Genetic Engineering for Nitrogen Fixation

There is a time in scientific research when a number of developments coincide making it possible to progress with a tough and complicated problem. It is believed that such a time has come in the area of biological nitrogen fixation. A better understanding of photosynthesis, cell hybridization, plasmid, and gene transfer between cells not necessarily genetically related, have opened new avenues of research. New developments in traditional genetics, cell biology, biochemistry, including enzyme chemistry, and plant physi ology have brought about the feeling this is a most appro priate time to pull together the different approaches in a conference where the lines of research could be discussed and thus help to speed up developments in this area. What makes biological nitrogen fixation especially im portant is the promise that a good understanding of the basic problem would help us to make organisms more amenable to fix nitrogen, not only in symbiosis with legumes, but also with other plant species and develop a wider variety of organisms with the ability to fix N • It will also 2 encourage a search for naturally occurring N2 fixing organ isms other than the traditional N2 fixers. Some success has already been encountered in this area. Success in broadening the field of nitrogen fixing would help to increase food supply, especially in de veloping countries which cannot afford to purchase synthetic nitrogen sources.

Contenu
Opening Remarks.- General Introduction.- Overview of Nitrogen Fixation.- Plasmids as Vectors for Gene Cloning.- The Nitrogen Fixation Cistrons of Klebsiella pneumoniae.- Transformation of Nitrogen-Fixation Genes in Azotobacter.- Genetic Hybridization of Root-Nodule Bacteria (Rhizobium).- Genetic Mapping of Rhizobium meliloti using RP4.- Nitrogen Fixation (NIF) Regulatory Mutants of Klebsiella: Determination of the Energy Cost of N2 Fixation in vivo.- Cloning Nitrogen Fixing Genes from Klebsiella pneumoniae in vitro and the Isolation of NIF Promoter Mutants Affecting Glutamine Synthetase Regulation.- The Development of a Molecular Cloning System in Higher Plants.- The Ti-Plasmid of Agrobacterium tumefaciens, a Natural Vector for the Introduction of NIF Genes in Plants?.- The Incorporation and Expression of Agrobacterium Plasmid Genes in Crown Gall Tumors.- Engineered Plant Cell or Fungal Association with Bacteria that Fix Nitrogen.- Uptake of the Nitrogen Fixing Blue-Green Alga Gloeocapsa by Plant Protoplasts.- The Azolla Anabaena azollae symbiosis.- Nitrogen Fixation by Azolla in Rice Fields.- Lectins as Determinants of Specificity in Legume-Rhizobium Symbiosis.- Plant Protoplast Fusion and Hybridization.- Biochemistry of Nitrogenase.- Energy Coupling Efficiency of Symbiotic Nitrogen Fixation.- Approaches for Increasing Photosynthetic Efficiency Efficiency.- Rate-Limiting Steps in Biological Photoproductivity.- Photosynthesis and Symbiotic Nitrogen Fixation in Phaseolus vulgaris L..- Contributed Papers.- Use of RP4 Plasmids Carrying Bacteriophage Mu Insertions in Nitrogen Fixing Bacteria Klebsiella pneumoniae and Rhizobium meliloti.- Genetic Control of Symbiotic Nitrogen Fixation in Soybeans.- Glutamine Synthetase Control of Nitrogen Fixation in Rhizobia.- ofPotential Sex Factors into Rhizobium japonicum.- Antibiotic Resistance in Rhizobium japonicum: Implications for Safety and Interpretation of NIF Transfer from Rhizobium.- Limitations to Field Application of Rhizobium inoculants.- Fast Reaction Kinetics of Ferredoxin.- Transient Intermediate Species in the Oxidation of Hydrazine.- Roundtable Discussions and Special Topics.- Recombinant DNA Guidelines for Nitrogen Fixation in Plant Sciences Roundtable Summary.- Potential Associated Nitrogen Fixing Systems Roundtable.- Panel on Public Impact Issues.- Environmental Impact.- Legal Aspects of Recombinant DNA Research Legal Aspects.- Agricultural Productivity and Biological Nitrogen Fixation, An International View.- List of Participants.