Das Projekt "Carbon acquisition during pathogenic development of Ustilago maydis and Colletotrichum graminicola" wird/wurde gefördert durch: Deutsche Forschungsgemeinschaft. Es wird/wurde ausgeführt durch: Karlsruher Institut für Technologie (KIT), Institut für Toxikologie und Genetik (ITG).The biotrophic fungus Ustilago maydis infects corn and induces the formation of tumors. In order for the fungus to proliferate in the infected tissue, U. maydis has to redirect the metabolism of the host to the site of infection. We wish to elucidate how this is accomplished. To this end we will perform transcript profiling during the time course of infection for both, the fungus and the maize plant. This will be complemented by metabolome analysis of different tissues during infection as well as by apoplastic fluid analysis. The goals will be to identify the carbon sources taken up by the fungus during biotrophic growth, to identify the transporters required for uptake, determine their specificity and elucidate how these carbon sources are provided by the plant. Fungal mutants affected in discrete stages of pathogenic development will be included in these studies. Likely candidate genes for carbon uptake/supply as well as for redirecting host metabolism will be functionally characterized by generating knockouts in the fungus and by isolating plants carrying mutations in respective genes or by generating transgenic plants expressing RNAi constructs.
Das Projekt "Barley compatibility factors pivotal for root colonisation and manipulation of basal defence by Piriformospora indica" wird/wurde gefördert durch: Deutsche Forschungsgemeinschaft. Es wird/wurde ausgeführt durch: Justus-Liebig-Universität Gießen, Institut für Phytopathologie.This project is aimed at the characterization of the systemic reprogramming in barley, which modulates the compatible interaction with the biotrophic leaf pathogen Blumeria graminis f.sp. hordei upon root infestation with the mutualistic endophyte Piriformospora indica. We have recently shown that the basidiomycete P. indica - upon successful establishment in the roots - reprograms barley to salt stress tolerance, resistance to root diseases and higher yield (Waller et al., 2005). Successful powdery mildew infections in barley leaves are also disturbed by the mutualistic fungus. These processes are associated with a strong change in plant metabolism, especially with a drastic alteration of leaf and root antioxidants. On the basis of these findings we will perform an in-depth analysis of the barley metabolome (B6) and transcriptome (B7) with two specific foci: First, to elucidate the process of establishment of the mutualistic fungus within the barley roots; second, to characterize elements of the systemic response in leaves leading to an interruption or failure of compatibility processes required for successful establishment of biotrophic leaf pathogens like Blumeria. New gene candidates will be pre-selected systematically for their regulatory role in compatibility by means of transiently transformed barley leaves upon Blumeria inoculation. Stable transgenic barley and maize lines (B3) generated with verified gene candidates and genes identified by other projects (A1, A2, B5, B6) will be tested with Blumeria and P. indica. By comparing candidate genes in the different plant - microbe systems, we will identify common regulatory processes, metabolites and metabolic networks implicated in compatibility including those required for successful interactions with mutualistic fungi.
Das Projekt "Transgenic wheat and non-target impacts on insect herbivores and food webs" wird/wurde gefördert durch: Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung. Es wird/wurde ausgeführt durch: Forschungsanstalt Agroscope Reckenholz-Tänikon ART.Genetically engineered (transgenic) crop varieties are grown on a steadily increasing area, covering an estimated 114 million ha in 2007. More than 42 million ha were planted with insect-resistant cotton and maize varieties that express cry genes derived from the soil bacterium Bacillus thuringiensis (Bt). A major concern with the widespread use of insecticidal transgenic crops is their potential impact on non-target organisms. This includes effects on herbivores that are not affected by the expressed toxins and could develop into secondary pests as well as predators and parasitoids that play an important role in natural pest regulation. To date, studies have primarily addressed direct effects of insecticidal proteins on non-target organisms. Here we address an important novel indirect interaction between insect-resistant transgenic plants and non-target organisms. We study the interactions between the plant's inherent defence mechanisms with the introduced trait and how this affects herbivores and their natural enemies. The studies will include detailed investigations on insect-plant interactions under protected conditions. Complementary field studies in the USA will investigate whether effects observed in the laboratory/glasshouse are of ecological relevance, i.e. also expressed under field conditions. The proposed studies address basic questions on plant-insect interactions. The results obtained within this project will thus be of fundamental scientific interest and of importance for ecological risk assessments related to the use of insect-resistant transgenic crops.
Das Projekt "Transformation von Perlhirse zur Verbesserung der Pilzresistenz" wird/wurde gefördert durch: Deutsche Forschungsgemeinschaft. Es wird/wurde ausgeführt durch: Universität Hamburg, Fachbereich Biologie, Biozentrum Klein Flottbek und Botanischer Garten.
Das Projekt "Glufosinat: Metabolismus in transgenen und nicht-transgenen Pflanzengeweben sowie Schicksal im Boden" wird/wurde gefördert durch: Höchst-Schering AgrEvo GmbH / RWTH Aachen University, Institut für Umweltforschung, Biologie V, Lehrstuhl für Umweltbiologie und -chemodynamik. Es wird/wurde ausgeführt durch: RWTH Aachen University, Institut für Umweltforschung, Biologie V, Lehrstuhl für Umweltbiologie und -chemodynamik.Glufosinat (oder Phosphinotricin) ist ein vergleichsweise modernes Herbizid, das seit etwa 25 Jahren in Gebrauch ist. Bei der Verbindung handelt es sich um eine Aminosäure; üblicherweise bezeichnet man das DL-Racemat als Glufosinat, das L-Enantiomer als Phosphinothricin. Die Verbindung ist Teilstruktur eines von den Pilzen Streptomyces viridochromogenes und Streptomyces hygroscopicus produzierten natürlichen Antibiotikums (Tripeptid: L-Alanin-L-Alanin-L-Phosphinothricin). Neben seiner antibakteriellen Wirkung zeigt Glufosinat eine nicht-selektive herbizide Wirkung. Der antibakterielle und herbizide Effekt geht nur vom L-Enantiomer aus; das D-Enantiomer ist inaktiv. Sowohl Glufosinat (Racemat) als auch das Tripeptid (Bialaphos oder Bilanaphos; mit L-Enantiomer) werden als Herbizide vermarktet. Die herbizide Wirkung von Phosphinothricin beruht auf einer Inhibition der Glutaminsynthetase. Glufosinat weist günstige ökotoxikologische Eigenschaften auf, z.B. bezüglich Versickerung, Abbau sowie Toxizität gegenüber Tier und Mensch. Auf Grund dieser Eigenschaften ist Glufosinat ein geeigneter Kandidat zur Herstellung gentechnisch modifizierter Herbizid-resistenter Pflanzen, um Glufosinat auch selektiv - im Nachauflauf - einsetzen zu können. Dazu wurden verschiedene Spezies, wie z.B. die Zuckerrübe, mit dem bar-Gen aus Streptomyces hygroscopicus transformiert. Das bar-Gen codiert für eine Phosphinothricin-N-acetyltransferase, die Phosphinothricin zum nicht herbizid-wirksamen, stabilen N-Acetylderivat umsetzt. Bei entsprechend hoher Expression des bar-Gens resultiert eine Glufosinat-resistente Pflanze. Ein Ziel unseres Forschungsvorhabens war es, den Metabolismus von Glufosinat und der einzelnen Enantiomere (L- und D-Phyosphinothricin) in transgenen und nicht transgenen Pflanzenzellkulturen zu untersuchen. Die transgenen Kulturen, die von der Zuckerrübe (Beta vulgaris) stammten, waren mit dem bar-Gen transformiert, exprimierten demnach die Phosphinothricin-N-acetyltransferase. Sie wurden aus entsprechenden Sprosskulturen initiiert. Daneben wurden nicht-transgene Kulturen von Zuckerrübe, Karotte (Daucus carota), Fingerhut (Digitalis purpurea) und Stechapfel (Datura stramonium) untersucht. In einer zweiten Versuchsserie wurden abgetrennte Sprosse und Blätter von 20 Wildpflanzen auf den Metabolismus von Glufosinat untersucht. Es sollte überprüft werden, ob qualitative und quantitative Unterschiede im Umsatz des Herbizids im Pflanzenreich vorkommen und möglicherweise eine natürliche (teilweise) Resistenz gegenüber Glufosinat existiert. Schließlich wurde das Schicksal des Herbizids im Boden (Abbau, Versickerung) nach Aufbringung des Wirksstoffs in einer handelsüblichen Formulierung auf ein bewachsenes Versuchsfeld im Freiland untersucht.
Das Projekt "Stickstoff: Kohlenstoffallokation in Agrarpflanzen" wird/wurde ausgeführt durch: Universität Heidelberg, Botanisches Institut.Verbundprojekt, finanziert von EG. Transgene Kartoffel, Tabak und Aradopsis mit veraenderter Aktivitaet an Enzymen der Nitrat-und Ammoniakassimilation werden hergestellt und die Auswirkung auf Stickstoffwechsel, Saccharose- und Staerkestoffwechsel sowie Whole-Plant Allokation und Wachstum untersucht.
Das Projekt "Towards a Better Sunlight to Biomass Conversion Efficiency in Microalgae (SUNBIOPATH)" wird/wurde gefördert durch: Kommission der Europäischen Gemeinschaften Brüssel. Es wird/wurde ausgeführt durch: Universite Liege.SUNBIOPATH - towards a better sunlight to biomass conversion efficiency in microalgae - is an integrated program of research aimed at improving biomass yields and valorisation of biomass for two Chlorophycean photosynthetic microalgae, Chlamydomonas reinhardtii and Dunaliella salina. Biomass yields will be improved at the level of primary processes that occur in the chloroplasts (photochemistry and sunlight capture by the light harvesting complexes) and in the cell (biochemical pathways and signalling mechanisms that influence ATP synthesis). Optimal growth of the engineered microalgae will be determined in photobioreactors, and biomass yields will be tested using a scale up approach in photobioreactors of different sizes (up to 250 L), some of which being designed and built during SUNBIOPATH. Biomethane production will be evaluated. Compared to other biofuels, biomethane is attractive because the yield of biomass to fuel conversion is higher. Valorisation of biomass will also be achieved through the production of biologicals. Significant progress has been made in the development of chloroplast genetic engineering in microalgae such as Chlamydomonas, however the commercial exploitation of this technology still requires additional research. SUNBIOPATH will address the problem of maximising transgenic expression in the chloroplast and will develop a robust system for chloroplast metabolic engineering by developing methodologies such as inducible expression and trans-operon expression. A techno economic analysis will be made to evaluate the feasibility of using these algae for the purposes proposed (biologicals production in the chloroplast and/or biomethane production) taking into account their role in CO2 mitigation.
Das Projekt "Activation tagging in aspen using an inducible two component Ac/Ds-enhancer element system" wird/wurde gefördert durch: Deutsche Forschungsgemeinschaft. Es wird/wurde ausgeführt durch: Johann Heinrich von Thünen-Institut, Bundesforschungsinstitut für Ländliche Räume, Wald und Fischerei, Institut für Forstgenetik.Based on the Ac/Ds two element transposition system from maize an activation tagging approach is suggested for the hybrid aspen (Populus tremula x tremuloides) line -Esch5-. The proposed approach is based on results obtained from our earlier work on the genetic transfer of the maize transposable element Ac and its functional analysis in hybrid and pure aspen lines. It was shown that the Ac element is active in aspen and reintegrates elsewhere in genomic regions in high frequency. However, a two element transposon tagging system where Ac and Ds are put together in crosses is not feasible in trees due to the in part long vegetative phases. To overcome this barrier, an inducible two element Ac/ATDs element system is suggested to induce activation tagged variants following two independent transformation steps. In combination with a 35S enhancer tetramer and outward facing two CaMV 35S promoter located near both ends of the ATDs element, expression of genes can be elevated which are located adjacent to the new integration site of the element. As selective marker for ATDs transposition, both knocking-out the expression of a phenotypic marker (rolC gene) and a negative selection marker gene (tms) are considered. Thus, the transposition can easily be screened in primary transgenic lines.
Das Projekt "Impact of transgenic crops on fertility of soils with different management history" wird/wurde gefördert durch: Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung. Es wird/wurde ausgeführt durch: Forschungsinstitut für biologischen Landbau Deutschland e.V..What impact does transgenic maize have on soil fertility? Among the factors that determine soil fertility is the diversity of the bacteria living in it. This is in turn affected by the form of agriculture practiced on the land. What role do transgenic plants play in this interaction? Background Soil fertility is the product of the interactions between the parental geological material from which the soil originated, the climate and colonization by soil organisms. Soil organisms and their diversity play a major role in soil fertility, and these factors can be affected by the way the soil is managed. The type of farming, i.e. how fertilizers and pesticides are used, has a major impact on the fertility of the soil. It is known that the complex interaction of bacterial diversity and other soil properties regulates the efficacy of plant resistance. But little is known about how transgenic plants affect soil fertility. Objectives The project will investigate selected soil processes as indicators for how transgenic maize may possibly alter soil fertility. The intention is in particular to establish whether the soil is better able to cope with such effects if it contains a great diversity of soil bacteria. Methods Transgenic maize will be planted in climate chambers containing soils managed in different ways. The soil needed for these trials originates from open field trials that have been used for decades to compare various forms of organic and conventional farming. These soils differ, for example, in the way they have been treated with pesticides and fertilizers and thus also with respect to their diversity of bacteria. The trial with transgenic maize will measure various parameters: the number of soil bacteria and the diversity of their species, the quantity of a small number of selected nutrients and the decomposition of harvest residues. It will be possible to conclude from this work how transgenic plants affect soil fertility. Significance The project will create an important basis for developing risk assessments that incorporate the effects of transgenic plants on soil fertility.
Das Projekt "Powdery mildew resistance, field performance and molecular analysis of GM wheat expressing barley chitinase and glucanase" wird/wurde gefördert durch: Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung. Es wird/wurde ausgeführt durch: Eidgenössische Technische Hochschule Zürich, Institut für Agrarwissenschaften, Departement Biologie.How does fungal resistance of transgenic wheat behave in the open? Fungi, and most particularly mildew, cause enormous losses in wheat harvests. To overcome this, wheat was genetically engineered to resist mildew. But there is still very little information about how this resistance functions in open cultivation. Background Mildew and other fungi cause tremendous damage in wheat production, necessitating the use of sprayed crop-protection products. It has been possible to use genetic engineering to overcome this problem by incorporating a specific barley gene in the wheat genome. This gene produces proteins that degrade the cell walls of fungi and destroy the pests. Little is known, though, about the efficacy of this method in open cultivation or the conceivable risks. Objectives The project aims to investigate how fungal resistance in genetically modified wheat behaves in the open. The aim is to measure the efficacy of this resistance against fungal diseases and to assess the potential benefit for agriculture. Methods The efficacy of mildew resistance will be investigated in three successive years as part of the field trial with transgenic wheat (cf. Keller project I). Among other things, the activity of the resistance genes and the productivity of the wheat lines will be measured. Parallel trials will check the results of the field trial under greenhouse conditions. Significance Plants behave differently in the greenhouse and in the open. It is therefore necessary to test the action of the additional resistance genes in field trials. This project will evaluate both resistance to true mildew and resistance to other pathogenic fungi.
