Journal articles: 'Constitutive defense'

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Li, Ran, Ming Wang, Yang Wang, Meredith C. Schuman, Arne Weinhold, Martin Schäfer, Guillermo H. Jiménez-Alemán, Andrea Barthel, and Ian T. Baldwin. "Flower-specific jasmonate signaling regulates constitutive floral defenses in wild tobacco." Proceedings of the National Academy of Sciences 114, no. 34 (August 7, 2017): E7205—E7214. http://dx.doi.org/10.1073/pnas.1703463114.

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Optimal defense (OD) theory predicts that within a plant, tissues are defended in proportion to their fitness value and risk of predation. The fitness value of leaves varies greatly and leaves are protected by jasmonate (JA)-inducible defenses. Flowers are vehicles of Darwinian fitness in flowering plants and are attacked by herbivores and pathogens, but how they are defended is rarely investigated. We used Nicotiana attenuata, an ecological model plant with well-characterized herbivore interactions to characterize defense responses in flowers. Early floral stages constitutively accumulate greater amounts of two well-characterized defensive compounds, the volatile (E)-α-bergamotene and trypsin proteinase inhibitors (TPIs), which are also found in herbivore-induced leaves. Plants rendered deficient in JA biosynthesis or perception by RNA interference had significantly attenuated floral accumulations of defensive compounds known to be regulated by JA in leaves. By RNA-seq, we found a JAZ gene, NaJAZi, specifically expressed in early-stage floral tissues. Gene silencing revealed that NaJAZi functions as a flower-specific jasmonate repressor that regulates JAs, (E)-α-bergamotene, TPIs, and a defensin. Flowers silenced in NaJAZi are more resistant to tobacco budworm attack, a florivore. When the defensin was ectopically expressed in leaves, performance of Manduca sexta larvae, a folivore, decreased. NaJAZi physically interacts with a newly identified NINJA-like protein, but not the canonical NINJA. This NINJA-like recruits the corepressor TOPLESS that contributes to the suppressive function of NaJAZi on floral defenses. This study uncovers the defensive function of JA signaling in flowers, which includes components that tailor JA signaling to provide flower-specific defense.

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Coppola, Mariangela, Pasquale Cascone, Simone Bossi, Giandomenico Corrado, Antonio Garonna, Massimo Maffei, Rosa Rao, and Emilio Guerrieri. "TPS Genes Silencing Alters Constitutive Indirect and Direct Defense in Tomato." International Journal of Molecular Sciences 19, no. 9 (September 13, 2018): 2748. http://dx.doi.org/10.3390/ijms19092748.

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Following herbivore attacks, plants modify a blend of volatiles organic compounds (VOCs) released, resulting in the attraction of their antagonists. However, volatiles released constitutively may affect herbivores and natural enemies’ fitness too. In tomato there is still a lack of information on the genetic bases responsible for the constitutive release of VOC involved in direct and indirect defenses. Here we studied the constitutive emissions related to the two most abundant sesquiterpene synthase genes expressed in tomato and their functional role in plant defense. Using an RNA interference approach, we silenced the expression of TPS9 and TPS12 genes and assessed the effect of this transformation on herbivores and parasitoids. We found that silenced plants displayed a different constitutive volatiles emission from controls, resulting in reduced attractiveness for the aphid parasitoid Aphidius ervi and in an impaired development of Spodoptera exigua larvae. We discussed these data considering the transcriptional regulation of key-genes involved in the pathway of VOC metabolism. We provide several lines of evidence on the metabolic flux from terpenoids to phenylpropanoids. Our results shed more light on constitutive defenses mediated by plant volatiles and on the molecular mechanisms involved in their metabolic regulation.

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Ito, Kiyoshi, and Satoki Sakai. "Optimal defense strategy against herbivory in plants: Conditions selecting for induced defense, constitutive defense, and no-defense." Journal of Theoretical Biology 260, no. 3 (October 2009): 453–59. http://dx.doi.org/10.1016/j.jtbi.2009.07.002.

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Nandi, Ashis, Pradeep Kachroo, Hirotada Fukushige, David F. Hildebrand, Daniel F. Klessig, and Jyoti Shah. "Ethylene and Jasmonic Acid Signaling Affect the NPR1-Independent Expression of Defense Genes Without Impacting Resistance to Pseudomonas syringae and Peronospora parasitica in the Arabidopsis ssi1 Mutant." Molecular Plant-Microbe Interactions® 16, no. 7 (July 2003): 588–99. http://dx.doi.org/10.1094/mpmi.2003.16.7.588.

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Salicylic acid (SA), ethylene, and jasmonic acid (JA) are important signaling molecules in plant defense to biotic stress. An intricate signaling network involving SA, ethylene, and JA fine tunes plant defense responses. SA-dependent defense responses in Arabidopsis thaliana are mediated through NPR1-dependent and -independent mechanisms. We have previously shown that activation of an NPR1-independent defense mechanism confers enhanced disease resistance and constitutive expression of the pathogenesis-related (PR) genes in the Arabidopsis ssi1 mutant. In addition, the ssi1 mutant constitutively expresses the defensin gene PDF1.2. Moreover, SA is required for the ssi1-conferred constitutive expression of PDF1.2 in addition to PR genes. Hence, the ssi1 mutant appears to target a step common to SA- and ethylene- or JA-regulated defense pathways. In the present study, we show that, in addition to SA, ethylene and JA signaling also are required for the ssi1-conferred constitutive expression of PDF1.2 and the NPR1-independent expression of PR-1. Furthermore, the ethylene-insensitive ein2 and JA-insensitive jar1 mutants enhance susceptibility of ssi1 plants to the necrotrophic fungus Botrytis cinerea. However, defects in either the ethylene- or JA-signaling pathways do not compromise ssi1-conferred resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola and the oomycete pathogen Peronospora parasitica. Interestingly, ssi1 exhibits a marginal increase in the levels of ethylene and JA, suggesting that low endogenous levels of these phytohormones are sufficient to activate expression of defense genes. Taken together, our results indicate that although cross talk in ssi1 renders expression of ethylene- or JA-responsive defense genes sensitive to SA and vice versa, it does not affect downstream signaling leading to resistance.

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Arnason, John T., and Mark A. Bernards. "Impact of constitutive plant natural products on herbivores and pathogensThe present review is one in the special series of reviews on animal–plant interactions." Canadian Journal of Zoology 88, no. 7 (July 2010): 615–27. http://dx.doi.org/10.1139/z10-038.

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Plants defend themselves from pests with deterrent or toxic phytochemicals. In addition to the development of preformed mechanical barriers such as cutin and suberin, the first line of defense for plants against pathogens and herbivores is constitutive (preformed) biologically active inhibitors. Because of the adaptation of insects and pathogens to these inhibitors, plants have evolved a stunning diversity of new and different bioactive molecules to combat pests. Some representative mechanisms of plant defense include the use of antimicrobial, anitfeedant, and phototoxic molecules. Examples of natural product defenses of specific plant families are also described. Diversity and redundancy in plant defenses is key to slowing pest resistance to host-plant defenses.

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Bixenmann, Ryan J., Phyllis D. Coley, Alexander Weinhold, and Thomas A. Kursar. "High herbivore pressure favors constitutive over induced defense." Ecology and Evolution 6, no. 17 (July 29, 2016): 6037–49. http://dx.doi.org/10.1002/ece3.2208.

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Ellis, Christine, Ioannis Karafyllidis, and John G. Turner. "Constitutive Activation of Jasmonate Signaling in an Arabidopsis Mutant Correlates with Enhanced Resistance to Erysiphe cichoracearum, Pseudomonas syringae, and Myzus persicae." Molecular Plant-Microbe Interactions® 15, no. 10 (October 2002): 1025–30. http://dx.doi.org/10.1094/mpmi.2002.15.10.1025.

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In Arabidopsis spp., the jasmonate (JA) response pathway generally is required for defenses against necrotrophic pathogens and chewing insects, while the salicylic acid (SA) response pathway is generally required for specific, resistance (R) gene-mediated defenses against both biotrophic and necrotrophic pathogens. For example, SA-dependent defenses are required for resistance to the biotrophic fungal pathogen Erysiphe cichoracearum UCSC1 and the bacterial pathogen Pseudomonas syringae pv. maculicola, and also are expressed during response to the green peach aphid Myzus persicae. However, recent evidence indicates that the expression of JA-dependent defenses also may confer resistance to E. cichoracearum. To confirm and to extend this observation, we have compared the disease and pest resistance of wild-type Arabidopsis plants with that of the mutants coi1, which is insensitive to JA, and cev1, which has constitutive JA signaling. Measurements of the colonization of these plants by E. cichoracearum, P. syringae pv. maculicola, and M. persicae indicated that activation of the JA signal pathway enhanced resistance, and was associated with the activation of JA-dependent defense genes and the suppression of SA-dependent defense genes. We conclude that JA and SA induce alternative defense pathways that can confer resistance to the same pathogens and pests.

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Van Alstyne, KL, L. Sutton, and SA Gifford. "Inducible versus constitutive antioxidant defenses in algae along an environmental stress gradient." Marine Ecology Progress Series 640 (April 23, 2020): 107–15. http://dx.doi.org/10.3354/meps13263.

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Optimal defense theory (ODT) predicts that antiherbivore defenses should be constitutive when plants are frequently attacked and inducible when the probability of attack is low. Like antiherbivore defenses, antioxidant defenses can be inducible or constitutive. We hypothesized the ODT predictions should apply to antioxidant defenses; thus, species inhabiting environments where oxidative stresses occur frequently should produce constitutive antioxidant defenses, whereas species in environments where stresses occur less frequently should produce inducible defenses. We tested this hypothesis by attempting to induce production of the antioxidant precursor dimethylsulfoniopropionate (DMSP) in 4 ulvoid algae species that experience different levels of environmental stress because they are zoned along a tidal gradient. The 2 lower intertidal species Ulvaria obscura and Ulva fenestrata, which experience oxidative stresses less frequently, induced DMSP production in response to applications of the chemical oxidant hydrogen peroxide within 7 d, whereas the higher intertidal species Ulva linza and Ulva intestinalis, which regularly experience oxidative stress, did not have increased DMSP concentrations. This study demonstrates a novel waterborne signaling mechanism for DMSP induction in marine macroalgae and provides evidence of selection for inducible antioxidant defenses in organisms experiencing less frequent environmental stresses.

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Yactayo-Chang, Jessica P., Hoang V. Tang, Jorrel Mendoza, Shawn A. Christensen, and Anna K. Block. "Plant Defense Chemicals against Insect Pests." Agronomy 10, no. 8 (August 8, 2020): 1156. http://dx.doi.org/10.3390/agronomy10081156.

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Insect pests cause significant global agricultural damage and lead to major financial and environmental costs. Crops contain intrinsic defenses to protect themselves from such pests, including a wide array of specialized secondary metabolite-based defense chemicals. These chemicals can be induced upon attack (phytoalexins) or are constitutive (phytoanticipins), and can have a direct impact on the pests or be used indirectly to attract their natural enemies. They form part of a global arms race between the crops and their insect pests, with the insects developing methods of suppression, avoidance, detoxification, or even capture of their hosts defensive chemicals. Harnessing and optimizing the chemical defense capabilities of crops has the potential to aid in the continuing struggle to enhance or improve agricultural pest management. Such strategies include breeding for the restoration of defense chemicals from ancestral varieties, or cross-species transfer of defense metabolite production.

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Buckley, James, Foteini G. Pashalidou, Martin C. Fischer, Alex Widmer, Mark C. Mescher, and Consuelo M. De Moraes. "Divergence in Glucosinolate Profiles between High- and Low-Elevation Populations of Arabidopsis halleri Correspond to Variation in Field Herbivory and Herbivore Behavioral Preferences." International Journal of Molecular Sciences 20, no. 1 (January 5, 2019): 174. http://dx.doi.org/10.3390/ijms20010174.

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Variation in local herbivore pressure along elevation gradients is predicted to drive variation in plant defense traits. Yet, the extent of intraspecific variation in defense investment along elevation gradients, and its effects on both herbivore preference and performance, remain relatively unexplored. Using populations of Arabidopsis halleri (Brassicaceae) occurring at different elevations in the Alps, we tested for associations between elevation, herbivore damage in the field, and constitutive chemical defense traits (glucosinolates) assayed under common-garden conditions. Additionally, we examined the feeding preferences and performance of a specialist herbivore, the butterfly Pieris brassicae, on plants from different elevations in the Alps. Although we found no effect of elevation on the overall levels of constitutive glucosinolates in leaves, relative amounts of indole glucosinolates increased significantly with elevation and were negatively correlated with herbivore damage in the field. In oviposition preference assays, P. brassicae females laid fewer eggs on plants from high-elevation populations, although larval performance was similar on populations from different elevations. Taken together, these results support the prediction that species distributed along elevation gradients exhibit genetic variation in chemical defenses, which can have consequences for interactions with herbivores in the field.

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Zheng, Zihui, Naiqi Wang, Meachery Jalajakumari, Leila Blackman, Enhui Shen, Saurabh Verma, Ming-Bo Wang, and Anthony A. Millar. "miR159 Represses a Constitutive Pathogen Defense Response in Tobacco." Plant Physiology 182, no. 4 (February 10, 2020): 2182–98. http://dx.doi.org/10.1104/pp.19.00786.

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Ooi, James Y., Yoshimasa Yagi, Xiaodi Hu, and Y. Tony Ip. "The Drosophila Toll‐9 activates a constitutive antimicrobial defense." EMBO reports 3, no. 1 (January 2002): 82–87. http://dx.doi.org/10.1093/embo-reports/kvf004.

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Shao, Yutao, Mingxin Guo, Xianfeng He, Qingxin Fan, Zhenjie Wang, Jin Jia, and Jiangbo Guo. "Constitutive H2O2 is involved in sorghum defense against aphids." Brazilian Journal of Botany 42, no. 2 (May 9, 2019): 271–81. http://dx.doi.org/10.1007/s40415-019-00525-2.

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Blanc, Catherine, Fania Coluccia, Floriane L’Haridon, Martha Torres, Marlene Ortiz-Berrocal, Elia Stahl, Philippe Reymond, et al. "The Cuticle Mutant eca2 Modifies Plant Defense Responses to Biotrophic and Necrotrophic Pathogens and Herbivory Insects." Molecular Plant-Microbe Interactions® 31, no. 3 (March 2018): 344–55. http://dx.doi.org/10.1094/mpmi-07-17-0181-r.

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We isolated previously several Arabidopsis thaliana mutants with constitutive expression of the early microbe-associated molecular pattern–induced gene ATL2, named eca (expresión constitutiva de ATL2). Here, we further explored the interaction of eca mutants with pest and pathogens. Of all eca mutants, eca2 was more resistant to a fungal pathogen (Botrytis cinerea) and a bacterial pathogen (Pseudomonas syringae) as well as to a generalist herbivorous insect (Spodoptera littoralis). Permeability of the cuticle is increased in eca2; chemical characterization shows that eca2 has a significant reduction of both cuticular wax and cutin. Additionally, we determined that eca2 did not display a similar compensatory transcriptional response, compared with a previously characterized cuticular mutant, and that resistance to B. cinerea is mediated by the priming of the early and late induced defense responses, including salicylic acid– and jasmonic acid–induced genes. These results suggest that ECA2-dependent responses are involved in the nonhost defense mechanism against biotrophic and necrotrophic pathogens and against a generalist insect by modulation and priming of innate immunity and late defense responses. Making eca2 an interesting model to characterize the molecular basis for plant defenses against different biotic interactions and to study the initial events that take place in the cuticle surface of the aerial organs.

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Schrumpf, Jasmijn A., Dennis K. Ninaber, Anne M. van der Does, and Pieter S. Hiemstra. "TGF-β1 Impairs Vitamin D-Induced and Constitutive Airway Epithelial Host Defense Mechanisms." Journal of Innate Immunity 12, no. 1 (April 10, 2019): 74–89. http://dx.doi.org/10.1159/000497415.

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Airway epithelium is an important site for local vitamin D (VD) metabolism; this can be negatively affected by inflammatory mediators. VD is an important regulator of respiratory host defense, for example, by increasing the expression of hCAP18/LL-37. TGF-β1 is increased in chronic obstructive pulmonary disease (COPD), and known to decrease the expression of constitutive host defense mediators such as secretory leukocyte protease inhibitor (SLPI) and polymeric immunoglobulin receptor (pIgR). VD has been shown to affect TGF-β1-signaling by inhibiting TGF-β1-induced epithelial-to-mesenchymal transition. However, interactions between VD and TGF-β1, relevant for the understanding host defense in COPD, are incompletely understood. Therefore, the aim of the present study was to investigate the combined effects of VD and TGF-β1 on airway epithelial cell host defense mechanisms. Exposure to TGF-β1 reduced both baseline and VD-induced expression of hCAP18/LL-37, partly by increasing the expression of the VD-degrading enzyme CYP24A1. TGF-β1 alone decreased the number of secretory club and goblet cells and reduced the expression of constitutive host defense mediators SLPI, s/lPLUNC and pIgR, effects that were not modulated by VD. These results suggest that TGF-β1 may decrease the respiratory host defense both directly by reducing the expression of host defense mediators, and indirectly by affecting VD-mediated effects such as expression of hCAP18/LL-37.

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Spiers, James D., Fred T. Davies, Chuanjiu He, Terri W. Starman, Scott A. Finlayson, Scott A. Senseman, and Kevin M. Heinz. "Fertilization Affects Constitutive and Wound-Induced Chemical Defenses in Gerbera jamesonii." Journal of Environmental Horticulture 29, no. 4 (December 1, 2011): 180–84. http://dx.doi.org/10.24266/0738-2898-29.4.180.

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Abstract The total phenolic content and jasmonic acid (JA) content of foliage from gerbera (Gerbera jamesonii ‘Festival Salmon’) subjected to low and high fertilization rates were measured to determine effects of fertilization on phytochemicals implicated in defense of insect pests. Gerbera seedlings were fertilized with low (only supplied with initial fertilizer charge present in professional growing media) or high (200 mg·liter−1 N; recommended rate) fertilization rates. Since JA is induced in response to wounding, treatments consisted of ± mechanical wounding with a hemostat to one physiologically mature leaf and the subsequent harvest of that leaf at specified time intervals (0, 0.5, 1, 3, and 10 h) for JA quantification. Total phenolic content was measured in mature and newly formed leaves. Plants receiving low fertility had reduced aboveground dry mass, were deficient in nitrogen and phosphorous, and had approximately a 9-fold higher concentration of total phenolics in mature leaf tissue compared to high fertility plants. Newly formed leaves had greater concentrations of phenolics than mature leaves in low fertility plants. In response to wounding, JA accumulation was more rapid and higher concentrations of JA were sustained longer in low fertility plants than in high fertility plants. These results show that altering fertilization does affect phytochemicals implicated in defense against insect pests, and these chemical defenses are increased in the foliage of low fertility gerberas.

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Zhang, Peng‐Jun, Chan Zhao, Zi‐Hong Ye, and Xiao‐Ping Yu. "Trade‐off between defense priming by herbivore‐induced plant volatiles and constitutive defense in tomato." Pest Management Science 76, no. 5 (January 8, 2020): 1893–901. http://dx.doi.org/10.1002/ps.5720.

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Westra, Edze R., Stineke van Houte, Sam Oyesiku-Blakemore, Ben Makin, Jenny M. Broniewski, Alex Best, Joseph Bondy-Denomy, Alan Davidson, Mike Boots, and Angus Buckling. "Parasite Exposure Drives Selective Evolution of Constitutive versus Inducible Defense." Current Biology 25, no. 8 (April 2015): 1043–49. http://dx.doi.org/10.1016/j.cub.2015.01.065.

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Preisser, Evan L., Sarah E. Gibson, Lynn S. Adler, and Edwin E. Lewis. "Underground herbivory and the costs of constitutive defense in tobacco." Acta Oecologica 31, no. 2 (March 2007): 210–15. http://dx.doi.org/10.1016/j.actao.2006.09.004.

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Sullivan, T. J., T. L. Bultman, J. Rodstrom, J. Vandop, J. Librizzi, C. Graham, A. Sielaff, and L. Fernandez. "Inducible defense provided by Neotyphodium to Lolium arundinacea and lolium pratense: an ecological and molecular approach." NZGA: Research and Practice Series 13 (January 1, 2007): 147–49. http://dx.doi.org/10.33584/rps.13.2006.3106.

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Plants have evolved a range of responses to herbivory ranging from tolerance to both inducible and constitutive chemical defenses. Previous research has shown lolines produced by Neotyphodium coenophialum are inducible by host damage. In this paper, we examined whether this inducibility can also be caused by damage from an invertebrate herbivore and whether this phenomenon also occurs in N. uncinatum. We also investigated whether changes in gene expression for lolC, a gene in the loline biosynthesis pathway, accompanies changes in defense response. For N. coenophialum, both mechanical and herbivore damage had a negative effect on subsequent aphid herbivores. For N. uncinatum, damage did not cause an increase in defense, although there was an increase in endophyte-free hosts. Relative expression of lolC varied significantly over time, and between damage types for N. uncinatum with herbivore damaged plants having a lower relative lolC -1 expression. Keywords: Neotyphodium, gene expression, inducible defense, loline, lolC

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Zangerl, Arthur R., and Claire E. Rutledge. "The Probability of Attack and Patterns of Constitutive and Induced Defense: A Test of Optimal Defense Theory." American Naturalist 147, no. 4 (April 1996): 599–608. http://dx.doi.org/10.1086/285868.

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Cheung, Ming-Yan, Nai-Yan Zeng, Suk-Wah Tong, Wing-Yen Francisca Li, Yan Xue, Kai-Jun Zhao, Chunlian Wang, et al. "Constitutive expression of a rice GTPase-activating protein induces defense responses." New Phytologist 179, no. 2 (July 2008): 530–45. http://dx.doi.org/10.1111/j.1469-8137.2008.02473.x.

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Levashina, E. A. "Constitutive Activation of Toll-Mediated Antifungal Defense in Serpin-Deficient Drosophila." Science 285, no. 5435 (September 17, 1999): 1917–19. http://dx.doi.org/10.1126/science.285.5435.1917.

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He, Ping, Randall F. Warren, Tiehan Zhao, Libo Shan, Lihuang Zhu, Xiaoyan Tang, and Jian-Min Zhou. "Overexpression of Pti5 in Tomato Potentiates Pathogen-Induced Defense Gene Expression and Enhances Disease Resistance to Pseudomonas syringae pv. tomato." Molecular Plant-Microbe Interactions® 14, no. 12 (December 2001): 1453–57. http://dx.doi.org/10.1094/mpmi.2001.14.12.1453.

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The tomato Pti5 gene encodes a pathogen-inducible ethylene response element-binding protein-like transcription factor that interacts with the disease resistance gene product Pto. Overexpression of Pti5 or Pti5-VP16, a translational fusion with a constitutive transcriptional activation domain, in tomato enhanced resistance to Pseudomonas syringae pv. tomato. Constitutive expression of Pti5 or Pti5-VP16 did not affect the basal level of pathogenesis-related gene expression, but it accelerated pathogen-induced expression of GluB and Catalase. The results demonstrate a positive role of Pti5 in defense gene regulation and disease resistance and suggest that a pathogen-activated posttran-scriptional regulatory step is necessary for the pathogen induction of the defense gene expression.

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Chen, Gang, Peter G. L. Klinkhamer, and Rocío Escobar-Bravo. "Constitutive and Inducible Resistance to Thrips Do Not Correlate With Differences in Trichome Density or Enzymatic-Related Defenses in Chrysanthemum." Journal of Chemical Ecology 46, no. 11-12 (October 22, 2020): 1105–16. http://dx.doi.org/10.1007/s10886-020-01222-1.

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AbstractWestern flower thrips (WFT), Frankliniella occidentalis, is a serious insect pest of Chrysanthemum [Chrysanthemum × morifolium Ramat. (Asteraceae)]. Here we have investigated whether genotypic variation in constitutive and inducible resistance to WFT correlates with phenotypic differences in leaf trichome density and the activity of the defense-related enzyme polyphenol oxidase (PPO) in chrysanthemum. Non-glandular and glandular leaf trichome densities significantly varied among ninety-five chrysanthemum cultivars. Additional analyses in a subset of these cultivars, differing in leaf trichome density, revealed significant variation in PPO activities and resistance to WFT as well. Constitutive levels of trichome densities and PPO activity, however, did not correlate with chrysanthemum resistance to WFT. Further tests showed that exogenous application of the phytohormone jasmonic acid (JA) increased non-glandular trichome densities, PPO activity and chrysanthemum resistance to WFT, and that these effects were cultivar dependent. In addition, no tradeoff between constitutive and inducible resistance to WFT was observed. JA-mediated induction of WFT resistance, however, did not correlate with changes in leaf trichome densities nor PPO activity levels. Taken together, our results suggest that chrysanthemum can display both high levels of constitutive and inducible resistance to WFT, and that leaf trichome density and PPO activity may not play a relevant role in chrysanthemum defenses against WFT.

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McMahan, Jeff. "War as Self-Defense." Ethics & International Affairs 18, no. 1 (March 2004): 75–80. http://dx.doi.org/10.1111/j.1747-7093.2004.tb00453.x.

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First imagine a case in which a person uses violence in self-defense; then imagine a case in which two people engage in self-defense against a threat they jointly face. Continue to imagine further cases in which increasing numbers of people act with increasing coordination to defend both themselves and each other against a common threat, or a range of threats they face together. What you are imagining is a spectrum of cases that begins with acts of individual self-defense and, as the threats become more complex and extensive, the threatened individuals more numerous, and their defensive action more integrated, eventually reaches cases involving a scale of violence that is constitutive of war. But if war, at least in some instances, lies on a continuum with individual self- and other-defense, and if acts of individual self- and other-defense can sometimes be morally justified, then war can in principle be morally justified as well. It follows that the only coherent forms of pacifism are those that reject the permissibility of individual self- or other-defense—for example, those based on an absolute prohibition of violence or killing.

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Christopher, Kenneth, Thomas F. Mueller, Rachel DeFina, Yurong Liang, Jianhua Zhang, Robert Gentleman, and David L. Perkins. "The graft response to transplantation: a gene expression profile analysis." Physiological Genomics 15, no. 1 (September 29, 2003): 52–64. http://dx.doi.org/10.1152/physiolgenomics.00139.2002.

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Little is known regarding the graft response to transplantation injury. This study investigates the posttransplantation response of genes that are constitutively expressed in the heart. Constitutive heart and lymph node tissue-restricted gene expression was first analyzed with DNA microarrays. To demonstrate changes following transplantation in genes constitutively expressed in the heart, we performed vascularized murine heart transplants in allogeneic (BALB/c to B6), syngeneic (B6 to B6), and alymphoid (BALB/c-RAG2−/− to B6-RAG1−/−) experimental groups. Temporal induction of genes posttransplant relative to constitutive expression was evaluated with DNA microarrays. Dendrograms and self-organizing maps were generated to determine the dissimilarity between the experimental groups and to identify subsets of differentially expressed genes within the groups, respectively. Expression patterns of selected genes were confirmed by real-time PCR. Biological processes were assigned to genes induced posttransplant using the AnnBuilder package via the Gene Ontology Database. Post-transplant, a shift was noted in genes classified as defense, communication, and metabolism. Our results identify novel components of the graft response to transplantation injury and rejection.

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Azmi, Nur Sabrina Ahmad, Suthitar Singkaravanit-Ogawa, Kyoko Ikeda, Saeko Kitakura, Yoshihiro Inoue, Yoshihiro Narusaka, Ken Shirasu, Masanori Kaido, Kazuyuki Mise, and Yoshitaka Takano. "Inappropriate Expression of an NLP Effector in Colletotrichum orbiculare Impairs Infection on Cucurbitaceae Cultivars via Plant Recognition of the C-Terminal Region." Molecular Plant-Microbe Interactions® 31, no. 1 (January 2018): 101–11. http://dx.doi.org/10.1094/mpmi-04-17-0085-fi.

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The hemibiotrophic pathogen Colletotrichum orbiculare preferentially expresses a necrosis and ethylene-inducing peptide 1 (Nep1)-like protein named NLP1 during the switch to necrotrophy. Here, we report that the constitutive expression of NLP1 in C. orbiculare blocks pathogen infection in multiple Cucurbitaceae cultivars via their enhanced defense responses. NLP1 has a cytotoxic activity that induces cell death in Nicotiana benthamiana. However, C. orbiculare transgenic lines constitutively expressing a mutant NLP1 lacking the cytotoxic activity still failed to infect cucumber, indicating no clear relationship between cytotoxic activity and the NLP1-dependent enhanced defense. NLP1 also possesses the microbe-associated molecular pattern (MAMP) sequence called nlp24, recognized by Arabidopsis thaliana at its central region, similar to NLPs of other pathogens. Surprisingly, inappropriate expression of a mutant NLP1 lacking the MAMP signature is also effective for blocking pathogen infection, uncoupling the infection block from the corresponding MAMP. Notably, the deletion analyses of NLP1 suggested that the C-terminal region of NLP1 is critical to enhance defense in cucumber. The expression of mCherry fused with the C-terminal 32 amino acids of NLP1 was enough to trigger the defense of cucurbits, revealing that the C-terminal region of the NLP1 protein is recognized by cucurbits and, then, terminates C. orbiculare infection.

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Li, Yongqing, Shuhua Yang, Huijun Yang, and Jian Hua. "The TIR-NB-LRR Gene SNC1 Is Regulated at the Transcript Level by Multiple Factors." Molecular Plant-Microbe Interactions® 20, no. 11 (November 2007): 1449–56. http://dx.doi.org/10.1094/mpmi-20-11-1449.

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SNC1 (suppressor of NPR1, constitutive 1) is a haplotype-specific Toll and interleukin-1 receptor-like nucleotide-binding site leucine-rich repeat type of resistance (R)-like gene possibly mediating race-specific disease resistance. Inactivation of its negative regulator BON1 (BONZAI1)/CPN1 and BAP1 genes or upregulation of its expression epigenetically lead to constitutive defense responses and dwarf phenotype. Here, we report an autoactivation of SNC1 by introducing it into Arabidopsis as a transgene. The SNC1 genomic fragment confers a dwarf phenotype induced by defense response upregulation associated with a higher SNC1 transcript level. Analysis of the β-glucuronidase reporter gene under the control of the SNC1 promoter suggests three modes of regulation on the SNC1 transcript level: a repression by the chromosomal structure, a feedback amplification from SNC1 on its promoter sequences, and a repression by BON1. These regulations appear to be independent of each other. The regulation of SNC1 possibly exemplifies a universally complex control of R genes to ensure a repression of R activation under nonstress conditions and a robust activation of defense responses once the R gene is induced.

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Wittstock, Ute, and Jonathan Gershenzon. "Constitutive plant toxins and their role in defense against herbivores and pathogens." Current Opinion in Plant Biology 5, no. 4 (August 2002): 300–307. http://dx.doi.org/10.1016/s1369-5266(02)00264-9.

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Liu, Mu, Xiaoyun Pan, Zhijie Zhang, Mark van Kleunen, and Bo Li. "Testing the shifting defense hypothesis for constitutive and induced resistance and tolerance." Journal of Pest Science 93, no. 1 (September 16, 2019): 355–64. http://dx.doi.org/10.1007/s10340-019-01162-0.

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Moreira, Xoaquín, Rafael Zas, and Luis Sampedro. "Differential Allocation of Constitutive and Induced Chemical Defenses in Pine Tree Juveniles: A Test of the Optimal Defense Theory." PLoS ONE 7, no. 3 (March 28, 2012): e34006. http://dx.doi.org/10.1371/journal.pone.0034006.

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Zandt, Peter A. Van. "PLANT DEFENSE, GROWTH, AND HABITAT: A COMPARATIVE ASSESSMENT OF CONSTITUTIVE AND INDUCED RESISTANCE." Ecology 88, no. 8 (August 2007): 1984–93. http://dx.doi.org/10.1890/06-1329.1.

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Mathews, Clayton E., and Edward H. Leiter. "Constitutive differences in antioxidant defense status distinguish alloxan-resistant and alloxan-susceptible mice." Free Radical Biology and Medicine 27, no. 3-4 (August 1999): 449–55. http://dx.doi.org/10.1016/s0891-5849(99)00084-2.

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Azuma, Yasutaka, Kiyoshi Ohura, Pao-Li Wang, and Mitsuko Shinohara. "Endomorphins delay constitutive apoptosis and alter the innate host defense functions of neutrophils." Immunology Letters 81, no. 1 (April 2002): 31–40. http://dx.doi.org/10.1016/s0165-2478(01)00335-2.

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Crawford, Dana R., Paul A. Amstad, Debra D. Yin Foo, and Peter A. Cerutti. "Constitutive and phorbol-myristate-acetate regulated antioxidant defense of mouse epidermal JB6 cells." Molecular Carcinogenesis 2, no. 3 (1989): 136–43. http://dx.doi.org/10.1002/mc.2940020306.

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Yamada, Taisho, Hiromasa Horimoto, Takeshi Kameyama, Sumio Hayakawa, Hiroaki Yamato, Masayoshi Dazai, Ayato Takada, et al. "Constitutive aryl hydrocarbon receptor signaling constrains type I interferon–mediated antiviral innate defense." Nature Immunology 17, no. 6 (April 18, 2016): 687–94. http://dx.doi.org/10.1038/ni.3422.

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Hecht, Gail. "Innate mechanisms of epithelial host defense: spotlight on intestine." American Journal of Physiology-Cell Physiology 277, no. 3 (September 1, 1999): C351—C358. http://dx.doi.org/10.1152/ajpcell.1999.277.3.c351.

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The single layer of epithelial cells lining the intestinal tract is charged with a most difficult task: protecting the underlying biological compartments from both the normal commensal flora that reside within the intestinal lumen as well as the uninvited pathogens. To such an end, the intestinal epithelial cells are equipped with a panoply of defense mechanisms, both constitutive and inducible. This review focuses only on those defense mechanisms that are initiated and executed by the intestinal epithelial cell. Fitting these strict criteria are three major categories of epithelial host defense: enhanced salt and water secretion, expression of antimicrobial proteins and peptides, and production of intestinal mucins. Each of these areas is discussed in this review.

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Junell, Anna, Hanna Uvell, Monica M. Davis, Esther Edlundh-Rose, Åsa Antonsson, Leslie Pick, and Ylva Engström. "The POU Transcription Factor Drifter/Ventral veinless Regulates Expression of Drosophila Immune Defense Genes." Molecular and Cellular Biology 30, no. 14 (May 10, 2010): 3672–84. http://dx.doi.org/10.1128/mcb.00223-10.

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ABSTRACT Innate immunity operates as a first line of defense in multicellular organisms against infections caused by different classes of microorganisms. Antimicrobial peptides (AMPs) are synthesized constitutively in barrier epithelia to protect against microbial attack and are also upregulated in response to infection. Here, we implicate Drifter/Ventral veinless (Dfr/Vvl), a class III POU domain transcription factor, in tissue-specific regulation of the innate immune defense of Drosophila. We show that Dfr/Vvl is highly expressed in a range of immunocompetent tissues, including the male ejaculatory duct, where its presence overlaps with and drives the expression of cecropin, a potent broad-spectrum AMP. Dfr/Vvl overexpression activates transcription of several AMP genes in uninfected flies in a Toll pathway- and Imd pathway-independent manner. Dfr/Vvl activates a CecA1 reporter gene both in vitro and in vivo by binding to an upstream enhancer specific for the male ejaculatory duct. Further, Dfr/Vvl and the homeodomain protein Caudal (Cad) activate transcription synergistically via this enhancer. We propose that the POU protein Dfr/Vvl acts together with other regulators in a combinatorial manner to control constitutive AMP gene expression in a gene-, tissue-, and sex-specific manner, thus promoting a first-line defense against infection in tissues that are readily exposed to pathogens.

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Zhang, Zhongqin, Chika Tateda, Shang-Chuan Jiang, Jay Shrestha, Joanna Jelenska, DeQuantarius J. Speed, and Jean T. Greenberg. "A Suite of Receptor-Like Kinases and a Putative Mechano-Sensitive Channel Are Involved in Autoimmunity and Plasma Membrane–Based Defenses in Arabidopsis." Molecular Plant-Microbe Interactions® 30, no. 2 (February 2017): 150–60. http://dx.doi.org/10.1094/mpmi-09-16-0184-r.

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In plants, cell surface pattern recognition receptors (PRRs) provide a first line of defense against pathogens. Although each PRR recognizes a specific ligand, they share common signaling outputs, such as callose and other cell wall–based defenses. Several PRRs are also important for callose induction in response to the defense signal salicylic acid (SA). The extent to which common components are needed for PRR signaling outputs is not known. The gain-of-function Arabidopsis mutant of ACCELERATED CELL DEATH6 (ACD6) acd6-1 shows constitutive callose production that partially depends on PRRs. ACD6-1 (and ACD6) forms complexes with the PRR FLAGELLIN SENSING2, and ACD6 is needed for responses to several PRR ligands. Thus, ACD6-1 could serve as a probe to identify additional proteins important for PRR-mediated signaling. Candidate signaling proteins (CSPs), identified in our proteomic screen after immunoprecipitation of hemagglutinin (HA)-tagged ACD6-1, include several subfamilies of receptor-like kinase (RLK) proteins and a MECHANO-SENSITIVE CHANNEL OF SMALL CONDUCTANCE-LIKE 4 (MSL4). In acd6-1, CSPs contribute to autoimmunity. In wild type, CSPs are needed for defense against bacteria and callose responses to two or more microbial-derived patterns and an SA agonist. CSPs may function to either i) promote the assembly of signaling complexes, ii) regulate the output of known PRRs, or both.

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Luna-Martínez, Mariela, Norma Martínez-Gallardo, Kena Casarrubias-Castillo, Simona M. Monti, Mariangela Coppola, Rosa Rao, and John P. Délano-Frier. "Development and Yield Traits Indicate That the Constitutive Wound Response Phenotype of Prosystemin Overexpressing Tomato Plants Entails No Fitness Penalty." Agronomy 11, no. 6 (June 3, 2021): 1148. http://dx.doi.org/10.3390/agronomy11061148.

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Systemin is a peptide hormone that regulates the wound response in tomato plants. Consequently, the overexpression of its prosystemin (ProSys) precursor protein leads to a resource-demanding constitutive activation of tomato’s wound-response. According to the growth vs. defense resource allocation premise, ProSys overexpression should negatively affect the physiological fitness of tomato plants. The present study was performed to explore why the opposite effect was steadily observed, instead. It was based on the premise that a better understanding of this unexpected outcome could help establish improved wound and related defense responses without negatively affecting crop productivity. To this effect, an experimental strategy was deployed to measure various physiological, biochemical and molecular parameters associated with either development, productivity, defense or in combination in untransformed (WT) and ProSys overexpressing (ProSys-OE) tomato plants. Thus, the chlorophyll fluorescence data obtained from plants grown under greenhouse experiments indicated that photosynthetic performance was not affected in ProSys-OE plants which also grew 7–14% taller than WT plants. Moreover, they showed accelerated flowering and yielded fruits of increased size (7–16% taller and wider) and weight (16–58% heavier), with modified fruit quality in terms of firmness (28% higher), titratable acidity (27–32% higher) and chemical composition. These findings suggest two complementary possibilities: (i) systemin is able to modulate both the wound response and plant development through the activation of jasmonic acid biosynthesis and signaling, and (ii) ProSys, an intrinsically disordered protein, acts as a signaling hub to regulate development and defense programs. These results shed light on the understanding of this plant regulatory mechanism and further suggest that systemin/ProSys-based regulation is central to control the defense-development balance in tomato. This knowledge could eventually lead to improved and more environmentally sound agricultural production practices.

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Vergne, E., T. Dugé de Bernonville, F. Dupuis, S. Sourice, R. Cournol, P. Berthelot, M. A. Barny, M. N. Brisset, and E. Chevreau. "Membrane-Targeted HrpNEa Can Modulate Apple Defense Gene Expression." Molecular Plant-Microbe Interactions® 27, no. 2 (February 2014): 125–35. http://dx.doi.org/10.1094/mpmi-10-13-0305-r.

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Fire blight caused by Erwinia amylovora is the major bacterial disease of tribe Maleae, including apple. Among the proteins secreted by this bacterium, HrpNEa, also called harpin, is known to induce hypersensitive response in nonhost plants and to form amyloid oligomers leading to pore opening in the plasma membrane and alteration of membrane homeostasis. To better understand the physiological effects of HrpNEa in the host plant, we produced transgenic apple plants expressing HrpNEa with or without a secretion signal peptide (SP). HrpNEa expressed with a SP was found to be associated within the membrane fraction, in accordance with amyloidogenic properties and the presence of transmembrane domains revealed by in silico analysis. Expression analysis of 28 apple defense-related genes revealed gene modulations in the transgenic line expressing membrane-targeted HrpNEa. While apple transgenic trees displaying a high constitutive expression level of SP-HrpNEa showed a slight reduction of infection frequency after E. amylovora inoculation, there was no decrease in the disease severity. Thus HrpNEa seems to act as an elicitor of host defenses, when localized in the host membrane.

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Firoved, Aaron M., Simon R. Wood, Wojciech Ornatowski, Vojo Deretic, and Graham S. Timmins. "Microarray Analysis and Functional Characterization of the Nitrosative Stress Response in Nonmucoid and Mucoid Pseudomonas aeruginosa." Journal of Bacteriology 186, no. 12 (June 15, 2004): 4046–50. http://dx.doi.org/10.1128/jb.186.12.4046-4050.2004.

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ABSTRACT The type strain of Pseudomonas aeruginosa, PAO1, showed great upregulation of many nitrosative defense genes upon treatment with S-nitrosoglutathione, while the mucoid strain PAO578II showed no further upregulation above its constitutive upregulation of nor and fhp. NO· consumption however, showed that both strains mount functional, protein synthesis-dependent NO·-consumptive responses.

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Jurkowski, Grace I., Roger K. Smith, I.-ching Yu, Jong Hyun Ham, Shashi B. Sharma, Daniel F. Klessig, Kevin A. Fengler, and Andrew F. Bent. "Arabidopsis DND2, a Second Cyclic Nucleotide-Gated Ion Channel Gene for Which Mutation Causes the “Defense, No Death” Phenotype." Molecular Plant-Microbe Interactions® 17, no. 5 (May 2004): 511–20. http://dx.doi.org/10.1094/mpmi.2004.17.5.511.

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A previous mutant screen identified Arabidopsis dnd1 and dnd2 “defense, no death” mutants, which exhibit loss of hypersensitive response (HR) cell death without loss of gene-for-gene resistance. The dnd1 phenotype is caused by mutation of the gene encoding cyclic nucleotide-gated (CNG) ion channel AtCNGC2. This study characterizes dnd2 plants. Even in the presence of high titers of Pseudomonas syringae expressing avrRpt2, most leaf mesophyll cells in the dnd2 mutant exhibited no HR. These plants retained strong RPS2-, RPM1-, or RPS4-mediated restriction of P. syringae pathogen growth. Mutant dnd2 plants also exhibited enhanced broad-spectrum resistance against virulent P. syringae and constitutively elevated levels of salicylic acid, and pathogenesis-related (PR) gene expression. Unlike the wild type, dnd2 plants responding to virulent and avirulent P. syringae exhibited elevated expression of both salicylatedependent PR-1 and jasmonate and ethylene—dependent PDF1.2. Introduction of nahG+ (salicylate hydroxylase) into the dnd2 background, which removes salicylic acid and causes other defense alterations, eliminated constitutive disease resistance and PR gene expression but only weakly impacted the HR¯ phenotype. Map-based cloning revealed that dnd2 phenotypes are caused by mutation of a second CNG ion channel gene, AtCNGC4. Hence, loss of either of two functionally nonredundant CNG ion channels can cause dnd phenotypes. The dnd mutants provide a unique genetic background for dissection of defense signaling.

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Gallego-Giraldo, Lina, Yusuke Jikumaru, Yuji Kamiya, Yuhong Tang, and Richard A. Dixon. "Selective lignin downregulation leads to constitutive defense response expression in alfalfa (Medicago sativa L.)." New Phytologist 190, no. 3 (January 20, 2011): 627–39. http://dx.doi.org/10.1111/j.1469-8137.2010.03621.x.

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Pfundt, R., F. van Ruissen, I. M. van Vlijmen-Willems, H. A. Alkemade, P. L. Zeeuwen, P. H. Jap, H. Dijkman, et al. "Constitutive and inducible expression of SKALP/elafin provides anti-elastase defense in human epithelia." Journal of Clinical Investigation 98, no. 6 (September 15, 1996): 1389–99. http://dx.doi.org/10.1172/jci118926.

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WELCHMAN, JENNIFER. "Aesthetics of Nature, Constitutive Goods, and Environmental Conservation: A Defense of Moderate Formalist Aesthetics." Journal of Aesthetics and Art Criticism 76, no. 4 (September 2018): 419–28. http://dx.doi.org/10.1111/jaac.12599.

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Body, Mélanie J. A., Matthew S. Zinkgraf, Thomas G. Whitham, Chung-Ho Lin, Ryan A. Richardson, Heidi M. Appel, and Jack C. Schultz. "Heritable Phytohormone Profiles of Poplar Genotypes Vary in Resistance to a Galling Aphid." Molecular Plant-Microbe Interactions® 32, no. 6 (June 2019): 654–72. http://dx.doi.org/10.1094/mpmi-11-18-0301-r.

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Insect galls are highly specialized structures arising from atypical development of plant tissue induced by insects. Galls provide the insect enhanced nutrition and protection against natural enemies and environmental stresses. Galls are essentially plant organs formed by an intimate biochemical interaction between the gall-inducing insect and its host plant. Because galls are plant organs, their development is likely to be governed by phytohormones involved in normal organogenesis. We characterized concentrations of both growth and defensive phytohormones in ungalled control leaves and galls induced by the aphid Pemphigus betae on narrowleaf cottonwood Populus angustifolia that differ genotypically in resistance to this insect. We found that susceptible trees differed from resistant trees in constitutive concentrations of both growth and defense phytohormones. Susceptible trees were characterized by significantly higher constitutive cytokinin concentrations in leaves, significantly greater ability of aphids to elicit cytokinin increases, and significantly lower constitutive defense phytohormone concentrations than observed in resistant trees. Phytohormone concentrations in both constitutive and induced responses in galled leaves exhibited high broad-sense heritability that, respectively, ranged from 0.39 to 0.93 and from 0.28 to 0.66, suggesting that selection can act upon these traits and that they might vary across the landscape. Increased cytokinin concentrations may facilitate forming strong photosynthate sinks in the galls, a requirement for galling insect success. By characterizing for the first time the changes in 15 phytohormones belonging to five different classes, this study offers a better overview of the signaling alteration occurring in galls that has likely been important for their ecology and evolution. [Formula: see text] Copyright © 2019 The Author(s). This is an open-access article distributed under the CC BY-NC-ND 4.0 International license .

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Zhang, Yuelin, and Xin Li. "A Putative Nucleoporin 96 Is Required for Both Basal Defense and Constitutive Resistance Responses Mediated by suppressor of npr1-1,constitutive 1." Plant Cell 17, no. 4 (March 16, 2005): 1306–16. http://dx.doi.org/10.1105/tpc.104.029926.

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DUVALL, RAYMOND, and JONATHAN HAVERCROFT. "Taking sovereignty out of this world: space weapons and empire of the future." Review of International Studies 34, no. 4 (October 2008): 755–75. http://dx.doi.org/10.1017/s0260210508008267.

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Programs to deploy weapons in orbital space have important implications for international relations. In this paper, we analyze the constitutive logic of three modes of space weaponization currently being pursued by the United States – space-based missile defense, space control, and force application from orbital space. We show that these technologies of killing, when bundled together, constitute a new form of centralized sovereign power in a context of de-territorialized sovereignty. This is a new type of international political society, which we call empire of the future, distinct from and more ominous than the de-centralized form of Empire theorized by Hardt and Negri and the modern expression of classical hegemony now widely debated in discussions of putative American empire.

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Journal articles on the topic 'Constitutive defense'

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