Quantification of the Processes of Secondary Xylem Fibre Development in Eucalyptus Globulus at Two Height Levels

IAWA Journal ◽  
1994 ◽  
Vol 15 (4) ◽  
pp. 417-424 ◽  
Author(s):  
B.G. Ridoutt ◽  
R. Sands
Keyword(s):  
Eucalyptus Globulus ◽  
Secondary Wall ◽  
Secondary Xylem ◽  
Indirect Evidence ◽  
Tree Height ◽  
Strong Positive Correlation ◽  
Vessel Elements ◽  
Fibre Development ◽  
Xylem Fibre ◽  
Number Of Cells

The rate and duration of the phases of secondary xylem fibre development were quantified at 10 and 60% of tree height from the base in three trees of Eucalyptus globulus. At 60% of tree height the number of cells undergoing division, en1argement and secondary wall development was fewer than at 10% of tree height (P < 0.0001). A very strong positive correlation (r = 0.968, df = 4, P< 0.01) also existed between the rate of radial cell production and the number of cells in the cambial zone. At 60% of tree height cambial derivatives differentiating into fibre tracheids required an average of 5.3 days to complete enlargement and 25.2 days to complete secondary wall development. At 10% of tree height the average duration of these phases was 6.0 and 32.8 days respectively. Although not statistically significant these differences suggest that the duration of fibre differentiation increases basipetally. The average rate of fibre elongation was 66 µm d-1 at 60% of tree height and 99 µm d-1 at 10% of tree height. The duration of the differentiation of vessel elements and cells associated with vessels was shorter than for fibres, indicating that the different cell types in the developing secondary xylem have their own characteristic rate and duration for the processes of differentiation. Considering theories that suggest vessel development is promoted by auxin, this observation is regarded as indirect evidence that auxin reduces the duration of the differentiation process.

Perforation Plate Strucrure in Comptonia Peregrina (Myricaceae)

IAWA Journal ◽  
1984 ◽  
Vol 5 (3) ◽  
pp. 217-223 ◽  
Author(s):  
A. F. Muhammad
Keyword(s):  
Secondary Wall ◽  
Structural Variation ◽  
Secondary Xylem ◽  
Wall Material ◽  
Perforation Plate ◽  
Plate Structure ◽  
Developmental Factors ◽  
Sequential Development ◽  
Vessel Elements ◽  
Perforation Plates

The sequential development of vessel elements in the primary and secondary xylem of Comptonia peregrina (L.) Coult. was studied. Scalariform, transitional, simple and scalaroid perforation plates were common in this species. The structural variation of these plates was interpreted on the basis of some developmental factors such as: I) width of the ceJl face and the distance between helical gyres; 2) type and distribution of secondary wall material in the form of strand, sheet or both; 3) localised and differential deposition of wall material and bar breakdown. These factors may work alone or in combination to determine the perforation plate structure.

Phenological Comparison of the Onset of Vessel Formation Between Ring-Porous and Diffuse-Porous Deciduous Trees in a Japanese Temperate Forest

IAWA Journal ◽  
1996 ◽  
Vol 17 (4) ◽  
pp. 431-444 ◽  
Author(s):  
Mitsuo Suzuki ◽  
Kiyotsugu Yoda ◽  
Hitoshi Suzuki
Keyword(s):  
Secondary Wall ◽  
Leaf Expansion ◽  
Vessel Element ◽  
Early Maturation ◽  
Vessel Formation ◽  
Wall Deposition ◽  
Water Conduction ◽  
Vessel Elements ◽  
Secondary Wall Deposition ◽  
Diffuse Porous

Initiation of vessel formation and vessel maturation indicated by secondary wall deposition have been compared in eleven deciduous broadleaved tree species. In ring-porous species the first vessel element formation in the current growth ring was initiated two to six weeks prior to the onset of leaf expansion, and secondary wall deposition on the vessel elements was completed from one week before to three weeks after leaf expansion. In diffuse-porous species, the first vessel element formation was initiated two to seven weeks after the onset of leaf expansion, and secondary wall deposition was completed four to nine weeks after leaf expansion. These results suggest that early maturation of the first vessel elements in the ring-porous species will serve for water conduction in early spring. On the contrary, the late maturation of the first vessel elements in the diffuse-porous species indicates that no new functional vessels exist at the time of the leaf expansion.

Microarray analysis of bast fibre producing tissues of Cannabis sativa identifies transcripts associated with conserved and specialised processes of secondary wall development

2007 ◽  
Vol 34 (8) ◽  
pp. 737 ◽  
Author(s):  
Mary A. De Pauw ◽  
John J. Vidmar ◽  
JoAnn Collins ◽  
Rick A. Bennett ◽  
Michael K. Deyholos
Keyword(s):  
Secondary Wall ◽  
Cannabis Sativa ◽  
Wall Thickening ◽  
Large Set ◽  
Lipid Transfer ◽  
Bast Fibre ◽  
Specific Expression ◽  
Stage Of Development ◽  
Wall Deposition ◽  
Fibre Development

The mechanisms underlying bast fibre differentiation in hemp (Cannabis sativa L.) are largely unknown. We hybridised a cDNA microarray with RNA from fibre enriched tissues extracted at three different positions along the stem axis. Accordingly, we identified transcripts that were enriched in tissues in which phloem fibres were elongating or undergoing secondary wall thickening. These results were consistent with a dynamic pattern of cell wall deposition involving tissue specific expression of a large set of distinct glycosyltransferases and glycosylhydrolases apparently acting on polymers containing galactans, mannans, xylans, and glucans, as well as raffinose-series disaccharides. Putative arabinogalactan proteins and lipid transfer proteins were among the most highly enriched transcripts in various stem segments, with different complements of each expressed at each stage of development. We also detected stage-specific expression of brassinosteroid-related transcripts, various transporters, polyamine and phenylpropanoid related genes, and seven putative transcription factors. Finally, we observed enrichment of many transcripts with unknown biochemical function, some of which had been previously implicated in fibre development in poplar or cotton. Together these data complement and extend existing biochemical models of bast fibre development and secondary wall deposition and highlight uncharacterised, but conserved, components of these processes.

WITHIN–TREE VARIATION IN PHLOEM CELL DIMENSIONS AND PROPORTIONS IN EUCALYPTUS GLOBULUS

IAWA Journal ◽  
2000 ◽  
Vol 21 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Teresa Quilhó ◽  
Helena Pereira ◽  
Hans Georg Richter
Keyword(s):  
Wall Thickness ◽  
Eucalyptus Globulus ◽  
Tree Height ◽  
Sieve Tube ◽  
Bark Thickness ◽  
Cell Type ◽  
Fibre Width ◽  
Axial Variation ◽  
Sieve Tubes ◽  
Old Trees

The axial variation of bark thickness and quantitative anatomical features of Eucalyptus globulus bark were analysed for one site based on individual measurements of ten 15-year-old trees at six height levels (DBH, 5%, 15%, 35%, 55% and 75% of total tree height). The parameters studied were: length, tangential diameter and percentage of sieve tubes; length, width, cell wall thickness and percentage of fibres; height and percentage of rays; percentage of sclereids in the secondary phloem. Bark thickness decreases from base to top of the tree. Fibre width and wall thickness decrease from base upwards. No distinct axial patterns of variation were observed for the other biometric variables studied. Parenchyma is the main cell type of the bark (50%) followed by fibres (27.9%), rays (12.1%), sieve tubes (2.7%), and sclereids (7.3%). The cell type proportions vary significantly within the tree, i.e., parenchyma, ray and sclereid proportions decrease, fibre and sieve tube proportions increase towards the top of the tree.

scholarly journals Comparación de la citocompatibilidad in vitro entre los biomateriales, fibroína y polipropileno

2017 ◽  
Vol 26 (45) ◽  
Author(s):  
Alejandro Arboleda-Carvajal ◽  
Julián González ◽  
Manuel Hernando Franco-Arias ◽  
Liliana Valladares-Torres
Keyword(s):  
Cell Proliferation ◽  
Statistical Difference ◽  
Indirect Evidence ◽  
Live Cells ◽  
Cell Behavior ◽  
In Vitro Methods ◽  
Polypropylene Material ◽  
Metabolic Reduction ◽  
Number Of Cells

This study evaluates the cell behavior of HeLa cells in vitro on fibroin and polypropylene. In order to determine cell proliferation in culture much fibroin material such as polypropylene, as the number of cells / sample was performed by the metabolic reduction of  3-(4,5- dimetiltiazol-2-ilo)-2,5-difeniltetrazol Bromide, MTT assay, using direct and indirect evidence of cytotoxicity. For direct and indirect testing of cytotoxicity in fibroin and polypropylene material, a statistical difference was found in the average number of live cells for fibroin sample regardless of the type of test (p<0.005). By the use of in vitro methods, it is shown that fibroin material has better cell behavior in terms of viability, compared with polypropylene.

Resistance of hardwood vessels to degradation by white rot Basidiomycetes

1988 ◽  
Vol 66 (9) ◽  
pp. 1841-1847 ◽  
Author(s):  
Robert A. Blanchette ◽  
John R. Obst ◽  
John I. Hedges ◽  
Karen Weliky
Keyword(s):  
Cell Wall ◽  
Secondary Wall ◽  
White Rot ◽  
Fungal Decay ◽  
Acacia Koa ◽  
Monomer Composition ◽  
Lignin Removal ◽  
Vessel Elements ◽  
Parenchyma Cells ◽  
Unusual Type

White stringy rot, an unusual type of selective fungal decay, can be found in wood of some dicotyledonous angiosperms. Stages of advanced decay consist of a mass of vessel elements with only remnants of other cells adhering to the vessel walls. Degradation by various white rot Basidiomycetes causes loss of fibers, fiber tracheids, and parenchyma cells but not vessels. In wood of Acacia koa var. koa with a white pocket rot caused by Phellinus kawakamii, fibers and parenchyma cells were preferentially delignified. After extensive lignin removal the cellulose remaining in the secondary wall was degraded. Large vessel elements remained relatively intact after other cells were completely degraded. The resistance of vessels to degradation appears to be due to their high ligninxarbohydrate ratio, lignin monomer composition, and cell wall morphology.

Lignin Distribution in Coppice Poplar, Linseed and Wheat Straw

Holzforschung ◽  
2001 ◽  
Vol 55 (4) ◽  
pp. 379-385 ◽  
Author(s):  
Lloyd Donaldson ◽  
Jamie Hague ◽  
Rebecca Snell
Keyword(s):  
Wheat Straw ◽  
Secondary Wall ◽  
Middle Lamella ◽  
Laser Scanning Microscopy ◽  
Interference Microscopy ◽  
Confocal Laser ◽  
Lignin Concentration ◽  
Lignin Distribution ◽  
Vessel Elements ◽  
Parenchyma Cells

Summary Lignin distribution was determined by interference microscopy, and by confocal laser scanning microscopy (CLSM) for a range of agricultural residues including coppice poplar, linseed, and wheat straw. Interference microscopy was used to determine the lignin concentration in the middle lamella at the cell corner, and for the secondary wall of libriform fibres in the secondary xylem of poplar and linseed. Wheat was examined in the same way for cortical fibres. In addition the secondary wall of vessel elements was examined for poplar. Confocal microscopy was used to confirm the results from interference microscopy by providing semiquantitative information based on lignin autofluorescence, and by staining with acriflavine. Wheat had the lowest level of lignification, with 31 % lignin in the middle lamella of cortical fibres and 9% lignin in the secondary wall. Poplar had a lignin concentration of 63% in the middle lamella and 6% in the secondary wall of libriform fibres, while linseed had corresponding values of 69 % and 13 %. The secondary wall of poplar vessel elements had a lignin concentration of 25 %. In all three species most of the stem tissue was lignified except for phloem and bark, where present. In linseed the pith was unlignified. In wheat, most of the parenchyma cells were lignified except for a few cells lining the stem cavity. Libriform fibres in poplar and linseed sometimes had an unlignified gelatinous layer in samples containing tension wood. In linseed, lignification was greater in xylem fibres compared to bast fibres. Ray parenchyma cells of poplar and linseed appeared to be lignified to the same extent as xylem fibres.

Cell wall ultrastructure of palm leaf fibers

IAWA Journal ◽  
2014 ◽  
Vol 35 (2) ◽  
pp. 127-137 ◽  
Author(s):  
Shengcheng Zhai ◽  
Yoshiki Horikawa ◽  
Tomoya Imai ◽  
Junji Sugiyama
Keyword(s):  
Cell Wall ◽  
Secondary Wall ◽  
Secondary Xylem ◽  
Polarized Light ◽  
Leaf Sheath ◽  
Mean Value ◽  
Attenuated Total Reflection ◽  
Cellulose Microfibrils ◽  
Palm Species ◽  
Palm Leaf

The cell wall organization of leaf sheath fibers in different palm species was studied with polarized light microscopy (PLM) and transmission electron microscopy (TEM). The secondary wall of the fibers consisted of only two layers, S1 and S2. The thickness of the S1 layer in leaf sheath fibers from the different palm species ranged from 0.31 to 0.90 μm, with a mean value of 0.57 μm, which was thicker than that of tracheids and fibers in secondary xylem of conifers and dicotyledons. The thickness of the S2 layer ranged from 0.44 to 3.43 μm, with a mean value of 1.86 μm. The ratio of S1 thickness to the whole cell wall thickness in palm fibers appears to be higher than in secondary xylem fibers and tracheids. The lignin in the fiber walls is very electron dense which makes it difficult to obtain high contrast of the different layers in the secondary wall. To clarify the cell wall layering with cellulose microfibrils in different orientations, the fibrovascular bundles of the windmill palm (Trachycarpus fortunei) were delignified with different reaction time intervals. The treated fibers were surveyed using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy analysis and TEM. The secondary fiber walls of windmill palm clearly showed only two layers at different reaction intervals with different lignin contents, even after almost all lignin was removed. We suggest that the two-layered structure in the secondary wall of palm leaf fibers, which presumably also applies to the homologous fibers in palm stems, is a specific character different from the fibers in other monocotyledons (such as bamboo and rattan) and dicot wood.

Geometric analysis of intrusive growth of wood fibres in Robinia pseudoacacia

IAWA Journal ◽  
2018 ◽  
Vol 39 (2) ◽  
pp. 191-208 ◽  
Author(s):  
Anna B. Wilczek ◽  
Muhammad Iqbal ◽  
Wieslaw Wloch ◽  
Marcin Klisz
Keyword(s):  
Secondary Xylem ◽  
Robinia Pseudoacacia ◽  
Geometric Analysis ◽  
Cell Types ◽  
Vascular Cambium ◽  
Tangential Plane ◽  
Intrusive Growth ◽  
Thin Sections ◽  
Growing Cell ◽  
Vessel Elements

ABSTRACTAll cell types of the secondary xylem arise from the meristematic cells (initials) of the vascular cambium and grow under mechanical constraints emerging from the circular-symmetrical geometry that characterises many tree trunks. The course of intrusive growth of cambial initials has been elucidated, but is yet to be described in the case of xylem fibres. This study explains the geometry of intrusive growth of the secondary xylem fibres in the trunk ofRobinia pseudoacacia.Long series of serial semi-thin sections of the vascular cambium and the differentiating secondary xylem were analysed. Since fibres grow in close vicinity to expanding cells of the derivatives of the vascular cambium, we assumed that they have similar growth conditions. Dealing with the cylindrical tissue of the vascular cambium in a previous study, we used a circularly symmetrical equation for describing the growth mechanism of cambial initials. Like the cambial initials, some of the cambial derivatives differentiating into the various cell types composing the secondary xylem also exhibit intrusive growth between the tangential walls of adjacent cells. As seen in cross sections of the cambium, intrusively growing initials form slanted walls by a gradual transformation of tangential (periclinal) walls into radial (anticlinal) walls. Similarly, the intrusive growth of xylem fibres manifests initially as slants, which are formed due to axial growth of the growing cell tips along the tangential walls of adjacent cells. During this process, the tangential walls of adjacent cells are partly separated and dislocated from the tangential plane. The final shape of xylem fibres, or that of vessel elements and axial parenchyma cells, depends upon the ratio of their intrusiveversussymplastic growths in the axial, circumferential and radial directions.

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