Signal Molecules In Plants And Plant Microbe Interactions

Proceedings of the NATO Advanced Research Workshop on Molecular Signals in Microbe-Plant Symbiotic and Pathogenic Systems, held at Biddinghuizen, The Netherlands, May 21-26, 1989

Research on the interaction between plants and microbes has attracted considerable attention in recent years. The use of modem genetic techniques has now made possible a detailed analysis both of plant and of microbial genes involved in phytopathogenic and beneficial interactions. At the biochemical level, signal molecules and their receptors, either of plant or of microbial origins, have been detected which act in signal transduction pathways or as co-regulators of gene expression. We begin to understand the molecular basis of classical concepts such as gene-for-gene relationships, hypersensitive response, induced resistance, to name just a few. We realize, and will soon exploit, the tremendous potential of the results of this research for practical application, in particular to protect crop plants against diseases and to increase crop yield and quality. This exclung field of research, which is also of truly interdisciplinary nature, is expanding rapidly. A Symposium series has been devoted to it which began in 1982. Recently, the 5th International Symposium on the Molecular Genetics of Plant-Microbe Interactions was held in Interlaken, Switzerland. It brought together 640 scientists from almost 30 different countries who reported their latest research progress in 47 lectures, 10 short oral presentations, and on over 400 high-quality posters. This book presents a collection of papers that comprehensively reflect the major areas under study, explain novel experimental approaches currently in use, highlight significant advances made over the last one or two years but also emphasize the obstacles still ahead of us.

This book, divided into 13 chapters, explores recent discoveries in the area of molecular plant-microbe interactions. It focuses mainly on the mechanisms controlling plant disease resistance and the cross talk among the signalling pathways involved, and the strategies used by fungi and viruses to suppress these defences. Two chapters deal with the role of symbionts (such as the symbiotic actinobacteria and vesicular arbuscular mycorrhizal fungi) during their interactions with plants.

These proceedings from the July 1999 Amsterdam conference include 80 papers describing the interactions between plants and rhiizobium, nematodes, microbes, agrobacterium, pathogenic fungus, viruses, and bacterium. They also cover topics like signal transduction, virulence and avirulence of bacteria and fungi, secretion and transport of virulence and avirulence factors, perception of microbial signals, mycorrhizae, plant disease resistance genes, local and systemic resistance, biological control, plant biotechnology, upcoming model systems, developmental biology, programmed cell death, and functional genomics. Indexed only by name. c. Book News Inc.

Research on the interaction between plants and microbes has attracted considerable attention in recent years. The use of modem genetic techniques has now made possible a detailed analysis both of plant and of microbial genes involved in phytopathogenic and beneficial interactions. At the biochemical level, signal molecules and their receptors, either of plant or of microbial origins, have been detected which act in signal transduction pathways or as co-regulators of gene expression. We begin to understand the molecular basis of classical concepts such as gene-for-gene relationships, hypersensitive response, induced resistance, to name just a few. We realize, and will soon exploit, the tremendous potential of the results of this research for practical application, in particular to protect crop plants against diseases and to increase crop yield and quality. This exclung field of research, which is also of truly interdisciplinary nature, is expanding rapidly. A Symposium series has been devoted to it which began in 1982. Recently, the 5th International Symposium on the Molecular Genetics of Plant-Microbe Interactions was held in Interlaken, Switzerland. It brought together 640 scientists from almost 30 different countries who reported their latest research progress in 47 lectures, 10 short oral presentations, and on over 400 high-quality posters. This book presents a collection of papers that comprehensively reflect the major areas under study, explain novel experimental approaches currently in use, highlight significant advances made over the last one or two years but also emphasize the obstacles still ahead of us.

Plant-Microbe Interactions, Volume 2 Volume 1 of this series has made its appearance and dealt forcefully with impor tant current topics in the field of plant-microbe interactions. We believe that the quality of those chapters was high and should serve as a focal point for the state of the art as well as an enduring reference. Volume 2 builds upon these accom plishments. Chapter 1 discusses the fascinating lipo-chitin signal molecules from Rhizo bium, aspects regarding their biosynthesis, and the basis for host specificity. These molecules are a cardinal example of how microorganisms influence plant development and stimulate speculation that they have identified a previously un known aspect of plant hormone activity. Chapter 2 continues the discussion of Rhizobium by considering the trafficking of carbon and nitrogen in nodules. Al though the ostensible advantage of nodules to plants is the fixation of atmos pheric nitrogen, the actual process involved in supplying reduced nitrogen to the plant host is complex.

Recent years have seen tremendous progress in unraveling the molecular basis of different plant-microbe interactions. Knowledge has accumulated on the mecha nisms of the microbial infection of plants, which can lead to either disease or resistance. The mechanisms developed by plants to interact with microbes, whether viruses, bacteria, or fungi, involve events that can lead to symbiotic association or to disease or tumor formation. Cell death caused by pathogen infection has been of great interest for many years because of its association with plant resistance. There appear to be two types of plant cell death associated with pathogen infection, a rapid hypersensitive cell death localized at the site of infection during an incompatible interaction between a resistant plant and an avirulent pathogen, and a slow, normosensitive plant cell death that spreads beyond the site of infection during some compatible interactions involving a susceptible plant and a virulent, necrogenic pathogen. Plants possess a number of defense mechanisms against infection, such as (i) production of phytoalexin, (ii) formation of hydrolases, (iii) accumulation of hydroxyproline-rich glycoprotein and lignin deposition, (iv) production of pathogen-related proteins, (v) produc tion of oligosaccharides, jasmonic acid, and various other phenolic substances, and (vi) production of toxin-metabolizing enzymes. Based on these observations, insertion of a single suitable gene in a particular plant has yielded promising results in imparting resistance against specific infection or disease. It appears that a signal received after microbe infection triggers different signal transduction pathways.