An automated, high-throughput plant phenotyping system using machine learning-based plant segmentation and image analysis.

Science.gov (United States)

Lee, Unseok; Chang, Sungyul; Putra, Gian Anantrio; Kim, Hyoungseok; Kim, Dong Hwan

2018-01-01

A high-throughput plant phenotyping system automatically observes and grows many plant samples. Many plant sample images are acquired by the system to determine the characteristics of the plants (populations). Stable image acquisition and processing is very important to accurately determine the characteristics. However, hardware for acquiring plant images rapidly and stably, while minimizing plant stress, is lacking. Moreover, most software cannot adequately handle large-scale plant imaging. To address these problems, we developed a new, automated, high-throughput plant phenotyping system using simple and robust hardware, and an automated plant-imaging-analysis pipeline consisting of machine-learning-based plant segmentation. Our hardware acquires images reliably and quickly and minimizes plant stress. Furthermore, the images are processed automatically. In particular, large-scale plant-image datasets can be segmented precisely using a classifier developed using a superpixel-based machine-learning algorithm (Random Forest), and variations in plant parameters (such as area) over time can be assessed using the segmented images. We performed comparative evaluations to identify an appropriate learning algorithm for our proposed system, and tested three robust learning algorithms. We developed not only an automatic analysis pipeline but also a convenient means of plant-growth analysis that provides a learning data interface and visualization of plant growth trends. Thus, our system allows end-users such as plant biologists to analyze plant growth via large-scale plant image data easily.

Development of Simultaneous Beta-and-Coincidence-Gamma Imager for Plant Imaging Research

Energy Technology Data Exchange (ETDEWEB)

Tai, Yuan-Chuan [Washington Univ., St. Louis, MO (United States). School of Medicine

2016-09-30

The goal of this project is to develop a novel imaging system that can simultaneously acquire beta and coincidence gamma images of positron sources in thin objects such as leaves of plants. This hybrid imager can be used to measure carbon assimilation in plants quantitatively and in real-time after C-11 labeled carbon-dioxide is administered. A better understanding of carbon assimilation, particularly under the increasingly elevated atmospheric CO₂ level, is extremely critical for plant scientists who study food crop and biofuel production. Phase 1 of this project is focused on the technology development with 3 specific aims: (1) develop a hybrid detector that can detect beta and gamma rays simultaneously; (2) develop an imaging system that can differentiate these two types of radiation and acquire beta and coincidence gamma images in real-time; (3) develop techniques to quantify radiotracer distribution using beta and gamma images. Phase 2 of this project is to apply technologies developed in phase 1 to study plants using positron-emitting radionuclide such as ¹¹C to study carbon assimilation in biofuel plants.

Plant stem cell niches.

Science.gov (United States)

Aichinger, Ernst; Kornet, Noortje; Friedrich, Thomas; Laux, Thomas

2012-01-01

Multicellular organisms possess pluripotent stem cells to form new organs, replenish the daily loss of cells, or regenerate organs after injury. Stem cells are maintained in specific environments, the stem cell niches, that provide signals to block differentiation. In plants, stem cell niches are situated in the shoot, root, and vascular meristems-self-perpetuating units of organ formation. Plants' lifelong activity-which, as in the case of trees, can extend over more than a thousand years-requires that a robust regulatory network keep the balance between pluripotent stem cells and differentiating descendants. In this review, we focus on current models in plant stem cell research elaborated during the past two decades, mainly in the model plant Arabidopsis thaliana. We address the roles of mobile signals on transcriptional modules involved in balancing cell fates. In addition, we discuss shared features of and differences between the distinct stem cell niches of Arabidopsis.

Secondary Metabolite Localization by Autofluorescence in Living Plant Cells

Directory of Open Access Journals (Sweden)

Pascale Talamond

2015-03-01

Full Text Available Autofluorescent molecules are abundant in plant cells and spectral images offer means for analyzing their spectra, yielding information on their accumulation and function. Based on their fluorescence characteristics, an imaging approach using multiphoton microscopy was designed to assess localization of the endogenous fluorophores in living plant cells. This method, which requires no previous treatment, provides an effective experimental tool for discriminating between multiple naturally-occurring fluorophores in living-tissues. Combined with advanced Linear Unmixing, the spectral analysis extends the possibilities and enables the simultaneous detection of fluorescent molecules reliably separating overlapping emission spectra. However, as with any technology, the possibility for artifactual results does exist. This methodological article presents an overview of the applications of tissular and intra-cellular localization of these intrinsic fluorophores in leaves and fruits (here for coffee and vanilla. This method will provide new opportunities for studying cellular environments and the behavior of endogenous fluorophores in the intracellular environment.

Visualizing metabolite distribution and enzymatic conversion in plant tissues by desorption electrospray ionization mass spectrometry imaging

DEFF Research Database (Denmark)

Li, Bin; Baden, Camilla Knudsen; Hansen, Natascha Kristine Krahl

2013-01-01

In comparison to the technology platforms developed to localize transcripts and proteins, imaging tools for visualization of metabolite distributions in plant tissues are less well developed and lack versatility. This hampers our understanding of plant metabolism and dynamics. In this study we...... demonstrate that Desorption Electrospray Ionization Mass Spectrometry Imaging (DESI-MSI) of tissue imprints on porous Teflon can be used to accurately image the distribution of even labile plant metabolites such as hydroxynitrile glucosides, which normally undergo enzymatic hydrolysis by specific ß......-glucosidases upon cell disruption. This fast and simple sample preparation resulted in no substantial differences in the distribution and ratios of all hydroxynitrile glucosides between leaves from wildtype Lotus japonicus and a ß-glucosidase mutant plant lacking the ability to hydrolyze certain hydroxynitrile...

Plant stem cell niches.

Science.gov (United States)

Stahl, Yvonne; Simon, Rüdiger

2005-01-01

Stem cells are required to support the indeterminate growth style of plants. Meristems are a plants stem cell niches that foster stem cell survival and the production of descendants destined for differentiation. In shoot meristems, stem cell fate is decided at the populational level. The size of the stem cell domain at the meristem tip depends on signals that are exchanged with cells of the organizing centre underneath. In root meristems, individual stem cells are controlled by direct interaction with cells of the quiescent centre that lie in the immediate neighbourhood. Analysis of the interactions and signaling processes in the stem cell niches has delivered some insights into the molecules that are involved and revealed that the two major niches for plant stem cells are more similar than anticipated.

Imaging the Dynamics of Cell Wall Polymer Deposition in the Unicellular Model Plant, Penium margaritaceum.

Science.gov (United States)

Domozych, David; Lietz, Anna; Patten, Molly; Singer, Emily; Tinaz, Berke; Raimundo, Sandra C

2017-01-01

The unicellular green alga, Penium margaritaceum, represents a novel and valuable model organism for elucidating cell wall dynamics in plants. This organism's cell wall contains several polymers that are highly similar to those found in the primary cell walls of land plants. Penium is easily grown in laboratory culture and is effectively manipulated in various experimental protocols including microplate assays and correlative microscopy. Most importantly, Penium can be live labeled with cell wall-specific antibodies or other probes and returned to culture where specific cell wall developmental events can be monitored. Additionally, live cells can be rapidly cryo-fixed and cell wall surface microarchitecture can be observed with variable pressure scanning electron microscopy. Here, we describe the methodology for maintaining Penium for experimental cell wall enzyme studies.

Recent advances in matrix-assisted laser desorption/ionisation mass spectrometry imaging (MALDI-MSI) for in situ analysis of endogenous molecules in plants.

Science.gov (United States)

Qin, Liang; Zhang, Yawen; Liu, Yaqin; He, Huixin; Han, Manman; Li, Yanyan; Zeng, Maomao; Wang, Xiaodong

2018-04-17

Mass spectrometry imaging (MSI) as a label-free and powerful imaging technique enables in situ evaluation of a tissue metabolome and/or proteome, becoming increasingly popular in the detection of plant endogenous molecules. The characterization of structure and spatial information of endogenous molecules in plants are both very important aspects to better understand the physiological mechanism of plant organism. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is a commonly-used tissue imaging technique, which requires matrix to assist in situ detection of a variety of molecules on the surface of a tissue section. In previous studies, MALDI-MSI was mostly used for the detection of molecules from animal tissue sections, compared to plant samples due to cell structural limitations, such as plant cuticles, epicuticular waxes, and cell walls. Despite the enormous progress that has been made in tissue imaging, there is still a challenge for MALDI-MSI suitable for the imaging of endogenous compounds in plants. This review summarises the recent advances in MALDI-MSI, focusing on the application of in situ detection of endogenous molecules in different plant organs, i.e. root, stem, leaf, flower, fruit, and seed. Further improvements on instrumentation sensitivity, matrix selection, image processing and sample preparation will expand the application of MALDI-MSI in plant research. Copyright © 2018 John Wiley & Sons, Ltd.

Predicting plant biomass accumulation from image-derived parameters

Science.gov (United States)

Chen, Dijun; Shi, Rongli; Pape, Jean-Michel; Neumann, Kerstin; Graner, Andreas; Chen, Ming; Klukas, Christian

2018-01-01

Abstract Background Image-based high-throughput phenotyping technologies have been rapidly developed in plant science recently, and they provide a great potential to gain more valuable information than traditionally destructive methods. Predicting plant biomass is regarded as a key purpose for plant breeders and ecologists. However, it is a great challenge to find a predictive biomass model across experiments. Results In the present study, we constructed 4 predictive models to examine the quantitative relationship between image-based features and plant biomass accumulation. Our methodology has been applied to 3 consecutive barley (Hordeum vulgare) experiments with control and stress treatments. The results proved that plant biomass can be accurately predicted from image-based parameters using a random forest model. The high prediction accuracy based on this model will contribute to relieving the phenotyping bottleneck in biomass measurement in breeding applications. The prediction performance is still relatively high across experiments under similar conditions. The relative contribution of individual features for predicting biomass was further quantified, revealing new insights into the phenotypic determinants of the plant biomass outcome. Furthermore, methods could also be used to determine the most important image-based features related to plant biomass accumulation, which would be promising for subsequent genetic mapping to uncover the genetic basis of biomass. Conclusions We have developed quantitative models to accurately predict plant biomass accumulation from image data. We anticipate that the analysis results will be useful to advance our views of the phenotypic determinants of plant biomass outcome, and the statistical methods can be broadly used for other plant species. PMID:29346559

3D Plant Cell Architecture of Arabidopsis thaliana (Brassicaceae Using Focused Ion Beam–Scanning Electron Microscopy

Directory of Open Access Journals (Sweden)

Bhawana

2014-06-01

Full Text Available Premise of the study: Focused ion beam–scanning electron microscopy (FIB-SEM combines the ability to sequentially mill the sample surface and obtain SEM images that can be used to create 3D renderings with micron-level resolution. We have applied FIB-SEM to study Arabidopsis cell architecture. The goal was to determine the efficacy of this technique in plant tissue and cellular studies and to demonstrate its usefulness in studying cell and organelle architecture and distribution. Methods: Seed aleurone, leaf mesophyll, stem cortex, root cortex, and petal lamina from Arabidopsis were fixed and embedded for electron microscopy using protocols developed for animal tissues and modified for use with plant cells. Each sample was sectioned using the FIB and imaged with SEM. These serial images were assembled to produce 3D renderings of each cell type. Results: Organelles such as nuclei and chloroplasts were easily identifiable, and other structures such as endoplasmic reticula, lipid bodies, and starch grains were distinguishable in each tissue. Discussion: The application of FIB-SEM produced 3D renderings of five plant cell types and offered unique views of their shapes and internal content. These results demonstrate the usefulness of FIB-SEM for organelle distribution and cell architecture studies.

Image Harvest: an open-source platform for high-throughput plant image processing and analysis

Science.gov (United States)

Knecht, Avi C.; Campbell, Malachy T.; Caprez, Adam; Swanson, David R.; Walia, Harkamal

2016-01-01

High-throughput plant phenotyping is an effective approach to bridge the genotype-to-phenotype gap in crops. Phenomics experiments typically result in large-scale image datasets, which are not amenable for processing on desktop computers, thus creating a bottleneck in the image-analysis pipeline. Here, we present an open-source, flexible image-analysis framework, called Image Harvest (IH), for processing images originating from high-throughput plant phenotyping platforms. Image Harvest is developed to perform parallel processing on computing grids and provides an integrated feature for metadata extraction from large-scale file organization. Moreover, the integration of IH with the Open Science Grid provides academic researchers with the computational resources required for processing large image datasets at no cost. Image Harvest also offers functionalities to extract digital traits from images to interpret plant architecture-related characteristics. To demonstrate the applications of these digital traits, a rice (Oryza sativa) diversity panel was phenotyped and genome-wide association mapping was performed using digital traits that are used to describe different plant ideotypes. Three major quantitative trait loci were identified on rice chromosomes 4 and 6, which co-localize with quantitative trait loci known to regulate agronomically important traits in rice. Image Harvest is an open-source software for high-throughput image processing that requires a minimal learning curve for plant biologists to analyzephenomics datasets. PMID:27141917

Imaging corn plants with PhytoPET, a modular PET system for plant biology

Energy Technology Data Exchange (ETDEWEB)

Lee, S.; Kross, B.; McKisson, J.; McKisson, J. E.; Weisenberger, A. G.; Xi, W.; Zorn, C.; Bonito, G.; Howell, C. R.; Reid, C. D.; Crowell, A.; Cumberbatch, L. C.; Topp, C.; Smith, M. F.

2013-11-01

PhytoPET is a modular positron emission tomography (PET) system designed specifically for plant imaging. The PhytoPET design allows flexible arrangements of PET detectors based on individual standalone detector modules built from single Hamamatsu H8500 position sensitive photomultiplier tubes and pixelated LYSO arrays. We have used the PhytoPET system to perform preliminary corn plant imaging studies at the Duke University Biology Department Phytotron. Initial evaluation of the PhytoPET system to image the biodistribution of the positron emitting tracer {sup 11}C in corn plants is presented. {sup 11}CO{sub 2} is loaded into corn seedlings by a leaf-labeling cuvette and translocation of {sup 11}C-sugars is imaged by a flexible arrangement of PhytoPET modules on each side. The PhytoPET system successfully images {sup 11}C within corn plants and allows for the dynamic measurement of {sup 11}C-sugar translocation from the leaf to the roots.

Plant cell wall polysaccharide analysis during cell elongation

DEFF Research Database (Denmark)

Guo, Xiaoyuan

Plant cell walls are complex structures whose composition and architecture are important to various cellular activities. Plant cell elongation requires a high level of rearrangement of the cell wall polymers to enable cell expansion. However, the cell wall polysaccharides dynamics during plant cell...... elongation is poorly understood. This PhD project aims to elucidate the cell wall compositional and structural change during cell elongation by using Comprehensive Microarray Polymer Profiling (CoMPP), microscopic techniques and molecular modifications of cell wall polysaccharide. Developing cotton fibre......, pea and Arabidopsis thaliana were selected as research models to investigate different types of cell elongation, developmental elongation and tropism elongation. A set of comprehensive analysis covering 4 cotton species and 11 time points suggests that non-cellulosic polysaccharides contribute...

Plant cell nucleolus as a hot spot for iron.

Science.gov (United States)

Roschzttardtz, Hannetz; Grillet, Louis; Isaure, Marie-Pierre; Conéjéro, Geneviève; Ortega, Richard; Curie, Catherine; Mari, Stéphane

2011-08-12

Many central metabolic processes require iron as a cofactor and take place in specific subcellular compartments such as the mitochondrion or the chloroplast. Proper iron allocation in the different organelles is thus critical to maintain cell function and integrity. To study the dynamics of iron distribution in plant cells, we have sought to identify the different intracellular iron pools by combining three complementary imaging approaches, histochemistry, micro particle-induced x-ray emission, and synchrotron radiation micro X-ray fluorescence. Pea (Pisum sativum) embryo was used as a model in this study because of its large cell size and high iron content. Histochemical staining with ferrocyanide and diaminobenzidine (Perls/diaminobenzidine) strongly labeled a unique structure in each cell, which co-labeled with the DNA fluorescent stain DAPI, thus corresponding to the nucleus. The unexpected presence of iron in the nucleus was confirmed by elemental imaging using micro particle-induced x-ray emission. X-ray fluorescence on cryo-sectioned embryos further established that, quantitatively, the iron concentration found in the nucleus was higher than in the expected iron-rich organelles such as plastids or vacuoles. Moreover, within the nucleus, iron was particularly accumulated in a subcompartment that was identified as the nucleolus as it was shown to transiently disassemble during cell division. Taken together, our data uncover an as yet unidentified although abundant iron pool in the cell, which is located in the nuclei of healthy, actively dividing plant tissues. This result paves the way for the discovery of a novel cellular function for iron related to nucleus/nucleolus-associated processes.

Live-cell imaging.

Science.gov (United States)

Cole, Richard

2014-01-01

It would be hard to argue that live-cell imaging has not changed our view of biology. The past 10 years have seen an explosion of interest in imaging cellular processes, down to the molecular level. There are now many advanced techniques being applied to live cell imaging. However, cellular health is often under appreciated. For many researchers, if the cell at the end of the experiment has not gone into apoptosis or is blebbed beyond recognition, than all is well. This is simply incorrect. There are many factors that need to be considered when performing live-cell imaging in order to maintain cellular health such as: imaging modality, media, temperature, humidity, PH, osmolality, and photon dose. The wavelength of illuminating light, and the total photon dose that the cells are exposed to, comprise two of the most important and controllable parameters of live-cell imaging. The lowest photon dose that achieves a measureable metric for the experimental question should be used, not the dose that produces cover photo quality images. This is paramount to ensure that the cellular processes being investigated are in their in vitro state and not shifted to an alternate pathway due to environmental stress. The timing of the mitosis is an ideal canary in the gold mine, in that any stress induced from the imaging will result in the increased length of mitosis, thus providing a control model for the current imagining conditions.

Image Harvest: an open-source platform for high-throughput plant image processing and analysis.

Science.gov (United States)

Knecht, Avi C; Campbell, Malachy T; Caprez, Adam; Swanson, David R; Walia, Harkamal

2016-05-01

High-throughput plant phenotyping is an effective approach to bridge the genotype-to-phenotype gap in crops. Phenomics experiments typically result in large-scale image datasets, which are not amenable for processing on desktop computers, thus creating a bottleneck in the image-analysis pipeline. Here, we present an open-source, flexible image-analysis framework, called Image Harvest (IH), for processing images originating from high-throughput plant phenotyping platforms. Image Harvest is developed to perform parallel processing on computing grids and provides an integrated feature for metadata extraction from large-scale file organization. Moreover, the integration of IH with the Open Science Grid provides academic researchers with the computational resources required for processing large image datasets at no cost. Image Harvest also offers functionalities to extract digital traits from images to interpret plant architecture-related characteristics. To demonstrate the applications of these digital traits, a rice (Oryza sativa) diversity panel was phenotyped and genome-wide association mapping was performed using digital traits that are used to describe different plant ideotypes. Three major quantitative trait loci were identified on rice chromosomes 4 and 6, which co-localize with quantitative trait loci known to regulate agronomically important traits in rice. Image Harvest is an open-source software for high-throughput image processing that requires a minimal learning curve for plant biologists to analyzephenomics datasets. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Microbial Cell Imaging

Energy Technology Data Exchange (ETDEWEB)

Doktycz, Mitchel John [ORNL; Sullivan, Claretta [Eastern Virginia Medical School; Mortensen, Ninell P [ORNL; Allison, David P [ORNL

2011-01-01

Atomic force microscopy (AFM) is finding increasing application in a variety of fields including microbiology. Until the emergence of AFM, techniques for ivnestigating processes in single microbes were limited. From a biologist's perspective, the fact that AFM can be used to generate high-resolution images in buffers or media is its most appealing feature as live-cell imaging can be pursued. Imaging living cells by AFM allows dynamic biological events to be studied, at the nanoscale, in real time. Few areas of biological research have as much to gain as microbiology from the application of AFM. Whereas the scale of microbes places them near the limit of resolution for light microscopy. AFM is well suited for the study of structures on the order of a micron or less. Although electron microscopy techniques have been the standard for high-resolution imaging of microbes, AFM is quickly gaining favor for several reasons. First, fixatives that impair biological activity are not required. Second, AFM is capable of detecting forces in the pN range, and precise control of the force applied to the cantilever can be maintained. This combination facilitates the evaluation of physical characteristics of microbes. Third, rather than yielding the composite, statistical average of cell populations, as is the case with many biochemical assays, the behavior of single cells can be monitored. Despite the potential of AFM in microbiology, there are several limitations that must be considered. For example, the time required to record an image allows for the study of gross events such as cell division or membrane degradation from an antibiotic but precludes the evaluation of biological reactions and events that happen in just fractions of a second. Additionally, the AFM is a topographical tool and is restricted to imaging surfaces. Therefore, it cannot be used to look inside cells as with opticla and transmission electron microscopes. other practical considerations are the

Fine-grained recognition of plants from images.

Science.gov (United States)

Šulc, Milan; Matas, Jiří

2017-01-01

Fine-grained recognition of plants from images is a challenging computer vision task, due to the diverse appearance and complex structure of plants, high intra-class variability and small inter-class differences. We review the state-of-the-art and discuss plant recognition tasks, from identification of plants from specific plant organs to general plant recognition "in the wild". We propose texture analysis and deep learning methods for different plant recognition tasks. The methods are evaluated and compared them to the state-of-the-art. Texture analysis is only applied to images with unambiguous segmentation (bark and leaf recognition), whereas CNNs are only applied when sufficiently large datasets are available. The results provide an insight in the complexity of different plant recognition tasks. The proposed methods outperform the state-of-the-art in leaf and bark classification and achieve very competitive results in plant recognition "in the wild". The results suggest that recognition of segmented leaves is practically a solved problem, when high volumes of training data are available. The generality and higher capacity of state-of-the-art CNNs makes them suitable for plant recognition "in the wild" where the views on plant organs or plants vary significantly and the difficulty is increased by occlusions and background clutter.

Outside-in control -Does plant cell wall integrity regulate cell cycle progression?

Science.gov (United States)

Gigli-Bisceglia, Nora; Hamann, Thorsten

2018-04-13

During recent years it has become accepted that plant cell walls are not inert objects surrounding all plant cells but are instead highly dynamic, plastic structures. They are involved in a large number of cell biological processes and contribute actively to plant growth, development and interaction with environment. Therefore, it is not surprising that cellular processes can control plant cell wall integrity while, simultaneously, cell wall integrity can influence cellular processes. In yeast and animal cells such a bi-directional relationship also exists between the yeast/animal extra-cellular matrices and the cell cycle. In yeast, the cell wall integrity maintenance mechanism and a dedicated plasmamembrane integrity checkpoint are mediating this relationship. Recent research has yielded insights into the mechanism controlling plant cell wall metabolism during cytokinesis. However, knowledge regarding putative regulatory pathways controlling adaptive modifications in plant cell cycle activity in response to changes in the state of the plant cell wall are not yet identified. In this review, we summarize similarities and differences in regulatory mechanisms coordinating extra cellular matrices and cell cycle activity in animal and yeast cells, discuss the available evidence supporting the existence of such a mechanism in plants and suggest that the plant cell wall integrity maintenance mechanism might also control cell cycle activity in plant cells. This article is protected by copyright. All rights reserved.

Method and apparatus to image biological interactions in plants

Science.gov (United States)

Weisenberger, Andrew; Bonito, Gregory M.; Reid, Chantal D.; Smith, Mark Frederick

2015-12-22

A method to dynamically image the actual translocation of molecular compounds of interest in a plant root, root system, and rhizosphere without disturbing the root or the soil. The technique makes use of radioactive isotopes as tracers to label molecules of interest and to image their distribution in the plant and/or soil. The method allows for the study and imaging of various biological and biochemical interactions in the rhizosphere of a plant, including, but not limited to, mycorrhizal associations in such regions.

RootAnalyzer: A Cross-Section Image Analysis Tool for Automated Characterization of Root Cells and Tissues.

Directory of Open Access Journals (Sweden)

Joshua Chopin

Full Text Available The morphology of plant root anatomical features is a key factor in effective water and nutrient uptake. Existing techniques for phenotyping root anatomical traits are often based on manual or semi-automatic segmentation and annotation of microscopic images of root cross sections. In this article, we propose a fully automated tool, hereinafter referred to as RootAnalyzer, for efficiently extracting and analyzing anatomical traits from root-cross section images. Using a range of image processing techniques such as local thresholding and nearest neighbor identification, RootAnalyzer segments the plant root from the image's background, classifies and characterizes the cortex, stele, endodermis and epidermis, and subsequently produces statistics about the morphological properties of the root cells and tissues. We use RootAnalyzer to analyze 15 images of wheat plants and one maize plant image and evaluate its performance against manually-obtained ground truth data. The comparison shows that RootAnalyzer can fully characterize most root tissue regions with over 90% accuracy.

Radiation-induced cell death in embryogenic cells of coniferous plants

International Nuclear Information System (INIS)

Watanabe, Yoshito; Homma-Takeda, Shino; Yukawa, Masae; Nishimura, Yoshikazu; Sasamoto, Hamako; Takahagi, Masahiko

2004-01-01

Reproductive processes are particularly radiosensitive in plant development, which was clearly illustrated in reduction of seed formation in native coniferous plants around Chernobyl after the nuclear accident. For the purpose to investigate the effects of ionizing radiation on embryonic formation in coniferous plants, we used an embryo-derived embryogenic cell culture of a Japanese native coniferous plant, Japanese cedar (Cryplomeria japonica). The embryogenic cells were so radiosensitive that most of the cells died by X-ray irradiation of 5 Gy. This indicated that the embryogenic cells are as radiosensitive as some mammalian cells including lymphocytes. We considered that this type of radiosensitive cell death in the embryogenic cells should be responsible for reproductive damages of coniferous plants by low dose of ionizing radiation. The cell death of the embryogenic cells was characteristic of nuclear DNA fragmentation, which is typically observed in radiation-induced programmed cell death, i.e. apoptosis, in mammalian cells. On the other hand, cell death with nuclear DNA fragmentation did not develop by X-ray irradiation in vegetative cells including meristematic cells of Japanese cedar. This suggests that an apoptosis-like programmed cell death should develop cell-specifically in embryogenic cells by ionizing radiation. The abortion of embryogenic cells may work to prevent transmission of radiation-induced genetic damages to the descendants. (author)

Regulation of Water in Plant Cells

Science.gov (United States)

Kowles, Richard V.

2010-01-01

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…

Imaging of plant materials using indirect desorption electrospray ionization mass spectrometry

DEFF Research Database (Denmark)

Janfelt, Christian

2015-01-01

Indirect desorption electrospray ionization mass spectrometry (DESI-MS) imaging is a method for imaging distributions of metabolites in plant materials, in particular leaves and petals. The challenge in direct imaging of such plant materials with DESI-MS is particularly the protective layer of cu...... of interest from parts of their matrix while preserving the spatial information in the two dimensions. The imprint can then easily be imaged by DESI-MS. The method delivers simple and robust mass spectrometry imaging of plant material with very high success ratios....... of cuticular wax present in leaves and petals. The cuticle protects the plant from drying out, but also makes it difficult for the DESI sprayer to reach the analytes of interest inside the plant material. A solution to this problem is to imprint the plant material onto a surface, thus releasing the analytes...

Nanometrology of Biomass for Bioenergy: The Role of Atomic Force Microscopy and Spectroscopy in Plant Cell Characterization

Directory of Open Access Journals (Sweden)

Anne M. Charrier

2018-03-01

Full Text Available Ethanol production using extracted cellulose from plant cell walls (PCW is a very promising approach to biofuel production. However, efficient throughput has been hindered by the phenomenon of recalcitrance, leading to high costs for the lignocellulosic conversion. To overcome recalcitrance, it is necessary to understand the chemical and structural properties of the plant biological materials, which have evolved to generate the strong and cohesive features observed in plants. Therefore, tools and methods that allow the investigation of how the different molecular components of PCW are organized and distributed and how this impacts the mechanical properties of the plants are needed but challenging due to the molecular and morphological complexity of PCW. Atomic force microscopy (AFM, capitalizing on the interfacial nanomechanical forces, encompasses a suite of measurement modalities for nondestructive material characterization. Here, we present a review focused on the utilization of AFM for imaging and determination of physical properties of plant-based specimens. The presented review encompasses the AFM derived techniques for topography imaging (AM-AFM, mechanical properties (QFM, and surface/subsurface (MSAFM, HPFM chemical composition imaging. In particular, the motivation and utility of force microscopy of plant cell walls from the early fundamental investigations to achieve a better understanding of the cell wall architecture, to the recent studies for the sake of advancing the biofuel research are discussed. An example of delignification protocol is described and the changes in morphology, chemical composition and mechanical properties and their correlation at the nanometer scale along the process are illustrated.

Size, Shape, and Arrangement of Cellulose Microfibril in Higher Plant Cell Walls

Energy Technology Data Exchange (ETDEWEB)

Ding, S. Y.

2013-01-01

Plant cell walls from maize (Zea mays L.) are imaged using atomic force microscopy (AFM) at the sub-nanometer resolution. We found that the size and shape of fundamental cellulose elementary fibril (CEF) is essentially identical in different cell wall types, i.e., primary wall (PW), parenchyma secondary wall (pSW), and sclerenchyma secondary wall (sSW), which is consistent with previously proposed 36-chain model (Ding et al., 2006, J. Agric. Food Chem.). The arrangement of individual CEFs in these wall types exhibits two orientations. In PW, CEFs are horizontally associated through their hydrophilic faces, and the planar faces are exposed, forming ribbon-like macrofibrils. In pSW and sSW, CEFs are vertically oriented, forming layers, in which hemicelluloses are interacted with the hydrophobic faces of the CEF and serve as spacers between CEFs. Lignification occurs between CEF-hemicelluloses layers in secondary walls. Furthermore, we demonstrated quantitative analysis of plant cell wall accessibility to and digestibility by different cellulase systems at real-time using chemical imaging (e.g., stimulated Raman scattering) and fluorescence microscopy of labeled cellulases (Ding et al., 2012, Science, in press).

Synthesis of plant cell wall oligosaccharides

DEFF Research Database (Denmark)

Clausen, Mads Hartvig

Plant cell walls are structurally complex and contain a large number of diverse carbohydrate polymers. These plant fibers are a highly valuable bio-resource and the focus of food, energy and health research. We are interested in studying the interplay of plant cell wall carbohydrates with proteins...... for characterizing protein-carbohydrate binding. The presentation will highlight chemical syntheses of plant cell wall oligosaccharides from the group and provide examples from studies of their interactions with proteins....... such as enzymes, cell surface lectins, and antibodies. However, detailed molecular level investigations of such interactions are hampered by the heterogeneity and diversity of the polymers of interest. To circumvent this, we target well-defined oligosaccharides with representative structures that can be used...

Morphological classification of plant cell deaths.

Science.gov (United States)

van Doorn, W G; Beers, E P; Dangl, J L; Franklin-Tong, V E; Gallois, P; Hara-Nishimura, I; Jones, A M; Kawai-Yamada, M; Lam, E; Mundy, J; Mur, L A J; Petersen, M; Smertenko, A; Taliansky, M; Van Breusegem, F; Wolpert, T; Woltering, E; Zhivotovsky, B; Bozhkov, P V

2011-08-01

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: vacuolar cell death and necrosis. 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.

Identifying biological landmarks using a novel cell measuring image analysis tool: Cell-o-Tape

Directory of Open Access Journals (Sweden)

French Andrew P

2012-03-01

Full Text Available Abstract Background The ability to quantify the geometry of plant organs at the cellular scale can provide novel insights into their structural organization. Hitherto manual methods of measurement provide only very low throughput and subjective solutions, and often quantitative measurements are neglected in favour of a simple cell count. Results We present a tool to count and measure individual neighbouring cells along a defined file in confocal laser scanning microscope images. The tool allows the user to extract this generic information in a flexible and intuitive manner, and builds on the raw data to detect a significant change in cell length along the file. This facility can be used, for example, to provide an estimate of the position of transition into the elongation zone of an Arabidopsis root, traditionally a location sensitive to the subjectivity of the experimenter. Conclusions Cell-o-tape is shown to locate cell walls with a high degree of accuracy and estimate the location of the transition feature point in good agreement with human experts. The tool is an open source ImageJ/Fiji macro and is available online.

Attachment of Salmonella strains to a plant cell wall model is modulated by surface characteristics and not by specific carbohydrate interactions.

Science.gov (United States)

Tan, Michelle Sze-Fan; Moore, Sean C; Tabor, Rico F; Fegan, Narelle; Rahman, Sadequr; Dykes, Gary A

2016-09-15

Processing of fresh produce exposes cut surfaces of plant cell walls that then become vulnerable to human foodborne pathogen attachment and contamination, particularly by Salmonella enterica. Plant cell walls are mainly composed of the polysaccharides cellulose, pectin and hemicelluloses (predominantly xyloglucan). Our previous work used bacterial cellulose-based plant cell wall models to study the interaction between Salmonella and the various plant cell wall components. We demonstrated that Salmonella attachment was favoured in the presence of pectin while xyloglucan had no effect on its attachment. Xyloglucan significantly increased the attachment of Salmonella cells to the plant cell wall model only when it was in association with pectin. In this study, we investigate whether the plant cell wall polysaccharides mediate Salmonella attachment to the bacterial cellulose-based plant cell wall models through specific carbohydrate interactions or through the effects of carbohydrates on the physical characteristics of the attachment surface. We found that none of the monosaccharides that make up the plant cell wall polysaccharides specifically inhibit Salmonella attachment to the bacterial cellulose-based plant cell wall models. Confocal laser scanning microscopy showed that Salmonella cells can penetrate and attach within the tightly arranged bacterial cellulose network. Analysis of images obtained from atomic force microscopy revealed that the bacterial cellulose-pectin-xyloglucan composite with 0.3 % (w/v) xyloglucan, previously shown to have the highest number of Salmonella cells attached to it, had significantly thicker cellulose fibrils compared to other composites. Scanning electron microscopy images also showed that the bacterial cellulose and bacterial cellulose-xyloglucan composites were more porous when compared to the other composites containing pectin. Our study found that the attachment of Salmonella cells to cut plant cell walls was not mediated by

pH within pores in plant fiber cell walls assessed by Fluorescence Ratio Imaging

DEFF Research Database (Denmark)

Hidayat, Budi Juliman; Thygesen, Lisbeth Garbrecht; Johansen, Katja Salomon

2013-01-01

The pH within cell wall pores of filter paper fibers and hemp fibers was assessed by Fluorescence Ratio Imaging (FRIM). It was found that the Donnan effect affected the pH measured within the fibers. When the conductivity of the added liquid was low (0. 7 mS), pH values were lower within the cell...

Fast automatic quantitative cell replication with fluorescent live cell imaging

Directory of Open Access Journals (Sweden)

Wang Ching-Wei

2012-01-01

Full Text Available Abstract Background live cell imaging is a useful tool to monitor cellular activities in living systems. It is often necessary in cancer research or experimental research to quantify the dividing capabilities of cells or the cell proliferation level when investigating manipulations of the cells or their environment. Manual quantification of fluorescence microscopic image is difficult because human is neither sensitive to fine differences in color intensity nor effective to count and average fluorescence level among cells. However, auto-quantification is not a straightforward problem to solve. As the sampling location of the microscopy changes, the amount of cells in individual microscopic images varies, which makes simple measurement methods such as the sum of stain intensity values or the total number of positive stain within each image inapplicable. Thus, automated quantification with robust cell segmentation techniques is required. Results An automated quantification system with robust cell segmentation technique are presented. The experimental results in application to monitor cellular replication activities show that the quantitative score is promising to represent the cell replication level, and scores for images from different cell replication groups are demonstrated to be statistically significantly different using ANOVA, LSD and Tukey HSD tests (p-value Conclusion A robust automated quantification method of live cell imaging is built to measure the cell replication level, providing a robust quantitative analysis system in fluorescent live cell imaging. In addition, the presented unsupervised entropy based cell segmentation for live cell images is demonstrated to be also applicable for nuclear segmentation of IHC tissue images.

Precision automation of cell type classification and sub-cellular fluorescence quantification from laser scanning confocal images

Directory of Open Access Journals (Sweden)

Hardy Craig Hall

2016-02-01

Full Text Available While novel whole-plant phenotyping technologies have been successfully implemented into functional genomics and breeding programs, the potential of automated phenotyping with cellular resolution is largely unexploited. Laser scanning confocal microscopy has the potential to close this gap by providing spatially highly resolved images containing anatomic as well as chemical information on a subcellular basis. However, in the absence of automated methods, the assessment of the spatial patterns and abundance of fluorescent markers with subcellular resolution is still largely qualitative and time-consuming. Recent advances in image acquisition and analysis, coupled with improvements in microprocessor performance, have brought such automated methods within reach, so that information from thousands of cells per image for hundreds of images may be derived in an experimentally convenient time-frame. Here, we present a MATLAB-based analytical pipeline to 1 segment radial plant organs into individual cells, 2 classify cells into cell type categories based upon random forest classification, 3 divide each cell into sub-regions, and 4 quantify fluorescence intensity to a subcellular degree of precision for a separate fluorescence channel. In this research advance, we demonstrate the precision of this analytical process for the relatively complex tissues of Arabidopsis hypocotyls at various stages of development. High speed and robustness make our approach suitable for phenotyping of large collections of stem-like material and other tissue types.

Meeting report--Imaging the Cell.

Science.gov (United States)

Moreau, Violaine; Cordelières, Fabrice P; Poujol, Christel; Sagot, Isabelle; Saltel, Frédéric

2015-11-01

Every two years, the French Society for Cell Biology (SBCF) organises an international meeting called 'Imaging the Cell'. This year, the 8th edition was held on 24-26 June 2015 at University of Bordeaux Campus Victoire in the city of Bordeaux, France, a UNESCO World Heritage site. Over the course of three days, the meeting provided a forum for experts in different areas of cell imaging. Its unique approach was to combine conventional oral presentations during morning sessions with practical workshops at hosting institutes and the Bordeaux Imaging Center during the afternoons. The meeting, co-organised by Violaine Moreau and Frédéric Saltel (both INSERM U1053, Bordeaux, France), Christel Poujol and Fabrice Cordelières (both Bordeaux Imaging Center, Bordeaux, France) and Isabelle Sagot (Institut de Biochimie et Génétique Cellulaires, Bordeaux, France), brought together about 120 scientists including 16 outstanding speakers to discuss the latest advances in cell imaging. Thanks to recent progress in imaging technologies, cell biologists are now able to visualise, follow and manipulate cellular processes with unprecedented accuracy. The meeting sessions and workshops highlighted some of the most exciting developments in the field, with sessions dedicated to optogenetics, high-content screening, in vivo and live-cell imaging, correlative light and electron microscopy, as well as super-resolution imaging. © 2015. Published by The Company of Biologists Ltd.

Sample Preparation for Mass Spectrometry Imaging of Plant Tissues: A Review

Science.gov (United States)

Dong, Yonghui; Li, Bin; Malitsky, Sergey; Rogachev, Ilana; Aharoni, Asaph; Kaftan, Filip; Svatoš, Aleš; Franceschi, Pietro

2016-01-01

Mass spectrometry imaging (MSI) is a mass spectrometry based molecular ion imaging technique. It provides the means for ascertaining the spatial distribution of a large variety of analytes directly on tissue sample surfaces without any labeling or staining agents. These advantages make it an attractive molecular histology tool in medical, pharmaceutical, and biological research. Likewise, MSI has started gaining popularity in plant sciences; yet, information regarding sample preparation methods for plant tissues is still limited. Sample preparation is a crucial step that is directly associated with the quality and authenticity of the imaging results, it therefore demands in-depth studies based on the characteristics of plant samples. In this review, a sample preparation pipeline is discussed in detail and illustrated through selected practical examples. In particular, special concerns regarding sample preparation for plant imaging are critically evaluated. Finally, the applications of MSI techniques in plants are reviewed according to different classes of plant metabolites. PMID:26904042

Sample Preparation for Mass Spectrometry Imaging of Plant Tissues: A Review.

Science.gov (United States)

Dong, Yonghui; Li, Bin; Malitsky, Sergey; Rogachev, Ilana; Aharoni, Asaph; Kaftan, Filip; Svatoš, Aleš; Franceschi, Pietro

2016-01-01

Mass spectrometry imaging (MSI) is a mass spectrometry based molecular ion imaging technique. It provides the means for ascertaining the spatial distribution of a large variety of analytes directly on tissue sample surfaces without any labeling or staining agents. These advantages make it an attractive molecular histology tool in medical, pharmaceutical, and biological research. Likewise, MSI has started gaining popularity in plant sciences; yet, information regarding sample preparation methods for plant tissues is still limited. Sample preparation is a crucial step that is directly associated with the quality and authenticity of the imaging results, it therefore demands in-depth studies based on the characteristics of plant samples. In this review, a sample preparation pipeline is discussed in detail and illustrated through selected practical examples. In particular, special concerns regarding sample preparation for plant imaging are critically evaluated. Finally, the applications of MSI techniques in plants are reviewed according to different classes of plant metabolites.

Stem cells: a plant biology perspective

NARCIS (Netherlands)

Scheres, B.J.G.

2005-01-01

A recent meeting at the Juan March Foundation in Madrid, Spain brought together plant biologists to discuss the characteristics of plant stem cells that are unique and those that are shared by stem cells from the animal kingdom

Laser-mediated perforation of plant cells

Science.gov (United States)

Wehner, Martin; Jacobs, Philipp; Esser, Dominik; Schinkel, Helga; Schillberg, Stefan

2007-07-01

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 1064 nm wavelength or a continuous wave laser diode emitting at 405 nm are coupled into an inverse microscope. The beams are focused to a spot size of about 1.5 μm and the tobacco cell protoplasts are irradiated. 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 0.4 μJ was sufficient to perforate the plasma membrane enabling the uptake of dye or DNA from the surrounding medium into the cytosol. When the ultraviolet laser diode at a power level of 17 mW is employed an irradiation time of 200 - 500 milliseconds is necessary to enable the uptake of macromolecules. In the presence of an EYFP encoding plasmid with a C-terminal peroxisomal signal sequence in the surrounding medium transient transformation of tobacco protoplasts could be achieved in up to 2% of the optoporated cells. 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.

Visualization of Plant Fibres via Difusion Tensor Imaging

Czech Academy of Sciences Publication Activity Database

Gescheidtová, E.; Marcon, P.; Bartušek, Karel

2011-01-01

Roč. 7, č. 6 (2011), s. 543-546 ISSN 1931-7360 R&D Projects: GA ČR GAP102/11/0318 Institutional research plan: CEZ:AV0Z20650511 Keywords : plant fibres * difusion weighted imaging * difusion tensor imaging * MR imaging Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

Snapshot imaging Fraunhofer line discriminator for detection of plant fluorescence

Science.gov (United States)

Gupta Roy, S.; Kudenov, M. W.

2015-05-01

Non-invasive quantification of plant health is traditionally accomplished using reflectance based metrics, such as the normalized difference vegetative index (NDVI). However, measuring plant fluorescence (both active and passive) to determine photochemistry of plants has gained importance. Due to better cost efficiency, lower power requirements, and simpler scanning synchronization, detecting passive fluorescence is preferred over active fluorescence. In this paper, we propose a high speed imaging approach for measuring passive plant fluorescence, within the hydrogen alpha Fraunhofer line at ~656 nm, using a Snapshot Imaging Fraunhofer Line Discriminator (SIFOLD). For the first time, the advantage of snapshot imaging for high throughput Fraunhofer Line Discrimination (FLD) is cultivated by our system, which is based on a multiple-image Fourier transform spectrometer and a spatial heterodyne interferometer (SHI). The SHI is a Sagnac interferometer, which is dispersion compensated using blazed diffraction gratings. We present data and techniques for calibrating the SIFOLD to any particular wavelength. This technique can be applied to quantify plant fluorescence at low cost and reduced complexity of data collection.

Systems and synthetic biology approaches to alter plant cell walls and reduce biomass recalcitrance.

Science.gov (United States)

Kalluri, Udaya C; Yin, Hengfu; Yang, Xiaohan; Davison, Brian H

2014-12-01

Fine-tuning plant cell wall properties to render plant biomass more amenable to biofuel conversion is a colossal challenge. A deep knowledge of the biosynthesis and regulation of plant cell wall and a high-precision genome engineering toolset are the two essential pillars of efforts to alter plant cell walls and reduce biomass recalcitrance. The past decade has seen a meteoric rise in use of transcriptomics and high-resolution imaging methods resulting in fresh insights into composition, structure, formation and deconstruction of plant cell walls. Subsequent gene manipulation approaches, however, commonly include ubiquitous mis-expression of a single candidate gene in a host that carries an intact copy of the native gene. The challenges posed by pleiotropic and unintended changes resulting from such an approach are moving the field towards synthetic biology approaches. Synthetic biology builds on a systems biology knowledge base and leverages high-precision tools for high-throughput assembly of multigene constructs and pathways, precision genome editing and site-specific gene stacking, silencing and/or removal. Here, we summarize the recent breakthroughs in biosynthesis and remodelling of major secondary cell wall components, assess the impediments in obtaining a systems-level understanding and explore the potential opportunities in leveraging synthetic biology approaches to reduce biomass recalcitrance. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

System-wide organization of actin cytoskeleton determines organelle transport in hypocotyl plant cells

Science.gov (United States)

Nowak, Jacqueline; Ivakov, Alexander; Somssich, Marc; Persson, Staffan; Nikoloski, Zoran

2017-01-01

The actin cytoskeleton is an essential intracellular filamentous structure that underpins cellular transport and cytoplasmic streaming in plant cells. However, the system-level properties of actin-based cellular trafficking remain tenuous, largely due to the inability to quantify key features of the actin cytoskeleton. Here, we developed an automated image-based, network-driven framework to accurately segment and quantify actin cytoskeletal structures and Golgi transport. We show that the actin cytoskeleton in both growing and elongated hypocotyl cells has structural properties facilitating efficient transport. Our findings suggest that the erratic movement of Golgi is a stable cellular phenomenon that might optimize distribution efficiency of cell material. Moreover, we demonstrate that Golgi transport in hypocotyl cells can be accurately predicted from the actin network topology alone. Thus, our framework provides quantitative evidence for system-wide coordination of cellular transport in plant cells and can be readily applied to investigate cytoskeletal organization and transport in other organisms. PMID:28655850

Recent developments in plant science involving use of gamma-ray imaging technology

International Nuclear Information System (INIS)

Kawachi, Naoki

2014-01-01

Gamma-ray imaging technologies based on the use of radiotracers enable us to clearly determine the physiological function of an organ not only during pre-clinical and clinical studies but also in the field of plant science. Serial time-course images can be used to indicate the changing spatial distribution of a radiotracer within a living plant system and to describe the dynamics and kinetics of a substance in an intact plant. Gamma-rays almost completely penetrate a plant body, and the image data obtained using them can potentially be used to quantitatively analyze physiological function parameters. This paper briefly reviews recent progress in the field of plant science to explore the use of positron emission tomography, a gamma camera, and the positron-emitting tracer imaging system, which is one of the most advanced gamma-ray imaging systems available for studying plant physiology, for solving problems in the field of environment and agriculture. (author)

Super-resolution imaging with Pontamine Fast Scarlet 4BS enables direct visualization of cellulose orientation and cell connection architecture in onion epidermis cells

DEFF Research Database (Denmark)

Liesche, Johannes; Ziomkiewicz, Iwona; Schulz, Alexander

2013-01-01

of cellulose fibril orientation and growth. The fluorescent dye Pontamine Fast Scarlet 4BS (PFS) was shown to stain cellulose with high specificity and could be used to visualize cellulose bundles in cell walls of Arabidopsis root epidermal cells with confocal microscopy. The resolution limit of confocal...... present the first super-resolution images of cellulose bundles in the plant cell wall produced by direct stochastic optical reconstruction microscopy (dSTORM) in combination with total internal reflection fluorescence (TIRF) microscopy. Since TIRF limits observation to the cell surface, we tested...... as alternatives 3D-structured illumination microscopy (3D-SIM) and confocal microscopy, combined with image deconvolution. Both methods offer lower resolution than STORM, but enable 3D imaging. While 3D-SIM produced strong artifacts, deconvolution gave good results. The resolution was improved over conventional...

Alien plant monitoring with ultralight airborne imaging spectroscopy.

Directory of Open Access Journals (Sweden)

María Calviño-Cancela

Full Text Available Effective management of invasive plants requires a precise determination of their distribution. Remote sensing techniques constitute a promising alternative to field surveys and hyperspectral sensors (also known as imaging spectrometers, with a large number of spectral bands and high spectral resolution are especially suitable when very similar categories are to be distinguished (e.g. plant species. A main priority in the development of this technology is to lower its cost and simplify its use, so that its demonstrated aptitude for many environmental applications can be truly realized. With this aim, we have developed a system for hyperspectral imaging (200 spectral bands in the 380-1000 nm range and circa 3 nm spectral resolution operated on board ultralight aircraft (namely a gyrocopter, which allows a drastic reduction of the running costs and operational complexity of image acquisition, and also increases the spatial resolution of the images (circa 5-8 pixels/m(2 at circa 65 km/h and 300 m height. The detection system proved useful for the species tested (Acacia melanoxylon, Oxalis pes-caprae, and Carpobrotus aff. edulis and acinaciformis, with user's and producer's accuracy always exceeding 90%. The detection accuracy reported corresponds to patches down to 0.125 m(2 (50% of pixels 0.5 × 0.5 m in size, a very small size for many plant species, making it very effective for initial stages of invasive plant spread. In addition, its low operating costs, similar to those of a 4WD ground vehicle, facilitate frequent image acquisition. Acquired images constitute a permanent record of the status of the study area, with great amount of information that can be analyzed in the future for other purposes, thus greatly facilitating the monitoring of natural areas at detailed spatial and temporal scales for improved management.

UV-Induced Cell Death in Plants

Science.gov (United States)

Nawkar, Ganesh M.; Maibam, Punyakishore; Park, Jung Hoon; Sahi, Vaidurya Pratap; Lee, Sang Yeol; Kang, Chang Ho

2013-01-01

Plants are photosynthetic organisms that depend on sunlight for energy. Plants respond to light through different photoreceptors and show photomorphogenic development. Apart from Photosynthetically Active Radiation (PAR; 400–700 nm), plants are exposed to UV light, which is comprised of UV-C (below 280 nm), UV-B (280–320 nm) and UV-A (320–390 nm). The atmospheric ozone layer protects UV-C radiation from reaching earth while the UVR8 protein acts as a receptor for UV-B radiation. 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. The studies on salicylic and jasmonic acid signaling mutants revealed that SA and JA regulate the ROS level and antagonize ROS mediated cell death. Recently, molecular studies have revealed genes involved in response to UV exposure, with respect to programmed cell death (PCD). PMID:23344059

Enzymatic Modification of Plant Cell Wall Polysaccharides

DEFF Research Database (Denmark)

Øbro, Jens; Hayashi, Takahisa; Mikkelsen, Jørn Dalgaard

2011-01-01

Plant cell walls are intricate structures with remarkable properties, widely used in almost every aspect of our life. Cell walls consist largely of complex polysaccharides and there is often a need for chemical and biochemical processing before industrial use. There is an increasing demand...... for sustainable processes that replace chemical treatments with white biotechnology. Plants can contribute significantly to this sustainable process by producing plant or microbialenzymes in planta that are necessary for plant cell wall modification or total degradation. This will give rise to superior food...... fibres, hydrocolloids, paper,textile, animal feeds or biofuels. Classical microbial-based fermentation systems could in the future face serious competition from plant-based expression systems for enzyme production. Plant expressed enzymes can either be targeted to specific cellular compartments...

Cell fusion and nuclear fusion in plants.

Science.gov (United States)

Maruyama, Daisuke; Ohtsu, Mina; Higashiyama, Tetsuya

2016-12-01

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

In Vivo Imaging of Diacylglycerol at the Cytoplasmic Leaflet of Plant Membranes.

Science.gov (United States)

Vermeer, Joop E M; van Wijk, Ringo; Goedhart, Joachim; Geldner, Niko; Chory, Joanne; Gadella, Theodorus W J; Munnik, Teun

2017-07-01

Diacylglycerol (DAG) is an important intermediate in lipid biosynthesis and plays key roles in cell signaling, either as a second messenger itself or as a precursor of phosphatidic acid. Methods to identify distinct DAG pools have proven difficult because biochemical fractionation affects the pools, and concentrations are limiting. Here, we validate the use of a genetically encoded DAG biosensor in living plant cells. The sensor is composed of a fusion between yellow fluorescent protein and the C1a domain of protein kinase C (YFP-C1aPKC) that specifically binds DAG, and was stably expressed in suspension-cultured tobacco BY-2 cells and whole Arabidopsis thaliana plants. Confocal imaging revealed that the majority of the YFP-C1aPKC fluorescence did not locate to membranes but was present in the cytosol and nucleus. Treatment with short-chain DAG or PMA (phorbol-12-myristate-13-acetate), a phorbol ester that binds the C1a domain of PKC, caused the recruitment of the biosensor to the plasma membrane. These results indicate that the biosensor works and that the basal DAG concentration in the cytoplasmic leaflet of membranes (i.e. accessible to the biosensor) is in general too low, and confirms that the known pools in plastids, the endoplasmic reticulum and mitochondria are located at the luminal face of these compartments (i.e. inaccessible to the biosensor). Nevertheless, detailed further analysis of different cells and tissues discovered four novel DAG pools, namely at: (i) the trans-Golgi network; (ii) the cell plate during cytokinesis; (iii) the plasma membrane of root epidermal cells in the transition zone, and (iv) the apex of growing root hairs. The results provide new insights into the spatiotemporal dynamics of DAG in plants and offer a new tool to monitor this in vivo. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

A REVIEW ON DIAGNOSIS OF NUTRIENT DEFICIENCY SYMPTOMS IN PLANT LEAF IMAGE USING DIGITAL IMAGE PROCESSING

Directory of Open Access Journals (Sweden)

S Jeyalakshmi

2017-05-01

Full Text Available Plants, for their growth and survival, need 13 mineral nutrients. Toxicity or deficiency in any one or more of these nutrients affects the growth of plant and may even cause the destruction of the plant. Hence, a constant monitoring system for tracking the nutrient status in plants becomes essential for increase in production as well as quality of yield. A diagnostic system using digital image processing would diagnose the deficiency symptoms much earlier than human eyes could recognize. This will enable the farmers to adopt appropriate remedial action in time. This paper focuses on the review of work using image processing techniques for diagnosing nutrient deficiency in plants.

Direct FuelCell/Turbine Power Plant

Energy Technology Data Exchange (ETDEWEB)

Hossein Ghezel-Ayagh

2008-09-30

This report summarizes the progress made in development of Direct FuelCell/Turbine (DFC/T{reg_sign}) power plants for generation of clean power at very high efficiencies. The DFC/T system employs an indirectly heated Turbine Generator to supplement fuel cell generated power. The concept extends the high efficiency of the fuel cell by utilizing the fuel cell's byproduct heat in a Brayton cycle. Features of the DFC/T system include: electrical efficiencies of up to 75% on natural gas, minimal emissions, reduced carbon dioxide release to the environment, simplicity in design, direct reforming internal to the fuel cell, and potential cost competitiveness with existing combined cycle power plants. Proof-of-concept tests using a sub-MW-class DFC/T power plant at FuelCell Energy's (FCE) Danbury facility were conducted to validate the feasibility of the concept and to measure its potential for electric power production. A 400 kW-class power plant test facility was designed and retrofitted to conduct the tests. The initial series of tests involved integration of a full-size (250 kW) Direct FuelCell stack with a 30 kW Capstone microturbine. The operational aspects of the hybrid system in relation to the integration of the microturbine with the fuel cell, process flow and thermal balances, and control strategies for power cycling of the system, were investigated. A subsequent series of tests included operation of the sub-MW Direct FuelCell/Turbine power plant with a Capstone C60 microturbine. The C60 microturbine extended the range of operation of the hybrid power plant to higher current densities (higher power) than achieved in initial tests using the 30kW microturbine. The proof-of-concept test results confirmed the stability and controllability of operating a fullsize (250 kW) fuel cell stack in combination with a microturbine. Thermal management of the system was confirmed and power plant operation, using the microturbine as the only source of fresh air supply

Effect of stimulation by foliage plant display images on prefrontal cortex activity: a comparison with stimulation using actual foliage plants.

Science.gov (United States)

Igarashi, Miho; Song, Chorong; Ikei, Harumi; Miyazaki, Yoshifumi

2015-01-01

Natural scenes like forests and flowers evoke neurophysiological responses that can suppress anxiety and relieve stress. We examined whether images of natural objects can elicit neural responses similar to those evoked by real objects by comparing the activation of the prefrontal cortex during presentation of real foliage plants with a projected image of the same foliage plants. Oxy-hemoglobin concentrations in the prefrontal cortex were measured using time-resolved near-infrared spectroscopy while the subjects viewed the real plants or a projected image of the same plants. Compared with a projected image of foliage plants, viewing the actual foliage plants significantly increased oxy-hemoglobin concentrations in the prefrontal cortex. However, using the modified semantic differential method, subjective emotional response ratings ("comfortable vs. uncomfortable" and "relaxed vs. awakening") were similar for both stimuli. The frontal cortex responded differently to presentation of actual plants compared with images of these plants even when the subjective emotional response was similar. These results may help explain the physical and mental health benefits of urban, domestic, and workplace foliage. © 2014 The Authors. Journal of Neuroimaging published by the American Society of Neuroimaging.

A universal fluid cell for the imaging of biological specimens in the atomic force microscope.

Science.gov (United States)

Kasas, Sandor; Radotic, Ksenja; Longo, Giovanni; Saha, Bashkar; Alonso-Sarduy, Livan; Dietler, Giovanni; Roduit, Charles

2013-04-01

Recently, atomic force microscope (AFM) manufacturers have begun producing instruments specifically designed to image biological specimens. In most instances, they are integrated with an inverted optical microscope, which permits concurrent optical and AFM imaging. An important component of the set-up is the imaging chamber, whose design determines the nature of the experiments that can be conducted. Many different imaging chamber designs are available, usually designed to optimize a single parameter, such as the dimensions of the substrate or the volume of fluid that can be used throughout the experiment. In this report, we present a universal fluid cell, which simultaneously optimizes all of the parameters that are important for the imaging of biological specimens in the AFM. This novel imaging chamber has been successfully tested using mammalian, plant, and microbial cells. Copyright © 2013 Wiley Periodicals, Inc.

Hyperspectral imaging system for disease scanning on banana plants

Science.gov (United States)

Ochoa, Daniel; Cevallos, Juan; Vargas, German; Criollo, Ronald; Romero, Dennis; Castro, Rodrigo; Bayona, Oswaldo

2016-05-01

Black Sigatoka (BS) is a banana plant disease caused by the fungus Mycosphaerella fijiensis. BS symptoms can be observed at late infection stages. By that time, BS has probably spread to other plants. In this paper, we present our current work on building an hyper-spectral (HS) imaging system aimed at in-vivo detection of BS pre-symptomatic responses in banana leaves. The proposed imaging system comprises a motorized stage, a high-sensitivity VIS-NIR camera and an optical spectrograph. To capture images of the banana leaf, the stage's speed and camera's frame rate must be computed to reduce motion blur and to obtain the same resolution along both spatial dimensions of the resulting HS cube. Our continuous leaf scanning approach allows imaging leaves of arbitrary length with minimum frame loss. Once the images are captured, a denoising step is performed to improve HS image quality and spectral profile extraction.

Determination of Dynamics of Plant Plasma Membrane Proteins with Fluorescence Recovery and Raster Image Correlation Spectroscopy.

Science.gov (United States)

Laňková, Martina; Humpolíčková, Jana; Vosolsobě, Stanislav; Cit, Zdeněk; Lacek, Jozef; Čovan, Martin; Čovanová, Milada; Hof, Martin; Petrášek, Jan

2016-04-01

A number of fluorescence microscopy techniques are described to study dynamics of fluorescently labeled proteins, lipids, nucleic acids, and whole organelles. However, for studies of plant plasma membrane (PM) proteins, the number of these techniques is still limited because of the high complexity of processes that determine the dynamics of PM proteins and the existence of cell wall. Here, we report on the usage of raster image correlation spectroscopy (RICS) for studies of integral PM proteins in suspension-cultured tobacco cells and show its potential in comparison with the more widely used fluorescence recovery after photobleaching method. For RICS, a set of microscopy images is obtained by single-photon confocal laser scanning microscopy (CLSM). Fluorescence fluctuations are subsequently correlated between individual pixels and the information on protein mobility are extracted using a model that considers processes generating the fluctuations such as diffusion and chemical binding reactions. As we show here using an example of two integral PM transporters of the plant hormone auxin, RICS uncovered their distinct short-distance lateral mobility within the PM that is dependent on cytoskeleton and sterol composition of the PM. RICS, which is routinely accessible on modern CLSM instruments, thus represents a valuable approach for studies of dynamics of PM proteins in plants.

Plant Systems Biology at the Single-Cell Level.

Science.gov (United States)

Libault, Marc; Pingault, Lise; Zogli, Prince; Schiefelbein, John

2017-11-01

Our understanding of plant biology is increasingly being built upon studies using 'omics and system biology approaches performed at the level of the entire plant, organ, or tissue. Although these approaches open new avenues to better understand plant biology, they suffer from the cellular complexity of the analyzed sample. Recent methodological advances now allow plant scientists to overcome this limitation and enable biological analyses of single-cells or single-cell-types. Coupled with the development of bioinformatics and functional genomics resources, these studies provide opportunities for high-resolution systems analyses of plant phenomena. In this review, we describe the recent advances, current challenges, and future directions in exploring the biology of single-cells and single-cell-types to enhance our understanding of plant biology as a system. Copyright © 2017 Elsevier Ltd. All rights reserved.

Holistic and component plant phenotyping using temporal image sequence.

Science.gov (United States)

Das Choudhury, Sruti; Bashyam, Srinidhi; Qiu, Yumou; Samal, Ashok; Awada, Tala

2018-01-01

Image-based plant phenotyping facilitates the extraction of traits noninvasively by analyzing large number of plants in a relatively short period of time. It has the potential to compute advanced phenotypes by considering the whole plant as a single object (holistic phenotypes) or as individual components, i.e., leaves and the stem (component phenotypes), to investigate the biophysical characteristics of the plants. The emergence timing, total number of leaves present at any point of time and the growth of individual leaves during vegetative stage life cycle of the maize plants are significant phenotypic expressions that best contribute to assess the plant vigor. However, image-based automated solution to this novel problem is yet to be explored. A set of new holistic and component phenotypes are introduced in this paper. To compute the component phenotypes, it is essential to detect the individual leaves and the stem. Thus, the paper introduces a novel method to reliably detect the leaves and the stem of the maize plants by analyzing 2-dimensional visible light image sequences captured from the side using a graph based approach. The total number of leaves are counted and the length of each leaf is measured for all images in the sequence to monitor leaf growth. To evaluate the performance of the proposed algorithm, we introduce University of Nebraska-Lincoln Component Plant Phenotyping Dataset (UNL-CPPD) and provide ground truth to facilitate new algorithm development and uniform comparison. The temporal variation of the component phenotypes regulated by genotypes and environment (i.e., greenhouse) are experimentally demonstrated for the maize plants on UNL-CPPD. Statistical models are applied to analyze the greenhouse environment impact and demonstrate the genetic regulation of the temporal variation of the holistic phenotypes on the public dataset called Panicoid Phenomap-1. The central contribution of the paper is a novel computer vision based algorithm for

Penium margaritaceum as a model organism for cell wall analysis of expanding plant cells.

Science.gov (United States)

Rydahl, Maja G; Fangel, Jonatan U; Mikkelsen, Maria Dalgaard; Johansen, I Elisabeth; Andreas, Amanda; Harholt, Jesper; Ulvskov, Peter; Jørgensen, Bodil; Domozych, David S; Willats, William G T

2015-01-01

The growth of a plant cell encompasses a complex set of subcellular components interacting in a highly coordinated fashion. Ultimately, these activities create specific cell wall structural domains that regulate the prime force of expansion, internally generated turgor pressure. The precise organization of the polymeric networks of the cell wall around the protoplast also contributes to the direction of growth, the shape of the cell, and the proper positioning of the cell in a tissue. In essence, plant cell expansion represents the foundation of development. Most studies of plant cell expansion have focused primarily upon late divergent multicellular land plants and specialized cell types (e.g., pollen tubes, root hairs). Here, we describe a unicellular green alga, Penium margaritaceum (Penium), which can serve as a valuable model organism for understanding cell expansion and the underlying mechanics of the cell wall in a single plant cell.

Live imaging of H3K9 acetylation in plant cells

Science.gov (United States)

Kurita, Kazuki; Sakamoto, Takuya; Yagi, Noriyoshi; Sakamoto, Yuki; Ito, Akihiro; Nishino, Norikazu; Sako, Kaori; Yoshida, Minoru; Kimura, Hiroshi; Seki, Motoaki; Matsunaga, Sachihiro

2017-01-01

Proper regulation of histone acetylation is important in development and cellular responses to environmental stimuli. However, the dynamics of histone acetylation at the single-cell level remains poorly understood. Here we established a transgenic plant cell line to track histone H3 lysine 9 acetylation (H3K9ac) with a modification-specific intracellular antibody (mintbody). The H3K9ac-specific mintbody fused to the enhanced green fluorescent protein (H3K9ac-mintbody-GFP) was introduced into tobacco BY-2 cells. We successfully demonstrated that H3K9ac-mintbody-GFP interacted with H3K9ac in vivo. The ratio of nuclear/cytoplasmic H3K9ac-mintbody-GFP detected in quantitative analysis reflected the endogenous H3K9ac levels. Under chemically induced hyperacetylation conditions with histone deacetylase inhibitors including trichostatin A, Ky-2 and Ky-14, significant enhancement of H3K9ac was detected by H3K9ac-mintbody-GFP dependent on the strength of inhibitors. Conversely, treatment with a histone acetyltransferase inhibitor, C646 caused a reduction in the nuclear to cytoplasmic ratio of H3K9ac-mintbody-GFP. Using this system, we assessed the environmental responses of H3K9ac and found that cold and salt stresses enhanced H3K9ac in tobacco BY-2 cells. In addition, a combination of H3K9ac-mintbody-GFP with 5-ethynyl-2′-deoxyuridine labelling confirmed that H3K9ac level is constant during interphase. PMID:28418019

Electrophoretic Detection and Confocal Microscopic Imaging of Tyrosine Nitrated Proteins in Plant Tissue.

Science.gov (United States)

Arora, Dhara; Singh, Neha; Bhatla, Satish C

2018-01-01

Tyrosine nitrated proteins can be detected in plant cells electrophoretically and their distribution can be monitored by confocal laser scanning microscopy (CLSM) imaging. One-dimensional polyacrylamide gel electrophoresis (1D PAGE) followed by Western blotting using polyclonal antibody against 3-nitrotyrosine residues enables detection of tyrosine nitrated proteins in plant cells. Here we describe detection of tyrosine nitrated proteins in the homogenates derived from sunflower (Helianthus annuus L.) seedling cotyledons. Total soluble proteins obtained from tissue homogenates are resolved using vertical gel electrophoresis followed by their electrophoretic transfer on to a microporous membrane support for immunodetection. Spatial distribution of tyrosine nitrated proteins can be visualized using an antibody against 3-nitrotyrosine residues. Immunofluorescent localization is performed by cutting 7 μm thick wax sections of tissue followed by incubation in primary anti-nitrotyrosine antibody (dilution 1:200) and secondary Cy-3 labeled anti-rabbit IgG antibody (dilution 1:1500). Confocal laser scanning microscopy analysis is undertaken using argon lasers (ex: 530-550 nm and em: 570 nm) at pinhole 1. Modulation in the abundance and spatial localization of tyrosine nitrated proteins in plant tissues can be monitored using these techniques.

Investigations on the change of texture of plant cells due to preservative treatments by digital holographic microscopy

Science.gov (United States)

Vora, Priyanka; Anand, Arun

2014-10-01

Texture change is observed in preserved fruits and vegetables. Responsible factors for texture change during preservative treatments are cell morphology, cell wall structure, cell turger, water content and some biochemical components, and also the environmental conditions. Digital Holographic microscopy (DHM) is a quantitative phase contrast imaging technique, which provides three dimensional optical thickness profiles of transparent specimen. Using DHM the morphology of plant cells preserved by refrigeration or stored in vinegar or in sodium chloride can be obtained. This information about the spatio-temporal evolution of optical volume and thickness can be an important tool in area of food processing. Also from the three dimensional images, the texture of the cell can be retrieved and can be investigated under varying conditions.

[Genetic regulation of plant shoot stem cells].

Science.gov (United States)

Al'bert, E V; Ezhova, T A

2013-02-01

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.

Plant virus-resembling optical nano-materials conjugated with anti-EGFR for targeted cancer imaging

Science.gov (United States)

Gupta, Sharad; Wilder, Hailey; Rao, A. L. N.; Vullev, V. I.; Anvari, Bahman

2012-03-01

We recently reported the construction of a new type of optically active nano-particles composed of genome-depleted plant infecting brome mosaic virus (BMV) doped with indocyanine green (ICG), an FDA-approved chromophore . We refer to these constructs as optical viral ghosts (OVGs) since only the capsid protein (CP) subunits of BMV remain to encapsulate ICG. Herein, we covalently conjugated the surface of OVGs with anti-epidermal growth factor receptors (anti-EGFR) to target cancerous human bronchial epithelial cells (C-HBECs) in-vitro. Our preliminary results demonstrate the utility of conjugated OVGs for targeted imaging of cancer cells.

Plant and animal stem cells: similar yet different

NARCIS (Netherlands)

Heidstra, R.; Sabatini, S.

2014-01-01

The astonishingly long lives of plants and their regeneration capacity depend on the activity of plant stem cells. As in animals, stem cells reside in stem cell niches, which produce signals that regulate the balance between self-renewal and the generation of daughter cells that differentiate into

Vital Autofluorescence: Application to the Study of Plant Living Cells

Directory of Open Access Journals (Sweden)

Victoria V. Roshchina

2012-01-01

approach to study the autofluorescence of plant living cells—from cell diagnostics up to modelling the cell-cell contacts and cell interactions with fluorescent biologically active substances. It bases on the direct observations of secretions released from allelopathic and medicinal species and the cell-donor interactions with cell-acceptors as biosensors (unicellular plant generative and vegetative microspores. Special attention was paid to the interactions with pigmented and fluorescing components of the secretions released by the cells-donors from plant species. Colored components of secretions are considered as histochemical dyes for the analysis of cellular mechanisms at the cell-cell contacts and modelling of cell-cell interactions. The fluorescence of plant biosensors was also recommended for the testing of natural plant excretions as medical drugs.

A computational framework for cortical microtubule dynamics in realistically shaped plant cells.

Directory of Open Access Journals (Sweden)

Bandan Chakrabortty

2018-02-01

Full Text Available Plant morphogenesis is strongly dependent on the directional growth and the subsequent oriented division of individual cells. It has been shown that the plant cortical microtubule array plays a key role in controlling both these processes. This ordered structure emerges as the collective result of stochastic interactions between large numbers of dynamic microtubules. To elucidate this complex self-organization process a number of analytical and computational approaches to study the dynamics of cortical microtubules have been proposed. To date, however, these models have been restricted to two dimensional planes or geometrically simple surfaces in three dimensions, which strongly limits their applicability as plant cells display a wide variety of shapes. This limitation is even more acute, as both local as well as global geometrical features of cells are expected to influence the overall organization of the array. Here we describe a framework for efficiently simulating microtubule dynamics on triangulated approximations of arbitrary three dimensional surfaces. This allows the study of microtubule array organization on realistic cell surfaces obtained by segmentation of microscopic images. We validate the framework against expected or known results for the spherical and cubical geometry. We then use it to systematically study the individual contributions of global geometry, cell-edge induced catastrophes and cell-face induced stability to array organization in a cuboidal geometry. Finally, we apply our framework to analyze the highly non-trivial geometry of leaf pavement cells of Arabidopsis thaliana, Nicotiana benthamiana and Hedera helix. We show that our simulations can predict multiple features of the microtubule array structure in these cells, revealing, among others, strong constraints on the orientation of division planes.

A computational framework for cortical microtubule dynamics in realistically shaped plant cells

KAUST Repository

Chakrabortty, Bandan; Blilou, Ikram; Scheres, Ben; Mulder, Bela M.

2018-01-01

Plant morphogenesis is strongly dependent on the directional growth and the subsequent oriented division of individual cells. It has been shown that the plant cortical microtubule array plays a key role in controlling both these processes. This ordered structure emerges as the collective result of stochastic interactions between large numbers of dynamic microtubules. To elucidate this complex self-organization process a number of analytical and computational approaches to study the dynamics of cortical microtubules have been proposed. To date, however, these models have been restricted to two dimensional planes or geometrically simple surfaces in three dimensions, which strongly limits their applicability as plant cells display a wide variety of shapes. This limitation is even more acute, as both local as well as global geometrical features of cells are expected to influence the overall organization of the array. Here we describe a framework for efficiently simulating microtubule dynamics on triangulated approximations of arbitrary three dimensional surfaces. This allows the study of microtubule array organization on realistic cell surfaces obtained by segmentation of microscopic images. We validate the framework against expected or known results for the spherical and cubical geometry. We then use it to systematically study the individual contributions of global geometry, cell-edge induced catastrophes and cell-face induced stability to array organization in a cuboidal geometry. Finally, we apply our framework to analyze the highly non-trivial geometry of leaf pavement cells of Arabidopsis thaliana, Nicotiana benthamiana and Hedera helix. We show that our simulations can predict multiple features of the microtubule array structure in these cells, revealing, among others, strong constraints on the orientation of division planes.

A computational framework for cortical microtubule dynamics in realistically shaped plant cells

KAUST Repository

Chakrabortty, Bandan

2018-02-02

Plant morphogenesis is strongly dependent on the directional growth and the subsequent oriented division of individual cells. It has been shown that the plant cortical microtubule array plays a key role in controlling both these processes. This ordered structure emerges as the collective result of stochastic interactions between large numbers of dynamic microtubules. To elucidate this complex self-organization process a number of analytical and computational approaches to study the dynamics of cortical microtubules have been proposed. To date, however, these models have been restricted to two dimensional planes or geometrically simple surfaces in three dimensions, which strongly limits their applicability as plant cells display a wide variety of shapes. This limitation is even more acute, as both local as well as global geometrical features of cells are expected to influence the overall organization of the array. Here we describe a framework for efficiently simulating microtubule dynamics on triangulated approximations of arbitrary three dimensional surfaces. This allows the study of microtubule array organization on realistic cell surfaces obtained by segmentation of microscopic images. We validate the framework against expected or known results for the spherical and cubical geometry. We then use it to systematically study the individual contributions of global geometry, cell-edge induced catastrophes and cell-face induced stability to array organization in a cuboidal geometry. Finally, we apply our framework to analyze the highly non-trivial geometry of leaf pavement cells of Arabidopsis thaliana, Nicotiana benthamiana and Hedera helix. We show that our simulations can predict multiple features of the microtubule array structure in these cells, revealing, among others, strong constraints on the orientation of division planes.

Interaction between the moss Physcomitrella patens and Phytophthora : a novel pathosystem for live-cell imaging of subcellular defence

NARCIS (Netherlands)

Overdijk, Elysa J R; DE Keijzer, Jeroen; DE Groot, Deborah; Schoina, Charikleia; Bouwmeester, K.; Ketelaar, Tijs; Govers, Francine

Live-cell imaging of plant-pathogen interactions is often hampered by the tissue complexity and multicell layered nature of the host. Here, we established a novel pathosystem with the moss Physcomitrella patens as host for Phytophthora. The tip-growing protonema cells of this moss are ideal for

PECULIARITIES OF SECONDARY METABOLITES BIOSYNTHESIS IN PLANT CELL CULTURES

Directory of Open Access Journals (Sweden)

A.M. NOSOV

2014-06-01

Full Text Available metabolites formation in plant cell cultures of Panax spp., (ginsenosides; Dioscorea deltoidea (steroid glycosides; Ajuga reptans, Serratula coronata, Rhaponticum carthamoides (ecdisteroids; Polyscias spp., (triterpene glycosides, Taxus spp. (taxoids, Stevia rebaudiana (diterpene steviol-glycosides, Stephania glabra (alkaloids. They are some regular trends of secondary metabolites synthesis in the plant cell culture:It can be noted the stable synthesis of the compound promoting cell proliferation. Indeed, cell cultures of Dioscorea deltoidea were demonstrated to accumulate only furostanol glycosides, which promoted cell division. Furostanol glycoside content of Dioscorea strain DM-0.5 was up to 6 - 12% by dry biomass.Panax ginseng and P. japonicus plant cell cultures synthesize as minimum seven triterpene glycosides (ginsenosides, the productivity of these compounds was up to 6.0 - 8.0% on dry biomass.By contrast, the detectable synthesis of diterpene steviol-glycosides in cultivated cells of Stevia rebaudiana initiated in the mixotrophic cultures during chloroplast formation only.Despite these differences, or mainly due to them, plant cell cultures have become an attractive source of phytochemicals in alternative to collecting wild plants. It provides a guideline to bioreactor-based production of isoprenoids using undifferentiated plant cell cultures. 

Morphological classification of plant cell deaths

NARCIS (Netherlands)

Doorn, van W.G.; Beers, E.P.; Dangl, J.L.; Franklin-Tong, V.E.; Woltering, E.J.

2011-01-01

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

Plant cortical microtubule dynamics and cell division plane orientation

NARCIS (Netherlands)

Chakrabortty, Bandan

2017-01-01

This thesis work aimed at a better understanding of the molecular basis of oriented cell division in plant cell. As, the efficiency of plant morphogenesis depends on oriented cell division, this work should contribute towards a fundamental understanding of the molecular basis of efficient plant

Pep1, a secreted effector protein of Ustilago maydis, is required for successful invasion of plant cells.

Directory of Open Access Journals (Sweden)

Gunther Doehlemann

2009-02-01

Full Text Available The basidiomycete Ustilago maydis causes smut disease in maize. Colonization of the host plant is initiated by direct penetration of cuticle and cell wall of maize epidermis cells. The invading hyphae are surrounded by the plant plasma membrane and proliferate within the plant tissue. We identified a novel secreted protein, termed Pep1, that is essential for penetration. Disruption mutants of pep1 are not affected in saprophytic growth and develop normal infection structures. However, Deltapep1 mutants arrest during penetration of the epidermal cell and elicit a strong plant defense response. Using Affymetrix maize arrays, we identified 116 plant genes which are differentially regulated in Deltapep1 compared to wild type infections. Most of these genes are related to plant defense. By in vivo immunolocalization, live-cell imaging and plasmolysis approaches, we detected Pep1 in the apoplastic space as well as its accumulation at sites of cell-to-cell passages. Site-directed mutagenesis identified two of the four cysteine residues in Pep1 as essential for function, suggesting that the formation of disulfide bridges is crucial for proper protein folding. The barley covered smut fungus Ustilago hordei contains an ortholog of pep1 which is needed for penetration of barley and which is able to complement the U. maydis Deltapep1 mutant. Based on these results, we conclude that Pep1 has a conserved function essential for establishing compatibility that is not restricted to the U. maydis / maize interaction.

Penium margaritaceum as a model organism for cell wall analysis of expanding plant cells

DEFF Research Database (Denmark)

Rydahl, Maja Gro; Fangel, Jonatan Ulrik; Mikkelsen, Maria Dalgaard

2015-01-01

organization of the polymeric networks of the cell wall around the protoplast also contributes to the direction of growth, the shape of the cell, and the proper positioning of the cell in a tissue. In essence, plant cell expansion represents the foundation of development. Most studies of plant cell expansion...... have focused primarily upon late divergent multicellular land plants and specialized cell types (e.g., pollen tubes, root hairs). Here, we describe a unicellular green alga, Penium margaritaceum (Penium), which can serve as a valuable model organism for understanding cell expansion and the underlying......The growth of a plant cell encompasses a complex set of subcellular components interacting in a highly coordinated fashion. Ultimately, these activities create specific cell wall structural domains that regulate the prime force of expansion, internally generated turgor pressure. The precise...

Imaging and reconstruction of cell cortex structures near the cell surface

Science.gov (United States)

Jin, Luhong; Zhou, Xiaoxu; Xiu, Peng; Luo, Wei; Huang, Yujia; Yu, Feng; Kuang, Cuifang; Sun, Yonghong; Liu, Xu; Xu, Yingke

2017-11-01

Total internal reflection fluorescence microscopy (TIRFM) provides high optical sectioning capability and superb signal-to-noise ratio for imaging of cell cortex structures. The development of multi-angle (MA)-TIRFM permits high axial resolution imaging and reconstruction of cellular structures near the cell surface. Cytoskeleton is composed of a network of filaments, which are important for maintenance of cell function. The high-resolution imaging and quantitative analysis of filament organization would contribute to our understanding of cytoskeleton regulation in cell. Here, we used a custom-developed MA-TIRFM setup, together with stochastic photobleaching and single molecule localization method, to enhance the lateral resolution of TIRFM imaging to about 100 nm. In addition, we proposed novel methods to perform filament segmentation and 3D reconstruction from MA-TIRFM images. Furthermore, we applied these methods to study the 3D localization of cortical actin and microtubule structures in U373 cancer cells. Our results showed that cortical actins localize ∼ 27 nm closer to the plasma membrane when compared with microtubules. We found that treatment of cells with chemotherapy drugs nocodazole and cytochalasin B disassembles cytoskeletal network and induces the reorganization of filaments towards the cell periphery. In summary, this study provides feasible approaches for 3D imaging and analyzing cell surface distribution of cytoskeletal network. Our established microscopy platform and image analysis toolkits would facilitate the study of cytoskeletal network in cells.

Disposable Bioreactors for Plant Micropropagation and Mass Plant Cell Culture

Science.gov (United States)

Ducos, Jean-Paul; Terrier, Bénédicte; Courtois, Didier

Different types of bioreactors are used at Nestlé R&D Centre - Tours for mass propagation of selected plant varieties by somatic embryogenesis and for large scale culture of plants cells to produce metabolites or recombinant proteins. 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 3.0 million embryos per year. The pre-germination of the embryos was previously conducted by temporary immersion in liquid medium in 10-L glass bioreactors. An improved process has been developed using a 10-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 100 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.

Morphological classification of plant cell deaths

DEFF Research Database (Denmark)

van Doorn, W.G.; Beers, E.P.; Dangl, J.L.

2011-01-01

, 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....... 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: vacuolar cell death and necrosis. During vacuolar cell death...

Calcium in plant cells

Directory of Open Access Journals (Sweden)

V. V. Schwartau

2014-04-01

Full Text Available The paper gives the review on the role of calcium in many physiological processes of plant organisms, including growth and development, protection from pathogenic influences, response to changing environmental factors, and many other aspects of plant physiology. Initial intake of calcium ions is carried out by Ca2+-channels of plasma membrane and they are further transported by the xylem owing to auxins’ attractive ability. The level of intake and selectivity of calcium transport to ove-ground parts of the plant is controlled by a symplast. Ca2+enters to the cytoplasm of endoderm cells through calcium channels on the cortical side of Kaspary bands, and is redistributed inside the stele by the symplast, with the use of Ca2+-АТPases and Ca2+/Н+-antiports. Owing to regulated expression and activity of these calcium transporters, calclum can be selectively delivered to the xylem. Important role in supporting calcium homeostasis is given to the vacuole which is the largest depo of calcium. Regulated quantity of calcium movement through the tonoplast is provided by a number of potential-, ligand-gated active transporters and channels, like Ca2+-ATPase and Ca2+/H+ exchanger. They are actively involved in the inactivation of the calcium signal by pumping Ca2+ to the depo of cells. Calcium ATPases are high affinity pumps that efficiently transfer calcium ions against the concentration gradient in their presence in the solution in nanomolar concentrations. Calcium exchangers are low affinity, high capacity Ca2+ transporters that are effectively transporting calcium after raising its concentration in the cell cytosol through the use of protons gradients. Maintaining constant concentration and participation in the response to stimuli of different types also involves EPR, plastids, mitochondria, and cell wall. Calcium binding proteins contain several conserved sequences that provide sensitivity to changes in the concentration of Ca2+ and when you

Redox regulation of plant stem cell fate.

Science.gov (United States)

Zeng, Jian; Dong, Zhicheng; Wu, Haijun; Tian, Zhaoxia; Zhao, Zhong

2017-10-02

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. The superoxide anion (O2·-) is markedly enriched in stem cells to activate WUSCHEL and maintain stemness, whereas H 2 O 2 is more abundant in the differentiating peripheral zone to promote stem cell differentiation. Moreover, H 2 O 2 negatively regulates O2·- biosynthesis in stem cells, and increasing H 2 O 2 levels or scavenging O2·- leads to the termination of stem cells. Our results provide a mechanistic framework for ROS-mediated control of plant stem cell fate and demonstrate that the balance between O2·- and H 2 O 2 is key to stem cell maintenance and differentiation. © 2017 The Authors.

Pathological modifications of plant stem cell destiny

Science.gov (United States)

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...

Automatic detection of diseased tomato plants using thermal and stereo visible light images.

Directory of Open Access Journals (Sweden)

Shan-e-Ahmed Raza

Full Text Available Accurate and timely detection of plant diseases can help mitigate the worldwide losses experienced by the horticulture and agriculture industries each year. Thermal imaging provides a fast and non-destructive way of scanning plants for diseased regions and has been used by various researchers to study the effect of disease on the thermal profile of a plant. However, thermal image of a plant affected by disease has been known to be affected by environmental conditions which include leaf angles and depth of the canopy areas accessible to the thermal imaging camera. In this paper, we combine thermal and visible light image data with depth information and develop a machine learning system to remotely detect plants infected with the tomato powdery mildew fungus Oidium neolycopersici. We extract a novel feature set from the image data using local and global statistics and show that by combining these with the depth information, we can considerably improve the accuracy of detection of the diseased plants. In addition, we show that our novel feature set is capable of identifying plants which were not originally inoculated with the fungus at the start of the experiment but which subsequently developed disease through natural transmission.

Imaging of Human Hepatic Stem Cells In Vivo

International Nuclear Information System (INIS)

Hsu, E.W.

2006-01-01

Report on progress in MRI and PET of stem cell tracking. Human hepatic stem cell imaging for both MRI and PET have been accomplished within SCID/nod mice, and succeeded in cell specificity labeling with in vitro, ex vivo, and in vivo image tracking. For MRI, stem cell labeling was accomplished by two methods: (1) in vitro labeling the stem cells just prior to in vivo transplantation, and/or (2) transplanting the stem cells into SCID/nod mice and in vivo specificity labeling the cells just prior to MRI. For labeling techniques 1 and 2, multiple image controls were utilized and include: (A) stem cells(-) and contrast label(-), (B) stem cells(+) and contrast label(-), and (C) stem cells(-) and contrast label(+) help to confirm signal noise background interference, which is a result of slight nonspecific cell labeling. Contrast labeled stem cells are directly transplanted into liver tissues, the tissues excised, and immediately MR imaged to determine cell dispersion dynamics. In this method, the contrast labeled cells appear as void foci throughout the organs. The images are imported into Metamorph imaging software and analyzed for foci radii, diameter, and to discern spheroid volumes. Then, cell numbers are extrapolated to understand ''imaged'' cell aggregate requirements using this technique. For this ex vivo method, a cell aggregate of ∼100 stem cells is required to MRI monitor signal activities. For in vivo imaging, contrast labeled human stem cells within SCID/nod mice are also confirmed as small foci voids and are evident within liver tissues. Initially, these short-term studies where accomplished by in vitro labeling stem cells, transplanting the cells, then in vivo imaging the tissues between days 3-15. Next and to avoid imaged time limitations of detaching contrast agents, the proliferative stem cells were labeled after transplantation, and before MR imaging. This was accomplished to confirm the ability to specifically label unique cell subsets after the

Optical cell sorting with multiple imaging modalities

DEFF Research Database (Denmark)

Banas, Andrew; Carrissemoux, Caro; Palima, Darwin

2017-01-01

healthy cells. With the richness of visual information, a lot of microscopy techniques have been developed and have been crucial in biological studies. To utilize their complementary advantages we adopt both fluorescence and brightfield imaging in our optical cell sorter. Brightfield imaging has...... the advantage of being non-invasive, thus maintaining cell viability. Fluorescence imaging, on the other hand, takes advantages of the chemical specificity of fluorescence markers and can validate machine vision results from brightfield images. Visually identified cells are sorted using optical manipulation...

Development of fluorescence imaging-based assay for screening cardioprotective compounds from medicinal plants.

Science.gov (United States)

Wang, Yi; Zhao, Xiaoping; Gao, Xiumei; Nie, Xiaojing; Yang, Yingxin; Fan, Xiaohui

2011-09-19

Medicinal plants have been widely recognized as a renewable resource for the discovery of novel leads and drug. In this study, an approach for screening and identification compounds with cardioprotective activity from medicinal plant extracts by cellular-fluorescence imaging technique was developed. It is a cell-based assay for measuring mitochondrial membrane potential changes in H9c2 cardiac muscle cells exposed to H(2)O(2) by using a fluorescence automatic microscopy screening platform. Rhodamine 123 was used as the fluorescent dye to indicate the change of mitochondrial membrane potential. The sensitivity and linear range of the proposed approach were evaluated and validated using vitamin C, an antioxidative compound. The method was applied to screen active components with potent cardioprotective effects from a traditional Chinese formula. The potential cardioprotective components were identified by liquid chromatography coupled with mass spectrometry (LC/MS). Moreover, the utility of the proposed approach was further validated by three compounds (salvianolic acid B, protocatechuic aldehyde, and tanshinone II A) identified from the formula which showed cardioprotective effects in a dose-dependent manner. These applications suggested that the proposed rapid and sensitive screening approach offers an efficient way to discover active components or compounds from medicinal plants. Copyright © 2011 Elsevier B.V. All rights reserved.

High Throughput In vivo Analysis of Plant Leaf Chemical Properties Using Hyperspectral Imaging

Directory of Open Access Journals (Sweden)

Piyush Pandey

2017-08-01

Full Text Available Image-based high-throughput plant phenotyping in greenhouse has the potential to relieve the bottleneck currently presented by phenotypic scoring which limits the throughput of gene discovery and crop improvement efforts. Numerous studies have employed automated RGB imaging to characterize biomass and growth of agronomically important crops. The objective of this study was to investigate the utility of hyperspectral imaging for quantifying chemical properties of maize and soybean plants in vivo. These properties included leaf water content, as well as concentrations of macronutrients nitrogen (N, phosphorus (P, potassium (K, magnesium (Mg, calcium (Ca, and sulfur (S, and micronutrients sodium (Na, iron (Fe, manganese (Mn, boron (B, copper (Cu, and zinc (Zn. Hyperspectral images were collected from 60 maize and 60 soybean plants, each subjected to varying levels of either water deficit or nutrient limitation stress with the goal of creating a wide range of variation in the chemical properties of plant leaves. Plants were imaged on an automated conveyor belt system using a hyperspectral imager with a spectral range from 550 to 1,700 nm. Images were processed to extract reflectance spectrum from each plant and partial least squares regression models were developed to correlate spectral data with chemical data. Among all the chemical properties investigated, water content was predicted with the highest accuracy [R2 = 0.93 and RPD (Ratio of Performance to Deviation = 3.8]. All macronutrients were also quantified satisfactorily (R2 from 0.69 to 0.92, RPD from 1.62 to 3.62, with N predicted best followed by P, K, and S. The micronutrients group showed lower prediction accuracy (R2 from 0.19 to 0.86, RPD from 1.09 to 2.69 than the macronutrient groups. Cu and Zn were best predicted, followed by Fe and Mn. Na and B were the only two properties that hyperspectral imaging was not able to quantify satisfactorily (R2 < 0.3 and RPD < 1.2. This study suggested

Real-time imaging of radioisotope labeled compounds in a living plant

International Nuclear Information System (INIS)

Kanno, S.; Ohya, T.; Hayashi, Y.; Tanoi, K.; Nakanishi, T.M.

2007-01-01

We developed a quantitative, real-time imaging system of labeled compounds in a living plant. The system was composed of CsI scintillator to convert β-rays to visible light and an image intensifier unit (composed of GaAsP semiconductor and MCP; micro channel plate) to detect extremely weak light. When the sensitivity and resolution of the image of our system was compared with that of an imaging plate (IP), the sensitivity of our system (with 20 minutes) was higher than that of an IP, with similar quality to that of an IP. Using this system, the translocation of 32 P in a soybean plant tissue was shown in successive images. (author)

Plant cell wall extensibility: connecting plant cell growth with cell wall structure, mechanics, and the action of wall-modifying enzymes

Energy Technology Data Exchange (ETDEWEB)

Cosgrove, Daniel J.

2015-11-25

The advent of user-friendly instruments for measuring force/deflection curves of plant surfaces at high spatial resolution has resulted in a recent outpouring of reports of the ‘Young's modulus’ of plant cell walls. The stimulus for these mechanical measurements comes from biomechanical models of morphogenesis of meristems and other tissues, as well as single cells, in which cell wall stress feeds back to regulate microtubule organization, auxin transport, cellulose deposition, and future growth directionality. In this article I review the differences between elastic modulus and wall extensibility in the context of cell growth. Some of the inherent complexities, assumptions, and potential pitfalls in the interpretation of indentation force/deflection curves are discussed. Reported values of elastic moduli from surface indentation measurements appear to be 10- to >1000-fold smaller than realistic tensile elastic moduli in the plane of plant cell walls. Potential reasons for this disparity are discussed, but further work is needed to make sense of the huge range in reported values. The significance of wall stress relaxation for growth is reviewed and connected to recent advances and remaining enigmas in our concepts of how cellulose, hemicellulose, and pectins are assembled to make an extensible cell wall. A comparison of the loosening action of α-expansin and Cel12A endoglucanase is used to illustrate two different ways in which cell walls may be made more extensible and the divergent effects on wall mechanics.

Microtubule networks for plant cell division

NARCIS (Netherlands)

Keijzer, de Jeroen; Mulder, B.M.; Janson, M.E.

2014-01-01

During cytokinesis the cytoplasm of a cell is divided to form two daughter cells. In animal cells, the existing plasma membrane is first constricted and then abscised to generate two individual plasma membranes. Plant cells on the other hand divide by forming an interior dividing wall, the so-called

Vacuolar processing enzyme: an executor of plant cell death.

Science.gov (United States)

Hara-Nishimura, Ikuko; Hatsugai, Noriyuki; Nakaune, Satoru; Kuroyanagi, Miwa; Nishimura, Mikio

2005-08-01

Apoptotic cell death in animals is regulated by cysteine proteinases called caspases. Recently, vacuolar processing enzyme (VPE) was identified as a plant caspase. VPE deficiency prevents cell death during hypersensitive response and cell death of limited cell layers at the early stage of embryogenesis. Because plants do not have macrophages, dying cells must degrade their materials by themselves. VPE plays an essential role in the regulation of the lytic system of plants during the processes of defense and development. VPE is localized in the vacuoles, unlike animal caspases, which are localized in the cytosol. Thus, plants might have evolved a regulated cellular suicide strategy that, unlike animal apoptosis, is mediated by VPE and the vacuoles.

Dynamic simulation of a direct carbonate fuel cell power plant

Energy Technology Data Exchange (ETDEWEB)

Ernest, J.B. [Fluor Daniel, Inc., Irvine, CA (United States); Ghezel-Ayagh, H.; Kush, A.K. [Fuel Cell Engineering, Danbury, CT (United States)

1996-12-31

Fuel Cell Engineering Corporation (FCE) is commercializing a 2.85 MW Direct carbonate Fuel Cell (DFC) power plant. The commercialization sequence has already progressed through construction and operation of the first commercial-scale DFC power plant on a U.S. electric utility, the 2 MW Santa Clara Demonstration Project (SCDP), and the completion of the early phases of a Commercial Plant design. A 400 kW fuel cell stack Test Facility is being built at Energy Research Corporation (ERC), FCE`s parent company, which will be capable of testing commercial-sized fuel cell stacks in an integrated plant configuration. Fluor Daniel, Inc. provided engineering, procurement, and construction services for SCDP and has jointly developed the Commercial Plant design with FCE, focusing on the balance-of-plant (BOP) equipment outside of the fuel cell modules. This paper provides a brief orientation to the dynamic simulation of a fuel cell power plant and the benefits offered.

A Novel Plant Root Foraging Algorithm for Image Segmentation Problems

Directory of Open Access Journals (Sweden)

Lianbo Ma

2014-01-01

Full Text Available This paper presents a new type of biologically-inspired global optimization methodology for image segmentation based on plant root foraging behavior, namely, artificial root foraging algorithm (ARFO. The essential motive of ARFO is to imitate the significant characteristics of plant root foraging behavior including branching, regrowing, and tropisms for constructing a heuristic algorithm for multidimensional and multimodal problems. A mathematical model is firstly designed to abstract various plant root foraging patterns. Then, the basic process of ARFO algorithm derived in the model is described in details. When tested against ten benchmark functions, ARFO shows the superiority to other state-of-the-art algorithms on several benchmark functions. Further, we employed the ARFO algorithm to deal with multilevel threshold image segmentation problem. Experimental results of the new algorithm on a variety of images demonstrated the suitability of the proposed method for solving such problem.

High Throughput In vivo Analysis of Plant Leaf Chemical Properties Using Hyperspectral Imaging

Science.gov (United States)

Pandey, Piyush; Ge, Yufeng; Stoerger, Vincent; Schnable, James C.

2017-01-01

Image-based high-throughput plant phenotyping in greenhouse has the potential to relieve the bottleneck currently presented by phenotypic scoring which limits the throughput of gene discovery and crop improvement efforts. Numerous studies have employed automated RGB imaging to characterize biomass and growth of agronomically important crops. The objective of this study was to investigate the utility of hyperspectral imaging for quantifying chemical properties of maize and soybean plants in vivo. These properties included leaf water content, as well as concentrations of macronutrients nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca), and sulfur (S), and micronutrients sodium (Na), iron (Fe), manganese (Mn), boron (B), copper (Cu), and zinc (Zn). Hyperspectral images were collected from 60 maize and 60 soybean plants, each subjected to varying levels of either water deficit or nutrient limitation stress with the goal of creating a wide range of variation in the chemical properties of plant leaves. Plants were imaged on an automated conveyor belt system using a hyperspectral imager with a spectral range from 550 to 1,700 nm. Images were processed to extract reflectance spectrum from each plant and partial least squares regression models were developed to correlate spectral data with chemical data. Among all the chemical properties investigated, water content was predicted with the highest accuracy [R2 = 0.93 and RPD (Ratio of Performance to Deviation) = 3.8]. All macronutrients were also quantified satisfactorily (R2 from 0.69 to 0.92, RPD from 1.62 to 3.62), with N predicted best followed by P, K, and S. The micronutrients group showed lower prediction accuracy (R2 from 0.19 to 0.86, RPD from 1.09 to 2.69) than the macronutrient groups. Cu and Zn were best predicted, followed by Fe and Mn. Na and B were the only two properties that hyperspectral imaging was not able to quantify satisfactorily (R2 designing experiments to vary plant nutrients

Metabolism of fluoranthene in different plant cell cultures and intact plants

Energy Technology Data Exchange (ETDEWEB)

Kolb, M.; Harms, H.

2000-05-01

The metabolism of fluoranthene was investigated in 11 cell cultures of different plant species using a [{sup 14}C]-labeled standard. Most species metabolized less than 5% of fluoranthene to soluble metabolites and formed less than 5% nonextractable residues during the standardized 48-h test procedure. Higher metabolic rates were observed in lettuce (Lactuca sativa, 6%), wheat (Tricitum aestivum, 9%), and tomato (Lycopersicon esculentum, 15%). A special high metabolic rate of nearly 50% was determined for the rose species Paul's Scarlet. Chromatographic analysis of metabolites extracted from aseptically grown tomato plants proved that the metabolites detected in the cell cultures were also formed in the intact plants. Metabolites produced in tomato and rose cells from [{sup 14}C]-fluoranthene were conjugated with glucose, glucuronic acid, and other cell components. After acid hydrolyses, the main metabolite of both species was 1-hydroxyfluoranthene as identified by gas chromatography-mass spectrometry and high-performance liquid chromatography with diode array detection. The second metabolite formed by both species was 8-hydroxyfluoranthene. A third metabolite in tomatoes was 3-hydroxyfluoranthene.

High Throughput In vivo Analysis of Plant Leaf Chemical Properties Using Hyperspectral Imaging.

Science.gov (United States)

Pandey, Piyush; Ge, Yufeng; Stoerger, Vincent; Schnable, James C

2017-01-01

Image-based high-throughput plant phenotyping in greenhouse has the potential to relieve the bottleneck currently presented by phenotypic scoring which limits the throughput of gene discovery and crop improvement efforts. Numerous studies have employed automated RGB imaging to characterize biomass and growth of agronomically important crops. The objective of this study was to investigate the utility of hyperspectral imaging for quantifying chemical properties of maize and soybean plants in vivo . These properties included leaf water content, as well as concentrations of macronutrients nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca), and sulfur (S), and micronutrients sodium (Na), iron (Fe), manganese (Mn), boron (B), copper (Cu), and zinc (Zn). Hyperspectral images were collected from 60 maize and 60 soybean plants, each subjected to varying levels of either water deficit or nutrient limitation stress with the goal of creating a wide range of variation in the chemical properties of plant leaves. Plants were imaged on an automated conveyor belt system using a hyperspectral imager with a spectral range from 550 to 1,700 nm. Images were processed to extract reflectance spectrum from each plant and partial least squares regression models were developed to correlate spectral data with chemical data. Among all the chemical properties investigated, water content was predicted with the highest accuracy [ R 2 = 0.93 and RPD (Ratio of Performance to Deviation) = 3.8]. All macronutrients were also quantified satisfactorily ( R 2 from 0.69 to 0.92, RPD from 1.62 to 3.62), with N predicted best followed by P, K, and S. The micronutrients group showed lower prediction accuracy ( R 2 from 0.19 to 0.86, RPD from 1.09 to 2.69) than the macronutrient groups. Cu and Zn were best predicted, followed by Fe and Mn. Na and B were the only two properties that hyperspectral imaging was not able to quantify satisfactorily ( R 2 plant chemical traits. Future

Mechanochemical Polarization of Contiguous Cell Walls Shapes Plant Pavement Cells.

Science.gov (United States)

Majda, Mateusz; Grones, Peter; Sintorn, Ida-Maria; Vain, Thomas; Milani, Pascale; Krupinski, Pawel; Zagórska-Marek, Beata; Viotti, Corrado; Jönsson, Henrik; Mellerowicz, Ewa J; Hamant, Olivier; Robert, Stéphanie

2017-11-06

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. Copyright © 2017 Elsevier Inc. All rights reserved.

Electron tomography of cryo-immobilized plant tissue: a novel approach to studying 3D macromolecular architecture of mature plant cell walls in situ.

Directory of Open Access Journals (Sweden)

Purbasha Sarkar

Full Text Available Cost-effective production of lignocellulosic biofuel requires efficient breakdown of cell walls present in plant biomass to retrieve the wall polysaccharides for fermentation. In-depth knowledge of plant cell wall composition is therefore essential for improving the fuel production process. The precise spatial three-dimensional (3D organization of cellulose, hemicellulose, pectin and lignin within plant cell walls remains unclear to date since the microscopy techniques used so far have been limited to two-dimensional, topographic or low-resolution imaging, or required isolation or chemical extraction of the cell walls. In this paper we demonstrate that by cryo-immobilizing fresh tissue, then either cryo-sectioning or freeze-substituting and resin embedding, followed by cryo- or room temperature (RT electron tomography, respectively, we can visualize previously unseen details of plant cell wall architecture in 3D, at macromolecular resolution (∼ 2 nm, and in near-native state. Qualitative and quantitative analyses showed that wall organization of cryo-immobilized samples were preserved remarkably better than conventionally prepared samples that suffer substantial extraction. Lignin-less primary cell walls were well preserved in both self-pressurized rapidly frozen (SPRF, cryo-sectioned samples as well as high-pressure frozen, freeze-substituted and resin embedded (HPF-FS-resin samples. Lignin-rich secondary cell walls appeared featureless in HPF-FS-resin sections presumably due to poor stain penetration, but their macromolecular features could be visualized in unprecedented details in our cryo-sections. While cryo-tomography of vitreous tissue sections is currently proving to be instrumental in developing 3D models of lignin-rich secondary cell walls, here we confirm that the technically easier method of RT-tomography of HPF-FS-resin sections could be used immediately for routine study of low-lignin cell walls. As a proof of principle, we

Development of real-time radioisotope imaging system to study plant nutrition

International Nuclear Information System (INIS)

Nakanishi, Tomoko M.; Kobayashi, Natsuko I.; Hirose, Atsushi; Saito, Takayuki; Sugita, Ryohei; Tanoi, Keitaro; Suzuki, Hisashi; Iwata, Ren

2013-01-01

We have been developing two types of realtime radioisotope imaging systems, one for macroscopic imaging targeting the whole plant itself and the other for microscopic imaging under modified fulorescent microscope to get both fluorescent and radioisotope images (Hirose et al. 2012; Kanno et al. 2012; Kobayashi et al. 2012). Now we can visualize the realtime movement of C-14, Na-22, Mg-28, P-32, S-35, K- 42, Ca-45, Rb-86 or Cs-137, from root kept in dark to up-ground part where light was irradiated. There are a wide range of application of this imaging, such as to measure the uptake manner in root, speed or distribution or translocation manner, as well as distribution, translocation or deposition of the nutrient element in upground part. Here we present some representative real-time images in plants. (author)

Cell cycle and cell death are not necessary for appressorium formation and plant infection in the fungal plant pathogen Colletotrichum gloeosporioides

Directory of Open Access Journals (Sweden)

Barhoom Sima

2008-02-01

Full Text Available Abstract Background In order to initiate plant infection, fungal spores must germinate and penetrate into the host plant. Many fungal species differentiate specialized infection structures called appressoria on the host surface, which are essential for successful pathogenic development. In the model plant pathogen Magnaporthe grisea completion of mitosis and autophagy cell death of the spore are necessary for appressoria-mediated plant infection; blocking of mitosis prevents appressoria formation, and prevention of autophagy cell death results in non-functional appressoria. Results We found that in the closely related plant pathogen Colletotrichum gloeosporioides, blocking of the cell cycle did not prevent spore germination and appressoria formation. The cell cycle always lagged behind the morphogenetic changes that follow spore germination, including germ tube and appressorium formation, differentiation of the penetrating hypha, and in planta formation of primary hyphae. Nuclear division was arrested following appressorium formation and was resumed in mature appressoria after plant penetration. Unlike in M. grisea, blocking of mitosis had only a marginal effect on appressoria formation; development in hydroxyurea-treated spores continued only for a limited number of cell divisions, but normal numbers of fully developed mature appressoria were formed under conditions that support appressoria formation. Similar results were also observed in other Colletotrichum species. Spores, germ tubes, and appressoria retained intact nuclei and remained viable for several days post plant infection. Conclusion We showed that in C. gloeosporioides the differentiation of infection structures including appressoria precedes mitosis and can occur without nuclear division. This phenomenon was also found to be common in other Colletotrichum species. Spore cell death did not occur during plant infection and the fungus primary infection structures remained viable

One-pot synthesis of gold nanostars using plant polyphenols for cancer photoacoustic imaging and photothermal therapy

International Nuclear Information System (INIS)

Zhang, Xiao-Long; Zheng, Cheng; Zhang, Yun; Yang, Huang-Hao; Liu, Xiaolong; Liu, Jingfeng

2016-01-01

Branched plasmonic nanostructures have been found to exhibit strong enhancement of the electromagnetic field surrounding their multi-branched petals. This feature endows them with improved performance in catalysis, surface-enhanced Raman scattering, photoacoustic imaging, and photothermal therapy. Albeit several synthesis techniques have been developed, the precisely controlled growth of highly branched nanostructures with a one-pot surfactant-free procedure is still challenging. Herein, we present a simple seedless route to synthesize gold nanostars (AuNSs) using a natural plant polyphenol, gallic acid (GA), as a reducing and stabilizing agent. The size and shape of AuNSs can be tuned by simply adjusting the amount of added GA. Under the optimum condition, the as-prepared AuNSs with diameters about 100 nm exhibit strong near-infrared absorption, good photothermal efficiency, and high biocompatibility. We demonstrate that AuNSs can be utilized for simultaneous photoacoustic imaging and photothermal therapy in living cancer cells. This study highlights facile synthesized AuNSs could serve as a promising platform for cancer diagnosis and therapy.Graphical AbstractGold nanostars (AuNSs) are synthesized by a simple seedless route using a natural plant polyphenol, gallic acid (GA), as a reducing and stabilizing agent. The AuNSs can be utilized for simultaneous photoacoustic imaging and photothermal therapy in living cancer cells. This study highlights facile synthesized AuNSs could serve as a promising platform for cancer diagnosis and therapy.

One-pot synthesis of gold nanostars using plant polyphenols for cancer photoacoustic imaging and photothermal therapy

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xiao-Long [Mengchao Hepatobiliary Hospital of Fujian Medical University, The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province (China); Zheng, Cheng [Fuzhou University, The Key Lab of Analysis and Detection Technology for Food Safety of the MOE, College of Chemistry (China); Zhang, Yun [Chinese Academy of Sciences, Xiamen Institute of Rare Earth Materials, Haixi Institute (China); Yang, Huang-Hao [Fuzhou University, The Key Lab of Analysis and Detection Technology for Food Safety of the MOE, College of Chemistry (China); Liu, Xiaolong, E-mail: xiaoloong.liu@gmail.com; Liu, Jingfeng, E-mail: drjingfeng@126.com [Mengchao Hepatobiliary Hospital of Fujian Medical University, The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province (China)

2016-07-15

Branched plasmonic nanostructures have been found to exhibit strong enhancement of the electromagnetic field surrounding their multi-branched petals. This feature endows them with improved performance in catalysis, surface-enhanced Raman scattering, photoacoustic imaging, and photothermal therapy. Albeit several synthesis techniques have been developed, the precisely controlled growth of highly branched nanostructures with a one-pot surfactant-free procedure is still challenging. Herein, we present a simple seedless route to synthesize gold nanostars (AuNSs) using a natural plant polyphenol, gallic acid (GA), as a reducing and stabilizing agent. The size and shape of AuNSs can be tuned by simply adjusting the amount of added GA. Under the optimum condition, the as-prepared AuNSs with diameters about 100 nm exhibit strong near-infrared absorption, good photothermal efficiency, and high biocompatibility. We demonstrate that AuNSs can be utilized for simultaneous photoacoustic imaging and photothermal therapy in living cancer cells. This study highlights facile synthesized AuNSs could serve as a promising platform for cancer diagnosis and therapy.Graphical AbstractGold nanostars (AuNSs) are synthesized by a simple seedless route using a natural plant polyphenol, gallic acid (GA), as a reducing and stabilizing agent. The AuNSs can be utilized for simultaneous photoacoustic imaging and photothermal therapy in living cancer cells. This study highlights facile synthesized AuNSs could serve as a promising platform for cancer diagnosis and therapy.

DIRECT DISMANTLING OF REPROCESSING PLANT CELLS THE EUREX PLANT EXPERIENCEe2d12c

International Nuclear Information System (INIS)

Gili, M.; Troiani, F.; Risoluti, P.

2003-01-01

After finishing the reprocessing campaigns in 1970-1983, the EUREX pilot reprocessing plant of ENEA Saluggia Research Center started into a new phase, aiming to materials and irradiated fuel systemation and radioactive wastes conditioning. In 1997 the project ''CORA'' for a vitrification plant for the high and intermediate liquid radioactive wastes started. The ''CORA'' plant will be hosted in some dismantled cells of the EUREX plant, reusing many of the EUREX plant auxiliary systems, duly refurbished, saving money and construction time and avoiding a new nuclear building in the site. Two of the cells that will be reused were part of the EUREX chemical process (solvent recovery and 2nd extraction cycle) and the components were obviously internally contaminated. In 2000 the direct (hands-on) dismantling of one of them started and has been completed in summer 2002; the second one will be dismantled in the next year and then the ''CORA'' plant will be assembled inside the cells. Special care w as taken to avoid spread of contamination in the cells, where ''CORA'' installation activities will start in the next years, during the dismantling process The analysis of data and results collected during the dismantling of the first cell shows that direct dismantling can be achieved with careful choice of tools, procedures and techniques, to reduce volumes of wastes to be disposed and radiological burden

Plant Cell Cultures as Source of Cosmetic Active Ingredients

Directory of Open Access Journals (Sweden)

Ani Barbulova

2014-04-01

Full Text Available The last decades witnessed a great demand of natural remedies. As a result, medicinal plants have been increasingly cultivated on a commercial scale, but the yield, the productive quality and the safety have not always been satisfactory. Plant cell cultures provide useful alternatives for the production of active ingredients for biomedical and cosmetic uses, since they represent standardized, contaminant-free and biosustainable systems, which allow the production of desired compounds on an industrial scale. Moreover, thanks to their totipotency, plant cells grown as liquid suspension cultures can be used as “biofactories” for the production of commercially interesting secondary metabolites, which are in many cases synthesized in low amounts in plant tissues and differentially distributed in the plant organs, such as roots, leaves, flowers or fruits. Although it is very widespread in the pharmaceutical industry, plant cell culture technology is not yet very common in the cosmetic field. The aim of the present review is to focus on the successful research accomplishments in the development of plant cell cultures for the production of active ingredients for cosmetic applications.

In vivo cell tracking with bioluminescence imaging

Energy Technology Data Exchange (ETDEWEB)

Kim, Jung Eun; Kalimuthu, Senthilkumar; Ahn, Byeong Cheol [Dept. of Nuclear Medicine, Kyungpook National University School of Medicine and Hospital, Daegu (Korea, Republic of)

2015-03-15

Molecular imaging is a fast growing biomedical research that allows the visual representation, characterization and quantification of biological processes at the cellular and subcellular levels within intact living organisms. In vivo tracking of cells is an indispensable technology for development and optimization of cell therapy for replacement or renewal of damaged or diseased tissue using transplanted cells, often autologous cells. With outstanding advantages of bioluminescence imaging, the imaging approach is most commonly applied for in vivo monitoring of transplanted stem cells or immune cells in order to assess viability of administered cells with therapeutic efficacy in preclinical small animal models. In this review, a general overview of bioluminescence is provided and recent updates of in vivo cell tracking using the bioluminescence signal are discussed.

Apoptosis-Inducing Effect of Three Medicinal Plants on Oral Cancer Cells KB and ORL-48

Directory of Open Access Journals (Sweden)

Mohd Zabidi Majid

2014-01-01

Full Text Available Brucea javanica, Azadirachta indica, and Typhonium flagelliforme are medicinal plants commonly used to treat conditions associated with tumour formation. This study aimed to determine the antiproliferative activity of these plants extracts on KB and ORL-48 oral cancer cell lines and to suggest their mode of cell death. The concentration producing 50% cell inhibition (IC50 was determined and the activity was examined under an inverted microscope. Immunohistochemistry fluorescent staining method (TUNEL was performed to indicate the mechanism of cell death and the fragmented DNA band pattern produced was obtained for verification. Compared to Azadirachta sp. and Typhonium sp., the antiproliferative activity of Brucea sp. extract was the most potent on both KB and ORL-48 cells with IC50 of 24.37 ± 1.75 and 6.67 ± 1.15 µg/mL, respectively. Signs of cell attrition were observed 24 hr after treatment. Green fluorescent spots indicating cell death by apoptosis were observed in images of both cells following treatment with all the three extracts. DNA fragments harvested from Brucea-treated cells produced bands in a ladder pattern suggesting the apoptotic effect of the extract. It is thus concluded that Brucea sp. extract exhibited cytotoxic activity on ORL-48 cells and their action mechanism is via apoptosis.

PET imaging of adoptive progenitor cell therapies

International Nuclear Information System (INIS)

Gelovani, Juri G.

2008-01-01

The overall objective of this application is to develop novel technologies for non-invasive imaging of adoptive stem cell-based therapies with positron emission tomography (PET) that would be applicable to human patients. To achieve this objective, stem cells will be genetically labeled with a PET-reporter gene and repetitively imaged to assess their distribution, migration, differentiation, and persistence using a radiolabeled reporter probe. This new imaging technology will be tested in adoptive progenitor cell-based therapy models in animals, including: delivery pro-apoptotic genes to tumors, and T-cell reconstitution for immunostimulatory therapy during allogeneic bone marrow progenitor cell transplantation. Technical and Scientific Merits. Non-invasive whole body imaging would significantly aid in the development and clinical implementation of various adoptive progenitor cell-based therapies by providing the means for non-invasive monitoring of the fate of injected progenitor cells over a long period of observation. The proposed imaging approaches could help to address several questions related to stem cell migration and homing, their long-term viability, and their subsequent differentiation. The ability to image these processes non-invasively in 3D and repetitively over a long period of time is very important and will help the development and clinical application of various strategies to control and direct stem cell migration and differentiation. Approach to accomplish the work. Stem cells will be genetically with a reporter gene which will allow for repetitive non-invasive 'tracking' of the migration and localization of genetically labeled stem cells and their progeny. This is a radically new approach that is being developed for future human applications and should allow for a long term (many years) repetitive imaging of the fate of tissues that develop from the transplanted stem cells. Why the approach is appropriate. The novel approach to stem cell imaging

PET imaging of adoptive progenitor cell therapies.

Energy Technology Data Exchange (ETDEWEB)

Gelovani, Juri G.

2008-05-13

Objectives. The overall objective of this application is to develop novel technologies for non-invasive imaging of adoptive stem cell-based therapies with positron emission tomography (PET) that would be applicable to human patients. To achieve this objective, stem cells will be genetically labeled with a PET-reporter gene and repetitively imaged to assess their distribution, migration, differentiation, and persistence using a radiolabeled reporter probe. This new imaging technology will be tested in adoptive progenitor cell-based therapy models in animals, including: delivery pro-apoptotic genes to tumors, and T-cell reconstitution for immunostimulatory therapy during allogeneic bone marrow progenitor cell transplantation. Technical and Scientific Merits. Non-invasive whole body imaging would significantly aid in the development and clinical implementation of various adoptive progenitor cell-based therapies by providing the means for non-invasive monitoring of the fate of injected progenitor cells over a long period of observation. The proposed imaging approaches could help to address several questions related to stem cell migration and homing, their long-term viability, and their subsequent differentiation. The ability to image these processes non-invasively in 3D and repetitively over a long period of time is very important and will help the development and clinical application of various strategies to control and direct stem cell migration and differentiation. Approach to accomplish the work. Stem cells will be genetically with a reporter gene which will allow for repetitive non-invasive “tracking” of the migration and localization of genetically labeled stem cells and their progeny. This is a radically new approach that is being developed for future human applications and should allow for a long term (many years) repetitive imaging of the fate of tissues that develop from the transplanted stem cells. Why the approach is appropriate. The novel approach to

Inducible cell death in plant immunity

DEFF Research Database (Denmark)

Hofius, Daniel; Tsitsigiannis, Dimitrios I; Jones, Jonathan D G

2006-01-01

Programmed cell death (PCD) occurs during vegetative and reproductive plant growth, as typified by autumnal leaf senescence and the terminal differentiation of the endosperm of cereals which provide our major source of food. PCD also occurs in response to environmental stress and pathogen attack......, and these inducible PCD forms are intensively studied due their experimental tractability. In general, evidence exists for plant cell death pathways which have similarities to the apoptotic, autophagic and necrotic forms described in yeast and metazoans. Recent research aiming to understand these pathways...

An Automated and Continuous Plant Weight Measurement System for Plant Factory.

Science.gov (United States)

Chen, Wei-Tai; Yeh, Yu-Hui F; Liu, Ting-Yu; Lin, Ta-Te

2016-01-01

In plant factories, plants are usually cultivated in nutrient solution under a controllable environment. Plant quality and growth are closely monitored and precisely controlled. For plant growth evaluation, plant weight is an important and commonly used indicator. Traditional plant weight measurements are destructive and laborious. In order to measure and record the plant weight during plant growth, an automated measurement system was designed and developed herein. The weight measurement system comprises a weight measurement device and an imaging system. The weight measurement device consists of a top disk, a bottom disk, a plant holder and a load cell. The load cell with a resolution of 0.1 g converts the plant weight on the plant holder disk to an analog electrical signal for a precise measurement. The top disk and bottom disk are designed to be durable for different plant sizes, so plant weight can be measured continuously throughout the whole growth period, without hindering plant growth. The results show that plant weights measured by the weight measurement device are highly correlated with the weights estimated by the stereo-vision imaging system; hence, plant weight can be measured by either method. The weight growth of selected vegetables growing in the National Taiwan University plant factory were monitored and measured using our automated plant growth weight measurement system. The experimental results demonstrate the functionality, stability and durability of this system. The information gathered by this weight system can be valuable and beneficial for hydroponic plants monitoring research and agricultural research applications.

An Automated and Continuous Plant Weight Measurement System for Plant Factory

Directory of Open Access Journals (Sweden)

Wei-Tai eChen

2016-03-01

Full Text Available In plant factories, plants are usually cultivated in nutrient solution under a controllable environment. Plant quality and growth are closely monitored and precisely controlled. For plant growth evaluation, plant weight is an important and commonly used indicator. Traditional plant weight measurements are destructive and laborious. In order to measure and record the plant weight during plant growth, an automated measurement system was designed and developed herein. The weight measurement system comprises a weight measurement device and an imaging system. The weight measurement device consists of a top disk, a bottom disk, a plant holder and a load cell. The load cell with a resolution of 0.1 g converts the plant weight on the plant holder disk to an analogue electrical signal for a precise measurement. The top disk and bottom disk are designed to be durable for different plant sizes, so plant weight can be measured continuously throughout the whole growth period, without hindering plant growth. The results show that plant weights measured by the weight measurement device are highly correlated with the weights estimated by the stereo-vision imaging system; hence, plant weight can be measured by either method. The weight growth of selected vegetables growing in the National Taiwan University plant factory were monitored and measured using our automated plant growth weight measurement system. The experimental results demonstrate the functionality, stability and durability of this system. The information gathered by this weight system can be valuable and beneficial for hydroponic plants monitoring research and agricultural research applications.

Plant cell technologies in space: Background, strategies and prospects

Science.gov (United States)

Kirkorian, A. D.; Scheld, H. W.

1987-01-01

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.

Measuring the elasticity of plant cells with atomic force microscopy.

Science.gov (United States)

Braybrook, Siobhan A

2015-01-01

The physical properties of biological materials impact their functions. This is most evident in plants where the cell wall contains each cell's contents and connects each cell to its neighbors irreversibly. Examining the physical properties of the plant cell wall is key to understanding how plant cells, tissues, and organs grow and gain the shapes important for their respective functions. Here, we present an atomic force microscopy-based nanoindentation method for examining the elasticity of plant cells at the subcellular, cellular, and tissue level. We describe the important areas of experimental design to be considered when planning and executing these types of experiments and provide example data as illustration. Copyright © 2015 Elsevier Inc. All rights reserved.

Roles of membrane trafficking in plant cell wall dynamics

Directory of Open Access Journals (Sweden)

Kazuo eEbine

2015-10-01

Full Text Available The cell wall is one of the characteristic components of plant cells. The cell wall composition differs among cell types and is modified in response to various environmental conditions. To properly generate and modify the cell wall, many proteins are transported to the plasma membrane or extracellular space through membrane trafficking, which is one of the key protein transport mechanisms in eukaryotic cells. Given the diverse composition and functions of the cell wall in plants, the transport of the cell wall components and proteins that are involved in cell wall-related events could be specialized for each cell type, i.e., the machinery for cell wall biogenesis, modification, and maintenance could be transported via different trafficking pathways. In this review, we summarize the recent progress in the current understanding of the roles and mechanisms of membrane trafficking in plant cells and focus on the biogenesis and regulation of the cell wall.

In-vivo elemental imaging of plants using in-air submilli-PIXE camera

International Nuclear Information System (INIS)

Matsuyama, Shigeo; Ishii, Keizo; Kikuchi, Yohei; Kawamura, Yu; Yamazaki, Hiromichi; Watanabe, Ryohei; Tashiro, Kumiko; Inoue, Chihiro

2008-01-01

We developed a PIXE analysis system which provides spatial distribution images of elements in a region of 3x3 cm 2 with a spatial resolution of ∼0.5 mm. We call this system a submilli-PIXE camera. For in-vivo imaging of plants, we combined the submilli-PIXE camera with an in-air analysis. The high-speed beam scanning and the in-air analysis also reduce the risk of damaging the plants, thus in-vivo imaging could be realized. We applied the in-air submilli-PIXE camera to phytoremediation research. Phytoremediation is a technology for cleaning metal-contaminated soils using plant physiology. To study accumulation mechanisms for heavy metals, elemental distribution in plant organ should be known as well as average concentration. Elemental images of fronds were obtained in-vivo without sample preparation. Elemental map of the fronds showed that arsenic was accumulated in the edges of Pteris vittata fronds. The in-air submilli-PIXE camera clearly shows the accumulation of arsenic in fronds. The in-air submilli-PIXE camera is an effective tool for undertaking phytoremediation research. (author)

FogBank: a single cell segmentation across multiple cell lines and image modalities.

Science.gov (United States)

Chalfoun, Joe; Majurski, Michael; Dima, Alden; Stuelten, Christina; Peskin, Adele; Brady, Mary

2014-12-30

Many cell lines currently used in medical research, such as cancer cells or stem cells, grow in confluent sheets or colonies. The biology of individual cells provide valuable information, thus the separation of touching cells in these microscopy images is critical for counting, identification and measurement of individual cells. Over-segmentation of single cells continues to be a major problem for methods based on morphological watershed due to the high level of noise in microscopy cell images. There is a need for a new segmentation method that is robust over a wide variety of biological images and can accurately separate individual cells even in challenging datasets such as confluent sheets or colonies. We present a new automated segmentation method called FogBank that accurately separates cells when confluent and touching each other. This technique is successfully applied to phase contrast, bright field, fluorescence microscopy and binary images. The method is based on morphological watershed principles with two new features to improve accuracy and minimize over-segmentation. First, FogBank uses histogram binning to quantize pixel intensities which minimizes the image noise that causes over-segmentation. Second, FogBank uses a geodesic distance mask derived from raw images to detect the shapes of individual cells, in contrast to the more linear cell edges that other watershed-like algorithms produce. We evaluated the segmentation accuracy against manually segmented datasets using two metrics. FogBank achieved segmentation accuracy on the order of 0.75 (1 being a perfect match). We compared our method with other available segmentation techniques in term of achieved performance over the reference data sets. FogBank outperformed all related algorithms. The accuracy has also been visually verified on data sets with 14 cell lines across 3 imaging modalities leading to 876 segmentation evaluation images. FogBank produces single cell segmentation from confluent cell

Cell-specific expression of plant nutrient transporter genes in orchid mycorrhizae.

Science.gov (United States)

Fochi, Valeria; Falla, Nicole; Girlanda, Mariangela; Perotto, Silvia; Balestrini, Raffaella

2017-10-01

Orchid mycorrhizal protocorms and roots are heterogeneous structures composed of different plant cell-types, where cells colonized by intracellular fungal coils (the pelotons) are close to non-colonized plant cells. Moreover, the fungal coils undergo rapid turnover inside the colonized cells, so that plant cells containing coils at different developmental stages can be observed in the same tissue section. Here, we have investigated by laser microdissection (LMD) the localization of specific plant gene transcripts in different cell-type populations collected from mycorrhizal protocorms and roots of the Mediterranean orchid Serapias vomeracea colonized by Tulasnella calospora. RNAs extracted from the different cell-type populations have been used to study plant gene expression, focusing on genes potentially involved in N uptake and transport and previously identified as up-regulated in symbiotic protocorms. Results clearly showed that some plant N transporters are differentially expressed in cells containing fungal coils at different developmental stages, as well as in non-colonized cells, and allowed the identification of new functional markers associated to coil-containing cells. Copyright © 2017 Elsevier B.V. All rights reserved.

Animal and plant stem cells concepts, propagation and engineering

CERN Document Server

Pavlović, Mirjana

2017-01-01

This book provides a multifaceted look into the world of stem cells and explains the similarities and differences between plant and human stem cells. It explores the intersection between animals and plants and explains their cooperative role in bioengineering studies. The book treats both theoretical and practical aspects of stem cell research. It covers the advantages and limitations of many common applications related to stem cells: their sources, categories, engineering of these cells, reprogramming of their functions, and their role as novel cellular therapeutic approach. Written by experts in the field, the book focuses on aspects of stem cells ranging from expansion-propagation to metabolic reprogramming. It introduces the emergence of cancer stem cells and different modalities in targeted cancer stem cell therapies. It is a valuable source of fresh information for academics and researchers, examining molecular mechanisms of animal and plant stem cell regulation and their usage for therapeutic applicati...

Cell-based therapies and imaging in cardiology.

Science.gov (United States)

Bengel, Frank M; Schachinger, Volker; Dimmeler, Stefanie

2005-12-01

Cell therapy for cardiac repair has emerged as one of the most exciting and promising developments in cardiovascular medicine. Evidence from experimental and clinical studies is increasing that this innovative treatment will influence clinical practice in the future. But open questions and controversies with regard to the basic mechanisms of this therapy continue to exist and emphasise the need for specific techniques to visualise the mechanisms and success of therapy in vivo. Several non-invasive imaging approaches which aim at tracking of transplanted cells in the heart have been introduced. Among these are direct labelling of cells with radionuclides or paramagnetic agents, and the use of reporter genes for imaging of cell transplantation and differentiation. Initial studies have suggested that these molecular imaging techniques have great potential. Integration of cell imaging into studies of cardiac cell therapy holds promise to facilitate further growth of the field towards a broadly clinically useful application.

Cell-based therapies and imaging in cardiology

Energy Technology Data Exchange (ETDEWEB)

Bengel, Frank M. [Technische Universitaet Muenchen, Nuklearmedizinische Klinik und Poliklinik, Munich (Germany); Schachinger, Volker; Dimmeler, Stefanie [University of Frankfurt, Department of Molecular Cardiology, Frankfurt (Germany)

2005-12-01

Cell therapy for cardiac repair has emerged as one of the most exciting and promising developments in cardiovascular medicine. Evidence from experimental and clinical studies is increasing that this innovative treatment will influence clinical practice in the future. But open questions and controversies with regard to the basic mechanisms of this therapy continue to exist and emphasise the need for specific techniques to visualise the mechanisms and success of therapy in vivo. Several non-invasive imaging approaches which aim at tracking of transplanted cells in the heart have been introduced. Among these are direct labelling of cells with radionuclides or paramagnetic agents, and the use of reporter genes for imaging of cell transplantation and differentiation. Initial studies have suggested that these molecular imaging techniques have great potential. Integration of cell imaging into studies of cardiac cell therapy holds promise to facilitate further growth of the field towards a broadly clinically useful application. (orig.)

Prospects for advanced coal-fuelled fuel cell power plants

International Nuclear Information System (INIS)

Jansen, D.; Laag, P.C. van der; Oudhuis, A.B.J.; Ribberink, J.S.

1994-01-01

As part of ECN's in-house R and D programmes on clean energy conversion systems with high efficiencies and low emissions, system assessment studies have been carried out on coal gasification power plants integrated with high-temperature fuel cells (IGFC). The studies also included the potential to reduce CO 2 emissions, and to find possible ways for CO 2 extraction and sequestration. The development of this new type of clean coal technology for large-scale power generation is still far off. A significant market share is not envisaged before the year 2015. To assess the future market potential of coal-fuelled fuel cell power plants, the promise of this fuel cell technology was assessed against the performance and the development of current state-of-the-art large-scale power generation systems, namely the pulverized coal-fired power plants and the integrated coal gasification combined cycle (IGCC) power plants. With the anticipated progress in gas turbine and gas clean-up technology, coal-fuelled fuel cell power plants will have to face severe competition from advanced IGCC power plants, despite their higher efficiency. (orig.)

Structural Studies of Complex Carbohydrates of Plant Cell Walls

Energy Technology Data Exchange (ETDEWEB)

Darvill, Alan [Univ. of Georgia, Athens, GA (United States); Hahn, Michael G. [Univ. of Georgia, Athens, GA (United States); O' Neill, Malcolm A. [Univ. of Georgia, Athens, GA (United States); York, William S. [Univ. of Georgia, Athens, GA (United States)

2015-02-17

Most of the solar energy captured by land plants is converted into the polysaccharides (cellulose, hemicellulose, and pectin) that are the predominant components of the cell wall. These walls, which account for the bulk of plant biomass, have numerous roles in the growth and development of plants. Moreover, these walls have a major impact on human life as they are a renewable source of biomass, a source of diverse commercially useful polymers, a major component of wood, and a source of nutrition for humans and livestock. Thus, understanding the molecular mechanisms that lead to wall assembly and how cell walls and their component polysaccharides contribute to plant growth and development is essential to improve and extend the productivity and value of plant materials. The proposed research will develop and apply advanced analytical and immunological techniques to study specific changes in the structures and interactions of the hemicellulosic and pectic polysaccharides that occur during differentiation and in response to genetic modification and chemical treatments that affect wall biosynthesis. These new techniques will make it possible to accurately characterize minute amounts of cell wall polysaccharides so that subtle changes in structure that occur in individual cell types can be identified and correlated to the physiological or developmental state of the plant. Successful implementation of this research will reveal fundamental relationships between polysaccharide structure, cell wall architecture, and cell wall functions.

Raman imaging to investigate ultrastructure and composition of plant cell walls : distribution of lignin and cellulose in black spruce wood (Picea mariana)

Science.gov (United States)

Umesh P. Agarwal

2006-01-01

A detailed understanding of the structural organization of the cell wall of vascular plants is important from both the perspectives of plant biology and chemistry and of commercial utilization. A state-of-the-art 633-nm laser-based confocal Raman microscope was used to determine the distribution of cell wall components in the cross section of black spruce wood in situ...

Nanobiotechnology meets plant cell biology: Carbon nanotubes as organelle targeting nanocarriers

KAUST Repository

Serag, Maged F.; Kaji, Noritada; Habuchi, Satoshi; Bianco, Alberto; Baba, Yoshinobu

2013-01-01

For years, nanotechnology has shown great promise in the fields of biomedical and biotechnological sciences and medical research. In this review, we demonstrate its versatility and applicability in plant cell biology studies. Specifically, we discuss the ability of functionalized carbon nanotubes to penetrate the plant cell wall, target specific organelles, probe protein-carrier activity and induce organelle recycling in plant cells. We also, shed light on prospective applications of carbon nanomaterials in cell biology and plant cell transformation. © 2013 The Royal Society of Chemistry.

Preparation of Single Cells for Imaging Mass Spectrometry

Energy Technology Data Exchange (ETDEWEB)

Berman, E S; Fortson, S L; Kulp, K S; Checchi, K D; Wu, L; Felton, J S; Wu, K J

2007-10-24

Characterizing chemical changes within single cells is important for determining fundamental mechanisms of biological processes that will lead to new biological insights and improved disease understanding. Imaging biological systems with mass spectrometry (MS) has gained popularity in recent years as a method for creating precise chemical maps of biological samples. In order to obtain high-quality mass spectral images that provide relevant molecular information about individual cells, samples must be prepared so that salts and other cell-culture components are removed from the cell surface and the cell contents are rendered accessible to the desorption beam. We have designed a cellular preparation protocol for imaging MS that preserves the cellular contents for investigation and removes the majority of the interfering species from the extracellular matrix. Using this method, we obtain excellent imaging results and reproducibility in three diverse cell types: MCF7 human breast cancer cells, Madin-Darby canine kidney (MDCK) cells, and NIH/3T3 mouse fibroblasts. This preparation technique allows routine imaging MS analysis of cultured cells, allowing for any number of experiments aimed at furthering scientific understanding of molecular processes within individual cells.

Intelligent and interactive computer image of a nuclear power plant: The ImagIn project

International Nuclear Information System (INIS)

Haubensack, D.; Malvache, P.; Valleix, P.

1998-01-01

The ImagIn project consists in a method and a set of computer tools apt to bring perceptible and assessable improvements in the operational safety of a nuclear plant. Its aim is to design an information system that would maintain a highly detailed computerized representation of a nuclear plant in its initial state and throughout its in-service life. It is not a tool to drive or help driving the nuclear plant, but a tool that manages concurrent operations that modify the plant configuration in a very general was (maintenance for example). The configuration of the plant, as well as rules and constraints about it, are described in a object-oriented knowledge database, which is built using a generic ImagIn meta-model based on the semantical network theory. An inference engine works on this database and is connected to reality through interfaces to operators and captors on the installation; it verifies constantly in real-time the consistency of the database according to its inner rules, and reports eventual problems to concerned operators. A special effort is made on interfaces to provide natural and intuitive tools (using virtual reality, natural language, voice recognition and synthesis). A laboratory application on a fictive but realistic installation already exists and is used to simulate various tests and scenarii. A real application is being constructed on Siloe, an experimental reactor of the CEA. (author)

Myosin-Powered Membrane Compartment Drives Cytoplasmic Streaming, Cell Expansion and Plant Development.

Science.gov (United States)

Peremyslov, Valera V; Cole, Rex A; Fowler, John E; Dolja, Valerian V

2015-01-01

Using genetic approaches, particle image velocimetry and an inert tracer of cytoplasmic streaming, we have made a mechanistic connection between the motor proteins (myosins XI), cargo transported by these motors (distinct endomembrane compartment defined by membrane-anchored MyoB receptors) and the process of cytoplasmic streaming in plant cells. It is shown that the MyoB compartment in Nicotiana benthamiana is highly dynamic moving with the mean velocity of ~3 μm/sec. In contrast, Golgi, mitochondria, peroxisomes, carrier vesicles and a cytosol flow tracer share distinct velocity profile with mean velocities of 0.6-1.5 μm/sec. Dominant negative inhibition of the myosins XI or MyoB receptors using overexpression of the N. benthamiana myosin cargo-binding domain or MyoB myosin-binding domain, respectively, resulted in velocity reduction for not only the MyoB compartment, but also each of the tested organelles, vesicles and cytoplasmic streaming. Furthermore, the extents of this reduction were similar for each of these compartments suggesting that MyoB compartment plays primary role in cytosol dynamics. Using gene knockout analysis in Arabidopsis thaliana, it is demonstrated that inactivation of MyoB1-4 results in reduced velocity of mitochondria implying slower cytoplasmic streaming. It is also shown that myosins XI and MyoB receptors genetically interact to contribute to cell expansion, plant growth, morphogenesis and proper onset of flowering. These results support a model according to which myosin-dependent, MyoB receptor-mediated transport of a specialized membrane compartment that is conserved in all land plants drives cytoplasmic streaming that carries organelles and vesicles and facilitates cell growth and plant development.

Investigation Study on Gamma Ray Imaging Technology for Nuclear Power Plant Decommissioning

Energy Technology Data Exchange (ETDEWEB)

Lee, Sang Guk; Jeong, Woo Tae [Machinery and Materials Laboratory, Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

2014-10-15

The gamma ray imaging system provides an estimated dose-rate of the source at 30 cm above. The gamma detector is a terbium activated glass scintillator. The system is capable of producing a color two dimensional image of a radiation field superimposed on a black and white visual image. The system used in US power plants consists of a portable sensor head that contains both gamma ray and visual imaging systems and a portable control computer. The gamma ray imaging system has been successfully used as an ALARA tool for identifying source terms and determining the adequacy of existing shielding. Because the control system can be positioned away from the camera, the radiation exposure to personnel can be reduced without extensive shielding requirements. The gamma ray imaging system has been used to date in the decommissioning of Maine Yankee, Big Rock point,Trojan, San Onofre1, and Millstone 1. The equipment has also been used at normal refueling outages at a number of commercial nuclear power plants and at several Department of Energy Decommissioning sites. This paper is intended to review the applicability of gamma ray imaging system as decommissioning tool. In order to review the actual applicability, we are going to introduce applications for US power plants.

Sonication reduces the attachment of Salmonella Typhimurium ATCC 14028 cells to bacterial cellulose-based plant cell wall models and cut plant material.

Science.gov (United States)

Tan, Michelle S F; Rahman, Sadequr; Dykes, Gary A

2017-04-01

This study investigated the removal of bacterial surface structures, particularly flagella, using sonication, and examined its effect on the attachment of Salmonella Typhimurium ATCC 14028 cells to plant cell walls. S. Typhimurium ATCC 14028 cells were subjected to sonication at 20 kHz to remove surface structures without affecting cell viability. Effective removal of flagella was determined by staining flagella of sonicated cells with Ryu's stain and enumerating the flagella remaining by direct microscopic counting. The attachment of sonicated S. Typhimurium cells to bacterial cellulose-based plant cell wall models and cut plant material (potato, apple, lettuce) was then evaluated. Varying concentrations of pectin and/or xyloglucan were used to produce a range of bacterial cellulose-based plant cell wall models. As compared to the non-sonicated controls, sonicated S. Typhimurium cells attached in significantly lower numbers (between 0.5 and 1.0 log CFU/cm 2 ) to all surfaces except to the bacterial cellulose-only composite without pectin and xyloglucan. Since attachment of S. Typhimurium to the bacterial cellulose-only composite was not affected by sonication, this suggests that bacterial surface structures, particularly flagella, could have specific interactions with pectin and xyloglucan. This study indicates that sonication may have potential applications for reducing Salmonella attachment during the processing of fresh produce. Copyright © 2016 Elsevier Ltd. All rights reserved.

Plant cell tissue culture: A potential source of chemicals

Energy Technology Data Exchange (ETDEWEB)

Scott, C.D.; Dougall, D.K.

1987-08-01

Higher plants produce many industrially important products. Among these are drugs and medicinal chemicals, essential oils and flavors, vegetable oils and fats, fine and specialty chemicals, and even some commodity chemicals. Although, currently, whole-plant extraction is the primary means of harvesting these materials, the advent of plant cell tissue culture could be a much more effective method of producing many types of phytochemicals. The use of immobilized plant cells in an advanced bioreactor configuration with excretion of the product into the reactor medium may represent the most straightforward way of commercializing such techniques for lower-value chemicals. Important research and development opportunities in this area include screening for plant cultures for nonmedical, lower-value chemicals; understanding and controlling plant cell physiology and biochemistry; optimizing effective immobilization methods; developing more efficient bioreactor concepts; and perfecting product extraction and purification techniques. 62 refs., 2 figs.

Plant cell culture initiation

NARCIS (Netherlands)

Hall, R.D.

2000-01-01

The use of cultured plant cells in either organized or unorganized form has increased vey considerably in the last 10-15 yr. Many new technologies have been developed and applications in both fundamental and applied research have led to the development of some powerful tools for improving our

Profiling pleural effusion cells by a diffraction imaging method

Science.gov (United States)

Al-Qaysi, Safaa; Hong, Heng; Wen, Yuhua; Lu, Jun Q.; Feng, Yuanming; Hu, Xin-Hua

2018-02-01

Assay of cells in pleural effusion (PE) is an important means of disease diagnosis. Conventional cytology of effusion samples, however, has low sensitivity and depends heavily on the expertise of cytopathologists. We applied a polarization diffraction imaging flow cytometry method on effusion cells to investigate their features. Diffraction imaging of the PE cell samples has been performed on 6000 to 12000 cells for each effusion cell sample of three patients. After prescreening to remove images by cellular debris and aggregated non-cellular particles, the image textures were extracted with a gray level co-occurrence matrix (GLCM) algorithm. The distribution of the imaged cells in the GLCM parameters space was analyzed by a Gaussian Mixture Model (GMM) to determine the number of clusters among the effusion cells. These results yield insight on textural features of diffraction images and related cellular morphology in effusion samples and can be used toward the development of a label-free method for effusion cells assay.

Measuring the Mechanical Properties of Plant Cell Walls

Directory of Open Access Journals (Sweden)

Hannes Vogler

2015-03-01

Full Text Available The size, shape and stability of a plant depend on the flexibility and integrity of its cell walls, which, at the same time, need to allow cell expansion for growth, while maintaining mechanical stability. Biomechanical studies largely vanished from the focus of plant science with the rapid progress of genetics and molecular biology since the mid-twentieth century. However, the development of more sensitive measurement tools renewed the interest in plant biomechanics in recent years, not only to understand the fundamental concepts of growth and morphogenesis, but also with regard to economically important areas in agriculture, forestry and the paper industry. Recent advances have clearly demonstrated that mechanical forces play a crucial role in cell and organ morphogenesis, which ultimately define plant morphology. In this article, we will briefly review the available methods to determine the mechanical properties of cell walls, such as atomic force microscopy (AFM and microindentation assays, and discuss their advantages and disadvantages. But we will focus on a novel methodological approach, called cellular force microscopy (CFM, and its automated successor, real-time CFM (RT-CFM.

A Model-Based Approach to Recovering the Structure of a Plant from Images

KAUST Repository

Ward, Ben

2015-03-19

We present a method for recovering the structure of a plant directly from a small set of widely-spaced images for automated analysis of phenotype. Structure recovery is more complex than shape estimation, but the resulting structure estimate is more closely related to phenotype than is a 3D geometric model. The method we propose is applicable to a wide variety of plants, but is demonstrated on wheat. Wheat is composed of thin elements with few identifiable features, making it difficult to analyse using standard feature matching techniques. Our method instead analyses the structure of plants using only their silhouettes. We employ a generate-and-test method, using a database of manually modelled leaves and a model for their composition to synthesise plausible plant structures which are evaluated against the images. The method is capable of efficiently recovering accurate estimates of plant structure in a wide variety of imaging scenarios, without manual intervention.

A Model-Based Approach to Recovering the Structure of a Plant from Images

KAUST Repository

Ward, Ben; Bastian, John; van den Hengel, Anton; Pooley, Daniel; Bari, Rajendra; Berger, Bettina; Tester, Mark A.

2015-01-01

We present a method for recovering the structure of a plant directly from a small set of widely-spaced images for automated analysis of phenotype. Structure recovery is more complex than shape estimation, but the resulting structure estimate is more closely related to phenotype than is a 3D geometric model. The method we propose is applicable to a wide variety of plants, but is demonstrated on wheat. Wheat is composed of thin elements with few identifiable features, making it difficult to analyse using standard feature matching techniques. Our method instead analyses the structure of plants using only their silhouettes. We employ a generate-and-test method, using a database of manually modelled leaves and a model for their composition to synthesise plausible plant structures which are evaluated against the images. The method is capable of efficiently recovering accurate estimates of plant structure in a wide variety of imaging scenarios, without manual intervention.

Plant Cell Division Analyzed by Transient Agrobacterium-Mediated Transformation of Tobacco BY-2 Cells.

Science.gov (United States)

Buschmann, Henrik

2016-01-01

The continuing analysis of plant cell division will require additional protein localization studies. This is greatly aided by GFP-technology, but plant transformation and the maintenance of transgenic lines can present a significant technical bottleneck. In this chapter I describe a method for the Agrobacterium-mediated genetic transformation of tobacco BY-2 cells. The method allows for the microscopic analysis of fluorescence-tagged proteins in dividing cells in within 2 days after starting a coculture. This transient transformation procedure requires only standard laboratory equipment. It is hoped that this rapid method would aid researchers conducting live-cell localization studies in plant mitosis and cytokinesis.

Imaging plant leaves to determine changes in radioactive contamination status in Fukushima, Japan.

Science.gov (United States)

Nakajima, Hiroo; Fujiwara, Mamoru; Tanihata, Isao; Saito, Tadashi; Matsuda, Norihiro; Todo, Takeshi

2014-05-01

The chemical composition of plant leaves often reflects environmental contamination. The authors analyzed images of plant leaves to investigate the regional radioactivity ecology resulting from the 2011 accident at the Fukushima No. 1 nuclear power plant, Japan. The present study is not an evaluation of the macro radiation dose per weight, which has been performed previously, but rather an image analysis of the radioactive dose per leaf, allowing the capture of various gradual changes in radioactive contamination as a function of elapsed time. In addition, the leaf analysis method has potential applications in the decontamination of food plants or other materials.

Eduard Strasburger (1844-1912): founder of modern plant cell biology.

Science.gov (United States)

Volkmann, Dieter; Baluška, František; Menzel, Diedrik

2012-10-01

Eduard Strasburger, director of the Botany Institute and the Botanical Garden at the University of Bonn from 1881 to 1912, was one of the most admirable scientists in the field of plant biology, not just as the founder of modern plant cell biology but in addition as an excellent teacher who strongly believed in "education through science." He contributed to plant cell biology by discovering the discrete stages of karyokinesis and cytokinesis in algae and higher plants, describing cytoplasmic streaming in different systems, and reporting on the growth of the pollen tube into the embryo sac and guidance of the tube by synergides. Strasburger raised many problems which are hot spots in recent plant cell biology, e.g., structure and function of the plasmodesmata in relation to phloem loading (Strasburger cells) and signaling, mechanisms of cell plate formation, vesicle trafficking as a basis for most important developmental processes, and signaling related to fertilization.

AUTOMATED CELL SEGMENTATION WITH 3D FLUORESCENCE MICROSCOPY IMAGES.

Science.gov (United States)

Kong, Jun; Wang, Fusheng; Teodoro, George; Liang, Yanhui; Zhu, Yangyang; Tucker-Burden, Carol; Brat, Daniel J

2015-04-01

A large number of cell-oriented cancer investigations require an effective and reliable cell segmentation method on three dimensional (3D) fluorescence microscopic images for quantitative analysis of cell biological properties. In this paper, we present a fully automated cell segmentation method that can detect cells from 3D fluorescence microscopic images. Enlightened by fluorescence imaging techniques, we regulated the image gradient field by gradient vector flow (GVF) with interpolated and smoothed data volume, and grouped voxels based on gradient modes identified by tracking GVF field. Adaptive thresholding was then applied to voxels associated with the same gradient mode where voxel intensities were enhanced by a multiscale cell filter. We applied the method to a large volume of 3D fluorescence imaging data of human brain tumor cells with (1) small cell false detection and missing rates for individual cells; and (2) trivial over and under segmentation incidences for clustered cells. Additionally, the concordance of cell morphometry structure between automated and manual segmentation was encouraging. These results suggest a promising 3D cell segmentation method applicable to cancer studies.

Cryo-imaging of fluorescently labeled single cells in a mouse

Science.gov (United States)

Steyer, Grant J.; Roy, Debashish; Salvado, Olivier; Stone, Meredith E.; Wilson, David L.

2009-02-01

We developed a cryo-imaging system to provide single-cell detection of fluorescently labeled cells in mouse, with particular applicability to stem cells and metastatic cancer. The Case cryoimaging system consists of a fluorescence microscope, robotic imaging positioner, customized cryostat, PC-based control system, and visualization/analysis software. The system alternates between sectioning (10-40 μm) and imaging, collecting color brightfield and fluorescent blockface image volumes >60GB. In mouse experiments, we imaged quantum-dot labeled stem cells, GFP-labeled cancer and stem cells, and cell-size fluorescent microspheres. To remove subsurface fluorescence, we used a simplified model of light-tissue interaction whereby the next image was scaled, blurred, and subtracted from the current image. We estimated scaling and blurring parameters by minimizing entropy of subtracted images. Tissue specific attenuation parameters were found [uT : heart (267 +/- 47.6 μm), liver (218 +/- 27.1 μm), brain (161 +/- 27.4 μm)] to be within the range of estimates in the literature. "Next image" processing removed subsurface fluorescence equally well across multiple tissues (brain, kidney, liver, adipose tissue, etc.), and analysis of 200 microsphere images in the brain gave 97+/-2% reduction of subsurface fluorescence. Fluorescent signals were determined to arise from single cells based upon geometric and integrated intensity measurements. Next image processing greatly improved axial resolution, enabled high quality 3D volume renderings, and improved enumeration of single cells with connected component analysis by up to 24%. Analysis of image volumes identified metastatic cancer sites, found homing of stem cells to injury sites, and showed microsphere distribution correlated with blood flow patterns. We developed and evaluated cryo-imaging to provide single-cell detection of fluorescently labeled cells in mouse. Our cryo-imaging system provides extreme (>60GB), micron

Optofluidic fluorescent imaging cytometry on a cell phone.

Science.gov (United States)

Zhu, Hongying; Mavandadi, Sam; Coskun, Ahmet F; Yaglidere, Oguzhan; Ozcan, Aydogan

2011-09-01

Fluorescent microscopy and flow cytometry are widely used tools in biomedical sciences. Cost-effective translation of these technologies to remote and resource-limited environments could create new opportunities especially for telemedicine applications. Toward this direction, here we demonstrate the integration of imaging cytometry and fluorescent microscopy on a cell phone using a compact, lightweight, and cost-effective optofluidic attachment. In this cell-phone-based optofluidic imaging cytometry platform, fluorescently labeled particles or cells of interest are continuously delivered to our imaging volume through a disposable microfluidic channel that is positioned above the existing camera unit of the cell phone. The same microfluidic device also acts as a multilayered optofluidic waveguide and efficiently guides our excitation light, which is butt-coupled from the side facets of our microfluidic channel using inexpensive light-emitting diodes. Since the excitation of the sample volume occurs through guided waves that propagate perpendicular to the detection path, our cell-phone camera can record fluorescent movies of the specimens as they are flowing through the microchannel. The digital frames of these fluorescent movies are then rapidly processed to quantify the count and the density of the labeled particles/cells within the target solution of interest. We tested the performance of our cell-phone-based imaging cytometer by measuring the density of white blood cells in human blood samples, which provided a decent match to a commercially available hematology analyzer. We further characterized the imaging quality of the same platform to demonstrate a spatial resolution of ~2 μm. This cell-phone-enabled optofluidic imaging flow cytometer could especially be useful for rapid and sensitive imaging of bodily fluids for conducting various cell counts (e.g., toward monitoring of HIV+ patients) or rare cell analysis as well as for screening of water quality in

Analysis of live cell images: Methods, tools and opportunities.

Science.gov (United States)

Nketia, Thomas A; Sailem, Heba; Rohde, Gustavo; Machiraju, Raghu; Rittscher, Jens

2017-02-15

Advances in optical microscopy, biosensors and cell culturing technologies have transformed live cell imaging. Thanks to these advances live cell imaging plays an increasingly important role in basic biology research as well as at all stages of drug development. Image analysis methods are needed to extract quantitative information from these vast and complex data sets. The aim of this review is to provide an overview of available image analysis methods for live cell imaging, in particular required preprocessing image segmentation, cell tracking and data visualisation methods. The potential opportunities recent advances in machine learning, especially deep learning, and computer vision provide are being discussed. This review includes overview of the different available software packages and toolkits. Copyright © 2017. Published by Elsevier Inc.

Förster resonance energy transfer demonstrates a flavonoid metabolon in living plant cells that displays competitive interactions between enzymes

NARCIS (Netherlands)

Crosby, K.C.; Pietraszewska-Bogiel, A.; Gadella (jr.), T.W.J.; Winkel, B.S.J.

2011-01-01

We have used Förster resonance energy transfer detected by fluorescence lifetime imaging microscopy (FLIM-FRET) to provide the first evidence from living plants cells for the existence of a flavonoid metabolon. The distribution of flux within this system may be regulated by the direct competition of

On the track of transfer cell formation by specialized plant-parasitic nematodes.

Science.gov (United States)

Rodiuc, Natalia; Vieira, Paulo; Banora, Mohamed Youssef; de Almeida Engler, Janice

2014-01-01

Transfer cells are ubiquitous plant cells that play an important role in plant development as well as in responses to biotic and abiotic stresses. They are highly specialized and differentiated cells playing a central role in the acquisition, distribution and exchange of nutrients. Their unique structural traits are characterized by augmented ingrowths of invaginated secondary wall material, unsheathed by an amplified area of plasma membrane enriched in a suite of solute transporters. Similar morphological features can be perceived in vascular root feeding cells induced by sedentary plant-parasitic nematodes, such as root-knot and cyst nematodes, in a wide range of plant hosts. Despite their close phylogenetic relationship, these obligatory biotrophic plant pathogens engage different approaches when reprogramming root cells into giant cells or syncytia, respectively. Both nematode feeding-cells types will serve as the main source of nutrients until the end of the nematode life cycle. In both cases, these nematodes are able to remarkably maneuver and reprogram plant host cells. In this review we will discuss the structure, function and formation of these specialized multinucleate cells that act as nutrient transfer cells accumulating and synthesizing components needed for survival and successful offspring of plant-parasitic nematodes. Plant cells with transfer-like functions are also a renowned subject of interest involving still poorly understood molecular and cellular transport processes.

On the track of transfer cells formation by specialized plant-parasitic nematodes

Directory of Open Access Journals (Sweden)

Natalia eRodiuc

2014-05-01

Full Text Available Transfer cells are ubiquitous plant cells that play an important role in plant development as well as in responses to biotic and abiotic stresses. They are highly specialized and differentiated cells playing a central role in the acquisition, distribution and exchange of nutrients. Their unique structural traits are characterized by augmented ingrowths of invaginated secondary wall material, unsheathed by an amplified area of plasma membrane enriched in a suite of solute transporters. Similar morphological features can be perceived in vascular root feeding cells induced by sedentary plant-parasitic nematodes, such as root-knot and cyst nematodes, in a wide range of plant hosts. Despite their close phylogenetic relationship, these obligatory biotrophic plant pathogens engage different approaches when reprogramming root cells into giant cells or syncytia, respectively. Both nematode feeding-cells types will serve as the main source of nutrients until the end of the nematode life cycle. In both cases, these nematodes are able to remarkably maneuver and reprogram plant host cells. In this review we will discuss the structural, functional and morphogenetic characteristics function and formation of these specialized multinucleate cells that act as nutrient transfer cells to accumulate and synthesize components needed for survival and successful offspring of plant-parasitic nematodes. Plant cells with transfer-like functions are also a renowned subject of interest involving still poorly understood molecular and cellular transport processes.

Progress and prospects for phosphoric acid fuel cell power plants

Energy Technology Data Exchange (ETDEWEB)

Bonville, L.J.; Scheffler, G.W.; Smith, M.J. [International Fuel Cells Corp., South Windsor, CT (United States)

1996-12-31

International Fuel Cells (IFC) has developed the fuel cell power plant as a new, on-site power generation source. IFC`s commercial fuel cell product is the 200-kW PC25{trademark} power plant. To date over 100 PC25 units have been manufactured. Fleet operating time is in excess of one million hours. Individual units of the initial power plant model, the PC25 A, have operated for more than 30,000 hours. The first model {open_quotes}C{close_quotes} power plant has over 10,000 hours of operation. The manufacturing, application and operation of this power plant fleet has established a firm base for design and technology development in terms of a clear understanding of the requirements for power plant reliability and durability. This fleet provides the benchmark against which power plant improvements must be measured.

Multimodal quantitative phase and fluorescence imaging of cell apoptosis

Science.gov (United States)

Fu, Xinye; Zuo, Chao; Yan, Hao

2017-06-01

Fluorescence microscopy, utilizing fluorescence labeling, has the capability to observe intercellular changes which transmitted and reflected light microscopy techniques cannot resolve. However, the parts without fluorescence labeling are not imaged. Hence, the processes simultaneously happen in these parts cannot be revealed. Meanwhile, fluorescence imaging is 2D imaging where information in the depth is missing. Therefore the information in labeling parts is also not complete. On the other hand, quantitative phase imaging is capable to image cells in 3D in real time through phase calculation. However, its resolution is limited by the optical diffraction and cannot observe intercellular changes below 200 nanometers. In this work, fluorescence imaging and quantitative phase imaging are combined to build a multimodal imaging system. Such system has the capability to simultaneously observe the detailed intercellular phenomenon and 3D cell morphology. In this study the proposed multimodal imaging system is used to observe the cell behavior in the cell apoptosis. The aim is to highlight the limitations of fluorescence microscopy and to point out the advantages of multimodal quantitative phase and fluorescence imaging. The proposed multimodal quantitative phase imaging could be further applied in cell related biomedical research, such as tumor.

Plant cell walls to ethanol.

Science.gov (United States)

Conversion of plant cell walls to ethanol constitutes generation 2 bioethanol production. The process consists of several steps: biomass selection/genetic modification, physiochemical pretreatment, enzymatic saccharification, fermentation, and separation. Ultimately, it is desired to combine as man...

A probabilistic cell model in background corrected image sequences for single cell analysis

Directory of Open Access Journals (Sweden)

Fieguth Paul

2010-10-01

Full Text Available Abstract Background Methods of manual cell localization and outlining are so onerous that automated tracking methods would seem mandatory for handling huge image sequences, nevertheless manual tracking is, astonishingly, still widely practiced in areas such as cell biology which are outside the influence of most image processing research. The goal of our research is to address this gap by developing automated methods of cell tracking, localization, and segmentation. Since even an optimal frame-to-frame association method cannot compensate and recover from poor detection, it is clear that the quality of cell tracking depends on the quality of cell detection within each frame. Methods Cell detection performs poorly where the background is not uniform and includes temporal illumination variations, spatial non-uniformities, and stationary objects such as well boundaries (which confine the cells under study. To improve cell detection, the signal to noise ratio of the input image can be increased via accurate background estimation. In this paper we investigate background estimation, for the purpose of cell detection. We propose a cell model and a method for background estimation, driven by the proposed cell model, such that well structure can be identified, and explicitly rejected, when estimating the background. Results The resulting background-removed images have fewer artifacts and allow cells to be localized and detected more reliably. The experimental results generated by applying the proposed method to different Hematopoietic Stem Cell (HSC image sequences are quite promising. Conclusion The understanding of cell behavior relies on precise information about the temporal dynamics and spatial distribution of cells. Such information may play a key role in disease research and regenerative medicine, so automated methods for observation and measurement of cells from microscopic images are in high demand. The proposed method in this paper is capable

Study of Plant Cell Wall Polymers Affected by Metal Accumulation Using Stimulated Raman Scattering Microscopy

Energy Technology Data Exchange (ETDEWEB)

Ding, Shi-You [Harvard Univ., Cambridge, MA (United States)

2015-03-02

This project aims to employ newly-developed chemical imaging techniques to measure, in real-time, the concentration, dynamics and spatial distribution of plant cell wall polymers during biomass growth with inoculation of transgenic symbiotic fungi, and to explore a new pathway of delivering detoxified metal to plant apoplast using transgenic symbiotic fungi, which will enhance metal accumulation from soil, and potentially these metals may in turn be used as catalysts to improve the efficiency of biomass conversion to biofuels. The proposed new pathway of biomass production will: 1) benefit metal and radionuclide contaminant mobility in subsurface environments, and 2) potentially improve biomass production and process for bioenergy

Low cost delivery of proteins bioencapsulated in plant cells to human non-immune or immune modulatory cells.

Science.gov (United States)

Xiao, Yuhong; Kwon, Kwang-Chul; Hoffman, Brad E; Kamesh, Aditya; Jones, Noah T; Herzog, Roland W; Daniell, Henry

2016-02-01

Targeted oral delivery of GFP fused with a GM1 receptor binding protein (CTB) or human cell penetrating peptide (PTD) or dendritic cell peptide (DCpep) was investigated. Presence of GFP(+) intact plant cells between villi of ileum confirm their protection in the digestive system from acids/enzymes. Efficient delivery of GFP to gut-epithelial cells by PTD or CTB and to M cells by all these fusion tags confirm uptake of GFP in the small intestine. PTD fusion delivered GFP more efficiently to most tissues or organs than the other two tags. GFP was efficiently delivered to the liver by all fusion tags, likely through the gut-liver axis. In confocal imaging studies of human cell lines using purified GFP fused with different tags, GFP signal of DCpep-GFP was only detected within dendritic cells. PTD-GFP was only detected within kidney or pancreatic cells but not in immune modulatory cells (macrophages, dendritic, T, B, or mast cells). In contrast, CTB-GFP was detected in all tested cell types, confirming ubiquitous presence of GM1 receptors. Such low-cost oral delivery of protein drugs to sera, immune system or non-immune cells should dramatically lower their cost by elimination of prohibitively expensive fermentation, protein purification cold storage/transportation and increase patient compliance. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Deep Neural Networks Based Recognition of Plant Diseases by Leaf Image Classification

Directory of Open Access Journals (Sweden)

Srdjan Sladojevic

2016-01-01

Full Text Available The latest generation of convolutional neural networks (CNNs has achieved impressive results in the field of image classification. This paper is concerned with a new approach to the development of plant disease recognition model, based on leaf image classification, by the use of deep convolutional networks. Novel way of training and the methodology used facilitate a quick and easy system implementation in practice. The developed model is able to recognize 13 different types of plant diseases out of healthy leaves, with the ability to distinguish plant leaves from their surroundings. According to our knowledge, this method for plant disease recognition has been proposed for the first time. All essential steps required for implementing this disease recognition model are fully described throughout the paper, starting from gathering images in order to create a database, assessed by agricultural experts. Caffe, a deep learning framework developed by Berkley Vision and Learning Centre, was used to perform the deep CNN training. The experimental results on the developed model achieved precision between 91% and 98%, for separate class tests, on average 96.3%.

Plant cell wall sugars: sweeteners for a bio-based economy.

Science.gov (United States)

Van de Wouwer, Dorien; Boerjan, Wout; Vanholme, Bartel

2018-02-12

Global warming and the consequent climate change is one of the major environmental challenges we are facing today. The driving force behind the rise in temperature is our fossil-based economy, which releases massive amounts of the greenhouse gas carbon dioxide into the atmosphere. In order to reduce greenhouse gas emission, we need to scale down our dependency on fossil resources, implying that we need other sources for energy and chemicals to feed our economy. Here, plants have an important role to play; by means of photosynthesis, plants capture solar energy to split water and fix carbon derived from atmospheric carbon dioxide. A significant fraction of the fixed carbon ends up as polysaccharides in the plant cell wall. Fermentable sugars derived from cell wall polysaccharides form an ideal carbon source for the production of bio-platform molecules. However, a major limiting factor in the use of plant biomass as feedstock for the bio-based economy is the complexity of the plant cell wall and its recalcitrance towards deconstruction. To facilitate the release of fermentable sugars during downstream biomass processing, the composition and structure of the cell wall can be engineered. Different strategies to reduce cell wall recalcitrance will be described in this review. The ultimate goal is to obtain a tailor-made biomass, derived from plants with a cell wall optimized for particular industrial or agricultural applications, without affecting plant growth and development. This article is protected by copyright. All rights reserved.

A new level set model for cell image segmentation

Science.gov (United States)

Ma, Jing-Feng; Hou, Kai; Bao, Shang-Lian; Chen, Chun

2011-02-01

In this paper we first determine three phases of cell images: background, cytoplasm and nucleolus according to the general physical characteristics of cell images, and then develop a variational model, based on these characteristics, to segment nucleolus and cytoplasm from their relatively complicated backgrounds. In the meantime, the preprocessing obtained information of cell images using the OTSU algorithm is used to initialize the level set function in the model, which can speed up the segmentation and present satisfactory results in cell image processing.

Accurate inference of shoot biomass from high-throughput images of cereal plants

Directory of Open Access Journals (Sweden)

Tester Mark

2011-02-01

Full Text Available Abstract With the establishment of advanced technology facilities for high throughput plant phenotyping, the problem of estimating plant biomass of individual plants from their two dimensional images is becoming increasingly important. The approach predominantly cited in literature is to estimate the biomass of a plant as a linear function of the projected shoot area of plants in the images. However, the estimation error from this model, which is solely a function of projected shoot area, is large, prohibiting accurate estimation of the biomass of plants, particularly for the salt-stressed plants. In this paper, we propose a method based on plant specific weight for improving the accuracy of the linear model and reducing the estimation bias (the difference between actual shoot dry weight and the value of the shoot dry weight estimated with a predictive model. For the proposed method in this study, we modeled the plant shoot dry weight as a function of plant area and plant age. The data used for developing our model and comparing the results with the linear model were collected from a completely randomized block design experiment. A total of 320 plants from two bread wheat varieties were grown in a supported hydroponics system in a greenhouse. The plants were exposed to two levels of hydroponic salt treatments (NaCl at 0 and 100 mM for 6 weeks. Five harvests were carried out. Each time 64 randomly selected plants were imaged and then harvested to measure the shoot fresh weight and shoot dry weight. The results of statistical analysis showed that with our proposed method, most of the observed variance can be explained, and moreover only a small difference between actual and estimated shoot dry weight was obtained. The low estimation bias indicates that our proposed method can be used to estimate biomass of individual plants regardless of what variety the plant is and what salt treatment has been applied. We validated this model on an independent

Plant Cell Adaptive Responses to Microgravity

Science.gov (United States)

Kordyum, Elizabeth; Kozeko, Liudmyla; Talalaev, Alexandr

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. In real microgravity in space flight under the more or less optimal conditions for plant growing, namely temperature, humidity, CO2, light intensity and directivity in the hardware angiosperm plants perform an “reproductive imperative”, i.e. they flower, fruit and yield viable seeds. 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

Role of proline in cell wall synthesis and plant development and its implications in plant ontogeny

Directory of Open Access Journals (Sweden)

POLAVARAPU BILHAN KAVI KISHOR

2015-07-01

Full Text Available Proline is a proteogenic amino acid and accumulates both under stress and non-stress conditions as a beneficial solute in plants. Recent discoveries point out that proline plays an important role in plant growth and differentiation across life cycle. It is a key determinant of many cell wall proteins that plays important roles in plant development. The role of extensins (EXTs, arabinogalactan proteins (AGPs and hydroxyproline- and proline-rich proteins (H/PRPs as important components of cell wall proteins that play pivotal roles in cell wall signal transduction cascades, plant development and stress tolerance is discussed in this review. Molecular insights are also provided here into the plausible roles of proline transporters modulating key events in plant development. In addition, the roles of proline during seed developmental transitions including storage protein synthesis are discussed.

Apoptotic induction of skin cancer cell death by plant extracts.

Science.gov (United States)

Thuncharoen, Walairat; Chulasiri, Malin; Nilwarangkoon, Sirinun; Nakamura, Yukio; Watanapokasin, Ramida

2013-01-01

The aim of the present study was to investigate the effects of plant extracts on cancer apoptotic induction. Human epidermoid carcinoma A431 cell line, obtained from the American Type Culture Collection (ATCC, Manassas, VA), was maintained in Dulbecco's Modified Eagle Medium (DMEM) supplemented with 10% fetal bovine serum (FBS) at 37 degrees C, 5% carbon dioxide (CO2). Plant extract solutions were obtained from S & J international enterprises public company limited. These plant extracts include 50% hydroglycol extracts from Etlingera elatior (Jack) R.M.Smith (torch ginger; EE), Rosa damascene (damask rose; DR) and Rafflesia kerrii Meijer (bua phut; RM). The cell viability, time and dose dependency were determined by MTT (3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay. A431 cells were treated with the plant extracts and stained with Hoechst 33342 fluorescent staining dye. Cell viability was demonstrated by the inhibitory concentration 50% (IC50). The anti-proliferative effects were shown to be dependent on time and dose. Typical characteristics of apoptosis which are cell morphological changes and chromatin condensation were clearly observed. The plant extracts was shown to be effective for anti-proliferation and induction of apoptosis cell death in skin cancer cells. Therefore, mechanisms underlying the cell death and its potential use for treatment of skin cancer will be further studied.

Detection of plant leaf diseases using image segmentation and soft computing techniques

Directory of Open Access Journals (Sweden)

Vijai Singh

2017-03-01

Full Text Available Agricultural productivity is something on which economy highly depends. This is the one of the reasons that disease detection in plants plays an important role in agriculture field, as having disease in plants are quite natural. If proper care is not taken in this area then it causes serious effects on plants and due to which respective product quality, quantity or productivity is affected. For instance a disease named little leaf disease is a hazardous disease found in pine trees in United States. Detection of plant disease through some automatic technique is beneficial as it reduces a large work of monitoring in big farms of crops, and at very early stage itself it detects the symptoms of diseases i.e. when they appear on plant leaves. This paper presents an algorithm for image segmentation technique which is used for automatic detection and classification of plant leaf diseases. It also covers survey on different diseases classification techniques that can be used for plant leaf disease detection. Image segmentation, which is an important aspect for disease detection in plant leaf disease, is done by using genetic algorithm.

1000kW phosphoric acid fuel cell power plant. Outline of the plant

Energy Technology Data Exchange (ETDEWEB)

Shinobe, Kenji; Suzuki, Kazuo; Kaneko, Hideo

1988-02-10

The outline of the 1000KW phosphoric acid fuel cell power plant, developed as part of the Moonlight plan, was described. The plant was composed of 4 stacks of 260KW DC output. They were devided into two train with 680V and 765A. The generation efficiency of the plant was 40% and more. Steam reforming of natural gas was used. As the fuel, fuel cell exhaust gas was used in composition with the natural gas. The DC-AC inverter had an efficiency of 96%. The capacity of hot water generator and demineralized water plant for cell cooling were 2t/h and 1.6t/h, respectively, and air-system was incorporated. In September of 1987, the plant has succeeded in 1000KW power generation, and put in operation now. Under the 100% loaded condition, each cell had a voltage of 0.7V with little variation, and the current was 200mA/cm/sup 2/. No problems were found in cooling conditions and in the control of interpole differential pressure. The reformer has been operated for 1200h scince its commisioning, and had experiences of 100 times on start up-shut down operations, the reformer also indicated good performances in the gas compositions. The starting time of 8h and the load follow-up rate 10%/min remain as the subjects for shortening. DC-AC conversion was good. The concentration of NOx and the noise level satisfied the target values. (12 figs, 1 tab)

Deep Learning Automates the Quantitative Analysis of Individual Cells in Live-Cell Imaging Experiments.

Science.gov (United States)

Van Valen, David A; Kudo, Takamasa; Lane, Keara M; Macklin, Derek N; Quach, Nicolas T; DeFelice, Mialy M; Maayan, Inbal; Tanouchi, Yu; Ashley, Euan A; Covert, Markus W

2016-11-01

Live-cell imaging has opened an exciting window into the role cellular heterogeneity plays in dynamic, living systems. A major critical challenge for this class of experiments is the problem of image segmentation, or determining which parts of a microscope image correspond to which individual cells. Current approaches require many hours of manual curation and depend on approaches that are difficult to share between labs. They are also unable to robustly segment the cytoplasms of mammalian cells. Here, we show that deep convolutional neural networks, a supervised machine learning method, can solve this challenge for multiple cell types across the domains of life. We demonstrate that this approach can robustly segment fluorescent images of cell nuclei as well as phase images of the cytoplasms of individual bacterial and mammalian cells from phase contrast images without the need for a fluorescent cytoplasmic marker. These networks also enable the simultaneous segmentation and identification of different mammalian cell types grown in co-culture. A quantitative comparison with prior methods demonstrates that convolutional neural networks have improved accuracy and lead to a significant reduction in curation time. We relay our experience in designing and optimizing deep convolutional neural networks for this task and outline several design rules that we found led to robust performance. We conclude that deep convolutional neural networks are an accurate method that require less curation time, are generalizable to a multiplicity of cell types, from bacteria to mammalian cells, and expand live-cell imaging capabilities to include multi-cell type systems.

A Public Image Database for Benchmark of Plant Seedling Classification Algorithms

DEFF Research Database (Denmark)

Giselsson, Thomas Mosgaard; Nyholm Jørgensen, Rasmus; Jensen, Peter Kryger

A database of images of approximately 960 unique plants belonging to 12 species at several growth stages is made publicly available. It comprises annotated RGB images with a physical resolution of roughly 10 pixels per mm. To standardise the evaluation of classification results obtained...

Automatic Cell Segmentation in Fluorescence Images of Confluent Cell Monolayers Using Multi-object Geometric Deformable Model

OpenAIRE

Yang, Zhen; Bogovic, John A.; Carass, Aaron; Ye, Mao; Searson, Peter C.; Prince, Jerry L.

2013-01-01

With the rapid development of microscopy for cell imaging, there is a strong and growing demand for image analysis software to quantitatively study cell morphology. Automatic cell segmentation is an important step in image analysis. Despite substantial progress, there is still a need to improve the accuracy, efficiency, and adaptability to different cell morphologies. In this paper, we propose a fully automatic method for segmenting cells in fluorescence images of confluent cell monolayers. T...

Plant cells oxidize hydroxylamines to NO

Science.gov (United States)

Rümer, Stefan; Gupta, Kapuganti Jagadis; Kaiser, Werner M.

2009-01-01

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). Here it is shown that tobacco cell suspensions emitted NO when hydroxylamine (HA) or salicylhydroxamate (SHAM), a frequently used AOX inhibitor, was added. NG-hydroxy-L-arginine, a putative intermediate in the NOS-reaction, gave no NO emission. Only a minor fraction (≤1%) of the added HA or SHAM was emitted as NO. 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. Unexpectedly, the addition of superoxide dismutase (SOD) to cell suspensions stimulated NO formation from hydroxylamines, and SOD alone (without cells) also catalysed the production of NO from HA or SHAM. NO production by SOD plus HA was higher in nitrogen than in air, but from SOD plus SHAM it was lower in nitrogen. Thus, SOD-catalysed NO formation from SHAM and from HA may involve different mechanisms. 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. PMID:19357430

Analysis of high-throughput plant image data with the information system IAP

Directory of Open Access Journals (Sweden)

Klukas Christian

2012-06-01

Full Text Available This work presents a sophisticated information system, the Integrated Analysis Platform (IAP, an approach supporting large-scale image analysis for different species and imaging systems. In its current form, IAP supports the investigation of Maize, Barley and Arabidopsis plants based on images obtained in different spectra.

A new level set model for cell image segmentation

International Nuclear Information System (INIS)

Ma Jing-Feng; Chen Chun; Hou Kai; Bao Shang-Lian

2011-01-01

In this paper we first determine three phases of cell images: background, cytoplasm and nucleolus according to the general physical characteristics of cell images, and then develop a variational model, based on these characteristics, to segment nucleolus and cytoplasm from their relatively complicated backgrounds. In the meantime, the preprocessing obtained information of cell images using the OTSU algorithm is used to initialize the level set function in the model, which can speed up the segmentation and present satisfactory results in cell image processing. (cross-disciplinary physics and related areas of science and technology)

Oral Delivery of Protein Drugs Bioencapsulated in Plant Cells.

Science.gov (United States)

Kwon, Kwang-Chul; Daniell, Henry

2016-08-01

Plants cells are now approved by the FDA for cost-effective production of protein drugs (PDs) in large-scale current Good Manufacturing Practice (cGMP) hydroponic growth facilities. In lyophilized plant cells, PDs are stable at ambient temperature for several years, maintaining their folding and efficacy. Upon oral delivery, PDs bioencapsulated in plant cells are protected in the stomach from acids and enzymes but are subsequently released into the gut lumen by microbes that digest the plant cell wall. The large mucosal area of the human intestine offers an ideal system for oral drug delivery. When tags (receptor-binding proteins or cell-penetrating peptides) are fused to PDs, they efficiently cross the intestinal epithelium and are delivered to the circulatory or immune system. Unique tags to deliver PDs to human immune or nonimmune cells have been developed recently. After crossing the epithelium, ubiquitous proteases cleave off tags at engineered sites. PDs are also delivered to the brain or retina by crossing the blood-brain or retinal barriers. This review highlights recent advances in PD delivery to treat Alzheimer's disease, diabetes, hypertension, Gaucher's or ocular diseases, as well as the development of affordable drugs by eliminating prohibitively expensive purification, cold chain and sterile delivery.

Integrating cell biology and proteomic approaches in plants.

Science.gov (United States)

Takáč, Tomáš; Šamajová, Olga; Šamaj, Jozef

2017-10-03

Significant improvements of protein extraction, separation, mass spectrometry and bioinformatics nurtured advancements of proteomics during the past years. The usefulness of proteomics in the investigation of biological problems can be enhanced by integration with other experimental methods from cell biology, genetics, biochemistry, pharmacology, molecular biology and other omics approaches including transcriptomics and metabolomics. This review aims to summarize current trends integrating cell biology and proteomics in plant science. Cell biology approaches are most frequently used in proteomic studies investigating subcellular and developmental proteomes, however, they were also employed in proteomic studies exploring abiotic and biotic stress responses, vesicular transport, cytoskeleton and protein posttranslational modifications. They are used either for detailed cellular or ultrastructural characterization of the object subjected to proteomic study, validation of proteomic results or to expand proteomic data. In this respect, a broad spectrum of methods is employed to support proteomic studies including ultrastructural electron microscopy studies, histochemical staining, immunochemical localization, in vivo imaging of fluorescently tagged proteins and visualization of protein-protein interactions. Thus, cell biological observations on fixed or living cell compartments, cells, tissues and organs are feasible, and in some cases fundamental for the validation and complementation of proteomic data. Validation of proteomic data by independent experimental methods requires development of new complementary approaches. Benefits of cell biology methods and techniques are not sufficiently highlighted in current proteomic studies. This encouraged us to review most popular cell biology methods used in proteomic studies and to evaluate their relevance and potential for proteomic data validation and enrichment of purely proteomic analyses. We also provide examples of

Temperature-dependent imaging of living cells by AFM

International Nuclear Information System (INIS)

Espenel, Cedric; Giocondi, Marie-Cecile; Seantier, Bastien; Dosset, Patrice; Milhiet, Pierre-Emmanuel; Le Grimellec, Christian

2008-01-01

Characterization of lateral organization of plasma membranes is a prerequisite to the understanding of membrane structure-function relationships in living cells. Lipid-lipid and lipid-protein interactions are responsible for the existence of various membrane microdomains involved in cell signalization and in numerous pathologies. Developing approaches for characterizing microdomains associate identification tools like recognition imaging with high-resolution topographical imaging. Membrane properties are markedly dependent on temperature. However, mesoscopic scale topographical information of cell surface in a temperature range covering most of cell biology experimentation is still lacking. In this work we have examined the possibility of imaging the temperature-dependent behavior of eukaryotic cells by atomic force microscopy (AFM). Our results establish that the surface of living CV1 kidney cells can be imaged by AFM, between 5 and 37 deg. C, both in contact and tapping modes. These first temperature-dependent data show that large cell structures appeared essentially stable at a microscopic scale. On the other hand, as shown by contact mode AFM, the surface was highly dynamic at a mesoscopic scale, with marked changes in apparent topography, friction, and deflection signals. When keeping the scanning conditions constant, a progressive loss in the image contrast was however observed, using tapping mode, on decreasing the temperature

Communication between filamentous pathogens and plants at the biotrophic interface.

Science.gov (United States)

Yi, Mihwa; Valent, Barbara

2013-01-01

Fungi and oomycetes that colonize living plant tissue form extensive interfaces with plant cells in which the cytoplasm of the microorganism is closely aligned with the host cytoplasm for an extended distance. In all cases, specialized biotrophic hyphae function to hijack host cellular processes across an interfacial zone consisting of a hyphal plasma membrane, a specialized interfacial matrix, and a plant-derived membrane. The interface is the site of active secretion by both players. This cross talk at the interface determines the winner in adversarial relationships and establishes the partnership in mutualistic relationships. Fungi and oomycetes secrete many specialized effector proteins for controlling the host, and they can stimulate remarkable cellular reorganization even in distant plant cells. Breakthroughs in live-cell imaging of fungal and oomycete encounter sites, including live-cell imaging of pathogens secreting fluorescently labeled effector proteins, have led to recent progress in understanding communication across the interface.

Intact plant MRI for the study of cell water relations, membrane permeability, cell-to-cell and long distance water transport

NARCIS (Netherlands)

As, van H.

2007-01-01

Water content and hydraulic conductivity, including transport within cells, over membranes, cell-to-cell, and long-distance xylem and phloem transport, are strongly affected by plant water stress. By being able to measure these transport processes non-invasely in the intact plant situation in

Super-Resolution of Plant Disease Images for the Acceleration of Image-based Phenotyping and Vigor Diagnosis in Agriculture.

Science.gov (United States)

Yamamoto, Kyosuke; Togami, Takashi; Yamaguchi, Norio

2017-11-06

Unmanned aerial vehicles (UAVs or drones) are a very promising branch of technology, and they have been utilized in agriculture-in cooperation with image processing technologies-for phenotyping and vigor diagnosis. One of the problems in the utilization of UAVs for agricultural purposes is the limitation in flight time. It is necessary to fly at a high altitude to capture the maximum number of plants in the limited time available, but this reduces the spatial resolution of the captured images. In this study, we applied a super-resolution method to the low-resolution images of tomato diseases to recover detailed appearances, such as lesions on plant organs. We also conducted disease classification using high-resolution, low-resolution, and super-resolution images to evaluate the effectiveness of super-resolution methods in disease classification. Our results indicated that the super-resolution method outperformed conventional image scaling methods in spatial resolution enhancement of tomato disease images. The results of disease classification showed that the accuracy attained was also better by a large margin with super-resolution images than with low-resolution images. These results indicated that our approach not only recovered the information lost in low-resolution images, but also exerted a beneficial influence on further image analysis. The proposed approach will accelerate image-based phenotyping and vigor diagnosis in the field, because it not only saves time to capture images of a crop in a cultivation field but also secures the accuracy of these images for further analysis.

Agrobacterium -induced hypersensitive necrotic reaction in plant cells

African Journals Online (AJOL)

High necrosis and poor survival rate of target plant tissues are some of the major factors that affect the efficiency of Agrobacterium-mediated T-DNA transfer into plant cells. These factors may be the result of, or linked to, hypersensitive defense reaction in plants to Agrobacterium infection, which may involve the recognition ...

Neutron Imaging Reveals Internal Plant Hydraulic Dynamics

Energy Technology Data Exchange (ETDEWEB)

Warren, Jeffrey [ORNL; Bilheux, Hassina Z [ORNL; Kang, Misun [ORNL; Voisin, Sophie [ORNL; Cheng, Chu-Lin [ORNL; Horita, Jusuke [ORNL; Perfect, Edmund [ORNL

2013-01-01

Many terrestrial ecosystem processes are constrained by water availability and transport within the soil. Knowledge of plant water fluxes is thus critical for assessing mechanistic processes linked to biogeochemical cycles, yet resolution of root structure and xylem water transport dynamics has been a particularly daunting task for the ecologist. Through neutron imaging, we demonstrate the ability to non-invasively monitor individual root functionality and water fluxes within Zea mays L. (maize) and Panicum virgatum L. (switchgrass) seedlings growing in a sandy medium. Root structure and growth were readily imaged by neutron radiography and neutron computed tomography. Seedlings were irrigated with water or deuterium oxide and imaged through time as a growth lamp was cycled on to alter leaf demand for water. Sub-millimeter scale resolution reveals timing and magnitudes of root water uptake, redistribution within the roots, and root-shoot hydraulic linkages, relationships not well characterized by other techniques.

Recent advances in live cell imaging of hepatoma cells

Science.gov (United States)

2014-01-01

Live cell imaging enables the study of dynamic processes of living cells in real time by use of suitable reporter proteins and the staining of specific cellular structures and/or organelles. With the availability of advanced optical devices and improved cell culture protocols it has become a rapidly growing research methodology. The success of this technique relies mainly on the selection of suitable reporter proteins, construction of recombinant plasmids possessing cell type specific promoters as well as reliable methods of gene transfer. This review aims to provide an overview of the recent developments in the field of marker proteins (bioluminescence and fluorescent) and methodologies (fluorescent resonance energy transfer, fluorescent recovery after photobleaching and proximity ligation assay) employed as to achieve an improved imaging of biological processes in hepatoma cells. Moreover, different expression systems of marker proteins and the modes of gene transfer are discussed with emphasis on the study of lipid droplet formation in hepatocytes as an example. PMID:25005127

Information management for high content live cell imaging

Directory of Open Access Journals (Sweden)

White Michael RH

2009-07-01

Full Text Available Abstract Background High content live cell imaging experiments are able to track the cellular localisation of labelled proteins in multiple live cells over a time course. Experiments using high content live cell imaging will generate multiple large datasets that are often stored in an ad-hoc manner. This hinders identification of previously gathered data that may be relevant to current analyses. Whilst solutions exist for managing image data, they are primarily concerned with storage and retrieval of the images themselves and not the data derived from the images. There is therefore a requirement for an information management solution that facilitates the indexing of experimental metadata and results of high content live cell imaging experiments. Results We have designed and implemented a data model and information management solution for the data gathered through high content live cell imaging experiments. Many of the experiments to be stored measure the translocation of fluorescently labelled proteins from cytoplasm to nucleus in individual cells. The functionality of this database has been enhanced by the addition of an algorithm that automatically annotates results of these experiments with the timings of translocations and periods of any oscillatory translocations as they are uploaded to the repository. Testing has shown the algorithm to perform well with a variety of previously unseen data. Conclusion Our repository is a fully functional example of how high throughput imaging data may be effectively indexed and managed to address the requirements of end users. By implementing the automated analysis of experimental results, we have provided a clear impetus for individuals to ensure that their data forms part of that which is stored in the repository. Although focused on imaging, the solution provided is sufficiently generic to be applied to other functional proteomics and genomics experiments. The software is available from: fhttp://code.google.com/p/livecellim/

Use of image analysis to assess color response on plants caused by herbicide application

DEFF Research Database (Denmark)

Asif, Ali; Streibig, Jens Carl; Duus, Joachim

2013-01-01

by herbicides. The range of color components of green and nongreen parts of the plants and soil in Hue, Saturation, and Brightness (HSB) color space were used for segmentation. The canopy color changes of barley, winter wheat, red fescue, and brome fescue caused by doses of a glyphosate and diflufenican mixture...... for the green and nongreen parts of the plants and soil were different. The relative potencies were not significantly different from one, indicating that visual and image analysis estimations were about the same. The comparison results suggest that image analysis can be used to assess color changes of plants......In herbicide-selectivity experiments, response can be measured by visual inspection, stand counts, plant mortality, and biomass. Some response types are relative to nontreated control. We developed a nondestructive method by analyzing digital color images to quantify color changes in leaves caused...

Quantitative imaging of epithelial cell scattering identifies specific inhibitors of cell motility and cell-cell dissociation

NARCIS (Netherlands)

Loerke, D.; le Duc, Q.; Blonk, I.; Kerstens, A.; Spanjaard, E.; Machacek, M.; Danuser, G.; de Rooij, J.

2012-01-01

The scattering of cultured epithelial cells in response to hepatocyte growth factor (HGF) is a model system that recapitulates key features of metastatic cell behavior in vitro, including disruption of cell-cell adhesions and induction of cell migration. We have developed image analysis tools that

Methods of expressing and detecting activity of expansin in plant cells

Energy Technology Data Exchange (ETDEWEB)

Hood, Elizabeth E.; Yoon, Sangwoong

2017-10-10

A method of expressing heterologous expansin in a plant cell is provided where a nucleic acid molecule encoding expansin is introduced into the plant cell and in an embodiment is operably linked to a promoter preferentially expressing in the seed tissue of the plant, and in another embodiment is linked to a promoter preferentially expressing in the embryo tissue of the seed. An embodiment provides the nucleic acid molecule is operably linked to a second nucleic acid molecule that directs expression to the endoplasmic reticulum, vacuole or cell wall. Plants and plant parts expressing expansin are provided. An assay for detection of expansin activity is also provided.

Automatic Cell Segmentation in Fluorescence Images of Confluent Cell Monolayers Using Multi-object Geometric Deformable Model.

Science.gov (United States)

Yang, Zhen; Bogovic, John A; Carass, Aaron; Ye, Mao; Searson, Peter C; Prince, Jerry L

2013-03-13

With the rapid development of microscopy for cell imaging, there is a strong and growing demand for image analysis software to quantitatively study cell morphology. Automatic cell segmentation is an important step in image analysis. Despite substantial progress, there is still a need to improve the accuracy, efficiency, and adaptability to different cell morphologies. In this paper, we propose a fully automatic method for segmenting cells in fluorescence images of confluent cell monolayers. This method addresses several challenges through a combination of ideas. 1) It realizes a fully automatic segmentation process by first detecting the cell nuclei as initial seeds and then using a multi-object geometric deformable model (MGDM) for final segmentation. 2) To deal with different defects in the fluorescence images, the cell junctions are enhanced by applying an order-statistic filter and principal curvature based image operator. 3) The final segmentation using MGDM promotes robust and accurate segmentation results, and guarantees no overlaps and gaps between neighboring cells. The automatic segmentation results are compared with manually delineated cells, and the average Dice coefficient over all distinguishable cells is 0.88.

Real-time imaging of {sup 35}S-sulfate uptake in a rape seed plant

Energy Technology Data Exchange (ETDEWEB)

Nakanishi, T.M.; Yamawaki, M.; Ishibashi, H.; Tanoi, K. [Tokyo Univ. (Japan). Lab. of Radioisotope Plant Physiology

2011-07-01

We present real-time images of {sup 35}S-sulfate uptake in a rapeseed plant visualized by the system we developed. In the leaves of rapeseed plants, {sup 35}S accumulated in higher amounts and more rapidly in the more developed leaves. This real-time imaging system can be used to visualize the movement of both {sup 35}S and {sup 32}P in the same plant. In the pods of rapeseed, images of {sup 35}S show that {sup 35}S accumulated mostly in the terminal parts; on the other hand {sup 32}P, when applied as {sup 32}P-phosphoric acid, accumulated in the middle part of the pods. (orig.)

Optical Imaging for Stem Cell Differentiation to Neuronal Lineage

International Nuclear Information System (INIS)

Hwang, Do Won; Lee, Dong Soo

2012-01-01

In regenerative medicine, the prospect of stem cell therapy hold great promise for the recovery of injured tissues and effective treatment of intractable diseases. Tracking stem cell fate provides critical information to understand and evaluate the success of stem cell therapy. The recent emergence of in vivo noninvasive molecular imaging has enabled assessment of the behavior of grafted stem cells in living subjects. In this review, we provide an overview of current optical imaging strategies based on cell or tissue specific reporter gene expression and of in vivo methods to monitor stem cell differentiation into neuronal lineages. These methods use optical reporters either regulated by neuron-specific promoters or containing neuron-specific microRNA binding sites. Both systems revealed dramatic changes in optical reporter imaging signals in cells differentiating a yeast GAL4 amplification system or an engineering-enhanced luciferase reported gene. Furthermore, we propose an advanced imaging system to monitor neuronal differentiation during neurogenesis that uses in vivo multiplexed imaging techniques capable of detecting several targets simultaneously

Plant programmed cell death, ethylene and flower senescence

NARCIS (Netherlands)

Woltering, E.J.; Jong, de A.; Hoeberichts, F.A.; Iakimova, E.T.; Kapchina, V.

2005-01-01

Programmed cell death (PCD) applies to cell death that is part of the normal life of multicellular organisms. PCD is found throughout the animal and plant kingdoms; it is an active process in which a cell suicide pathway is activated resulting in controlled disassembly of the cell. Most cases of PCD

Plant cell wall signalling and receptor-like kinases.

Science.gov (United States)

Wolf, Sebastian

2017-02-15

Communication between the extracellular matrix and the cell interior is essential for all organisms as intrinsic and extrinsic cues have to be integrated to co-ordinate development, growth, and behaviour. This applies in particular to plants, the growth and shape of which is governed by deposition and remodelling of the cell wall, a rigid, yet dynamic, extracellular network. It is thus generally assumed that cell wall surveillance pathways exist to monitor the state of the wall and, if needed, elicit compensatory responses such as altered expression of cell wall remodelling and biosynthesis genes. Here, I highlight recent advances in the field of cell wall signalling in plants, with emphasis on the role of plasma membrane receptor-like kinase complexes. In addition, possible roles for cell wall-mediated signalling beyond the maintenance of cell wall integrity are discussed. © 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

The plant cell nucleus: a true arena for the fight between plants and pathogens.

Science.gov (United States)

Deslandes, Laurent; Rivas, Susana

2011-01-01

Communication between the cytoplasm and the nucleus is a fundamental feature shared by both plant and animal cells. Cellular factors involved in the transport of macromolecules through the nuclear envelope, including nucleoporins, importins and Ran-GTP related components, are conserved among a variety of eukaryotic systems. Interestingly, mutations in these nuclear components compromise resistance signalling, illustrating the importance of nucleocytoplasmic trafficking in plant innate immunity. Indeed, spatial restriction of defence regulators by the nuclear envelope and stimulus-induced nuclear translocation constitute an important level of defence-associated gene regulation in plants. A significant number of effectors from different microbial pathogens are targeted to the plant cell nucleus. In addition, key host factors, including resistance proteins, immunity components, transcription factors and transcriptional regulators shuttle between the cytoplasm and the nucleus, and their level of nuclear accumulation determines the output of the defence response, further confirming the crucial role played by the nucleus during the interaction between plants and pathogens. Here, we discuss recent findings that situate the nucleus at the frontline of the mutual recognition between plants and invading microbes.

Automated Leaf Tracking using Multi-view Image Sequences of Maize Plants for Leaf-growth Monitoring

Science.gov (United States)

Das Choudhury, S.; Awada, T.; Samal, A.; Stoerger, V.; Bashyam, S.

2017-12-01

Extraction of phenotypes with botanical importance by analyzing plant image sequences has the desirable advantages of non-destructive temporal phenotypic measurements of a large number of plants with little or no manual intervention in a relatively short period of time. The health of a plant is best interpreted by the emergence timing and temporal growth of individual leaves. For automated leaf growth monitoring, it is essential to track each leaf throughout the life cycle of the plant. Plants are constantly changing organisms with increasing complexity in architecture due to variations in self-occlusions and phyllotaxy, i.e., arrangements of leaves around the stem. The leaf cross-overs pose challenges to accurately track each leaf using single view image sequence. Thus, we introduce a novel automated leaf tracking algorithm using a graph theoretic approach by multi-view image sequence analysis based on the determination of leaf-tips and leaf-junctions in the 3D space. The basis of the leaf tracking algorithm is: the leaves emerge using bottom-up approach in the case of a maize plant, and the direction of leaf emergence strictly alternates in terms of direction. The algorithm involves labeling of the individual parts of a plant, i.e., leaves and stem, following graphical representation of the plant skeleton, i.e., one-pixel wide connected line obtained from the binary image. The length of the leaf is measured by the number of pixels in the leaf skeleton. To evaluate the performance of the algorithm, a benchmark dataset is indispensable. Thus, we publicly release University of Nebraska-Lincoln Component Plant Phenotyping dataset-2 (UNL-CPPD-2) consisting of images of the 20 maize plants captured by visible light camera of the Lemnatec Scanalyzer 3D high throughout plant phenotyping facility once daily for 60 days from 10 different views. The dataset is aimed to facilitate the development and evaluation of leaf tracking algorithms and their uniform comparisons.

Single-cell magnetic imaging using a quantum diamond microscope.

Science.gov (United States)

Glenn, D R; Lee, K; Park, H; Weissleder, R; Yacoby, A; Lukin, M D; Lee, H; Walsworth, R L; Connolly, C B

2015-08-01

We apply a quantum diamond microscope for detection and imaging of immunomagnetically labeled cells. This instrument uses nitrogen-vacancy (NV) centers in diamond for correlated magnetic and fluorescence imaging. Our device provides single-cell resolution and a field of view (∼1 mm(2)) two orders of magnitude larger than that of previous NV imaging technologies, enabling practical applications. To illustrate, we quantified cancer biomarkers expressed by rare tumor cells in a large population of healthy cells.

Super-Resolution of Plant Disease Images for the Acceleration of Image-based Phenotyping and Vigor Diagnosis in Agriculture

Directory of Open Access Journals (Sweden)

Kyosuke Yamamoto

2017-11-01

Full Text Available Unmanned aerial vehicles (UAVs or drones are a very promising branch of technology, and they have been utilized in agriculture—in cooperation with image processing technologies—for phenotyping and vigor diagnosis. One of the problems in the utilization of UAVs for agricultural purposes is the limitation in flight time. It is necessary to fly at a high altitude to capture the maximum number of plants in the limited time available, but this reduces the spatial resolution of the captured images. In this study, we applied a super-resolution method to the low-resolution images of tomato diseases to recover detailed appearances, such as lesions on plant organs. We also conducted disease classification using high-resolution, low-resolution, and super-resolution images to evaluate the effectiveness of super-resolution methods in disease classification. Our results indicated that the super-resolution method outperformed conventional image scaling methods in spatial resolution enhancement of tomato disease images. The results of disease classification showed that the accuracy attained was also better by a large margin with super-resolution images than with low-resolution images. These results indicated that our approach not only recovered the information lost in low-resolution images, but also exerted a beneficial influence on further image analysis. The proposed approach will accelerate image-based phenotyping and vigor diagnosis in the field, because it not only saves time to capture images of a crop in a cultivation field but also secures the accuracy of these images for further analysis.

Analysis of redox relationships in the plant cell cycle: determinations of ascorbate, glutathione and poly (ADPribose)polymerase (PARP) in plant cell cultures.

Science.gov (United States)

Foyer, Christine H; Pellny, Till K; Locato, Vittoria; De Gara, Laura

2008-01-01

Reactive oxygen species (ROS) and low molecular weight antioxidants, such as glutathione and ascorbate, are powerful signaling molecules that participate in the control of plant growth and development, and modulate progression through the mitotic cell cycle. Enhanced reactive oxygen species accumulation or low levels of ascorbate or glutathione cause the cell cycle to arrest and halt progression especially through the G1 checkpoint. Plant cell suspension cultures have proved to be particularly useful tools for the study of cell cycle regulation. Here we provide effective and accurate methods for the measurement of changes in the cellular ascorbate and glutathione pools and the activities of related enzymes such poly (ADP-ribose) polymerase during mitosis and cell expansion, particularly in cell suspension cultures. These methods can be used in studies seeking to improve current understanding of the roles of redox controls on cell division and cell expansion.

Why plants make puzzle cells, and how their shape emerges.

Science.gov (United States)

Sapala, Aleksandra; Runions, Adam; Routier-Kierzkowska, Anne-Lise; Das Gupta, Mainak; Hong, Lilan; Hofhuis, Hugo; Verger, Stéphane; Mosca, Gabriella; Li, Chun-Biu; Hay, Angela; Hamant, Olivier; Roeder, Adrienne Hk; Tsiantis, Miltos; Prusinkiewicz, Przemyslaw; Smith, Richard S

2018-02-27

The shape and function of plant cells are often highly interdependent. The puzzle-shaped cells that appear in the epidermis of many plants are a striking example of a complex cell shape, however their functional benefit has remained elusive. We propose that these intricate forms provide an effective strategy to reduce mechanical stress in the cell wall of the epidermis. When tissue-level growth is isotropic, we hypothesize that lobes emerge at the cellular level to prevent formation of large isodiametric cells that would bulge under the stress produced by turgor pressure. Data from various plant organs and species support the relationship between lobes and growth isotropy, which we test with mutants where growth direction is perturbed. Using simulation models we show that a mechanism actively regulating cellular stress plausibly reproduces the development of epidermal cell shape. Together, our results suggest that mechanical stress is a key driver of cell-shape morphogenesis. © 2018, Sapala et al.

Variable-angle epifluorescence microscopy characterizes protein dynamics in the vicinity of plasma membrane in plant cells.

Science.gov (United States)

Chen, Tong; Ji, Dongchao; Tian, Shiping

2018-03-14

The assembly of protein complexes and compositional lipid patterning act together to endow cells with the plasticity required to maintain compositional heterogeneity with respect to individual proteins. Hence, the applications for imaging protein localization and dynamics require high accuracy, particularly at high spatio-temporal level. We provided experimental data for the applications of Variable-Angle Epifluorescence Microscopy (VAEM) in dissecting protein dynamics in plant cells. The VAEM-based co-localization analysis took penetration depth and incident angle into consideration. Besides direct overlap of dual-color fluorescence signals, the co-localization analysis was carried out quantitatively in combination with the methodology for calculating puncta distance and protein proximity index. Besides, simultaneous VAEM tracking of cytoskeletal dynamics provided more insights into coordinated responses of actin filaments and microtubules. Moreover, lateral motility of membrane proteins was analyzed by calculating diffusion coefficients and kymograph analysis, which represented an alternative method for examining protein motility. The present study presented experimental evidence on illustrating the use of VAEM in tracking and dissecting protein dynamics, dissecting endosomal dynamics, cell structure assembly along with membrane microdomain and protein motility in intact plant cells.

Imaging cell competition in Drosophila imaginal discs.

Science.gov (United States)

Ohsawa, Shizue; Sugimura, Kaoru; Takino, Kyoko; Igaki, Tatsushi

2012-01-01

Cell competition is a process in which cells with higher fitness ("winners") survive and proliferate at the expense of less fit neighbors ("losers"). It has been suggested that cell competition is involved in a variety of biological processes such as organ size control, tissue homeostasis, cancer progression, and the maintenance of stem cell population. By advent of a genetic mosaic technique, which enables to generate fluorescently marked somatic clones in Drosophila imaginal discs, recent studies have presented some aspects of molecular mechanisms underlying cell competition. Now, with a live-imaging technique using ex vivo-cultured imaginal discs, we can dissect the spatiotemporal nature of competitive cell behaviors within multicellular communities. Here, we describe procedures and tips for live imaging of cell competition in Drosophila imaginal discs. Copyright © 2012 Elsevier Inc. All rights reserved.

Influence of lead upon the plant cell. [Lactuca sativa L

Energy Technology Data Exchange (ETDEWEB)

Sekerka, V; Bobak, M

1975-01-01

An attempt is made to study the influence of tetramethyl lead upon the mitotic activity of cells, structural changes of the chromosomes, upon the mitotic apparatus and the ultrastructure of the cells in lettuce (Lactuca sativa L.) Tetramethyl lead is an antidetonant additive to the gasoline of automobiles. The authors have found that the Pb ions are toxic for the plant cell, its toxicity increases with an increasing concentration and the prolonged time of action of the Pb solution. Tetramethyl lead influences the cell division causing especially different disturbances of the chromosomes and of the dividing figure during karykinesis and evoking damages of the submicroscopic structure of the plant cell. First of all, the following organels are damaged: the nucleus, the mitochondria, the Golgi apparatus, the endoplasmatic reticulum and the proplastids. A considerable number of formations similar to translosomes arises in the plant cells at the same time.

Panorama Image Processing for Condition Monitoring with Thermography in Power Plant

Energy Technology Data Exchange (ETDEWEB)

Jeon, Byoung Joon; Kim, Tae Hwan; Kim, Soon Geol; Mo, Yoon Syub [UNETWARE, Seoul (Korea, Republic of); Kim, Won Tae [Kongju National University, Gongju (Korea, Republic of)

2010-04-15

In this paper, imaging processing study obtained from CCD image and thermography image was performed in order to treat easily thermographic data without any risks of personnel who conduct the condition monitoring for the abnormal or failure status occurrable in industrial power plants. This imaging processing is also applicable to the predictive maintenance. For confirming the broad monitoring, a methodology producting single image from the panorama technique was developed no matter how many cameras are employed, including fusion method for discrete configuration for the target. As results, image fusion from quick realtime processing was obtained and it was possible to save time to track the location monitoring in matching the images between CCTV and thermography

Panorama Image Processing for Condition Monitoring with Thermography in Power Plant

International Nuclear Information System (INIS)

Jeon, Byoung Joon; Kim, Tae Hwan; Kim, Soon Geol; Mo, Yoon Syub; Kim, Won Tae

2010-01-01

In this paper, imaging processing study obtained from CCD image and thermography image was performed in order to treat easily thermographic data without any risks of personnel who conduct the condition monitoring for the abnormal or failure status occurrable in industrial power plants. This imaging processing is also applicable to the predictive maintenance. For confirming the broad monitoring, a methodology producting single image from the panorama technique was developed no matter how many cameras are employed, including fusion method for discrete configuration for the target. As results, image fusion from quick realtime processing was obtained and it was possible to save time to track the location monitoring in matching the images between CCTV and thermography

Advances of reporter gene imaging monitoring stem cell therapy

International Nuclear Information System (INIS)

Pei Zhijun; Zhang Yongxue

2010-01-01

Stem cell transplantation in the treatment of various tissue damage or degenerative diseases are research hotspots both at home and abroad. However, ignorance of the homing, differentiation and functional expression of the stem cell in vivo influence the further development of stem cell therapy. As an important component of molecular imaging technology, reporter gene imaging dynamically monitors the change of stem cell in vivo via monitoring the expression of transfected reporter gene. This paper briefly describes the latest research progress and the future development trend of the monitoring of reporter gene imaging in stem cell therapy in vivo. (authors)

Imaging of single cells and tissue using MeV ions

International Nuclear Information System (INIS)

Watt, F.; Bettiol, A.A.; Kan, J.A. van; Ynsa, M.D.; Ren Minqin; Rajendran, R.; Cui Huifang; Sheu, F.-S.; Jenner, A.M.

2009-01-01

With the attainment of sub-100 nm high energy (MeV) ion beams, comes the opportunity to image cells and tissue at nano-dimensions. The advantage of MeV ion imaging is that the ions will penetrate whole cells, or relatively thick tissue sections, without any significant loss of resolution. In this paper, we demonstrate that whole cells (cultured N2A neuroblastoma cells ATCC) and tissue sections (rabbit pancreas tissue) can be imaged at sub-100 nm resolutions using scanning transmission ion microscopy (STIM), and that sub-cellular structural details can be identified. In addition to STIM imaging we have also demonstrated for the first time, that sub-cellular proton induced fluorescence imaging (on cultured N2A neuroblastoma cells ATCC) can also be carried out at resolutions of 200 nm, compared with 300-400 nm resolutions achieved by conventional optical fluorescence imaging. The combination of both techniques offers a potentially powerful tool in the quest for elucidating cell function, particularly when it should be possible in the near future to image down to sub-50 nm.

Cell-to-cell communication in plants, animals, and fungi: a comparative review.

Science.gov (United States)

Bloemendal, Sandra; Kück, Ulrich

2013-01-01

Cell-to-cell communication is a prerequisite for differentiation and development in multicellular organisms. This communication has to be tightly regulated to ensure that cellular components such as organelles, macromolecules, hormones, or viruses leave the cell in a precisely organized way. During evolution, plants, animals, and fungi have developed similar ways of responding to this biological challenge. For example, in higher plants, plasmodesmata connect adjacent cells and allow communication to regulate differentiation and development. In animals, two main general structures that enable short- and long-range intercellular communication are known, namely gap junctions and tunneling nanotubes, respectively. Finally, filamentous fungi have also developed specialized structures called septal pores that allow intercellular communication via cytoplasmic flow. This review summarizes the underlying mechanisms for intercellular communication in these three eukaryotic groups and discusses its consequences for the regulation of differentiation and developmental processes.

FOOT ROT DISEASE IDENTIFICATION FOR VELLAIKODI VARIETY OF BETELVINE PLANTS USING DIGITAL IMAGE PROCESSING

Directory of Open Access Journals (Sweden)

J. Vijayakumar

2012-11-01

Full Text Available Betelvine plants are infected variety of diseases in the complete plantation without any premature warning of the diseases. The aim of this paper is to detection of foot rot disease in the vellaikodi variety of betelvine plants using digital image processing techniques. The digital images of the uninfected or normal betelvine leaves and the digital images of the infected in foot rot diseased betelvine leaves at different stages are collected from different Betelvine plants using a high resolution digital camera and collected betelvine images are stored with JPEG format. The digital images of the betelvine leaves analyses are done using the image processing toolbox in MATLAB which gives the normal patterns of the digital images. Using RGB encoding process, the RGB components of the betelvine leaves are separated. The mean and median values for all sample leaves are computed and calculated values are stored in the system. The mean and median values of test leaves are computed and compared with the stored values. As the result of this comparison, it is identified whether test leaves are affected by foot rot disease or not. Finally this analysis helps to recognize the foot rot disease can be identified before it spreads to entire crop.

Live cell imaging of actin dynamics in dexamethasone-treated porcine trabecular meshwork cells.

Science.gov (United States)

Fujimoto, Tomokazu; Inoue, Toshihiro; Inoue-Mochita, Miyuki; Tanihara, Hidenobu

2016-04-01

The regulation of the actin cytoskeleton in trabecular meshwork (TM) cells is important for controlling outflow of the aqueous humor. In some reports, dexamethasone (DEX) increased the aqueous humor outflow resistance and induced unusual actin structures, such as cross-linked actin networks (CLAN), in TM cells. However, the functions and dynamics of CLAN in TM cells are not completely known, partly because actin stress fibers have been observed only in fixed cells. We conducted live-cell imaging of the actin dynamics in TM cells with or without DEX treatment. An actin-green fluorescent protein (GFP) fusion construct with a modified insect virus was transfected into porcine TM cells. Time-lapse imaging of live TM cells treated with 25 μM Y-27632 and 100 nM DEX was performed using an inverted fluorescence microscope. Fluorescent images were recorded every 15 s for 30 min after Y-27632 treatment or every 30 min for 72 h after DEX treatment. The GFP-actin was expressed in 22.7 ± 10.9% of the transfected TM cells. In live TM cells, many actin stress fibers were observed before the Y-27632 treatment. Y-27632 changed the cell shape and decreased stress fibers in a time-dependent manner. In fixed cells, CLAN-like structures were seen in 26.5 ± 1.7% of the actin-GFP expressed PTM cells treated with DEX for 72 h. In live imaging, there was 28% CLAN-like structure formation at 72 h after DEX treatment, and the lifetime of CLAN-like structures increased after DEX treatment. The DEX-treated cells with CLAN-like structures showed less migration than DEX-treated cells without CLAN-like structures. Furthermore, the control cells (without DEX treatment) with CLAN-like structures also showed less migration than the control cells without CLAN-like structures. These results suggested that CLAN-like structure formation was correlated with cell migration in TM cells. Live cell imaging of the actin cytoskeleton provides valuable information on the actin dynamics in TM

Plant Identification Based on Leaf Midrib Cross-Section Images Using Fractal Descriptors.

Directory of Open Access Journals (Sweden)

Núbia Rosa da Silva

Full Text Available The correct identification of plants is a common necessity not only to researchers but also to the lay public. Recently, computational methods have been employed to facilitate this task, however, there are few studies front of the wide diversity of plants occurring in the world. This study proposes to analyse images obtained from cross-sections of leaf midrib using fractal descriptors. These descriptors are obtained from the fractal dimension of the object computed at a range of scales. In this way, they provide rich information regarding the spatial distribution of the analysed structure and, as a consequence, they measure the multiscale morphology of the object of interest. In Biology, such morphology is of great importance because it is related to evolutionary aspects and is successfully employed to characterize and discriminate among different biological structures. Here, the fractal descriptors are used to identify the species of plants based on the image of their leaves. A large number of samples are examined, being 606 leaf samples of 50 species from Brazilian flora. The results are compared to other imaging methods in the literature and demonstrate that fractal descriptors are precise and reliable in the taxonomic process of plant species identification.

A spectral k-means approach to bright-field cell image segmentation.

Science.gov (United States)

Bradbury, Laura; Wan, Justin W L

2010-01-01

Automatic segmentation of bright-field cell images is important to cell biologists, but difficult to complete due to the complex nature of the cells in bright-field images (poor contrast, broken halo, missing boundaries). Standard approaches such as level set segmentation and active contours work well for fluorescent images where cells appear as round shape, but become less effective when optical artifacts such as halo exist in bright-field images. In this paper, we present a robust segmentation method which combines the spectral and k-means clustering techniques to locate cells in bright-field images. This approach models an image as a matrix graph and segment different regions of the image by computing the appropriate eigenvectors of the matrix graph and using the k-means algorithm. We illustrate the effectiveness of the method by segmentation results of C2C12 (muscle) cells in bright-field images.

Interaction between the moss Physcomitrella patens and Phytophthora: a novel pathosystem for live-cell imaging of subcellular defence.

Science.gov (United States)

Overdijk, Elysa J R; DE Keijzer, Jeroen; DE Groot, Deborah; Schoina, Charikleia; Bouwmeester, Klaas; Ketelaar, Tijs; Govers, Francine

2016-08-01

Live-cell imaging of plant-pathogen interactions is often hampered by the tissue complexity and multicell layered nature of the host. Here, we established a novel pathosystem with the moss Physcomitrella patens as host for Phytophthora. The tip-growing protonema cells of this moss are ideal for visualizing interactions with the pathogen over time using high-resolution microscopy. We tested four Phytophthora species for their ability to infect P. patens and showed that P. sojae and P. palmivora were only rarely capable to infect P. patens. In contrast, P. infestans and P. capsici frequently and successfully penetrated moss protonemal cells, showed intracellular hyphal growth and formed sporangia. Next to these successful invasions, many penetration attempts failed. Here the pathogen was blocked by a barrier of cell wall material deposited in papilla-like structures, a defence response that is common in higher plants. Another common response is the upregulation of defence-related genes upon infection and also in moss we observed this upregulation in tissues infected with Phytophthora. For more advanced analyses of the novel pathosystem we developed a special set-up that allowed live-cell imaging of subcellular defence processes by high-resolution microscopy. With this set-up, we revealed that Phytophthora infection of moss induces repositioning of the nucleus, accumulation of cytoplasm and rearrangement of the actin cytoskeleton, but not of microtubules. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

Glycoprotein component of plant cell walls

International Nuclear Information System (INIS)

Cooper, J.B.; Chen, J.A.; Varner, J.E.

1984-01-01

The primary wall surrounding most dicotyledonous plant cells contains a hydroxyproline-rich glycoprotein (HRGP) component named extensin. A small group of glycopeptides solubilized from isolated cell walls by proteolysis contained a repeated pentapeptide glycosylated by tri- and tetraarabinosides linked to hydroxyproline and, by galactose, linked to serine. Recently, two complementary approaches to this problem have provided results which greatly increase the understanding of wall extensin. In this paper the authors describe what is known about the structure of soluble extensin secreted into the walls of the carrot root cells

The role of the cell wall in plant immunity

DEFF Research Database (Denmark)

Malinovsky, Frederikke Gro; Fangel, Jonatan Ulrik; Willats, William George Tycho

2014-01-01

The battle between plants and microbes is evolutionarily ancient, highly complex, and often co-dependent. A primary challenge for microbes is to breach the physical barrier of host cell walls whilst avoiding detection by the plant's immune receptors. While some receptors sense conserved microbial...... features, others monitor physical changes caused by an infection attempt. Detection of microbes leads to activation of appropriate defense responses that then challenge the attack. Plant cell walls are formidable and dynamic barriers. They are constructed primarily of complex carbohydrates joined...... by numerous distinct connection types, and are subject to extensive post-synthetic modification to suit prevailing local requirements. Multiple changes can be triggered in cell walls in response to microbial attack. Some of these are well described, but many remain obscure. The study of the myriad of subtle...

Actin based processes that could determine the cytoplasmic architecture of plant cells

NARCIS (Netherlands)

Honing, van der H.S.; Emons, A.M.C.; Ketelaar, M.J.

2007-01-01

Actin polymerisation can generate forces that are necessary for cell movement, such as the propulsion of a class of bacteria, including Listeria, and the protrusion of migrating animal cells. Force generation by the actin cytoskeleton in plant cells has not been studied. One process in plant cells

DAE-BRNS workshop on applications of image processing in plant sciences and agriculture: lecture notes

International Nuclear Information System (INIS)

1998-10-01

Images form important data and information in biological sciences. Until recently photography was the only method to reproduce and report such data. It is difficult to quantify or treat the photographic data mathematically. Digital image processing and image analysis technology based on recent advances in microelectronics and computers circumvents these problems associated with traditional photography. WIPSA (Workshop on Applications of Image Processing in Plant Sciences and Agriculture) will feature topics on the basic aspects of computers, imaging hardware and software as well advanced aspects such as colour image processing, high performance computing, neural networks, 3-D imaging and virtual reality. Imaging done using ultrasound, thermal, x-rays and γ rays, neutron radiography and the film-less phosphor-imager technology will also be discussed. Additionally application of image processing/analysis in plant sciences, medicine and satellite imagery are discussed. Papers relevant to INIS are indexed separately

Meristem Plant Cells as a Sustainable Source of Redox Actives for Skin Rejuvenation

Science.gov (United States)

Korkina, Liudmila G.; Mayer, Wolfgang; de Luca, Chiara

2017-01-01

Recently, aggressive advertisement claimed a “magic role” for plant stem cells in human skin rejuvenation. This review aims to shed light on the scientific background suggesting feasibility of using plant cells as a basis of anti-age cosmetics. When meristem cell cultures obtained from medicinal plants are exposed to appropriate elicitors/stressors (ultraviolet, ultrasound ultraviolet (UV), ultrasonic waves, microbial/insect metabolites, heavy metals, organic toxins, nutrient deprivation, etc.), a protective/adaptive response initiates the biosynthesis of secondary metabolites. Highly bioavailable and biocompatible to human cells, low-molecular weight plant secondary metabolites share structural/functional similarities with human non-protein regulatory hormones, neurotransmitters, pigments, polyamines, amino-/fatty acids. Their redox-regulated biosynthesis triggers in turn plant cell antioxidant and detoxification molecular mechanisms resembling human cell pathways. Easily isolated in relatively large quantities from contaminant-free cell cultures, plant metabolites target skin ageing mechanisms, above all redox imbalance. Perfect modulators of cutaneous oxidative state via direct/indirect antioxidant action, free radical scavenging, UV protection, and transition-metal chelation, they are ideal candidates to restore photochemical/redox/immune/metabolic barriers, gradually deteriorating in the ageing skin. The industrial production of plant meristem cell metabolites is toxicologically and ecologically sustainable for fully “biological” anti-age cosmetics. PMID:28498360

Video-rate confocal microscopy for single-molecule imaging in live cells and superresolution fluorescence imaging.

Science.gov (United States)

Lee, Jinwoo; Miyanaga, Yukihiro; Ueda, Masahiro; Hohng, Sungchul

2012-10-17

There is no confocal microscope optimized for single-molecule imaging in live cells and superresolution fluorescence imaging. By combining the swiftness of the line-scanning method and the high sensitivity of wide-field detection, we have developed a, to our knowledge, novel confocal fluorescence microscope with a good optical-sectioning capability (1.0 μm), fast frame rates (fluorescence detection efficiency. Full compatibility of the microscope with conventional cell-imaging techniques allowed us to do single-molecule imaging with a great ease at arbitrary depths of live cells. With the new microscope, we monitored diffusion motion of fluorescently labeled cAMP receptors of Dictyostelium discoideum at both the basal and apical surfaces and obtained superresolution fluorescence images of microtubules of COS-7 cells at depths in the range 0-85 μm from the surface of a coverglass. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

A dynamical model for plant cell wall architecture formation.

NARCIS (Netherlands)

Mulder, B.M.; Emons, A.M.C.

2001-01-01

We discuss a dynamical mathematical model to explain cell wall architecture in plant cells. The highly regular textures observed in cell walls reflect the spatial organisation of the cellulose microfibrils (CMFs), the most important structural component of cell walls. Based on a geometrical theory

An introduction to plant cell culture: the future ahead.

Science.gov (United States)

Loyola-Vargas, Víctor M; Ochoa-Alejo, Neftalí

2012-01-01

Plant cell, tissue, and organ culture (PTC) techniques were developed and established as an experimental necessity for solving important fundamental questions in plant biology, but they currently represent very useful biotechnological tools for a series of important applications such as commercial micropropagation of different plant species, generation of disease-free plant materials, production of haploid and doublehaploid plants, induction of epigenetic or genetic variation for the isolation of variant plants, obtention of novel hybrid plants through the rescue of hybrid embryos or somatic cell fusion from intra- or intergeneric sources, conservation of valuable plant germplasm, and is the keystone for genetic engineering of plants to produce disease and pest resistant varieties, to engineer metabolic pathways with the aim of producing specific secondary metabolites or as an alternative for biopharming. Some other miscellaneous applications involve the utilization of in vitro cultures to test toxic compounds and the possibilities of removing them (bioremediation), interaction of root cultures with nematodes or mycorrhiza, or the use of shoot cultures to maintain plant viruses. With the increased worldwide demand for biofuels, it seems that PTC will certainly be fundamental for engineering different plants species in order to increase the diversity of biofuel options, lower the price marketing, and enhance the production efficiency. Several aspects and applications of PTC such as those mentioned above are the focus of this edition.

Cellular growth in plants requires regulation of cell wall biochemistry.

Science.gov (United States)

Chebli, Youssef; Geitmann, Anja

2017-02-01

Cell and organ morphogenesis in plants are regulated by the chemical structure and mechanical properties of the extracellular matrix, the cell wall. The two primary load bearing components in the plant cell wall, the pectin matrix and the cellulose/xyloglucan network, are constantly remodelled to generate the morphological changes required during plant development. This remodelling is regulated by a plethora of loosening and stiffening agents such as pectin methyl-esterases, calcium ions, expansins, and glucanases. The tight spatio-temporal regulation of the activities of these agents is a sine qua non condition for proper morphogenesis at cell and tissue levels. The pectin matrix and the cellulose-xyloglucan network operate in concert and their behaviour is mutually dependent on their chemical, structural and mechanical modifications. Copyright © 2017 Elsevier Ltd. All rights reserved.

In vivo SPECT reporter gene imaging of regulatory T cells.

Directory of Open Access Journals (Sweden)

Ehsan Sharif-Paghaleh

Full Text Available Regulatory T cells (Tregs were identified several years ago and are key in controlling autoimmune diseases and limiting immune responses to foreign antigens, including alloantigens. In vivo imaging techniques including intravital microscopy as well as whole body imaging using bioluminescence probes have contributed to the understanding of in vivo Treg function, their mechanisms of action and target cells. Imaging of the human sodium/iodide symporter via Single Photon Emission Computed Tomography (SPECT has been used to image various cell types in vivo. It has several advantages over the aforementioned imaging techniques including high sensitivity, it allows non-invasive whole body studies of viable cell migration and localisation of cells over time and lastly it may offer the possibility to be translated to the clinic. This study addresses whether SPECT/CT imaging can be used to visualise the migratory pattern of Tregs in vivo. Treg lines derived from CD4(+CD25(+FoxP3(+ cells were retrovirally transduced with a construct encoding for the human Sodium Iodide Symporter (NIS and the fluorescent protein mCherry and stimulated with autologous DCs. NIS expressing self-specific Tregs were specifically radiolabelled in vitro with Technetium-99m pertechnetate ((99mTcO(4(- and exposure of these cells to radioactivity did not affect cell viability, phenotype or function. In addition adoptively transferred Treg-NIS cells were imaged in vivo in C57BL/6 (BL/6 mice by SPECT/CT using (99mTcO(4(-. After 24 hours NIS expressing Tregs were observed in the spleen and their localisation was further confirmed by organ biodistribution studies and flow cytometry analysis. The data presented here suggests that SPECT/CT imaging can be utilised in preclinical imaging studies of adoptively transferred Tregs without affecting Treg function and viability thereby allowing longitudinal studies within disease models.

SU-E-I-39: Molecular Image Guided Cancer Stem Cells Therapy

Energy Technology Data Exchange (ETDEWEB)

Abdollahi, H

2014-06-01

Purpose: Cancer stem cells resistance to radiation is a problematic issue that has caused a big fail in cancer treatment. Methods: As a primary work, molecular imaging can indicate the main mechanisms of radiation resistance of cancer stem cells. By developing and commissioning new probes and nanomolecules and biomarkers, radiation scientist will able to identify the essential pathways of radiation resistance of cancer stem cells. As the second solution, molecular imaging is a best way to find biological target volume and delineate cancer stem cell tissues. In the other hand, by molecular imaging techniques one can image the treatment response in tumor and also in normal tissue. In this issue, the response of cancer stem cells to radiation during therapy course can be imaged, also the main mechanisms of radiation resistance and finding the best radiation modifiers (sensitizers) can be achieved by molecular imaging modalities. In adaptive radiotherapy the molecular imaging plays a vital role to have higher tumor control probability by delivering high radiation doses to cancer stem cells in any time of treatment. The outcome of a feasible treatment is dependent to high cancer stem cells response to radiation and removing all of which, so a good imaging modality can show this issue and preventing of tumor recurrence and metastasis. Results: Our results are dependent to use of molecular imaging as a new modality in the clinic. We propose molecular imaging as a new radiobiological technique to solve radiation therapy problems due to cancer stem cells. Conclusion: Molecular imaging guided cancer stem cell diagnosis and therapy is a new approach in the field of cancer treatment. This new radiobiological imaging technique should be developed in all clinics as a feasible tool that is more biological than physical imaging.

SU-E-I-39: Molecular Image Guided Cancer Stem Cells Therapy

International Nuclear Information System (INIS)

Abdollahi, H

2014-01-01

Purpose: Cancer stem cells resistance to radiation is a problematic issue that has caused a big fail in cancer treatment. Methods: As a primary work, molecular imaging can indicate the main mechanisms of radiation resistance of cancer stem cells. By developing and commissioning new probes and nanomolecules and biomarkers, radiation scientist will able to identify the essential pathways of radiation resistance of cancer stem cells. As the second solution, molecular imaging is a best way to find biological target volume and delineate cancer stem cell tissues. In the other hand, by molecular imaging techniques one can image the treatment response in tumor and also in normal tissue. In this issue, the response of cancer stem cells to radiation during therapy course can be imaged, also the main mechanisms of radiation resistance and finding the best radiation modifiers (sensitizers) can be achieved by molecular imaging modalities. In adaptive radiotherapy the molecular imaging plays a vital role to have higher tumor control probability by delivering high radiation doses to cancer stem cells in any time of treatment. The outcome of a feasible treatment is dependent to high cancer stem cells response to radiation and removing all of which, so a good imaging modality can show this issue and preventing of tumor recurrence and metastasis. Results: Our results are dependent to use of molecular imaging as a new modality in the clinic. We propose molecular imaging as a new radiobiological technique to solve radiation therapy problems due to cancer stem cells. Conclusion: Molecular imaging guided cancer stem cell diagnosis and therapy is a new approach in the field of cancer treatment. This new radiobiological imaging technique should be developed in all clinics as a feasible tool that is more biological than physical imaging

High-performance imaging of stem cells using single-photon emissions

Science.gov (United States)

Wagenaar, Douglas J.; Moats, Rex A.; Hartsough, Neal E.; Meier, Dirk; Hugg, James W.; Yang, Tang; Gazit, Dan; Pelled, Gadi; Patt, Bradley E.

2011-10-01

Radiolabeled cells have been imaged for decades in the field of autoradiography. Recent advances in detector and microelectronics technologies have enabled the new field of "digital autoradiography" which remains limited to ex vivo specimens of thin tissue slices. The 3D field-of-view (FOV) of single cell imaging can be extended to millimeters if the low energy (10-30 keV) photon emissions of radionuclides are used for single-photon nuclear imaging. This new microscope uses a coded aperture foil made of highly attenuating elements such as gold or platinum to form the image as a kind of "lens". The detectors used for single-photon emission microscopy are typically silicon detectors with a pixel pitch less than 60 μm. The goal of this work is to image radiolabeled mesenchymal stem cells in vivo in an animal model of tendon repair processes. Single-photon nuclear imaging is an attractive modality for translational medicine since the labeled cells can be imaged simultaneously with the reparative processes by using the dual-isotope imaging technique. The details our microscope's two-layer gold aperture and the operation of the energy-dispersive, pixellated silicon detector are presented along with the first demonstration of energy discrimination with a 57Co source. Cell labeling techniques have been augmented by genetic engineering with the sodium-iodide symporter, a type of reporter gene imaging method that enables in vivo uptake of free 99mTc or an iodine isotope at a time point days or weeks after the insertion of the genetically modified stem cells into the animal model. This microscopy work in animal research may expand to the imaging of reporter-enabled stem cells simultaneously with the expected biological repair process in human clinical trials of stem cell therapies.

Detection of programmed cell death in plant embryos.

Science.gov (United States)

Filonova, Lada H; Suárez, María F; Bozhkov, Peter V

2008-01-01

Programmed cell death (PCD) is an integral part of embryogenesis. In plant embryos, PCD functions during terminal differentiation and elimination of the temporary organ, suspensor, as well as during establishment of provascular system. Embryo abortion is another example of embryonic PCD activated at pathological situations and in polyembryonic seeds. Recent studies identified the sequence of cytological events leading to cellular self-destruction in plant embryos. As in most if not all the developmental cell deaths in plants, embryonic PCD is hallmarked by autophagic degradation of the cytoplasm and nuclear disassembly that includes breakdown of the nuclear envelope and DNA fragmentation. The optimized setup of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) allows the routine in situ analysis of nuclear DNA fragmentation in plant embryos. This chapter provides step-by-step procedure of how to process embryos for TUNEL and how to combine TUNEL with immunolocalization of the protein of interest.

High-resolution solution-state NMR of unfractionated plant cell walls

Science.gov (United States)

John Ralph; Fachuang Lu; Hoon Kim; Dino Ress; Daniel J. Yelle; Kenneth E. Hammel; Sally A. Ralph; Bernadette Nanayakkara; Armin Wagner; Takuya Akiyama; Paul F. Schatz; Shawn D. Mansfield; Noritsugu Terashima; Wout Boerjan; Bjorn Sundberg; Mattias Hedenstrom

2009-01-01

Detailed structural studies on the plant cell wall have traditionally been difficult. NMR is one of the preeminent structural tools, but obtaining high-resolution solution-state spectra has typically required fractionation and isolation of components of interest. With recent methods for dissolution of, admittedly, finely divided plant cell wall material, the wall can...

Macro optical projection tomography for large scale 3D imaging of plant structures and gene activity.

Science.gov (United States)

Lee, Karen J I; Calder, Grant M; Hindle, Christopher R; Newman, Jacob L; Robinson, Simon N; Avondo, Jerome J H Y; Coen, Enrico S

2017-01-01

Optical projection tomography (OPT) is a well-established method for visualising gene activity in plants and animals. However, a limitation of conventional OPT is that the specimen upper size limit precludes its application to larger structures. To address this problem we constructed a macro version called Macro OPT (M-OPT). We apply M-OPT to 3D live imaging of gene activity in growing whole plants and to visualise structural morphology in large optically cleared plant and insect specimens up to 60 mm tall and 45 mm deep. We also show how M-OPT can be used to image gene expression domains in 3D within fixed tissue and to visualise gene activity in 3D in clones of growing young whole Arabidopsis plants. A further application of M-OPT is to visualise plant-insect interactions. Thus M-OPT provides an effective 3D imaging platform that allows the study of gene activity, internal plant structures and plant-insect interactions at a macroscopic scale. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Supplemental Blue LED Lighting Array to Improve the Signal Quality in Hyperspectral Imaging of Plants

Directory of Open Access Journals (Sweden)

Anne-Katrin Mahlein

2015-06-01

Full Text Available Hyperspectral imaging systems used in plant science or agriculture often have suboptimal signal-to-noise ratio in the blue region (400–500 nm of the electromagnetic spectrum. Typically there are two principal reasons for this effect, the low sensitivity of the imaging sensor and the low amount of light available from the illuminating source. In plant science, the blue region contains relevant information about the physiology and the health status of a plant. We report on the improvement in sensitivity of a hyperspectral imaging system in the blue region of the spectrum by using supplemental illumination provided by an array of high brightness light emitting diodes (LEDs with an emission peak at 470 nm.

The plant cell wall integrity maintenance mechanism--a case study of a cell wall plasma membrane signaling network.

Science.gov (United States)

Hamann, Thorsten

2015-04-01

Some of the most important functions of plant cell walls are protection against biotic/abiotic stress and structural support during growth and development. A prerequisite for plant cell walls to perform these functions is the ability to perceive different types of stimuli in both qualitative and quantitative manners and initiate appropriate responses. The responses in turn involve adaptive changes in cellular and cell wall metabolism leading to modifications in the structures originally required for perception. While our knowledge about the underlying plant mechanisms is limited, results from Saccharomyces cerevisiae suggest the cell wall integrity maintenance mechanism represents an excellent example to illustrate how the molecular mechanisms responsible for stimulus perception, signal transduction and integration can function. Here I will review the available knowledge about the yeast cell wall integrity maintenance system for illustration purposes, summarize the limited knowledge available about the corresponding plant mechanism and discuss the relevance of the plant cell wall integrity maintenance mechanism in biotic stress responses. Copyright © 2014 Elsevier Ltd. All rights reserved.

Molecular imaging in stem cell-based therapies of cardiac diseases.

Science.gov (United States)

Li, Xiang; Hacker, Marcus

2017-10-01

In the past 15years, despite that regenerative medicine has shown great potential for cardiovascular diseases, the outcome and safety of stem cell transplantation has shown controversial results in the published literature. Medical imaging might be useful for monitoring and quantifying transplanted cells within the heart and to serially characterize the effects of stem cell therapy of the myocardium. From the multiple available noninvasive imaging techniques, magnetic resonance imaging and nuclear imaging by positron (PET) or single photon emission computer tomography (SPECT) are the most used clinical approaches to follow the fate of transplanted stem cells in vivo. In this article, we provide a review on the role of different noninvasive imaging modalities and discuss their advantages and disadvantages. We focus on the different in-vivo labeling and reporter gene imaging strategies for stem cell tracking as well as the concept and reliability to use imaging parameters as noninvasive surrogate endpoints for the evaluation of the post-therapeutic outcome. Copyright © 2017 Elsevier B.V. All rights reserved.

The Role of Pectin Acetylation in the Organization of Plant Cell Walls

DEFF Research Database (Denmark)

Fimognari, Lorenzo

adopt defined 3D organization to allow their composition/interactions to be tweaked upon developmental need. Failure to build functional cell wall architecture will affect plant growth and resistance to stresses. In this PhD dissertation I explored the role of pectin acetylation in controlling...... wall organization, namely polysaccharides-to-polysaccharides interactions. These results suggest that cell wall acetylation is a mechanism that plants evolved to control cell wall organization. In Manuscript III, we report the characterization of Arabidopsis mutants trichome birefringence like (tbl) 10......All plant cells are surrounded by one or more cell wall layers. The cell wall serves as a stiff mechanical support while it allows cells to expand and provide a protective barrier to invading pathogens. Cell walls are dynamic structures composed of entangled cell wall polysaccharides that must...

Autofluorescence-Free Live-Cell Imaging Using Terbium Nanoparticles.

Science.gov (United States)

Cardoso Dos Santos, M; Goetz, J; Bartenlian, H; Wong, K-L; Charbonnière, L J; Hildebrandt, N

2018-04-18

Fluorescent nanoparticles (NPs) have become irreplaceable tools for advanced cellular and subcellular imaging. While very bright NPs require excitation with UV or visible light, which can create strong autofluorescence of biological components, NIR-excitable NPs without autofluorescence issues exhibit much lower brightness. Here, we show the application of a new type of surface-photosensitized terbium NPs (Tb-NPs) for autofluorescence-free intracellular imaging in live HeLa cells. The combination of exceptionally high brightness, high photostability, and long photoluminecence (PL) lifetimes for highly efficient suppression of the short-lived autofluorescence allowed for time-gated PL imaging of intracellular vesicles over 72 h without toxicity and at extremely low Tb-NP concentrations down to 12 pM. Detection of highly resolved long-lifetime (ms) PL decay curves from small (∼10 μm 2 ) areas within single cells within a few seconds emphasized the unprecedented photophysical properties of Tb-NPs for live-cell imaging that extend well beyond currently available nanometric imaging agents.

Synthesis and Application of Plant Cell Wall Oligogalactans

DEFF Research Database (Denmark)

Andersen, Mathias Christian Franch

The plant cell walls represent almost 50% of the biomass found in plants and are therefore one of the main targets for biotechnological research. Major motivators are their potential as a renewable energy source for transport fuels, as functional foods, and as a source of raw materials to generate...

Role of the plant cell wall in gravity resistance.

Science.gov (United States)

Hoson, Takayuki; Wakabayashi, Kazuyuki

2015-04-01

Gravity resistance, mechanical resistance to the gravitational force, is a principal graviresponse in plants, comparable to gravitropism. The cell wall is responsible for the final step of gravity resistance. The gravity signal increases the rigidity of the cell wall via the accumulation of its constituents, polymerization of certain matrix polysaccharides due to the suppression of breakdown, stimulation of cross-link formation, and modifications to the wall environment, in a wide range of situations from microgravity in space to hypergravity. Plants thus develop a tough body to resist the gravitational force via an increase in cell wall rigidity and the modification of growth anisotropy. The development of gravity resistance mechanisms has played an important role in the acquisition of responses to various mechanical stresses and the evolution of land plants. Copyright © 2014 Elsevier Ltd. All rights reserved.

Imaging and etching, soft x-ray microscopy on whole wet cells

International Nuclear Information System (INIS)

Gilbert, J.R.; Pine, J.

1993-01-01

The authors have produced images of whole wet tissue culture cells with the Stony Brook/BNL scanning transmission x-ray microscope (STXM). For fixed cells the authors have taken images at theoretical resolutions of ∼50-75nm, and in practice have measured FWHM of features down to near 100nm, without any exotic image processing. For unfixed (i.e., initially live) cells the authors have imaged with 100nm pixels and measured features down to 250nm. In order to do this the authors have developed, tested and used a wet cell for maintaining fixed or live cells on the STXM stage during imaging. The design of the wet cell and the culture substrates that go with it make the STXM compatible with almost all standard systems for surface adherent tissue culture. The authors will show some new images of whole wet fixed and unfixed cells, with visible sub-micron features. The authors will also report data that helps to characterize the tissue damage due to x-ray absorption during STXM imaging

The Mechanism Forming the Cell Surface of Tip-Growing Rooting Cells Is Conserved among Land Plants.

Science.gov (United States)

Honkanen, Suvi; Jones, Victor A S; Morieri, Giulia; Champion, Clement; Hetherington, Alexander J; Kelly, Steve; Proust, Hélène; Saint-Marcoux, Denis; Prescott, Helen; Dolan, Liam

2016-12-05

To discover mechanisms that controlled the growth of the rooting system in the earliest land plants, we identified genes that control the development of rhizoids in the liverwort Marchantia polymorpha. 336,000 T-DNA transformed lines were screened for mutants with defects in rhizoid growth, and a de novo genome assembly was generated to identify the mutant genes. We report the identification of 33 genes required for rhizoid growth, of which 6 had not previously been functionally characterized in green plants. We demonstrate that members of the same orthogroup are active in cell wall synthesis, cell wall integrity sensing, and vesicle trafficking during M. polymorpha rhizoid and Arabidopsis thaliana root hair growth. This indicates that the mechanism for constructing the cell surface of tip-growing rooting cells is conserved among land plants and was active in the earliest land plants that existed sometime more than 470 million years ago [1, 2]. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Image diagnosis of plant function under environmental pollution. Shokubutsu de kankyo osen wo shindansuru

Energy Technology Data Exchange (ETDEWEB)

Omasa, K. (National Inst. for Environmental studies, Tsukuba (Japan))

1993-12-20

Various physiological reaction of plants would be obstructed and troubles of their growth would be met under environmental pollution. There are also cases that the polluted materials as nutritious components are absorbed by plants. Consequently, if plant's reaction on this environmental pollution would be used, indexes of environmental pollution and environment can be improved. For examples, Ipomoea Nil and Petunia having high reaction on photochemical oxidate are widely used as index plant of air pollution. Zelkova trees and poplars planted as street trees can also greatly absorbed the polluted gas and have a function to clear air. In this paper, a diagnosis method by visualizing plant's reaction on environmental pollution by using technique of image measurement was explained. As devices of usable image measurement, a thermal camera, a solid measuring cameras, an ultrasonic camera, a multi-spectral camera and an X-ray TV camera were given. 6 refs., 4 figs., 1 tab.

Dual photon excitation microscopy and image threshold segmentation in live cell imaging during compression testing.

Science.gov (United States)

Moo, Eng Kuan; Abusara, Ziad; Abu Osman, Noor Azuan; Pingguan-Murphy, Belinda; Herzog, Walter

2013-08-09

Morphological studies of live connective tissue cells are imperative to helping understand cellular responses to mechanical stimuli. However, photobleaching is a constant problem to accurate and reliable live cell fluorescent imaging, and various image thresholding methods have been adopted to account for photobleaching effects. Previous studies showed that dual photon excitation (DPE) techniques are superior over conventional one photon excitation (OPE) confocal techniques in minimizing photobleaching. In this study, we investigated the effects of photobleaching resulting from OPE and DPE on morphology of in situ articular cartilage chondrocytes across repeat laser exposures. Additionally, we compared the effectiveness of three commonly-used image thresholding methods in accounting for photobleaching effects, with and without tissue loading through compression. In general, photobleaching leads to an apparent volume reduction for subsequent image scans. Performing seven consecutive scans of chondrocytes in unloaded cartilage, we found that the apparent cell volume loss caused by DPE microscopy is much smaller than that observed using OPE microscopy. Applying scan-specific image thresholds did not prevent the photobleaching-induced volume loss, and volume reductions were non-uniform over the seven repeat scans. During cartilage loading through compression, cell fluorescence increased and, depending on the thresholding method used, led to different volume changes. Therefore, different conclusions on cell volume changes may be drawn during tissue compression, depending on the image thresholding methods used. In conclusion, our findings confirm that photobleaching directly affects cell morphology measurements, and that DPE causes less photobleaching artifacts than OPE for uncompressed cells. When cells are compressed during tissue loading, a complicated interplay between photobleaching effects and compression-induced fluorescence increase may lead to interpretations in

Unraveling the response of plant cells to cytotoxic saponins

Science.gov (United States)

Balestrazzi, Alma; Macovei, Anca; Tava, Aldo; Avato, Pinarosa; Raimondi, Elena

2011-01-01

A wide range of pharmacological properties are ascribed to natural saponins, in addition to their biological activities against herbivores, plant soil-borne pathogens and pests. As for animal cells, the cytotoxicity and the chemopreventive role of saponins are mediated by a complex network of signal transduction pathways which include reactive oxygen species (ROS) and nitric oxide (NO). The involvement of other relevant components of the saponin-related signaling routes, such as the Tumor Necrosis Factor (TNF)α, the interleukin (IL)-6 and the Nuclear Transcription FactorκB (NFκB), has been highlighted in animal cells. By contrast, information concerning the response of plant cells to saponins and the related signal transduction pathways is almost missing. To date, there are only a few common features which link plant and animal cells in their response to saponins, such as the early burst in ROS and NO production and the induction of metallothioneins (MTs), small cysteine-rich, metal-binding proteins. This aspect is discussed in the present paper in view of the recent hypothesis that MTs and NO are part of a novel signal transduction pathway participating in the cell response to oxidative stress. PMID:21673512

Skeletal MR imaging in sickle cell disease

International Nuclear Information System (INIS)

Effmann, E.L.; Kinney, T.R.; Utz, J.A.; Merten, D.F.; Herfkens, R.J.

1986-01-01

The authors evaluated eight patients with sickle cell disease (mean age, 15.75 years; range 5-19 years) using MR imaging performed 24-72 hours after hospital admission for crisis. Coronal images of the lower extremities were obtained with a General Electric 1.5-T system and pulse sequences of TR/TE = 500/25 msec and 2,000/40, 80 msec. In three patients a mild decrease in signal intensity was seen on both T1- and T2-weighted images, probably secondary to marrow hyperplasia. In two patients a marked decrease in signal intensity was seen on both T1- and T2-weighted images, probably secondary to the diamagnetic effects of marrow iron. Six patients had bone infarct(s) which appeared as well-defined areas with prolonged T2 relaxation times. MR imaging appears promising for the evaluation of bone marrow in sickle cell anemia

The study of accumulation of Sr 90 by plant cells

International Nuclear Information System (INIS)

Matusov, G.D.; Kudryashova, N.N.

2002-01-01

In this work the absorption and desorption of ions Sr 90 by plant cells and influence of different physical and chemical factors of environment on that processes were investigated. The kinetics of strontium accumulation have been obtained and the factors of accumulation of Sr 90 have been determined for a plant cell itself and its separate compartments

Phenotype-Based Screening of Small Molecules to Modify Plant Cell Walls Using BY-2 Cells.

Science.gov (United States)

Okubo-Kurihara, Emiko; Matsui, Minami

2018-01-01

The plant cell wall is an important and abundant biomass with great potential for use as a modern recyclable resource. For effective utilization of this cellulosic biomass, its ability to degrade efficiently is key point. With the aim of modifying the cell wall to allow easy decomposition, we used chemical biological technology to alter its structure. As a first step toward evaluating the chemicals in the cell wall we employed a phenotype-based approach using high-throughput screening. As the plant cell wall is essential in determining cell morphology, phenotype-based screening is particularly effective in identifying compounds that bring about alterations in the cell wall. For rapid and reproducible screening, tobacco BY-2 cell is an excellent system in which to observe cell morphology. In this chapter, we provide a detailed chemical biological methodology for studying cell morphology using tobacco BY-2 cells.

Development of high-spatial and high-mass resolution mass spectrometric imaging (MSI) and its application to the study of small metabolites and endogenous molecules of plants

Energy Technology Data Exchange (ETDEWEB)

Jun, Ji Hyun [Iowa State Univ., Ames, IA (United States)

2012-01-01

High-spatial and high-mass resolution laser desorption ionization (LDI) mass spectrometric (MS) imaging technology was developed for the attainment of MS images of higher quality containing more information on the relevant cellular and molecular biology in unprecedented depth. The distribution of plant metabolites is asymmetric throughout the cells and tissues, and therefore the increase in the spatial resolution was pursued to reveal the localization of plant metabolites at the cellular level by MS imaging. For achieving high-spatial resolution, the laser beam size was reduced by utilizing an optical fiber with small core diameter (25 μm) in a vacuum matrix-assisted laser desorption ionization-linear ion trap (vMALDI-LTQ) mass spectrometer. Matrix application was greatly improved using oscillating capillary nebulizer. As a result, single cell level spatial resolution of ~ 12 μm was achieved. MS imaging at this high spatial resolution was directly applied to a whole Arabidopsis flower and the substructures of an anther and single pollen grains at the stigma and anther were successfully visualized. MS imaging of high spatial resolution was also demonstrated to the secondary roots of Arabidopsis thaliana and a high degree of localization of detected metabolites was successfully unveiled. This was the first MS imaging on the root for molecular species. MS imaging with high mass resolution was also achieved by utilizing the LTQ-Orbitrap mass spectrometer for the direct identification of the surface metabolites on the Arabidopsis stem and root and differentiation of isobaric ions having the same nominal mass with no need of tandem mass spectrometry (MS/MS). MS imaging at high-spatial and high-mass resolution was also applied to cer1 mutant of the model system Arabidopsis thaliana to demonstrate its usefulness in biological studies and reveal associated metabolite changes in terms of spatial distribution and/or abundances compared to those of wild-type. The spatial

Alterations of the cytoskeleton in human cells in space proved by life-cell imaging

Science.gov (United States)

Corydon, Thomas J.; Kopp, Sascha; Wehland, Markus; Braun, Markus; Schütte, Andreas; Mayer, Tobias; Hülsing, Thomas; Oltmann, Hergen; Schmitz, Burkhard; Hemmersbach, Ruth; Grimm, Daniela

2016-01-01

Microgravity induces changes in the cytoskeleton. This might have an impact on cells and organs of humans in space. Unfortunately, studies of cytoskeletal changes in microgravity reported so far are obligatorily based on the analysis of fixed cells exposed to microgravity during a parabolic flight campaign (PFC). This study focuses on the development of a compact fluorescence microscope (FLUMIAS) for fast live-cell imaging under real microgravity. It demonstrates the application of the instrument for on-board analysis of cytoskeletal changes in FTC-133 cancer cells expressing the Lifeact-GFP marker protein for the visualization of F-actin during the 24th DLR PFC and TEXUS 52 rocket mission. Although vibration is an inevitable part of parabolic flight maneuvers, we successfully for the first time report life-cell cytoskeleton imaging during microgravity, and gene expression analysis after the 31st parabola showing a clear up-regulation of cytoskeletal genes. Notably, during the rocket flight the FLUMIAS microscope reveals significant alterations of the cytoskeleton related to microgravity. Our findings clearly demonstrate the applicability of the FLUMIAS microscope for life-cell imaging during microgravity, rendering it an important technological advance in live-cell imaging when dissecting protein localization. PMID:26818711

Glioblastoma cells labeled by robust Raman tags for enhancing imaging contrast.

Science.gov (United States)

Huang, Li-Ching; Chang, Yung-Ching; Wu, Yi-Syuan; Sun, Wei-Lun; Liu, Chan-Chuan; Sze, Chun-I; Chen, Shiuan-Yeh

2018-05-01

Complete removal of a glioblastoma multiforme (GBM), a highly malignant brain tumor, is challenging due to its infiltrative characteristics. Therefore, utilizing imaging agents such as fluorophores to increase the contrast between GBM and normal cells can help neurosurgeons to locate residual cancer cells during image guided surgery. In this work, Raman tag based labeling and imaging for GBM cells in vitro is described and evaluated. The cell membrane of a GBM adsorbs a substantial amount of functionalized Raman tags through overexpression of the epidermal growth factor receptor (EGFR) and "broadcasts" stronger pre-defined Raman signals than normal cells. The average ratio between Raman signals from a GBM cell and autofluorescence from a normal cell can be up to 15. In addition, the intensity of these images is stable under laser illuminations without suffering from the severe photo-bleaching that usually occurs in fluorescent imaging. Our results show that labeling and imaging GBM cells via robust Raman tags is a viable alternative method to distinguish them from normal cells. This Raman tag based method can be used solely or integrated into an existing fluorescence system to improve the identification of infiltrative glial tumor cells around the boundary, which will further reduce GBM recurrence. In addition, it can also be applied/extended to other types of cancer to improve the effectiveness of image guided surgery.

Cross-Sectional Transport Imaging in a Multijunction Solar Cell

Energy Technology Data Exchange (ETDEWEB)

Haegel, Nancy M.; Ke, Chi-Wen; Taha, Hesham; Guthrey, Harvey; Fetzer, C. M.; King, Richard

2015-06-14

Combining highly localized electron-beam excitation at a point with the spatial resolution capability of optical near-field imaging, we have imaged carrier transport in a cross-sectioned multijunction (GaInP/GaInAs/Ge) solar cell. We image energy transport associated with carrier diffusion throughout the full width of the middle (GaInAs) cell and luminescent coupling from point excitation in the top cell GaInP to the middle cell. Supporting cathodoluminescence and near-field photoluminescence measurements demonstrate excitation-dependent Fermi level splitting effects that influence cross-sectioned spectroscopy results as well as transport limitations on the spatial resolution of cross-sectional measurements.

Imaging protein-protein interactions in living cells

NARCIS (Netherlands)

Hink, M.A.; Bisseling, T.; Visser, A.J.W.G.

2002-01-01

The complex organization of plant cells makes it likely that the molecular behaviour of proteins in the test tube and the cell is different. For this reason, it is essential though a challenge to study proteins in their natural environment. Several innovative microspectroscopic approaches provide

Catalysts of plant cell wall loosening [version 1; referees: 2 approved

OpenAIRE

Daniel J. Cosgrove

2016-01-01

The growing cell wall in plants has conflicting requirements to be strong enough to withstand the high tensile forces generated by cell turgor pressure while selectively yielding to those forces to induce wall stress relaxation, leading to water uptake and polymer movements underlying cell wall expansion. In this article, I review emerging concepts of plant primary cell wall structure, the nature of wall extensibility and the action of expansins, family-9 and -12 endoglucanases, family-16 xyl...

CARS hyperspectral imaging of cartilage aiming for state discrimination of cell

Science.gov (United States)

Shiozawa, Manabu; Shirai, Masataka; Izumisawa, Junko; Tanabe, Maiko; Watanabe, Koichi

2016-03-01

Non-invasive cell analyses are increasingly important for medical field. A CARS microscope is one of the non-invasive imaging equipments and enables to obtain images indicating molecular distribution. Some studies on discrimination of cell state by using CARS images of lipid are reported. However, due to low signal intensity, it is still challenging to obtain images of the fingerprint region (800~1800 cm-1), in which many spectrum peaks correspond to compositions of a cell. Here, to identify cell differentiation by using multiplex CARS, we investigated hyperspectral imaging of fingerprint region of living cells. To perform multiplex CARS, we used a prototype of a compact light source, which consists of a microchip laser, a single-mode fiber, and a photonic crystal fiber to generate supercontinuum light. Assuming application to regenerative medicine, we chose a cartilage cell, whose differentiation is difficult to be identified by change of the cell morphology. Because one of the major components of cartilage is collagen, we focused on distribution of proline, which accounts for approximately 20% of collagen in general. The spectrum quality was improved by optical adjustments about power branching ratio and divergence of broadband Stokes light. Hyperspectral images were successfully obtained by the improvement. Periphery of a cartilage cell was highlighted in CARS image of proline, and this result suggests correspondence with collagen generated as extracellular matrix. A possibility of cell analyses by using CARS hyperspectral imaging was indicated.

Plant cells : immobilization and oxygen transfer

NARCIS (Netherlands)

Hulst, A.C.

1987-01-01

The study described in this thesis is part of the integrated project 'Biotechnological production of non-persistent bioinsecticides by means of plant cells invitro ' and was done in close cooperation with the research Institute Ital within the framework

Nano-imaging of single cells using STIM

Energy Technology Data Exchange (ETDEWEB)

Ren Minqin [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Department of Biochemistry, National University of Singapore (Singapore); Kan, J.A. van [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Bettiol, A.A. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Daina, Lim [Department of Anatomy, National University of Singapore (Singapore); Gek, Chan Yee [Department of Anatomy, National University of Singapore (Singapore); Huat, Bay Boon [Department of Anatomy, National University of Singapore (Singapore); Whitlow, H.J. [Department of Physics, University of Jyvaskyla, P.O. Box 35 (YFL), FIN-40014 (Finland); Osipowicz, T. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Watt, F. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore)]. E-mail: phywattf@nus.edu.sg

2007-07-15

Scanning transmission ion microscopy (STIM) is a technique which utilizes the energy loss of high energy (MeV) ions passing through a sample to provide structural images. In this paper, we have successfully demonstrated STIM imaging of single cells at the nano-level using the high resolution capability of the proton beam writing facility at the Centre for Ion Beam Applications, National University of Singapore. MCF-7 breast cancer cells (American Type Culture Collection [ATCC]) were seeded on to silicon nitride windows, backed by a Hamamatsu pin diode acting as a particle detector. A reasonable contrast was obtained using 1 MeV protons and excellent contrast obtained using 1 MeV alpha particles. In a further experiment, nano-STIM was also demonstrated using cells seeded on to the pin diode directly, and high quality nano-STIM images showing the nucleus and multiple nucleoli were extracted before the detector was significantly damaged.

Design of microdevices for long-term live cell imaging

International Nuclear Information System (INIS)

Chen, Huaying; Nordon, Robert E; Rosengarten, Gary; Li, Musen

2012-01-01

Advances in fluorescent live cell imaging provide high-content information that relates a cell's life events to its ancestors. An important requirement to track clonal growth and development is the retention of motile cells derived from an ancestor within the same microscopic field of view for days to weeks, while recording fluorescence images and controlling the mechanical and biochemical microenvironments that regulate cell growth and differentiation. The aim of this study was to design a microwell device for long-term, time-lapse imaging of motile cells with the specific requirements of (a) inoculating devices with an average of one cell per well and (b) retaining progeny of cells within a single microscopic field of view for extended growth periods. A two-layer PDMS microwell culture device consisting of a parallel-plate flow cell bonded on top of a microwell array was developed for cell capture and clonal culture. Cell deposition statistics were related to microwell geometry (plate separation and well depth) and the Reynolds number. Computational fluid dynamics was used to simulate flow in the microdevices as well as cell–fluid interactions. Analysis of the forces acting upon a cell was used to predict cell docking zones, which were confirmed by experimental observations. Cell–fluid dynamic interactions are important considerations for design of microdevices for long-term, live cell imaging. The analysis of force and torque balance provides a reasonable approximation for cell displacement forces. It is computationally less intensive compared to simulation of cell trajectories, and can be applied to a wide range of microdevice geometries to predict the cell docking behavior. (paper)

Cell tracking with gadophrin-2: a bifunctional contrast agent for MR imaging, optical imaging, and fluorescence microscopy

International Nuclear Information System (INIS)

Daldrup-Link, Heike E.; Rudelius, Martina; Piontek, Guido; Schlegel, Juergen; Metz, Stephan; Settles, Marcus; Rummeny, Ernst J.; Pichler, Bernd; Heinzmann, Ulrich; Oostendorp, Robert A.J.

2004-01-01

The purpose of this study was to assess the feasibility of use of gadophrin-2 to trace intravenously injected human hematopoietic cells in athymic mice, employing magnetic resonance (MR) imaging, optical imaging (OI), and fluorescence microscopy. Mononuclear peripheral blood cells from GCSF-primed patients were labeled with gadophrin-2 (Schering AG, Berlin, Germany), a paramagnetic and fluorescent metalloporphyrin, using established transfection techniques with cationic liposomes. The labeled cells were evaluated in vitro with electron microscopy and inductively coupled plasma atomic emission spectrometry. Then, 1 x 10 6 -3 x 10 8 labeled cells were injected into 14 nude Balb/c mice and the in vivo cell distribution was evaluated with MR imaging and OI before and 4, 24, and 48 h after intravenous injection (p.i.). Five additional mice served as controls: three mice were untreated controls and two mice were investigated after injection of unlabeled cells. The contrast agent effect was determined quantitatively for MR imaging by calculating signal-to-noise-ratio (SNR) data. After completion of in vivo imaging studies, fluorescence microscopy of excised organs was performed. Intracellular cytoplasmatic uptake of gadophrin-2 was confirmed by electron microscopy. Spectrometry determined an uptake of 31.56 nmol Gd per 10 6 cells. After intravenous injection, the distribution of gadophrin-2 labeled cells in nude mice could be visualized by MR, OI, and fluorescence microscopy. At 4 h p.i., the transplanted cells mainly distributed to lung, liver, and spleen, and 24 h p.i. they also distributed to the bone marrow. Fluorescence microscopy confirmed the distribution of gadophrin-2 labeled cells to these target organs. Gadophrin-2 is suited as a bifunctional contrast agent for MR imaging, OI, and fluorescence microscopy and may be used to combine the advantages of each individual imaging modality for in vivo tracking of intravenously injected hematopoietic cells. (orig.)

Nanosecond electric pulses trigger actin responses in plant cells

International Nuclear Information System (INIS)

Berghoefer, Thomas; Eing, Christian; Flickinger, Bianca; Hohenberger, Petra; Wegner, Lars H.; Frey, Wolfgang; Nick, Peter

2009-01-01

We have analyzed the cellular effects of nanosecond pulsed electrical fields on plant cells using fluorescently tagged marker lines in the tobacco cell line BY-2 and confocal laser scanning microscopy. We observe a disintegration of the cytoskeleton in the cell cortex, followed by contraction of actin filaments towards the nucleus, and disintegration of the nuclear envelope. These responses are accompanied by irreversible permeabilization of the plasma membrane manifest as uptake of Trypan Blue. By pretreatment with the actin-stabilizing drug phalloidin, the detachment of transvacuolar actin from the cell periphery can be suppressed, and this treatment can also suppress the irreversible perforation of the plasma membrane. We discuss these findings in terms of a model, where nanosecond pulsed electric fields trigger actin responses that are key events in the plant-specific form of programmed cell death.

2009 Plant Cell Walls Gordon Research Conference-August 2-7,2009

Energy Technology Data Exchange (ETDEWEB)

Mohnen, Debra [Univ. of Georgia, Athens, GA (United States)

2009-08-07

Plant cell walls are a complex cellular compartment essential for plant growth, development and response to biotic and abiotic stress and a major biological resource for meeting our future bioenergy and natural product needs. The goal of the 2009 Plant Cell Walls Gordon Research Conference is to summarize and critically evaluate the current level of understanding of the structure, synthesis and function of the whole plant extracellular matrix, including the polysaccharides, proteins, lignin and waxes that comprise the wall, and the enzymes and regulatory proteins that drive wall synthesis and modification. Innovative techniques to study how both primary and secondary wall polymers are formed and modified throughout plant growth will be emphasized, including rapid advances taking place in the use of anti-wall antibodies and carbohydrate binding proteins, comparative and evolutionary wall genomics, and the use of mutants and natural variants to understand and identify wall structure-function relationships. Discussions of essential research advances needed to push the field forward toward a systems biology approach will be highlighted. The meeting will include a commemorative lecture in honor of the career and accomplishments of the late Emeritus Professor Bruce A. Stone, a pioneer in wall research who contributed over 40 years of outstanding studies on plant cell wall structure, function, synthesis and remodeling including emphasis on plant cell wall beta-glucans and arabinogalactans. The dwindling supply of fossil fuels will not suffice to meet our future energy and industrial product needs. Plant biomass is the renewable resource that will fill a large part of the void left by vanishing fossil fuels. It is therefore critical that basic research scientists interact closely with industrial researchers to critically evaluate the current state of knowledge regarding how plant biomass, which is largely plant cell walls, is synthesized and utilized by the plant. A final

The fusarium mycotoxin deoxynivalenol can inhibit plant apoptosis-like programmed cell death.

Directory of Open Access Journals (Sweden)

Mark Diamond

Full Text Available The Fusarium genus of fungi is responsible for commercially devastating crop diseases and the contamination of cereals with harmful mycotoxins. Fusarium mycotoxins aid infection, establishment, and spread of the fungus within the host plant. We investigated the effects of the Fusarium mycotoxin deoxynivalenol (DON on the viability of Arabidopsis cells. Although it is known to trigger apoptosis in animal cells, DON treatment at low concentrations surprisingly did not kill these cells. On the contrary, we found that DON inhibited apoptosis-like programmed cell death (PCD in Arabidopsis cells subjected to abiotic stress treatment in a manner independent of mitochondrial cytochrome c release. This suggested that Fusarium may utilise mycotoxins to suppress plant apoptosis-like PCD. To test this, we infected Arabidopsis cells with a wild type and a DON-minus mutant strain of F. graminearum and found that only the DON producing strain could inhibit death induced by heat treatment. These results indicate that mycotoxins may be capable of disarming plant apoptosis-like PCD and thereby suggest a novel way that some fungi can influence plant cell fate.

In vivo imaging of the retinal pigment epithelial cells

Science.gov (United States)

Morgan, Jessica Ijams Wolfing

The retinal pigment epithelial (RPE) cells form an important layer of the retina because they are responsible for providing metabolic support to the photoreceptors. Techniques to image the RPE layer include autofluorescence imaging with a scanning laser ophthalmoscope (SLO). However, previous studies were unable to resolve single RPE cells in vivo. This thesis describes the technique of combining autofluorescence, SLO, adaptive optics (AO), and dual-wavelength simultaneous imaging and registration to visualize the individual cells in the RPE mosaic in human and primate retina for the first time in vivo. After imaging the RPE mosaic non-invasively, the cell layer's structure and regularity were characterized using quantitative metrics of cell density, spacing, and nearest neighbor distances. The RPE mosaic was compared to the cone mosaic, and RPE imaging methods were confirmed using histology. The ability to image the RPE mosaic led to the discovery of a novel retinal change following light exposure; 568 nm exposures caused an immediate reduction in autofluorescence followed by either full recovery or permanent damage in the RPE layer. A safety study was conducted to determine the range of exposure irradiances that caused permanent damage or transient autofluorescence reductions. Additionally, the threshold exposure causing autofluorescence reduction was determined and reciprocity of radiant exposure was confirmed. Light exposures delivered by the AOSLO were not significantly different than those delivered by a uniform source. As all exposures tested were near or below the permissible light levels of safety standards, this thesis provides evidence that the current light safety standards need to be revised. Finally, with the retinal damage and autofluorescence reduction thresholds identified, the methods of RPE imaging were modified to allow successful imaging of the individual cells in the RPE mosaic while still ensuring retinal safety. This thesis has provided a

Live cell imaging of in vitro human trophoblast syncytialization.

Science.gov (United States)

Wang, Rui; Dang, Yan-Li; Zheng, Ru; Li, Yue; Li, Weiwei; Lu, Xiaoyin; Wang, Li-Juan; Zhu, Cheng; Lin, Hai-Yan; Wang, Hongmei

2014-06-01

Human trophoblast syncytialization, a process of cell-cell fusion, is one of the most important yet least understood events during placental development. Investigating the fusion process in a placenta in vivo is very challenging given the complexity of this process. Application of primary cultured cytotrophoblast cells isolated from term placentas and BeWo cells derived from human choriocarcinoma formulates a biphasic strategy to achieve the mechanism of trophoblast cell fusion, as the former can spontaneously fuse to form the multinucleated syncytium and the latter is capable of fusing under the treatment of forskolin (FSK). Live-cell imaging is a powerful tool that is widely used to investigate many physiological or pathological processes in various animal models or humans; however, to our knowledge, the mechanism of trophoblast cell fusion has not been reported using a live- cell imaging manner. In this study, a live-cell imaging system was used to delineate the fusion process of primary term cytotrophoblast cells and BeWo cells. By using live staining with Hoechst 33342 or cytoplasmic dyes or by stably transfecting enhanced green fluorescent protein (EGFP) and DsRed2-Nuc reporter plasmids, we observed finger-like protrusions on the cell membranes of fusion partners before fusion and the exchange of cytoplasmic contents during fusion. In summary, this study provides the first video recording of the process of trophoblast syncytialization. Furthermore, the various live-cell imaging systems used in this study will help to yield molecular insights into the syncytialization process during placental development. © 2014 by the Society for the Study of Reproduction, Inc.

Preparation of labelled lipids by the use of plant cell cultures

International Nuclear Information System (INIS)

Mangold, H.K.

1978-01-01

The preparation of some radioacitvely labelled lipids by the use of plant cell cultures is discussed and further applications of the new method are suggested. Cell suspension cultures of rape (Brassica napus) and soya (Glycine max) have been used for the preparation of lipids labelled with radioisotopes. Radioactive acetic acid as well as various long-chain fatty acids are readily incorporated into the neutral and ionic lipids of plant cell cultures. In addition, 14 C-labelled glycerol, ethanolamine and choline are well utilized by the cells. Randomly labelled lipids have been obtained by incubating cell suspension cultures of rape and soya with [1- 14 C] acetic acid, and uniformly labelled lipids have been isolated from cultures that had been incubated with a mixture of [1- 14 C] acetic acid plus [2- 14 C] acetic acid. The use of techniques of plant cell cultures for the preparation of lipds labelled with stable or radioactive isotopesappears particularly rewarding because the uptake of precursors by the cells and their incorporation into various lipid compounds proceeds rapidly and often quanitatively.This new approach should be useful also for the biosynthesis of lipids whose acyl moieties contain a spn radical, a fluorescent group, or a light-sensitive label. Thus, plant cell cultures constitute valuable new tools for the biosynthetic preparation of a great variety of labelled lipids. (A.G.)

Handbook of plant cell culture. Volume 2. Crop species

Energy Technology Data Exchange (ETDEWEB)

Sharp, W.R.; Evans, D.A.; Ammirato, P.V.; Yamada, Y. (eds.)

1984-01-01

In this volume the state-of-the-art plant cell culture techniques described in the first volume are applied to several agricultural and horticultural crops. In 21 chapters, they include maize, oats, wheat, beans, red clover and other forage legumes, asparagus, celery, cassava, sweet potato, banana, pawpaw, apple, grapes, conifers, date palm, rubber, sugarcane and tobacco. Each chapter contains (1) detailed protocols to serve as the foundation for current research, (2) a critical review of the literature, and (3) in-depth evaluations of the potential shown by plant cell culture for crop improvement. The history and economic importance of each crop are discussed. This volume also includes an essay, ''Oil from plants'', by M. Calvin.

Hierarchical imaging: a new concept for targeted imaging of large volumes from cells to tissues.

Science.gov (United States)

Wacker, Irene; Spomer, Waldemar; Hofmann, Andreas; Thaler, Marlene; Hillmer, Stefan; Gengenbach, Ulrich; Schröder, Rasmus R

2016-12-12

Imaging large volumes such as entire cells or small model organisms at nanoscale resolution seemed an unrealistic, rather tedious task so far. Now, technical advances have lead to several electron microscopy (EM) large volume imaging techniques. One is array tomography, where ribbons of ultrathin serial sections are deposited on solid substrates like silicon wafers or glass coverslips. To ensure reliable retrieval of multiple ribbons from the boat of a diamond knife we introduce a substrate holder with 7 axes of translation or rotation specifically designed for that purpose. With this device we are able to deposit hundreds of sections in an ordered way in an area of 22 × 22 mm, the size of a coverslip. Imaging such arrays in a standard wide field fluorescence microscope produces reconstructions with 200 nm lateral resolution and 100 nm (the section thickness) resolution in z. By hierarchical imaging cascades in the scanning electron microscope (SEM), using a new software platform, we can address volumes from single cells to complete organs. In our first example, a cell population isolated from zebrafish spleen, we characterize different cell types according to their organelle inventory by segmenting 3D reconstructions of complete cells imaged with nanoscale resolution. In addition, by screening large numbers of cells at decreased resolution we can define the percentage at which different cell types are present in our preparation. With the second example, the root tip of cress, we illustrate how combining information from intermediate resolution data with high resolution data from selected regions of interest can drastically reduce the amount of data that has to be recorded. By imaging only the interesting parts of a sample considerably less data need to be stored, handled and eventually analysed. Our custom-designed substrate holder allows reproducible generation of section libraries, which can then be imaged in a hierarchical way. We demonstrate, that EM

Molecular Imaging in Stem Cell Therapy for Spinal Cord Injury

Directory of Open Access Journals (Sweden)

Fahuan Song

2014-01-01

Full Text Available Spinal cord injury (SCI is a serious disease of the center nervous system (CNS. It is a devastating injury with sudden loss of motor, sensory, and autonomic function distal to the level of trauma and produces great personal and societal costs. Currently, there are no remarkable effective therapies for the treatment of SCI. Compared to traditional treatment methods, stem cell transplantation therapy holds potential for repair and functional plasticity after SCI. However, the mechanism of stem cell therapy for SCI remains largely unknown and obscure partly due to the lack of efficient stem cell trafficking methods. Molecular imaging technology including positron emission tomography (PET, magnetic resonance imaging (MRI, optical imaging (i.e., bioluminescence imaging (BLI gives the hope to complete the knowledge concerning basic stem cell biology survival, migration, differentiation, and integration in real time when transplanted into damaged spinal cord. In this paper, we mainly review the molecular imaging technology in stem cell therapy for SCI.

Optical imaging of non-fluorescent nanoparticle probes in live cells

Energy Technology Data Exchange (ETDEWEB)

Wang, Gufeng; Stender, Anthony S.; Sun, Wei; and Fang, Ning

2009-12-17

Precise imaging of cellular and subcellular structures and dynamic processes in live cells is crucial for fundamental research in life sciences and in medical applications. Non-fluorescent nanoparticles are an important type of optical probe used in live-cell imaging due to their photostability, large optical cross-sections, and low toxicity. Here, we provide an overview of recent developments in the optical imaging of non-fluorescent nanoparticle probes in live cells.

The endoplasmic reticulum in plant immunity and cell death.

Science.gov (United States)

Eichmann, Ruth; Schäfer, Patrick

2012-01-01

The endoplasmic reticulum (ER) is a highly dynamic organelle in eukaryotic cells and a major production site of proteins destined for vacuoles, the plasma membrane, or apoplast in plants. At the ER, these secreted proteins undergo multiple processing steps, which are supervised and conducted by the ER quality control system. Notably, processing of secreted proteins can considerably elevate under stress conditions and exceed ER folding capacities. The resulting accumulation of unfolded proteins is defined as ER stress. The efficiency of cells to re-establish proper ER function is crucial for stress adaptation. Besides delivering proteins directly antagonizing and resolving stress conditions, the ER monitors synthesis of immune receptors. This indicates the significance of the ER for the establishment and function of the plant immune system. Recent studies point out the fragility of the entire system and highlight the ER as initiator of programed cell death (PCD) in plants as was reported for vertebrates. This review summarizes current knowledge on the impact of the ER on immune and PCD signaling. Understanding the integration of stress signals by the ER bears a considerable potential to optimize development and to enhance stress resistance of plants.

The endoplasmic reticulum in plant immunity and cell death

Directory of Open Access Journals (Sweden)

Patrick eSchäfer

2012-08-01

Full Text Available The endoplasmic reticulum (ER is a highly dynamic organelle in eukaryotic cells and a major production site of proteins destined for vacuoles, the plasma membrane or apoplast in plants. At the ER, these secreted proteins undergo multiple processing steps, which are supervised and conducted by the ER quality control system. Notably, processing of secreted proteins can considerably elevate under stress conditions and exceed ER folding capacities. The resulting accumulation of unfolded proteins is defined as ER stress. The efficiency of cells to re-establish proper ER function is crucial for stress adaptation. Besides delivering proteins directly antagonizing and resolving stress conditions, the ER monitors synthesis of immune receptors. This indicates the significance of the ER for the establishment and function of the plant immune system. Recent studies point out the fragility of the entire system and highlight the ER as initiator of programmed cell death (PCD in plants as was reported for vertebrates. This review summarizes current knowledge on the impact of the ER on immune and PCD signalling. Understanding the integration of stress signals by the ER bears a considerable potential to optimize development and to enhance stress resistance of plants.

In situ single molecule imaging of cell membranes: linking basic nanotechniques to cell biology, immunology and medicine

Science.gov (United States)

Pi, Jiang; Jin, Hua; Yang, Fen; Chen, Zheng W.; Cai, Jiye

2014-10-01

The cell membrane, which consists of a viscous phospholipid bilayer, different kinds of proteins and various nano/micrometer-sized domains, plays a very important role in ensuring the stability of the intracellular environment and the order of cellular signal transductions. Exploring the precise cell membrane structure and detailed functions of the biomolecules in a cell membrane would be helpful to understand the underlying mechanisms involved in cell membrane signal transductions, which could further benefit research into cell biology, immunology and medicine. The detection of membrane biomolecules at the single molecule level can provide some subtle information about the molecular structure and the functions of the cell membrane. In particular, information obtained about the molecular mechanisms and other information at the single molecule level are significantly different from that detected from a large amount of biomolecules at the large-scale through traditional techniques, and can thus provide a novel perspective for the study of cell membrane structures and functions. However, the precise investigations of membrane biomolecules prompts researchers to explore cell membranes at the single molecule level by the use of in situ imaging methods, as the exact conformation and functions of biomolecules are highly controlled by the native cellular environment. Recently, the in situ single molecule imaging of cell membranes has attracted increasing attention from cell biologists and immunologists. The size of biomolecules and their clusters on the cell surface are set at the nanoscale, which makes it mandatory to use high- and super-resolution imaging techniques to realize the in situ single molecule imaging of cell membranes. In the past few decades, some amazing imaging techniques and instruments with super resolution have been widely developed for molecule imaging, which can also be further employed for the in situ single molecule imaging of cell membranes. In

MR-based imaging of neural stem cells

Energy Technology Data Exchange (ETDEWEB)

Politi, Letterio S. [San Raffaele Scientific Institute, Neuroradiology Department, Milano (Italy)

2007-06-15

The efficacy of therapies based on neural stem cells (NSC) has been demonstrated in preclinical models of several central nervous system (CNS) diseases. Before any potential human application of such promising therapies can be envisaged, there are some important issues that need to be solved. The most relevant one is the requirement for a noninvasive technique capable of monitoring NSC delivery, homing to target sites and trafficking. Knowledge of the location and temporospatial migration of either transplanted or genetically modified NSC is of the utmost importance in analyzing mechanisms of correction and cell distribution. Further, such a technique may represent a crucial step toward clinical application of NSC-based approaches in humans, for both designing successful protocols and monitoring their outcome. Among the diverse imaging approaches available for noninvasive cell tracking, such as nuclear medicine techniques, fluorescence and bioluminescence, magnetic resonance imaging (MRI) has unique advantages. Its high temporospatial resolution, high sensitivity and specificity render MRI one of the most promising imaging modalities available, since it allows dynamic visualization of migration of transplanted cells in animal models and patients during clinically useful time periods. Different cellular and molecular labeling approaches for MRI depiction of NSC are described and discussed in this review, as well as the most relevant issues to be considered in optimizing molecular imaging techniques for clinical application. (orig.)

MR-based imaging of neural stem cells

International Nuclear Information System (INIS)

Politi, Letterio S.

2007-01-01

The efficacy of therapies based on neural stem cells (NSC) has been demonstrated in preclinical models of several central nervous system (CNS) diseases. Before any potential human application of such promising therapies can be envisaged, there are some important issues that need to be solved. The most relevant one is the requirement for a noninvasive technique capable of monitoring NSC delivery, homing to target sites and trafficking. Knowledge of the location and temporospatial migration of either transplanted or genetically modified NSC is of the utmost importance in analyzing mechanisms of correction and cell distribution. Further, such a technique may represent a crucial step toward clinical application of NSC-based approaches in humans, for both designing successful protocols and monitoring their outcome. Among the diverse imaging approaches available for noninvasive cell tracking, such as nuclear medicine techniques, fluorescence and bioluminescence, magnetic resonance imaging (MRI) has unique advantages. Its high temporospatial resolution, high sensitivity and specificity render MRI one of the most promising imaging modalities available, since it allows dynamic visualization of migration of transplanted cells in animal models and patients during clinically useful time periods. Different cellular and molecular labeling approaches for MRI depiction of NSC are described and discussed in this review, as well as the most relevant issues to be considered in optimizing molecular imaging techniques for clinical application. (orig.)

Chronological alterations of diagnostic imaging of renal cell carcinoma

International Nuclear Information System (INIS)

Arima, Kiminobu; Sugimura, Yoshiki; Yanagawa, Makoto; Tochigi, Hiromi; Kawamura, Juichi

1994-01-01

A review of 156 cases of renal cell carcinoma diagnosed during a 20-year period demonstrated the changes of initial signs/symptoms and imaging modalities for detection and definition. According to the imaging modality used for diagnosing renal cell carcinoma, clinical pictures were chronologically examined over 4 periods: 1973 to 1979 (before CT era), 1980 to 1984 (early CT era), 1985 to 1987 (CT era) and 1988 to 1992 (CT/MRI era). With regards to initial signs or symptoms, the proportion of classical trials has gradually decreased, while that of tumors noted incidentally has increased. As for imaging modalities for detection, the proportion of IVP has gradually decreased and that of CT and US has increased over the periods. With regard to imaging modalities for definition, the proportion of angiography has decreased and that of CT has increased. From chronological changes in clinical pictures and imaging modalities, we suggested a decision tree of imaging modalities for detection and definition of renal cell carcinoma. (author)

A novel approach for studying programmed cell death in living plant tissues

DEFF Research Database (Denmark)

Mark, Christina

to traditional approaches. Future applications of this type of setup could be used for other types of plant tissues such as leaves or germinating embryos for studying the effects of e.g. biotic and abiotic stresses or for screening of compounds for biological effects. Due to the ease of use and many......Programmed cell death (PCD) is a highly regulated process in which cells are killed as part of developmental programmes or as defence mechanisms against pathogens, but the process is less well understood in plant cells compared to animal cells. Reactive oxygen species (ROS) are involved in PCD...... in plants, but the relationship between and mechanisms behind ROS and PCDhas not yet been fully elucidated due to the involvement of complex signalling networks. Elucidation of these mechanisms and signalling pathways will allow manipulation of cell death in plants, which could help to improve yield...

In vivo fluorescence imaging of primate retinal ganglion cells and retinal pigment epithelial cells

Science.gov (United States)

Gray, Daniel C.; Merigan, William; Wolfing, Jessica I.; Gee, Bernard P.; Porter, Jason; Dubra, Alfredo; Twietmeyer, Ted H.; Ahamd, Kamran; Tumbar, Remy; Reinholz, Fred; Williams, David R.

2006-08-01

The ability to resolve single cells noninvasively in the living retina has important applications for the study of normal retina, diseased retina, and the efficacy of therapies for retinal disease. We describe a new instrument for high-resolution, in vivo imaging of the mammalian retina that combines the benefits of confocal detection, adaptive optics, multispectral, and fluorescence imaging. The instrument is capable of imaging single ganglion cells and their axons through retrograde transport in ganglion cells of fluorescent dyes injected into the monkey lateral geniculate nucleus (LGN). In addition, we demonstrate a method involving simultaneous imaging in two spectral bands that allows the integration of very weak signals across many frames despite inter-frame movement of the eye. With this method, we are also able to resolve the smallest retinal capillaries in fluorescein angiography and the mosaic of retinal pigment epithelium (RPE) cells with lipofuscin autofluorescence.

Long-Term Live Cell Imaging of Cell Migration: Effects of Pathogenic Fungi on Human Epithelial Cell Migration.

Science.gov (United States)

Wöllert, Torsten; Langford, George M

2016-01-01

Long-term live cell imaging was used in this study to determine the responses of human epithelial cells to pathogenic biofilms formed by Candida albicans. Epithelial cells of the skin represent the front line of defense against invasive pathogens such as C. albicans but under certain circumstances, especially when the host's immune system is compromised, the skin barrier is breached. The mechanisms by which the fungal pathogen penetrates the skin and invade the deeper layers are not fully understood. In this study we used keratinocytes grown in culture as an in vitro model system to determine changes in host cell migration and the actin cytoskeleton in response to virulence factors produced by biofilms of pathogenic C. albicans. It is clear that changes in epithelial cell migration are part of the response to virulence factors secreted by biofilms of C. albicans and the actin cytoskeleton is the downstream effector that mediates cell migration. Our goal is to understand the mechanism by which virulence factors hijack the signaling pathways of the actin cytoskeleton to alter cell migration and thereby invade host tissues. To understand the dynamic changes of the actin cytoskeleton during infection, we used long-term live cell imaging to obtain spatial and temporal information of actin filament dynamics and to identify signal transduction pathways that regulate the actin cytoskeleton and its associated proteins. Long-term live cell imaging was achieved using a high resolution, multi-mode epifluorescence microscope equipped with specialized light sources, high-speed cameras with high sensitivity detectors, and specific biocompatible fluorescent markers. In addition to the multi-mode epifluorescence microscope, a spinning disk confocal long-term live cell imaging system (Olympus CV1000) equipped with a stage incubator to create a stable in vitro environment for long-term real-time and time-lapse microscopy was used. Detailed descriptions of these two long-term live

Cysteine-rich peptides (CRPs) mediate diverse aspects of cell-cell communication in plant reproduction and development.

Science.gov (United States)

Marshall, Eleanor; Costa, Liliana M; Gutierrez-Marcos, Jose

2011-03-01

Cell-cell communication in plants is essential for the correct co-ordination of reproduction, growth, and development. Studies to dissect this mode of communication have previously focussed primarily on the action of plant hormones as mediators of intercellular signalling. In animals, peptide signalling is a well-documented intercellular communication system, however, relatively little is known about this system in plants. In recent years, numerous reports have emerged about small, secreted peptides controlling different aspects of plant reproduction. Interestingly, most of these peptides are cysteine-rich, and there is convincing evidence suggesting multiple roles for related cysteine-rich peptides (CRPs) as signalling factors in developmental patterning as well as during plant pathogen responses and symbiosis. In this review, we discuss how CRPs are emerging as key signalling factors in regulating multiple aspects of vegetative growth and reproductive development in plants.

Navigating the plant cell: intracellular transport logistics in the green kingdom.

Science.gov (United States)

Geitmann, Anja; Nebenführ, Andreas

2015-10-01

Intracellular transport in plant cells occurs on microtubular and actin arrays. Cytoplasmic streaming, the rapid motion of plant cell organelles, is mostly driven by an actin-myosin mechanism, whereas specialized functions, such as the transport of large cargo or the assembly of a new cell wall during cell division, are performed by the microtubules. Different modes of transport are used, fast and slow, to either haul cargo over long distances or ascertain high-precision targeting, respectively. Various forms of the actin-specific motor protein myosin XI exist in plant cells and might be involved in different cellular functions. © 2015 Geitmann and Nebenführ. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Matrix-assisted laser desorption/ionisation mass spectrometry imaging and its development for plant protein imaging

Directory of Open Access Journals (Sweden)

Millar A Harvey

2011-07-01

Full Text Available Abstract Matrix-Assisted Laser Desorption/Ionisation (MALDI mass spectrometry imaging (MSI uses the power of high mass resolution time of flight (ToF mass spectrometry coupled to the raster of lasers shots across the cut surface of tissues to provide new insights into the spatial distribution of biomolecules within biological tissues. The history of this technique in animals and plants is considered and the potential for analysis of proteins by this technique in plants is discussed. Protein biomarker identification from MALDI-MSI is a challenge and a number of different approaches to address this bottleneck are discussed. The technical considerations needed for MALDI-MSI are reviewed and these are presented alongside examples from our own work and a protocol for MALDI-MSI of proteins in plant samples.

Gene Delivery into Plant Cells for Recombinant Protein Production

Directory of Open Access Journals (Sweden)

Qiang Chen

2015-01-01

Full Text Available Recombinant proteins are primarily produced from cultures of mammalian, insect, and bacteria cells. In recent years, the development of deconstructed virus-based vectors has allowed plants to become a viable platform for recombinant protein production, with advantages in versatility, speed, cost, scalability, and safety over the current production paradigms. In this paper, we review the recent progress in the methodology of agroinfiltration, a solution to overcome the challenge of transgene delivery into plant cells for large-scale manufacturing of recombinant proteins. General gene delivery methodologies in plants are first summarized, followed by extensive discussion on the application and scalability of each agroinfiltration method. New development of a spray-based agroinfiltration and its application on field-grown plants is highlighted. The discussion of agroinfiltration vectors focuses on their applications for producing complex and heteromultimeric proteins and is updated with the development of bridge vectors. Progress on agroinfiltration in Nicotiana and non-Nicotiana plant hosts is subsequently showcased in context of their applications for producing high-value human biologics and low-cost and high-volume industrial enzymes. These new advancements in agroinfiltration greatly enhance the robustness and scalability of transgene delivery in plants, facilitating the adoption of plant transient expression systems for manufacturing recombinant proteins with a broad range of applications.

Induction and selection of mutants from in vitro cultured plant cells

Energy Technology Data Exchange (ETDEWEB)

Lee, Yung Il; Kim, Jae Sung; Shin, In Chul; Lee, Sang Jae [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1994-07-01

Mutant cell lines are useful for biochemical, physiological and genetical material for marker in various genetic manipulation experiments and for the direct use in crop plant improvement. Mutant selection may lead to the production of plants showing resistance or tolerance to specific environmental stress, such as solinity, drought, toxed metals, herbicides, pathogens and low temperature. In this review, these included the production of the somatic variation, the selection process itself and stability of the selected characters in cell culture and regenerated plant. Which would seem to be useful for improving plants and securring genetic resources. 45 refs. (Author).

Induction and selection of mutants from in vitro cultured plant cells

International Nuclear Information System (INIS)

Lee, Yung Il; Kim, Jae Sung; Shin, In Chul; Lee, Sang Jae

1994-07-01

Mutant cell lines are useful for biochemical, physiological and genetical material for marker in various genetic manipulation experiments and for the direct use in crop plant improvement. Mutant selection may lead to the production of plants showing resistance or tolerance to specific environmental stress, such as solinity, drought, toxed metals, herbicides, pathogens and low temperature. In this review, these included the production of the somatic variation, the selection process itself and stability of the selected characters in cell culture and regenerated plant. Which would seem to be useful for improving plants and securring genetic resources. 45 refs. (Author)

Plant Cell Culture Initiation: practical tips

NARCIS (Netherlands)

Hall, R.D.

2001-01-01

The use of cultured plant cells in either organized or unorganized form has increased vey considerably in the last 10-15 yr. Many new technologies have been developed and applications in both fundamental and applied research have led to the development of some powerful tools for improving our

The Arabidopsis synaptotagmin SYTA regulates the cell-to-cell movement of diverse plant viruses

Directory of Open Access Journals (Sweden)

Asako eUchiyama

2014-11-01

Full Text Available Synaptotagmins are a large gene family in animals that have been extensively characterized due to their role as calcium sensors to regulate synaptic vesicle exocytosis and endocytosis in neurons, and dense core vesicle exocytosis for hormone secretion from neuroendocrine cells. Thought to be exclusive to animals, synaptotagmins have recently been characterized in Arabidopsis thaliana, in which they comprise a five gene family. Using infectivity and leaf-based functional assays, we have shown that Arabidopsis SYTA regulates endocytosis and marks an endosomal vesicle recycling pathway to regulate movement protein-mediated trafficking of the Begomovirus Cabbage leaf curl virus (CaLCuV and the Tobamovirus Tobacco mosaic virus (TMV through plasmodesmata (Lewis and Lazarowitz, 2010. To determine whether SYTA has a central role in regulating the cell-to-cell trafficking of a wider range of diverse plant viruses, we extended our studies here to examine the role of SYTA in the cell-to-cell movement of additional plant viruses that employ different modes of movement, namely the Potyvirus Turnip mosaic virus (TuMV, the Caulimovirus Cauliflower mosaic virus (CaMV and the Tobamovirus Turnip vein clearing virus (TVCV, which in contrast to TMV does efficiently infect Arabidopsis. We found that both TuMV and TVCV systemic infection, and the cell-to-cell trafficking of the their movement proteins, were delayed in the Arabidopsis Col-0 syta-1 knockdown mutant. In contrast, CaMV systemic infection was not inhibited in syta-1. Our studies show that SYTA is a key regulator of plant virus intercellular movement, being necessary for the ability of diverse cell-to-cell movement proteins encoded by Begomoviruses (CaLCuV MP, Tobamoviruses (TVCV and TMV 30K protein and Potyviruses (TuMV P3N-PIPO to alter PD and thereby mediate virus cell-to-cell spread.

Wall extensibility: its nature, measurement and relationship to plant cell growth

Science.gov (United States)

Cosgrove, D. J.

1993-01-01

Expansive growth of plant cells is controlled principally by processes that loosen the wall and enable it to expand irreversibly. The central role of wall relaxation for cell expansion is reviewed. The most common methods for assessing the extension properties of plant cell walls ( wall extensibility') are described, categorized and assessed critically. What emerges are three fundamentally different approaches which test growing cells for their ability (a) to enlarge at different values of turgor, (b) to induce wall relaxation, and (c) to deform elastically or plastically in response to an applied tensile force. Analogous methods with isolated walls are similarly reviewed. The results of these different assays are related to the nature of plant cell growth and pertinent biophysical theory. I argue that the extensibilities' measured by these assays are fundamentally different from one another and that some are more pertinent to growth than others.

Plant cell engineering: current research, application and future prospects

International Nuclear Information System (INIS)

Wang Xunqing; Liu Luxiang

2008-01-01

This paper reviewed the current status of basic research in plant cell engineering, highlighted the application of embryo culture, double haploid (DH) technology, protoplast culture and somatic hybridization, somaclonal variation, rapid propagation, and bio-products production of plant-origin, and t he prospects. (authors)

A quantitative and dynamic model for plant stem cell regulation.

Directory of Open Access Journals (Sweden)

Florian Geier

Full Text Available Plants maintain pools of totipotent stem cells throughout their entire life. These stem cells are embedded within specialized tissues called meristems, which form the growing points of the organism. The shoot apical meristem of the reference plant Arabidopsis thaliana is subdivided into several distinct domains, which execute diverse biological functions, such as tissue organization, cell-proliferation and differentiation. The number of cells required for growth and organ formation changes over the course of a plants life, while the structure of the meristem remains remarkably constant. Thus, regulatory systems must be in place, which allow for an adaptation of cell proliferation within the shoot apical meristem, while maintaining the organization at the tissue level. To advance our understanding of this dynamic tissue behavior, we measured domain sizes as well as cell division rates of the shoot apical meristem under various environmental conditions, which cause adaptations in meristem size. Based on our results we developed a mathematical model to explain the observed changes by a cell pool size dependent regulation of cell proliferation and differentiation, which is able to correctly predict CLV3 and WUS over-expression phenotypes. While the model shows stem cell homeostasis under constant growth conditions, it predicts a variation in stem cell number under changing conditions. Consistent with our experimental data this behavior is correlated with variations in cell proliferation. Therefore, we investigate different signaling mechanisms, which could stabilize stem cell number despite variations in cell proliferation. Our results shed light onto the dynamic constraints of stem cell pool maintenance in the shoot apical meristem of Arabidopsis in different environmental conditions and developmental states.

Pectinous cell wall thickenings formation - A common defense strategy of plants to cope with Pb.

Science.gov (United States)

Krzesłowska, Magdalena; Rabęda, Irena; Basińska, Aneta; Lewandowski, Michał; Mellerowicz, Ewa J; Napieralska, Anna; Samardakiewicz, Sławomir; Woźny, Adam

2016-07-01

Lead, one of the most abundant and hazardous trace metals affecting living organisms, has been commonly detected in plant cell walls including some tolerant plants, mining ecotypes and hyperaccumulators. We have previously shown that in tip growing Funaria sp. protonemata cell wall is remodeled in response to lead by formation of thickenings rich in low-methylesterified pectins (pectin epitope JIM5 - JIM5-P) able to bind metal ions, which accumulate large amounts of Pb. Hence, it leads to the increase of cell wall capacity for Pb compartmentalization. Here we show that diverse plant species belonging to different phyla (Arabidopsis, hybrid aspen, star duckweed), form similar cell wall thickenings in response to Pb. These thickenings are formed in tip growing cells such as the root hairs, and in diffuse growing cells such as meristematic and root cap columella cells of root apices in hybrid aspen and Arabidopsis and in mesophyll cells in star duckweed fronds. Notably, all analyzed cell wall thickenings were abundant in JIM5-P and accumulated high amounts of Pb. In addition, the co-localization of JIM5-P and Pb commonly occurred in these cells. Hence, cell wall thickenings formed the extra compartment for Pb accumulation. In this way plant cells increased cell wall capacity for compartmentalization of this toxic metal, protecting protoplast from its toxicity. As cell wall thickenings occurred in diverse plant species and cell types differing in the type of growth we may conclude that pectinous cell wall thickenings formation is a widespread defense strategy of plants to cope with Pb. Moreover, detection of natural defense strategy, increasing plant cell walls capacity for metal accumulation, reveals a promising direction for enhancing plant efficiency in phytoremediation. Copyright © 2016 Elsevier Ltd. All rights reserved.

3D/4D multiscale imaging in acute lymphoblastic leukemia cells: visualizing dynamics of cell death

Science.gov (United States)

Sarangapani, Sreelatha; Mohan, Rosmin Elsa; Patil, Ajeetkumar; Lang, Matthew J.; Asundi, Anand

2017-06-01

Quantitative phase detection is a new methodology that provides quantitative information on cellular morphology to monitor the cell status, drug response and toxicity. In this paper the morphological changes in acute leukemia cells treated with chitosan were detected using d'Bioimager a robust imaging system. Quantitative phase image of the cells was obtained with numerical analysis. Results show that the average area and optical volume of the chitosan treated cells is significantly reduced when compared with the control cells, which reveals the effect of chitosan on the cancer cells. From the results it can be attributed that d'Bioimager can be used as a non-invasive imaging alternative to measure the morphological changes of the living cells in real time.

In vivo imaging of cell nuclei by photoacoustic microscopy without staining

Science.gov (United States)

Yao, Da-Kang; Chen, Ruimin; Maslov, Konstantin; Zhou, Qifa; Wang, Lihong V.

2012-02-01

Ultraviolet photoacoustic microscopy (UVPAM) can image cell nuclei in vivo with high contrast and resolution noninvasively without staining. Here, we used UV light at wavelengths of 210-310 nm for excitation of DNA and RNA to produce photoacoustic waves. We applied the UVPAM to in vivo imaging of cell nuclei in mouse skin, and obtained UVPAM images of the unstained cell nuclei at wavelengths of 245-282 nm as ultrasound gel was used for acoustic coupling. The largest ratio of contrast to noise was found for the images of cell nuclei at a 250 nm wavelength.

Molecular regulation of plant cell wall extensibility

Science.gov (United States)

Cosgrove, D. J.

1998-01-01

Gravity responses in plants often involve spatial and temporal changes in cell growth, which is regulated primarily by controlling the ability of the cell wall to extend. The wall is thought to be a cellulose-hemicellulose network embedded in a hydrated matrix of complex polysaccharides and a small amount of structural protein. The wall extends by a form of polymer creep, which is mediated by expansins, a novel group of wall-loosening proteins. Expansins were discovered during a molecular dissection of the "acid growth" behavior of cell walls. Expansin alters the rheology of plant walls in profound ways, yet its molecular mechanism of action is still uncertain. It lacks detectable hydrolytic activity against the major components of the wall, but it is able to disrupt noncovalent adhesion between wall polysaccharides. The discovery of a second family of expansins (beta-expansins) sheds light on the biological role of a major group of pollen allergens and implies that expansins have evolved for diverse developmental functions. Finally, the contribution of other processes to wall extensibility is briefly summarized.

Deployment of a Prototype Plant GFP Imager at the Arthur Clarke Mars Greenhouse of the Haughton Mars Project

Directory of Open Access Journals (Sweden)

Robert J. Ferl

2008-04-01

Full Text Available The use of engineered plants as biosensors has made elegant strides in the past decades, providing keen insights into the health of plants in general and particularly in the nature and cellular location of stress responses. However, most of the analytical procedures involve laboratory examination of the biosensor plants. With the advent of the green fluorescence protein (GFP as a biosensor molecule, it became at least theoretically possible for analyses of gene expression to occur telemetrically, with the gene expression information of the plant delivered to the investigator over large distances simply as properly processed fluorescence images. Spaceflight and other extraterrestrial environments provide unique challenges to plant life, challenges that often require changes at the gene expression level to accommodate adaptation and survival. Having previously deployed transgenic plant biosensors to evaluate responses to orbital spaceflight, we wished to develop the plants and especially the imaging devices required to conduct such experiments robotically, without operator intervention, within extraterrestrial environments. This requires the development of an autonomous and remotely operated plant GFP imaging system and concomitant development of the communications infrastructure to manage dataflow from the imaging device. Here we report the results of deploying a prototype GFP imaging system within the Arthur Clarke Mars Greenhouse (ACMG an autonomously operated greenhouse located within the Haughton Mars Project in the Canadian High Arctic. Results both demonstrate the applicability of the fundamental GFP biosensor technology and highlight the difficulties in collecting and managing telemetric data from challenging deployment environments.

Comparison of segmentation algorithms for fluorescence microscopy images of cells.

Science.gov (United States)

Dima, Alden A; Elliott, John T; Filliben, James J; Halter, Michael; Peskin, Adele; Bernal, Javier; Kociolek, Marcin; Brady, Mary C; Tang, Hai C; Plant, Anne L

2011-07-01

The analysis of fluorescence microscopy of cells often requires the determination of cell edges. This is typically done using segmentation techniques that separate the cell objects in an image from the surrounding background. This study compares segmentation results from nine different segmentation techniques applied to two different cell lines and five different sets of imaging conditions. Significant variability in the results of segmentation was observed that was due solely to differences in imaging conditions or applications of different algorithms. We quantified and compared the results with a novel bivariate similarity index metric that evaluates the degree of underestimating or overestimating a cell object. The results show that commonly used threshold-based segmentation techniques are less accurate than k-means clustering with multiple clusters. Segmentation accuracy varies with imaging conditions that determine the sharpness of cell edges and with geometric features of a cell. Based on this observation, we propose a method that quantifies cell edge character to provide an estimate of how accurately an algorithm will perform. The results of this study will assist the development of criteria for evaluating interlaboratory comparability. Published 2011 Wiley-Liss, Inc.

Quantitative volumetric Raman imaging of three dimensional cell cultures

Science.gov (United States)

Kallepitis, Charalambos; Bergholt, Mads S.; Mazo, Manuel M.; Leonardo, Vincent; Skaalure, Stacey C.; Maynard, Stephanie A.; Stevens, Molly M.

2017-03-01

The ability to simultaneously image multiple biomolecules in biologically relevant three-dimensional (3D) cell culture environments would contribute greatly to the understanding of complex cellular mechanisms and cell-material interactions. Here, we present a computational framework for label-free quantitative volumetric Raman imaging (qVRI). We apply qVRI to a selection of biological systems: human pluripotent stem cells with their cardiac derivatives, monocytes and monocyte-derived macrophages in conventional cell culture systems and mesenchymal stem cells inside biomimetic hydrogels that supplied a 3D cell culture environment. We demonstrate visualization and quantification of fine details in cell shape, cytoplasm, nucleus, lipid bodies and cytoskeletal structures in 3D with unprecedented biomolecular specificity for vibrational microspectroscopy.

Unleashing the potential of the root hair cell as a single plant cell type model in root systems biology

Directory of Open Access Journals (Sweden)

Zhenzhen eQiao

2013-11-01

Full Text Available Plant root is an organ composed of multiple cell types with different functions. This multicellular complexity limits our understanding of root biology because –omics studies performed at the level of the entire root reflect the average responses of all cells composing the organ. To overcome this difficulty and allow a more comprehensive understanding of root cell biology, an approach is needed that would focus on one single cell type in the plant root. Because of its biological functions (i.e. uptake of water and various nutrients; primary site of infection by nitrogen-fixing bacteria in legumes, the root hair cell is an attractive single cell model to study root cell response to various stresses and treatments. To fully study their biology, we have recently optimized procedures in obtaining root hair cell samples. We culture the plants using an ultrasound aeroponic system maximizing root hair cell density on the entire root systems and allowing the homogeneous treatment of the root system. We then isolate the root hair cells in liquid nitrogen. Isolated root hair yields could be up to 800 to 1000 mg of plant cells from 60 root systems. Using soybean as a model, the purity of the root hair was assessed by comparing the expression level of genes previously identified as soybean root hair specific between preparations of isolated root hair cells and stripped roots, roots devoid in root hairs. Enlarging our tests to include other plant species, our results support the isolation of large quantities of highly purified root hair cells which is compatible with a systems biology approach.

2003 Plant Cell Walls Gordon Conference

Energy Technology Data Exchange (ETDEWEB)

Daniel J. Cosgrove

2004-09-21

This conference will address recent progress in many aspects of cell wall biology. Molecular, genetic, and genomic approaches are yielding major advances in our understanding of the composition, synthesis, and architecture of plant cell walls and their dynamics during growth, and are identifying the genes that encode the machinery needed to make their biogenesis possible. This meeting will bring together international scientists from academia, industry and government labs to share the latest breakthroughs and perspectives on polysaccharide biosynthesis, wood formation, wall modification, expansion and interaction with other organisms, and genomic & evolutionary analyses of wall-related genes, as well as to discuss recent ''nanotechnological'' advances that take wall analysis to the level of a single cell.

The Specific Nature of Plant Cell Wall Polysaccharides 1

Science.gov (United States)

Nevins, Donald J.; English, Patricia D.; Albersheim, Peter

1967-01-01

Polysaccharide compositions of cell walls were assessed by quantitative analyses of the component sugars. Cell walls were hydrolyzed in 2 n trifluoroacetic acid and the liberated sugars reduced to their respective alditols. The alditols were acetylated and the resulting alditol acetates separated by gas chromatography. Quantitative assay of the alditol acetates was accomplished by electronically integrating the detector output of the gas chromatograph. Myo-inositol, introduced into the sample prior to hydrolysis, served as an internal standard. The cell wall polysaccharide compositions of plant varieties within a given species are essentially identical. However, differences in the sugar composition were observed in cell walls prepared from different species of the same as well as of different genera. The fact that the wall compositions of different varieties of the same species are the same indicates that the biosynthesis of cell wall polysaccharides is genetically regulated. The cell walls of various morphological parts (roots, hypocotyls, first internodes and primary leaves) of bean plants were each found to have a characteristic sugar composition. It was found that the cell wall sugar composition of suspension-cultured sycamore cells could be altered by growing the cells on different carbon sources. This demonstrates that the biosynthesis of cell wall polysaccharides can be manipulated without fatal consequences. PMID:16656594

Micrasterias as a model system in plant cell biology

Directory of Open Access Journals (Sweden)

Ursula Luetz-Meindl

2016-07-01

Full Text Available The unicellular freshwater alga Micrasterias denticulata is an exceptional organism due to its extraordinary star-shaped, highly symmetric morphology and has thus attracted the interest of researchers for many decades. As a member of the Streptophyta, Micrasterias is not only genetically closely related to higher land plants but shares common features with them in many physiological and cell biological aspects. These facts, together with its considerable cell size of about 200 µm, its modest cultivation conditions and the uncomplicated accessibility particularly to any microscopic techniques, make Micrasterias a very well suited cell biological plant model system. The review focuses particularly on cell wall formation and composition, dictyosomal structure and function, cytoskeleton control of growth and morphogenesis as well as on ionic regulation and signal transduction. It has been also shown in the recent years that Micrasterias is a highly sensitive indicator for environmental stress impact such as heavy metals, high salinity, oxidative stress or starvation. Stress induced organelle degradation, autophagy, adaption and detoxification mechanisms have moved in the center of interest and have been investigated with modern microscopic techniques such as 3-D- and analytical electron microscopy as well as with biochemical, physiological and molecular approaches. This review is intended to summarize and discuss the most important results obtained in Micrasterias in the last 20 years and to compare the results to similar processes in higher plant cells.

Aberration-free FTIR spectroscopic imaging of live cells in microfluidic devices.

Science.gov (United States)

Chan, K L Andrew; Kazarian, Sergei G

2013-07-21

The label-free, non-destructive chemical analysis offered by FTIR spectroscopic imaging is a very attractive and potentially powerful tool for studies of live biological cells. FTIR imaging of live cells is a challenging task, due to the fact that cells are cultured in an aqueous environment. While the synchrotron facility has proven to be a valuable tool for FTIR microspectroscopic studies of single live cells, we have demonstrated that high quality infrared spectra of single live cells using an ordinary Globar source can also be obtained by adding a pair of lenses to a common transmission liquid cell. The lenses, when placed on the transmission cell window, form pseudo hemispheres which removes the refraction of light and hence improve the imaging and spectral quality of the obtained data. This study demonstrates that infrared spectra of single live cells can be obtained without the focus shifting effect at different wavenumbers, caused by the chromatic aberration. Spectra of the single cells have confirmed that the measured spectral region remains in focus across the whole range, while spectra of the single cells measured without the lenses have shown some erroneous features as a result of the shift of focus. It has also been demonstrated that the addition of lenses can be applied to the imaging of cells in microfabricated devices. We have shown that it was not possible to obtain a focused image of an isolated cell in a droplet of DPBS in oil unless the lenses are applied. The use of the approach described herein allows for well focused images of single cells in DPBS droplets to be obtained.

In vivo stem cell tracking with imageable nanoparticles that bind bioorthogonal chemical receptors on the stem cell surface.

Science.gov (United States)

Lee, Sangmin; Yoon, Hwa In; Na, Jin Hee; Jeon, Sangmin; Lim, Seungho; Koo, Heebeom; Han, Sang-Soo; Kang, Sun-Woong; Park, Soon-Jung; Moon, Sung-Hwan; Park, Jae Hyung; Cho, Yong Woo; Kim, Byung-Soo; Kim, Sang Kyoon; Lee, Taekwan; Kim, Dongkyu; Lee, Seulki; Pomper, Martin G; Kwon, Ick Chan; Kim, Kwangmeyung

2017-09-01

It is urgently necessary to develop reliable non-invasive stem cell imaging technology for tracking the in vivo fate of transplanted stem cells in living subjects. Herein, we developed a simple and well controlled stem cell imaging method through a combination of metabolic glycoengineering and bioorthogonal copper-free click chemistry. Firstly, the exogenous chemical receptors containing azide (-N 3 ) groups were generated on the surfaces of stem cells through metabolic glycoengineering using metabolic precursor, tetra-acetylated N-azidoacetyl-d-mannosamine(Ac 4 ManNAz). Next, bicyclo[6.1.0]nonyne-modified glycol chitosan nanoparticles (BCN-CNPs) were prepared as imageable nanoparticles to deliver different imaging agents. Cy5.5, iron oxide nanoparticles and gold nanoparticles were conjugated or encapsulated to BCN-CNPs for optical, MR and CT imaging, respectively. These imageable nanoparticles bound chemical receptors on the Ac 4 ManNAz-treated stem cell surface specifically via bioorthogonal copper-free click chemistry. Then they were rapidly taken up by the cell membrane turn-over mechanism resulting in higher endocytic capacity compared non-specific uptake of nanoparticles. During in vivo animal test, BCN-CNP-Cy5.5-labeled stem cells could be continuously tracked by non-invasive optical imaging over 15 days. Furthermore, BCN-CNP-IRON- and BCN-CNP-GOLD-labeled stem cells could be efficiently visualized using in vivo MR and CT imaging demonstrating utility of our stem cell labeling method using chemical receptors. These results conclude that our method based on metabolic glycoengineering and bioorthogonal copper-free click chemistry can stably label stem cells with diverse imageable nanoparticles representing great potential as new stem cell imaging technology. Copyright © 2017 Elsevier Ltd. All rights reserved.

Analysis of gene expression levels in individual bacterial cells without image segmentation

International Nuclear Information System (INIS)

Kwak, In Hae; Son, Minjun; Hagen, Stephen J.

2012-01-01

Highlights: ► We present a method for extracting gene expression data from images of bacterial cells. ► The method does not employ cell segmentation and does not require high magnification. ► Fluorescence and phase contrast images of the cells are correlated through the physics of phase contrast. ► We demonstrate the method by characterizing noisy expression of comX in Streptococcus mutans. -- Abstract: Studies of stochasticity in gene expression typically make use of fluorescent protein reporters, which permit the measurement of expression levels within individual cells by fluorescence microscopy. Analysis of such microscopy images is almost invariably based on a segmentation algorithm, where the image of a cell or cluster is analyzed mathematically to delineate individual cell boundaries. However segmentation can be ineffective for studying bacterial cells or clusters, especially at lower magnification, where outlines of individual cells are poorly resolved. Here we demonstrate an alternative method for analyzing such images without segmentation. The method employs a comparison between the pixel brightness in phase contrast vs fluorescence microscopy images. By fitting the correlation between phase contrast and fluorescence intensity to a physical model, we obtain well-defined estimates for the different levels of gene expression that are present in the cell or cluster. The method reveals the boundaries of the individual cells, even if the source images lack the resolution to show these boundaries clearly.

Prospects and challenges of quantitative phase imaging in tumor cell biology

Science.gov (United States)

Kemper, Björn; Götte, Martin; Greve, Burkhard; Ketelhut, Steffi

2016-03-01

Quantitative phase imaging (QPI) techniques provide high resolution label-free quantitative live cell imaging. Here, prospects and challenges of QPI in tumor cell biology are presented, using the example of digital holographic microscopy (DHM). It is shown that the evaluation of quantitative DHM phase images allows the retrieval of different parameter sets for quantification of cellular motion changes in migration and motility assays that are caused by genetic modifications. Furthermore, we demonstrate simultaneously label-free imaging of cell growth and morphology properties.

Plasmid-dependent attachment of Agrobacterium tumefaciens to plant tissue culture cells.

Science.gov (United States)

Matthysse, A G; Wyman, P M; Holmes, K V

1978-11-01

Kinetic, microscopic, and biochemical studies show that virulent Ti (tumor inducing)-plasmid-containing strains of Agrobacterium attach to normal tobacco and carrot tissue culture cells. Kinetic studies showed that virulent strains of A. tumefaciens attach to the plant tissue culture cells in increasing numbers during the first 1 to 2 h of incubation of the bacteria with the plant cells. Five Ti-plasmid-containing virulent Agrobacterium strains showed greater attachment to tobacco cells than did five avirulent strains. Light and scanning electron microscopic observations confirmed that virulent strains showed little attachment. Bacterial attachment was blocked by prior incubation of the plant cells with lipopolysaccharide extracted from A. tumefaciens, but not from A. radiobacter, suggesting that bacterial lipopolysaccharide is one of the components involved in the attachment process. At least one other bacterial product may be required for attachment in tissue culture because the virulent A. tumefaciens NT1, which lacks the Ti plasmid, does not itself attach to tobacco cells, but its lipopolysaccharide does inhibit the attachment of virulent strains.

Direct observation of the effects of cellulose synthesis inhibitors using live cell imaging of Cellulose Synthase (CESA) in Physcomitrella patens.

Science.gov (United States)

Tran, Mai L; McCarthy, Thomas W; Sun, Hao; Wu, Shu-Zon; Norris, Joanna H; Bezanilla, Magdalena; Vidali, Luis; Anderson, Charles T; Roberts, Alison W

2018-01-15

Results from live cell imaging of fluorescently tagged Cellulose Synthase (CESA) proteins in Cellulose Synthesis Complexes (CSCs) have enhanced our understanding of cellulose biosynthesis, including the mechanisms of action of cellulose synthesis inhibitors. However, this method has been applied only in Arabidopsis thaliana and Brachypodium distachyon thus far. Results from freeze fracture electron microscopy of protonemal filaments of the moss Funaria hygrometrica indicate that a cellulose synthesis inhibitor, 2,6-dichlorobenzonitrile (DCB), fragments CSCs and clears them from the plasma membrane. This differs from Arabidopsis, in which DCB causes CSC accumulation in the plasma membrane and a different cellulose synthesis inhibitor, isoxaben, clears CSCs from the plasma membrane. In this study, live cell imaging of the moss Physcomitrella patens indicated that DCB and isoxaben have little effect on protonemal growth rates, and that only DCB causes tip rupture. Live cell imaging of mEGFP-PpCESA5 and mEGFP-PpCESA8 showed that DCB and isoxaben substantially reduced CSC movement, but had no measureable effect on CSC density in the plasma membrane. These results suggest that DCB and isoxaben have similar effects on CSC movement in P. patens and Arabidopsis, but have different effects on CSC intracellular trafficking, cell growth and cell integrity in these divergent plant lineages.

Extraction of the number of peroxisomes in yeast cells by automated image analysis.

Science.gov (United States)

Niemistö, Antti; Selinummi, Jyrki; Saleem, Ramsey; Shmulevich, Ilya; Aitchison, John; Yli-Harja, Olli

2006-01-01

An automated image analysis method for extracting the number of peroxisomes in yeast cells is presented. Two images of the cell population are required for the method: a bright field microscope image from which the yeast cells are detected and the respective fluorescent image from which the number of peroxisomes in each cell is found. The segmentation of the cells is based on clustering the local mean-variance space. The watershed transformation is thereafter employed to separate cells that are clustered together. The peroxisomes are detected by thresholding the fluorescent image. The method is tested with several images of a budding yeast Saccharomyces cerevisiae population, and the results are compared with manually obtained results.

High-speed cell recognition algorithm for ultrafast flow cytometer imaging system

Science.gov (United States)

Zhao, Wanyue; Wang, Chao; Chen, Hongwei; Chen, Minghua; Yang, Sigang

2018-04-01

An optical time-stretch flow imaging system enables high-throughput examination of cells/particles with unprecedented high speed and resolution. A significant amount of raw image data is produced. A high-speed cell recognition algorithm is, therefore, highly demanded to analyze large amounts of data efficiently. A high-speed cell recognition algorithm consisting of two-stage cascaded detection and Gaussian mixture model (GMM) classification is proposed. The first stage of detection extracts cell regions. The second stage integrates distance transform and the watershed algorithm to separate clustered cells. Finally, the cells detected are classified by GMM. We compared the performance of our algorithm with support vector machine. Results show that our algorithm increases the running speed by over 150% without sacrificing the recognition accuracy. This algorithm provides a promising solution for high-throughput and automated cell imaging and classification in the ultrafast flow cytometer imaging platform.

Evolution of plant cell wall: Arabinogalactan-proteins from three moss genera show structural differences compared to seed plants.

Science.gov (United States)

Bartels, Desirée; Baumann, Alexander; Maeder, Malte; Geske, Thomas; Heise, Esther Marie; von Schwartzenberg, Klaus; Classen, Birgit

2017-05-01

Arabinogalactan-proteins (AGPs) are important proteoglycans of plant cell walls. They seem to be present in most, if not all seed plants, but their occurrence and structure in bryophytes is widely unknown and actually the focus of AGP research. With regard to evolution of plant cell wall, we isolated AGPs from the three mosses Sphagnum sp., Physcomitrella patens and Polytrichastrum formosum. The moss AGPs show structural characteristics common for AGPs of seed plants, but also unique features, especially 3-O-methyl-rhamnose (trivial name acofriose) as terminal monosaccharide not found in arabinogalactan-proteins of angiosperms and 1,2,3-linked galactose as branching point never found in arabinogalactan-proteins before. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Effective productions of plant secondary metabolites having antitumor activity by plant cell and tissue cultures].

Science.gov (United States)

Taniguchi, Shoko

2005-06-01

Methods for the effective production of plant secondary metabolites with antitumor activity using plant cell and tissue cultures were developed. The factors in tannin productivity were investigated using culture strains producing different types of hydrolyzable tannins, i.e., gallotannins (mixture of galloylglucoses), ellagi-, and dehydroellagitannins. Production of ellagi- and dehydroellagitannins was affected by the concentrations and ratio of nitrogen sources in the medium. The formation of oligomeric ellagitannins in shoots of Oenothera tetraptera was correlated with the differentiation of tissues. Cultured cells of Eriobotrya japonica producing ursane- and oleanane-type triterpenes with antitumor activities were also established.

Digital image processing for radiography in nuclear power plants

International Nuclear Information System (INIS)

Heidt, H.; Rose, P.; Raabe, P.; Daum, W.

1985-01-01

With the help of digital processing of radiographic images from reactor-components it is possible to increase the security and objectiveness of the evaluation. Several examples of image processing procedures (contrast enhancement, density profiles, shading correction, digital filtering, superposition of images etc.) show the advantages for the visualization and evaluation of radiographs. Digital image processing can reduce some of the restrictions of radiography in nuclear power plants. In addition a higher degree of automation can be cost-saving and increase the quality of radiographic evaluation. The aim of the work performed was to to improve the readability of radiographs for the human observer. The main problem is lack of contrast and the presence of disturbing structures like weld seams. Digital image processing of film radiographs starts with the digitization of the image. Conventional systems use TV-cameras or scanners and provide a dynamic range of 1.5. to 3 density units, which are digitized to 256 grey levels. For the enhancement process it is necessary that the grey level range covers the density range of the important regions of the presented film. On the other hand the grey level coverage should not be wider than necessary to minimize the width of digitization steps. Poor digitization makes flaws and cracks invisible and spoils all further image processing

Protein diffusion in plant cell plasma membranes: the cell-wall corral.

Science.gov (United States)

Martinière, Alexandre; Runions, John

2013-01-01

Studying protein diffusion informs us about how proteins interact with their environment. Work on protein diffusion over the last several decades has illustrated the complex nature of biological lipid bilayers. The plasma membrane contains an array of membrane-spanning proteins or proteins with peripheral membrane associations. Maintenance of plasma membrane microstructure can be via physical features that provide intrinsic ordering such as lipid microdomains, or from membrane-associated structures such as the cytoskeleton. Recent evidence indicates, that in the case of plant cells, the cell wall seems to be a major player in maintaining plasma membrane microstructure. This interconnection / interaction between cell-wall and plasma membrane proteins most likely plays an important role in signal transduction, cell growth, and cell physiological responses to the environment.

A high-resolution method for the localization of proanthocyanidins in plant tissues

Directory of Open Access Journals (Sweden)

Panter Stephen

2011-05-01

Full Text Available Abstract Background Histochemical staining of plant tissues with 4-dimethylaminocinnamaldehyde (DMACA or vanillin-HCl is widely used to characterize spatial patterns of proanthocyanidin accumulation in plant tissues. These methods are limited in their ability to allow high-resolution imaging of proanthocyanidin deposits. Results Tissue embedding techniques were used in combination with DMACA staining to analyze the accumulation of proanthocyanidins in Lotus corniculatus (L. and Trifolium repens (L. tissues. Embedding of plant tissues in LR White or paraffin matrices, with or without DMACA staining, preserved the physical integrity of the plant tissues, allowing high-resolution imaging that facilitated cell-specific localization of proanthocyanidins. A brown coloration was seen in proanthocyanidin-producing cells when plant tissues were embedded without DMACA staining and this was likely to have been due to non-enzymatic oxidation of proanthocyanidins and the formation of colored semiquinones and quinones. Conclusions This paper presents a simple, high-resolution method for analysis of proanthocyanidin accumulation in organs, tissues and cells of two plant species with different patterns of proanthocyanidin accumulation, namely Lotus corniculatus (birdsfoot trefoil and Trifolium repens (white clover. This technique was used to characterize cell type-specific patterns of proanthocyanidin accumulation in white clover flowers at different stages of development.

"Afterlife experiment": use of MALDI-MS and SIMS imaging for the study of the nitrogen cycle within plants.

Science.gov (United States)

Seaman, Callie; Flinders, Bryn; Eijkel, Gert; Heeren, Ron M A; Bricklebank, Neil; Clench, Malcolm R

2014-10-21

As part of a project to demonstrate the science of decay, a series of mass spectrometry imaging experiments were performed. The aim was to demonstrate that decay and decomposition are only part of the story and to show pictorially that atoms and molecules from dead plants and animals are incorporated into new life. Radish plants (Raphanus sativus) were grown hydroponically using a nutrient system containing (15)N KNO3 (98% labeled) as the only source of nitrogen. Plants were cropped and left to ferment in water for 2 weeks to create a radish "tea", which was used as a source of nitrogen for radish grown in a second hydroponics experiment. After 5 weeks of growth, the radish plants were harvested and cryosectioned, and sections were imaged by positive-ion MALDI and SIMS mass spectrometry imaging. The presence of labeled species in the plants grown using (15)N KNO3 as nutrient and those grown from the radish "tea" was readily discernible. The uptake of (15)N into a number of identifiable metabolites has been studied by MALDI-MS and SIMS imaging.

Vacuolar processing enzyme in plant programmed cell death

Directory of Open Access Journals (Sweden)

Noriyuki eHatsugai

2015-04-01

Full Text Available Vacuolar processing enzyme (VPE is a cysteine proteinase originally identified as the proteinase responsible for the maturation and activation of vacuolar proteins in plants, and it is known to be an orthologue of animal asparaginyl endopeptidase (AEP/VPE/legumain. VPE has been shown to exhibit enzymatic properties similar to that of caspase 1, which is a cysteine protease that mediates the programmed cell death (PCD pathway in animals. Although there is limited sequence identity between VPE and caspase 1, their predicted three-dimensional structures revealed that the essential amino-acid residues for these enzymes form similar pockets for the substrate peptide YVAD. In contrast to the cytosolic localization of caspases, VPE is localized in vacuoles. VPE provokes vacuolar rupture, initiating the proteolytic cascade leading to PCD in the plant immune response. It has become apparent that the VPE-dependent PCD pathway is involved not only in the immune response, but also in the responses to a variety of stress inducers and in the development of various tissues. This review summarizes the current knowledge on the contribution of VPE to plant PCD and its role in vacuole-mediated cell death, and it also compares VPE with the animal cell death executor caspase 1.

Single guard cell recordings in intact plants : light-induced hyperpolarization of the plasma membrane

NARCIS (Netherlands)

Roelfsema, MRG; Steinmeyer, R; Staal, M; Hedrich, R

Guard cells are electrically isolated from other plant cells and therefore offer the unique possibility to conduct current- and voltage-clamp recordings on single cells in an intact plant. Guard cells in their natural environment were impaled with double-barreled electrodes and found to exhibit

Microbial community structure elucidates performance of Glyceria maxima plant microbial fuel cell

NARCIS (Netherlands)

Timmers, R.A.; Rothballer, M.; Strik, D.P.B.T.B.; Engel, M.; Schulz, M.; Hartmann, A.; Hamelers, H.V.M.; Buisman, C.J.N.

2012-01-01

The plant microbial fuel cell (PMFC) is a technology in which living plant roots provide electron donor, via rhizodeposition, to a mixed microbial community to generate electricity in a microbial fuel cell. Analysis and localisation of the microbial community is necessary for gaining insight into

Live Cell in Vitro and in Vivo Imaging Applications: Accelerating Drug Discovery

Directory of Open Access Journals (Sweden)

Neil O Carragher

2011-04-01

Full Text Available Dynamic regulation of specific molecular processes and cellular phenotypes in live cell systems reveal unique insights into cell fate and drug pharmacology that are not gained from traditional fixed endpoint assays. Recent advances in microscopic imaging platform technology combined with the development of novel optical biosensors and sophisticated image analysis solutions have increased the scope of live cell imaging applications in drug discovery. We highlight recent literature examples where live cell imaging has uncovered novel insight into biological mechanism or drug mode-of-action. We survey distinct types of optical biosensors and associated analytical methods for monitoring molecular dynamics, in vitro and in vivo. We describe the recent expansion of live cell imaging into automated target validation and drug screening activities through the development of dedicated brightfield and fluorescence kinetic imaging platforms. We provide specific examples of how temporal profiling of phenotypic response signatures using such kinetic imaging platforms can increase the value of in vitro high-content screening. Finally, we offer a prospective view of how further application and development of live cell imaging technology and reagents can accelerate preclinical lead optimization cycles and enhance the in vitro to in vivo translation of drug candidates.

Quantitative volumetric Raman imaging of three dimensional cell cultures

KAUST Repository

Kallepitis, Charalambos

2017-03-22

The ability to simultaneously image multiple biomolecules in biologically relevant three-dimensional (3D) cell culture environments would contribute greatly to the understanding of complex cellular mechanisms and cell–material interactions. Here, we present a computational framework for label-free quantitative volumetric Raman imaging (qVRI). We apply qVRI to a selection of biological systems: human pluripotent stem cells with their cardiac derivatives, monocytes and monocyte-derived macrophages in conventional cell culture systems and mesenchymal stem cells inside biomimetic hydrogels that supplied a 3D cell culture environment. We demonstrate visualization and quantification of fine details in cell shape, cytoplasm, nucleus, lipid bodies and cytoskeletal structures in 3D with unprecedented biomolecular specificity for vibrational microspectroscopy.

Ceratopteris richardii (C-fern: A model for investigating adaptive modification of vascular plant cell walls

Directory of Open Access Journals (Sweden)

Olivier eLeroux

2013-09-01

Full Text Available Plant cell walls are essential for most aspects of plant growth, development, and survival, including cell division, expansive cell growth, cell-cell communication, biomechanical properties, and stress responses. Therefore, characterising cell wall diversity contributes to our overall understanding of plant evolution and development. Recent biochemical analyses, concomitantly with whole genome sequencing of plants located at pivotal points in plant phylogeny, have helped distinguish between homologous characters and those which might be more derived. Most plant lineages now have at least one fully sequenced representative and although genome sequences for fern species are in progress they not yet available this group. Ferns offer key advantages for the study of developmental processes leading to vascularisation and complex organs as well as the specific differences between diploid sporophyte tissues and haploid gametophyte tissues and the interplay between them. Ceratopteris richardii has been well investigated building a body of knowledge which combined with the genomic and biochemical information available for other plants will progress our understanding of wall diversity and its impact on evolution and development.

Tracking multi-walled carbon nanotubes inside oat (Avena sativa L.) plants and assessing their effect on growth, yield, and mammalian (human) cell viability

Science.gov (United States)

Joshi, Anjali; Kaur, Simranjeet; Singh, Pargat; Dharamvir, Keya; Nayyar, Harsh; Verma, Gaurav

2018-05-01

Our findings show that oxidized multi-walled carbon nanotubes (MWCNT) having serpent-like morphology and smaller sizes (diameter of 35 nm and lengths of 200-300 nm) are compatible with oat plant tissues. Applied by seed-priming method as 90 µg/ml concentration, these serpentine MWCNT (having open-end caps) enter the oat plant and traverse the cells. Tracking of MWCNT inside sections and tissues during growth of oat plant has been done using special sample preparation. We present clear images of MWCNT inside the primed seeds and vascular bundles, the conducting tissues of root and shoot of oat. A dye fluorescein isothiocyanate non-covalently bonded to MWCNT also helped in detecting the path through circumferential perimeters of the oat channels, using fluorescence and confocal microscopy. The presence of MWCNT inside oat enhanced the growth of xylem cells by about 1.85-fold in vasculature of shoots. Compared to controls, the chlorophyll content increased by 57%, while photosynthetic activity enhanced by 15% for the same sample in MWCNT-primed plants. Overall, the growth factors were also augmented leading to significant increase in yield components. No toxic effects of MWCNT were observed in the DNA of the primed plants, and in the human cell lines treated with grains harvested from the MWCNT-primed plants. Our study provides some new insights about the role of MWCNT in plants and their potential benefits in agriculture.

Roles of autophagy in male reproductive development in plants

Directory of Open Access Journals (Sweden)

Shigeru eHanamata

2014-09-01

Full Text Available Autophagy, a major catabolic pathway in eukaryotic cells, is essential in development, maintenance of cellular homeostasis, immunity and programmed cell death (PCD in multicellular organisms. In plant cells, autophagy plays roles in recycling of proteins and metabolites including lipids, and is involved in many physiological processes such as abiotic and biotic stress responses. However, its roles during reproductive development had remained poorly understood. Quantitative live cell imaging techniques for the autophagic flux and genetic studies in several plant species have recently revealed significant roles of autophagy in developmental processes, regulation of PCD and lipid metabolism. We here review the novel roles of autophagic fluxes in plant cells, and discuss their possible significance in PCD and metabolic regulation, with particular focus on male reproductive development during the pollen maturation.

Immunomagnetic cell separation, imaging, and analysis using Captivate ferrofluids

Science.gov (United States)

Jones, Laurie; Beechem, Joseph M.

2002-05-01

We have developed applications of CaptivateTM ferrofluids, paramagnetic particles (approximately 200 nm diameter), for isolating and analyzing cell populations in combination with fluorescence-based techniques. Using a microscope-mounted magnetic yoke and sample insertion chamber, fluorescent images of magnetically captured cells were obtained in culture media, buffer, or whole blood, while non-magnetically labeled cells sedimented to the bottom of the chamber. We combined this immunomagnetic cell separation and imaging technique with fluorescent staining, spectroscopy, and analysis to evaluate cell surface receptor-containing subpopulations, live/dead cell ratios, apoptotic/dead cell ratios, etc. The acquired images were analyzed using multi-color parameters, as produced by nucleic acid staining, esterase activity, or antibody labeling. In addition, the immunomagnetically separated cell fractions were assessed through microplate analysis using the CyQUANT Cell Proliferation Assay. These methods should provide an inexpensive alternative to some flow cytometric measurements. The binding capacities of the streptavidin- labled Captivate ferrofluid (SA-FF) particles were determined to be 8.8 nmol biotin/mg SA-FF, using biotin-4- fluorescein, and > 106 cells/mg SA-FF, using several cell types labeled with biotinylated probes. For goat anti- mouse IgG-labeled ferrofluids (GAM-FF), binding capacities were established to be approximately 0.2 - 7.5 nmol protein/mg GAM-FF using fluorescent conjugates of antibodies, protein G, and protein A.

Spirally-patterned pinhole arrays for long-term fluorescence cell imaging.

Science.gov (United States)

Koo, Bon Ung; Kang, YooNa; Moon, SangJun; Lee, Won Gu

2015-11-07

Fluorescence cell imaging using a fluorescence microscope is an extensively used technique to examine the cell nucleus, internal structures, and other cellular molecules with fluorescence response time and intensity. However, it is difficult to perform high resolution cell imaging for a long period of time with this technique due to necrosis and apoptosis depending on the type and subcellular location of the damage caused by phototoxicity. A large number of studies have been performed to resolve this problem, but researchers have struggled to meet the challenge between cellular viability and image resolution. In this study, we employ a specially designed disc to reduce cell damage by controlling total fluorescence exposure time without deterioration of the image resolution. This approach has many advantages such as, the apparatus is simple, cost-effective, and easily integrated into the optical pathway through a conventional fluorescence microscope.

Using simulated fluorescence cell micrographs for the evaluation of cell image segmentation algorithms.

Science.gov (United States)

Wiesmann, Veit; Bergler, Matthias; Palmisano, Ralf; Prinzen, Martin; Franz, Daniela; Wittenberg, Thomas

2017-03-18

Manual assessment and evaluation of fluorescent micrograph cell experiments is time-consuming and tedious. Automated segmentation pipelines can ensure efficient and reproducible evaluation and analysis with constant high quality for all images of an experiment. Such cell segmentation approaches are usually validated and rated in comparison to manually annotated micrographs. Nevertheless, manual annotations are prone to errors and display inter- and intra-observer variability which influence the validation results of automated cell segmentation pipelines. We present a new approach to simulate fluorescent cell micrographs that provides an objective ground truth for the validation of cell segmentation methods. The cell simulation was evaluated twofold: (1) An expert observer study shows that the proposed approach generates realistic fluorescent cell micrograph simulations. (2) An automated segmentation pipeline on the simulated fluorescent cell micrographs reproduces segmentation performances of that pipeline on real fluorescent cell micrographs. The proposed simulation approach produces realistic fluorescent cell micrographs with corresponding ground truth. The simulated data is suited to evaluate image segmentation pipelines more efficiently and reproducibly than it is possible on manually annotated real micrographs.

Analysis of gene expression levels in individual bacterial cells without image segmentation

Energy Technology Data Exchange (ETDEWEB)

Kwak, In Hae; Son, Minjun [Physics Department, University of Florida, P.O. Box 118440, Gainesville, FL 32611-8440 (United States); Hagen, Stephen J., E-mail: sjhagen@ufl.edu [Physics Department, University of Florida, P.O. Box 118440, Gainesville, FL 32611-8440 (United States)

2012-05-11

Highlights: Black-Right-Pointing-Pointer We present a method for extracting gene expression data from images of bacterial cells. Black-Right-Pointing-Pointer The method does not employ cell segmentation and does not require high magnification. Black-Right-Pointing-Pointer Fluorescence and phase contrast images of the cells are correlated through the physics of phase contrast. Black-Right-Pointing-Pointer We demonstrate the method by characterizing noisy expression of comX in Streptococcus mutans. -- Abstract: Studies of stochasticity in gene expression typically make use of fluorescent protein reporters, which permit the measurement of expression levels within individual cells by fluorescence microscopy. Analysis of such microscopy images is almost invariably based on a segmentation algorithm, where the image of a cell or cluster is analyzed mathematically to delineate individual cell boundaries. However segmentation can be ineffective for studying bacterial cells or clusters, especially at lower magnification, where outlines of individual cells are poorly resolved. Here we demonstrate an alternative method for analyzing such images without segmentation. The method employs a comparison between the pixel brightness in phase contrast vs fluorescence microscopy images. By fitting the correlation between phase contrast and fluorescence intensity to a physical model, we obtain well-defined estimates for the different levels of gene expression that are present in the cell or cluster. The method reveals the boundaries of the individual cells, even if the source images lack the resolution to show these boundaries clearly.

Evidence for land plant cell wall biosynthetic mechanisms in charophyte green algae

DEFF Research Database (Denmark)

Mikkelsen, Maria Dalgaard; Harholt, Jesper; Ulvskov, Peter

2014-01-01

in CGA is currently unknown, as no genomes are available, so this study sought to give insight into the evolution of the biosynthetic machinery of CGA through an analysis of available transcriptomes. METHODS: Available CGA transcriptomes were mined for cell wall biosynthesis GTs and compared with GTs...... to colonize land. These cell walls provide support and protection, are a source of signalling molecules, and provide developmental cues for cell differentiation and elongation. The cell wall of land plants is a highly complex fibre composite, characterized by cellulose cross-linked by non......-cellulosic polysaccharides, such as xyloglucan, embedded in a matrix of pectic polysaccharides. How the land plant cell wall evolved is currently unknown: early-divergent chlorophyte and prasinophyte algae genomes contain a low number of glycosyl transferases (GTs), while land plants contain hundreds. The number of GTs...

The Complex Cell Wall Composition of Syncytia Induced by Plant Parasitic Cyst Nematodes Reflects Both Function and Host Plant.

Science.gov (United States)

Zhang, Li; Lilley, Catherine J; Imren, Mustafa; Knox, J Paul; Urwin, Peter E

2017-01-01

Plant-parasitic cyst nematodes induce the formation of specialized feeding structures, syncytia, within their host roots. These unique plant organs serve as the sole nutrient resource for development and reproduction throughout the biotrophic interaction. The multinucleate syncytium, which arises through local dissolution of cell walls and protoplast fusion of multiple adjacent cells, has dense cytoplasm containing numerous organelles, surrounded by thickened outer cell walls that must withstand high turgor pressure. However, little is known about how the constituents of the syncytial cell wall and their conformation support its role during nematode parasitism. We used a set of monoclonal antibodies, targeted to a range of plant cell wall components, to reveal the microstructures of syncytial cell walls induced by four of the most economically important cyst nematode species, Globodera pallida , Heterodera glycines , Heterodera avenae and Heterodera filipjevi , in their respective potato, soybean, and spring wheat host roots. In situ fluorescence analysis revealed highly similar cell wall composition of syncytia induced by G. pallida and H. glycines . Both consisted of abundant xyloglucan, methyl-esterified homogalacturonan and pectic arabinan. In contrast, the walls of syncytia induced in wheat roots by H. avenae and H. filipjevi contain little xyloglucan but are rich in feruloylated xylan and arabinan residues, with variable levels of mixed-linkage glucan. The overall chemical composition of syncytial cell walls reflected the general features of root cell walls of the different host plants. We relate specific components of syncytial cell walls, such as abundant arabinan, methyl-esterification status of pectic homogalacturonan and feruloylation of xylan, to their potential roles in forming a network to support both the strength and flexibility required for syncytium function.

Altered Cell Wall Plasticity Can Restrict Plant Growth under Ammonium Nutrition.

Science.gov (United States)

Podgórska, Anna; Burian, Maria; Gieczewska, Katarzyna; Ostaszewska-Bugajska, Monika; Zebrowski, Jacek; Solecka, Danuta; Szal, Bożena

2017-01-01

Plants mainly utilize inorganic forms of nitrogen (N), such as nitrate (NO 3 - ) and ammonium (NH 4 + ). However, the composition of the N source is important, because excess of NH 4 + promotes morphological disorders. Plants cultured on NH 4 + as the sole N source exhibit serious growth inhibition, commonly referred to as "ammonium toxicity syndrome." NH 4 + -mediated suppression of growth may be attributable to both repression of cell elongation and reduction of cell division. The precondition for cell enlargement is the expansion of the cell wall, which requires the loosening of the cell wall polymers. Therefore, to understand how NH 4 + nutrition may trigger growth retardation in plants, properties of their cell walls were analyzed. We found that Arabidopsis thaliana using NH 4 + as the sole N source has smaller cells with relatively thicker cell walls. Moreover, cellulose, which is the main load-bearing polysaccharide revealed a denser assembly of microfibrils. Consequently, the leaf blade tissue showed elevated tensile strength and indicated higher cell wall stiffness. These changes might be related to changes in polysaccharide and ion content of cell walls. Further, NH 4 + toxicity was associated with altered activities of cell wall modifying proteins. The lower activity and/or expression of pectin hydrolyzing enzymes and expansins might limit cell wall expansion. Additionally, the higher activity of cell wall peroxidases can lead to higher cross-linking of cell wall polymers. Overall, the NH 4 + -mediated inhibition of growth is related to a more rigid cell wall structure, which limits expansion of cells. The changes in cell wall composition were also indicated by decreased expression of Feronia , a receptor-like kinase involved in the control of cell wall extension.

Quantitative image analysis for investigating cell-matrix interactions

Science.gov (United States)

Burkel, Brian; Notbohm, Jacob

2017-07-01

The extracellular matrix provides both chemical and physical cues that control cellular processes such as migration, division, differentiation, and cancer progression. Cells can mechanically alter the matrix by applying forces that result in matrix displacements, which in turn may localize to form dense bands along which cells may migrate. To quantify the displacements, we use confocal microscopy and fluorescent labeling to acquire high-contrast images of the fibrous material. Using a technique for quantitative image analysis called digital volume correlation, we then compute the matrix displacements. Our experimental technology offers a means to quantify matrix mechanics and cell-matrix interactions. We are now using these experimental tools to modulate mechanical properties of the matrix to study cell contraction and migration.

Using SPOT-5 images in rice farming for detecting BPH (Brown Plant Hopper)

International Nuclear Information System (INIS)

Ghobadifar, F; Wayayok, A; Shattri, M; Shafri, H

2014-01-01

Infestation of rice plant-hopper such as Brown Plant Hopper (BPH) (Nilaparvata lugens) is one of the most notable risk in rice yield in tropical areas especially in Asia. In order to use visible and infrared images to detect stress in rice production caused by BPH infestation, several remote sensing techniques have been developed. Initial recognition of pest infestation by means of remote sensing will spreads, for precision farming practice. To address this issue, detection of sheath blight in rice farming was examined by using SPOT-5 images. Specific image indices such as Normalized decrease food production costs, limit environmental hazards, and enhance natural pest control before the problem Normalized Difference Vegetation Index (NDVI), Standard difference indices (SDI) and Ratio Vegetation Index (RVI) were used for analyses using ENVI 4.8 and SPSS software. Results showed that all the indices to recognize infected plants are significant at α = 0.01. Examination of the association between the disease indices indicated that band 3 (near infrared) and band 4 (mid infrared) have a relatively high correlation. The selected indices declared better association for detecting healthy plants from diseased ones. Consequently, these sorts of indices especially NDVI could be valued as indicators for developing techniques for detecting the sheath blight of rice by using remote sensing. This infers that they are useful for crop disease detection but the spectral resolution is probably not sufficient to distinguish plants with light infections (low severity level). Using the index as an indicator can clarify the threshold for zoning the outbreaks. Quick assessment information is very useful in precision farming to practice site specific management such as pesticide application

Using SPOT-5 images in rice farming for detecting BPH (Brown Plant Hopper)

Science.gov (United States)

Ghobadifar, F.; Wayayok, A.; Shattri, M.; Shafri, H.

2014-06-01

Infestation of rice plant-hopper such as Brown Plant Hopper (BPH) (Nilaparvata lugens) is one of the most notable risk in rice yield in tropical areas especially in Asia. In order to use visible and infrared images to detect stress in rice production caused by BPH infestation, several remote sensing techniques have been developed. Initial recognition of pest infestation by means of remote sensing will spreads, for precision farming practice. To address this issue, detection of sheath blight in rice farming was examined by using SPOT-5 images. Specific image indices such as Normalized decrease food production costs, limit environmental hazards, and enhance natural pest control before the problem Normalized Difference Vegetation Index (NDVI), Standard difference indices (SDI) and Ratio Vegetation Index (RVI) were used for analyses using ENVI 4.8 and SPSS software. Results showed that all the indices to recognize infected plants are significant at α = 0.01. Examination of the association between the disease indices indicated that band 3 (near infrared) and band 4 (mid infrared) have a relatively high correlation. The selected indices declared better association for detecting healthy plants from diseased ones. Consequently, these sorts of indices especially NDVI could be valued as indicators for developing techniques for detecting the sheath blight of rice by using remote sensing. This infers that they are useful for crop disease detection but the spectral resolution is probably not sufficient to distinguish plants with light infections (low severity level). Using the index as an indicator can clarify the threshold for zoning the outbreaks. Quick assessment information is very useful in precision farming to practice site specific management such as pesticide application.

The stem cell state in plant development and in response to stress