scholarly journals Unveiling the impact of embedding resins on the physicochemical traits of wood cell walls with subcellular functional probing

2021 ◽  
Vol 201 ◽  
pp. 108485
Author(s):  
Raphaël Coste ◽  
Mikhael Soliman ◽  
Nicolas B. Bercu ◽  
Sylvain Potiron ◽  
Karima Lasri ◽  
...  
Keyword(s):  
Cell Walls ◽  
The Impact

scholarly journals Heterologous Expression of Rhizobial CelC2 Cellulase Impairs Symbiotic Signaling and Nodulation in Medicago truncatula

2018 ◽  
Vol 31 (5) ◽  
pp. 568-575 ◽  
Author(s):  
Marta Robledo ◽  
Esther Menéndez ◽  
Jose Ignacio Jiménez-Zurdo ◽  
Raúl Rivas ◽  
Encarna Velázquez ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Cell Walls ◽  
Rhizobium Leguminosarum ◽  
Root Nodules ◽  
Root Hairs ◽  
Nod Factors ◽  
Model Legume ◽  
Ensifer Meliloti ◽  
Early Nodulin ◽  
The Impact

The infection of legume plants by rhizobia is tightly regulated to ensure accurate bacterial penetration, infection, and development of functionally efficient nitrogen-fixing root nodules. Rhizobial Nod factors (NF) have key roles in the elicitation of nodulation signaling. Infection of white clover roots also involves the tightly regulated specific breakdown of the noncrystalline apex of cell walls in growing root hairs, which is mediated by Rhizobium leguminosarum bv. trifolii cellulase CelC2. Here, we have analyzed the impact of this endoglucanase on symbiotic signaling in the model legume Medicago truncatula. Ensifer meliloti constitutively expressing celC gene exhibited delayed nodulation and elicited aberrant ineffective nodules, hampering plant growth in the absence of nitrogen. Cotreatment of roots with NF and CelC2 altered Ca2+ spiking in root hairs and induction of the early nodulin gene ENOD11. Our data suggest that CelC2 alters early signaling between partners in the rhizobia-legume interaction.

scholarly journals Gas Permeability of Cellulose Aerogels with a Designed Dual Pore Space System

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2688 ◽  
Author(s):  
Kathirvel Ganesan ◽  
Adam Barowski ◽  
Lorenz Ratke
Keyword(s):  
Porous Materials ◽  
Cell Walls ◽  
Gas Permeability ◽  
Pore Space ◽  
Nitrogen Adsorption ◽  
Space System ◽  
Fixed Amount ◽  
Hydrophilic Lipophilic Balance ◽  
Wide Range ◽  
The Impact

The gas permeability of a porous material is a key property determining the impact of the material in an application such as filter/separation techniques. In the present study, aerogels of cellulose scaffolds were designed with a dual pore space system consisting of macropores with cell walls composing of mesopores and a nanofibrillar network. The gas permeability properties of these dual porous materials were compared with classical cellulose aerogels. Emulsifying the oil droplets in the hot salt–hydrate melt with a fixed amount of cellulose was performed in the presence of surfactants. The surfactants varied in physical, chemical and structural properties and a range of hydrophilic–lipophilic balance (HLB) values, 13.5 to 18. A wide range of hierarchical dual pore space systems were produced and analysed using nitrogen adsorption–desorption analysis and scanning electron microscopy. The microstructures of the dual pore system of aerogels were quantitatively characterized using image analysis methods. The gas permeability was measured and discussed with respect to the well-known model of Carman–Kozeny for open porous materials. The gas permeability values implied that the kind of the macropore channel’s size, shape, their connectivity through the neck parts and the mesoporous structures on the cell walls are significantly controlling the flow resistance of air. Adaption of this new design route for cellulose-based aerogels can be suitable for advanced filters/membranes production and also biological or catalytic supporting materials since the emulsion template method allows the tailoring of the gas permeability while the nanopores of the cell walls can act simultaneously as absorbers.

scholarly journals Accumulation and distribution of lead (Pb) in different tissues of Lucky bamboo plants (Dracaena sanderiana)

2021 ◽  
Vol 20 (03) ◽  
pp. 50-60
Author(s):  
Lien B. Ho
Keyword(s):  
Cell Walls ◽  
Anatomical Structure ◽  
Tolerance Limit ◽  
Vascular Bundles ◽  
Lead Accumulation ◽  
Leaf Tissues ◽  
Dracaena Sanderiana ◽  
Stems And Leaves ◽  
The Impact ◽  
Different Tissues

Lucky bamboo plants (Dracaena sanderiana) were used to study the accumulation and distribution of lead (Pb) in tissues of root, stem and leaf, as well as the impact of lead accumulation on the anatomical structure of these tissues. Dracaena sanderiana plants were exposed to Pb(NO3)2 solution at the Pb concentrations of 0; 200; 400; 600; 800; 1,000; 2,000; 3,000 and 4,000 mg/L for 60 days. The results showed that the more the Pb concentration was used, the more the amount of lead was accumulated and deposited. The tolerance limit of Dracaena sanderiana was 800 mg/L of Pb in water. The lethal concentration for plants was 4,000 mg/L Pb. When the concentrations of Pb in the solution were higher than the tolerance limit of the plant, the growth of Dracaena sanderiana could be inhibited. Dracaena sanderiana could accumulate up to 39,235 mg/kg Pb in the presence of Pb at 800 mg/L. Lead was accumulated mainly in roots (97.5%) and deposited mainly in the cell walls and the spaces between cells in tissues of roots. In the stems and leaves of Dracaena sanderiana, lead accumulation was limited and distributed mainly around vascular bundles. Lead accumulation caused changes in the anatomical structure of root, stem and leaf tissues. The accumulation and distribution of Pb is mainly in the cell walls and the space of cells; it could be a detoxification

scholarly journals Unique lignin modifications pattern the nucleation of silica in sorghum endodermis

2020 ◽  
Vol 71 (21) ◽  
pp. 6818-6829 ◽  
Author(s):  
Nerya Zexer ◽  
Rivka Elbaum
Keyword(s):  
Cell Wall ◽  
Silicic Acid ◽  
Cell Walls ◽  
Dry Weight ◽  
Cell Wall Chemistry ◽  
Modified Lignin ◽  
Trace Concentrations ◽  
High Degree ◽  
Micrometer Scale ◽  
The Impact

Abstract Silicon dioxide in the form of hydrated silica is a component of plant tissues that can constitute several percent by dry weight in certain taxa. Nonetheless, the mechanism of plant silica formation is mostly unknown. Silicon (Si) is taken up from the soil by roots in the form of monosilicic acid molecules. The silicic acid is carried in the xylem and subsequently polymerizes in target sites to silica. In roots of sorghum (Sorghum bicolor), silica aggregates form in an orderly pattern along the inner tangential cell walls of endodermis cells. Using Raman microspectroscopy, autofluorescence, and scanning electron microscopy, we investigated the structure and composition of developing aggregates in roots of sorghum seedlings. Putative silica aggregation loci were identified in roots grown under Si starvation. These micrometer-scale spots were constructed of tightly packed modified lignin, and nucleated trace concentrations of silicic acid. Substantial variation in cell wall autofluorescence between Si+ and Si– roots demonstrated the impact of Si on cell wall chemistry. We propose that in Si– roots, the modified lignin cross-linked into the cell wall and lost its ability to nucleate silica. In Si+ roots, silica polymerized on the modified lignin and altered its structure. Our work demonstrates a high degree of control over lignin and silica deposition in cell walls.

scholarly journals The impact of natural and artificial weathering on the anatomy of selected tropical hardwoods

IAWA Journal ◽  
2020 ◽  
Vol 41 (3) ◽  
pp. 333-355 ◽  
Author(s):  
Miroslava Mamoňová ◽  
Ladislav Reinprecht
Keyword(s):  
Cell Walls ◽  
Parenchyma Cell ◽  
Middle Lamella ◽  
Artificial Weathering ◽  
Hymenaea Courbaril ◽  
Anatomical Changes ◽  
Micro Cracks ◽  
Parenchyma Cells ◽  
Dipteryx Odorata ◽  
The Impact

Abstract The effect of natural and artificial weathering on the anatomy of seven tropical hardwoods: Bangkirai (Shorea obtusa Wall.), Cumaru (Dipteryx odorata (Aubl.) Wild.), Cumaru Rosa (Dipteryx magnifica (Ducke) Ducke), Ipé (Tabebuia serratifolia Nichols.), Jatobá (Hymenaea courbaril L.), Kusia (Nauclea diderrichii Merill) and Massaranduba (Manilkara bidentata A. Chev.), was studied. As a result of weathering some characteristic anatomical changes occurred: the weakening of connections between cell elements related to the degradation of the middle lamella; micro-cracks in cell walls; total degradation of parenchyma cells in xylem rays, or significant thinning of parenchyma cell walls and their extreme shrinkage; micro-cracks in the vicinity of xylem rays; significant transversal disruptions in libriform fibres; ablation of pit membranes in vessels and parenchyma cells; changes in the secondary wall of libriform fibres, for example, their defibrillation and weathering-degradation of the S1 layer; and spherical formations on the S3 layer of cell walls produced from condensing compounds of degraded lignin and hemicelluloses as well as thermo-mechanical wrinkling. The highest incidence of micro-cracks after both modes of weathering was found in the densest species; Cumaru, Ipé, and Massaranduba.

Effect of Random Defects on Dynamic Response of Honeycomb Structures

2012 ◽  
Vol 706-709 ◽  
pp. 805-810 ◽  
Author(s):  
Zhi Jun Zheng ◽  
Ji Lin Yu
Keyword(s):  
Impact Velocity ◽  
Cell Walls ◽  
Plateau Stress ◽  
Impact Surface ◽  
Critical Impact Velocity ◽  
Crushing Behavior ◽  
The Impact ◽  
Stress Uniformity ◽  
Random Defects ◽  
Deformation Modes

The dynamic crushing behavior of cellular metals is closely related to their microstructure. Two types of random defects by randomly thickening/removing cell walls are investigated in this paper. Their influences on the deformation modes and plateau stresses of honeycombs are studied by finite element simulation using ABAQUS/Explicit code. Three deformation modes, i.e. the Homogeneous Mode, the Transitional Mode and the Shock Mode, are used to distinguish the deformation patterns of honeycombs under different impact velocities. The critical impact velocity for mode transition between the Homogeneous and Transitional modes is quantitatively determined by evaluating a stress uniformity index, defined as the ratio between the plateau stresses on the support and impact surfaces. It is found that the critical impact velocity decreases with increasing thickening ratio but increases with increasing removing ratio. The plateau stress on the impact surface heavily depends on the impact velocity due to the inertia effect. The random defects lead to a weakening effect on the plateau stress. For the honeycombs with randomly removing cell walls, the weakening effect is especially obvious at a moderate impact velocity. For the honeycombs with randomly thickening cell walls, the weakening effect is particularly severe at a low impact velocity, but this effect almost disappears when the impact velocity is high enough.

A chemical window into the impact of RNAi silencing of the StNAC103 gene in potato tuber periderms: Soluble metabolites, suberized cell walls, and antibacterial defense

2021 ◽  
Vol 190 ◽  
pp. 112885
Author(s):  
Keyvan Dastmalchi ◽  
Oseloka Chira ◽  
Mathiu Perez Rodriguez ◽  
Barney Yoo ◽  
Olga Serra ◽  
...  
Keyword(s):  
Potato Tuber ◽  
Cell Walls ◽  
Rnai Silencing ◽  
The Impact

scholarly journals Incorporation of In Situ Synthesized Nano-Copper Modified Phenol-Formaldehyde Resin to Improve the Mechanical Properties of Chinese Fir: A Preliminary Study

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 876
Author(s):  
Fan Li ◽  
Cuiyin Ye ◽  
Yanhui Huang ◽  
Xianmiao Liu ◽  
Benhua Fei
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Cell Walls ◽  
Phenol Formaldehyde ◽  
Environmental Scanning Electron Microscopy ◽  
Phenol Formaldehyde Resin ◽  
Chinese Fir ◽  
Formaldehyde Resin ◽  
The Impact

Phenol-formaldehyde (PF) resin, modified using nano-copper with varying contents (0 wt%, 1 wt%, 3 wt%), was manufactured to improve the mechanical properties of Chinese fir. The morphology, chemical, micromechanical and micromechanical properties of the samples were determined by transmission electron microscopy (TEM), atomic force microscopy (AFM), environmental scanning electron microscopy (ESEM), Fourier transform infrared spectroscopy (FTIR), nanoindentation (NI) and traditional mechanical testing. The TEM and AFM results indicated that the in situ synthesized nano-copper particles were well-dispersed, and spherical, with a diameter of about 70 nm in PF resin. From the FTIR chemical changes detected by FTIR inferred that the nano-copper modified PF resin penetrated into the Chinese fir cell walls and interacted with the acetyl groups of hemicellulose by forming a crosslinked structure. Accordingly, the micro-mechanical properties of the Chinese fir cell walls were enhanced after treatment with nano-copper modified PF resin. The filling of the PF-1-Cu resin (1 wt% nano-copper) in the wood resulted in 13.7% and 22.2% increases in the elastic modulus (MOE) and hardness, respectively, of the cell walls. Besides, the impact toughness and compressive strength of the Chinese fir impregnated with PF-1-Cu resin were 21.8% and 8.2% higher than that of the PF-0-Cu resin. Therefore, in situ synthesized nano-copper-modified PF resin is a powerful treatment method for Chinese fir due to improved diffusive properties and reinforcement of the mechanical properties.

scholarly journals A phylogenetic and transcriptomic study of the β-1,3-glucanase family in tomato identifies candidate targets for fruit improvement

2021 ◽  
Author(s):  
Candelas Paniagua ◽  
Louisa Perry ◽  
Yoselin Benitez-Alfonso
Keyword(s):  
Cell Walls ◽  
Tomato Fruit ◽  
Fruit Softening ◽  
Pathogen Invasion ◽  
Qrt Pcr ◽  
Symplasmic Transport ◽  
And Function ◽  
The Impact ◽  
And Storage ◽  
Selection Of

Tomato, Solanum lycopersicum, is one of the most cultivated fruits. However, between one-quarter and half of their production is lost during transport and storage. Modifications in cell walls, and specifically pectin composition, delay fruit softening but, so far, the impact of callose metabolism in this process has not been investigated. Callose accumulates in cell walls around plasmodesmata to modify symplasmic transport. It also plays a role in reinforcing cell walls in response to bruising or pathogen invasion. The aim of this work is to identify cell wall β-1,3-glucanases expressed in tomato fruit that can be used as targets to modify callose accumulation during ripening. A phylogenetic analysis identified fifty candidate β-1,3-glucanases in tomato distributed in three clusters (α, β and γ) with evolutionary relations previously characterised in the model Arabidopsis thaliana. Analysis of tomato microarray data indicates different regulatory patterns: the expression of a subset of enzymes in cluster α decreased during ripening, while enzymes in cluster β and γ displayed higher expression in white-red stages. qRT-PCR experiments confirm the differential regulation of enzymes in different clusters suggesting evolutionary divergences that correlate with differences in their predicted localization and function. The potential to exploit this information in the selection of targets to modify cell walls and fruit development is discussed.

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