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.

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.

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.

It is now well established that jasmonates, originally identified as the major component of jasmine scent, play a universal role in the plant kingdom and are involved in the regulation of diverse aspects of plant biology, including growth, development, metabolism, and interaction with the environment. In Jasmonate Signaling: Methods and Protocols, experts in the field aim to unite powerful emerging omics platforms with a number of key reductionist approaches to form a comprehensive collection of tools and protocols. The detailed chapters in this book embrace physiological, environmental, molecular, omics, and bioinformatics approaches that allow dissecting jasmonate actions in the model species Arabidopsis thaliana or in other plants. Written in the highly successful Methods in Molecular Biology series format, chapters feature introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, along with tips on troubleshooting and avoiding known pitfalls. Authoritative and cutting-edge, Jasmonate Signaling: Methods and Protocols will empower interested researchers to dissect all steps of jasmonate signaling and the processes they modulate.

As the highly anticipated update to Lipid Second Messengers (CRC Press, 1999), Lipid-Mediating Signaling is a current and comprehensive overview of research methods used in lipid-mediated signal transduction. Pioneering experts provide a much-needed distillation of a decade's worth of advances in research techniques that are pertinent in understand