Salinity Responses And Tolerance In Plants Transport And Signaling Mechanisms

Soil salinity is a key abiotic-stress and poses serious threats to crop yields and quality of produce. Owing to the underlying complexity, conventional breeding programs have met with limited success. Even genetic engineering approaches, via transferring/overexpressing a single ‘direct action gene’ per event did not yield optimal results. Nevertheless, the biotechnological advents in last decade coupled with the availability of genomic sequences of major crops and model plants have opened new vistas for understanding salinity-responses and improving salinity tolerance in important glycophytic crops. Our goal is to summarize these findings for those who wish to understand and target the molecular mechanisms for producing salt-tolerant and high-yielding crops. Through this 2-volume book series, we critically assess the potential venues for imparting salt stress tolerance to major crops in the post-genomic era. Accordingly, perspectives on improving crop salinity tolerance by targeting the sensory, ion-transport and signaling mechanisms are presented here in volume 1. Volume 2 will focus on the potency of post-genomic era tools that include RNAi, genomic intervention, genome editing and systems biology approaches for producing salt tolerant crops.

Plants need to adapt to a variety of environmental conditions such as salinity, drought, light and temperature which affect their growth, flowering and fruiting. Plant cells communicate with each other in order to respond to changing external environment. Soil salinity is one of the major abiotic stresses which affect the plant growth. It induces cytotoxicity due to excessive uptake of sodium and chloride ions. Salinity is also accompanied by oxidative stress. It can be induced due to poor quality of water for irrigation and soil salinization. Some of the tolerance mechanisms adopted by plants are ion homeostasis, hormone modulation, synthesis of polyamines, compartmentalization, and activation of antioxidant enzymes. The book aims to shed light on some of the unexplored aspects of salinity response and tolerance in plants and the recent researches in this field. From theories to research to practical applications, case studies related to all contemporary topics of relevance to this field have been included herein. This book is a vital tool for all researching or studying salinity response and tolerance in plants as it gives incredible insights into emerging trends and concepts.

Soil salinity is a key abiotic-stress and poses serious threats to crop yields and quality of produce. Owing to the underlying complexity, conventional breeding programs have met with limited success. Even genetic engineering approaches, via transferring/overexpressing a single ‘direct action gene’ per event did not yield optimal results. Nevertheless, the biotechnological advents in last decade coupled with the availability of genomic sequences of major crops and model plants have opened new vistas for understanding salinity-responses and improving salinity tolerance in important glycophytic crops. Our goal is to summarize these findings for those who wish to understand and target the molecular mechanisms for producing salt-tolerant and high-yielding crops. Through this 2-volume book series, we critically assess the potential venues for imparting salt stress tolerance to major crops in the post-genomic era. Accordingly, perspectives on improving crop salinity tolerance by targeting the sensory, ion-transport and signaling mechanisms were presented in Volume 1. Volume 2 now focuses on the potency of post-genomic era tools that include RNAi, genomic intervention, genome editing and systems biology approaches for producing salt tolerant crops.

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. ​​

Life presumably arose in the primeval oceans with similar or even greater salinity than the present ocean, so the ancient cells were designed to withstand salinity. However, the immediate ancestors of land plants most likely lived in fresh, or slightly brackish, water. The fresh/brackish water origins might explain why many land plants, including some cereals, can withstand moderate salinity, but only 1 – 2 % of all the higher plant species were able to re-discover their saline origins again and survive at increased salinities close to that of seawater. From a practical side, salinity is among the major threats to agriculture, having been one of the reasons for the demise of the ancient Mesopotamian Sumer civilisation and in the present time causing huge annual economic losses of over 10 billion USD. The effects of salinity on plants include osmotic stress, disruption of membrane ion transport, direct toxicity of high cytoplasmic concentrations of sodium and chloride on cellular processes and induced oxidative stress. Ion transport is the crucial starting point that determines salinity tolerance in plants. Transport via membranes is mediated mostly by the ion channels and transporters, which ensure selective passage of specific ions. The molecular and structural diversity of these ion channels and transporters is amazing. Obtaining the detailed descriptions of distinct ion channels and transporters present in halophytes, marine algae and salt-tolerant fungi and then progressing to the cellular and the whole organism mechanisms, is one of the logical ways to understand high salinity tolerance. Transfer of the genes from halophytes to agricultural crops is a means to increase salt tolerance of the crops. The theoretical scientific approaches involve protein chemistry, structure-function relations of membrane proteins, synthetic biology, systems biology and physiology of stress and ion homeostasis. At the time of compiling this e-book many aspects of ion transport under salinity stress are not yet well understood. The e-book has attracted researchers in ion transport and salinity tolerance. We have combined our efforts to achieve a wider, more detailed understanding of salt tolerance in plants mediated by ion transport, to understand present and future ways to modify and manipulate ion transport and salinity tolerance and also to find natural limits for the modifications.

"Intense farming and irrigation practices are the important causes of salinity which limit plant growth and productivity. Salinity has now impacted 6 % of the total and 33 % of the irrigated land. The severest salinity problem has arisen in semiarid or arid lands when they were subjected to excessive irrigation which turned hundreds of hectares of cultivated fertile lands into saline lands. When a change in salinity around the environment of a plant exceeds to a certain threshold level, the morphology and physiology of the plants are affected. This book emphasizes the menace of salinity in agriculture and crop production. It encompasses various studies on plants sensitive to salt (glycophytes) and tolerant to salt (halophytes). This book includes diversity of glycophytes and halophytes, effects of salinity on different stages of growth and development, ion homeostasis and cellular ion transport, their photosynthetic responses, effects on biological nitrogen fixation, redox regulation and phytohormonal adjustment, significance of mineral nutrients in combating salinity in food crops. The most significant feature of the present book is its extensive coverage of genomics, metabolomics, ionomics, proteomics and transcriptomics approach which provide a better understanding towards salt and its interaction with plants. This book is beneficial for the students of stress physiology, environmental sciences, agronomy, life sciences and crop sciences at university level"--

Salt stress is one of the most damaging abiotic stresses because most crop plants are susceptible to salinity to different degrees. According to the FAO, about 800 million Has of land are affected by salinity worldwide. Unfortunately, this situation will worsen in the context of climate change, where there will be an overall increase in temperature and a decrease in average annual rainfall worldwide. This Special Issue presents different research works and reviews on the response of plants to salinity, focused from different points of view: physiological, biochemical, and molecular levels. Although an important part of the studies on the response to salinity have been carried out with Arabidopsis plants, the use of other species with agronomic interest is also notable, including woody plants. Most of the conducted studies in this Special Issue were focused on the identification and characterization of candidate genes for salt tolerance in higher plants. This identification would provide valuable information about the molecular and genetic mechanisms involved in the salt tolerance response, and it also supplies important resources to breeding programs for salt tolerance in plants.

PHYSIOLOGY OF SALT STRESS IN PLANTS Discover how soil salinity affects plants and other organisms and the techniques used to remedy the issue In Physiology of Salt Stress in Plants, an editorial team of internationally renowned researchers delivers an extensive exploration of the problem of soil salinity in modern agricultural practices. It also discusses the social and environmental issues caused by salt stress. The book covers the impact of salt on soil microorganisms, crops, and other plants, and presents that information alongside examinations of salt’s effects on other organisms, including aquatic fauna, terrestrial animals, and human beings. Physiology of Salt Stress in Plants describes the morphological, anatomical, physiological, and biochemical dimensions of increasing soil salinity. It also discusses potential remedies and encourages further thought and exploration of this issue. Readers are encouraged to consider less hazardous fertilizers and pesticides, to use safer doses, and to explore and work upon salt resistant varieties of plants. Readers will also benefit from the inclusion of: Thorough introductions to salt stress perception and toxicity levels and the effects of salt stress on the physiology of crop plants at a cellular level Explorations of the effects of salt stress on the biochemistry of crop plants and salt ion transporters in crop plants at a cellular level Practical discussions of salt ion and nutrient interactions in crop plants, including prospective signalling, and the effects of salt stress on the morphology, anatomy, and gene expression of crop plants An examination of salt stress on soil chemistry and the plant-atmosphere continuum Perfect for researchers, academics, and students working and studying in the fields of agriculture, botany, entomology, biotechnology, soil science, and plant physiology, Physiology of Salt Stress in Plants will also earn a place on the bookshelves of agronomists, crop scientists, and plant biochemists.