CELL-WALL LIGNIN CONTENT RELATED TO TRACHEID DIMENSIONS IN DROUGHT-SENSITIVE AUSTRIAN PINE (PINUS NIGRA)

IAWA Journal ◽  
2001 ◽  
Vol 22 (2) ◽  
pp. 113-120 ◽  
Author(s):  
Wolfgang Gindl
Keyword(s):  
Cell Wall ◽  
Lignin Content ◽  
Water Status ◽  
Pinus Nigra ◽  
Lignin Concentration ◽  
Wall Area ◽  
Pine Tree ◽  
Cell Dimensions ◽  
Highly Correlated ◽  
Annual Distribution

The intra-annual distribution of cell-wall lignin concentration was determined in Austrian pine tree rings and compared with tracheid diameter, lumen width, cell wall thickness and proportion of cell wall area. Lignin concentration was highly correlated with all tracheid dimensions, but only the proportion of cell wall area exhibited a direct statistically significant relationship. Since cell dimensions in Austrian pine are subjected to the indirect and direct influences of the water status of trees, the negative correlation between cellular lignin content and the proportion of cell wall area is attributed to an indirect effect of water stress on lignification in pine tracheids.

scholarly journals Tissue-specific Transcriptome Analysis Reveals Lignocellulose Synthesis Regulation in Elephant Grass (Pennisetum Purpureum Schum.)

2020 ◽  
Author(s):  
Wenqing Zhang ◽  
Shengkui Zhang ◽  
Xianqin Lu ◽  
Can Li ◽  
Xingwang Liu ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candidate Genes ◽  
Molecular Mechanisms ◽  
Lignin Content ◽  
Pennisetum Purpureum ◽  
Cellulose Synthesis ◽  
Elephant Grass ◽  
Development Stages ◽  
Lignin Synthesis ◽  
Highly Correlated

Abstract Background:The characteristics of elephant grass, especially its stem lignocellulose, are of great significance for its quality as feed or other industrial raw materials. Because the genome of elephant grass has not been deciphered, the study of its lignocellulose synthesis pathway and key genes is limited. Results:In this study, RNA sequencing (RNA-seq) combining with lignocellulose content analysis and cell wall morphology observation using elephant grass stems from different development stages as materials, were applied to reveal the genes regulating cellulose and lignin synthesis. A total of 3852 differentially expressed genes (DEGs) were identified in three periods of T1, T2 and T3. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the two most abundant metabolic pathways were phenylpropanemetabolism, starch and sucrose metabolism, which closely related to cell wall development, hemicellulose, lignin and cellulose synthesis. Through weighted gene co-expression network analysis (WGCNA) of DEGs, a ‘blue’ module highly correlated with cellulose synthesis and a ‘turquoise’ module highly correlated with lignin synthesis were exhibited. A total of 43 candidate genes were screened, of which 17 had function annotations in other species. In addition, the expression of CesA, PAL, CAD, C4H, COMT, CCoAMT, F5H, CAD and CCR at different development stages were analyzed, and found that the content of lignocellulose was correlated with the expression levels of these structural genes. Conclusions:This study not only provides new insights into the molecular mechanisms of cellulose and lignin synthesis pathways in elephant grass, but also offers a new and extensive list of candidate genes for more specialized functional studies in the future which may promote the development of high-quality elephant grass varieties with high cellulose and low lignin content.

scholarly journals Cell water content and lignification in maize regulated by rhizobacteria under salinity

2017 ◽  
Vol 4 (7) ◽  
pp. 9-18 ◽  
Author(s):  
Yachana Jha
Keyword(s):  
Cell Wall ◽  
Plant Growth ◽  
Water Content ◽  
Growth Promotion ◽  
Lignin Content ◽  
Water Status ◽  
Physiological Mechanism ◽  
Cell Permeability ◽  
Maize Plant ◽  
Cell Water

Inoculation of plant growth promoting rhizobacteria (PGPR) Pseudomonas aeruginosa and Bacillus megaterium in maize plant under salinity stress was analyzed for its growth promotion efficacy and induction of physiological mechanism. In this study effect of these isolates were focused on the cellular level as with lignin deposition, cell wall lignin content and cell water status of maize under salinity. Maize plants get protected from the salinity induced injury by enhancing the plant growth, regulating relative water content, enhancing phenols, flavonoids as well as lignification of cell and antioxidant enzymes also. The study states that, PGPR helps in maize plant under salinity to increase the cell membrane stability, plays a significant action in the directive of cell permeability for the survival of plants. Nevertheless, the cell wall bounded peroxidase and phenylalanine ammonia-lyase (PAL) activity reduced with gradual increase soil in non-inoculated plants. So plants inoculated with selected root-associated bacteria has a positive response on cell content and water status in maize under salinity.

Shading Correction Methods for Digital Image Analysis of Confocal Wood Images

IAWA Journal ◽  
2007 ◽  
Vol 28 (3) ◽  
pp. 349-364 ◽  
Author(s):  
Mattias K. Moëll ◽  
Lloyd A. Donaldson
Keyword(s):  
Cell Wall ◽  
Image Analysis ◽  
Digital Image ◽  
Digital Image Analysis ◽  
Sample Surface ◽  
Field Of View ◽  
Wall Area ◽  
Cell Dimensions ◽  
Confocal Fluorescence ◽  
Imaging Plane

Confocal fluorescence microscopy provides a rapid method for acquiring high quality optically thin section images of wood suitable for measurement of cell dimensions. Single optical slice images of wood may occasionally contain artefacts due to differential light absorption caused by variation in the distance between the sample surface and the imaging plane across the field of view. Regional brightness variations, which we call shading, may cause problems when such images are used for wood cell measurements using digital image analysis, affecting the accuracy of wood cell dimensions. We have compared various shading correction methods for confocal microscope images and investigated the effect of shading on both the c1assification of cell wall pixels and the resulting cell dimension measurements. Severe shading results in significant errors for measurement of cell wall area, but smaller errors for cell wall thickness and lumen diameter. Some shading correction methods have unwanted effects on pixel c1assification and cell dimensions, while more effective methods remove the shading without introducing further artefacts. The effect of shading is influenced by choice of thresholding method.

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 Evaluating polymer interplay after hot water pretreatment to investigate maize stem internode recalcitrance

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Amandine Leroy ◽  
Xavier Falourd ◽  
Loïc Foucat ◽  
Valérie Méchin ◽  
Fabienne Guillon ◽  
...  
Keyword(s):  
Cell Wall ◽  
Negative Impact ◽  
Lignin Content ◽  
Structural Features ◽  
Hot Water ◽  
Condensed State ◽  
Structural Factors ◽  
Water Pretreatment ◽  
Hot Water Pretreatment ◽  
The Impact

Abstract Background Biomass recalcitrance is governed by various molecular and structural factors but the interplay between these multiscale factors remains unclear. In this study, hot water pretreatment (HWP) was applied to maize stem internodes to highlight the impact of the ultrastructure of the polymers and their interactions on the accessibility and recalcitrance of the lignocellulosic biomass. The impact of HWP was analysed at different scales, from the polymer ultrastructure or water mobility to the cell wall organisation by combining complementary compositional, spectral and NMR analyses. Results HWP increased the kinetics and yield of saccharification. Chemical characterisation showed that HWP altered cell wall composition with a loss of hemicelluloses (up to 45% in the 40-min HWP) and of ferulic acid cross-linking associated with lignin enrichment. The lignin structure was also altered (up to 35% reduction in β–O–4 bonds), associated with slight depolymerisation/repolymerisation depending on the length of treatment. The increase in $${T}_{1\rho }^{H}$$ T 1 ρ H , $${T}_{HH}$$ T HH and specific surface area (SSA) showed that the cellulose environment was looser after pretreatment. These changes were linked to the increased accessibility of more constrained water to the cellulose in the 5–15 nm pore size range. Conclusion The loss of hemicelluloses and changes in polymer structural features caused by HWP led to reorganisation of the lignocellulose matrix. These modifications increased the SSA and redistributed the water thereby increasing the accessibility of cellulases and enhancing hydrolysis. Interestingly, lignin content did not have a negative impact on enzymatic hydrolysis but a higher lignin condensed state appeared to promote saccharification. The environment and organisation of lignin is thus more important than its concentration in explaining cellulose accessibility. Elucidating the interactions between polymers is the key to understanding LB recalcitrance and to identifying the best severity conditions to optimise HWP in sustainable biorefineries.

scholarly journals Effect of Exogenously Applied 24-Epibrassinolide and Brassinazole on Xylogenesis and Microdistribution of Cell Wall Polymers in Leucaena leucocephala (Lam) De Wit

2021 ◽  
Author(s):  
S. Pramod ◽  
M. Anju ◽  
H. Rajesh ◽  
A. Thulaseedharan ◽  
Karumanchi S. Rao
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Leucaena Leucocephala ◽  
Higher Plants ◽  
Lignin Content ◽  
Wood Quality ◽  
Wall Structure ◽  
Vessel Element ◽  
Xylem Differentiation ◽  
Cell Wall Polymers

AbstractPlant growth regulators play a key role in cell wall structure and chemistry of woody plants. Understanding of these regulatory signals is important in advanced research on wood quality improvement in trees. The present study is aimed to investigate the influence of exogenous application of 24-epibrassinolide (EBR) and brassinosteroid inhibitor, brassinazole (BRZ) on wood formation and spatial distribution of cell wall polymers in the xylem tissue of Leucaena leucocephala using light and immuno electron microscopy methods. Brassinazole caused a decrease in cambial activity, xylem differentiation, length and width of fibres, vessel element width and radial extent of xylem suggesting brassinosteroid inhibition has a concomitant impact on cell elongation, expansion and secondary wall deposition. Histochemical studies of 24-epibrassinolide treated plants showed an increase in syringyl lignin content in the xylem cell walls. Fluorescence microscopy and transmission electron microscopy studies revealed the inhomogenous pattern of lignin distribution in the cell corners and middle lamellae region of BRZ treated plants. Immunolocalization studies using LM10 and LM 11 antibodies have shown a drastic change in the micro-distribution pattern of less substituted and highly substituted xylans in the xylem fibres of plants treated with EBR and BRZ. In conclusion, present study demonstrates an important role of brassinosteroid in plant development through regulating xylogenesis and cell wall chemistry in higher plants.

Determination of cotton fiber maturity and linear density (fineness) by examination of fiber cross-sections. Part 2: A comparison optical and scanning electron microscopy

2014 ◽  
Vol 84 (18) ◽  
pp. 1939-1947 ◽  
Author(s):  
Geoffrey RS Naylor ◽  
Margaret Pate ◽  
Graham J Higgerson
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Wall ◽  
Optical Microscopy ◽  
Cross Sections ◽  
Linear Density ◽  
Wall Area ◽  
Density Values ◽  
Fiber Maturity ◽  
Scanning Electron

Previous researchers established a set of reference cottons with known fiber maturity and linear density (fineness) values based on the analysis of a large number of individual transverse fiber cross-sections viewed under the optical microscope. Part 1 identified that the limited optical resolution of the captured images may be the source of a significant systematic error in the assigned values of cell wall area and hence fiber maturity and linear density values. In this paper the optical microscopy technique was implemented. Individual cross-sections were measured using this approach and also higher resolution and higher magnification images were obtained using scanning electron microscopy. It was found that the data obtained from optical microscopy were similar to the SEM data, with the perimeter being 2% smaller, the cell wall area being 6% larger and the maturity ratio values being 8% higher. It was concluded that the combined approach of utilizing SEM in conjunction with optical imaging is a useful approach for verifying and perhaps correcting the data obtained from optical imaging. Further the SEM images highlighted that the current experimental protocol does not adequately address the challenge of ensuring that the fibers are mounted normal to the plane of cutting the transverse cross-section. Modeling demonstrated that while maturity ratio values are relatively insensitive to this misalignment, measured cell wall area values and hence fiber linear density values will be overestimated. This may be the major source of error associated with the technique and warrants further attention in future studies.

scholarly journals Hypolignification: A Decisive Factor in the Development of Hyperhydricity

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2625
Author(s):  
Nurashikin Kemat ◽  
Richard G. F. Visser ◽  
Frans A. Krens
Keyword(s):  
Cell Wall ◽  
Lignin Content ◽  
Coumaric Acid ◽  
Wild Type ◽  
Higher Plant ◽  
Gene Coding ◽  
Phenylpropanoid Biosynthesis ◽  
Total Lignin ◽  
Total Lignin Content

One of the characteristics of hyperhydric plants is the reduction of cell wall lignification (hypolignification), but how this is related to the observed abnormalities of hyperhydricity (HH), is still unclear. Lignin is hydrophobic, and we speculate that a reduction in lignin levels leads to more capillary action of the cell wall and consequently to more water in the apoplast. p-coumaric acid is the hydroxyl derivative of cinnamic acid and a precursor for lignin and flavonoids in higher plant. In the present study, we examined the role of lignin in the development of HH in Arabidopsis thaliana by checking the wild-types (Ler and Col-0) and mutants affected in phenylpropanoid biosynthesis, in the gene coding for cinnamate 4-hydroxylase, C4H (ref3-1 and ref3-3). Exogenously applied p-coumaric acid decreased the symptoms of HH in both wild-type and less-lignin mutants. Moreover, the results revealed that exogenously applied p-coumaric acid inhibited root growth and increased the total lignin content in both wild-type and less-lignin mutants. These effects appeared to diminish the symptoms of HH and suggest an important role for lignin in HH.

scholarly journals Edaphic characteristics of Austrian pine (Pinus nigra Arn.) forests in the Visegrad area

2016 ◽  
Vol 68 (2) ◽  
pp. 355-362
Author(s):  
Velibor Blagojevic ◽  
Milan Knezevic ◽  
Olivera Kosanin ◽  
Marijana Kapovic-Solomun ◽  
Radovan Lucic ◽  
...  
Keyword(s):  
Pinus Nigra ◽  
Research Area ◽  
Geological Structure ◽  
Forest Communities ◽  
Production Potential ◽  
High Production ◽  
Highly Correlated ◽  
The Impact ◽  
Important Basis ◽  
Forest Habitats

This paper presents the results of soil research in Austrian pine (Pinus nigra Arn.) forest communities in the Visegrad area, carried out to determine the basic soil characteristics and eco-production potential of forest habitats as an important basis and framework for the successful management of these forests on the principles of sustainable development. Austrian pine forests in this region are an important and ecologically valuable community. The complexity of the geological structure and relief dynamics are dominant environmental factors that condition the expressed variability of soils in the study area. Forest communities of Austrian pine are formed on the peridotites and serpentinites, eutric ranker (haplic leptosol), eutric cambisol (haplic cambisols) and pseudogley (haplic planosol), dense granular and marl limestones calcomelanosol (mollic leptosol), rendzina (rendzic leptosol) and calcocambisol (leptic cambisol). The productivity of these soils is highly correlated with depth and texture composition, and the impact of these factors is linked with soil type, climate and other site conditions. In the research area, soil types with low production potential such as rankers, rendzinas, limestone and dolomite calcomelanosol are dominant. Deeper variants of eutric cambisol, pseudogley and calcocambisol can be classified as soils with moderate to high production potential.

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