scholarly journals THE STRUCTURE OF THE PRIMARY EPIDERMAL CELL WALL OF AVENA COLEOPTILES

1957 ◽  
Vol 3 (2) ◽  
pp. 171-182 ◽  
Author(s):  
S. T. Bayley ◽  
J. R. Colvin ◽  
F. P. Cooper ◽  
Cecily A. Martin-Smith
Keyword(s):  
Cell Wall ◽  
Outer Wall ◽  
Epidermal Cells ◽  
Cellulose Microfibrils ◽  
X Rays ◽  
Primary Wall ◽  
Normal Type ◽  
Number Of Layers ◽  
Angle Scattering ◽  
Epidermal Cell Wall

The primary walls of epidermal cells in Avena coleoptiles ranging in length from 2 to 40 mm. have been studied in the electron and polarizing microscopes and by the low-angle scattering of x-rays. The outer walls of these cells are composed of multiple layers of cellulose microfibrils oriented longitudinally; initially the number of layers is between 10 and 15 but this increases to about 25 in older tissue. Where epidermal cells touch, these multiple layers fuse gradually into a primary wall of the normal type between cells. In these radial walls, the microfibrils are oriented transversely. Possible mechanisms for the growth of the multilayered outer wall during cell elongation are discussed.

The root–fungus interface as an indicator of symbiont interaction in ectomycorrhizae

1987 ◽  
Vol 17 (8) ◽  
pp. 846-854 ◽  
Author(s):  
H. B. Massicotte ◽  
C. A. Ackerley ◽  
R. L. Peterson
Keyword(s):  
Cell Wall ◽  
Epidermal Cell ◽  
Apical Meristem ◽  
Epidermal Cells ◽  
Wall Ingrowths ◽  
Wall Ingrowth ◽  
Hartig Net ◽  
Epidermal Cell Wall ◽  
Different Strains ◽  
Cell Wall Ingrowths

Seedlings of Alnuscrispa (Ait.) Pursh, Alnusrubra Bong., Eucalyptuspilularis Sm., and Betulaalleghaniensis Britt. were grown in plastic pouches and subsequently inoculated with Alpovadiplophloeus (Zeller & Dodge) Trappe & Smith (two different strains), Pisolithustinctorius (Pers.) Coker & Couch, and Laccariabicolor (R. Mre) Orton, respectively, to form ectomycorrhizae insitu. Alnus seedlings were inoculated with Frankia prior to inoculation with the mycosymbiont. The interface established between A. crispa and A. diplophloeus was complex, involving wall ingrowth formation in root epidermal cells and infoldings in Hartig net hyphae. Alnusrubra – A. diplophloeus ectomycorrhizae had an interface lacking epidermal cell wall ingrowths but with infoldings in Hartig net hyphae. The interface between E. pilularis –. tinctorius consisted of branching Hartig net hyphae between radially enlarged epidermal cells lacking wall ingrowths. Ectomycorrhizae between B. alleghaniensis and L. bicolor developed unique interfaces with radially enlarged epidermal cells near the apical meristem, which synthesized dense vacuolar deposits. Very fine branchings occurred in Hartig net hyphae.

The nature of surface growth in plant cells

1956 ◽  
Vol 4 (3) ◽  
pp. 193 ◽  
Author(s):  
AB Wardrop
Keyword(s):  
Cell Wall ◽  
Plant Cells ◽  
Outer Wall ◽  
Surface Growth ◽  
Radioactive Material ◽  
Cellulose Microfibrils ◽  
Similar Material ◽  
Microfibril Orientation ◽  
Cell Form ◽  
Inner Surface

Autoradiographs have been prepared from parenchyma isolated from Avena coleoptile segments grown in a medium containing labelled glucose. The autoradiographs show that there is no concentration of radioactive material at the cell tips and labelled cellulose appears to be uniformly distributed in the cell wall. Electron micrographs of similar material show that the cellulose microfibrils are almost transversely oriented on the inner surface of the cell wall but are considerably dispersed from this direction on the outer surface. From this evidence it is concluded that growth in coleoptile parenchyma is not of the "bipolar" or "mosaic" types previously suggested, but corresponds to the "multi-net growth" of Roelofsen and Houwink. In addition a study has been made of the relation of microfibril orientation to cell form in parenchyma of onion root and in roots after treatment with colchicine, from which it is concluded that the final microfibril orientation on the outer wall surface is determined by the extent and polarity of its surface growth.

Cell wall structures of Epicoccum nigrum (Hyphomycetes)

1973 ◽  
Vol 51 (5) ◽  
pp. 1071-1073 ◽  
Author(s):  
J. A. Brushaber ◽  
R. H. Haskins
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Outer Layer ◽  
Secondary Wall ◽  
Outer Wall ◽  
Wall Layer ◽  
Wall Material ◽  
Primary Wall ◽  
Electron Dense Material ◽  
Wall Structures

Two structurally distinct types of secondary wall layers are present in older hyphae in addition to the primary wall. A coarsely fibrous outer wall layer often becomes quite massive and frequently fuses with the outer wall layers of adjacent cells in the formation of hyphal strands. The uneven deposition of this outer layer often produces large verrucosities. The inner secondary wall layer is relatively electron transparent and contains a reticulum of electron-dense lines. The interface of the inner secondary wall with the cytoplasm is often very irregular, and sections of the plasma membrane are frequently overlain by wall material. The outer secondary wall of conidia is composed of an electron-dense material different from that of the outer wall of hyphae. Cells in the multicellular conidia tend to be polyhedral in shape with either very thick primary walls or thin primary walls having a thick inner wall deposit.

The ultrastructure of the Spilocaea state of Venturia inaequalis in vivo

1976 ◽  
Vol 22 (8) ◽  
pp. 1144-1152 ◽  
Author(s):  
Michael Corlett ◽  
James Chong ◽  
E. G. Kokko
Keyword(s):  
Cell Wall ◽  
Epidermal Cell ◽  
Venturia Inaequalis ◽  
Conidiogenous Cell ◽  
Epidermal Cells ◽  
Apical Region ◽  
Mesophyll Cells ◽  
Epidermal Cell Wall ◽  
Primary Conidium

There are indications that the fungus enzymatically degrades the cuticle and epidermal cell wall. The epidermal cells and to a lesser degree the palisade mesophyll cells beneath a sporulating lesion (susceptible reaction) are killed or seriously disrupted. Various stages of conidiogenesis, including development of the primary conidium, were observed. A conidium is delimited by a two-layered transverse septum. Before conidium secession, a new two-layered inner wall is laid down around the entire conidiogenous cell adjacent to the plasmalemma. The apical region of the new inner wall proliferates beyond the annellation scar left by the seceded conidium and eventually produces another conidium.

Light and electron microscopy of the spermogonial stage of Gymnoconia peckiana, one of the causes of orange rust of Rubus

Botany ◽  
2008 ◽  
Vol 86 (5) ◽  
pp. 533-538 ◽  
Author(s):  
Charles W. Mims ◽  
Elizabeth A. Richardson
Keyword(s):  
Cell Wall ◽  
Epidermal Cell ◽  
Leaf Surface ◽  
Light And Electron Microscopy ◽  
Epidermal Cells ◽  
Wall Material ◽  
Cell Wall Material ◽  
Leaf Epidermis ◽  
Single Nucleus ◽  
Epidermal Cell Wall

Hyphae of Gymnoconia peckiana (Howe in Peck) Trotter spread from infected Rubus argutus Link. stems into leaf primordia where they proliferated in an intercellular fashion as leaves differentiated. Hyphae were septate, and each compartment appeared to contain a single nucleus. Hyphae gave rise to numerous haustoria that resembled the monokaryotic haustoria of other rust fungi. Hyphae located immediately adjacent to the upper and lower leaf epidermis gave rise to spermogonial initials. Each initial consisted of a small group of tightly packed hyphae that developed in an intercellular space adjacent to the epidermis. As an initial enlarged, the proliferating hyphae pushed their way between, as well as into, epidermal cells. Invaded epidermal cells soon died. A layer of spermatiophores then developed within each young spermogonium and appeared to push the epidermal cell wall material and leaf cuticle covering the spermogonium out from the leaf surface. Once mature, spermatiophores gave rise to a succession of uninucleate spermatia that emerged from the tip of each spermatiophore. Spermatia initially accumulated beneath the layer of epidermal cell wall material and cuticle that covered the developing spermogonium and appeared to push this layer further out from the leaf surface until it ruptured. A few receptive hyphae were observed in mature spermogonia.

Development of Colletotrichum trifolii races 1 and 2 on alfalfa clones resistant and susceptible to anthracnose

1988 ◽  
Vol 66 (1) ◽  
pp. 75-81 ◽  
Author(s):  
A. C. L. Churchill ◽  
C. J. Baker ◽  
N. R. O'Neill ◽  
J. H. Elgin Jr.
Keyword(s):  
Cell Wall ◽  
Epidermal Cell ◽  
Pore Formation ◽  
Epidermal Cells ◽  
Germ Pore ◽  
Colletotrichum Trifolii ◽  
Direct Penetration ◽  
Race 1 ◽  
Epidermal Cell Wall ◽  
Race 2

Resistant and susceptible alfalfa clones derived from the cultivar Arc were spray inoculated with conidia from race 1 or race 2 isolates of Colletotrichum trifolii Bain in compatible and incompatible combinations. No significant differences were found in the frequencies of formation of immature or mature appressoria or in germ-pore formation by either race of C. trifolii on resistant or susceptible plants. These results indicate that incompatibility is not associated with the failure of conidia to germinate or to form appressoria with germ pores. In a small number of observations, penetration pegs were observed in tissue of both resistant and susceptible plants. Colletotrichum trifolii initiated infections in alfalfa by direct penetration of the epidermis via a penetration peg from the appressorium. Although the fungus spread rapidly throughout susceptible hosts, we observed fungus penetration only of epidermal cells of resistant hosts. Therefore, it appears that expression of alfalfa resistance to C. trifolii occurs near the time of epidermal cell wall penetration.

The arrangement of microtubules in leaves of monocotyledonous and dicotyledonous plants

1989 ◽  
Vol 67 (12) ◽  
pp. 3506-3512 ◽  
Author(s):  
Taizo Hogetsu
Keyword(s):  
Cell Wall ◽  
Zea Mays ◽  
Avena Sativa ◽  
Epidermal Cells ◽  
Cellulose Microfibrils ◽  
Cortical Microtubules ◽  
Monocotyledonous Plant ◽  
Pisum Sativum L ◽  
Dicotyledonous Plants ◽  
Parenchymal Cells

The first leaf of Avena sativa L., a monocotyledonous plant, grows in a region that lies within 10 mm of the base of the leaf. Cells in that region elongate longitudinally but hardly expand laterally. The orientation of cortical microtubules in the elongating region is transverse in both epidermal and parenchymal cells. The same features of the arrangement of microtubules are also observed in the leaves of Zea mays. Cellulose microfibrils in the cell wall are coaligned with microtubules, lying approximately transverse to the axis of elongation, as if they function as hoops to facilitate the longitudinal elongation of the cell. The cells of growing leaves of Pisum sativum L., a dicotyledonous plant, expand superficially in every direction at every point on the leaf. Cortical microtubules lining the outer walls of epidermal cells are arranged randomly or in parallel. The parallel microtubules are oriented in various directions. In the outer walls of epidermal cells of growing leaves, areas with different predominant orientations of microfibrils are found within a single cell, consistent with the arrangement of microtubules. These results indicate that the orientation of cortical microtubules is correlated with the orientation of microfibrils and the direction of growth in growing leaves of both monocotyledons and dicotyledons, suggesting the involvement of cortical microtubules in control of the direction of growth in leaves.

Synchrotron Radiation X-Ray Scattering Techniques for Studying the Micro- and Nanostructure of Wood and their Relation to the Mechanical Properties

2008 ◽  
Vol 599 ◽  
pp. 107-125 ◽  
Author(s):  
Martin Müller
Keyword(s):  
Cell Wall ◽  
Synchrotron Radiation ◽  
Mechanical Stress ◽  
Structural Changes ◽  
Structural Parameters ◽  
Cellulose Microfibrils ◽  
X Rays ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

X-ray scattering techniques have been a very useful tool for the non-destructive analysis of the wood structure. X-rays are sensitive to structural parameters such as the composite structure of wood cell walls, the crystal structure of cellulose microfibrils and their helical arrangement in the cell wall, which is usually described by the microfibril angle (MFA). With the availability of synchrotron radiation sources novel experiments on wood have become possible. The increased flux of X-rays makes the in situ and time-resolved investigation of structural changes upon mechanical stress possible. The low-divergence synchrotron radiation X-rays can be focused down to sub-micrometer size, enabling scanning studies of the wood nanostructure with (sub-)microscopic position resolution. This chapter highlights very recent advances in the understanding of wood micro- and nanostructure, which were only possible using synchrotron radiation. Examples include the MFA determination in the individual layers of the secondary cell wall, the imaging of the helical structure of the cellulose microfibrils in the cell wall, lattice strain as induced by applied mechanical stress and the structural changes of different wood types under external tensile stress.

Structural Insight into Cell Wall Architecture ofMicanthus sinensiscv. using Correlative Microscopy Approaches

2015 ◽  
Vol 21 (5) ◽  
pp. 1304-1313 ◽  
Author(s):  
Jianfeng Ma ◽  
Xunli Lv ◽  
Shumin Yang ◽  
Genlin Tian ◽  
Xing’e Liu
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Secondary Wall ◽  
Plant Cell Wall ◽  
Single Layer ◽  
Cellulose Microfibrils ◽  
Miscanthus Sinensis ◽  
Primary Wall ◽  
Cell Axis ◽  
Cell Wall Architecture

AbstractStructural organization of the plant cell wall is a key parameter for understanding anisotropic plant growth and mechanical behavior. Four imaging platforms were used to investigate the cell wall architecture ofMiscanthus sinensiscv. internode tissue. Using transmission electron microscopy with potassium permanganate, we found a great degree of inhomogeneity in the layering structure (4–9 layers) of the sclerenchymatic fiber (Sf). However, the xylem vessel showed a single layer. Atomic force microscopy images revealed that the cellulose microfibrils (Mfs) deposited in the primary wall of the protoxylem vessel (Pxv) were disordered, while the secondary wall was composed of Mfs oriented in parallel in the cross and longitudinal section. Furthermore, Raman spectroscopy images indicated no variation in the Mf orientation of Pxv and the Mfs in Pxv were oriented more perpendicular to the cell axis than that of Sfs. Based on the integrated results, we have proposed an architectural model of Pxv composed of two layers: an outermost primary wall composed of a meshwork of Mfs and inner secondary wall containing parallel Mfs. This proposed model will support future ultrastructural analysis of plant cell walls in heterogeneous tissues, an area of increasing scientific interest particularly for liquid biofuel processing.

A histological and histochemical comparison of the mucilages on the root tips of several grasses

1980 ◽  
Vol 58 (24) ◽  
pp. 2581-2593 ◽  
Author(s):  
N. K. Miki ◽  
K. J. Clarke ◽  
M. E. McCully
Keyword(s):  
Cell Wall ◽  
Epidermal Cell ◽  
Outer Layer ◽  
Epidermal Cells ◽  
Root Cap ◽  
Carboxyl Groups ◽  
Root Tips ◽  
Sudan Grass ◽  
Epidermal Cell Wall ◽  
Inner Region

Young, axenically grown roots of grasses are covered by two types of mucilage. Gelatinous material originates from the root cap, and a firm, uniformly thick mucilage overlies the columnar epidermal cells. Histochemical properties of these mucilages are similar in corn, wheat, barley, oats, sorghum, and a Sudan grass – sorghum hybrid.The epidermal mucilage has a thin outer and a thicker inner layer distinct from the epidermal cell wall. Both mucilage layers are strongly autofluorescent, birefringent, and PAS positive. Reactions of the outer layer and cell wall indicate carboxyl groups. These are absent from the inner mucilage. Root cap mucilage has a inner region with histochemical properties resembling those of the inner epidermal mucilage. The outer portion of the root cap mucilage is not fluorescent, not birefringent, weakly PAS positive, and carboxylated.

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