Organic Xenobiotics And Plants

Natural and agro-ecosystems are frequently exposed to natural or synthetic substances, which, while they have no direct nutritional value or significance in metabolism, may negatively affect plant functioning. These, xenobiotics, may originate from both natural (fires, volcano eruptions, soil or rock erosion, biodegradation) and anthropogenic (air and soil pollution, herbicides) sources. And, while affected plants have only a limited number of possibilities for avoiding accumulation of these compounds, they do exhibit several enzymatic reactions for detoxification including oxidation, reduction, hydrolysis and conjugation reactions. In agro-ecosystems in particular these mechanisms have great significance in relation to herbicide detoxification and tolerance. In this volume an international group of experts present an overview of the nature and distribution of organic xenobiotics, including their uptake, effects on plant functioning and detoxification mechanisms. The particular significance of glutathione S-transferases in bio-indication and bio-monitoring, and in the detoxification of volatile organic air pollutants and herbicides is evaluated, and their potential significance in phytoremediation and bioaccumulation will be discussed. This volume will be of interest to a wide audience, from graduate students to senior researchers in a wide range of disciplines including plant ecology, plant biochemistry, agriculture and environmental management. It will also be of practical interest to environmentalists, policy makers and resource managers.

In the continuing fight against organic environmental xenobiotics, the initial success attributed to bioremediation has paled, in part due to the low availability of xenobiotics entrapped within a soil or sediment matrix. This has generated a very significant wave of interest in the bioavailability issue. However, much experimental evidence is puzzling or contradictory, mechanistic theories are embryonic, and implications for the practice of bioremediation or concerning the natural fate of xenobiotics are still tentative. The debate in Europe and the USA is vigorous. Eastern Europe, following the liberalisation of the economy and political life, is evolving in a similar direction. In many cases, however, limited access to literature sources, severe language barriers, and the lack of a strong pluridisciplinary tradition are hampering the adoption of state of the art techniques. Originally intended to allow scientists in East European countries to become acquainted with the key aspects of the bioavailability debate that is unfolding in the scientific literature in the West, and with its implications for bioremediation efforts, the present book presents a very complete coverage of the theoretical and practical aspects of the (limited) bioavailability of organic xenobiotics in the environment.

This book is compilation of studies related with the xenobiotics i.e. chemical or other substance that is not normally found in the ecosystems and get accumulated at higher concentration in the biological system due to rampant industrialisation and urbanisation activities. This book has tried to give information on various issues to give comprehensive and concise knowledge of the recent advancement in the field of environmental xenobiotics and how it disturbs the plants metabolism. Other key features of the book are related to xenobiotic toxicity and detoxification mechanism, biochemical tools toward its remediation processes, molecular mechanism for xenobiotics detoxification and effect on metallomics. It also focuses on recent development in the field of waste water remediation concerned with the xenobiotics involvement. This book is different in such a way that it includes all the initial information along with the new researches. It includes the description of problem along with its solution. This volume describe the effects of xenobiotics at different levels i.e. biochemical, physiological and molecular, giving the details on signaling pathways to modify the responses of xenobiotics in plant system. Thus, it gives confirming crosstalk between xenobiotic effects and signalling pathways. This book includes description about both the organic contaminants such as pesticides, solvents and petroleum products as well as inorganic xenobiotics that include heavy metals, non-metals, metalloids, and simple soluble salts. Here the plant is main objective and that have to deal with these kinds of compounds either by avoiding accumulation of these compounds or by exhibiting several enzymatic reactions for detoxification including oxidation, reduction, and conjugation reactions. Affected plants exhibit several enzymatic and non-enzymatic antioxidant and other reactions for detoxification of ROS including oxidation, reduction, hydrolysis and conjugation reactions. The book focuses on different forms and sources of xenobiotics including organic and inorganic xenobiotics. The matter of this book will definitely increase the knowledge about the impacts of xenobiotics on plants system. There must be potentially broad readership who could find this fruitful for their study as well as for their research. As this book has balance between basic plant physiology and toxicity caused by the xenobiotics so it can be widely used in several disciplines. Overall, the book will bring deep knowledge in the field of xenobiotics toxicity in plants during recent years and it is definitely a compilation of interesting information which isn't fully covered elsewhere in the current market.

Plant hormone signaling plays an important role in many physiological and developmental processes including stress response. With the advent of new post-genomic molecular techniques, the potential for increasing our understanding of the impact of hormone signaling on gene expression and adaptive processes has never been higher. Unlocking the molecular underpinnings of these processes shows great promise for the development of new plant biotechnologies and improved crop varieties. The topics included in this book emphasize on genomics and functional genomics aspects, to understand the global and whole genome level changes upon particular stress conditions. With the functional genomics tools, the mechanism of phytohormone signaling and their target genes can be defined in a more systematic manner. The integrated analysis of phytohormone signaling under single or multiple stress conditions may prove exceptional to design stress tolerant crop plants in the field conditions. Bringing together the latest advances, as well as the work being done to apply these findings to plant and crop science, Mechanism of Plant Hormone Signaling Under Stress will prove extremely useful to plant and stress biologists, plant biotechnology researchers, as well as students and teachers.

The NATO Advanced Research Workshop (ARW) on "Regulation of Enzymatic Systems Detoxifying Xenobiotics in Plants" intended to provide a forum to scientists from academia, industry, and govemment for discussing and critically assessing recent advances in the field of xenobiotic metabolism in plants and for identifying new directions for future research. Plants function in a chemical environment made up of nutrients and xenobiotics. Xenobiotics (foreign chemicals) are natural or synthetic compounds that can not be utilized by plants for energy-yielding metabolism. Plants may be exposed to xenobiotics either deliberately, due to their use as pesticides or accidentally, from industrial, agricultural, and other uses. Plants, like most other organisms, evolved a remarkable battery or metabolic reactions to defend themselves against the potentially toxic effects of xenobiotics. The main enzymatic reactions utilized by plants for xenobiotic detoxification include oxidation, reduction, hydrolysis and conjugation with glutathione, sugars (e.g., glucose), and amino acids. Eventually, xenobiotic conjugates are converted to insoluble bound residues or to secondary conjugates, which are deposited in the vacuole of plant cells.

This book describes the vast variety of xenobiotics, such as pesticides, antibiotics, antibiotic resistance genes, agrochemicals and other pollutants, their interactions with the soil environment, and the currently available strategies and techniques for soil decontamination and bioremediation. Topics covered include: transport mechanisms of pollutants along the Himalayas; use of earthworms in biomonitoring; metagenomic strategies for assessing contaminated sites; xenobiotics in the food chain; phyto-chemical remediation; biodegradation by fungi; and the use of enzymes and potential microbes in biotransformation. Accordingly, the book offers a valuable guide for scientists in the fields of environmental ecology, soil and food sciences, agriculture, and applied microbiology.

This book describes the physiological and anatomical principles and the chemical and physical factors that determine uptake, translocation, accumulation, loss, and metabolism of anthropogenic chemicals in plants. Expert authors in the fields of biology, chemistry, ecology, environmental physics, and biochemistry provide recently developed methods and models for estimation of the behavior of environmental chemicals in the soil-plant-air system-information that is essential in the hazard assessment of new and existing chemicals.

Physiological: anatomy and physiology of plant conductive systems. Chemical: principles governing uptake and transport of chemicals - metabolic processes for organic chemicals in plants. Modeling: model for uptake of xenobiotics into plants - partitioning and transport of organic chemicals between the atmospheric environment and leaves - interpeting chemical partitioning in soil-plant-air systems with a fugacity model - dynamics of leaching, uptake, and translocation: the simulation model network - atmosphere-plant-soil (SNAPS).