Early changes in the radial walls of storied fusiform cambial cells during fiber differentiation

IAWA Journal ◽  
2011 ◽  
Vol 32 (3) ◽  
pp. 333-340 ◽  
Author(s):  
Karumanchi S. Rao ◽  
Jong Sik Kim ◽  
Yoon Soo Kim
Keyword(s):  
Cell Wall ◽  
Middle Lamella ◽  
Ultrastructural Changes ◽  
Pectic Polysaccharides ◽  
Axial Extension ◽  
Cambial Zone ◽  
Entire Cell ◽  
Cambial Cells ◽  
Wall Loosening ◽  
Hydrolysis Of

There is little information about the ultrastructural changes taking place in the radial walls of fusiform cambial cells during differentiation into xylem derivatives. The present study reports the early events occurring in the radial walls of fusiform cambial cells (FCCs) during fiber elongation in Holoptelea integrifolia, a deciduous tropical tree with storied cambium. Serial tangential sections of active cambial zone cells demonstrate the initiation of intrusive cell wall elongation from gabled ends of FCCs during fiber development. The elongation at the tip is followed by the axial extension of the entire cell. It was evident from ultrastructural observations made on the tangential sections that the thick beaded pattern on FCC radial walls disappear following cell elongation. PATAg staining, specific for wall polysaccharides showed that, initially, the beaded structures undergo wall loosening following hydrolysis of pectic polysaccharides in the middle lamella. Then the loosened primary walls come together with the axial extension of cells. Thus the beaded nature disappears in the differentiating cambial cells. This study highlights the cell wall changes associated with the differentiation of FCCs into fibers.

Ultrastructural Changes in the Cell Walls of Cambial Derivatives During Wood Formation in Indian ELM (Holoptelea Integrifolia)

IAWA Journal ◽  
2012 ◽  
Vol 33 (4) ◽  
pp. 403-416 ◽  
Author(s):  
Karumanchi S. Rao ◽  
Yoon Soo Kim ◽  
Pramod Sivan
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Middle Lamella ◽  
Ultrastructural Changes ◽  
Cell Wall Polysaccharides ◽  
Lignin Distribution ◽  
Parenchyma Cells ◽  
Ray Cells ◽  
Xylem Elements ◽  
S2 Layer

Sequential changes occurring in cell walls during expansion, secondary wall (SW) deposition and lignification have been studied in the differentiating xylem elements of Holoptelea integrifolia using transmission electron microscopy. The PATAg staining revealed that loosening of the cell wall starts at the cell corner middle lamella (CCML) and spreads to radial and tangential walls in the zone of cell expansion (EZ). Lignification started at the CCML region between vessels and associated parenchyma during the final stages of S2 layer formation. The S2 layer in the vessel appeared as two sublayers,an inner one and outer one.The contact ray cells showed SW deposition soon after axial paratracheal parenchyma had completed it, whereas noncontact ray cells underwent SW deposition and lignification following apotracheal parenchyma cells. The paratracheal and apotracheal parenchyma cells differed noticeably in terms of proportion of SW layers and lignin distribution pattern. Fibres were found to be the last xylem elements to complete SW deposition and lignification with differential polymerization of cell wall polysaccharides. It appears that the SW deposition started much earlier in the middle region of the fibres while their tips were still undergoing elongation. In homogeneous lignin distribution was noticed in the CCML region of fibres.

Immunocytochemical studies of axial resin canals. I. Localization of non-cellulosic polysaccharides in epithelium of Norway spruce xylem

IAWA Journal ◽  
2014 ◽  
Vol 35 (3) ◽  
pp. 236-252 ◽  
Author(s):  
Jong Sik Kim ◽  
Geoffrey Daniel
Keyword(s):  
Cell Wall ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Norway Spruce ◽  
Cell Walls ◽  
Middle Lamella ◽  
Distribution Patterns ◽  
Boundary Structure ◽  
Pectic Polysaccharides ◽  
Resin Canals

The microdistribution of non-cellulosic polysaccharides in epithelial cells of axial resin canals was investigated in Norway spruce xylem using immunolocalization methods combined with monoclonal antibodies specific for (1→4)-β-galactan (LM5), (1→5)-α-arabinan (LM6), homogalacturonan (LM 19, LM20), xyloglucan (LM15), xylan (LM10, LM11) and mannan (LM21, LM22). The ultrastructure and lignin distribution of epithelial cell walls was also examined after cytochemical staining for lignin. Compared with tracheids, epithelial cells showed several different ultrastructural characteristics, such as the thickness of three layers forming the cell wall, the boundary structure between layers and the lamellate structure of cell walls, with slightly stronger reaction with chemical staining for lignin than tracheids. After staining with potassium permanganate, the layer of the epithelial cell wall adjacent to the canal showed typical characteristics of middle lamella (C-ML). However, C-ML regions showed completely different chemical characteristics from E-ML (middle lamella between epithelial cells) regions of epithelial cells and compound middle lamella (CML) regions of tracheids. Unlike tracheids, epitopes of pectic polysaccharides were detected in the epithelial cell wall with variations in amounts between cell wall layers. Epitopes of hemicelluloses were also detected in the epithelial cells with differences in distribution patterns from tracheids, particularly xyloglucan (LM15) and low substituted xylan (LM10) epitopes. Together, our results suggest that the ultrastructure and chemistry of epithelial cells including C-ML regions significantly differ from tracheids.

Seasonal ultrastructural changes in the cambial zone of beech (Fagus sylvatica) grown at two different altitudes

IAWA Journal ◽  
2011 ◽  
Vol 32 (4) ◽  
pp. 443-459 ◽  
Author(s):  
Peter Prislan ◽  
Uwe Schmitt ◽  
Gerald Koch ◽  
Jožica Gričar ◽  
Katarina Čufar
Keyword(s):  
Fagus Sylvatica ◽  
Cell Walls ◽  
Structural Changes ◽  
Cambial Activity ◽  
Ultrastructural Changes ◽  
Seasonal Patterns ◽  
Cell Divisions ◽  
Cambial Zone ◽  
Cambial Cells ◽  
Different Altitudes

Seasonal structural changes of cambial cells in mature beech (Fagus sylvatica L.) trees growing at elevations of 400 m a.s.l. (lowland) and 1200 m a.s.l. (mountains) are presented on the basis of light (LM) and electron microscopy (TEM). For LM, samples from trees were collected at weekly intervals and for TEM at two-month intervals from March till September, 2008. LM enabled us to follow the production of new xylem and phloem cells that lasted for 16.5 ± 3.7 weeks at the lowland site and for 10.7 ± 1.3 weeks in the mountains. TEM revealed differences in ultrastructure of cambial cells in the phases of dormancy, reactivation, activity and transition to dormancy. The seasonal patterns of ultrastructural changes in cambial cells were similar at both sites but their timing was different. TEM revealed changes in the fine structure of cambial cells, indicating their activation in spring and the earliest stages of cell divisions and development of new cell walls. When using LM, the onset of cambial activity could be observed one month later, compared with TEM. LM therefore enabled us to follow cambial productivity but not the activity and related cytoplasmic modifications during reactivation.

Chemical and ultrastructural changes of ash wood thermally modified (TMW) using the thermo-vacuum process: II. Immunocytochemical study of the distribution of noncellulosic polysaccharides

Holzforschung ◽  
2015 ◽  
Vol 69 (5) ◽  
pp. 615-625 ◽  
Author(s):  
Jong Sik Kim ◽  
Jie Gao ◽  
Nasko Terziev ◽  
Ottaviano Allegretti ◽  
Geoffrey Daniel
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Middle Lamella ◽  
Degradation Process ◽  
Thermal Modification ◽  
Ultrastructural Changes ◽  
Immunogold Localization ◽  
Immunocytochemical Study ◽  
Rhamnogalacturonan I ◽  
Compound Middle Lamella

AbstractFollowing structural and cytochemical studies (Part I) on thermally modified ash wood (TMW) by the thermo-vacuum (Termovuoto) process, changes in the distribution of noncellulosic polysaccharides have been investigated in TMW treated for 3 h at 220°C (TMW3 h, 220°C) by means of immunogold localization methods. Pectins (homogalacturonan, rhamnogalacturonan-I) and xyloglucan were significantly degraded in compound middle lamella (CML), including the middle lamella cell corner regions (CMLcc), of all xylem cells after thermal modification. Xylan and mannan degradation were also visible in fiber cell walls. In particular, degradation of mannan was very significant and showed variation between cell wall regions even within the same cell wall. The degradation of pectins was more significant than that of hemicelluloses. In summary, results suggest that each noncellulosic polysaccharide may have a different degradation process in ash TMWs.

Ultrastructure and Senescence in an Achloroplastic Mutant of Hordeum vulgare L. cv. Dyan

1992 ◽  
Vol 50 (1) ◽  
pp. 844-845
Author(s):  
R.H.M. Cross ◽  
C.E.J. Botha ◽  
A.K. Cowan ◽  
B.J. Hartley
Keyword(s):  
Cell Wall ◽  
Hordeum Vulgare ◽  
Leaf Tissue ◽  
Ultrastructural Changes ◽  
Hordeum Vulgare L ◽  
Mesophyll Cells ◽  
Lethal Mutant ◽  
Cytoplasmic Matrix ◽  
Close Proximity ◽  
Pinocytotic Vesicles

Senescence is an ordered degenerative process leading to death of individual cells, organs and organisms. The detection of a conditional lethal mutant (achloroplastic) of Hordeum vulgare has enabled us to investigate ultrastructural changes occurring in leaf tissue during foliar senescence.Examination of the tonoplast structure in six and 14 day-old mutant tissue revealed a progressive degeneration and disappearance of the membrane, apparently starting by day six in the vicinity of the mitochondria associated with the degenerating proplastid (Fig. 1.) where neither of the plastid membrane leaflets is evident (arrows, Fig. 1.). At this stage there was evidence that the mitochondrial membranes were undergoing retrogressive changes, coupled with disorganization of cristae (Fig. 2.). Proplastids (P) lack definitive prolamellar bodies. The cytoplasmic matrix is largely agranular, with few endoplasmic reticulum (ER) cisternae or polyribosomal aggregates. Interestingly, large numbers of actively-budding dictysomes, associated with pinocytotic vesicles, were observed in close proximity to the plasmalemma of mesophyll cells (Fig. 3.). By day 14 however, mesophyll cells showed almost complete breakdown of subcellular organelle structure (Fig. 4.), and further evidence for the breakdown of the tonoplast. The final stage of senescence is characterized by the solubilization of the cell wall due to expression and activity of polygalacturonase and/or cellulose. The presence of dictyosomes with associated pinocytotic vesicles formed from the mature face, in close proximity to both the plasmalemma and the cell wall, would appear to support the model proposed by Christopherson for the secretion of cellulase. This pathway of synthesis is typical for secretory glycoproteins.

Silicification of wood-cell walls

1994 ◽  
Vol 52 ◽  
pp. 428-429
Author(s):  
S. E. Keckler ◽  
D. M. Dabbs ◽  
N. Yao ◽  
I. A. Aksay
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Cell Walls ◽  
Lignin Content ◽  
Resin Composite ◽  
Middle Lamella ◽  
Cellulose Fibers ◽  
Complex Structures ◽  
Rich Region ◽  
Inorganic Precursors

Cellular organic structures such as wood can be used as scaffolds for the synthesis of complex structures of organic/ceramic nanocomposites. The wood cell is a fiber-reinforced resin composite of cellulose fibers in a lignin matrix. A single cell wall, containing several layers of different fiber orientations and lignin content, is separated from its neighboring wall by the middle lamella, a lignin-rich region. In order to achieve total mineralization, deposition on and in the cell wall must be achieved. Geological fossilization of wood occurs as permineralization (filling the void spaces with mineral) and petrifaction (mineralizing the cell wall as the organic component decays) through infiltration of wood with inorganics after growth. Conversely, living plants can incorporate inorganics into their cells and in some cases into the cell walls during growth. In a recent study, we mimicked geological fossilization by infiltrating inorganic precursors into wood cells in order to enhance the properties of wood. In the current work, we use electron microscopy to examine the structure of silica formed in the cell walls after infiltration of tetraethoxysilane (TEOS).

scholarly journals Cell wall and organelle modifications during nitrogen starvation in Nannochloropsis oceanica F&M-M24

2021 ◽  
Author(s):  
Roncaglia Bianca ◽  
Papini Alessio ◽  
Chini Zittelli Graziella ◽  
Rodolfi Liliana ◽  
Mario R. Tredici
Keyword(s):  
Cell Wall ◽  
Wall Thickness ◽  
Lipid Droplets ◽  
Nitrogen Starvation ◽  
Photosynthetic Apparatus ◽  
Ultrastructural Changes ◽  
Total Biomass ◽  
Nannochloropsis Oceanica ◽  
Final Phase ◽  
Cell Functions

AbstractNannochloropsis oceanica F&M-M24 is able to increase its lipid content during nitrogen starvation to more than 50% of the total biomass. We investigated the ultrastructural changes and the variation in the content of main cell biomolecules that accompany the final phase of lipid accumulation. Nitrogen starvation induced a first phase of thylakoid disruption followed by chloroplast macroautophagy and formation of lipid droplets. During this phase, the total amount of proteins decreased by one-third, while carbohydrates decreased by 12–13%, suggesting that lipid droplets were formed by remodelling of chloroplast membranes and synthesis of fatty acids from carbohydrates and amino acids. The change in mitochondrial ultrastructure suggests also that these organelles were involved in the process. The cell wall increased its thickness and changed its structure during starvation, indicating that a disruption process could be partially affected by the increase in wall thickness for biomolecules recovery from starved cells. The wall thickness in strain F&M-M24 was much lower than that observed in other strains of N. oceanica, showing a possible advantage of this strain for the purpose of biomolecules extraction. The modifications following starvation were interpreted as a response to reduction of availability of a key nutrient (nitrogen). The result is a prolonged survival in quiescence until an improvement of the environmental conditions (nutrient availability) allows the rebuilding of the photosynthetic apparatus and the full recovery of cell functions.

scholarly journals Characterization of Glycoside Hydrolase Family 5 Proteins in Schizosaccharomyces pombe

2010 ◽  
Vol 9 (11) ◽  
pp. 1650-1660 ◽  
Author(s):  
Encarnación Dueñas-Santero ◽  
Ana Belén Martín-Cuadrado ◽  
Thierry Fontaine ◽  
Jean-Paul Latgé ◽  
Francisco del Rey ◽  
...  
Keyword(s):  
Cell Wall ◽  
Schizosaccharomyces Pombe ◽  
Protein Characterization ◽  
Wall Material ◽  
Glycoside Hydrolase Family ◽  
Content Type ◽  
Hydrolysis Of ◽  
Controlled Hydrolysis ◽  
Hydrolase Family

ABSTRACT In yeast, enzymes with β-glucanase activity are thought to be necessary in morphogenetic events that require controlled hydrolysis of the cell wall. Comparison of the sequence of the Saccharomyces cerevisiae exo-β(1,3)-glucanase Exg1 with the Schizosaccharomyces pombe genome allowed the identification of three genes that were named exg1 + (locus SPBC1105.05), exg2 + (SPAC12B10.11), and exg3 + (SPBC2D10.05). The three proteins have different localizations: Exg1 is secreted to the periplasmic space, Exg2 is a membrane protein, and Exg3 is a cytoplasmic protein. Characterization of the biochemical activity of the proteins indicated that Exg1 and Exg3 are active only against β(1,6)-glucans while no activity was detected for Exg2. Interestingly, Exg1 cleaves the glucans with an endohydrolytic mode of action. exg1 + showed periodic expression during the cell cycle, with a maximum coinciding with the septation process, and its expression was dependent on the transcription factor Sep1. The Exg1 protein localizes to the septum region in a pattern that was different from that of the endo-β(1,3)-glucanase Eng1. Overexpression of Exg2 resulted in an increase in cell wall material at the poles and in the septum, but the putative catalytic activity of the protein was not required for this effect.

scholarly journals Optimization of a minimal synergistic enzyme system for hydrolysis of raw cassava pulp

RSC Advances ◽  
2017 ◽  
Vol 7 (76) ◽  
pp. 48444-48453 ◽  
Author(s):  
Benjarat Bunterngsook ◽  
Thanaporn Laothanachareon ◽  
Suda Natrchalayuth ◽  
Sirithorn Lertphanich ◽  
Tatsuya Fujii ◽  
...  
Keyword(s):  
Cell Wall ◽  
Enzyme System ◽  
Starch Granules ◽  
Cell Wall Polysaccharides ◽  
Cassava Pulp ◽  
Lignocellulosic Wastes ◽  
Hydrolysis Of

Cassava pulp is an underused agricultural by-product comprising residual starch granules entrapped in cell wall polysaccharides, making it unique from other lignocellulosic wastes in terms of enzymatic processing.

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