Das Projekt "Carbon acquisition during pathogenic development of Ustilago maydis and Colletotrichum graminicola" wird vom Umweltbundesamt gefördert und von Karlsruher Institut für Technologie (KIT), Institut für Toxikologie und Genetik (ITG) durchgeführt. 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 vom Umweltbundesamt gefördert und von Justus-Liebig-Universität Gießen, Institut für Phytopathologie durchgeführt. 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 "Towards a Better Sunlight to Biomass Conversion Efficiency in Microalgae (SUNBIOPATH)" wird vom Umweltbundesamt gefördert und von Universite Liege durchgeführt. 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 vom Umweltbundesamt gefördert und von Johann Heinrich von Thünen-Institut, Bundesforschungsinstitut für Ländliche Räume, Wald und Fischerei, Institut für Forstgenetik durchgeführt. 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 vom Umweltbundesamt gefördert und von Forschungsinstitut für biologischen Landbau Deutschland e.V. durchgeführt. 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 vom Umweltbundesamt gefördert und von Eidgenössische Technische Hochschule Zürich, Institut für Agrarwissenschaften, Departement Biologie durchgeführt. 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.
Das Projekt "Potential for transgene flow from wheat to its wild relatives Aegilops sp." wird vom Umweltbundesamt gefördert und von Universite de Neuchatel, Institut de Biologie durchgeführt. Transgenes inserted into crop plants could migrate into the genetic material of closely related wild types and cause undesirable effects - such as the development of resistance to herbicides. Background Goatgrasses (Aegilops) are genetically closely related to wheat and are often found in wheat fields, where they can be very aggressive weeds. If genetically modified wheat - for example a variety resistant to a certain herbicide - was brought onto the market on a large scale, there would be a danger of the modified genes migrating by means of wheat pollen into the genetic material (genome) of goatgrasses, making these weeds resistant to herbicides too. This risk has been demonstrated on many occasions. However, little is known about the actual probability of this gene migration occurring. Objectives The project aims to quantify to which extent the genes of genetically unmodified wheat have already mingled naturally with the genome of goatgrasses growing in the vicinity. The project also aims to assess the extent to which modified genes from transgenic wheat could spread into other, related wild types if they were to cross. Methods Various goat grasses from the Mediterranean region and North America will be investigated using genetic markers to establish how many genes have already migrated from unmodified wheat into the genome of these grasses through foreign pollination. The way these migrated genes are passed on to other related wild species will be investigated by cross-breeding various goatgrasses under both natural and experimental conditions. Significance The frequency with which wheat genes are transferred to closely related wild types and an understanding of the mechanisms by which the transferred genes spread among the wild types are important in assessing the risk associated with the development of marketable transgenic wheat varieties. In addition, the goatgrasses that will be studied are currently native predominantly around the Mediterranean and in North America but are likely to become more common in our country in the future, not least because of their migratory potential and the effects of global warming.
Das Projekt "Effects of GM wheat cultivation on the decomposition of GM biomass by soil arthropods and annelids" wird vom Umweltbundesamt gefördert und von Universität Bern, Abteilung Synökologie Institut für Ökologie und Evolution durchgeführt. How digestible is transgenic wheat for earthworms? Genetically modified crops are intended to be toxic for the pests that attack them. At the same time, however, they could harm beneficial organisms. Background Crop plants can be genetically modified to make them immune to pathogens such as fungi, or unpalatable or toxic for pests that feed on them. The overriding objective of plant breeders is to reduce the use of crop protection products. The same substances may, however, be harmful to animals that are important for plants, such as woodlice and worms, as they play a central role in decomposing plant material and releasing nutrients into the soil. Objectives The diversity of species and activity of selected soil-dwelling organisms are expected to provide information on the impact of transgenic plants on these important groups of animals. In addition, nutrient uptake and reproduction of selected soil-dwelling organisms will be compared in areas used to grow genetically modified wheat and areas used to grow conventional wheat. Methods Arthropods (such as woodlice) and segmented worms (such as earthworms) are beneficial invertebrates that live in the soil. Their diversity will be investigated using soil samples as part of the field trial with transgenic wheat (cf. Keller project I). Their activity and nutrient uptake will be determined by burying a constant volume of leaf material derived from transgenic wheat plants and conventional wheat plants for a period of several months. The amount eaten by the soil-living organisms will subsequently be measured. Significance Little is known about the effect of substances that may be released into the soil from the transgenic plants being investigated here. The project is using arthropods and annelid worms as an example of how to investigate this question. The ecologically oriented design of the project will also create a basis for assessing the risk of transgenic plants affecting soil fertility in open cultivation.
Das Projekt "Analysis of Pm3 resistance gene function in transgenic wheat" wird vom Umweltbundesamt gefördert und von Universität Zürich, Institut für Pflanzenbiologie durchgeführt. Can wheat be genetically engineered to become durably resistant to mildew? Individual resistance genes to mildew protect wheat plants against some, but not all, variants of this pathogen. A series of field trials will be carried out to test various means of genetically engineering wheat to enhance its resistance. The combination of several genes will play a central role in this project. Background Wheat has various genes that are responsible for resistance to mildew. One of these genes has seven variants, known as alleles. Individually, these alleles make wheat resistant to some, but not all, variants of the mildew fungus. There are in fact varieties of conventional wheat that have a certain degree of resistance to mildew. However, this resistance is often lost within a short time-frame. To overcome this shortcoming, genetic engineering will be used to combine the alleles. Field trials are the only way to find out whether long-term resistance can be achieved by this means. Objectives Various transgenic wheat lines will undergo comprehensive testing in a field trial (cf. Keller project I). The aim is first to establish whether the individual lines do indeed have better resistance to mildew. The second aim is to investigate how the additional gene affects the performance of the plant - in terms of yield, for example. The project also aims to analyse the effect of the environment on the plants' resistance properties. Methods Transgenic wheat lines - each containing one of the seven resistance alleles - will be developed and tested over three years for properties including seed maturation, yield and resistance following artificial and natural infection with mildew. Some of these lines will also be cultivated as a seed mixture. At the same time, wheat lines will be produced which combine the different alleles in the same plant. Both trials will test whether and to what extent mildew develops less frequently. Significance This is the first time that a field trial of this size will be carried out with transgenic plants in Switzerland. The project will not only elicit a major response from the general public, it will also provide new facts about the possible benefits of genetically modified plants.
Das Projekt "Transgenic wheat and non-target impacts on insect herbivores and food webs" wird vom Umweltbundesamt gefördert und von Forschungsanstalt Agroscope Reckenholz-Tänikon ART durchgeführt. 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.
