A quantitative investigation of symplasmic transport in Chara corallina. I. Ultrastructure of the nodal complex cell walls

1974 ◽  
Vol 52 (6) ◽  
pp. 1209-1214 ◽  
Author(s):  
R. A. Fischer ◽  
J. Dainty ◽  
M. T. Tyree
Keyword(s):  
Cell Walls ◽  
Pore Diameter ◽  
Chara Corallina ◽  
Central Cell ◽  
Relative Area ◽  
Complex Cell ◽  
Quantitative Investigation ◽  
Peripheral Cell ◽  
Internodal Cell ◽  
Symplasmic Transport

We present a quantitative ultrastructural study of the size and frequency (density distribution) of plasmodesmata in the cell wall in common between the internodal cell and peripheral cell (and central cell) of Chara corallina. In the wall in common between the central cell and internodal cell the relative area occupied by plasmodesmata is 15.3%; the pore diameter (less the plasmalemma) is 118 nm; the length is 1.54 μm, and the frequency is 1.4 × 109 pores/cm2. In the wall in common between the peripheral cell and internodal cell the relative area occupied by the plasmodesmata is 9.6%; the pore diameter is 100 nm; the length is 1.07 μm; and the frequency is 1.2 × 109 pores/cm2. The plasmodesmata have an anastomosing structure like Nitella translucens but the pore diameter and frequency are much greater.

A quantitative investigation of symplasmic transport in Chara corallina. III. An evaluation of chemical and freeze-substituting techniques in determining the in vivo condition of the plasmodesmata

1975 ◽  
Vol 53 (18) ◽  
pp. 1988-1993 ◽  
Author(s):  
R. A. Fischer ◽  
T. J. MacAlister
Keyword(s):  
Electron Microscopy ◽  
Cell Walls ◽  
Room Temperature ◽  
Freeze Substitution ◽  
Chara Corallina ◽  
Chemical Fixation ◽  
Quantitative Investigation ◽  
Internodal Cell ◽  
Symplasmic Transport

We present data on a comparison of plasmodesmata in the nodal complexes of Chara corallina prepared for electron microscopy by chemical fixation of specimens at room temperature and those that have been freeze-substituted. The freeze-substitution technique was applied to intact nodal complexes with the internodal cells on either side intact and showed that most plasmodesmata in the cell walls joining a nodal cell with an internodal cell were free of any occluding substance. We feel that the nonoccluded plasmodesma is the in vivo condition and that previous results using chemical fixation at room temperature where occlusions were reported in Nitella translucens and Chara corallina are artifacts of preparation.

A quantitative investigation of symplasmic transport in Chara corallina. II. The symplasmic transport of chloride

1974 ◽  
Vol 52 (6) ◽  
pp. 1325-1334 ◽  
Author(s):  
M. T. Tyree ◽  
R. A. Fischer ◽  
J. Dainty
Keyword(s):  
Ultrastructural Study ◽  
Chara Corallina ◽  
Quantitative Investigation ◽  
Cl Transport ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Symplasmic Transport ◽  
Rate Limiting

We report measurements of the tempo of 36Cl transport across the nodal complex of Chara corallina. By combining these data with the results of a quantitative ultrastructural study of the size and frequency of plasmodesmata in the nodal complex, we can calculate the resistance offered to diffusion by the plasmodesmata, assuming that diffusion is the rate-limiting step. Based on this assumption, the plasmodesmatal fluid is about 31 times more resistant to diffusion than water; but it is suggested that cyclosis in the internodal cells up to the nodal complex may have some rate-controlling influence. Also the viscosity of flowing cytoplasm can increase the resistance to diffusion above that in water. Therefore it is possible that the plasmodesmata are filled only with viscous or gelled cytoplasm.

The specificity and the ability ofAspergillus feruloyl esterase to releasep-coumaric acid from complex cell walls of oat hulls

2004 ◽  
Vol 79 (7) ◽  
pp. 729-733 ◽  
Author(s):  
Peiqiang Yu ◽  
John J McKinnon ◽  
David D Maenz ◽  
Vern J Racz ◽  
David A Christensen
Keyword(s):  
Cell Walls ◽  
Feruloyl Esterase ◽  
Complex Cell ◽  
Coumaric Acid ◽  
Oat Hulls

scholarly journals Domain-specific and cell type-specific localization of two types of cell wall matrix polysaccharides in the clover root tip.

1992 ◽  
Vol 118 (2) ◽  
pp. 467-479 ◽  
Author(s):  
M A Lynch ◽  
L A Staehelin
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Cellular Differentiation ◽  
Cortical Cell ◽  
Middle Lamella ◽  
Root Cap ◽  
Root Tip ◽  
Cortical Cells ◽  
Peripheral Cell ◽  
Clover Root

Using immunocytochemical techniques and antibodies that specifically recognize xyloglucan (anti-XG), polygalacturonic acid/rhamnogalacturonan I (anti-PGA/RG-I), and methylesterified pectins (JIM 7), we have shown that these polysaccharides are differentially synthesized and localized during cell development and differentiation in the clover root tip. In cortical cells XG epitopes are present at a threefold greater density in the newly formed cross walls than in the older longitudinal walls, and PGA/RG-I epitopes are detected solely in the expanded middle lamella of cortical cell corners, even after pretreatment of sections with pectinmethylesterase to uncover masked epitopes. These results suggest that in cortical cells XG and PGA/RG-I are differentially localized not only to particular wall domains, but also to particular cell walls. In contrast to their nonoverlapping distribution in cortical cells, XG epitopes and PGA/RG-I epitopes largely colocalize in the epidermal cell walls. The results also demonstrate that the middle lamella of the longitudinal walls shared by epidermal cells and by epidermal and cortical cells constitutes a barrier to the diffusion of cell wall and mucilage molecules. Synthesis of XG and PGA/RG-I epitope-containing polysaccharides also varies during cellular differentiation in the root cap. The differentiation of gravitropic columella cells into mucilage-secreting peripheral cells is marked by a dramatic increase in the synthesis and secretion of molecules containing XG and PGA/RG-I epitopes. In contrast, JIM 7 epitopes are present at abundant levels in columella cell walls, but are not detectable in peripheral cell walls or in secreted mucilage. There were also changes in the cisternal labeling of the Golgi stacks during cellular differentiation in the root tip. Whereas PGA/RG-I epitopes are detected primarily in cis- and medial Golgi cisternae in cortical cells (Moore, P. J., K. M. M. Swords, M. A. Lynch, and L. A. Staehelin. 1991. J. Cell Biol. 112:589-602), they are localized predominantly in the trans-Golgi cisternae and the trans-Golgi network in epidermal and peripheral root cap cells. These observations suggest that during cellular differentiation the plant Golgi apparatus can be both structurally and functionally reorganized.

scholarly journals Pectin Rhamnogalacturonan II: On the “Small Stem with Four Branches” in the Primary Cell Walls of Plants

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Beda M. Yapo
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Vascular Plants ◽  
Minor Component ◽  
Primary Cell ◽  
Side Chains ◽  
Complex Cell ◽  
Rhamnogalacturonan Ii ◽  
Branching Point ◽  
A Chain

Rhamnogalacturonan II (RG-II) is a type of block copolymer of complex pectins that represents a quantitatively minor component of the primary cell walls of land (vascular) plants. The structural composition of RG-II is almost totally sequenced and appears to be remarkably conserved in all tracheophytes so far examined. The backbone of RG-II, released from complex (cell wall) pectins by endo-polygalacturonase (Endo-PG) treatment, has been found to contain up to 15 (1→4)-linked-α-D-GalpA units, some of which carry four well-defined side chains, often referred to as A-, B-, C-, and D-side chains. Nevertheless, the relative locations on the backbone of these four branches, especially the A chain, remain to be ascertained. A combination of different data suggests that neither the terminal nonreducing GalA nor the contiguous GalA unit is likely to be the branching point of the A chain, but probably the ninth GalA residue from the reducing end, assuming a minimum backbone length of 11 (1→4)-linked-α-d-GalpA. The latest reports on RG-II are here highlighted, with a provided update for the macrostructure and array of functionalities.

Studies on the camparative physiology of Chara corallina. III. Nitrogen relations of internodal cell components during internodal cell expansion

1971 ◽  
Vol 19 (1) ◽  
pp. 1 ◽  
Author(s):  
MJ Mercer ◽  
FV Mercer
Keyword(s):  
Cell Wall ◽  
Nitrogen Content ◽  
Total Nitrogen ◽  
Higher Plants ◽  
Chara Corallina ◽  
Soluble Nitrogen ◽  
Internodal Cell ◽  
Wall Cell ◽  
Cell Components ◽  
Chloroplast Fraction

Changes in the total nitrogen content of single internodal cells and in the nitrogen content of the cell wall, chloroplast fraction, TCA-insoluble cytoplasmic fraction, cytoplasmic sap, and vacuolar sap during the growth of the internodal cell are described. The nitrogen content of all fractions increases as the cells expand from c. 10 �l to over 200 �l in volume, and protein increases in the cytoplasm, the chloroplast fraction, and the cell wall. Cell wall nitrogen accounts for over half the total nitrogen of the cell and the bulk of the soluble nitrogen is present in the cytoplasm; only about 1% is found in the vacuole. The observations are discussed in relation to the cells of higher plants.

De l'utilisation du lanthane comme traceur de la voie apoplastique chez Cystoseira nodicaulis (Fucales, Cystoseiraceae)

1991 ◽  
Vol 69 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Liliane Pellegrini ◽  
Marie Epiard-Lahaye ◽  
Michel Penot
Keyword(s):  
Cell Walls ◽  
Long Distance ◽  
Long Distance Transport ◽  
Dense Deposits ◽  
Symplasmic Transport ◽  
Apoplastic Pathway ◽  
Distance Transport ◽  
Kinetics Of ◽  
Dense Marker ◽  
Over Time

Lanthanum was used as an electron-dense marker of apoplastic transport in the brown alga Cystoseira nodicaulis. A lanthanum salt, La(NO3)3, was given in seawater at the base of excised branches for 2–8 days. Lanthanum transport into two regions distant from the point of application, the base and apex of the branches, was followed over time by electron microscopy. Restricted localisation of the deposits confirmed that an apoplastic pathway exists in this alga. The kinetics of transport are slow. Dense deposits were located exclusively in the cell walls of meristoderm and cortex cells. The significance of apoplastic transport in algae is discussed in the context of long-distance transport. The existence of an apoplastic route does not exclude the occurrence of symplasmic transport, which is suggested by the numerous plasmodesmata present in the medulla. Key words: algae, apoplast, Cystoseira, lanthanum, long-distance transport.

Pore-Forming Activity of Outer Membrane Extracts from the Unicellular Cyanobacterium Synechocystis sp. PCC 6714

1989 ◽  
Vol 44 (1-2) ◽  
pp. 165-169 ◽  
Author(s):  
Uwe J. Jürgens ◽  
Roland Benz
Keyword(s):  
Outer Membrane ◽  
Cell Walls ◽  
Pore Diameter ◽  
Single Channel ◽  
Outer Membrane Proteins ◽  
Lipid Bilayer Membranes ◽  
Bilayer Membranes ◽  
Unicellular Cyanobacterium ◽  
Sds Page ◽  
Synechocystis Sp

Abstract Cell walls of the unicellular cyanobacterium Synechocystis sp. PCC 6714, isolated from cell homogenates, were found to be unusually resistant against extraction with various detergents, organic solvents, chaotropic agents, and proteases. The major outer membrane proteins (M r 67,000; 61,000; 94,000) were solubilized by differential SDS-extraction and purified by preparative SDS-PAGE. The extracted proteins, reconstituted into lipid bilayer membranes, formed two types of pores with single-channel conductances of 2.2 nS (pore diameter of 1.4 nm) and 0.3 nS (pore diameter not determined), respectively. Carotenoids and lipopolysaccharide were found to be associated with the extracted major proteins.

Microsporogenesis in Amelanchier alnifolia: sporogenous cells, microsporocytes, and tetrads

2005 ◽  
Vol 83 (9) ◽  
pp. 1106-1116 ◽  
Author(s):  
Michael J. Sumner ◽  
William R. Remphrey
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Walls ◽  
Developmental Changes ◽  
Bright Field ◽  
Peripheral Cell ◽  
Amelanchier Alnifolia ◽  
Transmission Electron ◽  
Wall Materials ◽  
Thin Walled

As part of an overall program aimed at increasing our knowledge of the male reproductive system of Amelanchier alnifolia Nutt., this study documents structural and developmental changes that occur in the sporogenous cells, microsporocytes, and tetrads of microspores during microsporogenesis using general cytochemical techniques in conjunction with bright field, fluorescence, and transmission electron microscopy. The sporogenous cells are thin walled and stain positively for β-1,4-glucans, pectic acids, and cellulose, but not callose. At the microsporocyte and tetrad stages of microsporogenesis, thick walls develop and stain positively for β-1,4-glucans (hemicelluloses but not cellulose), pectic acids, and callose. Thus, the eventual release of maturing microspores from the tetrads requires the digestion of all three of these carbohydrate wall materials. Postmeiotic cytokinesis is of the simultaneous type and is initiated when Golgi vesicles aggregate simultaneously into a network of cylindrical tubules in both central and peripheral cell locations of the coenocytic tetrad. Eventually, this network fuses to form the new cell walls within the microspore tetrad.

scholarly journals Structural Characteristics of Developing Nitella Internodal Cell Walls

1958 ◽  
Vol 4 (5) ◽  
pp. 505-516 ◽  
Author(s):  
Paul B. Green
Keyword(s):  
Cell Walls ◽  
Relative Elongation ◽  
Structural Characteristics ◽  
Apical Cell ◽  
Elongation Rate ◽  
Wall Surface ◽  
Initial Length ◽  
Internodal Cell ◽  
Inner Surface ◽  
Segment Cell

The Nilella intermodal cell is formed by a division of the segment cell, the latter being a direct derivative of the shoot apical cell. The internodal cell is remarkable in that it elongates from an initial length of about 20 microns to a mature length of about 60 millimeters. The structures of the apical and segment cells, and the internodal cells in all stages of development were examined with the techniques of interference, polarization, and electron microscopy. The apical and segment cells were found to be isotropic. The upper part of the segment cell, destined to form a node, shows a curious pitted structure that was characteristic of certain node structures. The lower part of the segment cell, destined to become an internodal cell, shows a vague transverse arrangement of fibrils at the inner wall surface. The internodal cells, from the time they are first formed, show negative birefringence and a transverse arrangement of microfibrils at the inner wall surface. The elongation of the internodal cell is characterized by a rise, dip, and rise in both the optical thickness and retardation of the cell wall. The dip in both these variables coincides with the attainment of the maximum relative elongation rate. After the cessation of elongation, wall deposition continues, but the fibrils at .the inner surface of the wall are now seen to occur in fields of nearly parallel microfibrils. These fields, with varying fibrillar directions, may partly overlap each other or may merge with one another. Unlike the growing wall, this wall which is deposited after the end of elongation is isotropic.

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