Genetic Engineering of Symbiotic Nitrogen Fixation and Conservation of Fixed Nitrogen

Genetic Engineering of Symbiotic Nitrogen Fixation and Conservation of Fixed Nitrogen
Author: J. M. Lyons
Publisher: Springer Science & Business Media
Total Pages: 681
Release: 2012-12-06
Genre: Medical
ISBN: 1468439537

The present volume developed from a symposium entitled "Enhancing Biological Production of Ammonia From Atmospheric Nitrogen and Soil Nitrate" that was held at Lake Tahoe, California in June, 1980. The meeting was supported by the National Science Foundation, Division of Engineering and Applied Sciences and by the College of Agricultural and Environmental Sciences, University of California, Davis. A total of 99 scientists from 41 insti tutions participated. Plants capture solar energy in photosynthesis and use mineral nutrients to produce human food and fiber products. The extent to which such materials are removed from agricultural production sites represents a permanent drain of mineral nutrients. Some plants of agronomic importance such as alfalfa, soybean, and clover associate with soil bacteria and use photosynthetic energy to reduce N2 to NH3. Many other free-living bacteria and some symbioses involving procaryotes and eucaryotes also reduce N2. Such processes repre sent one natural mechanism by which Man can augment soil N for agronomic purposes without using fossil fuel to synthesize and distribute N fertilizer. Other metabolic conversions in the N cycle and physical leaching processes remove N made available through N2 fixation. Thus nitrification, denitrification, and utilization of soil N by plants are processes that must be con sidered if one is to conserve N captured by N2 fixation. The meeting at Lake Tahoe united scientists from many disci plines to review the literature and to discuss current research directed toward the goal stated in the symposium title.

Genetically Engineered Crops

Genetically Engineered Crops
Author: National Academies of Sciences, Engineering, and Medicine
Publisher: National Academies Press
Total Pages: 607
Release: 2017-01-28
Genre: Science
ISBN: 0309437385

Genetically engineered (GE) crops were first introduced commercially in the 1990s. After two decades of production, some groups and individuals remain critical of the technology based on their concerns about possible adverse effects on human health, the environment, and ethical considerations. At the same time, others are concerned that the technology is not reaching its potential to improve human health and the environment because of stringent regulations and reduced public funding to develop products offering more benefits to society. While the debate about these and other questions related to the genetic engineering techniques of the first 20 years goes on, emerging genetic-engineering technologies are adding new complexities to the conversation. Genetically Engineered Crops builds on previous related Academies reports published between 1987 and 2010 by undertaking a retrospective examination of the purported positive and adverse effects of GE crops and to anticipate what emerging genetic-engineering technologies hold for the future. This report indicates where there are uncertainties about the economic, agronomic, health, safety, or other impacts of GE crops and food, and makes recommendations to fill gaps in safety assessments, increase regulatory clarity, and improve innovations in and access to GE technology.

Symbiotic Nitrogen Fixation

Symbiotic Nitrogen Fixation
Author: P. Graham
Publisher: Springer Science & Business Media
Total Pages: 206
Release: 2012-12-06
Genre: Science
ISBN: 9401110883

During the past three decades there has been a large amount of research on biological nitrogen fixation, in part stimulated by increasing world prices of nitrogen-containing fertilizers and environmental concerns. In the last several years, research on plant--microbe interactions, and symbiotic and asymbiotic nitrogen fixation has become truly interdisciplinary in nature, stimulated to some degree by the use of modern genetic techniques. These methodologies have allowed us to make detailed analyses of plant and bacterial genes involved in symbiotic processes and to follow the growth and persistence of the root-nodule bacteria and free-living nitrogen-fixing bacteria in soils. Through the efforts of a large number of researchers we now have a better understanding of the ecology of rhizobia, environmental parameters affecting the infection and nodulation process, the nature of specificity, the biochemistry of host plants and microsymbionts, and chemical signalling between symbiotic partners. This volume gives a summary of current research efforts and knowledge in the field of biological nitrogen fixation. Since the research field is diverse in nature, this book presents a collection of papers in the major research area of physiology and metabolism, genetics, evolution, taxonomy, ecology, and international programs.

Biological Nitrogen Fixation for Sustainable Agriculture

Biological Nitrogen Fixation for Sustainable Agriculture
Author: J.K. Ladha
Publisher: Springer Science & Business Media
Total Pages: 212
Release: 2013-03-09
Genre: Nature
ISBN: 9401709106

Chemical fertilizers have had a significant impact on food production in the recent past, and are today an indispensable part of modern agriculture. On the other hand, the oil crisis of the 1970s and the current Middle East problems are constant reminders of the vulnerability of our fossil fuel dependent agriculture. There are vast areas of the developing world where N fertilizers are neither available nor affordable and, in most of these countries, balance of payment problems have resulted in the removal of N fertilizer subsidies. The external costs of environmental degradation and human health far exceed economic concerns. Input efficiency of N fertilizer is one of the lowest and, in turn, contributes substantially to environmental pollution. Nitrate in ground and surface waters and the threat to the stability of the ozone layer from gaseous oxides of nitrogen are major health and environmental concerns. The removal of large quantities of crop produce from the land also depletes soil of its native N reserves. Another concern is the decline in crop yields under continuous use of N fertilizers. These economic, environmental and production considerations dictate that biological alternatives which can augment, and in some cases replace, N fertilizers must be exploited. Long-term sustainability of agricultural systems must rely on the use and effective management of internal resources. The process of biological nitrogen fixation offers and economically attractive and ecologically sound means of reducing external nitrogen input and improving the quality and quantity of internal resources. In this book, we outline sustainability issues that dictate an increased use of biological nitrogen fixation and the constraints on its optimal use in agriculture.

Principles and Applications of Soil Microbiology

Principles and Applications of Soil Microbiology
Author: Terry Gentry
Publisher: Elsevier
Total Pages: 744
Release: 2021-06-06
Genre: Science
ISBN: 0323851401

Written by leading experts in their respective fields, Principles and Applications of Soil Microbiology 3e, provides a comprehensive, balanced introduction to soil microbiology, and captures the rapid advances in the field such as recent discoveries regarding habitats and organisms, microbially mediated transformations, and applied environmental topics. Carefully edited for ease of reading, it aids users by providing an excellent multi-authored reference, the type of book that is continually used in the field. Background information is provided in the first part of the book for ease of comprehension. The following chapters then describe such fundamental topics as soil environment and microbial processes, microbial groups and their interactions, and thoroughly addresses critical nutrient cycles and important environmental and agricultural applications. An excellent textbook and desk reference, Principles and Applications of Soil Microbiology, 3e, provides readers with broad, foundational coverage of the vast array of microorganisms that live in soil and the major biogeochemical processes they control. Soil scientists, environmental scientists, and others, including soil health and conservation specialists, will find this material invaluable for understanding the amazingly diverse world of soil microbiology, managing agricultural and environmental systems, and formulating environmental policy. - Includes discussion of major microbial methods, embedded within topical chapters - Includes information boxes and case studies throughout the text to illustrate major concepts and connect fundamental knowledge with potential applications - Study questions at the end of each chapter allow readers to evaluate their understanding of the materials

The Rhizobiaceae

The Rhizobiaceae
Author: Herman P. Spaink
Publisher: Springer Science & Business Media
Total Pages: 576
Release: 2012-12-06
Genre: Science
ISBN: 9401150605

The Rhizobiaceae, Molecular Biology of Model Plant-Associated Bacteria. This book gives a comprehensive overview on our present molecular biological knowledge about the Rhizobiaceae, which currently can be called the best-studied family of soil bacteria. For many centuries they have attracted the attention of scientists because of their capacity to associate with plants and as a consequence also to specifically modify plant development. Some of these associations are beneficial for the plant, as is the case for the Rhizobiaceae subgroups collectively called rhizobia, which are able to fix nitrogen in a symbiosis with the plant hosts. This symbiosis results in the fonnation of root or stem nodules, as illustrated on the front cover. In contrast, several Rhizobiaceae subgroups can negatively affect plant development and evoke plant diseases. Examples are Agrobacterium tumefaciens andA. rhizogenes which induce the formation of crown galls or hairy roots on the stems of their host plants, respectively (bottom panels on front cover). In addition to the obvious importance of studies on the Rhizobiaceae for agronomy, this research field has resulted in the discovery of many fundamental scientific principles of general interest, which are highlighted in this book. To mention three examples: (i) the discovery of DNA transfer of A.

Biological Nitrogen Fixation

Biological Nitrogen Fixation
Author: Gary S. Stacey
Publisher: Springer Science & Business Media
Total Pages: 960
Release: 1992-04-30
Genre: Nature
ISBN: 9780412024214

Phylogenetic classification of nitrogen-fixing organisms. Physiology of nitrogen fixation in free-living heterotrophs. Nitrogen fixation by photosynthetic bacteria. Nitrogen fixation in cyanobacteria. Nitrogen fixation by methanogenic bacteria. Associative nitrogen-fixing bacteria. Actinorhizal symbioses. Ecology of bradyrhizobium and rhizobium. The rhizobium infection process. Physiology of nitrogen-fixing legume nodules: compartments, and functions. Hydrogen cycling in symbiotic bacteria. Evolution of nitrogen-fixing symbioses. The rhizobium symbiosis of the nonlegume parasponia. Genetic analysis of rhizobium nodulation. Nodulins in root nodule development. Plant genetics of symbiotic nitrogen fixation. Molecular genetics of bradyrhizobium symbioses. The enzymology of molybdenum-dependent nitrogen fixation. Alternative nitrogen fixation systems. Biochemical genetics of nitrogenase. Regulation of nitrogen fixation genes in free-living and symbiotic bacteria. Isolated iron-molybdenum cofactor of nitrogenase.

Cycles of Soils

Cycles of Soils
Author: F. J. Stevenson
Publisher: John Wiley & Sons
Total Pages: 450
Release: 1999-04-05
Genre: Technology & Engineering
ISBN: 9780471320715

An updated edition of the classic work on the inorganic chemistry of soils. * With its companion volume, Humus Chemistry, forms a complete, advanced-level treatment of both organic and inorganic aspects of soil chemistry. * Revised to keep pace with the latest developments in the field. * Provides more in-depth treatment of all topics.

Enhancement of Biological Nitrogen Fixation of Common Bean in Latin America

Enhancement of Biological Nitrogen Fixation of Common Bean in Latin America
Author: F.A. Bliss
Publisher: Springer Science & Business Media
Total Pages: 164
Release: 2012-12-06
Genre: Science
ISBN: 9401121001

The common bean (Phaseolus vulgaris L.) is the most important pulse crop in Latin America, as well as in large parts of Asia and Africa. It is particularly important due to its ability, in symbiosis with Rhizobium bacteria, to fix atmospheric nitrogen and due to its high nutrient value. Incorporating contributions from plant breeders, microbiologists, plant physiologists and soil scientists, this volume reports the results of an FAO/IAEA Coordinated Research Programme (1985--1991), whose main objective was to enhance yield and biological nitrogen fixation in common bean by reducing its reliance on soil and fertilizer nitrogen. The volume will be invaluable to scientists working on biological nitrogen fixation and legume production.