Arbuscular Mycorrhizas

In the years since the first edition of “Arbuscular Mycorrhizas: Physiology and Function” was published, an exceptional proliferation of interest in mycorrhizal biology has developed. This has been associated with advances in different research disciplines such as genetics, genomics, proteomics, metabolomics and physiology, advances which have generated better insight into topics of mycorrhizal biology, including the mechanisms of host-mycorrhiza interactions pre- and post-penetration, the influence of the symbiosis on the host and its surroundings, and the evolution and diversity of mycorrhization. It therefore became necessary to both update and expand the book's coverage in this, its second edition.

This book reviews the potential mechanisms in arbuscular mycorrhizas (AMs), in the hope that this can help arbuscular mycorrhizal fungi (AMF) to be more used efficiently as a biostimulant to enhance stress tolerance in the host plants. AMF, as well as plants, are often exposed to all or many of the abiotic and biotic stresses, including extreme temperatures, pH, drought, water-logging, toxic metals and soil pathogens. Studies have indicated a quick response to these stresses involving several mechanisms, such as root morphological modification, reactive oxygen species change, osmotic adjustment, direct absorption of water by extraradical hyphae, up-regulated expression of relevant stressed genes, glomalin-related soil protein release, etc. The underlying complex, multi-dimensional strategy is involved in morphological, physiological, biochemical, and molecular processes. The AMF responses are often associated with homeostatic regulation of the internal and external environment, and are therefore critical for plant health, survival and restoration in native ecosystems and good soil structure.

This book, prepared by participants of the European network COST ACTION 810 (1989-93) is the outcome of a meeting held in Switzerland (Einsiedeln, September 29 to October 2, 1993) on the "Impact of arbuscular mycorrhizas on sustainable agriculture and natural ecosystems". COST(Cooperation Scientifique et Technique) Networks were created in 1971 by the Commission of European Communities, and later enlarged to include non-European Member States, to promote pre-competitive scientific and technical research in fields of common interest. During the eighties, COST ACTIONS were launched in bio technological fields, including the network on arbuscular mycorrhizas. Arbuscular mycorrhizas are a universally found symbiosis between plants and certain soil fungi and essential components of soil-plant systems. They act as a major inter face by influencing or regulating resource allocation between abiotic and biotic components of the soil-plant system. Arbuscular mycorrhizas are involved in many key ecosystem processes including nutrient cycling and conservation of soil struc ture, and have been shown to improve plant health through increased protection against abiotic and biotic stresses. Sustainability can be defined as the successful management of resources to satisfy changing human needs while maintaining or enhancing the quality of the environ ment and conserving resources. Increasing environmental degradation and instability, due to anthropogenic activities and in particular the increasing fragility of the soil resource, has led to an increased awareness of the need to develop practices resulting in more sustainable natural and agroecosystems.

Recent years have brought an upsurge of interest in the study of arbuscular mycorrhizal (AM) fungi, partly due to the realization that the effective utilization of these symbiotic soil fungi is likely to be essential in sustainable agriculture. Impressive progress has been made during the last decade in the study of this symbiosis largely as a result of increasing exploitation of molecular tools. Although early emphasis was placed on the use of molecular tools to study physiological processes triggered by the symbiosis, such as expression of symbiosis-specific polypeptides and modulation of host defences, other applications await. It was obvious to us that gathering leaders in the field to summarize these topics and point out research needs was necessary if we were to understand the physiology and function of AM fungi at a molecular level. In addition, we have taken the opportunity to present these reviews in a logical sequence of topics ranging from the initiation of the life cycle of the fungus to its functions in plant growth and in the below ground ecosystem. It was a challenge to limit this flood of information to the confines of one text. This is a very exciting time for mycorrhiza biologists and it is our hope that some of this excitement is conveyed to our readers.

The second edition of Mycorrhiza falls into a time period of excep tionally rapid growth in mycorrhizal research. Therefore the edi tors have been most pleased with the decision of the Springer Verlag to revise the first edition and to incorporate the remarkable advances experienced in the mycorrhizal field. The pace of discovery has been particularly fast at the two poles of biological complexity, the molecular events leading to changes in growth and differentiation, as well as the factors regulating the structure and diversity of natural populations and communities. Therefore the most significant changes introduced in the new edition of this book are found within these topics. Not only were many chapters up dated, but also new chapters have replaced existing ones. The individual decisions have not been easy, since valuable contribu tions had to be sacrificed in favour of new aspects; but the authors hope that a highly topical new edition will be of greatest benefit for a rapidly expanding field of research. We welcome comments and critics from readers. Since it was possible again to find leading scientists as contribu tors, we are confident that this revised second edition will stimulate further progress and contribute to a deeper understanding of advances in the mycorrhizal field. We are grateful to the Springer Verlag, especially Dr. Dieter Czeschlik, for his continued interest and active help. Dr. Maja Hilber-Bodmer and Dr.

This is the first book describing in vitro cultivation of root organs. The text describes various biological aspects such as the physiology, biochemistry, biodiversity, and life cycles of fungi, as well as the effects of symbiosis on plant growth and development, including large-scale fungus production for biotechnological use. Detailed protocols allow the immediate application of the method to culture mycorrhizal fungi in vitro.

A mycorrhizae is a symbiotic relationship between plants and fungi. Mycorrhizal fungi play important roles in plant root systems and soil biology and chemistry. Arbuscular Mycorrhizal Fungi in Agriculture - New Insights provides a comprehensive overview of arbuscular mycorrhizae. It is divided into three sections: “The Role of Mycorrhizae Fungi in Plant Growth”, “The Effect of Mycorrhizae on Plant Nutrition and Protection” and “Mycorrhizae Biology and Development”. Chapters provide a better understanding of these fungi, their application and management, and their effects on different types of plants.

Arbuscular Mycorrhiza (AM) is the most common mycorrhizal type involved in agricultural systems, and the most widespread plant root symbiosis. The fungi involved (Glomales) are known to promote plant growth and health by acting as biofertilizers, bioprotectors and bioregulators. The main aim of this book is to provide readers with theoretical and applied knowledge essential for the use of AM fungi in improving plant health and fitness, production of high quality food and in conservation of natural resources. The different chapters target understanding the role of AM fungi in sustainable crop production, discussing ways to improve biological equilibria between microorganisms in the mycorrhizosphere, analysing genetic, physiological, cellular and molecular bases of AM functioning and establishing technologies for inoculum production, according to the regulatory guidelines for application.