Plant Responses To Biotic And Abiotic Stresses Lessons From Cell Signaling

Facing stressful conditions imposed by their environment and affecting their growth and their development throughout their life cycle, plants must be able to perceive, to process and to translate different stimuli into adaptive responses. Understanding the organism-coordinated responses involves a fine description of the mechanisms occurring at the cellular and molecular level. A major challenge is also to understand how the large diversity of molecules identified as signals, sensors or effectors could drive a cell to the appropriate plant response and to finally cope with various environmental cues. In this Research Topic we aim to provide an overview of various signaling mechanisms or to present new molecular signals involved in stress response and to demonstrate how basic/fundamental research on cell signaling will help to understand stress responses at the whole plant level.

The natural environment for plants is composed of a complex set of abiotic and biotic stresses; plant responses to these stresses are equally complex. Systems biology allows us to identify regulatory hubs in complex networks. It also examines the molecular “parts” (transcripts, proteins and metabolites) of an organism and attempts to combine them into functional networks or models that effectively describe and predict the dynamic activities of that organism in different environments. This book focuses on research advances regarding plant responses to abiotic stresses, from the physiological level to the molecular level. It highlights new insights gained from the integration of omics datasets and identifies remaining gaps in our knowledge, outlining additional focus areas for future crop improvement research. Plants have evolved a wide range of mechanisms for coping with various abiotic stresses. In many crop plants, the molecular mechanisms involved in a single type of stress tolerance have since been identified; however, in order to arrive at a holistic understanding of major and common events concerning abiotic stresses, the signaling pathways involved must also be elucidated. To date several molecules, like transcription factors and kinases, have been identified as promising candidates that are involved in crosstalk between stress signalling pathways. However, there is a need to better understand the tolerance mechanisms for different abiotic stresses by thoroughly grasping the signalling and sensing mechanisms involved. Accordingly, this book covers a range of topics, including the impacts of different abiotic stresses on plants, the molecular mechanisms leading to tolerance for different abiotic stresses, signaling cascades revealing cross-talk among various abiotic stresses, and elucidation of major candidate molecules that may provide abiotic stress tolerance in plants.

Plant diseases, extreme weather caused by climate change, drought and an increase in metals in soil are amongst the major limiting factors of crop production worldwide. They devastate not only food supply but also the economy of a nation. Keeping in view of the global food scarcity, there is, an urgent need to develop crop plants with increased stress tolerance so as to meet the global food demands and to preserve the quality of our planet. In order to do this, it is necessary to understand how plants react and adapt to stress from the genomic and proteomic perspective. Plants adapt to stress conditions by activation of cascades of molecular mechanisms, which result in alterations in gene expression and synthesis of protective proteins/compounds. From the perception of the stimulus to transduction of the signal, followed by an appropriate response, the plants employ a complex network of primary and secondary messenger molecules. Cell signaling is the component of a complex system of communication that directs basic cellular activities and synchronizes cell actions. Cells exercise a large number of noticeably distinct signaling pathways to regulate their activity. In order to contend with different environmental adversities plants have developed a series of mechanisms at the physiological, cellular and molecular level. This two volume set takes an in-depth look at the Stress Signaling in Plants from a uniquely genomic and proteomics perspective. Stress Signaling in Plants offers a comprehensive treatise on the Chapter, covering all of the signaling pathways and mechanisms that have been researched so far. Each chapter provides in-depth explanation of what we currently know of a particular aspect of stress signaling and where we are headed. All authors have currently agreed and abstracts have been complied for the first volume, due out midway through 2012. We aim to have the second volume out at the beginning of 2013.​

Environmental stresses represent the most limiting factors for agricultural productivity. Apart from biotic stress caused by plant pathogens, there are a number of abiotic stresses such as extremes in temperature, drought, salinity, heavy metals and radiation which all have detrimental effects on plant growth and yield. However, certain plant species and ecotypes have developed various mechanisms to adapt to such stress conditions. Recent advances in the understanding of these abiotic stress responses provided the impetus for compiling up-to-date reviews discussing all relevant topics in abiotic stress signaling of plants in a single volume. Topical reviews were prepared by selected experts and contain an introduction, discussion of the state of the art and important future tasks of the particular fields.

Abiotic stresses such as high temperature, low-temperature, drought and salinity limit crop productivity worldwide. Understanding plant responses to these stresses is essential for rational engineering of crop plants. In Arabidopsis, the signal transduction pathways for abiotic stresses, light, several phytohormones and pathogenesis have been elucidated. A significant portion of plant genomes (Arabidopsis and rice were mostly studied) encodes for proteins involves in signaling such as receptor, sensors, kinases, phosphatases, transcription factors and transporters/channels. Despite decades of physiological and molecular effort, knowledge pertaining to how plants sense and transduce low and high temperature, low-water availability (drought), water-submergence, microgravity and salinity signals is still a major question for plant biologist. One major constraint hampering our understanding of these signal transduction processes in plants has been the lack or slow pace of application of molecular genomic and genetics knowledge in the form of gene function. In the post-genomic era, one of the major challenges is investigation and understanding of multiple genes and gene families regulating a particular physiological and developmental aspect of plant life cycle. One of the important physiological processes is regulation of stress response, which leads to adaptation or adjustment in response to adverse stimuli. With the holistic understanding of the signaling pathways involving not only one gene family but multiple genes or gene families, plant biologist can lay a foundation for designing and generating future crops, which can withstand the higher degree of environmental stresses (especially abiotic stresses, which are the major cause of crop loss throughout the world) without losing crop yield and productivity. Therefore, in this e-Book, we intend to incorporate the contribution from leading plant biologists to elucidate several aspects of stress signaling by functional genomics approaches.

Signal Crosstalk in Plant Stress Responses focuses on current findings on signal crosstalk between abiotic and biotic stresses, including information on drought, cold, and salt stress and pathogen infection. Divided into seven chapters on critical topics in the field, the book is written by an international team of expert authors. The book is aimed at plant scientists, agronomists, and horticulturalists, as well as students.

Plant responses to environmental stress are governed by complex molecular and biochemical signal transduction processes, which act in coordination to determine tolerance or sensitivity at the whole plant level. Upon exposure to abiotic stress, plants express a sophisticated coordinated response to reprogram interconnected defense networks and metabolic pathways, by alterations in the transcription, translation, and post-translational modification of defense-related genes and proteins. Traditionally, physiological and phenotypic responses were the major ones to be collected in plant stress biology. However, modern studies include the identification of key genes that influence stress tolerance and plant growth under the imposing stress and the verification of gene functions using knock out mutants or overexpression lines. In addition, genomics has become a necessary tool for the understanding of plant stress responses at the whole genome levels. The identification of stress-tolerant plant resources and the investigation of the functional role of the genetic variants is also a valuable tool in this research field. Recently, the advent of CRISPR/Cas genome editing technology, enables these variations to be introduced in crops for improved stress tolerance traits. Through the understanding of the molecular mechanisms involved in plant signaling in response to abiotic stress and crop performance characters under stress conditions, we hope to open new ways for the breeding of superior crops.

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.