ABSTRACT
In many societies, the majority of adults regularly consume alcohol. However, only a small proportion develops alcohol addiction. Individuals at risk often show a high sensation-seeking/low-anxiety behavioural phenotype. Here we asked which role EF hand domain containing 2 (EFhd2; Swiprosin-1) plays in the control of alcohol addiction-associated behaviours. EFhd2 knockout (KO) mice drink more alcohol than controls and spontaneously escalate their consumption. This coincided with a sensation-seeking and low-anxiety phenotype. A reversal of the behavioural phenotype with ß-carboline, an anxiogenic inverse benzodiazepine receptor agonist, normalized alcohol preference in EFhd2 KO mice, demonstrating an EFhd2-driven relationship between personality traits and alcohol preference. These findings were confirmed in a human sample where we observed a positive association of the EFhd2 single-nucleotide polymorphism rs112146896 with lifetime drinking and a negative association with anxiety in healthy adolescents. The lack of EFhd2 reduced extracellular dopamine levels in the brain, but enhanced responses to alcohol. In confirmation, gene expression analysis revealed reduced tyrosine hydroxylase expression and the regulation of genes involved in cortex development, Eomes and Pax6, in EFhd2 KO cortices. These findings were corroborated in Xenopus tadpoles by EFhd2 knockdown. Magnetic resonance imaging (MRI) in mice showed that a lack of EFhd2 reduces cortical volume in adults. Moreover, human MRI confirmed the negative association between lifetime alcohol drinking and superior frontal gyrus volume. We propose that EFhd2 is a conserved resilience factor against alcohol consumption and its escalation, working through Pax6/Eomes. Reduced EFhd2 function induces high-risk personality traits of sensation-seeking/low anxiety associated with enhanced alcohol consumption, which may be related to cortex function.
Subject(s)
Alcoholism/genetics , Anxiety/genetics , Calcium-Binding Proteins/genetics , Adolescent , Adult , Alcohol Drinking/genetics , Animals , Anxiety Disorders/genetics , Female , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Polymorphism, Single Nucleotide , Risk-Taking , Xenopus laevisABSTRACT
The role of soluble silicon (Si) in alleviating viral plant infections is largely unknown. In order to analyse this gap in knowledge, this study provides insights into the relative gene expression data obtained from 1) control, 2) Cucumber mosaic virus (CMV)-infected and 3) sodium silica-treated, CMV-infected Cucumis sativus line B10 tissue cultures regenerated plants. The absence or presence of CMV was determined through RT-PCR, six days' post-inoculation. qRT-PCR was performed on five selected host genes related to CMV-defence (argonaute protein, WRKY transcription factor) and replication (chaperone, heat shock cognate protein, aquaporin). Relative gene expressions from Si-treated, CMV-infected clones were not significantly different from CMV-infected clones, but they were significantly different from the control plants. The upregulation of the chaperone, and heat shock cognate genes in Si-treated clones, is associated with enhanced virus replication, while the gene expression of the transcription factor increases and is related to defence, in contrast to decreased expression in CMV-infected clones. Aquaporin gene expression was downregulated and the argonaute expression was unaffected in both Si-treated, CMV-infected as well as CMV-infected clones. Since both alleviating and supportive gene shifts are observed in Si-treated plantlets for key genes related to the virus infection examined herein, sodium silica is suggested to have a neutral and limited impact on CMV infection in cucumber cultures.
Subject(s)
Antiviral Agents/pharmacology , Cucumis sativus/virology , Cucumovirus/drug effects , Plant Diseases/virology , Silicon/pharmacology , Cucumovirus/genetics , Cucumovirus/physiology , Gene Expression Regulation, Viral/drug effects , Viral Proteins/genetics , Viral Proteins/metabolismABSTRACT
The wall-less bacteria of the provisory taxon 'Candidatus Phytoplasma' are obligate parasites and associated to diseases in many important crops and trees worldwide. 'Ca. Phytoplasma ulmi', assigned to 16SrV-A subgroup, is a quarantine pest and described to be associated to elm phloem necrosis, leaf yellowing, stunting, witches broom and decline in various elm species. Elm yellows phytoplasmas (EY) have been reported in several European countries but not in Ulmus laevis in Germany so far. Leaf samples from European white elms (Ulmus leavis PALL.) with and without chlorotic symptoms were investigated for EYs infection in Berlin and Brandenburg, Germany, through performing diagnostic nested PCR targeting partial rRNA operon of phytoplasmas. Specific PCR-products were obtained from 30 out of 59 samples. Partial 16S-rDNA sequences were assigned to 'Ca. P. ulmi' through sequence analysis, while sequence variation was observed. This is the first report of U. laevis infected with 'Ca. P. ulmi' in Germany.
Subject(s)
Phytoplasma/isolation & purification , Plant Diseases/microbiology , Ulmus/microbiology , Base Sequence , Genetic Variation , Germany , Molecular Sequence Data , Phytoplasma/classification , Phytoplasma/genetics , Plant Leaves/microbiologyABSTRACT
Mathematical models on properties and behavior of harmful organisms in the food chain are an increas- ingly relevant approach of the agriculture and food industry. As a consequence, there are many efforts to develop biological models in science, economics and risk assessment nowadays. However, there is a lack of international harmonized standards on model annotation and model formats, which would be neces- sary to set up efficient tools supporting broad model application and information exchange. There are some established standards in the field of systems biology, but there is currently no corresponding provi- sion in the area of plant protection. This work therefore aimed at the development of an annotation scheme using domain-specific metadata. The proposed scheme has been validated in a prototype implementation of a web-database model repository. This prototypic community resource currently contains models on aflatoxin secreting fungal Aspergillus flavus in maize, as these models have a high relevance to food safety and economic impact. Specifically, models describing biological processes of the fungus (growth, Aflatoxin secreting), as well as dose-response- and carry over models were included. Furthermore, phenological models for maize were integrated as well. The developed annotation scheme is based on the well-established data exchange format SBML, which is broadly applied in the field of systems biology. The identified example models were annotated according to the developed scheme and entered into a Web-table (Google Sheets), which was transferred to a web based demonstrator available at https://sites.google.com/site/test782726372685/. By implementation of a software demonstrator it became clear that the proposed annotation scheme can be applied to models on plant pathogens and that broad adoption within the domain could promote communication and application of mathematical models.
Subject(s)
Plant Diseases/prevention & control , Models, Biological , Models, Theoretical , Plant Diseases/microbiology , SoftwareABSTRACT
In July 2012, leaf mottle and intensive chlorotic ringspots were observed on urban, forest, or roadside mountain ash trees (Sorbus aucuparia L., rowan) of different ages in Norway during visual inspection of native broadleaf forest tree species. Symptoms resembled those caused by European mountain ash ringspot-associated virus (EMARaV), the type-member of the newly established genus Emaravirus, containing segmented ss(-)RNA and infecting woody host species (2). Leaves of nine out of 30 assessed rowan trees exhibiting characteristic symptoms were sampled in the counties of Nordland and Nord-Trøndelag (between 63.511806° and 66.304680°N latitude). Three of them were infested by the potential vector the eriophyid gall mite Phytoptus pyri. EMARaV was detected from total RNA extracts of leaves by reverse transcription-PCR using virus-specific primers amplifying 300 bp of RNA2 and 204 bp of RNA3, respectively (3). PCR fragments were directly sequenced from both ends and submitted to the EMBL database (accession nos. HG428680 to 97). Sequenced fragments comprising the partial gene encoding the glycoprotein-precursor (261 nucleotides of RNA2 omitting primer sequences) obtained from the nine sampled trees showed identities of 97 to 98% to the sequence of the reference strain of EMARaV from Hamburg, Germany (database accession AY563041). Comparison of 159 nucleotides of the 3' untranslated region (3' UTR) of viral RNA3 of the nine investigated rowans in Norway exhibited higher sequence diversity on nucleotide level (up to 50 nucleotide exchanges, or 31%) as previously reported from EMARaV variants from other European countries (4). When subjected to BLASTn search through GenBank, only three partial RNA3 sequences generated in this study showed sequence identities of 96% to the reference isolate (accession DQ831831). The other six sequences revealed only 68 to 73% identity to RNA3 sequences of EMARaV variants from GenBank. This led to formation of a separate cluster in phylogenetic analysis of partial RNA3 sequences of the six EMARaV variants from Norway when compared to previously characterized strains from the Czech Republic (n = 2), Finland (n = 17), Germany (n = 1), Great Britain (n = 5), Russia (n = 3), and Sweden (n = 10). From three Norwegian samples clustering separately in the tree based on the partial 3' UTR of RNA3, the partial vRNA1 was amplified by RT-PCR using a generic primer set Motif-A-sense/Motif-C-antisense (1). Sequence analyses of these PCR fragments confirmed the viruses as members of the Emaravirus genus which were most closely related to EMARaV (data not shown). This is the first report of EMARaV in Norway infecting Sorbus aucuparia, a valuable native plant of northern Europe. The data obtained suggest a higher genetic variability of the EMARaV population in mountain ash trees in Norway than in other locations in Central and Northern Europe. However, whether the EMARaV variants identified in this study represent new strains of the virus have to be investigated in the future. References: (1) T. Elbeaino et al. J. Virol. Meth. 188:37, 2013. (2) N. Mielke-Ehret. and H. P. Mühlbach. Viruses 4:1515, 2012. (3) N. Mielke et al. For. Pathol. 38:371, 2008. (4) S. von Bargen et al. For. Pathol. 43: 429, 2013.
ABSTRACT
The survival of Alternaria alternate during anaerobic digestion was investigated in context of a joint research project. The aim of this project was to estimate the phytosanitary risk of dissemination of pathogens by returning treated biomass as organic fertilizer to arable land. The studies were carried out in lab-scale stirred tank reactors under mesophilic conditions. After insertion of infected plant material into the reactors the influence on the viability of the fungal pathogen was studied concerning exposure time, pretreatment and storage of the digestates for four weeks or six months. The results clearly showed that anaerobic digestion leads to a complete inactivation of A. alternate already after an exposure time of six hours.
Subject(s)
Alternaria/physiology , Biomass , Bioreactors , Anaerobiosis/physiology , Renewable Energy , Secale/microbiologyABSTRACT
Asparagus spears collected from a total of six commercial plantings in Austria during the main harvest periods in May and June of 2003 and 2004 were examined for endophytic colonization byFusarium spp., particularlyF. proliferatum. Potentially toxigenic fungi such asF. proliferatum were isolated and identified by morphological characteristics using light microscopy. Fumonisin B1 inF. proliferatum-infected asparagus spears was detected with IAS-HPLC-FLD or HPLC-MS/MS. The identity of endophytic fungi colonizing of a total of 816 individual spears was determined. The incidence of infection byF. proliferatum and otherFusarium spp. was highly dependent on location and sampling date. The dominantFusarium species among the endophytic microflora wasF. oxysporum. Other frequently isolated species includedF. proliferatum, F. sambucinum, F. culmorum, F. avenaceum andF. equiseti. The incidence ofF. proliferatum-infected asparagus spears was less than 10% at four of the six sampling locations. At the two remaining locations, 20-47% of the spears examined were infected withF. proliferatum. Further exploration of FB1 generation in asparagus is required because the low levels of FB1 (10-50 (µg/kg) detected in harvested spears in 2003 and 2004 cannot be explained by the results of this study.
ABSTRACT
In 1999, reports of spring rapeseed plants (Brassica napus L.) exhibiting wilt symptoms were received by agricultural extension personnel from farmers near Fort Vermillion and Andrew, Alberta, Canada. Fungal colonies recovered from affected plants after surface disinfection were identified as Fusarium oxysporum by comparison of morphology on carnation leaf and potato dextrose agars with literature descriptions and reference cultures. Root-dip inoculation of young rapeseed plants with spore suspensions prepared from recovered F. oxysporum colonies resulted in rapid development of symptoms seen in the field. An initial estimate of yield loss in an affected field near Andrew was performed by removing all rapeseed plants from three 1 m2 quadrats. Each plant was evaluated according to a simple three point severity scale, and then the seed from each plant was individually threshed and weighed. Fully- and partially-wilted plants yielded 0.2 and 19.3% of asymptomatic plants, respectively. In 2000, wilt symptoms were observed at a plot research site near Ranfurly, Alberta. Disease symptoms were restricted to one B. napus cultivar, Nexera 705. A similar procedure to that used at Andrew in 1999 was applied at Ranfurly, except quadrat size was 2.5 m2, and replicated comparisons were made between Nexera 705 and an unaffected cultivar, Quantum. The average number of unaffected Quantum plants was 99.4%, while only 66.9% of Nexera 705 plants were asymptomatic. No Quantum plants were severely wilted, while 11.7% of Nexera 705 plants were wilted. Yield of Nexera 705 was 38.6% of Quantum. In 2004, the impact of fusarium wilt on yield of 6 susceptible and 9 resistant B. napus cultivars was determined at nine locations in western Canada. Cultivars were selected on the basis of survey results and agronomist's reports. Across all sites, yield of the most severely affected cultivar, 45A55, was 15.9% lower than the least severely affected cultivar 3455. At the most severely affected site, yield of the most severely affected cultivar, Bianca II, was 75.2% lower than the least severely affected cultivar, Option 501. Yield of wilt-susceptible (Canterra 1604) and resistant (Cougar CL) rapeseed was compared at a replicated large-plot (576 m2 per plot) experiment at Lavoy, Alberta in 2005. The susceptible variety was severely affected and yielded 44% of Cougar CL.
Subject(s)
Brassica rapa/genetics , Brassica rapa/microbiology , Fusarium/pathogenicity , Plant Diseases/microbiology , Alberta , Brassica rapa/growth & development , Brassica rapa/immunology , Disease Susceptibility , Genotype , Immunity, Innate , Plant Diseases/immunology , Species SpecificityABSTRACT
The effect of composting and pasteurization on the quarantine pests of potato Clavibacter michiganensis ssp. sepedonicus (Cms) and Synchytrium endobioticum (Se) were examined on an experimental scale. Composting was performed with 2-L pots and 60-L composters for two months at temperatures below 50 degrees C and for 12 and 21 days at temperatures above 65 degrees C. Pasteurization was performed via water bath at 70 degrees C for maximum 2 hours. Pathogens were introduced directly or via carriers into the processes. After composting for two months and for 12 and 21 days it was possible to isolate vital Cms cells from bioassay plants and vital resting spores of Se could be extracted from sample material. Likewise it was possible to isolate vital Cms cells and resting spores of Se after pasteurization for up to two hours. Both pests could not be killed completely during the performed processes. Further studies concerning sanitization of potato wastes are necessary.
Subject(s)
Actinomycetales/growth & development , Chytridiomycota/growth & development , Crops, Agricultural/microbiology , Refuse Disposal/methods , Solanum tuberosum/microbiology , Hot Temperature , Manure , Risk Assessment , Time FactorsABSTRACT
Investigation into virulence and mycotoxin formation of the dry rot causing pathogen Fusarium sambucinum on potatos 11 strains ofFusarium sambucinum were isolated from tubers with dry rot symptoms from three different depots in the Land Brandenburg and Saxony-Anhalt. All isolates produced diacetoxyscripenol in artificially infected potato tubers. Additionally, two isolates produced T-2 and HT-2 toxins as well. The virulence and mycotoxin formation of the isolates was dependent on the potato varieties 'Sieglinde' and 'Berber' used in the experiment. The amount of diacetoxyscripenol in diseased tissue was positively correlated with the virulence of theF. sambucinum isolate and the susceptibility of the potato variety as well.
ABSTRACT
Double-stranded RNA (dsRNA) has been extracted from tissue of European mountain ash trees (Sorbus aucuparia L.) showing typical ringspot and mottling symptoms on leaves and a gradual decay in general. A characteristic dsRNA pattern was found in leaf samples of symptomatic mountain ash trees from various stands in Germany. Bands of dsRNA molecules of approximately 7 kb, 2.3 kb, 1.5 kb, and 1.3 kb, respectively, were repeatedly detected. By random primed reverse transcription cDNA was synthesised from dsRNA and amplified by degenerate oligonucleotide primed PCR. After TA cloning, the cDNA clones obtained were screened with an enhanced-chemiluminescence-labelled dsRNA probe. Positive clones were further analysed by using them as hybridisation probes in Northern blots of total plant RNA and in Southern hybridisation with genomic DNA from Sorbus aucuparia leaves. From cDNA clones that were found to be specific for dsRNA in Northern analysis, primers were deduced for 5'-RACE analyses and further cloning. Finally, a cDNA fragment of 3,737 bp was obtained, which showed homology to viral proteins, particularly to the RNA-dependent RNA polymerase of members of the family Bunyaviridae, but without high similarity to a known genus. The dsRNA pattern and the sequence information strongly indicate a virus associated with the mountain ash ringspot disease. The putative virus remains still unidentified.
Subject(s)
Plant Diseases/virology , Plant Leaves/virology , Plant Viruses/genetics , RNA, Double-Stranded/isolation & purification , Sorbus/virology , Amino Acid Sequence , Genome, Viral , Molecular Sequence Data , Plant Diseases/genetics , RNA, Viral/analysis , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
Noninvasive tools to quantitate transgene expression directly are a prerequisite for clinical gene therapy. We established a method to determine location, magnitude, and duration of low-density lipoprotein (LDL) receptor (LDLR) transgene expression after adenoviral gene transfer into LDLR-deficient Watanabe hypercholesterolemic rabbits by following tissue uptake of intravenously injected (111)In-labeled LDL using a scintillation camera. Liver-specific tracer uptake was calculated by normalizing the counts measured over the liver to counts measured over the heart that represent the circulating blood pool of the tracer (liver/heart (L/H) ratio). Our results indicate that the optimal time point for transgene imaging is 4 h after the tracer injection. Compared with control virus-injected rabbits, animals treated with the LDLR-expressing adenovirus showed seven-fold higher L/H ratios on day 6 after gene transfer, and had still 4.5-fold higher L/H ratios on day 30. This imaging method might be a useful strategy to obtain reliable data on functional transgene expression in clinical gene therapy trials of familial hypercholesterolemia.
Subject(s)
Genetic Therapy/methods , Hyperlipoproteinemias/therapy , Indium Radioisotopes , Lipoproteins, LDL/administration & dosage , Liver/metabolism , Receptors, LDL/genetics , Adenoviridae/genetics , Animals , Female , Gene Expression , Genetic Vectors/administration & dosage , Hyperlipoproteinemias/metabolism , Injections, Intravenous , Lipoproteins, LDL/pharmacokinetics , Liver/diagnostic imaging , Rabbits , Radionuclide Imaging , Receptors, LDL/metabolism , Transduction, Genetic/methods , Transgenes , Treatment OutcomeABSTRACT
Fusarium proliferatum is able to produce fumonisins and is considered a pathogen of many economically important plants (e.g. corn, rice, asparagus) [1]. The occurrence of fumonisin FB1 inF. proliferatum infected asparagus spears from Germany was investigated using a liquid chromatography/electrospray ionization-mass spectrometry (LC-ESI-MS) method with isotopically labeled fumonisin FB1-d6 as internal standard. Asparagus samples were harvested in July 2000 and screened forFusarium species. AltogetherF. oxysporum, F. proliferatum and F. sambucinum were isolated from the spears. The samples infected with F.proliferatum were subsequently analyzed for fumonisins. FB1 was detected in 9 of the 10 samples in amounts ranging from 36.4 ng/g to 4513.7 ng/g (based on dry weight). Fumonisins FB2 and FB3 were found in six samples in lower concentrations. In asparagus spears of June 2002 we could findF. proliferatum in 6% of the samples, however no fumonisins were detectable.Furthermore the capability of producing FB1 by the fungus in garlic bulbs was investigated. Therefore garlic was cultured inF. proliferatum contaminated soil and the bulbs were screened for infection with F.proliferatum and for the occurrence of fumonisins by LC-MS. F.proliferatum was detectable in the garlic tissue and all samples contained FB1 (26.0 ng/g to 94.6 ng/g).This is the first report of the natural occurrence of FB1 in German asparagus spears and furthermore our findings suggest a potential for natural contamination of garlic bulbs with fumonisins. For detailed results and methods see Ref. [2].
ABSTRACT
Influx of eosinophils in airway mucosa and airway lumen is a hallmark of bronchial asthma. In-vitro data and animal studies indicate that the T-helper (Th) type-2 cell cytokine, interleukin (IL)-5, plays an important role in eosinophil maturation, differentiation, recruitment, and survival. The objective of this study was to determine whether intravenous treatment with monoclonal anti-IL-5 would affect the number of peripheral blood eosinophils, their activation status, T-cell activation or the pattern of Th1 and Th2 cytokine production. Over a period of 6 months, 19 asthmatics were investigated in a double-blind, placebo-controlled, multicentre study with mepolizumab (SB 240563) anti-IL-5 antibody administered three times. Before each infusion and 12 weeks after the last infusion, peripheral blood leukocytes were examined, qualitative and quantitative distribution of eosinophils and lymphocyte subpopulations, frequencies of IL-2, -3, -4, -5, -10, -13, interferon-gamma-producing CD4 T-cells and serum eosinophil cationic protein (ECP) levels were determined. Treatment with mepolizumab resulted in a marked, rapid and sustained decrease of eosinophil numbers (median values from 300 to 45 per microL) paralleled by decreased levels of serum ECP (median values from 15 to 5 microg x L(-1)). Distribution of T-cell subsets and T-cell cytokine production were not altered during antibody treatment. In conclusion, administration of mepolizumab to asthmatic patients markedly reduces peripheral blood eosinophils without altering the distribution and activation status of lymphocytes.
Subject(s)
Antibodies, Monoclonal/therapeutic use , Eosinophils/immunology , Interleukin-5/immunology , Ribonucleases , T-Lymphocytes/immunology , Adult , Antibodies, Monoclonal/pharmacology , Antibodies, Monoclonal, Humanized , Asthma/drug therapy , Blood Proteins/analysis , Blood Proteins/immunology , Double-Blind Method , Eosinophil Granule Proteins , Female , Humans , Lymphocyte Activation/drug effects , Lymphocyte Activation/physiology , Male , Middle AgedABSTRACT
The Russian wheat aphid, Diuraphis noxia (Kurdj.), is a serious threat for the production of barley, Hordeum vulgare L., in Ethiopia. The pest can cause up to 100% yield losses in years of heavy infestation. Natural control of D. noxia by using predators and parasitoids might be the best alternative both from economical and ecological point of view. In this regard, a field investigation was conducted during the 2001 spring cropping season at Fitche, central Ethiopia to determine abundance of D. noxia and associated natural enemies and evaluate their effectiveness as natural control agents for this pest. In addition, the data collected during the 1995-1997 spring and summer cropping seasons at Chacha was analysed and presented. There was a highly significant difference (P < 0.01) on the population density of D. noxia between spring and summer and among sampling dates. The average aphid density was 23.1 and 0.7 aphids per tiller during spring and summer, respectively. The quantitative analyses based on predator units (PU) showed a highly significant difference (P < 0.01) among the predator groups, coccinellids and syrphids being more important, however, the coccinellid beetle, Hippodamia variegata Goeze, was the dominant species from all predator species or groups. Moreover, syrphid fly larvae were the only predators consistently found feeding on aphids within D. noxia rolled leaves. The polyphagous predators: Chrysopids, spiders and staphylinids were found to have less effect on D. noxia populations. Only two primary parasitoid species were recorded both during spring and summer cropping seasons: Aphidius colemani Vier. and Aphidius spp. Of these, A. colemani was more abundant in both seasons. The rate of parasitism was also generally low during the season. In general, the population build up of these natural enemies is slow and maximum population size is reached after the aphid population peaks and the crop has already been damaged. Further extensive work is necessary to maximize the effectiveness of natural enemies against this pest.
Subject(s)
Aphids/pathogenicity , Hordeum/parasitology , Pest Control, Biological/methods , Triticum/parasitology , Animals , Ethiopia , Hemiptera , Hordeum/growth & development , Population Density , Predatory Behavior , Reproducibility of Results , Seasons , Triticum/growth & developmentABSTRACT
P. hsyterophorus is an exotic invasive annual weed now causing severe infestation in Ethiopia. Studies on diagnosis, incidence and distribution of pathogens associated with parthenium weed in Ethiopia were carried out from 1998-2002. Several fungal isolates were obtained from seed and other parts of parthenium plants. Among them were putative pathogenic fungal species of the genus Helminthosporium, Phoma, Curvularia, Chaetomium, Alternaria, and Fusarium. However, pathogenecity test of the isolates obtained showed no or non-specific symptoms. It was concluded that these pathogens could be opportunistic with insignificant potential for biological control of parthenium. Two most important diseases associated with parthenium were a rust disease, caused by Puccinia abrupta var. partheniicola, and a phyllody disease, caused by a phytoplasma of fababean phyllody (PBP) phytoplasma group. The rust was commonly found in cool mid altitude (1500-2500 m) areas while phyllody was observed in low to mid altitude regions (900-2500 m) of Ethiopia, with a disease incidence up to 100% and 75%, respectively, in some locations. Study of the individual effects of the rust and phyllody diseases under field conditions showed a reduction on weed morphological parameters (plant height, leaf area, and dry matter yield). Parthenium seed production was reduced by 42% and 85% due to rust and phyllody, respectively. Phyllody and rust diseases of parthenium showed significant potential for classical biological control of parthenium after further confirmation of insect vectors that transmit phyllody and host range of phyllody disease to the related economic plants in Ethiopia.
Subject(s)
Asteraceae/microbiology , Fungi/growth & development , Pest Control, Biological/methods , Plant Diseases/microbiology , Alternaria/growth & development , Alternaria/isolation & purification , Asteraceae/growth & development , Chaetomium/growth & development , Chaetomium/isolation & purification , Ethiopia , Fungi/isolation & purification , Fusarium/growth & development , Fusarium/isolation & purification , Helminthosporium/growth & development , Helminthosporium/isolation & purificationABSTRACT
Wilted and rotted plants of Vicia faba were received from different localities in the Sudan. Among several Fusarium spp., Fusarium nygamai was recovered. Conspicuous symptoms were among others black root rot, associated with rot and death of the lateral root system. Severely infected plants showed black neck canker at soil level. These symptoms were usually accompanied by loss of the leaves' turgor, these then turned brown and died. Death of intact leaves also occurred. Most of the strains proved to be pathogenic to Vicia faba. Disease intensity varied between 28-100%. This is the first report of Fusarium nygamai as a pathogen of Vicia faba.
Subject(s)
Fusarium/growth & development , Plant Diseases/microbiology , Plant Roots/microbiology , Vicia faba/microbiology , Apoptosis/physiology , Fusarium/isolation & purification , Models, Biological , Plant Leaves/microbiology , SudanABSTRACT
The pulse beetle, Callosobruchus maculatus (F.) is a destructive pest of pulses in both storage and field. It is well known that diatomaceous earth (DE) kill the insects by locally absorbing the epicuticular lipid layers leading to high rate of water loss through the cuticle. However, the effectiveness of DE depends on its ability to kill the adults before copulation and egg-laying. Newly emerged virgin males and females of Callosobruchus maculatus (F.) were exposed to the DEs, Fossil-Shield and Silico-Sec on 30 treated mungbeans (Vigna radita (L)). Fecundity, number of beans used for egg-laying and beans without eggs were evaluated after four days; the number of unhatched eggs was evaluated after ten days. It was determined, that the fecundity of female insects decreased sigmoidely with increasing rate of DE content. Percentages of unhatched eggs and seeds without eggs increased with increasing DE dosages. However, the maximum egg densities (eggs per used secd) occurred at 1200 mg DE/kg for Fossil-Shield and Silico-Sec. The reason for such DE-stimulated behaviour of egg laying expressed as a number of seeds with eggs of C. maculatus is not known, but it may be related to the stress caused by the inert dusts or to the reduction of both chemical and physical (tactile) stimuli. Treatment with DEs altered the surface texture of the beans and caused less cohesion between eggs and the seed surface. Only few larvae managed to penetrate into the grains, possibly due to increased grain roughness and repellent effect of DE. A relatively high number of eggs were laid on the surface of those beans where the amount of dust had been locally reduced by adults' movement and their pick up of DE. Therefore, several larvae tried to penetrate into these treated beans, causing a high larval density per partially cleaned bean. All these reasons lead to a progeny decline.
Subject(s)
Coleoptera/anatomy & histology , Diatomaceous Earth/toxicity , Fabaceae/parasitology , Oviposition/physiology , Animals , Coleoptera/drug effects , Entomology/methods , Fabaceae/drug effects , Female , Larva/drug effects , Larva/growth & development , Male , Oviposition/drug effects , Ovum/drug effects , Ovum/growth & development , Reproduction/drug effects , Reproduction/physiologyABSTRACT
The afferent (excitability) and efferent functions (release of neuropeptides) of primary afferent nerve fibres are based on Ca(2+)-influx. The aim of the present study was to examine the presence of L- and N-type Ca(2+)-channels at sensory nerve fibres in the mouse knee joint capsule. Specific fluorescent labelled channel blockers and antisera against these channel subtypes were combined with an immunohistochemical staining for calcitonin gene-related peptide (CGRP), a neuropeptide that is widely distributed in primary afferents. There was a nearly complete colocalisation of CGRP immunoreactivity and the binding of omega-conotoxin GVIA (toxin VIA of Conus geographus or BODIPY-verapamil (BODIPY(R) FL verapamil, hydrochloride) demonstrating the presence of N-type and L-type Ca(2+)-channels, respectively. These data were further confirmed by identical results obtained after an immunohistochemical demonstration of the two channel subtypes at the peptidergic nerve fibres.
Subject(s)
Calcitonin Gene-Related Peptide/metabolism , Calcium Channels/metabolism , Knee Joint/innervation , Nerve Fibers/metabolism , Neurons, Afferent/metabolism , Nociceptors/metabolism , Peripheral Nerves/metabolism , Verapamil/analogs & derivatives , Animals , Binding Sites/drug effects , Binding Sites/physiology , Calcium Channels, L-Type/metabolism , Calcium Channels, N-Type/metabolism , Immunohistochemistry , Knee Joint/metabolism , Mice , Nerve Fibers/ultrastructure , Neural Conduction/physiology , Neurons, Afferent/ultrastructure , Nociceptors/ultrastructure , Pain/metabolism , Pain/physiopathology , Peripheral Nerves/ultrastructure , Verapamil/pharmacokinetics , omega-Conotoxin GVIA/pharmacokineticsABSTRACT
The inhibitory glycine receptor (GlyR) in developing spinal neurones is internalized efficiently upon antagonist inhibition. Here we used surface labeling combined with affinity purification to show that homopentameric alpha1 GlyRs generated in Xenopus oocytes are proteolytically nicked into fragments of 35 and 13 kDa upon prolonged incubation. Nicked GlyRs do not exist at the cell surface, indicating that proteolysis occurs exclusively in the endocytotic pathway. Consistent with this interpretation, elevation of the lysosomal pH, but not the proteasome inhibitor lactacystin, prevents GlyR cleavage. Prior to internalization, alpha1 GlyRs are conjugated extensively with ubiquitin in the plasma membrane. Our results are consistent with ubiquitination regulating the endocytosis and subsequent proteolysis of GlyRs residing in the plasma membrane. Ubiquitin-conjugating enzymes thus may have a crucial role in synaptic plasticity by determining postsynaptic receptor numbers.