Cellular Aspects of Wood Formation: 20 (Plant Cell Monographs)

Plant Cell Monographs

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The Best Books of Check out the top books of the year on our page Best Books of Product details Format Hardback pages Dimensions x x Looking for beautiful books? Visit our Beautiful Books page and find lovely books for kids, photography lovers and more. Other books in this series. Somatic Embryogenesis Abdul Mujib. Root Hairs Anne Mie C. Viral Transport in Plants Elisabeth Waigmann. Plant Endocytosis Jozef Samaj. Somatic Embryogenesis Jozef Samaj. The Pollen Tube Rui Malho. Plant Microtubules Peter Nick. Back cover copy This book discusses central concepts and theories in cell biology from the ancient past to the 21st century, based on the premise that understanding the works of scientists like Hooke, Hofmeister, Caspary, Strasburger, Sachs, Schleiden, Schwann, Mendel, Nemec, McClintock, etc.

Table of contents Attached. Presently he is working in the field of plant cell biology to understand the role of actin and microtubules in the development of rice plants. His main interest is plant cell biology, especially root apices, as related to the cytoskeleton, endocytosis, vesicle trafficking and polarity. He has investigated root apices for more than twenty years, and made original contribution to the root apex organization by the discovery of a transition zone interpolated between the apical meristem and the rapid cell elongation region.

Introduction to energy sources. Energy resources are reviewed in lay terms in an effort to increase the public's awareness of energy issues. Summaries of the principal sources of energy describe availability, technological requirements, and environmental impacts. The emphasis is placed on making energy use more efficient and the implications of shifting to centralized power plants , with more reliance on electricity. The purpose of this monograph is to demonstrate that energy issues can be examined and assessed by non-experts. Plant cell walls to ethanol.

Conversion of plant cell walls to ethanol constitutes generation 2 bioethanol production. The process consists of several steps: Ultimately, it is desired to combine as man This monograph examines the issue of task analysis as used in workplace literacy programs, debating the need for it and how to perform it in a rapidly changing environment. Based on experiences of community colleges in Texas, the report analyzes ways that task analysis can be done and how to implement work force education programs more quickly. Multiple Primary Cancer Monograph.

To identify groups of cancer survivors that are at increased risk for multiple primary cancers, investigators led an effort to provide the first comprehensive population-based analysis of the risk of subsequent cancer in the U. This publication is an annotated bibliography of technical books and monographs sponsored by the Energy Research and Development Administration ERDA and its predecessor agencies. These entries have been published by commercial publishers, nonprofit institutions and organizations, and the federal government.

The books and monographs are grouped…. Regulation of Water in Plant Cells. Cell water relationships are important topics to be included in cell biology courses. Differences exist in the control of water relationships in plant cells relative to control in animal cells. One important reason for these differences is that turgor pressure is a consideration in plant cells. Diffusion and osmosis are the underlying factors…. Regio- and stereoselectivities in plant cell biotransformation. The ability of plant cultured cells to convert foreign substrates into more useful substances is of considerable interest.

Therefore I have studied biotransformation of foreign substrate by plant cell suspension cultures. In this presentation, I report regio- and stereoselectivities in biotransformation of steroids and indole alkaloids and taxol by plant tobacco, periwinkle, moss, orchid cell suspension cultures. Single- Cell Genomic Analysis in Plants. Individual cells in an organism are variable, which strongly impacts cellular processes. Advances in sequencing technologies have enabled single- cell genomic analysis to become widespread, addressing shortcomings of analyses conducted on populations of bulk cells.

While the field of single- cell plant genomics is in its infancy, there is great potential to gain insights into cell lineage and functional cell types to help understand complex cellular interactions in plants. In this review, we discuss current approaches for single- cell plant genomic analysis, with a focus on single- cell isolation, DNA amplification, next-generation sequencing, and bioinformatics analysis.

We outline the technical challenges of analysing material from a single plant cell , and then examine applications of single- cell genomics and the integration of this approach with genome editing. Finally, we indicate future directions we expect in the rapidly developing field of plant single- cell genomic analysis. Embryogenic plant cells in microgravity. In view of circumstantial evidence for the role of gravity g in shaping the embryo environment, normal embryo development may not occur reliably and efficiently in the microgravity environment of space.

Attention must accordingly be given to those aspects of higher plant reproductive biology in space environments required for the production of viable embryos in a 'seed to seed to seed' experiment. It is suggested that cultured cells can be grown to be morphogenetically competent, and can be evaluated as to their ability to simulate embryogenic events usually associated with fertilized eggs in the embryo sac of the ovule in the ovary.

This volume a companion to the Energy Guide, Vol. Refractive index of plant cell walls. Air was replaced with media of higher refractive indices by vacuum infiltration in leaves of cucumber, blackeye pea, tomato, and string bean plants , and reflectance of noninfiltrated and infiltrated leaves was spectrophotometrically measured. Infiltrated leaves reflected less light than noninfiltrated leaves over the nm wavelength interval because cell wall-air interfaces were partly eliminated.

Minimal reflectance should occur when the average refractive index of plant cell walls was matched by the infiltrating fluid. Although refractive indices that resulted in minimal reflectance differed among the four plant genera, an average value of 1. Monograph of Coccinia Cucurbitaceae.

This monograph deals with all 95 names described in the Cucurbitaceae genus Coccinia and recognizes 25 species. Taxonomic novelties are Cocciniaadoensisvar. For the 25 species collections were examined, of which were georeferenced to produce distribution maps. Coccinia species are dioecious creepers or climbers with simple or bifid tendrils that occupy a range of habitats from arid scrubland, woodlands to lowland rainforest and mist forest.

The corolla of Coccinia species is sympetalous, usually pale yellow to orange, and 1 to 4. Pollination is by bees foraging for pollen or nectar. After pollination, the developing ovary often exhibits longitudinal mottling, which usually disappears during maturation. All species produce berries with a pericarp in reddish colors orange-red through to scarlet red , hence the generic name. The globose to cylindrical fruits contain numerous grayish-beige flat to lenticular seeds.

Many Coccinia species are used for food, either as roasted tubers, greens as spinach, or the fruits as vegetables. Medicinal value is established in Cocciniagrandis, of which leaves and sap are used against diabetes. Plant stem cells as innovation in cosmetics. The stem cells thanks to their ability of unlimited division number or transformation into different cell types creating organs, are responsible for regeneration processes.

Depending on the organism in which the stem cells exists, they divide to the plant or animal ones. The later group includes the stem cells existing in both embryo's and adult human's organs. It includes, among others, epidermal stem cells , located in the hair follicle relieves and also in its basal layers, and responsible for permanent regeneration of the epidermis.

Temporary science looks for method suitable for stimulation of the epidermis stem cells , amongst the other by delivery of e. One of the methods is the use of the plant cell culture technology, including a number of methods that should ensure growth of plant cells , issues or organs in the environment with the microorganism-free medium. It uses abilities of the different plant cells to dedifferentiation into stem cells and coming back to the pluripotent status.

The extracts obtained this way from the plant stem cells are currently used for production of both common or professional care cosmetics. This article describes the main features of plant stem cells and summarizes the results of studies of the genetic control of stem cell maintenance in the apical meristem of the shoot. It is demonstrated that the WUS-CLV gene system plays a key role in the maintenance of shoot apical stem cells and the formation of adventitious buds and somatic embryos.

Unconventional concepts of plant stem cells are considered. Permanganate Fixation of Plant Cells. In an evaluation of procedures explored to circumvent some of the problems of osmium tetroxide-fixation and methacrylate embedding of plant materials, excised segments of root tips of Zea mays were fixed for electron microscopy in potassium permanganate in the following treatment variations: After fixation the segments were dehydrated, embedded in epoxy resin, sectioned, and observed or photographed.

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The cells of the central region of the rootcap are described. The fixation procedures employing unbuffered solutions containing 2. Similar results were obtained using a solution containing 2. The fixation procedure utilizing veronal-acetate buffered, 0. However, preservation of the plasma membrane was not so good, nor was the intensity of staining so great, as that with the group of fixatives containing greater concentrations of KMnO4. The other fixation procedures did not give satisfactory preservation of fine structure. Abstract This monograph deals with all 95 names described in the Cucurbitaceae genus Coccinia and recognizes 25 species.

Taxonomic novelties are Coccinia adoensis var. Medicinal value is established in Coccinia grandis, of which leaves and sap are used against diabetes. Stem cell function during plant vascular development. The plant vascular system, composed of xylem and phloem, evolved to connect plant organs and transport various molecules between them.

During the post-embryonic growth, these conductive tissues constitutively form from cells that are derived from a lateral meristem, commonly called procambium and cambium. Because vascular plants continue to form new tissues and organs throughout their life cycle, the formation and maintenance of stem cells are crucial for plant growth and development. In this decade, there has been considerable progress in understanding the molecular control of the organization and maintenance of stem cells in vascular plants. Noticeable advance has been made in elucidating the role of transcription factors and major plant hormones in stem cell maintenance and vascular tissue differentiation.

These studies suggest the shared regulatory mechanisms among various types of plant stem cell pools. In this review, we focus on two aspects of stem cell function in the vascular cambium, cell proliferation and cell differentiation. Cell fusion and nuclear fusion in plants. Eukaryotic cells are surrounded by a plasma membrane and have a large nucleus containing the genomic DNA, which is enclosed by a nuclear envelope consisting of the outer and inner nuclear membranes.

Although these membranes maintain the identity of cells , they sometimes fuse to each other, such as to produce a zygote during sexual reproduction or to give rise to other characteristically polyploid tissues. Recent studies have demonstrated that the mechanisms of plasma membrane or nuclear membrane fusion in plants are shared to some extent with those of yeasts and animals, despite the unique features of plant cells including thick cell walls and intercellular connections.

Here, we summarize the key factors in the fusion of these membranes during plant reproduction, and also focus on "non-gametic cell fusion," which was thought to be rare in plant tissue, in which each cell is separated by a cell wall. Pathological modifications of plant stem cell destiny.

In higher plants , the shoot apex contains undifferentiated stem cells that give rise to various tissues and organs. The fate of these stem cells determines the pattern of plant growth as well as reproduction; and such fate is genetically preprogrammed. We found that a bacterial infection can derai Monographs on the Rural Community in Poland. Documenting the development of monographs on the rural community in Poland, this paper discusses: Comparative Analysis of Monographic Collections in Nursing. The results of a project comparing the nursing monograph collections of academic health science center libraries in the Southwest are reported.

Modern European monographs for quality control of Chinese herbs.

Introduction

The actual concern about the safety and efficacy of herbal drugs originating from traditional Chinese medicine TCM is based on observations that these medicinal plants may have a high risk potential due to insufficient definitions, problems with identity, purity and falsifications.

No uniform legal status for these groups of herbal drugs currently exists in the European Union. Based on these facts the Commission of the European Pharmacopoeia decided in to establish TCM-herbal drug monographs for the most important medicinal plants imported from Far East. These new monographs had to be established and evaluated on the basis of existing monographs in the Chinese Pharmacopoeia ChP , English edition Therefore, specialist groups were mandated with a corresponding working programme.

Some results and actual problems related to this working programme will be presented and discussed. This document contains 10 short monographs on priority issues relevant to the health and well-being of migrant and seasonal farmworkers and their families. An introduction by Daniel Hawkins discusses the important role of migrant health centers in providing primary and preventive health care services to this disadvantaged and underserved….

Monograph Acquisitions Unit Staff Manual. This staff manual provides a thorough description of the functions, procedures, and files of the monograph acquisitions department at South Carolina's Clemson University Library. It is noted that the department is responsible for both firm order and standing order purchases. Following introductory material, the principal processes of searching,…. Morphological classification of plant cell deaths. Programmed cell death PCD is an integral part of plant development and of responses to abiotic stress or pathogens.

Although the morphology of plant PCD is, in some cases, well characterised and molecular mechanisms controlling plant PCD are beginning to emerge, there is still confusion about the classification of PCD in plants. Here we suggest a classification based on morphological criteria. According to this classification, the use of the term 'apoptosis' is not justified in plants , but at least two classes of PCD can be distinguished: During vacuolar cell death, the cell contents are removed by a combination of autophagy-like process and release of hydrolases from collapsed lytic vacuoles.

Necrosis is characterised by early rupture of the plasma membrane, shrinkage of the protoplast and absence of vacuolar cell death features. Vacuolar cell death is common during tissue and organ formation and elimination, whereas necrosis is typically found under abiotic stress. Some examples of plant PCD cannot be ascribed to either major class and are therefore classified as separate modalities.

These are PCD associated with the hypersensitive response to biotrophic pathogens, which can express features of both necrosis and vacuolar cell death, PCD in starchy cereal endosperm and during self-incompatibility. The present classification is not static, but will be subject to further revision, especially when specific biochemical pathways are better defined. Never too much acetate. Here, plant cell walls incorporate a variety of acetylated polysaccharides.

In addition to enzymes catalysing acetylation acetyltransferases , plants could produce enzymes to remove acetyl groups acetylesterases. Previously, pectin acetylesterases were known and now a xylan acetylesterase has been identified — and it has many surprises. Plant cell shape, seen as an integrative output, is of considerable interest in various fields, such as cell wall research, cytoskeleton dynamics and biomechanics. In this review we summarize the current state of knowledge on cell shape formation in plants focusing on shape of simple cylindrical cells , as well as in complex multipolar cells such as leaf pavement cells and trichomes.

We summarize established concepts as well as recent additions to the understanding of how cells construct cell walls of a given shape and the underlying processes. These processes include cell wall synthesis, activity of the actin and microtubule cytoskeletons, in particular their regulation by microtubule associated proteins, actin-related proteins, GTP'ases and their effectors, as well as the recently-elucidated roles of plant hormone signaling and vesicular membrane trafficking.

We discuss some of the challenges in cell shape research with a particular emphasis on quantitative imaging and statistical analysis of shape in 2D and 3D, as well as novel developments in this area. Finally, we review recent examples of the use of novel imaging techniques and how they have contributed to our understanding of cell shape formation. Recent studies have been directed to cut down the production costs of these two processes by developing disposable cell culture systems.

Vegetative propagation of elite plant varieties is achieved through somatic embryogenesis in liquid medium. A pilot scale process has recently been set up for the industrial propagation of Coffea canephora Robusta coffee. The current production capacity is 3. The pre-germination of the embryos was previously conducted by temporary immersion in liquid medium in L glass bioreactors. An improved process has been developed using a L disposable bioreactor consisting of a bag containing a rigid plastic box 'Box-in-Bag' bioreactor , insuring, amongst other advantages, a higher light transmittance to the biomass due to its horizontal design.

For large scale cell culture, two novel flexible plastic-based disposable bioreactors have been developed from 10 to L working volumes, validated with several plant species 'Wave and Undertow' and 'Slug Bubble' bioreactors. The advantages and the limits of these new types of bioreactor are discussed, based mainly on our own experience on coffee somatic embryogenesis and mass cell culture of soya and tobacco. Quantitative Aspects of Cyclosis in Plant Cells. Describes an exercise which is currently used in a course in cell physiology at Oxford Polytechnic in England.

This exercise can give students some idea of the molecular events involved in bringing about movement of chloroplasts and other organelles in plant cells. Redox regulation of plant stem cell fate. Despite the importance of stem cells in plant and animal development, the common mechanisms of stem cell maintenance in both systems have remained elusive. Recently, the importance of hydrogen peroxide H 2 O 2 signaling in priming stem cell differentiation has been extensively studied in animals. Here, we show that different forms of reactive oxygen species ROS have antagonistic roles in plant stem cell regulation, which were established by distinct spatiotemporal patterns of ROS-metabolizing enzymes.

Wisconsin Monographs on Education of the Gifted and Talented.

Functional Organization of the Plant Nucleus

These four monographs on the education of the gifted and the talented were prepared by the Wisconsin Department of Public Instruction. Monograph 1 addresses the questions of who the gifted and talented are and why they need special programs. Monograph 2 concerns staff involvement, and covers such topics as staff development, the role of the…. Laser-mediated perforation of plant cells. The functional analysis of plant cells at the cellular and subcellular levels requires novel technologies for the directed manipulation of individual cells.

Lasers are increasingly exploited for the manipulation of plant cells , enabling the study of biological processes on a subcellular scale including transformation to generate genetically modified plants. In our setup either a picosecond laser operating at nm wavelength or a continuous wave laser diode emitting at nm are coupled into an inverse microscope.

The beams are focused to a spot size of about 1. Optoporation is achieved when targeting the laser focal spot at the outermost edge of the plasma membrane. In case of the picosecond laser a single pulse with energy of about 0. When the ultraviolet laser diode at a power level of 17 mW is employed an irradiation time of - milliseconds is necessary to enable the uptake of macromolecules. Single cell perforation using this novel optoporation method shows that isolated plant cells can be permeabilized without direct manipulation.

This is a valuable procedure for cell -specific applications, particularly where the import of specific molecules into plant cells is required for functional analysis. Tocopherol production in plant cell cultures. Tocopherols, collectively known as vitamin E, are lipophilic antioxidants, essential dietary components for mammals and exclusively synthesized by photosynthetic organisms. Of the four forms alpha, beta, gamma and delta , alpha-tocopherol is the major vitamin E form present in green plant tissues, and has the highest vitamin E activity.

Synthetic alpha-tocopherol, being a racemic mixture of eight different stereoisomers, always results less effective than the natural form R,R,R alpha-tocopherol. This raises interest in obtaining this molecule from natural sources, such as plant cell cultures. Plant cell and tissue cultures are able to produce and accumulate valuable metabolites that can be used as food additives, nutraceuticals and pharmaceuticals.

Sunflower cell cultures, growing under heterotrophic conditions, were exploited to establish a suitable in vitro production system of natural alpha-tocopherol. Optimization of culture conditions, precursor feeding and elicitor application were used to improve the tocopherol yields of these cultures.

Furthermore, these cell cultures were useful to investigate the relationship between alpha-tocopherol biosynthesis and photomixotrophic culture conditions, revealing the possibility to enhance tocopherol production by favouring sunflower cell photosynthetic properties. The modulation of alpha-tocopherol levels in plant cell cultures can provide useful hints for a regulatory impact on tocopherol metabolism.

UV-Induced cell death in plants. Plants are photosynthetic organisms that depend on sunlight for energy. Plants respond to light through different photoreceptors and show photomorphogenic development. Low levels of UV-B exposure initiate signaling through UVR8 and induce secondary metabolite genes involved in protection against UV while higher dosages are very detrimental to plants. It has also been reported that genes involved in MAPK cascade help the plant in providing tolerance against UV radiation.

The important targets of UV radiation in plant cells are DNA, lipids and proteins and also vital processes such as photosynthesis. Recent studies showed that, in response to UV radiation, mitochondria and chloroplasts produce a reactive oxygen species ROS. Arabidopsis metacaspase-8 AtMC8 is induced in response to oxidative stress caused by ROS, which acts downstream of the radical induced cell death AtRCD1 gene making plants vulnerable to cell death. Recently, molecular studies have revealed genes involved in response to UV exposure, with respect to programmed cell death PCD.

Osmosis in Poisoned Plant Cells. Describes two simple laboratory exercises that allow students to test hypotheses concerning the requirement of cell energy for osmosis. The first exercise involves osmotically-caused changes in the length of potato tubers and requires detailed quantitative observations.

The second exercise involves osmotically-caused changes in turgor of Elodea…. Calcium signaling in plant cells in microgravity. Calcium as a second messenger is known to play a crucial role in stimulus - response coupling for many plant cellular signaling pathways.

Fromm, Jörg

Its messenger functions are realized by transient changes in the cytosolic ion concentration induced by a variety of internal and external stimuli such as light, hormones, temperature, anoxia, salinity, and gravity. In this paper, an attempt was made to summarize the available experimental results and to consider some hypotheses in this field of research. It is proposed to distinguish between cell gravisensing and cell graviperception; the former is related to cell structure and metabolism stability in the gravitational field and their changes in microgravity cells not specialized to gravity perception , the latter is related to active use of a gravitational stimulus by cells presumably specialized to gravity perception for realization of normal space orientation, growth, and vital activity gravitropism, gravitaxis in plants.

Based on the gravitational decompensation hypothesis, the consequence of events occurring in gravis ensing cells not specialized to gravity perception under altered gravity are considered in the following order: Spectro-microscopy of living plant cells. Spectro-microscopy, a combination of fluorescence microscopy with spatially resolved spectroscopic techniques, provides new and exciting tools for functional cell biology in living organisms.

This review focuses on recent developments in spectro-microscopic applications for the investigation of living plant cells in their native tissue context. The application of spectro-microscopic methods led to the recent discovery of a fast signal response pathway for the brassinosteroide receptor BRI1 in the plasma membrane of living plant cells.

Moreover, the competence of different plant cell types to respond to environmental or endogenous stimuli was determined in vivo by correlation analysis of different optical and spectroscopic readouts such as fluorescence lifetime FLT. Furthermore, a new spectro-microscopic technique, fluorescence intensity decay shape analysis microscopy FIDSAM , has been developed. FIDSAM is capable of imaging low-expressed fluorophore-tagged proteins at high spatial resolution and precludes the misinterpretation of autofluorescence artifacts. In summary, the information content of standard microscopic images is extended by several dimensions by the use of spectro-microscopic approaches.

Therefore, novel cell physiological and molecular topics can be addressed and valuable insights into. The results of the scoping phase of an interdisciplinary assessment of the impact of the increased use of coal are reported in this monograph. The epidermis of aerial plant organs is thought to be limiting for growth, because it acts as a continuous load-bearing layer, resisting tension.

Leaf epidermis contains jigsaw puzzle piece-shaped pavement cells whose shape has been proposed to be a result of subcellular variations in expansion rate that induce local buckling events. Paradoxically, such local compressive buckling should not occur given the tensile stresses across the epidermis. Using computational modeling, we show that the simplest scenario to explain pavement cell shapes within an epidermis under tension must involve mechanical wall heterogeneities across and along the anticlinal pavement cell walls between adjacent cells.

Combining genetics, atomic force microscopy, and immunolabeling, we demonstrate that contiguous cell walls indeed exhibit hybrid mechanochemical properties. Such biochemical wall heterogeneities precede wall bending. Altogether, this provides a possible mechanism for the generation of complex plant cell shapes. Design criteria monograph on axial flow turbines. Monograph provides guidelines for predicting turbine performance, sizing gas-path elements, and avoiding problems associated with mechanical design and development.

Material in monograph is organized along lines of design and development effort necessary to produce turbine that satisfies requirements imposed on it. The recent biotechnology boom has triggered increased interest in plant cell cultures, since a number of firms and academic institutions investigated intensively to rise the production of very promising bioactive compounds. In alternative to wild collection or plant cultivation, the production of useful and valuable secondary metabolites in large bioreactors is an attractive proposal; it should contribute significantly to future attempts to preserve global biodiversity and alleviate associated ecological problems.

The advantages of such processes include the controlled production according to demand and a reduced man work requirement. Plant cells have been grown in different shape bioreactors, however, there are a variety of problems to be solved before this technology can be adopted on a wide scale for the production of useful plant secondary metabolites. There are different factors affecting the culture growth and secondary metabolite production in bioreactors: Moreover agitation systems and sterilization conditions may negatively influence the whole process.

Many types ofbioreactors have been successfully used for cultivating transformed root cultures, depending on both different aeration system and nutrient supply. Several examples of medicinal and aromatic plant cultures were here summarized for the scale up cultivation in bioreactors. Quantification of plant cell coupling with live- cell microscopy. Movement of nutrients and signaling compounds from cell to cell is an essential process for plant growth and development. To understand processes such as carbon allocation, cell communication, and reaction to pathogen attack it is important to know a specific molecule's capacity to pass a specific cell wall interface.

Transport through plasmodesmata, the cell wall channels that directly connect plant cells , is regulated not only by a fixed size exclusion limit, but also by physiological and pathological adaptation. The noninvasive approach described here offers the possibility of precisely determining the plasmodesmata-mediated cell wall permeability for small molecules in living cells. The method is based on photoactivation of the fluorescent tracer caged fluorescein. Non-fluorescent caged fluorescein is applied to a target tissue, where it is taken up passively into all cells.

Imaged by confocal microscopy, loaded tracer is activated by UV illumination in a target cell and its spread to neighboring cells monitored. When combined with high-speed acquisition by resonant scanning or spinning disc confocal microscopy, the high signal-to-noise ratio of photoactivation allows collection of three-dimensional 3D time series. These contain all necessary functional and anatomical data to measure cell coupling in complex tissues noninvasively. Cell-to-cell movement of plastids in plants.

Our objective was to test whether or not plastids and mitochondria, the two DNA-containing organelles, move between cells in plants. As our experimental approach, we grafted two different species of tobacco, Nicotiana tabacum and Nicotiana sylvestris. Grafting triggers formation of new cell-to-cell contacts, creating an opportunity to detect cell-to-cell organelle movement between the genetically distinct plants. We initiated tissue culture from sliced graft junctions and selected for clonal lines in which gentamycin resistance encoded in the N.

Here, we present evidence for cell-to-cell movement of the entire kb plastid genome in these plants , most likely in intact plastids. We also found that the related mitochondria were absent, suggesting independent movement of the two DNA-containing organelles. Acquisition of plastids from neighboring cells provides a mechanism by which cells may be repopulated with functioning organelles.

Our finding supports the universality of intercellular organelle trafficking and may enable development of future biotechnological applications. Biosynthesis of plant cell wall polysaccharides. The cell wall is the principal structural element of plant form. Cellulose, long crystals of several dozen glucan chains, forms the microfibrillar foundation of plant cell walls and is synthesized at the plasma membrane. Except for callose, all other noncellulosic components are secreted to the cell surface and form a porous matrix assembled around the cellulose microfibrils.

These diverse noncellulosic polysaccharides and proteins are made in the endomembrane system. Many questions about the biosynthesis and modification within the Golgi apparatus and integration of cell components at the cell surface remain unanswered. The lability of synthetic complexes upon isolation is one reason for slow progress.

However, with new methods of membrane isolation and analysis of products in vitro, recent advances have been made in purifying active synthases from plasma membrane and Golgi apparatus. Likely synthase polypeptides have been identified by affinity-labeling techniques, but we are just beginning to understand the unique features of the coordinated assembly of complex polysaccharides.

Nevertheless, such progress renews hope that the first gene of a synthase for a wall polysaccharide from higher plants is within our grasp. Visualizing chemical functionality in plant cell walls. Understanding plant cell wall cross-linking chemistry and polymeric architecture is key to the efficient utilization of biomass in all prospects from rational genetic modification to downstream chemical and biological conversion to produce fuels and value chemicals.

In fact, the bulk properties of cell wall recalcitrance are collectively determined by its chemical features over a wide range of length scales from tissue, cellular to polymeric architectures. Microscopic visualization of cell walls from the nanometer to the micrometer scale offers an in situ approach to study their chemical functionality considering its spatial and chemical complexity, particularly the capabilities of characterizing biomass non-destructively and in real-time during conversion processes. Microscopic characterization has revealed heterogeneity in the distribution of chemical features, which would otherwise be hidden in bulk analysis.

Key microscopic features include cell wall type, wall layering, and wall composition-especially cellulose and lignin distributions. Microscopic tools, such as atomic force microscopy, stimulated Raman scattering microscopy, and fluorescence microscopy, have been applied to investigations of cell wall structure and chemistry from the native wall to wall treated by thermal chemical pretreatment and enzymatic hydrolysis. While advancing our current understanding of plant cell wall recalcitrance and deconstruction, microscopic tools with improved spatial resolution will steadily enhance our fundamental understanding of cell wall function.

Microanalysis of plant cell wall polysaccharides. The short time required for sample preparation and analysis makes possible the study of a wide range of plant organs, revealing a high degree of heterogeneity in the substitution pattern of wall polymers such as the cross-linking glycan xyloglucan and the pectic polysaccharide homogalacturonan. The high sensitivity of MALDI-TOF allows the use of small amounts of samples, thus making it possible to investigate the wall structure of single cell types when material is collected by such methods as laser micro-dissection.

As an example, the analysis of the xyloglucan structure in the leaf cell types outer epidermis layer, entire epidermis cell layer, palisade mesophyll cells , and vascular bundles were investigated. OLIMP is amenable to in situ wall analysis, where wall polymers are analyzed on unprepared plant tissue itself without first isolating cell walls.

In addition, OLIMP enables analysis of wall polymers in Golgi-enriched fractions, the location of nascent matrix polysaccharide biosynthesis, enabling separation of the processes of wall biosynthesis versus post-deposition apoplastic metabolism. These new tools will make possible a semi-quantitative analysis of the cell wall at an unprecedented level. Key microscopic features include cell wall type, wall layering, and wall composition - especially cellulose and lignin distributions.

Passage of Trojan peptoids into plant cells. Efficient drug delivery is essential for many therapeutic applications. In this context, Trojan peptoids have attracted attention as powerful tools to deliver bioactive molecules into living cells. Certain cell -penetrating peptides, peptide mimetics, and peptoids have been shown to be endowed with a transport function and the structural features of this function have been characterized. However, most of the research has been done by using mammalian cell cultures as model organisms and the actual cellular mechanism of membrane passage has not been elucidated.

Plant cells , which are encased in a cellulosic cell wall and differ in membrane composition, represent an alternative experimental system to address this issue, but so far, have attracted only little attention for both peptide- and peptoid-based carrier systems. Moreover, efficient delivery of nonproteinaceous bioactive macromolecules into living plant cells could complement genetic engineering in biotechnological applications, such as metabolic engineering and molecular farming.

In the present study, we investigated carrier peptoids with or without guanidinium side chains with regard to their uptake into plant cells , the cellular mechanism of uptake, and intracellular localization. We can show that in contrast to polyamine peptoids polylysine-like fluorescently labeled polyguanidine peptoids polyarginine-like enter rapidly into tobacco BY-2 cells without affecting the viability of these cells. A quantitative comparison of this uptake with endocytosis of fluorescently labeled dextranes indicates that the main uptake of the guanidinium peptoids occurs between min after the start of incubation and clearly precedes endocytosis.

Dual visualization with the endosomal marker FM shows that the intracellular guanidinium peptoid is distinct from endocytotic vesicles. Once the polyguanidine peptoids have entered the cell , they associate with actin filaments and microtubules.

Bestselling Series

Plant cells oxidize hydroxylamines to NO. Plants are known to produce NO via the reduction of nitrite. Oxidative NO production in plants has been considered only with respect to a nitric oxide synthase NOS. Production of NO was decreased by anoxia or by the addition of catalase, but was increased by conditions inducing reactive oxygen ROS or by the addition of hydrogen peroxide.

Cell -free enzyme solutions generating superoxide or hydrogen peroxide also led to the formation of NO from HA or with lower rates from SHAM, and nitrite was also an oxidation product. While our data open a new possibility for oxidative NO formation in plants , the existence and role of these reactions under physiological conditions is not yet clear. Right side of Zinc Plant , from Cell Room midpoint View is to the east. Fuel cell power plant economic and operational considerations. Fuel cell power plants intended for electric utility and cogeneration applications are now in the design and construction stage.

This paper describes economic and operational considerations being used in the development and design of plants utilizing air cooled phosphoric acid fuel cells. Fuel cell power plants have some unique characteristics relative to other types of power plants. As a result it was necessary to develop specific definitions of the fuel cell power plant characteristics in order to perform cost of electricity calculations. This paper describes these characteristics and describes the economic analyses used in the Westinghouse fuel cell power plant program.

Characterization of Cellulose Synthesis in Plant Cells. Cellulose is the most significant structural component of plant cell wall. The CSC is involved in biosynthesis of cellulose microfibrils containing 18 cellulose synthase CesA proteins. Macrofibrils can be formed with side by side arrangement of microfibrils. Understanding the mechanisms of cellulose biosynthesis is of great importance not only for improving wood production in economically important forest trees to mankind but also for plant development.

This review article covers the current knowledge about the cellulose biosynthesis-related gene family. Cell-to-cell communication via plasmodesmata in vascular plants. In plant development, cell-to-cell signaling is mediated by mobile signals, including transcription factors and small RNA molecules. This communication is essential for growth and patterning. Short-range movement of signals occurs in the extracellular space via the apoplastic pathway or directly from cell-to-cell via the symplastic pathway.

Symplastic transport is mediated by plant specific structures called plasmodesmata, which are plasma membrane-lined pores that traverse the cell walls of adjacent cells thus connecting their cytoplasms. However, a thorough understanding of molecules moving via plasmodesmata and regulatory networks relying on symplastic signaling is lacking. Traffic via plasmodesmata is highly regulated, and callose turnover is known to be one mechanism. In Arabidopsis, plasmodesmata apertures can be regulated in a spatially and temporally specific manner with the icals3m, an inducible vector system expressing the mutated CalS3 gene encoding a plasmodesmata localized callose synthase that increases callose deposition at plasmodesmata.

We discuss strategies to use the icals3m system for global analyses on symplastic signaling in plants. Force Limited Vibration Testing Monograph.

The practice of limiting the shaker force in vibration tests was investigated at the NASA Jet Propulsion Laboratory JPL in after the mechanical failure of an aerospace component during a vibration test. The basic ideas behind force limiting have been in the literature for several decades, but the piezo-electric force transducers necessary to conveniently implement force limiting have been available only in the last decade.

Plant Endocytosis

In , funding was obtained from the NASA headquarters Office of Chief Engineer to develop and document the technology needed to establish force limited vibration testing as a standard approach available to all NASA centers and aerospace contractors. This monograph is the final report on that effort and discusses the history, theory, and applications of the method in some detail. Plant cell technologies in space: Background, strategies and prospects. An attempt is made to summarize work in plant cell technologies in space. The evolution of concepts and the general principles of plant tissue culture are discussed.

The potential for production of high value secondary products by plant cells and differentiated tissue in automated, precisely controlled bioreactors is discussed. The general course of the development of the literature on plant tissue culture is highlighted. How do plant cell walls extend? This article briefly summarizes recent work that identifies the biophysical and biochemical processes that give rise to the extension of plant cell walls.

I begin with the biophysical notion of stress relaxation of the wall and follow with recent studies of wall enzymes thought to catalyze wall extension and relaxation. Readers should refer to detailed reviews for more comprehensive discussion of earlier literature Taiz, ; Carpita and Gibeaut, ; Cosgrove, Do plant cell walls have a code? A code is a set of rules that establish correspondence between two worlds, signs consisting of encrypted information and meaning of the decrypted message.

A third element, the adaptor, connects both worlds, assigning meaning to a code. We propose that a Glycomic Code exists in plant cell walls where signs are represented by monosaccharides and phenylpropanoids and meaning is cell wall architecture with its highly complex association of polymers. Cell wall biosynthetic mechanisms, structure, architecture and properties are addressed according to Code Biology perspective, focusing on how they oppose to cell wall deconstruction. Cell wall hydrolysis is mainly focused as a mechanism of decryption of the Glycomic Code.

Evidence for encoded information in cell wall polymers fine structure is highlighted and the implications of the existence of the Glycomic Code are discussed. Aspects related to fine structure are responsible for polysaccharide packing and polymer-polymer interactions, affecting the final cell wall architecture. The question whether polymers assembly within a wall display similar properties as other biological macromolecules i. Plant Cell Adaptive Responses to Microgravity. Microgravity is an abnormal environmental condition that plays no role in the functioning of biosphere.

Nevertheless, the chronic effect of microgravity in space flight as an unfamiliar factor does not prevent the development of adaptive reactions at the cellular level. It is known that cells of a multicellular organism not only take part on reactions of the organism but also carry out processes that maintain their integrity.

In light of these principles, the problem of the identification of biochemical, physiological and structural patterns that can have adaptive significance at the cellular and subcellular level in real and simulated microgravity is considered. Cytological studies of plants developing in real and simulated microgravity made it possible to establish that the processes of mitosis, cytokinesis, and tissue differentiation of vegetative and generative organs are largely normal. At the same time, under microgravity, essential reconstruction in the structural and functional organization of cell organelles and cytoskeleton, as well as changes in cell metabolism and homeostasis have been described.

In addition, new interesting data concerning the influence of altered gravity on lipid peroxidation intensity, the level of reactive oxygen species, and antioxidant system activity, just like on the level of gene expression and synthesis of low-molecular and high-molecular heat shock proteins were recently obtained. So, altered gravity caused time-dependent increasing of the HSP70 and HSP90 levels in cells , that may indicate temporary strengthening of their functional loads that is necessary for re-establish a new cellular homeostasis.

Relative qPCR results showed that. The monograph program of the International Agency for Research on Cancer IARC , which relies on the efforts of volunteer Working Groups, uses a transparent approach to evaluate the carcinogenicity of agents for which scoping has determined that there is sufficient evidence to warrant a review. Because of the potentially powerful implications of the conclusions of the monographs and the sometimes challenging nature of the evidence reviewed, the monographs and the IARC process have been criticized from time to time.

This commentary describes the IARC monograph process and addresses recent criticisms of the program, drawing on a recent defense of the program authored by researchers. These authors concluded that the IARC processes are robust and transparent and not flawed and biased as suggested by some critics. Published by Oxford University Press. For Permissions, please email: Technical books and monographs. This booklet lists technical books and monographs published since the issuance of Technical Books and Monographs , Catalog, a bibliography of books and monographs sponsored by the US Department of Energy DOE or by one of the earlier organizations that were brought together to form DOE.

The books and monographs are grouped under twelve subject categories: Design criteria monograph for pressurized metal cases. Organiation and presentation of data pertaining to design of solid propellant rocket engine cases are discussed. Design criteria are presented in form of monograph based on accumulated experience and knowledge.

Improvements in reliability, cost effectiveness, and engine efficiency are stressed. Design criteria monograph for valve assemblies. Monograph is limited to valve selection factors for trade-off studies, configuration analyses, actuator selection, and integration of components. Material is organized along lines of valve design sequence. Plant cell wall lignification and monolignol metabolism. Plants are built of various specialized cell types that differ in their cell wall composition and structure. The cell walls of certain tissues xylem, sclerenchyma are characterized by the presence of the heterogeneous lignin polymer that plays an essential role in their physiology.

This phenolic polymer is composed of different monomeric units — the monolignols — that are linked together by several covalent bonds. Numerous studies have shown that monolignol biosynthesis and polymerization to form lignin are tightly controlled in different cell types and tissues. However, our understanding of the genetic control of monolignol transport and polymerization remains incomplete, despite some recent promising results. This situation is made more complex since we know that monolignols or related compounds are sometimes produced in non-lignified tissues.

In this review, we focus on some key steps of monolignol metabolism including polymerization, transport, and compartmentation. As well as being of fundamental interest, the quantity of lignin and its nature are also known to have a negative effect on the industrial processing of plant lignocellulose biomass. A more complete view of monolignol metabolism and the relationship that exists between lignin and other monolignol-derived compounds thereby appears essential if we wish to improve biomass quality.

Plant stem cells in cosmetics: Plant regeneration at the cellular and tissue level is a unique process. Similar to animals, the stem cells in plants have properties that help stimulate and regenerate plants after injury. This special report focuses on the current evidence-based trends in plant stem cell -based cosmetics and sheds light on the challenges that we need to overcome in order to see meaningful changes in human skin using topical cosmetics derived from plant stem cells.

Monograph on prospective developments in oceanology. The author of this chapter is A. The monograph is said to be the collective work of a group of specialists. Monin views prospective developments of oceanology and oceanology related research and development, technology and expedition research. Movement of macromolecules in plant cells through plasmodesmata. Plasmodesmata are intercellular organelles in plants that allow the passage of molecules between plant cells.

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