Fine structure during ontogeny of xylem transfer cells in the rhizome of Hieracium floribundum

1975 ◽  
Vol 53 (5) ◽  
pp. 432-438 ◽  
Author(s):  
Edward C. Yeung ◽  
R. L. Peterson
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Wall Layer ◽  
Transfer Cells ◽  
Cellulose Microfibrils ◽  
Tracheary Elements ◽  
Large Vacuole ◽  
Wall Ingrowths ◽  
Cytological Changes ◽  
Thickened Wall

A number of cytological changes occur in rhizome transfer cells with age, the most striking being the appearance of microbodies each with a crystalline nucleoid and the presence of unusual plastids. Plastids in older transfer cells develop one or more electron-translucent regions and lack a defined thylakoid system. The number and size of vacuoles increases until ultimately one large vacuole is formed in old transfer cells. Accompanying these cytological changes in the cytoplasm the wall ingrowths change from being highly involuted and reaching a considerable distance into the cytoplasm of the cell to becoming thicker and less numerous, and finally form a rather uniformly thickened wall layer. The orientation of microfibrils in the thickened cell wall, resulting from the joining of the original wall projections adjacent to the tracheary elements, is random, while the wall thickenings away from the tracheary elements have more orderly arrangements of cellulose microfibrils.

scholarly journals The Placenta of Physcomitrium patens: Transfer Cell Wall Polymers Compared across the Three Bryophyte Groups

Diversity ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 378
Author(s):  
Jason S. Henry ◽  
Karen S. Renzaglia
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Cell Wall Composition ◽  
Transfer Cells ◽  
Primary Cell ◽  
Transfer Cell ◽  
Primary Cell Wall ◽  
Slight Variation ◽  
Wall Ingrowths ◽  
Cell Wall Polymers

Following similar studies of cell wall constituents in the placenta of Phaeoceros and Marchantia, we conducted immunogold labeling TEM studies of Physcomitrium patens to determine the composition of cell wall polymers in transfer cells on both sides of the placenta. Sixteen monoclonal antibodies were used to localize cell wall epitopes in the basal walls and wall ingrowths in this moss. In general, placental transfer cell walls of P. patens contained fewer pectins and far fewer arabinogalactan proteins AGPs than those of the hornwort and liverwort. P. patens also lacked the differential labeling that is pronounced between generations in the other bryophytes. In contrast, transfer cell walls on either side of the placenta of P. patens were relatively similar in composition, with slight variation in homogalacturonan HG pectins. Compositional similarities between wall ingrowths and primary cell walls in P. patens suggest that wall ingrowths may simply be extensions of the primary cell wall. Considerable variability in occurrence, abundance, and types of polymers among the three bryophytes and between the two generations suggested that similarity in function and morphology of cell walls does not require a common cell wall composition. We propose that the specific developmental and life history traits of these plants may provide even more important clues in understanding the basis for these differences. This study significantly builds on our knowledge of cell wall composition in bryophytes in general and in transfer cells across plants.

The fine structure and development of chlamydospores of Fusarium oxysporum

1972 ◽  
Vol 18 (7) ◽  
pp. 997-1002 ◽  
Author(s):  
I. L. Stevenson ◽  
S. A. W. E. Becker
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Fine Structure ◽  
Electron Microscope ◽  
Cell Surface ◽  
Outer Layer ◽  
Outer Wall ◽  
Wall Layer ◽  
Thin Sections ◽  
Hyphal Wall

Methods have been developed for the rapid, reproducible induction of high-density populations of F. oxysporum chlamydospores. On transferring washed pregerminated conidia to a simple two-salts medium, chlamydospore morphogenesis was evident by 12 h and masses of mature spores could be harvested at the end of 4 days. Electron-microscope studies of thin sections of mature chlamydospores reveal a thick triple-layered cell wall. The cytoplasm contains, in addition to large lipid deposits, a nucleus, mitochondria, and endoplasmic reticulum all typical of fungal cells. Chlamydospores of F. oxysporum exhibit two distinct types of cell surface in thin section. The outer wall layer of two of the isolates studied was smooth-surfaced while the outer layer of the two other isolates was distinctly fibrillose. Some evidence is presented suggesting that the fibrillose material arises through the partial breakdown of the original hyphal wall.

The fine structure of some strains of Humicola Traaen

1974 ◽  
Vol 20 (2) ◽  
pp. 237-239 ◽  
Author(s):  
M. de Bertoldi ◽  
F. Mariotti ◽  
C. Filippi
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Cell Surface ◽  
Outer Wall ◽  
Wall Layer ◽  
The Other ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Different Types ◽  
Microscopic Studies

The fine structure of three unclassified strains of Humicola and of H. grisea has been investigated. The hyphae of all the strains show septa with Woronin bodies of the ascomycetous type. The cytoplasm contains many nuclei per cell, mitochondria, ribosomes, and endoplasmic vesicles, all typical of fungal cells. Electron-microscopic studies of thin sections of mature aleuriospores reveal a thick multilayered cell wall and an accumulation, inside the spore, of β-hydroxybutyrate granules. Aleuriospores exhibit different types of cell surface; the outer wall layer of two strains is smooth, while the outer layer of the other strains is rough because of the presence of melanizing bodies on the cell wall matrix. The fine structure of phialospores and microconidia is also described. Differences in the fine structure among the strains studied are reported.

Research note: Deposition patterns of cellulose microfibrils in flange wall ingrowths of transfer cells indicate clear parallels with those of secondary wall thickenings

2007 ◽  
Vol 34 (4) ◽  
pp. 307 ◽  
Author(s):  
Mark J. Talbot ◽  
Geoffrey Wasteneys ◽  
David W. McCurdy ◽  
Christina E. Offler
Keyword(s):  
Secondary Wall ◽  
Cell Types ◽  
Transfer Cells ◽  
Cellulose Microfibrils ◽  
Crystalline Cellulose ◽  
Acid Extraction ◽  
Endosperm Tissue ◽  
Wall Ingrowths ◽  
Immunofluorescence Labelling ◽  
Parallel Arrays

The arrangement of cellulose microfibrils and cortical microtubules in transfer cells depositing flange wall ingrowths have been determined with field emission scanning electron microscopy and immunofluorescence confocal microscopy. In xylem transfer cells of wheat (Triticum aestivum) stem nodes and transfer cells of corn (Zea mays) endosperm tissue, cellulose microfibrils were aligned in parallel bundles to form the linear wall ingrowths characteristic of flange ingrowth morphology. In both cell types, linear bundles of cellulose microfibrils were deposited over an underlying wall composed of randomly arranged microfibrils. Acid extraction of wheat xylem transfer cells established that flange ingrowths were composed of crystalline cellulose. Immunofluorescence labelling of microtubules in wheat xylem transfer cells showed that bundles of microtubules were positioned directly below and parallel with developing flange ingrowths, whereas more mature ingrowths were flanked by bundles of microtubules. These results show that the parallel organisation of cellulose microfibrils in flange wall ingrowths is similar to those in secondary wall thickenings in xylem elements, and that deposition of these structures in transfer cells is also likely to involve bundling of parallel arrays of microtubules. Our observations are discussed in terms of the possible role of microtubules in building flange-type wall ingrowths and the consequences in terms of predicted mechanisms required to build the fundamentally different reticulate-type wall ingrowths.

Transfer cells in the sporophyte–gametophyte junction of Lycopodium appressum

1991 ◽  
Vol 69 (1) ◽  
pp. 222-226 ◽  
Author(s):  
R. L. Peterson ◽  
D. P. Whittier
Keyword(s):  
Key Words ◽  
Transfer Cells ◽  
Central Vacuole ◽  
Wall Ingrowths ◽  
Narrow Wall ◽  
Membrane Apparatus ◽  
Large Central Vacuole ◽  
Sporophyte Development ◽  
Thickened Wall ◽  
Young Sporophytes

The sporophyte–gametophyte interface in cultured Lycopodium appressum gametophytes consists of a sporophytic foot embedded in gametophyte tissue. Foot cells and contiguous gametophytic cells develop extensive wall ingrowths, making them transfer cells. Transfer cells in the foot of young sporophytes and in adjacent gametophyte cells have elongated, narrow wall ingrowths forming a labrynthine wall–membrane apparatus, numerous mitochondria, and plastids with variable amounts of starch. Transfer cells in older interfaces have thickened wall ingrowths, few mitochondria, plastids with numerous plastoglobuli and little starch, and a large central vacuole. Plasmodesmata do not develop between cells of sporophyte and gametophyte generations and these are, therefore, isolated symplastically during all stages of sporophyte development. Key words: Lycopodium, foot, haustorium, transfer cells, ultrastructure.

The ultrastructure of the outer cell wall-layer ofChlorella mutants with and without sporopollenin

1981 ◽  
Vol 138 (1-2) ◽  
pp. 121-137 ◽  
Author(s):  
J. Burczyk ◽  
M. Hesse
Keyword(s):  
Cell Wall ◽  
Wall Layer ◽  
Outer Cell ◽  
Cell Wall Layer ◽  
Outer Cell Wall

Haustorial development of Peronospora tabacina infecting Nicotiana tabacum

1983 ◽  
Vol 61 (12) ◽  
pp. 3444-3453 ◽  
Author(s):  
R. N. Trigiano ◽  
C. G. Van Dyke ◽  
H. W. Spurr Jr.
Keyword(s):  
Cell Wall ◽  
Toluidine Blue ◽  
Mesophyll Cell ◽  
Wall Layer ◽  
Peronospora Tabacina ◽  
Host Cytoplasm ◽  
Transmission Electron ◽  
Mold Fungus ◽  
Host Cell Wall ◽  
Hyphal Wall

The development of haustoria in tobacco by the blue-mold fungus Peronospora tabacina was examined using light, scanning, and transmission electron microscopy. Electron-lucent, callose-like appositions were observed between the host plasmalemma and the host mesophyll cell wall prior to haustorial penetration. An electron-opaque penetration matrix was present between the apposition and the host cell wall. The intercellular hyphal wall consisted of two layers which differed in staining quality. The haustorial wall was also two layered, but was primarily composed of and continuous with the inner wall layer of the intercellular hypha. Haustoria were either finger-like or branched and were encased with callose-like material. Most encasements were thickened at the proximal regions of haustoria but were thinner along the distal portions. Vesicles were present in host cytoplasm and were occasionally attached to the invaginated host plasmalemma. These vesicles might contribute to the deposition of the encasement material. The encasement stained positively for callose using aniline blue; calcofluor and toluidine blue O tests for cellulose were inconclusive, and lignin was not detected using toluidine blue O or phloroglucinol–HCl.

Fine Structure of Swarmers of Cladophora and Chaetomorpha

1971 ◽  
Vol 9 (3) ◽  
pp. 581-601
Author(s):  
D. G. ROBINSON ◽  
R. D. PRESTON
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Spatial Arrangement ◽  
Cell Wall Synthesis ◽  
Fibrous Layer ◽  
Etching Technique ◽  
Freeze Etching

Naked swarmers of both Cladophora rupestris and Chaetomorpha melagonium have been examined by the freeze-etching technique. The swarmers of Cladophora, collected just after settling, reveal several layers of granules external to the plasmalemma and internal to the so-called ‘fibrous-layer’. Chaetomorpha swarmers collected just before settling show extrusion of vesicles through the plasmalemma. The structures associated with the membranes are discussed in relation to known features of these swarmers already observed by sectioning. The role of granules in the synthesis of cell wall microfibrils is strengthened though the spatial arrangement of the granules seen in this investigation does not completely fulfil the ‘ordered granule’ hypothesis. Description of, and comments on, features related to cell wall synthesis, particularly the Golgi and vacuolar systems, are given.

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