Lipid Signalling In Plant Development And Responses To Environmental Stresses

In response to environmental stresses, or during development, plant cells will produce lipids that will act as intracellular or intercellular mediators. Glycerophospholipid and/or sphingolipid second messengers resulting from the action of lipid metabolizing enzymes (e.g. lipid-kinases or lipases) are commonly found within cells. The importance of such mediating lipids in plants has become increasingly apparent. Responses to biotic and abiotic stresses, and to plant hormones, all appear to involve and require lipid signals. Likewise, developmental processes, in particular polarized growth, seem also to involve signalling lipids. Amongst these lipids, phosphatidic acid (PA) has received the most attention. It can be produced by phospholipases D, but also by diacylglycerol kinases coupled to phospholipases C. Proteins that bind phosphatidic acid, and for which the activity is altered upon binding, have been identified. Furthermore, other lipids are also important in signalling processes. PA can be phosphorylated into diacylglycerol-pyrophosphate, and plants are one of the first biological models where the production of this lipid has been reported, and its implication in signal transduction have been demonstrated. PA can also be deacylated into lyso- phosphatidic acid. The phosphorylated phosphatidylinositols, i.e. the phosphoinositides, can act as substrate of phospholipases C, but are also mediating lipids per se, since proteins that bind them have been identified. Other important lipid mediators belong to the sphingolipid family such the phosphorylated phytosphingosine, or long-chain bases. Many questions remain unanswered concerning lipid signalling in plants. Understanding and discussing current knowledge on these mechanisms will provide insights into plant mechanisms in response to constraints, either developmental or environmental.

In response to environmental stresses, or during development, plant cells will produce lipids that will act as intracellular or intercellular mediators. Glycerophospholipid and/or sphingolipid second messengers resulting from the action of lipid metabolizing enzymes (e.g. lipid-kinases or lipases) are commonly found within cells. The importance of such mediating lipids in plants has become increasingly apparent. Responses to biotic and abiotic stresses, and to plant hormones, all appear to involve and require lipid signals. Likewise, developmental processes, in particular polarized growth, seem also to involve signalling lipids. Amongst these lipids, phosphatidic acid (PA) has received the most attention. It can be produced by phospholipases D, but also by diacylglycerol kinases coupled to phospholipases C. Proteins that bind phosphatidic acid, and for which the activity is altered upon binding, have been identified. Furthermore, other lipids are also important in signalling processes. PA can be phosphorylated into diacylglycerol-pyrophosphate, and plants are one of the first biological models where the production of this lipid has been reported, and its implication in signal transduction have been demonstrated. PA can also be deacylated into lyso- phosphatidic acid. The phosphorylated phosphatidylinositols, i.e. the phosphoinositides, can act as substrate of phospholipases C, but are also mediating lipids per se, since proteins that bind them have been identified. Other important lipid mediators belong to the sphingolipid family such the phosphorylated phytosphingosine, or long-chain bases. Many questions remain unanswered concerning lipid signalling in plants. Understanding and discussing current knowledge on these mechanisms will provide insights into plant mechanisms in response to constraints, either developmental or environmental.

Cell membranes are the initial and focal sites of stimulus perception and signal transduction. Membrane lipids are rich sources for the production of signaling messengers that mediate plant growth, development, and response to nutrient status and stresses. In recent years, substantial progress has been made toward understanding lipid signaling in plants, but many fundamental questions remain: What lipids are signaling messengers or mediators in plants? How are the signaling lipids produced and metabolized? In what plant cellular and physiological processes are various lipid mediators involved? How do they carry out their signaling functions? How do lipid signaling networks contribute to modulating plant growth, development, and responses to hormones and stresses? In this Research Topic issue, we invite the broad plant community to address the above questions.Cell membranes are the initial and focal sites of stimulus perception and signal transduction. Membrane lipids are rich sources for the production of signaling messengers that mediate plant growth, development, and response to nutrient status and stresses. In recent years, substantial progress has been made toward understanding lipid signaling in plants, but many fundamental questions remain: What lipids are signaling messengers or mediators in plants? How are the signaling lipids produced and metabolized? In what plant cellular and physiological processes are various lipid mediators involved? How do they carry out their signaling functions? How do lipid signaling networks contribute to modulating plant growth, development, and responses to hormones and stresses? In this Research Topic issue, we invite the broad plant community to address the above questions.

A collection of papers that comprehensively describe the major areas of research on lipid metabolism of plants. State-of-the-art knowledge about research on fatty acid and glycerolipid biosynthesis, isoprenoid metabolism, membrane structure and organization, lipid oxidation and degradation, lipids as intracellular and extracellular messengers, lipids and environment, oil seeds and gene technology is reviewed. The different topics covered show that modern tools of plant cellular and molecular biology, as well as molecular genetics, have been recently used to characterize several key enzymes of plant lipid metabolism (in particular, desaturases, thioesterases, fatty acid synthetase) and to isolate corresponding cDNAs and genomic clones, allowing the use of genetic engineering methods to modify the composition of membranes or storage lipids. These findings open fascinating perspectives, both for establishing the roles of lipids in membrane function and intracellular signalling and for adapting the composition of seed oil to the industrial needs. This book will be a good reference source for research scientists, advanced students and industrialists wishing to follow the considerable progress made in recent years on plant lipid metabolism and to envision the new opportunities offered by genetic engineering for the development of novel oil seeds.

This comprehensive update on plant lipid signaling covers the measurement, regulation and function of phospholipases, lipid kinases, lipid phosphatases, inositolpolphosphates, polyphosphoinositides, phosphatic acid, and other lipid signals such as oxylipins.

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.

Bei vielen physiologischen und Entwicklungsprozessen sowie bei Stressreaktionen spielen Hormonsignale, die Pflanzen aussenden, eine große Rolle. Mit Aufkommen der neuen post-genomischen Molekulartechnologien sind auch unsere Möglichkeiten, die Wirkung von Hormonsignalen auf die Genexpression und adaptive Prozesse zu verstehen, heute einzigartig. Wenn wir die molekularen Grundlagen dieser Prozesse entschlüsseln, ergeben sich für die Entwicklung neuer Pflanzenbiotechnologien und verbesserter Varianten von Kulturpflanzen große Chancen. Die Themen dieses Buches legen den Schwerpunkt auf die Genomik und funktionale Aspekte der Genomik. Damit lassen sich globale Veränderungen und Veränderungen auf Ebene des gesamten Genoms unter spezifischen Stressbedingungen verstehen. Mit funktionalen Werkzeugen der Genomik kann der Mechanismus von Phytohormonsignalen in Verbindung mit den zugehörigen Zielgenen systematischer definiert werden. Die integrierte Analyse von Phytohormonsignalen bei einzelnen oder mehreren Stressbedingungen ist unter Umständen für die Entwicklung stresstoleranter Kulturpflanzen eine außergewöhnliche Möglichkeit. Mechanism of Plant Hormone Signaling Under Stress beschreibt die jüngsten Fortschritte und zeigt, wie heutige Erkenntnisse in der wissenschaftlichen Erforschung von Pflanzen und Kulturpflanzen Anwendung finden. Dieses Buch ist für Pflanzenbiologen, Biologen, die sich mit Stressfaktoren beschäftigen, Forscher im Bereich Pflanzenbiotechnologie, Studenten und Dozenten überaus nützlich.

Molecular oxygen deficiency leads to altered cellular metabolism and can dramatically reduce crop productivity. Nearly all crops are negatively affected by a lack of oxygen (hypoxia) due to adverse environmental conditions such as excessive rain and soil waterlogging. Extensive efforts to fully understand how plants sense oxygen deficiency and their ability to respond using different strategies are crucial to increase hypoxia tolerance. Progress in our understanding has been significant in recent years. This topic certainly deserves more attention from the academic community; therefore, we have compiled a series of articles reflecting the advancements made thus far.

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.