic plants constitutively expressing the human type I inositol polyphosphate 5-phosphatase (InsP 5-ptase which have greatly reduced InsP3 levels. Flagellin induced Ca2+-release as well as the expressions of some flg22 responsive genes were attenuated in the InsP 5-ptase plants. Furthermore, the InsP 5-ptase plants were more susceptible to virulent and avirulent strains of Pseudomonas syringae pv. tomato (PstDC3000. The InsP 5-ptase plants had lower basal salicylic acid (SA levels and the induction of SAR in systemic leaves was reduced and delayed. Reciprocal exudate experiments showed that although the InsP 5-ptase plants produced equally effective molecules that could trigger PR-1 gene expression in wild type plants, exudates collected from either wild type or InsP 5-ptase plants triggered less PR-1 gene expression in InsP 5-ptase plants. Additionally, expression profiles indicated that several defense genes including PR-1, PR-2, PR-5 and AIG1 were basally down regulated in the InsP 5-ptase plants compared with wild type. Upon pathogen attack, expression of these genes was either not induced or showed delayed induction in systemic leaves. Our study shows that phosphoinositide signaling is one component of the plant defense network and is involved in both basal and systemic responses. The dampening of InsP3-mediated signaling affects Ca2+ release, modulates defense gene expression and compromises plant defense responses.

  5. Seaweed polysaccharides and derived oligosaccharides stimulate defense responses and protection against pathogens in plants.

    Science.gov (United States)

    Vera, Jeannette; Castro, Jorge; Gonzalez, Alberto; Moenne, Alejandra

    2011-12-01

    Plants interact with the environment by sensing "non-self" molecules called elicitors derived from pathogens or other sources. These molecules bind to specific receptors located in the plasma membrane and trigger defense responses leading to protection against pathogens. In particular, it has been shown that cell wall and storage polysaccharides from green, brown and red seaweeds (marine macroalgae) corresponding to ulvans, alginates, fucans, laminarin and carrageenans can trigger defense responses in plants enhancing protection against pathogens. In addition, oligosaccharides obtained by depolymerization of seaweed polysaccharides also induce protection against viral, fungal and bacterial infections in plants. In particular, most seaweed polysaccharides and derived oligosaccharides trigger an initial oxidative burst at local level and the activation of salicylic (SA), jasmonic acid (JA) and/or ethylene signaling pathways at systemic level. The activation of these signaling pathways leads to an increased expression of genes encoding: (i) Pathogenesis-Related (PR) proteins with antifungal and antibacterial activities; (ii) defense enzymes such as pheylalanine ammonia lyase (PAL) and lipoxygenase (LOX) which determine accumulation of phenylpropanoid compounds (PPCs) and oxylipins with antiviral, antifugal and antibacterial activities and iii) enzymes involved in synthesis of terpenes, terpenoids and/or alkaloids having antimicrobial activities. Thus, seaweed polysaccharides and their derived oligosaccharides induced the accumulation of proteins and compounds with antimicrobial activities that determine, at least in part, the enhanced protection against pathogens in plants.

  6. Seaweed Polysaccharides and Derived Oligosaccharides Stimulate Defense Responses and Protection Against Pathogens in Plants

    Directory of Open Access Journals (Sweden)

    Alejandra Moenne

    2011-11-01

    Full Text Available Plants interact with the environment by sensing “non-self” molecules called elicitors derived from pathogens or other sources. These molecules bind to specific receptors located in the plasma membrane and trigger defense responses leading to protection against pathogens. In particular, it has been shown that cell wall and storage polysaccharides from green, brown and red seaweeds (marine macroalgae corresponding to ulvans, alginates, fucans, laminarin and carrageenans can trigger defense responses in plants enhancing protection against pathogens. In addition, oligosaccharides obtained by depolymerization of seaweed polysaccharides also induce protection against viral, fungal and bacterial infections in plants. In particular, most seaweed polysaccharides and derived oligosaccharides trigger an initial oxidative burst at local level and the activation of salicylic (SA, jasmonic acid (JA and/or ethylene signaling pathways at systemic level. The activation of these signaling pathways leads to an increased expression of genes encoding: (i Pathogenesis-Related (PR proteins with antifungal and antibacterial activities; (ii defense enzymes such as pheylalanine ammonia lyase (PAL and lipoxygenase (LOX which determine accumulation of phenylpropanoid compounds (PPCs and oxylipins with antiviral, antifugal and antibacterial activities and iii enzymes involved in synthesis of terpenes, terpenoids and/or alkaloids having antimicrobial activities. Thus, seaweed polysaccharides and their derived oligosaccharides induced the accumulation of proteins and compounds with antimicrobial activities that determine, at least in part, the enhanced protection against pathogens in plants.

  7. Involvement of the Electrophilic Isothiocyanate Sulforaphane in Arabidopsis Local Defense Responses1

    Science.gov (United States)

    Andersson, Mats X.; Nilsson, Anders K.; Johansson, Oskar N.; Boztaş, Gülin; Adolfsson, Lisa E.; Pinosa, Francesco; Petit, Christel Garcia; Aronsson, Henrik; Mackey, David; Tör, Mahmut; Hamberg, Mats; Ellerström, Mats

    2015-01-01

    Plants defend themselves against microbial pathogens through a range of highly sophisticated and integrated molecular systems. Recognition of pathogen-secreted effector proteins often triggers the hypersensitive response (HR), a complex multicellular defense reaction where programmed cell death of cells surrounding the primary site of infection is a prominent feature. Even though the HR was described almost a century ago, cell-to-cell factors acting at the local level generating the full defense reaction have remained obscure. In this study, we sought to identify diffusible molecules produced during the HR that could induce cell death in naive tissue. We found that 4-methylsulfinylbutyl isothiocyanate (sulforaphane) is released by Arabidopsis (Arabidopsis thaliana) leaf tissue undergoing the HR and that this compound induces cell death as well as primes defense in naive tissue. Two different mutants impaired in the pathogen-induced accumulation of sulforaphane displayed attenuated programmed cell death upon bacterial and oomycete effector recognition as well as decreased resistance to several isolates of the plant pathogen Hyaloperonospora arabidopsidis. Treatment with sulforaphane provided protection against a virulent H. arabidopsidis isolate. Glucosinolate breakdown products are recognized as antifeeding compounds toward insects and recently also as intracellular signaling and bacteriostatic molecules in Arabidopsis. The data presented here indicate that these compounds also trigger local defense responses in Arabidopsis tissue. PMID:25371552

  8. Extracellular Alkalinization as a Defense Response in Potato Cells.

    Science.gov (United States)

    Moroz, Natalia; Fritch, Karen R; Marcec, Matthew J; Tripathi, Diwaker; Smertenko, Andrei; Tanaka, Kiwamu

    2017-01-01

    A quantitative and robust bioassay to assess plant defense response is important for studies of disease resistance and also for the early identification of disease during pre- or non-symptomatic phases. An increase in extracellular pH is known to be an early defense response in plants. In this study, we demonstrate extracellular alkalinization as a defense response in potatoes. Using potato suspension cell cultures, we observed an alkalinization response against various pathogen- and plant-derived elicitors in a dose- and time-dependent manner. We also assessed the defense response against a variety of potato pathogens, such as protists ( Phytophthora infestans and Spongospora subterranea ) and fungi ( Verticillium dahliae and Colletotrichum coccodes ). Our results show that extracellular pH increases within 30 min in proportion to the number of pathogen spores added. Consistently with the alkalinization effect, the higher transcription level of several defense-related genes and production of reactive oxygen species was observed. Our results demonstrate that the alkalinization response is an effective marker to study early stages of defense response in potatoes.

  9. TRIGGER

    CERN Multimedia

    W. Smith

    Level-1 Trigger Hardware The CERN group is working on the TTC system. Seven out of nine sub-detector TTC VME crates with all fibers cabled are installed in USC55. 17 Local Trigger Controller (LTC) boards have been received from production and are in the process of being tested. The RF2TTC module replacing the TTCmi machine interface has been delivered and will replace the TTCci module used to mimic the LHC clock. 11 out of 12 crates housing the barrel ECAL off-detector electronics have been installed in USC55 after commissioning at the Electronics Integration Centre in building 904. The cabling to the Regional Calorimeter Trigger (RCT) is terminated. The Lisbon group has completed the Synchronization and Link mezzanine board (SLB) production. The Palaiseau group has fully tested and installed 33 out of 40 Trigger Concentrator Cards (TCC). The seven remaining boards are being remade. The barrel TCC boards have been tested at the H4 test beam, and good agreement with emulator predictions were found. The cons...

  10. Ribonucleotide triggered DNA damage and RNA-DNA damage responses.

    Science.gov (United States)

    Wallace, Bret D; Williams, R Scott

    2014-01-01

    Research indicates that the transient contamination of DNA with ribonucleotides exceeds all other known types of DNA damage combined. The consequences of ribose incorporation into DNA, and the identity of protein factors operating in this RNA-DNA realm to protect genomic integrity from RNA-triggered events are emerging. Left unrepaired, the presence of ribonucleotides in genomic DNA impacts cellular proliferation and is associated with chromosome instability, gross chromosomal rearrangements, mutagenesis, and production of previously unrecognized forms of ribonucleotide-triggered DNA damage. Here, we highlight recent findings on the nature and structure of DNA damage arising from ribonucleotides in DNA, and the identification of cellular factors acting in an RNA-DNA damage response (RDDR) to counter RNA-triggered DNA damage.

  11. The sulfated laminarin triggers a stress transcriptome before priming the SA- and ROS-dependent defenses during grapevine's induced resistance against Plasmopara viticola.

    Directory of Open Access Journals (Sweden)

    Adrien Gauthier

    Full Text Available Grapevine (Vitis vinifera is susceptible to many pathogens which cause significant losses to viticulture worldwide. Chemical control is available, but agro-ecological concerns have raised interest in alternative methods, especially in triggering plant immunity by elicitor treatments. The β-glucan laminarin (Lam and its sulfated derivative (PS3 have been previously demonstrated to induce resistance in grapevine against downy mildew (Plasmopara viticola. However, if Lam elicits classical grapevine defenses such as oxidative burst, pathogenesis-related (PR-proteins and phytoalexin production, PS3 triggered grapevine resistance via a poorly understood priming phenomenon. The aim of this study was to identify the molecular mechanisms of the PS3-induced resistance. For this purpose we studied i the signaling events and transcriptome reprogramming triggered by PS3 treatment on uninfected grapevine, ii grapevine immune responses primed by PS3 during P. viticola infection. Our results showed that i PS3 was unable to elicit reactive oxygen species (ROS production, cytosolic Ca(2+ concentration variations, mitogen-activated protein kinase (MAPK activation but triggered a long lasting plasma membrane depolarization in grapevine cells, ii PS3 and Lam shared a common stress-responsive transcriptome profile that partly overlapped the salicylate- (SA and jasmonate-(JA-dependent ones. After P. viticola inoculation, PS3 specifically primed the SA- and ROS-dependent defense pathways leading to grapevine induced resistance against this biotroph. Interestingly pharmacological approaches suggested that the plasma membrane depolarization and the downstream ROS production are key events of the PS3-induced resistance.

  12. Alternative Strategy for Alzheimer’s Disease: Stress Response Triggers

    Directory of Open Access Journals (Sweden)

    Joan Smith Sonneborn

    2012-01-01

    Full Text Available Stress resistance capacity is a hallmark of longevity protection and survival throughout the plant and animal kingdoms. Latent pathway activation of protective cascades, triggered by environmental challenges to tolerate heat, oxygen deprivation, reactive oxygen species (ROS, diet restriction, and exercise provides tolerance to these stresses. Age-related changes and disease vulnerability mark an increase in damage, like damage induced by environmental challenges. An alternative approach to immunotherapy intervention in Alzheimer’s Disease is the use of mimetics of stress to upregulate endogenous protective cascades to repair age damage, shift the balance of apoptosis to regeneration to promote delay of onset, and even progression of Alzheimer’s disease memory dysfunction. Mimetics of environmental stress, hormetic agents, and triggers, endogenous or engineered, can “trick” activation of expression patterns of repair and rejuvenation. Examples of known candidate triggers of heat response, endogenous antioxidants, DNA repair, exercise, hibernation, and telomeres are available for AD intervention trials. Telomeres and telomerase emerge as major regulators in crossroads of senescence, cancer, and rejuvenation responsive to mimetics of telomeres. Lessons emerge from transgenic rodent models, the long-lived mole rat, clinical studies, and conserved innate pathways of stress resistance. Cross-reaction of benefits of different triggers promises intervention into seemingly otherwise unrelated diseases.

  13. Impact of defense conversion and US response

    International Nuclear Information System (INIS)

    Montanarelli, N.

    1994-01-01

    Conversion from military to civilian products due to defense conversion after the end of the Cold War takes a long as 20 years. In USA there are over 50 government programs funded to assist in defence conversion. This paper concentrates on the three major programs that will have the greatest impact on the economy, in the framework of the issues and needs of American industry. Federal government and US industry are making a considerable effort to transform how to do business today. One of the most important emerging themes in the federal program is international competitiveness. Large federal expenditures are made to support research and development that will increase productivity, thereby helping industry in global economic competition. This, in turn will play a key role in absorbing a large quantity od resources affected by the end of the Cold War

  14. Defense response in Nopal Cladodes infiltrated with Salmonella Typhimurium

    Science.gov (United States)

    Foodborne outbreaks associated with fresh produce have increased in recent years. Pre-harvest contamination of fresh produce via irrigation water, soil, or other animal vectors may be responsible for many of these outbreaks. We evaluated defense response of nopal plants when contaminated in intern...

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

    Directory of Open Access Journals (Sweden)

    Choong-Min Ryu

    2013-05-01

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

  16. Enhancement of defense responses by oligandrin against Botrytis ...

    African Journals Online (AJOL)

    Oligandrin is an elicitin-like protein with a molecular mass of ∼10 kDa secreted by Pythium oligandrum. Here, the effect of oligandrin on defense response against Botrytis cinerea in tomato leaves is reported. Tomato seedlings were pretreated with 5 ml oligandrin (10 g/ml) by root submerging and then inoculated with B.

  17. Nanosecond electric pulses trigger actin responses in plant cells

    International Nuclear Information System (INIS)

    Berghoefer, Thomas; Eing, Christian; Flickinger, Bianca; Hohenberger, Petra; Wegner, Lars H.; Frey, Wolfgang; Nick, Peter

    2009-01-01

    We have analyzed the cellular effects of nanosecond pulsed electrical fields on plant cells using fluorescently tagged marker lines in the tobacco cell line BY-2 and confocal laser scanning microscopy. We observe a disintegration of the cytoskeleton in the cell cortex, followed by contraction of actin filaments towards the nucleus, and disintegration of the nuclear envelope. These responses are accompanied by irreversible permeabilization of the plasma membrane manifest as uptake of Trypan Blue. By pretreatment with the actin-stabilizing drug phalloidin, the detachment of transvacuolar actin from the cell periphery can be suppressed, and this treatment can also suppress the irreversible perforation of the plasma membrane. We discuss these findings in terms of a model, where nanosecond pulsed electric fields trigger actin responses that are key events in the plant-specific form of programmed cell death.

  18. The biocontrol endophytic bacterium Pseudomonas fluorescens PICF7 induces systemic defense responses in aerial tissues upon colonization of olive roots

    Directory of Open Access Journals (Sweden)

    Carmen eGómez-Lama Cabanás

    2014-09-01

    Full Text Available Pseudomonas fluorescens PICF7, a native olive root endophyte and effective biocontrol agent (BCA against Verticillium wilt of olive, is able to trigger a broad range of defense responses in root tissues of this woody plant. In order to elucidate whether strain PICF7 also induces systemic defense responses in above-ground organs, aerial tissues of olive plants grown under non-gnotobiotic conditions were collected at different time points after root bacterization with this endophytic BCA. A suppression subtractive hybridization (SSH cDNA library, enriched in up-regulated genes, was generated. This strategy enabled the identification of 376 ESTs (99 contigs and 277 singlets, many of them related to response to different stresses. Five ESTs, involved in defense responses, were selected to carry out time-course quantitative real-time PCR (qRT-PCR experiments aiming to: (i validate the induction of these genes, and (ii shed light on their expression pattern along time (from 1 to 15 days. Induction of olive genes potentially coding for lypoxigenase 2, catalase, 1-aminocyclopropane-1-carboxylate oxidase and phenylananine ammonia-lyase was thus confirmed at some time points. Computational analysis also revealed that different transcription factors were up-regulated in olive aerial tissues (i.e. jerf, bHLH, WRKYs, as previously reported for roots. Results confirmed that root colonization by this endophytic bacterium does not only trigger defense responses in this organ but also mount a wide array of systemic defense responses in distant tissues (stems, leaves. This sheds light on how olive plants respond to the ‘non-hostile’ colonization by a bacterial endophyte and how induced defense response can contribute to the biocontrol activity of strain PICF7.

  19. The biocontrol endophytic bacterium Pseudomonas fluorescens PICF7 induces systemic defense responses in aerial tissues upon colonization of olive roots.

    Science.gov (United States)

    Gómez-Lama Cabanás, Carmen; Schilirò, Elisabetta; Valverde-Corredor, Antonio; Mercado-Blanco, Jesús

    2014-01-01

    Pseudomonas fluorescens PICF7, a native olive root endophyte and effective biocontrol agent (BCA) against Verticillium wilt of olive, is able to trigger a broad range of defense responses in root tissues of this woody plant. In order to elucidate whether strain PICF7 also induces systemic defense responses in above-ground organs, aerial tissues of olive plants grown under non-gnotobiotic conditions were collected at different time points after root bacterization with this endophytic BCA. A suppression subtractive hybridization (SSH) cDNA library, enriched in up-regulated genes, was generated. This strategy enabled the identification of 376 ESTs (99 contigs and 277 singlets), many of them related to response to different stresses. Five ESTs, involved in defense responses, were selected to carry out time-course quantitative real-time PCR (qRT-PCR) experiments aiming to: (1) validate the induction of these genes, and (2) shed light on their expression pattern along time (from 1 to 15 days). Induction of olive genes potentially coding for lipoxygenase 2, catalase, 1-aminocyclopropane-1-carboxylate oxidase, and phenylananine ammonia-lyase was thus confirmed at some time points. Computational analysis also revealed that different transcription factors were up-regulated in olive aerial tissues (i.e., JERF, bHLH, WRKY), as previously reported for roots. Results confirmed that root colonization by this endophytic bacterium does not only trigger defense responses in this organ but also mounts a wide array of systemic defense responses in distant tissues (stems, leaves). This sheds light on how olive plants respond to the "non-hostile" colonization by a bacterial endophyte and how induced defense response can contribute to the biocontrol activity of strain PICF7.

  20. Self-defensive layer-by-layer films with bacteria-triggered antibiotic release.

    Science.gov (United States)

    Zhuk, Iryna; Jariwala, Freneil; Attygalle, Athula B; Wu, Yong; Libera, Matthew R; Sukhishvili, Svetlana A

    2014-08-26

    We report on highly efficient, bioresponsive, controlled-release antibacterial coatings constructed by direct assembly of tannic acid (TA) with one of several cationic antibiotics (tobromycin, gentamicin, and polymyxin B) using the layer-by-layer (LbL) technique. These films exhibit a distinct “self-defense” behavior triggered by acidification of the immediate environment by pathogenic bacteria, such as Staphylococcus epidermidis (S. epidermidis) or Escherichia coli (E. coli). Films assembled using spin-assisted and dip-assisted techniques show drastically different morphology, thickness and pH-/bacteria-triggered antibiotic release characteristics. While dip-deposited films have rough surfaces with island-like, granular structures regardless of the film thickness, spin-assisted LbL assemblies demonstrate a transition from linear deposition of uniform 2D films to a highly developed 3D morphology for films thicker than ∼45 nm. Ellipsometry, UV–vis and mass spectrometry confirm that all coatings do not release antibiotics in phosphate buffered saline at pH 7.4 for as long as one month in the absence of bacteria and therefore do not contribute to the development of antibiotic resistance. These films do, however, release antibiotics upon pH lowering. The rate of triggered release can be controlled through the choice of assembled antibiotic and the assembly technique (spin- vs dip-deposition) and by the spinning rate used during deposition, which all affect the strength of TA–antibiotic binding. TA/antibiotic coatings as thin as 40 nm strongly inhibit S. epidermidis and E. coli bacterial growth both at surfaces and in surrounding medium, but support adhesion and proliferation of murine osteoblast cells. These coatings thus present a promising way to incorporate antibacterial agents at surfaces to prevent bacterial colonization of implanted biomedical devices.

  1. Demand Response an Alternative Solution to Prevent Load Shedding Triggering

    Directory of Open Access Journals (Sweden)

    K. Mollah

    2014-12-01

    Full Text Available This paper investigates an alternative solution to prevent Load Shedding (LS triggering during underfrequency and proposes a new technique to restore the frequency during emergency events. Demand response (DR is considered as one of the most promising Smart Grid concepts that can be used to support the peak demand, whereas, LS is an existing last resort method during emergency grid situations. Both schemes aim to balance the load and generation in real-time and restore the frequency very quickly. This paper incorporates integrating Incentive based Demand Response (IDR with spinning reserve for smaller underfrequency events to manage the system peak demand. It also introduces a new frequency band for an Emergency Demand Response (EDR as an alternative inexpensive solution that can replace costly spinning reserves and help to prevent LS. An energy index factor is used to identify the consumption pattern of consumers to enable them to participate in IDR. An illustrative example of the performance of the proposed scheme on a modified 15 bus test system is shown. Simulation results on different scenarios confirm that the proposed method is effective to improve the frequency restoration process along with enabling participation of new services.

  2. Responsive block copolymer photonics triggered by protein-polyelectrolyte coacervation.

    Science.gov (United States)

    Fan, Yin; Tang, Shengchang; Thomas, Edwin L; Olsen, Bradley D

    2014-11-25

    Ionic interactions between proteins and polyelectrolytes are demonstrated as a method to trigger responsive transitions in block copolymer (BCP) photonic gels containing one neutral hydrophobic block and one cationic hydrophilic block. Poly(2-vinylpyridine) (P2VP) blocks in lamellar poly(styrene-b-2-vinylpyridine) block copolymer thin films are quaternized with primary bromides to yield swollen gels that show strong reflectivity peaks in the visible range; exposure to aqueous solutions of various proteins alters the swelling ratios of the quaternized P2VP (QP2VP) gel layers in the PS-QP2VP materials due to the ionic interactions between proteins and the polyelectrolyte. Parameters such as charge density, hydrophobicity, and cross-link density of the QP2VP gel layers as well as the charge and size of the proteins play significant roles on the photonic responses of the BCP gels. Differences in the size and pH-dependent charge of proteins provide a basis for fingerprinting proteins based on their temporal and equilibrium photonic response. The results demonstrate that the BCP gels and their photonic effect provide a robust and visually interpretable method to differentiate different proteins.

  3. The Venturia Apple Pathosystem: Pathogenicity Mechanisms and Plant Defense Responses

    Directory of Open Access Journals (Sweden)

    Gopaljee Jha

    2009-01-01

    Full Text Available Venturia inaequalis is the causal agent of apple scab, a devastating disease of apple. We outline several unique features of this pathogen which are useful for molecular genetics studies intended to understand plant-pathogen interactions. The pathogenicity mechanisms of the pathogen and overview of apple defense responses, monogenic and polygenic resistance, and their utilization in scab resistance breeding programs are also reviewed.

  4. Self-defensive antibiotic-loaded layer-by-layer coatings : Imaging of localized bacterial acidification and pH-triggering of antibiotic release

    NARCIS (Netherlands)

    Albright, Victoria; Zhuk, Iryna; Wang, Yuhao; Selin, Victor; van de Belt-Gritter, Betsy; Busscher, Henk J.; van der Mei, Henny C.; Sukhishvili, Svetlana A.

    2017-01-01

    Self-defensive antibiotic-loaded coatings have shown promise in inhibiting growth of pathogenic bacteria adhering to biomaterial implants and devices, but direct proof that their antibacterial release is triggered by bacterially-induced acidification of the immediate environment under buffered

  5. A Localized Pseudomonas syringae Infection Triggers Systemic Clock Responses in Arabidopsis.

    Science.gov (United States)

    Li, Zheng; Bonaldi, Katia; Uribe, Francisco; Pruneda-Paz, Jose L

    2018-02-19

    The circadian clock drives daily rhythms of many plant physiological responses, providing a competitive advantage that improves plant fitness and survival rates [1-5]. Whereas multiple environmental cues are predicted to regulate the plant clock function, most studies focused on understanding the effects of light and temperature [5-8]. Increasing evidence indicates a significant role of plant-pathogen interactions on clock regulation [9, 10], but the underlying mechanisms remain elusive. In Arabidopsis, the clock function largely relies on a transcriptional feedback loop between morning (CCA1 and LHY)- and evening (TOC1)-expressed transcription factors [6-8]. Here, we focused on these core components to investigate the Arabidopsis clock regulation using a unique biotic stress approach. We found that a single-leaf Pseudomonas syringae infection systemically lengthened the period and reduced the amplitude of circadian rhythms in distal uninfected tissues. Remarkably, the low-amplitude phenotype observed upon infection was recapitulated by a transient treatment with the defense-related phytohormone salicylic acid (SA), which also triggered a significant clock phase delay. Strikingly, despite SA-modulated circadian rhythms, we revealed that the master regulator of SA signaling, NPR1 [11, 12], antagonized clock responses triggered by both SA treatment and P. syringae. In contrast, we uncovered that the NADPH oxidase RBOHD [13] largely mediated the aforementioned clock responses after either SA treatment or the bacterial infection. Altogether, we demonstrated novel and unexpected roles for SA, NPR1, and redox signaling in clock regulation by P. syringae and revealed a previously unrecognized layer of systemic clock regulation by locally perceived environmental cues. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Investigating Proteome and Transcriptome Defense Response of Apples Induced by Yarrowia lipolytica.

    Science.gov (United States)

    Zhang, Hongyin; Chen, Liangliang; Sun, Yiwen; Zhao, Lina; Zheng, Xiangfeng; Yang, Qiya; Zhang, Xiaoyun

    2017-04-01

    A better understanding of the mode of action of postharvest biocontrol agents on fruit surfaces is critical for the advancement of successful implementation of postharvest biocontrol products. This is due to the increasing importance of biological control of postharvest diseases over chemical and other control methods. However, most of the mechanisms involved in biological control remain unknown and need to be explored. Yarrowia lipolytica significantly inhibited blue mold decay of apples caused by Penicillium expansum. The findings also demonstrated that Y. lipolytica stimulated the activities of polyphenoloxidase, peroxidase, chitinase, l-phenylalanine ammonia lyase involved in enhancing defense responses in apple fruit tissue. Proteomic and transcriptomic analysis revealed a total of 35 proteins identified as up- and down-regulated in response to the Y. lipolytica inducement. These proteins were related to defense, biotic stimulus, and stress responses, such as pathogenesis-related proteins and dehydrin. The analysis of the transcriptome results proved that the induced resistance was mediated by a crosstalk between salicylic acid (SA) and ethylene/jasmonate (ET/JA) pathways. Y. lipolytica treatment activated the expression of isochorismate synthase gene in the SA pathway, which up-regulates the expression of PR4 in apple. The expression of 1-aminocyclopropane-1-carboxylate oxidase gene and ET-responsive transcription factors 2 and 4, which are involved in the ET pathway, were also activated. In addition, cytochrome oxidase I, which plays an important role in JA signaling for resistance acquisition, was also activated. However, not all of the genes had a positive effect on the SA and ET/JA signal pathways. As transcriptional repressors in JA signaling, TIFY3B and TIFY11B were triggered by the yeast, but the gene expression levels were relatively low. Taken together, Y. lipolytica induced the SA and ET/JA signal mediating the defense pathways by stimulating

  7. Complement-triggered pathways orchestrate regenerative responses throughout phylogenesis

    Science.gov (United States)

    Mastellos, Dimitrios C.; DeAngelis, Robert A.; Lambris, John D.

    2014-01-01

    Adult tissue plasticity, cell reprogramming, and organ regeneration are major challenges in the field of modern regenerative medicine. Devising strategies to increase the regenerative capacity of tissues holds great promise for dealing with donor organ shortages and low transplantation outcomes and also provides essential impetus to tissue bioengineering approaches for organ repair and replacement. The inherent ability of cells to reprogram their fate by switching into an embryonic-like, pluripotent progenitor state is an evolutionary vestige that in mammals has been retained mostly in fetal tissues and persists only in a few organs of the adult body. Tissue regeneration reflects the capacity of terminally differentiated cells to re-enter the cell cycle and proliferate in response to acute injury or environmental stress signals. In lower vertebrates, this regenerative capacity extends to several organs and remarkably culminates in precise tissue patterning, through cellular transdifferentiation and complex morphogenetic processes that can faithfully reconstruct entire body parts. Many lessons have been learned from robust regeneration models in amphibians such as the newt and axolotl. However, the dynamic interactions between the regenerating tissue, the surrounding stroma, and the host immune response, as it adapts to the actively proliferating tissue, remain ill-defined. The regenerating zone, through a sequence of distinct molecular events, adopts phenotypic plasticity and undergoes rigorous tissue remodeling that, in turn, evokes a significant inflammatory response. Complement is a primordial sentinel of the innate immune response that engages in multiple inflammatory cascades as it becomes activated during tissue injury and remodeling. In this respect, complement proteins have been implicated in tissue and organ regeneration in both urodeles and mammals. Distinct complement-triggered pathways have been shown to modulate critical responses that promote tissue

  8. Physcomitrella patens Activates Defense Responses against the Pathogen Colletotrichum gloeosporioides

    Directory of Open Access Journals (Sweden)

    Guillermo Reboledo

    2015-09-01

    Full Text Available The moss Physcomitrella patens is a suitable model plant to analyze the activation of defense mechanisms after pathogen assault. In this study, we show that Colletotrichum gloeosporioides isolated from symptomatic citrus fruit infects P. patens and cause disease symptoms evidenced by browning and maceration of tissues. After C. gloeosporioides infection, P. patens reinforces the cell wall by the incorporation of phenolic compounds and induces the expression of a Dirigent-protein-like encoding gene that could lead to the formation of lignin-like polymers. C. gloeosporioides-inoculated protonemal cells show cytoplasmic collapse, browning of chloroplasts and modifications of the cell wall. Chloroplasts relocate in cells of infected tissues toward the initially infected C. gloeosporioides cells. P. patens also induces the expression of the defense genes PAL and CHS after fungal colonization. P. patens reporter lines harboring the auxin-inducible promoter from soybean (GmGH3 fused to β-glucuronidase revealed an auxin response in protonemal tissues, cauloids and leaves of C. gloeosporioides-infected moss tissues, indicating the activation of auxin signaling. Thus, P. patens is an interesting plant to gain insight into defense mechanisms that have evolved in primitive land plants to cope with microbial pathogens.

  9. Response of direct or priming defense against Botrytis cinerea to methyl jasmonate treatment at different concentrations in grape berries.

    Science.gov (United States)

    Wang, Kaituo; Liao, Yunxia; Kan, Jianquan; Han, Lin; Zheng, Yonghua

    2015-02-02

    This study was conducted to characterize the forms of disease resistance induced by methyl jasmonate (MeJA) in harvested grape berries and to evaluate the impact of the induced resistance on fruit quality. The results showed that MeJA treatment at concentrations from 10 to 100μmol/L could effectively induce disease resistance against Botrytis cinerea and reduce disease incidence in grape berries. The induced disease resistance was tightly associated with increased H2O2 generation, enhanced expression of the defense-related gene VvNPR1.1 and accumulation of stilbene phytoalexins such as tran-resveratrol and its oligomer (trans-)ε-viniferin. The expression of the defense-related gene and synthesis of phytoalexins in 10μmol/L MeJA-treated grape berries were only significantly enhanced upon inoculating the berries with B. cinerea, whereas the 50 or 100μmol/L of MeJA treatment directly induced these defense responses. Hence, we deduce that the low concentration of MeJA (10μmol/L) triggered a priming defense mechanism, while higher concentrations of MeJA (50 or 100μmol/L) directly activated defense responses, thus enhancing disease resistance in grape berries. Moreover, the primed grape berries maintained higher contents of soluble sugars and higher DPPH radical scavenging activity and reducing power compared with those expressing direct defense responses. These results indicate that priming of defense is a cost-effective strategy to protect harvested grape berries from B. cinerea infection in terms of minimizing quality loss. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. DMPD: Cytosolic DNA recognition for triggering innate immune responses. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18280611 Cytosolic DNA recognition for triggering innate immune responses. Takaoka ...A, Taniguchi T. Adv Drug Deliv Rev. 2008 Apr 29;60(7):847-57. Epub 2007 Dec 31. (.png) (.svg) (.html) (.csml) Show Cytosolic DNA reco...gnition for triggering innate immune responses. PubmedID 18280611 Title Cytosolic DNA reco

  11. Melatonin modulates the fetal cardiovascular defense response to acute hypoxia.

    Science.gov (United States)

    Thakor, Avnesh S; Allison, Beth J; Niu, Youguo; Botting, Kimberley J; Serón-Ferré, Maria; Herrera, Emilio A; Giussani, Dino A

    2015-08-01

    Experimental studies in animal models supporting protective effects on the fetus of melatonin in adverse pregnancy have prompted clinical trials in human pregnancy complicated by fetal growth restriction. However, the effects of melatonin on the fetal defense to acute hypoxia, such as that which may occur during labor, remain unknown. This translational study tested the hypothesis, in vivo, that melatonin modulates the fetal cardiometabolic defense responses to acute hypoxia in chronically instrumented late gestation fetal sheep via alterations in fetal nitric oxide (NO) bioavailability. Under anesthesia, 6 fetal sheep at 0.85 gestation were instrumented with vascular catheters and a Transonic flow probe around a femoral artery. Five days later, fetuses were exposed to acute hypoxia with or without melatonin treatment. Fetal blood was taken to determine blood gas and metabolic status and plasma catecholamine concentrations. Hypoxia during melatonin treatment was repeated during in vivo NO blockade with the NO clamp. This technique permits blockade of de novo synthesis of NO while compensating for the tonic production of the gas, thereby maintaining basal cardiovascular function. Melatonin suppressed the redistribution of blood flow away from peripheral circulations and the glycemic and plasma catecholamine responses to acute hypoxia. These are important components of the fetal brain sparing response to acute hypoxia. The effects of melatonin involved NO-dependent mechanisms as the responses were reverted by fetal treatment with the NO clamp. Melatonin modulates the in vivo fetal cardiometabolic responses to acute hypoxia by increasing NO bioavailability. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Heavy Metal Stress and Some Mechanisms of Plant Defense Response

    Directory of Open Access Journals (Sweden)

    Abolghassem Emamverdian

    2015-01-01

    Full Text Available Unprecedented bioaccumulation and biomagnification of heavy metals (HMs in the environment have become a dilemma for all living organisms including plants. HMs at toxic levels have the capability to interact with several vital cellular biomolecules such as nuclear proteins and DNA, leading to excessive augmentation of reactive oxygen species (ROS. This would inflict serious morphological, metabolic, and physiological anomalies in plants ranging from chlorosis of shoot to lipid peroxidation and protein degradation. In response, plants are equipped with a repertoire of mechanisms to counteract heavy metal (HM toxicity. The key elements of these are chelating metals by forming phytochelatins (PCs or metallothioneins (MTs metal complex at the intra- and intercellular level, which is followed by the removal of HM ions from sensitive sites or vacuolar sequestration of ligand-metal complex. Nonenzymatically synthesized compounds such as proline (Pro are able to strengthen metal-detoxification capacity of intracellular antioxidant enzymes. Another important additive component of plant defense system is symbiotic association with arbuscular mycorrhizal (AM fungi. AM can effectively immobilize HMs and reduce their uptake by host plants via binding metal ions to hyphal cell wall and excreting several extracellular biomolecules. Additionally, AM fungi can enhance activities of antioxidant defense machinery of plants.

  13. Heavy Metal Stress and Some Mechanisms of Plant Defense Response

    Science.gov (United States)

    Emamverdian, Abolghassem; Ding, Yulong; Mokhberdoran, Farzad; Xie, Yinfeng

    2015-01-01

    Unprecedented bioaccumulation and biomagnification of heavy metals (HMs) in the environment have become a dilemma for all living organisms including plants. HMs at toxic levels have the capability to interact with several vital cellular biomolecules such as nuclear proteins and DNA, leading to excessive augmentation of reactive oxygen species (ROS). This would inflict serious morphological, metabolic, and physiological anomalies in plants ranging from chlorosis of shoot to lipid peroxidation and protein degradation. In response, plants are equipped with a repertoire of mechanisms to counteract heavy metal (HM) toxicity. The key elements of these are chelating metals by forming phytochelatins (PCs) or metallothioneins (MTs) metal complex at the intra- and intercellular level, which is followed by the removal of HM ions from sensitive sites or vacuolar sequestration of ligand-metal complex. Nonenzymatically synthesized compounds such as proline (Pro) are able to strengthen metal-detoxification capacity of intracellular antioxidant enzymes. Another important additive component of plant defense system is symbiotic association with arbuscular mycorrhizal (AM) fungi. AM can effectively immobilize HMs and reduce their uptake by host plants via binding metal ions to hyphal cell wall and excreting several extracellular biomolecules. Additionally, AM fungi can enhance activities of antioxidant defense machinery of plants. PMID:25688377

  14. Knocking down expression of the auxin-amidohydrolase IAR3 alters defense responses in Solanaceae family plants.

    Science.gov (United States)

    D'Ippolito, Sebastian; Vankova, Radomira; Joosten, Matthieu H A J; Casalongué, Claudia A; Fiol, Diego F

    2016-12-01

    In plants, indole-3-acetic acid (IAA) amido hydrolases (AHs) participate in auxin homeostasis by releasing free IAA from IAA-amino acid conjugates. We investigated the role of IAR3, a member of the IAA amido hydrolase family, in the response of Solanaceous plants challenged by biotrophic and hemi-biotrophic pathogens. By means of genome inspection and phylogenic analysis we firstly identified IAA-AH sequences and putative IAR3 orthologs in Nicotiana benthamiana, tomato and potato. We evaluated the involvement of IAR3 genes in defense responses by using virus-induced gene silencing. We observed that N. benthamiana and tomato plants with knocked-down expression of IAR3 genes contained lower levels of free IAA and presented altered responses to pathogen attack, including enhanced basal defenses and higher tolerance to infection in susceptible plants. We showed that IAR3 genes are consistently up-regulated in N. benthamiana and tomato upon inoculation with Phytophthora infestans and Cladosporium fulvum respectively. However, IAR3 expression decreased significantly when hypersensitive response was triggered in transgenic tomato plants coexpressing the Cf-4 resistance gene and the avirulence factor Avr4. Altogether, our results indicate that changes in IAR3 expression lead to alteration in auxin homeostasis that ultimately affects plant defense responses. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Neonicotinoid insecticides induce salicylate-associated plant defense responses

    Science.gov (United States)

    Ford, Kevin A.; Casida, John E.; Chandran, Divya; Gulevich, Alexander G.; Okrent, Rachel A.; Durkin, Kathleen A.; Sarpong, Richmond; Bunnelle, Eric M.; Wildermuth, Mary C.

    2010-01-01

    Neonicotinoid insecticides control crop pests based on their action as agonists at the insect nicotinic acetylcholine receptor, which accepts chloropyridinyl- and chlorothiazolyl-analogs almost equally well. In some cases, these compounds have also been reported to enhance plant vigor and (a)biotic stress tolerance, independent of their insecticidal function. However, this mode of action has not been defined. Using Arabidopsis thaliana, we show that the neonicotinoid compounds, imidacloprid (IMI) and clothianidin (CLO), via their 6-chloropyridinyl-3-carboxylic acid and 2-chlorothiazolyl-5-carboxylic acid metabolites, respectively, induce salicylic acid (SA)-associated plant responses. SA is a phytohormone best known for its role in plant defense against pathogens and as an inducer of systemic acquired resistance; however, it can also modulate abiotic stress responses. These neonicotinoids effect a similar global transcriptional response to that of SA, including genes involved in (a)biotic stress response. Furthermore, similar to SA, IMI and CLO induce systemic acquired resistance, resulting in reduced growth of a powdery mildew pathogen. The action of CLO induces the endogenous synthesis of SA via the SA biosynthetic enzyme ICS1, with ICS1 required for CLO-induced accumulation of SA, expression of the SA marker PR1, and fully enhanced resistance to powdery mildew. In contrast, the action of IMI does not induce endogenous synthesis of SA. Instead, IMI is further bioactivated to 6-chloro-2-hydroxypyridinyl-3-carboxylic acid, which is shown here to be a potent inducer of PR1 and inhibitor of SA-sensitive enzymes. Thus, via different mechanisms, these chloropyridinyl- and chlorothiazolyl-neonicotinoids induce SA responses associated with enhanced stress tolerance. PMID:20876120

  16. Report of the Defense Science Board Task Force on University Responsiveness to National Security Requirements.

    Science.gov (United States)

    1982-01-01

    R.ugustine Chairman iv OFFICE OF THE SECRETARY OF DEFENSE WASHINGTON, D.C. 20301 27 January 1982 DEFENSE SCIENCIE BOARD Mr. Norman R. Augustine Chai rman...critical needs for special attention. Responsible Office: DUSD(R&AT) 3. The USDRE direct the Defense Acquisition Regulations Committee to revise current...Responsible Office: DUSD(R&AT) 4. The USORE direct Services to provide funding to the universities for a sustained period, over and above 6.1 Research

  17. Host plant defense signaling in response to a coevolved herbivore combats introduced herbivore attack

    OpenAIRE

    Woodard, Anastasia M; Ervin, Gary N; Marsico, Travis D

    2012-01-01

    Defense-free space resulting from coevolutionarily naïve host plants recently has been implicated as a factor facilitating invasion success of some insect species. Host plants, however, may not be entirely defenseless against novel herbivore threats. Volatile chemical-mediated defense signaling, which allows plants to mount specific, rapid, and intense responses, may play a role in systems experiencing novel threats. Here we investigate defense responses of host plants to a native and exotic ...

  18. MicroRNA regulated defense responses in Triticum aestivum L. during Puccinia graminis f.sp. tritici infection.

    Science.gov (United States)

    Gupta, Om Prakash; Permar, Vipin; Koundal, Vikas; Singh, Uday Dhari; Praveen, Shelly

    2012-02-01

    Plants have evolved diverse mechanism to recognize pathogen attack and triggers defense responses. These defense responses alter host cellular function regulated by endogenous, small, non-coding miRNAs. To understand the mechanism of miRNAs regulated cellular functions during stem rust infection in wheat, we investigated eight different miRNAs viz. miR159, miR164, miR167, miR171, miR444, miR408, miR1129 and miR1138, involved in three different independent cellular defense response to infection. The investigation reveals that at the initiation of disease, accumulation of miRNAs might be playing a key role in hypersensitive response (HR) from host, which diminishes at the maturation stage. This suggests a possible host-fungal synergistic relation leading to susceptibility. Differential expression of these miRNAs in presence and absence of R gene provides a probable explanation of miRNA regulated R gene mediated independent pathways.

  19. Extracellular ATP induces graded reactive response of astrocytes and strengthens their antioxidative defense in vitro.

    Science.gov (United States)

    Adzic, Marija; Stevanovic, Ivana; Josipovic, Natasa; Laketa, Danijela; Lavrnja, Irena; Bjelobaba, Ivana M; Bozic, Iva; Jovanovic, Marija; Milosevic, Milena; Nedeljkovic, Nadezda

    2017-04-01

    It is widely accepted that adenosine triphosphate (ATP) acts as a universal danger-associated molecular pattern with several known mechanisms for immune cell activation. In the central nervous system, ATP activates microglia and astrocytes and induces a neuroinflammatory response. The aim of the present study was to describe responses of isolated astrocytes to increasing concentrations of ATP (5 µM to 1 mM), which were intended to mimic graded intensity of the extracellular stimulus. The results show that ATP induces graded activation response of astrocytes in terms of the cell proliferation, stellation, shape remodeling, and underlying actin and GFAP filament rearrangement, although the changes occurred without an apparent increase in GFAP and actin protein expression. On the other hand, ATP in the range of applied concentrations did not evoke IL-1β release from cultured astrocytes, nor did it modify the release from LPS and LPS+IFN-γ-primed astrocytes. ATP did not promote astrocyte migration in the wound-healing assay, nor did it increase production of reactive oxygen and nitrogen species and lipid peroxidation. Instead, ATP strengthened the antioxidative defense of astrocytes by inducing Cu/ZnSOD and MnSOD activities and by increasing their glutathione content. Our current results suggest that although ATP triggers several attributes of activated astrocytic phenotype with a magnitude that increases with the concentration, it is not sufficient to induce full-blown reactive phenotype of astrocytes in vitro. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  20. Tidal heat pulses on a reef trigger a fine-tuned transcriptional response in corals to maintain homeostasis.

    Science.gov (United States)

    Ruiz-Jones, Lupita J; Palumbi, Stephen R

    2017-03-01

    For reef-building corals, extreme stress exposure can result in loss of endosymbionts, leaving colonies bleached. However, corals in some habitats are commonly exposed to natural cycles of sub-bleaching stress, often leading to higher stress tolerance. We monitored transcription in the tabletop coral Acropora hyacinthus daily for 17 days over a strong tidal cycle that included extreme temperature spikes, and show that increases in temperature above 30.5°C triggered a strong transcriptional response. The transcriptomic time series data allowed us to identify a set of genes with coordinated expression that were activated only on days with strong tides, high temperature, and large diel pH and oxygen changes. The responsive genes are enriched for gene products essential to the unfolded protein response, an ancient cellular response to endoplasmic reticulum stress. After the temporary heat pulses passed, expression of these genes immediately decreased, suggesting that homeostasis was restored to the endoplasmic reticulum. In a laboratory temperature stress experiment, we found that the expression of these environmentally responsive genes increased as corals bleached, showing that the unfolded protein response becomes more intense during more severe stress. Our results point to the unfolded protein response as a first line of defense that acroporid corals use when coping with environmental stress on the reef, thus enhancing our understanding of coral stress physiology during a time of major concern for reefs.

  1. Responsive triggering systems for delivery in chronic wound healing.

    Science.gov (United States)

    Morey, Mangesh; Pandit, Abhay

    2018-03-02

    Non-communicable diseases including cancer, cardiovascular disease, diabetes, and neuropathy are chronic in nature. Treatment of these diseases with traditional delivery systems is limited due to lack of site-specificity, non-spatiotemporal release and insufficient doses. Numerous responsive delivery systems which respond to both physiological and external stimuli have been reported in the literature. However, effective strategies incorporating a multifactorial approach are required to control these complex wounds. This can be achieved by fabricating spatiotemporal release systems, multimodal systems or dual/multi-stimuli responsive delivery systems loaded with one or more bioactive components. Critically, these next generation stimuli responsive delivery systems that are at present not feasible are required to treat chronic wounds. This review provides a critical assessment of recent developments in the field of responsive delivery systems, highlighting their limitations and providing a perspective on how these challenges can be overcome. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Overcompensation of herbivore reproduction through hyper-suppression of plant defenses in response to competition.

    Science.gov (United States)

    Schimmel, Bernardus C J; Ataide, Livia M S; Chafi, Rachid; Villarroel, Carlos A; Alba, Juan M; Schuurink, Robert C; Kant, Merijn R

    2017-06-01

    Spider mites are destructive arthropod pests on many crops. The generalist herbivorous mite Tetranychus urticae induces defenses in tomato (Solanum lycopersicum) and this constrains its fitness. By contrast, the Solanaceae-specialist Tetranychus evansi maintains a high reproductive performance by suppressing tomato defenses. Tetranychus evansi outcompetes T. urticae when infesting the same plant, but it is unknown whether this is facilitated by the defenses of the plant. We assessed the extent to which a secondary infestation by a competitor affects local plant defense responses (phytohormones and defense genes), mite gene expression and mite performance. We observed that T. evansi switches to hyper-suppression of defenses after its tomato host is also invaded by its natural competitor T. urticae. Jasmonate (JA) and salicylate (SA) defenses were suppressed more strongly, albeit only locally at the feeding site of T. evansi, upon introduction of T. urticae to the infested leaflet. The hyper-suppression of defenses coincided with increased expression of T. evansi genes coding for salivary defense-suppressing effector proteins and was paralleled by an increased reproductive performance. Together, these observations suggest that T. evansi overcompensates its reproduction through hyper-suppression of plant defenses in response to nearby competitors. We hypothesize that the competitor-induced overcompensation promotes competitive population growth of T. evansi on tomato. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  3. The defensive response of the honeybee Apis mellifera.

    Science.gov (United States)

    Nouvian, Morgane; Reinhard, Judith; Giurfa, Martin

    2016-11-15

    Honeybees (Apis mellifera) are insects living in colonies with a complex social organization. Their nest contains food stores in the form of honey and pollen, as well as the brood, the queen and the bees themselves. These resources have to be defended against a wide range of predators and parasites, a task that is performed by specialized workers, called guard bees. Guards tune their response to both the nature of the threat and the environmental conditions, in order to achieve an efficient trade-off between defence and loss of foraging workforce. By releasing alarm pheromones, they are able to recruit other bees to help them handle large predators. These chemicals trigger both rapid and longer-term changes in the behaviour of nearby bees, thus priming them for defence. Here, we review our current understanding on how this sequence of events is performed and regulated depending on a variety of factors that are both extrinsic and intrinsic to the colony. We present our current knowledge on the neural bases of honeybee aggression and highlight research avenues for future studies in this area. We present a brief overview of the techniques used to study honeybee aggression, and discuss how these could be used to gain further insights into the mechanisms of this behaviour. © 2016. Published by The Company of Biologists Ltd.

  4. Different chemical cues originating from a shared predator induce common defense responses in two prey species.

    Science.gov (United States)

    Takahara, Teruhiko; Doi, Hideyuki; Kohmatsu, Yukihiro; Yamaoka, Ryohei

    2013-01-01

    In freshwater ecosystems, inducible defenses that involve behavioral or morphological changes in response to chemical cue detection are key phenomena in prey-predator interactions. Many species with different phylogenetic and ecological traits (e.g., general activity patterns and microhabitats) use chemical cues to avoid predators. We hypothesized that prey species with a shared predator, but having different ecological traits, would be adapted to detect different chemical cues from the predator. However, the proximate mechanisms by which prey use chemical cues to avoid predation remain little known. Here, we tested our hypothesis by using fractionated chemical components from predatory dragonfly nymphs (Lesser Emperor, Anax parthenope julius) to trigger anti-predator behavioral responses in two anuran tadpoles, the wrinkled frog Glandirana (Rana) rugosa and the Japanese tree frog Hyla japonica. Glandirana rugosa detected chemical cues that had either high or low hydrophobic properties, but H. japonica responded only to chemical cues with hydrophilic properties. During the normal behaviors of these tadpole species, G. rugosa remains immobile in benthic habitats, whereas H. japonica exhibits active swimming at the surface or in the middle of the water column. As we had hypothesized, these tadpole species, which have different general activity levels and microhabitats, detected different chemical cues that were exuded by their shared predator and responded by changing their activities to avoid predation. The specific chemical cues detected by each tadpole species are likely to have characteristics that optimize effective predator detection and encounter avoidance of the shared dragonfly predator.

  5. Periodic forces trigger a complex mechanical response in ubiquitin.

    Science.gov (United States)

    Szymczak, Piotr; Janovjak, Harald

    2009-07-17

    Mechanical forces govern physiological processes in all living organisms. Many cellular forces, for example, those generated in cyclic conformational changes of biological machines, have repetitive components. In apparent contrast, little is known about how dynamic protein structures respond to periodic mechanical information. Ubiquitin is a small protein found in all eukaryotes. We developed molecular dynamics simulations to unfold single and multimeric ubiquitins with periodic forces. By using a coarse-grained representation, we were able to model forces with periods about 2 orders of magnitude longer than the protein's relaxation time. We found that even a moderate periodic force weakened the protein and shifted its unfolding pathways in a frequency- and amplitude-dependent manner. A complex dynamic response with secondary structure refolding and an increasing importance of local interactions was revealed. Importantly, repetitive forces with broadly distributed frequencies elicited very similar molecular responses compared to fixed-frequency forces. When testing the influence of pulling geometry on ubiquitin's mechanical stability, it was found that the linkage involved in the mechanical degradation of cellular proteins renders the protein remarkably insensitive to periodic forces. We also devised a complementary kinetic energy landscape model that traces these observations and explains periodic-force, single-molecule measurements. In turn, this analytical model is capable of predicting dynamic protein responses. These results provide new insights into ubiquitin mechanics and a potential mechanical role during protein degradation, as well as first frameworks for dynamic protein stability and the modeling of repetitive mechanical processes.

  6. Hantaan virus triggers TLR4-dependent innate immune responses.

    Science.gov (United States)

    Yu, Hai-Tao; Jiang, Hong; Zhang, Ye; Nan, Xue-Ping; Li, Yu; Wang, Wei; Jiang, Wei; Yang, Dong-Qiang; Su, Wen-Jing; Wang, Jiu-Ping; Wang, Ping-Zhong; Bai, Xue-Fan

    2012-10-01

    The innate immune response induced by Hantavirus is responsible for endothelial cell dysfunction and viral pathogenicity. Recent studies demonstrate that TLR4 expression is upregulated and mediates the secretion of several cytokines in Hantaan virus (HTNV)-infected endothelial cells. To examine viral interactions with host endothelial cells and characterize the innate antiviral responses associated with Toll-like receptors, we selected TLR4 as the target molecule to investigate anti-hantavirus immunity. TLR4 mRNA-silenced EVC-304 (EVC-304 TLR4-) cells and EVC-304 cells were used to investigate signaling molecules downstream of TLR4. The expression of the adaptor protein TRIF was higher in HTNV-infected EVC-304 cells than in EVC-304 TLR4- cells. However, there was no apparent difference in the expression of MyD88 in either cell line. The transcription factors for NF-κB and IRF-3 were translocated from the cytoplasm into the nucleus in HTNV-infected EVC-304 cells, but not in HTNV-infected EVC-304 TLR4- cells. Our results demonstrate that TLR4 may play an important role in the antiviral immunity of the host against HTNV infection through an MyD88-independent signaling pathway.

  7. The MAP kinase substrate MKS1 is a regulator of plant defense responses

    DEFF Research Database (Denmark)

    Andreasson, E.; Jenkins, T.; Brodersen, P.

    2005-01-01

    Arabidopsis MAP kinase 4 (MPK4) functions as a regulator of pathogen defense responses, because it is required for both repression of salicylic acid (SA)-dependent resistance and for activation of jasmonate (JA)-dependent defense gene expression. To understand MPK4 signaling mechanisms, we used...

  8. Herboxidiene triggers splicing repression and abiotic stress responses in plants

    KAUST Repository

    Alshareef, Sahar

    2017-03-27

    Background Constitutive and alternative splicing of pre-mRNAs from multiexonic genes controls the diversity of the proteome; these precisely regulated processes also fine-tune responses to cues related to growth, development, and stresses. Small-molecule inhibitors that perturb splicing provide invaluable tools for use as chemical probes to uncover the molecular underpinnings of splicing regulation and as potential anticancer compounds. Results Here, we show that herboxidiene (GEX1A) inhibits both constitutive and alternative splicing. Moreover, GEX1A activates genome-wide transcriptional patterns involved in abiotic stress responses in plants. GEX1A treatment -activated ABA-inducible promoters, and led to stomatal closure. Interestingly, GEX1A and pladienolide B (PB) elicited similar cellular changes, including alterations in the patterns of transcription and splicing, suggesting that these compounds might target the same spliceosome complex in plant cells. Conclusions Our study establishes GEX1A as a potent splicing inhibitor in plants that can be used to probe the assembly, dynamics, and molecular functions of the spliceosome and to study the interplay between splicing stress and abiotic stresses, as well as having potential biotechnological applications.

  9. Selective lignin downregulation leads to constitutive defense response expression in alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Gallego-Giraldo, Lina; Jikumaru, Yusuke; Kamiya, Yuji; Tang, Yuhong; Dixon, Richard A

    2011-05-01

    • Downregulation of hydroxycinnamoyl CoA: shikimate hydroxycinnamoyl transferase (HCT) in alfalfa (Medicago sativa) reduces lignin levels and improves forage quality and saccharification efficiency for bioethanol production. However, the plants have reduced stature. It was previously reported that HCT-down-regulated Arabidopsis have impaired auxin transport, but this has recently been disproved. • To address the basis for the phenotypes of lignin-modified alfalfa, we measured auxin transport, profiled a range of metabolites including flavonoids and hormones, and performed in depth transcriptome analyses. • Auxin transport is unaffected in HCT antisense alfalfa despite increased flavonoid biosynthesis. The plants show increased cytokinin and reduced auxin levels, and gibberellin levels and sensitivity are both reduced. Levels of salicylic, jasmonic and abscisic acids are elevated, associated with massive upregulation of pathogenesis and abiotic stress-related genes and enhanced tolerance to fungal infection and drought. • We suggest that HCT downregulated alfalfa plants exhibit constitutive activation of defense responses, triggered by release of bioactive cell wall fragments and production of hydrogen peroxide as a result of impaired secondary cell wall integrity. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  10. Dynamic intracellular reorganization of cytoskeletons and the vacuole in defense responses and hypersensitive cell death in plants.

    Science.gov (United States)

    Higaki, Takumi; Kurusu, Takamitsu; Hasezawa, Seiichiro; Kuchitsu, Kazuyuki

    2011-05-01

    Plants have evolved various means for controlled and organized cell destruction, known as programmed cell death (PCD). In plant immune responses against microbial infection, hypersensitive cell death as a form of PCD is a crucial event to prevent the spread of biotrophic pathogens. Recent live cell imaging techniques have revealed dynamic features and significant roles of cytoskeletons and the vacuole during defense responses and the PCD. Actin microfilaments (MFs) focus on the infection sites and function as tracks for the polar transport of antimicrobial materials. To accomplish hypersensitive cell death, further dynamic changes in cytoskeletons are induced. MFs play a role in the structural and functional regulation of the vacuole, leading to execution of the PCD. We here overview spatiotemporal dynamic changes in the cytoskeletons and the vacuoles triggered by signals from pathogens, and propose a hypothetical model for MF-regulated vacuole-mediated PCD in plant immunity.

  11. Structural Characterization of Oligochitosan Elicitor from Fusarium sambucinum and Its Elicitation of Defensive Responses in Zanthoxylum bungeanum.

    Science.gov (United States)

    Li, Peiqin; Linhardt, Robert J; Cao, Zhimin

    2016-12-10

    Oligosaccharide elicitors from pathogens have been shown to play major roles in host plant defense responses involving plant-pathogen chemoperception and interaction. In the present study, chitosan and oligochitosan were prepared from pathogen Fusarium sambucinum , and their effects on infection of Zanthoxylum bungeanum stems were investigated. Results showed that oligochitosan inhibited the infection of the pathogen, and that the oligochitosan fraction with a degree of polymerization (DP) between 5 and 6 showed the optimal effect. Oligochitosan DP5 was purified from fraction DP5-6 and was structurally characterized using electrospray ionization mass spectrometry, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy. Oligochitosan DP5 showed significant inhibition against the infection of the pathogenic fungi on host plant stems. An investigation of the mechanism underlying this effect showed that oligochitosan DP5 increased the activities of defensive enzymes and accumulation of phenolics in host Z. bungeanum . These results suggest that oligochitosan from pathogenic fungi can mediate the infection of host plants with a pathogen by acting as an elicitor that triggers the defense system of a plant. This information will be valuable for further exploration of the interactions between the pathogen F. sambucinum and host plant Z. bungeanum .

  12. Structural Characterization of Oligochitosan Elicitor from Fusarium sambucinum and Its Elicitation of Defensive Responses in Zanthoxylum bungeanum

    Directory of Open Access Journals (Sweden)

    Peiqin Li

    2016-12-01

    Full Text Available Oligosaccharide elicitors from pathogens have been shown to play major roles in host plant defense responses involving plant–pathogen chemoperception and interaction. In the present study, chitosan and oligochitosan were prepared from pathogen Fusarium sambucinum, and their effects on infection of Zanthoxylum bungeanum stems were investigated. Results showed that oligochitosan inhibited the infection of the pathogen, and that the oligochitosan fraction with a degree of polymerization (DP between 5 and 6 showed the optimal effect. Oligochitosan DP5 was purified from fraction DP5-6 and was structurally characterized using electrospray ionization mass spectrometry, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy. Oligochitosan DP5 showed significant inhibition against the infection of the pathogenic fungi on host plant stems. An investigation of the mechanism underlying this effect showed that oligochitosan DP5 increased the activities of defensive enzymes and accumulation of phenolics in host Z. bungeanum. These results suggest that oligochitosan from pathogenic fungi can mediate the infection of host plants with a pathogen by acting as an elicitor that triggers the defense system of a plant. This information will be valuable for further exploration of the interactions between the pathogen F. sambucinum and host plant Z. bungeanum.

  13. Defense Enzyme Responses in Dormant Wild Oat and Wheat Caryopses Challenged with a Seed Decay Pathogen

    Directory of Open Access Journals (Sweden)

    E. Patrick Fuerst

    2018-01-01

    Full Text Available Seeds have well-established passive physical and chemical defense mechanisms that protect their food reserves from decay-inducing organisms and herbivores. However, there are few studies evaluating potential biochemical defenses of dormant seeds against pathogens. Caryopsis decay by the pathogenic Fusarium avenaceum strain F.a.1 was relatively rapid in wild oat (Avena fatua L. isoline “M73,” with >50% decay after 8 days with almost no decay in wheat (Triticum aestivum L. var. RL4137. Thus, this fungal strain has potential for selective decay of wild oat relative to wheat. To study defense enzyme activities, wild oat and wheat caryopses were incubated with F.a.1 for 2–3 days. Whole caryopses were incubated in assay reagents to measure extrinsic defense enzyme activities. Polyphenol oxidase, exochitinase, and peroxidase were induced in whole caryopses, but oxalate oxidase was reduced, in response to F.a.1 in both species. To evaluate whether defense enzyme activities were released from the caryopsis surface, caryopses were washed with buffer and enzyme activity was measured in the leachate. Significant activities of polyphenol oxidase, exochitinase, and peroxidase, but not oxalate oxidase, were leached from caryopses. Defense enzyme responses were qualitatively similar in the wild oat and wheat genotypes evaluated. Although the absolute enzyme activities were generally greater in whole caryopses than in leachates, the relative degree of induction of polyphenol oxidase, exochitinase, and peroxidase by F.a.1 was greater in caryopsis leachates, indicating that a disproportionate quantity of the induced activity was released into the environment from the caryopsis surface, consistent with their assumed role in defense. It is unlikely that the specific defense enzymes studied here play a key role in the differential susceptibility to decay by F.a.1 in these two genotypes since defense enzyme activities were greater in the more susceptible wild

  14. Defense Enzyme Responses in Dormant Wild Oat and Wheat Caryopses Challenged with a Seed Decay Pathogen.

    Science.gov (United States)

    Fuerst, E Patrick; James, Matthew S; Pollard, Anne T; Okubara, Patricia A

    2017-01-01

    Seeds have well-established passive physical and chemical defense mechanisms that protect their food reserves from decay-inducing organisms and herbivores. However, there are few studies evaluating potential biochemical defenses of dormant seeds against pathogens. Caryopsis decay by the pathogenic Fusarium avenaceum strain F.a .1 was relatively rapid in wild oat ( Avena fatua L.) isoline "M73," with >50% decay after 8 days with almost no decay in wheat ( Triticum aestivum L.) var. RL4137. Thus, this fungal strain has potential for selective decay of wild oat relative to wheat. To study defense enzyme activities, wild oat and wheat caryopses were incubated with F.a .1 for 2-3 days. Whole caryopses were incubated in assay reagents to measure extrinsic defense enzyme activities. Polyphenol oxidase, exochitinase, and peroxidase were induced in whole caryopses, but oxalate oxidase was reduced, in response to F.a .1 in both species. To evaluate whether defense enzyme activities were released from the caryopsis surface, caryopses were washed with buffer and enzyme activity was measured in the leachate. Significant activities of polyphenol oxidase, exochitinase, and peroxidase, but not oxalate oxidase, were leached from caryopses. Defense enzyme responses were qualitatively similar in the wild oat and wheat genotypes evaluated. Although the absolute enzyme activities were generally greater in whole caryopses than in leachates, the relative degree of induction of polyphenol oxidase, exochitinase, and peroxidase by F.a .1 was greater in caryopsis leachates, indicating that a disproportionate quantity of the induced activity was released into the environment from the caryopsis surface, consistent with their assumed role in defense. It is unlikely that the specific defense enzymes studied here play a key role in the differential susceptibility to decay by F.a .1 in these two genotypes since defense enzyme activities were greater in the more susceptible wild oat, compared to

  15. Covert manual response preparation triggers attentional modulations of visual but not auditory processing.

    Science.gov (United States)

    Eimer, Martin; van Velzen, José

    2006-05-01

    We investigated whether covert unimanual response preparation triggers attention shifts, as postulated by the premotor theory of attention, and whether these result in spatially specific modulations of visual and auditory processing. Visual response cues instructed participants to prepare to lift their left or right index finger in response to a subsequent target stimulus. Irrelevant visual or auditory probes were delivered to the left or right hand during the response preparation interval. ERPs were measured time-locked to cue onset, and time-locked to probe stimulus onset. Lateralised ERP components triggered during covert response preparation (ADAN, LDAP) were similar to components previously found during attention shifts. N1 components were enhanced to visual probes delivered adjacent to the cued response relative to those delivered to the opposite hand. Auditory probe ERPs were unaffected by manual response preparation. Shifts of spatial attention that are triggered during covert unimanual response preparation result in spatially specific modulations of visual but not auditory processing. Results support the claim of the premotor theory that the preparation of manual responses is associated with attention shifts. However, such shifts are not based on purely supramodal processes, as they result in a modality-specific pattern of sensory modulations.

  16. Signal transduction during defense response and source-sink transition in tomato

    OpenAIRE

    Hofmann, Markus

    2003-01-01

    Plants have evolved an elaborate system to cope with a variety of biotic and abiotic stresses. Typically, under stress conditions an appropriate defense response is invoked which is accompanied by changes in the metabolic status of the plant. Photosynthesis is downregulated and sucrose is imported into the tissue, which provides a faster and more constant flux of energy and carbon skeletons to perform the defense response. Interestingly, these processes are co-ordinately regulated and the sig...

  17. Sensory determinants of the autonomous sensory meridian response (ASMR: understanding the triggers

    Directory of Open Access Journals (Sweden)

    Emma L. Barratt

    2017-10-01

    Full Text Available The autonomous sensory meridian response (ASMR is an atypical sensory phenomenon involving electrostatic-like tingling sensations in response to certain sensory, primarily audio-visual, stimuli. The current study used an online questionnaire, completed by 130 people who self-reported experiencing ASMR. We aimed to extend preliminary investigations into the experience, and establish key multisensory factors contributing to the successful induction of ASMR through online media. Aspects such as timing and trigger load, atmosphere, and characteristics of ASMR content, ideal spatial distance from various types of stimuli, visual characteristics, context and use of ASMR triggers, and audio preferences are explored. Lower-pitched, complex sounds were found to be especially effective triggers, as were slow-paced, detail-focused videos. Conversely, background music inhibited the sensation for many respondents. These results will help in designing media for ASMR induction.

  18. Small-molecule-hosting nanocomposite films with multiple bacteria-triggered responses

    NARCIS (Netherlands)

    Pavlukhina, Svetlana; Zhuk, Iryna; Mentbayeva, Almagul; Rautenberg, Emily; Chang, Wei; Yu, Xiaojun; van de Belt-Gritter, Betsy; Busscher, Henk J.; van der Mei, Henny C.; Sukhishvili, Svetlana A.

    We report pH/bacteria-responsive nanocomposite coatings with multiple mechanisms of antibacterial protection that include the permanent retention of antimicrobials, bacteria-triggered release of antibiotics and bacteria-induced film swelling. A novel small-molecule-hosting film was constructed using

  19. Inflammation and vascular responses to acute mental stress : implications for the triggering of myocardial infarction

    NARCIS (Netherlands)

    Paine, N.J.; Bosch, J.A.; Veldhuijzen Van Zanten, J.J.C.S.

    2012-01-01

    There is evidence that mental stress can trigger myocardial infarction. Even though the underlying mechanisms remain to be determined, both inflammation and vascular responses to mental stress have been implicated as contributing factors. This review explores the effects of inflammation on the

  20. Parasitic wasp responses to symbiont-based defense in aphids

    Directory of Open Access Journals (Sweden)

    Oliver Kerry M

    2012-02-01

    Full Text Available Abstract Background Recent findings indicate that several insect lineages receive protection against particular natural enemies through infection with heritable symbionts, but little is yet known about whether enemies are able to discriminate and respond to symbiont-based defense. The pea aphid, Acyrthosiphon pisum, receives protection against the parasitic wasp, Aphidius ervi, when infected with the bacterial symbiont Hamiltonella defensa and its associated bacteriophage APSE (Acyrthosiphon pisum secondary endosymbiont. Internally developing parasitoid wasps, such as A. ervi, use maternal and embryonic factors to create an environment suitable for developing wasps. If more than one parasitoid egg is deposited into a single aphid host (superparasitism, then additional complements of these factors may contribute to the successful development of the single parasitoid that emerges. Results We performed experiments to determine if superparasitism is a tactic allowing wasps to overcome symbiont-mediated defense. We found that the deposition of two eggs into symbiont-protected aphids significantly increased rates of successful parasitism relative to singly parasitized aphids. We then conducted behavioral assays to determine whether A. ervi selectively superparasitizes H. defensa-infected aphids. In choice tests, we found that A. ervi tends to deposit a single egg in uninfected aphids, but two or more eggs in H. defensa-infected aphids, indicating that oviposition choices may be largely determined by infection status. Finally, we identified differences in the quantity of the trans-β-farnesene, the major component of aphid alarm pheromone, between H. defensa-infected and uninfected aphids, which may form the basis for discrimination. Conclusions Here we show that the parasitic wasp A. ervi discriminates among symbiont-infected and uninfected aphids, and changes its oviposition behavior in a way that increases the likelihood of overcoming symbiont

  1. The MAP kinase substrate MKS1 is a regulator of plant defense responses

    DEFF Research Database (Denmark)

    Andreasson, E.; Jenkins, T.; Brodersen, P.

    2005-01-01

    Arabidopsis MAP kinase 4 (MPK4) functions as a regulator of pathogen defense responses, because it is required for both repression of salicylic acid (SA)-dependent resistance and for activation of jasmonate (JA)-dependent defense gene expression. To understand MPK4 signaling mechanisms, we used......-dependent resistance, but does not interfere with induction of a defense gene by JA. Further yeast two-hybrid screening revealed that MKS1 interacts with the WRKY transcription factors WRKY25 and WRKY33. WRKY25 and WRKY33 were shown to be in vitro substrates of MPK4, and a wrky33 knockout mutant was found to exhibit...... increased expression of the SA-related defense gene PR1. MKS1 may therefore contribute to MPK4-regulated defense activation by coupling the kinase to specific WRKY transcription factors....

  2. Role of UPR Pathway in Defense Response of Aedes aegypti against Cry11Aa Toxin from Bacillus thuringiensis

    Directory of Open Access Journals (Sweden)

    Alejandra Bravo

    2013-04-01

    Full Text Available The insecticidal Cry toxins are pore-forming toxins produced by the bacteria Bacillus thuringiensis that disrupt insect-midgut cells. Cells can trigger different survival mechanisms to counteract the effects of sub-lytic doses of pore forming toxins. Particularly, two signaling pathways have been demonstrated to play a role in the defense mechanism to other toxins in Caenorhabditis elegans and in mammalian cells. These are the unfolded protein response (UPR and the sterol regulatory element binding proteins (SREBP pathways, which are proposed to facilitate membrane repair responses. In this work we analyzed the role of these pathways in Aedes aegypti response to intoxication with Cry11Aa toxin. We show that UPR is activated upon toxin ingestion. The role of these two pathways was analyzed in vivo by using RNA interference. We silenced the expression of specific proteins in A. aegypti larvae. Gene silencing of Ire-1 and Xbp-1 proteins from UPR system, resulted in hypersensitive to Cry11Aa toxin action. In contrast, silencing of Cas-1, Scap and S2P from SREBP pathway had no affect on Cry11Aa toxicity in A. aegypti larvae. However, the role of SREBP pathway requires further studies to be conclusive. Our data indicate that the UPR pathway is involved in the insect defense against Cry toxins.

  3. Transcriptional regulatory network triggered by oxidative signals configures the early response mechanisms of japonica rice to chilling stress

    KAUST Repository

    Yun, Kil-Young

    2010-01-25

    Background: The transcriptional regulatory network involved in low temperature response leading to acclimation has been established in Arabidopsis. In japonica rice, which can only withstand transient exposure to milder cold stress (10C), an oxidative-mediated network has been proposed to play a key role in configuring early responses and short-term defenses. The components, hierarchical organization and physiological consequences of this network were further dissected by a systems-level approach.Results: Regulatory clusters responding directly to oxidative signals were prominent during the initial 6 to 12 hours at 10C. Early events mirrored a typical oxidative response based on striking similarities of the transcriptome to disease, elicitor and wounding induced processes. Targets of oxidative-mediated mechanisms are likely regulated by several classes of bZIP factors acting on as1/ocs/TGA-like element enriched clusters, ERF factors acting on GCC-box/JAre-like element enriched clusters and R2R3-MYB factors acting on MYB2-like element enriched clusters.Temporal induction of several H2O2-induced bZIP, ERF and MYB genes coincided with the transient H2O2spikes within the initial 6 to 12 hours. Oxidative-independent responses involve DREB/CBF, RAP2 and RAV1 factors acting on DRE/CRT/rav1-like enriched clusters and bZIP factors acting on ABRE-like enriched clusters. Oxidative-mediated clusters were activated earlier than ABA-mediated clusters.Conclusion: Genome-wide, physiological and whole-plant level analyses established a holistic view of chilling stress response mechanism of japonica rice. Early response regulatory network triggered by oxidative signals is critical for prolonged survival under sub-optimal temperature. Integration of stress and developmental responses leads to modulated growth and vigor maintenance contributing to a delay of plastic injuries. 2010 Yun et al; licensee BioMed Central Ltd.

  4. Sensing microorganisms in the gut triggers the immune response in Eisenia andrei earthworms.

    Science.gov (United States)

    Dvořák, Jiří; Roubalová, Radka; Procházková, Petra; Rossmann, Pavel; Škanta, František; Bilej, Martin

    2016-04-01

    The tube-within-tube body plan of earthworms is appropriate for studying the interactions of microorganisms with the immune system of body cavities such as the digestive tract and coelom. This study aims to describe the immune response on the molecular and cellular level in the coelomic cavity and the gut of the earthworm Eisenia andrei after experimental microbial challenge by administering two bacterial strains (Escherichia coli and Bacillus subtilis) or yeast Saccharomyces cerevisiae to the environment. The changes in mRNA levels of defense molecules (pattern recognition receptor CCF, lysozyme, fetidin/lysenins) in the coelomocytes and gut tissue were determined by quantitative PCR. The immune response at a cellular level was captured in histological sections, and the expression of CCF was localized using in situ hybridization. Coelomocytes respond to the presence of bacteria in the coelomic cavity by increasing the mRNA levels of defense molecules, especially CCF. The immune response in gut tissue is less affected by microbial stimulation because the epithelial cells of gut exhibit basically strong mRNA synthesis of ccf as a defense against the continuous microbial load in the gut lumen. The cellular immune response is mediated by coelomocytes released from the mesenchymal lining of the coelomic cavity. These combined immune mechanisms are necessary for the survival of earthworms in the microbially rich environment of soil. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Defense-related proteins involved in sugarcane responses to biotic stress

    Science.gov (United States)

    Souza, Thais P.; Dias, Renata O.; Silva-Filho, Marcio C.

    2017-01-01

    Abstract Sugarcane is one of the most important agricultural crops in the world. However, pathogen infection and herbivore attack cause constant losses in yield. Plants respond to pathogen infection by inducing the expression of several protein types, such as glucanases, chitinases, thaumatins, peptidase inhibitors, defensins, catalases and glycoproteins. Proteins induced by pathogenesis are directly or indirectly involved in plant defense, leading to pathogen death or inducing other plant defense responses. Several of these proteins are induced in sugarcane by different pathogens or insects and have antifungal or insecticidal activity. In this review, defense-related proteins in sugarcane are described, with their putative mechanisms of action, pathogen targets and biotechnological perspectives. PMID:28222203

  6. A Rice Gene Homologous to Arabidopsis AGD2-LIKE DEFENSE1 Participates in Disease Resistance Response against Infection with Magnaporthe oryzae

    Directory of Open Access Journals (Sweden)

    Ga Young Jung

    2016-08-01

    Full Text Available ALD1 (ABERRANT GROWTH AND DEATH2 [AGD2]-LIKE DEFENSE1 is one of the key defense regulators in Arabidopsis thaliana and Nicotiana benthamiana. In these model plants, ALD1 is responsible for triggering basal defense response and systemic resistance against bacterial infection. As well ALD1 is involved in the production of pipecolic acid and an unidentified compound(s for systemic resistance and priming syndrome, respectively. These previous studies proposed that ALD1 is a potential candidate for developing genetically modified (GM plants that may be resistant to pathogen infection. Here we introduce a role of ALD1-LIKE gene of Oryza sativa, named as OsALD1, during plant immunity. OsALD1 mRNA was strongly transcribed in the infected leaves of rice plants by Magnaporthe oryzae, the rice blast fungus. OsALD1 proteins predominantly localized at the chloroplast in the plant cells. GM rice plants over-expressing OsALD1 were resistant to the fungal infection. The stable expression of OsALD1 also triggered strong mRNA expression of PATHOGENESIS-RELATED PROTEIN1 genes in the leaves of rice plants during infection. Taken together, we conclude that OsALD1 plays a role in disease resistance response of rice against the infection with rice blast fungus.

  7. Incompatibility between plant-derived defensive chemistry and immune response of two sphingid herbivores.

    Science.gov (United States)

    Lampert, Evan C; Bowers, M Deane

    2015-01-01

    Herbivorous insects use several different defenses against predators and parasites, and tradeoffs among defensive traits may occur if these traits are energetically demanding. Chemical defense and immune response potentially can interact, and both can be influenced by host plant chemistry. Two closely related caterpillars in the lepidopteran family Sphingidae are both attacked by the same specialist endoparasitoid species but have mostly non-overlapping host plant ranges that differ in secondary chemistry. Ceratomia catalpae is a specialist on Catalpa and also will feed on Chilopsis, which both produce iridoid glycosides. Ceratomia undulosa consumes members of the Oleaceae, which produce seco-iridoid glycosides. Immune response of the two species on a typical host plant species (Catalpa bignonioides for C. catalpa; Fraxinus americana for C. undulosa) was compared using a melanization assay, and did not differ. In a second experiment, the iridoid glycoside catalpol was added to the diets of both insects, and growth rate, mass, chemical defense, and immune response were evaluated. Increased dietary catalpol weakened the immune response of C. undulosa and altered the development rate of C. catalpae by prolonging the third instar and accelerating the fourth instar. Catalpol sequestration was negatively correlated with immune response of C. catalpae, while C. undulosa was unable to sequester catalpol. These results show that immune response can be negatively influenced by increasing concentrations of sequestered defensive compounds.

  8. IBR5 Modulates Temperature-Dependent, R Protein CHS3-Mediated Defense Responses in Arabidopsis.

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    Jingyan Liu

    2015-10-01

    Full Text Available Plant responses to low temperature are tightly associated with defense responses. We previously characterized the chilling-sensitive mutant chs3-1 resulting from the activation of the Toll and interleukin 1 receptor-nucleotide binding-leucine-rich repeat (TIR-NB-LRR-type resistance (R protein harboring a C-terminal LIM (Lin-11, Isl-1 and Mec-3 domains domain. Here we report the identification of a suppressor of chs3, ibr5-7 (indole-3-butyric acid response 5, which largely suppresses chilling-activated defense responses. IBR5 encodes a putative dual-specificity protein phosphatase. The accumulation of CHS3 protein at chilling temperatures is inhibited by the IBR5 mutation. Moreover, chs3-conferred defense phenotypes were synergistically suppressed by mutations in HSP90 and IBR5. Further analysis showed that IBR5, with holdase activity, physically associates with CHS3, HSP90 and SGT1b (Suppressor of the G2 allele of skp1 to form a complex that protects CHS3. In addition to the positive role of IBR5 in regulating CHS3, IBR5 is also involved in defense responses mediated by R genes, including SNC1 (Suppressor of npr1-1, Constitutive 1, RPS4 (Resistance to P. syringae 4 and RPM1 (Resistance to Pseudomonas syringae pv. maculicola 1. Thus, the results of the present study reveal a role for IBR5 in the regulation of multiple R protein-mediated defense responses.

  9. Responsiveness of Myofascial Trigger Points to Single and Multiple Trigger Point Release Massages: A Randomized, Placebo Controlled Trial.

    Science.gov (United States)

    Moraska, Albert F; Schmiege, Sarah J; Mann, John D; Butryn, Nathan; Krutsch, Jason P

    2017-09-01

    This study aimed to assess the effects of single and multiple massage treatments on pressure-pain threshold (PPT) at myofascial trigger points (MTrPs) in people with myofascial pain syndrome expressed as tension-type headache. Individuals (n = 62) with episodic or chronic tension-type headache were randomized to receive 12 twice-weekly 45-min massage or sham ultrasound sessions or wait-list control. Massage focused on trigger point release (ischemic compression) of MTrPs in the bilateral upper trapezius and suboccipital muscles. PPT was measured at MTrPs with a pressure algometer pre and post the first and final (12th) treatments. PPT increased across the study timeframe in all four muscle sites tested for massage, but not sham ultrasound or wait-list groups (P trigger points to myofascial pain; (2) Describe an effective treatment for decreasing tenderness of a myofascial trigger point; and (3) Discuss the relative values of single vs. multiple massage sessions on increasing pressure-pain thresholds at myofascial trigger points. Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 0.5 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

  10. Acute injury in the peripheral nervous system triggers an alternative macrophage response

    Directory of Open Access Journals (Sweden)

    Ydens Elke

    2012-07-01

    Full Text Available Abstract Background The activation of the immune system in neurodegeneration has detrimental as well as beneficial effects. Which aspects of this immune response aggravate the neurodegenerative breakdown and which stimulate regeneration remains an open question. To unravel the neuroprotective aspects of the immune system we focused on a model of acute peripheral nerve injury, in which the immune system was shown to be protective. Methods To determine the type of immune response triggered after axotomy of the sciatic nerve, a model for Wallerian degeneration in the peripheral nervous system, we evaluated markers representing the two extremes of a type I and type II immune response (classical vs. alternative using real-time quantitative polymerase chain reaction (RT-qPCR, western blot, and immunohistochemistry. Results Our results showed that acute peripheral nerve injury triggers an anti-inflammatory and immunosuppressive response, rather than a pro-inflammatory response. This was reflected by the complete absence of classical macrophage markers (iNOS, IFNγ, and IL12p40, and the strong up-regulation of tissue repair markers (arginase-1, Ym1, and Trem2. The signal favoring the alternative macrophage environment was induced immediately after nerve damage and appeared to be established within the nerve, well before the infiltration of macrophages. In addition, negative regulators of the innate immune response, as well as the anti-inflammatory cytokine IL-10 were induced. The strict regulation of the immune system dampens the potential tissue damaging effects of an over-activated response. Conclusions We here demonstrate that acute peripheral nerve injury triggers an inherent protective environment by inducing the M2 phenotype of macrophages and the expression of arginase-1. We believe that the M2 phenotype, associated with a sterile inflammatory response and tissue repair, might explain their neuroprotective capacity. As such, shifting the

  11. The Defense Mechanisms Inventory as a Predictor of Affective Response to Threat.

    Science.gov (United States)

    Klusman, Lawrence E.

    1982-01-01

    Sought to validate the Defense Mechanisms Inventory (DMI) as a predictor of affective response to stress. Two groups of male Army trainees participated in a group-ranking procedure. Findings suggested that affective response was a function of the interaction between DMI personality variables and type of situational threat. (Author)

  12. Contrasting Regulation of NO and ROS in Potato Defense-Associated Metabolism in Response to Pathogens of Different Lifestyles.

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    Jolanta Floryszak-Wieczorek

    Full Text Available Our research provides new insights into how the low and steady-state levels of nitric oxide (NO and reactive oxygen species (ROS in potato leaves are altered after the challenge with the hemibiotroph Phytophthora infestans or the necrotroph Botrytis cinerea, with the subsequent rapid and invader-dependent modification of defense responses with opposite effects. Mainly in the avirulent (avr P. infestans-potato system, NO well balanced with the superoxide level was tuned with a battery of SA-dependent defense genes, leading to the establishment of the hypersensitive response (HR successfully arresting the pathogen. Relatively high levels of S-nitrosoglutathione and S-nitrosothiols concentrated in the main vein of potato leaves indicated the mobile function of these compounds as a reservoir of NO bioactivity. In contrast, low-level production of NO and ROS during virulent (vr P. infestans-potato interactions might be crucial in the delayed up-regulation of PR-1 and PR-3 genes and compromised resistance to the hemibiotrophic pathogen. In turn, B. cinerea triggered huge NO overproduction and governed inhibition of superoxide production by blunting NADPH oxidase. Nevertheless, a relatively high level of H2O2 was found owing to the germin-like activity in cooperation with NO-mediated HR-like cell death in potato genotypes favorable to the necrotrophic pathogen. Moreover, B. cinerea not only provoked cell death, but also modulated the host redox milieu by boosting protein nitration, which attenuated SA production but not SA-dependent defense gene expression. Finally, based on obtained data the organismal cost of having machinery for HR in plant resistance to biotrophs is also discussed, while emphasizing new efforts to identify other components of the NO/ROS cell death pathway and improve plant protection against pathogens of different lifestyles.

  13. Hormone-regulated defense and stress response networks contribute to heterosis in Arabidopsis F1 hybrids.

    Science.gov (United States)

    Groszmann, Michael; Gonzalez-Bayon, Rebeca; Lyons, Rebecca L; Greaves, Ian K; Kazan, Kemal; Peacock, W James; Dennis, Elizabeth S

    2015-11-17

    Plant hybrids are extensively used in agriculture to deliver increases in yields, yet the molecular basis of their superior performance (heterosis) is not well understood. Our transcriptome analysis of a number of Arabidopsis F1 hybrids identified changes to defense and stress response gene expression consistent with a reduction in basal defense levels. Given the reported antagonism between plant immunity and growth, we suggest that these altered patterns of expression contribute to the greater growth of the hybrids. The altered patterns of expression in the hybrids indicate decreases to the salicylic acid (SA) biosynthesis pathway and increases in the auxin [indole-3-acetic acid (IAA)] biosynthesis pathway. SA and IAA are hormones known to control stress and defense responses as well as plant growth. We found that IAA-targeted gene activity is frequently increased in hybrids, correlating with a common heterotic phenotype of greater leaf cell numbers. Reduced SA concentration and target gene responses occur in the larger hybrids and promote increased leaf cell size. We demonstrated the importance of SA action to the hybrid phenotype by manipulating endogenous SA concentrations. Increasing SA diminished heterosis in SA-reduced hybrids, whereas decreasing SA promoted growth in some hybrids and phenocopied aspects of hybrid vigor in parental lines. Pseudomonas syringae infection of hybrids demonstrated that the reductions in basal defense gene activity in these hybrids does not necessarily compromise their ability to mount a defense response comparable to the parents.

  14. Dynamics of defense responses and cell fate change during Arabidopsis-Pseudomonas syringae interactions.

    Directory of Open Access Journals (Sweden)

    Safae Hamdoun

    Full Text Available Plant-pathogen interactions involve sophisticated action and counteraction strategies from both parties. Plants can recognize pathogen derived molecules, such as conserved pathogen associated molecular patterns (PAMPs and effector proteins, and subsequently activate PAMP-triggered immunity (PTI and effector-triggered immunity (ETI, respectively. However, pathogens can evade such recognitions and suppress host immunity with effectors, causing effector-triggered susceptibility (ETS. The differences among PTI, ETS, and ETI have not been completely understood. Toward a better understanding of PTI, ETS, and ETI, we systematically examined various defense-related phenotypes of Arabidopsis infected with different Pseudomonas syringae pv. maculicola ES4326 strains, using the virulence strain DG3 to induce ETS, the avirulence strain DG34 that expresses avrRpm1 (recognized by the resistance protein RPM1 to induce ETI, and HrcC(- that lacks the type three secretion system to activate PTI. We found that plants infected with different strains displayed dynamic differences in the accumulation of the defense signaling molecule salicylic acid, expression of the defense marker gene PR1, cell death formation, and accumulation/localization of the reactive oxygen species, H2O2. The differences between PTI, ETS, and ETI are dependent on the doses of the strains used. These data support the quantitative nature of PTI, ETS, and ETI and they also reveal qualitative differences between PTI, ETS, and ETI. Interestingly, we observed the induction of large cells in the infected leaves, most obviously with HrcC(- at later infection stages. The enlarged cells have increased DNA content, suggesting a possible activation of endoreplication. Consistent with strong induction of abnormal cell growth by HrcC(-, we found that the PTI elicitor flg22 also activates abnormal cell growth, depending on a functional flg22-receptor FLS2. Thus, our study has revealed a comprehensive

  15. Arabidopsis GH3-LIKE DEFENSE GENE 1 is required for accumulation of salicylic acid, activation of defense responses and resistance to Pseudomonas syringae.

    Science.gov (United States)

    Jagadeeswaran, Guru; Raina, Surabhi; Acharya, Biswa R; Maqbool, Shahina B; Mosher, Stephen L; Appel, Heidi M; Schultz, Jack C; Klessig, Daniel F; Raina, Ramesh

    2007-07-01

    In Arabidopsis, the GH3-like gene family consists of 19 members, several of which have been shown to adenylate the plant hormones jasmonic acid, indole acetic acid and salicylic acid (SA). In some cases, this adenylation has been shown to catalyze hormone conjugation to amino acids. Here we report molecular characterization of the GH3-LIKE DEFENSE GENE 1 (GDG1), a member of the GH3-like gene family, and show that GDG1 is an important component of SA-mediated defense against the bacterial pathogen Pseudomonas syringae. Expression of GDG1 is induced earlier and to a higher level in response to avirulent pathogens compared to virulent pathogens. gdg1 null mutants are compromised in several pathogen defense responses, including activation of defense genes and resistance against virulent and avirulent bacterial pathogens. Accumulation of free and glucoside-conjugated SA (SAG) in response to pathogen infection is compromised in gdg1 mutants. All defense-related phenotypes of gdg1 can be rescued by external application of SA, suggesting that gdg1 mutants are defective in the SA-mediated defense pathway(s) and that GDG1 functions upstream of SA. Our results suggest that GDG1 contributes to both basal and resistance gene-mediated inducible defenses against P. syringae (and possibly other pathogens) by playing a critical role in regulating the levels of pathogen-inducible SA. GDG1 is allelic to the PBS3 (avrPphB susceptible) gene.

  16. Temperature responsive porous silicon nanoparticles for cancer therapy - spatiotemporal triggering through infrared and radiofrequency electromagnetic heating.

    Science.gov (United States)

    Tamarov, Konstantin; Xu, Wujun; Osminkina, Liubov; Zinovyev, Sergey; Soininen, Pasi; Kudryavtsev, Andrey; Gongalsky, Maxim; Gaydarova, Azha; Närvänen, Ale; Timoshenko, Victor; Lehto, Vesa-Pekka

    2016-11-10

    One critical functionality of the carrier system utilized in targeted drug delivery is its ability to trigger the release of the therapeutic cargo once the carrier has reached its target. External triggering is an alluring approach as it can be applied in a precise spatiotemporal manner. In the present study, we achieved external triggering through the porous silicon (PSi) nanoparticles (NPs) by providing a pulse of infrared or radiofrequency radiation. The NPs were grafted with a temperature responsive polymer whose critical temperature was tailored to be slightly above 37°C. The polymer coating improved the biocompatibility of the NPs significantly in comparison with their uncoated counterparts. Radiation induced a rapid temperature rise, which resulted in the collapse of the polymer chains facilitating the cargo release. Both infrared and radiofrequency radiation were able to efficiently trigger the release of the encapsulated drug in vitro and induce significant cell death in comparison to the control groups. Radiofrequency radiation was found to be more efficient in vitro, and the treatment efficacy was verified in vivo in a lung carcinoma (3LL) mice model. After a single intratumoral administration of the carrier system combined with radiofrequency radiation, there was clear suppression of the growth of the carcinoma and a prolongation of the survival time of the animals. The temperature responsive (TR) polymer grafted on the surface of porous silicon nanoparticles (PSi NPs) changes its conformation in response to the heating induced by infrared or radiofrequency radiation. The conformation change allows the loaded doxorubicin to escape from the pores, achieving controlled drug release from TR PSi NPs, which displayed efficacy against malignant cells both in vitro and in vivo. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. A new cellular stress response that triggers centriolar satellite reorganization and ciliogenesis

    DEFF Research Database (Denmark)

    Villumsen, Bine H; Danielsen, Jannie R; Povlsen, Lou

    2013-01-01

    , and transcription blocks, invoking acute and selective displacement of the factors AZI1/CEP131, PCM1, and CEP290 from this compartment triggered by activation of the stress-responsive kinase p38/MAPK14. We demonstrate that the E3 ubiquitin ligase MIB1 is a new component of centriolar satellites, which interacts...... with and ubiquitylates AZI1 and PCM1 and suppresses primary cilium formation. In response to cell stress, MIB1 is abruptly inactivated in a p38-independent manner, leading to loss of AZI1, PCM1, and CEP290 ubiquitylation and concomitant stimulation of ciliogenesis, even in proliferating cells. Collectively, our findings...

  18. Spatiotemporal heterogeneity of tomato induced defense responses affects spider mite performance and behavior.

    Science.gov (United States)

    Schimmel, Bernardus C J; Ataide, Livia M S; Kant, Merijn R

    2017-10-03

    When feeding from tomato (Solanum lycopersicum), the generalist spider mite Tetranychus urticae induces jasmonate (JA)- and salicylate (SA)-regulated defense responses that hamper its performance. The related T. evansi, a Solanaceae-specialist, suppresses these defenses, thereby upholding a high performance. On a shared leaf, T. urticae can be facilitated by T. evansi, likely via suppression of defenses by the latter. Yet, when infesting the same plant, T. evansi outcompetes T. urticae. Recently, we found that T. evansi intensifies suppression of defenses locally, i.e., at its feeding site, after T. urticae mites were introduced onto adjacent leaf tissue. This hyper-suppression is paralleled by an increased oviposition rate of T. evansi, probably promoting its competitive population growth. Here we present additional data that not only provide insight into the spatiotemporal dynamics of defense induction and suppression by mites, but that also suggest T. evansi to manipulate more than JA and SA defenses alone.

  19. 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

  20. Multi-Tiered Observation and Response Charts: Prevalence and Incidence of Triggers, Modifications and Calls, to Acutely Deteriorating Adult Patients.

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    Arthas Flabouris

    Full Text Available Observation charts are the primary tool for recording patient vital signs. They have a critical role in documenting triggers for a multi-tiered escalation response to the deteriorating patient. The objectives of this study were to ascertain the prevalence and incidence of triggers, trigger modifications and escalation response (Call amongst general medical and surgical inpatients following the introduction of an observation and response chart (ORC.Prospective (prevalence, over two 24-hour periods, and retrospective (incidence, over entire hospital stay, observational study of documented patient observations intended to trigger one of three escalation responses, being a MER-Medical Emergency Response [highest tier], MDT-Multidisciplinary Team [admitting team], or Nurse-senior ward nurse [lowest tier] response amongst adult general medical and surgical patients.416 patients, 321 (77.2% being medical admissions, median age 76 years (IQR 62, 85 and 95 (22.8% Not for Resuscitation (NFR. Overall, 193 (46.4% patients had a Trigger, being 17 (4.1% MER, 45 (10.8% MDT and 178 (42.8% Nurse triggers. 60 (14.4% patients had a Call, and 72 (17.3% a modified Trigger.206 patients, of similar age, of whom 166 (80.5% had a Trigger, 122 (59.2% a Call, and 91 (44.2% a modified Trigger. PREVALENCE and incidence of failure to Call was 33.2% and 68% of patients, respectively, particular for Nurse Triggers (26.7% and 62.1%, respectively. The number of Modifications, Calls, and failure to Call, correlated with the number of Triggers (0.912 [p<0.01], 0.631 [p<0.01], 0.988 [p<0.01].Within a multi-tiered response system for the detection and response to the deteriorating patient Triggers, their Modifications and failure to Call are common, particularly within the lower tiers of escalation. The number of Triggers and their Modifications may erode the structure, compliance, and potential efficacy of structured observation and response charts within a multi-tiered response

  1. Sulforaphane prevents pulmonary damage in response to inhaled arsenic by activating the Nrf2-defense response

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Yi [Department of Environmental and Occupational Health, School of Public Health, China Medical University, Shenyang, Liaoning 110001 (China); Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, 1703 East Mabel Street, Tucson, AZ 85721 (United States); Tao, Shasha [Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, 1703 East Mabel Street, Tucson, AZ 85721 (United States); Lian, Fangru [Department of Pathology, University of Arizona, 1501 North Campbell Ave, Tucson, AZ 85724 (United States); Chau, Binh T. [Department of Cellular and Molecular Medicine, The University of Arizona, 1501 North Campbell Ave, Tucson, AZ 85724 (United States); Chen, Jie; Sun, Guifan [Department of Environmental and Occupational Health, School of Public Health, China Medical University, Shenyang, Liaoning 110001 (China); Fang, Deyu [Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611 (United States); Lantz, R. Clark [Department of Cellular and Molecular Medicine, The University of Arizona, 1501 North Campbell Ave, Tucson, AZ 85724 (United States); Arizona Cancer Center, University of Arizona, 1515 North Campbell Avenue, Tucson, AZ 85724 (United States); Zhang, Donna D., E-mail: dzhang@pharmacy.arizona.edu [Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, 1703 East Mabel Street, Tucson, AZ 85721 (United States); Arizona Cancer Center, University of Arizona, 1515 North Campbell Avenue, Tucson, AZ 85724 (United States)

    2012-12-15

    Exposure to arsenic is associated with an increased risk of lung disease. Novel strategies are needed to reduce the adverse health effects associated with arsenic exposure in the lung. Nrf2, a transcription factor that mediates an adaptive cellular defense response, is effective in detoxifying environmental insults and prevents a broad spectrum of diseases induced by environmental exposure to harmful substances. In this report, we tested whether Nrf2 activation protects mice from arsenic-induced toxicity. We used an in vivo arsenic inhalation model that is highly relevant to low environmental human exposure to arsenic-containing dusts. Two-week exposure to arsenic-containing dust resulted in pathological alterations, oxidative DNA damage, and mild apoptotic cell death in the lung; all of which were blocked by sulforaphane (SF) in an Nrf2-dependent manner. Mechanistically, SF-mediated activation of Nrf2 alleviated inflammatory responses by modulating cytokine production. This study provides strong evidence that dietary intervention targeting Nrf2 activation is a feasible approach to reduce adverse health effects associated with arsenic exposure. -- Highlights: ► Exposed to arsenic particles and/or SF have elevated Nrf2 and its target genes. ► Sulforaphane prevents pathological alterations, oxidative damage and cell death. ► Sulforaphane alleviates infiltration of inflammatory cells into the lungs. ► Sulforaphane suppresses arsenic-induced proinflammatory cytokine production.

  2. Reducing Defensive Responses to Thoughts of Death: Meditation, Mindfulness, and Buddhism.

    Science.gov (United States)

    Park, Young Chin; Pyszczynski, Tom

    2017-08-24

    Three studies investigated the effects of meditation on responses to reminders of death. Study 1 took a quasi-experimental approach, comparing defensive responses to mortality salience (MS) of South Korean participants with varying levels of experience with Buddhism and meditation. Whereas non-Buddhists without meditation showed the typical increase in worldview defense after mortality salience (MS), this effect was not found among non-Buddhists immediately after an initial meditation experience, nor among lay Buddhists who meditated regularly or Buddhist monks with intensive meditation experience. Study 2, a fully randomized experiment, showed that MS increased worldview defense among South Koreans at a meditation training who were assessed before meditating but not among participants assessed after their first meditation experience. Study 3 showed that whereas American students without prior meditation experience showed increased worldview defense and suppression of death-related thoughts after MS, these effects were eliminated immediately after an initial meditation experience. Death thought accessibility mediated the effect of MS on worldview defense without meditation, but meditation eliminated this mediation. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  3. Erwinia carotovora elicitors and Botrytis cinerea activate defense responses in Physcomitrella patens

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    Bentancor Marcel

    2007-10-01

    Full Text Available Abstract Background Vascular plants respond to pathogens by activating a diverse array of defense mechanisms. Studies with these plants have provided a wealth of information on pathogen recognition, signal transduction and the activation of defense responses. However, very little is known about the infection and defense responses of the bryophyte, Physcomitrella patens, to well-studied phytopathogens. The purpose of this study was to determine: i whether two representative broad host range pathogens, Erwinia carotovora ssp. carotovora (E.c. carotovora and Botrytis cinerea (B. cinerea, could infect Physcomitrella, and ii whether B. cinerea, elicitors of a harpin (HrpN producing E.c. carotovora strain (SCC1 or a HrpN-negative strain (SCC3193, could cause disease symptoms and induce defense responses in Physcomitrella. Results B. cinerea and E.c. carotovora were found to readily infect Physcomitrella gametophytic tissues and cause disease symptoms. Treatments with B. cinerea spores or cell-free culture filtrates from E.c. carotovoraSCC1 (CF(SCC1, resulted in disease development with severe maceration of Physcomitrella tissues, while CF(SCC3193 produced only mild maceration. Although increased cell death was observed with either the CFs or B. cinerea, the occurrence of cytoplasmic shrinkage was only visible in Evans blue stained protonemal cells treated with CF(SCC1 or inoculated with B. cinerea. Most cells showing cytoplasmic shrinkage accumulated autofluorescent compounds and brown chloroplasts were evident in a high proportion of these cells. CF treatments and B. cinerea inoculation induced the expression of the defense-related genes: PR-1, PAL, CHS and LOX. Conclusion B. cinerea and E.c. carotovora elicitors induce a defense response in Physcomitrella, as evidenced by enhanced expression of conserved plant defense-related genes. Since cytoplasmic shrinkage is the most common morphological change observed in plant PCD, and that harpins and B

  4. Transcriptional response of bronchial epithelial cells to Pseudomonas aeruginosa: identification of early mediators of host defense.

    NARCIS (Netherlands)

    Vos, J.B.; Sterkenburg, M.A. van; Rabe, K.F.; Schalkwijk, J.; Hiemstra, P.S.; Datson, N.A.

    2005-01-01

    The airway epithelium responds to microbial exposure by altering expression of a variety of genes to increase innate host defense. We aimed to delineate the early transcriptional response in human primary bronchial epithelial cells exposed for 6 h to a mixture of IL-1beta and TNF-alpha or

  5. Ethanol cellular defense induce unfolded protein response in yeast

    Directory of Open Access Journals (Sweden)

    Elisabet eNavarro-Tapia

    2016-02-01

    Full Text Available Ethanol is a valuable industrial product and a common metabolite used by many cell types. However, this molecule produces high levels of cytotoxicity affecting cellular performance at several levels. In the presence of ethanol, cells must adjust some of their components, such as the membrane lipids to maintain homeostasis. In the case of microorganism as Saccharomyces cerevisiae, ethanol is one of the principal products of their metabolism and is the main stress factor during fermentation. Although many efforts have been made, mechanisms of ethanol tolerance are not fully understood and very little evidence is available to date for specific signaling by ethanol in the cell. This work studied two Saccharomyces cerevisiae strains, CECT10094 and Temohaya-MI26, isolated from flor wine and agave fermentation (a traditional fermentation from Mexico respectively, which differ in ethanol tolerance, in order to understand the molecular mechanisms underlying the ethanol stress response and the reasons for different ethanol tolerance. The transcriptome was analyzed after ethanol stress and, among others, an increased activation of genes related with the unfolded protein response (UPR and its transcription factor, Hac1p, was observed in the tolerant strain CECT10094. We observed that this strain also resist more UPR agents than Temohaya-MI26 and the UPR-ethanol stress correlation was corroborated observing growth of 15 more strains and discarding UPR correlation with other stresses as thermal or oxidative stress. Furthermore, higher activation of UPR pathway in the tolerant strain CECT10094 was observed using a UPR mCherry reporter. Finally, we observed UPR activation in response to ethanol stress in other S. cerevisiae ethanol tolerant strains as the wine strains T73 and EC1118. This work demonstrates that the UPR pathway is activated under ethanol stress occurring in a standard fermentation and links this response to an enhanced ethanol tolerance. Thus

  6. Tracheostomy Complications as a Trigger for an Airway Rapid Response: Analysis and Quality Improvement Considerations.

    Science.gov (United States)

    Rassekh, Christopher H; Zhao, Jing; Martin, Niels D; Chalian, Ara A; Atkins, Joshua H

    2015-12-01

    To analyze the subset of airway rapid response (ARR) calls related to tracheostomy identified over a 46-month period from August 2011 to May 2015 to determine proximate cause, intervention, and outcome and to develop process improvement initiatives. Single-institution multidisciplinary retrospective cohort study. Tertiary care academic medical center in a large urban setting. Hospital inpatients with an in situ tracheostomy or laryngectomy who experienced an ARR. Detailed review of operator, hospital, and patient records related to ARR system activations over a 46-month period. ARR was activated for 28 patients with existing tracheostomy. The cohort included open tracheostomy (n = 14), percutaneous tracheostomy (n = 8), laryngectomy stoma (n = 3), and indeterminate technique (n = 3). The most frequent triggers for emergency airway intervention were decannulation (n = 16), followed by mucus plugging (n = 4). The mean body mass index of ARR patients was higher than that of a comparator tracheostomy cohort (32.9 vs 26.3, P 40 in 9 ARR patients. There was 1 mortality in the series. Tracheostomy is a major trigger for ARR with potential fatal outcome. Factors that may contribute to tracheostomy emergencies include high body mass index, surgical technique for open tracheostomy or percutaneous tracheostomy, tracheostomy tube size, and bedside tracheostomy management. Results have triggered a hospital-wide practice improvement plan focused on tracheostomy awareness and documentation, discrete process changes, and implementation of guidelines for emergency management. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

  7. Induction of phenolics, lignin and key defense enzymes in eggplant ...

    African Journals Online (AJOL)

    Elicitors are capable of mimicking the perception of a pathogen by a plant, thereby triggering induction of a sophisticated defense response in plants. In this study, we investigated an induced resistance in eggplant in respect to cell wall strengthening and defense enzyme activation affected by four elicitors such as, chitosan ...

  8. Civil Support: DOD Needs to Clarify Its Roles and Responsibilities for Defense Support of Civil Authorities during Cyber Incidents

    Science.gov (United States)

    2016-04-01

    CIVIL SUPPORT DOD Needs to Clarify Its Roles and Responsibilities for Defense Support of Civil Authorities during...Clarify Its Roles and Responsibilities for Defense Support of Civil Authorities during Cyber Incidents Why GAO Did This Study Cyber threats to U.S...recognizes that the department plays a crucial role in supporting a national effort to confront cyber threats to critical infrastructure. House

  9. Induction of defensive response in Eucalyptus globulus plants and its persistence in vegetative propagation.

    Science.gov (United States)

    Troncoso, Christian; Perez, Claudia; Hernandez, Victor; Sanchez-Olate, Manuel; Rios, Darcy; San Martin, Aurelio; Becerra, José

    2013-03-01

    The expression of defensive compounds derived from secondary metabolism in plants of Eucalyptus globulus Labill, and the persistence of these in vegetative propagation was evaluated by gas chromatography with flame ionization (GC-FID) and mass spectrometry (MS). The plants were induced by attack from the insect Ctenarytaina eucalypti ("blue gum psyllid") and by mechanical damage. Defense responses were activated in plants for the different types of tested induction. We identified four defensive compounds present in the leaves of plants induced in entomological form (beta-terpineol, aromadendrene, caryophyllene-oxide and eremophilene); all remained in the vegetative propagation. After mechanical induction, we identified three compounds (beta-terpineol, aromadendrene and ledol), of which ledol and aromadendrene persisted in the vegetative propagation. Virtually all the compounds detected, in addition to persisting in the vegetative propagation, showed specificity for the induction type, whether entomological or mechanical, except for aromadendrene, which was expressed in both types of induction.

  10. The interferon response circuit in antiviral host defense.

    Science.gov (United States)

    Haller, O; Weber, F

    2009-01-01

    Viruses have learned to multiply in the face of a powerful innate and adaptive immune response of the host. They have evolved multiple strategies to evade the interferon (IFN) system which would otherwise limit virus growth at an early stage of infection. IFNs induce the synthesis of a range of antiviral proteins which serve as cell-autonomous intrinsic restriction factors. For example, the dynamin-like MxA GTPase inhibits the multiplication of influenza and bunyaviruses (such as La Crosse virus, Hantaan virus, Rift Valley Fever virus, and Crimean-Congo hemorrhagic fever virus) by binding and sequestering the nucleocapsid protein into large perinuclear complexes. To overcome such intracellular restrictions, virulent viruses either inhibit IFN synthesis, bind and inactivate secreted IFN molecules, block IFN-activated signaling, or disturb the action of IFN-induced antiviral proteins. Many viruses produce specialized proteins to disarm the danger signal or express virulence genes that target members of the IFN regulatory factor family (IRFs) or components of the JAK-STAT signaling pathway. An alternative evasion strategy is based on extreme viral replication speed which out-competes the IFN response. The identification of viral proteins with IFN antagonistic functions has great implications for disease prevention and therapy. Virus mutants lacking IFN antagonistic properties represent safe yet highly immunogenic candidate vaccines. Furthermore, novel drugs intercepting viral IFN-antagonists could be used to disarm the viral intruders.

  11. ETHYLENE RESPONSE FACTOR1 Integrates Signals from Ethylene and Jasmonate Pathways in Plant DefenseW⃞

    Science.gov (United States)

    Lorenzo, Oscar; Piqueras, Raquel; Sánchez-Serrano, Jose J.; Solano, Roberto

    2003-01-01

    Cross-talk between ethylene and jasmonate signaling pathways determines the activation of a set of defense responses against pathogens and herbivores. However, the molecular mechanisms that underlie this cross-talk are poorly understood. Here, we show that ethylene and jasmonate pathways converge in the transcriptional activation of ETHYLENE RESPONSE FACTOR1 (ERF1), which encodes a transcription factor that regulates the expression of pathogen response genes that prevent disease progression. The expression of ERF1 can be activated rapidly by ethylene or jasmonate and can be activated synergistically by both hormones. In addition, both signaling pathways are required simultaneously to activate ERF1, because mutations that block any of them prevent ERF1 induction by any of these hormones either alone or in combination. Furthermore, 35S:ERF1 expression can rescue the defense response defects of coi1 (coronative insensitive1) and ein2 (ethylene insensitive2); therefore, it is a likely downstream component of both ethylene and jasmonate signaling pathways. Transcriptome analysis in Col;35S:ERF1 transgenic plants and ethylene/jasmonate-treated wild-type plants further supports the notion that ERF1 regulates in vivo the expression of a large number of genes responsive to both ethylene and jasmonate. These results suggest that ERF1 acts downstream of the intersection between ethylene and jasmonate pathways and suggest that this transcription factor is a key element in the integration of both signals for the regulation of defense response genes. PMID:12509529

  12. Molecular defense response of oil palm to Ganoderma infection.

    Science.gov (United States)

    Ho, C-L; Tan, Y-C

    2015-06-01

    Basal stem rot (BSR) of oil palm roots is due to the invasion of fungal mycelia of Ganoderma species which spreads to the bole of the stem. In addition to root contact, BSR can also spread by airborne basidiospores. These fungi are able to break down cell wall components including lignin. BSR not only decreases oil yield, it also causes the stands to collapse thus causing severe economic loss to the oil palm industry. The transmission and mode of action of Ganoderma, its interactions with oil palm as a hemibiotroph, and the molecular defence responses of oil palm to the infection of Ganoderma boninense in BSR are reviewed, based on the transcript profiles of infected oil palms. The knowledge gaps that need to be filled in oil palm-Ganoderma molecular interactions i.e. the associations of hypersensitive reaction (HR)-induced cell death and reactive oxygen species (ROS) kinetics to the susceptibility of oil palm to Ganoderma spp., the interactions of phytohormones (salicylate, jasmonate and ethylene) at early and late stages of BSR, and cell wall strengthening through increased production of guaiacyl (G)-type lignin, are also discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Prevalence and Mechanisms of Dynamic Chemical Defenses in Tropical Sponges

    Science.gov (United States)

    Rohde, Sven; Nietzer, Samuel; Schupp, Peter J.

    2015-01-01

    Sponges and other sessile invertebrates are lacking behavioural escape or defense mechanisms and rely therefore on morphological or chemical defenses. Studies from terrestrial systems and marine algae demonstrated facultative defenses like induction and activation to be common, suggesting that sessile marine organisms also evolved mechanisms to increase the efficiency of their chemical defense. However, inducible defenses in sponges have not been investigated so far and studies on activated defenses are rare. We investigated whether tropical sponge species induce defenses in response to artificial predation and whether wounding triggers defense activation. Additionally, we tested if these mechanisms are also used to boost antimicrobial activity to avoid bacterial infection. Laboratory experiments with eight pacific sponge species showed that 87% of the tested species were chemically defended. Two species, Stylissa massa and Melophlus sarasinorum, induced defenses in response to simulated predation, which is the first demonstration of induced antipredatory defenses in marine sponges. One species, M. sarasinorum, also showed activated defense in response to wounding. Interestingly, 50% of the tested sponge species demonstrated induced antimicrobial defense. Simulated predation increased the antimicrobial defenses in Aplysinella sp., Cacospongia sp., M. sarasinorum, and S. massa. Our results suggest that wounding selects for induced antimicrobial defenses to protect sponges from pathogens that could otherwise invade the sponge tissue via feeding scars. PMID:26154741

  14. Negative regulation of defense responses in plants by a conserved MAPKK kinase.

    Science.gov (United States)

    Frye, C A; Tang, D; Innes, R W

    2001-01-02

    The enhanced disease resistance 1 (edr1) mutation of Arabidopsis confers resistance to powdery mildew disease caused by the fungus Erysiphe cichoracearum. Resistance mediated by the edr1 mutation is correlated with induction of several defense responses, including host cell death. Double mutant analysis revealed that all edr1-associated phenotypes are suppressed by mutations that block salicylic acid (SA) perception (nim1) or reduce SA production (pad4 and eds1). The NahG transgene, which lowers endogenous SA levels, also suppressed edr1. In contrast, the ein2 mutation did not suppress edr1-mediated resistance and associated phenotypes, indicating that ethylene and jasmonic acid-induced responses are not required for edr1 resistance. The EDR1 gene was isolated by positional cloning and was found to encode a putative MAP kinase kinase kinase similar to CTR1, a negative regulator of ethylene responses in Arabidopsis. Taken together, these data suggest that EDR1 functions at the top of a MAP kinase cascade that negatively regulates SA-inducible defense responses. Putative orthologs of EDR1 are present in monocots such as rice and barley, indicating that EDR1 may regulate defense responses in a wide range of crop species.

  15. Exploring the Structure of Human Defensive Responses from Judgments of Threat Scenarios.

    Directory of Open Access Journals (Sweden)

    Laura A Harrison

    Full Text Available How humans react to threats is a topic of broad theoretical importance, and also relevant for understanding anxiety disorders. Many animal threat reactions exhibit a common structure, a finding supported by human evaluations of written threat scenarios that parallel patterns of rodent defensive behavior to actual threats. Yet the factors that underlie these shared behavioral patterns remain unclear. Dimensional accounts rooted in Darwin's conception of antithesis explain many defensive behaviors. Across species, it is also clear that defensive reactions depend on specific situational factors, a feature long emphasized by psychological appraisal theories. Our study sought to extend prior investigations of human judgments of threat to a broader set of threats, including natural disasters, threats from animals, and psychological (as opposed to physical threats. Our goal was to test whether dimensional and specific patterns of threat evaluation replicate across different threat classes. 85 healthy adult subjects selected descriptions of defensive behaviors that indicated how they would react to 29 threatening scenarios. Scenarios differed with respect to ten factors, e.g., perceived dangerousness or escapability. Across scenarios, we correlated these factor ratings with the pattern of defensive behaviors subjects endorsed. A decision tree hierarchically organized these correlation patterns to successfully predict each scenario's most common reaction, both for the original sample of subjects and a separate replication group (n = 22. At the top of the decision tree, degree of dangerousness interacted with threat type (physical or psychological to predict dimensional approach/avoidance behavior. Subordinate nodes represented specific defensive responses evoked by particular contexts. Our ecological approach emphasizes the interplay of situational factors in evoking a broad range of threat reactions. Future studies could test predictions made by our

  16. The local twitch response during trigger point dry needling: Is it necessary for successful outcomes?

    Science.gov (United States)

    Perreault, Thomas; Dunning, James; Butts, Raymond

    2017-10-01

    Myofascial trigger point (MTrP) injection and trigger point dry needling (TrPDN) are widely accepted therapies for myofascial pain syndrome (MPS). Empirical evidence suggests eliciting a local twitch response (LTR) during needling is essential. This is the first review exploring the available literature, regardless of study design, on the neurophysiological effects and clinical significance of the LTR as it relates to reductions in pain and disability secondary to MTrP needling. PubMed, MEDLINE, Science Direct and Google Scholar were searched up until October 2016 using terms related to trigger point needling and the LTR. and Discussion: Several studies show that eliciting a LTR does not correlate with changes in pain and disability, and multiple systematic reviews have failed to conclude whether the LTR is relevant to the outcome of TrPDN. Post needling soreness is consistently reported in studies using repeated in and out needling to elicit LTRs and increases in proportion to the number of needle insertions. In contrast, needle winding without LTRs to MTrPs and connective tissue is well supported in the literature, as it is linked to anti-nociception and factors related to tissue repair and remodeling. Additionally, the positive biochemical changes in the MTrP after needling may simply be a wash out effect related to local vasodilation. While the LTR during TrPDN appears unnecessary for managing myofascial pain and unrelated to many of the positive effects of TrPDN, further investigation is required. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  17. Cucumber Pti1-L is a cytoplasmic protein kinase involved in defense responses and salt tolerance.

    Science.gov (United States)

    Oh, Sang-Keun; Jang, Hyun A; Lee, Sang Sook; Cho, Hye Sun; Lee, Dong-Hee; Choi, Doil; Kwon, Suk-Yoon

    2014-06-15

    Homologs of the cytoplasmic protein kinase Pti1 are found in diverse plant species. A clear role of Pti1 in plant defense response has not been established. We identified a Pti1 homolog in cucumber (CsPti1-L). CsPti1-L expression was induced when cucumber plants were challenged with the fungal pathogen Sphaerotheca fuliginea or with salt treatment. CsPti1-L expression in cucumber leaves also was induced by methyl jasmonate, salicylic acid, and abscisic acid. CsPti1-L exhibited autophosphorylation activity and was targeted to the cytoplasm. Transgenic Nicotiana benthamiana expressing CsPti1-L exhibited greater cell death and increased ion leakage in response to the bacterial pathogen Pseudomonas syringae pv. tomato DC3000, resistance to Botrytis cinerea infection, and higher tolerance to salt stress. RT-PCR analysis of transgenic N. benthamiana overexpressing CsPti1-L revealed constitutive upregulation of multiple genes involved in plant-defense and osmotic-stress responses. Our results suggest a functional role for CsPti1-L as a positive regulator of pathogen-defense and salt-stress responses. Copyright © 2014 Elsevier GmbH. All rights reserved.

  18. Layers of defense responses to Leptosphaeria maculans below the RLM1- and camalexin-dependent resistances.

    Science.gov (United States)

    Persson, Mattias; Staal, Jens; Oide, Shinichi; Dixelius, Christina

    2009-01-01

    Plants have evolved different defense components to counteract pathogen attacks. The resistance locus resistance to Leptosphaeria maculans 1 (RLM1) is a key factor for Arabidopsis thaliana resistance to L. maculans. The present work aimed to reveal downstream defense responses regulated by RLM1. Quantitative assessment of fungal colonization in the host was carried out using quantitative polymerase chain reaction (qPCR) and GUS expression analyses, to further characterize RLM1 resistance and the role of salicylic acid (SA), jasmonic acid (JA), and ethylene (ET) in disease development. Additional assessments of A. thaliana mutants were performed to expand our understanding of this pathosystem. Resistance responses such as lignification and the formation of vascular plugs were found to occur in an RLM1-dependent manner, in contrast to the RLM1-independent increase in reactive oxygen species at the stomata and hydathodes. Analyses of mutants defective in hormone signaling in the camalexin-free rlm1(Ler)pad3 background revealed a significant influence of JA and ET on symptom development and pathogen colonization. The overall results indicate that the defense responses of primary importance induced by RLM1 are all associated with physical barriers, and that responses of secondary importance involve complex cross-talk among SA, JA and ET. Our observations further suggest that ET positively affects fungal colonization.

  19. Assessing Defense Structure in School-Age Children Using the Response Evaluation Measure-71-Youth Version (REM-Y-71)

    Science.gov (United States)

    Araujo, Katy B.; Medic, Sanja; Yasnovsky, Jessica; Steiner, Hans

    2006-01-01

    This study used the Response Evaluation Measure-Youth (REM-Y-71), a self-report measure of 21 defense reactions, among school-age children. Participants were elementary and middle school students (n=290; grades 3-8; age range: 8-15; mean=11.73). Factor analysis revealed a 2-factor defense structure consistent with structure among high school and…

  20. Thermo-responsive magnetic liposomes for hyperthermia-triggered local drug delivery.

    Science.gov (United States)

    Dai, Min; Wu, Cong; Fang, Hong-Ming; Li, Li; Yan, Jia-Bao; Zeng, Dan-Lin; Zou, Tao

    2017-06-01

    We prepared and characterised thermo-responsive magnetic liposomes, which were designed to combine features of magnetic targeting and thermo-responsive control release for hyperthermia-triggered local drug delivery. The particle size and zeta-potential of the thermo-responsive magnetic ammonium bicarbonate (MagABC) liposomes were about 210 nm and -14 mV, respectively. The MagABC liposomes showed encapsulation efficiencies of about 15% and 82% for magnetic nanoparticles (mean crystallite size 12 nm) and doxorubicin (DOX), respectively. The morphology of the MagABC liposomes was visualised using transmission electron microscope (TEM). The MagABC liposomes showed desired thermo-responsive release. The MagABC liposomes, when physically targeted to tumour cells in culture by a permanent magnetic field yielded a substantial increase in intracellular accumulation of DOX as compared to non-magnetic ammonium bicarbonate (ABC) liposomes. This resulted in a parallel increase in cytotoxicity for DOX loaded MagABC liposomes over DOX loaded ABC liposomes in tumour cells.

  1. Human Mincle Binds to Cholesterol Crystals and Triggers Innate Immune Responses.

    Science.gov (United States)

    Kiyotake, Ryoko; Oh-Hora, Masatsugu; Ishikawa, Eri; Miyamoto, Tomofumi; Ishibashi, Tatsuro; Yamasaki, Sho

    2015-10-16

    C-type lectin receptors (CLRs) are an emerging family of pattern recognition receptors that recognizes pathogens or damaged tissue to trigger innate immune responses. However, endogenous ligands for CLRs are not fully understood. In this study, we sought to identify an endogenous ligand(s) for human macrophage-inducible C-type lectin (hMincle). A particular fraction of lipid extracts from liver selectively activated reporter cells expressing hMincle. MS analysis determined the chemical structure of the active component as cholesterol. Purified cholesterol in plate-coated and crystalized forms activates reporter cells expressing hMincle but not murine Mincle (mMincle). Cholesterol crystals are known to activate immune cells and induce inflammatory responses through lysosomal damage. However, direct innate immune receptors for cholesterol crystals have not been identified. Murine macrophages transfected with hMincle responded to cholesterol crystals by producing pro-inflammatory cytokines. Human dendritic cells expressed a set of inflammatory genes in response to cholesterol crystals, and this was inhibited by anti-human Mincle. Importantly, other related CLRs did not bind cholesterol crystals, whereas other steroids were not recognized by hMincle. These results suggest that cholesterol crystals are an endogenous ligand for hMincle and that they activate innate immune responses. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  2. Different patterns of neuronal activity trigger distinct responses of oligodendrocyte precursor cells in the corpus callosum.

    Directory of Open Access Journals (Sweden)

    Balint Nagy

    2017-08-01

    Full Text Available In the developing and adult brain, oligodendrocyte precursor cells (OPCs are influenced by neuronal activity: they are involved in synaptic signaling with neurons, and their proliferation and differentiation into myelinating glia can be altered by transient changes in neuronal firing. An important question that has been unanswered is whether OPCs can discriminate different patterns of neuronal activity and respond to them in a distinct way. Here, we demonstrate in brain slices that the pattern of neuronal activity determines the functional changes triggered at synapses between axons and OPCs. Furthermore, we show that stimulation of the corpus callosum at different frequencies in vivo affects proliferation and differentiation of OPCs in a dissimilar way. Our findings suggest that neurons do not influence OPCs in "all-or-none" fashion but use their firing pattern to tune the response and behavior of these nonneuronal cells.

  3. Induction of defense responses in cucumber plants by using the cell-free filtrate of the plant growth-promoting fungus Penicillium simplicissimum GP17-2.

    Science.gov (United States)

    Shimizu, Kaori; Hossain, Mohamed Motaher; Kato, Kimihiko; Kubota, Mashaharu; Hyakumachi, Mitsuro

    2013-01-01

    Penicillium simplicissimum GP17-2 is a plant growth-promoting fungus (PGPF) and an inducer of systemic defense responses. The mechanisms underlying the effect of GP17-2 on the reduction of cucumber leaf damage caused by the anthracnose pathogen Colletotrichum orbiculare were investigated. Cucumber leaves treated with the culture filtrate (CF) of GP17-2 exhibited a clear systemic resistance against subsequent infection with C. orbiculare. The number and size of lesions caused by the disease were reduced in CF-treated plants, in comparison with that in the control plants. The results showed that CF treatment could trigger a set of defense responses, including the production of hydrogen peroxide, formation of lignin, emission of ultra-weak photons, accumulation of salicylic acid, and increase in the transcription of the genes for the defense-related enzymes chitinase and peroxidase. Furthermore, subsequent inoculation of CF-pretreated plants with C. orbiculare resulted in higher systemic expression of the genes for chitinase, β-1,3-glucanase, and peroxidase relative to nontreated, inoculated plants; this indicated that CF mediates a potentiation state in the plant, enabling it to mount a rapid and effective response on infection by C. orbiculare. Our results indicate that the ability of CF of GP17-2 to stimulate active oxygen species, lignification, SA accumulation, and defense gene activation and potentiation in the host is the possible mode of action of the GP17-2 elicitor and inducer of induced systemic resistance against C. orbiculare infection in cucumber plants.

  4. Hormetic response triggers multifaceted anti-oxidant strategies in immature king penguins (Aptenodytes patagonicus).

    Science.gov (United States)

    Rey, Benjamin; Dégletagne, Cyril; Bodennec, Jacques; Monternier, Pierre-Axel; Mortz, Mathieu; Roussel, Damien; Romestaing, Caroline; Rouanet, Jean-Louis; Tornos, Jeremy; Duchamp, Claude

    2016-08-01

    Repeated deep dives are highly pro-oxidative events for air-breathing aquatic foragers such as penguins. At fledging, the transition from a strictly terrestrial to a marine lifestyle may therefore trigger a complex set of anti-oxidant responses to prevent chronic oxidative stress in immature penguins but these processes are still undefined. By combining in vivo and in vitro approaches with transcriptome analysis, we investigated the adaptive responses of sea-acclimatized (SA) immature king penguins (Aptenodytes patagonicus) compared with pre-fledging never-immersed (NI) birds. In vivo, experimental immersion into cold water stimulated a higher thermogenic response in SA penguins than in NI birds, but both groups exhibited hypothermia, a condition favouring oxidative stress. In vitro, the pectoralis muscles of SA birds displayed increased oxidative capacity and mitochondrial protein abundance but unchanged reactive oxygen species (ROS) generation per g tissue because ROS production per mitochondria was reduced. The genes encoding oxidant-generating proteins were down-regulated in SA birds while mRNA abundance and activity of the main antioxidant enzymes were up-regulated. Genes encoding proteins involved in repair mechanisms of oxidized DNA or proteins and in degradation processes were also up-regulated in SA birds. Sea life also increased the degree of fatty acid unsaturation in muscle mitochondrial membranes resulting in higher intrinsic susceptibility to ROS. Oxidative damages to protein or DNA were reduced in SA birds. Repeated experimental immersions of NI penguins in cold-water partially mimicked the effects of acclimatization to marine life, modified the expression of fewer genes related to oxidative stress but in a similar way as in SA birds and increased oxidative damages to DNA. It is concluded that the multifaceted plasticity observed after marine life may be crucial to maintain redox homeostasis in active tissues subjected to high pro-oxidative pressure

  5. Differences and Similarities of Soybean Defense-Related Genes Suppressed by Pathogenic and Symbiotic Bacteria

    Science.gov (United States)

    Bacterial effector proteins secreted through type III secretion systems (T3SS) play a crucial role in establishing plant and human diseases. Type III effectors have been shown to trigger defense responses when recognized by resistant plants, and to suppress defense responses in susceptible host plan...

  6. Conflict-triggered goal shielding: response conflicts attenuate background monitoring for prospective memory cues.

    Science.gov (United States)

    Goschke, Thomas; Dreisbach, Gesine

    2008-01-01

    Action control in a changing environment requires that one shield current goals from distracting information (goal shielding) and at the same time monitor the environment for potentially significant stimuli that may afford a goal switch (background monitoring). Response conflicts modulate the balance between goal shielding and background monitoring, as indicated by reduced susceptibility to interference after response conflicts. Such conflict-adaptation effects have been attributed to enhanced recruitment of cognitive control on trials following conflicts. Here we show that conflict triggers increased goal shielding on the conflict trial itself. Subjects performed a spatial compatibility task during which they had to notice rare prospective memory cues. Such cues were overlooked more often on conflict trials than on nonconflict trials, a result indicating that shielding of the current goal and inhibition of distractors were increased on the current trial when it involved a response conflict. Thus, evidence for enhanced recruitment of control following conflict may partly reflect aftereffects of goal shielding on the conflict trial itself.

  7. LysM receptor-like kinases to improve plant defense response against fungal pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Jinrong; Stacey, Gary; Stacey, Minviluz; Zhang, Xuecheng

    2013-10-15

    Perception of chitin fragments (chitooligosaccharides) is an important first step in plant defense response against fungal pathogen. LysM receptor-like kinases (LysM RLKs) are instrumental in this perception process. LysM RLKs also play a role in activating transcription of chitin-responsive genes (CRGs) in plants. Mutations in the LysM kinase receptor genes or the downstream CRGs may affect the fungal susceptibility of a plant. Mutations in LysM RLKs or transgenes carrying the same may be beneficial in imparting resistance against fungal pathogens.

  8. LysM receptor-like kinases to improve plant defense response against fungal pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Jinrong [Columbia, MO; Stacey, Gary [Columbia, MO; Stacey, Minviluz [Columbia, MO; Zhang, Xuecheng [Columbia, MO

    2012-01-17

    Perception of chitin fragments (chitooligosaccharides) is an important first step in plant defense response against fungal pathogen. LysM receptor-like kinases (LysM RLKs) are instrumental in this perception process. LysM RLKs also play a role in activating transcription of chitin-responsive genes (CRGs) in plants. Mutations in the LysM kinase receptor genes or the downstream CRGs may affect the fungal susceptibility of a plant. Mutations in LysM RLKs or transgenes carrying the same may be beneficial in imparting resistance against fungal pathogens.

  9. "Hand down, man down." Analysis of defensive adjustments in response to the hot hand in basketball using novel defense metrics.

    Directory of Open Access Journals (Sweden)

    Peter Csapo

    Full Text Available The hot-hand phenomenon, according to which a player's performance is significantly elevated during certain phases relative to the expected performance based on the player's base rate, has left many researchers and fans in basketball puzzled: The vast majority of players, coaches and fans believe in its existence but statistical evidence supporting this belief has been scarce. It has frequently been argued that the hot hand in basketball is unobservable because of strategic adjustments and defensive interference of the opposing team. We use a dataset with novel metrics, such as the number of defenders and the defensive intensity for each shot attempt, which enable us to directly measure defensive pressure. First, we examine how the shooting percentage of NBA players changes relative to the attributes of each metric. We find that it is of lesser importance by how many defenders a player is guarded but that defensive intensity, e.g., whether a defender raises his hand when his opponent shoots, has a larger impact on shot difficulty. Second, we explore how the underlying metrics and shooting accuracy change as a function of streak length. Our results indicate that defensive pressure and shot difficulty increase (decrease during hot (cold streaks, so that defenders seem to behave according to the hot-hand belief and try to force hot players into more difficult shots. However, we find that shooting percentages of presumably hot players do not increase and that shooting performance is not related to streakiness, so that the defenders' hot-hand behavior cannot be considered ecologically rational. Therefore, we are unable to find evidence in favor of the hot-hand effect even when accounting for defensive pressure.

  10. Molecular Dynamics Simulation and Statistics Analysis Reveals the Defense Response Mechanism in Plants

    Science.gov (United States)

    Liu, Zhichao; Zhao, Yunjie; Zeng, Chen; Computational Biophysics Lab Team

    As the main protein of the bacterial flagella, flagellin plays an important role in perception and defense response. The newly discovered locus, FLS2, is ubiquitously expressed. FLS2 encodes a putative receptor kinase and shares many homologies with some plant resistance genes and even with some components of immune system of mammals and insects. In Arabidopsis, FLS2 perception is achieved by the recognition of epitope flg22, which induces FLS2 heteromerization with BAK1 and finally the plant immunity. Here we use both analytical methods such as Direct Coupling Analysis (DCA) and Molecular Dynamics (MD) Simulations to get a better understanding of the defense mechanism of FLS2. This may facilitate a redesign of flg22 or de-novo design for desired specificity and potency to extend the immune properties of FLS2 to other important crops and vegetables.

  11. Induction of RNAi Responses by Short Left-Handed Hairpin RNAi Triggers.

    Science.gov (United States)

    Hagopian, Jonathan C; Hamil, Alexander S; van den Berg, Arjen; Meade, Bryan R; Eguchi, Akiko; Palm-Apergi, Caroline; Dowdy, Steven F

    2017-10-01

    Small double-stranded, left-handed hairpin (LHP) RNAs containing a 5'-guide-loop-passenger-3' structure induce RNAi responses by a poorly understood mechanism. To explore LHPs, we synthesized fully 2'-modified LHP RNAs targeting multiple genes and found all to induce robust RNAi responses. Deletion of the loop and nucleotides at the 5'-end of the equivalent passenger strand resulted in a smaller LHP that still induced strong RNAi responses. Surprisingly, progressive deletion of up to 10 nucleotides from the 3'-end of the guide strand resulted in a 32mer LHP capable of inducing robust RNAi responses. However, further guide strand deletion inhibited LHP activity, thereby defining the minimal length guide targeting length to 13 nucleotides. To dissect LHP processing, we examined LHP species that coimmunoprecipitated with Argonaute 2 (Ago2), the catalytic core of RNA-induced silencing complex, and found that the Ago2-associated processed LHP species was of a length that correlated with Ago2 cleavage of the passenger strand. Placement of a blocking 2'-OMe blocking modification at the LHP predicted Ago2 cleavage site resulted in an intact LHP loaded into Ago2 and no RNAi response. Taken together, these data argue that in the absence of a substantial loop, this novel class of small LHP RNAs enters the RNAi pathway by a Dicer-independent mechanism that involves Ago2 cleavage and results in an extended guide strand. This work establishes LHPs as an alternative RNAi trigger that can be produced from a single synthesis for potential use as an RNAi therapeutic.

  12. Response of sunflower (Helianthus annuus L.) leaf surface defenses to exogenous methyl jasmonate.

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    Rowe, Heather C; Ro, Dae-kyun; Rieseberg, Loren H

    2012-01-01

    Helianthus annuus, the common sunflower, produces a complex array of secondary compounds that are secreted into glandular trichomes, specialized structures found on leaf surfaces and anther appendages of flowers. The primary components of these trichome secretions are sesquiterpene lactones (STL), a diverse class of compounds produced abundantly by the plant family Compositae and believed to contribute to plant defense against herbivory. We treated wild and cultivated H. annuus accessions with exogenous methyl jasmonate, a plant hormone that mediates plant defense against insect herbivores and certain classes of fungal pathogens. The wild sunflower produced a higher density of glandular trichomes on its leaves than the cultivar. Comparison of the profiles of glandular trichome extracts obtained by liquid chromatography-mass spectroscopy (LC-MS) showed that wild and cultivated H. annuus were qualitatively similar in surface chemistry, although differing in the relative size and proportion of various compounds detected. Despite observing consistent transcriptional responses to methyl jasmonate treatment, we detected no significant effect on glandular trichome density or LC-MS profile in cultivated or wild sunflower, with wild sunflower exhibiting a declining trend in overall STL production and foliar glandular trichome density of jasmonate-treated plants. These results suggest that glandular trichomes and associated compounds may act as constitutive defenses or require greater levels of stimulus for induction than the observed transcriptional responses to exogenous jasmonate. Reduced defense investment in domesticated lines is consistent with predicted tradeoffs caused by selection for increased yield; future research will focus on the development of genetic resources to explicitly test the ecological roles of glandular trichomes and associated effects on plant growth and fitness.

  13. ROS-Responsive Polyprodrug Nanoparticles for Triggered Drug Delivery and Effective Cancer Therapy.

    Science.gov (United States)

    Xu, Xiaoding; Saw, Phei Er; Tao, Wei; Li, Yujing; Ji, Xiaoyuan; Bhasin, Sushant; Liu, Yanlan; Ayyash, Dana; Rasmussen, Jonathan; Huo, Marc; Shi, Jinjun; Farokhzad, Omid C

    2017-09-01

    The application of nanoparticles (NPs) to drug delivery has led to the development of novel nanotherapeutics for the treatment of various diseases including cancer. However, clinical use of NP-mediated drug delivery has not always translated into improved survival of cancer patients, in part due to the suboptimal properties of NP platforms, such as premature drug leakage during preparation, storage, or blood circulation, lack of active targeting to tumor tissue and cells, and poor tissue penetration. Herein, an innovative reactive oxygen species (ROS)-responsive polyprodrug is reported that can self-assemble into stable NPs with high drug loading. This new NP platform is composed of the following key components: (i) polyprodrug inner core that can respond to ROS for triggered release of intact therapeutic molecules, (ii) polyethylene glycol (PEG) outer shell to prolong blood circulation; and (iii) surface-encoded internalizing RGD (iRGD) to enhance tumor targeting and tissue penetration. These targeted ROS-responsive polyprodrug NPs show significant inhibition of tumor cell growth both in vitro and in vivo. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Mucopolysaccharidosis IIIB, a lysosomal storage disease, triggers a pathogenic CNS autoimmune response

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    Popovich Phillip G

    2010-07-01

    Full Text Available Abstract Background Recently, using a mouse model of mucopolysaccharidosis (MPS IIIB, a lysosomal storage disease with severe neurological deterioration, we showed that MPS IIIB neuropathology is accompanied by a robust neuroinflammatory response of unknown consequence. This study was to assess whether MPS IIIB lymphocytes are pathogenic. Methods Lymphocytes from MPS IIIB mice were adoptively transferred to naïve wild-type mice. The recipient animals were then evaluated for signs of disease and inflammation in the central nervous system. Results Our results show for the first time, that lymphocytes isolated from MPS IIIB mice caused a mild paralytic disease when they were injected systemically into naïve wild-type mice. This disease is characterized by mild tail and lower trunk weakness with delayed weight gain. The MPS IIIB lymphocytes also trigger neuroinflammation within the CNS of recipient mice characterized by an increase in transcripts of IL2, IL4, IL5, IL17, TNFα, IFNα and Ifi30, and intraparenchymal lymphocyte infiltration. Conclusions Our data suggest that an autoimmune response directed at CNS components contributes to MPS IIIB neuropathology independent of lysosomal storage pathology. Adoptive transfer of purified T-cells will be needed in future studies to identify specific effector T-cells in MPS IIIB neuroimmune pathogenesis.

  15. Host translational inhibition by Pseudomonas aeruginosa Exotoxin A Triggers an immune response in Caenorhabditis elegans.

    Science.gov (United States)

    McEwan, Deborah L; Kirienko, Natalia V; Ausubel, Frederick M

    2012-04-19

    Intestinal epithelial cells are exposed to both innocuous and pathogenic microbes, which need to be distinguished to mount an effective immune response. To understand the mechanisms underlying pathogen recognition, we investigated how Pseudomonas aeruginosa triggers intestinal innate immunity in Caenorhabditis elegans, a process independent of Toll-like pattern recognition receptors. We show that the P. aeruginosa translational inhibitor Exotoxin A (ToxA), which ribosylates elongation factor 2 (EF2), upregulates a significant subset of genes normally induced by P. aeruginosa. Moreover, immune pathways involving the ATF-7 and ZIP-2 transcription factors, which protect C. elegans from P. aeruginosa, are required for preventing ToxA-mediated lethality. ToxA-responsive genes are not induced by enzymatically inactive ToxA protein but can be upregulated independently of ToxA by disruption of host protein translation. Thus, C. elegans has a surveillance mechanism to recognize ToxA through its effect on protein translation rather than by direct recognition of either ToxA or ribosylated EF2. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. The Multifaceted Role of T-Helper Responses in Host Defense against Aspergillus fumigatus

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    Intan M. W. Dewi

    2017-10-01

    Full Text Available The ubiquitous opportunistic fungal pathogen Aspergillus fumigatus rarely causes infections in immunocompetent individuals. A healthy functional innate immune system plays a crucial role in preventing Aspergillus-infection. This pivotal role for the innate immune system makes it a main research focus in studying the pathogenesis of aspergillosis. Although sometimes overshadowed by the innate immune response, the adaptive immune response, and in particular T-helper responses, also represents a key player in host defense against Aspergillus. Virtually all T-helper subsets have been described to play a role during aspergillosis, with the Th1 response being crucial for fungal clearance. However; morbidity and mortality of aspergillosis can also be partly attributed to detrimental immune responses resulting from adaptive immune activation. Th2 responses benefit fungal persistence; and are the foundation of allergic forms of aspergillosis. The Th17 response has two sides; although crucial for granulocyte recruitment, it can be involved in detrimental immunopathology. Regulatory T-cells, the endogenous regulators of inflammatory responses, play a key role in controlling detrimental inflammatory responses during aspergillosis. The current knowledge of the adaptive immune response against A. fumigatus is summarized in this review. A better understanding on how T-helper responses facilitate clearance of Aspergillus-infection and control inflammation can be the fundamental basis for understanding the pathogenesis of aspergillosis and for the development of novel host-directed therapies.

  17. Human cytomegalovirus infection in lung transplant recipients triggers a CXCL-10 response.

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    Weseslindtner, L; Nachbagauer, R; Kundi, M; Jaksch, P; Kerschner, H; Simon, B; Hatos-Agyi, L; Scheed, A; Aberle, J H; Klepetko, W; Puchhammer-Stöckl, E

    2011-03-01

    Human cytomegalovirus (HCMV) causes significant morbidity in lung transplant recipients (LTRs). The clinical effects of HCMV replication are determined partly by a type 1 T-helper cell (Th1) response. Because the chemokine interferon-inducible protein of 10 kilodaltons (IP-10, CXCL-10) induces a Th1 response, we investigated whether HCMV triggers IP-10 in LTRs. The IP-10 concentration and HCMV DNA load were determined in 107 plasma and 46 bronchoalveolar lavage fluid (BALF) samples from 36 LTRs. Initial HCMV detection posttransplantation was significantly associated with increased plasma IP-10, regardless of whether the patients showed HCMV DNAemia (p = 0.001) or HCMV replication only in the allograft (p < 0.0001). In subsequent episodes of HCMV detection, plasma IP-10 increased regardless of whether HCMV was detected in blood (p = 0.0078) or only in BALF (p < 0.0001) and decreased after successful antiviral therapy (p = 0.0005). Furthermore, levels of HCMV DNA and IP-10 correlated statistically (p = 0.0033). Increased IP-10 levels in HCMV-positive BALF samples were significantly associated with severe airflow obstruction, as indicated by a decrease in forced expiratory volume in one second (FEV1). Our data indicate that HCMV replication in LTRs evokes a plasma IP-10 response and that, when an IP-10 response is observed in BALF, it is associated with inflammatory airway obstruction in the allograft. ©2011 The Authors Journal compilation©2011 The American Society of Transplantation and the American Society of Transplant Surgeons.

  18. Different Candida parapsilosis clinical isolates and lipase deficient strain trigger an altered cellular immune response.

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    Tóth, Renáta; Alonso, Maria F; Bain, Judith M; Vágvölgyi, Csaba; Erwig, Lars-Peter; Gácser, Attila

    2015-01-01

    Numerous human diseases can be associated with fungal infections either as potential causative agents or as a result of changed immune status due to a primary disease. Fungal infections caused by Candida species can vary from mild to severe dependent upon the site of infection, length of exposure, and past medical history. Patients with impaired immune status are at increased risk for chronic fungal infections. Recent epidemiologic studies have revealed the increasing incidence of candidiasis caused by non-albicans species such as Candida parapsilosis. Due to its increasing relevance we chose two distinct C. parapsilosis strains, to describe the cellular innate immune response toward this species. In the first section of our study we compared the interaction of CLIB 214 and GA1 cells with murine and human macrophages. Both strains are commonly used to investigate C. parapsilosis virulence properties. CLIB 214 is a rapidly pseudohyphae-forming strain and GA1 is an isolate that mainly exists in a yeast form. Our results showed, that the phagocyte response was similar in terms of overall uptake, however differences were observed in macrophage migration and engulfment of fungal cells. As C. parapsilosis releases extracellular lipases in order to promote host invasion we further investigated the role of these secreted components during the distinct stages of the phagocytic process. Using a secreted lipase deficient mutant strain and the parental strain GA1 individually and simultaneously, we confirmed that fungal secreted lipases influence the fungi's virulence by detecting altered innate cellular responses. In this study we report that two isolates of a single species can trigger markedly distinct host responses and that lipase secretion plays a role on the cellular level of host-pathogen interactions.

  19. Different Candida parapsilosis clinical isolates and lipase deficient strain trigger an altered cellular immune response

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    Renata eToth

    2015-10-01

    Full Text Available Numerous human diseases can be associated with fungal infections either as potential causative agents or as a result of changed immune status due to a primary disease. Fungal infections caused by Candida species can vary from mild to severe dependent upon the site of infection, length of exposure and past medical history. Patients with impaired immune status are at increased risk for chronic fungal infections. Recent epidemiologic studies have revealed the increasing incidence of candidiasis caused by non-albicans species such as C. parapsilosis. Due to its increasing relevance we chose two distinct C. parapsilosis strains, to describe the cellular innate immune response towards this species. In the first section of our study we compared the interaction of CLIB 214 and GA1 cells with murine and human macrophages. Both strains are commonly used to investigate C. parapsilosis virulence properties. CLIB 214 is a rapidly pseudohyphae-forming strain and GA1 is an isolate that mainly exists in a yeast form. Our results showed, that the phagocyte response was similar in terms of overall uptake, however differences were observed in macrophage migration and engulfment of fungal cells. As C. parapsilosis releases extracellular lipases in order to promote host invasion we further investigated the role of these secreted components during the distinct stages of the phagocytic process. Using a secreted lipase deficient mutant strain and the parental strain GA1 individually and simultaneously, we confirmed that fungal secreted lipases influence the fungi’s virulence by detecting altered innate cellular responses.In this study we report that two isolates of a single species can trigger markedly distinct host responses and that lipase secretion plays a role on the cellular level of host pathogen interactions.

  20. Multiple roles of plant volatiles in jasmonate-induced defense response in rice

    Science.gov (United States)

    Tanaka, Keiichiro; Taniguchi, Shiduku; Tamaoki, Daisuke; Yoshitomi, Kayo; Akimitsu, Kazuya; Gomi, Kenji

    2014-01-01

    The plant hormone jasmonic acid (JA) has a crucial role in defense responses against pathogens in rice. We recently reported that some volatile compounds accumulate in response to JA treatment, and that the monoterpene linalool plays an important role in JA-induced resistance to rice bacterial blight caused by Xanthomonas oryzae pv oryzae (Xoo) in rice. One of the JA-responsive volatiles, (E,E)-2,4-heptadienal, has both antibacterial and antifungal activity against Xoo, and the rice fungal pathogen Magnaporthe oryzae. In addition, (E,E)-2,4-heptadienal was toxic to rice plants. These phenomena were not observed when linalool was treated. These results indicate that accumulation of the (E,E)-2,4-heptadienal in response to JA is a double-edged sword, but it is essential for survival against pathogen attacks in rice. PMID:25763498

  1. Plant methyl salicylate induces defense responses in the rhizobacterium Bacillus subtilis.

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    Kobayashi, Kazuo

    2015-04-01

    Bacillus subtilis is a rhizobacterium that promotes plant growth and health. Cultivation of B. subtilis with an uprooted weed on solid medium produced pleat-like architectures on colonies near the plant. To test whether plants emit signals that affect B. subtilis colony morphology, we examined the effect of plant-related compounds on colony morphology. Bacillus subtilis formed mucoid colonies specifically in response to methyl salicylate, which is a plant-defense signal released in response to pathogen infection. Methyl salicylate induced mucoid colony formation by stimulating poly-γ-glutamic acid biosynthesis, which formed enclosing capsules that protected the cells from exposure to antimicrobial compounds. Poly-γ-glutamic acid synthesis depended on the DegS-DegU two-component regulatory system, which activated DegSU-dependent gene transcription in response to methyl salicylate. Bacillus subtilis did not induce plant methyl salicylate production, indicating that the most probable source of methyl salicylate in the rhizosphere is pathogen-infected plants. Methyl salicylate induced B. subtilis biosynthesis of the antibiotics bacilysin and fengycin, the latter of which exhibited inhibitory activity against the plant pathogenic fungus Fusarium oxysporum. We propose that B. subtilis may sense plants under pathogen attack via methyl salicylate, and express defense responses that protect both B. subtilis and host plants in the rhizosphere. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  2. Nitric oxide antagonizes the acid tolerance response that protects Salmonella against innate gastric defenses.

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    Travis J Bourret

    2008-03-01

    Full Text Available Reactive nitrogen species (RNS derived from dietary and salivary inorganic nitrogen oxides foment innate host defenses associated with the acidity of the stomach. The mechanisms by which these reactive species exert antimicrobial activity in the gastric lumen are, however, poorly understood.The genetically tractable acid tolerance response (ATR that enables enteropathogens to survive harsh acidity was screened for signaling pathways responsive to RNS. The nitric oxide (NO donor spermine NONOate derepressed the Fur regulon that controls secondary lines of resistance against organic acids. Despite inducing a Fur-mediated adaptive response, acidified RNS largely repressed oral virulence as demonstrated by the fact that Salmonella bacteria exposed to NO donors during mildly acidic conditions were shed in low amounts in feces and exhibited ameliorated oral virulence. NO prevented Salmonella from mounting a de novo ATR, but was unable to suppress an already functional protective response, suggesting that RNS target regulatory cascades but not their effectors. Transcriptional and translational analyses revealed that the PhoPQ signaling cascade is a critical ATR target of NO in rapidly growing Salmonella. Inhibition of PhoPQ signaling appears to contribute to most of the NO-mediated abrogation of the ATR in log phase bacteria, because the augmented acid sensitivity of phoQ-deficient Salmonella was not further enhanced after RNS treatment.Since PhoPQ-regulated acid resistance is widespread in enteric pathogens, the RNS-mediated inhibition of the Salmonella ATR described herein may represent a common component of innate host defenses.

  3. Priming of the Arabidopsis pattern-triggered immunity response upon infection by necrotrophic Pectobacterium carotovorum bacteria.

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    Po-Wen, Chen; Singh, Prashant; Zimmerli, Laurent

    2013-01-01

    Boosted responsiveness of plant cells to stress at the onset of pathogen- or chemically induced resistance is called priming. The chemical β-aminobutyric acid (BABA) enhances Arabidopsis thaliana resistance to hemibiotrophic bacteria through the priming of the salicylic acid (SA) defence response. Whether BABA increases Arabidopsis resistance to the necrotrophic bacterium Pectobacterium carotovorum ssp. carotovorum (Pcc) is not clear. In this work, we show that treatment with BABA protects Arabidopsis against the soft-rot pathogen Pcc. BABA did not prime the expression of the jasmonate/ethylene-responsive gene PLANT DEFENSIN 1.2 (PDF1.2), the up-regulation of which is usually associated with resistance to necrotrophic pathogens. Expression of the SA marker gene PATHOGENESIS RELATED 1 (PR1) on Pcc infection was primed by BABA treatment, but SA-defective mutants demonstrated a wild-type level of BABA-induced resistance against Pcc. BABA primed the expression of the pattern-triggered immunity (PTI)-responsive genes FLG22-INDUCED RECEPTOR-LIKE KINASE 1 (FRK1), ARABIDOPSIS NON-RACE SPECIFIC DISEASE RESISTANCE GENE (NDR1)/HAIRPIN-INDUCED GENE (HIN1)-LIKE 10 (NHL10) and CYTOCHROME P450, FAMILY 81 (CYP81F2) after inoculation with Pcc or after treatment with purified bacterial microbe-associated molecular patterns, such as flg22 or elf26. PTI-mediated callose deposition was also potentiated in BABA-treated Arabidopsis, and BABA boosted Arabidopsis stomatal immunity to Pcc. BABA treatment primed the PTI response in the SA-defective mutants SA induction deficient 2-1 (sid2-1) and phytoalexin deficient 4-1 (pad4-1). In addition, BABA priming was associated with open chromatin configurations in the promoter region of PTI marker genes. Our data indicate that BABA primes the PTI response upon necrotrophic bacterial infection and suggest a role for the PTI response in BABA-induced resistance. © 2012 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

  4. Soybean aphid (Hemiptera: Aphididae) response to soybean plant defense: stress levels, tradeoffs, and cross-virulence.

    Science.gov (United States)

    Enders, Laramy; Bickel, Ryan; Brisson, Jennifer; Heng-Moss, Tiffany; Siegfried, Blair; Zera, Anthony; Miller, Nick

    2014-02-01

    A variety of management methods to control the soybean aphid (Aphis glycines Matsumura) have been investigated since its invasion into North America in 2000, among them plant resistance has emerged as a viable option for reducing aphid damage to soybeans and preventing outbreaks. Plant resistance methods often use natural soybean plant defenses that impose stress on aphids by reducing fitness and altering behavior. Research efforts have heavily focused on identification and development of aphid resistant soybean varieties, leaving much unknown about soybean aphid response to stressful host plant defenses. In this study, we aimed to 1) evaluate lifetime fitness consequences and phenotypic variation in response to host plant-induced stress and 2) investigate whether trade-offs involving fitness costs and/or cross-virulence to multiple antibiotic soybean varieties exists. We compared aphid survival and reproduction during and after a short period of exposure to soybeans with the Rag2 resistance gene and measured aphid clonal variation in response to Rag2 soybeans. In addition, we measured the performance of Rag2 virulent and avirulent aphids on five soybean varieties with various forms of antibiotic resistance. Our results indicate that plant defenses impose high levels of stress and have long-term fitness consequences, even after aphids are removed from resistant plants. We identified one aphid clone that was able to colonize Rag2 among the seven clones tested, suggesting that virulent genotypes may be prevalent in natural populations. Finally, although we did not find evidence of cross-virulence to multiple antibiotic soybean varieties, our results suggest independent mechanisms of aphid virulence to Rag1 and Rag2 that may involve fitness costs.

  5. Neural response in obsessive-compulsive washers depends on individual fit of triggers

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    Ali eBaioui

    2013-04-01

    Full Text Available BackgroundPatients with obsessive-compulsive disorder (OCD have highly idiosyncratic triggers. To fully understand which role this idiosyncrasy plays in the neurobiological mechanisms behind OCD, it is necessary to elucidate the impact of individualization regarding the applied investigation methods.This functional magnetic resonance imaging (fMRI study explores the neural correlates of contamination/washing-related OCD with a highly individualized symptom provocation paradigm. Additionally, it is the first study to directly compare individualized and standardized symptom provocation. MethodsNineteen patients with washing compulsions created individual OCD hierarchies, which later served as instructions to photograph their own individualized stimulus sets. The patients and 19 case-by-case matched healthy controls participated in a symptom provocation fMRI experiment with individualized and standardized stimulus sets created for each patient. ResultsOCD patients compared to healthy controls displayed stronger activation in the basal ganglia (nucleus accumbens, nucleus caudatus, pallidum for individualized symptom provocation. Using standardized symptom provocation, this group comparison led to stronger activation in the nucleus caudatus. The direct comparison of between-group effects for both symptom provocation approaches revealed stronger activation of the orbitofronto-striatal network for individualized symptom provocation.ConclusionsThe present study provides insight into the differential impact of individualized and standardized symptom provocation on the orbitofronto-striatal network of OCD washers. Behavioral and neural responses imply a higher symptom-specificity of individualized symptom provocation.

  6. Behavioral characteristics of Internet gamblers who trigger corporate responsible gambling interventions.

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    Gray, Heather M; LaPlante, Debi A; Shaffer, Howard J

    2012-09-01

    As the worldwide popularity of Internet gambling increases, concerns about the potential for gambling-related harm also increase. This paper reports the results of a study examining actual Internet gambling behavior during 10 years of play. We examined the electronic gambling records of subscribers (N=2,066) who triggered a responsible gaming alert system at a large international online gaming company. We compared these cases with control subscribers (N=2,066) who had the same amount of exposure to the Internet gambling service provider. We used discriminant function analysis to explore what aspects of gambling behavior distinguish cases from controls. Indices of the intensity of gambling activity (e.g., total number of bets made, number of bets per betting day) best distinguished cases from controls, particularly in the case of live-action sports betting. Control group players evidenced behavior similar to the population of players using this service. These results add to our understanding of behavioral markers for disordered Internet gambling and will aid in the development of behavior-based algorithms capable of predicting the presence and/or the onset of disordered Internet gambling. PsycINFO Database Record (c) 2012 APA, all rights reserved.

  7. UV-crosslinkable and thermo-responsive chitosan hybrid hydrogel for NIR-triggered localized on-demand drug delivery.

    Science.gov (United States)

    Wang, Lei; Li, Baoqiang; Xu, Feng; Xu, Zheheng; Wei, Daqing; Feng, Yujie; Wang, Yaming; Jia, Dechang; Zhou, Yu

    2017-10-15

    Innovative drug delivery technologies based on smart hydrogels for localized on-demand drug delivery had aroused great interest. To acquire smart UV-crosslinkable chitosan hydrogel for NIR-triggered localized on-demanded drug release, a novel UV-crosslinkable and thermo-responsive chitosan was first designed and synthesized by grafting with poly N-isopropylacrylamide, acetylation of methacryloyl groups and embedding with photothermal carbon. The UV-crosslinkable unit (methacryloyl groups) endowed chitosan with gelation via UV irradiation. The thermo-responsive unit (poly N-isopropylacrylamide) endowed chitosan hydrogel with temperature-triggered volume shrinkage and reversible swelling/de-swelling behavior. The chitosan hybrid hydrogel embedded with photothermal carbon exhibited distinct NIR-triggered volume shrinkage (∼42% shrinkage) in response to temperature elevation as induced by NIR laser irradiation. As a demonstration, doxorubicin release rate was accelerated and approximately 40 times higher than that from non-irradiated hydrogels. The UV-crosslinkable and thermal-responsive hybrid hydrogel served as in situ forming hydrogel-based drug depot is developed for NIR-triggered localized on-demand release. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. How Human Amygdala and Bed Nucleus of the Stria Terminalis May Drive Distinct Defensive Responses.

    Science.gov (United States)

    Klumpers, Floris; Kroes, Marijn C W; Baas, Johanna M P; Fernández, Guillén

    2017-10-04

    The ability to adaptively regulate responses to the proximity of potential danger is critical to survival and imbalance in this system may contribute to psychopathology. The bed nucleus of the stria terminalis (BNST) is implicated in defensive responding during uncertain threat anticipation whereas the amygdala may drive responding upon more acute danger. This functional dissociation between the BNST and amygdala is however controversial, and human evidence scarce. Here we used data from two independent functional magnetic resonance imaging studies [ n = 108 males and n = 70 (45 females)] to probe how coordination between the BNST and amygdala may regulate responses during shock anticipation and actual shock confrontation. In a subset of participants from Sample 2 ( n = 48) we demonstrate that anticipation and confrontation evoke bradycardic and tachycardic responses, respectively. Further, we show that in each sample when going from shock anticipation to the moment of shock confrontation neural activity shifted from a region anatomically consistent with the BNST toward the amygdala. Comparisons of functional connectivity during threat processing showed overlapping yet also consistently divergent functional connectivity profiles for the BNST and amygdala. Finally, childhood maltreatment levels predicted amygdala, but not BNST, hyperactivity during shock anticipation. Our results support an evolutionary conserved, defensive distance-dependent dynamic balance between BNST and amygdala activity. Shifts in this balance may enable shifts in defensive reactions via the demonstrated differential functional connectivity. Our results indicate that early life stress may tip the neural balance toward acute threat responding and via that route predispose for affective disorder. SIGNIFICANCE STATEMENT Previously proposed differential contributions of the BNST and amygdala to fear and anxiety have been recently debated. Despite the significance of understanding their

  9. Green tea polyphenol (−)-epigallocatechin-3-gallate triggered hepatotoxicity in mice: Responses of major antioxidant enzymes and the Nrf2 rescue pathway

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    Wang, Dongxu; Wang, Yijun; Wan, Xiaochun [Key Laboratory of Tea Biochemistry & Biotechnology, School of Tea & Food Science, Anhui Agricultural University, Hefei, Anhui 230036 (China); Yang, Chung S. [Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (United States); Zhang, Jinsong, E-mail: zjs@ahau.edu.cn [Key Laboratory of Tea Biochemistry & Biotechnology, School of Tea & Food Science, Anhui Agricultural University, Hefei, Anhui 230036 (China)

    2015-02-15

    (−)-Epigallocatechin-3-gallate (EGCG), a constituent of green tea, has been suggested to have numerous health-promoting effects. On the other hand, high-dose EGCG is able to evoke hepatotoxicity. In the present study, we elucidated the responses of hepatic major antioxidant enzymes and nuclear factor erythroid 2-related factor 2 (Nrf2) rescue pathway to high-dose levels of EGCG in Kunming mice. At a non-lethal toxic dose (75 mg/kg, i.p.), repeated EGCG treatments markedly decreased the levels of superoxide dismutase, catalase, and glutathione peroxidase. As a rescue response, the nuclear distribution of Nrf2 was significantly increased; a battery of Nrf2-target genes, including heme oxygenase 1 (HO1), NAD(P)H:quinone oxidoreductase 1 (NQO1), glutathione S-transferase (GST), and those involved in glutathione and thioredoxin systems, were all up-regulated. At the maximum tolerated dose (45 mg/kg, i.p.), repeated EGCG treatments did not disturb the major antioxidant defense. Among the above-mentioned genes, only HO1, NQO1, and GST genes were significantly but modestly up-regulated, suggesting a comprehensive and extensive activation of Nrf2-target genes principally occurs at toxic levels of EGCG. At a lethal dose (200 mg/kg, i.p.), a single EGCG treatment dramatically decreased not only the major antioxidant defense but also the Nrf2-target genes, demonstrating that toxic levels of EGCG are able to cause a biphasic response of Nrf2. Overall, the mechanism of EGCG-triggered hepatotoxicity involves suppression of major antioxidant enzymes, and the Nrf2 rescue pathway plays a vital role for counteracting EGCG toxicity. - Highlights: • EGCG at maximum tolerated dose does not disturb hepatic major antioxidant defense. • EGCG at maximum tolerated dose modestly upregulates hepatic Nrf2 target genes. • EGCG at toxic dose suppresses hepatic major antioxidant enzymes. • EGCG at non-lethal toxic dose pronouncedly activates hepatic Nrf2 rescue response. • EGCG at

  10. Defense mechanisms of Solanum tuberosum L. in response to attack by plant-pathogenic bacteria.

    Science.gov (United States)

    Poiatti, Vera A D; Dalmas, Fernando R; Astarita, Leandro V

    2009-01-01

    The natural resistance of plants to disease is based not only on preformed mechanisms, but also on induced mechanisms. The defense mechanisms present in resistant plants may also be found in susceptible ones. This study attempted to analyze the metabolic alterations in plants of the potato Solanum tuberosum L. cv. Agata that were inoculated with the incompatible plant-pathogenic bacteria X. axonopodis and R. solanacearum, and the compatible bacterium E. carotovora. Levels of total phenolic compounds, including the flavonoid group, and the activities of polyphenol oxidase (PPO) and peroxidase (POX) were evaluated. Bacteria compatibility was evaluated by means of infiltration of tubers. The defense response was evaluated in the leaves of the potato plants. Leaves were inoculated depending on their number and location on the stem. Multiple-leaf inoculation was carried out on basal, intermediate, and apical leaves, and single inoculations on intermediate leaves. Leaves inoculated with X. axonopodis and with R. solanacearum showed hypersensitive responses within 24 hours post-inoculation, whereas leaves inoculated with E. carotovora showed disease symptoms. Therefore, the R. solanacearum isolate used in the experiments did not exhibit virulence to this potato cultivar. Regardless of the bacterial treatments, the basal leaves showed higher PPO and POX activities and lower levels of total phenolic compounds and flavonoids, compared to the apical leaves. However, basal and intermediate leaves inoculated with R. solanacearum and X. axonopodis showed increases in total phenolic compounds and flavonoid levels. In general, multiple-leaf inoculation showed the highest levels of total phenolics and flavonoids, whereas the single inoculations resulted in the highest increase in PPO activity. The POX activity showed no significant difference between single- and multiple-leaf inoculations. Plants inoculated with E. carotovora showed no significant increase in defense mechanisms

  11. Defense mechanisms of Solanum tuberosum L. in response to attack by plant-pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    VERA A D POIATTI

    2009-01-01

    Full Text Available The natural resistance of plants to disease is based not only on preformed mechanisms, but also on induced mechanisms. The defense mechanisms present in resistant plants may also be found in susceptible ones. This study attempted to analyze the metabolic alterations in plants of the potato Solanum tuberosum L. cv. Agata that were inoculated with the incompatible plant-pathogenic bacteria X. axonopodis and R. solanacearum, and the compatible bacterium E. carotovora. Levels of total phenolic compounds, including the flavonoid group, and the activities of polyphenol oxidase (PPO and peroxidase (POX were evaluated. Bacteria compatibility was evaluated by means of infiltration of tubers. The defense response was evaluated in the leaves of the potato plants. Leaves were inoculated depending on their number and location on the stem. Multiple-leaf inoculation was carried out on basal, intermediate, and apical leaves, and single inoculations on intermediate leaves. Leaves inoculated with X. axonopodis and with R. solanacearum showed hypersensitive responses within 24 hours post-inoculation, whereas leaves inoculated with E. carotovora showed disease symptoms. Therefore, the R. solanacearum isolate used in the experiments did not exhibit virulence to this potato cultivar. Regardless of the bacterial treatments, the basal leaves showed higher PPO and POX activities and lower levels of total phenolic compounds and flavonoids, compared to the apical leaves. However, basal and intermediate leaves inoculated with R. solanacearum and X. axonopodis showed increases in total phenolic compounds and flavonoid levels. In general, multiple-leaf inoculation showed the highest levels of total phenolics and flavonoids, whereas the single inoculations resulted in the highest increase in PPO activity. The POX activity showed no significant difference between single- and multiple-leaf inoculations. Plants inoculated with E. carotovora showed no significant increase in

  12. The ecology and evolution of inducible defenses.

    Science.gov (United States)

    Harvell, C D

    1990-09-01

    Inducible defenses are responses activated through a previous encounter with a consumer or competitor that confer some degree of resistance to subsequent attacks. While the importance of inducible resistance has long been known in host-parasite interactions, it is only recently that its importance has emerged in other natural systems. Although the structural defenses produced by invertebrates to their competitors and predators are by no means the same as an immune response triggered by parasites, these responses all share the properties of (1) specificity, (2) amplification and (3) memory. This review discusses the following ecological consequences and evolutionary causes of inducible defenses: (1) Inducible defenses render historical factors important in biological interactions and can affect the probability of individual survival and growth, as well as affect population dynamics of consumers in some circumstances. (2) Although the benefits of inducible defenses are often balanced by fitness costs, including reduced growth, reproductive output and survivorship, the role of costs and benefits in the evolution of inducible defenses is by no means clear. A more integrated approach would involve a multivariate analysis of the role of natural selection on the inducible characters of interest, their norms of reaction and correlated fitness characters. (3) The disproportionate representation of inducible, morphological defenses among clonal organisms may be due to both a higher rate of origination and enhanced selection to maintain these defenses in clonal taxa. (4) Inducible defenses should be most common when reliable cues are available, attacks by biological agents are unpredictable, and the fitness gains of defenses are balanced by the costs. An integrated approach to studying inducible defenses would thus combine mechanistic estimates of costs, population-level estimates of defense effectiveness, and genetic estimates of correlations between fitness and inducible

  13. First Steps Toward Improving DoD STEM Workforce Diversity: Response to the 2012 Department of Defense STEM Diversity Summit

    Science.gov (United States)

    2013-01-01

    Abigail Haddad, Dwayne M. Butler, Kate Giglio NATIONAL DEFENSE RESEARCH INSTITUTE First Steps Toward Improving DoD STEM Workforce Diversity Response to...the 2012 Department of Defense STEM Diversity Summit Nelson Lim, Abigail Haddad, Dwayne M. Butler, Kate Giglio Prepared for the Office of the...Acknowledgments The authors wish to thank Reginald Brothers and Clarence Johnson for giving us an opportunity to support their effort in aligning DoD STEM and

  14. Are Law and Policy Clear and Consistent? Roles and Responsibilities of the Defense Acquisition Executive and the Chief Information Officer

    Science.gov (United States)

    2010-01-01

    entire Defense Information Enterprise Architecture ( DIEA ). Most important, DoDD 8000.01 gives the Assistant Secretary of Defense for Networks and...Information Integration (ASD(NII))/DoD CIO the responsibility for providing standards for developing, maintaining, and implementing the DIEA , but not...for developing IT architectures based on DIEA standards. This means that DIEA standards specified by the DoD CIO can be used to electronically

  15. Defensive behaviors of the Oriental armywormMythimna separatain response to different parasitoid species (Hymenoptera: Braconidae).

    Science.gov (United States)

    Zhou, Jincheng; Meng, Ling; Li, Baoping

    2017-01-01

    This study examined defensive behaviors of Mythimna separata (Lepidoptera: Noctuidae) larvae varying in body size in response to two parasitoids varying in oviposition behavior; Microplitis mediator females sting the host with the ovipositor after climbing onto it while Meteorus pulchricornis females make the sting by standing at a close distance from the host. Mythimna separata larvae exhibited evasive (escaping and dropping) and aggressive (thrashing) behaviors to defend themselves against parasitoids M. mediator and M. pulchricornis . Escaping and dropping did not change in probability with host body size or parasitoid species. Thrashing did not vary in frequency with host body size, yet performed more frequently in response to M. mediator than to M. pulchricornis . Parasitoid handling time and stinging likelihood varied depending not only on host body size but also on parasitoid species. Parasitoid handling time increased with host thrashing frequency, similar in slope for both parasitoids yet on a higher intercept for M. mediator than for M. pulchricornis . Handling time decreased with host size for M. pulchricornis but not for M. mediator . The likelihood of realizing an ovipositor sting decreased with thrashing frequency of both small and large hosts for M. pulchricornis , while this was true only for large hosts for M. mediator . Our results suggest that the thrashing behavior of M. separata larvae has a defensive effect on parasitism, depending on host body size and parasitoid species with different oviposition behaviors.

  16. Defensive responses to threat scenarios in Brazilians reproduce the pattern of Hawaiian Americans and non-human mammals.

    Science.gov (United States)

    Shuhama, R; Del-Ben, C M; Loureiro, S R; Graeff, F G

    2008-04-01

    A former study with scenarios conducted in Hawaii has suggested that humans share with non-human mammals the same basic defensive strategies - risk assessment, freezing, defensive threat, defensive attack, and flight. The selection of the most adaptive strategy is strongly influenced by features of the threat stimulus - magnitude, escapability, distance, ambiguity, and availability of a hiding place. Aiming at verifying if these strategies would be consistent in a different culture, 12 defensive scenarios were translated into Portuguese and adapted to the Brazilian culture. The sample consisted of male and female undergraduate students divided into two groups: 76 students, who evaluated the five dimensions of each scenario and 248 medical students, who chose the most likely response for each scenario. In agreement with the findings from studies of non-human mammal species, the scenarios were able to elicit different defensive behavioral responses, depending on features of the threat. "Flight" was chosen as the most likely response in scenarios evaluated as an unambiguous and intense threat, but with an available route of escape, whereas "attack" was chosen in an unambiguous, intense and close dangerous situation without an escape route. Less urgent behaviors, such as "check out", were chosen in scenarios evaluated as less intense, more distant and more ambiguous. Moreover, the results from the Brazilian sample were similar to the results obtained in the original study with Hawaiian students. These data suggest that a basic repertoire of defensive strategies is conserved along the mammalian evolution because they share similar functional benefits in maintaining fitness.

  17. Inducible defenses against herbivory and fouling in seaweeds

    Science.gov (United States)

    Pereira, Renato Crespo; Costa, Erica da Silva; Sudatti, Daniela Bueno; da Gama, Bernardo Antonio Perez

    2017-04-01

    Secondary metabolites play an important ecological role as a defense mechanism in seaweeds. Chemical defenses are well known to change in response to herbivory, but other driving factors, either biotic or abiotic, are often neglected. Epibiosis may not only reduce seaweed fitness, but also increase attractiveness to consumers, and thus defense production should also be triggered by epibionts. In this study, three Southwestern Atlantic seaweeds, Gracilaria cearensis, Pterocladiella capillacea (Rhodophyceae) and Codium decorticatum (Chlorophyceae) were investigated in laboratory bioassays designed to test whether the action of herbivory or simulated epibiosis influences chemical defenses. Crossed induction experiments were also performed in order to assess whether herbivore induction influences antifouling chemical defense, as well as whether epibiont induction would affect defense against herbivores. The effect of laboratory conditions on seaweeds in the absence of field stimuli was also investigated by comparing consumption of artificial food with extracts from acclimatized and non-acclimatized seaweeds (i.e., natural defense levels). Only the green seaweed C. decorticatum exhibited inducible antifouling defenses triggered by simulated epibiosis, but not by herbivores. In the other seaweeds there was no induction either by herbivory or simulated epibiosis. Acclimatization did not affect C. decorticatum defenses. However, non-acclimatized G. cearensis artificial foods were preferred over acclimatized ones, while extracts from acclimatized P. capillacea increased herbivore consumption, highlighting the need to acclimatize seaweeds before the main induction experiments. This is the first report of inducible defenses due to simulated fouling in seaweeds.

  18. Similar, but different: structurally related azelaic acid and hexanoic acid trigger differential metabolomic and transcriptomic responses in tobacco cells.

    Science.gov (United States)

    Djami-Tchatchou, Arnaud T; Ncube, Efficient N; Steenkamp, Paul A; Dubery, Ian A

    2017-11-29

    Plants respond to various stress stimuli by activating an enhanced broad-spectrum defensive ability. The development of novel resistance inducers represents an attractive, alternative crop protection strategy. In this regard, hexanoic acid (Hxa, a chemical elicitor) and azelaic acid (Aza, a natural signaling compound) have been proposed as inducers of plant defense, by means of a priming mechanism. Here, we investigated both the mode of action and the complementarity of Aza and Hxa as priming agents in Nicotiana tabacum cells in support of enhanced defense. Metabolomic analyses identified signatory biomarkers involved in the establishment of a pre-conditioned state following Aza and Hxa treatment. Both inducers affected the metabolomes in a similar manner and generated common biomarkers: caffeoylputrescine glycoside, cis-5-caffeoylquinic acid, feruloylglycoside, feruloyl-3-methoxytyramine glycoside and feruloyl-3-methoxytyramine conjugate. Subsequently, quantitative real time-PCR was used to investigate the expression of inducible defense response genes: phenylalanine ammonia lyase, hydroxycinnamoyl CoA quinate transferase and hydroxycinnamoyl transferase to monitor activation of the early phenylpropanoid pathway and chlorogenic acids metabolism, while ethylene response element-binding protein, small sar1 GTPase, heat shock protein 90, RAR1, SGT1, non-expressor of PR genes 1 and thioredoxin were analyzed to report on signal transduction events. Pathogenesis-related protein 1a and defensin were quantified to investigate the activation of defenses regulated by salicylic acid and jasmonic acid respectively. The qPCR results revealed differential expression kinetics and, in general (except for NPR1, Thionin and PR1a), the relative gene expression ratios observed in the Hxa-treated cells were significantly greater than the expression observed in the cells treated with Aza. The results indicate that Aza and Hxa have a similar priming effect through activation of genes

  19. Triggering of inflammasome by aggregated α-synuclein, an inflammatory response in synucleinopathies.

    Directory of Open Access Journals (Sweden)

    Gaia Codolo

    Full Text Available Parkinson's disease (PD is one of the most common neurodegenerative diseases. It is characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta of the brain. Another feature is represented by the formation in these cells of inclusions called Lewy bodies (LB, principally constituted by fibrillar α-synuclein (αSyn. This protein is considered a key element in the aetiology of a group of neurodegenerative disorders termed synucleinopathies, which include PD, but the cellular and molecular mechanisms involved are not completely clear. It is established that the inflammatory process plays a crucial role in the pathogenesis and/or progression of PD; moreover, it is known that aggregated αSyn, released by neurons, activates microglia cells to produce pro-inflammatory mediators, such as IL-1β. IL-1β is one of the strongest pro-inflammatory cytokines; it is produced as an inactive mediator, and its maturation and activation requires inflammasome activation. In particular, the NLRP3 inflammasome is activated by a wide variety of stimuli, among which are crystallized and particulate material. In this work, we investigated the possibility that IL-1β production, induced by fibrillar αSyn, is involved the inflammasome activation. We demonstrated the competence of monomeric and fibrillar αSyn to induce synthesis of IL-1β, through TLR2 interaction; we found that the secretion of the mature cytokine was a peculiarity of the fibrillated protein. Moreover, we observed that the secretion of IL-1β involves NLRP3 inflammasome activation. The latter relies on the phagocytosis of fibrillar αSyn, followed by increased ROS production and cathepsin B release into the cytosol. Taken together, our data support the notion that fibrillar αSyn, likely released by neuronal degeneration, acts as an endogenous trigger inducing a strong inflammatory response in PD.

  20. Superoxide generated at mitochondrial complex III triggers acute responses to hypoxia in the pulmonary circulation.

    Science.gov (United States)

    Waypa, Gregory B; Marks, Jeremy D; Guzy, Robert D; Mungai, Paul T; Schriewer, Jacqueline M; Dokic, Danijela; Ball, Molly K; Schumacker, Paul T

    2013-02-15

    The role of reactive oxygen species (ROS) signaling in the O(2) sensing mechanism underlying acute hypoxic pulmonary vasoconstriction (HPV) has been controversial. Although mitochondria are important sources of ROS, studies using chemical inhibitors have yielded conflicting results, whereas cellular models using genetic suppression have precluded in vivo confirmation. Hence, genetic animal models are required to test mechanistic hypotheses. We tested whether mitochondrial Complex III is required for the ROS signaling and vasoconstriction responses to acute hypoxia in pulmonary arteries (PA). A mouse permitting Cre-mediated conditional deletion of the Rieske iron-sulfur protein (RISP) of Complex III was generated. Adenoviral Cre recombinase was used to delete RISP from isolated PA vessels or smooth muscle cells (PASMC). In PASMC, RISP depletion abolished hypoxia-induced increases in ROS signaling in the mitochondrial intermembrane space and cytosol, and it abrogated hypoxia-induced increases in [Ca(2+)](i). In isolated PA vessels, RISP depletion abolished hypoxia-induced ROS signaling in the cytosol. Breeding the RISP mice with transgenic mice expressing tamoxifen-activated Cre in smooth muscle permitted the depletion of RISP in PASMC in vivo. Precision-cut lung slices from those mice revealed that RISP depletion abolished hypoxia-induced increases in [Ca(2+)](i) of the PA. In vivo RISP depletion in smooth muscle attenuated the acute hypoxia-induced increase in right ventricular systolic pressure in anesthetized mice. Acute hypoxia induces superoxide release from Complex III of smooth muscle cells. These oxidant signals diffuse into the cytosol and trigger increases in [Ca(2+)](i) that cause acute hypoxic pulmonary vasoconstriction.

  1. Different infective forms trigger distinct immune response in experimental Chagas disease.

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    Paula Melo de Abreu Vieira

    Full Text Available Although metacyclic and blood trypomastigotes are completely functional in relation to parasite-host interaction and/or target cell invasion, they differ in the molecules present on the surface. Thus, aspects related to the variability that the forms of T. cruzi interacts with host cells may lead to fundamental implications on the immune response against this parasite and, consequently, the clinical evolution of Chagas disease. We have shown that BT infected mice presented higher levels of parasitemia during all the acute phase of infection. Moreover, the infection with either MT or BT forms resulted in increased levels of total leukocytes, monocytes and lymphocytes, specifically later for MT and earlier for BT. The infection with BT forms presented earlier production of proinflammatory cytokine TNF-α and later of IFN-γ by both T cells subpopulations. This event was accompanied by an early cardiac inflammation with an exacerbation of this process at the end of the acute phase. On the other hand, infection with MT forms result in an early production of IFN-γ, with subsequent control in the production of this cytokine by IL-10, which provided to these animals an immunomodulatory profile in the end of the acute phase. These results are in agreement with what was found for cardiac inflammation where animals infected with MT forms showed intense cardiac inflammation later at infection, with a decrease in the same at the end of this phase. In summary, our findings emphasize the importance of taking into account the inoculums source of T. cruzi, since vectorial or transfusional routes of T. cruzi infection may trigger distinct parasite-host interactions during the acute phase that may influence relevant biological aspects of chronic Chagas disease.

  2. Escherichia coli α-hemolysin counteracts the anti-virulence innate immune response triggered by the Rho GTPase activating toxin CNF1 during bacteremia.

    Directory of Open Access Journals (Sweden)

    Mamady Diabate

    2015-03-01

    Full Text Available The detection of the activities of pathogen-encoded virulence factors by the innate immune system has emerged as a new paradigm of pathogen recognition. Much remains to be determined with regard to the molecular and cellular components contributing to this defense mechanism in mammals and importance during infection. Here, we reveal the central role of the IL-1β signaling axis and Gr1+ cells in controlling the Escherichia coli burden in the blood in response to the sensing of the Rho GTPase-activating toxin CNF1. Consistently, this innate immune response is abrogated in caspase-1/11-impaired mice or following the treatment of infected mice with an IL-1β antagonist. In vitro experiments further revealed the synergistic effects of CNF1 and LPS in promoting the maturation/secretion of IL-1β and establishing the roles of Rac, ASC and caspase-1 in this pathway. Furthermore, we found that the α-hemolysin toxin inhibits IL-1β secretion without affecting the recruitment of Gr1+ cells. Here, we report the first example of anti-virulence-triggered immunity counteracted by a pore-forming toxin during bacteremia.

  3. Identification of a Maize Locus that Modulates the Hypersensitive Defense Response, Using Mutant-Assisted Gene Identification and Characterization (MAGIC)

    Science.gov (United States)

    The hypersensitive response (HR) is the most visible and arguably the most important defense response in plants, although the details of how it is controlled and executed remain patchy. In this paper a novel genetic technique called MAGIC (Mutant-Assisted Gene Identification and Characterization) i...

  4. TcNPR3 from Theobroma cacao functions as a repressor of the pathogen defense response.

    Science.gov (United States)

    Shi, Zi; Zhang, Yufan; Maximova, Siela N; Guiltinan, Mark J

    2013-12-06

    Arabidopsis thaliana (Arabidopsis) NON-EXPRESSOR OF PR1 (NPR1) is a transcription coactivator that plays a central role in regulating the transcriptional response to plant pathogens. Developing flowers of homozygous npr3 mutants are dramatically more resistant to infection by the pathogenic bacterium Pseudomonas syringae, suggesting a role of NPR3 as a repressor of NPR1-mediated defense response with a novel role in flower development. We report here the characterization of a putative NPR3 gene from the tropical tree species Theobroma cacao (TcNPR3). Like in Arabidopsis, TcNPR3 was constitutively expressed across a wide range of tissue types and developmental stages but with some differences in relative levels compared to Arabidopsis. To test the function of TcNPR3, we performed transgenic complementation analysis by introducing a constitutively expressing putative TcNPR3 transgene into an Arabidopsis npr3 mutant. TcNPR3 expressing Arabidopsis plants were partially restored to the WT pathogen phenotype (immature flowers susceptible to bacterial infection). To test TcNPR3 function directly in cacao tissues, a synthetic microRNA targeting TcNPR3 mRNA was transiently expressed in cacao leaves using an Agrobacterium-infiltration method. TcNPR3 knock down leaf tissues were dramatically more resistance to infection with Phytophthora capsici in a leaf bioassay, showing smaller lesion sizes and reduced pathogen replication. We conclude that TcNPR3 functions similar to the Arabidopsis NPR3 gene in the regulation of the cacao defense response. Since TcNPR3 did not show a perfect complementation of the Arabidopsis NPR3 mutation, the possibility remains that other functions of TcNPR3 remain to be found. This novel knowledge can contribute to the breeding of resistant cacao varieties against pathogens through molecular markers based approaches or biotechnological strategies.

  5. Immune responses against human papillomavirus (HPV) infection and evasion of host defense in cervical cancer.

    Science.gov (United States)

    Sasagawa, Toshiyuki; Takagi, Hiroaki; Makinoda, Satoru

    2012-12-01

    Human papillomavirus (HPV) is the most important etiological factor for cervical cancer. A recent study demonstrated that more than 20 HPV types were thought to be oncogenic for uterine cervical cancer. Notably, more than one-half of women show cervical HPV infections soon after their sexual debut, and about 90 % of such infections are cleared within 3 years. Immunity against HPV might be important for elimination of the virus. The innate immune responses involving macrophages, natural killer cells, and natural killer T cells may play a role in the first line of defense against HPV infection. In the second line of defense, adaptive immunity via cytotoxic T lymphocytes (CTLs) targeting HPV16 E2 and E6 proteins appears to eliminate cells infected with HPV16. However, HPV can evade host immune responses. First, HPV does not kill host cells during viral replication and therefore neither presents viral antigen nor induces inflammation. HPV16 E6 and E7 proteins downregulate the expression of type-1 interferons (IFNs) in host cells. The lack of co-stimulatory signals by inflammatory cytokines including IFNs during antigen recognition may induce immune tolerance rather than the appropriate responses. Moreover, HPV16 E5 protein downregulates the expression of HLA-class 1, and it facilitates evasion of CTL attack. These mechanisms of immune evasion may eventually support the establishment of persistent HPV infection, leading to the induction of cervical cancer. Considering such immunological events, prophylactic HPV16 and 18 vaccine appears to be the best way to prevent cervical cancer in women who are immunized in adolescence.

  6. An activated unfolded protein response promotes retinal degeneration and triggers an inflammatory response in the mouse retina.

    Science.gov (United States)

    Rana, T; Shinde, V M; Starr, C R; Kruglov, A A; Boitet, E R; Kotla, P; Zolotukhin, S; Gross, A K; Gorbatyuk, M S

    2014-12-18

    Recent studies on the endoplasmic reticulum stress have shown that the unfolded protein response (UPR) is involved in the pathogenesis of inherited retinal degeneration caused by mutant rhodopsin. However, the main question of whether UPR activation actually triggers retinal degeneration remains to be addressed. Thus, in this study, we created a mouse model for retinal degeneration caused by a persistently activated UPR to assess the physiological and morphological parameters associated with this disease state and to highlight a potential mechanism by which the UPR can promote retinal degeneration. We performed an intraocular injection in C57BL6 mice with a known unfolded protein response (UPR) inducer, tunicamycin (Tn) and examined animals by electroretinography (ERG), spectral domain optical coherence tomography (SD-OCT) and histological analyses. We detected a significant loss of photoreceptor function (over 60%) and retinal structure (35%) 30 days post treatment. Analysis of retinal protein extracts demonstrated a significant upregulation of inflammatory markers including interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1) and IBA1. Similarly, we detected a strong inflammatory response in mice expressing either Ter349Glu or T17M rhodopsin (RHO). These mutant rhodopsin species induce severe retinal degeneration and T17M rhodopsin elicits UPR activation when expressed in mice. RNA and protein analysis revealed a significant upregulation of pro- and anti-inflammatory markers such as IL-1β, IL-6, p65 nuclear factor kappa B (NF-kB) and MCP-1, as well as activation of F4/80 and IBA1 microglial markers in both the retinas expressing mutant rhodopsins. We then assessed if the Tn-induced inflammatory marker IL-1β was capable of inducing retinal degeneration by injecting C57BL6 mice with a recombinant IL-1β. We observed ~19% reduction in ERG a-wave amplitudes and a 29% loss of photoreceptor cells compared with

  7. NIR-triggered high-efficient photodynamic and chemo-cascade therapy using caspase-3 responsive functionalized upconversion nanoparticles.

    Science.gov (United States)

    Zhao, Na; Wu, Baoyan; Hu, Xianglong; Xing, Da

    2017-10-01

    Stimuli-responsive nanoparticles with multiple therapeutic/diagnostic functions are highly desirable for effective tumor treatment. Herein novel caspase-3 responsive functionalized upconversion nanoparticles (CFUNs) were fabricated with three-in-one functional integration: near-infrared (NIR) triggered photodynamic damage along with caspase-3 activation, subsequent caspase-3 responsive drug release, and cascade chemotherapeutic activation. CFUNs were formulated from the self-assembly of caspase-3 responsive doxorubicin (DOX) prodrug tethered with DEVD peptide (DEVD-DOX), upconversion nanoparticles (UCNP), a photosensitizer (pyropheophorbide-a methyl ester, MPPa), and tumor-targeting cRGD-PEG-DSPE to afford multifunctional CFUNs, MPPa/UCNP-DEVD-DOX/cRGD. Upon cellular uptake and NIR irradiation, the visible light emission of UCNP could excite MPPa to produce reactive oxygen species for photodynamic therapy (PDT) along with the activation of caspase-3, which further cleaved DEVD peptide to release DOX within tumor cells, thus accomplishing NIR-triggered PDT and cascade chemotherapy. CFUNs presented silent therapeutic potency and negligible cytotoxicity in the dark, whereas in vitro and in vivo experiments demonstrated the NIR-triggered cascade therapeutic activation and tumor inhibition due to consecutive PDT and chemotherapy. Current NIR-activated cascade tumor therapy with two distinct mechanisms is significantly favorable to overcome multidrug resistance and tumor heterogeneity for persistent tumor treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Oxidation Responsive Polymers with a Triggered Degradation via Arylboronate Self-Immolative Motifs on a Polyphosphazene Backbone.

    Science.gov (United States)

    Iturmendi, Aitziber; Monkowius, Uwe; Teasdale, Ian

    2017-02-21

    Oxidation responsive polymers with triggered degradation pathways have been prepared via attachment of self-immolative moieties onto a hydrolytically unstable polyphosphazene backbone. After controlled main-chain growth, postpolymerization functionalization allows the preparation of hydrolytically stable poly(organo)phosphazenes decorated with a phenylboronic ester caging group. In oxidative environments, triggered cleavage of the caging group is followed by self-immolation, exposing the unstable glycine-substituted polyphosphazene which subsequently undergoes to backbone degradation to low-molecular weight molecules. As well as giving mechanistic insights, detailed GPC and 1 H and 31 P NMR analysis reveal the polymers to be stable in aqueous solutions, but show a selective, fast degradation upon exposure to hydrogen peroxide containing solutions. Since the post-polymerization functionalization route allows simple access to polymer backbones with a broad range of molecular weights, the approach of using the inorganic backbone as a platform significantly expands the toolbox of polymers capable of stimuli-responsive degradation.

  9. Host Defense and the Airway Epithelium: Frontline Responses That Protect against Bacterial Invasion and Pneumonia

    Directory of Open Access Journals (Sweden)

    Nicholas A. Eisele

    2011-01-01

    Full Text Available Airway epithelial cells are the first line of defense against invading microbes, and they protect themselves through the production of carbohydrate and protein matrices concentrated with antimicrobial products. In addition, they act as sentinels, expressing pattern recognition receptors that become activated upon sensing bacterial products and stimulate downstream recruitment and activation of immune cells which clear invading microbes. Bacterial pathogens that successfully colonize the lungs must resist these mechanisms or inhibit their production, penetrate the epithelial barrier, and be prepared to resist a barrage of inflammation. Despite the enormous task at hand, relatively few virulence factors coordinate the battle with the epithelium while simultaneously providing resistance to inflammatory cells and causing injury to the lung. Here we review mechanisms whereby airway epithelial cells recognize pathogens and activate a program of antibacterial pathways to prevent colonization of the lung, along with a few examples of how bacteria disrupt these responses to cause pneumonia.

  10. Blast Responses and Vibration of Flood-Defense Structures under High-Intensity Blast Loadings

    Directory of Open Access Journals (Sweden)

    Yonghee Ryu

    2018-01-01

    Full Text Available This study presented the blast behavior of flood-defense structures subjected to high-intensity loadings such as blast shock waves. In order to understand the blast behavior of weir structures, PHAST program was used to predict blast loadings in consideration of material reactivity and congestion levels. Environment factors such as weather data and atmospheric parameters were also considered in this study. Then, nonlinear dynamic analyses were performed using the ABAQUS platform to evaluate structural responses and blast vibration of concrete weir structures subjected to various types of blast loadings, due to uncertainties of the magnitude and durations of blast loads as a function of distance from the explosion. It was shown that the blast damage to concrete weir structure was significantly influenced by congestion levels or material reactivity. Also, the stress concentration under blast loading was observed at the connection area between the concrete weir body and stilling basin.

  11. Defensive responses of Brandt's voles (Lasiopodomys brandtii) to stored cat feces.

    Science.gov (United States)

    Hegab, Ibrahim M; Jin, Yajuan; Ye, Manhong; Wang, Aiqin; Yin, Baofa; Yang, Shengmei; Wei, Wanhong

    2014-01-17

    Predator odors are non-intrusive natural stressors of high ethological relevance. Animals are daily challenged with stressors of varying intensity and it is essential for their survival to respond to a wide range of threats. Behavioral and hormonal responses and changes in the level of medial hypothalamic c-fos mRNA were examined in Brandt's voles (Lasiopodomys brandtii) exposed to the feces of a domestic cat (Felis catus) stored for different periods. One hundred voles were tested in the defensive withdrawal apparatus. The voles showed an aversion to freshly collected cat feces, indicated by high levels of flight-related behaviors, increased freezing behavior, and more vigilant rearing compared to old feces. The serum levels of adrenocorticotropic hormone and corticosterone significantly increased when the voles were exposed to fresh cat feces. The level of c-fos mRNA in the medial hypothalamic region was highest in the individuals exposed to fresh cat feces. All of these behavioral, endocrine and c-fos-mRNA responses were lower when voles were subjected to older cat feces. We conclude that these responses depend on volatile chemical constituents of cat feces rather than their physical characteristics and that this accounts for the lower responses to feces stored for longer periods. © 2013. Published by Elsevier Inc. All rights reserved.

  12. Integration of danger peptide signals with herbivore-associated molecular pattern signaling amplifies anti-herbivore defense responses in rice.

    Science.gov (United States)

    Shinya, Tomonori; Yasuda, Shigetaka; Hyodo, Kiwamu; Tani, Rena; Hojo, Yuko; Fujiwara, Yuka; Hiruma, Kei; Ishizaki, Takuma; Fujita, Yasunari; Saijo, Yusuke; Galis, Ivan

    2018-03-07

    Plant defense against herbivores is modulated by herbivore-associated molecular patterns (HAMPs) from oral secretions (OS) and/or saliva of insects. Furthermore, feeding wounds initiate plant self-damage responses modulated by danger-associated molecular patterns (DAMPs) such as immune defense-promoting plant elicitor peptides (Peps). While temporal and spatial co-existence of both patterns during herbivory implies a possibility of their close interaction, the molecular mechanisms remain undetermined. Here we report that exogenous application of rice (Oryza sativa) peptides (OsPeps) can elicit multiple defense responses in rice cell cultures. Specific activation of OsPROPEP3 gene transcripts in rice leaves by wounding and OS treatments further suggests a possible involvement of the OsPep3 peptide in rice-herbivore interactions. Correspondingly, we found that simultaneous application of OsPep3 and Mythimna loreyi OS significantly amplifies an array of defense responses in rice cells, including mitogen-activated protein kinase activation, and generation of defense-related hormones and metabolites. The induction of OsPROPEP3/4 by OsPep3 points to a positive auto-feedback loop in OsPep signaling which may contribute to additional enhancement of defense signal(s). Finally, the overexpression of the OsPep receptor OsPEPR1 increases the sensitivity of rice plants not only to the cognate OsPeps but also to OS signals. Our findings collectively suggest that HAMP-DAMP signal integration provides a critical step in the amplification of defense signaling in plants. © 2018 The Authors The Plant Journal © 2018 John Wiley & Sons Ltd.

  13. Rainfall-triggering response patterns of post-seismic debris flows in the Wenchuan earthquake area

    NARCIS (Netherlands)

    Zhou, W.; Tang, C.; van Asch, Th.W.J.; Zhou, nn.

    2013-01-01

    Several giant debris flows occurred in southwestern China after the Wenchuan earthquake, causing serious casualties and economic losses. Debris flows were frequently triggered after the earthquake. A relatively accurate prediction of these post-seismic debris flows can help to reduce the consequent

  14. Synthetic RNAs Mimicking Structural Domains in the Foot-and-Mouth Disease Virus Genome Elicit a Broad Innate Immune Response in Porcine Cells Triggered by RIG-I and TLR Activation

    Directory of Open Access Journals (Sweden)

    Belén Borrego

    2015-07-01

    Full Text Available The innate immune system is the first line of defense against viral infections. Exploiting innate responses for antiviral, therapeutic and vaccine adjuvation strategies is being extensively explored. We have previously described, the ability of small in vitro RNA transcripts, mimicking the sequence and structure of different domains in the non-coding regions of the foot-and-mouth disease virus (FMDV genome (ncRNAs, to trigger a potent and rapid innate immune response. These synthetic non-infectious molecules have proved to have a broad-range antiviral activity and to enhance the immunogenicity of an FMD inactivated vaccine in mice. Here, we have studied the involvement of pattern-recognition receptors (PRRs in the ncRNA-induced innate response and analyzed the antiviral and cytokine profiles elicited in swine cultured cells, as well as peripheral blood mononuclear cells (PBMCs.

  15. Augmented supraorbital skin sympathetic nerve activity responses to symptom trigger events in rosacea patients.

    Science.gov (United States)

    Metzler-Wilson, Kristen; Toma, Kumika; Sammons, Dawn L; Mann, Sarah; Jurovcik, Andrew J; Demidova, Olga; Wilson, Thad E

    2015-09-01

    Facial flushing in rosacea is often induced by trigger events. However, trigger causation mechanisms are currently unclear. This study tested the central hypothesis that rosacea causes sympathetic and axon reflex-mediated alterations resulting in trigger-induced symptomatology. Twenty rosacea patients and age/sex-matched controls participated in one or a combination of symptom triggering stressors. In protocol 1, forehead skin sympathetic nerve activity (SSNA; supraorbital microneurography) was measured during sympathoexcitatory mental (2-min serial subtraction of novel numbers) and physical (2-min isometric handgrip) stress. In protocol 2, forehead skin blood flow (laser-Doppler flowmetry) and transepithelial water loss/sweat rate (capacitance hygrometry) were measured during sympathoexcitatory heat stress (whole body heating by perfusing 50°C water through a tube-lined suit). In protocol 3, cheek, forehead, forearm, and palm skin blood flow were measured during nonpainful local heating to induce axon reflex vasodilation. Heart rate (HR) and mean arterial pressure (MAP) were recorded via finger photoplethysmography to calculate cutaneous vascular conductance (CVC; flux·100/MAP). Higher patient transepithelial water loss was observed (rosacea 0.20 ± 0.02 vs. control 0.10 ± 0.01 mg·cm(-2)·min(-1), P rosacea and controls, respectively) stress was augmented in rosacea (both P rosacea compared with controls. No axon reflex vasodilation differences were observed between groups. These data indicate that rosacea affects SSNA and that hyperresponsiveness to trigger events appears to have a sympathetic component. Copyright © 2015 the American Physiological Society.

  16. Polyamines attenuate ethylene-mediated defense responses to abrogate resistance to Botrytis cinerea in tomato.

    Science.gov (United States)

    Nambeesan, Savithri; AbuQamar, Synan; Laluk, Kristin; Mattoo, Autar K; Mickelbart, Michael V; Ferruzzi, Mario G; Mengiste, Tesfaye; Handa, Avtar K

    2012-02-01

    Transgenic tomato (Solanum lycopersicum) lines overexpressing yeast spermidine synthase (ySpdSyn), an enzyme involved in polyamine (PA) biosynthesis, were developed. These transgenic lines accumulate higher levels of spermidine (Spd) than the wild-type plants and were examined for responses to the fungal necrotrophs Botrytis cinerea and Alternaria solani, bacterial pathogen Pseudomonas syringae pv tomato DC3000, and larvae of the chewing insect tobacco hornworm (Manduca sexta). The Spd-accumulating transgenic tomato lines were more susceptible to B. cinerea than the wild-type plants; however, responses to A. solani, P. syringae, or M. sexta were similar to the wild-type plants. Exogenous application of ethylene precursors, S-adenosyl-Met and 1-aminocyclopropane-1-carboxylic acid, or PA biosynthesis inhibitors reversed the response of the transgenic plants to B. cinerea. The increased susceptibility of the ySpdSyn transgenic tomato to B. cinerea was associated with down-regulation of gene transcripts involved in ethylene biosynthesis and signaling. These data suggest that PA-mediated susceptibility to B. cinerea is linked to interference with the functions of ethylene in plant defense.

  17. Toll-Like Receptor Mediated Modulation of T Cell Response by Commensal Intestinal Microbiota as a Trigger for Autoimmune Arthritis

    Directory of Open Access Journals (Sweden)

    Rebecca Rogier

    2015-01-01

    Full Text Available In autoimmune diseases, a disturbance of the balance between T helper 17 (Th17 and regulatory T cells (Tregs is often observed. This disturbed balance is also the case in rheumatoid arthritis (RA. Genetic predisposition to RA confers the presence of several polymorphisms mainly regulating activation of T lymphocytes. However, the presence of susceptibility factors is neither necessary nor sufficient to explain the disease development, emphasizing the importance of environmental factors. Multiple studies have shown that commensal gut microbiota is of great influence on immune homeostasis and can trigger the development of autoimmune diseases by favoring induction of Th17 cells over Tregs. However the mechanism by which intestinal microbiota influences the Th cell balance is not completely understood. Here we review the current evidence supporting the involvement of commensal intestinal microbiota in rheumatoid arthritis, along with a potential role of Toll-like receptors (TLRs in modulating the relevant Th cell responses to trigger autoimmunity. A better understanding of TLR triggering by intestinal microbiota and subsequent T cell activation might offer new perspectives for manipulating the T cell response in RA patients and may lead to the discovery of new therapeutic targets or even preventive measures.

  18. Temporal and spatial resolution of activated plant defense responses in leaves of Nicotiana benthamiana infected with Dickeya dadantii

    Directory of Open Access Journals (Sweden)

    María Luisa ePérez-Bueno

    2016-01-01

    Full Text Available The necrotrophic bacteria Dickeya dadantii is the causal agent of soft-rot disease in a broad range of hosts. The model plant Nicotiana benthamiana, commonly used as experimental host for a very broad range of plant pathogens, is susceptible to infection by D. dadantii. The inoculation with D. dadantii at high dose seems to overcome the plant defense capacity, inducing maceration and death of the tissue, although restricted to the infiltrated area. By contrast, the output of the defense response to low dose inoculation is inhibition of maceration and limitation in the growth, or even eradication, of bacteria. Responses of tissue invaded by bacteria (neighbouring the infiltrated areas after 2-3 days post-inoculation included: i inhibition of photosynthesis in terms of photosystem II efficiency; ii activation of energy dissipation as non-photochemical quenching in photosystem II, which is related to the activation of plant defense mechanisms; and iii accumulation of secondary metabolites in cell walls of the epidermis (lignins and the apoplast of the mesophyll (phytoalexins. Infiltrated tissues showed an increase in the content of the main hormones regulating stress responses, including abscisic acid (ABA, jasmonic acid (JA and salicylic acid (SA. We propose a mechanism involving the three hormones by which N. benthamiana could activate an efficient defense response against D. dadantii.

  19. Defensive responses to threat scenarios in Brazilians reproduce the pattern of Hawaiian Americans and non-human mammals

    Directory of Open Access Journals (Sweden)

    R. Shuhama

    2008-04-01

    Full Text Available A former study with scenarios conducted in Hawaii has suggested that humans share with non-human mammals the same basic defensive strategies - risk assessment, freezing, defensive threat, defensive attack, and flight. The selection of the most adaptive strategy is strongly influenced by features of the threat stimulus - magnitude, escapability, distance, ambiguity, and availability of a hiding place. Aiming at verifying if these strategies would be consistent in a different culture, 12 defensive scenarios were translated into Portuguese and adapted to the Brazilian culture. The sample consisted of male and female undergraduate students divided into two groups: 76 students, who evaluated the five dimensions of each scenario and 248 medical students, who chose the most likely response for each scenario. In agreement with the findings from studies of non-human mammal species, the scenarios were able to elicit different defensive behavioral responses, depending on features of the threat. "Flight" was chosen as the most likely response in scenarios evaluated as an unambiguous and intense threat, but with an available route of escape, whereas "attack" was chosen in an unambiguous, intense and close dangerous situation without an escape route. Less urgent behaviors, such as "check out", were chosen in scenarios evaluated as less intense, more distant and more ambiguous. Moreover, the results from the Brazilian sample were similar to the results obtained in the original study with Hawaiian students. These data suggest that a basic repertoire of defensive strategies is conserved along the mammalian evolution because they share similar functional benefits in maintaining fitness.

  20. Surveillance-activated defenses block the ROS-induced mitochondrial unfolded protein response.

    Directory of Open Access Journals (Sweden)

    Eva D Runkel

    Full Text Available Disturbance of cellular functions results in the activation of stress-signaling pathways that aim at restoring homeostasis. We performed a genome-wide screen to identify components of the signal transduction of the mitochondrial unfolded protein response (UPR(mt to a nuclear chaperone promoter. We used the ROS generating complex I inhibitor paraquat to induce the UPR(mt, and we employed RNAi exposure post-embryonically to allow testing genes whose knockdown results in embryonic lethality. We identified 54 novel regulators of the ROS-induced UPR(mt. Activation of the UPR(mt, but not of other stress-signaling pathways, failed when homeostasis of basic cellular mechanisms such as translation and protein transport were impaired. These mechanisms are monitored by a recently discovered surveillance system that interprets interruption of these processes as pathogen attack and depends on signaling through the JNK-like MAP-kinase KGB-1. Mutation of kgb-1 abrogated the inhibition of ROS-induced UPR(mt, suggesting that surveillance-activated defenses specifically inhibit the UPR(mt but do not compromise activation of the heat shock response, the UPR of the endoplasmic reticulum, or the SKN-1/Nrf2 mediated response to cytosolic stress. In addition, we identified PIFK-1, the orthologue of the Drosophila PI 4-kinase four wheel drive (FWD, and found that it is the only known factor so far that is essential for the unfolded protein responses of both mitochondria and endoplasmic reticulum. This suggests that both UPRs may share a common membrane associated mechanism.

  1. Silicon induced systemic defense responses in perennial ryegrass against Magnaporthe oryzae infection

    Science.gov (United States)

    Sustainable integrated disease management for gray leaf spot of perennial ryegrass may involve use of plant defense elicitors with compatible traditional fungicides to reduce disease incidence and severity. Silicon (Si) is a potential inducer or modulator of plant defenses against different pathogen...

  2. Chemical defense, mycorrhizal colonization and growth responses in Plantago lanceolata L.

    NARCIS (Netherlands)

    De Deyn, G.B.; Biere, A.; Van der Putten, W.H.; Wagenaar, R.; Klironomos, J.N.

    2009-01-01

    Allelochemicals defend plants against herbivore and pathogen attack aboveground and belowground. Whether such plant defenses incur ecological costs by reducing benefits from plant mutualistic symbionts is largely unknown. We explored a potential trade-off between inherent plant chemical defense and

  3. Defensive Responses to Early Memories with Peers: a Possible Pathway to Disordered Eating.

    Science.gov (United States)

    Ferreira, Cláudia; Marta-Simões, Joana; Trindade, Inês A

    2016-07-18

    Childhood and early adolescence experiences, specifically those that provide an adulthood enriched with warm and safe memories, are consistently stated in literature as powerful emotional regulators. In contrast, individuals who scarcely recall positive experiences may begin to believe that others see the self as inferior, inadequate and unattractive. In order to cope with a perceived loss of social desirability and achieve other's acceptance, individuals may become submissive, and women, particularly, may resort to the presentation of a perfect body image. Both mechanisms are defensive responses suggested to be associated with mental health difficulties, particularly disordered eating behaviors. The present study aimed at exploring the association between early memories of warmth and safeness with peers and eating psychopathology. Also, a path analysis was conducted to investigate the mediator role of submissiveness and perfectionistic self-presentation focused on body image on this association, in a sample of 342 female students. Results revealed that the absence of early positive memories with peers holds a significant effect over eating psychopathology's severity, and also that this effect is mediated through submissiveness and body image-related perfectionistic self-presentation. This model accounted for 13%, 19% and 51% of submissiveness, perfectionistic self-presentation of body image and eating psychopathology's variances, respectively, and showed excellent model fit.

  4. Identification and validation of reference genes for transcript normalization in strawberry (Fragaria × ananassa) defense responses.

    Science.gov (United States)

    Amil-Ruiz, Francisco; Garrido-Gala, José; Blanco-Portales, Rosario; Folta, Kevin M; Muñoz-Blanco, Juan; Caballero, José L

    2013-01-01

    Strawberry (Fragaria spp) is an emerging model for the development of basic genomics and recombinant DNA studies among rosaceous crops. Functional genomic and molecular studies involve relative quantification of gene expression under experimental conditions of interest. Accuracy and reliability are dependent upon the choice of an optimal reference control transcript. There is no information available on validated endogenous reference genes for use in studies testing strawberry-pathogen interactions. Thirteen potential pre-selected strawberry reference genes were tested against different tissues, strawberry cultivars, biotic stresses, ripening and senescent conditions, and SA/JA treatments. Evaluation of reference candidate's suitability was analyzed by five different methodologies, and information was merged to identify best reference transcripts. A combination of all five methods was used for selective classification of reference genes. The resulting superior reference genes, FaRIB413, FaACTIN, FaEF1α and FaGAPDH2 are strongly recommended as control genes for relative quantification of gene expression in strawberry. This report constitutes the first systematic study to identify and validate optimal reference genes for accurate normalization of gene expression in strawberry plant defense response studies.

  5. Thc6 protein, isolated from Trichoderma harzianum, can induce maize defense response against Curvularia lunata.

    Science.gov (United States)

    Fan, Lili; Fu, Kehe; Yu, Chuanjin; Li, Yingying; Li, Yaqian; Chen, Jie

    2015-05-01

    Mutant T66 was isolated from 450 mutants (constructed with Agrobacterium tumefaciens-mediated transformation method) of Trichoderma harzianum. Maize seeds coated with T66 were more susceptible to Curvularia lunata when compared with those coated with wild-type (WT) strain. The disease index of maize treated with T66 and WT were 62.5 and 42.1%, respectively. Further research showed T-DNA has inserted into the ORF of one gene, which resulted in the functional difference between WT and T66. The gene was cloned and named Thc6, which encodes a novel 327 amino acid protein. To investigate its function, we obtained knockout, complementation, and overexpression mutants of Thc6. Challenge inoculation studies suggested that the Thc6 overexpression mutant can reduce the disease index of maize inbred line Huangzao 4 against the leaf spot pathogen (C. lunata). Meanwhile, The Thc6 mutants were found to affect the resistance of maize inbred line Huangzao 4 against C. lunata by enhancing the activation of jasmonate-responsive genes expression. Liquid chromatography-mass spectrometry (LC-MS) data further confirmed that the concentration of jasmonate in the induced maize exhibits a parallel change tendency with the expression level of defense-related genes. Hence, the Thc6 gene could be participated in the induced resistance of maize inbred line Huangzao 4 against C. lunata infection through a jasmonic acid-dependent pathway. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Triggering DTH and CTL activity by fd filamentous bacteriophages: role of CD4+ T cells in memory responses.

    Science.gov (United States)

    Del Pozzo, Giovanna; Mascolo, Dina; Sartorius, Rossella; Citro, Alessandra; Barba, Pasquale; D'Apice, Luciana; De Berardinis, Piergiuseppe

    2010-01-01

    The ability of fd bacteriophage particles to trigger different arms of the immune system has been previously shown by us with particular emphasis on the ability of phages to raise CTL responses in vitro and in vivo. Here we show that fd virions in the absence of adjuvants are able to evoke a DTH reaction mediated by antigen specific CD8+ T cells. In addition, we analyzed the induction of CTL responses in mice depleted of CD4+ T cells, and we observed that short-term secondary CTL responses were induced in the absence of CD4+ T cells while induction of long-term memory CTLs required the presence of CD4+ T lymphocytes. These results examine the cellular mechanism at the basis of fd efficiency and provide new elements to further validate the use of fd particles for eliciting and monitoring antigen-specific CTLs.

  7. The mosquito melanization response is implicated in defense against the entomopathogenic fungus Beauveria bassiana.

    Directory of Open Access Journals (Sweden)

    Hassan Yassine

    Full Text Available Mosquito immunity studies have focused mainly on characterizing immune effector mechanisms elicited against parasites, bacteria and more recently, viruses. However, those elicited against entomopathogenic fungi remain poorly understood, despite the ubiquitous nature of these microorganisms and their unique invasion route that bypasses the midgut epithelium, an important immune tissue and physical barrier. Here, we used the malaria vector Anopheles gambiae as a model to investigate the role of melanization, a potent immune effector mechanism of arthropods, in mosquito defense against the entomopathogenic fungus Beauveria bassiana, using in vivo functional genetic analysis and confocal microscopy. The temporal monitoring of fungal growth in mosquitoes injected with B. bassiana conidia showed that melanin eventually formed on all stages, including conidia, germ tubes and hyphae, except the single cell hyphal bodies. Nevertheless, melanin rarely aborted the growth of any of these stages and the mycelium continued growing despite being melanized. Silencing TEP1 and CLIPA8, key positive regulators of Plasmodium and bacterial melanization in A. gambiae, abolished completely melanin formation on hyphae but not on germinating conidia or germ tubes. The detection of a layer of hemocytes surrounding germinating conidia but not hyphae suggested that melanization of early fungal stages is cell-mediated while that of late stages is a humoral response dependent on TEP1 and CLIPA8. Microscopic analysis revealed specific association of TEP1 with surfaces of hyphae and the requirement of both, TEP1 and CLIPA8, for recruiting phenoloxidase to these surfaces. Finally, fungal proliferation was more rapid in TEP1 and CLIPA8 knockdown mosquitoes which exhibited increased sensitivity to natural B. bassiana infections than controls. In sum, the mosquito melanization response retards significantly B. bassiana growth and dissemination, a finding that may be exploited to

  8. Corn defense responses to nitrogen availability and subsequent performance and feeding preferences of beet armyworm (Lepidoptera: Noctuidae).

    Science.gov (United States)

    Ren, Li-Li; Hardy, Giles; Liu, Zhu-Dong; Wei, Wei; Dai, Hua-Guo

    2013-06-01

    Many studies have reported the effect of nitrogen (N) fertilization on plant constitutive defense responses; however, little is known about their effects on plant induced defense patterns and its consequence for insect herbivores. In our experiments, the effects of N availability on growth, nutritional quality (N content, protein/carbohydrate [P:C] ratio, modified gross energy [MGE]), and constitutive phenolics of corn, Zea mays L. were quantified. Moreover, the indirect effects of N fertilization on the beet armyworm, Spodoptera exigua Hübner through larval performance and feeding preference were examined. N fertilization increased plant growth, and depressed defense traits by increasing N content and the P:C ratio, as well as decreasing the constitutive concentration of phenolics. Subsequently, beet armyworm showed higher performance and preferentially fed on high-N corn because of its low defense traits. After beet armyworm feeding, high-N corn significantly deterred larval feeding, and had negative effects on the performance of beet armyworm through decreasing P:C ratio and increasing induced phenolics. On the contrary, there were no significant changes in P:C ratio and phenolics in low-N corn after feeding damage. Larval performance and preference were also not affected by induced compounds in low-N corn, which suggested that the expression of induced defense was dependent on N availability. The result indicates that N availability can exert a variety of bottom-up effect on plant defense patterns to influence insect population dynamics, and thereby may represent a source of variation in plant-insect interactions.

  9. Signaling in plant resistance responses: divergence and cross-talk of defense pathways

    NARCIS (Netherlands)

    Pieterse, C.M.J.; Schaller, A.; Mauch-Mani, B.; Conrath, U.

    2006-01-01

    Plants possess inducible defense mechanisms to protect themselves against attack by microbial pathogens and herbivorous insects. The endogenous signalling molecules salicylic acid, ethylene, and jasmonic acid, and the peptide messenger systemin play important roles in the regulation of these induced

  10. Proteomic analysis of the defense response of wheat to the powdery mildew fungus, Blumeria graminis f. sp. tritici.

    Science.gov (United States)

    Mandal, Md Siddikun Nabi; Fu, Ying; Zhang, Sheng; Ji, Wanquan

    2014-12-01

    Powdery mildew of wheat is caused by Blumeria graminis f. sp. tritici (Bgt). Although many wheat cultivars resistant to this disease have been developed, little is known about their resistance mechanisms. The aim of this study was to identify proteins showing changes in abundance during the resistance response of the wheat line N0308 infected by Bgt. In two-dimensional electrophoresis analyses, 45 spots on the gels showed significant changes in abundance at 24, 48, and 72 h after inoculation, as compared to non-inoculated plants. Of these 45 proteins, 44 were identified by mass spectrometry analysis using the NCBInr database of Triticum aestivum (26 spots) and closely related species in the Triticum genus (18 spots). These proteins were associated with the defense response, photosynthesis, metabolism, and other cellular processes in wheat. Most of the up-regulated proteins were identified as stress- and defense-related proteins. In particular, the product of a specific powdery mildew resistance gene (Pm3b and its homolog) and some other defense- and pathogenesis-related proteins were overexpressed. The resistance gene product mediates the immune response and coordinates other cellular processes during the resistance response to Bgt.

  11. Metallothionein-mediated antioxidant defense system and its response to exercise training are impaired in human type 2 diabetes

    DEFF Research Database (Denmark)

    Scheede-Bergdahl, Celena; Penkowa, Milena; Hidalgo, Juan

    2005-01-01

    the MT-I+II-mediated antioxidant capacity and its response to exercise training in the skeletal muscle of patients with type 2 diabetes, biopsies and blood samples were taken from 13 matched subjects (type 2 diabetes n = 8, control subjects n = 5) both before and after 8 weeks of exercise training......-I+II in muscle and plasma, as well as the deficient MT-I+II response to exercise, indicate that this antioxidant defense is impaired. This study presents a novel candidate in the pathogenesis of complications related to oxidative stress in type 2 diabetes.......Oxidative stress is implicated in diabetes complications, during which endogenous antioxidant defenses have important pathophysiological consequences. To date, the significance of endogenous antioxidants such as metallothioneins I and II (MT-I+II) in type 2 diabetes remains unclear. To examine...

  12. Copper Uptake in Mammary Epithelial Cells Activates Cyclins and Triggers Antioxidant Response

    Directory of Open Access Journals (Sweden)

    Nathália Villa dos Santos

    2015-01-01

    Full Text Available The toxicologic effects of copper (Cu on tumor cells have been studied during the past decades, and it is suggested that Cu ion may trigger antiproliferative effects in vitro. However, in normal cells the toxicologic effects of high exposures of free Cu are not well understood. In this work, Cu uptake, the expression of genes associated with cell cycle regulation, and the levels of ROS production and related oxidative processes were evaluated in Cu-treated mammary epithelial MCF10A nontumoral cells. We have shown that the Cu additive is associated with the activation of cyclin D1 and cyclin B1, as well as cyclin-dependent kinase 2 (CDK2. These nontumor cells respond to Cu-induced changes in the oxidative balance by increase of the levels of reduced intracellular glutathione (GSH, decrease of reactive oxygen species (ROS generation, and accumulation during progression of the cell cycle, thus preventing the cell abnormal proliferation or death. Taken together, our findings revealed an effect that contributes to prevent a possible damage of normal cells exposed to chemotherapeutic effects of drugs containing the Cu ion.

  13. Stress-Triggered Phase Separation Is an Adaptive, Evolutionarily Tuned Response

    Energy Technology Data Exchange (ETDEWEB)

    Riback, Joshua A.; Katanski, Christopher D.; Kear-Scott, Jamie L.; Pilipenko, Evgeny V.; Rojek, Alexandra E.; Sosnick, Tobin R.; Drummond, D. Allan

    2017-03-01

    In eukaryotic cells, diverse stresses trigger coalescence of RNA-binding proteins into stress granules. In vitro, stress-granule-associated proteins can demix to form liquids, hydrogels, and other assemblies lacking fixed stoichiometry. Observing these phenomena has generally required conditions far removed from physiological stresses. We show that poly(A)-binding protein (Pab1 in yeast), a defining marker of stress granules, phase separates and forms hydrogels in vitro upon exposure to physiological stress conditions. Other RNA-binding proteins depend upon low-complexity regions (LCRs) or RNA for phase separation, whereas Pab1’s LCR is not required for demixing, and RNA inhibits it. Based on unique evolutionary patterns, we create LCR mutations, which systematically tune its biophysical properties and Pab1 phase separation in vitro and in vivo. Mutations that impede phase separation reduce organism fitness during prolonged stress. Poly(A)-binding protein thus acts as a physiological stress sensor, exploiting phase separation to precisely mark stress onset, a broadly generalizable mechanism.

  14. Different Narrow-Band Light Ranges Alter Plant Secondary Metabolism and Plant Defense Response to Aphids.

    Science.gov (United States)

    Rechner, Ole; Neugart, Susanne; Schreiner, Monika; Wu, Sasa; Poehling, Hans-Michael

    2016-10-01

    Light of different wavelengths affects various physiological processes in plants. Short-wavelength radiation (like UV) can activate defense pathways in plants and enhance the biosynthesis of secondary metabolites (such as flavonoids and glucosinolates) responsible for resistance against certain herbivorous insects. The intensity of light-induced, metabolite-based resistance is plant- and insect species-specific and depends on herbivore feeding guild and specialization. In this study, broccoli (Brassica oleracea var. italica) plants were grown for 4 weeks in a climate chamber under conventional fluorescent tubes and were additionally treated with UV-B (310 nm), UV-A (365 or 385 nm), or violet (420 nm) light generated with UV-B tubes or light-emitting diodes (LEDs). The objective was to determine the influence of narrow bandwidths of light (from UV-B to violet) on plant secondary metabolism and on the performance of the cabbage aphid Brevicoryne brassicae (a specialist) and the green peach aphid Myzus persicae (a generalist). Among flavonol glycosides, specific quercetin and kaempferol glycosides increased markedly under UV-B, while among glucosinolates only 4-methoxy-3-indolylmethyl showed a 2-fold increase in plants exposed to UV-B and UV-A. The concentration of 3-indolylmethyl glucosinolate in broccoli plants increased with UV-B treatment. Brevicoryne brassicae adult weights and fecundity were lower on UV-B treated plants compared to UV-A or violet light-treated plants. Adult weights and fecundity of M. persicae were increased under UV-B and UV-A treatments. When specific light wavelengths are used to induce metabolic changes in plants, the specificity of the induced effects on herbivores should be considered.

  15. Response of winter chemical defense in Alaska paper birch and green alder to manipulation of plant carbon/nutrient balance.

    Science.gov (United States)

    Bryant, J P; Chapin, F S; Reichardt, P B; Clausen, T P

    1987-07-01

    Plant carbon/nutrient balance has been implicated as an important factor in plant defensive chemistry and palatability to herbivores. We tested this hypothesis by fertilizing juvenile growth form Alaska paper birch and green alder with N, P and N-plus-P in a balanced 2x2 factorial experiment. Additionally, we shaded unfertilized plants of both species. Fertilization with N and N-plus-P increased growth of Alaska paper birch, reduced the concentration of papyriferic acid in internodes and increased the palatability of birch twigs to snowshoe hares. Shading decreased birch growth, decreased the concentration of papyriferic acid in internodes and increased twig palatability. These results indicate that the defensive chemistry and palatability of winter-dormant juvenile Alaska paper birch are sensitive to soil fertility and shade. Conversely the defensive chemistry and palatability of green alder twigs to snowshoe hares were not significantly affected by soil fertility or shade. The greater sensitivity of Alaska paper birch defensive chemistry and palatability to snowshoe hares in comparison to green alder is in agreement with the hypothesis that early successional woody plants that are adapted to high resource availability are more plastic in their chemical responses to the physical environment than are species from less favorable environments.

  16. How Streptomyces anulatus Primes Grapevine Defenses to Cope with Gray Mold: A Study of the Early Responses of Cell Suspensions.

    Science.gov (United States)

    Vatsa-Portugal, Parul; Aziz, Aziz; Rondeau, Marine; Villaume, Sandra; Morjani, Hamid; Clément, Christophe; Ait Barka, Essaid

    2017-01-01

    Gray mold, caused by Botrytis cinerea , is one of the most destructive diseases of grapevine and is controlled with an intense application of fungicides. As alternatives to chemicals, beneficial microbes may promote plant health by stimulating the plant's immune system. An actinomycete, Streptomyces anulatus S37, has been screened from the rhizosphere microbiome of healthy Vitis vinifera on the basis of its ability to promote grapevine growth and to induce resistance against various phytopathogens, including B. cinerea . However, molecular mechanisms involved locally after direct perception of these bacteria by plant cells still remain unknown. This study focuses on local defense events induced in grapevine cells during interactions with S. anulatus S37 before and after pathogen challenge. We demonstrated that S. anulatus S37 induced early responses including oxidative burst, extracellular alkalinization, activation of protein kinases, induction of defense gene expression and phytoalexin accumulation, but not the programmed cell death. Interestingly, upon challenge with the B. cinerea , the S. anulatus S37 primed grapevine cells for enhanced defense reactions with a decline in cell death. In the presence of the EGTA, a calcium channel inhibitor, the induced oxidative burst, and the protein kinase activity were inhibited, but not the extracellular alkalinization, suggesting that Ca 2+ may also contribute upstream to the induced defenses. Moreover, desensitization assays using extracellular pH showed that once increased by S. anulatus S37, cells became refractory to further stimulation by B. cinerea , suggesting that grapevine cells perceive distinctly beneficial and pathogenic microbes.

  17. How Streptomyces anulatus Primes Grapevine Defenses to Cope with Gray Mold: A Study of the Early Responses of Cell Suspensions

    Directory of Open Access Journals (Sweden)

    Parul Vatsa-Portugal

    2017-06-01

    Full Text Available Gray mold, caused by Botrytis cinerea, is one of the most destructive diseases of grapevine and is controlled with an intense application of fungicides. As alternatives to chemicals, beneficial microbes may promote plant health by stimulating the plant’s immune system. An actinomycete, Streptomyces anulatus S37, has been screened from the rhizosphere microbiome of healthy Vitis vinifera on the basis of its ability to promote grapevine growth and to induce resistance against various phytopathogens, including B. cinerea. However, molecular mechanisms involved locally after direct perception of these bacteria by plant cells still remain unknown. This study focuses on local defense events induced in grapevine cells during interactions with S. anulatus S37 before and after pathogen challenge. We demonstrated that S. anulatus S37 induced early responses including oxidative burst, extracellular alkalinization, activation of protein kinases, induction of defense gene expression and phytoalexin accumulation, but not the programmed cell death. Interestingly, upon challenge with the B. cinerea, the S. anulatus S37 primed grapevine cells for enhanced defense reactions with a decline in cell death. In the presence of the EGTA, a calcium channel inhibitor, the induced oxidative burst, and the protein kinase activity were inhibited, but not the extracellular alkalinization, suggesting that Ca2+ may also contribute upstream to the induced defenses. Moreover, desensitization assays using extracellular pH showed that once increased by S. anulatus S37, cells became refractory to further stimulation by B. cinerea, suggesting that grapevine cells perceive distinctly beneficial and pathogenic microbes.

  18. The rice hydroperoxide lyase OsHPL3 functions in defense responses by modulating the oxylipin pathway.

    Science.gov (United States)

    Tong, Xiaohong; Qi, Jinfeng; Zhu, Xudong; Mao, Bizeng; Zeng, Longjun; Wang, Baohui; Li, Qun; Zhou, Guoxin; Xu, Xiaojing; Lou, Yonggen; He, Zuhua

    2012-09-01

    As important signal molecules, jasmonates (JAs) and green leaf volatiles (GLVs) play diverse roles in plant defense responses against insect pests and pathogens. However, how plants employ their specific defense responses by modulating the levels of JA and GLVs remains unclear. Here, we describe identification of a role for the rice HPL3 gene, which encodes a hydroperoxide lyase (HPL), OsHPL3/CYP74B2, in mediating plant-specific defense responses. The loss-of-function mutant hpl3-1 produced disease-resembling lesions spreading through the whole leaves. A biochemical assay revealed that OsHPL3 possesses intrinsic HPL activity, hydrolyzing hydroperoxylinolenic acid to produce GLVs. The hpl3-1 plants exhibited enhanced induction of JA, trypsin proteinase inhibitors and other volatiles, but decreased levels of GLVs including (Z)-3-hexen-1-ol. OsHPL3 positively modulates resistance to the rice brown planthopper [BPH, Nilaparvata lugens (Stål)] but negatively modulates resistance to the rice striped stem borer [SSB, Chilo suppressalis (Walker)]. Moreover, hpl3-1 plants were more attractive to a BPH egg parasitoid, Anagrus nilaparvatae, than the wild-type, most likely as a result of increased release of BPH-induced volatiles. Interestingly, hpl3-1 plants also showed increased resistance to bacterial blight (Xanthomonas oryzae pv. oryzae). Collectively, these results indicate that OsHPL3, by affecting the levels of JA, GLVs and other volatiles, modulates rice-specific defense responses against different invaders. © 2012 The Authors. The Plant Journal © 2012 Blackwell Publishing Ltd.

  19. A maize landrace that emits defense volatiles in response to?herbivore eggs possesses a strongly inducible terpene synthase gene

    OpenAIRE

    Tamiru, Amanuel; Bruce, Toby J. A.; Richter, Annett; Woodcock, Christine M.; Midega, Charles A. O.; Degenhardt, J?rg; Kelemu, Segenet; Pickett, John A.; Khan, Zeyaur R.

    2017-01-01

    Maize (Zea mays) emits volatile terpenes in response to insect feeding and egg deposition\\ud to defend itself against harmful pests. However, maize cultivars differ strongly in\\ud their ability to produce the defense signal. To further understand the agroecological\\ud role and underlying genetic mechanisms for variation in terpene emission among\\ud maize cultivars, we studied the production of an important signaling component (E)-caryophyllene\\ud in a South American maize landrace Braz1006 po...

  20. Self-Reported Pleasantness Ratings and Examiner-Coded Defensiveness in Response to Touch in Children with ASD: Effects of Stimulus Material and Bodily Location

    Science.gov (United States)

    Cascio, Carissa J.; Lorenzi, Jill; Baranek, Grace T.

    2016-01-01

    Tactile defensiveness, characterized by behavioral hyperresponsiveness and negative emotional responses to touch, is a common manifestation of aberrant sensory processing in autism spectrum disorders (ASD) and other developmental disabilities (DD). Variations in tactile defensiveness with the properties of the stimulus and the bodily site of…

  1. The Thrombin-Derived Host Defense Peptide GKY25 Inhibits Endotoxin-Induced Responses through Interactions with Lipopolysaccharide and Macrophages/Monocytes

    DEFF Research Database (Denmark)

    Hansen, Finja C; Kalle-Brune, Martina; van der Plas, Mariena J A

    2015-01-01

    Host defense peptides have recently gained much interest as novel anti-infectives owing to their ability to kill bacteria and simultaneously modulate host cell responses. The cationic host defense peptide GKY25 (GKYGFYTHVFRLKKWIQKVIDQFGE), derived from the C terminus of human thrombin, inhibits p...

  2. Heat treatment in combination with antagonistic yeast reduces diseases and elicits the active defense responses in harvested cherry tomato fruit.

    Science.gov (United States)

    Zhao, Yan; Tu, Kang; Su, Jing; Tu, Sicong; Hou, Yuepeng; Liu, Fengjuan; Zou, Xiurong

    2009-08-26

    This study investigated the effects of heat treatment (hot air at 38 degrees C) and antagonistic yeast (Pichia guilliermondii) alone or in combination against postharvest diseases (Botrytis cinerea, Alternaria alternata and Rhizopus nigricans) on cherry tomato fruit, and evaluated the elicitation of active defense responses. Results showed that heat treatment at 38 degrees C for 24 h in combination with P. guilliermondii at 1 x 10(8) CFU mL(-1) was the most effective approach to reduce various infections on cherry tomato fruit's wounds. Moreover, the combined heat and P. guilliermondii treatment stimulated a rapid increase of H(2)O(2) and higher lignin deposition in cherry tomato fruit showing that the oxidative burst and biological synthesis of lignin might play important roles in the fruit's active defense responses. In addition, the reduction of the fruit's susceptibility to pathogens by the combined treatment was positively correlated with higher activities of phenylalanine ammonia-lyase (PAL) and beta-1,3-glucanase in cherry tomato fruits, both of which are associated with plant defense responses.

  3. Mycobacteria attenuate nociceptive responses by formyl peptide receptor triggered opioid peptide release from neutrophils.

    Directory of Open Access Journals (Sweden)

    Heike L Rittner

    2009-04-01

    Full Text Available In inflammation, pain is regulated by a balance of pro- and analgesic mediators. Analgesic mediators include opioid peptides which are secreted by neutrophils at the site of inflammation, leading to activation of opioid receptors on peripheral sensory neurons. In humans, local opioids and opioid peptides significantly downregulate postoperative as well as arthritic pain. In rats, inflammatory pain is induced by intraplantar injection of heat inactivated Mycobacterium butyricum, a component of complete Freund's adjuvant. We hypothesized that mycobacterially derived formyl peptide receptor (FPR and/or toll like receptor (TLR agonists could activate neutrophils, leading to opioid peptide release and inhibition of inflammatory pain. In complete Freund's adjuvant-induced inflammation, thermal and mechanical nociceptive thresholds of the paw were quantified (Hargreaves and Randall-Selitto methods, respectively. Withdrawal time to heat was decreased following systemic neutrophil depletion as well as local injection of opioid receptor antagonists or anti-opioid peptide (i.e. Met-enkephalin, beta-endorphin antibodies indicating an increase in pain. In vitro, opioid peptide release from human and rat neutrophils was measured by radioimmunoassay. Met-enkephalin release was triggered by Mycobacterium butyricum and formyl peptides but not by TLR-2 or TLR-4 agonists. Mycobacterium butyricum induced a rise in intracellular calcium as determined by FURA loading and calcium imaging. Opioid peptide release was blocked by intracellular calcium chelation as well as phosphoinositol-3-kinase inhibition. The FPR antagonists Boc-FLFLF and cyclosporine H reduced opioid peptide release in vitro and increased inflammatory pain in vivo while TLR 2/4 did not appear to be involved. In summary, mycobacteria activate FPR on neutrophils, resulting in tonic secretion of opioid peptides from neutrophils and in a decrease in inflammatory pain. Future therapeutic strategies may aim

  4. Atrazine Triggers DNA Damage Response and Induces DNA Double-Strand Breaks in MCF-10A Cells

    Directory of Open Access Journals (Sweden)

    Peixin Huang

    2015-06-01

    Full Text Available Atrazine, a pre-emergent herbicide in the chloro-s-triazine family, has been widely used in crop lands and often detected in agriculture watersheds, which is considered as a potential threat to human health. Although atrazine and its metabolites showed an elevated incidence of mammary tumors in female Sprague–Dawley (SD rats, no molecular evidence was found relevant to its carcinogenesis in humans. This study aims to determine whether atrazine could induce the expression of DNA damage response-related proteins in normal human breast epithelial cells (MCF-10A and to examine the cytotoxicity of atrazine at a molecular level. Our results indicate that a short-term exposure of MCF-10A to an environmentally-detectable concentration of atrazine (0.1 µg/mL significantly increased the expression of tumor necrosis factor receptor-1 (TNFR1 and phosphorylated Rad17 in the cells. Atrazine treatment increased H2AX phosphorylation (γH2AX and the formation of γH2AX foci in the nuclei of MCF-10A cells. Atrazine also sequentially elevated DNA damage checkpoint proteins of ATM- and RAD3-related (ATR, ATRIP and phospho-Chk1, suggesting that atrazine could induce DNA double-strand breaks and trigger the DNA damage response ATR-Chk1 pathway in MCF-10A cells. Further investigations are needed to determine whether atrazine-triggered DNA double-strand breaks and DNA damage response ATR-Chk1 pathway occur in vivo.

  5. Trigger finger

    Science.gov (United States)

    ... digit; Trigger finger release; Locked finger; Digital flexor tenosynovitis ... cut or hand Yellow or green drainage from the cut Hand pain or discomfort Fever If your trigger finger returns, call your surgeon. You may need another surgery.

  6. Comparison of Fusarium graminearum transcriptomes on living or dead wheat differentiates substrate-responsive and defense-responsive genes.

    Directory of Open Access Journals (Sweden)

    Stefan Boedi

    2016-07-01

    Full Text Available Fusarium graminearum is an opportunistic pathogen of cereals where it causes severe yield losses and concomitant mycotoxin contamination of the grains. The pathogen has mixed biotrophic and necrotrophic (saprophytic growth phases during infection and the regulatory networks associated with these phases have so far always been analyzed together. In this study we compared the transcriptomes of fungal cells infecting a living, actively defending plant representing the mixed live style (pathogenic growth on living flowering wheat heads to the response of the fungus infecting identical, but dead plant tissues (cold-killed flowering wheat heads representing strictly saprophytic conditions. We found that the living plant actively suppressed fungal growth and promoted much higher toxin production in comparison to the identical plant tissue without metabolism suggesting that molecules signaling secondary metabolite induction are not pre-existing or not stable in the plant in sufficient amounts before infection. Differential gene expression analysis was used to define gene sets responding to the active or the passive plant as main impact factor and driver for gene expression. We correlated our results to the published F. graminearum transcriptomes, proteomes and secretomes and found that only a limited number of in planta- expressed genes require the living plant for induction but the majority uses simply the plant tissue as signal. Many secondary metabolite (SM gene clusters show a heterogeneous expression pattern within the cluster indicating that different genetic or epigenetic signals govern the expression of individual genes within a physically linked cluster. Our bioinformatic approach also identified fungal genes which were actively repressed by signals derived from the active plant and may thus represent direct targets of the plant defense against the invading pathogen.

  7. Pretreatment anxiety and pain acceptance are associated with response to trigger point injection therapy for chronic myofascial pain.

    Science.gov (United States)

    Healy, Gerard M; Finn, David P; O'Gorman, David A; Maharaj, Chris; Raftery, Miriam; Ruane, Nancy; Mitchell, Caroline; Sarma, Kiran; Bohacek, Marek; McGuire, Brian E

    2015-10-01

    This study examined the psychosocial profile of patients who responded or did not respond to trigger point injection therapy for chronic myofascial pain. Seventy one patients with a diagnosis of chronic myofascial pain of the paraspinous muscles completed a pretreatment questionnaire measuring demographic and social factors, and validated scales to assess pain intensity, pain interference (physical and emotional), and defined psychological characteristics (pain catastrophizing, pain acceptance, pain self-efficacy, mood and anxiety). Trigger point injection therapy of the affected areas of myofascial pain was performed and follow-up was conducted by telephone at one week (n = 65) and one month (n = 63) post intervention to assess treatment outcome (pain intensity and pain-related physical interference). At one week follow-up and one-month follow-up, using pain-related physical interference as the outcome measure, we found that those who responded well to treatment were characterized by a lower level of pretreatment anxiety and a higher level of pain acceptance, with anxiety being the strongest predictor. These results suggest that responses to interventional pain management in chronic myofascial paraspinous pain may be influenced by psychological characteristics, especially pretreatment anxiety. Wiley Periodicals, Inc.

  8. Systemic above- and belowground cross talk: hormone-based responses triggered by Heterodera schachtii and shoot herbivores in Arabidopsis thaliana

    Science.gov (United States)

    Kammerhofer, Nina; Egger, Barbara; Dobrev, Petre; Vankova, Radomira; Hofmann, Julia; Schausberger, Peter; Wieczorek, Krzysztof

    2015-01-01

    Above- and belowground plant parts are simultaneously attacked by different pests and pathogens. The host mediates these interactions and physiologically reacts, e.g. with local and systemic alterations of endogenous hormone levels coupled with coordinated transcriptional changes. This in turn affects attractiveness and susceptibility of the plant to subsequent attackers. Here, the model plant Arabidopsis thaliana is used to study stress hormone-based systemic responses triggered by simultaneous root parasitism by the cyst nematode Heterodera schachtii and shoot herbivory by the thrips Frankliniella occidentalis and the spider mite Tetranychus urticae. First, HPLC/MS and quantitative reverse transcriptase PCR are used to show that nematode parasitism strongly affects stress hormone levels and expression of hormone marker genes in shoots. Previous nematode infection is then demonstrated to affect the behavioural and life history performance of both arthropods. While thrips explicitly avoid nematode-infected plants, spider mites prefer them. In addition, the life history performance of T. urticae is significantly enhanced by nematode infection. Finally, systemic changes triggered by shoot-feeding F. occidentalis but not T. urticae are shown to make the roots more attractive for H. schachtii. This work emphasises the importance of above- and belowground signalling and contributes to a better understanding of plant systemic defence mechanisms against plant-parasitic nematodes. PMID:26324462

  9. Reducing contingent self-worth: a defensive response to self-threats.

    Science.gov (United States)

    Buckingham, Justin; Lam, Tiffany A; Andrade, Fernanda C; Boring, Brandon L; Emery, Danielle

    2018-04-10

    Previous research shows that people with high self-esteem cope with threats to the self by reducing the extent to which their self-worth is contingent on the threatened domain (Buckingham, Weber, & Sypher, 2012). The present studies tested the hypothesis that this is a defensive process. In support of this hypothesis, Study 1 (N = 160), showed that self-affirmation attenuates the tendency for people with high self-esteem to reduce their contingencies of self-worth following self-threat. Furthermore, Study 2 (N = 286), showed that this tendency was more prevalent among people with defensive self-esteem than among those with secure self-esteem. The present studies imply that reducing contingent self-worth after self-threat is a defensive process. We discuss implications for theories of contingent self-worth.

  10. A PR-4 gene identified from Malus domestica is involved in the defense responses against Botryosphaeria dothidea.

    Science.gov (United States)

    Bai, Suhua; Dong, Chaohua; Li, Baohua; Dai, Hongyi

    2013-01-01

    Pathogenesis-related protein-4 (PR-4) family is a group of proteins with a Barwin domain in C-terminus and generally thought to be involved in plant defense responses. However, their detailed roles are poorly understood in defense of apple plant against pathogenic infection. In the present study, a new PR-4 gene (designated as MdPR-4) was identified from Malus domestica, and its roles in defense responses of apple were investigated. The open reading frame of MdPR-4 gene is of 447 bp encoding a protein of 148 amino acids with a Barwin domain in C-terminus and a signal peptide of 26 amino acids in N-terminus. Sequence and structural analysis indicated that MdPR-4 protein belongs to class II of PR-4 family. The high-level expression of MdPR-4 was observed in flowers and leaves as revealed by quantitative real time PCR. The temporal expression analysis demonstrated that MdPR-4 expression could be up-regulated by Botryosphaeria dothidea infection and salicylic acid (SA) or methyl jasmonate (MeJA) treatment, but suppressed by diethyldithiocarbamic acid (DIECA). In vitro assays, recombinant MdPR-4 protein exhibited ribonuclease activity specific for single strand RNA and significant inhibition to hyphal growth of three apple pathogenic fungi B. dothidea, Valsa ceratosperma and Glomerella cingulata. Moreover, the inhibition was reduced by the presence of 5'-ADP. Taken all together, the results indicate that MdPR-4 protein is involved in the defense responses of apple against pathogenic attack by directly inhibiting hyphal growth, and the inhibition is correlated with its ribonuclease activity, where as MdPR-4 expression is regulated by both SA and JA signaling pathway. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  11. Relative roles of the cellular and humoral responses in the Drosophila host defense against three gram-positive bacterial infections.

    Directory of Open Access Journals (Sweden)

    Nadine T Nehme

    2011-03-01

    Full Text Available Two NF-kappaB signaling pathways, Toll and immune deficiency (imd, are required for survival to bacterial infections in Drosophila. In response to septic injury, these pathways mediate rapid transcriptional activation of distinct sets of effector molecules, including antimicrobial peptides, which are important components of a humoral defense response. However, it is less clear to what extent macrophage-like hemocytes contribute to host defense.In order to dissect the relative importance of humoral and cellular defenses after septic injury with three different gram-positive bacteria (Micrococcus luteus, Enterococcus faecalis, Staphylococcus aureus, we used latex bead pre-injection to ablate macrophage function in flies wildtype or mutant for various Toll and imd pathway components. We found that in all three infection models a compromised phagocytic system impaired fly survival--independently of concomitant Toll or imd pathway activation. Our data failed to confirm a role of the PGRP-SA and GNBP1 Pattern Recognition Receptors for phagocytosis of S. aureus. The Drosophila scavenger receptor Eater mediates the phagocytosis by hemocytes or S2 cells of E. faecalis and S. aureus, but not of M. luteus. In the case of M. luteus and E. faecalis, but not S. aureus, decreased survival due to defective phagocytosis could be compensated for by genetically enhancing the humoral immune response.Our results underscore the fundamental importance of both cellular and humoral mechanisms in Drosophila immunity and shed light on the balance between these two arms of host defense depending on the invading pathogen.

  12. A transcriptomics approach uncovers novel roles for poly(ADP-ribosylation in the basal defense response in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Amy G Briggs

    Full Text Available Pharmacological inhibition of poly(ADP-ribose polymerase (PARP or loss of Arabidopsis thaliana PARG1 (poly(ADP-ribose glycohydrolase disrupt a subset of plant defenses. In the present study we examined the impact of altered poly(ADP-ribosylation on early gene expression induced by the microbe-associate molecular patterns (MAMPs flagellin (flg22 and EF-Tu (elf18. Stringent statistical analyses and filtering identified 178 genes having MAMP-induced mRNA abundance patterns that were altered by either PARP inhibitor 3-aminobenzamide (3AB or PARG1 knockout. From the identified set of 178 genes, over fifty Arabidopsis T-DNA insertion lines were chosen and screened for altered basal defense responses. Subtle alterations in callose deposition and/or seedling growth in response to those MAMPs were observed in knockouts of At3g55630 (FPGS3, a cytosolic folylpolyglutamate synthetase, At5g15660 (containing an F-box domain, At1g47370 (a TIR-X (Toll-Interleukin Receptor domain, and At5g64060 (a predicted pectin methylesterase inhibitor. Over-represented GO terms for the gene expression study included "innate immune response" for elf18/parg1, highlighting a subset of elf18-activated defense-associated genes whose expression is altered in parg1 plants. The study also allowed a tightly controlled comparison of early mRNA abundance responses to flg22 and elf18 in wild-type Arabidopsis, which revealed many differences. The PARP inhibitor 3-methoxybenzamide (3MB was also used in the gene expression profiling, but pleiotropic impacts of this inhibitor were observed. This transcriptomics study revealed targets for further dissection of MAMP-induced plant immune responses, impacts of PARP inhibitors, and the molecular mechanisms by which poly(ADP-ribosylation regulates plant responses to MAMPs.

  13. Lipogels responsive to near-infrared light for the triggered release of therapeutic agents

    NARCIS (Netherlands)

    Martín-Saavedra, Francisco; Ruiz-Hernández, Eduardo; Escudero-Duch, Clara; Prieto, Martín; Arruebo, Manuel; Sadeghi, Negar; Deckers, Roel|info:eu-repo/dai/nl/341697834; Storm, Gert|info:eu-repo/dai/nl/073356328; Hennink, Wim E.; Santamaría, Jesús; Vilaboa, Nuria

    2017-01-01

    Here we report a composite system based on fibrin hydrogels that incorporate in their structure near-infrared (NIR) responsive nanomaterials and thermosensitive liposomes (TSL). Polymerized fibrin networks entrap simultaneously gold-based nanoparticles (NPs) capable of transducing NIR photon energy

  14. Use of a test of perceived authenticity to trigger affective responses when testing food

    NARCIS (Netherlands)

    Boutrolle, I.; Delarue, J.; Köster, E.P.; Aranz, D.; Danzart, M.

    2009-01-01

    Food developers frequently check the liking for their recipes by asking consumers to state their preferences. This approach is often criticised for the lack of commitment of the participants and the artificiality of the hedonic response. This study tested whether an authenticity test could also be

  15. Coxsackievirus cloverleaf RNA containing a 5' triphosphate triggers an antiviral response via RIG-I activation

    NARCIS (Netherlands)

    Feng, Qian; Langereis, Martijn A; Olagnier, David; Chiang, Cindy; van de Winkel, Roel; van Essen, Peter; Zoll, Jan; Hiscott, John; van Kuppeveld, Frank J M

    2014-01-01

    Upon viral infections, pattern recognition receptors (PRRs) recognize pathogen-associated molecular patterns (PAMPs) and stimulate an antiviral state associated with the production of type I interferons (IFNs) and inflammatory markers. Type I IFNs play crucial roles in innate antiviral responses by

  16. Acrolein inhalation alters arterial blood gases and triggers carotid body-mediated cardiovascular responses in hypertensive rats.

    Science.gov (United States)

    Perez, Christina M; Hazari, Mehdi S; Ledbetter, Allen D; Haykal-Coates, Najwa; Carll, Alex P; Cascio, Wayne E; Winsett, Darrell W; Costa, Daniel L; Farraj, Aimen K

    2015-01-01

    Air pollution exposure affects autonomic function, heart rate, blood pressure and left ventricular function. While the mechanism for these effects is uncertain, several studies have reported that air pollution exposure modifies activity of the carotid body, the major organ that senses changes in arterial oxygen and carbon dioxide levels, and elicits downstream changes in autonomic control and cardiac function. We hypothesized that exposure to acrolein, an unsaturated aldehyde and mucosal irritant found in cigarette smoke and diesel exhaust, would activate the carotid body chemoreceptor response and lead to secondary cardiovascular responses in rats. Spontaneously hypertensive (SH) rats were exposed once for 3 h to 3 ppm acrolein gas or filtered air in whole body plethysmograph chambers. To determine if the carotid body mediated acrolein-induced cardiovascular responses, rats were pretreated with an inhibitor of cystathionine γ-lyase (CSE), an enzyme essential for carotid body signal transduction. Acrolein exposure induced several cardiovascular effects. Systolic, diastolic and mean arterial blood pressure increased during exposure, while cardiac contractility decreased 1 day after exposure. The cardiovascular effects were associated with decreases in pO2, breathing frequency and expiratory time, and increases in sympathetic tone during exposure followed by parasympathetic dominance after exposure. The CSE inhibitor prevented the cardiovascular effects of acrolein exposure. Pretreatment with the CSE inhibitor prevented the cardiovascular effects of acrolein, suggesting that the cardiovascular responses with acrolein may be mediated by carotid body-triggered changes in autonomic tone. (This abstract does not reflect EPA policy.).

  17. Prunus domestica pathogenesis-related protein-5 activates the defense response pathway and enhances the resistance to fungal infection.

    Science.gov (United States)

    El-kereamy, Ashraf; El-sharkawy, Islam; Ramamoorthy, Rengasamy; Taheri, Ali; Errampalli, Deena; Kumar, Prakash; Jayasankar, Subramanian

    2011-03-23

    Pathogenesis-related protein-5 (PR-5) has been implicated in plant disease resistance and its antifungal activity has been demonstrated in some fruit species. However, their roles, especially their interactions with the other defense responses in plant cells, are still not fully understood. In this study, we have cloned and characterized a new PR-5 cDNA named PdPR5-1 from the European plum (Prunus domestica). Expression of PdPR5-1 was studied in different cultivars varying in resistance to the brown rot disease caused by the necrotrophic fungus Monilinia fructicola. In addition transgenic Arabidopsis, ectopically expressing PdPR5-1 was used to study its role in other plant defense responses after fungal infection. We show that the resistant cultivars exhibited much higher levels of transcripts than the susceptible cultivars during fruit ripening. However, significant rise in the transcript levels after infection with M. fructicola was observed in the susceptible cultivars too. Transgenic Arabidopsis plants exhibited more resistance to Alternaria brassicicola. Further, there was a significant increase in the transcripts of genes involved in the phenylpropanoid biosynthesis pathway such as phenylalanine ammonia-lyase (PAL) and phytoalexin (camalexin) pathway leading to an increase in camalexin content after fungal infection. Our results show that PdPR5-1 gene, in addition to its anti-fungal properties, has a possible role in activating other defense pathways, including phytoalexin production.

  18. Prunus domestica pathogenesis-related protein-5 activates the defense response pathway and enhances the resistance to fungal infection.

    Directory of Open Access Journals (Sweden)

    Ashraf El-kereamy

    Full Text Available Pathogenesis-related protein-5 (PR-5 has been implicated in plant disease resistance and its antifungal activity has been demonstrated in some fruit species. However, their roles, especially their interactions with the other defense responses in plant cells, are still not fully understood. In this study, we have cloned and characterized a new PR-5 cDNA named PdPR5-1 from the European plum (Prunus domestica. Expression of PdPR5-1 was studied in different cultivars varying in resistance to the brown rot disease caused by the necrotrophic fungus Monilinia fructicola. In addition transgenic Arabidopsis, ectopically expressing PdPR5-1 was used to study its role in other plant defense responses after fungal infection. We show that the resistant cultivars exhibited much higher levels of transcripts than the susceptible cultivars during fruit ripening. However, significant rise in the transcript levels after infection with M. fructicola was observed in the susceptible cultivars too. Transgenic Arabidopsis plants exhibited more resistance to Alternaria brassicicola. Further, there was a significant increase in the transcripts of genes involved in the phenylpropanoid biosynthesis pathway such as phenylalanine ammonia-lyase (PAL and phytoalexin (camalexin pathway leading to an increase in camalexin content after fungal infection. Our results show that PdPR5-1 gene, in addition to its anti-fungal properties, has a possible role in activating other defense pathways, including phytoalexin production.

  19. RNA-seq profiling reveals defense responses in a tolerant potato cultivar to stem infection by Pectobacterium carotovorum ssp. brasiliense

    Directory of Open Access Journals (Sweden)

    Stanford Kwenda

    2016-12-01

    Full Text Available Pectobacterium carotovorum subsp. brasiliense is a member of the soft rot Enterobacteriaceae (SRE family that causes tuber soft rot and blackleg diseases of stems in potato plants. Currently, there are no effective chemical strategies for the control of members of the SRE. Thus, an understanding of the inducible defense responses in stems of potato plants is important, particularly during colonization of the vascular system. Here, time-course RNA-sequencing analysis was used to compare expressed genes between a susceptible potato cultivar (Solanum tubersoum cv Valor and a tolerant cultivar (S. tuberosum cv BP1 at 0, 6, 12, 24, and 72 h post-inoculation with P. c. brasiliense. In total, we identified 6,139 and 8,214 differentially expressed genes (DEGs in the tolerant and susceptible cultivars, compared to mock-inoculated controls, respectively. Key DEGs distinguishing between tolerance and susceptibility were associated with negative regulation of cell death and plant-type cell wall organization/ biogenesis biological processes in the tolerant and susceptible cultivars, respectively. Among these were DEGs involved in signaling (mainly MAPK cascade and ethylene pathway, defense-related transcription regulation including WRKY transcription factors, and downstream secondary cell biosynthesis. Together, our results suggest that S. tuberosum cv BP1 likely employs quantitative defense response against P.c brasiliense. Overall, our study provides the first transcriptome-wide insight into the molecular basis of tolerance and/or resistance of potato stems to SRE infection.

  20. RNA-seq Profiling Reveals Defense Responses in a Tolerant Potato Cultivar to Stem Infection by Pectobacterium carotovorum ssp. brasiliense.

    Science.gov (United States)

    Kwenda, Stanford; Motlolometsi, Tshepiso V; Birch, Paul R J; Moleleki, Lucy N

    2016-01-01

    Pectobacterium carotovorum subsp. brasiliense is a member of the soft rot Enterobacteriaceae (SRE) family that causes tuber soft rot and blackleg diseases of stems in potato plants. Currently, there are no effective chemical strategies for the control of members of the SRE. Thus, an understanding of the inducible defense responses in stems of potato plants is important, particularly during colonization of the vascular system. Here, time-course RNA-sequencing analysis was used to compare expressed genes between a susceptible potato cultivar ( Solanum tuberosum cv Valor) and a tolerant cultivar ( S. tuberosum cv BP1) at 0, 6, 12, 24, and 72 h post-inoculation with P. c. brasiliense . In total, we identified 6139 and 8214 differentially expressed genes (DEGs) in the tolerant and susceptible cultivars, compared to mock-inoculated controls, respectively. Key DEGs distinguishing between tolerance and susceptibility were associated with negative regulation of cell death and plant-type cell wall organization/biogenesis biological processes in the tolerant and susceptible cultivars, respectively. Among these were DEGs involved in signaling (mainly MAPK cascade and ethylene pathway), defense-related transcription regulation including WRKY transcription factors, and downstream secondary cell biosynthesis. Together, our results suggest that S. tuberosum cv BP1 likely employs quantitative defense response against P. c. brasiliense . Overall, our study provides the first transcriptome-wide insight into the molecular basis of tolerance and/or resistance of potato stems to SRE infection.

  1. SnRK1-triggered switch of bZIP63 dimerization mediates the low-energy response in plants.

    Science.gov (United States)

    Mair, Andrea; Pedrotti, Lorenzo; Wurzinger, Bernhard; Anrather, Dorothea; Simeunovic, Andrea; Weiste, Christoph; Valerio, Concetta; Dietrich, Katrin; Kirchler, Tobias; Nägele, Thomas; Vicente Carbajosa, Jesús; Hanson, Johannes; Baena-González, Elena; Chaban, Christina; Weckwerth, Wolfram; Dröge-Laser, Wolfgang; Teige, Markus

    2015-08-11

    Metabolic adjustment to changing environmental conditions, particularly balancing of growth and defense responses, is crucial for all organisms to survive. The evolutionary conserved AMPK/Snf1/SnRK1 kinases are well-known metabolic master regulators in the low-energy response in animals, yeast and plants. They act at two different levels: by modulating the activity of key metabolic enzymes, and by massive transcriptional reprogramming. While the first part is well established, the latter function is only partially understood in animals and not at all in plants. Here we identified the Arabidopsis transcription factor bZIP63 as key regulator of the starvation response and direct target of the SnRK1 kinase. Phosphorylation of bZIP63 by SnRK1 changed its dimerization preference, thereby affecting target gene expression and ultimately primary metabolism. A bzip63 knock-out mutant exhibited starvation-related phenotypes, which could be functionally complemented by wild type bZIP63, but not by a version harboring point mutations in the identified SnRK1 target sites.

  2. Metallothionein-mediated antioxidant defense system and its response to exercise training are impaired in human type 2 diabetes

    DEFF Research Database (Denmark)

    Scheede-Bergdahl, Celena; Penkowa, Milena; Hidalgo, Juan

    2005-01-01

    lower levels of MT-I+II were also detected in the plasma of type 2 diabetic subjects compared with control subjects. These results suggest that, in control subjects, the MT-I+II defense system is active and inducible within skeletal muscle tissue and plasma. In type 2 diabetes, reduced levels of MT......Oxidative stress is implicated in diabetes complications, during which endogenous antioxidant defenses have important pathophysiological consequences. To date, the significance of endogenous antioxidants such as metallothioneins I and II (MT-I+II) in type 2 diabetes remains unclear. To examine....... Immunohistochemical analysis revealed reduced MT-I+II levels in the skeletal muscle of type 2 diabetic subjects compared with control subjects. Control subjects produced a robust increase of MT-I+II in response to training; however, in type 2 diabetes, MT-I+II levels remained essentially unchanged. Significantly...

  3. Persistent bias in expert judgments about free will and moral responsibility: a test of the expertise defense.

    Science.gov (United States)

    Schulz, Eric; Cokely, Edward T; Feltz, Adam

    2011-12-01

    Many philosophers appeal to intuitions to support some philosophical views. However, there is reason to be concerned about this practice as scientific evidence has documented systematic bias in philosophically relevant intuitions as a function of seemingly irrelevant features (e.g., personality). One popular defense used to insulate philosophers from these concerns holds that philosophical expertise eliminates the influence of these extraneous factors. Here, we test this assumption. We present data suggesting that verifiable philosophical expertise in the free will debate-as measured by a reliable and validated test of expert knowledge-does not eliminate the influence of one important extraneous feature (i.e., the heritable personality trait extraversion) on judgments concerning freedom and moral responsibility. These results suggest that, in at least some important cases, the expertise defense fails. Implications for the practice of philosophy, experimental philosophy, and applied ethics are discussed. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Effect of Therapeutic Sequence of Hot Pack and Ultrasound on Physiological Response Over Trigger Point of Upper Trapezius.

    Science.gov (United States)

    Benjaboonyanupap, Dararat; Paungmali, Aatit; Pirunsan, Ubon

    2015-09-01

    Musculoskeletal pain is a common problem among athletes. Apart from sport injuries, the myofascial pain syndrome is another important problem that affects performance of the athlete. The aim of this study was to evaluate the effects of therapeutic sequences of the hot pack in combination with ultrasound on the physiological responses over the latent myofascial trigger point (LMTrP) of upper trapezius muscle. Thirty subjects with a latent myofascial trigger point (LMTrP) in both sides of the upper trapezius muscle participated in the study (age 27.33 ± 4.34 years, weight 58.11 ± 7.47 kg, height 161.50 ± 5.82 cm, pressure pain threshold 2.28 ± 0.24 kg/cm(2), pain intensity 7.17 ± 2.25 VAS). All subjects received both treatments (hot pack followed by ultrasound: HP + US; and ultrasound followed by hot pack: US + HP) by randomization with a 24 to 48-hour interval between sessions. Outcome measures, including the tissue blood flow (TBF), pressure pain threshold (PPT), supra-thermal threshold (STT) and visual analog scale (VAS) were evaluated at baseline, immediately, after 30 minutes and after 60 minutes. The TBF and PPT significantly increased from baseline in both treatment conditions (i.e. HP + US and US + HP), while the HP + US condition showed a trend toward significant difference in VAS and STT in 45°C. The application of HP and US treatment induces physiological responses (especially, TBF and PPT) on the LMTrP. This finding provides the direction toward the management of MTrPs condition.

  5. Disease-related amyloidogenic variants of human lysozyme trigger the unfolded protein response and disturb eye development in Drosophila melanogaster

    Science.gov (United States)

    Kumita, Janet R.; Helmfors, Linda; Williams, Jocy; Luheshi, Leila M.; Menzer, Linda; Dumoulin, Mireille; Lomas, David A.; Crowther, Damian C.; Dobson, Christopher M.; Brorsson, Ann-Christin

    2012-01-01

    We have created a Drosophila model of lysozyme amyloidosis to investigate the in vivo behavior of disease-associated variants. To achieve this objective, wild-type (WT) protein and the amyloidogenic variants F57I and D67H were expressed in Drosophila melanogaster using the UAS-gal4 system and both the ubiquitous and retinal expression drivers Act5C-gal4 and gmr-gal4. The nontransgenic w1118 Drosophila line was used as a control throughout. We utilized ELISA experiments to probe lysozyme protein levels, scanning electron microscopy for eye phenotype classification, and immunohistochemistry to detect the unfolded protein response (UPR) activation. We observed that expressing the destabilized F57I and D67H lysozymes triggers UPR activation, resulting in degradation of these variants, whereas the WT lysozyme is secreted into the fly hemolymph. Indeed, the level of WT was up to 17 times more abundant than the variant proteins. In addition, the F57I variant gave rise to a significant disruption of the eye development, and this correlated to pronounced UPR activation. These results support the concept that the onset of familial amyloid disease is linked to an inability of the UPR to degrade completely the amyloidogenic lysozymes prior to secretion, resulting in secretion of these destabilized variants, thereby leading to deposition and associated organ damage.—Kumita, J. R., Helmfors, L., Williams, J., Luheshi, L. M., Menzer, L., Dumoulin, M., Lomas, D. A., Crowther, D. C., Dobson, C. M., Brorsson, A.-C. Disease-related amyloidogenic variants of human lysozyme trigger the unfolded protein response and disturb eye development in Drosophila melanogaster. PMID:21965601

  6. Defense enzyme responses in dormant wild oat and wheat caryopses challenged with a seed decay pathogen

    Science.gov (United States)

    Seed dormancy and resistance to seed decay organisms are fundamental ecological strategies for weed seed persistence in the weed seed-bank. Seeds have well-established physical, chemical, and biological defense mechanisms that protect their food reserves from decay-inducing organisms and herbivores....

  7. Brain Insulin Administration Triggers Distinct Cognitive and Neurotrophic Responses in Young and Aged Rats.

    Science.gov (United States)

    Haas, Clarissa B; Kalinine, Eduardo; Zimmer, Eduardo R; Hansel, Gisele; Brochier, Andressa W; Oses, Jean P; Portela, Luis V; Muller, Alexandre P

    2016-11-01

    Aging is a major risk factor for cognitive deficits and neurodegenerative disorders, and impaired brain insulin receptor (IR) signaling is mechanistically linked to these abnormalities. The main goal of this study was to investigate whether brain insulin infusions improve spatial memory in aged and young rats. Aged (24 months) and young (4 months) male Wistar rats were intracerebroventricularly injected with insulin (20 mU) or vehicle for five consecutive days. The animals were then assessed for spatial memory using a Morris water maze. Insulin increased memory performance in young rats, but not in aged rats. Thus, we searched for cellular and molecular mechanisms that might account for this distinct memory response. In contrast with our expectation, insulin treatment increased the proliferative activity in aged rats, but not in young rats, implying that neurogenesis-related effects do not explain the lack of insulin effects on memory in aged rats. Furthermore, the expression levels of the IR and downstream signaling proteins such as GSK3-β, mTOR, and presynaptic protein synaptophysin were increased in aged rats in response to insulin. Interestingly, insulin treatment increased the expression of the brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB) receptors in the hippocampus of young rats, but not of aged rats. Our data therefore indicate that aged rats can have normal IR downstream protein expression but failed to mount a BDNF response after challenge in a spatial memory test. In contrast, young rats showed insulin-mediated TrkB/BDNF response, which paralleled with improved memory performance.

  8. Phytohormone and Putative Defense Gene Expression Differentiates the Response of ‘Hayward’ Kiwifruit to Psa and Pfm Infections

    Directory of Open Access Journals (Sweden)

    Kirstin V. Wurms

    2017-08-01

    Full Text Available Pseudomonas syringae pv. actinidiae (Psa and Pseudomonas syringae pv. actinidifoliorum (Pfm are closely related pathovars infecting kiwifruit, but Psa is considered one of the most important global pathogens, whereas Pfm is not. In this study of Actinidia deliciosa ‘Hayward’ responses to the two pathovars, the objective was to test whether differences in plant defense responses mounted against the two pathovars correlated with the contrasting severity of the symptoms caused by them. Results showed that Psa infections were always more severe than Pfm infections, and were associated with highly localized, differential expression of phytohormones and putative defense gene transcripts in stem tissue closest to the inoculation site. Phytohormone concentrations of jasmonic acid (JA, jasmonate isoleucine (JA-Ile, salicylic acid (SA and abscisic acid were always greater in stem tissue than in leaves, and leaf phytohormones were not affected by pathogen inoculation. Pfm inoculation induced a threefold increase in SA in stems relative to Psa inoculation, and a smaller 1.6-fold induction of JA. Transcript expression showed no effect of inoculation in leaves, but Pfm inoculation resulted in the greatest elevation of the SA marker genes, PR1 and glucan endo-1,3-beta-glucosidase (β-1,3-glucosidase (32- and 25-fold increases, respectively in stem tissue surrounding the inoculation site. Pfm inoculation also produced a stronger response than Psa inoculation in localized stem tissue for the SA marker gene PR6, jasmonoyl-isoleucine-12-hydrolase (JIH1, which acts as a negative marker of the JA pathway, and APETALA2/Ethylene response factor 2 transcription factor (AP2 ERF2, which is involved in JA/SA crosstalk. WRKY40 transcription factor (a SA marker was induced equally in stems by wounding (mock inoculation and pathovar inoculation. Taken together, these results suggest that the host appears to mount a stronger, localized, SA-based defense response to Pfm

  9. Tomato NAC transcription factor SlSRN1 positively regulates defense response against biotic stress but negatively regulates abiotic stress response.

    Directory of Open Access Journals (Sweden)

    Bo Liu

    Full Text Available Biotic and abiotic stresses are major unfavorable factors that affect crop productivity worldwide. NAC proteins comprise a large family of transcription factors that play important roles in plant growth and development as well as in responses to biotic and abiotic stresses. In a virus-induced gene silencing-based screening to identify genes that are involved in defense response against Botrytis cinerea, we identified a tomato NAC gene SlSRN1 (Solanum lycopersicum Stress-related NAC1. SlSRN1 is a plasma membrane-localized protein with transactivation activity in yeast. Expression of SlSRN1 was significantly induced by infection with B. cinerea or Pseudomonas syringae pv. tomato (Pst DC3000, leading to 6-8 folds higher than that in the mock-inoculated plants. Expression of SlSRN1 was also induced by salicylic acid, jasmonic acid and 1-amino cyclopropane-1-carboxylic acid and by drought stress. Silencing of SlSRN1 resulted in increased severity of diseases caused by B. cinerea and Pst DC3000. However, silencing of SlSRN1 resulted in increased tolerance against oxidative and drought stresses. Furthermore, silencing of SlSRN1 accelerated accumulation of reactive oxygen species but attenuated expression of defense genes after infection by B. cinerea. Our results demonstrate that SlSRN1 is a positive regulator of defense response against B. cinerea and Pst DC3000 but is a negative regulator for oxidative and drought stress response in tomato.

  10. Tomato NAC transcription factor SlSRN1 positively regulates defense response against biotic stress but negatively regulates abiotic stress response.

    Science.gov (United States)

    Liu, Bo; Ouyang, Zhigang; Zhang, Yafen; Li, Xiaohui; Hong, Yongbo; Huang, Lei; Liu, Shixia; Zhang, Huijuan; Li, Dayong; Song, Fengming

    2014-01-01

    Biotic and abiotic stresses are major unfavorable factors that affect crop productivity worldwide. NAC proteins comprise a large family of transcription factors that play important roles in plant growth and development as well as in responses to biotic and abiotic stresses. In a virus-induced gene silencing-based screening to identify genes that are involved in defense response against Botrytis cinerea, we identified a tomato NAC gene SlSRN1 (Solanum lycopersicum Stress-related NAC1). SlSRN1 is a plasma membrane-localized protein with transactivation activity in yeast. Expression of SlSRN1 was significantly induced by infection with B. cinerea or Pseudomonas syringae pv. tomato (Pst) DC3000, leading to 6-8 folds higher than that in the mock-inoculated plants. Expression of SlSRN1 was also induced by salicylic acid, jasmonic acid and 1-amino cyclopropane-1-carboxylic acid and by drought stress. Silencing of SlSRN1 resulted in increased severity of diseases caused by B. cinerea and Pst DC3000. However, silencing of SlSRN1 resulted in increased tolerance against oxidative and drought stresses. Furthermore, silencing of SlSRN1 accelerated accumulation of reactive oxygen species but attenuated expression of defense genes after infection by B. cinerea. Our results demonstrate that SlSRN1 is a positive regulator of defense response against B. cinerea and Pst DC3000 but is a negative regulator for oxidative and drought stress response in tomato.

  11. Demonstration of innate immune responses in the thyroid gland: potential to sense danger and a possible trigger for autoimmune reactions.

    Science.gov (United States)

    Kawashima, Akira; Yamazaki, Kazuko; Hara, Takeshi; Akama, Takeshi; Yoshihara, Aya; Sue, Mariko; Tanigawa, Kazunari; Wu, Huhehasi; Ishido, Yuko; Takeshita, Fumihiko; Ishii, Norihisa; Sato, Kanji; Suzuki, Koichi

    2013-04-01

    Autoimmune thyroid disease is an archetypal organ-specific autoimmune disorder that is characterized by the production of thyroid autoantibodies and lymphocytic infiltration into the thyroid. However, the underlying mechanisms by which specific thyroid antibodies are produced are largely unknown. Recent studies have shown that innate immune responses affect both the phenotype and the severity of autoimmune reactions. Moreover, it appears that even non-immune cells, including thyroid cells, have an ability to launch such responses. The aim of this study was to conduct a more detailed analysis of innate immune responses of the thyroid upon stimulation with various "non-self" and "self" factors that might contribute to the initiation of autoimmune reactions. We used rat thyroid FRTL-5 cells, human thyroid cells, and mice to investigate the effects of various pathogen-associated molecular patterns (PAMPs), danger-associated molecular patterns (DAMPs), and iodide on gene expression and function that were related to innate immune responses. RT-PCR analysis showed that both rat and human thyroid cells expressed mRNAs for Toll-like receptors (TLRs) that sensed PAMPs. Stimulation of thyrocytes with TLR ligands resulted in activation of the interferon-beta (IFN-β) promoter and the nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB)-dependent promoter. As a result, pro-inflammatory cytokines, chemokines, and type I interferons were produced. Similar activation was observed when thyroid cells were stimulated with double-stranded DNA, one of the typical DAMPs. In addition to these PAMPs and DAMPs, treatment of thyroid cells with high concentrations of iodide increased mRNA expression of various cytokines. We show that thyroid cells express functional sensors for exogenous and endogenous dangers, and that they are capable of launching innate immune responses without the assistance of immune cells. Such responses may relate to the development of thyroiditis

  12. Coxsackievirus cloverleaf RNA containing a 5' triphosphate triggers an antiviral response via RIG-I activation.

    Directory of Open Access Journals (Sweden)

    Qian Feng

    Full Text Available Upon viral infections, pattern recognition receptors (PRRs recognize pathogen-associated molecular patterns (PAMPs and stimulate an antiviral state associated with the production of type I interferons (IFNs and inflammatory markers. Type I IFNs play crucial roles in innate antiviral responses by inducing expression of interferon-stimulated genes and by activating components of the adaptive immune system. Although pegylated IFNs have been used to treat hepatitis B and C virus infections for decades, they exert substantial side effects that limit their use. Current efforts are directed toward the use of PRR agonists as an alternative approach to elicit host antiviral responses in a manner similar to that achieved in a natural infection. RIG-I is a cytosolic PRR that recognizes 5' triphosphate (5'ppp-containing RNA ligands. Due to its ubiquitous expression profile, induction of the RIG-I pathway provides a promising platform for the development of novel antiviral agents and vaccine adjuvants. In this study, we investigated whether structured RNA elements in the genome of coxsackievirus B3 (CVB3, a picornavirus that is recognized by MDA5 during infection, could activate RIG-I when supplied with 5'ppp. We show here that a 5'ppp-containing cloverleaf (CL RNA structure is a potent RIG-I inducer that elicits an extensive antiviral response that includes induction of classical interferon-stimulated genes, as well as type III IFNs and proinflammatory cytokines and chemokines. In addition, we show that prophylactic treatment with CVB3 CL provides protection against various viral infections including dengue virus, vesicular stomatitis virus and enterovirus 71, demonstrating the antiviral efficacy of this RNA ligand.

  13. The Effect of Water Limitation on Volatile Emission, Tree Defense Response, and Brood Success of Dendroctonus ponderosae in Two Pine Hosts, Lodgepole, and Jack Pine

    OpenAIRE

    Lusebrink, Inka; Erbilgin, Nadir; Evenden, Maya L.

    2016-01-01

    The mountain pine beetle (MPB; Dendroctonus ponderosae) has recently expanded its range from lodgepole pine forest into the lodgepole × jack pine hybrid zone in central Alberta, within which it has attacked pure jack pine. This study tested the effects of water limitation on tree defense response of mature lodgepole and jack pine (Pinus contorta and Pinus banksiana) trees in the field. Tree defense response was initiated by inoculation of trees with the MPB-associated fungus Grosmannia clavig...

  14. Uncoupling salicylic acid-dependent cell death and defense-related responses from disease resistance in the Arabidopsis mutant acd5.

    OpenAIRE

    Greenberg, J T; Silverman, F P; Liang, H

    2000-01-01

    Salicylic acid (SA) is required for resistance to many diseases in higher plants. SA-dependent cell death and defense-related responses have been correlated with disease resistance. The accelerated cell death 5 mutant of Arabidopsis provides additional genetic evidence that SA regulates cell death and defense-related responses. However, in acd5, these events are uncoupled from disease resistance. acd5 plants are more susceptible to Pseudomonas syringae early in development and show spontaneou...

  15. Neuronal Serotonin Release Triggers the Heat Shock Response in C. elegans in the Absence of Temperature Increase

    Science.gov (United States)

    Tatum, Marcus C.; Ooi, Felicia K.; Chikka, Madhusudana Rao; Chauve, Laetitia; Martinez-Velazquez, Luis A.; Steinbusch, Harry W.M.; Morimoto, Richard I.; Prahlad, Veena

    2016-01-01

    Summary Background Cellular mechanisms aimed at repairing protein damage and maintaining homeostasis, widely understood to be triggered by the damage itself, have recently been shown to be under cell nonautonomous control in the metazoan C. elegans. The heat shock response (HSR) is one such conserved mechanism, activated by cells upon exposure to proteotoxic conditions such as heat. Previously, we had shown that this conserved cytoprotective response is regulated by the thermosensory neuronal circuitry of C. elegans. Here, we investigate the mechanisms and physiological relevance of neuronal control. Results By combining optogenetic methods with live visualization of the dynamics of the heat shock transcription factor (HSF1), we show that excitation of the AFD thermosensory neurons is sufficient to activate HSF1 in another cell, even in the absence of temperature increase. Excitation of the AFD thermosensory neurons enhances serotonin release. Serotonin release elicited by direct optogenetic stimulation of serotonergic neurons activates HSF1 and upregulates molecular chaperones through the metabotropic serotonin receptor SER-1. Consequently, excitation of serotonergic neurons alone can suppress protein misfolding in C. elegans peripheral tissue. Conclusions These studies imply that thermosensory activity coupled to serotonergic signaling is sufficient to activate the protective HSR prior to frank proteotoxic damage. The ability of neurosensory release of serotonin to control cellular stress responses and activate HSF1 has powerful implications for the treatment of protein conformation diseases. PMID:25557666

  16. Magnetocaloric effect in magnetothermally-responsive nanocarriers for hyperthermia-triggered drug release

    International Nuclear Information System (INIS)

    Li Jianbo; Qu Yang; Ren Jie; Yuan Weizhong; Shi Donglu

    2012-01-01

    The magnetocaloric effects and lower critical solution temperature (LCST) were investigated in a magnetothermally-responsive nanocarrier for magnetothermal drug release under alternating magnetic field (AMF). The Mn 0.2 Zn 0.8 Fe 2 O 4 nanoparticles with low T c were dispersed in a polymeric matrix consisting of N-Isopropyl acrylamide (NIPAAm) and N-hydroxymethyl acrylamide (HMAAm). The magnetocaloric effects and LCST of the nanocarriers were characterized by using high-resolution electron transmission microscopy, thermogravimetric analyses, and vibrating sample magnetometer. The maximum self-heating temperature of 42.9 °C was achieved by optimizing the Mn 0.2 Zn 0.8 Fe 2 O 4 concentration in the polymer matrix. By adjusting the NIPAAm to HMAAm ratio, the LCST was controlled at an ideal level of 40.1 °C for efficient thermosensitive drug delivery. Magnetothermally responsive drug release of Doxorubicin, an anticancer drug, was significantly enhanced by application of an external AMF on the nanocarriers. The cytotoxicity experimental results in vitro show good biocompatibility and efficient therapeutic effects in cancer treatment. (paper)

  17. Characterization of the cellular response triggered by gold nanoparticle-mediated laser manipulation.

    Science.gov (United States)

    Kalies, Stefan; Keil, Sebastian; Sender, Sina; Hammer, Susanne C; Antonopoulos, Georgios C; Schomaker, Markus; Ripken, Tammo; Murua Escobar, Hugo; Meyer, Heiko; Heinemann, Dag

    2015-11-01

    Laser-based transfection techniques have proven high applicability in several cell biologic applications. The delivery of different molecules using these techniques has been extensively investigated. In particular, new high-throughput approaches such as gold nanoparticle–mediated laser transfection allow efficient delivery of antisense molecules or proteins into cells preserving high cell viabilities. However, the cellular response to the perforation procedure is not well understood. We herein analyzed the perforation kinetics of single cells during resonant gold nanoparticle–mediated laser manipulation with an 850-ps laser system at a wavelength of 532 nm. Inflow velocity of propidium iodide into manipulated cells reached a maximum within a few seconds. Experiments based on the inflow of FM4-64 indicated that the membrane remains permeable for a few minutes for small molecules. To further characterize the cellular response postmanipulation, we analyzed levels of oxidative heat or general stress. Although we observed an increased formation of reactive oxygen species by an increase of dichlorofluorescein fluorescence, heat shock protein 70 was not upregulated in laser-treated cells. Additionally, no evidence of stress granule formation was visible by immunofluorescence staining. The data provided in this study help to identify the cellular reactions to gold nanoparticle–mediated laser manipulation.

  18. Supplementary Material for: Herboxidiene triggers splicing repression and abiotic stress responses in plants

    KAUST Repository

    Alshareef, Sahar

    2017-01-01

    Abstract Background Constitutive and alternative splicing of pre-mRNAs from multiexonic genes controls the diversity of the proteome; these precisely regulated processes also fine-tune responses to cues related to growth, development, and stresses. Small-molecule inhibitors that perturb splicing provide invaluable tools for use as chemical probes to uncover the molecular underpinnings of splicing regulation and as potential anticancer compounds. Results Here, we show that herboxidiene (GEX1A) inhibits both constitutive and alternative splicing. Moreover, GEX1A activates genome-wide transcriptional patterns involved in abiotic stress responses in plants. GEX1A treatment -activated ABA-inducible promoters, and led to stomatal closure. Interestingly, GEX1A and pladienolide B (PB) elicited similar cellular changes, including alterations in the patterns of transcription and splicing, suggesting that these compounds might target the same spliceosome complex in plant cells. Conclusions Our study establishes GEX1A as a potent splicing inhibitor in plants that can be used to probe the assembly, dynamics, and molecular functions of the spliceosome and to study the interplay between splicing stress and abiotic stresses, as well as having potential biotechnological applications.

  19. Divergent forms of endoplasmic reticulum stress trigger a robust unfolded protein response in honey bees.

    Science.gov (United States)

    Johnston, Brittany A; Hooks, Katarzyna B; McKinstry, Mia; Snow, Jonathan W

    2016-03-01

    Honey bee colonies in the United States have suffered from an increased rate of die-off in recent years, stemming from a complex set of interacting stresses that remain poorly described. While we have some understanding of the physiological stress responses in the honey bee, our molecular understanding of honey bee cellular stress responses is incomplete. Thus, we sought to identify and began functional characterization of the components of the UPR in honey bees. The IRE1-dependent splicing of the mRNA for the transcription factor Xbp1, leading to translation of an isoform with more transactivation potential, represents the most conserved of the UPR pathways. Honey bees and other Apoidea possess unique features in the Xbp1 mRNA splice site, which we reasoned could have functional consequences for the IRE1 pathway. However, we find robust induction of target genes upon UPR stimulation. In addition, the IRE1 pathway activation, as assessed by splicing of Xbp1 mRNA upon UPR, is conserved. By providing foundational knowledge about the UPR in the honey bee and the relative sensitivity of this species to divergent stresses, this work stands to improve our understanding of the mechanistic underpinnings of honey bee health and disease. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Transcriptional regulation of ethylene and jasmonate mediated defense response in apple (Malus domestica) root during Pythium ultimum infection.

    Science.gov (United States)

    Shin, Sungbong; Lv, Jingyi; Fazio, Gennaro; Mazzola, Mark; Zhu, Yanmin

    2014-01-01

    Apple replant disease (ARD) is a significant economic restraint to the successful re-establishment of new apple orchards on sites previously planted to the same crop. Pythium ultimum, an oomycete, is a significant component of the ARD pathogen complex. Although ethylene (ET)- and jasmonic acid (JA)-mediated defense responses are intensively studied in the foliar pathosystem, the transferability of this knowledge to the interaction between a perennial root system and soilborne pathogens is unknown. The aim of this study was to test the hypothesis that the ET/JA-mediated defense response is conserved in roots of tree crops in response to infection by P. ultimum. Apple genes with the annotated function of ET/JA biosynthesis, MdERF (ethylene response factor) for signaling transduction and a gene encoding a pathogenesis-related (PR) protein (β-chitinase, the target of ERF) were identified from the apple genome sequences. The transcriptional profiles of these genes during P. ultimum infection and after exogenous ET and/or JA treatment were characterized using qRT-PCR. Several genes showed a 10- to 60-fold upregulation in apple root tissue 24-48 h post inoculation (hpi). Exogenous ET and JA treatment exhibited either a positive or negative influence on expression of ET or JA biosynthesis genes, depending upon gene isoforms and the tissue types, while the expression of MdERF and the PR protein encoding gene was upregulated by both ET and JA treatment. Our data are consistent with the hypothesis that ET/JA-mediated defense pathways are functional in the root system of perennial tree species defending soilborne pathogens.

  1. Arginine-responsive terbium luminescent hybrid sensors triggered by two crown ether carboxylic acids

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Lasheng [Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Tang, Ke; Ding, Xiaoping [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Wang, Qianming, E-mail: qmwang@scnu.edu.cn [Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Zhou, Zhan; Xiao, Rui [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China)

    2013-12-01

    Crown ether carboxylic acids constitute main building blocks for the synthesis of terbium containing covalent cross-linked luminescent materials. Both the complexes and the hybrid nanomaterials could exhibit remarkable green emissions in pure water. More importantly, they were found to have a profound effect on the luminescence responses to arginine compared with glutamic acid, histidine, tryptophan, threonine, tyrosine and phenylalanine in aqueous environment. The present study provided the possibility of using a host–guest mechanism as a way of signal transduction based on lanthanide supramolecular hybrid materials. - Highlights: • Crown ether carboxylic acids were found to sensitize terbium ions among a group of ethers. • The complexes and silica hybrid materials were both prepared and characterized. • They could exhibit remarkable green emissions in pure water.

  2. Impaired rRNA synthesis triggers homeostatic responses in hippocampal neurons

    Directory of Open Access Journals (Sweden)

    Anna eKiryk

    2013-11-01

    Full Text Available Decreased rRNA synthesis and nucleolar disruption, known as nucleolar stress, are primary signs of cellular stress associated with aging and neurodegenerative disorders. Silencing of rDNA occurs during early stages of Alzheimer´s disease (AD and may play a role in dementia. Moreover aberrant regulation of the protein synthesis machinery is present in the brain of suicide victims and implicates the epigenetic modulation of rRNA. Recently, we developed unique mouse models characterized by nucleolar stress in neurons. We inhibited RNA polymerase I by genetic ablation of the basal transcription factor TIF-IA in adult hippocampal neurons. Nucleolar stress resulted in progressive neurodegeneration, although with a differential vulnerability within the CA1, CA3 and dentate gyrus. Here, we investigate the consequences of nucleolar stress on learning and memory. The mutant mice show normal performance in the Morris water maze and in other behavioral tests, suggesting the activation of adaptive mechanisms. In fact, we observe a significantly enhanced learning and re-learning corresponding to the initial inhibition of rRNA transcription. This phenomenon is accompanied by aberrant synaptic plasticity. By the analysis of nucleolar function and integrity, we find that the synthesis of rRNA is later restored. Gene expression profiling shows that thirty-six transcripts are differentially expressed in comparison to the control group in absence of neurodegeneration. Additionally, we observe a significant enrichment of the putative serum response factor (SRF binding sites in the promoters of the genes with changed expression, indicating potential adaptive mechanisms mediated by the mitogen-activated protein kinase pathway. In the dentate gyrus a neurogenetic response might compensate the initial molecular deficits. These results underscore the role of nucleolar stress in neuronal homeostasis and open a new ground for therapeutic strategies aiming at preserving

  3. Differential responses of innate immunity triggered by different subtypes of influenza a viruses in human and avian hosts.

    Science.gov (United States)

    Cao, Yingying; Huang, Yaowei; Xu, Ke; Liu, Yuanhua; Li, Xuan; Xu, Ye; Zhong, Wu; Hao, Pei

    2017-12-21

    Innate immunity provides first line of defense against viral infections. The interactions between hosts and influenza A virus and the response of host innate immunity to viral infection are critical determinants for the pathogenicity or virulence of influenza A viruses. This study was designed to investigate global changes of gene expression and detailed responses of innate immune systems in human and avian hosts during the course of infection with various subtypes of influenza A viruses, using collected and self-generated transcriptome sequencing data from human bronchial epithelial (HBE), human tracheobronchial epithelial (HTBE), and A549 cells infected with influenza A virus subtypes, namely H1N1, H3N2, H5N1 HALo mutant, and H7N9, and from ileum and lung of chicken and quail infected with H5N1, or H5N2. We examined the induction of various cytokines and chemokines in human hosts infected with different subtypes of influenza A viruses. Type I and III interferons were found to be differentially induced with each subtype. H3N2 caused abrupt and the strongest response of IFN-β and IFN-λ, followed by H1N1 (though much weaker), whereas H5N1 HALo mutant and H7N9 induced very minor change in expression of type I and III interferons. Similarly, differential responses of other innate immunity-related genes were observed, including TMEM173, MX1, OASL, IFI6, IFITs, IFITMs, and various chemokine genes like CCL5, CX3CL1, and chemokine (C-X-C motif) ligands, SOCS (suppressors of cytokine signaling) genes. Third, the replication kinetics of H1N1, H3N2, H5N1 HALo mutant and H7N9 subtypes were analyzed, H5N1 HALo mutant was found to have the highest viral replication rate, followed by H3N2, and H1N1, while H7N9 had a rate similar to that of H1N1 or H3N2 though in different host cell type. Our study illustrated the differential responses of innate immunity to infections of different subtypes of influenza A viruses. We found the influenza viruses which induced stronger innate

  4. A Novel Meloidogyne incognita Effector Misp12 Suppresses Plant Defense Response at Latter Stages of Nematode Parasitism

    Science.gov (United States)

    Xie, Jialian; Li, Shaojun; Mo, Chenmi; Wang, Gaofeng; Xiao, Xueqiong; Xiao, Yannong

    2016-01-01

    Secreted effectors in plant root-knot nematodes (RKNs, or Meloidogyne spp.) play key roles in their parasite processes. Currently identified effectors mainly focus on the early stage of the nematode parasitism. There are only a few reports describing effectors that function in the latter stage. In this study, we identified a potential RKN effector gene, Misp12, that functioned during the latter stage of parasitism. Misp12 was unique in the Meloidogyne spp., and highly conserved in Meloidogyne incognita. It encoded a secretory protein that specifically expressed in the dorsal esophageal gland, and highly up-regulated during the female stages. Transient expression of Misp12-GUS-GFP in onion epidermal cell showed that Misp12 was localized in cytoplast. In addition, in planta RNA interference targeting Misp12 suppressed the expression of Misp12 in nematodes and attenuated parasitic ability of M. incognita. Furthermore, up-regulation of jasmonic acid (JA) and salicylic acid (SA) pathway defense-related genes in the virus-induced silencing of Misp12 plants, and down-regulation of SA pathway defense-related genes in Misp12-expressing plants indicated the gene might be associated with the suppression of the plant defense response. These results demonstrated that the novel nematode effector Misp12 played a critical role at latter parasitism of M. incognita. PMID:27446188

  5. Physiological and Metabolic Responses Triggered by Omeprazole Improve Tomato Plant Tolerance to NaCl Stress.

    Science.gov (United States)

    Rouphael, Youssef; Raimondi, Giampaolo; Lucini, Luigi; Carillo, Petronia; Kyriacou, Marios C; Colla, Giuseppe; Cirillo, Valerio; Pannico, Antonio; El-Nakhel, Christophe; De Pascale, Stefania

    2018-01-01

    Interest in the role of small bioactive molecules (< 500 Da) in plants is on the rise, compelled by plant scientists' attempt to unravel their mode of action implicated in stimulating growth and enhancing tolerance to environmental stressors. The current study aimed at elucidating the morphological, physiological and metabolomic changes occurring in greenhouse tomato (cv. Seny) treated with omeprazole (OMP), a benzimidazole inhibitor of animal proton pumps. The OMP was applied at three rates (0, 10, or 100 μM) as substrate drench for tomato plants grown under nonsaline (control) or saline conditions sustained by nutrient solutions of 1 or 75 mM NaCl, respectively. Increasing NaCl concentration from 1 to 75 mM decreased the tomato shoot dry weight by 49% in the 0 μM OMP treatment, whereas the reduction was not significant at 10 or 100 μM of OMP. Treatment of salinized (75 mM NaCl) tomato plants with 10 and especially 100 μM OMP decreased Na + and Cl - while it increased Ca 2+ concentration in the leaves. However, OMP was not strictly involved in ion homeostasis since the K + to Na + ratio did not increase under combined salinity and OMP treatment. OMP increased root dry weight, root morphological characteristics (total length and surface), transpiration, and net photosynthetic rate independently of salinity. Metabolic profiling of leaves through UHPLC liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry facilitated identification of the reprogramming of a wide range of metabolites in response to OMP treatment. Hormonal changes involved an increase in ABA, decrease in auxins and cytokinin, and a tendency for GA down accumulation. Cutin biosynthesis, alteration of membrane lipids and heightened radical scavenging ability related to the accumulation of phenolics and carotenoids were observed. Several other stress-related compounds, such as polyamine conjugates, alkaloids and sesquiterpene lactones, were altered in response to OMP. Although a

  6. Physiological and Metabolic Responses Triggered by Omeprazole Improve Tomato Plant Tolerance to NaCl Stress

    Directory of Open Access Journals (Sweden)

    Youssef Rouphael

    2018-02-01

    Full Text Available Interest in the role of small bioactive molecules (< 500 Da in plants is on the rise, compelled by plant scientists' attempt to unravel their mode of action implicated in stimulating growth and enhancing tolerance to environmental stressors. The current study aimed at elucidating the morphological, physiological and metabolomic changes occurring in greenhouse tomato (cv. Seny treated with omeprazole (OMP, a benzimidazole inhibitor of animal proton pumps. The OMP was applied at three rates (0, 10, or 100 μM as substrate drench for tomato plants grown under nonsaline (control or saline conditions sustained by nutrient solutions of 1 or 75 mM NaCl, respectively. Increasing NaCl concentration from 1 to 75 mM decreased the tomato shoot dry weight by 49% in the 0 μM OMP treatment, whereas the reduction was not significant at 10 or 100 μM of OMP. Treatment of salinized (75 mM NaCl tomato plants with 10 and especially 100 μM OMP decreased Na+ and Cl− while it increased Ca2+ concentration in the leaves. However, OMP was not strictly involved in ion homeostasis since the K+ to Na+ ratio did not increase under combined salinity and OMP treatment. OMP increased root dry weight, root morphological characteristics (total length and surface, transpiration, and net photosynthetic rate independently of salinity. Metabolic profiling of leaves through UHPLC liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry facilitated identification of the reprogramming of a wide range of metabolites in response to OMP treatment. Hormonal changes involved an increase in ABA, decrease in auxins and cytokinin, and a tendency for GA down accumulation. Cutin biosynthesis, alteration of membrane lipids and heightened radical scavenging ability related to the accumulation of phenolics and carotenoids were observed. Several other stress-related compounds, such as polyamine conjugates, alkaloids and sesquiterpene lactones, were altered in response to OMP

  7. Security Assistance and Cooperation: Shared Responsibility of the Departments of State and Defense

    Science.gov (United States)

    2016-04-04

    the Greek -Turkish Aid Act, 1947, and the Mutual Defense Assistance Act of 1949, and continued through the Mutual Security Acts of the 1950s. For most...not generally present in the Middle East or Africa, RAND found the most successful efforts to be in Latin America, the Asia/Pacific region, and Europe...56 For instance: 10 U.S.C. 1050, Latin American (LATAM) Cooperation Payment of Personnel Expenses; 10

  8. BcIEB1, a Botrytis cinerea secreted protein, elicits a defense response in plants.

    Science.gov (United States)

    Frías, Marcos; González, Mario; González, Celedonio; Brito, Nélida

    2016-09-01

    BcIEB1 is a very abundant protein in the secretome of Botrytis cinerea but it has no known function and no similarity to any characterized protein family. Previous results suggested that this protein is an elicitor of the plant defense system. In this work we have generated loss-of-function B. cinerea mutants lacking BcIEB1 and we have expressed the protein in yeast to assay its activity on plants. Analysis of the Δbcieb1 mutants did not result in any observable phenotype, including no difference in the virulence on a variety of hosts. However, when BcIEB1 was applied to plant tissues it produced necrosis as well as a whole range of symptoms: inhibition of seedling growth in Arabidopsis and tobacco, ion leakage from tobacco leaf disks, a ROS burst, cell death and autofluorescence in onion epidermis, as well as the expression of defense genes in tobacco. Moreover, tobacco plants treated with BcIEB1 showed an increased systemic resistance to B. cinerea. A small 35-amino acids peptide derived from a conserved region of BcIEB1 is almost as active on plants as the whole protein. These results clearly indicate that BcIEB1 elicits plant defenses, probably as a consequence of its recognition as a pathogen associated molecular pattern. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Sucrose-mediated priming of plant defense responses and broad-spectrum disease resistance by overexpression of the maize pathogenesis-related PRms protein in rice plants.

    Science.gov (United States)

    Gómez-Ariza, Jorge; Campo, Sonia; Rufat, Mar; Estopà, Montserrat; Messeguer, Joaquima; San Segundo, Blanca; Coca, María

    2007-07-01

    Expression of pathogenesis-related (PR) genes is part of the plant's natural defense response against pathogen attack. The PRms gene encodes a fungal-inducible PR protein from maize. Here, we demonstrate that expression of PRms in transgenic rice confers broad-spectrum protection against pathogens, including fungal (Magnaporthe oryzae, Fusarium verticillioides, and Helminthosporium oryzae) and bacterial (Erwinia chrysanthemi) pathogens. The PRms-mediated disease resistance in rice plants is associated with an enhanced capacity to express and activate the natural plant defense mechanisms. Thus, PRms rice plants display a basal level of expression of endogenous defense genes in the absence of the pathogen. PRms plants also exhibit stronger and quicker defense responses during pathogen infection. We also have found that sucrose accumulates at higher levels in leaves of PRms plants. Sucrose responsiveness of rice defense genes correlates with the pathogen-responsive priming of their expression in PRms rice plants. Moreover, pretreatment of rice plants with sucrose enhances resistance to M. oryzae infection. Together, these results support a sucrose-mediated priming of defense responses in PRms rice plants which results in broad-spectrum disease resistance.

  10. Phaseolus vulgaris L. Seedlings Exposed to Prometryn Herbicide Contaminated Soil Trigger an Oxidative Stress Response.

    Science.gov (United States)

    Boulahia, Kerima; Carol, Pierre; Planchais, Séverine; Abrous-Belbachir, Ouzna

    2016-04-27

    Herbicides from the family of S-triazines, such as prometryn, have been widely used in crop production and can constitute an environmental pollution in both water and soil. As a valuable crop, the common bean (Phaseolus vulgaris L.) is grown all over the world and could be exposed to such herbicides. We wanted to investigate the possible stress sustained by the common bean growing in prometryn-polluted soil. Two situations were observed: when soil was treated with ≥100 μM prometryn, some, but not all, measured growth parameters were affected in a dose-dependent manner. Growth was reduced, and photosynthetic pigments and photosynthetic products were less accumulated when soil was treated with ≥100 μM prometryn. Reactive oxygen species (ROS) produced had a deleterious effect, as seen by the accumulation of oxidized lipid in the form of malondialdehyde (MDA). Higher prometryn (500 μM) concentrations had a disastrous effect, reducing antioxidant activities. At a low (10 μM) concentration, prometryn increased antioxidant enzymatic activities without affecting plant growth or MDA production. Gene expression of proline metabolism genes and proline accumulation confirm that bean plants respond to a stress according to the prometryn concentration. Physiological responses such as antioxidative enzymes APX, CAT, and the enzyme implicated in the metabolization of xenobiotics, GST, were increased at 10 and 100 μM, which indicated a prevention of deleterious effects of prometryn, suggesting that bean is a suitable material both for herbicide pollution sensing and as a crop on a low level of herbicide pollution.

  11. Temporal Feasibility of Rapid Joint Inversions in Response to Tsunamis Triggered by Megathrust Earthquakes

    Science.gov (United States)

    Williamson, A.; Newman, A. V.

    2014-12-01

    Joint inversions of sub-areal surface deformation and tsunami waves generated by seafloor ground motions, while still in their infancy, have the opportunity for realistic representations of megathrust earthquake slip responsible, which occurs primarily offshore. Such joint inversions, including Gusman, et al. [JGR, 2010] and Wei et al. [PAGEOPH, 2014], highlight fault slip unobservable with on land measurements alone. Careful detection of possible slip patterns can affect how nearby communities prepare for future events, therefore their discovery is important for hazard mitigation. Joint inversions could also prove invaluable during a large even through a rapid inversion of real time data. This study looks at the availability and accessibility of land-based GPS and deep-ocean pressure sensor data for rapid join inversions, and the latency between such solutions and both local and global tsunami wave arrivals. We consider GPS rather than other ground-based deformation techniques because of its ability to provide rapid and continuous translations of the ground surface. For tsunami observations, we focus on deep-ocean pressure sensors such as those used in DART systems, because of similarly rapid and continues data availability. Similarly tsunami waves traveling through the deep-ocean have negligible non-linear components, making them ideal for inversion methods. We create a source event in a zone with an elevated seismic risk and then track tsunami travel times to the coast and the nearest deep-ocean pressure sensors to determine a temporal limit to warnings that can be issued to nearby regions. By assessing this latency, focus can be given to areas where an inversion of this type has the potential to improve warning information. This study also identifies regions that lack necessary on and offshore instrumentation to warn coastal communities at risk for tsunamigenic earthquakes. By assessing the feasibility of joint inversions, it becomes easier to move forward with

  12. Activated α2-Macroglobulin Binding to Human Prostate Cancer Cells Triggers Insulin-like Responses

    Science.gov (United States)

    Misra, Uma Kant; Pizzo, Salvatore Vincent

    2015-01-01

    Ligation of cell surface GRP78 by activated α2-macroglobulin (α2M*) promotes cell proliferation and suppresses apoptosis. α2M*-treated human prostate cancer cells exhibit a 2–3-fold increase in glucose uptake and lactate secretion, an effect similar to insulin treatment. In both α2M* and insulin-treated cells, the mRNA levels of SREBP1-c, SREBP2, fatty-acid synthase, acetyl-CoA carboxylase, ATP citrate lyase, and Glut-1 were significantly increased together with their protein levels, except for SREBP2. Pretreatment of cells with α2M* antagonist antibody directed against the carboxyl-terminal domain of GRP78 blocks these α2M*-mediated effects, and silencing GRP78 expression by RNAi inhibits up-regulation of ATP citrate lyase and fatty-acid synthase. α2M* induces a 2–3-fold increase in lipogenesis as determined by 6-[14C]glucose or 1-[14C]acetate incorporation into free cholesterol, cholesterol esters, triglycerides, free fatty acids, and phosphatidylcholine, which is blocked by inhibitors of fatty-acid synthase, PI 3-kinase, mTORC, or an antibody against the carboxyl-terminal domain of GRP78. We also assessed the incorporation of [14CH3]choline into phosphatidylcholine and observed similar effects. Lipogenesis is significantly affected by pretreatment of prostate cancer cells with fatostatin A, which blocks sterol regulatory element-binding protein proteolytic cleavage and activation. This study demonstrates that α2M* functions as a growth factor, leading to proliferation of prostate cancer cells by promoting insulin-like responses. An antibody against the carboxyl-terminal domain of GRP78 may have important applications in prostate cancer therapy. PMID:25720493

  13. Vesicles from different Trypanosoma cruzi strains trigger differential innate and chronic immune responses

    Directory of Open Access Journals (Sweden)

    Paula M. Nogueira

    2015-11-01

    Full Text Available Trypomastigote forms of Trypanosoma cruzi, the causative agent of Chagas Disease, shed extracellular vesicles (EVs enriched with glycoproteins of the gp85/trans-sialidase (TS superfamily and other α-galactosyl (α-Gal-containing glycoconjugates, such as mucins. Here, purified vesicles from T. cruzi strains (Y, Colombiana, CL-14 and YuYu were quantified according to size, intensity and concentration. Qualitative analysis revealed differences in their protein and α-galactosyl contents. Later, those polymorphisms were evaluated in the modulation of immune responses (innate and in the chronic phase in C57BL/6 mice. EVs isolated from YuYu and CL-14 strains induced in macrophages higher levels of proinflammatory cytokines (TNF-α and IL-6 and nitric oxide via TLR2. In general, no differences were observed in MAPKs activation (p38, JNK and ERK 1/2 after EVs stimulation. In splenic cells derived from chronically infected mice, a different modulation pattern was observed, where Colombiana (followed by Y strain EVs were more proinflammatory. This modulation was independent of the T. cruzi strain used in the mice infection. To test the functional importance of this modulation, the expression of intracellular cytokines after in vitro exposure was evaluated using EVs from YuYu and Colombiana strains. Both EVs induced cytokine production with the appearance of IL-10 in the chronically infected mice. A high frequency of IL-10 in CD4+ and CD8+ T lymphocytes was observed. A mixed profile of cytokine induction was observed in B cells with the production of TNF-α and IL-10. Finally, dendritic cells produced TNF-α after stimulation with EVs. Polymorphisms in the vesicles surface may be determinant in the immunopathologic events not only in the early steps of infection but also in the chronic phase.

  14. Proteome and phosphoproteome characterization reveals new response and defense mechanisms of Brachypodium distachyon leaves under salt stress.

    Science.gov (United States)

    Lv, Dong-Wen; Subburaj, Saminathan; Cao, Min; Yan, Xing; Li, Xiaohui; Appels, Rudi; Sun, Dong-Fa; Ma, Wujun; Yan, Yue-Ming

    2014-02-01

    Salinity is a major abiotic stress affecting plant growth and development. Understanding the molecular mechanisms of salt response and defense in plants will help in efforts to improve the salt tolerance of crops. Brachypodium distachyon is a new model plant for wheat, barley, and several potential biofuel grasses. In the current study, proteome and phosphoproteome changes induced by salt stress were the focus. The Bd21 leaves were initially treated with salt in concentrations ranging from 80 to 320 mm and then underwent a recovery process prior to proteome analysis. A total of 80 differentially expressed protein spots corresponding to 60 unique proteins were identified. The sample treated with a median salt level of 240 mm and the control were selected for phosphopeptide purification using TiO2 microcolumns and LC-MS/MS for phosphoproteome analysis to identify the phosphorylation sites and phosphoproteins. A total of 1509 phosphoproteins and 2839 phosphorylation sites were identified. Among them, 468 phosphoproteins containing 496 phosphorylation sites demonstrated significant changes at the phosphorylation level. Nine phosphorylation motifs were extracted from the 496 phosphorylation sites. Of the 60 unique differentially expressed proteins, 14 were also identified as phosphoproteins. Many proteins and phosphoproteins, as well as potential signal pathways associated with salt response and defense, were found, including three 14-3-3s (GF14A, GF14B, and 14-3-3A) for signal transduction and several ABA signal-associated proteins such as ABF2, TRAB1, and SAPK8. Finally, a schematic salt response and defense mechanism in B. distachyon was proposed.

  15. Role of the 4-phosphopantetheinyl transferase of Trichoderma virens in secondary metabolism and induction of plant defense responses.

    Science.gov (United States)

    Velazquez-Robledo, R; Contreras-Cornejo, H A; Macias-Rodriguez, L; Hernandez-Morales, A; Aguirre, J; Casas-Flores, S; Lopez-Bucio, J; Herrera-Estrella, A

    2011-12-01

    Trichoderma virens is a ubiquitous soil fungus successfully used in biological control due to its efficient colonization of plant roots. In fungi, 4-phosphopantetheinyl transferases (PPTases) activate enzymes involved in primary and secondary metabolism. Therefore, we cloned the PPTase gene ppt1 from T. virens and generated PPTase-deficient (?ppt1) and overexpressing strains to investigate the role of this enzyme in biocontrol and induction of plant defense responses. The ?ppt1 mutants were auxotrophic for lysine, produced nonpigmented conidia, and were unable to synthesize nonribosomal peptides. Although spore germination was severely compromised under both low and high iron availability, mycelial growth occurred faster than the wild type, and the mutants were able to efficiently colonize plant roots. The ?ppt1 mutants were unable of inhibiting growth of phytopathogenic fungi in vitro. Arabidopsis thaliana seedlings co-cultivated with wild-type T. virens showed increased expression of pPr1a:uidA and pLox2:uidA markers, which correlated with enhanced accumulation of salicylic acid (SA), jasmonic acid, camalexin, and resistance to Botrytis cinerea. Co-cultivation of A. thaliana seedlings with ?ppt1 mutants compromised the SA and camalexin responses, resulting in decreased protection against the pathogen. Our data reveal an important role of T. virens PPT1 in antibiosis and induction of SA and camalexin-dependent plant defense responses.

  16. Arabidopsis thaliana natural variation reveals connections between UV radiation stress and plant pathogen-like defense responses.

    Science.gov (United States)

    Piofczyk, Thomas; Jeena, Ganga; Pecinka, Ales

    2015-08-01

    UV radiation is a ubiquitous component of solar radiation that affects plant growth and development. Here we studied growth related traits of 345 Arabidopsis thaliana accessions in response to UV radiation stress. We analyzed the genetic basis of this natural variation by genome-wide association studies, which suggested a specific candidate genomic region. RNA-sequencing of three sensitive and three resistant accessions combined with mutant analysis revealed five large effect genes. Mutations in PHE ammonia lyase 1 (PAL1) and putative kinase At1g76360 rendered Arabidopsis hypersensitive to UV stress, while loss of function from putative methyltransferase At4g22530, novel plant snare 12 (NPSN12) and defense gene activated disease resistance 2 (ADR2) conferred higher UV stress resistance. Three sensitive accessions showed strong ADR2 transcriptional activation, accumulation of salicylic acid (SA) and dwarf growth upon UV stress, while these phenotypes were much less affected in resistant plants. The phenotype of sensitive accessions resembles autoimmune reactions due to overexpression of defense related genes, and suggests that natural variation in response to UV radiation stress is driven by pathogen-like responses in Arabidopsis. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  17. An analysis of the effect of STEM initiatives on socially responsible diversity management in the US aerospace and defense industry

    Science.gov (United States)

    Johnson-Oliver, Patrick

    Workforce diversity is a growing concern at a global level and enlightened economic self-interest and corporate image compels industries to leverage it as a competitive advantage. The US aerospace and defense industry (US ADI) addresses workforce diversity through socially responsible diversity management. Prior research into the topic of approaching workforce diversity as a business rationale and a moral imperative has been limited. Scharmer and Kaufer's (2013) Theory U guided this longitudinal explanatory quantitative study, leading from the future as it emerged relative to socially responsible diversity management to compel industry to remove blind spots and co-create an economy that benefits all by promoting workforce diversity as a dual agenda. This study filled a research gap investigating the business case for diversity as a dual agenda in aerospace industry science, technology, engineering, and mathematics (STEM) disciplines. The study also investigated the America COMPETES Act as a moderator of the relationship between historically black colleges and universities (HBCUs) and industry. Data was retrieved for secondary data analysis from the National Science Foundation (NSF) and other public government services and agency websites. Two hypotheses were tested using quantitative analysis including descriptive statistics, linear regression, ANOVA, and two factor analysis. The statistical results were analyzed and deductive logic employed to develop conclusions for the study. There was a significant relationship found between both predictors and socially responsible diversity management. The results reinforce the necessity for the aerospace defense industry to promote the dual agenda of the business case for diversity as complementary; not as competing mandates.

  18. Transcriptional Analysis of The Adaptive Digestive System of The Migratory Locust in Response to Plant Defensive Protease Inhibitors

    Science.gov (United States)

    Spit, Jornt; Holtof, Michiel; Badisco, Liesbet; Vergauwen, Lucia; Vogel, Elise; Knapen, Dries; vanden Broeck, Jozef

    2016-09-01

    Herbivorous insects evolved adaptive mechanisms to compensate for the presence of plant defensive protease inhibitors (PI) in their food. The underlying regulatory mechanisms of these compensatory responses remain largely elusive. In the current study, we investigated the initiation of this adaptive response in the migratory locust, Locusta migratoria, via microarray analysis of gut tissues. Four hours after dietary uptake of PIs, 114 and 150 transcripts were respectively found up- or downregulated. The results suggest a quick trade-off between compensating for potential loss of digestive activity on the one hand, and stress tolerance, defense, and structural integrity of the gut on the other hand. We additionally addressed the role of a group of related upregulated hexamerin-like proteins in the PI-induced response. Simultaneous knockdown of corresponding transcripts by means of RNA interference resulted in a reduced capacity of the locust nymphs to cope with the effects of PI. Moreover, since insect hexamerins have been shown to bind Juvenile Hormone (JH), we also investigated the effect of JH on the proteolytic digestion in L. migratoria. Our results indicate that JH has a stimulatory effect on the expression of three homologous chymotrypsin genes, while knocking down the JH receptor (methoprene tolerant) led to opposite effects.

  19. A meal or a male: the 'whispers' of black widow males do not trigger a predatory response in females.

    Science.gov (United States)

    Vibert, Samantha; Scott, Catherine; Gries, Gerhard

    2014-01-17

    Female spiders are fine-tuned to detect and quickly respond to prey vibrations, presenting a challenge to courting males who must attract a female's attention but not be mistaken for prey. This is likely particularly important at the onset of courtship when a male enters a female's web. In web-dwelling spiders, little is known about how males solve this conundrum, or about their courtship signals. Here we used laser Doppler vibrometry to study the vibrations produced by males and prey (house flies and crickets) on tangle webs of the western black widow Latrodectus hesperus and on sheet webs of the hobo spider Tegenaria agrestis. We recorded the vibrations at the location typically occupied by a hunting female spider. We compared the vibrations produced by males and prey in terms of their waveform, dominant frequency, frequency bandwidth, amplitude and duration. We also played back recorded male and prey vibrations through the webs of female L. hesperus to determine the vibratory parameters that trigger a predatory response in females. We found overlap in waveform between male and prey vibrations in both L. hesperus and T. agrestis. In both species, male vibrations were continuous, of long duration (on average 6.35 s for T. agrestis and 9.31 s for L. hesperus), and lacked complex temporal patterning such as repeated motifs or syllables. Prey vibrations were shorter (1.38 - 2.59 s), sporadic and often percussive. Based on the parameters measured, courtship signals of male L. hesperus differed more markedly from prey cues than did those of T. agrestis. Courtship vibrations of L. hesperus males differed from prey vibrations in terms of dominant frequency, amplitude and duration. Vibrations of T. agrestis males differed from prey in terms of duration only. During a playback experiment, L. hesperus females did not respond aggressively to low-amplitude vibrations irrespective of whether the playback recording was from a prey or a male. Unlike courtship signals of other

  20. A codimension-2 bifurcation controlling endogenous bursting activity and pulse-triggered responses of a neuron model.

    Science.gov (United States)

    Barnett, William H; Cymbalyuk, Gennady S

    2014-01-01

    The dynamics of individual neurons are crucial for producing functional activity in neuronal networks. An open question is how temporal characteristics can be controlled in bursting activity and in transient neuronal responses to synaptic input. Bifurcation theory provides a framework to discover generic mechanisms addressing this question. We present a family of mechanisms organized around a global codimension-2 bifurcation. The cornerstone bifurcation is located at the intersection of the border between bursting and spiking and the border between bursting and silence. These borders correspond to the blue sky catastrophe bifurcation and the saddle-node bifurcation on an invariant circle (SNIC) curves, respectively. The cornerstone bifurcation satisfies the conditions for both the blue sky catastrophe and SNIC. The burst duration and interburst interval increase as the inverse of the square root of the difference between the corresponding bifurcation parameter and its bifurcation value. For a given set of burst duration and interburst interval, one can find the parameter values supporting these temporal characteristics. The cornerstone bifurcation also determines the responses of silent and spiking neurons. In a silent neuron with parameters close to the SNIC, a pulse of current triggers a single burst. In a spiking neuron with parameters close to the blue sky catastrophe, a pulse of current temporarily silences the neuron. These responses are stereotypical: the durations of the transient intervals-the duration of the burst and the duration of latency to spiking-are governed by the inverse-square-root laws. The mechanisms described here could be used to coordinate neuromuscular control in central pattern generators. As proof of principle, we construct small networks that control metachronal-wave motor pattern exhibited in locomotion. This pattern is determined by the phase relations of bursting neurons in a simple central pattern generator modeled by a chain of

  1. Arsenic alters transcriptional responses to Pseudomonas aeruginosa infection and decreases antimicrobial defense of human airway epithelial cells.

    Science.gov (United States)

    Goodale, Britton C; Rayack, Erica J; Stanton, Bruce A

    2017-09-15

    Arsenic contamination of drinking water and food threatens the health of hundreds of millions of people worldwide by increasing the risk of numerous diseases. Arsenic exposure has been associated with infectious lung disease in epidemiological studies, but it is not yet understood how ingestion of low levels of arsenic increases susceptibility to bacterial infection. Accordingly, the goal of this study was to examine the effect of arsenic on gene expression in primary human bronchial epithelial (HBE) cells and to determine if arsenic altered epithelial cell responses to Pseudomonas aeruginosa, an opportunistic pathogen. Bronchial epithelial cells line the airway surface, providing a physical barrier and serving critical roles in antimicrobial defense and signaling to professional immune cells. We used RNA-seq to define the transcriptional response of HBE cells to Pseudomonas aeruginosa, and investigated how arsenic affected HBE gene networks in the presence and absence of the bacterial challenge. Environmentally relevant levels of arsenic significantly changed the expression of genes involved in cellular redox homeostasis and host defense to bacterial infection, and decreased genes that code for secreted antimicrobial factors such as lysozyme. Using pathway analysis, we identified Sox4 and Nrf2-regulated gene networks that are predicted to mediate the arsenic-induced decrease in lysozyme secretion. In addition, we demonstrated that arsenic decreased lysozyme in the airway surface liquid, resulting in reduced lysis of Microccocus luteus. Thus, arsenic alters the expression of genes and proteins in innate host defense pathways, thereby decreasing the ability of the lung epithelium to fight bacterial infection. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Defense Signaling in Plants

    Indian Academy of Sciences (India)

    Self defense is the basic response of every living organism. This response is readily observed in animals because of their physical movements typically involved in that pro- cess. Being immobile, plants have evolved highly complex defense mechanisms that differ from those commonly seen in animals. Plants are able to ...

  3. Recombinant modified vaccinia virus Ankara generating excess early double-stranded RNA transiently activates protein kinase R and triggers enhanced innate immune responses.

    Science.gov (United States)

    Wolferstätter, Michael; Schweneker, Marc; Späth, Michaela; Lukassen, Susanne; Klingenberg, Marieken; Brinkmann, Kay; Wielert, Ursula; Lauterbach, Henning; Hochrein, Hubertus; Chaplin, Paul; Suter, Mark; Hausmann, Jürgen

    2014-12-01

    Double-stranded RNA (dsRNA) is an important molecular pattern associated with viral infection and is detected by various extra- and intracellular recognition molecules. Poxviruses have evolved to avoid producing dsRNA early in infection but generate significant amounts of dsRNA late in infection due to convergent transcription of late genes. Protein kinase R (PKR) is activated by dsRNA and triggers major cellular defenses against viral infection, including protein synthesis shutdown, apoptosis, and type I interferon (IFN-I) production. The poxviral E3 protein binds and sequesters viral dsRNA and is a major antagonist of the PKR pathway. We found that the highly replication-restricted modified vaccinia virus Ankara (MVA) engineered to produce excess amounts of dsRNA early in infection showed enhanced induction of IFN-β in murine and human cells in the presence of an intact E3L gene. IFN-β induction required a minimum overlap length of 300 bp between early complementary transcripts and was strongly PKR dependent. Excess early dsRNA produced by MVA activated PKR early but transiently in murine cells and induced enhanced systemic levels of IFN-α, IFN-γ, and other cytokines and chemokines in mice in a largely PKR-dependent manner. Replication-competent chorioallantois vaccinia virus Ankara (CVA) generating excess early dsRNA also enhanced IFN-I production and was apathogenic in mice even at very high doses but showed no in vitro host range defect. Thus, genetically adjuvanting MVA and CVA to generate excess early dsRNA is an effective method to enhance innate immune stimulation by orthopoxvirus vectors and to attenuate replicating vaccinia virus in vivo. Efficient cellular sensing of pathogen-specific components, including double-stranded RNA (dsRNA), is an important prerequisite of an effective antiviral immune response. The prototype poxvirus vaccinia virus (VACV) and its derivative modified vaccinia virus Ankara (MVA) produce dsRNA as a by-product of viral

  4. Nuclear DNA damage-triggered NLRP3 inflammasome activation promotes UVB-induced inflammatory responses in human keratinocytes

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Tatsuya, E-mail: tatsuya.hasegawa@to.shiseido.co.jp; Nakashima, Masaya; Suzuki, Yoshiharu

    2016-08-26

    Ultraviolet (UV) radiation in sunlight can result in DNA damage and an inflammatory reaction of the skin commonly known as sunburn, which in turn can lead to cutaneous tissue disorders. However, little has been known about how UV-induced DNA damage mediates the release of inflammatory mediators from keratinocytes. Here, we show that UVB radiation intensity-dependently increases NLRP3 gene expression and IL-1β production in human keratinocytes. Knockdown of NLRP3 with siRNA suppresses UVB-induced production of not only IL-1β, but also other inflammatory mediators, including IL-1α, IL-6, TNF-α, and PGE{sub 2}. In addition, inhibition of DNA damage repair by knockdown of XPA, which is a major component of the nucleotide excision repair system, causes accumulation of cyclobutane pyrimidine dimer (CPD) and activation of NLRP3 inflammasome. In vivo immunofluorescence analysis confirmed that NLRP3 expression is also elevated in UV-irradiated human epidermis. Overall, our findings indicate that UVB-induced DNA damage initiates NLRP3 inflammasome activation, leading to release of various inflammatory mediators from human keratinocytes. - Highlights: • UVB radiation induces NLRP3 inflammasome activation in human keratinocytes. • NLRP3 knockdown suppresses production of UVB-induced inflammatory mediators. • UVB-induced DNA damage triggers NLRP3 inflammasome activation. • NLRP3 expression in human epidermis is elevated in response to UV radiation.

  5. Smart pH-responsive upconversion nanoparticles for enhanced tumor cellular internalization and near-infrared light-triggered photodynamic therapy.

    Science.gov (United States)

    Wang, Sheng; Zhang, Lei; Dong, Chunhong; Su, Lin; Wang, Hanjie; Chang, Jin

    2015-01-01

    A smart pH-responsive photodynamic therapy system based on upconversion nanoparticle loaded PEG coated polymeric lipid vesicles (RB-UPPLVs) was designed and prepared. These RB-UPPLVs which are promising agents for deep cancer photodynamic therapy applications can achieve enhanced tumor cellular internalization and near-infrared light-triggered photodynamic therapy.

  6. NAD1 Controls Defense-Like Responses in Medicago truncatula Symbiotic Nitrogen Fixing Nodules Following Rhizobial Colonization in a BacA-Independent Manner.

    Science.gov (United States)

    Domonkos, Ágota; Kovács, Szilárd; Gombár, Anikó; Kiss, Ernő; Horváth, Beatrix; Kováts, Gyöngyi Z; Farkas, Attila; Tóth, Mónika T; Ayaydin, Ferhan; Bóka, Károly; Fodor, Lili; Ratet, Pascal; Kereszt, Attila; Endre, Gabriella; Kaló, Péter

    2017-12-14

    Legumes form endosymbiotic interaction with host compatible rhizobia, resulting in the development of nitrogen-fixing root nodules. Within symbiotic nodules, rhizobia are intracellularly accommodated in plant-derived membrane compartments, termed symbiosomes. In mature nodule, the massively colonized cells tolerate the existence of rhizobia without manifestation of visible defense responses, indicating the suppression of plant immunity in the nodule in the favur of the symbiotic partner. Medicago truncatula DNF2 (defective in nitrogen fixation 2) and NAD1 (nodules with activated defense 1) genes are essential for the control of plant defense during the colonization of the nitrogen-fixing nodule and are required for bacteroid persistence. The previously identified nodule-specific NAD1 gene encodes a protein of unknown function. Herein, we present the analysis of novel NAD1 mutant alleles to better understand the function of NAD1 in the repression of immune responses in symbiotic nodules. By exploiting the advantage of plant double and rhizobial mutants defective in establishing nitrogen-fixing symbiotic interaction, we show that NAD1 functions following the release of rhizobia from the infection threads and colonization of nodule cells. The suppression of plant defense is self-dependent of the differentiation status of the rhizobia. The corresponding phenotype of nad1 and dnf2 mutants and the similarity in the induction of defense-associated genes in both mutants suggest that NAD1 and DNF2 operate close together in the same pathway controlling defense responses in symbiotic nodules.

  7. HMGB1 blockade differentially impacts pulmonary inflammation and defense responses in poly(I:C)/LPS-exposed heart transplant mice.

    Science.gov (United States)

    Ming, Bingxia; Gao, Ming; Zou, Huijuan; Chen, Huoying; Sun, Yan; Xiao, Yifan; Lai, Lin; Xiong, Ping; Xu, Yong; Tan, Zheng; Wang, Jing; Chen, Gang; Gong, Feili; Xia, Jiahong; Zheng, Fang

    2016-08-01

    A large number of recipients are in a compromised immune defense condition because of the routine application of immunosuppressive regimens after heart transplantation. Our previous work demonstrated that blockade of high-mobility group box 1 (HMGB1) prolongs the graft survival. Whether and how HMGB1 blockade impacts respiratory responses against pathogen-like challenge in organ transplant recipients when it improves cardiac graft are not elucidated. At the present study, after abdominal heterotopic heart transplantation, the recipient mice were treated with HMGB1 mAb, and then challenged with poly(I:C) or LPS intratracheally on day 7 post transplantation. We found that the level of bronchoalveolar lavage (BAL) HMGB1 was elevated after heart transplantation, and aggravated responses to respiratory tract poly(I:C)/LPS challenge were observed. HMGB1 neutralizing mAb treatment in poly(I:C)-challenged recipient mice alleviated pulmonary histopathological changes, neutrophil infiltration and inflammatory cytokine release, but unaffected the level of IFN-β, the distribution of CD11b(+)CD27(+)/CD11b(+)CD27(-) NK cell subsets, and CD8(+) T cell responses. In LPS-exposed recipient mice, HMGB1 mAb treatment ameliorated pulmonary inflammatory damage and enhanced the phagocytosis of phagocytic cells. Thus, this study may establish a basis for the application of HMGB1 blockade to improve the outcomes of heart transplant recipients because HMGB1 inhibition ameliorates pulmonary inflammation, but maintains defense-associated responses. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Different Arabidopsis thaliana photosynthetic and defense responses to hemibiotrophic pathogen induced by local or distal inoculation of Burkholderia phytofirmans.

    Science.gov (United States)

    Su, Fan; Villaume, Sandra; Rabenoelina, Fanja; Crouzet, Jérôme; Clément, Christophe; Vaillant-Gaveau, Nathalie; Dhondt-Cordelier, Sandrine

    2017-11-01

    Pathogen infection of plant results in modification of photosynthesis and defense mechanisms. Beneficial microorganisms are known to improve plant tolerance to stresses. Burkholderia phytofirmans PsJN (Bp), a beneficial endophytic bacterium, promotes growth of a wide range of plants and induces plant resistance against abiotic and biotic stresses such as coldness and infection by a necrotrophic pathogen. However, mechanisms underlying its role in plant tolerance towards (hemi)biotrophic invaders is still lacking. We thus decipher photosynthetic and defense responses during the interaction between Arabidopsis, Bp and the hemibiotrophic bacterium Pseudomonas syringae pv. tomato DC3000 (Pst). Different Bp inoculations allowed analyzes at both systemic and local levels. Despite no direct antibacterial action, our results showed that only local presence of Bp alleviates Pst growth in planta during the early stage of infection. Molecular investigations showed that seed inoculation of Bp, leading to a restricted presence in the root system, transiently primed PR1 expression after challenge with Pst but continuously primed PDF1.2 expression. Bacterization with Bp reduced Y(ND) but had no impact on PSII activity or RuBisCO accumulation. Pst infection caused an increase of Y(NA) and a decrease in ΦPSI, ETRI and in PSII activity, showed by a decrease in Fv/Fm, Y(NPQ), ΦPSII, and ETRII values. Inoculation with both bacteria did not display any variation in photosynthetic activity compared to plants inoculated with only Pst. Our findings indicated that the role of Bp here is not multifaceted, and relies only on priming of defense mechanisms but not on improving photosynthetic activity.

  9. Induction of defense responses in common bean plants by arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Abdel-Fattah, G M; El-Haddad, S A; Hafez, E E; Rashad, Y M

    2011-05-20

    Interaction between arbuscular mycorrhizal fungi as a bio-agent and Rhizoctonia root rot disease of common bean plant was investigated in this study under natural conditions in pot experiment. A mixture of Egyptian formulated AM (Multi-VAM) in suspension form (1 × 10(6) unit L(-1) in concentration) was used at dilution of 5 ml L(-1) water. The results demonstrated that colonization of bean plants with AM fungi significantly increased growth parameters, yield parameters and mineral nutrient concentrations and reduced the negative effects on these parameters as well as both disease severity and disease incidence. Different physical and biochemical mechanisms have been shown to play a role in enhancement of plant resistance against Rhizoctonia solani, namely, improved plant nutrition, improved plant growth, increase in cell wall thickening, cytoplasmic granulation, and accumulation of some antimicrobial substances (phenolic compounds and defense related enzymes). Copyright © 2010 Elsevier GmbH. All rights reserved.

  10. Activation of Proinflammatory Responses in Cells of the Airway Mucosa by Particulate Matter: Oxidant- and Non-Oxidant-Mediated Triggering Mechanisms

    Directory of Open Access Journals (Sweden)

    Johan Øvrevik

    2015-07-01

    Full Text Available Inflammation is considered to play a central role in a diverse range of disease outcomes associated with exposure to various types of inhalable particulates. The initial mechanisms through which particles trigger cellular responses leading to activation of inflammatory responses are crucial to clarify in order to understand what physico-chemical characteristics govern the inflammogenic activity of particulate matter and why some particles are more harmful than others. Recent research suggests that molecular triggering mechanisms involved in activation of proinflammatory genes and onset of inflammatory reactions by particles or soluble particle components can be categorized into direct formation of reactive oxygen species (ROS with subsequent oxidative stress, interaction with the lipid layer of cellular membranes, activation of cell surface receptors, and direct interactions with intracellular molecular targets. The present review focuses on the immediate effects and responses in cells exposed to particles and central down-stream signaling mechanisms involved in regulation of proinflammatory genes, with special emphasis on the role of oxidant and non-oxidant triggering mechanisms. Importantly, ROS act as a central second-messenger in a variety of signaling pathways. Even non-oxidant mediated triggering mechanisms are therefore also likely to activate downstream redox-regulated events.

  11. Pseudomonas fluorescens induces strain-dependent and strain-independent host plant responses in defense networks, primary metabolism and photosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Pelletier, Dale A [ORNL; Morrell-Falvey, Jennifer L [ORNL; Karve, Abhijit A [ORNL; Lu, Tse-Yuan S [ORNL; Tschaplinski, Timothy J [ORNL; Tuskan, Gerald A [ORNL; Chen, Jay [ORNL; Martin, Madhavi Z [ORNL; Jawdy, Sara [ORNL; Weston, David [ORNL; Doktycz, Mitchel John [ORNL; Schadt, Christopher Warren [ORNL

    2012-01-01

    Colonization of plants by nonpathogenic Pseudomonas fluorescens strains can confer enhanced defense capacity against a broad spectrum of pathogens. Few studies, however, have linked defense pathway regulation to primary metabolism and physiology. In this study, physiological data, metabolites, and transcript profiles are integrated to elucidate how molecular networks initiated at the root-microbe interface influence shoot metabolism and whole-plant performance. Experiments with Arabidopsis thaliana were performed using the newly identified P. fluorescens GM30 or P. fluorescens Pf-5 strains. Co-expression networks indicated that Pf-5 and GM30 induced a subnetwork specific to roots enriched for genes participating in RNA regulation, protein degradation, and hormonal metabolism. In contrast, only GM30 induced a subnetwork enriched for calcium signaling, sugar and nutrient signaling, and auxin metabolism, suggesting strain dependence in network architecture. In addition, one subnetwork present in shoots was enriched for genes in secondary metabolism, photosynthetic light reactions, and hormone metabolism. Metabolite analysis indicated that this network initiated changes in carbohydrate and amino acid metabolism. Consistent with this, we observed strain-specific responses in tryptophan and phenylalanine abundance. Both strains reduced host plant carbon gain and fitness, yet provided a clear fitness benefit when plants were challenged with the pathogen P. syringae DC3000.

  12. Overexpression of a rice NPR1 homolog leads to constitutive activation of defense response and hypersensitivity to light.

    Science.gov (United States)

    Chern, Mawsheng; Fitzgerald, Heather A; Canlas, Patrick E; Navarre, Duroy A; Ronald, Pamela C

    2005-06-01

    Arabidopsis NPR1/NIM1 is a key regulator of systemic acquired resistance (SAR), which confers lasting broad-spectrum resistance. Previous reports indicate that rice has a disease-resistance pathway similar to the Arabidopsis SAR pathway. Here we report the isolation and characterization of a rice NPR1 homologue (NH1). Transgenic rice plants overexpressing NH1 (NH1ox) acquire high levels of resistance to Xanthomonas oryzae pv. oryzae. The resistance phenotype is heritable and correlates with the presence of the transgene and reduced bacterial growth. Northern analysis shows that NH1ox rice spontaneously activates defense genes, contrasting with NPR1-overexpressing Arabidopsis, where defense genes are not activated until induction. Wild-type NH1, but not a point mutant corresponding to npr1-1, interacts strongly with the rice transcription factor rTGA2.2 in yeast two-hybrid. Greenhouse-grown NH1ox plants develop lesion-mimic spots on leaves at preflowering stage although no other developmental effects are observed. However, when grown in growth chambers (GCs) under low light, NH1ox plants are dwarfed, indicating elevated sensitivity to light. The GC-grown NH1ox plants show much higher salicylic acid (SA) levels than the wild type, whereas greenhouse-grown NH1ox plants contain lower SA. These results indicate that NH1 may be involved in the regulation of SA in response to environmental changes.

  13. Bacillus cereus AR156 induces resistance against Rhizopus rot through priming of defense responses in peach fruit.

    Science.gov (United States)

    Wang, Xiaoli; Xu, Feng; Wang, Jing; Jin, Peng; Zheng, Yonghua

    2013-01-15

    The biocontrol effects of Bacillus cereus AR156 on Rhizopus rot caused by Rhizopus stolonifer in postharvest peach fruit and the possible mechanisms were investigated. The results showed that fruit treated with B. cereus AR156 had significantly lower disease incidence and smaller lesion diameter than the control fruit did. B. cereus AR156 treatment remarkably enhanced activities of chitinase and β-1,3-glucanase, promoted accumulation of H(2)O(2), and improved total phenolic content and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity. Transcripts of four defense related genes were only significantly enhanced in fruit both treated with B. cereus AR156 and inoculated with R. stolonifer compared with those that were only treated with B. cereus AR156 or inoculated with R. stolonifer. These results suggest that B. cereus AR156 can effectively inhibit Rhizopus rot caused by R. stolonifer and enhance antioxidant activity in peach fruit through the priming of defense responses. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Behavioral responses to a repetitive visual threat stimulus express a persistent state of defensive arousal in Drosophila.

    Science.gov (United States)

    Gibson, William T; Gonzalez, Carlos R; Fernandez, Conchi; Ramasamy, Lakshminarayanan; Tabachnik, Tanya; Du, Rebecca R; Felsen, Panna D; Maire, Michael R; Perona, Pietro; Anderson, David J

    2015-06-01

    The neural circuit mechanisms underlying emotion states remain poorly understood. Drosophila offers powerful genetic approaches for dissecting neural circuit function, but whether flies exhibit emotion-like behaviors has not been clear. We recently proposed that model organisms may express internal states displaying "emotion primitives," which are general characteristics common to different emotions, rather than specific anthropomorphic emotions such as "fear" or "anxiety." These emotion primitives include scalability, persistence, valence, and generalization to multiple contexts. Here, we have applied this approach to determine whether flies' defensive responses to moving overhead translational stimuli ("shadows") are purely reflexive or may express underlying emotion states. We describe a new behavioral assay in which flies confined in an enclosed arena are repeatedly exposed to an overhead translational stimulus. Repetitive stimuli promoted graded (scalable) and persistent increases in locomotor velocity and hopping, and occasional freezing. The stimulus also dispersed feeding flies from a food resource, suggesting both negative valence and context generalization. Strikingly, there was a significant delay before the flies returned to the food following stimulus-induced dispersal, suggestive of a slowly decaying internal defensive state. The length of this delay was increased when more stimuli were delivered for initial dispersal. These responses can be mathematically modeled by assuming an internal state that behaves as a leaky integrator of stimulus exposure. Our results suggest that flies' responses to repetitive visual threat stimuli express an internal state exhibiting canonical emotion primitives, possibly analogous to fear in mammals. The mechanistic basis of this state can now be investigated in a genetically tractable insect species. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. A genome-wide association study of the maize hypersensitive defense response identifies genes that cluster in related pathways.

    Directory of Open Access Journals (Sweden)

    Bode A Olukolu

    2014-08-01

    Full Text Available Much remains unknown of molecular events controlling the plant hypersensitive defense response (HR, a rapid localized cell death that limits pathogen spread and is mediated by resistance (R- genes. Genetic control of the HR is hard to quantify due to its microscopic and rapid nature. Natural modifiers of the ectopic HR phenotype induced by an aberrant auto-active R-gene (Rp1-D21, were mapped in a population of 3,381 recombinant inbred lines from the maize nested association mapping population. Joint linkage analysis was conducted to identify 32 additive but no epistatic quantitative trait loci (QTL using a linkage map based on more than 7000 single nucleotide polymorphisms (SNPs. Genome-wide association (GWA analysis of 26.5 million SNPs was conducted after adjusting for background QTL. GWA identified associated SNPs that colocalized with 44 candidate genes. Thirty-six of these genes colocalized within 23 of the 32 QTL identified by joint linkage analysis. The candidate genes included genes predicted to be in involved programmed cell death, defense response, ubiquitination, redox homeostasis, autophagy, calcium signalling, lignin biosynthesis and cell wall modification. Twelve of the candidate genes showed significant differential expression between isogenic lines differing for the presence of Rp1-D21. Low but significant correlations between HR-related traits and several previously-measured disease resistance traits suggested that the genetic control of these traits was substantially, though not entirely, independent. This study provides the first system-wide analysis of natural variation that modulates the HR response in plants.

  16. A Genome-Wide Association Study of the Maize Hypersensitive Defense Response Identifies Genes That Cluster in Related Pathways

    Science.gov (United States)

    Venkata, Bala P.; Marla, Sandeep; Ji, Jiabing; Gachomo, Emma; Chu, Kevin; Negeri, Adisu; Benson, Jacqueline; Nelson, Rebecca; Bradbury, Peter; Nielsen, Dahlia; Holland, James B.; Balint-Kurti, Peter J.; Johal, Gurmukh

    2014-01-01

    Much remains unknown of molecular events controlling the plant hypersensitive defense response (HR), a rapid localized cell death that limits pathogen spread and is mediated by resistance (R-) genes. Genetic control of the HR is hard to quantify due to its microscopic and rapid nature. Natural modifiers of the ectopic HR phenotype induced by an aberrant auto-active R-gene (Rp1-D21), were mapped in a population of 3,381 recombinant inbred lines from the maize nested association mapping population. Joint linkage analysis was conducted to identify 32 additive but no epistatic quantitative trait loci (QTL) using a linkage map based on more than 7000 single nucleotide polymorphisms (SNPs). Genome-wide association (GWA) analysis of 26.5 million SNPs was conducted after adjusting for background QTL. GWA identified associated SNPs that colocalized with 44 candidate genes. Thirty-six of these genes colocalized within 23 of the 32 QTL identified by joint linkage analysis. The candidate genes included genes predicted to be in involved programmed cell death, defense response, ubiquitination, redox homeostasis, autophagy, calcium signalling, lignin biosynthesis and cell wall modification. Twelve of the candidate genes showed significant differential expression between isogenic lines differing for the presence of Rp1-D21. Low but significant correlations between HR-related traits and several previously-measured disease resistance traits suggested that the genetic control of these traits was substantially, though not entirely, independent. This study provides the first system-wide analysis of natural variation that modulates the HR response in plants. PMID:25166276

  17. Mining whole genomes and transcriptomes of Jatropha (Jatropha curcas) and Castor bean (Ricinus communis) for NBS-LRR genes and defense response associated transcription factors.

    Science.gov (United States)

    Sood, Archit; Jaiswal, Varun; Chanumolu, Sree Krishna; Malhotra, Nikhil; Pal, Tarun; Chauhan, Rajinder Singh

    2014-11-01

    Jatropha (Jatropha curcas L.) and Castor bean (Ricinus communis) are oilseed crops of family Euphorbiaceae with the potential of producing high quality biodiesel and having industrial value. Both the bioenergy plants are becoming susceptible to various biotic stresses directly affecting the oil quality and content. No report exists as of today on analysis of Nucleotide Binding Site-Leucine Rich Repeat (NBS-LRR) gene repertoire and defense response transcription factors in both the plant species. In silico analysis of whole genomes and transcriptomes identified 47 new NBS-LRR genes in both the species and 122 and 318 defense response related transcription factors in Jatropha and Castor bean, respectively. The identified NBS-LRR genes and defense response transcription factors were mapped onto the respective genomes. Common and unique NBS-LRR genes and defense related transcription factors were identified in both the plant species. All NBS-LRR genes in both the species were characterized into Toll/interleukin-1 receptor NBS-LRRs (TNLs) and coiled-coil NBS-LRRs (CNLs), position on contigs, gene clusters and motifs and domains distribution. Transcript abundance or expression values were measured for all NBS-LRR genes and defense response transcription factors, suggesting their functional role. The current study provides a repertoire of NBS-LRR genes and transcription factors which can be used in not only dissecting the molecular basis of disease resistance phenotype but also in developing disease resistant genotypes in Jatropha and Castor bean through transgenic or molecular breeding approaches.

  18. Responses to falling lll: defense mechanisms used by women with Turner syndrome and variants

    Directory of Open Access Journals (Sweden)

    Vera Lúcia Soares Chvatal

    2009-01-01

    Full Text Available BACKGROUND: Article extracted from the doctoral research entitled "Experiences of the infertility phenomenon by patients suffering from Turner syndrome and variants: a clinical-qualitative study" approved by the University of Campinas. OBJECTIVES: To understand the defenses employed by women suffering from TS and different ways of dealing with the disease. METHOD: Qualitative research with exploratory design, non-experimental. The instrument consisted of a semidirect psychological interview, involving 13 women, undergoing semestral medical follow-up at the Center for Integral Attention to Women's Health (CAISM, and whose sampling was determined by saturation. Data was interpreted using the psychodynamic approach along with an eclectic framework of theoretical references for discussion in the spirit of interdisciplinary approach. RESULTS:These women displayed psychosocial conflicts such as difficulties in interpersonal relationships; feelings of resignation, anger, impotence, devaluation and depression symptoms. Defenses used were: repression, denial, annulment, fantasizing, adaptation and sublimation. DISCUSSION: Women suffering from TS and variants must deal with the disease's organic and psychic implications that cause great suffering and often hinder a saner social insertion. In this case, the study's findings can guide ambulatory psychological support concomitantly to the routine clinical protocol.OBJETIVO:Conhecer as defesas utilizadas por mulheres com síndrome de Turner (ST ou formas variantes para lidar com a doença. MÉTODO: Pesquisa qualitativa com desenho exploratório, não experimental. O instrumento consistiu em entrevista psicológica semidirigida, aplicada em 13 mulheres, cuja amostragem deu-se por saturação, as quais fazem acompanhamento semestral no Centro de Atendimento Integral à Saúde da Mulher. Os dados foram interpretados utilizando-se da abordagem psicodinâmica, aliada a um quadro eclético de referenciais te

  19. Disruption of Ethylene Responses by Turnip mosaic virus Mediates Suppression of Plant Defense against the Green Peach Aphid Vector.

    Science.gov (United States)

    Casteel, Clare L; De Alwis, Manori; Bak, Aurélie; Dong, Haili; Whitham, Steven A; Jander, Georg

    2015-09-01

    Plants employ diverse responses mediated by phytohormones to defend themselves against pathogens and herbivores. Adapted pathogens and herbivores often manipulate these responses to their benefit. Previously, we demonstrated that Turnip mosaic virus (TuMV) infection suppresses callose deposition, an important plant defense induced in response to feeding by its aphid vector, the green peach aphid (Myzus persicae), and increases aphid fecundity compared with uninfected control plants. Further, we determined that production of a single TuMV protein, Nuclear Inclusion a-Protease (NIa-Pro) domain, was responsible for changes in host plant physiology and increased green peach aphid reproduction. To characterize the underlying molecular mechanisms of this phenomenon, we examined the role of three phytohormone signaling pathways, jasmonic acid, salicylic acid, and ethylene (ET), in TuMV-infected Arabidopsis (Arabidopsis thaliana), with or without aphid herbivory. Experiments with Arabidopsis mutants ethylene insensitive2 and ethylene response1, and chemical inhibitors of ET synthesis and perception (aminoethoxyvinyl-glycine and 1-methylcyclopropene, respectively), show that the ET signaling pathway is required for TuMV-mediated suppression of Arabidopsis resistance to the green peach aphid. Additionally, transgenic expression of NIa-Pro in Arabidopsis alters ET responses and suppresses aphid-induced callose formation in an ET-dependent manner. Thus, disruption of ET responses in plants is an additional function of NIa-Pro, a highly conserved potyvirus protein. Virus-induced changes in ET responses may mediate vector-plant interactions more broadly and thus represent a conserved mechanism for increasing transmission by insect vectors across generations. © 2015 American Society of Plant Biologists. All Rights Reserved.

  20. Proteomic analysis of Daphnia magna hints at molecular pathways involved in defensive plastic responses

    Science.gov (United States)

    2014-01-01

    Background Phenotypic plasticity in defensive traits occurs in many species when facing heterogeneous predator regimes. The waterflea Daphnia is well-known for showing a variety of these so called inducible defences. However, molecular mechanisms underlying this plasticity are poorly understood so far. We performed proteomic analysis on Daphnia magna exposed to chemical cues of the predator Triops cancriformis. D. magna develops an array of morphological changes in the presence of Triops including changes of carapace morphology and cuticle hardening. Results Using the 2D-DIGE technique, 1500 protein spots could be matched and quantified. We discovered 179 protein spots with altered intensity when comparing Triops exposed animals to a control group, and 69 spots were identified using nano-LC MS/MS. Kairomone exposure increased the intensity of spots containing muscle proteins, cuticle proteins and chitin-modifying enzymes as well as enzymes of carbohydrate and energy metabolism. The yolk precursor protein vitellogenin decreased in abundance in 41 of 43 spots. Conclusion Identified proteins may be either directly involved in carapace stability or reflect changes in energy demand and allocation costs in animals exposed to predator kairomones. Our results present promising candidate proteins involved in the expression of inducible defences in Daphnia and enable further in depth analysis of this phenomenon. PMID:24762235

  1. System response of a DOE Defense Program package in a transportation accident environment

    International Nuclear Information System (INIS)

    Chen, T.F.; Hovingh, J.; Kimura, C.Y.

    1992-01-01

    The system response in a transportation accident environment is an element to be considered in an overall Transportation System Risk Assessment (TSRA) framework. The system response analysis uses the accident conditions and the subsequent accident progression analysis to develop the accident source term, which in turn, is used in the consequence analysis. This paper proposes a methodology for the preparation of the system response aspect of the TSRA

  2. Involvement of an antioxidant defense system in the adaptive response to cadmium in maize seedlings (Zea mays L.).

    Science.gov (United States)

    Xu, Xianghua; Liu, Cuiying; Zhao, Xiaoyan; Li, Renying; Deng, Wenjing

    2014-11-01

    Chemical and biological analyses were used to investigate the growth response and antioxidant defense mechanism of maize seedlings (Zea mays L.) grown in soils with 0-100 mg kg(-1) Cd. Results showed that maize seedlings have strong abilities to accumulate and tolerate high concentrations of Cd. For soil with 50 mg kg(-1) Cd, the Cd contents in roots and shoots of maize seedlings are as large as 295.6 and 153.0 mg kg(-1) DW, respectively, without visible symptoms of toxicity. Lower soil Cd concentrations lead to a decrease in reduced glutathione (GSH) content in leaves of maize seedlings, whereas higher soil Cd concentrations resulted in an increase in the activities of superoxide dismutase, guaiacol peroxidase, catalase, and ascorbate peroxidase. Maize seedlings have strong capacities to adapt to low concentrations of Cd by consuming GSH and to develop an antioxidative enzyme system to defend against high-Cd stress.

  3. Possible role of glutamine synthetase in the NO signaling response in root nodules by contributing to the antioxidant defenses

    Directory of Open Access Journals (Sweden)

    Liliana Santos Silva

    2013-09-01

    Full Text Available Nitric oxide (NO is emerging as an important regulatory player in the Rhizobium-legume symbiosis. The occurrence of NO during several steps of the symbiotic interaction suggests an important, but yet unknown, signaling role of this molecule for root nodule formation and functioning. The identification of the molecular targets of NO is key for the assembly of the signal transduction cascade that will ultimately help to unravel NO function. We have recently shown that the key nitrogen assimilatory enzyme Glutamine Synthetase (GS is a molecular target of NO in root nodules of Medicago truncatula, being post-translationally regulated by tyrosine nitration in relation to nitrogen fixation. In functional nodules of M. truncatula NO formation has been located in the bacteroid containing cells of the fixation zone, where the ammonium generated by bacterial nitrogenase is released to the plant cytosol and assimilated into the organic pools by plant GS. We propose that the NO-mediated GS post-translational inactivation is connected to nitrogenase inhibition induced by NO and is related to metabolite channeling to boost the nodule antioxidant defenses. Glutamate, a substrate for GS activity is also the precursor for the synthesis of glutathione (GSH, which is highly abundant in root nodules of several plant species and known to play a major role in the antioxidant defense participating in the ascorbate/GSH cycle. Existing evidence suggests that upon NO-mediated GS inhibition, glutamate could be channeled for the synthesis of GSH. According to this hypothesis, GS would be involved in the NO-signaling responses in root nodules and the NO-signaling events would meet the nodule metabolic pathways to provide an adaptive response to the inhibition of symbiotic nitrogen fixation by reactive nitrogen species (RNS.

  4. Peroxisomal hydrogen peroxide is coupled to biotic defense responses by ISOCHORISMATE SYNTHASE1 in a daylength-related manner.

    Science.gov (United States)

    Chaouch, Sejir; Queval, Guillaume; Vanderauwera, Sandy; Mhamdi, Amna; Vandorpe, Michaël; Langlois-Meurinne, Mathilde; Van Breusegem, Frank; Saindrenan, Patrick; Noctor, Graham

    2010-08-01

    While it is well established that reactive oxygen species can induce cell death, intracellularly generated oxidative stress does not induce lesions in the Arabidopsis (Arabidopsis thaliana) photorespiratory mutant cat2 when plants are grown in short days (SD). One interpretation of this observation is that a function necessary to couple peroxisomal hydrogen peroxide (H(2)O(2))-triggered oxidative stress to cell death is only operative in long days (LD). Like lesion formation, pathogenesis-related genes and camalexin were only induced in cat2 in LD, despite less severe intracellular redox perturbation compared with SD. Lesion formation triggered by peroxisomal H(2)O(2) was modified by introducing secondary mutations into the cat2 background and was completely absent in cat2 sid2 double mutants, in which ISOCHORISMATE SYNTHASE1 (ICS1) activity is defective. In addition to H(2)O(2)-induced salicylic acid (SA) accumulation, the sid2 mutation in ICS1 abolished a range of LD-dependent pathogen responses in cat2, while supplementation of cat2 with SA in SD activated these responses. Nontargeted transcript and metabolite profiling identified clusters of genes and small molecules associated with the daylength-dependent ICS1-mediated relay of H(2)O(2) signaling. The effect of oxidative stress in cat2 on resistance to biotic challenge was dependent on both growth daylength and ICS1. We conclude that (1) lesions induced by intracellular oxidative stress originating in the peroxisomes can be genetically reverted; (2) the isochorismate pathway of SA synthesis couples intracellular oxidative stress to cell death and associated disease resistance responses; and (3) camalexin accumulation was strictly dependent on the simultaneous presence of both H(2)O(2) and SA signals.

  5. Heterogeneity in Signaled Active Avoidance: Substantive and Methodological Relevance of Diversity in Instrumental Defensive Responses to Threat Cues

    Directory of Open Access Journals (Sweden)

    Isaac Robert Galatzer-Levy

    2014-09-01

    Full Text Available Individuals exposed to traumatic stressors follow divergent patterns including resilience and chronic stress. However, researchers utilizing animal models that examine threat responses typically use central tendency statistics that assume population homogeneity, potentially overlooking fundamental differences that can explain human diversity in response to traumatic stressors. The current study tests this assumption by identifying and replicating common heterogeneous patterns of response to signaled active avoidance (AA training where rats are trained to prevent an aversive outcome (shock by performing a instrumental behavior (shuttling between chambers during the presentation of a conditioned threat cue (tone. Study 1 conducted three days of signaled AA training (n = 81 animals and study 2 conducted five days of training (n = 186 animals. Four trajectories were identified in both samples including animals that acquired and retained avoidance behavior on the first day (Rapid Avoiders: 22% & 25%; those who never successfully acquired avoidance (Non-Avoiders; 20% &16%; a modal class who acquired avoidance over three days (Modal Avoiders; 37% & 50%; and a population who demonstrated a slow pattern of avoidance, failed to fully acquire avoidance in study 1 and did acquire avoidance on days 4 and 5 in study 2 (Slow Avoiders; 22.0% & 9%. With the exception of the Slow Avoiders in Study 1, populations that acquired demonstrated rapid step-like increases leading to asymptotic levels of avoidance. These findings indicate that avoidance responses are heterogeneous in a way that may be informative for understanding resilience and chronic stress responses such as PTSD as well as the nature of instrumental behavior acquisition. Characterizing heterogeneous populations based on their response to threat cues would increase the accuracy and translatability of such models and potentially lead to new discoveries that explain diversity in instrumental defensive

  6. Polyamines Attenuate Ethylene-Mediated Defense Responses to Abrogate Resistance to Botrytis cinerea in Tomato1[C][W][OA

    Science.gov (United States)

    Nambeesan, Savithri; AbuQamar, Synan; Laluk, Kristin; Mattoo, Autar K.; Mickelbart, Michael V.; Ferruzzi, Mario G.; Mengiste, Tesfaye; Handa, Avtar K.

    2012-01-01

    Transgenic tomato (Solanum lycopersicum) lines overexpressing yeast spermidine synthase (ySpdSyn), an enzyme involved in polyamine (PA) biosynthesis, were developed. These transgenic lines accumulate higher levels of spermidine (Spd) than the wild-type plants and were examined for responses to the fungal necrotrophs Botrytis cinerea and Alternaria solani, bacterial pathogen Pseudomonas syringae pv tomato DC3000, and larvae of the chewing insect tobacco hornworm (Manduca sexta). The Spd-accumulating transgenic tomato lines were more susceptible to B. cinerea than the wild-type plants; however, responses to A. solani, P. syringae, or M. sexta were similar to the wild-type plants. Exogenous application of ethylene precursors, S-adenosyl-Met and 1-aminocyclopropane-1-carboxylic acid, or PA biosynthesis inhibitors reversed the response of the transgenic plants to B. cinerea. The increased susceptibility of the ySpdSyn transgenic tomato to B. cinerea was associated with down-regulation of gene transcripts involved in ethylene biosynthesis and signaling. These data suggest that PA-mediated susceptibility to B. cinerea is linked to interference with the functions of ethylene in plant defense. PMID:22128140

  7. Inactivation of PNKP by mutant ATXN3 triggers apoptosis by activating the DNA damage-response pathway in SCA3.

    Directory of Open Access Journals (Sweden)

    Rui Gao

    2015-01-01

    Full Text Available Spinocerebellar ataxia type 3 (SCA3, also known as Machado-Joseph disease (MJD, is an untreatable autosomal dominant neurodegenerative disease, and the most common such inherited ataxia worldwide. The mutation in SCA3 is the expansion of a polymorphic CAG tri-nucleotide repeat sequence in the C-terminal coding region of the ATXN3 gene at chromosomal locus 14q32.1. The mutant ATXN3 protein encoding expanded glutamine (polyQ sequences interacts with multiple proteins in vivo, and is deposited as aggregates in the SCA3 brain. A large body of literature suggests that the loss of function of the native ATNX3-interacting proteins that are deposited in the polyQ aggregates contributes to cellular toxicity, systemic neurodegeneration and the pathogenic mechanism in SCA3. Nonetheless, a significant understanding of the disease etiology of SCA3, the molecular mechanism by which the polyQ expansions in the mutant ATXN3 induce neurodegeneration in SCA3 has remained elusive. In the present study, we show that the essential DNA strand break repair enzyme PNKP (polynucleotide kinase 3'-phosphatase interacts with, and is inactivated by, the mutant ATXN3, resulting in inefficient DNA repair, persistent accumulation of DNA damage/strand breaks, and subsequent chronic activation of the DNA damage-response ataxia telangiectasia-mutated (ATM signaling pathway in SCA3. We report that persistent accumulation of DNA damage/strand breaks and chronic activation of the serine/threonine kinase ATM and the downstream p53 and protein kinase C-δ pro-apoptotic pathways trigger neuronal dysfunction and eventually neuronal death in SCA3. Either PNKP overexpression or pharmacological inhibition of ATM dramatically blocked mutant ATXN3-mediated cell death. Discovery of the mechanism by which mutant ATXN3 induces DNA damage and amplifies the pro-death signaling pathways provides a molecular basis for neurodegeneration due to PNKP inactivation in SCA3, and for the first time offers

  8. GnRHa trigger and individualized luteal phase hCG support according to ovarian response to stimulation

    DEFF Research Database (Denmark)

    Humaidan, Peter; Polyzos, N P; Alsbjerg, B

    2013-01-01

    of OHSS the administration of two boluses of 1.500 IU hCG after GnRHa trigger should be avoided as it may induce OHSS. STUDY FUNDING/POTENTIAL COMPETING INTERESTS: The study was supported by a research grant by MSD, Denmark. No conflict of interest was declared. TRIAL REGISTRATION NUMBER: Project number...

  9. Maternal Vitamin D Level Is Associated with Viral Toll-Like Receptor Triggered IL-10 Response but Not the Risk of Infectious Diseases in Infancy

    Directory of Open Access Journals (Sweden)

    Sui-Ling Liao

    2016-01-01

    Full Text Available Reports on the effect of prenatal vitamin D status on fetal immune development and infectious diseases in childhood are limited. The aim of this study was to investigate the role of maternal and cord blood vitamin D level in TLR-related innate immunity and its effect on infectious outcome. Maternal and cord blood 25 (OHD level were examined from 372 maternal-neonatal pairs and their correlation with TLR-triggered TNF-α, IL-6, and IL-10 response at birth was assessed. Clinical outcomes related to infection at 12 months of age were also evaluated. The result showed that 75% of the pregnant mothers and 75.8% of the neonates were vitamin deficient. There was a high correlation between maternal and cord 25(OHD levels (r=0.67, p<0.001. Maternal vitamin D level was inversely correlated with IL-10 response to TLR3 (p=0.004 and TLR7-8 stimulation (p=0.006. However, none of the TLR-triggered cytokine productions were associated with cord 25(OHD concentration. There was no relationship between maternal and cord blood vitamin D status with infectious diseases during infancy. In conclusion, our study had shown that maternal vitamin D, but not cord vitamin D level, was associated with viral TLR-triggered IL-10 response.

  10. Maternal Vitamin D Level Is Associated with Viral Toll-Like Receptor Triggered IL-10 Response but Not the Risk of Infectious Diseases in Infancy.

    Science.gov (United States)

    Liao, Sui-Ling; Lai, Shen-Hao; Tsai, Ming-Han; Hua, Man-Chin; Yeh, Kuo-Wei; Su, Kuan-Wen; Chiang, Chi-Hsin; Huang, Shih-Yin; Kao, Chuan-Chi; Yao, Tsung-Chieh; Huang, Jing-Long

    2016-01-01

    Reports on the effect of prenatal vitamin D status on fetal immune development and infectious diseases in childhood are limited. The aim of this study was to investigate the role of maternal and cord blood vitamin D level in TLR-related innate immunity and its effect on infectious outcome. Maternal and cord blood 25 (OH)D level were examined from 372 maternal-neonatal pairs and their correlation with TLR-triggered TNF-α, IL-6, and IL-10 response at birth was assessed. Clinical outcomes related to infection at 12 months of age were also evaluated. The result showed that 75% of the pregnant mothers and 75.8% of the neonates were vitamin deficient. There was a high correlation between maternal and cord 25(OH)D levels (r = 0.67, p vitamin D level was inversely correlated with IL-10 response to TLR3 (p = 0.004) and TLR7-8 stimulation (p = 0.006). However, none of the TLR-triggered cytokine productions were associated with cord 25(OH)D concentration. There was no relationship between maternal and cord blood vitamin D status with infectious diseases during infancy. In conclusion, our study had shown that maternal vitamin D, but not cord vitamin D level, was associated with viral TLR-triggered IL-10 response.

  11. Transient Expression of CRISPR/Cas9 Machinery Targeting TcNPR3 Enhances Defense Response in Theobroma cacao

    Science.gov (United States)

    Fister, Andrew S.; Landherr, Lena; Maximova, Siela N.; Guiltinan, Mark J.

    2018-01-01

    Theobroma cacao, the source of cocoa, suffers significant losses to a variety of pathogens resulting in reduced incomes for millions of farmers in developing countries. Development of disease resistant cacao varieties is an essential strategy to combat this threat, but is limited by sources of genetic resistance and the slow generation time of this tropical tree crop. In this study, we present the first application of genome editing technology in cacao, using Agrobacterium-mediated transient transformation to introduce CRISPR/Cas9 components into cacao leaves and cotyledon cells. As a first proof of concept, we targeted the cacao Non-Expressor of Pathogenesis-Related 3 (TcNPR3) gene, a suppressor of the defense response. After demonstrating activity of designed single-guide RNAs (sgRNA) in vitro, we used Agrobacterium to introduce a CRISPR/Cas9 system into leaf tissue, and identified the presence of deletions in 27% of TcNPR3 copies in the treated tissues. The edited tissue exhibited an increased resistance to infection with the cacao pathogen Phytophthora tropicalis and elevated expression of downstream defense genes. Analysis of off-target mutagenesis in sequences similar to sgRNA target sites using high-throughput sequencing did not reveal mutations above background sequencing error rates. These results confirm the function of NPR3 as a repressor of the cacao immune system and demonstrate the application of CRISPR/Cas9 as a powerful functional genomics tool for cacao. Several stably transformed and genome edited somatic embryos were obtained via Agrobacterium-mediated transformation, and ongoing work will test the effectiveness of this approach at a whole plant level. PMID:29552023

  12. Transient Expression of CRISPR/Cas9 Machinery TargetingTcNPR3Enhances Defense Response inTheobroma cacao.

    Science.gov (United States)

    Fister, Andrew S; Landherr, Lena; Maximova, Siela N; Guiltinan, Mark J

    2018-01-01

    Theobroma cacao , the source of cocoa, suffers significant losses to a variety of pathogens resulting in reduced incomes for millions of farmers in developing countries. Development of disease resistant cacao varieties is an essential strategy to combat this threat, but is limited by sources of genetic resistance and the slow generation time of this tropical tree crop. In this study, we present the first application of genome editing technology in cacao, using Agrobacterium-mediated transient transformation to introduce CRISPR/Cas9 components into cacao leaves and cotyledon cells. As a first proof of concept, we targeted the cacao Non-Expressor of Pathogenesis-Related 3 (TcNPR3) gene, a suppressor of the defense response. After demonstrating activity of designed single-guide RNAs (sgRNA) in vitro , we used Agrobacterium to introduce a CRISPR/Cas9 system into leaf tissue, and identified the presence of deletions in 27% of TcNPR3 copies in the treated tissues. The edited tissue exhibited an increased resistance to infection with the cacao pathogen Phytophthora tropicalis and elevated expression of downstream defense genes. Analysis of off-target mutagenesis in sequences similar to sgRNA target sites using high-throughput sequencing did not reveal mutations above background sequencing error rates. These results confirm the function of NPR3 as a repressor of the cacao immune system and demonstrate the application of CRISPR/Cas9 as a powerful functional genomics tool for cacao. Several stably transformed and genome edited somatic embryos were obtained via Agrobacterium -mediated transformation, and ongoing work will test the effectiveness of this approach at a whole plant level.

  13. Phosphoproteome analysis reveals new drought response and defense mechanisms of seedling leaves in bread wheat (Triticum aestivum L.).

    Science.gov (United States)

    Zhang, Ming; Lv, Dongwen; Ge, Pei; Bian, Yanwei; Chen, Guanxing; Zhu, Gengrui; Li, Xiaohui; Yan, Yueming

    2014-09-23

    Drought is a major form of abiotic stress that significantly affects plant growth and development. In this study, we performed the first phosphoproteome analysis of seedling leaves from two bread wheat cultivars (Hanxuan 10 and Ningchun 47) subjected to drought stress. As a result, a total of 191 and 251 unique phosphopeptides, representing 173 and 227 phosphoproteins in two cultivars, respectively, were identified as being significant changes in phosphorylation level (SCPL) under drought stress. Through the comparison of SCPL phosphoproteins between two cultivars, 31 common SCPL phosphoproteins were found in both cultivars. Function analysis showed that the SCPL phosphoproteins in the two cultivars are mainly involved in three biological processes: RNA transcription/processing, stress/detoxification/defense, and signal transduction. Further analyses revealed that some SCPL phosphoproteins may play key roles in signal transduction and the signaling cascade under drought stress. Furthermore, some phosphoproteins related to drought tolerance and osmotic regulation exhibited significant phosphorylation changes. This study used a series of bioinformatics tools to profile the phosphorylation status of wheat seedling leaves under drought stress with greater accuracy. Drought is of the most studied abiotic stresses, because it severely restricts the development and yield of plants. In this study, large numbers of stress-related phosphoproteins are identified from the two bread wheat cultivars. These phosphoproteins contribute to signal transduction, osmotic regulation and ROS scavenging under water stress. This work provides a detailed insight into the mechanisms of drought response and defense in bread wheat from the perspective of phosphoproteomics, and identifies some important drought-tolerant candidates for further transgenosis study and incorporation into the breeding of resistant cultivars. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Conservation and divergence of chemical defense system in the tunicate Oikopleura dioica revealed by genome wide response to two xenobiotics

    Directory of Open Access Journals (Sweden)

    Yadetie Fekadu

    2012-02-01

    Full Text Available Abstract Background Animals have developed extensive mechanisms of response to xenobiotic chemical attacks. Although recent genome surveys have suggested a broad conservation of the chemical defensome across metazoans, global gene expression responses to xenobiotics have not been well investigated in most invertebrates. Here, we performed genome survey for key defensome genes in Oikopleura dioica genome, and explored genome-wide gene expression using high density tiling arrays with over 2 million probes, in response to two model xenobiotic chemicals - the carcinogenic polycyclic aromatic hydrocarbon benzo[a]pyrene (BaP the pharmaceutical compound Clofibrate (Clo. Results Oikopleura genome surveys for key genes of the chemical defensome suggested a reduced repertoire. Not more than 23 cytochrome P450 (CYP genes could be identified, and neither CYP1 family genes nor their transcriptional activator AhR was detected. These two genes were present in deuterostome ancestors. As in vertebrates, the genotoxic compound BaP induced xenobiotic biotransformation and oxidative stress responsive genes. Notable exceptions were genes of the aryl hydrocarbon receptor (AhR signaling pathway. Clo also affected the expression of many biotransformation genes and markedly repressed genes involved in energy metabolism and muscle contraction pathways. Conclusions Oikopleura has the smallest number of CYP genes among sequenced animal genomes and lacks the AhR signaling pathway. However it appears to have basic xenobiotic inducible biotransformation genes such as a conserved genotoxic stress response gene set. Our genome survey and expression study does not support a role of AhR signaling pathway in the chemical defense of metazoans prior to the emergence of vertebrates.

  15. Transforming Defense

    National Research Council Canada - National Science Library

    Lamb, Christopher J; Bunn, M. E; Lutes, Charles; Cavoli, Christopher

    2005-01-01

    .... Despite the resources and attention consumed by the war on terror, and recent decisions by the White House to curtail the growth of defense spending, the senior leadership of the Department of Defense (DoD...

  16. A Logistical Response to Assist in Answering the Call of Defense Support to Civilian Authorities in Disaster Response

    National Research Council Canada - National Science Library

    Britton, Jeffrey J

    2007-01-01

    .... The public began to question the responsibility and requirements of the United States (US) government in responding to the total devastation of New Orleans as the media continually showed the death and destruction...

  17. Polyamines attenuate ethylene-mediated defense responses to abrogate resistance to Botrytis cinerea in tomato

    Science.gov (United States)

    Transgenic tomato (Solanum lycopersicum) lines over-expressing yeast spermidine synthase (ySpdSyn), an enzyme involved in polyamine (PA) biosynthesis, were developed. These transgenic lines accumulate higher levels of spermidine (Spd) than the wild type plants and were examined for responses to the...

  18. 76 FR 71823 - Defense Federal Acquisition Regulation Supplement: Responsibility and Liability for Government...

    Science.gov (United States)

    2011-11-18

    ... little sense for the Government to both finance the contract and self-insure against property loss. There... insurance (see GAO-04-261SP, Principles of Appropriations Law, Volume I, section 10a, ``The Self-Insurance... costs passed on to the Government. Response: Paragraph (d) of the cost principle at FAR 31.205-19...

  19. Effects of dietary L-glutamine supplementation on specific and general defense responses in mice immunized with inactivated Pasteurella multocida vaccine.

    Science.gov (United States)

    Chen, Shuai; Liu, Shuping; Zhang, Fengmei; Ren, Wenkai; Li, Nengzhang; Yin, Jie; Duan, Jielin; Peng, Yuanyi; Liu, Gang; Yin, Yulong; Wu, Guoyao

    2014-10-01

    Little is known about effects of dietary glutamine supplementation on specific and general defense responses in a vaccine-immunized animal model. Thus, this study determined roles for dietary glutamine supplementation in specific and general defense responses in mice immunized with inactivated Pasteurella multocida vaccine. The measured variables included: (1) the production of pathogen-specific antibodies; (2) mRNA levels for pro-inflammatory cytokines, toll-like receptors and anti-oxidative factors; and (3) the distribution of P. multocida in tissues and the expression of its major virulence factors in vivo. Dietary supplementation with 0.5 % glutamine had a better protective role than 1 or 2 % glutamine against P. multocida infection in vaccine-immunized mice, at least partly resulting from its effects in modulation of general defense responses. Dietary glutamine supplementation had little effects on the production of P. multocida-specific antibodies. Compared to the non-supplemented group, dietary supplementation with 0.5 % glutamine had no effect on bacterial burden in vivo but decreased the expression of major virulence factors in the spleen. Collectively, supplementing 0.5 % glutamine to a conventional diet provides benefits in vaccine-immunized mice by enhancing general defense responses and decreasing expression of specific virulence factors.

  20. Bodily ownership modulation in defensive responses: physiological evidence in brain-damaged patients with pathological embodiment of other’s body parts

    Science.gov (United States)

    Fossataro, C.; Gindri, P.; Mezzanato, T.; Pia, L.; Garbarini, F.

    2016-01-01

    Do conscious beliefs about the body affect defensive mechanisms within the body? To answer this question we took advantage from a monothematic delusion of bodily ownership, in which brain-damaged patients misidentify alien limbs as their own. We investigated whether the delusional belief that an alien hand is their own hand modulates a subcortical defensive response, such as the hand-blink reflex. The blink, dramatically increases when the threated hand is inside the defensive peripersonal-space of the face. In our between-subjects design, including patients and controls, the threat was brought near the face either by the own hand or by another person’s hand. Our results show an ownership-dependent modulation of the defensive response. In controls, as well as in the patients’ intact-side, the response enhancement is significantly greater when the threat was brought near the face by the own than by the alien hand. Crucially, in the patients’ affected-side (where the pathological embodiment occurs), the alien (embodied) hand elicited a response enhancement comparable to that found when the threat is brought near the face by the real hand. These findings suggest the existence of a mutual interaction between our conscious beliefs about the body and the physiological mechanisms within the body. PMID:27292285

  1. LrABCF1, a GCN-type ATP-binding cassette transporter from lilium regale, is involved in defense responses against viral and fungal pathogens

    Science.gov (United States)

    ATP-binding cassette (ABC) transporters are essential for membrane translocation in diverse biological processes, such as plant development and defense response. Here, a general control non-derepressible (GCN)-type ABC transporter gene, designated LrABCF1, was identified from Cucumber mosaic virus (...

  2. Cross talk in defense signaling

    NARCIS (Netherlands)

    Koornneef, A.; Pieterse, C.M.J.

    2008-01-01

    Plants are equipped with an array of defense mechanisms to protect themselves against attack by herbivorous insects and microbial pathogens. Some of these defense mechanisms are preexisting, whereas others are only activated upon insect or pathogen invasion. Induced defense responses entail fitness

  3. Thyme and Savory Essential Oil Efficacy and Induction of Resistance against Botrytis cinerea through Priming of Defense Responses in Apple.

    Science.gov (United States)

    Banani, Houda; Olivieri, Leone; Santoro, Karin; Garibaldi, Angelo; Gullino, Maria Lodovica; Spadaro, Davide

    2018-01-23

    The efficacy of thyme and savory essential oils were investigated against Botrytis cinerea on apple fruit. Apples treated with thyme and savory essential oils showed significantly lower gray mold severity and incidence. Thyme essential oil at 1% concentration showed the highest efficacy, with lower disease incidence and smaller lesion diameter. The expression of specific pathogenesis-related (PR) genes PR-8 and PR-5 was characterized in apple tissues in response to thyme oil application and B. cinerea inoculation. After 6 h of pathogen inoculation, thyme essential oil induced a 2.5-fold increase of PR-8 gene expression compared to inoculated fruits. After 24 h of inoculation, PR-8 was highly induced (7-fold) in both thyme oil-treated and untreated apples inoculated with B. cinerea . After 48 h of inoculation, PR-8 expression in thyme-treated and inoculated apples was 4- and 6-fold higher than in inoculated and water-treated apples. Neither thyme oil application nor B. cinerea inoculation markedly affected PR-5 expression. These results suggest that thyme oil induces resistance against B. cinerea through the priming of defense responses in apple fruit, and the PR-8 gene of apple may play a key role in the mechanism by which thyme essential oil effectively inhibits gray mold in apple fruit.

  4. Salicylic acid is involved in the Nb-mediated defense responses to Potato virus X in Solanum tuberosum.

    Science.gov (United States)

    Sánchez, Gerardo; Gerhardt, Nadia; Siciliano, Florencia; Vojnov, Adrián; Malcuit, Isabelle; Marano, María Rosa

    2010-04-01

    To evaluate the role of salicylic acid (SA) in Nb-mediated hypersensitive resistance to Potato virus X (PVX) avirulent strain ROTH1 in Solanum tuberosum, we have constructed SA-deficient transgenic potato plant lines by overexpressing the bacterial enzyme salicylate hydroxylase (NahG), which degrades SA. Evaluation of these transgenic lines revealed hydrogen peroxide accumulation and spontaneous lesion formation in an age- and light-dependent manner. In concordance, NahG potato plants were more sensitive to treatment with methyl viologen, a reactive oxygen species-generating compound. In addition, when challenged with PVX ROTH1, NahG transgenic lines showed a decreased disease-resistance response to infection and were unable to induce systemic acquired resistance. However, the avirulent viral effector, the PVX 25-kDa protein, does induce expression of the pathogenesis-related gene PR-1a in NahG potato plants. Taken together, our data indicate that SA is involved in local and systemic defense responses mediated by the Nb gene in Solanum tuberosum. This is the first report to show that basal levels of SA correlate with hypersensitive resistance to PVX.

  5. Thyme and Savory Essential Oil Efficacy and Induction of Resistance against Botrytis cinerea through Priming of Defense Responses in Apple

    Directory of Open Access Journals (Sweden)

    Houda Banani

    2018-01-01

    Full Text Available The efficacy of thyme and savory essential oils were investigated against Botrytis cinerea on apple fruit. Apples treated with thyme and savory essential oils showed significantly lower gray mold severity and incidence. Thyme essential oil at 1% concentration showed the highest efficacy, with lower disease incidence and smaller lesion diameter. The expression of specific pathogenesis-related (PR genes PR-8 and PR-5 was characterized in apple tissues in response to thyme oil application and B. cinerea inoculation. After 6 h of pathogen inoculation, thyme essential oil induced a 2.5-fold increase of PR-8 gene expression compared to inoculated fruits. After 24 h of inoculation, PR-8 was highly induced (7-fold in both thyme oil-treated and untreated apples inoculated with B. cinerea. After 48 h of inoculation, PR-8 expression in thyme-treated and inoculated apples was 4- and 6-fold higher than in inoculated and water-treated apples. Neither thyme oil application nor B. cinerea inoculation markedly affected PR-5 expression. These results suggest that thyme oil induces resistance against B. cinerea through the priming of defense responses in apple fruit, and the PR-8 gene of apple may play a key role in the mechanism by which thyme essential oil effectively inhibits gray mold in apple fruit.

  6. Thyme and Savory Essential Oil Efficacy and Induction of Resistance against Botrytis cinerea through Priming of Defense Responses in Apple

    Science.gov (United States)

    Banani, Houda; Olivieri, Leone; Santoro, Karin; Garibaldi, Angelo; Gullino, Maria Lodovica

    2018-01-01

    The efficacy of thyme and savory essential oils were investigated against Botrytis cinerea on apple fruit. Apples treated with thyme and savory essential oils showed significantly lower gray mold severity and incidence. Thyme essential oil at 1% concentration showed the highest efficacy, with lower disease incidence and smaller lesion diameter. The expression of specific pathogenesis-related (PR) genes PR-8 and PR-5 was characterized in apple tissues in response to thyme oil application and B. cinerea inoculation. After 6 h of pathogen inoculation, thyme essential oil induced a 2.5-fold increase of PR-8 gene expression compared to inoculated fruits. After 24 h of inoculation, PR-8 was highly induced (7-fold) in both thyme oil-treated and untreated apples inoculated with B. cinerea. After 48 h of inoculation, PR-8 expression in thyme-treated and inoculated apples was 4- and 6-fold higher than in inoculated and water-treated apples. Neither thyme oil application nor B. cinerea inoculation markedly affected PR-5 expression. These results suggest that thyme oil induces resistance against B. cinerea through the priming of defense responses in apple fruit, and the PR-8 gene of apple may play a key role in the mechanism by which thyme essential oil effectively inhibits gray mold in apple fruit. PMID:29360731

  7. Augmentation of arsenic enhances lipid yield and defense responses in alga Nannochloropsis sp.

    Science.gov (United States)

    Upadhyay, A K; Mandotra, S K; Kumar, N; Singh, N K; Singh, Lav; Rai, U N

    2016-12-01

    The present study was conducted with microalga Nannochloropsis sp. to evaluate its tolerance responses and biofuel perspectives under different arsenic regime (0-1000μM As(III)). Results showed that optimal biomass (61.00±3.72mg/L/d) and lipid productivity (20.27mg/L/d) were obtained in culture treated with 100μM As(III) in comparison to other treatments. In addition, fatty acid profile of alga was in accordance with European biodiesel standards (EN 14214), which reflects good oxidative stability of oil. High antioxidants viz., ascorbic acid, GSH and cysteine tolerance responses as well as lipid yield at 100μM As(III), opens a new insight in the field of algal biology. Thus, microalgae Nannochloropsis sp. may be employ in remediation as well as biodiesel production. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Host Defenses in Experimental Scrub Typhus: Delayed-Type Hypersensitivity Responses of Inbred Mice

    OpenAIRE

    Jerrells, Thomas R.; Osterman, Joseph V.

    1982-01-01

    Delayed-type hypersensitivity responses of inbred mice during the course of lethal and chronic infections with strains of Rickettsia tsutsugamushi were evaluated by using the influx of radiolabeled cells into antigen-injected ears. Congenic strains of C3H mice, which previously have been shown to be resistant (C3H/RV) or sensitive (C3H/HeDub) to lethal intraperitoneal infection with the Gilliam strain of rickettsiae, both expressed delayed-type hypersensitivity early in the course of infectio...

  9. The antimicrobial peptide LL-37 modulates the inflammatory and host defense response of human neutrophils.

    Science.gov (United States)

    Alalwani, Sadek M; Sierigk, Johannes; Herr, Christian; Pinkenburg, Olaf; Gallo, Richard; Vogelmeier, Claus; Bals, Robert

    2010-04-01

    The human cathelicidin antimicrobial peptide acts as an effector molecule of the innate immune system with direct antimicrobial and immunomodulatory effects. The aim of this study was to test whether the cathelicidin LL-37 modulates the response of neutrophils to microbial stimulation. Human neutrophils were exposed to LPS, Staphylococcus aureus and Pseudomonas aeruginosa subsequent to incubation with LL-37 and cytokine release was measured by ELISA. The incubation with LL-37 significantly decreased the release of proinflammatory cytokines from stimulated human neutrophils. ROS production of neutrophils was determined by a luminometric and a flow cytometry method. The peptide induced the production of ROS and the engulfment of bacteria into neutrophils. Peritoneal mouse neutrophils isolated from CRAMP-deficient and WT animals were treated with LPS and TNF-alpha in the supernatant was measured by ELISA. Antimicrobial activity of neutrophils was detected by incubating neutrophils isolated from CRAMP-knockout and WT mice with bacteria. Neutrophils from CRAMP-deficient mice released significantly more TNF-alpha after bacterial stimulation and showed decreased antimicrobial activity as compared to cells from WT animals. In conclusion, LL-37 modulates the response of neutrophils to bacterial activation. Cathelicidin controls the release of inflammatory mediators while increasing antimicrobial activity of neutrophils.

  10. A Logistical Response to Assist in Answering the Call of Defense Support to Civilian Authorities in Disaster Response

    Science.gov (United States)

    2007-03-01

    1993): 20-25. Bea, Keith, Henry Hogue, Library of Congress, and Congressional Research Service. "FEMA Reorganization Legislation in the 109th...System the Need to Leverage Networks and Knowledge." (2006). Corbin , Randy. "Aftermath Afterglow: Lessons from Katrina Response." Fire Engineering...Hogue, Henry B., Keith Bea, Library of Congress, and Congressional Research Service. "Federal Emergency Management and Homeland Security

  11. Hypothesis: apoptosis caused by cytotoxins represents a defensive response that evolved to combat intracellular pathogens.

    Science.gov (United States)

    Vaux, D L; Häcker, G

    1995-11-01

    1. Over 100 different agents have been shown, under certain circumstances, to cause apoptosis, a form of cell death with characteristic morphology. In most cases, the mechanism of cell death is likely to be the same, as expression of the cell death inhibitory gene bcl-2 can frequently prevent apoptotic changes and/or delay cell death. 2. These observations raise the question of how and why cells detect these agents and why they respond by implementing the suicide mechanism that bcl-2 can control. Our hypothesis is that apoptosis is used as an anti-viral strategy, and that cells interpret any metabolic disturbance as evidence of infection by a virus and thereby kill themselves in response to these toxins before they are killed by the action of the toxin itself. 3. Experiments on the effect of sodium azide upon growth factor-dependent cells support this idea. Bcl-2 can delay cell death caused by azide, and inhibit apoptotic changes seen by electron microscopy, but cannot prevent the eventual death of the cells. 4. These ideas suggest that drugs designed to regulate cell death may be useful for the treatment of ischaemic or neoplastic diseases. For example, human cells may activate a suicide pathway in response to sub-lethal amounts of anoxia following a stroke or heart attack and so blocking apoptosis may be a useful therapy to limit tissue damage. On the other hand, increasing the propensity of cells to activate their physiological cell death mechanisms may enhance the effectiveness of toxins designed to kill tumour cells.

  12. Ministry of Defense Budged and the Economic Responsibilities as NATO Member

    Directory of Open Access Journals (Sweden)

    Mirela Metushaj

    2015-03-01

    Full Text Available Every four years Albania is confronted with several social issues which demand real and immediate solutions. These issues are often confronted with political implications offering no benefit for the civil society in general, or any of its levels, given the fact that all Albanian citizens are part of it in different levels. The main level affected by these social issues is the poor, women, unemployed, the youth and retired people. Albania is classified as the poorest country in the Balkan Peninsula and overcoming the social challenge of life quality in all social levels is the main challenge. During the last 10 years, the Albanian Governments has undertaken several reforms to meet all the criteria for the European integration. One of the most important criteria is the economical reform affecting the unemployment and the decrease of poverty, as these problems affect a considerable number of families, and in the same time they affect education and health service, two other rings of the social chains that are very important. Becoming a NATO member gave Albania a great encouragement to face the next challenges of the international arena and in this sense the Albanian Government is aware that being part of such an important organization would require availability and involvement of human resources and financial responsibilities, which would be a further burden for the budget. Therefore, it is important to create a suitable ground to implement these fundamental projects for the society. This is another challenge for the Albanian people with requires responsibility and sacrifice to meet the so much hoped ideals of democracy and solidarity, which establish peace, stability and prosperity for our country.

  13. Defense responses regulated by jasmonate and delayed senescence caused by ethylene receptor mutation contribute to tolerance of petunia to Botrytis cinerea

    Science.gov (United States)

    The death of cells can be a programmed event that occurs when plants are attacked by pathogens. Botrytis cinerea (B. cinerea), a model necrotrophic pathogen, triggers the host cell death response because it produces toxins. A hypersensitive reaction (HR) occurs at the site of contact. In Arabidopsis...

  14. Ceftaroline modulates the innate immune and host defense responses of immunocompetent cells exposed to cigarette smoke.

    Science.gov (United States)

    Bruno, A; Cipollina, C; Di Vincenzo, S; Siena, L; Dino, P; Di Gaudio, F; Gjomarkaj, M; Pace, E

    2017-09-05

    Cigarette smoke, the principal risk factor for chronic obstructive pulmonary disease (COPD), negatively influences the effectiveness of the immune system's response to a pathogen. The antibiotic ceftaroline exerts immune-modulatory effects in bronchial epithelial cells exposed to cigarette smoke. The present study aims to assess the effects of ceftaroline on TLR2 and TLR4 expression, LPS binding and TNF-α and human beta defensin (HBD2) release in an undifferentiated and PMA-differentiated human monocyte cell line (THP-1) exposed or not to cigarette smoke extracts (CSE). TLR2, TLR4, and LPS binding were assessed by flow cytometry, TNF-α and HBD2 release were evaluated by ELISA. The constitutive expression of TLR2 and TLR4 and LPS binding were higher in differentiated compared to undifferentiated THP-1 cells. In undifferentiated THP-1 cells, CSE increased TLR2 and TLR4 protein levels, LPS binding and TNF-α release and reduced HBD2 release and ceftaroline counteracted all these effects. In differentiated THP-1, CSE did not significantly affect TLR2 and TLR4 expression and LPS binding but reduced HBD2 release and increased TNF-α release. Ceftaroline counteracted the effects of CSE on HBD2 release in differentiated THP-1. Ceftaroline counteracts the effect of CSE in immune cells by increasing the effectiveness of the innate immune system. This effect may also assist in reducing pathogen activity and recurrent exacerbations in COPD patients. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Interactive Effects of Elevated [CO2] and Drought on the Maize Phytochemical Defense Response against Mycotoxigenic Fusarium verticillioides

    Science.gov (United States)

    Vaughan, Martha M.; Huffaker, Alisa; Schmelz, Eric A.; Dafoe, Nicole J.; Christensen, Shawn A.; McAuslane, Heather J.; Alborn, Hans T.; Allen, Leon Hartwell; Teal, Peter E. A.

    2016-01-01

    Changes in climate due to rising atmospheric carbon dioxide concentration ([CO2]) are predicted to intensify episodes of drought, but our understanding of how these combined conditions will influence crop-pathogen interactions is limited. We recently demonstrated that elevated [CO2] alone enhances maize susceptibility to the mycotoxigenic pathogen, Fusarium verticillioides (Fv) but fumonisin levels remain unaffected. In this study we show that maize simultaneously exposed to elevated [CO2] and drought are even more susceptible to Fv proliferation and also prone to higher levels of fumonisin contamination. Despite the increase in fumonisin levels, the amount of fumonisin produced in relation to pathogen biomass remained lower than corresponding plants grown at ambient [CO2]. Therefore, the increase in fumonisin contamination was likely due to even greater pathogen biomass rather than an increase in host-derived stimulants. Drought did not negate the compromising effects of elevated [CO2] on the accumulation of maize phytohormones and metabolites. However, since elevated [CO2] does not influence the drought-induced accumulation of abscisic acid (ABA) or root terpenoid phytoalexins, the effects elevated [CO2] are negated belowground, but the stifled defense response aboveground may be a consequence of resource redirection to the roots. PMID:27410032

  16. A nanosized Ag–silica hybrid complex prepared by γ-irradiation activates the defense response in Arabidopsis

    International Nuclear Information System (INIS)

    Chu, Hyosub; Kim, Hwa-Jung; Su Kim, Joong; Kim, Min-Soo; Yoon, Byung-Dae; Park, Hae-Jun; Kim, Cha Young

    2012-01-01

    Silver nanoparticles have antimicrobial activity against many pathogenic microbes. Here, the preparation of a nanosized Ag–silica hybrid complex (NSS) prepared by γ-irradiation is described. The effects of both NSS and reduced Ag nanoparticles (Ag 0 ) on the growth of the model plant Arabidopsis thaliana were tested. The application of 1–10 ppm NSS complex improved Arabidopsis growth in soil, whereas 100 ppm NSS resulted in weakly curled leaves. In addition, supplementation of Murashige and Skoog (MS) growth medium with 1 ppm NSS promoted the root growth of Arabidopsis seedlings, but root growth was inhibited by supplementation with 10 ppm NSS. To investigate whether the NSS complex could induce plant defense responses, the expression of pathogenesis-related (PR) genes that are implicated in systemic acquired resistance (SAR) in Arabidopsis plants was examined. PR1, PR2 and PR5 were significantly up-regulated by each application of 10 ppm NSS complex or Ag 0 to the rosette leaves. Furthermore, pretreatment with the NSS complex induced more pathogen resistance to the virulent pathogen Pseudomonas syringae pv. tomato DC3000 (Pst) compared to water treatment in Arabidopsis plants. - Research highlights: ► We describe the preparation of silver nanoparticles using γ-irradiation technique. ► We examine the effects of silver nanoparticles on the growth of Arabidopsis. ► Silver nanoparticles induced the expression of SAR marker genes. ► Silver nanoparticles exhibited enhanced disease resistance to the bacterial pathogen.

  17. A nanosized Ag-silica hybrid complex prepared by γ-irradiation activates the defense response in Arabidopsis

    Science.gov (United States)

    Chu, Hyosub; Kim, Hwa-Jung; Su Kim, Joong; Kim, Min-Soo; Yoon, Byung-Dae; Park, Hae-Jun; Kim, Cha Young

    2012-02-01

    Silver nanoparticles have antimicrobial activity against many pathogenic microbes. Here, the preparation of a nanosized Ag-silica hybrid complex (NSS) prepared by γ-irradiation is described. The effects of both NSS and reduced Ag nanoparticles (Ag 0) on the growth of the model plant Arabidopsis thaliana were tested. The application of 1-10 ppm NSS complex improved Arabidopsis growth in soil, whereas 100 ppm NSS resulted in weakly curled leaves. In addition, supplementation of Murashige and Skoog (MS) growth medium with 1 ppm NSS promoted the root growth of Arabidopsis seedlings, but root growth was inhibited by supplementation with 10 ppm NSS. To investigate whether the NSS complex could induce plant defense responses, the expression of pathogenesis-related ( PR) genes that are implicated in systemic acquired resistance (SAR) in Arabidopsis plants was examined. PR1, PR2 and PR5 were significantly up-regulated by each application of 10 ppm NSS complex or Ag 0 to the rosette leaves. Furthermore, pretreatment with the NSS complex induced more pathogen resistance to the virulent pathogen Pseudomonas syringae pv. tomato DC3000 ( Pst) compared to water treatment in Arabidopsis plants.

  18. Chamomile confers protection against hydrogen peroxide-induced toxicity through activation of Nrf2-mediated defense response.

    Science.gov (United States)

    Bhaskaran, Natarajan; Srivastava, Janmejai K; Shukla, Sanjeev; Gupta, Sanjay

    2013-01-01

    Oxidative stress plays an important role in the development of various human diseases. Aqueous chamomile extract is used as herbal medicine, in the form of tea, demonstrated to possess antiinflammatory and antioxidant properties. We demonstrate the cytoprotective effects of chamomile on hydrogen peroxide (H₂O₂)-induced cellular damage in macrophage RAW 264.7 cells. Pretreatment of cells with chamomile markedly attenuated H₂O₂-induced cell viability loss in a dose-dependent manner. The mechanisms by which chamomile-protected macrophages from oxidative stress was through the induction of several antioxidant enzymes including NAD(P)H:quinone oxidoreductase, superoxide dismutase, and catalase and increase nuclear accumulation of the transcription factor Nrf2 and its binding to antioxidant response elements. Furthermore, chamomile dose-dependently reduced H₂O₂-mediated increase in the intracellular levels of reactive oxygen species. Our results, for the first time, demonstrate that chamomile has protective effects against oxidative stress and might be beneficial to provide defense against cellular damage. Copyright © 2012 John Wiley & Sons, Ltd.

  19. Regulation of plant defense responses in Arabidopsis by EDR2, a PH and START domain-containing protein.

    Science.gov (United States)

    Tang, Dingzhong; Ade, Jules; Frye, Catherine A; Innes, Roger W

    2005-10-01

    We have identified an Arabidopsis mutant that displays enhanced disease resistance (edr2) to the biotrophic powdery mildew pathogen Erysiphe cichoracearum. Inhibition of fungal growth on edr2 mutant leaves occurred at a late stage of the infection process and coincided with formation of necrotic lesions approximately 5 days after inoculation. Double-mutant analysis revealed that edr2-mediated resistance is suppressed by mutations that inhibit salicylic acid (SA)-induced defense signaling, including npr1, pad4 and sid2, demonstrating that edr2-mediated disease resistance is dependent on SA. However, edr2 showed normal responses to the bacterial pathogen Pseudomonas syringae pv. tomato strain DC3000. EDR2 appears to be constitutively transcribed in all tissues and organs and encodes a novel protein, consisting of a putative pleckstrin homology (PH) domain and a steroidogenic acute regulatory protein-related lipid-transfer (START) domain, and contains an N-terminal mitochondrial targeting sequence. The PH and START domains are implicated in lipid binding, suggesting that EDR2 may provide a link between lipid signaling and activation of programmed cell death mediated by mitochondria.

  20. Interactive Effects of Elevated [CO2] and Drought on the Maize Phytochemical Defense Response against Mycotoxigenic Fusarium verticillioides.

    Directory of Open Access Journals (Sweden)

    Martha M Vaughan

    Full Text Available Changes in climate due to rising atmospheric carbon dioxide concentration ([CO2] are predicted to intensify episodes of drought, but our understanding of how these combined conditions will influence crop-pathogen interactions is limited. We recently demonstrated that elevated [CO2] alone enhances maize susceptibility to the mycotoxigenic pathogen, Fusarium verticillioides (Fv but fumonisin levels remain unaffected. In this study we show that maize simultaneously exposed to elevated [CO2] and drought are even more susceptible to Fv proliferation and also prone to higher levels of fumonisin contamination. Despite the increase in fumonisin levels, the amount of fumonisin produced in relation to pathogen biomass remained lower than corresponding plants grown at ambient [CO2]. Therefore, the increase in fumonisin contamination was likely due to even greater pathogen biomass rather than an increase in host-derived stimulants. Drought did not negate the compromising effects of elevated [CO2] on the accumulation of maize phytohormones and metabolites. However, since elevated [CO2] does not influence the drought-induced accumulation of abscisic acid (ABA or root terpenoid phytoalexins, the effects elevated [CO2] are negated belowground, but the stifled defense response aboveground may be a consequence of resource redirection to the roots.

  1. Triggering Artefacts

    DEFF Research Database (Denmark)

    Mogensen, Preben Holst; Robinson, Mike

    1995-01-01

    The paper presents a general critique of the use of conceptual frameworks in design, illustrated by the well known synchronous/asynchronous, co-located/non-co-located framework. It argues that while frameworks are a necessary and inevitable starting point for design, the business of tailoring...... and adapting them to specific situations need not be ad hoc.Triggering artefacts are a way of systematically challenging both designers' preunderstandings and the conservatism of work practice. Experiences from the Great Belt tunnel and bridge project are used to illustrate howtriggering artefacts change...

  2. Ascorbic acid accumulates as a defense response to Turnip mosaic virus in resistant Brassica rapa cultivars.

    Science.gov (United States)

    Fujiwara, Ayaka; Togawa, Satoko; Hikawa, Takahiro; Matsuura, Hideyuki; Masuta, Chikara; Inukai, Tsuyoshi

    2016-07-01

    We initially observed that Brassica rapa cultivars containing the Turnip mosaic virus (TuMV) resistance gene, Rnt1-1, accumulated a high level of endogenous ascorbic acid (AS) and dehydroascobic acid (DHA) when infected with TuMV. We here hypothesized a possible contribution of an elevated level of AS+DHA (TAA) to the Rnt1-1-mediated resistance, and conducted a series of experiments using B. rapa and Arabidopsis plants. The application of l-galactose (the key substrate in AS synthesis) to a susceptible cultivar could increase the TAA level ~2-fold, and simultaneously lead to some degree of enhanced viral resistance. To confirm some positive correlation between TAA levels and viral resistance, we analyzed two Arabidopsis knockout mutants (ao and vtc1) in the AS pathways; the TAA levels were significantly increased and decreased in ao and vtc1 plants, respectively. While the ao plants showed enhanced resistance to TuMV, vtc1 plants were more susceptible than the control, supporting our hypothesis. When we analyzed the expression profiles of the genes involved in the AS pathways upon TuMV infection, we found that the observed TAA increase was mainly brought about by the reduction of AS oxidation and activation of AS recycling. We then investigated the secondary signals that regulate endogenous TAA levels in response to viral infection, and found that jasmonic acid (JA) might play an important role in TAA accumulation. In conclusion, we reason that the elevated TAA accumulation in B. rapa plants would be at least partly mediated by the JA-dependent signaling pathway and may significantly contribute to viral resistance. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  3. Defensive Responses of Rice Genotypes for Resistance Against Rice Leaffolder Cnaphalocrocis medinalis

    Directory of Open Access Journals (Sweden)

    M. PUNITHAVALLI

    2013-09-01

    Full Text Available The experiment was carried out to assess the reaction of different categories of rice genotypes viz., resistant, susceptible, hybrid, scented, popular and wild in response to the infestation by rice leaffolder (RLF, Cnaphalocrocis medinalis (Guenee and to explore the possible use of these genotypes in developing RLF-resistant rice varieties. The changes of various biochemical constituents such as leaf soluble protein, phenol, ortho-dihydroxy phenol, tannin and enzymes viz., peroxidase, phenyl alanine ammonia lyase (PAL were assessed spectrophotometrically in all the rice genotypes before and after RLF infestation. The protein profile was analyzed using sodium dodecyl sulphate-poly acrylamide gel electrophoresis (SDS-PAGE method. A significant constituent of biochemical content such as tannin, phenol and ortho-dihydroxy phenol has been increased along with enzyme activities of peroxidase and PAL in the infested resistant (Ptb 33, TKM6 and LFR831311 and wild rice genotypes (Oryza minuta and O. rhizomatis. A decrease in leaf protein content was evident invariably in all the infested rice genotypes. It is also evident that the contents of biochemicals such as phenol, ortho-dihydroxy phenol and tannin were negatively correlated with leaffolder damage. However, leaf protein content was positively correlated with the damage by rice leaffolder. SDS-PAGE analysis for total protein profiling of healthy and C. medinalis-infested genotypes revealed the enhanced expression of a high molecular weight (> 97 kDa protein in all the genotypes. Besides, there was also an increased induction of a 38 kDa protein in C. medinalis infested resistant genotypes, which was absent in uninfested plants. The present investigation proved that the elevated levels of biochemicals and enzymes may play a vital role in rice plants resistance to RLF.

  4. Priming with a double-stranded DNA virus alters Brassica rapa seed architecture and facilitates a defense response.

    Science.gov (United States)

    Kalischuk, Melanie L; Johnson, Dan; Kawchuk, Lawrence M

    2015-02-25

    Abiotic and biotic stresses alter genome stability and physiology of plants. Under some stressful situations, a state of stress tolerance can be passed on to the offspring rendering them more suitable to stressful events than their parents. In plants, the exploration of transgenerational response has remained exclusive to model species, such as Arabidopsis thaliana. Here, we expand transgenerational research to include Brassica rapa, a close relative to economically important plant canola (Brassica napus), as it is exposed to the biotic stress of a double-stranded DNA virus Cauliflower mosaic virus (CaMV). Parent plants exposed to a low dose of 50ng purified CaMV virions just prior to the bolting stage produced significantly larger seeds than mock inoculated and healthy treatments. The progeny from these large seeds displayed resistance to the pathogen stress applied in the parental generation. Differences in defense pathways involving fatty acids, and primary and secondary metabolites were detected by de novo transcriptome sequencing of CaMV challenged progeny exhibiting different levels of resistance. Our study highlights biological and cellular processes that may be linked to the growth and yield of economically important B. rapa, in a transgenerational manner. Although much remains unknown as to the mechanisms behind transgenerational inheritance, our work shows a disease resistance response that persists for several weeks and is associated with an increase in seed size. Evidence suggests that a number of changes involved in the persistent stress adaption are reflected in the transcriptome. The results from this study demonstrate that treating B. rapa with dsDNA virus within a critical time frame and with a specified amount of infectious pathogen produces economically important agricultural plants with superior coping strategies for growing in unfavorable conditions. Copyright © 2014. Published by Elsevier B.V.

  5. Trichoderma-plant root colonization: escaping early plant defense responses and activation of the antioxidant machinery for saline stress tolerance.

    Science.gov (United States)

    Brotman, Yariv; Landau, Udi; Cuadros-Inostroza, Álvaro; Tohge, Takayuki; Takayuki, Tohge; Fernie, Alisdair R; Chet, Ilan; Viterbo, Ada; Willmitzer, Lothar

    2013-03-01

    Trichoderma spp. are versatile opportunistic plant symbionts which can colonize the apoplast of plant roots. Microarrays analysis of Arabidopsis thaliana roots inoculated with Trichoderma asperelloides T203, coupled with qPCR analysis of 137 stress responsive genes and transcription factors, revealed wide gene transcript reprogramming, proceeded by a transient repression of the plant immune responses supposedly to allow root colonization. Enhancement in the expression of WRKY18 and WRKY40, which stimulate JA-signaling via suppression of JAZ repressors and negatively regulate the expression of the defense genes FMO1, PAD3 and CYP71A13, was detected in Arabidopsis roots upon Trichoderma colonization. Reduced root colonization was observed in the wrky18/wrky40 double mutant line, while partial phenotypic complementation was achieved by over-expressing WRKY40 in the wrky18 wrky40 background. On the other hand increased colonization rate was found in roots of the FMO1 knockout mutant. Trichoderma spp. stimulate plant growth and resistance to a wide range of adverse environmental conditions. Arabidopsis and cucumber (Cucumis sativus L.) plants treated with Trichoderma prior to salt stress imposition show significantly improved seed germination. In addition, Trichoderma treatment affects the expression of several genes related to osmo-protection and general oxidative stress in roots of both plants. The MDAR gene coding for monodehydroascorbate reductase is significantly up-regulated and, accordingly, the pool of reduced ascorbic acid was found to be increased in Trichoderma treated plants. 1-Aminocyclopropane-1-carboxylate (ACC)-deaminase silenced Trichoderma mutants were less effective in providing tolerance to salt stress, suggesting that Trichoderma, similarly to ACC deaminase producing bacteria, can ameliorate plant growth under conditions of abiotic stress, by lowering ameliorating increases in ethylene levels as well as promoting an elevated antioxidative capacity.

  6. Trichoderma-plant root colonization: escaping early plant defense responses and activation of the antioxidant machinery for saline stress tolerance.

    Directory of Open Access Journals (Sweden)

    Yariv Brotman

    2013-03-01

    Full Text Available Trichoderma spp. are versatile opportunistic plant symbionts which can colonize the apoplast of plant roots. Microarrays analysis of Arabidopsis thaliana roots inoculated with Trichoderma asperelloides T203, coupled with qPCR analysis of 137 stress responsive genes and transcription factors, revealed wide gene transcript reprogramming, proceeded by a transient repression of the plant immune responses supposedly to allow root colonization. Enhancement in the expression of WRKY18 and WRKY40, which stimulate JA-signaling via suppression of JAZ repressors and negatively regulate the expression of the defense genes FMO1, PAD3 and CYP71A13, was detected in Arabidopsis roots upon Trichoderma colonization. Reduced root colonization was observed in the wrky18/wrky40 double mutant line, while partial phenotypic complementation was achieved by over-expressing WRKY40 in the wrky18 wrky40 background. On the other hand increased colonization rate was found in roots of the FMO1 knockout mutant. Trichoderma spp. stimulate plant growth and resistance to a wide range of adverse environmental conditions. Arabidopsis and cucumber (Cucumis sativus L. plants treated with Trichoderma prior to salt stress imposition show significantly improved seed germination. In addition, Trichoderma treatment affects the expression of several genes related to osmo-protection and general oxidative stress in roots of both plants. The MDAR gene coding for monodehydroascorbate reductase is significantly up-regulated and, accordingly, the pool of reduced ascorbic acid was found to be increased in Trichoderma treated plants. 1-Aminocyclopropane-1-carboxylate (ACC-deaminase silenced Trichoderma mutants were less effective in providing tolerance to salt stress, suggesting that Trichoderma, similarly to ACC deaminase producing bacteria, can ameliorate plant growth under conditions of abiotic stress, by lowering ameliorating increases in ethylene levels as well as promoting an elevated

  7. Defense Primer: The National Defense Budget Function (050)

    Science.gov (United States)

    2017-03-17

    provides a framework for examining spending patterns of the federal government by category of activity, rather than by agency or type of financing ...federal spending. Since federal agencies often have diverse, overlapping responsibilities , it is not uncommon for them to be associated with multiple...agency responsible for approximately 96% of spending within the National Defense Budget (050). Defense Primer: The National Defense Budget Function

  8. Arabidopsis Histone Methyltransferase SET DOMAIN GROUP8 Mediates Induction of the Jasmonate/Ethylene Pathway Genes in Plant Defense Response to Necrotrophic Fungi1[W][OA

    Science.gov (United States)

    Berr, Alexandre; McCallum, Emily J.; Alioua, Abdelmalek; Heintz, Dimitri; Heitz, Thierry; Shen, Wen-Hui

    2010-01-01

    As sessile organisms, plants have to endure a wide variety of biotic and abiotic stresses, and accordingly they have evolved intricate and rapidly inducible defense strategies associated with the activation of a battery of genes. Among other mechanisms, changes in chromatin structure are thought to provide a flexible, global, and stable means for the regulation of gene transcription. In support of this idea, we demonstrate here that the Arabidopsis (Arabidopsis thaliana) histone methyltransferase SET DOMAIN GROUP8 (SDG8) plays a crucial role in plant defense against fungal pathogens by regulating a subset of genes within the jasmonic acid (JA) and/or ethylene signaling pathway. We show that the loss-of-function mutant sdg8-1 displays reduced resistance to the necrotrophic fungal pathogens Alternaria brassicicola and Botrytis cinerea. While levels of JA, a primary phytohormone involved in plant defense, and camalexin, a major phytoalexin against fungal pathogens, remain unchanged or even above normal in sdg8-1, induction of several defense genes within the JA/ethylene signaling pathway is severely compromised in response to fungal infection or JA treatment in mutant plants. Both downstream genes and, remarkably, also upstream mitogen-activated protein kinase kinase genes MKK3 and MKK5 are misregulated in sdg8-1. Accordingly, chromatin immunoprecipitation analysis shows that sdg8-1 impairs dynamic changes of histone H3 lysine 36 methylation at defense marker genes as well as at MKK3 and MKK5, which normally occurs upon infection with fungal pathogens or methyl JA treatment in wild-type plants. Our data indicate that SDG8-mediated histone H3 lysine 36 methylation may serve as a memory of permissive transcription for a subset of defense genes, allowing rapid establishment of transcriptional induction. PMID:20810545

  9. Behavioral stress response of genetically selected aggressive and nonaggressive wild house mice in the shock-probe/defensive burying test

    NARCIS (Netherlands)

    Sluyter, F; Korte, SM; Bohus, B; VanOortmerssen, GA

    Genetically selected aggressive and nonaggressive male wild house mice were tested in the shock-probe/defensive burying test. Five distinct behaviors (burying, immobility, rearing, grooming, and exploration) were recorded in two environmental situations: fresh and home cage sawdust. Nonaggressive

  10. Defense Emergency Response Fund

    Science.gov (United States)

    2008-06-20

    of Inspector General who contributed to the report are listed below. Patricia A. Marsh Lorin T. Pfeil Henry Y. Adu Emmanuel A. Appiah Sharon A. Loftin Sonya T. Davis Sue-milney Sepulveda -Recio Ellen Kleiman-Redden

  11. Induction of defense response against Rhizoctonia solani in cucumber plants by endophytic bacterium Bacillus thuringiensis GS1.

    Science.gov (United States)

    Seo, Dong-Jun; Nguyen, Dang-Minh-Chanh; Song, Yong-Su; Jung, Woo-Jin

    2012-03-01

    An endophytic bacterium, Bacillus thuringiensis GS1, was isolated from bracken (Pteridium aquilinum) and found to have maximal production of chitinase (4.3 units/ml) at 5 days after culture. This study investigated the ability of B. thuringiensis GS1 to induce resistance to Rhizoctonia solani KACC 40111 (RS) in cucumber plants. Chitinase activity was greatest in RS-treated plants at 4 days. beta-1,3- Glucanase activity was highest in GS1-treated plants at 5 days. Guaiacol peroxidase (GPOD) activity increased continuously in all treated plants for 5 days. Ascorbate peroxidase (APX) activity in RS-treated plants was increased 1.5-fold compared with the control at 4 days. Polyphenol oxidase (PPO) activity in RS-treated plants was increased 1.5-fold compared with the control at 3 days. At 5 days after treatment, activity staining revealed three bands with chitinase activity (Ch1, Ch2, and Ch3) on SDSPAGE of cucumber plants treated with GS1+RS, whereas only one band was observed for RS-treated plants (Ch2). One GPOD isozyme (Gp1) was also observed in response to treatment with RS and GS1+RS at 4 days. One APX band (Ap2) was present on the native-PAGE gel of the control, and GS1- and GS1+RS-treated plants at 1 day. PPO bands (Po1 and Po2) from RS- and GS1+RS-treated plants were stronger than in the control and GS1-treated plants upon native-PAGE at 5 days. Taken together, these results indicate that the induction of PR proteins and defense-related enzymes by B. thuringiensis GS1 might have suppressed the damping-off caused by R. solani KACC 40111 in cucumber plants.

  12. Structural Basis for Dual Functionality of Isoflavonoid O-Methyltransferases in the Evolution of Plant Defense Responses

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.-J.; Deavours, B.E.; Richard, S.B.; Ferrer, J.-L.; Blount, J.W.; Huhman, D.; Dixon, R.A.; Noel, J.

    2007-07-10

    In leguminous plants such as pea (Pisum sativum), alfalfa (Medicago sativa), barrel medic (Medicago truncatula), and chickpea (Cicer arietinum), 4'-O-methylation of isoflavonoid natural products occurs early in the biosynthesis of defense chemicals known as phytoalexins. However, among these four species, only pea catalyzes 3-O-methylation that converts the pterocarpanoid isoflavonoid 6a-hydroxymaackiain to pisatin. In pea, pisatin is important for chemical resistance to the pathogenic fungus Nectria hematococca. While barrel medic does not biosynthesize 6a-hydroxymaackiain, when cell suspension cultures are fed 6a-hydroxymaackiain, they accumulate pisatin. In vitro, hydroxyisoflavanone 4'-O-methyltransferase (HI4'OMT) from barrel medic exhibits nearly identical steady state kinetic parameters for the 4'-O-methylation of the isoflavonoid intermediate 2,7,4'-trihydroxyisoflavanone and for the 3-O-methylation of the 6a-hydroxymaackiain isoflavonoid-derived pterocarpanoid intermediate found in pea. Protein x-ray crystal structures of HI4'OMT substrate complexes revealed identically bound conformations for the 2S,3R-stereoisomer of 2,7,4'-trihydroxyisoflavanone and the 6aR,11aR-stereoisomer of 6a-hydroxymaackiain. These results suggest how similar conformations intrinsic to seemingly distinct chemical substrates allowed leguminous plants to use homologous enzymes for two different biosynthetic reactions. The three-dimensional similarity of natural small molecules represents one explanation for how plants may rapidly recruit enzymes for new biosynthetic reactions in response to changing physiological and ecological pressures.

  13. Structural Basis for Dual Functionality of Isoflavonoid O-Methyltransferases in the Evolution of Plant Defense Responses

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.; Deavours, B; Richard, S; Ferrer, J; Blount, J; Huhman, D; Dixon, R; Noel, J

    2006-01-01

    In leguminous plants such as pea (Pisum sativum), alfalfa (Medicago sativa), barrel medic (Medicago truncatula), and chickpea (Cicer arietinum), 4'-O-methylation of isoflavonoid natural products occurs early in the biosynthesis of defense chemicals known as phytoalexins. However, among these four species, only pea catalyzes 3-O-methylation that converts the pterocarpanoid isoflavonoid 6a-hydroxymaackiain to pisatin. In pea, pisatin is important for chemical resistance to the pathogenic fungus Nectria hematococca. While barrel medic does not biosynthesize 6a-hydroxymaackiain, when cell suspension cultures are fed 6a-hydroxymaackiain, they accumulate pisatin. In vitro, hydroxyisoflavanone 4'-O-methyltransferase (HI4'OMT) from barrel medic exhibits nearly identical steady state kinetic parameters for the 4'-O-methylation of the isoflavonoid intermediate 2,7,4'-trihydroxyisoflavanone and for the 3-O-methylation of the 6a-hydroxymaackiain isoflavonoid-derived pterocarpanoid intermediate found in pea. Protein x-ray crystal structures of HI4'OMT substrate complexes revealed identically bound conformations for the 2S,3R-stereoisomer of 2,7,4'-trihydroxyisoflavanone and the 6aR,11aR-stereoisomer of 6a-hydroxymaackiain. These results suggest how similar conformations intrinsic to seemingly distinct chemical substrates allowed leguminous plants to use homologous enzymes for two different biosynthetic reactions. The three-dimensional similarity of natural small molecules represents one explanation for how plants may rapidly recruit enzymes for new biosynthetic reactions in response to changing physiological and ecological pressures.

  14. Curdlan β-1,3-glucooligosaccharides induce the defense responses against Phytophthora infestans infection of potato (Solanum tuberosum L. cv. McCain G1) leaf cells.

    Science.gov (United States)

    Li, Jing; Zhu, Li; Lu, Guangxing; Zhan, Xiao-Bei; Lin, Chi-Chung; Zheng, Zhi-Yong

    2014-01-01

    Activation of the innate immune system before the invasion of pathogens is a promising way to improve the resistance of plant against infection while reducing the use of agricultural chemicals. Although several elicitors were used to induce the resistance of potato plant to microbial pathogen infection, the role of curdlan oligosaccharide (CurdO) has not been established. In the current study, the defense responses were investigated at biochemical and proteomic levels to elucidate the elicitation effect of CurdOs in foliar tissues of potato (Solanum tuberosum L. cv. McCain G1). The results indicate that the CurdOs exhibit activation effect on the early- and late-defense responses in potato leaves. In addition, glucopentaose was proved to be the shortest active curdlan molecule based on the accumulation of H₂O₂ and salicylic acid and the activities of phenylalanine amino-lyase, β-1,3-glucanase and chitinase. The 2D-PAGE analysis reveals that CurdOs activate the integrated response reactions in potato cells, as a number of proteins with various functions are up-regulated including disease/defense, metabolism, transcription, and cell structure. The pathogenesis assay shows that the ratio of lesion area of potato leaf decreased from 15.82%±5.44% to 7.79%±3.03% when the plants were treated with CurdOs 1 day before the infection of Phytophthora infestans. Furthermore, the results on potato yield and induction reactions indicate that the defense responses induced by CurdOs lasted for short period of time but disappeared gradually.

  15. Curdlan β-1,3-glucooligosaccharides induce the defense responses against Phytophthora infestans infection of potato (Solanum tuberosum L. cv. McCain G1 leaf cells.

    Directory of Open Access Journals (Sweden)

    Jing Li

    Full Text Available Activation of the innate immune system before the invasion of pathogens is a promising way to improve the resistance of plant against infection while reducing the use of agricultural chemicals. Although several elicitors were used to induce the resistance of potato plant to microbial pathogen infection, the role of curdlan oligosaccharide (CurdO has not been established. In the current study, the defense responses were investigated at biochemical and proteomic levels to elucidate the elicitation effect of CurdOs in foliar tissues of potato (Solanum tuberosum L. cv. McCain G1. The results indicate that the CurdOs exhibit activation effect on the early- and late-defense responses in potato leaves. In addition, glucopentaose was proved to be the shortest active curdlan molecule based on the accumulation of H₂O₂ and salicylic acid and the activities of phenylalanine amino-lyase, β-1,3-glucanase and chitinase. The 2D-PAGE analysis reveals that CurdOs activate the integrated response reactions in potato cells, as a number of proteins with various functions are up-regulated including disease/defense, metabolism, transcription, and cell structure. The pathogenesis assay shows that the ratio of lesion area of potato leaf decreased from 15.82%±5.44% to 7.79%±3.03% when the plants were treated with CurdOs 1 day before the infection of Phytophthora infestans. Furthermore, the results on potato yield and induction reactions indicate that the defense responses induced by CurdOs lasted for short period of time but disappeared gradually.

  16. Triggered Release from Polymer Capsules

    Energy Technology Data Exchange (ETDEWEB)

    Esser-Kahn, Aaron P. [Univ. of Illinois, Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology and Dept. of Chemistry; Odom, Susan A. [Univ. of Illinois, Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology and Dept. of Chemistry; Sottos, Nancy R. [Univ. of Illinois, Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology and Dept. of Materials Science and Engineering; White, Scott R. [Univ. of Illinois, Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology and Dept. of Aerospace Engineering; Moore, Jeffrey S. [Univ. of Illinois, Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology and Dept. of Chemistry

    2011-07-06

    Stimuli-responsive capsules are of interest in drug delivery, fragrance release, food preservation, and self-healing materials. Many methods are used to trigger the release of encapsulated contents. Here we highlight mechanisms for the controlled release of encapsulated cargo that utilize chemical reactions occurring in solid polymeric shell walls. Triggering mechanisms responsible for covalent bond cleavage that result in the release of capsule contents include chemical, biological, light, thermal, magnetic, and electrical stimuli. We present methods for encapsulation and release, triggering methods, and mechanisms and conclude with our opinions on interesting obstacles for chemically induced activation with relevance for controlled release.

  17. Decreased B and T lymphocyte attenuator in Behcet's disease may trigger abnormal Th17 and Th1 immune responses.

    Science.gov (United States)

    Ye, Zi; Deng, Bolin; Wang, Chaokui; Zhang, Dike; Kijlstra, Aize; Yang, Peizeng

    2016-02-04

    Behcet's disease (BD) is a chronic, systemic and recurrent inflammatory disease associated with hyperactive Th17 and Th1 immune responses. Recent studies have shown that B and T lymphocyte attenuator (BTLA) negatively regulates the immune response. In this study, we investigated whether BTLA activation could be exploited to inhibit the development of abnormal immune responses in BD patients. BTLA expression in PBMCs and CD4(+) T cells was significantly decreased in active BD patients. Decreased BTLA level was associated with increased Th17 and Th1 responses. Activation of BTLA inhibited the abnormal Th17 and Th1 responses and IL-22 expression in both patients and controls. Addition of an agonistic anti-BTLA antibody remarkably inhibited DC-induced Th17 and Th1 cell responses, resulted in decreased production of the Th17 and Th1-related cytokines IL-1beta, IL-6, IL-23 and IL-12p70 and reduced CD40 expression in DCs. In conclusion, decreased BTLA expression in ocular BD may lead to inappropriate control of the Th17 and Th1 immune responses and DC functions. Therefore, BTLA may be involved in the development and recurrence of this disease. Agonistic agents of BTLA may represent a potential therapeutic approach for the treatment of BD and other inflammatory diseases mediated by abnormal Th17 and Th1 immune responses.

  18. Induction of DIMBOA accumulation and systemic defense responses as a mechanism of enhanced resistance of mycorrhizal corn (Zea mays L.) to sheath blight.

    Science.gov (United States)

    Song, Yuan Yuan; Cao, Man; Xie, Li Jun; Liang, Xiao Ting; Zeng, Ren Sen; Su, Yi Juan; Huang, Jing Hua; Wang, Rui Long; Luo, Shi Ming

    2011-11-01

    Arbuscular mycorrhizas are the most important symbioses in terrestrial ecosystems and they enhance the plant defense against numerous soil-borne pathogenic fungi and nematodes. Two corn (Zea mays) varieties, Gaoyou-115 that is susceptible to sheath blight disease caused by Rhizoctonia solani and Yuenong-9 that is resistant, were used for mycorrhizal inoculation in this study. Pre-inoculation of susceptible Gaoyou-115 with arbuscular mycorrhizal fungus (AMF) Glomus mosseae significantly reduced the disease incidence and disease severity of sheath blight of corn. HPLC analysis showed that AMF inoculation led to significant increase in 2,4-dihydroxy-7-methoxy-2 H-1,4-benzoxazin-3(4 H)-one (DIMBOA) accumulation in the roots of both corn varieties and in leaves of resistant Yuenong-9. R. solani inoculation alone did not result in accumulation of DIMBOA in both roots and leaves of the two corn varieties. Our previous study showed that DIMBOA strongly inhibited mycelial growth of R. solani in vitro. Real-time PCR analysis showed that mycorrhizal inoculation itself did not affect the transcripts of most genes tested. However, pre-inoculation with G. mosseae induced strong responses of three defense-related genes PR2a, PAL, and AOS, as well as BX9, one of the key genes in DIMBOA biosynthesis pathway, in the leaves of corn plants of both Yuenong-9 and Gaoyou-115 after the pathogen attack. Induction of defense responses in pre-inoculated plants was much higher and quicker than that in non-inoculated plants upon R. solani infection. These results indicate that induction of accumulation of DIMBOA, an important phytoalexin in corn, and systemic defense responses by AMF, plays a vital role in enhanced disease resistance of mycorrhizal plants of corn against sheath blight. This study also suggests that priming is an important mechanism in mycorrhiza-induced resistance.

  19. The effect of water limitation on volatile emission, tree defense response, and brood success of Dendroctonus ponderosae in two pine hosts, lodgepole and jack pine

    Directory of Open Access Journals (Sweden)

    Inka eLusebrink

    2016-02-01

    Full Text Available The mountain pine beetle (MPB; Dendroctonus ponderosae has recently expanded its range from lodgepole pine forest into the lodgepole × jack pine hybrid zone in central Alberta, within which it has attacked pure jack pine. This study tested the effects of water limitation on tree defense response of mature lodgepole and jack pine (Pinus contorta and Pinus banksiana trees in the field. Tree defense response was initiated by inoculation of trees with the MPB-associated fungus Grosmannia clavigera and measured through monoterpene emission from tree boles and concentration of defensive compounds in phloem, needles, and necrotic tissues. Lodgepole pine generally emitted higher amounts of monoterpenes than jack pine; particularly from fungal-inoculated trees. Compared to non-inoculated trees, fungal inoculation increased monoterpene emission in both species, whereas water treatment had no effect on monoterpene emission. The phloem of both pine species contains (--α-pinene, the precursor of the beetle’s aggregation pheromone, however lodgepole pine contains two times as much as jack pine. The concentration of defensive compounds was 70-fold greater in the lesion tissue in jack pine, but only 10-fold in lodgepole pine compared to healthy phloem tissue in each species, respectively. Water-deficit treatment inhibited an increase of L-limonene as response to fungal inoculation in lodgepole pine phloem. The amount of myrcene in jack pine phloem was higher in water-deficit trees compared to ambient trees. Beetles reared in jack pine were not affected by either water or biological treatment, whereas beetles reared in lodgepole pine benefited from fungal inoculation by producing larger and heavier female offspring. Female beetles that emerged from jack pine bolts contained more fat than those that emerged from lodgepole pine, even though lodgepole pine phloem had a higher nitrogen content than jack pine phloem. These results suggest that jack pine chemistry

  20. What happens in the pith stays in the pith: tissue-localized defense responses facilitate chemical niche differentiation between two spatially separated herbivores.

    Science.gov (United States)

    Lee, Gisuk; Joo, Youngsung; Kim, Sang-Gyu; Baldwin, Ian T

    2017-11-01

    Herbivore attack is known to elicit systemic defense responses that spread throughout the host plant and influence the performance of other herbivores. While these plant-mediated indirect competitive interactions are well described, and the co-existence of herbivores from different feeding guilds is common, the mechanisms of co-existence are poorly understood. In both field and glasshouse experiments with a native tobacco, Nicotiana attenuata, we found no evidence of negative interactions when plants were simultaneously attacked by two spatially separated herbivores: a leaf chewer Manduca sexta and a stem borer Trichobaris mucorea. T. mucorea attack elicited jasmonic acid (JA) and jasmonoyl-l-isoleucine bursts in the pith of attacked stems similar to those that occur in leaves when M. sexta attacks N. attenuata leaves. Pith chlorogenic acid (CGA) levels increased 1000-fold to levels 6-fold higher than leaf levels after T. mucorea attack; these increases in pith CGA levels, which did not occur in M. sexta-attacked leaves, required JA signaling. With plants silenced in CGA biosynthesis (irHQT plants), CGA, as well as other caffeic acid conjugates, was demonstrated in both glasshouse and field experiments to function as a direct defense protecting piths against T. mucorea attack, but not against leaf chewers or sucking insects. T. mucorea attack does not systemically activate JA signaling in leaves, while M. sexta leaf-attack transiently induces detectable but minor pith JA levels that are dwarfed by local responses. We conclude that tissue-localized defense responses allow tissue-specialized herbivores to share the same host and occupy different chemical defense niches in the same hostplant. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  1. Redox-responsive core cross-linked prodrug micelles prepared by click chemistry for pH-triggered doxorubicin delivery

    Directory of Open Access Journals (Sweden)

    X. T. Cao

    2017-10-01

    Full Text Available A pH-triggered drug delivery system of degradable core cross-linked (CCL prodrug micelles was prepared by click chemistry. Doxorubicin conjugated block copolymers of azido functional poly(ethylene oxide-b-poly(glycidyl methacrylate were synthesized by the combination of RAFT polymerization, epoxide ring-opening reaction, and acid-cleavable hydrazone linkages. The CCL prodrug micelles were produced by the reaction of dipropargyl 3,3′-dithiodipropionate and dipropargyl adipate cross-linking agents with the azido groups of the micellar core via alkyne-azide click reaction, which were denoted as CCL/SS and CCL/noSS, respectively. The TEM images of CCL/SS prodrug micelles showed a spherical shape with the average diameter of 61.0 nm from water, and the shape was maintained with an increased diameter upon dilution with 5-fold DMF. The high DOX conjugation efficiency was 88.4%. In contrast to a very slow DOX release from CCL/SS prodrug micelles under the physiological condition (pH 7.4, the drug release is much faster (90% at pH 5.0 and 10 mM of GSH after 96 h. The cytotoxicity test and confocal laser scanning microscopy analysis revealed that CCL/SS prodrug micelles had much enhanced intracellular drug release capability in HepG2 cells than CCL/noSS prodrug micelles.

  2. Aspirin-triggered resolvin D1 down-regulates inflammatory responses and protects against endotoxin-induced acute kidney injury

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jiao [Center for Research on Environmental Disease, University of Kentucky, Lexington, KY 40536 (United States); Shetty, Sreerama [Center for Biomedical Research, University of Texas Health Science Center at Tyler, Tyler, TX 75708 (United States); Zhang, Ping [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Gao, Rong; Hu, Yuxin [Center for Research on Environmental Disease, University of Kentucky, Lexington, KY 40536 (United States); Wang, Shuxia [Graduate Center for Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Li, Zhenyu [Division of Cardiovascular Medicine, University of Kentucky, Lexington, KY 40536 (United States); Fu, Jian, E-mail: jian.fu@uky.edu [Center for Research on Environmental Disease, University of Kentucky, Lexington, KY 40536 (United States); Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States)

    2014-06-01

    The presence of endotoxin in blood can lead to acute kidney injury (AKI) and septic shock. Resolvins, the endogenous lipid mediators derived from docosahexaenoic acid, have been reported to exhibit potent anti-inflammatory action. Using a mouse model of lipopolysaccharide (LPS)-induced AKI, we investigated the effects of aspirin-triggered resolvin D1 (AT-RvD1) on inflammatory kidney injury. Administration of AT-RvD1 1 h after LPS challenge protected the mice from kidney injury as indicated by the measurements of blood urea nitrogen, serum creatinine, and morphological alterations associated with tubular damage. The protective effects were evidenced by decreased neutrophil infiltration in the kidney indicating reduction in inflammation. AT-RvD1 treatment restored kidney cell junction protein claudin-4 expression, which was otherwise reduced after LPS challenge. AT-RvD1 treatment inhibited endotoxin-induced NF-κB activation and suppressed LPS-induced ICAM-1 and VCAM-1 expression in the kidney. Moreover, AT-RvD1 treatment markedly decreased LPS-induced IL-6 level in the kidney and blocked IL-6-mediated signaling including STAT3 and ERK phosphorylation. Our findings demonstrate that AT-RvD1 is a potent anti-inflammatory mediator in LPS-induced kidney injury, and AT-RvD1 has therapeutic potential against AKI during endotoxemia.

  3. Aspirin-triggered resolvin D1 down-regulates inflammatory responses and protects against endotoxin-induced acute kidney injury

    International Nuclear Information System (INIS)

    Chen, Jiao; Shetty, Sreerama; Zhang, Ping; Gao, Rong; Hu, Yuxin; Wang, Shuxia; Li, Zhenyu; Fu, Jian

    2014-01-01

    The presence of endotoxin in blood can lead to acute kidney injury (AKI) and septic shock. Resolvins, the endogenous lipid mediators derived from docosahexaenoic acid, have been reported to exhibit potent anti-inflammatory action. Using a mouse model of lipopolysaccharide (LPS)-induced AKI, we investigated the effects of aspirin-triggered resolvin D1 (AT-RvD1) on inflammatory kidney injury. Administration of AT-RvD1 1 h after LPS challenge protected the mice from kidney injury as indicated by the measurements of blood urea nitrogen, serum creatinine, and morphological alterations associated with tubular damage. The protective effects were evidenced by decreased neutrophil infiltration in the kidney indicating reduction in inflammation. AT-RvD1 treatment restored kidney cell junction protein claudin-4 expression, which was otherwise reduced after LPS challenge. AT-RvD1 treatment inhibited endotoxin-induced NF-κB activation and suppressed LPS-induced ICAM-1 and VCAM-1 expression in the kidney. Moreover, AT-RvD1 treatment markedly decreased LPS-induced IL-6 level in the kidney and blocked IL-6-mediated signaling including STAT3 and ERK phosphorylation. Our findings demonstrate that AT-RvD1 is a potent anti-inflammatory mediator in LPS-induced kidney injury, and AT-RvD1 has therapeutic potential against AKI during endotoxemia

  4. Leaf shedding as an anti-bacterial defense in Arabidopsis cauline leaves.

    Science.gov (United States)

    Patharkar, O Rahul; Gassmann, Walter; Walker, John C

    2017-12-01

    Plants utilize an innate immune system to protect themselves from disease. While many molecular components of plant innate immunity resemble the innate immunity of animals, plants also have evolved a number of truly unique defense mechanisms, particularly at the physiological level. Plant's flexible developmental program allows them the unique ability to simply produce new organs as needed, affording them the ability to replace damaged organs. Here we develop a system to study pathogen-triggered leaf abscission in Arabidopsis. Cauline leaves infected with the bacterial pathogen Pseudomonas syringae abscise as part of the defense mechanism. Pseudomonas syringae lacking a functional type III secretion system fail to elicit an abscission response, suggesting that the abscission response is a novel form of immunity triggered by effectors. HAESA/HAESA-like 2, INFLORESCENCE DEFICIENT IN ABSCISSION, and NEVERSHED are all required for pathogen-triggered abscission to occur. Additionally phytoalexin deficient 4, enhanced disease susceptibility 1, salicylic acid induction-deficient 2, and senescence-associated gene 101 plants with mutations in genes necessary for bacterial defense and salicylic acid signaling, and NahG transgenic plants with low levels of salicylic acid fail to abscise cauline leaves normally. Bacteria that physically contact abscission zones trigger a strong abscission response; however, long-distance signals are also sent from distal infected tissue to the abscission zone, alerting the abscission zone of looming danger. We propose a threshold model regulating cauline leaf defense where minor infections are handled by limiting bacterial growth, but when an infection is deemed out of control, cauline leaves are shed. Together with previous results, our findings suggest that salicylic acid may regulate both pathogen- and drought-triggered leaf abscission.

  5. Nitric oxide-mediated maintenance of redox homeostasis contributes to NPR1-dependent plant innate immunity triggered by lipopolysaccharides.

    Science.gov (United States)

    Sun, Aizhen; Nie, Shengjun; Xing, Da

    2012-10-01

    The perception of lipopolysaccharides (LPS) by plant cells can lead to nitric oxide (NO) production and defense gene induction. However, the signaling cascades underlying these cellular responses have not yet been resolved. This work investigated the biosynthetic origin of NO and the role of NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 (NPR1) to gain insight into the mechanism involved in LPS-induced resistance of Arabidopsis (Arabidopsis thaliana). Analysis of inhibitors and mutants showed that LPS-induced NO synthesis was mainly mediated by an arginine-utilizing source of NO generation. Furthermore, LPS-induced NO caused transcript accumulation of alternative oxidase genes and increased antioxidant enzyme activity, which enhanced antioxidant capacity and modulated redox state. We also analyzed the subcellular localization of NPR1 to identify the mechanism for protein-modulated plant innate immunity triggered by LPS. LPS-activated defense responses, including callose deposition and defense-related gene expression, were found to be regulated through an NPR1-dependent pathway. In summary, a significant NO synthesis induced by LPS contributes to the LPS-induced defense responses by up-regulation of defense genes and modulation of cellular redox state. Moreover, NPR1 plays an important role in LPS-triggered plant innate immunity.

  6. Chlamydia trachomatis recombinant MOMP encapsulated in PLGA nanoparticles triggers primarily T helper 1 cellular and antibody immune responses in mice: a desirable candidate nanovaccine

    Directory of Open Access Journals (Sweden)

    Fairley SJ

    2013-05-01

    Full Text Available Stacie J Fairley, Shree R Singh, Abebayehu N Yilma, Alain B Waffo, Praseetha Subbarayan, Saurabh Dixit, Murtada A Taha, Chino D Cambridge, Vida A Dennis Center for NanoBiotechnology Research, Alabama State University, Montgomery, AL, USA Abstract: We recently demonstrated by in vitro experiments that PLGA (poly D, L-lactide-co-glycolide potentiates T helper 1 (Th1 immune responses induced by a peptide derived from the recombinant major outer membrane protein (rMOMP of Chlamydia trachomatis, and may be a promising vaccine delivery system. Herein we evaluated the immune-potentiating potential of PLGA by encapsulating the full-length rMOMP (PLGA-rMOMP, characterizing it in vitro, and investigating its immunogenicity in vivo. Our hypothesis was that PLGA-rMOMP triggers Th1 immune responses in mice, which are desirable prerequisites for a C. trachomatis candidate nanovaccine. Physical-structural characterizations of PLGA-rMOMP revealed its size (approximately 272 nm, zeta potential (−14.30 mV, apparent spherical smooth morphology, and continuous slow release pattern. PLGA potentiated the ability of encapsulated rMOMP to trigger production of cytokines and chemokines by mouse J774 macrophages. Flow cytometric analyses revealed that spleen cells from BALB/c mice immunized with PLGA-rMOMP had elevated numbers of CD4+ and CD8+ T cell subsets, and secreted more rMOMP-specific interferon-gamma (Th1 and interleukin (IL-12p40 (Th1/Th17 than IL-4 and IL-10 (Th2 cytokines. PLGA-rMOMP-immunized mice produced higher serum immunoglobulin (IgG and IgG2a (Th1 than IgG1 (Th2 rMOMP-specific antibodies. Notably, sera from PLGA-rMOMP-immunized mice had a 64-fold higher Th1 than Th2 antibody titer, whereas mice immunized with rMOMP in Freund's adjuvant had only a four-fold higher Th1 than Th2 antibody titer, suggesting primarily induction of a Th1 antibody response in PLGA-rMOMP-immunized mice. Our data underscore PLGA as an effective delivery system for a C

  7. Transfer RNA Derived Small RNAs Targeting Defense Responsive Genes Are Induced during Phytophthora capsici Infection in Black Pepper (Piper nigrum L.).

    Science.gov (United States)

    Asha, Srinivasan; Soniya, Eppurath V

    2016-01-01

    Small RNAs derived from transfer RNAs were recently assigned as potential gene regulatory candidates for various stress responses in eukaryotes. In this study, we report on the cloning and identification of tRNA derived small RNAs from black pepper plants in response to the infection of the quick wilt pathogen, Phytophthora capsici. 5'tRFs cloned from black pepper were validated as highly expressed during P. capsici infection. A high-throughput systematic analysis of the small RNAome (sRNAome) revealed the predominance of 5'tRFs in the infected leaf and root. The abundance of 5'tRFs in the sRNAome and the defense responsive genes as their potential targets indicated their regulatory role during stress response in black pepper. The 5'Ala(CGC) tRF mediated cleavage was experimentally mapped at the tRF binding sites on the mRNA targets of Non-expresser of pathogenesis related protein (NPR1), which was down-regulated during pathogen infection. Comparative sRNAome further demonstrated sequence conservation of 5'Ala tRFs across the angiosperm plant groups, and many important genes in the defense response were identified in silico as their potential targets. Our findings uncovered the diversity, differential expression and stress responsive functional role of tRNA-derived small RNAs during Phytophthora infection in black pepper.

  8. Induction of Defense-Related Responses in Cf9 Tomato Cells by the AVR9 Elicitor Peptide of Cladosporium fulvum Is Developmentally Regulated1

    Science.gov (United States)

    Honée, Guy; Buitink, Julia; Jabs, Thorsten; De Kloe, José; Sijbolts, Fred; Apotheker, Marion; Weide, Rob; Sijen, Titia; Stuiver, Maarten; De Wit, Pierre J.G.M.

    1998-01-01

    The AVR9 elicitor from the fungal pathogen Cladosporium fulvum induces defense-related responses, including cell death, specifically in tomato (Lycopersicon esculentum Mill.) plants that carry the Cf-9 resistance gene. To study biochemical mechanisms of resistance in detail, suspension cultures of tomato cells that carry the Cf-9 resistance gene were initiated. Treatment of cells with various elicitors, except AVR9, induced an oxidative burst, ion fluxes, and expression of defense-related genes. Agrobacterium tumefaciens-mediated transformation of Cf9 tomato leaf discs with Avr9-containing constructs resulted efficiently in transgenic callus formation. Although transgenic callus tissue showed normal regeneration capacity, transgenic plants expressing both the Cf-9 and the Avr9 genes were never obtained. Transgenic F1 seedlings that were generated from crosses between tomato plants expressing the Avr9 gene and wild-type Cf9 plants died within a few weeks. However, callus cultures that were initiated on cotyledons from these seedlings could be maintained for at least 3 months and developed similarly to callus cultures that contained only the Cf-9 or the Avr9 gene. It is concluded, therefore, that induction of defense responses in Cf9 tomato cells by the AVR9 elicitor is developmentally regulated and is absent in callus tissue and cell-suspension cultures, which consists of undifferentiated cells. These results are significant for the use of suspension-cultured cells to investigate signal transduction cascades. PMID:9662523

  9. FY 1997 Financial Reporting by The Defense Automated Printing Service

    National Research Council Canada - National Science Library

    1998-01-01

    .... The accuracy of information in the financial systems and reported on financial statements is the joint responsibility of the Defense Automated Printing Service and the Defense Logistics Agency...

  10. Accounting for Unliquidated Obligations for the Defense Fuel Supply Center

    National Research Council Canada - National Science Library

    1996-01-01

    .... The Defense Finance and Accounting Service (DFAS) Columbus Center, Columbus, Ohio, and the Defense Fuel Supply Center share responsibility for accurate accounting information and financial reporting...

  11. Plant Defense against Insect Herbivores

    Science.gov (United States)

    Fürstenberg-Hägg, Joel; Zagrobelny, Mika; Bak, Søren

    2013-01-01

    Plants have been interacting with insects for several hundred million years, leading to complex defense approaches against various insect feeding strategies. Some defenses are constitutive while others are induced, although the insecticidal defense compound or protein classes are often similar. Insect herbivory induce several internal signals from the wounded tissues, including calcium ion fluxes, phosphorylation cascades and systemic- and jasmonate signaling. These are perceived in undamaged tissues, which thereafter reinforce their defense by producing different, mostly low molecular weight, defense compounds. These bioactive specialized plant defense compounds may repel or intoxicate insects, while defense proteins often interfere with their digestion. Volatiles are released upon herbivory to repel herbivores, attract predators or for communication between leaves or plants, and to induce defense responses. Plants also apply morphological features like waxes, trichomes and latices to make the feeding more difficult for the insects. Extrafloral nectar, food bodies and nesting or refuge sites are produced to accommodate and feed the predators of the herbivores. Meanwhile, herbivorous insects have adapted to resist plant defenses, and in some cases even sequester the compounds and reuse them in their own defense. Both plant defense and insect adaptation involve metabolic costs, so most plant-insect interactions reach a stand-off, where both host and herbivore survive although their development is suboptimal. PMID:23681010

  12. Suppressing Farnesyl Diphosphate Synthase Alters Chloroplast Development and Triggers Sterol-Dependent Induction of Jasmonate- and Fe-Related Responses1[OPEN

    Science.gov (United States)

    Andrade, Paola; Caudepón, Daniel; Arró, Montserrat

    2016-01-01

    Farnesyl diphosphate synthase (FPS) catalyzes the synthesis of farnesyl diphosphate from isopentenyl diphosphate and dimethylallyl diphosphate. Arabidopsis (Arabidopsis thaliana) contains two genes (FPS1 and FPS2) encoding FPS. Single fps1 and fps2 knockout mutants are phenotypically indistinguishable from wild-type plants, while fps1/fps2 double mutants are embryo lethal. To assess the effect of FPS down-regulation at postembryonic developmental stages, we generated Arabidopsis conditional knockdown mutants expressing artificial microRNAs devised to simultaneously silence both FPS genes. Induction of silencing from germination rapidly caused chlorosis and a strong developmental phenotype that led to seedling lethality. However, silencing of FPS after seed germination resulted in a slight developmental delay only, although leaves and cotyledons continued to show chlorosis and altered chloroplasts. Metabolomic analyses also revealed drastic changes in the profile of sterols, ubiquinones, and plastidial isoprenoids. RNA sequencing and reverse transcription-quantitative polymerase chain reaction transcriptomic analysis showed that a reduction in FPS activity levels triggers the misregulation of genes involved in biotic and abiotic stress responses, the most prominent one being the rapid induction of a set of genes related to the jasmonic acid pathway. Down-regulation of FPS also triggered an iron-deficiency transcriptional response that is consistent with the iron-deficient phenotype observed in FPS-silenced plants. The specific inhibition of the sterol biosynthesis pathway by chemical and genetic blockage mimicked these transcriptional responses, indicating that sterol depletion is the primary cause of the observed alterations. Our results highlight the importance of sterol homeostasis for normal chloroplast development and function and reveal important clues about how isoprenoid and sterol metabolism is integrated within plant physiology and development. PMID

  13. Pepper osmotin-like protein 1 (CaOSM1) is an essential component for defense response, cell death, and oxidative burst in plants.

    Science.gov (United States)

    Choi, Du Seok; Hong, Jeum Kyu; Hwang, Byung Kook

    2013-12-01

    Osmotin or osmotin-like protein, a PR-5 family member, is differentially induced in plants by abiotic and biotic stresses. Here, we demonstrate that the pepper (Capsicum annuum) osmotin-like protein 1 gene, CaOSM1, was required for the defense and hypersensitive cell death response and oxidative burst signaling during Xanthomonas campestris pv. vesicatoria (Xcv) infection. CaOSM1 protein was localized to the plasma membrane in leaf cells of Nicotiana benthamiana. Agrobacterium-mediated transient expression of CaOSM1 in pepper distinctly induced the hypersensitive cell death response and H2O2 accumulation. Knock-down of CaOSM1 in pepper by virus-induced gene silencing increased the susceptibility to Xcv infection, which was accompanied by attenuation of the cell death response and decreased accumulation of H2O2. CaOSM1 overexpression in transgenic Arabidopsis conferred reduced susceptibility and accelerated cell death response and H2O2 accumulation to infection by Pseudomonas syringe pv. tomato and Hyaloperonospora arabidopsidis. Together, these results suggest that CaOSM1 is involved in cell death and oxidative burst responses during plant defense against microbial pathogens.

  14. Salt-tolerant and -sensitive alfalfa (Medicago sativa) cultivars have large variations in defense responses to the lepidopteran insect Spodoptera litura under normal and salt stress condition.

    Science.gov (United States)

    Lei, Yunting; Liu, Qing; Hettenhausen, Christian; Cao, Guoyan; Tan, Qing; Zhao, Weiye; Lin, Honghui; Wu, Jianqiang

    2017-01-01

    In nature, plants are often exposed to multiple stress factors at the same time. Yet, little is known about how plants modulate their physiology to counteract simultaneous abiotic and biotic stresses, such as soil salinity and insect herbivory. In this study, insect performance bioassays, phytohormone measurements, quantification of transcripts, and protein determination were employed to study the phenotypic variations of two alfalfa (Medicago sativa) cultivars in response to insect Spodoptera litura feeding under normal and salt stress condition. When being cultivated in normal soil, the salt-tolerant alfalfa cultivar Zhongmu-1 exhibited lower insect resistance than did the salt-sensitive cultivar Xinjiang Daye. Under salinity stress, the defense responses of Xinjiang Daye were repressed, whereas Zhongmu-1 did not show changes in resistance levels. It is likely that salinity influenced the resistance of Xinjiang Daye through suppressing the accumulation of jasmonic acid-isoleucine (JA-Ile), which is the bioactive hormone inducing herbivore defense responses, leading to attenuated trypsin proteinase inhibitor (TPI) activity. Furthermore, exogenous ABA supplementation suppressed the insect herbivory-induced JA/JA-Ile accumulation and levels of JAR1 (jasmonate resistant 1) and TPI, and further decreased the resistance of Xinjiang Daye, whereas Zhongmu-1 showed very little response to the increased ABA level. We propose a mechanism, in which high levels of abscisic acid induced by salt treatment may affect the expression levels of JAR1 and consequently decrease JA-Ile accumulation and thus partly suppress the defense of Xinjiang Daye against insects under salt stress. This study provides new insight into the mechanism by which alfalfa responds to concurrent abiotic and biotic stresses.

  15. Induction of defensive enzymes (isozymes) during defense against ...

    African Journals Online (AJOL)

    These results suggest that enhancing defensive enzymes' activities and inducing new isozymes may be related to mitigating pathogen-induced oxidative damage which result in the decrease of calli decay, and this implies that antioxidant defense response may be involved in the mechanisms of plant against fungal ...

  16. Vagal nerve stimulation triggers widespread responses and alters large-scale functional connectivity in the rat brain.

    Directory of Open Access Journals (Sweden)

    Jiayue Cao

    Full Text Available Vagus nerve stimulation (VNS is a therapy for epilepsy and depression. However, its efficacy varies and its mechanism remains unclear. Prior studies have used functional magnetic resonance imaging (fMRI to map brain activations with VNS in human brains, but have reported inconsistent findings. The source of inconsistency is likely attributable to the complex temporal characteristics of VNS-evoked fMRI responses that cannot be fully explained by simplified response models in the conventional model-based analysis for activation mapping. To address this issue, we acquired 7-Tesla blood oxygenation level dependent fMRI data from anesthetized Sprague-Dawley rats receiving electrical stimulation at the left cervical vagus nerve. Using spatially independent component analysis, we identified 20 functional brain networks and detected the network-wise activations with VNS in a data-driven manner. Our results showed that VNS activated 15 out of 20 brain networks, and the activated regions covered >76% of the brain volume. The time course of the evoked response was complex and distinct across regions and networks. In addition, VNS altered the strengths and patterns of correlations among brain networks relative to those in the resting state. The most notable changes in network-network interactions were related to the limbic system. Together, such profound and widespread effects of VNS may underlie its unique potential for a wide range of therapeutics to relieve central or peripheral conditions.

  17. LrABCF1, a GCN-type ATP-binding cassette transporter from Lilium regale, is involved in defense responses against viral and fungal pathogens.

    Science.gov (United States)

    Sun, Daoyang; Zhang, Xinguo; Li, Shaohua; Jiang, Cai-Zhong; Zhang, Yanlong; Niu, Lixin

    2016-12-01

    The L. regale ATP-binding cassette transporter gene, LrABCF1 belonging to GCN subfamily, functions as a positive regulator of plant defense against Cucumber mosaic virus, Tobacco rattle virus , and Botrytis cinerea in petunia. ATP-binding cassette (ABC) transporters are essential for membrane translocation in diverse biological processes, such as plant development and defense response. Here, a general control non-derepressible (GCN)-type ABC transporter gene, designated LrABCF1, was identified from Cucumber mosaic virus (CMV)-induced cDNA library of L. regale. LrABCF1 was up-regulated upon inoculation with CMV and Lily mottle virus (LMoV). Salicylic acid (SA) and ethylene (ET) application and treatments with abiotic stresses such as cold, high salinity, and wounding increased the transcript abundances of LrABCF1. Constitutive overexpression of LrABCF1 in petunia (Petunia × hybrida) resulted in an impairment of plant growth and development. LrABCF1 overexpression conferred reduced susceptibility to CMV, Tobacco rattle virus (TRV), and B. cinerea infection in transgenic petunia plants, accompanying by elevated transcripts of PhGCN2 and a few defense-related genes in SA-signaling pathway. Our data indicate that LrABCF1 positively modulates viral and fungal resistance.

  18. RNA-Seq analysis of Citrus reticulata in the early stages of Xylella fastidiosa infection reveals auxin-related genes as a defense response.

    Science.gov (United States)

    Rodrigues, Carolina M; de Souza, Alessandra A; Takita, Marco A; Kishi, Luciano T; Machado, Marcos A

    2013-10-03

    Citrus variegated chlorosis (CVC), caused by Xylella fastidiosa, is one the most important citrus diseases, and affects all varieties of sweet orange (Citrus sinensis L. Osb). On the other hand, among the Citrus genus there are different sources of resistance against X. fastidiosa. For these species identifying these defense genes could be an important step towards obtaining sweet orange resistant varieties through breeding or genetic engineering. To assess these genes we made use of mandarin (C. reticulata Blanco) that is known to be resistant to CVC and shares agronomical characteristics with sweet orange. Thus, we investigated the gene expression in Ponkan mandarin at one day after infection with X. fastidiosa, using RNA-seq. A set of genes considered key elements in the resistance was used to confirm its regulation in mandarin compared with the susceptible sweet orange. Gene expression analysis of mock inoculated and infected tissues of Ponkan mandarin identified 667 transcripts repressed and 724 significantly induced in the later. Among the induced transcripts, we identified genes encoding proteins similar to Pattern Recognition Receptors. Furthermore, many genes involved in secondary metabolism, biosynthesis and cell wall modification were upregulated as well as in synthesis of abscisic acid, jasmonic acid and auxin. This work demonstrated that the defense response to the perception of bacteria involves cell wall modification and activation of hormone pathways, which probably lead to the induction of other defense-related genes. We also hypothesized the induction of auxin-related genes indicates that resistant plants initially recognize X. fastidiosa as a necrotrophic pathogen.

  19. Human Neutrophil Clearance of Bacterial Pathogens Triggers Anti-Microbial γδ T Cell Responses in Early Infection

    Science.gov (United States)

    Roberts, Gareth W.; Heuston, Sinéad; Brown, Amanda C.; Chess, James A.; Toleman, Mark A.; Gahan, Cormac G. M.; Hill, Colin; Parish, Tanya; Williams, John D.; Davies, Simon J.; Johnson, David W.; Topley, Nicholas; Moser, Bernhard; Eberl, Matthias

    2011-01-01

    Human blood Vγ9/Vδ2 T cells, monocytes and neutrophils share a responsiveness toward inflammatory chemokines and are rapidly recruited to sites of infection. Studying their interaction in vitro and relating these findings to in vivo observations in patients may therefore provide crucial insight into inflammatory events. Our present data demonstrate that Vγ9/Vδ2 T cells provide potent survival signals resulting in neutrophil activation and the release of the neutrophil chemoattractant CXCL8 (IL-8). In turn, Vγ9/Vδ2 T cells readily respond to neutrophils harboring phagocytosed bacteria, as evidenced by expression of CD69, interferon (IFN)-γ and tumor necrosis factor (TNF)-α. This response is dependent on the ability of these bacteria to produce the microbial metabolite (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMB-PP), requires cell-cell contact of Vγ9/Vδ2 T cells with accessory monocytes through lymphocyte function-associated antigen-1 (LFA-1), and results in a TNF-α dependent proliferation of Vγ9/Vδ2 T cells. The antibiotic fosmidomycin, which targets the HMB-PP biosynthesis pathway, not only has a direct antibacterial effect on most HMB-PP producing bacteria but also possesses rapid anti-inflammatory properties by inhibiting γδ T cell responses in vitro. Patients with acute peritoneal-dialysis (PD)-associated bacterial peritonitis – characterized by an excessive influx of neutrophils and monocytes into the peritoneal cavity – show a selective activation of local Vγ9/Vδ2 T cells by HMB-PP producing but not by HMB-PP deficient bacterial pathogens. The γδ T cell-driven perpetuation of inflammatory responses during acute peritonitis is associated with elevated peritoneal levels of γδ T cells and TNF-α and detrimental clinical outcomes in infections caused by HMB-PP positive microorganisms. Taken together, our findings indicate a direct link between invading pathogens, neutrophils, monocytes and microbe-responsive γδ T cells in early

  20. Unmasking host and microbial strategies in the Agrobacterium-plant defense tango

    Directory of Open Access Journals (Sweden)

    Elizabeth E. Hwang

    2015-03-01

    Full Text Available Coevolutionary forces drive adaptation of both plant-associated microbes and their hosts. Eloquently captured in the Red Queen Hypothesis, the complexity of each plant-pathogen relationship reflects escalating adversarial strategies, but also external biotic and abiotic pressures on both partners. Innate immune responses are triggered by highly conserved pathogen-associated molecular patterns, or PAMPs, that are harbingers of microbial presence. Upon cell surface receptor-mediated recognition of these pathogen-derived molecules, host plants mount a variety of physiological responses to limit pathogen survival and/or invasion. Successful pathogens often rely on secretion systems to translocate host-modulating effectors that subvert plant defenses, thereby increasing virulence. Host plants, in turn, have evolved to recognize these effectors, activating what has typically been characterized as a pathogen-specific form of immunity. Recent data support the notion that PAMP-triggered and effector-triggered defenses are complementary facets of a convergent, albeit differentially regulated, set of immune responses. This review highlights the key players in the plant’s recognition and signal transduction pathways, with a focus on the aspects that may limit Agrobacterium tumefaciens infection and the ways it might overcome those defenses. Recent advances in the field include a growing appreciation for the contributions of cytoskeletal dynamics and membrane trafficking to the regulation of these exquisitely tuned defenses. Pathogen counter-defenses frequently manipulate the interwoven hormonal pathways that mediate host responses. Emerging systems-level analyses include host physiological factors such as circadian cycling. The existing literature indicates that varying or even conflicting results from different labs may well be attributable to environmental factors including time of day of infection, temperature, and/or developmental stage of the host

  1. Ficolins Promote Fungal Clearance in vivo and Modulate the Inflammatory Cytokine Response in Host Defense against Aspergillus fumigatus

    DEFF Research Database (Denmark)

    Genster, N; Cramer, E Præstekjær; Rosbjerg, A

    2016-01-01

    Aspergillus fumigatus is an opportunistic fungal pathogen that causes severe invasive infections in immunocompromised patients. Innate immunity plays a major role in protection against A. fumigatus. The ficolins are a family of soluble pattern recognition receptors that are capable of activating...... the lectin pathway of complement. Previous in vitro studies reported that ficolins bind to A. fumigatus, but their part in host defense against fungal infections in vivo is unknown. In this study, we used ficolin-deficient mice to investigate the role of ficolins during lung infection with A. fumigatus......-mediated complement activation in ficolin knockout mice and wild-type mice. In conclusion, this study demonstrates that ficolins are important in initial innate host defense against A. fumigatus infections in vivo....

  2. Surfactin Protects Wheat against Zymoseptoria tritici and Activates Both Salicylic Acid- and Jasmonic Acid-Dependent Defense Responses

    OpenAIRE

    Geraldine Le Mire; Ali Siah; Marie-Noëlle Brisset; Matthieu Gaucher; Magali Deleu; M. Haissam Jijakli

    2018-01-01

    Natural elicitors induce plant resistance against a broad spectrum of diseases, and are currently among the most promising biocontrol tools. The present study focuses on the elicitor properties of the cyclic lipopeptide surfactin on wheat, in order to stimulate the defenses of this major crop against the challenging fungal pathogen Zymoseptoria tritici. The protection efficacy of surfactin extracted from the strain Bacillus amyloliquefaciens S499 was investigated through greenhouse trials. Su...

  3. Suspended Disbelief: The Role of the Department of Defense in Interagency Foreign Humanitarian Assistance and Disaster Response

    Science.gov (United States)

    2015-05-21

    director will initiate an executive secretariat memorandum routed from the USAID administrator via the Secretary of State to the Secretary of Defense...Publication of the disaster declaration cable and the executive secretariat memo facilitated the near immediate action of the Marine Expeditionary...Clausewitz offered a compelling way forward: “Habit hardens the body for great exertions, strengthens the heart in great peril, and fortifies judgment

  4. Surfactin Protects Wheat against Zymoseptoria tritici and Activates Both Salicylic Acid- and Jasmonic Acid-Dependent Defense Responses

    Directory of Open Access Journals (Sweden)

    Geraldine Le Mire

    2018-01-01

    Full Text Available Natural elicitors induce plant resistance against a broad spectrum of diseases, and are currently among the most promising biocontrol tools. The present study focuses on the elicitor properties of the cyclic lipopeptide surfactin on wheat, in order to stimulate the defenses of this major crop against the challenging fungal pathogen Zymoseptoria tritici. The protection efficacy of surfactin extracted from the strain Bacillus amyloliquefaciens S499 was investigated through greenhouse trials. Surfactin protected wheat by 70% against Z. tritici, similarly to the chemical reference elicitor Bion®50WG. In vitro biocidal assays revealed no antifungal activities of surfactin towards the pathogen. A biomolecular RT-qPCR based low-density microarray tool was used to study the relative expression of 23 wheat defense genes. Surfactin significantly induced wheat natural defenses by stimulating both salicylic acid- and jasmonic acid-dependent signaling pathways. Surfactin was successfully tested as an elicitor on the pathosystem wheat–Z. tritici. These results promote further sustainable agricultural practices and the reduction of chemical inputs.

  5. Uncoupling Oncogene-Induced Senescence (OIS) and DNA Damage Response (DDR) triggered by DNA hyper-replication: lessons from primary mouse embryo astrocytes (MEA).

    Science.gov (United States)

    Seoane, Marcos; Costoya, José A; Arce, Víctor M

    2017-10-11

    Oncogene-induced senescence (OIS) is a complex process, in which activation of oncogenic signals during early tumorigenesis results in a high degree of DNA replication stress. The ensuing response to the DNA damage produces a permanent G1 arrest that prevents unlimited cell proliferation and lessens the development of tumours. However, despite the role of OIS in the proliferative arrest resulting from an activating oncogenic-lesion has obtained wide support, there is also evidence indicating that cells may overcome oncogene-induced senescence under some circumstances. In this study, we have investigated the possibility that some of the assumptions on the role of DNA damage response (DDR) in triggering OIS may depend on the fact that most of the available data were obtained in mouse embryo fibroblast. By comparing the degree of OIS observed in mouse embryo fibroblasts (MEF) and mouse embryo astrocytes (MEA) obtained from the same individuals we have demonstrated that, despite truthful activation of DDR in both cell types, significant levels of OIS were only detected in MEF. Therefore, this uncoupling between OIS and DDR observed in astrocytes supports the intriguingly possibility that OIS is not a widespread response mechanism to DDR.

  6. Role of ER stress response in photodynamic therapy: ROS generated in different subcellular compartments trigger diverse cell death pathways.

    Directory of Open Access Journals (Sweden)

    Irena Moserova

    Full Text Available We have analyzed the molecular mechanisms of photoinduced cell death using porphyrins with similar structure differing only in the position of the ethylene glycol (EG chain on the phenyl ring. Meta- and para-positioned EG chains targeted porphyrins to different subcellular compartments. After photoactivation, both types of derivatives induced death of tumor cells via reactive oxygen species (ROS. Para derivatives pTPP(EG4 and pTPPF(EG4 primarily accumulated in lysosomes activated the p38 MAP kinase cascade, which in turn induced the mitochondrial apoptotic pathway. In contrast, meta porphyrin derivative mTPP(EG4 localized in the endoplasmic reticulum (ER induced dramatic changes in Ca(2+ homeostasis manifested by Ca(2+ rise in the cytoplasm, activation of calpains and stress caspase-12 or caspase-4. ER stress developed into unfolded protein response. Immediately after irradiation the PERK pathway was activated through phosphorylation of PERK, eIF2α and induction of transcription factors ATF4 and CHOP, which regulate stress response genes. PERK knockdown and PERK deficiency protected cells against mTPP(EG4-mediated apoptosis, confirming the causative role of the PERK pathway.

  7. The Arabidopsis ATAF1, a NAC transcription factor, is a negative regulator of defense responses against necrotrophic fungal and bacterial pathogens.

    Science.gov (United States)

    Wang, Xiao'e; Basnayake, B M Vindhya S; Zhang, Huijuan; Li, Guojun; Li, Wei; Virk, Nasar; Mengiste, Tesfaye; Song, Fengming

    2009-10-01

    Transcription factors of the NAC family are known to be involved in various growth or developmental processes and in regulation of response to environmental stresses. In the present study, we report that Arabidopsis ATAF1 is a negative regulator of defense responses against both necrotrophic fungal and bacterial pathogens. Expression of ATAF1 was downregulated after infection with Botrytis cinerea or Pseudomonas syringae pv. tomato or after treatment with salicylic acid (SA), jasmonic acid, and 1-amino cyclopropane-1-carboxylic acid (the precursor of ethylene biosynthesis). Transgenic plants that overexpress the ATAF1 gene (ATAF1-OE) showed increased susceptibility while expression of an ATAF1 chimeric repressor construct (ATAF1-SRDX) exhibited enhanced resistance to P. syringae pv. tomato DC3000, B. cinerea, and Alternaria brassicicola. The ataf1 mutant plants showed no significant resistance against the pathogens tested. After inoculation with B. cinerea or P. syringae pv. tomato DC3000, expressions of defense-related genes PR-1, PR-5. and PDF1.2 were upregulated in the ATAF1-SRDX plants but attenuated or unchanged in the ATAF1-OE plants. In ATAF1-OE plants, SA-induced expression of pathogenesis-related genes and disease resistance against P. syringae pv. tomato DC3000 was partially suppressed. Increased levels of reactive oxygen species (i.e., H(2)O(2) and superoxide anion) accumulated only in the ATAF1-OE but not in the ATAF1-SRDX plants after Botrytis spp. infection. Our studies provide direct genetic evidence for the role of ATAF1 as a negative regulator of defense response against different type of pathogens.

  8. The SA-dependent defense pathway is active against different pathogens in tomato and tobacco.

    Science.gov (United States)

    Achuo, A E; Audenaert, K; Meziane, H; Höfte, M

    2002-01-01

    The importance of salicylic acid (SA) in plant defense against pathogen attack has been elaborately documented. Benzothiadiazole (BTH, BION), a chemical analogue of SA, also induces resistance through the SA-dependent pathway. We investigated the role of SA in both basal defense and induced resistance of tomato (Lycopersicon esculentum) and tobacco (Nicotiana tabacum) against Oidium neolycopersici (a biotrophic pathogen) and Botrytis cinerea (a necrotrophic pathogen). A comparison of NahG transgenic tomato and tobacco (unable to accumulate SA) to their respective wild types revealed that in both crops, SA was not involved in basal defense against O. neolycopersici. SA also played no role in the basal defense of tobacco against B. cinerea but NahG tomato plants were significantly more sensitive to B. cinerea than wild type plants. Activation of the SA-dependent defense pathway via BTH resulted in induced resistance against B. cinerea in tomato but not in tobacco. In contrast, BTH induced resistance against O. neolycopersci in tobacco but not in tomato. Microscopic analysis revealed that BTH treatment could prevent penetration of the odium germ tube through the epidermal cell wall of tobacco leaves whereas penetration was successful on tomato leaves, irrespective of BTH treatment. We conclude that even in two related plant species such as tomato and tobacco, the SA-dependent defense pathway does not trigger the same defense responses. It also means that the outcome of a BTH treatment cannot be predicted and has to be tested for each plant-pathogen combination.

  9. Mechanisms that Trigger a Good Health-Care Response to Intimate Partner Violence in Spain. Combining Realist Evaluation and Qualitative Comparative Analysis Approaches.

    Science.gov (United States)

    Goicolea, Isabel; Vives-Cases, Carmen; Hurtig, Anna-Karin; Marchal, Bruno; Briones-Vozmediano, Erica; Otero-García, Laura; García-Quinto, Marta; San Sebastian, Miguel

    2015-01-01

    Health care professionals, especially those working in primary health-care services, can play a key role in preventing and responding to intimate partner violence. However, there are huge variations in the way health care professionals and primary health care teams respond to intimate partner violence. In this study we tested a previously developed programme theory on 15 primary health care center teams located in four different Spanish regions: Murcia, C Valenciana, Castilla-León and Cantabria. The aim was to identify the key combinations of contextual factors and mechanisms that trigger a good primary health care center team response to intimate partner violence. A multiple case-study design was used. Qualitative and quantitative information was collected from each of the 15 centers (cases). In order to handle the large amount of information without losing familiarity with each case, qualitative comparative analysis was undertaken. Conditions (context and mechanisms) and outcomes, were identified and assessed for each of the 15 cases, and solution formulae were calculated using qualitative comparative analysis software. The emerging programme theory highlighted the importance of the combination of each team's self-efficacy, perceived preparation and women-centredness in generating a good team response to intimate partner violence. The use of the protocol and accumulated experience in primary health care were the most relevant contextual/intervention conditions to trigger a good response. However in order to achieve this, they must be combined with other conditions, such as an enabling team climate, having a champion social worker and having staff with training in intimate partner violence. Interventions to improve primary health care teams' response to intimate partner violence should focus on strengthening team's self-efficacy, perceived preparation and the implementation of a woman-centred approach. The use of the protocol combined with a large working

  10. Mechanisms that Trigger a Good Health-Care Response to Intimate Partner Violence in Spain. Combining Realist Evaluation and Qualitative Comparative Analysis Approaches

    Science.gov (United States)

    Goicolea, Isabel; Vives-Cases, Carmen; Hurtig, Anna-Karin; Marchal, Bruno; Briones-Vozmediano, Erica; Otero-García, Laura; García-Quinto, Marta; San Sebastian, Miguel

    2015-01-01

    Background Health care professionals, especially those working in primary health-care services, can play a key role in preventing and responding to intimate partner violence. However, there are huge variations in the way health care professionals and primary health care teams respond to intimate partner violence. In this study we tested a previously developed programme theory on 15 primary health care center teams located in four different Spanish regions: Murcia, C Valenciana, Castilla-León and Cantabria. The aim was to identify the key combinations of contextual factors and mechanisms that trigger a good primary health care center team response to intimate partner violence. Methods A multiple case-study design was used. Qualitative and quantitative information was collected from each of the 15 centers (cases). In order to handle the large amount of information without losing familiarity with each case, qualitative comparative analysis was undertaken. Conditions (context and mechanisms) and outcomes, were identified and assessed for each of the 15 cases, and solution formulae were calculated using qualitative comparative analysis software. Results The emerging programme theory highlighted the importance of the combination of each team’s self-efficacy, perceived preparation and women-centredness in generating a good team response to intimate partner violence. The use of the protocol and accumulated experience in primary health care were the most relevant contextual/intervention conditions to trigger a good response. However in order to achieve this, they must be combined with other conditions, such as an enabling team climate, having a champion social worker and having staff with training in intimate partner violence. Conclusions Interventions to improve primary health care teams’ response to intimate partner violence should focus on strengthening team’s self-efficacy, perceived preparation and the implementation of a woman-centred approach. The use of the

  11. Magnetic and thermal responses triggered by structural changes in the double perovskite Sr2YRuO6.

    Science.gov (United States)

    Bernardo, P L; Ghivelder, L; Eslava, G G; Amorim, H S; Sinnecker, E H C; Felner, I; Neumeier, J J; García, S

    2012-12-05

    Among double perovskites, the interpretation of the magnetic, thermal and transport properties of Sr(2)YRuO(6) remains a challenge. Characterization using different techniques reveals a variety of features that are not understood, described as anomalous, and yields contradictory values for several relevant parameters. We solved this situation through detailed susceptibility, specific heat, thermal expansion and x-ray diffraction measurements, including a quantitative correlation of the parameters characterizing the so-called anomalies. The emergence of short-range magnetic correlations, surviving well above the long-range transition, naturally accounts for the observed unconventional behavior of this compound. High resolution x-ray powder diffraction and thermal expansion results conclusively show that the magnetic and thermal responses are driven by lattice changes, providing a comprehensive scenario in which the interplay between the spin and structural degrees of freedom plays a relevant role.

  12. Magnetic and thermal responses triggered by structural changes in the double perovskite Sr2YRuO6

    International Nuclear Information System (INIS)

    Bernardo, P L; Ghivelder, L; Eslava, G G; Amorim, H S; Sinnecker, E H C; García, S; Felner, I; Neumeier, J J

    2012-01-01

    Among double perovskites, the interpretation of the magnetic, thermal and transport properties of Sr 2 YRuO 6 remains a challenge. Characterization using different techniques reveals a variety of features that are not understood, described as anomalous, and yields contradictory values for several relevant parameters. We solved this situation through detailed susceptibility, specific heat, thermal expansion and x-ray diffraction measurements, including a quantitative correlation of the parameters characterizing the so-called anomalies. The emergence of short-range magnetic correlations, surviving well above the long-range transition, naturally accounts for the observed unconventional behavior of this compound. High resolution x-ray powder diffraction and thermal expansion results conclusively show that the magnetic and thermal responses are driven by lattice changes, providing a comprehensive scenario in which the interplay between the spin and structural degrees of freedom plays a relevant role.

  13. Auxins in defense strategies

    Czech Academy of Sciences Publication Activity Database

    Čarná, Mária; Repka, V.; Skůpa, Petr; Šturdík, E.

    2014-01-01

    Roč. 69, č. 10 (2014), s. 1255-1263 ISSN 0006-3088 R&D Projects: GA TA ČR TA01011802 Institutional support: RVO:61389030 Keywords : auxin * defense responses * JA Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection Impact factor: 0.827, year: 2014

  14. Lipopolysaccharide derived from the digestive tract triggers an inflammatory response in the uterus of mid-lactating dairy cows during SARA.

    Science.gov (United States)

    Bilal, Muhammad Shahid; Abaker, Juma Ahamed; Ul Aabdin, Zain; Xu, Tianle; Dai, Hongyu; Zhang, Kai; Liu, Xinxin; Shen, Xiangzhen

    2016-12-12

    The aims of the current study were to evaluate the inflammatory response in cow uterus and to explore the molecular mechanism triggered by high concentrate-induced subacute ruminal acidosis (SARA) in mid-lactating dairy cows. Twelve mid-lactating Holstein cows with an average weight of 455 kg were allocated into two groups subjected to two diets for 18-weeks either a low-concentrate (LC) group containing 4:6 (NDF: NFC) and a high-concentrate (HC) group containing 6:4 (non-forage carbohydrates, NFC): (neutral detergent fiber, NDF) ratio based on dry matter. The HC group showed lower ruminal pH and higher lipopolysaccharide (LPS) concentrations in both the rumen and peripheral plasma compared to the LC group. The LPS concentrations in the rumen fluid and the peripheral plasma were found significantly increased in the HC group compared to the LC group. The concentrations of IL-1β, TNF-α and IL-6 were significantly higher in the HC group compared to the LC group. The uterus of SARA cows revealed elevated mRNA concentrations of nuclear transcription factors and pro-inflammatory cytokines, which confirmed the presence of inflammation. The occurrence of uterine inflammation was further validated by the increased protein expression of NF-κB-p65 and its active phosphorylated variant in the uterus of SARA cows. Similarly, the inflammatory genes TLR4, LBP, MyD88, TRAF-6, NF-κB, IL-6, IL-8, TNF-α and IL-1β were significantly upregulated in the uterus of the HC versus the LC group. Therefore, the results indicated that LPS derived from the rumen triggered the genes associated with inflammation in the uterus of mid-lactating dairy cows fed a high-concentrate diet, causing endometritis.

  15. 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.

  16. Tetanus toxoid-loaded cationic non-aggregated nanostructured lipid particles triggered strong humoral and cellular immune responses.

    Science.gov (United States)

    Kaur, Amandeep; Jyoti, Kiran; Rai, Shweta; Sidhu, Rupinder; Pandey, Ravi Shankar; Jain, Upendra Kumar; Katyal, Anju; Madan, Jitender

    2016-05-01

    In the present investigation, non-aggregated cationic and unmodified nanoparticles (TT-C-NLPs4 and TT-NLPs1) were prepared of about 49.2 ± 6.8-nm and 40.8 ± 8.3-nm, respectively. In addition, spherical shape, crystalline architecture and cationic charge were also noticed. Furthermore, integrity and conformational stability of TT were maintained in both TT-C-NLPs4 and TT-NLPs1, as evidenced by symmetrical position of bands and superimposed spectra, respectively in SDS-PAGE and circular dichroism. Cellular uptake in RAW264.7 cells indicating the concentration-dependent internalisation of nanoparticles. Qualitatively, CLSM exhibited enhanced cellular uptake of non-aggregated TT-C-NLPs4 owing to interaction with negatively charged plasma membrane and clevaloe mediated/independent endocytosis. In last, in vivo immunisation with non-aggregated TT-C-NLPs4 elicited strong humoral (anti-TT IgG) and cellular (IFN-γ) immune responses at day 42, as compared to non-aggregated TT-NLPs1 and TT-Alum following booster immunisation at day 14 and 28. Thus, non-aggregated cationic lipid nanoparticles may be a potent immune-adjuvant for parenteral delivery of weak antigens.

  17. Distinct roles of ATR and DNA-PKcs in triggering DNA damage responses in ATM-deficient cells

    Science.gov (United States)

    Tomimatsu, Nozomi; Mukherjee, Bipasha; Burma, Sandeep

    2009-01-01

    The cellular response to DNA double-strand breaks involves direct activation of ataxia telangiectasia mutated (ATM) and indirect activation of ataxia telangiectasia and Rad3 related (ATR) in an ATM/Mre11/cell-cycle-dependent manner. Here, we report that the crucial checkpoint signalling proteins—p53, structural maintainance of chromosomes 1 (SMC1), p53 binding protein 1 (53BP1), checkpoint kinase (Chk)1 and Chk2—are phosphorylated rapidly by ATR in an ATM/Mre11/cell-cycle-independent manner, albeit at low levels. We observed the sequential recruitment of replication protein A (RPA) and ATR to the sites of DNA damage in ATM-deficient cells, which provides a mechanistic basis for the observed phosphorylations. The recruitment of ATR and consequent phosphorylations do not require Mre11 but are dependent on Exo1. We show that these low levels of phosphorylation are biologically important, as ATM-deficient cells enforce an early G2/M checkpoint that is ATR-dependent. ATR is also essential for the late G2 accumulation that is peculiar to irradiated ATM-deficient cells. Interestingly, phosphorylation of KRAB associated protein 1 (KAP-1), a protein involved in chromatin remodelling, is mediated by DNA-dependent protein kinase catalytic subunit (DNA-PKcs) in a spatio-temporal manner in addition to ATM. We posit that ATM substrates involved in cell-cycle checkpoint signalling can be minimally phosphorylated independently by ATR, while a small subset of proteins involved in chromatin remodelling are phosphorylated by DNA-PKcs in addition to ATM. PMID:19444312

  18. A maize landrace that emits defense volatiles in response to herbivore eggs possesses a strongly inducible terpene synthase gene.

    Science.gov (United States)

    Tamiru, Amanuel; Bruce, Toby J A; Richter, Annett; Woodcock, Christine M; Midega, Charles A O; Degenhardt, Jörg; Kelemu, Segenet; Pickett, John A; Khan, Zeyaur R

    2017-04-01

    Maize ( Zea mays ) emits volatile terpenes in response to insect feeding and egg deposition to defend itself against harmful pests. However, maize cultivars differ strongly in their ability to produce the defense signal. To further understand the agroecological role and underlying genetic mechanisms for variation in terpene emission among maize cultivars, we studied the production of an important signaling component ( E )-caryophyllene in a South American maize landrace Braz1006 possessing stemborer Chilo partellus egg inducible defense trait, in comparison with the European maize line Delprim and North American inbred line B73. The ( E) - caryophyllene production level and transcript abundance of TPS23, terpene synthase responsible for ( E) - caryophyllene formation, were compared between Braz1006, Delprim, and B73 after mimicked herbivory. Braz1006-TPS23 was heterologously expressed in E. coli , and amino acid sequences were determined. Furthermore, electrophysiological and behavioral responses of a key parasitic wasp Cotesia sesamiae to C .  partellus egg-induced Braz1006 volatiles were determined using coupled gas chromatography electroantennography and olfactometer bioassay studies. After elicitor treatment, Braz1006 released eightfold higher ( E) -caryophyllene than Delprim, whereas no ( E) -caryophyllene was detected in B73. The superior (E)- caryophyllene production by Braz1006 was positively correlated with high transcript levels of TPS23 in the landrace compared to Delprim. TPS23 alleles from Braz1006 showed dissimilarities at different sequence positions with Delprim and B73 and encodes an active enzyme. Cotesia sesamiae was attracted to egg-induced volatiles from Braz1006 and synthetic (E)- caryophyllene. The variation in ( E) -caryophyllene emission between Braz1006 and Delprim is positively correlated with induced levels of TPS23 transcripts. The enhanced TPS23 activity and corresponding ( E) -caryophyllene production by the maize landrace could be

  19. Dorsal periaqueductal gray stimulation facilitates anxiety-, but not panic-related, defensive responses in rats tested in the elevated T-maze

    International Nuclear Information System (INIS)

    Camplesi, M. Jr.; Bortoli, V.C. de; Paula Soares, V. de; Nogueira, R.L.; Zangrossi, H. Jr.

    2012-01-01

    The escape response to electrical or chemical stimulation of the dorsal periaqueductal gray matter (DPAG) has been associated with panic attacks. In order to explore the validity of the DPAG stimulation model for the study of panic disorder, we determined if the aversive consequences of the electrical or chemical stimulation of this midbrain area can be detected subsequently in the elevated T-maze. This animal model, derived from the elevated plus-maze, permits the measurement in the same rat of a generalized anxiety- and a panic-related defensive response, i.e., inhibitory avoidance and escape, respectively. Facilitation of inhibitory avoidance, suggesting an anxiogenic effect, was detected in male Wistar rats (200-220 g) tested in the elevated T-maze 30 min after DPAG electrical stimulation (current generated by a sine-wave stimulator, frequency at 60 Hz) or after local microinjection of the GABA A receptor antagonist bicuculline (5 pmol). Previous electrical (5, 15, 30 min, or 24 h before testing) or chemical stimulation of this midbrain area did not affect escape performance in the elevated T-maze or locomotion in an open-field. No change in the two behavioral tasks measured by the elevated T-maze was observed after repetitive (3 trials) electrical stimulation of the DPAG. The results indicate that activation of the DPAG caused a short-lived, but selective, increase in defensive behaviors associated with generalized anxiety

  20. Dorsal periaqueductal gray stimulation facilitates anxiety-, but not panic-related, defensive responses in rats tested in the elevated T-maze

    Energy Technology Data Exchange (ETDEWEB)

    Camplesi, M. Jr. [Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO (Brazil); Bortoli, V.C. de [Departamento de Ciências da Saúde, Centro Universitário Norte do Espírito Santo, Universidade Federal do Espírito Santo, São Mateus, ES (Brazil); Paula Soares, V. de [Departamento de Biofísica e Farmacologia, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil); Nogueira, R.L. [Laboratório de Psicologia Comparada, Universidade Estácio de Sá, Rio de Janeiro, RJ (Brazil); Zangrossi, H. Jr. [Departamento de Farmacologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

    2012-08-03

    The escape response to electrical or chemical stimulation of the dorsal periaqueductal gray matter (DPAG) has been associated with panic attacks. In order to explore the validity of the DPAG stimulation model for the study of panic disorder, we determined if the aversive consequences of the electrical or chemical stimulation of this midbrain area can be detected subsequently in the elevated T-maze. This animal model, derived from the elevated plus-maze, permits the measurement in the same rat of a generalized anxiety- and a panic-related defensive response, i.e., inhibitory avoidance and escape, respectively. Facilitation of inhibitory avoidance, suggesting an anxiogenic effect, was detected in male Wistar rats (200-220 g) tested in the elevated T-maze 30 min after DPAG electrical stimulation (current generated by a sine-wave stimulator, frequency at 60 Hz) or after local microinjection of the GABA{sub A} receptor antagonist bicuculline (5 pmol). Previous electrical (5, 15, 30 min, or 24 h before testing) or chemical stimulation of this midbrain area did not affect escape performance in the elevated T-maze or locomotion in an open-field. No change in the two behavioral tasks measured by the elevated T-maze was observed after repetitive (3 trials) electrical stimulation of the DPAG. The results indicate that activation of the DPAG caused a short-lived, but selective, increase in defensive behaviors associated with generalized anxiety.

  1. The LHCb trigger

    International Nuclear Information System (INIS)

    Korolko, I.

    1998-01-01

    This paper describes progress in the development of the LHCb trigger system since the letter of intent. The trigger philosophy has significantly changed, resulting in an increase of trigger efficiency for signal B events. It is proposed to implement a level-1 vertex topology trigger in specialised hardware. (orig.)

  2. GnRH agonist triggering

    DEFF Research Database (Denmark)

    Kol, Shahar; Humaidan, Peter; Al Humaidan, Peter Samir Heskjær

    2013-01-01

    The concept that a bolus of gonadotrophin-releasing hormone agonist (GnRHa) can replace human chorionic gonadotrophin (HCG) as a trigger of final oocyte maturation was introduced several years ago. Recent developments in the area strengthen this premise. GnRHa trigger offers important advantages......, including virtually complete prevention of ovarian hyperstimulation syndrome (OHSS), the introduction of a surge of FSH in addition to the LH surge and finally the possibility to individualize luteal-phase supplementation based on ovarian response to stimulation. We maintain that the automatic HCG...... triggering concept should be challenged and that the GnRHa trigger is the way to move forward with thoughtful consideration of the needs, safety and comfort of our patients. Routinely, human chorionic gonadotrophin (HCG) is used to induce ovulation in fertility treatments. This approach deviates...

  3. A meal or a male: the ‘whispers’ of black widow males do not trigger a predatory response in females

    Science.gov (United States)

    2014-01-01

    Introduction Female spiders are fine-tuned to detect and quickly respond to prey vibrations, presenting a challenge to courting males who must attract a female’s attention but not be mistaken for prey. This is likely particularly important at the onset of courtship when a male enters a female’s web. In web-dwelling spiders, little is known about how males solve this conundrum, or about their courtship signals. Here we used laser Doppler vibrometry to study the vibrations produced by males and prey (house flies and crickets) on tangle webs of the western black widow Latrodectus hesperus and on sheet webs of the hobo spider Tegenaria agrestis. We recorded the vibrations at the location typically occupied by a hunting female spider. We compared the vibrations produced by males and prey in terms of their waveform, dominant frequency, frequency bandwidth, amplitude and duration. We also played back recorded male and prey vibrations through the webs of female L. hesperus to determine the vibratory parameters that trigger a predatory response in females. Results We found overlap in waveform between male and prey vibrations in both L. hesperus and T. agrestis. In both species, male vibrations were continuous, of long duration (on average 6.35 s for T. agrestis and 9.31 s for L. hesperus), and lacked complex temporal patterning such as repeated motifs or syllables. Prey vibrations were shorter (1.38 - 2.59 s), sporadic and often percussive. Based on the parameters measured, courtship signals of male L. hesperus differed more markedly from prey cues than did those of T. agrestis. Courtship vibrations of L. hesperus males differed from prey vibrations in terms of dominant frequency, amplitude and duration. Vibrations of T. agrestis males differed from prey in terms of duration only. During a playback experiment, L. hesperus females did not respond aggressively to low-amplitude vibrations irrespective of whether the playback recording was from a prey or a male

  4. Anandamide attenuates Th-17 cell-mediated delayed-type hypersensitivity response by triggering IL-10 production and consequent microRNA induction.

    Directory of Open Access Journals (Sweden)

    Austin R Jackson

    Full Text Available Endogenous cannabinoids [endocannabinoids] are lipid signaling molecules that have been shown to modulate immune functions. However, their role in the regulation of Th17 cells has not been studied previously. In the current study, we used methylated Bovine Serum Albumin [mBSA]-induced delayed type hypersensitivity [DTH] response in C57BL/6 mice, mediated by Th17 cells, as a model to test the anti-inflammatory effects of endocannabinoids. Administration of anandamide [AEA], a member of the endocannabinoid family, into mice resulted in significant mitigation of mBSA-induced inflammation, including foot pad swelling, cell infiltration, and cell proliferation in the draining lymph nodes [LN]. AEA treatment significantly reduced IL-17 and IFN-γ production, as well as decreased RORγt expression while causing significant induction of IL-10 in the draining LNs. IL-10 was critical for the AEA-induced mitigation of DTH response inasmuch as neutralization of IL-10 reversed the effects of AEA. We next analyzed miRNA from the LN cells and found that 100 out of 609 miRNA species were differentially regulated in AEA-treated mice when compared to controls. Several of these miRNAs targeted proinflammatory mediators. Interestingly, many of these miRNA were also upregulated upon in vitro treatment of LN cells with IL-10. Together, the current study demonstrates that AEA may suppress Th-17 cell-mediated DTH response by inducing IL-10 which in turn triggers miRNA that target proinflammatory pathways.

  5. A harpin elicitor induces the expression of a coiled-coil nucleotide binding leucine rich repeat (CC-NB-LRR) defense signaling gene and others functioning during defense to parasitic nematodes.

    Science.gov (United States)

    Aljaafri, Weasam A R; McNeece, Brant T; Lawaju, Bisho R; Sharma, Keshav; Niruala, Prakash M; Pant, Shankar R; Long, David H; Lawrence, Kathy S; Lawrence, Gary W; Klink, Vincent P

    2017-12-01

    The bacterial effector harpin induces the transcription of the Arabidopsis thaliana NON-RACE SPECIFIC DISEASE RESISTANCE 1/HARPIN INDUCED1 (NDR1/HIN1) coiled-coil nucleotide binding leucine rich repeat (CC-NB-LRR) defense signaling gene. In Glycine max, Gm-NDR1-1 transcripts have been detected within root cells undergoing a natural resistant reaction to parasitism by the syncytium-forming nematode Heterodera glycines, functioning in the defense response. Expressing Gm-NDR1-1 in Gossypium hirsutum leads to resistance to Meloidogyne incognita parasitism. In experiments presented here, the heterologous expression of Gm-NDR1-1 in G. hirsutum impairs Rotylenchulus reniformis parasitism. These results are consistent with the hypothesis that Gm-NDR1-1 expression functions broadly in generating a defense response. To examine a possible relationship with harpin, G. max plants topically treated with harpin result in induction of the transcription of Gm-NDR1-1. The result indicates the topical treatment of plants with harpin, itself, may lead to impaired nematode parasitism. Topical harpin treatments are shown to impair G. max parasitism by H. glycines, M. incognita and R. reniformis and G. hirsutum parasitism by M. incognita and R. reniformis. How harpin could function in defense has been examined in experiments showing it also induces transcription of G. max homologs of the proven defense genes ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1), TGA2, galactinol synthase, reticuline oxidase, xyloglucan endotransglycosylase/hydrolase, alpha soluble N-ethylmaleimide-sensitive fusion protein (α-SNAP) and serine hydroxymethyltransferase (SHMT). In contrast, other defense genes are not directly transcriptionally activated by harpin. The results indicate harpin induces pathogen associated molecular pattern (PAMP) triggered immunity (PTI) and effector-triggered immunity (ETI) defense processes in the root, activating defense to parasitic nematodes. Copyright © 2017. Published by Elsevier

  6. CaCDPK15 positively regulates pepper responses to Ralstonia solanacearum inoculation and forms a positive-feedback loop with CaWRKY40 to amplify defense signaling

    Science.gov (United States)

    Shen, Lei; Yang, Sheng; Yang, Tong; Liang, Jiaqi; Cheng, Wei; Wen, Jiayu; Liu, Yanyan; Li, Jiazhi; Shi, Lanping; Tang, Qian; Shi, Wei; Hu, Jiong; Liu, Cailing; Zhang, Yangwen; Mou, Shaoliang; Liu, Zhiqin; Cai, Hanyang; He, Li; Guan, Deyi; Wu, Yang; He, Shuilin

    2016-01-01

    CaWRKY40 is a positive regulator of pepper (Capsicum annum) response to Ralstonia solanacearum inoculation (RSI), but the underlying mechanism remains largely unknown. Here, we functionally characterize CaCDPK15 in the defense signaling mediated by CaWRKY40. Pathogen-responsive TGA, W, and ERE boxes were identified in the CaCDPK15 promoter (pCaCDPK15), and pCaCDPK15-driven GUS expression was significantly enhanced in response to RSI and exogenously applied salicylic acid, methyl jasmonate, abscisic acid, and ethephon. Virus-induced gene silencing (VIGS) of CaCDPK15 significantly increased the susceptibility of pepper to RSI and downregulated the immunity-associated markers CaNPR1, CaPR1, and CaDEF1. By contrast, transient CaCDPK15 overexpression significantly activated hypersensitive response associated cell death, upregulated the immunity-associated marker genes, upregulated CaWRKY40 expression, and enriched CaWRKY40 at the promoters of its targets genes. Although CaCDPK15 failed to interact with CaWRKY40, the direct binding of CaWRKY40 to pCaCDPK15 was detected by chromatin immunoprecipitation, which was significantly potentiated by RSI in pepper plants. These combined results suggest that RSI in pepper induces CaCDPK15 and indirectly activates downstream CaWRKY40, which in turn potentiates CaCDPK15 expression. This positive-feedback loop would amplify defense signaling against RSI and efficiently activate strong plant immunity. PMID:26928570

  7. Infections with the Sexually Transmitted Pathogen Nosema apis Trigger an Immune Response in the Seminal Fluid of Honey Bees (Apis mellifera).

    Science.gov (United States)

    Grassl, Julia; Peng, Yan; Baer-Imhoof, Barbara; Welch, Mat; Millar, A Harvey; Baer, Boris

    2017-01-06

    Honey bee (Apis mellifera) males are highly susceptible to infections with the sexually transmitted fungal pathogen Nosema apis. However, they are able to suppress this parasite in the ejaculate using immune molecules in the seminal fluid. We predicted that males respond to infections by altering the seminal fluid proteome to minimize the risk to sexually transmit the parasite to the queen and her colony. We used iTRAQ isotopic labeling to compare seminal fluid proteins from infected and noninfected males and found that N. apis infections resulted in significant abundance changes in 111 of the 260 seminal fluid proteins quantitated. The largest group of proteins with significantly changed abundances consisted of 15 proteins with well-known immune-related functions, which included two significantly more abundant chitinases in the seminal fluid of infected males. Chitinases were previously hypothesized to be involved in honey bee antifungal activity against N. apis. Here we show that infection with N. apis triggers a highly specific immune response in the seminal fluid of honey bee males.

  8. Antigen delivery by filamentous bacteriophage fd displaying an anti-DEC-205 single-chain variable fragment confers adjuvanticity by triggering a TLR9-mediated immune response.

    Science.gov (United States)

    Sartorius, Rossella; D'Apice, Luciana; Trovato, Maria; Cuccaro, Fausta; Costa, Valerio; De Leo, Maria Giovanna; Marzullo, Vincenzo Manuel; Biondo, Carmelo; D'Auria, Sabato; De Matteis, Maria Antonietta; Ciccodicola, Alfredo; De Berardinis, Piergiuseppe

    2015-07-01

    Filamentous bacteriophage fd particles delivering antigenic determinants via DEC-205 (fdsc-αDEC) represent a powerful delivery system that induces CD8(+) T-cell responses even when administered in the absence of adjuvants or maturation stimuli for dendritic cells. In order to investigate the mechanisms of this activity, RNA-Sequencing of fd-pulsed dendritic cells was performed. A significant differential expression of genes involved in innate immunity, co-stimulation and cytokine production was observed. In agreement with these findings, we demonstrate that induction of proinflammatory cytokines and type I interferon by fdsc-αDEC was MYD88 mediated and TLR9 dependent. We also found that fdsc-αDEC is delivered into LAMP-1-positive compartments and co-localizes with TLR9. Thus, phage particles containing a single-strand DNA genome rich in CpG motifs delivered via DEC-205 are able to intercept and trigger the active TLR9 innate immune receptor into late endosome/lysosomes and to enhance the immunogenicity of the displayed antigenic determinants. These findings make fd bacteriophage a valuable tool for immunization without administering exogenous adjuvants. © 2015 The Authors. Published under the terms of the CC BY 4.0 license.

  9. Glucosinolate metabolites required for an Arabidopsis innate immune response.

    Science.gov (United States)

    Clay, Nicole K; Adio, Adewale M; Denoux, Carine; Jander, Georg; Ausubel, Frederick M

    2009-01-02

    The perception of pathogen or microbe-associated molecular pattern molecules by plants triggers a basal defense response analogous to animal innate immunity and is defined partly by the deposition of the glucan polymer callose at the cell wall at the site of pathogen contact. Transcriptional and metabolic profiling in Arabidopsis mutants, coupled with the monitoring of pathogen-triggered callose deposition, have identified major roles in pathogen response for the plant hormone ethylene and the secondary metabolite 4-methoxy-indol-3-ylmethylglucosinolate. Two genes, PEN2 and PEN3, are also necessary for resistance to pathogens and are required for both callose deposition and glucosinolate activation, suggesting that the pathogen-triggered callose response is required for resistance to microbial pathogens. Our study shows that well-studied plant metabolites, previously identified as important in avoiding damage by herbivores, are also required as a component of the plant defense response against microbial pathogens.

  10. Glucosinolate Metabolites Required for an Arabidopsis Innate Immune Response*

    Science.gov (United States)

    Clay, Nicole K.; Adio, Adewale M.; Denoux, Carine; Jander, Georg; Ausubel, Frederick M.

    2008-01-01

    Summary The perception of pathogen or microbe-associated molecular pattern molecules by plants triggers a basal defense response analogous to animal innate immunity, and is defined in part by the deposition of the glucan polymer callose at the cell wall at the site of pathogen contact. Transcriptional and metabolic profiling in Arabidopsis mutants, coupled with the monitoring of pathogen triggered callose deposition, have identified major roles in pathogen response for the plant hormone ethylene and the secondary metabolite 4-methoxy-indol-3-ylmethylglucosinolate. Two genes, PEN2 and PEN3, are also necessary for resistance to pathogens and are required for both callose deposition and glucosinolate activation, suggesting that the pathogen triggered callose response is required for resistance to microbial pathogens. Our study shows that well-studied plant metabolites, previously identified as important in avoiding damage by herbivores, are also required as a component of the plant defense response against microbial pathogens. PMID:19095898

  11. Myofascial trigger point pain.

    Science.gov (United States)

    Jaeger, Bernadette

    2013-01-01

    Myofascial trigger point pain is an extremely prevalent cause of persistent pain disorders in all parts of the body, not just the head, neck, and face. Features include deep aching pain in any structure, referred from focally tender points in taut bands of skeletal muscle (the trigger points). Diagnosis depends on accurate palpation with 2-4 kg/cm2 of pressure for 10 to 20 seconds over the suspected trigger point to allow the referred pain pattern to develop. In the head and neck region, cervical muscle trigger points (key trigger points) often incite and perpetuate trigger points (satellite trigger points) and referred pain from masticatory muscles. Management requires identification and control of as many perpetuating factors as possible (posture, body mechanics, psychological stress or depression, poor sleep or nutrition). Trigger point therapies such as spray and stretch or trigger point injections are best used as adjunctive therapy.

  12. The IL-15-Based ALT-803 Complex Enhances FcγRIIIa-Triggered NK Cell Responses and In Vivo Clearance of B Cell Lymphomas.

    Science.gov (United States)

    Rosario, Maximillian; Liu, Bai; Kong, Lin; Collins, Lynne I; Schneider, Stephanie E; Chen, Xiaoyue; Han, Kaiping; Jeng, Emily K; Rhode, Peter R; Leong, Jeffrey W; Schappe, Timothy; Jewell, Brea A; Keppel, Catherine R; Shah, Keval; Hess, Brian; Romee, Rizwan; Piwnica-Worms, David R; Cashen, Amanda F; Bartlett, Nancy L; Wong, Hing C; Fehniger, Todd A

    2016-02-01

    Anti-CD20 monoclonal antibodies (mAb) are an important immunotherapy for B-cell lymphoma, and provide evidence that the immune system may be harnessed as an effective lymphoma treatment approach. ALT-803 is a superagonist IL-15 mutant and IL-15Rα-Fc fusion complex that activates the IL-15 receptor constitutively expressed on natural killer (NK) cells. We hypothesized that ALT-803 would enhance anti-CD20 mAb-directed NK-cell responses and antibody-dependent cellular cytotoxicity (ADCC). We tested this hypothesis by adding ALT-803 immunostimulation to anti-CD20 mAb triggering of NK cells in vitro and in vivo. Cell lines and primary human lymphoma cells were utilized as targets for primary human NK cells. Two complementary in vivo mouse models were used, which included human NK-cell xenografts in NOD/SCID-γc (-/-) mice. We demonstrate that short-term ALT-803 stimulation significantly increased degranulation, IFNγ production, and ADCC by human NK cells against B-cell lymphoma cell lines or primary follicular lymphoma cells. ALT-803 augmented cytotoxicity and the expression of granzyme B and perforin, providing one potential mechanism for this enhanced functionality. Moreover, in two distinct in vivo B-cell lymphoma models, the addition of ALT-803 to anti-CD20 mAb therapy resulted in significantly reduced tumor cell burden and increased survival. Long-term ALT-803 stimulation of human NK cells induced proliferation and NK-cell subset changes with preserved ADCC. ALT-803 represents a novel immunostimulatory drug that enhances NK-cell antilymphoma responses in vitro and in vivo, thereby supporting the clinical investigation of ALT-803 plus anti-CD20 mAbs in patients with indolent B-cell lymphoma. ©2015 American Association for Cancer Research.

  13. Arabidopsis LIP5, a positive regulator of multivesicular body biogenesis, is a critical target of pathogen-responsive MAPK cascade in plant basal defense.

    Directory of Open Access Journals (Sweden)

    Fei Wang

    2014-07-01

    Full Text Available Multivesicular bodies (MVBs play essential roles in many cellular processes. The MVB pathway requires reversible membrane association of the endosomal sorting complexes required for transports (ESCRTs for sustained protein trafficking. Membrane dissociation of ESCRTs is catalyzed by the AAA ATPase SKD1, which is stimulated by LYST-interacting protein 5 (LIP5. We report here that LIP5 is a target of pathogen-responsive mitogen-activated protein kinases (MPKs and plays a critical role in plant basal resistance. Arabidopsis LIP5 interacts with MPK6 and MPK3 and is phosphorylated in vitro by activated MPK3 and MPK6 and in vivo upon expression of MPK3/6-activating NtMEK2DD and pathogen infection. Disruption of LIP5 has little effects on flg22-, salicylic acid-induced defense responses but compromises basal resistance to Pseudomonas syringae. The critical role of LIP5 in plant basal resistance is dependent on its ability to interact with SKD1. Mutation of MPK phosphorylation sites in LIP5 does not affect interaction with SKD1 but reduces the stability and compromises the ability to complement the lip5 mutant phenotypes. Using the membrane-selective FM1-43 dye and transmission electron microscopy, we demonstrated that pathogen infection increases formation of both intracellular MVBs and exosome-like paramural vesicles situated between the plasma membrane and the cell wall in a largely LIP5-dependent manner. These results indicate that the MVB pathway is positively regulated by pathogen-responsive MPK3/6 through LIP5 phosphorylation and plays a critical role in plant immune system likely through relocalization of defense-related molecules.

  14. UV-B Irradiation Changes Specifically the Secondary Metabolite Profile in Broccoli Sprouts: Induced Signaling Overlaps with Defense Response to Biotic Stressors

    Science.gov (United States)

    Mewis, Inga; Schreiner, Monika; Nguyen, Chau Nhi; Krumbein, Angelika; Ulrichs, Christian; Lohse, Marc; Zrenner, Rita

    2012-01-01

    Only a few environmental factors have such a pronounced effect on plant growth and development as ultraviolet light (UV). Concerns have arisen due to increased UV-B radiation reaching the Earth’s surface as a result of stratospheric ozone depletion. Ecologically relevant low to moderate UV-B doses (0.3–1 kJ m–2 d–1) were applied to sprouts of the important vegetable crop Brassica oleracea var. italica (broccoli), and eco-physiological responses such as accumulation of non-volatile secondary metabolites were related to transcriptional responses with Agilent One-Color Gene Expression Microarray analysis using the 2×204 k format Brassica microarray. UV-B radiation effects have usually been linked to increases in phenolic compounds. As expected, the flavonoids kaempferol and quercetin accumulated in broccoli sprouts (the aerial part of the seedlings) 24 h after UV-B treatment. A new finding is the specific UV-B-mediated induction of glucosinolates (GS), especially of 4-methylsulfinylbutyl GS and 4-methoxy-indol-3-ylmethyl GS, while carotenoids and Chl levels remained unaffected. Accumulation of defensive GS metabolites was accompanied by increased expression of genes associated with salicylate and jasmonic acid signaling defense pathways and up-regulation of genes responsive to fungal and bacterial pathogens. Concomitantly, plant pre-exposure to moderate UV-B doses had negative effects on the performance of the caterpillar Pieris brassicae (L.) and on the population growth of the aphid Myzus persicae (Sulzer). Moreover, insect-specific induction of GS in broccoli sprouts was affected by UV-B pre-treatment. PMID:22773681

  15. The intake of water containing a mix of pollutants at environmentally relevant concentrations leads to defensive response deficit in male C57Bl/6J mice.

    Science.gov (United States)

    de Souza, Joyce Moreira; Rabelo, Letícia Martins; de Faria, Denise Braga Gomes; Guimarães, Abraão Tiago Batista; da Silva, Wellington Alves Mizael; Rocha, Thiago Lopes; Estrela, Fernanda Neves; Chagas, Thales Quintão; de Oliveira Mendes, Bruna; Malafaia, Guilherme

    2018-02-09

    Previous studies have individually confirmed the toxic effects from different pollutants on mammals. However, effects resulting from the exposure of these animals to multi-pollutant mixes have not been studied so far. Thus, the aim of the current study is to assess the effect from the chronic exposure (105days) of C57Bl/6J mice to a mix of pollutants on their response to potential predators. In order to do so, the following groups were formed: "control", "Mix 1× [compounds from 15 pollutants identified in surface waters at environmentally relevant concentration (ERC)]", "Mix 10×" and "Mix 25×" (concentrations 10 and 25 times higher than the ERC). From the 100th experimental day on, the animals were subjected to tests in order to investigate whether they showed locomotor, visual, olfactory and auditory changes, since these abilities are essential to their anti-predatory behavior. Next, the animals' behavior towards potential predators (Felis catus and Pantherophis guttatus) was assessed. The herein collected data did not show defensive response from any of the experimental groups to the predatory stimulus provided by P. guttatus. However, the control animals, only, presented anti-predatory behavior when F. catus was introduced in the apparatus, fact that suggests defensive response deficit resulting from the treatments. Thus, the current study is pioneer in showing that the chronic intake of water containing a mix of pollutants (even at low concentrations) leads to behavioral disorders able to affect the survival and population dynamics of mammalian species at ecological level. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Integrated physiological and proteomic analysis reveals underlying response and defense mechanisms of Brachypodium distachyon seedling leaves under osmotic stress, cadmium and their combined stresses.

    Science.gov (United States)

    Cheng, Zhi-Wei; Chen, Zi-Yan; Yan, Xing; Bian, Yan-Wei; Deng, Xiong; Yan, Yue-Ming

    2018-01-06

    Drought stress, a major abiotic stress, commonly occurs in metal-contaminated environments and affects crop growth and yield. In this study, we performed the first integrated phenotypic, physiological, and proteomic analysis of Brachypodium distachyon L. seedling leaves under polyethylene glycol (PEG) mock osmotic stress, cadmium (Cd 2+ ), and their combined stresses. Combined osmotic and Cd 2+ stress had more significant effects than each individual stress on seedling growth, and the physiological traits and ultrastructures of leaves. Totally 117 differentially accumulated protein (DAP) spots detected by two-dimensional difference gel electrophoresis (2D-DIGE) were identified, and representing 89 unique proteins under individual and combined stresses. These DAPs were involved in photosynthesis/respiration (34%), energy and carbon metabolism (21%), stress/defense/detoxification (13%), protein folding and degradation (12%), and amino acid metabolism (7%). Principal component analysis (PCA) revealed that DAPs from the Cd 2+ and combined stresses grouped much closer than those from osmotic stress, indicating Cd 2+ and combined stresses resulted in more changes to the leaf proteome than osmotic stress alone. Protein-protein interaction analyses showed that a 14-3-3 centered sub-network could play important roles in responses to abiotic stresses. An overview pathway of proteome metabolic changes in Bd21 seedling leaves under combined stresses is proposed, representing a synergistic responsive network and underlying response and defense mechanisms. Drought stress is one of the major abiotic stresses, which commonly occurs in metal-contaminated environments, and affects crop growth and yield performance. We performed the first integrated phenotypic, physiological and proteomic analysis of Brachypodium distachyon L. seedling leaves under drought (PEG), cadmium (Cd 2+ ) and their combined stresses. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. An essential role for the VASt domain of the Arabidopsis VAD1 protein in the regulation of defense and cell death in response to pathogens.

    Science.gov (United States)

    Khafif, Mehdi; Balagué, Claudine; Huard-Chauveau, Carine; Roby, Dominique

    2017-01-01

    Several regulators of programmed cell death (PCD) have been identified in plants which encode proteins with putative lipid-binding domains. Among them, VAD1 (Vascular Associated Death) contains a novel protein domain called VASt (VAD1 analog StAR-related lipid transfer) still uncharacterized. The Arabidopsis mutant vad1-1 has been shown to exhibit a lesion mimic phenotype with light-conditional appearance of propagative hypersensitive response-like lesions along the vascular system, associated with defense gene expression and increased resistance to Pseudomonas strains. To test the potential of ectopic expression of VAD1 to influence HR cell death and to elucidate the role of the VASt domain in this function, we performed a structure-function analysis of VAD1 by transient over-expression in Nicotiana benthamiana and by complementation of the mutant vad1-1. We found that (i) overexpression of VAD1 controls negatively the HR cell death and defense expression either transiently in Nicotiana benthamania or in Arabidopsis plants in response to avirulent strains of Pseudomonas syringae, (ii) VAD1 is expressed in multiple subcellular compartments, including the nucleus, and (iii) while the GRAM domain does not modify neither the subcellular localization of VAD1 nor its immunorepressor activity, the domain VASt plays an essential role in both processes. In conclusion, VAD1 acts as a negative regulator of cell death associated with the plant immune response and the VASt domain of this unknown protein plays an essential role in this function, opening the way for the functional analysis of VASt-containing proteins and the characterization of novel mechanisms regulating PCD.

  18. An essential role for the VASt domain of the Arabidopsis VAD1 protein in the regulation of defense and cell death in response to pathogens.

    Directory of Open Access Journals (Sweden)

    Mehdi Khafif

    Full Text Available Several regulators of programmed cell death (PCD have been identified in plants which encode proteins with putative lipid-binding domains. Among them, VAD1 (Vascular Associated Death contains a novel protein domain called VASt (VAD1 analog StAR-related lipid transfer still uncharacterized. The Arabidopsis mutant vad1-1 has been shown to exhibit a lesion mimic phenotype with light-conditional appearance of propagative hypersensitive response-like lesions along the vascular system, associated with defense gene expression and increased resistance to Pseudomonas strains. To test the potential of ectopic expression of VAD1 to influence HR cell death and to elucidate the role of the VASt domain in this function, we performed a structure-function analysis of VAD1 by transient over-expression in Nicotiana benthamiana and by complementation of the mutant vad1-1. We found that (i overexpression of VAD1 controls negatively the HR cell death and defense expression either transiently in Nicotiana benthamania or in Arabidopsis plants in response to avirulent strains of Pseudomonas syringae, (ii VAD1 is expressed in multiple subcellular compartments, including the nucleus, and (iii while the GRAM domain does not modify neither the subcellular localization of VAD1 nor its immunorepressor activity, the domain VASt plays an essential role in both processes. In conclusion, VAD1 acts as a negative regulator of cell death associated with the plant immune response and the VASt domain of this unknown protein plays an essential role in this function, opening the way for the functional analysis of VASt-containing proteins and the characterization of novel mechanisms regulating PCD.

  19. The Central Trigger Processor (CTP)

    CERN Multimedia

    Franchini, Matteo

    2016-01-01

    The Central Trigger Processor (CTP) receives trigger information from the calorimeter and muon trigger processors, as well as from other sources of trigger. It makes the Level-1 decision (L1A) based on a trigger menu.

  20. CCL2 as a trigger of manifestations of compensatory anti-inflammatory response syndrome in mice with severe systemic inflammatory response syndrome.

    Science.gov (United States)

    Takahashi, Hitoshi; Tsuda, Yasuhiro; Kobayashi, Makiko; Herndon, David N; Suzuki, Fujio

    2006-04-01

    Patients with compensatory anti-inflammatory response syndrome (CARS) are at a higher risk for infection with various opportunistic pathogens. CARS develops commonly in association with the manifestation of systemic inflammatory response syndrome (SIRS). In the present study, the role of SIRS-associated soluble factors on the CARS development was examined in mice with pancreatitis, a carrier of typical SIRS. Following the production of SIRS-related cytokines [tumor necrosis factor alpha and interleukin (IL)-1beta], CC chemokine ligand 2 (CCL2), IL-4, and IL-10 (typical CARS cytokines) were detected in the sera of mice with pancreatitis. CCL2 has been described as an essential chemokine for the T helper cell type 2 manifestation. CARS effector cells (cells with an ability to produce IL-4 and IL-10) were not generated from normal T cells after stimulation with SIRS-related cytokines. However, these cells were generated from normal T cells after cultivation with peripheral blood neutrophils (PMN) from SIRS mice in a dual-chamber transwell. Normal T cells did not convert to CARS effector cells after transwell cultures with PMN from normal mice. CCL2 was detected in culture fluids of PMN from SIRS mice, and PMN from normal mice did not produce CCL2 into their culture fluids. CARS effector cells did not appear in PMN-depleted SIRS mice or SIRS mice treated with anti-CCL2 monoclonal antibody, and these cells were demonstrated in PMN-depleted SIRS mice after treatment with recombinant murine CCL2. These results indicate that CCL2 produced by PMN from SIRS mice is an active molecule on the SIRS-associated CARS manifestation.

  1. External triggering and triggered targeting strategies for drug delivery

    Science.gov (United States)

    Wang, Yanfei; Kohane, Daniel S.

    2017-06-01

    Drug delivery systems that are externally triggered to release drugs and/or target tissues hold considerable promise for improving the treatment of many diseases by minimizing nonspecific toxicity and enhancing the efficacy of therapy. These drug delivery systems are constructed from materials that are sensitive to a wide range of external stimuli, including light, ultrasound, electrical and magnetic fields, and specific molecules. The responsiveness conferred by these materials allows the release of therapeutics to be triggered on demand and remotely by a physician or patient. In this Review, we describe the rationales for such systems and the types of stimuli that can be deployed, and provide an outlook for the field.

  2. Strain-Related Differences on Response of Liver and Kidney Antioxidant Defense System in Two Rat Strains Following Diazinon Exposure

    Directory of Open Access Journals (Sweden)

    Maryam Salehi

    2016-02-01

    Full Text Available Background Diazinon (DZN is one of the most organophosphates that widely used in agriculture and ectoparasiticide formulations. Its extensive use as an effective pesticide was associated with the environmental deleterious effects on biological systems. Objectives The aim of this study was to investigate the potency of DZN to affect serum biochemical parameters and the antioxidant defense system in the liver and kidney of two rat strains. Materials and Methods In this experimental study, 30 female Wistar and 30 female Norway rats were randomly divided into control and DZN groups. DZN group was divided into four subgroups: 25, 50, 100 and 200 mg/kg of DZN administered groups by i.p. injection. The parameters were evaluated after 24 hours. Results At higher doses of DZN, superoxide dismutase, catalase, glutathione S-transferase and lactate dehydrogenase activities and glutathione (GSH and malondialdehyde levels in liver and kidney of Wistar rats were higher than Norway rats. At these concentrations, DZN increased some serum biochemical indices such as liver enzymes activities and levels of urea, uric acid and creatinine in Wistar rat. Conclusions DZN at higher doses alters the oxidant-antioxidant balance in liver and kidney of both rat strains and induces oxidative stress, which is associated with a depletion of GSH and increased lipid peroxidation. However, Wistar rats are found to be more sensitive to the toxicity of DZN compared to Norway rats. In addition, the effect of DZN on liver antioxidant system was more than kidney.

  3. Methyl jasmonate-induced defense responses are associated with elevation of 1-aminocyclopropane-1-carboxylate oxidase in Lycopersicon esculentum fruit.

    Science.gov (United States)

    Yu, Mengmeng; Shen, Lin; Zhang, Aijun; Sheng, Jiping

    2011-10-15

    It has been known that methyl jasmonate (MeJA) interacts with ethylene to elicit resistance. In green mature tomato fruits (Lycopersicon esculentum cv. Lichun), 0.02mM MeJA increased the activity of 1-aminocyclopropane-1-carboxylate oxidase (ACO), and consequently influenced the last step of ethylene biosynthesis. Fruits treated with a combination of 0.02 MeJA and 0.02 α-aminoisobutyric acid (AIB, a competitive inhibitor of ACO) exhibited a lower ethylene production comparing to that by 0.02mM MeJA alone. The increased activities of defense enzymes and subsequent control of disease incidence caused by Botrytis cinerea with 0.2mM MeJA treatment was impaired by AIB as well. A close relationship (Ptomato, and the concentration influence of MeJA on ACO was attributable to the variation of gene transcripts and enzymatic properties. Copyright © 2011 Elsevier GmbH. All rights reserved.

  4. Atg7 deficiency impairs host defense against Klebsiella pneumoniae by impacting bacterial clearance, survival and inflammatory responses in mice.

    Science.gov (United States)

    Ye, Yan; Li, Xuefeng; Wang, Wenxue; Ouedraogo, Kiswendsida Claude; Li, Yi; Gan, Changpei; Tan, Shirui; Zhou, Xikun; Wu, Min

    2014-09-01

    Klebsiella pneumoniae (Kp) is a Gram-negative bacterium that can cause serious infections in humans. Autophagy-related gene 7 (Atg7) has been implicated in certain bacterial infections; however, the role of Atg7 in macrophage-mediated immunity against Kp infection has not been elucidated. Here we showed that Atg7 expression was significantly increased in murine alveolar macrophages (MH-S) upon Kp infection, indicating that Atg7 participated in host defense. Knocking down Atg7 with small-interfering RNA increased bacterial burdens in MH-S cells. Using cell biology assays and whole animal imaging analysis, we found that compared with wild-type mice atg7 knockout (KO) mice exhibited increased susceptibility to Kp infection, with decreased survival rates, decreased bacterial clearance, and intensified lung injury. Moreover, Kp infection induced excessive proinflammatory cytokines and superoxide in the lung of atg7 KO mice. Similarly, silencing Atg7 in MH-S cells markedly increased expression levels of proinflammatory cytokines. Collectively, these findings reveal that Atg7 offers critical resistance to Kp infection by modulating both systemic and local production of proinflammatory cytokines. Copyright © 2014 the American Physiological Society.

  5. The Database Driven ATLAS Trigger Configuration System

    CERN Document Server

    Martyniuk, Alex; The ATLAS collaboration

    2015-01-01

    This contribution describes the trigger selection configuration system of the ATLAS low- and high-level trigger (HLT) and the upgrades it received in preparation for LHC Run 2. The ATLAS trigger configuration system is responsible for applying the physics selection parameters for the online data taking at both trigger levels and the proper connection of the trigger lines across those levels. Here the low-level trigger consists of the already existing central trigger (CT) and the new Level-1 Topological trigger (L1Topo), which has been added for Run 2. In detail the tasks of the configuration system during the online data taking are Application of the selection criteria, e.g. energy cuts, minimum multiplicities, trigger object correlation, at the three trigger components L1Topo, CT, and HLT On-the-fly, e.g. rate-dependent, generation and application of prescale factors to the CT and HLT to adjust the trigger rates to the data taking conditions, such as falling luminosity or rate spikes in the detector readout ...

  6. Common Asthma Triggers

    Science.gov (United States)

    ... Grass Other Triggers If you have asthma, an asthma attack can happen when you are exposed to “asthma ... a second person. Secondhand smoke can trigger an asthma attack. If you have asthma, people should never smoke ...

  7. The activated SA and JA signaling pathways have an influence on flg22-triggered oxidative burst and callose deposition.

    Directory of Open Access Journals (Sweden)

    So Young Yi

    Full Text Available The first line of defense in plants against pathogens is induced by the recognition of microbe-associated molecular patterns (MAMP. Perception of bacterial flagellin (flg22 by the pattern recognition receptor flagellin-sensing 2 (FLS2 is the best characterized MAMP response, although the underlying molecular mechanisms are not fully understood. Here we studied the relationship between salicylic acid (SA or jasmonic acid (JA signaling and FLS2-mediated signaling by monitoring flg22-triggered responses in known SA or JA related mutants of Arabidopsis thaliana (L. Heynh. The sid2 mutant, impaired in SA biosynthesis, had less basal FLS2 mRNA accumulation than the wild type, which correlated with suppression of early flg22 responses such as ROS production and induction of marker genes, WRKY29 and FRK1. The JA-signaling mutants, jar1 and coi1, exhibited an enhanced flg22-triggered oxidative burst and more callose accumulation than the wild type, and pretreatment with SA or coronatine (COR, a structural mimic of JA-isoleucine, altered these flg22-induced responses. Nonexpressor of pathogenesis-related genes 1 (NPR1 acted downstream of SID2 and required SA-dependent priming for the enhanced flg22-triggered oxidative burst and callose deposition. Activation of JA signaling by COR pretreatment suppressed the flg22-triggered oxidative burst and callose accumulation in a coronatine insensitive 1 (COI1 dependent manner. COR had a negative effect on flg22 responses but only the flg22-triggered oxidative burst depended on SA-JA/COR signaling antagonism. Thus the activated SA and JA signaling pathways have an influence on flg22-triggered oxidative burst and callose deposition. These results may explain how SA and JA signaling are cross talked for regulation of flg22-triggered responses.

  8. The KLOE trigger system

    International Nuclear Information System (INIS)

    Adinolfi, M.; Aloisio, A.; Ambrosino, F.; Andryakov, A.; Antonelli, A.; Antonelli, M.; Anulli, F.; Bacci, C.; Bankamp, A.; Barbiellini, G.; Bellini, F.; Bencivenni, G.; Bertolucci, S.; Bini, C.; Bloise, C.; Bocci, V.; Bossi, F.; Branchini, P.; Bulychjov, S.A.; Cabibbo, G.; Calcaterra, A.; Caloi, R.; Campana, P.; Capon, G.; Carboni, G.; Cardini, A.; Casarsa, M.; Cataldi, G.; Ceradini, F.; Cervelli, F.; Cevenini, F.; Chiefari, G.; Ciambrone, P.; Conetti, S.; Conticelli, S.; De Lucia, E.; De Robertis, G.; De Sangro, R.; De Simone, P.; De Zorzi, G.; Dell'Agnello, S.; Denig, E.; Di Domenico, A.; Di Donato, C.; Di Falco, S.; Doria, A.; Drago, E.; Elia, V.; Erriquez, O.; Farilla, A.; Felici, G.; Ferrari, A.; Ferrer, M.L.; Finocchiaro, G.; Forti, C.; Franceschi, A.; Franzini, P.; Gao, M.L.; Gatti, C.; Gauzzi, P.; Giovannella, S.; Golovatyuk, V.; Gorini, E.; Grancagnolo, F.; Grandegger, W.; Graziani, E.; Guarnaccia, P.; Hagel, U. von; Han, H.G.; Han, S.W.; Huang, X.; Incagli, M.; Ingrosso, L.; Jang, Y.Y.; Kim, W.; Kluge, W.; Kulikov, V.; Lacava, F.; Lanfranchi, G.; Lee-Franzini, J.; Lomtadze, F.; Luisi, C.; Mao, C.S.; Martemianov, M.; Matsyuk, M.; Mei, W.; Merola, L.; Messi, R.; Miscetti, S.; Moalem, A.; Moccia, S.; Moulson, M.; Mueller, S.; Murtas, F.; Napolitano, M.; Nedosekin, A.; Panareo, M.; Pacciani, L.; Pages, P.; Palutan, M.; Paoluzi, L.; Pasqualucci, E.; Passalacqua, L.; Passaseo, M.; Passeri, A.; Patera, V.; Petrolo, E.; Petrucci, G.; Picca, D.; Pirozzi, G.; Pistillo, C.; Pollack, M.; Pontecorvo, L.; Primavera, M.; Ruggieri, F.; Santangelo, P.; Santovetti, E.; Saracino, G.; Schamberger, R.D.; Schwick, C.; Sciascia, B.; Sciubba, A.; Scuri, F.; Sfiligoi, I.; Shan, J.; Silano, P.; Spadaro, T.; Spagnolo, S.; Spiriti, E.; Stanescu, C.; Tong, G.L.; Tortora, L.; Valente, E.; Valente, P.; Valeriani, B.; Venanzoni, G.; Veneziano, S.; Wu, Y.; Xie, Y.G.; Zhao, P.P.; Zhou, Y.

    2001-01-01

    A double-level trigger system has been developed for the KLOE experiment. Custom electronics asserts a trigger in a 2 μs decision time. The decision is based on the combined information of the electromagnetic calorimeter and the drift chamber. The entire trigger system is continuously monitored, and data flowing from the trigger system have allowed both an efficient online monitoring of the detector and an online luminosity measurement

  9. Peroxisomal Hydrogen Peroxide Is Coupled to Biotic Defense Responses by ISOCHORISMATE SYNTHASE1 in a Daylength-Related Manner1[C][W][OA

    Science.gov (United States)

    Chaouch, Sejir; Queval, Guillaume; Vanderauwera, Sandy; Mhamdi, Amna; Vandorpe, Michaël; Langlois-Meurinne, Mathilde; Van Breusegem, Frank; Saindrenan, Patrick; Noctor, Graham

    2010-01-01

    While it is well established that reactive oxygen species can induce cell death, intracellularly generated oxidative stress does not induce lesions in the Arabidopsis (Arabidopsis thaliana) photorespiratory mutant cat2 when plants are grown in short days (SD). One interpretation of this observation is that a function necessary to couple peroxisomal hydrogen peroxide (H2O2)-triggered oxidative stress to cell death is only operative in long days (LD). Like lesion formation, pathogenesis-related genes and camalexin were only induced in cat2 in LD, despite less severe intracellular redox perturbation compared with SD. Lesion formation triggered by peroxisomal H2O2 was modified by introducing secondary mutations into the cat2 background and was completely absent in cat2 sid2 double mutants, in which ISOCHORISMATE SYNTHASE1 (ICS1) activity is defective. In addition to H2O2-induced salicylic acid (SA) accumulation, the sid2 mutation in ICS1 abolished a range of LD-dependent pathogen responses in cat2, while supplementation of cat2 with SA in SD activated these responses. Nontargeted transcript and metabolite profiling identified clusters of genes and small molecules associated with the daylength-dependent ICS1-mediated relay of H2O2 signaling. The effect of oxidative stress in cat2 on resistance to biotic challenge was dependent on both growth daylength and ICS1. We conclude that (1) lesions induced by intracellular oxidative stress originating in the peroxisomes can be genetically reverted; (2) the isochorismate pathway of SA synthesis couples intracellular oxidative stress to cell death and associated disease resistance responses; and (3) camalexin accumulation was strictly dependent on the simultaneous presence of both H2O2 and SA signals. PMID:20543092

  10. Purification of an elicitor from Magnaporthe oryzae inducing defense ...

    African Journals Online (AJOL)

    Yomi

    2012-04-12

    Apr 12, 2012 ... inducing defense resistance in rice. Chunyan Ji and Zhenzhong Wang*. Laboratory of Physiological Plant Pathology, South China Agricultural University, Guangzhou 510642, China. Accepted 1 March, 2012. Inducible defenses that contribute to overall resistance in plant can be triggered by elicitors.

  11. Profiling the secretion of soluble mediators by end stage osteoarthritis synovial tissue explants reveals a reduced responsiveness to an inflammatory trigger.

    Science.gov (United States)

    Gierman, Lobke M; van El, Benno; van der Ham, Frits; Koudijs, Angela; Stoop, Reinout; Verheijen, Jan H; Kloppenburg, Margreet; van Osch, Gerjo J V M; Stojanovic-Susulic, Vedrana; Huizinga, Tom W J; Zuurmond, Anne-Marie

    2013-01-01

    Evidence is accumulating that synovial tissue plays an active role in osteoarthritis (OA), however, exact understanding of its contribution is lacking. In order to further elucidate its role in the OA process, we aimed to identify the secretion pattern of soluble mediators by synovial tissue and to assess its ability to initiate cartilage degeneration. Synovial tissue explants (STEs) obtained from donors without history of OA (n = 8) or from end stage OA patients (n = 16) were cultured alone or together with bovine cartilage explants in the absence or presence of IL-1α. The secretion of 48 soluble mediators was measured and the effect on glycosaminoglycan (GAG) release and matrix metalloproteinase (MMP) activity was determined. Normal and OA STEs secreted comparable levels of almost all measured soluble mediators. However, in the presence of IL-1α these mediators were less secreted by OA than by normal STEs of which 15 differed significantly (peffect of normal or OA STEs on GAG release from the cartilage explants was observed, and no differences in MMP activity between OA and normal STEs were detected. Unexpectedly, a comparable secretion profile of soluble mediators was found for OA and normal STEs while the reduced responsiveness of OA STEs to an inflammatory trigger indicates a different state of this tissue in OA patients. The effects could be the result of prolonged exposure to an inflammatory environment in OA development. Further understanding of the pro-inflammatory and inflammation resolving mechanisms during disease progression in synovial tissue may provide valuable targets for therapy in the future.

  12. Profiling the secretion of soluble mediators by end stage osteoarthritis synovial tissue explants reveals a reduced responsiveness to an inflammatory trigger.

    Directory of Open Access Journals (Sweden)

    Lobke M Gierman

    Full Text Available OBJECTIVE: Evidence is accumulating that synovial tissue plays an active role in osteoarthritis (OA, however, exact understanding of its contribution is lacking. In order to further elucidate its role in the OA process, we aimed to identify the secretion pattern of soluble mediators by synovial tissue and to assess its ability to initiate cartilage degeneration. METHODS: Synovial tissue explants (STEs obtained from donors without history of OA (n = 8 or from end stage OA patients (n = 16 were cultured alone or together with bovine cartilage explants in the absence or presence of IL-1α. The secretion of 48 soluble mediators was measured and the effect on glycosaminoglycan (GAG release and matrix metalloproteinase (MMP activity was determined. RESULTS: Normal and OA STEs secreted comparable levels of almost all measured soluble mediators. However, in the presence of IL-1α these mediators were less secreted by OA than by normal STEs of which 15 differed significantly (p<0.01. No effect of normal or OA STEs on GAG release from the cartilage explants was observed, and no differences in MMP activity between OA and normal STEs were detected. CONCLUSIONS: Unexpectedly, a comparable secretion profile of soluble mediators was found for OA and normal STEs while the reduced responsiveness of OA STEs to an inflammatory trigger indicates a different state of this tissue in OA patients. The effects could be the result of prolonged exposure to an inflammatory environment in OA development. Further understanding of the pro-inflammatory and inflammation resolving mechanisms during disease progression in synovial tissue may provide valuable targets for therapy in the future.

  13. The family of Peps and their precursors in Arabidopsis: differential expression and localization but similar induction of pattern-triggered immune responses.

    Science.gov (United States)

    Bartels, Sebastian; Lori, Martina; Mbengue, Malick; van Verk, Marcel; Klauser, Dominik; Hander, Tim; Böni, Rainer; Robatzek, Silke; Boller, Thomas

    2013-12-01

    In Arabidopsis thaliana, the endogenous danger peptides, AtPeps, have been associated with plant defences reminiscent of those induced in pattern-triggered immunity. AtPeps are perceived by two homologous receptor kinases, PEPR1 and PEPR2, and are encoded in the C termini of the PROPEP precursors. Here, we report that, contrary to the seemingly redundant AtPeps, the PROPEPs fall at least into two distinct groups. As revealed by promoter-β-glucuronidase studies, expression patterns of PROPEP1-3, -5, and -8 partially overlapped and correlated with those of the PEPR1 and -2 receptors, whereas those of PROPEP4 and -7 did not share any similarities with the former. Moreover, bi-clustering analysis indicated an association of PROPEP1, -2, and -3 with plant defence, whereas PROPEP5 expression was related to patterns of plant reproduction. In addition, at the protein level, PROPEPs appeared to be distinct. PROPEP3::YFP (fused to yellow fluorescent protein) was present in the cytosol, but, in contrast to previous predictions, PROPEP1::YFP and PROPEP6::YFP localized to the tonoplast. Together with the expression patterns, this could point to potentially non-redundant roles among the members of the PROPEP family. By contrast, their derived AtPeps, including the newly reported AtPep8, when applied exogenously, provoked activation of defence-related responses in a similar manner, suggesting a high level of functional redundancy between the AtPeps. Taken together, our findings reveal an apparent antagonism between AtPep redundancy and PROPEP variability, and indicate new roles for PROPEPs besides plant immunity.

  14. Antioxidative defense

    Directory of Open Access Journals (Sweden)

    Stevanović Jelka

    2011-01-01

    Full Text Available Free radicals occur constantly during metabolism and take part in numerous physiological processes, such as: intra-cellular and inter-cellular signalization, gene expression, removal of damaged or senescent cells, and control of the tone of blood vessels. However, there is an increased quantity of free radicals in situations of so-called oxidative stress, when they cause serious damage to cellular membranes (peroxidation of their lipids, damage of membrane proteins, and similar, to interior cellular protein molecules, as well as DNA molecules and carbohydrates. This is precisely why the organism has developed numerous mechanisms for removing free radicals and/or preventing their production. Some of these are enzyme-related and include superoxide-dismutase, catalase, glutathione-peroxidase, and others. Other, non-enzyme mechanisms, imply antioxidative activities of vitamins E and C, provitamin A, coenzyme Q, reduced glutation, and others. Since free radicals can leave the cell that has produced them and become dispersed throughout the body, in addition to antioxidative defense that functions within cellular structures, antioxidant extra-cellular defense has also been developed. This is comprised by: transferrin, lactoferrin, haptoglobin, hemopexin, ceruloplasmin, albumins, extra-cellular isoform SOD, extracellular glutathione-peroxidase, glucose, bilirubin, urates, and many other molecules.

  15. Molecular functions of Xanthomonas type III effector AvrBsT and its plant interactors in cell death and defense signaling.

    Science.gov (United States)

    Han, Sang Wook; Hwang, Byung Kook

    2017-02-01

    Xanthomonas effector AvrBsT interacts with plant defense proteins and triggers cell death and defense response. This review highlights our current understanding of the molecular functions of AvrBsT and its host interactor proteins. The AvrBsT protein is a member of a growing family of effector proteins in both plant and animal pathogens. Xanthomonas type III effector AvrBsT, a member of the YopJ/AvrRxv family, suppresses plant defense responses in susceptible hosts, but triggers cell death signaling leading to hypersensitive response (HR) and defense responses in resistant plants. AvrBsT interacts with host defense-related proteins to trigger the HR cell death and defense responses in plants. Here, we review and discuss recent progress in understanding the molecular functions of AvrBsT and its host interactor proteins in pepper (Capsicum annuum). Pepper arginine decarboxylase1 (CaADC1), pepper aldehyde dehydrogenase1 (CaALDH1), pepper heat shock protein 70a (CaHSP70a), pepper suppressor of the G2 allele of skp1 (CaSGT1), pepper SNF1-related kinase1 (SnRK1), and Arabidopsis acetylated interacting protein1 (ACIP1) have been identified as AvrBsT interactors in pepper and Arabidopsis. Gene expression profiling, virus-induced gene silencing, and transient transgenic overexpression approaches have advanced the functional characterization of AvrBsT-interacting proteins in plants. AvrBsT is localized in the cytoplasm and forms protein-protein complexes with host interactors. All identified AvrBsT interactors regulate HR cell death and defense responses in plants. Notably, CaSGT1 physically binds to both AvrBsT and pepper receptor-like cytoplasmic kinase1 (CaPIK1) in the cytoplasm. During infection with Xanthomonas campestris pv. vesicatoria strain Ds1 (avrBsT), AvrBsT is phosphorylated by CaPIK1 and forms the active AvrBsT-CaSGT1-CaPIK1 complex, which ultimately triggers HR cell death and defense responses. Collectively, the AvrBsT interactor proteins are involved in plant

  16. Pep-13, a plant defense-inducing pathogen-associated pattern from Phytophthora transglutaminases.

    Science.gov (United States)

    Brunner, Frédéric; Rosahl, Sabine; Lee, Justin; Rudd, Jason J; Geiler, Carola; Kauppinen, Sakari; Rasmussen, Grethe; Scheel, Dierk; Nürnberger, Thorsten

    2002-12-16

    Innate immunity, an ancient form of defense against microbial infection, is well described for animals and is also suggested to be important for plants. Discrimination from self is achieved through receptors that recognize pathogen-associated molecular patterns (PAMPs) not found in the host. PAMPs are evolutionarily conserved structures which are functionally important and, thus, not subject to frequent mutation. Here we report that the previously described peptide elicitor of defense responses in parsley, Pep-13, constitutes a surface-exposed fragment within a novel calcium-dependent cell wall transglutaminase (TGase) from Phytophthora sojae. TGase transcripts and TGase activity are detectable in all Phytophthora species analyzed, among which are some of the most destructive plant pathogens. Mutational analysis within Pep-13 identified the same amino acids indispensable for both TGase and defense-eliciting activity. Pep-13, conserved among Phytophthora TGases, activates defense in parsley and potato, suggesting its function as a genus-specific recognition determinant for the activation of plant defense in host and non-host plants. In summary, plants may recognize PAMPs with characteristics resembling those known to trigger innate immune responses in animals.

  17. Nostalgia: content, triggers, functions.

    Science.gov (United States)

    Wildschut, Tim; Sedikides, Constantine; Arndt, Jamie; Routledge, Clay

    2006-11-01

    Seven methodologically diverse studies addressed 3 fundamental questions about nostalgia. Studies 1 and 2 examined the content of nostalgic experiences. Descriptions of nostalgic experiences typically featured the self as a protagonist in interactions with close others (e.g., friends) or in momentous events (e.g., weddings). Also, the descriptions contained more expressions of positive than negative affect and often depicted the redemption of negative life scenes by subsequent triumphs. Studies 3 and 4 examined triggers of nostalgia and revealed that nostalgia occurs in response to negative mood and the discrete affective state of loneliness. Studies 5, 6, and 7 investigated the functional utility of nostalgia and established that nostalgia bolsters social bonds, increases positive self-regard, and generates positive affect. These findings demarcate key landmarks in the hitherto uncharted research domain of nostalgia.

  18. Latent myofascial trigger points.

    Science.gov (United States)

    Ge, Hong-You; Arendt-Nielsen, Lars

    2011-10-01

    A latent myofascial trigger point (MTP) is defined as a focus of hyperirritability in a muscle taut band that is clinically associated with local twitch response and tenderness and/or referred pain upon manual examination. Current evidence suggests that the temporal profile of the spontaneous electrical activity at an MTP is similar to focal muscle fiber contraction and/or muscle cramp potentials, which contribute significantly to the induction of local tenderness and pain and motor dysfunctions. This review highlights the potential mechanisms underlying the sensory-motor dysfunctions associated with latent MTPs and discusses the contribution of central sensitization associated with latent MTPs and the MTP network to the spatial propagation of pain and motor dysfunctions. Treating latent MTPs in patients with musculoskeletal pain may not only decrease pain sensitivity and improve motor functions, but also prevent latent MTPs from transforming into active MTPs, and hence, prevent the development of myofascial pain syndrome.

  19. Trichoderma-Plant Root Colonization: Escaping Early Plant Defense Responses and Activation of the Antioxidant Machinery for Saline Stress Tolerance

    OpenAIRE

    Brotman, Yariv; Landau, Udi; Cuadros-Inostroza, ?lvaro; Takayuki, Tohge; Fernie, Alisdair R.; Chet, Ilan; Viterbo, Ada; Willmitzer, Lothar

    2013-01-01

    Trichoderma spp. are versatile opportunistic plant symbionts which can colonize the apoplast of plant roots. Microarrays analysis of Arabidopsis thaliana roots inoculated with Trichoderma asperelloides T203, coupled with qPCR analysis of 137 stress responsive genes and transcription factors, revealed wide gene transcript reprogramming, proceeded by a transient repression of the plant immune responses supposedly to allow root colonization. Enhancement in the expression of WRKY18 and WRKY40, wh...

  20. Public Response to Scientific Misconduct: Assessing Changes in Public Sentiment Toward the Stimulus-Triggered Acquisition of Pluripotency (STAP) Cell Case via Twitter.

    Science.gov (United States)

    Gayle, Alberto; Shimaoka, Motomu

    2017-04-20

    In this age of social media, any news-good or bad-has the potential to spread in unpredictable ways. Changes in public sentiment have the potential to either drive or limit investment in publicly funded activities, such as scientific research. As a result, understanding the ways in which reported cases of scientific misconduct shape public sentiment is becoming increasingly essential-for researchers and institutions, as well as for policy makers and funders. In this study, we thus set out to assess and define the patterns according to which public sentiment may change in response to reported cases of scientific misconduct. This study focuses on the public response to the events involved in a recent case of major scientific misconduct that occurred in 2014 in Japan-stimulus-triggered acquisition of pluripotency (STAP) cell case. The aims of this study were to determine (1) the patterns according to which public sentiment changes in response to scientific misconduct; (2) whether such measures vary significantly, coincident with major timeline events; and (3) whether the changes observed mirror the response patterns reported in the literature with respect to other classes of events, such as entertainment news and disaster reports. The recent STAP cell scandal is used as a test case. Changes in the volume and polarity of discussion were assessed using a sampling of case-related Twitter data, published between January 28, 2014 and March 15, 2015. Rapidminer was used for text processing and the popular bag-of-words algorithm, SentiWordNet, was used in Rapidminer to calculate sentiment for each sample Tweet. Relative volume and sentiment was then assessed overall, month-to-month, and with respect to individual entities. Despite the ostensibly negative subject, average sentiment over the observed period tended to be neutral (-0.04); however, a notable downward trend (y=-0.01 x +0.09; R ²=.45) was observed month-to-month. Notably polarized tweets accounted for less than

  1. GnRHa trigger for final oocyte maturation: is HCG trigger history?

    DEFF Research Database (Denmark)

    Humaidan, Peter; Alsbjerg, Birgit

    2014-01-01

    gonadotrophin (HCG) trigger. Early trials showed a severe luteal phase insufficiency after GnRHa trigger despite the application of standard luteal phase support protocols. Subsequent research has led to modifications of the luteal phase support, resulting in reproductive outcome comparable to that seen after...... HCG trigger in normal- and high-responders. GnRHa trigger facilitates a tailored approach to subsequent luteal phase support, taking into account the ovarian response to stimulation. In the future, GnRHa is likely to be used for trigger in all women co-treated with GnRH antagonists....

  2. Early defense responses in the freshwater bivalve Corbicula fluminea exposed to copper and cadmium: Transcriptional and histochemical studies.

    Science.gov (United States)

    Bigot, Aurélie; Minguez, Laëtitia; Giambérini, Laure; Rodius, François

    2011-11-01

    The aim of the present study was to measure the early effects of copper (10 and 50 μg L(-1)), cadmium (2, 10, and 50 μg L(-1)) and mixtures of these metals in the freshwater bivalve Corbicula fluminea exposed for 12 h in laboratory. Transcription levels of superoxide dismutase (SOD), catalase (CAT), selenium-dependent glutathione peroxidase (Se-GPx), pi-class glutathione S-transferase (pi-GST), metallothionein (MT) in digestive gland and gills, and response of lysosomal system and neutral lipids in digestive gland were determined after the exposure period. Results showed that lysosomal system, neutral lipids content, and mRNA levels were modified, suggesting their early response against oxidative stress and their important role in cell integrity. The integrated biomarker response was calculated and showed that the effects of the combinations of Cu and Cd on the biomarker responses are additive. MT and pi-GST mRNA expression correspond to the largest ranges of response. As efficient biomarkers should have an early warning capacity, SOD, CAT, Se-GPx, pi-GST, MT transcripts levels, lysosomal system, and neutral lipids could be used as biomarkers of metal contamination in the aquatic environment. Copyright © 2010 Wiley Periodicals, Inc.

  3. Orally administered Lactobacillus rhamnosus modulates the respiratory immune response triggered by the viral pathogen-associated molecular pattern poly(I:C).

    Science.gov (United States)

    Villena, Julio; Chiba, Eriko; Tomosada, Yohsuke; Salva, Susana; Marranzino, Gabriela; Kitazawa, Haruki; Alvarez, Susana

    2012-09-18

    Some studies have shown that probiotics, including Lactobacillus rhamnosus CRL1505, had the potential to beneficially modulate the outcome of certain bacterial and viral respiratory infections. However, these studies did not determine the mechanism(s) by which probiotics contribute to host defense against respiratory viruses. In this work we demonstrated that orally administered Lactobacillus rhamnosus CRL1505 (Lr1505) was able to increase the levels of IFN-γ, IL-10 and IL-6 in the respiratory tract and the number of lung CD3(+)CD4(+)IFN-γ(+) T cells. To mimic the pro-inflammatory and physiopathological consecuences of RNA viral infections in the lung, we used an experimental model of lung inflammation based on the administration of the artificial viral pathogen-associated molecular pattern poly(I:C). Nasal administration of poly(I:C) to mice induced a marked impairment of lung function that was accompanied by the production of pro-inflammatory mediators and inflammatory cell recruitment into the airways. The preventive administration of Lr1505 reduced lung injuries and the production of TNF-α, IL-6, IL-8 and MCP-1 in the respiratory tract after the challenge with poly(I:C). Moreover, Lr1505 induced a significant increase in lung and serum IL-10. We also observed that Lr1505 was able to increase respiratory IFN-γ levels and the number of lung CD3(+)CD4(+)IFN-γ(+) T cells after poly(I:C) challenge. Moreover, higher numbers of both CD103(+) and CD11b(high) dendritic cells and increased expression of MHC-II, IL-12 and IFN-γ in these cell populations were found in lungs of Lr1505-treated mice. Therefore, Lr1505 treatment would beneficially regulate the balance between pro-inflammatory mediators and IL-10, allowing an effective inflammatory response against infection and avoiding tissue damage. Results showed that Lr1505 would induce a mobilization of cells from intestine and changes in cytokine profile that would be able to beneficially modulate the respiratory

  4. Role of trichomes in defense against herbivores: comparison of herbivore response to woolly and hairless trichome mutants in tomato (Solanum lycopersicum).

    Science.gov (United States)

    Tian, Donglan; Tooker, John; Peiffer, Michelle; Chung, Seung Ho; Felton, Gary W

    2012-10-01

    Trichomes contribute to plant resistance against herbivory by physical and chemical deterrents. To better understand their role in plant defense, we systemically studied trichome morphology, chemical composition and the response of the insect herbivores Helicoverpa zea and Leptinotarsa decemlineata (Colorado potato beetle = CPB) on the tomato hairless (hl), hairy (woolly) mutants and wild-type Rutgers (RU) and Alisa Craig (AC) plants. Hairless mutants showed reduced number of twisted glandular trichomes (types I, IV, VI and VII) on leaf and stem compared to wild-type Rutgers (RU), while woolly mutants showed high density of non-glandular trichomes (types II, III and V) but only on the leaf. In both mutants, trichome numbers were increased by methyl jasmonate (MeJA), but the types of trichomes present were not affected by MeJA treatment. Glandular trichomes contained high levels of monoterpenes and sesquiterpenes. A similar pattern of transcript accumulation was observed for monoterpene MTS1 (=TPS5) and sesquiterpene synthase SST1 (=TPS9) genes in trichomes. While high density of non-glandular trichome on leaves negatively influenced CPB feeding behavior and growth, it stimulated H. zea growth. High glandular trichome density impaired H. zea growth, but had no effect on CPB. Quantitative real-time polymerase chain reaction (qRT-PCR) showed that glandular trichomes highly express protein inhibitors (PIN2), polyphenol oxidase (PPOF) and hydroperoxide lyase (HPL) when compared to non-glandular trichomes. The SlCycB2 gene, which participates in woolly trichome formation, was highly expressed in the woolly mutant trichomes. PIN2 in trichomes was highly induced by insect feeding in both mutant and wild-type plants. Thus, both the densities of trichomes and the chemical defenses residing in the trichomes are inducible.

  5. Response and Defense Mechanisms of Taxus chinensis Leaves Under UV-A Radiation are Revealed Using Comparative Proteomics and Metabolomics Analyses.

    Science.gov (United States)

    Zheng, Wen; Komatsu, Setsuko; Zhu, Wei; Zhang, Lin; Li, Ximin; Cui, Lei; Tian, Jingkui

    2016-09-01

    Taxus chinensis var. mairei is a species endemic to south-eastern China and one of the natural sources for the anticancer medicine paclitaxel. To investigate the molecular response and defense mechanisms of T. chinensis leaves to enhanced ultraviolet-A (UV-A) radiation, gel-free/label-free and gel-based proteomics and gas chromatography-mass spectrometry (GC-MS) analyses were performed. The transmission electron microscopy results indicated damage to the chloroplast under UV-A radiation. Proteomics analyses in leaves and chloroplasts showed that photosynthesis-, glycolysis-, secondary metabolism-, stress-, and protein synthesis-, degradation- and activation-related systems were mainly changed under UV-A radiation. Forty-seven PSII proteins and six PSI proteins were identified as being changed in leaves and chloroplasts under UV-A treatment. This indicated that PSII was more sensitive to UV-A than PSI as the target of UV-A light. Enhanced glycolysis, with four glycolysis-related key enzymes increased, provided precursors for secondary metabolism. The 1-deoxy-d-xylulose-5-phosphate reductoisomerase and 4-hydroxy-3-methylbut-2-enyl diphosphate reductase were identified as being significantly increased during UV-A radiation, which resulted in paclitaxel enhancement. Additionally, mRNA expression levels of genes involved in the paclitaxel biosynthetic pathway indicated a down-regulation under UV-A irradiation and up-regulation in dark incubation. These results reveal that a short-term high dose of UV-A radiation could stimulate the plant stress defense system and paclitaxel production. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  6. Identification of diverse defense mechanisms in trout red blood cells in response to VHSV halted viral replication.

    Science.gov (United States)

    Nombela, Ivan; Puente-Marin, Sara; Chico, Veronica; Villena, Alberto J; Carracedo, Begoña; Ciordia, Sergio; Mena, Maria Carmen; Mercado, Luis; Perez, Luis; Coll, Julio; Estepa, Amparo; Ortega-Villaizan, Maria Del Mar

    2017-01-01

    Background: It has been described that fish nucleated red blood cells (RBCs) generate a wide variety of immune-related gene transcripts when viruses highly replicate inside them and are their main target cell. The immune response and mechanisms of fish RBCs against viruses targeting other cells or tissues has not yet been explored and is the objective of our study. Methods: Trout RBCs were obtained from peripheral blood, ficoll purified and exposed to Viral Haemorrhagic Septicaemia virus (VHSV). Immune response was evaluated by means of RT-qPCR, flow cytometry, immunofluorescence and isobaric tag for relative and absolute quantification (iTRAQ) protein profiling Results: VHSV N gene transcripts incremented early postexposure and were drastically decreased after 6 hours postexposure (hpe). The expression of the type I interferon ( ifn1 ) gene was significantly downregulated at early postexposure (3 hpe), together with a gradual downregulation of interferon-inducible mx and pkr genes until 72 hpe. Type I IFN protein was downregulated and interferon-inducible Mx protein was maintained at basal levels. Co-culture assays of RBCs with TSS (stromal cell line from spleen) revealed the IFN crosstalk between both cell types. On the other hand, anti-microbial peptide β-defensin 1 and neutrophil chemotactic factor interleukin 8 were slightly upregulated in VHSV-exposed RBCs Isobaric tag for relative and absolute quantification (iTRAQ) revealed that VHSV exposure can induce a global protein downregulation in trout RBCs, mainly related to RNA stability and proteasome pathways. The antioxidant/antiviral response is also suggested to be involved in the response of trout RBCs to VHSV. Conclusions: A variety of mechanisms are proposed to be implicated in the antiviral response of trout RBCs against VHSV halted infection. Ongoing research is focused on understanding the mechanisms in detail. To our knowledge, this is the first report that implicates fish RBCs in the antiviral

  7. Defense Gene Expression Associated with responses during the Biotrophic Phase of Mycosphaerella fjiensis Morelet, Infection in Banana.

    NARCIS (Netherlands)

    Rodriguez, H.E.; Rodriguez-Arango, E.; Morales, J.; Kema, G.H.J.; Arango, R.E.

    2016-01-01

    Banana black leaf streak, caused by Mycosphaerella fijiensis M. Morelet, is a primary phytosanitary concern in export of this fruit around the world. To develop improved cultivars resistant to this disease, an understanding of host response to infection is necessary. In this study, we obtained

  8. Identification of diverse defense mechanisms in rainbow trout red blood cells in response to halted replication of VHS virus

    Science.gov (United States)

    Nombela, Ivan; Puente-Marin, Sara; Chico, Veronica; Villena, Alberto J.; Carracedo, Begoña; Ciordia, Sergio; Mena, Maria Carmen; Mercado, Luis; Perez, Luis; Coll, Julio; Ortega-Villaizan, Maria del Mar

    2018-01-01

    Background: It has been described that fish nucleated red blood cells (RBCs) generate a wide variety of immune-related gene transcripts when viruses highly replicate inside them and are their main target cell. The immune response and mechanisms of fish RBCs against viruses targeting other cells or tissues has not yet been explored and is the objective of our study. Methods: Rainbow trout RBCs were obtained from peripheral blood, ficoll purified and exposed to Viral Haemorrhagic Septicaemia virus (VHSV). Immune response was evaluated by means of RT-qPCR, flow cytometry, immunofluorescence and isobaric tag for relative and absolute quantification (iTRAQ) protein profiling. Results: VHSV N gene transcripts incremented early postexposure and were drastically decreased after 6 hours postexposure (hpe). The expression of type I interferon ( ifn1) gene was significantly downregulated at early postexposure (3 hpe), together with a gradual downregulation of interferon-inducible mx and pkr genes until 72 hpe. Type I IFN protein was downregulated and interferon-inducible Mx protein was maintained at basal levels. Co-culture assays of RBCs, previously exposed to UV-inactivated VHSV, and TSS (stromal cell line from spleen) revealed IFN crosstalk between both cell types. On the other hand, anti-microbial peptide β-defensin 1 and neutrophil chemotactic factor interleukin 8 were slightly upregulated in VHSV-exposed RBCs. iTRAQ profiling revealed that VHSV exposure can induce a global protein downregulation in rainbow trout RBCs, mainly related to RNA stability and proteasome pathways. Antioxidant/antiviral response is also suggested to be involved in the response of rainbow trout RBCs to VHSV. Conclusions: A variety of mechanisms are proposed to be implicated in the antiviral response of rainbow trout RBCs against VHSV halted infection. Ongoing research is focused on understanding the mechanisms in detail.

  9. Phytophthora megakarya and P. palmivora, Causal Agents of Black Pod Rot, Induce Similar Plant Defense Responses Late during Infection of Susceptible Cacao Pods

    Science.gov (United States)

    Ali, Shahin S.; Shao, Jonathan; Lary, David J.; Strem, Mary D.; Meinhardt, Lyndel W.; Bailey, Bryan A.

    2017-01-01

    Phytophthora megakarya (Pmeg) and Phytophthora palmivora (Ppal) cause black pod rot of Theobroma cacao L. (cacao). Of these two clade 4 species, Pmeg is more virulent and is displacing Ppal in many cacao production areas in Africa. Symptoms and species specific sporangia production were compared when the two species were co-inoculated onto pod pieces in staggered 24 h time intervals. Pmeg sporangia were predominantly recovered from pod pieces with unwounded surfaces even when inoculated 24 h after Ppal. On wounded surfaces, sporangia of Ppal were predominantly recovered if the two species were simultaneously applied or Ppal was applied first but not if Pmeg was applied first. Pmeg demonstrated an advantage over Ppal when infecting un-wounded surfaces while Ppal had the advantage when infecting wounded surfaces. RNA-Seq was carried out on RNA isolated from control and Pmeg and Ppal infected pod pieces 3 days post inoculation to assess their abilities to alter/suppress cacao defense. Expression of 4,482 and 5,264 cacao genes was altered after Pmeg and Ppal infection, respectively, with most genes responding to both species. Neural network self-organizing map analyses separated the cacao RNA-Seq gene expression profiles into 24 classes, 6 of which were largely induced in response to infection. Using KEGG analysis, subsets of genes composing interrelated pathways leading to phenylpropanoid biosynthesis, ethylene and jasmonic acid biosynthesis and action, plant defense signal transduction, and endocytosis showed induction in response to infection. A large subset of genes encoding putative Pr-proteins also showed differential expression in response to infection. A subset of 36 cacao genes was used to validate the RNA-Seq expression data and compare infection induced gene expression patterns in leaves and wounded and unwounded pod husks. Expression patterns between RNA-Seq and RT-qPCR were generally reproducible. The level and timing of altered gene expression was

  10. Stimulus conflict triggers behavioral avoidance.

    Science.gov (United States)

    Dignath, David; Eder, Andreas B

    2015-12-01

    According to a recent extension of the conflict-monitoring theory, conflict between two competing response tendencies is registered as an aversive event and triggers a motivation to avoid the source of conflict. In the present study, we tested this assumption. Over five experiments, we examined whether conflict is associated with an avoidance motivation and whether stimulus conflict or response conflict triggers an avoidance tendency. Participants first performed a color Stroop task. In a subsequent motivation test, participants responded to Stroop stimuli with approach- and avoidance-related lever movements. These results showed that Stroop-conflict stimuli increased the frequency of avoidance responses in a free-choice motivation test, and also increased the speed of avoidance relative to approach responses in a forced-choice test. High and low proportions of response conflict in the Stroop task had no effect on avoidance in the motivation test. Avoidance of conflict was, however, obtained even with new conflict stimuli that had not been presented before in a Stroop task, and when the Stroop task was replaced with an unrelated filler task. Taken together, these results suggest that stimulus conflict is sufficient to trigger avoidance.

  11. Induced Genome-Wide Binding of Three Arabidopsis WRKY Transcription Factors during Early MAMP-Triggered Immunity.

    Science.gov (United States)

    Birkenbihl, Rainer P; Kracher, Barbara; Somssich, Imre E

    2017-01-01

    During microbial-associated molecular pattern-triggered immunity (MTI), molecules derived from microbes are perceived by cell surface receptors and upon signaling to the nucleus initiate a massive transcriptional reprogramming critical to mount an appropriate host defense response. WRKY transcription factors play an important role in regulating these transcriptional processes. Here, we determined on a genome-wide scale the flg22-induced in vivo DNA binding dynamics of three of the most prominent WRKY factors, WRKY18, WRKY40, and WRKY33. The three WRKY factors each bound to more than 1000 gene loci predominantly at W-box elements, the known WRKY binding motif. Binding occurred mainly in the 500-bp promoter regions of these genes. Many of the targeted genes are involved in signal perception and transduction not only during MTI but also upon damage-associated molecular pattern-triggered immunity, providing a mechanistic link between these functionally interconnected basal defense pathways. Among the additional targets were genes involved in the production of indolic secondary metabolites and in modulating distinct plant hormone pathways. Importantly, among the targeted genes were numerous transcription factors, encoding predominantly ethylene response factors, active during early MTI, and WRKY factors, supporting the previously hypothesized existence of a WRKY subregulatory network. Transcriptional analysis revealed that WRKY18 and WRKY40 function redundantly as negative regulators of flg22-induced genes often to prevent exaggerated defense responses. © 2016 American Society of Plant Biologists. All rights reserved.

  12. Ability of Interleukin-33- and Immune Complex-Triggered Activation of Human Mast Cells to Down-Regulate Monocyte-Mediated Immune Responses.

    Science.gov (United States)

    Rivellese, Felice; Suurmond, Jolien; Habets, Kim; Dorjée, Annemarie L; Ramamoorthi, Nandhini; Townsend, Michael J; de Paulis, Amato; Marone, Gianni; Huizinga, Tom W J; Pitzalis, Costantino; Toes, René E M

    2015-09-01

    Mast cells have been implicated in the pathogenesis of rheumatoid arthritis (RA). In particular, their activation by interleukin-33 (IL-33) has been linked to the development of arthritis in animal models. The aim of this study was to evaluate the functional responses of human mast cells to IL-33 in the context of RA. Human mast cells were stimulated with IL-33 combined with plate-bound IgG or IgG anti-citrullinated protein antibodies (ACPAs), and their effects on monocyte activation were evaluated. Cellular interactions of mast cells in RA synovium were assessed by immunofluorescence analysis, and the expression of messenger RNA (mRNA) for mast cell-specific genes was evaluated in synovial biopsy tissue from patients with early RA who were naive to treatment with disease-modifying antirheumatic drugs. IL-33 induced the up-regulation of Fcγ receptor type IIa and enhanced the activation of mast cells by IgG, including IgG ACPAs, as indicated by the production of CXCL8/IL-8. Intriguingly, mast cell activation triggered with IL-33 and IgG led to the release of mediators such as histamine and IL-10, which inhibited monocyte activation. Synovial mast cells were found in contact with CD14+ monocyte/macrophages. Finally, mRNA levels of mast cell-specific genes were inversely associated with disease severity, and IL-33 mRNA levels showed an inverse correlation with the levels of proinflammatory markers. When human mast cells are activated by IL-33, an immunomodulatory phenotype develops, with human mast cells gaining the ability to suppress monocyte activation via the release of IL-10 and histamine. These findings, together with the presence of synovial mast cell-monocyte interactions and the inverse association between the expression of mast cell genes at the synovial level and disease activity, suggest that these newly described mast cell-mediated inhibitory pathways might have a functional relevance in the pathogenesis of RA. © 2015, American College of Rheumatology.

  13. MAPK-triggered chromatin reprogramming by histone deacetylase in plant innate immunity

    KAUST Repository

    Latrasse, David

    2017-07-06

    Microbial-associated molecular patterns activate several MAP kinases, which are major regulators of the innate immune response in Arabidopsis thaliana that induce large-scale changes in gene expression. Here, we determine whether microbial-associated molecular pattern-triggered gene expression involves modifications at the chromatin level.Histone acetylation and deacetylation are major regulators of microbial-associated molecular pattern-triggered gene expression and implicate the histone deacetylase HD2B in the reprogramming of defence gene expression and innate immunity. The MAP kinase MPK3 directly interacts with and phosphorylates HD2B, thereby regulating the intra-nuclear compartmentalization and function of the histone deacetylase.By studying a number of gene loci that undergo microbial-associated molecular pattern-dependent activation or repression, our data reveal a mechanistic model for how protein kinase signaling directly impacts chromatin reprogramming in plant defense.

  14. Thyme and Savory Essential Oil Efficacy and Induction of Resistance against Botrytis cinerea through Priming of Defense Responses in Apple

    OpenAIRE

    Houda Banani; Leone Olivieri; Karin Santoro; Angelo Garibaldi; Maria Lodovica Gullino; Davide Spadaro

    2018-01-01

    The efficacy of thyme and savory essential oils were investigated against Botrytis cinerea on apple fruit. Apples treated with thyme and savory essential oils showed significantly lower gray mold severity and incidence. Thyme essential oil at 1% concentration showed the highest efficacy, with lower disease incidence and smaller lesion diameter. The expression of specific pathogenesis-related (PR) genes PR-8 and PR-5 was characterized in apple tissues in response to thyme oil application and B...

  15. Cultivar-specific high temperature stress responses in bread wheat (Triticum aestivum L.) associated with physicochemical traits and defense pathways.

    Science.gov (United States)

    Mishra, Divya; Shekhar, Shubhendu; Agrawal, Lalit; Chakraborty, Subhra; Chakraborty, Niranjan

    2017-04-15

    The increasing global temperature by 1°C is estimated to reduce the harvest index in a crop by 6%, and this would certainly have negative impact on overall plant metabolism. Wheat is one of the most important crops with global annual production of over 600million tonnes. We investigated an array of physicochemical and molecular indexes to unravel differential response of nine commercial wheat cultivars to high temperature stress (HTS). The reduced rate in relative water content, higher membrane stability, slow chlorophyll degradation and increased accumulation of proline and secondary metabolites ingrained higher thermotolerance in cv. Unnat Halna, among others. The altered expression of several stress-responsive genes, particularly the genes associated with photosynthesis, heat shock proteins and antioxidants impinge on the complexity of HTS-induced responses over different genetic backgrounds and connectivity of adaptive mechanisms. This may facilitate the targeted manipulation of metabolic routes in crops for agricultural and industrial exploitation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Disease interactions in a shared host plant: effects of pre-existing viral infection on cucurbit plant defense responses and resistance to bacterial wilt disease.

    Directory of Open Access Journals (Sweden)

    Lori R Shapiro

    Full Text Available Both biotic and abiotic stressors can elicit broad-spectrum plant resistance against subsequent pathogen challenges. However, we currently have little understanding of how such effects influence broader aspects of disease ecology and epidemiology in natural environments where plants interact with multiple antagonists simultaneously. In previous work, we have shown that healthy wild gourd plants (Cucurbita pepo ssp. texana contract a fatal bacterial wilt infection (caused by Erwinia tracheiphila at significantly higher rates than plants infected with Zucchini yellow mosaic virus (ZYMV. We recently reported evidence that this pattern is explained, at least in part, by reduced visitation of ZYMV-infected plants by the cucumber beetle vectors of E. tracheiphila. Here we examine whether ZYMV-infection may also directly elicit plant resistance to subsequent E. tracheiphila infection. In laboratory studies, we assayed the induction of key phytohormones (SA and JA in single and mixed infections of these pathogens, as well as in response to the feeding of A. vittatum cucumber beetles on healthy and infected plants. We also tracked the incidence and progression of wilt disease symptoms in plants with prior ZYMV infections. Our results indicate that ZYMV-infection slightly delays the progression of wilt symptoms, but does not significantly reduce E. tracheiphila infection success. This observation supports the hypothesis that reduced rates of wilt disease in ZYMV-infected plants reflect reduced visitation by beetle vectors. We also documented consistently strong SA responses to ZYMV infection, but limited responses to E. tracheiphila in the absence of ZYMV, suggesting that the latter pathogen may effectively evade or suppress plant defenses, although we observed no evidence of antagonistic cross-talk between SA and JA signaling pathways. We did, however, document effects of E. tracheiphila on induced responses to herbivory that may influence host

  17. Disease Interactions in a Shared Host Plant: Effects of Pre-Existing Viral Infection on Cucurbit Plant Defense Responses and Resistance to Bacterial Wilt Disease

    Science.gov (United States)

    Mauck, Kerry E.; Pulido, Hannier; De Moraes, Consuelo M.; Stephenson, Andrew G.; Mescher, Mark C.

    2013-01-01

    Both biotic and abiotic stressors can elicit broad-spectrum plant resistance against subsequent pathogen challenges. However, we currently have little understanding of how such effects influence broader aspects of disease ecology and epidemiology in natural environments where plants interact with multiple antagonists simultaneously. In previous work, we have shown that healthy wild gourd plants (Cucurbita pepo ssp. texana) contract a fatal bacterial wilt infection (caused by Erwinia tracheiphila) at significantly higher rates than plants infected with Zucchini yellow mosaic virus (ZYMV). We recently reported evidence that this pattern is explained, at least in part, by reduced visitation of ZYMV-infected plants by the cucumber beetle vectors of E. tracheiphila. Here we examine whether ZYMV-infection may also directly elicit plant resistance to subsequent E. tracheiphila infection. In laboratory studies, we assayed the induction of key phytohormones (SA and JA) in single and mixed infections of these pathogens, as well as in response to the feeding of A. vittatum cucumber beetles on healthy and infected plants. We also tracked the incidence and progression of wilt disease symptoms in plants with prior ZYMV infections. Our results indicate that ZYMV-infection slightly delays the progression of wilt symptoms, but does not significantly reduce E. tracheiphila infection success. This observation supports the hypothesis that reduced rates of wilt disease in ZYMV-infected plants reflect reduced visitation by beetle vectors. We also documented consistently strong SA responses to ZYMV infection, but limited responses to E. tracheiphila in the absence of ZYMV, suggesting that the latter pathogen may effectively evade or suppress plant defenses, although we observed no evidence of antagonistic cross-talk between SA and JA signaling pathways. We did, however, document effects of E. tracheiphila on induced responses to herbivory that may influence host-plant quality for (and

  18. Histones as mediators of host defense, inflammation and thrombosis.

    Science.gov (United States)

    Hoeksema, Marloes; van Eijk, Martin; Haagsman, Henk P; Hartshorn, Kevan L

    2016-01-01

    Histones are known for their ability to bind to and regulate expression of DNA. However, histones are also present in cytoplasm and extracellular fluids where they serve host defense functions and promote inflammatory responses. Histones are a major component of neutrophil extracellular traps that contribute to bacterial killing but also to inflammatory injury. Histones can act as antimicrobial peptides and directly kill bacteria, fungi, parasites and viruses, in vitro and in a variety of animal hosts. In addition, histones can trigger inflammatory responses in some cases acting through Toll-like receptors or inflammasome pathways. Extracellular histones mediate organ injury (lung, liver), sepsis physiology, thrombocytopenia and thrombin generation and some proteins can bind histones and reduce these potentially harmful effects.

  19. NAD Acts as an Integral Regulator of Multiple Defense Layers.

    Science.gov (United States)

    Pétriacq, Pierre; Ton, Jurriaan; Patrit, Oriane; Tcherkez, Guillaume; Gakière, Bertrand

    2016-11-01

    Pyridine nucleotides, such as NAD, are crucial redox carriers and have emerged as important signaling molecules in stress responses. Previously, we have demonstrated in Arabidopsis (Arabidopsis thaliana) that the inducible NAD-overproducing nadC lines are more resistant to an avirulent strain of Pseudomonas syringae pv tomato (Pst-AvrRpm1), which was associated with salicylic acid-dependent defense. Here, we have further characterized the NAD-dependent immune response in Arabidopsis. Quinolinate-induced stimulation of intracellular NAD in transgenic nadC plants enhanced resistance against a diverse range of (a)virulent pathogens, including Pst-AvrRpt2, Dickeya dadantii, and Botrytis cinerea Characterization of the redox status demonstrated that elevated NAD levels induce reactive oxygen species (ROS) production and the expression of redox marker genes of the cytosol and mitochondrion. Using pharmacological and reverse genetics approaches, we show that NAD-induced ROS production functions independently of NADPH oxidase activity and