Phytosterols in the aleurone layer of corn kernels

2000 ◽  
Vol 28 (6) ◽  
pp. 803-806 ◽  
Author(s):  
R. A. Moreau ◽  
V. Singh ◽  
A. Nuñez ◽  
K. B. Hicks
Keyword(s):  
Outer Layer ◽  
Cell Walls ◽  
Single Layer ◽  
Living Cells ◽  
Aleurone Layer ◽  
High Concentration ◽  
Aleurone Cells ◽  
Phytosterol Esters ◽  
Corn Fibre ◽  
Corn Kernels

Corn hulls are composed of two major layers: the outer layer, the pericarp, is made up of non-living cell walls, and an inner layer, the aleurone, consists of a single layer of living cells, surrounded by thick cell walls. Dissected pure pericarp and aleurone fractions were ground and extracted with hexane and the yields and compositions of the resulting oils were examined. This study revealed that the high levels of ferulate-phytosterol esters and the high concentration of sitostanol previously reported in corn-fibre oil actually originate in the aleurone cells.

scholarly journals Ultrastructure of the Developing Aleurone Cells of Wheat Grain

1963 ◽  
Vol 16 (4) ◽  
pp. 768 ◽  
Author(s):  
MS Buttrose
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Cell Walls ◽  
Osmium Tetroxide ◽  
Aleurone Layer ◽  
Wheat Grain ◽  
Aleurone Cells ◽  
Wheat Kernel ◽  
Large Numbers ◽  
Inner Surface

The developing aleurone layer cells of the wheat kernel have been investigated by electron microscopy and the results compared with those of light microscopy. Two weeks after flowering vacuoles appear in the cells and deposits accumulate in these until maturity when the cells are filled 'with the resulting "vacuolar units" 2-3p. in diameter, corresponding to the aleurone grains of light microscopy. The wheat aleurone grain consists of a bounding membrane (of vacuole origin) enclosing a matrix in which are embedded spherical deposits. Some of these deposits are translucent and others opaque to electrons after potassium permanganate and osmium tetroxide fixation. At all stages examined the cytoplasm of aleurone cells contained large numbers of small unidentified bodies with irregular outline and dense contents. At first they are dispersed, but towards maturity are organized as a monolayer over the surface of each aleurone grain and the inner surface of the cell walls. The apparent specificity of these structures to aleurone cells is discussed in relation to future chemical and physiological studies of the tissue.

The development of the aleurone layer in canola (Brassica napus)

1993 ◽  
Vol 71 (9) ◽  
pp. 1193-1201 ◽  
Author(s):  
Edwin P. Groot ◽  
Lawrence A. Van Caeseele
Keyword(s):  
Image Analysis ◽  
Electron Microscope ◽  
Brassica Napus ◽  
Cell Walls ◽  
Cell Layer ◽  
Aleurone Layer ◽  
Electron Microscopic ◽  
Aleurone Cells ◽  
Mature Seeds ◽  
Microscopic Techniques

The presence of the aleurone layer in developing seeds of Brassica napus becomes apparent about 22 days after pollination when examined with light and electron microscopic techniques. Prior to aleurone differentiation, the endosperm cellularizes centripetally to form characteristic columns of cells. The pigmented cell layer of the inner integument, which is present in dark-hulled seeds of Brassica, is just external to the aleurone. The first characteristic structures that become apparent inside the aleurone are spherosomes formed by the coalescence of small oil droplets. Shortly thereafter, the cell walls of the aleurone become markedly thickened relative to the surrounding cells. The aleurone cells of mature seeds contain lipid and protein reserves but lack starch. Development of the aleurone layer occurs first near the adaxial area and proceeds until the micropylar area finally differentiates. Endosperm chloroplasts have a characteristic lens shape when viewed in section with the electron microscope. They appear to congregate around a nucleus along with a small amount of cytoplasm causing an astroid-shaped aggregation of cytoplasm in the majority of endosperm cells but only transiently in the aleurone. DNA fluorometry and image analysis showed that aleurone nuclei are triploid; therefore the aleurone layer is derived from the endosperm. Key words: aleurone layer, endosperm, seed development, ploidy, anatomy, Brassica napus.

Review — The Orientation of Cellulose Microfibrils in the cell walls of Tracheids in Conifers

IAWA Journal ◽  
2005 ◽  
Vol 26 (2) ◽  
pp. 161-174 ◽  
Author(s):  
Hisashi Abe ◽  
Ryo Funada
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Outer Layer ◽  
Cell Walls ◽  
Secondary Wall ◽  
Middle Layer ◽  
Cellulose Microfibrils ◽  
Conifer Species ◽  
Predominant Orientation ◽  
Scanning Electron

We examined the orientation of cellulose microfibrils (Mfs) in the cell walls of tracheids in some conifer species by field emission-scanning electron microscopy (FE-SEM) and developed a model on the basis of our observations. Mfs depositing on the primary walls in differentiating tracheids were not well-ordered. The predominant orientation of the Mfs changed from longitudinal to transverse, as the differentiation of tracheids proceeded. The first Mfs to be deposited in the outer layer of the secondary wall (S1 layer) were arranged as an S-helix. Then the orientation of Mfs changed gradually, with rotation in the clockwise direction as viewed from the lumen side of tracheids, from the outermost to the innermost S1 layer. Mfs in the middle layer of the secondary wall (S2 layer) were oriented in a steep Z-helix with a deviation of less than 15° within the layer. The orientation of Mfs in the inner layer of the secondary wall (S3 layer) changed, with rotation in a counterclockwise direction as viewed from the lumen side, from the outermost to the innermost S3 layer. The angle of orientation of Mfs that were deposited on the innermost S3 layer varied among tracheids from 40° in a Z-helix to 20° in an S-helix.

The Structure of the Macromolecular Units on the Cell Walls of Bacillus Polymyxa

1967 ◽  
Vol 2 (4) ◽  
pp. 587-591
Author(s):  
J. T. FINCH ◽  
A. KLUG ◽  
M.V. NERMUT
Keyword(s):  
Cell Wall ◽  
Electron Micrographs ◽  
Electron Scattering ◽  
Cell Walls ◽  
Single Layer ◽  
Optical Diffraction ◽  
Square Lattice ◽  
Bacillus Polymyxa ◽  
Optical Filtering ◽  
Diffraction Patterns

Electron micrographs of negatively stained preparations of cell walls of Bacillus polymyxa have been investigated by optical diffraction and optical filtering techniques. Images of single layers of the cell wall, from which the ‘noise’ has been filtered optically, show hollow, square-shaped morphological units arranged on a square lattice of side 100 Å. Single-layer images showing the same pattern have been filtered from moiré patterns arising from two overlapping single layers. The morphological units are composed of four smaller subunits. The optical diffraction patterns from regions of two overlapping layers show extra reflexions which are attributed to multiple electron scattering.

Observations on the Aleurone Layer. II. Fluorescence Microscopy of the Aleurone-Sub-Aleurone Junction With Emphasis on Possible β-1,3-Glucan Deposits in Barley

1977 ◽  
Vol 4 (6) ◽  
pp. 917 ◽  
Author(s):  
RG Fulcher ◽  
G Setterfield ◽  
ME Mccully ◽  
PJ Wood
Keyword(s):  
Hordeum Vulgare ◽  
Fluorescence Microscopy ◽  
Cell Walls ◽  
Structural Organization ◽  
Periodate Oxidation ◽  
Aleurone Layer ◽  
Hordeum Vulgare L ◽  
Aleurone Cell ◽  
Tissue Sections ◽  
Primary Substrate

The structural organization of the cell walls at the aleurone-sub-aleurone junction has been examined by fluorescence microscopy in ungerminated seeds of two varieties of Hordeum vulgare L. (cultivars Himalaya and Vanier). The sub-aleurone cell walls that are immediately adjacent to the aleurone layer are considerably thicker than the remainder of endosperm walls and contain extensive deposits of aniline blue-positive material. The latter was not significantly affected by periodate oxidation and was removed from tissue sections only by β-1,3-glucanases or hot dimethyl sulphoxide. These deposits may represent the primary substrate for endo-β-1,3-glucanases secreted by the aleurone layer during germination.

scholarly journals Further Observations on the Fine Structure of Chrysochromulina Ericina Parke & Manton

1961 ◽  
Vol 41 (1) ◽  
pp. 145-155 ◽  
Author(s):  
I. Manton ◽  
G. F. Leedale
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Cell Surface ◽  
Light Microscopy ◽  
Flat Plate ◽  
Outer Layer ◽  
Living Cells ◽  
Layered Plates ◽  
Thin Sections ◽  
Micro Anatomy

C. ericina Parke & Manton has been re-investigated to add salient features of micro-anatomy from the electron microscopy of thin sections and also to add photographs of living cells taken with anoptral contrast light microscopy.The most important new observations concern the scales which are shown to be essentially two-layered plates in which the layers in the very large spined scales have become separated except at their edges, with the outer layer greatly hypertrophied to produce a hollow spine with a flared base closed at the bottom by a flat plate. The patterns of external marking on the two layers are very similar in both plate-scales and spines in this species and the orientation of both with respect to the cell surface has been demonstrated by a section of the scales in situ.

scholarly journals Resistance to Aspergillus flavus in Corn Kernels Is Associated with a 14-kDa Protein

1998 ◽  
Vol 88 (4) ◽  
pp. 276-281 ◽  
Author(s):  
Z.-Y. Chen ◽  
R. L. Brown ◽  
A. R. Lax ◽  
B. Z. Guo ◽  
T. E. Cleveland ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
Trypsin Inhibitor ◽  
Aflatoxin Contamination ◽  
Inhibitor Protein ◽  
Trypsin Activity ◽  
Terminal Sequence ◽  
High Concentration ◽  
Resistant Varieties ◽  
Corn Kernels

Corn genotypes resistant or susceptible to Aspergillus flavus were extracted for protein analysis using a pH 2.8 buffer. The profile of protein extracts revealed that a 14-kDa protein is present in relatively high concentration in kernels of seven resistant corn genotypes, but is absent or present only in low concentration in kernels of six susceptible ones. The N-terminal sequence of this 14-kDa protein showed 100% homology to a corn trypsin inhibitor. The 14-kDa protein purified from resistant varieties also demonstrated in vitro inhibition of both trypsin activity and the growth of A. flavus. This is the first demonstration of antifungal activity of a corn 14-kDa trypsin inhibitor protein. The expression of this protein among tested genotypes may be related to their difference in resistance to A. flavus infection and subsequent aflatoxin contamination.

Water Pathways in Wheat Leaves. IV. The Interpretation of Images of a Fluorescent Apoplastic Tracer

1988 ◽  
Vol 15 (4) ◽  
pp. 541 ◽  
Author(s):  
MJ Canny
Keyword(s):  
Cell Walls ◽  
Water Movement ◽  
Freeze Substitution ◽  
Sheath Cell ◽  
High Concentration ◽  
Mestome Sheath ◽  
Wheat Leaves ◽  
Apoplastic Tracer ◽  
Very High ◽  
Wall Components

Sections of wheat leaves fed with the fluorescent apoplastic tracer sulforhodamine G (SR) through the xylem were prepared by freeze-substitution and resin embedding. The distribution of fluorescence intensity (FI) of the tracer was measured by microspectrofluorometry at a resolution of 0.4 �m. SR was found to move within cell walls in restricted paths less than 200 nm wide. The name 'nanopaths' is suggested for these. The highest FI was found around the mestome-sheath / parenchyma-sheath border on the xylem side, and was shown to be due, not to binding of the tracer to wall components, but to the generation of a very high concentration of SR there by the separation of water from the solute. This separation cannot be evaporative but must be osmotic, and is presented as evidence of a major symplastic water movement starting at the parenchyma sheath cell membrane. The main resistance to water loss from the veins is at the mestome sheath and appears to be controlled by the suberised lamellae.

Single-layer MnO2 nanosheet quenched fluorescence ruthenium complexes for sensitive detection of ferrous iron

RSC Advances ◽  
2016 ◽  
Vol 6 (82) ◽  
pp. 79204-79208 ◽  
Author(s):  
Xing He ◽  
Xiaoxiao Yang ◽  
Luo Hai ◽  
Dinggeng He ◽  
Xiaoxiao He ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Ferrous Iron ◽  
Ruthenium Complexes ◽  
Single Layer ◽  
Living Cells ◽  
Sensitive Detection ◽  
Label Free ◽  
Fluorescence Sensors ◽  
Turn On ◽  
Mno2 Nanosheet

Single-layer MnO2 nanosheet quenched fluorescence Ru(bipy)32+ complexes are established as turn-on fluorescence sensors for sensitive and label-free probing of ferrous iron in aqueous solutions, as well as living cells.

Actuation systems in plants as prototypes for bioinspired devices

2009 ◽  
Vol 367 (1893) ◽  
pp. 1541-1557 ◽  
Author(s):  
Ingo Burgert ◽  
Peter Fratzl
Keyword(s):  
Cell Walls ◽  
Cell Shape ◽  
Living Cells ◽  
Polymer Composition ◽  
Plant Cell Walls ◽  
Geometrical Constraints ◽  
Actuation Systems ◽  
Different Levels ◽  
Dead Tissue ◽  
Shape And Size

Plants have evolved a multitude of mechanisms to actuate organ movement. The osmotic influx and efflux of water in living cells can cause a rapid movement of organs in a predetermined direction. Even dead tissue can be actuated by a swelling or drying of the plant cell walls. The deformation of the organ is controlled at different levels of tissue hierarchy by geometrical constraints at the micrometre level (e.g. cell shape and size) and cell wall polymer composition at the nanoscale (e.g. cellulose fibril orientation). This paper reviews different mechanisms of organ movement in plants and highlights recent research in the field. Particular attention is paid to systems that are activated without any metabolism. The design principles of such systems may be particularly useful for a biomimetic translation into active technical composites and moving devices.

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