Salinity And Drought Stress In Plants Understanding Physiological Biochemical And Molecular Responses

Drought and salinity are two of the foremost environmental factors which restrict plant growth and yield in several regions of the world, especially in arid and semi‐arid regions. Due to global climate change, drought and salinity are predicted to become more widespread and eventually result in reduced plant growth and productivity in numerous plant species. Exposure of plants to extreme drought or salt stress ceases plant growth, while plants exposed to moderate stress generally show a slight change in their growth performance. Scientists are facing the challenging task of producing 70% more food to feed an additional 2.3 billion people by 2050. Therefore, it is imperative to develop stress-resilient crops with better yield under drought and salt stress to meet the food requirements of upcoming generations.

Abiotic stress adversely affects crop production worldwide, decreasing average yields for most of the crops to 50%. Among various abiotic stresses affecting agricultural production, drought stress is considered to be the main source of yield reduction around the globe. Due to an increasing world population, drought stress will lead to a serious food shortage by 2050. The situation may become worse due to predicated global climate change that may multiply the frequency and duration and severity of such abiotic stresses. Hence, there is an urgent need to improve our understanding on complex mechanisms of drought stress tolerance and to develop modern varieties that are more resilient to drought stress. Identification of the potential novel genes responsible for drought tolerance in crop plants will contribute to understanding the molecular mechanism of crop responses to drought stress. The discovery of novel genes, the analysis of their expression patterns in response to drought stress, and the determination of their potential functions in drought stress adaptation will provide the basis of effective engineering strategies to enhance crop drought stress tolerance. Although the in-depth water stress tolerance mechanisms is still unclear, it can be to some extent explained on the basis of ion homeostasis mediated by stress adaptation effectors, toxic radical scavenging, osmolyte biosynthesis, water transport, and long distance signaling response coordination. Importantly, complete elucidation of the physiological, biochemical, and molecular mechanisms for drought stress, perception, transduction, and tolerance is still a challenge to the plant biologists. The findings presented in volume 1 call attention to the physiological and biochemical modalities of drought stress that influence crop productivity, whereas volume 2 summarizes our current understanding on the molecular and genetic mechanisms of drought stress resistance in plants.

Environmental conditions and changes, irrespective of source, cause a variety of stresses, one of the most prevalent of which is salt stress. Excess amount of salt in the soil adversely affects plant growth and development, and impairs production. Nearly 20% of the world’s cultivated area and nearly half of the world’s irrigated lands are affected by salinity. Processes such as seed germination, seedling growth and vigour, vegetative growth, flowering and fruit set are adversely affected by high salt concentration, ultimately causing diminished economic yield and also quality of produce. Most plants cannot tolerate salt-stress. High salt concentrations decrease the osmotic potential of soil solution, creating a water stress in plants and severe ion toxicity. The interactions of salts with mineral nutrition may result in nutrient imbalances and deficiencies. The consequence of all these can ultimately lead to plant death as a result of growth arrest and molecular damage. To achieve salt-tolerance, the foremost task is either to prevent or alleviate the damage, or to re-establish homeostatic conditions in the new stressful environment. Barring a few exceptions, the conventional breeding techniques have been unsuccessful in transferring the salt-tolerance trait to the target species. A host of genes encoding different structural and regulatory proteins have been used over the past 5–6 years for the development of a range of abiotic stress-tolerant plants. It has been shown that using regulatory genes is a more effective approach for developing stress-tolerant plants. Thus, understanding the molecular basis will be helpful in developing selection strategies for improving salinity tolerance. This book will shed light on the effect of salt stress on plants development, proteomics, genomics, genetic engineering, and plant adaptations, among other topics. The book will cover around 25 chapters with contributors from all over the world. ​​

This edited book is a comprehensive collection of scientific research on different plants under drought and salt stress conditions. The main focus of this book is to elaborate on the mechanisms being operative in plants under stress and how various biological factors mitigate the adverse effects for better plant productivity. This book covers all physiological, biochemical, and molecular mechanisms operating under drought and saline stresses. The current status and impact of drought and salinity on various crop plants have been elaborated on in different chapters. Agricultural lands are either turning barren or becoming more saline and drought-prone with increasing temperatures, decreasing water tables, untimely rainfall, and other environmental factors. In India, salt-affected soils occupy an area of about 6.73 million ha of which saline and sodic soils constitute roughly 40 and 60%, respectively. All these factors individually or cumulatively, affect the plant growth and development and hence, the crop productivity with the monetary loss. The inbuilt plant's ability with modified/acclimatized mechanisms has been described in various chapters with step-wise descriptions. The role of various plant growth-promoting agents including nano-particles, micro-organisms, metabolites or phytohormones, etc in mitigating adverse effects of drought and salinity has been explained precisely. Updated information on the use of speed breeding, proteomics, epigenetics, and transcriptomics in different crops along with high throughput technologies is included for the cross-talk of various network mechanisms. This book is helpful for the readers in knowing salinity and drought through the physiological, biochemical and genetic, and molecular levels to understand plant behaviour under stress conditions. Also, the book serves as additional reading material for undergraduate and graduate students of agriculture, plant physiology, biochemistry, forestry, and environmental sciences. National and international agricultural scientists and policymakers will also find this to be a useful read.

The unique responses of plants to combined stresses have been observed at physiological, biochemical, and molecular levels. This book provides an analysis of all three levels of change in various plants in response to different combinations of stresses. The text provides a general review of the combined stress paradigm, focuses on the impact of higher CO2 levels in combination with other stresses, examines drought stress in conjunction with other abiotic factors in different crop plants as well as the combination of biotic and abiotic factors, and discusses the impact of combined stresses in forest ecosystems. Written by experts in the field, Combined Stresses in Plants: Physiological, Molecular, and Biochemical Aspects is a valuable resource for scientists, graduate students, and post-doctoral fellows alike working in plant stresses.

Plants, unlike animals, are sessile. This demands that adverse changes in their environment are quickly recognized, distinguished and responded to with suitable reactions. Drought, heat, cold and salinity are among the major abiotic stresses that adversely affect plant growth and productivity. In general, abiotic stress often causes a series of morphological, physiological, biochemical and molecular changes that unfavorably affect plant growth, development and productivity. Drought, salinity, extreme temperatures (cold and heat) and oxidative stress are often interrelated; these conditions singularly or in combination induce cellular damage. To cope with abiotic stresses, of paramount significance is to understand plant responses to abiotic stresses that disturb the homeostatic equilibrium at cellular and molecular level in order to identify a common mechanism for multiple stress tolerance. This multi authored edited compilation attempts to put forth an all-inclusive biochemical and molecular picture in a systems approach wherein mechanism and adaptation aspects of abiotic stress are dealt with. The chief objective of the book hence is to deliver state of the art information for comprehending the effects of abiotic stress in plants at the cellular level.

Advances in Botanical Research publishes in-depth and up-to-date reviews on a wide range of topics in plant sciences. Currently in its 57th volume, the series features a wide range of reviews by recognized experts on all aspects of plant genetics, biochemistry, cell biology, molecular biology, physiology and ecology. This thematic volume describes developments in understanding of plant responses to drought and salinity in post-genomic and are evaluated by world wide- known experts. 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

With near-comprehensive coverage of new advances in crop breeding for drought and salinity stress tolerance, this timely work seeks to integrate the most recent findings about key biological determinants of plant stress tolerance with modern crop improvement strategies. This volume is unique because is provides exceptionally wide coverage of current knowledge and expertise being applied in drought and salt tolerance research.