The structure of the cell wall in lignifield collenchyma of Eryngium sp. (Umbelliferae)

1969 ◽  
Vol 17 (2) ◽  
pp. 229 ◽  
Author(s):  
AB Wardrop
Keyword(s):  
Cell Wall ◽  
Cell Division ◽  
Cell Differentiation ◽  
Secondary Wall ◽  
Indoleacetic Acid ◽  
Cellulose Microfibrils ◽  
Cell Axis ◽  
Wall Formation ◽  
Microfibril Orientation ◽  
Secondary Wall Formation

In Eryngium vesiculosum and E. rostratum, the leaf collenchyma is characterized by the development of a lignified secondary wall in the final stages of cell differentiation. The collenchyma wall is rich in pectic substances which are distributed uniformly. In the outer limiting region of the collenchyma wall the microfibril orientation is random and this structure is considered to be the wall formed at cell division. The collenchyma wall consists of six to eight layers in which the microfibrils are alternately transversely and longitudinally oriented. Each layer consists of a number of lamellae of microfibrils. In the secondary lignified wall the cellulose microfibrils are arranged helically, the direction of their orientation making an angle of 40-45° to the cell axis. Excised leaf segments showed greatest elongation in solutions of glucose and 3-indoleacetic acid, when the collenchyma walls were thin, and no elongation occurred in segments in which secondary wall formation had commenced. In radial sections layers of transversely oriented microfibrils could not be seen distant from the lumen although discontinuities in wall texture were apparent. Layers of transversely oriented microfibrils could be seen adjacent to the lumen. It is suggested that reorientation of layers of initially transversely oriented microfibrils takes place during elongation of the cells.

scholarly journals The Nature of Reaction Wood III. Cell Division and Cell Wall Formation in Conifer Stems

1952 ◽  
Vol 5 (4) ◽  
pp. 385 ◽  
Author(s):  
ABW Ardrop ◽  
HE Dadswell
Keyword(s):  
Cell Wall ◽  
Cell Division ◽  
Secondary Wall ◽  
Compression Wood ◽  
Normal Wood ◽  
Reaction Wood ◽  
Primary Wall ◽  
Wall Formation ◽  
Tracheid Length ◽  
Secondary Wall Formation

Cell division, the nature of extra-cambial readjustment, and the development of the secondary wall in the tracheids of conifer stems have been investigated in both compression wood and normal wood. It has been shown that the reduction in tracheid length, accompanying the development of compression wood and, in normal wood, increased radial growth after suppression, result from an increase in the number of anticlinal divisions in the cambium. From observations of bifurcated and otherwise distorted cell tips in mature tracheids, of small but distinct terminal canals connecting the lumen to the primary wall in the tips of mature tracheids, and of the presence of only primary wall at the tips of partly differentiated tracheids, and from the failure to observe remnants of the parent primary walls at the ends of differentiating tracheids, it has been concluded that extra-cambial readjustment of developing cells proceeds by tip or intrusive growth. It has been further concluded that the development of the secondary wall is progressive towards the cell tips, on the bases of direct observation of secondary wall formation in developing tracheids and of the increase found in the number of turns of the micellar helix per cell with increasing cell length. The significance of this in relation to the submicroscopic organization of the cell wall has been discussed. Results of X-ray examinations and of measurements of� tracheid length in successive narrow tangential zones from the cambium into the xylem have indicated that secondary wall formation begins before the dimensional changes of differentiation are complete.

scholarly journals Engineering the Oryza sativa cell wall with rice NAC transcription factors regulating secondary wall formation

2013 ◽  
Vol 4 ◽  
Author(s):  
Kouki Yoshida ◽  
Shingo Sakamoto ◽  
Tetsushi Kawai ◽  
Yoshinori Kobayashi ◽  
Kazuhito Sato ◽  
...  
Keyword(s):  
Cell Wall ◽  
Oryza Sativa ◽  
Transcription Factors ◽  
Secondary Wall ◽  
Nac Transcription Factors ◽  
Wall Formation ◽  
Secondary Wall Formation

Periodicity as a Factor in the Generation of Isotropic Compressive Growth Stress Between Microfibrils in Cell Wall Formation during a Twenty-Four Hour Period

Holzforschung ◽  
2000 ◽  
Vol 54 (5) ◽  
pp. 469-473 ◽  
Author(s):  
Masato Yoshida ◽  
Yoshihiro Hosoo ◽  
Takashi Okuyama
Keyword(s):  
Cell Wall ◽  
Amorphous Material ◽  
Turgor Pressure ◽  
Growth Stress ◽  
Cellulose Microfibrils ◽  
Cell Wall Formation ◽  
Stress Growth ◽  
Wall Formation ◽  
Inner Surface ◽  
Secondary Wall Formation

Summary Field emission scanning electron microscopy and energy-dispersive X-ray microanalysis were used to investigate the generation of growth stress in connection with the deposition of cell wall materials along the innermost surface of radial walls during secondary wall formation of differentiating tracheids of Cryptomeria japonica. Samples were collected when the turgor pressure of the tree was low (16:00 h), and when the pressure was high (6:00 h). In samples collected at 16:00 h, cellulose microfibrils deposited on the innermost surface of radial walls were clearly evident and amorphous material was rarely found. Conversely, in samples collected at 6:00 h, cellulose microfibrils were rarely observed and the amorphous material was prevalent. Cellulose microfibrils were evident, however, after removing the amorphous material with chlorite. The concentration of potassium on the inner surface of radial walls was greater at 6:00 h than at 16:00 h. After chlorite treatment, the concentration of potassium measured in the samples collected at 6:00 h decreased to a level equivalent to that in samples collected at 16:00 h and thus potassium was found to be associated with the amorphous material on the cellulose microfibrils. The amorphous material is probably a matrix of hemicellulose and monolignol, material that is abundant on the inner surface of developing cell walls, especially during expansion (as a result of high turgor pressure) of differentiating tracheids. A matrix of hemicellulose and lignin deposited in the expanded gaps between cellulose microfibrils and daily expansion of the gaps probably produces an isotropic compressive stress (growth stress). This paper demonstrates periodicity in cell wall formation as a result of the cycles of compressive growth in the differentiating cell wall.

Localization of actin filaments and cortical microtubules in wood-forming tissues of conifers

IAWA Journal ◽  
2019 ◽  
Vol 40 (4) ◽  
pp. 703-720 ◽  
Author(s):  
Shahanara Begum ◽  
Osamu Furusawa ◽  
Masaki Shibagaki ◽  
Satoshi Nakaba ◽  
Yusuke Yamagishi ◽  
...  
Keyword(s):  
Final Stage ◽  
Actin Filaments ◽  
Secondary Wall ◽  
Cortical Microtubules ◽  
Cell Axis ◽  
Wall Formation ◽  
Bordered Pits ◽  
Secondary Wall Formation ◽  
Cambial Cells ◽  
Helical Thickenings

ABSTRACT The aim of the present study was to investigate the orientation and localization of actin filaments and cortical microtubules in wood-forming tissues in conifers to understand wood formation. Small blocks were collected from the main stems of Abies firma, Pinus densiflora, and Taxus cuspidata during active seasons of the cambium. Bundles of actin filaments were oriented axially or longitudinally relative to the cell axis in fusiform and ray cambial cells. In differentiating tracheids, actin filaments were oriented longitudinally relative to the cell axis during primary and secondary wall formation. In contrast, the orientation of well-ordered cortical microtubules in tracheids changed from transverse to longitudinal during secondary wall formation. There was no clear relationship between the orientation of actin filaments and cortical microtubules in cambial cells and cambial derivatives. Aggregates of actin filaments and a circular band of cortical microtubules were localized around bordered pits and cross-field pits in differentiating tracheids. In addition, rope-like bands of actin filaments were observed during the formation of helical thickenings at the final stage of formation of secondary walls in tracheids. Actin filaments might not play a major role in changes in the orientation of cortical microtubules in wood-forming tissues. However, since actin filaments were co-localized with cortical microtubules during the formation of bordered pits, cross-field pits and helical thickenings at the final stage of formation of the secondary wall in tracheids, it seems plausible that actin filaments might be closely related to the localization of cortical microtubules during the development of these modifications of wood structure.

Secondary walls in hyaline cells of Sphagnum

2004 ◽  
Vol 52 (2) ◽  
pp. 243 ◽  
Author(s):  
Celeste L. Kremer ◽  
Andrew N. Drinnan
Keyword(s):  
Cell Wall ◽  
Cell Differentiation ◽  
Secondary Wall ◽  
Secondary Cell Wall ◽  
Higher Plants ◽  
Cell Formation ◽  
Primary Wall ◽  
Random Arrays ◽  
Secondary Wall Formation ◽  
Hyaline Cell

The cytoskeleton and ultrastructural events associated with cell differentiation and secondary cell wall and pore formation in hyaline cells of Sphagnum are investigated. Microtubules reorient from random arrays in undifferentiated hyaline cells to transverse arrays in elongating cells. Once cells are fully elongated, broad bands of microtubules aggregate into a spiral that predicts the site of secondary cell wall deposition. The secondary wall has a similar fibrillar composition to the primary wall. After the secondary wall is deposited, the thin primary wall covering the pore breaks down, usually by cell-wall degradation at the centre of the pore and around its margin. Finally, the hyaline cell undergoes cytoplasmic degeneration. The orientation of microtubules associated with hyaline-cell formation and secondary cell wall patterning resembles ultrastructural development in tracheary elements of higher plants. The similarities in cytoskeletal arrays during cell differentiation and secondary-wall formation suggest a fundamental pathway of development shared by bryophytes and higher plants.

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.

scholarly journals MYB Transcription Factors and Its Regulation in Secondary Cell Wall Formation and Lignin Biosynthesis during Xylem Development

2021 ◽  
Vol 22 (7) ◽  
pp. 3560
Author(s):  
Ruixue Xiao ◽  
Chong Zhang ◽  
Xiaorui Guo ◽  
Hui Li ◽  
Hai Lu
Keyword(s):  
Cell Wall ◽  
Transcription Factors ◽  
Secondary Wall ◽  
Secondary Cell Wall ◽  
Lignin Biosynthesis ◽  
Cell Wall Formation ◽  
Long Distance ◽  
Secondary Cell Wall Formation ◽  
Myb Transcription Factors ◽  
Wall Formation

The secondary wall is the main part of wood and is composed of cellulose, xylan, lignin, and small amounts of structural proteins and enzymes. Lignin molecules can interact directly or indirectly with cellulose, xylan and other polysaccharide molecules in the cell wall, increasing the mechanical strength and hydrophobicity of plant cells and tissues and facilitating the long-distance transportation of water in plants. MYBs (v-myb avian myeloblastosis viral oncogene homolog) belong to one of the largest superfamilies of transcription factors, the members of which regulate secondary cell-wall formation by promoting/inhibiting the biosynthesis of lignin, cellulose, and xylan. Among them, MYB46 and MYB83, which comprise the second layer of the main switch of secondary cell-wall biosynthesis, coordinate upstream and downstream secondary wall synthesis-related transcription factors. In addition, MYB transcription factors other than MYB46/83, as well as noncoding RNAs, hormones, and other factors, interact with one another to regulate the biosynthesis of the secondary wall. Here, we discuss the biosynthesis of secondary wall, classification and functions of MYB transcription factors and their regulation of lignin polymerization and secondary cell-wall formation during wood formation.

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