Deformation mechanisms of wood cell walls under tensile loading: a comparative study of compression wood (CW) and normal wood (NW)

Cellulose ◽  
2020 ◽  
Vol 27 (8) ◽  
pp. 4161-4172 ◽  
Author(s):  
Dong Wang ◽  
Lanying Lin ◽  
Feng Fu
Keyword(s):  
Comparative Study ◽  
Cell Walls ◽  
Compression Wood ◽  
Tensile Loading ◽  
Deformation Mechanisms ◽  
Normal Wood

Deposition of Lignin in Differentiating Xylem Cell Walls of Normal and Compression Wood of Buxus microphylla var. insularis Nakai

Holzforschung ◽  
1999 ◽  
Vol 53 (2) ◽  
pp. 156-160 ◽  
Author(s):  
Nobuo Yoshizawa ◽  
Hiromi Ohba ◽  
Junko Uchiyama ◽  
Shinso Yokota
Keyword(s):  
Visible Light ◽  
Cell Walls ◽  
Compression Wood ◽  
Outer Region ◽  
Cell Types ◽  
Deposition Process ◽  
The Other ◽  
Normal Wood ◽  
Long Period ◽  
Buxus Microphylla

Summary The deposition process of lignins within differentiating xylem walls of normal and compression wood of Buxus microphylla var. insularis Nakai was examined by visible-light microspectrophotometry coupled with the Wiesner and Mäule reactions. Buxus formed compression wood on the underside of the leaning stems. The secondary walls of the vessels and fibre tracheids in compression wood showed an intense lignification in the outer region of S2 layer. The spectra of tissues after Mäule and Wiesner reactions showed absorption maxima of around 515 nm and 570 nm, respectively. In differentiating xylem cells of normal wood, lignin composed of both guaiacyl and syringyl units was deposited mainly during the S2 thickening and after formation of the S3 layer in fibre tracheids, whereas in vessels it was actively deposited mainly during the S2 thickening. In compression wood, the deposition of the lignin composed of guaiacyl units was observed for a long period from the early stages of the S2 thickening. Lignification was becoming particularly active at the outer portion of S2 layer after completion of the S2 thickening in both vessels and fibre tracheids. On the other hand, the syringyl units were deposited mainly during the S2 thickening in both cell types.

scholarly journals Fluorescence-Detected Linear Dichroism of Wood Cell Walls in Juvenile Serbian Spruce: Estimation of Compression Wood Severity

2016 ◽  
Vol 22 (2) ◽  
pp. 361-367 ◽  
Author(s):  
Aleksandar Savić ◽  
Aleksandra Mitrović ◽  
Lloyd Donaldson ◽  
Jasna Simonović Radosavljević ◽  
Jelena Bogdanović Pristov ◽  
...  
Keyword(s):  
Cross Sections ◽  
Cell Walls ◽  
Compression Wood ◽  
Linear Dichroism ◽  
Normal Wood ◽  
Qualitative Comparison ◽  
Cellulose Fibril ◽  
Cellulose Fibrils ◽  
Picea Omorika ◽  
Serbian Spruce

AbstractFluorescence-detected linear dichroism (FDLD) microscopy provides observation of structural order in a microscopic sample and its expression in numerical terms, enabling both quantitative and qualitative comparison among different samples. We applied FDLD microscopy to compare the distribution and alignment of cellulose fibrils in cell walls of compression wood (CW) and normal wood (NW) on stem cross-sections of juvenile Picea omorika trees. Our data indicate a decrease in cellulose fibril order in CW compared with NW. Radial and tangential walls differ considerably in both NW and CW. In radial walls, cellulose fibril order shows a gradual decrease from NW to severe CW, in line with the increase in CW severity. This indicates that FDLD analysis of cellulose fibril order in radial cell walls is a valuable method for estimation of CW severity.

Reaction Wood Anatomy in a Vessel-Less Angiosperm Sarcandra Glabra

IAWA Journal ◽  
2014 ◽  
Vol 35 (2) ◽  
pp. 116-126 ◽  
Author(s):  
Haruna Aiso ◽  
Futoshi Ishiguri ◽  
Yuya Takashima ◽  
Kazuya Iizuka ◽  
Shinso Yokota
Keyword(s):  
Cell Walls ◽  
Compression Wood ◽  
Wood Anatomy ◽  
Microfibril Angle ◽  
Normal Wood ◽  
Reaction Wood ◽  
Lower Side ◽  
Single Tree ◽  
Angiosperm Species ◽  
Guaiacyl Lignin

Anatomy and lignin distribution in artificially inclined stems of Sarcandra glabra were investigated to clarify the characteristics of reaction wood (RW) in a vessel-less angiosperm species. Of the five coppiced stems studied from a single tree, two stems were fixed straight and classified as normal wood (NW) and the remaining three stems were inclined at 50 degrees from the vertical to induce the formation of the RW. Compared with NW, the lower side of the inclined samples had a relatively high compressive surface-released strain and an increase in the microfibril angle of the S2 layer of tracheids. However, no significant change was observed in the length or cell wall thickness of the tracheids. The results of Wiesner and Mäule colour reactions indicated that the amount of guaiacyl lignin in the cell walls of tracheids was increased in RW. It appears that RW in Sarcandra is formed on the lower side of inclined stems, and its anatomical characteristics and chemical composition are similar to those of the compression wood (CW) found in gymnosperm species (the so-called “CW-like RW” type).

Juvenile and Compression Wood Cell Wall Layers Differ in Lignin Structure in Norway Spruce and Scots Pine

IAWA Journal ◽  
2008 ◽  
Vol 29 (1) ◽  
pp. 47-57 ◽  
Author(s):  
Eija Kukkola ◽  
Pekka Saranpää ◽  
Kurt Fagerstedt
Keyword(s):  
Cell Wall ◽  
Norway Spruce ◽  
Scots Pine ◽  
Cell Walls ◽  
Compression Wood ◽  
Wood Cell Wall ◽  
Outer Part ◽  
Wall Layer ◽  
Mature Wood ◽  
Normal Wood

Dibenzodioxocin, an 8-ring substructure of lignin identified in the mid- 1990's, is known to occur in softwood cell walls especially in the S3-layers of normal wood. In this study the lignin substructure was immunolocalised in juvenile and mature wood as well as in different degrees of compression wood of Norway spruce (Picea abies (L.) H. Karst.) and Scots pine (Pinus sylvestris L.). In juvenile wood of Norway spruce, dibenzodioxocin was hardly present in the tracheid cell wall, while in Scots pine some dibenzodioxocin was found evenly distributed in the S2-layers. In mature normal wood, dibenzodioxocin was localised in the S3-layers in both Scots pine and Norway spruce. In contrast, in compression wood tracheids of Scots pine, where the S3-layer is not present, dibenzodioxocin was found in the S1-layers and in the outer part of the S2-layers, while in Norway spruce the innermost cell wall layer showed a strong signal. These findings support the idea that in mature wood the condensed dibenzodioxocin structure is formed in Norway spruce at the end of lignification, when the supply of monolignols and probably also hydrogen peroxide is diminishing. The reasons for Scots pine juvenile and compression wood showing a different pattern of dibenzodioxocin labelling is discussed.

Changes in xylem tissue and laccase transcript abundance associated with posture recovery in Chamaecyparis obtusa saplings growing on an incline

2013 ◽  
Vol 40 (6) ◽  
pp. 637 ◽  
Author(s):  
Saori Sato ◽  
Hideto Hiraide ◽  
Masato Yoshida ◽  
Hiroyuki Yamamoto
Keyword(s):  
Cell Walls ◽  
Compression Wood ◽  
Lignin Content ◽  
Transcript Abundance ◽  
Chamaecyparis Obtusa ◽  
Normal Wood ◽  
Plant Cell Walls ◽  
Transcription Level ◽  
Wood Compression ◽  
Xylem Tissue

Lignin is a major component of plant cell walls and is synthesised through oxidative polymerisation of monolignols. The transcription level of laccase, an enzyme implicated in monolignol polymerisation, is higher in the tissue forming compression wood than in normal wood. Compression wood, which is a special xylem tissue that develops to reorient inclined stems, also has a higher lignin content than normal wood. In the present study, Chamaecyparis obtusa Endl. saplings were grown on an incline and the following variables were tracked for 10 weeks: posture recovery of the saplings; development of xylem tissue on the lower side of inclined stems; and the transcription level of laccase. The posture of saplings approached vertical after 8 weeks, the development of compression wood reached a peak around 6 weeks and laccase transcription was the highest after 4 weeks. These results suggest a sequence of righting mechanisms. Inclination stimulates an increase in the abundance of laccase transcript and this increase encourages the formation of compression wood. The accumulation of compression wood then causes the stem to bend upward.

scholarly journals Methods to extract the exopolymeric matrix from biofilms: a comparative study

1999 ◽  
Vol 39 (7) ◽  
pp. 243-250 ◽  
Author(s):  
Joana Azeredo ◽  
Valentina Lazarova ◽  
Rosário Oliveira
Keyword(s):  
Organic Carbon ◽  
Comparative Study ◽  
Mixed Culture ◽  
Pure Culture ◽  
Cell Walls ◽  
Extraction Method ◽  
Extraction Methods ◽  
Suitable Method ◽  
The Matrix ◽  
Biofilm Matrix

To study the composition of a biofilm a previous extraction method is required to separate cells from the matrix. There are several methods reported in the literature; however they are not efficient or promote leakage of intracellular material. In this work several extraction methods were assayed in mixed culture and pure culture biofilms and their efficiency was evaluated by the amount of organic carbon, proteins and intracellular material extracted. The results showed that the extraction with glutaraldehyde 3% (w/v) was the most suitable method, extracting great amounts of organic carbon without promoting cell lysis or permeabilization. Glutaraldehyde is a bifunctional reagent that binds to cell walls avoiding their permeabilization and the biofilm matrix is solubilized in the solution.

Design of bending dominated lattice architectures with improved stiffness using hierarchy

2018 ◽  
Vol 233 (11) ◽  
pp. 3976-3993 ◽  
Author(s):  
Maen Alkhader ◽  
Mohammad Nazzal ◽  
Karim Louca
Keyword(s):  
Finite Element ◽  
Cell Walls ◽  
Detrimental Effect ◽  
Diamond Lattice ◽  
Finite Element Simulations ◽  
Deformation Mechanisms ◽  
Manufacturing Processes ◽  
Cellular Solids ◽  
Stiffness Anisotropy

Micro-architectured lattices are a promising subclass of cellular solids whose inner topologies can be tailored to enhance their stiffness. Generally, enhancing lattices' stiffness is achieved by increasing their connectivity. This strategy gives rise to a stiffer response by forcing lattices' ligaments to deform mainly in an axial manner. Conversely, this work is interested in developing micro-architectured lattices with enhanced stiffness, but whose cell walls deform in a flexural manner. Such structures can be more ductile and exhibit better energy mitigation abilities than their stretching dominated counterparts. Enhancing the stiffness of bending dominated lattices without increasing their connectivity can be realized by transforming them to hierarchical ones. This work explores, using experimentally verified finite element simulations, the effect of fractal-inspired hierarchy and customized nonfractal-based hierarchy on stiffness, anisotropy, and deformation mechanisms of an anisotropic bending dominated diamond lattice. Results show that fractal-inspired hierarchy can significantly enhance the stiffness of bending dominated lattices without affecting their deformation mechanisms or anisotropy level; ill-designed hierarchy can have a detrimental effect on lattice's stiffness; and customized hierarchy are more effective than fractal-inspired hierarchy in enhancing lattices' stiffness as well as can be more compatible with traditional, reliable, mass-producing manufacturing processes.

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