Antioxidant Defense In Plants

This edited book highlights the molecular basis of various enzymatic and non-enzymatic antioxidants, defense mechanisms and adaptation strategies employed by plants to avoid the stressful conditions. Special focus is given to gene expression, omics and other latest technologies such as CRISPR-Cas mediated genome editing applications for defense related studies in plants. Environmental stresses such as drought, salinity or floods etc. induce the generation of reactive oxygen species (ROS) which causes severe damage to cell membrane integrity by accelerating lipid peroxidation. To counteract the detrimental effect of ROS, plants are inherited with an intricate and vibrant antioxidant defense system, comprised of enzymatic (catalase, peroxidase, superoxide dismutase, glutathione reductase, glutathione S-transferase, guaiacol peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase etc.), and non-enzymatic (glutathione, ascorbate, α-tocopherol, carotenoids, flavonoids etc.) antioxidants, which scavenge and/or reduce excess ROS and improve plant tolerance to various stresses. Stress tolerance in most crop plants is positively correlated with an efficient antioxidant system. Therefore, studying the efficiency of antioxidant defense systems in plants is necessary for facilitating the plant’s nature of adaptation against challenging environments. This book is of interest to teachers, researchers and academic experts. Also, the book serves as additional reading material for undergraduate and graduate students of biotechnology and molecular biology of plants.

Presents a multidisciplinary analysis of the integration among reactive oxygen species (ROS), reactive nitrogen species (RNS), and reactive sulfur species (RSS). Since plants are the main source of our food, the improvement of their productivity is the most important task for plant biologists. In this book, leading experts accumulate the recent development in the research on oxidative stress and approaches to enhance antioxidant defense system in crop plants. They discuss both the plant responses to oxidative stress and mechanisms of abiotic stress tolerance, and cover all of the recent approaches towards understanding oxidative stress in plants, providing comprehensive information about the topics. It also discusses how reactive nitrogen species and reactive sulfur species regulate plant physiology and plant tolerance to environmental stresses. Reactive Oxygen, Nitrogen and Sulfur Species in Plants: Production, Metabolism, Signaling and Defense Mechanisms covers everything readers need to know in four comprehensive sections. It starts by looking at reactive oxygen species metabolism and antioxidant defense. Next, it covers reactive nitrogen species metabolism and signaling before going on to reactive sulfur species metabolism and signaling. The book finishes with a section that looks at crosstalk among reactive oxygen, nitrogen, and sulfur species based on current research done by experts. Presents the newest method for understanding oxidative stress in plants. Covers both the plant responses to oxidative stress and mechanisms of abiotic stress tolerance Details the integration among reactive oxygen species (ROS), reactive nitrogen species (RNS) and reactive sulfur species (RSS) Written by 140 experts in the field of plant stress physiology, crop improvement, and genetic engineering Providing a comprehensive collection of up-to-date knowledge spanning from biosynthesis and metabolism to signaling pathways implicated in the involvement of RONSS to plant defense mechanisms, Reactive Oxygen, Nitrogen and Sulfur Species in Plants: Production, Metabolism, Signaling and Defense Mechanisms is an excellent book for plant breeders, molecular biologists, and plant physiologists, as well as a guide for students in the field of Plant Science.

The present edited book is an attempt to update the state of art of the knowledge on metabolism of ROS and antioxidants and their relationship in plant adaptation to abiotic stresses involving physiological, biochemical and molecular processes. The chapters are much focused on the current climate issues and how ROS metabolism can manipulate with antioxidant system to accelerate detoxification mechanism. It will enhance the mechanistic understanding on ROS and antioxidants system and will pave the path for agricultural scientists in developing tolerant crops to achieve sustainability under the changing environmental conditions. The increase in abiotic stress factors has become a major threat to sustainability of crop production. This situation has led to think ways which can help to come out with potential measures; for which it is necessary to understand the influence of abiotic stress factors on crops performance and the mechanisms by which these factors impact plants. It has now become evident that abiotic stress impacts negatively on plant growth and development at every stage of plant’s life. Plants adapt to the changing environment with the adjustment at physiological, biochemical and molecular levels. The possible mechanisms involved in the negative effects of abiotic stress factors are excess production of reactive oxygen species (ROS). They alter physiological and molecular mechanisms leading to poor performance of plants. Plants however, are able to cope with these adverse effects by inducing antioxidant systems as the priority. Nevertheless, the dual role of ROS has now been ascertained which provides an evidence for regulation of plant metabolism positively on a concentration-dependent manner. Under conditions of high ROS production, the antioxidant system plays a major role in diminishing the effects of ROS. Thus, ROS production and antioxidant system are interwoven with abiotic stress conditions. The antioxidants have the capacity to hold the stability in metabolism in order to avoid disruption due to environmental disturbances.

This Special Issue, "Approaches in Enhancing Antioxidant Defense in Plants" published 13 original research works and a couple of review articles that discuss the various aspects of plant oxidative stress biology and ROS metabolism, as well as the physiological mechanisms and approaches to enhancing antioxidant defense and mitigating oxidative stress. These papers will serve as a foundation for plant oxidative stress tolerance and, in the long term, provide further research directions in the development of crop plants' tolerance to abiotic stress in the era of climate change.

This book provides detailed and comprehensive information on oxidative damage caused by stresses in plants with especial reference to the metabolism of reactive oxygen species (ROS). In plants, as in all aerobic organisms, ROS are common by-products formed by the inevitable leakage of electrons onto O2 from the electron transport activities located in chloroplasts, mitochondria, peroxisomes and in plasma membranes or as a consequence of various metabolic pathways confined in different cellular loci. Environmental stresses such as heat, cold, drought, salinity, heavy-metal toxicity, ozone and ultraviolet radiation as well as pathogens/contagion attack lead to enhanced generation of ROS in plants due to disruption of cellular homeostasis. ROS play a dual role in plants; at low concentrations they act as signaling molecules that facilitate several responses in plant cells, including those promoted by biotic and abiotic agents. In divergence, at high levels they cause damage to cellular constituents triggering oxidative stress. In either case, small antioxidant molecules and enzymes modulate the action of these ambivalent species.

Plants have to manage a series of environmental stresses throughout their entire lifespan. Among these, abiotic stress is the most detrimental; one that is responsible for nearly 50% of crop yield reduction and appears to be a potential threat to global food security in coming decades. Plant growth and development reduces drastically due to adverse effects of abiotic stresses. It has been estimated that crop can exhibit only 30% of their genetic potentiality under abiotic stress condition. So, this is a fundamental need to understand the stress responses to facilitate breeders to develop stress resistant and stress tolerant cultivars along with good management practices to withstand abiotic stresses. Also, a holistic approach to understanding the molecular and biochemical interactions of plants is important to implement the knowledge of resistance mechanisms under abiotic stresses. Agronomic practices like selecting cultivars that is tolerant to wide range of climatic condition, planting date, irrigation scheduling, fertilizer management could be some of the effective short-term adaptive tools to fight against abiotic stresses. In addition, “system biology” and “omics approaches” in recent studies offer a long-term opportunity at the molecular level in dealing with abiotic stresses. The genetic approach, for example, selection and identification of major conditioning genes by linkage mapping and quantitative trait loci (QTL), production of mutant genes and transgenic introduction of novel genes, has imparted some tolerant characteristics in crop varieties from their wild ancestors. Recently research has revealed the interactions between micro-RNAs (miRNAs) and plant stress responses exposed to salinity, freezing stress and dehydration. Accordingly transgenic approaches to generate stress-tolerant plant are one of the most interesting researches to date. This book presents the recent development of agronomic and molecular approaches in conferring plant abiotic stress tolerance in an organized way. The present volume will be of great interest among research students and teaching community, and can also be used as reference material by professional researchers.

In this ready reference, a global team of experts comprehensively cover molecular and cell biology-based approaches to the impact of increasing global temperatures on crop productivity. The work is divided into four parts. Following an introduction to the general challenges for agriculture around the globe due to climate change, part two discusses how the resulting increase of abiotic stress factors can be dealt with. The third part then outlines the different strategies and approaches to address the challenge of climate change, and the whole is rounded off by a number of specific examples of improvements to crop productivity. With its forward-looking focus on solutions, this book is an indispensable help for the agro-industry, policy makers and academia.

This Special Issue, "Approaches in Enhancing Antioxidant Defense in Plants" published 13 original research works and a couple of review articles that discuss the various aspects of plant oxidative stress biology and ROS metabolism, as well as the physiological mechanisms and approaches to enhancing antioxidant defense and mitigating oxidative stress. These papers will serve as a foundation for plant oxidative stress tolerance and, in the long term, provide further research directions in the development of crop plants' tolerance to abiotic stress in the era of climate change.