Spatial and temporal deposition of suberin during maturation of the onion root exodermis

Botany ◽  
2011 ◽  
Vol 89 (2) ◽  
pp. 119-131 ◽  
Author(s):  
Chris J. Meyer ◽  
Carol A. Peterson ◽  
Mark A. Bernards
Keyword(s):  
Soluble Fraction ◽  
Cell Types ◽  
Gas Chromatography Mass Spectrometry ◽  
Enzymatic Characterization ◽  
Dioic Acid ◽  
Onion Root ◽  
Suberin Lamellae ◽  
Metabolite Profiles ◽  
Cell Layers

Suberin is a complex biopolymer composed of a poly(aliphatic) domain (SPAD) and a poly(phenolic) domain (SPPD). Suberin is typically confined to specialized cell types including root exodermal cells, but its synthesis in a maturing exodermis is still not well understood. For the current work, Allium cepa roots were used as a model to analyze SPAD and SPPD synthesis in a maturing uniseriate exodermis. Roots were divided into four maturation zones based on their growth rate and the deposition of suberin lamellae in maturing exodermal cells. Exodermal and epidermal cell layers were separated from the underlying layers in each maturation zone, then soluble and insoluble suberin monomers were extracted chemically, and quantified and identified by gas chromatography – mass spectrometry. Temporal patterns for the synthesis of the SPAD, but not for the SPPD, were revealed upon resolution of the metabolite profiles. The composition of the soluble fraction was essentially unchanged as the exodermis matured. In contrast, the SPAD composition differed during maturation, mainly owing to significant increases in the deposition of C18:1 α,ω-dioic acid and ω-OH fatty acids. It is proposed that the exodermal maturation zones with their corresponding metabolite profiles be used as targets for the functional enzymatic characterization of suberin biosynthetic pathways.

scholarly journals Flavor and Metabolite Profiles of Meat, Meat Substitutes, and Traditional Plant-Based High-Protein Food Products Available in Australia

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 801
Author(s):  
Kornelia Kaczmarska ◽  
Matthew Taylor ◽  
Udayasika Piyasiri ◽  
Damian Frank
Keyword(s):  
Mass Spectrometry ◽  
Solid Phase ◽  
Food Products ◽  
High Protein ◽  
Gas Chromatography Mass Spectrometry ◽  
Protein Food ◽  
Volatile Flavor ◽  
Orbitrap Mass Spectrometry ◽  
Metabolite Profiles

Demand for plant-based proteins and plant-based food products is increasing globally. This trend is driven mainly by global population growth and a consumer shift towards more sustainable and healthier diets. Existing plant-based protein foods and meat mimetics often possess undesirable flavor and sensory properties and there is a need to better understand the formation of desirable meat-like flavors from plant precursors to improve acceptance of novel high-protein plant foods. This study aimed to comprehensively characterize the non-volatile flavor metabolites and the volatiles generated in grilled meat (beef, chicken, and pork) and compare these to commercially available meat substitutes and traditional high-protein plant-based foods (natto, tempeh, and tofu). Solid phase microextraction with gas-chromatography mass-spectrometry was used for elucidation of the flavor volatilome. Untargeted characterization of the non-volatile metabolome was conducted using Orbitrap mass spectrometry and Compound DiscovererTM datamining software. The study revealed greater diversity and higher concentrations of flavor volatiles in plant-based foods in comparison to grilled meat, although the odor activity of specific volatiles was not considered. On average, the total amount of volatiles in plant-based products were higher than in meat. A range of concentrations of free amino acids, dipeptide, tripeptides, tetrapeptides, nucleotides, flavonoids, and other metabolites was identified in meat and plant-based foods.

The effect of suberin lamellae on the vitality and symplasmic permeability of the onion root exodermis

1996 ◽  
Vol 74 (8) ◽  
pp. 1220-1226 ◽  
Author(s):  
Carol A. Peterson ◽  
Janet L. Waite
Keyword(s):  
Cell Types ◽  
Ion Transfer ◽  
Onion Root ◽  
Cell Vitality ◽  
Casparian Bands ◽  
Allium Cepa L ◽  
Suberin Lamellae ◽  
Form Part ◽  
Wall Permeability ◽  
Suberin Lamella

The onion exodermis is made up of two cell types, i.e., long and short cells. Both form Casparian bands, but suberin lamella development is absent or delayed in the short cells. Long cells did not accumulate fluorescein, a common test for cell vitality, because of reduced wall permeability due to suberin lamella development. Immature, long cells without lamellae stained in 15 min, whereas mature cells with lamellae required a 3.5- to 4-h treatment before staining was visible. Long exposure to fluorescein was needed to show that mature long cells were alive. Their vitality appeared to decline slowly with age but was not affected by drought stress. Fluorescein staining was apparent in the long cells only after treatment of paradermal sections; when dye was applied only externally to root segments, it did not enter the long cells from the epidermis or from the neighbouring short cells. This result indicates that the long cells were connected symplasmically to the cells of the cortex but were either unconnected, or connected by plasmodesmata of small functional diameter, to the epidermal and short cells. If they were unconnected, they would not form part of the symplasmic path of ion transfer into the root. Keywords: Allium cepa L., drought, exodermis, suberin lamella, vitality.

scholarly journals Hidden cell diversity in Placozoa: Ultrastructural Insights from Hoilungia hongkongensis

2020 ◽  
Author(s):  
Daria Y. Romanova ◽  
Frederique Varoqueaux ◽  
Jean Daraspe ◽  
Mikhail A. Nikitin ◽  
Michael Eitel ◽  
...  
Keyword(s):  
Cell Types ◽  
Lower Surface ◽  
Point Of View ◽  
Cell Type ◽  
Free Living ◽  
Trichoplax Adhaerens ◽  
Genetic Complexity ◽  
Cell Diversity ◽  
Cell Layers

AbstractFrom a morphological point of view, placozoans are among the most simple free-living animals. This enigmatic phylum is critical for our understanding of the evolution of animals and their cell types. Their millimeter-sized, disc-like bodies consist of only three cell layers that are shaped by roughly six major cell types. Placozoans lack muscle cells and neurons but are able to move using their ciliated lower surface and take up food in a highly coordinated manner. Intriguingly, the genome of Trichoplax adhaerens, the founding member of the enigmatic phylum, has disclosed a surprising level of genetic complexity. Moreover, recent molecular and functional investigations have uncovered a much larger, so-far hidden cell-type diversity. Here, we have extended the microanatomical characterization of a recently described placozoan species – Hoilungia hongkongensis. In H. hongkongensis, we recognized the established canonical three-layered placozoan body plan but also came across several morphologically distinct and potentially novel cell types, among them novel gland cells and “shiny spheres”-bearing cells at the upper epithelium. Thus, the diversity of cell types in placozoans is indeed higher than anticipated.

scholarly journals Studies of Schwann cell proliferation. II. Characterization of the stimulation and specificity of the response to a neurite membrane fraction.

1980 ◽  
Vol 84 (3) ◽  
pp. 753-766 ◽  
Author(s):  
J L Salzer ◽  
A K Williams ◽  
L Glaser ◽  
R P Bunge
Keyword(s):  
Schwann Cells ◽  
Membrane Fraction ◽  
Tritiated Thymidine ◽  
Cell Types ◽  
Primary Cells ◽  
Sensory Ganglion ◽  
Cell Layers ◽  
Multiple Cell ◽  
Peripheral Sensory

When prepared by methods utilized in our laboratory, pure populations of Schwann cells in culture do not divide, but, after recombination with peripheral sensory neurons or their processes, proliferate rapidly (Wood and Bunge, 1975, Nature (Lond.) 256:661--664). In this paper, we demonstrate that a membrane fraction prepared from sensory ganglion neurites is also mitogenic for Schwann cells and increases the labeling index (assessed by autoradiography after incubation of cells with tritiated thymidine) from less than 0.2 to 10% for primary cells, and from 0.4 to 18--19% for replated cells. The increased responsiveness of replated cells may reflect their greater access to the neurite membranes which is a consequence of the elimination of multiple cell layers after replating and the removal of the basal lamina. This stimulation was specific; addition of membrane preparations from other cell types (3T3, C1300, etc.) was not mitogenic. Ultrastructural analysis demonstrated apparent binding of neurite membranes to Schwann cells as well as significant phagocytosis of the membranes by the cells. The uptake of nonmitogenic membranes suggests that phagocytosis per se is not the stimulus of proliferation.

Characterization of drug interferences caused by coelution of substances in gas chromatography/mass spectrometry confirmation of targeted drugs in full-scan and selected-ion monitoring modes

1994 ◽  
Vol 40 (2) ◽  
pp. 216-220 ◽  
Author(s):  
A H Wu ◽  
D Ostheimer ◽  
M Cremese ◽  
E Forte ◽  
D Hill
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography Mass Spectrometry ◽  
Spectrometric Analysis ◽  
Targeted Drugs ◽  
Selected Ion Monitoring ◽  
Internal Standards ◽  
Target Drug ◽  
Full Scan ◽  
Chromatographic Mass

Abstract Interference by substances coeluting with targeted drugs is a general problem for gas chromatographic/mass spectrometric analysis of urine. To characterize these interferences, we examined human urine samples containing benzoylecgonine and fluconazole, and other drug combinations including deuterated internal standards that coelute (ISd,c) with target drugs, by selected-ion monitoring (SIM) and full-scan mass spectrometry. We show that, by SIM analysis, detecting the presence of an interferent is dependent on the specific IS used for the assay. When an ISd,c is used, the presence of another coeluting substance (interferent) suggests that the intensity of IS ions is substantially diminished, because the interferent affects both the ISd,c and target drug. When a noncoeluting IS (ISnc) is used, the interferent cannot be discerned unless it coincidently contains one or more of the ions monitored for either the target drug or ISnc. Under full-scan analysis, a coeluting interferent is directly discernable by examining the total ion gas chromatogram.

scholarly journals Identification and Analytical Characterization of a Novel Synthetic Cannabinoid-Type Substance in Herbal Material in Europe

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 793
Author(s):  
Emmanouil D. Tsochatzis ◽  
Joao Alberto Lopes ◽  
Margaret V. Holland ◽  
Fabiano Reniero ◽  
Giovanni Palmieri ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cannabinoid Receptor ◽  
Analytical Data ◽  
Synthetic Cannabinoids ◽  
Synthetic Cannabinoid ◽  
Gas Chromatography Mass Spectrometry ◽  
New Psychoactive Substances ◽  
Synthetic Cannabinoid Receptor Agonists ◽  
Analytical Laboratories

The rapid diffusion of new psychoactive substances (NPS) presents unprecedented challenges to both customs authorities and analytical laboratories involved in their detection and characterization. In this study an analytical approach to the identification and structural elucidation of a novel synthetic cannabimimetic, quinolin-8-yl-3-[(4,4-difluoropiperidin-1-yl) sulfonyl]-4-methylbenzoate (2F-QMPSB), detected in seized herbal material, is detailed. An acid precursor 4-methyl-3-(4,4-difluoro-1-piperidinylsulfonyl) benzoic acid (2F-MPSBA), has also been identified in the same seized material. After extraction from the herbal material the synthetic cannabimimetic, also referred to as synthetic cannabinoid receptor agonists or “synthetic cannabinoids”, was characterized using gas chromatography-mass spectrometry (GC-MS), 1H, 13C, 19F and 15N nuclear magnetic resonance (NMR) and high-resolution tandem mass spectrometry (HR-MS/MS) combined with chromatographic separation. A cheminformatics platform was used to manage and interpret the analytical data from these techniques.

scholarly journals Enzymatic characterization of interferon-induced antiviral GTPases murine Mx1 and human MxA proteins.

1994 ◽  
Vol 269 (3) ◽  
pp. 2009-2015 ◽  
Author(s):  
K. Melén ◽  
T. Ronni ◽  
T. Lotta ◽  
I. Julkunen
Keyword(s):  
Enzymatic Characterization
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