scholarly journals Callose: a multifunctional (1, 3)-β–d-glucan involved in morphogenesis and function of angiosperm stomata

2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Panagiotis Apostolakos ◽  
Eleni Giannoutsou ◽  
Basil Galatis
Keyword(s):  
Cell Walls ◽  
Pore Formation ◽  
Cellulose Microfibril ◽  
Vigna Sinensis ◽  
Matrix Cell ◽  
Wall Materials ◽  
Asplenium Nidus ◽  
And Function ◽  
Cell Wall Materials

Abstract Background Although the cellulose microfibril organization in guard cell (GC) walls play a crucial role in the mechanism of the stomatal function, recent work showed that matrix cell wall materials are also involved. Especially in the kidney-shaped stomata of the fern Asplenium nidus, callose actively participates in the mechanism of opening and closure of the stomatal pore. Scope The present review briefly presents and discusses recent findings concerning the distribution and role of callose in the kidney-shaped stomata of the dicotyledon Vigna sinensis as well as in the dumbbell-shaped stomata of the monocotyledon Zea mays. Conclusion The discussed data support that, in both categories of angiosperm stomata, callose is implicated in the mechanism of stomatal pore formation and stomata function by locally affecting the mechanical properties of the GC cell walls.

scholarly journals Study on Improving the Fixation Rate of Impregnated Poplar Wood with Maltodextrin and 1,3-Dimethylol-4,5-Dihydroxyethyleneurea

2019 ◽  
Vol 9 (16) ◽  
pp. 3237
Author(s):  
Mingzhen Cai ◽  
Zongying Fu ◽  
Yingchun Cai ◽  
Yue Zhang
Keyword(s):  
Compressive Strength ◽  
Cell Wall ◽  
Fourier Transform ◽  
Cell Walls ◽  
Poplar Wood ◽  
Fixation Rate ◽  
Practical Applications ◽  
Wall Materials ◽  
Impregnated Wood ◽  
Cell Wall Materials

The impregnation of poplar wood (Populus adenopoda Maxim) with 1,3-dimethylol-4,5-dihydroxyethyleneurea and maltodextrin and the effects of ZnCl2 and curing at 103 °C and 120 °C on the fixation rate and the leaching resistance of modified samples were investigated (103 °C curing, ZnCl2 + 103 °C curing, 120 °C curing, and ZnCl2 + 120 °C curing are denoted as 103, ZC-103, 120, and ZC-120, respectively), with the aim of improving the modification effect. The results showed that ZC-103 had the highest fixation rate, and its weight leaching ratio was higher than that of 120. Fourier-transform infrared spectroscopy showed that ZnCl2 did not affect the functional groups of the modified chemicals. The flexural strength and modulus and the compressive strength perpendicular to the grain were highest for ZC-103. In summary, ZC-103 exhibited the highest fixation rate, indicating that the hardener ZnCl2 bridged and increased the interfacial properties between the chemicals and cell walls and therefore increased the potential for macromolecule polycondensation between the chemicals and cell wall materials. This research paves the way for improving the fixation rate of impregnated wood and provides new insights into practical applications.

Astrosclereids In Needles Of Old-Growth Douglas-Fir Trees

1999 ◽  
Vol 5 (S2) ◽  
pp. 1240-1241
Author(s):  
M. Apple ◽  
A. Soeldner ◽  
R. Hamill ◽  
K. Tiekotfer
Keyword(s):  
Pacific Northwest ◽  
Cell Walls ◽  
Douglas Fir ◽  
Old Growth ◽  
Mesophyll Cells ◽  
Mesophyll Tissue ◽  
The Pacific ◽  
And Function ◽  
Development Structure

Old-growth Douglas-fir trees in the Pacific Northwest are venerable giants that often live for 500 years and reach heights of over 75 meters. Their needles are relatively ephemeral and small but have the important role of interacting with the atmosphere in order to transpire and photosynthesize. Within the photosynthetic mesophyll tissue of Douglas-fir needles, there are large, non-living cells with lignified secondary cell walls that are known as astrosclereids. Apparent channels in the secondary wall may provide a route for exchange or transport of materials between the astrosclereid lumen and mesophyll cells or the vascular cylinder. Astrosclereids may be involvev d in storage of secondary metabolites such as tannin and may develop in response to fungi, mistletoe, or other pathogens. More knowledge is needed about the development, structure and function of astrosclereids.Needles were collected from sapling and old-growth Douglas-fir, Pseudotsuga menziesii, (Mirb.) Franco, trees at the Wind River Canopy Crane in Carson, Washington and from three sites in the Cascade Mountains of Oregon in 1997 and 1998.

The role of fungal polysaccharidases in the hydrolysis of cell wall materials from sunflower and palm-kernel meals

1993 ◽  
Vol 9 (5) ◽  
pp. 544-554 ◽  
Author(s):  
E. -M. D�sterh�ft ◽  
A. W. Bonte ◽  
J. C. Venekamp ◽  
A. G. J. Voragen
Keyword(s):  
Cell Wall ◽  
Palm Kernel ◽  
Wall Materials ◽  
Hydrolysis Of ◽  
Cell Wall Materials

scholarly journals Retention of Water by Plant Cell Walls and Implications for Drought Resistance

1967 ◽  
Vol 20 (1) ◽  
pp. 41 ◽  
Author(s):  
TS Teoh ◽  
LAG Aylmore ◽  
JP Quirk
Keyword(s):  
Cell Wall ◽  
Vicia Faba ◽  
Plant Cell ◽  
Drought Resistance ◽  
Cell Walls ◽  
Plant Cell Walls ◽  
Triticum Vulgare ◽  
Vicia Faba L ◽  
Wall Materials ◽  
Cell Wall Materials

The water�retaining properties of cell wall materials from the roots of two monocotyledons (Ehrharta calycina Sm. and Triticum vulgare Vill. cv. Gabo) and two dicotyledons (Salicornia australis Banks & Soland and Vicia faba L.) have been studied.

scholarly journals The role of callose in guard-cell wall differentiation and stomatal pore formation in the fern Asplenium nidus

2009 ◽  
Vol 104 (7) ◽  
pp. 1373-1387 ◽  
Author(s):  
P. Apostolakos ◽  
P. Livanos ◽  
T. L. Nikolakopoulou ◽  
B. Galatis
Keyword(s):  
Cell Wall ◽  
Guard Cell ◽  
Pore Formation ◽  
Asplenium Nidus

scholarly journals Ester- and ether-linked phenolic acids in orchardgrass (Dactylis glomerata L.) and their digestion from cell walls when fed to sheep

1991 ◽  
Vol 71 (4) ◽  
pp. 1179-1182 ◽  
Author(s):  
Tsuneo Kondo ◽  
Tomoko Ohshita ◽  
Tadashi Kyuma
Keyword(s):  
Cell Walls ◽  
Enzymatic Degradation ◽  
Dactylis Glomerata ◽  
Coumaric Acid ◽  
Wall Materials ◽  
Dactylis Glomerata L ◽  
Ferulic Acids ◽  
Acid Esters ◽  
Heading Stage ◽  
Cell Wall Materials

Ester- and ether-linked p-coumaric (PCA) and ferulic acids (FA) in cell wall materials from orchardgrass (Dactylis glomerata L.), hays harvested at the heading stage and feces samples from sheep fed the orchardgrass hays were analyzed. Results showed that ether-linked PCA and FA were more resistant to ruminant digestion and enzymatic degradation than ester-linked PCA and FA. Key words: p-coumaric acid, esters, ethers, ferulic acid, orchardgrass, sheep digestion

Scanning electron microscopic study of collagen fibrillogenesis and extracellular compartmentalization in the chick embryo tendon

1986 ◽  
Vol 44 ◽  
pp. 208-209
Author(s):  
Grace C.H. Yang
Keyword(s):  
Chick Embryo ◽  
Extracellular Space ◽  
Fibroblast Cell ◽  
Collagen Fibrils ◽  
Electron Microscopic ◽  
Voltage Electron ◽  
Scanning Electron Microscopic Study ◽  
Microscopic Studies ◽  
And Function

The size and organization of collagen fibrils in the extracellular matrix is an important determinant of tissue structure and function. The synthesis and deposition of collagen involves multiple steps which begin within the cell and continue in the extracellular space. High-voltage electron microscopic studies of the chick embryo cornea and tendon suggested that the extracellular space is compartmentalized by the fibroblasts for the regulation of collagen fibril, bundle, and tissue specific macroaggregate formation. The purpose of this study is to gather direct evidence regarding the association of the fibroblast cell surface with newly formed collagen fibrils, and to define the role of the fibroblast in the control and the precise positioning of collagen fibrils, bundles, and macroaggregates during chick tendon development.

Role of the Cilia Membrane in Control of Microtubule Sliding

1980 ◽  
Vol 38 ◽  
pp. 612-615
Author(s):  
Edna S. Kaneshiro
Keyword(s):  
Control Mechanism ◽  
Beat Frequency ◽  
Surface Membrane ◽  
Ciliary Membrane ◽  
Ciliary Beating ◽  
Ciliary Reversal ◽  
Voltage Dependent ◽  
Reversal Mechanism ◽  
And Function

It is currently believed that ciliary beating results from microtubule sliding which is restricted in regions to cause bending. Cilia beat can be modified to bring about changes in beat frequency, cessation of beat and reversal in beat direction. In ciliated protozoans these modifications which determine swimming behavior have been shown to be related to intracellular (intraciliary) Ca2+ concentrations. The Ca2+ levels are in turn governed by the surface ciliary membrane which exhibits increased Ca2+ conductance (permeability) in response to depolarization. Mutants with altered behaviors have been isolated. Pawn mutants fail to exhibit reversal of the effective stroke of ciliary beat and therefore cannot swim backward. They lack the increased inward Ca2+ current in response to depolarizing stimuli. Both normal and pawn Paramecium made leaky to Ca2+ by Triton extrac¬tion of the surface membrane exhibit backward swimming only in reactivating solutions containing greater than IO-6 M Ca2+ Thus in pawns the ciliary reversal mechanism itself is left operational and only the control mechanism at the membrane is affected. The topographic location of voltage-dependent Ca2+ channels has been identified as a component of the ciliary mem¬brane since the inward Ca2+ conductance response is eliminated by deciliation and the return of the response occurs during cilia regeneration. Since the ciliary membrane has been impli¬cated in the control of Ca2+ levels in the cilium and therefore is the site of at least one kind of control of microtubule sliding, we have focused our attention on understanding the structure and function of the membrane.

POPDC proteins and cardiac function

2019 ◽  
Vol 47 (5) ◽  
pp. 1393-1404 ◽  
Author(s):  
Thomas Brand
Keyword(s):  
Potential Role ◽  
Striated Muscle ◽  
Short Review ◽  
Effector Proteins ◽  
Muscle Disease ◽  
Disease Genes ◽  
Protein Protein Interaction ◽  
Interaction Partners ◽  
And Function

Abstract The Popeye domain-containing gene family encodes a novel class of cAMP effector proteins in striated muscle tissue. In this short review, we first introduce the protein family and discuss their structure and function with an emphasis on their role in cyclic AMP signalling. Another focus of this review is the recently discovered role of POPDC genes as striated muscle disease genes, which have been associated with cardiac arrhythmia and muscular dystrophy. The pathological phenotypes observed in patients will be compared with phenotypes present in null and knockin mutations in zebrafish and mouse. A number of protein–protein interaction partners have been discovered and the potential role of POPDC proteins to control the subcellular localization and function of these interacting proteins will be discussed. Finally, we outline several areas, where research is urgently needed.

Role of the 807 C/T Polymorphism of the α2 Gene in Platelet GP Ia Collagen Receptor Expression and Function

1999 ◽  
Vol 81 (06) ◽  
pp. 951-956 ◽  
Author(s):  
J. Corral ◽  
R. González-Conejero ◽  
J. Rivera ◽  
F. Ortuño ◽  
P. Aparicio ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Cell Types ◽  
Receptor Expression ◽  
Case Control Studies ◽  
Platelet Surface ◽  
Vitro Analysis ◽  
And Function ◽  
In Vitro Analysis

SummaryThe variability of the platelet GP Ia/IIa density has been associated with the 807 C/T polymorphism (Phe 224) of the GP Ia gene in American Caucasian population. We have investigated the genotype and allelic frequencies of this polymorphism in Spanish Caucasians. The T allele was found in 35% of the 284 blood donors analyzed. We confirmed in 159 healthy subjects a significant association between the 807 C/T polymorphism and the platelet GP Ia density. The T allele correlated with high number of GP Ia molecules on platelet surface. In addition, we observed a similar association of this polymorphism with the expression of this protein in other blood cell types. The platelet responsiveness to collagen was determined by “in vitro” analysis of the platelet activation and aggregation response. We found no significant differences in these functional platelet parameters according to the 807 C/T genotype. Finally, results from 3 case/control studies involving 302 consecutive patients (101 with coronary heart disease, 104 with cerebrovascular disease and 97 with deep venous thrombosis) determined that the 807 C/T polymorphism of the GP Ia gene does not represent a risk factor for arterial or venous thrombosis.

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