Role of xyloglucan breakdown in epidermal cell walls for auxininduced elongation of azuki bean epicotyl segments

Schumacher and Halbsguth first demonstrated ectodesmata as pores or channels in the epidermal cell walls in haustoria of Cuscuta odorata L. by light microscopy in tissues fixed in a sublimate fixative (30% ethyl alcohol, 30 ml:glacial acetic acid, 10 ml: 65% nitric acid, 1 ml: 40% formaldehyde, 5 ml: oxalic acid, 2 g: mecuric chloride to saturation 2-3 g). Other workers have published electron micrographs of structures transversing the outer epidermal cell in thin sections of plant leaves that have been interpreted as ectodesmata. Such structures are evident following treatment with Hg++ or Ag+ salts and are only rarely observed by electron microscopy. If ectodesmata exist without such treatment, and are not artefacts, they would afford natural pathways of entry for applied foliar solutions and plant viruses.

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Role of actin in epidermal cell indirect adhesion.

Nishi Nihon Hifuka ◽

10.2336/nishinihonhifu.53.3 ◽

1991 ◽

Vol 53 (1) ◽

pp. 3-6

Author(s):

SHIN'ICHI INOHARA

Keyword(s):

Epidermal Cell

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Role of (1,3)(1,4)-β-Glucan in Cell Walls: Interaction with Cellulose

Biomacromolecules ◽

10.1021/bm5001247 ◽

2014 ◽

Vol 15 (5) ◽

pp. 1727-1736 ◽

Cited By ~ 37

Author(s):

Sarah N. Kiemle ◽

Xiao Zhang ◽

Alan R. Esker ◽

Guillermo Toriz ◽

Paul Gatenholm ◽

...

Keyword(s):

Cell Walls

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Etude ultrastructurale des relations hôte–parasite au cours de l'infection des pommes par le Phytophthora cactorum

Canadian Journal of Botany ◽

10.1139/b81-036 ◽

1981 ◽

Vol 59 (2) ◽

pp. 251-263 ◽

Cited By ~ 11

Author(s):

X. Mourichon ◽

G. Sallé

Keyword(s):

Cell Walls ◽

Susceptible Variety ◽

Host Cells ◽

Phytophthora Cactorum ◽

Electron Microscopic ◽

Susceptible Host ◽

Golden Delicious ◽

Extrahaustorial Matrix ◽

Apple Fruits

An electron microscopic study was performed on haustoria of Phytophthora cactorum (L. et C.) Schroeter developed in tissues of two cultivars of apple fruits: a susceptible variety ('Golden delicious') and a resistant one ('Belle de Boskoop'). Ultrastructure of intercellular hyphae and some aspects of their penetration between contiguous host cells were described. A light dissolution of the host cell walls was observed. Ontogenic investigations indicated that in the susceptible host, the wall of the fungal haustoria was covered with a dense-stained extrahaustorial matrix. Its origin and its polysaccharide nature were demonstrated. On the other hand, the resistant host developed, immediately after the inoculation, a papilla which gave rise, later on, to a sheath enclosing adult haustoria. The role of these callosic structures in the phenomenon of resistance was discussed.

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Gab1 and SHP-2 promote Ras/MAPK regulation of epidermal growth and differentiation

The Journal of Cell Biology ◽

10.1083/jcb.200205017 ◽

2002 ◽

Vol 159 (1) ◽

pp. 103-112 ◽

Cited By ~ 57

Author(s):

Ti Cai ◽

Keigo Nishida ◽

Toshio Hirano ◽

Paul A. Khavari

Keyword(s):

Epidermal Cell ◽

Mapk Signaling ◽

Dominant Negative ◽

Mapk Activity ◽

Ras Activation ◽

Proliferation And Differentiation ◽

Epidermal Proliferation ◽

Epidermal Growth ◽

Docking Protein

În epidermis, Ras can influence proliferation and differentiation; however, regulators of epidermal Ras function are not fully characterized, and Ras effects on growth and differentiation are controversial. EGF induced Ras activation in epidermal cells along with phosphorylation of the multisubstrate docking protein Gab1 and its binding to SHP-2. Expression of mutant Gab1Y627F deficient in SHP-2 binding or dominant-negative SHP-2C459S reduced basal levels of active Ras and downstream MAPK proteins and initiated differentiation. Differentiation triggered by both Gab1Y627F and SHP-2C459S could be blocked by coexpression of active Ras, consistent with Gab1 and SHP-2 action upstream of Ras in this process. To study the role of Gab1 and SHP-2 in tissue, we generated human epidermis overexpressing active Gab1 and SHP-2. Both proteins stimulated proliferation. In contrast, Gab1Y627F and SHP-2C459S inhibited epidermal proliferation and enhanced differentiation. Consistent with a role for Gab1 and SHP-2 in sustaining epidermal Ras/MAPK activity, Gab1−/− murine epidermis displayed lower levels of active Ras and MAPK with postnatal Gab1−/− epidermis, demonstrating the hypoplasia and enhanced differentiation seen previously with transgenic epidermal Ras blockade. These data provide support for a Ras role in promoting epidermal proliferation and opposing differentiation and indicate that Gab1 and SHP-2 promote the undifferentiated epidermal cell state by facilitating Ras/MAPK signaling.

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Role of chemokines and cytokines in a reactivation model of arthritis in rats induced by injection with streptococcal cell walls

Journal of Leukocyte Biology ◽

10.1002/jlb.63.3.359 ◽

1998 ◽

Vol 63 (3) ◽

pp. 359-363 ◽

Cited By ~ 43

Author(s):

D. J. Schrier ◽

R. C. Schimmer ◽

C. M. Flory ◽

D. K.-L. Tung ◽

P. A. Ward

Keyword(s):

Cell Walls

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The role of benzoate secreted by Desulfotomaculum acetoxidans DSM 771 in sulfate uptake.

Acta Biochimica Polonica ◽

10.18388/abp.2005_3391 ◽

2005 ◽

Vol 52 (4) ◽

pp. 797-802

Author(s):

Lucyna Pawłowska-Cwiek ◽

Ryszard Pado

Keyword(s):

Salicylic Acid ◽

Hydrogen Sulfide ◽

Aromatic Compound ◽

Spectrum Analysis ◽

Cell Walls ◽

Sulfonic Acid ◽

Sulfate Uptake ◽

Diammonium Salt ◽

Benzoate Derivatives

This work was designed to find the cause of the delay in hydrogen sulfide dissimilation in Desulfotomaculum acetoxidans DSM 771, which is dependent on the sulfate uptake. This bacterium grown without addition of any aromatic compound was shown by spectrum analysis with the methylene method to contain hydroxy-benzoate derivatives. The presence of these compounds was confirmed by HPLC in fractions obtained from cell walls after 15 days of culture. The test with 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt seemed to indicate the presence of peroxidase, which probably oxidized benzoate to its hydroxy derivatives. The test with 5-sulfo-salicylic acid proved the ability of the investigated strain to utilize arylsulfates and to reduce sulfate group to hydrogen sulfide. On the basis of the above data, we propose the following sequence of reactions: 1, benzoate secretion; 2, benzoate hydroxylation; 3, sulfonation of hydroxy-benzoate derivatives.

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Processes in the Infection of Barley Leaves by Rhynchosporium Secalis

Australian Journal of Biological Sciences ◽

10.1071/bi9700300 ◽

1970 ◽

Vol 23 (2) ◽

pp. 300 ◽

Cited By ~ 17

Author(s):

EN AYESU-OFFEI ◽

BG CLARE

Keyword(s):

Epidermal Cell ◽

Cell Walls ◽

Rhynchosporium Secalis ◽

Barley Leaves ◽

Germ Tubes

Conidia of R. secalis (Oud.) Davis germinated on barley leaves to produoe , short germ tubes and appressoria. Hyphae below the appressoria penetrated the outicle and formed extensive myoelial mats between the cuticle and the outer epidermal cell walls. Epidermal cell walls beneath the subcuticular hyphae became swollen, lamellate, and collapsed so that the inner and outer walls of the epidermis came together.

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