bluuebunny/crossref_metadata_2025_split huggingface dataset:
Allelochemical stress causes inhibition of growth and oxidative damage in Lycopersicon esculentum Mill
Authors: LARA‐NUÑEZ AURORA , ROMERO‐ROMERO TERESA , VENTURA JOSÉ LUIS , BLANCAS VANIA , ANAYA ANA LUISA , CRUZ‐ORTEGA ROCIO 
Published: August 2006

ABSTRACTThe aim of this study was to analyse the effect of allelochemical stress on Lycopersicon esculentum growth. Our results showed that allelochemical stress caused by Sicyos deppei aqueous leachate inhibited root growth but not germination, and produced an imbalance in the oxidative status of cells in both ungerminated seeds and in primary roots. We observed changes in activity of catalase (CAT), ascorbate peroxidase (APX), superoxide dismutase (SOD), glutathione reductase (GR) and the plasma membrane NADPH oxidase, as well as in the levels of H2O2 and O2•− in seeds at 12 and 24 h, and in primary roots at 48 and 72 h of treatment, which could account for the oxidative imbalance. There were changes in levels of expression of the mentioned enzymes, but without a correlation with their respective activities. Higher levels of membrane lipid peroxidation were observed in primary roots at 48 and 72 h of treatment. No effect on the expression of metacaspase and the PR1 was observed as indicators of cell death or induction of plant defence. This paper contributes to the understanding of plant–plant interactions through the phytotoxic allelochemicals released in an aqueous leachate of the weed S. deppei, which cause a negative effect on other plants.
Both abscisic acid (ABA)‐dependent and ABA‐independent pathways govern the induction of NCED3, AAO3 and ABA1 in response to salt stress
Authors: BARRERO JOSÉ MARÍA , RODRÍGUEZ PEDRO L. , QUESADA VÍCTOR , PIQUERAS PEDRO , PONCE MARÍA ROSA , MICOL JOSÉ LUIS 
Published: August 2006

ABSTRACTThe responsiveness of plants to osmotic stress is critically mediated by the increase in abscisic acid (ABA) levels. Osmotic stress induces the biosynthesis of ABA, whose increased levels subsequently exert a positive feedback on its own biosynthetic pathway. As only qualitative or semi‐quantitative analyses were performed to test the inducibility of ABA biosynthetic genes in Arabidopsis thaliana, we used quantitative reverse transcriptase‐polymerase chain reaction to re‐examine the induction of the ABA1, ABA2, ABA3, NCED3 and AAO3 genes by NaCl and ABA. Quantitative gene expression data obtained from wild‐type plants and severely ABA‐deficient mutants support the prevailing notion that the 9‐cis‐epoxycarotenoid cleavage reaction is the key regulatory step in NaCl‐induced ABA biosynthesis. Interestingly, strong induction by NaCl of NCED3 was still observed in severe ABA‐deficient mutants, pointing to an ABA‐independent induction pathway for NCED3 that is NaCl‐dependent. Therefore, in the absence of the ABA‐mediated positive feedback on ABA biosynthesis, the ABA‐independent pathway makes a major contribution to the induction of key ABA biosynthetic genes, such as NCED3, AAO3 and ABA1. In addition, and in contrast to some previous reports, our data do not support the limited ability of ABA to induce NCED3 expression. Under our experimental conditions, the induction of NCED3 by ABA, either in wild‐type plants or ABA‐deficient mutants, was predominant over that of other ABA biosynthetic genes. Natural variability was found in the induction by NaCl and ABA of NCED3 and ABA1 expression in different Arabidopsis accessions, although NCED3 expression was clearly predominant.
Biomass partitioning and leaf N,P – stoichiometry: comparisons between tree and herbaceous current‐year shoots
Authors: NIKLAS KARL J. , COBB EDWARD D. 
Published: August 2006

ABSTRACTWe compare the biomass partitioning patterns and the nitrogen/phosphorus (N,P) stoichiometry of the current‐year shoots of tree and herbaceous species and ask whether they scale in the same ways. Our analyses indicate that few statistically significant differences exist between the shoot biomass partitioning patterns of the two functional species‐groups. In contrast, statistically significant N,P – stoichiometric differences exist between the two functional groups. Across all species, dry leaf mass scales nearly as the square of basal stem diameter and isometrically with respect to dry stem mass. However, total leaf N scales as the 1.37‐power and as the 1.09‐power of total leaf P across herbaceous and tree shoots, respectively. Therefore, tree shoots can be viewed as populations of herbs elevated by their older, woody herbaceous cohorts. However, tree leaf stoichiometry cannot be modelled in terms of herbaceous N,P – leaf stoichiometry.
Impact of the C–N status on the amino acid profile in tobacco source leaves
Authors: FRITZ CHRISTINA , MUELLER CATHRIN , MATT PETRA , FEIL REGINA , STITT MARK 
Published: August 2006

ABSTRACTThis paper investigates the influence of the carbon (C) and nitrogen (N) status on the amino acid profile in tobacco source leaves. Treatments used included growing plants at different light intensities, using an antisense RBCS (small subunit of ribulose‐1,5‐bisphosphate carboxylase/oxygenase) construct to inhibit Rubisco activity, growing plants on 12 or 0.5 mM nitrate, comparing wild‐types with genotypes that have small and large decreases in nitrate reductase (NIA) activity, and sampling plants at different times during the diurnal cycle. This combination of experiments provides information on how amino acid levels respond to several inputs including the C and N status, nitrate, excess light and light–dark transitions. The data set was analysed using principal component analysis, regression analysis and by normalizing the level of each individual amino acid on the total amino acid pool. Most amino acids show a downward trend when the C or the N status is decreased, and rise during day and fall at night during the diurnal cycle. However, individual amino acids often showed deviating responses. Furthermore, no evidence was found for feedback inhibition of minor amino acid synthesis, either within or between pathways, when 18 individual amino acids were supplied to detached leaves. Results indicate that regulation of amino acid metabolism, for example by the C and N status, leads to qualitatively similar responses of many amino acids, but homeostatic mechanisms involving feedback inhibition within or between individual amino acid biosynthesis pathways are not stringent. All of the above inputs affect the level of phenylalanine, an amino acid that is also the substrate for an important sector of secondary metabolism. The levels of glutamate were remarkably constant, indicating that unknown mechanisms stabilize the concentration of this key central amino acid. Analyses of metabolite levels and feeding experiments indicated that 2‐oxoglutarate plays an important role in regulating glutamate levels. Glutamate was the most effective inhibitor of NIA activity when 18 individual amino acids were supplied to detached leaves. Feeding glutamate, and other downstream amino acids, led to an increase of glutamine, indicating glutamate exerts feedback regulation on ammonium metabolism.
Hourly and seasonal variation in photosynthesis and stomatal conductance of soybean grown at future CO2 and ozone concentrations for 3 years under fully open‐air field conditions
Authors: BERNACCHI CARL J. , LEAKEY ANDREW D. B. , HEADY LINDSEY E. , MORGAN PATRICK B. , DOHLEMAN FRANK G. , MCGRATH JUSTIN M. , GILLESPIE KELLY M. , WITTIG VICTORIA E. , ROGERS ALISTAIR , LONG STEPHEN P. , ORT DONALD R. 
Published: August 2006

ABSTRACTIt is anticipated that enrichment of the atmosphere with CO2 will increase photosynthetic carbon assimilation in C3 plants. Analysis of controlled environment studies conducted to date indicates that plant growth at concentrations of carbon dioxide ([CO2]) anticipated for 2050 (∼ 550 µmol mol−1) will stimulate leaf photosynthetic carbon assimilation (A) by 20 to 40%. Simultaneously, concentrations of tropospheric ozone ([O3]) are expected to increase by 2050, and growth in controlled environments at elevated [O3] significantly reduces A. However, the simultaneous effects of both increases on a major crop under open‐air conditions have never been tested. Over three consecutive growing seasons > 4700 individual measurements of A, photosynthetic electron transport (JPSII) and stomatal conductance (gs) were measured on Glycine max (L.) Merr. (soybean). Experimental treatments used free‐air gas concentration enrichment (FACE) technology in a fully replicated, factorial complete block design. The mean A in the control plots was 14.5 µmol m−2 s−1. At elevated [CO2], mean A was 24% higher and the treatment effect was statistically significant on 80% of days. There was a strong positive correlation between daytime maximum temperatures and mean daily integrated A at elevated [CO2], which accounted for much of the variation in CO2 effect among days. The effect of elevated [CO2] on photosynthesis also tended to be greater under water stress conditions. The elevated [O3] treatment had no statistically significant effect on mean A, gs or JPSII on newly expanded leaves. Combined elevation of [CO2] and [O3] resulted in a slightly smaller increase in average A than when [CO2] alone was elevated, and was significantly greater than the control on 67% of days. Thus, the change in atmospheric composition predicted for the middle of this century will, based on the results of a 3 year open‐air field experiment, have smaller effects on photosynthesis, gs and whole chain electron transport through photosystem II than predicted by the substantial literature on relevant controlled environment studies on soybean and likely most other C3 plants.
Comparision of two‐flow cytometry methods for basophil degranulation in patients sensitized to grass pollen
Authors: Michova A. , Abugalia M. , Ivanova Ts. , Nikolov G. , Taskov H. , Petrunov B. 
Published: August 2006

Background:  Two‐flow cytometry methods for quantification of degranulated basophil after allergen‐specific activation were discussed. The methods are discerned by used membrane receptors – FcɛRI or IL‐3Rα Our goal was to evaluate the diagnostic potential of the methods and to correlate them to allergen‐specific IgE detection and skin prick test (SPT).Methods:  Patient's and control's groups were studied with Bulgarian grass pollen allergen B1 simultaneously by flow cytometry kits: Basotest and BD FastImmune test. Allergy diagnosis was based on clinical history and SPT. The determination of specific IgE was performed by ELISA ‐ RIDASCREENR.Results:  There were no significant differences between the patient's results from Basotest and FastImmune (P > 0.05). A significant correlation between values, analyzed by Basotest and by FastImmune was found (r = 0.88). The sensitivity and specificity of the Basotest, FastImmune, specific IgE and SPT were 85%, 72%, 92% and 92% sensitivity and 100%, 92%, 100% and 85% specificity respectively. The efficiency was between 82% and 97%. There were a significant correlation between the specific IgE and flow cytometry tests: tau = 0.92 (Basotest) and tau = 0.71 (FastImmune) and a moderate significant correlation between the SPT and the in vitro tests: tau = 0.26 (Basotest) and tau = 0.31 (FastImmune).Conclusion:  The successful use of the Bulgarian grass pollen allergen B1 and both flow cytometry tests was presented. These methods could be as specific tools for IgE‐mediated diagnosis especially FastImmune in the case of low IgE receptor expression.
Allergic hypersensitivity to the lentil pest Bruchus lentis
Authors: Armentia A. , Lombardero M. , Blanco C. , Fernández S. , Fernández A. , Sánchez‐Monge R 
Published: August 2006

Background:  Lentils are the most common legume involved in allergic reactions in the Mediterranean area and India. Lentil crops could be attacked by a wide range of insect species. Occupational asthma caused by the lentil pest Bruchus lentis has been described in the present study.Objective:  We studied the possibility of immunoglobulin (Ig)E‐mediated hypersensitivity to lentil pests in 16 patients who suffered from allergic symptoms (asthma and anaphylaxis) related to inhalation of lentil particles or ingestion of lentils, in which sensitization to legume proteins was not clear.Methods:  Extracts prepared either from noninfested and infested lentils, and from the lentil parasite B. lentis were used for skin prick testing (SPT), bronchial and oral challenges and in vitro determinations.Results:  Skin prick test were positive to infested lentils and B. lentis in all patients and negative to noninfested lentil extracts. Five asthmatic patients reacted in the bronchial challenge test with Bruchus extract. Oral challenges performed with boiled infested lentils were positive in six of seven patients. Immunoglobulin E immunoblotting with Bruchus and infested lentils extracts revealed protein bands that were reactive to serum IgE from six and four, respectively, out of 16 patients. These patients had no IgE to lentil‐specific proteins as determined by immunoblotting and Len c 1‐specific IgE test.Conclusions:  Lentil pest proteins can be a cause of IgE‐mediated rhinoconjunctivitis and asthma in patients eating or inhaling infested lentil particles.
Association between exposure to farming, allergies and genetic variation in CARD4/NOD1
Authors: Eder W. , Klimecki W. , Yu L. , Von Mutius E. , Riedler J. , Braun‐Fahrländer C. , Nowak D. , Holst O. , Martinez F. D. ,   the ALEX‐Team
Published: August 2006

Background:  Caspase recruitment domain protein (CARD) 4 has been recently identified as an intracellular pattern recognition receptor that interacts with muropeptides found in common Gram‐negative bacteria. We therefore aimed to explore whether the previously observed inverse association between exposure to microbial products and asthma and allergies in childhood is modified by genetic variation in CARD4.Methods:  We genotyped 668 children [mean age 9.3 (SD 1.5) years] enrolled in the cross‐sectional ALEX study for seven haplotype tagging single nucleotide polymorphisms in CARD4. We studied the association of asthma, hay fever and allergen‐specific serum immunoglobulin E with exposure to a farming environment and with levels of endotoxin and muramic acid measured in house dust samples. We tested whether these associations differed between the genotypes of the polymorphisms under study.Results:  A strong protective effect of a farming environment on allergies was only found in children homozygous for the T allele in CARD4/−21596, but not in children carrying the minor allele (C). Among the former, farmers’ children had a significantly lower frequency of sensitization against pollen (5.8%), hay fever (1.7%) and atopic asthma symptoms (1.7%) compared with children not living on a farm (19.4%, 13.0% and 7.6%, P < 0.01, <0.01 and <0.05, respectively). Conversely, no significant difference in prevalence of these phenotypes by farming status was found among children with a C allele in CARD4/−21596 (14.3%, 7.1% and 8.0%vs 16.5%, 9.0% and 5.7%, respectively).Conclusion:  Polymorphisms in CARD4 significantly modify the protective effect of exposure to a farming environment.
The challenge of diagnosing atopic diseases: outcomes in Cuban children depend on definition and methodology
Authors: Wördemann M. , Polman K. , Diaz R. J. , Menocal Heredia L. T. , Madurga A.‐M. C. , Sague K. A. , Gryseels B. , Gorbea M. B. 
Published: August 2006

Background:  Prevalences of childhood asthma and other atopic diseases are increasing worldwide, and so is the number of diagnostic methods and definitions used. We determined the occurrence of atopic diseases in Cuban children with a range of diagnostic approaches commonly used or proposed in epidemiological studies, and compared the different outcome measures.Methods:  A total of 398 Cuban schoolchildren between 5 and 13 years of age were diagnosed by International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire, clinical examination, pre‐ and post‐exercise spirometry, and skin prick testing. All results were considered separately, as well as jointly by using scores and definitions as described in the literature.Results:  Using questionnaire‐based approaches, 21–39% of the children were positive for asthma, 9–19% for atopic dermatitis, and 15–46% for rhinoconjunctivitis. With spirometry, 7% of the children had asthma. Definitions based on a combination of questionnaire and spirometry results yielded asthma rates of 5%. Of all children, 6% wheezed on clinical examination, and only one child showed clinical signs of atopic dermatitis. Eleven percent of the children had a positive skin prick test. In total, 254 children (64%) had an atopic disease as based on the ISAAC questionnaire, and 263 (66%) based on all approaches used.Conclusion:  Diagnostic outcomes on atopic diseases vary considerably depending on definition and methodology. Our results clearly demonstrate the need for consensus on diagnosing asthma and other atopic diseases in epidemiological studies. Based on the most commonly used ISAAC questionnaire, our data suggest prevalences of atopic diseases in Cuban children that rival those found in some other Latin American countries and developed nations with the highest prevalences in the world.
Omalizumab decreased IgE‐release and induced changes in cellular immunity in patients with allergic asthma
Authors: Hanf G. , Brachmann I. , Kleine‐Tebbe J. , Seybold J. , Kunkel G. , Suttorp N. , Noga O. 
Published: August 2006

Background:  Omalizumab, a recombinant monoclonal anti‐immunoglobulin E (IgE) antibody, shows proven efficacy in the treatment of allergic diseases. A little is known about the immunological pathways affected by the decrease of circulating free IgE during omalizumab treatment.Aim of the study:  To investigate the immunological consequence of IgE withdrawal, we studied the influence of omalizumab on stimulated IgE‐release of cultured peripheral blood mononuclear cells (PBMC) and on the relative number of lymphocytes in the peripheral blood (cellular immune status) in patients with allergic asthma.Methods:  Nineteen patients were enrolled and received omalizumab at a dose of at least 0.016 mg/kg/IgE (IU/ml) every 4 weeks. PBMC were isolated from peripheral blood. Cells were cultured and stimulated with IL‐4 (5 ng/ml) and CD40 ligand (1 μg/ml) for 10 days. IgE release was detected in cell culture supernatants by enzyme‐linked immunosorbent assay (ELISA). Cellular immune status was investigated by fluorescence‐activated cell sorting.Results:  Omalizumab treatment induced significant inhibition of stimulated IgE release (median 1.38–0 ng/ml vs. 1.64–2.0 ng/ml in placebo group, P < 0.05). B‐lymphocyte counts were also significantly lower in the omalizumab group compared with placebo after 12 weeks of treatment (median 18.2–15.6% lymphocytes vs 12.7–13.7% lymphocytes after placebo, P < 0.01). There were no significant differences in the other lymphocyte subpopulations between the groups.Conclusions:  These findings provide evidence of immunological influences of omalizumab treatment, leading to a downregulation of IgE secretion and decrease of lymphocyte subpopulations (B‐cells) indicating their anti‐inflammatory potency.
The cost of mating rises nonlinearly with copulation frequency in a laboratory population of Drosophila melanogaster
Authors: Kuijper B. , Stewart A. D. , Rice W. R. 
Published: August 2006

Abstract
Previous studies of Drosophila melanogaster have demonstrated a cost to females from male courtship and mating, but two critically important parameters remain unresolved: (i) the degree to which harm from multiple-mating reduces lifetime fitness and (ii) how harm from mating might change with successive matings (rematings). Here we use ‘laboratory island analysis’ to quantify the costs that females incur with each remating, in the currency of lifetime fitness and under conditions that closely match those to which the flies have adapted for hundreds of generations. We experimentally manipulated the number of female matings by varying the order of daily 2-h exposures of females to either sperm-less males (XO) or intact males (XY). Females that mated more often had substantially reduced lifetime fecundity, and importantly, the fitness cost from remating rapidly accelerated.
Character displacement:in situevolution of novel phenotypes or sorting of pre‐existing variation?
Authors: RICE A. M. , PFENNIG D. W. 
Published: August 2006

AbstractCharacter displacement – the divergence of traits between species in response to competition for resources or mates – has long been viewed as a major cause of adaptive diversification and species coexistence. Yet, we lack answers to basic questions concerning the causes and consequences of character displacement, not the least of which is why some species are more prone than others to undergo character displacement. Here, we address these questions by describing how character displacement can proceed through two nonexclusive routes that differ in the source of phenotypic variation, and, hence, in the ease with which character displacement may unfold. Duringin situevolution of novel phenotypes, new traits that are divergent from a heterospecific competitor are generated and spread in sympatry. During sorting of pre‐existing variation, such traits are initially favoured in allopatry before the two species encounter one another. Later, when they come into contact, character displacement transpires when these pre‐existing divergent phenotypes increase in frequency in sympatry relative to allopatry. Because such sorting of pre‐existing variation should unfold relatively rapidly, we suggest that species that express resource or mating polymorphism prior to interactions with heterospecifics may be more prone to undergo character displacement. We discuss the key differences between these two routes, review possible examples of each, and describe how the distinction between them provides unique insights into the evolutionary consequences of species interactions, the origins of diversity, and the factors that govern species coexistence.
Complementary sex determination in the parasitoid wasp Cotesia vestalis (C. plutellae)
Authors: DE BOER J. G. , ODE P. J. , VET L. E. M. , WHITFIELD J. , HEIMPEL G. E. 
Published: August 2006

AbstractIn the Hymenoptera, single locus complementary sex determination (sl‐CSD) describes a system where males develop either from unfertilized haploid eggs or from fertilized diploid eggs that are homozygous at a single polymorphic sex locus. Diploid males are often inviable or sterile, and are produced more frequently under inbreeding. Within families where sl‐CSD has been demonstrated, we predict that sl‐CSD should be more likely in species with solitary development than in species where siblings develop gregariously (and likely inbreed). We examine this prediction in the parasitoid wasp genus Cotesia, which contains both solitary and gregarious species. Previous studies have shown that sl‐CSD is absent in two gregarious species of Cotesia, but present in one gregarious species. Here, we demonstrate CSD in the solitary Cotesia vestalis, using microsatellite markers. Diploid sons are produced by inbred, but not outbred, females. However, frequencies of diploid males were lower than expected under sl‐CSD, suggesting that CSD in C. vestalis involves more than one locus.