Characterization of the complex locus of bean encoding polygalacturonase-inhibiting proteins reveals subfunctionalization for defense against fungi and insects.

Polygalacturonase-inhibiting proteins (PGIPs) are extracellular plant inhibitors of fungal endopolygalacturonases (PGs) that belong to the superfamily of Leu-rich repeat proteins. We have characterized the full complement of pgip genes in the bean (Phaseolus vulgaris) genotype BAT93. This comprises four clustered members that span a 50-kb region and, based on their similarity, form two pairs (Pvpgip1/Pvpgip2 and Pvpgip3/Pvpgip4). Characterization of the encoded products revealed both partial redundancy and subfunctionalization against fungal-derived PGs. Notably, the pair PvPGIP3/PvPGIP4 also inhibited PGs of two mirid bugs (Lygus rugulipennis and Adelphocoris lineolatus). Characterization of Pvpgip genes of Pinto bean showed variations limited to single synonymous substitutions or small deletions. A three-amino acid deletion encompassing a residue previously identified as crucial for recognition of PG of Fusarium moniliforme was responsible for the inability of BAT93 PvPGIP2 to inhibit this enzyme. Consistent with the large variations observed in the promoter sequences, reverse transcription-PCR expression analysis revealed that the different family members differentially respond to elicitors, wounding, and salicylic acid. We conclude that both biochemical and regulatory redundancy and subfunctionalization of pgip genes are important for the adaptation of plants to pathogenic fungi and phytophagous insects.

Selected wheat seed defense proteins exhibit competitive binding to model microbial lipid interfaces

Puroindolines (Pins) and purothionins (Pths) are basic, amphiphilic, cysteine-rich wheat proteins that play a role in plant defense against microbial pathogens. We have examined the co-adsorption and sequential addition of Pins (Pin-a, Pin-b and a mutant form of Pin-b with Trp-44 to Arg-44 substitution) and β-purothionin (β-Pth) model anionic lipid layers, using a combination of surface pressure measurements, external reflection FTIR spectroscopy and neutron reflectometry. Results highlighted differences in the protein binding mechanisms, and in the competitive binding and penetration of lipid layers between respective Pins and β-Pth. Pin-a formed a blanket-like layer of protein below the lipid surface that resulted in the reduction or inhibition of β-Pth penetration of the lipid layer. Wild-type Pin-b participated in co-operative binding with β-Pth, whereas the mutant Pin-b did not bind to the lipid layer in the presence of β-Pth. The results provide further insight into the role of hydrophobic and cationic amino acid residues in antimicrobial activity.

Location and characteristics of the reconnection X line deduced from low-altitude satellite and ground-based observations: 2. Defense Meteorological Satellite Program and European Incoherent Scatter data

We present an analysis of a cusp ion step, observed by the Defense Meteorological Satellite Program (DMSP) F10 spacecraft, between two poleward moving events of enhanced ionospheric electron temperature, observed by the European Incoherent Scatter (EISCAT) radar. From the ions detected by the satellite, the variation of the reconnection rate is computed for assumed distances along the open-closed field line separatrix from the satellite to the X line, do. Comparison with the onset times of the associated ionospheric events allows this distance to be estimated, but with an uncertainty due to the determination of the low-energy cutoff of the ion velocity distribution function, ƒ(ν). Nevertheless, the reconnection site is shown to be on the dayside magnetopause, consistent with the reconnection model of the cusp during southward interplanetary magnetic field (IMF). Analysis of the time series of distribution function at constant energies, ƒ(ts), shows that the best estimate of the distance do is 14.5±2 RE. This is consistent with various magnetopause observations of the signatures of reconnection for southward IMF. The ion precipitation is used to reconstruct the field-parallel part of the Cowley D ion distribution function injected into the open low-latitude boundary layer in the vicinity of the X line. From this reconstruction, the field-aligned component of the magnetosheath flow is found to be only −55±65 km s−1 near the X line, which means either that the reconnection X line is near the stagnation region at the nose of the magnetosphere, or that it is closely aligned with the magnetosheath flow streamline which is orthogonal to the magnetosheath field, or both. In addition, the sheath Alfvén speed at the X line is found to be 220±45 km s−1, and the speed with which newly opened field lines are ejected from the X line is 165±30 km s−1. We show that the inferred magnetic field, plasma density, and temperature of the sheath near the X line are consistent with a near-subsolar reconnection site and confirm that the magnetosheath field makes a large angle (>58°) with the X line.

The Article 51 reporting requirement for self-defense actions

This article examines one legal criterion for the exercise of the right of self-defense that has been significantly overlooked by commentators: the so-called “reporting requirement.” Article 51 of the United Nations (UN) Charter provides, inter alia, that “[m]easures taken by members in the exercise of this right of self-defense shall be immediately reported to the Security Council.” Although the requirement to report all self-defense actions to the Council is clearly set out in Article 51, the Charter offers no further guidance with regard to this obligation. Reference to the practice of states since the UN’s inception in 1945 is therefore essential to understanding the scope and nature of the reporting requirement. As such, this article is underpinned by an extensive original dataset of reporting practice covering the period from January 1, 1998 to December 31, 2013. We know from Article 51 that states “shall” report, but do they, and—if so—in what manner? What are the various implications of reporting, of failing to report, and of the way in which states report? How are reports used, and by whom? Most importantly, this article questions the ultimate value of states reporting their self-defense actions to the Security Council in modern interstate relations.

Resource defense polygyny shifts to female defense polygyny over the course of the reproductive season of a Neotropical harvestman

Although studies classify the polygynous mating system of a given species into female defense polygyny (FDP) or resource defense polygyny (RDP), the boundary between these two categories is often slight. Males of some species may even shift between these two types of polygyny in response to temporal variation in social and environmental conditions. Here, we examine the mating system of the Neotropical harvestman Acutisoma proximum and, in order to assess if mate acquisition in males corresponds to FDP or RDP, we tested four contrasting predictions derived from the mating system theory. At the beginning of the reproductive season, males fight with other males for the possession of territories on the vegetation where females will later oviposit, as expected in RDP. Females present a marked preference for specific host plant species, and males establish their territories in areas where these host plants are specially abundant, which is also expected in RDP. Later in the reproductive season, males reduce their patrolling activity and focus on defending individual females that are ovipositing inside their territories, as what occurs in FDP. This is the first described case of an arachnid that exhibits a shift in mating system over the reproductive season, revealing that we should be cautious when defining the mating system of a species based on few observations concentrated in a brief period.

CztR, a LysR-Type Transcriptional Regulator Involved in Zinc Homeostasis and Oxidative Stress Defense in Caulobacter crescentus

Caulobacter crescentus is a free-living alphaproteobacterium that has 11 predicted LysR-type transcriptional regulators (LTTRs). Previously, a C. crescentus mutant strain with a mini-Tn5lacZ transposon inserted into a gene encoding an LTTR was isolated; this mutant was sensitive to cadmium. In this work, a mutant strain with a deletion was obtained, and the role of this LTTR (called CztR here) was evaluated. The transcriptional start site of this gene was determined by primer extension analysis, and its promoter was cloned in front of a lacZ reporter gene. beta-Galactosidase activity assays, performed with the wild-type and mutant strains, indicated that this gene is 2-fold induced when cells enter stationary phase and that it is negatively autoregulated. Moreover, this regulator is essential for the expression of the divergent cztA gene at stationary phase, in minimal medium, and in response to zinc depletion. This gene encodes a hypothetical protein containing 10 predicted transmembrane segments, and its expression pattern suggests that it encodes a putative zinc transporter. The cztR strain was also shown to be sensitive to superoxide (generated by paraquat) and to hydrogen peroxide but not to tert-butyl hydroperoxide. The expression of katG and ahpC, but not that of the superoxide dismutase genes, was increased in the cztR mutant. A model is proposed to explain how CztR binding to the divergent regulatory regions could activate cztA expression and repress its own transcription.

Fur controls iron homeostasis and oxidative stress defense in the oligotrophic alpha-proteobacterium Caulobacter crescentus

In most bacteria, the ferric uptake regulator (Fur) is a global regulator that controls iron homeostasis and other cellular processes, such as oxidative stress defense. In this work, we apply a combination of bioinformatics, in vitro and in vivo assays to identify the Caulobacter crescentus Fur regulon. A C. crescentus fur deletion mutant showed a slow growth phenotype, and was hypersensitive to H(2)O(2) and organic peroxide. Using a position weight matrix approach, several predicted Fur-binding sites were detected in the genome of C. crescentus, located in regulatory regions of genes not only involved in iron uptake and usage but also in other functions. Selected Fur-binding sites were validated using electrophoretic mobility shift assay and DNAse I footprinting analysis. Gene expression assays revealed that genes involved in iron uptake were repressed by iron-Fur and induced under conditions of iron limitation, whereas genes encoding iron-using proteins were activated by Fur under conditions of iron sufficiency. Furthermore, several genes that are regulated via small RNAs in other bacteria were found to be directly regulated by Fur in C. crescentus. In conclusion, Fur functions as an activator and as a repressor, integrating iron metabolism and oxidative stress response in C. crescentus.

Stimulation of Acidic Reduction of Nitrite to Nitric Oxide by Soybean Phenolics: Possible Relevance to Gastrointestinal Host Defense

This study aimed to evaluate the potential of soybean-promoted acidic nitrite reduction and to correlate this activity with the content of phenolics and with the bactericidal activity against Escherichia coli O157:H7. Extracts of embrionary axes and cotyledons enriched in phenolics increased (center dot)NO formation at acidic pH at values that were 7.1 and 4.5 times higher, respectively, when compared to the reduction of the nonenriched extracts. Among the various phenolics accumulated in the soybean extracts, five stimulated nitrite reduction in the following decreasing order of potency: epicatechin gallate, chlorogenic acid, caffeic acid, galic acid and p-coumaric acid. Extracts of embrionary axes presented higher contents of epicatechin gallate and caffeic acid, compared to that of cotyledons, indicating a positive correlation between activity of the extracts and content of phenolics with regard to nitrite reducing activity. Soybean extracts enriched in phenolics interacted synergistically with acidified nitrite to prevent E. coli O157:H7 growth. The results suggest that soybean phenolics may interfere with the metabolism of (center dot)NO in an acidic environment by accelerating the reduction of nitrite, with a potential antimicrobial effect in the stomach.

Anton Nyström's Defense of Homosexuality

In 1919 Anton Nyström became the first person in Sweden to publish a comprehensive defense of homosexuality. He believed that its classification as a mental illness was erroneous and that Sweden's law against homosexual sex was both irrational and cruel. Nyström was a physician whose work in the medical area dealt primarily with dermatology, psychiatry and human sexuality; however he was also a prolific historian, who took a staunchly anti-Christian view in his analysis of how Christianity affected European culture, especially in the area of sexual morality. In fact, much of Nyström's medical texts dealing with human sexuality consisted of anti-Christian cultural and historical commentary. The object of this "C-uppsats" is to analyze Nyström's pamphlet, Om Homosexualitet och Hermafroditi: Belysning af Missförstådda Existenser and illustrate how its defensive structure was consistent with the pattern used by the author in his other books and articles on human sexuality. Specifically, that irrational and neurotic Christian beliefs caused both mental and physical suffering and were the source of deleterious forms of morality. Additionally, this paper will also show that the solution Nyström had for the problem of negative and erroneous attitudes towards homosexuality was to replace the sodomitic view of homosexuality with one based upon a more rational and naturalistic belief system, the basis of which could be found in the pre-Christian cultures of Europe, most especially in Greece. This new conception was to be constructed primarily out of historical example and cultural analyses. For Nyström, history writing was used both as a weapon to fight the source of negative attitudes towards homosexuality, as well as a tool that could be used to build a positive cultural model which would be beneficial for homosexuals.

A Psychoanalytical Reading of Emily Brontë's Wuthering Heights : An Analysis of the Defense Mechanisms of Some Characters

This essay presents a portrayal of Heathcliff, Catherine and Isabella from a psychoanalytical perspective with regard to four defense mechanisms; namely, repression, denial, sublimation and projection in order to see how these defense mechanisms have affected the characters’ decisions and behaviour, and led them to their destinations in life. It will include three major sections: repression in characters, denial in characters, and sublimation and projection in characters. These terms will be more clearly defined and explained in the subsequent sections.

The development of a Defense System against Coxsackievirus B5 Infection in Suckling Mice

There are many viruses that are able to infect the alimentary tract of man. Little is known, however, about the mechanism of infection itself or the pathophysiology of the gut during infection. 'The research reported here is concerned with the differences in susceptibility among suckling mice of various ages inoculated by the intraperitoneal and intragastric routes. Since the normal mode of entry of many viruses to the gut is via the oral route, Coxsackievirus B5, a human enterovirus which does attack this way, was utilized. It is a non-tumor producing RNA virus that has been shown to act similarly in the mouse and human. The virus was pooled in HeLa cell cultures and titered by a plaquing assay in the same cell cultures. CD-l mice, 10, 14, 18, and 22 days old , were infected either orally or intraperitoneally with 5.0 x 10^10 (10 day old animals) and 1.0 x10^9 plaque forming units per animal. Dissections were done at 1 and 3 days post infection with samples of the blood, heart, liver, and gut being taken from each animal. Each sample was titered individually and the data presented as an average of six samples. As a result of previous work, it is known that the gut of a newborn mouse isn't able to decrease the concentration of the infecting dose and therefore provides no defense against an enteric infection with Coxsackievirus B5. In contrat, mature mice are able to reduce the amount of viral dissemination across the gut as well as inhibit replication after absorption has occurred. The results of this study indicate that there is a double barrier system developing in suckling mice that is involved with and directly related to the gastrointestinal tract The first part of this defense is the inhibition of penetration of virus across the gut when the primary site of' infection is the intestinal mucosa. This mechanism develops sometime around 20 to 22 days after birth. At about 16-18 days of age, suckling mice that were challenged intragastrically are able to stop active replication and initiate clearance of virus from the systemic circulation. There are many factors that might contribute to the marked decrease in susceptibility with age of suckling mice. Some of these or possibly a combination of these factors might explain the defense mechanisms described above, but to date, the chemistry or mechanical functioning of the gastrointestinal barrier to enteric viral infection is unknown.

Antioxidant defense in rat brain regions after developmental lead exposure

Oxidative stress is considered a possible molecular mechanism involved in Pb neurotoxicity. Considering the vulnerability of the developing brain to Pb neurotoxicity, this study was carried out to investigate the effects of low-level developmental Pb exposure on brain regions antioxidant enzymes activities. Wister dams were exposed to 500 ppm of Pb, as Pb acetate, or to 660 ppm Na acetate in the drinking water during pregnancy and lactation. The activities of superoxide dismutase (SOD), glutathione peroxidase and glutathione reductase were determined in the hypothalamus, hippocampus and striatum of male pups at 23 (weaned) or 70 days (adult) of age. In the Pb-exposed 23-day-old pups, the activity of SOD was decreased in the hypothalamus. Regarding adults, there was no significant treatment effect in any of the enzymes and regions evaluated. Based on the present results, it seems that oxidative stress due to decreased antioxidant function may occur in weaned rats but it is suggested that this should not be the main mechanism involved in the neurotoxicity of low-level Pb exposure. (C) 2001 Elsevier B.V. Ireland Ltd. All rights reserved.

14-3-3: Defense and regulatory proteins coding by Eucalyptus genome

The data mining of Eucalyptus ESTs genome finds four clusters (EGCEST2257E11.g, EGBGRT3213F11.g, and EGCCFB1223H11.g) from highly conservative 14-3-3 protein family which modulates a wide variety of cellular processes. Multiple alignments were built from twenty four sequences of 14-3-3 proteins searched into the GenBank databases and into the four pools of Eucalyptus genome programs. The alignment has shown two regions highly conservative on the sequences corresponding to the motifs of protein phosphorylation and nine highly conservative regions on the sequence corresponding to the linkage regions of alpha helices structure based on three dimensional of dimer functional structure. The differences of amino acid into the structural and functional domains of 14-3-3 plant protein were identified and can explain the functional diversity of different isoforms. The phylogenic protein trees were built by the maximum parsimony and neighborjoining procedures of Clustal X alignments and PAUP software for phylogenic analysis.

Defense reactions of Dermatobia hominis (Diptera : Cuterebridae) larval hemocytes

The defense reactions against biological (Histoplasma capsulatum and Escherichia coli) and non-biological materials (China ink and nylon thread) were tested in vivo in third instar larvae of Dermatobia hominis. The cellular defense performed by larval hemocytes was observed under electron microscopy. China ink particles were phagocytosed by granular cells 5 h after injection. E. coli cells were internalized by granular cells as early as 5 min after injection and totally cleared 180 min post-injection, when many hemocytes appeared disintegrated and others in process of recovering. H. capsulatum yeasts provoked, 24 h after being injected, the beginning of nodule formation. Nylon thread was encapsulated 24 h after the introduction into the hemocoel. Our results suggest that granular cells were the phagocytic cells and also the responsible for the triggering of nodule and capsule formation. In the presence of yeasts cells and nylon thread, they released their granules that chemotactically attracted the plasmatocytes that on their turn, flattened to surround and isolate the foreign material.