Nitrogen fixation research progress : Proceedings of the 6th international symposium on Nitrogen Fixation, Corvallis, OR 97331, August 4-10, 1985

This Symposium, held August 4-10, 1985 on the campus of Oregon State University in Corvallis, is the sixth of a series of international symposia concerned with broad aspects of the fixation of nitrogen gas by biological and chemical means. The first symposium of this series was held in Pullman, Washington (1974), the second in Salamanca, Spain (1976), the third in Madison, Wisconsin (1978), the fourth in Canberra, Australia (1980) and the fifth in Noordwij~erhout, The Netherlands (1983). Prior to the organization of these symposia, small groups of usually no more than 10 or 12 of the now "old guard" in the field met in some obscure places, including Butternut Lake, Wisconsin, Sanabel Island, Florida and Camp Sage hen in California, to discuss developments in the field. Concern about an energy crisis in the nineteen seventies served as an impetus for the organization of workshops and preparatiol. of publications urging government agencies to provide funds for the support of several neglected areas in the field, including the genetics of nitrogen-fixing organisms and the biology of Frankia. In looking back, it becomes apparent that there have been drastic changes in the extent of research support in the field and in the contents of the programs of the continuing series of symposia.

Plant Genetics Relevant to Symbiotic Nitrogen Fixation.- A. Breeding Approaches.- Host Plant Characteristics of Common Bean Lines Selected Using Indirect Measures of N2 Fixation.- Genetic Improvement of Symbiotic Nitrogen Fixation in Legumes.- Plant Host Genetics of Nodulation and Symbiotic Nitrogen Fixation in Pea and Soybean.- Poster Summaries:.- (i) Genetic Improvement of Legume-Rhizobium Symbiosis.- (ii) Legume Nodulation Mutants.- B. Molecular Approaches.- Structure and Transcription of the Soybean Leghemoglobin and Nodulin Genes.- Nodulin Gene Expression in Pisum sativum.- Poster-Summaries.- Poster-Summaries.- Discussion Group Summary (Convenor: N.J. Brewin).- Microbial Genetics Relevant to Symbiotic Nitrogen Fixation.- A. Nodulation (nod) Genes.- Identification and Organization of Rhizobium meliloti Genes Relevant to the Initiation and Development of Nodules.- Plant-Secreted Factors Induce the Expression of R. trifolii Nodulation and Host-Range Genes.- Fine Structure Studies of R. Meliloti and NodDABC Genes.- Structure and Regulation of the Nodulation Genes of Rhizobium leguminosarum.- Genes of Rhizobium japonicum Involved in Development of Nodules.- Developmental Biology of the Rhizobium meliloti-Alfalfa Symbiosis: A Joint Genetic and Cytological Approach.- Poster Summaries:.- (i) nod Genes in Fast-Growing Rhizobia.- (ii) nod Genes in Slow-Growing Rhizobia.- (iii) Genes Involved in Nodule Development.- (iv) Genes Involved in Competitiveness.- (v) Miscellaneous.- Discussion Group Summary (Convenor: G. Ditta).- B. Organization and Regulation of nif Genes.- Organization and Regulation of Symbiotic Nitrogen Fixation Genes from Bradyrhizobium japonicum.- Organization and Regulation of Rhizobium meliloti and Parasponia bradyrhizobium Nitrogen Fixation Genes.- Rhizobium phaseoli: Nitrogen Fixation Genes and DNA Reiteration.- Poster Summaries.- Poster Summaries.- C. Genes Involved in Nodule Functioning.- A Model of Nutrient Exchange in the Rhizobium-Legume Symbiosis.- Genes Involved in the Carbon Metabolism of Bacteroids.- Characterization, Significance and Transfer of Hydrogen Uptake Genes from Rhizobium japonicum.- Poster Summaries:.- (i) Carbon Metabolism and Ammonia Assimilation.- (ii) Hydrogen Metabolism.- Discussion Group Summary (Convenor: N.J. Brewin).- Recognition and Infection in Symbiosis.- Recognition and Infection of Clover Root Hairs by Rhizobium trifolii.- Recognition and Infection by Slow-Growing Rhizobia.- Poster Summaries:.- (i) Competition and Attachment.- (ii) Host-Induced Phenomena.- (iii) Compositional Variations.- (iv) Actinorhizal Systems.- Discussion Group Summary (Convenor: R.W. Carlson).- Physiology of Nitrogen-Fixing Symbioses.- Carbon Metabolism in Legume Nodules.- Factors Limiting N2 Fixation by the Legume-Rhizobium Symbiosis.- Site of Nitrogenase in Frankia in Free-Living Culture and in Symbiosis.- Use of 13N to Study N2 Fixation and Assimilation By Cyanobacterial-Lower Plant Associations.- Poster Summaries:.- (i) Structural Studies.- (ii) Factors Affecting Nodulation.- (iii) Nitrogen Metabolism.- (iv) Carbon Metabolism.- (v) Oxygen Transport and Effects.- (vi) Hydrogen Uptake and Evolution.- (vii) Actinorhizal Systems.- (viii) Associative Relationships.- Discussion Group Summary (Convenor: R.V. Klucas).- Physiology and Ecology of Nitrogen-Fixing Microorganisms.- Recent Advances in the Ecology of Rhizobium.- Physiological and Biochemical Aspects of N2-Fixing Cyanobacteria.- Poster Summaries:.- (i) Rhizobium - Competition.- (ii) Rhizobium - Survival.- (iii) Rhizobium - General.- (iv) Associative Bacteria.- (v) Cyanobacteria.- (vi) Frankia.- (vii) Miscellaneous.- Discussion Group Summary (Convenor: M.G. Yates).- Genetics of Nitrogen Fixation in Free-Living Bacteria.- Progress in Understanding Organization and Expression of nif Genes in Klebsiella.- Regulation of Klebsiella pneumoniae Nitrogen Fixation Gene Promoters by Regulatory Proteins ntrC, nifA, and nifL.- Genetic and Physical Characterization of nif and ntr Genes in Azotobacter chroococcum and A. vinelandii.- Advances in The Genetics of Azospirillum.- Organization of the Genes For Nitrogen Fixation in the Cyanobacterium Anabaena.- Development of the Genetics Of Heterocyst-Forming Cyano-Bacteria.- Genetics of Nitrogen Fixation In Photosynthetic Bacteria.- Poster Summaries:.- (i) Identification, Cloning and Mapping of nif.- (ii) Analysis of nif Sequences.- (iii) Rearrangement of nif DNA.- (iv) nif Regulation.- (v) Biochemistry and Physiology of Mutants.- Discussion Group Summary (Convenor: C. Elmerich).- Enzymology and Chemistry of Nitrogen Fixation.- A. Nitrogenase.- Nitrogenase Mechanism - An Overview.- Regulation of Nitrogenase Activity in the Anoxygenic Phototrophic Bacteria.- Structure And Mechanism of the Azobobacter vinelandii Fe Protein.- Role of Fe Protein in Nitrogenase Catalysis.- Studies on the Structure And Function of The Mofe Protein Of Nitrogenase.- Redox Properties of The Nitrogenase Component Proteins From Azotobacter vinelandii.- Mossbauer and EPR Studies on Nitrogenase.- Iron-Molybdenum Cofactor of Nitrogenase.- Redox and Compositional Insights Into The Iron-Molybdenum Cofactor of Azotobacter vinelandii Nitrogenase as a Guide to Synthesis of New Mo-Fe-S Clusters.- Poster Summaries:.- (i) Mechanism.- (ii) Proteins and Cofactors.- (iii) Purification and Properties.- (iv) Regulation.- (iv) ATP Effects.- Discussion Group Summary (Convenor: R.H. Burris).- B. Chemical Approaches.- From Phosphorus Towards Sulphur: The Development of New Nitrogen Binding Sites.- Detection of Intermediates in Chemical N2 Fixation.- Poster Summaries.- Poster Summaries.- Discussion Group Summary (Convenor: G.J. Leigh).- Nitrogen Fixation in Agriculture and Forestry: Strategies, Limitations and Potential.- Nitrogen Fixation in Agriculture in Temperate Regions.- Current Research Strategies for Use of Actinorhizal Symbioses in Forestry.- Biological Nitrogen Fixation in Tropical Agriculture.- Applications of Nitrogen Fixation in Agriculture and Forestry.- Poster Summaries:.- (i) Management Practice.- (ii) Rhizobial Inoculant Technology.- (iii) Frankia.- (iv) Free-Living Fixers.- (v) Quantitation.- Discussion Group Summary (Convenors: D.B. Hannaway And T.L. Righetti).- Current Thoughts on Nitrogen Fixation.- Current Thoughts on Nitrogen Fixation.- Author Index.