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Found 15 results.

Is the immune system required to adapt to flowering time change?

Das Projekt "Is the immune system required to adapt to flowering time change?" wird vom Umweltbundesamt gefördert und von Universität Köln, Biozentrum, Botanisches Institut durchgeführt. For effective crop improvement, breeders must be able to select on relevant phenotypic traits without compromising yield. This project proposes to investigate the evolutionary consequences of flowering time modifications on a second trait of major importance for plant breeding: immunity. This will have implications both for understanding cross-talks between flowering time and defense network and for developing efficient breeding strategies. There is clear evidence that plant maturity influences levels and effectiveness of defense. Theoretical models actually predict that changes in life-history can modulate the balance between costs and benefits of immunity. Simultaneously, actors of the immune system have often been observed to alter flowering time. Two alternative and possibly complementary hypotheses can explain this link: genetic constraints due to the pleiotropic action of players in either systems, or co-evolution, if flowering-time changes modulate the cost-benefit balance of immunity. We will conduct field assays in Arabidopsis thaliana, using constructed lines as well as recombinant inbred lines and natural accessions, to differentiate the action of the two explanatory hypotheses. Using transcriptome analyses, we will identify defense genes associating with flowering time modification (f-t-a defense genes). We will quantify their expression along the assay and test whether it varies with both flowering time and fitness. We will further test whether flowering time and immunity interact to determine yield in tomato and potato.

Barley dwarfs acting big in agronomy. Identification of genes and characterization of proteins involved in dwarfism, lodging resistance and crop yield

Das Projekt "Barley dwarfs acting big in agronomy. Identification of genes and characterization of proteins involved in dwarfism, lodging resistance and crop yield" wird vom Umweltbundesamt gefördert und von Deutsche Forschungsgemeinschaft durchgeführt. Barley (Hordeum vulgare) is an important cereal grain which serves as major animal fodder crop as well as basis for malt beverages or staple food. Currently barley is ranked fourth in terms of quantity of cereal crops produced worldwide. In times of a constantly growing world population in conjunction with an unforeseeable climate change and groundwater depletion, the accumulation of knowledge concerning cereal growth and rate of yield gain is important. The Nordic Genetic Resource Center holds a major collection of barley mutants produced by irradiation or chemical treatment. One phenotypic group of barley varieties are dwarf mutants (erectoides, brachytic, semidwarf, uzu). They are characterized by a compact spike and high rate of yield while the straw is short and stiff, enhancing the lodging resistance of the plant. Obviously they are of applied interest, but they are also of scientific interest as virtually nothing is known about the genes behind the development of plant dwarfism. The aim of this project is to identify and isolate the genes carrying the mutations by using state of the art techniques for gene cloning at the Carlsberg Laboratory. The identified genes will be connected with the mutant phenotype to reveal the gene function in general. One or two genes will be overexpressed and the resulting recombinant proteins will be biochemically and structurally characterized. The insights how the mutation effects the protein will display the protein function in particular. Identified genes and their mutant alleles will be tested in the barley breeding program of the Carlsberg brewery.

Virus-resistant transgenic plants: ecological impact of gene flow (VRTP IMPACT)

Das Projekt "Virus-resistant transgenic plants: ecological impact of gene flow (VRTP IMPACT)" wird vom Umweltbundesamt gefördert und von RWTH Aachen University, Institut für Umweltforschung, Lehr- und Forschungsgebiet Ökosystemanalyse (ESA) durchgeführt. The objective of this project is to provide detailed evaluation of the two sources of potential genotypic impact that could result from large-scale cultivation of virus-resistant transgenic plants, and particularly ones expressing viral sequences. Genotypic impact could result from two types of gene flow: one involving recombination between viral sequences transcribed from the transgene and the genome of an infecting virus, and another due to the potential for sexual outcrossing between the transgenic plant and a compatible wild species. In both cases, this requires not only close examination of the interaction of the transgenic plants, on the one hand with the genome of other viruses, and on the other hand with related plant species, but also requires establishment of baselines on the role of these same processes in a non-transgenic context. Thus, the idea of impact as used here only concerns additional, i.e. above borderline, novel effects that could be caused by interaction of the transgenic plants with their biological environment. In order to address these interlocking concerns, the VRTP IMPACT project has been divided into four Workpackages. Each of these will involve collaboration among several participants, and as a result, most of the participants are involved in more than one Workpackage. The first two workpackages (WPs I & II) are organised in a parallel fashion to evaluate the impact of recombination between transgene sequences and those of the genome of two particularly important groups of plant viruses, the potyviruses and the cucumoviruses, which are extremely different in both their biological and molecular properties, and thus may have different aptitudes for recombination in transgenic plants. WPs I & II will centre on comparisons of the outcome of recombination in transgenic plants with that in non-transgenic ones. Since our knowledge of the prevalence in nature of recombinant virus genomes is extremely sparse, this question will be address in a separate workproject (WP III) that will involve molecular epidemiology studies of virus populations in Spain, France. In WP IV, we will examine the impact of plant to plant gene flow from two major crop species where this is known to occur, rapeseed and beet. In both cases, this will involve field and glasshouse studies to evaluate if a virus resistance gene could confer a fitness advantage on the receptor wild or weedy species.

Genomic dissection of floral transition in Brassica napus towards crop improvement by life cycle adaptation and hybrid yield increase

Das Projekt "Genomic dissection of floral transition in Brassica napus towards crop improvement by life cycle adaptation and hybrid yield increase" wird vom Umweltbundesamt gefördert und von Christian-Albrechts-Universität zu Kiel, Institut für Pflanzenbau und Pflanzenzüchtung, Lehrstuhl Pflanzenzüchtung durchgeführt. Rapeseed (Brassica napus L.) suffers from low genetic variation due to the short history of this species. Breeders try to broaden the genetic basis by gene introgression from non-adapted material from other geographic regions of the world. However, use of these materials is hampered, among others, by non-adapted flowering time (FTi). Here an integrated project is proposed to get a deeper understanding of FTi by global expression analysis and cloning of major FTi regulators. Candidate genes will be mapped by recombination mapping and, in collaboration with other groups, by association mapping. As a proof of concept study, relevant sequences will be mapped to recombinant lines carrying exotic rapeseed introgressions. The 2nd part of the project will study the relevance of 4 FTi genes for heterosis. Assuming that sequence variation within these genes will have an impact on seed yield and biomass heterosis, mutants will be identified by TILLING. The mutants will be analyzed and crosses will be made to determine heterosis of F1 hybrids in the 2nd funding period.

Studien zum metabolischen Schicksal von 13C-Nonylphenol in Wasser und Sediment und entsprechenden mikrobiellen Systemen

Das Projekt "Studien zum metabolischen Schicksal von 13C-Nonylphenol in Wasser und Sediment und entsprechenden mikrobiellen Systemen" wird vom Umweltbundesamt gefördert und von RWTH Aachen University, Institut für Umweltforschung, Biologie V, Lehrstuhl für Umweltbiologie und -chemodynamik durchgeführt. The aim of this research project is to study the metabolic fate of 13C-labelled nonylphenol in water, sediment and related microbial model systems. The main use of nonylphenol is the production of NP polyethoxilates. These nonionic surfactants have different application such as the production of industrial and household detergents. The most common route of nonylphenol to enter in the environment is through the wastewater. In fact NP polyethoxilates is most used in cleaners and for this reasons is discharged directly in the sewage system. Under anaerobic conditions NP polyetoxilates is degraded to NP. Laboratories studies on NP have demonstrated that NP can be classified as endocrine disrupter compound. Isomers highly branched in the alpha position of the nonyl chain show an higher estrogenic activity and that the para position is favorite as well for estrogenic activity.So far data on the metabolic fate of NP in water and soil are limitated in literature. Several studies have been performed in the laboratories about the metabolic fate of EDC using 14C labelled compounds. But this lead to 2 disadvantages: 1) the complete identification of the metabolites was not possible using GC/MS and 2) problems related with the discharge of radioactive compounds. For the previous reasons isomers of NP (353-NP, 363-NP, 33-NP) will be synthesised and labelled with 13C on the aromatic ring. An equimolar mixture of the labelled compound with the corresponding non labelled compound will yields a characteristic double peak with approximately the same abundance in MS analyses. Taking advantages of this it will be able to follow the degradation of nonylphenol in the experiments. The metabolic fate of NP exposed to different conditions will be studied: exposed to UV light, degraded by a recombinant yeast and in aerobic and anaerobic conditions. The first line of the project is to study the metabolic fate of NP exposed under condition of photo degradation. In fact NP can be exposed to sunlight when present in the aquatic environment. UV rays are of a short wavelength and have the energy to degrade products in sunlights. A lamp that had a ratio of UV-A and UV-B quite similar to the sun light was chosen. The NP degradation will be followed in a water/sediment system and in chlorinated water. The water sediment system and chlorinated water will be spiked with the nonylphenol, than the sample will be exposed to UV light at difference distance from the lamp and for different time. Than the metabolites will be extracted and analyzed via GC/MS. The second line of the project is to study the metabolic fate of NP after degradation with a recombinant yeast. The host used will be the yeast Saccharomyces cerevisiae, because it is well known and the genome of this yeast has been completely sequenced. The yeast will be transformed with an expression vector containing one cytochrome P-450 and the yeast reductase. Etc.

Development of specific recombinant anti-PrPSc antibodies (TUM 16)

Das Projekt "Development of specific recombinant anti-PrPSc antibodies (TUM 16)" wird vom Umweltbundesamt gefördert und von Bayerisches Staatsministerium für Umwelt, Gesundheit und Verbraucherschutz durchgeführt. BSE-Forschung im Rahmen des Forschungsverbundes Forprion. Im Zusammenhang mit dem Auftreten der ersten BSE-Fälle in Bayern wurden von der Bayerischen Staatsregierung Ende 2000 zusätzliche Maßnahmen zur Bekämpfung der Prionenkrankheiten beschlossen. Dazu wurde Anfang 2001 der Bayerische Forschungsverbund Prionen (FORPRION) gegründet. (Siehe auch www.abayfor.de/forprion) Ziel von FORPRION ist die Erforschung der Grundlagen der Prionenkrankheiten und anwendungsorientierter Fragestellungen in diesem Bereich. Durch die Ergebnisse sollen Fortschritte in der Pathogenese, Diagnostik, Therapie und dem Verbraucherschutz erzielt werden. Die Laufzeit des Forschungsverbundes wurde auf mindestens 5 Jahre festgelegt. Am Beispiel BSE wird deutlich, wie Krankheiten beim Tier auch zur Gefahr für den Menschen werden können. Nach wie vor sind im Bereich der Prionenforschung viele Fragen ungeklärt und werden auf internationaler Ebene diskutiert. Risikovorsorge und Forschung müssen daher weiterhin konsequent und im engen Zusammenwirken aller Fachdisziplinen betrieben werden. Entwicklung spezifischer rekombinanter anti-PrPSc Antikörper. Diagnostik und Therapie von Prionkrankheiten: Ziel dieses Projekts ist die Produktion von selektiven rekombinanten Antikörpern gegen PrPSc. Es gibt zwei Hauptanwendungen: 1.) Die Konstruktion einer selektiven Analyse zur Entdeckung von PrPSc in Blutproben und 2.) das Blockieren von infektiösem PrPSc im lebenden Organismus als Therapieansatz.

Einfluss eines rekombinanten humanen P450-Systems auf endogene Inhaltsstoffe in transformierten Pflanzen von Nicotiana tabacum L.

Das Projekt "Einfluss eines rekombinanten humanen P450-Systems auf endogene Inhaltsstoffe in transformierten Pflanzen von Nicotiana tabacum L." wird vom Umweltbundesamt gefördert und von RWTH Aachen University, Institut für Umweltforschung, Biologie V, Lehrstuhl für Umweltbiologie und -chemodynamik durchgeführt. Pflanzliche P450-Enzyme besitzen sowohl Aufgaben im Primär- und Sekundärstoffwechsel der Pflanzen als auch in der Metabolisierung von Xenobiotika einschließlich Herbiziden. Da z.B. Mais eine natürliche Resistenz gegenüber dem Triazin-Herbizid Atrazin aufweist, konnten suszeptible Wildpflanzen, die bei Feldanbau neben den Kulturpflanzen aufkommen, durch Anwendung des Herbizids ohne Schädigung der Kulturpflanzen selektiv bekämpft werden (Herbizidselektivität). Kulturpflanzen wie z.B. Tabak und Kartoffel, die keine oder nur eine unzureichende natürliche Resistenz gegenüber einem bestimmten Herbizid besitzen, können durch Agrobacterium tumefaciens-vermittelte Transformation mit einem Säuger-P450-Isoenzym (z.B. CYP1A1 oder CYP1A2) Herbizid-resistent werden. Seit einigen Jahren gibt es in dieser Richtung Bestrebungen, P450-transgene Pflanzen herzustellen. Aufgrund der überlappenden, breiten Substratspezifität des jeweils eingebrachten Säuger-P450-Isoenzyms (Ratte, Mensch) wird in den transgenen Pflanzen meist eine multiple Resistenz gegen verschiedene Herbizide mit unterschiedlichen Strukturen und Wirkmechanismen beobachtet. Vor der Vermarktung von transgenen Pflanzen müssen diese in Feldversuchen getestet werden. Dabei wird die Verträglichkeit des Genproduktes, die Eigenschaften der modifizierten Pflanze, die Expressionsstabilität des eingebrachten Fremd-Gens und mögliche ökologische Auswirkungen untersucht. Zusätzlich sollte neben der Substratspezifität des fremden P450-Isoenzyms gegenüber Xenobiotika getestet werden, ob pflanzliche Sekundärmetaboliten als Substrate in Frage kommen. Außerdem sind mögliche Einflüsse auf den normalen Stoffwechsel der Pflanzen von Interesse, die sich auf den Phänotyp der Pflanzen auswirken können. Z.B. wurde bei Cyp2c14-transformierten Tabak-Pflanzen (aus Kaninchen) eine verstärkte Seneszenz beschrieben, die sich in einem verringertem Chlorophyll-Gehalt, einem erhöhten Gehalt an Abbauprodukten der Lipid-Peroxidation und einem Abbauprodukt des Nornicotins und in einer Abnahme des Nicotin-Gehaltes äußerte. Außerdem wuchsen die Pflanzen langsamer und brauchten mehr Zeit zur Bewurzelung. Dies sind Anzeichen dafür, dass das Einbringen eines Fremd-P450-Gens in Tabak über die oxidative Veränderung der Membranlipide oder -sterole und damit über die Veränderung der Membranstruktur, durch einen hormonellen Eingriff durch Umsetzung eines Brassinosteroids oder die Unterdrückung endogener P450-Gene möglicherweise schwerwiegende metabolische Auswirkungen zur Folge haben kann. Vor diesem Hintergrund wurde untersucht, ob die Agrobakterien-vermittelte Transformation von Tabak mit der cDNA des humanen CYP1A2 Auswirkungen auf den endogenen Nicotin-Gehalt der Pflanzen zur Folge haben. CYP1A2 gehört dabei neben anderen Isoenzymen im Gegensatz zu den Hauptenzymen CYP2A6, CYP2B6 und CYP2D6 zu den Isoenzymen, die Nicotin nur bei hoher Substratkonzentration umsetzen. Nicotin besitzt dabei als natürliches Insektizid eine wichtige ökol u.s.w.

Untersuchungen zur Entwicklung und Validierung einer Testmethode zur Identifizierung endokriner Substanzen

Das Projekt "Untersuchungen zur Entwicklung und Validierung einer Testmethode zur Identifizierung endokriner Substanzen" wird vom Umweltbundesamt gefördert und von Fraunhofer-Institut für Molekularbiologie und Angewandte Oekologie durchgeführt. There is concern, that certain anthropogenic substances may modify the normal functioning of human and wildlife endocrine system. The endocrine system consists of glands and the hormones they produce guiding the development, growth, reproduction and behaviour of human beings and animals. Potential adverse effects of endocrine disrupters on humans and wildlife are controversially discussed among scientists, politicians and the public. Although there are associations between endocrine disrupting chemicals, so far investigated, and human health disturbances, a causative role of these chemicals in diseases and abnormalities possibly related to an endocrine disturbance has not been verified (CSTEE 1999). Concerning wildlife, there is strong evidence obtained from laboratory studies showing the potential of several environmental chemicals to cause endocrine disruption at environmentally realistic exposure levels. For investigating effects on wildlife, especially aquatic species, a number of bio-markers and screening tests are being developed, but so far, the ecological significance of the used endpoints for reproduction and population dynamics is not proven. This also applies for the relevance of environmental concentrations for compounds of concern. The aim of this project is to contribute to the development of testing strategies for endocrine disrupters. Due to the complexity of the endocrine system, the work focused on estrogen-receptor mediated processes being the mechanism of action of a large number of environmental chemicals. Within the scope of this project estrogen-receptor mediated reactions had been investigated at different levels from in-vitro systems up to the population level of fish (a) in intact cells, (b) in whole organisms, (c) on reproductive performance of a population and their usefulness for a tiered testing scheme had been discussed. With regard to the selection of in-vivo tests, it was not the intention to develop new tests but to proof the feasibility to enhance or refine, respectively, current test protocols, as agreed by several expert groups (OECD-EDTA, EPA-EDSTAC, CSTEE, EMSG). Deduced from these various levels of complexity following tests had been selected: 1. Transactivation assay in-vitro. Transactivation assays with recombinant receptor and recombinant reporter genes in yeast and mammalian cells were selected for testing the relative potencies of compounds to activate estrogen receptor mediated processes. 2. Assays towards the understanding of molecular mechanisms in intact cells. The expression of estrogen responsive genes, were investigated in a rat endometrium derived adenocarcinoma cell line (RUCA-I). These cells express relative high levels of estrogen receptor and exhibit estrogen inducible gene expression. usw.

Analysis of heterosis in Arabidopsis thaliana via metabolic profiling

Das Projekt "Analysis of heterosis in Arabidopsis thaliana via metabolic profiling" wird vom Umweltbundesamt gefördert und von Max-Planck-Institut für molekulare Pflanzenphysiologie durchgeführt. The project aims at comprehensively characterizing metabolic regulations that are observed in reciprocal crosses of Arabidopsis thaliana compared to the corresponding parental lines and in recombinant inbred lines and corresponding test crosses. In the first 2-years period of the project, emphasis is given to acquire data for large sets of plant populations (P, F1, F2, RIL and TCRIL) by routine gas chromatography/time-of-flight mass spectrometry (GC/TOF), and to extend this method to large and thermolabile compounds by liquid chromatography/tandem mass spectrometry (LC/MS2), specifically membrane lipids, organic phosphates and glycosylated compounds. All plants will be grown under controlled environmental conditions and randomised block designs to allow statistical evaluations. Observed metabolic alterations are then mapped to biochemical pathways and cycles in order to found links between metabolite, protein, and gene regulations. Changes in metabolism are statistically analysed with respect to hybrid vigour (incrase in dry shoot matter) observed in F1 lines and recombinant inbred lines. Metabolic inheritance will be assessed by a combination of different statistical and computational tools and linked to heterosis effects in total growth. Physiological, metabolomic, and genetic marker data will be used for the identification of quantitative trait loci (QTL) in close collaboration with partner projects.

Three-dimensional reconstruction of human corneas by tissue engineering (CORNEA ENGINEERING)

Das Projekt "Three-dimensional reconstruction of human corneas by tissue engineering (CORNEA ENGINEERING)" wird vom Umweltbundesamt gefördert und von Universitätsklinikum Hamburg-Eppendorf, Klinik und Poliklinik für Augenheilkunde, Hornhautbank durchgeführt. The goal of the proposed research project is to reconstruct a human cornea in vitro, for use both in corneal grafting and as an alternative to animal models for cosmeto-pharmacotoxicity testing. The project responds to the urgent need to develop new forms of corneal replacements as alternatives to the use of donor corneas, in view of the worldwide shortage of donors, the increasing risk of transmissible diseases, the widespread use of corrective surgery, which renders corneas unsuitable for grafting, and the severe limitations of currently available synthetic polymer-based artificial corneas (keratoprostheses). The originality of the proposal lies in the use of recombinant human extra cellular matrix proteins to build a engineered-engineered scaffold to support growth of the different cell types found in the cornea, cells to be derived from human adult stem cell pools. The development of a reconstructed human cornea will represent a real breakthrough, allowing diseased or damaged corneas to be replaced by tissue-engineered human corneal equivalents that resemble in all respects their natural counterparts. The proposal also responds to impending ED legislation banning the marketing of cosmetic products that have been tested on animals, using procedures such as the Raise rabbit eye irritation test. The development of tissue-engineered corneas will provide a non-animal alternative, which will therefore alleviate animal suffering. The project will lead to a transformation of industry to meet societal needs using innovative, knowledge-based approaches integrating Nan technology and biotechnology. The project brings together 14 participants with complementary expertise from 9 different countries, including basic scientists, ophthalmologists and industrialists (three Sees). Ethical and standardisation aspects will also be included. Prime Contractor: Centre National de la Recherche Scientifique, Institut de Biologie et Chimie des Proteines - UMR5086; Paris; France.

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