Defense Categories Research Articles

Characterization of gene expression associated with drought avoidance and tolerance traits in a perennial grass species.

To understand molecular mechanisms of perennial grass adaptation to drought stress, genes associated with drought avoidance or tolerance traits were identified and their expression patterns were characterized in C4 hybrid bermudagrass [Cynodon dactylon (L.) Pers.×C. transvaalensis Burtt Davy, cv. Tifway] and common bermudagrass (C. dactylon, cv. C299). Plants of drought-tolerant ‘Tifway’ and drought-sensitive ‘C299’ were exposed to drought for 5 d (mild stress) and 10 d (severe stress) by withholding irrigation in a growth chamber. ‘Tifway’ maintained significantly lower electrolyte leakage and higher relative water content than ‘C299’ at both 5 and 10 d of drought stress. Four cDNA libraries via suppression subtractive hybridization analysis were constructed and identified 277 drought-responsive genes in the two genotypes at 5 and 10 d of drought stress, which were mainly classified into the functional categories of stress defense, metabolism, osmoregulation, membrane system, signal and regulator, structural protein, protein synthesis and degradation, and energy metabolism. Quantitative-PCR analysis confirmed the expression of 36 drought up-regulated genes that were more highly expressed in drought-tolerant ‘Tifway’ than drought-sensitive ‘C299’, including those for drought avoidance traits, such as cuticle wax formation (CER1 and sterol desaturase), for drought tolerance traits, such as dehydration-protective proteins (dehydrins, HVA-22-like protein) and oxidative stress defense (superoxide dismutase, dehydroascorbate reductase, 2-Cys peroxiredoxins), and for stress signaling (EREBP-4 like protein and WRKY transcription factor). The results suggest that the expression of genes for stress signaling, cuticle wax accumulation, antioxidant defense, and dehydration-protective protein accumulation could be critically important for warm-season perennial grass adaptation to long-term drought stress.

Proteomic analysis of the Actinidia deliciosa leaf apoplast during biotrophic colonization by Pseudomonas syringae pv. actinidiae

For plant pathogenic bacteria, adaptation to the apoplast is considered as key in the establishment of the parasitic lifestyle. Pseudomonas syringae pv. actinidiae (Psa), the causal agent of the bacterial canker of kiwifruit, uses leaves as the entry site to colonize plants. Through a combined approach based on 2-DE, nanoLC-ESI-LIT-MS/MS and quantitative PCR, we investigated Psa colonization of the Actinidia deliciosa "Hayward" leaf apoplast during the bacterial biotrophic phase. A total of 58 differentially represented protein species were identified in artificially inoculated leaves. Although the pathogen increased its population density during the initial period of apoplast colonization, plant defense mechanisms were able to impede further disease development. We identified a concerted action of different proteins mainly belonging to the plant defense and metabolism category, which intervened at different times and participated in reducing the pathogen population. On the other hand, bacterial BamA was highly represented during the first week of leaf apoplast colonization, whereas OmpA and Cpn60 were induced later. In addition to presenting further proteomic information on the molecular factors actively participating in this pathosystem, our data characterize the early events of host colonization and will promote the eventual development of novel bioassays for pathogen detection in kiwiplants. This original study evaluates on a proteomic perspective the interaction occurring into the leaf apoplast between Actinidia deliciosa and its specific pathogen Pseudomonas syringae pv. actinidiae. Despite the initial bacterial multiplication, a concerted action of the plant defense mechanisms blocked the infection during 21days of apoplast colonization, as revealed by the number of differentially-represented proteins identified in artificially-inoculated and control leaves. Three bacterial proteins were also recognized among the over-represented molecules in infected plants. This study may contribute to improve breeding programs aimed at selecting resistant/tolerant kiwifruit cultivars toward P. syringae pv. actinidiae, which present a high representation of the plant proteins here shown to be involved in resistance mechanisms. In addition to present additional information on the molecular players actively participating in this pathosystem, our data will also facilitate the technological development of future bioassays for the detection of this pathogen in kiwiplants.

Protection of human rights and freedoms in the information sphere

The base categories of defence of information rights are examined in the article. On the basis of analysis of current domestic legislation conclusions are drawn in relation to the types of human and citizens’ information rights. The methods of defence of information rights are explored, recommendations of their application are given.

Mycorrhiza-induced resistance against the root–knot nematode Meloidogyne incognita involves priming of defense gene responses in tomato

Arbuscular mycorrhizal fungi (AMF) have great potential as biocontrol organisms against the root–knot nematode Meloidogyne incognita which causes severe gall formation in plants, but knowledge about the underlying molecular mechanisms involved in the biocontrol of nematodes is scarce. In the present study, suppression subtractive hybridization (SSH) was used to investigate plant genes that are specifically up-regulated in tomato roots (Solanum lycopersicum cv. Marmande) pre-colonized by the AMF Glomus mosseae (BEG 12) and 12 days after soil inoculation with M. incognita juveniles. Nematode infection was significantly lower in the mycorrhizal roots as compared to the non-mycorrhizal roots, and identified genes were classified mainly in the categories of defense, signal transduction and protein synthesis and modification. The higher expression of a selection of defense-related plant genes specifically in the biocontrol interaction compared to in plants that were only mycorrhizal or only nematode-infected was confirmed, which pleads for the existence of mycorrhiza-induced priming of plant defense responses. In conclusion, by focusing on up-regulated gene expression in the biocontrol interaction between mycorrhizal tomato and M. incognita, new insights were found into the molecular mechanisms underlying the mycorrhiza-induced resistance against root–knot nematodes. In particular, the involvement of the phenylpropanoid pathway and reactive oxygen species (ROS) metabolism could explain the reduced root–knot nematode infection in mycorrhizal tomato roots, processes that have also been reported to play a pivotal role in plant resistance to nematodes.

Proteomic analysis indicates massive changes in metabolism prior to the inhibition of growth and photosynthesis of grapevine (Vitis vinifera L.) in response to water deficit

BackgroundCabernet Sauvignon grapevines were exposed to a progressive, increasing water defict over 16 days. Shoot elongation and photosynthesis were measured for physiological responses to water deficit. The effect of water deficit over time on the abundance of individual proteins in growing shoot tips (including four immature leaves) was analyzed using nanoflow liquid chromatography - tandem mass spectrometry (nanoLC-MS/MS).ResultsWater deficit progressively decreased shoot elongation, stomatal conductance and photosynthesis after Day 4; 2277 proteins were identified by shotgun proteomics with an average CV of 9% for the protein abundance of all proteins. There were 472 out of 942 (50%) proteins found in all samples that were significantly affected by water deficit. The 472 proteins were clustered into four groups: increased and decreased abundance of early- and late-responding protein profiles. Vines sensed the water deficit early, appearing to acclimate to stress, because the abundance of many proteins changed before decreases in shoot elongation, stomatal conductance and photosynthesis. Predominant functional categories of the early-responding proteins included photosynthesis, glycolysis, translation, antioxidant defense and growth-related categories (steroid metabolism and water transport), whereas additional proteins for late-responding proteins were largely involved with transport, photorespiration, antioxidants, amino acid and carbohydrate metabolism.ConclusionsProteomic responses to water deficit were dynamic with early, significant changes in abundance of proteins involved in translation, energy, antioxidant defense and steroid metabolism. The abundance of these proteins changed prior to any detectable decreases in shoot elongation, stomatal conductance or photosynthesis. Many of these early-responding proteins are known to be regulated by post-transcriptional modifications such as phosphorylation. The proteomics analysis indicates massive and substantial changes in plant metabolism that appear to funnel carbon and energy into antioxidant defenses in the very early stages of plant response to water deficit before any significant injury.

Transcriptional profiling in Saccharomyces cerevisiae relevant for predicting alachlor mechanisms of toxicity

Alachlor has been a commonly applied herbicide and is a substance of ecotoxicological concern. The present study aims to identify molecular biomarkers in the eukaryotic model Saccharomyces cerevisiae that can be used to predict potential cytotoxic effects of alachlor, while providing new mechanistic clues with possible relevance for experimentally less accessible eukaryotes. It focuses on genome-wide expression profiling in a yeast population in response to two exposure scenarios exerting effects from slight to moderate magnitude at phenotypic level. In particular, 100 and 264 genes, respectively, were found as differentially expressed on a 2-h exposure of yeast cells to the lowest observed effect concentration (110 mg/L) and the 20% inhibitory concentration (200 mg/L) of alachlor, in comparison with cells not exposed to the herbicide. The datasets of alachlor-responsive genes showed functional enrichment in diverse metabolic, transmembrane transport, cell defense, and detoxification categories. In general, the modifications in transcript levels of selected candidate biomarkers, assessed by quantitative reverse transcriptase polymerase chain reaction, confirmed the microarray data and varied consistently with the growth inhibitory effects of alachlor. Approximately 16% of the proteins encoded by alachlor-differentially expressed genes were found to share significant homology with proteins from ecologically relevant eukaryotic species. The biological relevance of these results is discussed in relation to new insights into the potential adverse effects of alachlor in health of organisms from ecosystems, particularly in worst-case situations such as accidental spills or careless storage, usage, and disposal.

Arbuscular mycorrhizal fungi modulate the leaf transcriptome of a Populus alba L. clone grown on a zinc and copper-contaminated soil

Significant improvement of growth associated with increased, rather than decreased, uptake of Cu and Zn has been observed in poplar plants inoculated with Glomus spp. as compared with non-mycorrhizal plants. The beneficial effect exerted by these arbuscular mycorrhizal fungi (AMF) is likely to be controlled by specific gene expression patterns in the plant. Until now, however, very little is known about the transcriptional changes which occur in response to heavy metals (HMs) in mycorrhizal vs. non-mycorrhizal poplar plants. In order to identify such HM- and/or AMF-induced changes in leaves of white poplar ( Populus alba L.) plants grown, in the greenhouse, on Cu- and Zn-polluted soil, the cDNA-Amplified Fragment Length Polymorphism (AFLP) approach was adopted, resulting in the identification of a number of new differentially regulated genes. Transcript derived fragments (TDFs) mostly belonged to stress-related functional categories of defence and secondary metabolism. Genes belonging to different functional categories, plus other genes known to be related to HM stress (metallothioneins, phytochelatin synthase, glutathione synthase, arginine decarboxylase), were analysed by quantitative (q)RT-PCR. Transcript levels were generally down-regulated, or unaffected, in polluted soil compared with controls, the main exceptions being phytochelatin synthase and clathrin, and strongly up-regulated in the presence of AMF, especially Glomus mosseae.

Expression of defense-related genes in response to mechanical wounding and Phytophthora parasitica infection in Poncirus trifoliata and Citrus sunki

Phytophthora parasitica have caused severe damage in Citrus nurseries and orchards worldwide. The purpose of these experiments was to determine how plant defense pathways are induced by P. parasitica and if induction differs in susceptible (Citrus sunki) and resistant (Poncirus trifoliata) interactions. Furthermore, to test the effect of simple wounding on the induction of defense-related genes, plants were mechanically wounded and were monitored over the period. We monitored three categories of defense-related genes by reverse transcription real-time quantitative PCR (RT-qPCR), at 24, 48, 96, and 168 h after inoculation. The genes included pathogenesis-related, PR1 (function unknown), PR2 (β1-3 endoglucanase), PR3 (chitinase class I) and PR5 (Thaumatin-like protein); phenylpropanoid pathway such as CHS (chalcone synthase) and PAL (phenylalanine ammonia-lyase) that are involved in phytoalexin biosynthesis; and genes involved in defense and stress related categories, such as LOX (lipoxygenases) and POX (peroxidase). In accordance with the results of transcriptome changes during pathogen attack, we can suggest that all of genes are involved with resistance of the P. trifoliata to P parasitica, since the expression of these genes were significantly higher in the resistant than in susceptible genotype. Some genes were uniquely induced by pathogen (PR2, PAL and POX); or induced by the overlap involved in the response to pathogen attack and wound (PR1, PR3, PR5 and LOX); and the CHS gene was uniquely induced by wounding. This results will greatly contribute to improvement of plant resistance by genetic breeding and genetic manipulation. These genes serve as good candidates for functional studies.

Chromatin Dynamics of Gene Activation and Repression in Response to Interferon α (IFNα) Reveal New Roles for Phosphorylated and Unphosphorylated Forms of the Transcription Factor STAT2

Signal transducer and activator of transcription 2 (STAT2), the critical component of type I interferons signaling, is a prototype latent cytoplasmic signal-dependent transcription factor. Activated tyrosine-phosphorylated STAT2 associates with STAT1 and IRF9 to bind the ISRE elements in the promoters of a subset of IFN-inducible genes (ISGs). In addition to activate hundreds of ISGs, IFNα also represses numerous target genes but the mechanistic basis for this dual effect and transcriptional repression is largely unknown. We investigated by ChIP-chip the binding dynamics of STAT2 and "active" phospho(P)-STAT2 on 113 putative IFNα direct target promoters before and after IFNα induction in Huh7 cells and primary human hepatocytes (PHH). STAT2 is already bound to 62% of our target promoters, including most "classical" ISGs, before IFNα treatment. 31% of STAT2 basally bound promoters also show P-STAT2 positivity. By correlating in vivo promoter occupancy with gene expression and changes in histone methylation marks we found that: 1) STAT2 plays a role in regulating ISGs expression, independently from its phosphorylation; 2) P-STAT2 is involved in ISGs repression; 3) "activated" ISGs are marked by H3K4me1 and H3K4me3 before IFNα; 4) "repressed" genes are marked by H3K27me3 and histone methylation plays a dominant role in driving IFNα-mediated ISGs repression.

Image Repair Strategies, Local News Portrayals and Crisis Stage: A Case Study of Duke University's Lacrosse Team Crisis

The case analysis presented here studies Duke University's strategic use of communication to defend its image during the scandal involving its men's lacrosse team. Benoit's (1995, 1997) image repair theory is used to analyze Duke's strategy in 54 public statements, news releases, and documents. Additionally, 870 local newspaper stories about the Duke case from The News & Observer (n = 443) and The Herald Sun (n = 427) are analyzed by crisis stage. Results show that Duke initially relied most on simple denial and mortification to defend its athletes, and engaged in bolstering, corrective action, separation, and attacking one's accuser to defend the university's reputation. Findings suggest a new defense category: expression of disappointment, which is related to the concept of separation. Use of the strategy of attacking one's accuser was associated with the most positive local news coverage.

Use of PCR-array to profile expressed genes in human keratinocyte hacat cells after exposure to Quantum Dots

Quantum dots (QDs) nanoparticles have potential applications in biomedical research, as imaging and diagnostic agents, because of their fluorescent property. Despite the widespread use of nanoparticles, there are many unknowns in understanding on their nanotoxicities and mechanisms. This study evaluated the effects of Quantum Dots (QDs) on gene expression profiles of human keratinocyte HaCaT cells. Total RNA was prepared from the exposure groups to QDs with diverse physicochemical properties (565-PEG-amine, 565-carboxylic acid, 655-carboxylic acid) in various concentrations, and real-time RT-PCR analysis was performed using human oxidative stress and antioxidant defense array. Our study indicated that antioxidant defense and oxidative stress category, such as nitric oxide synthase 2A (NOS2A), dual specificity phosphatase 1 (DUSP1), dual oxidase (DUOX), 24-dehydrocholesterol reductase (DHCR24), peroxidase in homolog (Drosophila)-like (PXDNL), scavenger receptor class A (SCARA3) and thyroid peroxidase (TPO), were represented by all three QDs exposure groups. Therefore, the up-regulation of these enzymes by QDs could increase the production of reactive oxygen species (ROS). The results of our study showed that QDs contained a potential to produce ROS via metabolic pathways, inducing oxidative stress. The results supported that the mechanism of nanotoxicity could be correlated with active oxygen production, oxidative stress, apoptosis, and antioxidant defense mechanisms.

An orthogonal set of predictors for wins in major league baseball

In quantum mechanics theory the state of a system may be represented by a linear combination of what is known an orthogonal set of wave functions. The word, orthogonal, means that one wave function does not interfere with another in determining the properties of the system; rather, each wave function contributes independently to the properties of the system, each one by an amount a i , where the subscript, i , refers to one of the wave functions in the orthogonal set. Thus, designating a given wave function by ψ , the so called state vector of the system (or simply, “the state of the system”) would be given by S = a 1ψ1 + a 2ψ2 +…+ an ψ n , where n represents the total number of orthogonal wave functions in the set. Further, the sum of the must equal 1, i.e., ; the latter ensures that the sum of each wave function’s contribution to the state of the system adds to a 100% contribution overall. In the work which follows we proceed according to the above model in an attempt to develop seven “orthogonal categories” associated with the game of baseball, viz., singles, doubles, triples, home runs, {walks + hit batsmen}, errors, and ERA, which can be represented by φ i, i = 1, 2, 3, … , 7 , such that S = a 1φ1 + a 2φ2 + … + a 7φ7 with .We then utilize further mathematics borrowed from the same theory of quantum mechanics in order to determine the expectation value of the number of wins, W, associated with any given sample size of future games. Using the statistical record associated with the National League Clubs of 2009, we were successful in predicting the number of wins for a given club to within 8% on average. Of interest is that our findings show that by far the largest contribution to success on the diamond comes fromthe two defense categories, errors and ERA, with an overall theoretical contribution of 71% associated with the two combined.

Quantitative analysis of age specific variation in the abundance of human female parotid salivary proteins.

Human saliva is a protein-rich, easily accessible source of potential local and systemic biomarkers to monitor changes that occur under pathological conditions; however, little is known about the changes in abundance associated with normal aging. In this study, we performed a comprehensive proteomic profiling of pooled saliva collected from the parotid glands of healthy female subjects, divided into two age groups 1 and 2 (20-30 and 55-65 years old, respectively). Hydrophobic charge interaction chromatography was used to separate high- from low-abundance proteins prior to characterization of the parotid saliva using multidimensional protein identification technology (MudPIT). Collectively, 532 proteins were identified in the two age groups. Of these proteins, 266 were identified exclusively in one age group, while 266 proteins were common to both groups. The majority of the proteins identified in the two age groups belonged to the defense and immune response category. Of note, several defense related proteins (e.g., lysozyme, lactoferrin and histatin-1) were significantly more abundant in group 2 as determined by G-test. Selected representative mass spectrometric findings were validated by Western blot analysis. Our study reports the first quantitative analysis of differentially regulated proteins in ductal saliva collected from young and older female subjects. This study supports the use of high-throughput proteomics as a robust discovery tool. Such results provide a foundation for future studies to identify specific salivary proteins which may be linked to age-related diseases specific to women.

Les dérivés conscients des mécanismes de défense au questionnaire de Bond (DSQ 40) : stabilité ou variabilité entre une situation non anxiogène et une situation anxiogène

L’objectif de cette recherche est de tester la stabilité ou la variabilité des dérivés conscients des mécanismes de défense évalués à l’aide du questionnaire de Bond (DSQ 40) dans deux situations différemment anxiogènes afin de les intégrer dans le modèle transactionnel du stress de Lazarus et Folkman. Pour tester l’instabilité intersituationnelle des dérivés conscients des mécanismes de défense, une population de 161 étudiantes a complété le DSQ 40 et le questionnaire d’anxiété-état de Spielberger (STAI-Y), une première fois, en novembre, c’est-à-dire en l’absence d’évaluation de la performance universitaire, puis, une seconde fois, le premier jour de la session d’examen de janvier. Le score d’anxiété-état est significativement plus élevé à la seconde session qu’à la première. La majorité des 20 dérivés conscients des mécanismes de défense sont significativement différents aux deux sessions. L’inconstance intersituationnelle des dérivés conscients des mécanismes de défense observée dans cette recherche semble compatible avec l’hypothèse en faveur de leur variabilité. The aim of this research was to test the stability or variability of conscious by-products of defense mechanisms, evaluated with the Bond Defense Style Questionnaire (DSQ 40) so as to integrate them as transactional variables of stress in the model of Lazarus and Folkman. One hundred and sixty-one college girls (first-year students in a French university) engaged in psychology studies participated in this research. They participated in two collective sessions: a first session took place in November in a non-stressful situation, and a second session during the January examination week. Two questionnaires were used twice in this experiment: (a) the Anxiety State Questionnaire of Spielberger (STAI-Y) which evaluates the anxiety-state and anxiety-traits; (b) the DSQ 40, which estimates 20 conscious by-products of defense mechanisms and distinguishes three factors corresponding to the mature, neurotic and immature styles according to the factorial analyses of Guelfi and al. Two hypotheses were formulated: (a) a first hypothesis postulates that an examination situation increases the State Anxiety score; (b) a second hypothesis postulates a variability of defense mechanisms assessed by Bond's questionnaire (DSQ 40). It verified that the scores of the Bond defensive style questionnaire are significantly different in the two sessions. The mean state-anxiety score is higher in the second session. The great majority of students are described as more anxious during the week of examinations than during the previous month. The first hypothesis is then validated. The situation of evaluation of the university performance appears as a situation more stressful than the courses period. The three defense mechanism factors vary in a significant way from the first to the second session. In the second session the scores in mature and neurotic defense mechanisms increased significantly whereas the average scores in immature defense mechanisms decreased significantly. The majority of the 20 defense mechanisms are not stable between both situations. Indeed, 17 conscious by-products of defense mechanisms differ significantly in both sessions and only three defense mechanisms show a certain stability. Eleven defensive styles (55 %) decreased, six increased (30 %) and three remained stable (15 %). The instability of conscious by-products of defense mechanisms between the two sessions was confirmed by correlations analyses. The results show that the instability between situations is not limited to three categories of defenses (mature, neurotic and immature): 17 out of 20 mean scores in defense styles differed significantly. Conscious by-products of defense mechanisms are, indeed, influenced by situational factors.

Parasite Burden and CD36-Mediated Sequestration Are Determinants of Acute Lung Injury in an Experimental Malaria Model

Although acute lung injury (ALI) is a common complication of severe malaria, little is known about the underlying molecular basis of lung dysfunction. Animal models have provided powerful insights into the pathogenesis of severe malaria syndromes such as cerebral malaria (CM); however, no model of malaria-induced lung injury has been definitively established. This study used bronchoalveolar lavage (BAL), histopathology and gene expression analysis to examine the development of ALI in mice infected with Plasmodium berghei ANKA (PbA). BAL fluid of PbA-infected C57BL/6 mice revealed a significant increase in IgM and total protein prior to the development of CM, indicating disruption of the alveolar–capillary membrane barrier—the physiological hallmark of ALI. In contrast to sepsis-induced ALI, BAL fluid cell counts remained constant with no infiltration of neutrophils. Histopathology showed septal inflammation without cellular transmigration into the alveolar spaces. Microarray analysis of lung tissue from PbA-infected mice identified a significant up-regulation of expressed genes associated with the gene ontology categories of defense and immune response. Severity of malaria-induced ALI varied in a panel of inbred mouse strains, and development of ALI correlated with peripheral parasite burden but not CM susceptibility. Cd36 −/− mice, which have decreased parasite lung sequestration, were relatively protected from ALI. In summary, parasite burden and CD36-mediated sequestration in the lung are primary determinants of ALI in experimental murine malaria. Furthermore, differential susceptibility of mouse strains to malaria-induced ALI and CM suggests that distinct genetic determinants may regulate susceptibility to these two important causes of malaria-associated morbidity and mortality.

Analysis of differentially expressed transcripts of fungal elicitor- and wound-treated wild rice (Oryza grandiglumis)

Suppression subtractive hybridization was used to construct a subtracted library (ogfw) from plants of a wild rice species, Oryza grandiglumis, subjected to a fungal elicitor and physical wounding. To screen the differentially expressed transcripts in the library, we applied a reverse Northern blot analysis to a cDNA microarray containing 1,152 random clones. Based on the average expression ratio, we selected 156 clones showing an elevated expression level. The elevated expression levels and overall expression profiles over time were verified by Northern blot analysis. A comparative functional categorization of the subtracted expressed sequence tags (ESTs) of the ogfw library against ESTs isolated from blast-infected O. sativa showed that the functional categories of cell rescue, defense and virulence, transcription, and cellular transport and transport mechanism of the ogfw library were threefold higher in the former than in the latter. These subtracted ESTs can be presumed to be related to the defense/resistance system and will be used to investigate the defense mechanisms of wild rice and to provide new insights into the genome of wild rice, which in turn will assist molecular breeding strategies of cultivated rice.

Large-Scale Identification of Expressed Sequence Tags Involved in Rice and Rice Blast Fungus Interaction

To better understand the molecular basis of the defense response against the rice blast fungus (Magnaporthe grisea), a large-scale expressed sequence tag (EST) sequencing approach was used to identify genes involved in the early infection stages in rice (Oryza sativa). Six cDNA libraries were constructed using infected leaf tissues harvested from 6 conditions: resistant, partially resistant, and susceptible reactions at both 6 and 24 h after inoculation. Two additional libraries were constructed using uninoculated leaves and leaves from the lesion mimic mutant spl11. A total of 68,920 ESTs were generated from 8 libraries. Clustering and assembly analyses resulted in 13,570 unique sequences from 10,934 contigs and 2,636 singletons. Gene function classification showed that 42% of the ESTs were predicted to have putative gene function. Comparison of the pathogen-challenged libraries with the uninoculated control library revealed an increase in the percentage of genes in the functional categories of defense and signal transduction mechanisms and cell cycle control, cell division, and chromosome partitioning. In addition, hierarchical clustering analysis grouped the eight libraries based on their disease reactions. A total of 7,748 new and unique ESTs were identified from our collection compared with the KOME full-length cDNA collection. Interestingly, we found that rice ESTs are more closely related to sorghum (Sorghum bicolor) ESTs than to barley (Hordeum vulgare), wheat (Triticum aestivum), and maize (Zea mays) ESTs. The large cataloged collection of rice ESTs in this study provides a solid foundation for further characterization of the rice defense response and is a useful public genomic resource for rice functional genomics studies.

P.2.090 Bipolar patients in the Netherlands according to the EMBLEM

L’objectif de cette recherche est de tester la stabilité ou la variabilité des dérivés conscients des mécanismes de défense évalués à l’aide du questionnaire de Bond (DSQ 40) dans deux situations différemment anxiogènes afin de les intégrer dans le modèle transactionnel du stress de Lazarus et Folkman. Pour tester l’instabilité intersituationnelle des dérivés conscients des mécanismes de défense, une population de 161 étudiantes a complété le DSQ 40 et le questionnaire d’anxiété-état de Spielberger (STAI-Y), une première fois, en novembre, c’est-à-dire en l’absence d’évaluation de la performance universitaire, puis, une seconde fois, le premier jour de la session d’examen de janvier. Le score d’anxiété-état est significativement plus élevé à la seconde session qu’à la première. La majorité des 20 dérivés conscients des mécanismes de défense sont significativement différents aux deux sessions. L’inconstance intersituationnelle des dérivés conscients des mécanismes de défense observée dans cette recherche semble compatible avec l’hypothèse en faveur de leur variabilité.The aim of this research was to test the stability or variability of conscious by-products of defense mechanisms, evaluated with the Bond Defense Style Questionnaire (DSQ 40) so as to integrate them as transactional variables of stress in the model of Lazarus and Folkman.One hundred and sixty-one college girls (first-year students in a French university) engaged in psychology studies participated in this research. They participated in two collective sessions: a first session took place in November in a non-stressful situation, and a second session during the January examination week.Two questionnaires were used twice in this experiment: (a) the Anxiety State Questionnaire of Spielberger (STAI-Y) which evaluates the anxiety-state and anxiety-traits; (b) the DSQ 40, which estimates 20 conscious by-products of defense mechanisms and distinguishes three factors corresponding to the mature, neurotic and immature styles according to the factorial analyses of Guelfi and al.Two hypotheses were formulated: (a) a first hypothesis postulates that an examination situation increases the State Anxiety score; (b) a second hypothesis postulates a variability of defense mechanisms assessed by Bond's questionnaire (DSQ 40). It verified that the scores of the Bond defensive style questionnaire are significantly different in the two sessions.The mean state-anxiety score is higher in the second session. The great majority of students are described as more anxious during the week of examinations than during the previous month. The first hypothesis is then validated. The situation of evaluation of the university performance appears as a situation more stressful than the courses period. The three defense mechanism factors vary in a significant way from the first to the second session. In the second session the scores in mature and neurotic defense mechanisms increased significantly whereas the average scores in immature defense mechanisms decreased significantly. The majority of the 20 defense mechanisms are not stable between both situations. Indeed, 17 conscious by-products of defense mechanisms differ significantly in both sessions and only three defense mechanisms show a certain stability. Eleven defensive styles (55 %) decreased, six increased (30 %) and three remained stable (15 %). The instability of conscious by-products of defense mechanisms between the two sessions was confirmed by correlations analyses.The results show that the instability between situations is not limited to three categories of defenses (mature, neurotic and immature): 17 out of 20 mean scores in defense styles differed significantly. Conscious by-products of defense mechanisms are, indeed, influenced by situational factors.

Identification of differentially expressed transcripts from maturing stem of sugarcane by in silico analysis of stem expressed sequence tags and gene expression profiling.

Sugarcane accumulates high concentrations of sucrose in the mature stem and a number of physiological processes on-going in maturing stem tissue both directly and indirectly allow this process. To identify transcripts that are associated with stem maturation, we compared patterns of gene expression in maturing and immature stem tissue by expression profiling and bioinformatic analysis of sets of stem ESTs. This study complements a previous study of gene expression associated directly with sugar metabolism in sugarcane. A survey of sequences derived from stem tissue identified an abundance of several classes of sequence that are associated with fibre biosynthesis in the maturing stem. A combination of EST analyses and microarray hybridization revealed that genes encoding homologues of the dirigent protein, a protein that assists in the stereospecificity of lignin assembly, were the most abundant and most strongly differentially expressed transcripts in maturing stem tissue. There was also evidence of coordinated expression of other categories of fibre biosynthesis and putative defence- and stress-related transcripts in the maturing stem. This study has demonstrated the utility of genomic approaches using large-scale EST acquisition and microarray hybridization techniques to highlight the very significant transcriptional investment the maturing stem of sugarcane has placed in fibre biosynthesis and stress tolerance, in addition to its already well-documented role in sugar accumulation.

Transcriptome profiling of a Saccharomyces cerevisiae mutant with a constitutively activated Ras/cAMP pathway.

Often changes in gene expression levels have been considered significant only when above/below some arbitrarily chosen threshold. We investigated the effect of applying a purely statistical approach to microarray analysis and demonstrated that small changes in gene expression have biological significance. Whole genome microarray analysis of a pde2Delta mutant, constructed in the Saccharomyces cerevisiae reference strain FY23, revealed altered expression of approximately 11% of protein encoding genes. The mutant, characterized by constitutive activation of the Ras/cAMP pathway, has increased sensitivity to stress, reduced ability to assimilate nonfermentable carbon sources, and some cell wall integrity defects. Applying the Munich Information Centre for Protein Sequences (MIPS) functional categories revealed increased expression of genes related to ribosome biogenesis and downregulation of genes in the cell rescue, defense, cell death and aging category, suggesting a decreased response to stress conditions. A reduced level of gene expression in the unfolded protein response pathway (UPR) was observed. Cell wall genes whose expression was affected by this mutation were also identified. Several of the cAMP-responsive orphan genes, upon further investigation, revealed cell wall functions; others had previously unidentified phenotypes assigned to them. This investigation provides a statistical global transcriptome analysis of the cellular response to constitutive activation of the Ras/cAMP pathway.