Aquaporins are channel proteins that facilitate the diffusion of water and small uncharged solutes across cellular membranes. Plant aquaporins form a large family of highly divergent proteins that are involved in many different physiological processes. This book will summarize the recent advances regarding plant aquaporins, their phylogeny, structure, substrate specificity, mechanisms of regulation and roles in various important physiological processes related to the control of water flow and small solute distribution at the cell, tissue and plant level in an ever-changing environment.

Aquaporins are channel proteins that facilitate the diffusion of water and small uncharged solutes across cellular membranes. Plant aquaporins form a large family of highly divergent proteins that are involved in many different physiological processes. This book will summarize the recent advances regarding plant aquaporins, their phylogeny, structure, substrate specificity, mechanisms of regulation and roles in various important physiological processes related to the control of water flow and small solute distribution at the cell, tissue and plant level in an ever-changing environment.

Aquaporins are channel proteins that facilitate the diffusion of water and small uncharged solutes across cellular membranes. Plant aquaporins form a large family of highly divergent proteins that are involved in many different physiological processes. This book will summarize the recent advances regarding plant aquaporins, their phylogeny, structure, substrate specificity, mechanisms of regulation and roles in various important physiological processes related to the control of water flow and small solute distribution at the cell, tissue and plant level in an ever-changing environment.

Aquaporins (AQPs), a class of integral membrane proteins, form channels facilitating movement of water and many other solutes. In solute transport systems of all living organisms including plants, animals and fungi, AQPs play a vital role. Plants contain a much higher number of AQP genes compared to animals, the likely consequence of genome duplication events and higher ploidy levels. As a result of duplication and subsequent diversification, plant AQPs have evolved several subfamilies with very diverse functions. Plant AQPs are highly selective for specific solutes because of their unique structural features. For instance, ar/R selectivity filters and NPA domains have been found to be key elements in governing solute permeability through the AQP channels. Combination of conserved motifs and specific amino acids influencing pore morphology appears to regulate the permeability of specific solutes such as water, urea, CO2, H2O2, boric acid, silicic acid and many more. The discovery of novel AQPs has been accelerated over the last few years with the increasing availability of genomic and transcriptomic data. The expanding number of well characterised AQPs provides opportunities to understand factors influencing water transport, nutritional uptake, and elemental balance. Homology-based search tools and phylogenetic analyses offer efficient strategies for AQP identification. Subsequent characterization can be based on different approaches involving proteomics, genomics, and transcriptomic tools. The combination of these technological advances make it possible to efficiently study the inter-dependency of AQPs, regulation through phosphorylation and reversible phosphorylation, networking with other transporters, structural features, pH gating systems, trafficking and degradation. Several studies have supported the role of AQPs in differential phenotypic responses to abiotic and biotic stress in plants. Crop improvement programs aiming for the development of cultivars with higher tolerance against stresses like drought, flooding, salinity and many biotic diseases, can explore and exploit the finely tuned AQP-regulated transport system. For instance, a promising approach in crop breeding programs is the utilization of genetic variation in AQPs for the development of stress tolerant cultivars. Similarly, transgenic and mutagenesis approaches provide an opportunity to better understand the AQP transport system with subsequent applications for the development of climate-smart drought-tolerant cultivars. The contributions to this Frontiers in Plant Science Research Topic have highlighted the evolution and phylogenetic distribution of AQPs in several plant species. Numerous aspects of regulation that seek to explain AQP-mediated transport system have been addressed. These contributions will help to improve our understanding of AQPs and their role in important physiological aspects and will bring AQP research closer to practical applications.

Endocytosis is a fundamental cellular process by means of which cells internalize extracellular and plasma membrane cargos for recycling or degradation. It is important for the establishment and maintenance of cell polarity, subcellular signaling and uptake of nutrients into specialized cells, but also for plant cell interactions with pathogenic and symbiotic microbes. Endocytosis starts by vesicle formation at the plasma membrane and progresses through early and late endosomal compartments. In these endosomes cargo is sorted and it is either recycled back to the plasma membrane, or degraded in the lytic vacuole. This book presents an overview of our current knowledge of endocytosis in plants with a main focus on the key molecules undergoing and regulating endocytosis. It also provides up to date methodological approaches as well as principles of protein, structural lipid, sugar and microbe internalization in plant cells. The individual chapters describe clathrin-mediated and fluid-phase endocytosis, as well as flotillin-mediated endocytosis and internalization of microbes. The book was written for a broad spectrum of readers including students, teachers and researchers.

In plant cells, the plasma membrane is a highly elaborated structure that functions as the point of exchange with adjoining cells, cell walls and the external environment. Transactions at the plasma membrane include uptake of water and essential mineral nutrients, gas exchange, movement of metabolites, transport and perception of signaling molecules, and initial responses to external biota. Selective transporters control the rates and direction of small molecule movement across the membrane barrier and manipulate the turgor that maintains plant form and drives plant cell expansion. The plasma membrane provides an environment in which molecular and macromolecular interactions are enhanced by the clustering of proteins in oligimeric complexes for more efficient retention of biosynthetic intermediates, and by the anchoring of protein complexes to promote regulatory interactions. The coupling of signal perception at the membrane surface with intracellular second messengers also involves transduction across the plasma membrane. Finally, the generation and ordering of the external cell walls involves processes mediated at the plant cell surface by the plasma membrane. This volume is divided into three sections. The first section describes the basic mechanisms that regulate all plasma membrane functions. The second describes plasma membrane transport activity. The final section of the book describes signaling interactions at the plasma membrane. These topics are given a unique treatment in this volume, as the discussions are restricted to the plasma membrane itself as much as possible. A more complete knowledge of the plasma membrane’s structure and function is essential to current efforts to increase the sustainability of agricultural production of food, fiber, and fuel crops.

A guide to the chemical agents that protect plants from various environmental stressors Protective Chemical Agents in the Amelioration of Plant Abiotic Stress offers a guide to the diverse chemical agents that have the potential to mitigate different forms of abiotic stresses in plants. Edited by two experts on the topic, the book explores the role of novel chemicals and shows how using such unique chemical agents can tackle the oxidative damages caused by environmental stresses. Exogenous application of different chemical agents or chemical priming of seeds presents opportunities for crop stress management. The use of chemical compounds as protective agents has been found to improve plant tolerance significantly in various crop and non-crop species against a range of different individually applied abiotic stresses by regulating the endogenous levels of the protective agents within plants. This important book: Explores the efficacy of various chemical agents to eliminate abiotic stress Offers a groundbreaking look at the topic and reviews the most recent advances in the field Includes information from noted authorities on the subject Promises to benefit agriculture under stress conditions at the ground level Written for researchers, academicians, and scientists, Protective Chemical Agents in the Amelioration of Plant Abiotic Stress details the wide range of protective chemical agents, their applications, and their intricate biochemical and molecular mechanism of action within the plant systems during adverse situations.

Vascular Transport in Plants provides an up-to-date synthesis of new research on the biology of long distance transport processes in plants. It is a valuable resource and reference for researchers and graduate level students in physiology, molecular biology, physiology, ecology, ecological physiology, development, and all applied disciplines related to agriculture, horticulture, forestry and biotechnology. The book considers long-distance transport from the perspective of molecular level processes to whole plant function, allowing readers to integrate information relating to vascular transport across multiple scales. The book is unique in presenting xylem and phloem transport processes in plants together in a comparative style that emphasizes the important interactions between these two parallel transport systems. - Includes 105 exceptional figures - Discusses xylem and phloem transport in a single volume, highlighting their interactions - Syntheses of structure, function and biology of vascular transport by leading authorities - Poses unsolved questions and stimulates future research - Provides a new conceptual framework for vascular function in plants

The aquaporin field has matured at an exceptionally fast pace and we are at the verge to develop serious strategies to therapeutically modulate aquaporin function directly or via regulatory networks. Key prerequisites are available today: i. a considerable (and growing) number of aquaporin crystal structures for the rational design of inhibitory molecules, ii. elaborate molecular dynamics simulation techniques for theoretical analyses of selectivity mechanisms and docking experiments, iii. comprehensive data on aquaporin immunohistochemistry, iv. aquaporin knockout animals for physiological studies, and v. assay systems for compound library screenings. The structure of this volume on aquaporins follows the points laid out above and thus covers the developments from basic research to potential pharmacological use. Situated between pharmacology textbooks and recent scientific papers this book provides a timely overview for readers from the fundamental as well as the applied disciplines.