Objective The objectives of this proposal are to get an integrated view i) of the regulator networks operating in legumes and rhizobia leading to their symbiotic association and to symbiotic nitrogen fixation and ii) of the metabolic interactions implicated in nitrogen fixation. Studies directed towards these objectives will be performed on two grain legumes, faba bean and french bean, and one forage legume, alfalfa, and on their respective nodulating rhizobia. For reasons of application of the results obtained, two industrial partners will participate in the project. l.We will characterize and compare the expression pattern, inside the nodule and inside source tissues, of genes which encode diagnostic enzyme components of the major metabolic routes relevant for the process of nitrogen fixation: among these are the plant ADP-glucose pyrophosphorylase, the chloroplastidic fructose-1,6bisphosphatase, and the triose-phosphate translocator which are involved in the carbon flux to the nodules; plant sucrose synthase and carbonic anhydrase involved in the plant carbon metabolism in nodule tissues, the bacterial dicarboxylic acid permease which is involved in the uptake of carbon compounds by the microsymbiont, and the plant glutamine synthetase which participates in the assimilation of fixed nitrogen. 2.Recording the effects of modulating the individual expression of some of these genes of both plant and bacterial origin on the efficiency of nitrogen fixation in various environmental conditions, will give information on the implication of th; encoded enzymes and the corresponding metabolic pathways on the overall balance of the nitrogen fixation process and/or its flexibility towards environmental variations. We will use highly defined environmental conditions, e.g. in growth chambers and in addition non-artificial conditions, e.g. in field trials, to get an integrated view under conditions suitable for application. Evaluations on the expression of bacterial or plant genes in engineered symbiotic associations will give information on the physiological integration of the system and indications or possible regulatory signals. 3.We will attempt to further characterize these regulatory signals: metabolic signals will be looked for by expression studies in cell cultures or by transient expression in protoplasts. Identification and comparison of regulatory secIuences in the upstream regions of the genes will also be exploited in a search for developmental signals, specifically in case where expression patterns of several genes would be identical. 4.Regulation of the expression of bacterial genes, either directly involved in nitrogen fixation or indicative of the differentiation of endosymbiotic bacteria, will be studied as part of the carbon as well as the nitrogen regulatory and metabolic network of the nodule and as a means to identify the regulatory signals. Fields of science natural sciencesbiological sciencesmicrobiologybacteriologyagricultural sciencesagriculture, forestry, and fisheriesagricultureindustrial cropsfoddernatural sciencesbiological sciencesbiochemistrybiomoleculesproteinsenzymesagricultural sciencesagriculture, forestry, and fisheriesagriculturegrains and oilseedslegumes Programme(s) FP4-BIOTECH 2 - Specific research, technological development and demonstration programme in the field of biotechnology, 1994-1998 Topic(s) 030104 - Metabolisms Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator Universität Bielefeld EU contribution No data Address 25,Universitätsstraße 25 33615 Bielefeld Germany See on map Total cost No data Participants (8) Sort alphabetically Sort by EU Contribution Expand all Collapse all AACHEN UNIVERSITY OF TECHNOLOGY Germany EU contribution No data Address 1,Worringer Weg 1 52074 AACHEN See on map Total cost No data AGRIFUTUR SRL Italy EU contribution No data Address Via Campagnole 8 ALFIANELLO See on map Total cost No data ASSOCIACAO DO INSTITUTO DE BIOLOGIA MOLECULAR E CELULAR Portugal EU contribution No data Address Rua do Campo Alegre 823 4150-180 PORTO See on map Total cost No data Biological Research Centre - Hungarian Academy of Sciences Hungary EU contribution No data Address 62,Temesvári krt. 6701 Szeged See on map Total cost No data CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE France EU contribution No data Address Chemin de Borde-Rouge INRA 31326 AUREVILLE See on map Total cost No data CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE France EU contribution No data Address Avenue de la Terrasse 1Bètiment 23 91190 GIF SUR YVETTE See on map Total cost No data NATIONAL RESEARCH COUNCIL OF ITALY Italy EU contribution No data Address Via Guglielmo Marconi 10 80125 NAPOLI See on map Total cost No data Plantec Biotechnologie GmbH Germany EU contribution No data Address 14,Hermannswerder 14473 Potsdam See on map Total cost No data