Multigenic And Induced Systemic Resistance In Plants

Plants have developed very sophisticated mechanisms to combat pathogens and pestsusingtheleastamountofreservedorgeneratedenergypossible. Theydothis by activating major defense mechanisms after recognition of the organisms that are considered to be detrimental to their survival; therefore they have been able to exist on Earth longer than any other higher organisms. It has been known for the past century that plants carry genetic information for inherited resistance against many pathogenic organisms including fungi, bacteria, and viruses, and that the relationship between pathogenic organisms and hosts plants are rather complex and in some cases time dependent. This genetic information has been the basis for breeding for resistance that has been employed by plant breeders to develop better-yielding disease resistant varieties, some of which are still being cultivated. Single gene resistance is one type of resistance which has been extensively studied by many research groups all around the world using biotechnological methodologies that have been the subject of many books and journal articles; therefore, it is beyond the scope of this book. This type of resistance is very effective, although it can be overcome by the pressure of pathogenic organisms since it depends on interaction of a single elicitor molecule from the pathogen with a single receptor site in the host.

Induced or acquired resistance to disease in plants has been known for many years, but the phenomenon was studied in only a few laboratories until about a decade ago. Since then, there has been an increasing interest in induced resistance as a new, environmentally safe means of disease control, as well as a model for the study of the genes involved in host defence and the signals that control them. This increased interest led the editors of Induced Resistance to Disease in Plants to collect and summarise much of the current and older literature on the topic in a single volume. Each chapter covers its topic as comprehensively as possible, thus serving as a solid introduction to the literature, as well as expressing its writer's own views on the state of research in the area and giving an indication of where future research may lead. Induced Resistance to Disease in Plants addresses the biology of induced resistance in legumes, solanaceae, cucurbits and monocots, since these are the families that have received the most attention, followed by a discussion of the molecular basis of induced resistance, its genetic and evolutionary significance, and practical applications in disease control. The book will provide a background for those commencing work in the area, as well as a source of information for established workers who wish to learn about other areas of induced resistance.

Plant diseases worldwide are responsible for billions of dollarsworth of crop losses every year. With less agrochemicals being usedand less new fungicides coming on the market due to environmentalconcerns, more effort is now being put into the use of geneticpotential of plants for pathogen resistance and the development ofinduced or acquired resistance as an environmentally safe means ofdisease control. This comprehensive book examines in depth the development andexploitation of induced resistance. Chapters review currentknowledge of the agents that can elicit induced resistance,genomics, signalling cascades, mechanisms of defence to pests andpathogens and molecular tools. Further chapters consider thetopical application of inducers for disease control, microbialinduction of pathogen resistance, transgenic approaches, pathogenpopulation biology, trade offs associated with induced resistanceand integration of induced resistance in crop protection. The bookconcludes with a consideration of socio-economic driversdetermining the use of induced resistance, and the future ofinduced resistance in crop protection.

Plants have developed very sophisticated mechanisms to combat pathogens and pestsusingtheleastamountofreservedorgeneratedenergypossible. Theydothis by activating major defense mechanisms after recognition of the organisms that are considered to be detrimental to their survival; therefore they have been able to exist on Earth longer than any other higher organisms. It has been known for the past century that plants carry genetic information for inherited resistance against many pathogenic organisms including fungi, bacteria, and viruses, and that the relationship between pathogenic organisms and hosts plants are rather complex and in some cases time dependent. This genetic information has been the basis for breeding for resistance that has been employed by plant breeders to develop better-yielding disease resistant varieties, some of which are still being cultivated. Single gene resistance is one type of resistance which has been extensively studied by many research groups all around the world using biotechnological methodologies that have been the subject of many books and journal articles; therefore, it is beyond the scope of this book. This type of resistance is very effective, although it can be overcome by the pressure of pathogenic organisms since it depends on interaction of a single elicitor molecule from the pathogen with a single receptor site in the host.

With a focus on food safety, this book highlights the importance of microbes in sustainable agriculture. Plants, sessile organisms that are considered as primary producers in the ecosystem and communicate with above- and below-ground communities that consist of microbes, insects, and other vertebrate and invertebrate animals, are subjected to various kinds of stress. Broadly speaking, these can be subdivided into abiotic and biotic stresses. Plants have evolved to develop elaborate mechanisms for coping with and adapting to the environmental stresses. Among other stresses, habitat-imposed biotic stress is one serious condition causing major problems for crop productivity. Most plants employ plant-growth-promoting microorganisms (PGPMs) to combat and protect themselves from stresses and also for better growth. PGPMs are bacteria associated with plant roots and they augment plant productivity and immunity. They are also defined as root-colonizing bacteria that have beneficial effects on plant growth and development. Remarkably, PGPMs including mycorrhizae, rhizobia, and rhizobacteria (Acinetobacter, Agrobacterium, Arthrobacter, Azospirillum, Bacillus, Bradyrhizobium, Frankia, Pseudomonas, Rhizobium, Serratia, Thiobacillus) form associations with plant roots and can promote plant growth by increasing plants’ access to soil minerals and protecting them against pathogens. To combat the pathogens causing different diseases and other biotic stresses, PGPMs produce a higher level of resistance in addition to plants’ indigenous immune systems in the form of induced systemic resistance (ISR). The ISR elicited by PGPMs has suppressed plant diseases caused by a range of pathogens in both the greenhouse and field. As such, the role of these microbes can no longer be ignored for sustainable agriculture. Today, PGPMs are also utilized in the form of bio-fertilizers to increase plant productivity. However, the use of PGPMs requires a precise understanding of the interactions between plants and microbes, between microbes and microbiota, and how biotic factors influence these relationships. Consequently, continued research is needed to develop new approaches to boost the efficiency of PGPMs and to understand the ecological, genetic and biochemical relationships in their habitat. The book focuses on recent research concerning interactions between PGPMs and plants under biotic stress. It addresses key concerns such as – 1. The response of benign microbes that benefit plants under biotic stress 2. The physiological changes incurred in plants under harsh conditions 3. The role of microbial determinants in promoting plant growth under biotic stress The book focuses on a range of aspects related to PGPMs such as their mode of action, priming of plant defence and plant growth in disease challenged crops, multifunctional bio-fertilizers, PGPM-mediated disease suppression, and the effect of PGPMs on secondary metabolites etc. The book will be a valuable asset to researchers and professionals working in the area of microbial-mediated support of plants under biotic stress.

The future of agriculture strongly depends on our ability to enhance productivity without sacrificing long-term production potential. An ecologically and economically sustainable strategy is the application of microorganisms, such as the diverse bacterial species of plant growth promoting bacteria (PGPB). The use of these bio-resources for the enhancement of crop productivity is gaining worldwide importance. "Bacteria in Agrobiology: Stress Management" covers the major aspects on PGPR in amelioration of both abiotic and biotic stresses. PGPR mediated in priming of plant defense reactions, nutrient availability and management in saline and cold environment, hormonal signaling, ACC deaminase and its role in ethylene regulation under harsh conditions are suitably described.

In this century the human being must face the challenges of producing enough to feed a growing population in a sustainable and environmentally friendly way. The yields are with increasing frequency affected by abiotic stresses such as salinity, drought, and high temperature or by new diseases and plagues. The Research Topic on Induced Resistance for Plant Defense focuses on the understanding the mechanisms underlying plant resistance or tolerance since these will help us to develop fruitful new agricultural strategies for a sustainable crop protection. This topic and its potential applications provide a new sustainable approach to crop protection. This technology currently can offer promising molecules capable to provide new long lasting treatments for crop protection against biotic or abiotic stresses. The aim of this Research Topic is to review and discuss current knowledge of the mechanisms regulating plant induced resistance and how from our better understanding of these mechanisms we can find molecules capable of inducing this defence response in the plant, thereby contributing to sustainable agriculture we need for the next challenges of the XXI century.

Plant innate immunity is a collective term to describe a complex of interconnected mechanisms that plants use to withstand potential pathogens and herbivores. The last decade has seen a rapid advance in our understanding of the induction, signal transduction and expression of resistance responses to oomycetes, fungi, bacteria, viruses, nematodes and insects. This volume aims at providing an overview of these processes and mechanisms.Edited by Jean-Claude Kader and Michel Delseny and supported by an international Editorial Board, Advances in Botanical Research publishes in-depth and up-to-date reviews on a wide range of topics in plant sciences. Multidisciplinary reviews written from a broad range of scientific perspectives For over 40 years, series has enjoyed a reputation for excellence Contributors internationally recognized authorities in their respective fields