Ultrastructure of the Wall in Growing Cells and its Relation to the Direction of the Growth

Roelofsen, P. A.

doi:10.1016/s0065-2296(08)60250-5

Cited by 97 publications

(53 citation statements)

References 138 publications

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“…A similar result was obtained and reported by Cleland with Avena coleoptiles (6). Therefore, the elongation of the collenchyma cells is not only due to exogenous stresses, but also requires a wall loosening as in the case of the epidermis (21). Similar deformation obtained for young and senescent cells suggests some identical physical properties of their walls.…”

Section: Resultssupporting

confidence: 89%

“…Such microfibrils should act as rings incompassing a rubber tube and preventing radial extension, but not longitudinal extension. Such a phenomenon, called multinet growth (21,23), is much discussed to day. This leads to neglect of a t with regard to the problem of wall extension.…”

mentioning

confidence: 99%

“…Further, the joint effect of the turgor pressures of two cells under compression produces both longitudinal and transversal tensions due to the mechanical characteristics of the wall. Those tensions might induce migration of matrix polymers inside the wall (21). For short time analysis, such a reaction may be disregarded.…”

mentioning

confidence: 99%

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Extensibility and rheology of collenchyma I. Creep relaxation and viscoelasticity of young and senescent cells

Jaccard

Pilet

1975

Plant and Cell Physiology

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The extensibility of collenchyma cells was methodologically analyzed; extensibility (elasticity and plasticity) and rheology of this tissue are discussed. Experimental conditions are described. Rheological data for young and senescent cells were obtained; they were found to be not Boltzmannian. The permanent strain is not viscous, and is larger for young cells than older ones.Previous observations (17, 18) have shown that collenchyma cells are useful for extensibility experiments. The problem of the extensibility of these cells will be considered here methodologically. In order to describe the analyzing technique, the results of creep relaxation will be compared with those related to physical analysis of polymers. First, several general questions have to be discussed.Clearly, the elongation rate is related both to turgor pressure and deformability of the wall (8,20). On the other hand, wall extensibility is essential for growing cells (5,14). It depends on the metabolism and has been very often associated with protein formation (4, 7). The deformability of the wall can be analyzed also by comparing it with the physical properties of some polymers. The aim of such assays is to discover the physical nature of the wall by analyzing stress relaxation by rheological measurements. This can be easily done by simple tension with a pulled bar.Measuring extensibility and deformability is not an easy task; the stress developed in the cell wall is not a simple tension, but a hydrostatic one. A cellular model was proposed (11) and is presented in Fig.

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Section: Resultssupporting

confidence: 89%

mentioning

confidence: 99%

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Extensibility and rheology of collenchyma I. Creep relaxation and viscoelasticity of young and senescent cells

Jaccard

Pilet

1975

Plant and Cell Physiology

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“…Since the shape and mechanical properties of plant cells are determined primarily by the orientation of the cellulose microfibrils of their walls (25), microtubules ultimately control plant cell morphogenesis. As cells elongate, additional microtubules must be assembled to maintain the same relationship between cell surface area and cortical microtubule density (29).…”

Section: Discussionmentioning

confidence: 99%

Light Regulation of β-Tubulin Gene Expression during Internode Development in Soybean (Glycine max [L.] Merr.)

Bustos

Guiltinan²,

Cyr³

et al. 1989

Plant Physiol.

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The relationship between tubulin gene expression and cell elongation was explored in developing internodes of Glycine max (L.) Merr., using light as a variable to alter the rate of elongation. Illumination of 10-day-old etiolated seedlings not only stopped first internode elongation, but also brought about a 80% decrease in the steady state level of ,-tubulin mRNA over the course of the subsequent 12 hours. This strong down regulation of j6-tubulin mRNA occurred without significant changes in the size of the soluble tubulin pool and it was accompanied by a marked increase in chlorophyll a/b binding protein mRNA.cases, the tubulin dimer pool is maintained through both transcriptional and post-transcriptional control of tubulin gene expression (1,17). Little is known about the regulation of tubulin synthesis in plants, but Cyr et al. (8) observed changes of several fold in the levels of tubulin protein and mRNA during carrot somatic embryogenesis. Furthermore, Fukuda (11) reported that the rate of tubulin synthesis increased during the formation of cortical microtubules in differentiating tracheary elements. The involvement of cortical microtubules in cell elongation and the increase in tubulin levels and in microtubule assembly which has been shown to accompany cell elongation (9, 29), make elongating tissues attractive as systems for investigating the regulation oftubulin synthesis in higher plants. Here, we show that changes in ,Btubulin mRNA steady state levels and internode elongation rates vary concomitantly in light-grown and etiolated soybean seedlings. Internodes of etiolated seedlings exhibited elongation rates that were four to five fold greater than those observed in control seedlings grown under a 12 h light/dark cycle. The rapidly elongating internodes of dark-grown seedlings exhibited proportionally higher steady-state levels of jtubulin mRNA. Furthermore, subsequent illumination of the dark-grown seedlings brought about a reduction in the rate of elongation and a concomitant decrease in the steady-state level of #-tubulin mRNA.Microtubules are formed by the regulated self-assembly of the heterodimeric protein tubulin from a soluble tubulin dimer pool, and cytoplasmic microtubules are in a dynamic equilibrium with this tubulin dimer pool (18). Since microtubules can form and persist only when the tubulin dimer concentration exceeds a critical value, maintenance of the tubulin dimer pool at a level above this critical concentration is essential for microtubule formation. Where it has been examined, tubulin synthesis is regulated by a mechanism that is sensitive to changes in the amount of assembled microtubules. In cultured mammalian cells, tubulin synthesis is autoregulated by a post-transcriptional mechanism that is responsive to the size of the tubulin dimer pool (5).

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“…Electron microscopy and x-ray diffraction have led to a rather detailed description of the structure of this wall component (35,57,69 …”

Section: Introductionmentioning

confidence: 99%

The Structure of Plant Cell Walls

Talmadge¹,

Keegstra²,

Bauer³

et al. 1973

Plant Physiol.

500

166

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This is the first in a series of papers dealing with the structure of cell walls isolated from suspension-cultured sycamore cells (Acer pseudoplatanus) . These studies have been made possible by the availability of purified hydrolytic enzymes and by recent improvements in the techniques of methylation analysis. These techniques have permitted us to identify and quantitate the macromolecular components of sycamore cell walls. These walls are composed of 10% arabinan, 2% 3,6-linked arabinogalactan, 23% cellulose, 9 % oligo-arabinosides (attached to hydroxyproline), 8% 4-linked galactan, 10% hydroxyproline-rich protein, 16 % rhamnogalacturonan, and 21% xyloglucan.The structures of the pectic polymers (the neutral arabinan, the neutral galactan, and the acidic rhamnogalacturonan) were obtained, in part, by methylation analysis of fragments of these polymers which were released from the sycamore walls by the action of a highly purified endopolygalacturonase. The data suggest a branched arabinan and a linear 4-linked galactan occurring as side chains on the rhamnogalacturonan. Small amounts or pieces of a xyloglucan, the wall hemicellulose, appear to be covalently linked to some of the galactan chains. Thus, the galactan appears to serve as a bridge between the xyloglucan and rhamnogalacturonan components of the wall.The rhamnogalacturonan consists of an a-(1 -; 4)-linked galacturonan chain which is interspersed with 2-linked rham. nosyl residues. The rhamnosyl residues are not randomly distributed in the chain but probably occur in units of rhamnosyl-(1 -4 4)-galacturonosyl-(1 -e 2)-rhamnosyl. This sequence appears to alternate with a homogalacturonan sequence containing approximately 8 residues of 4-linked galacturonic acid. About half of the rhamnosyl residues are branched, having a substituent attached to carbon 4. This is likely to be the site of attachment of the 4-linked galactan.The hydroxyprolyl oligo-arabinosides of the hydroxyproline. rich glycoprotein contain 3-linked, 2-linked, and terminal arabinosyl residues. The structure of the hydroxyprolyl oligoarabinosides deduced from our methylation studies agrees with the structure reported for similar oligosaccharides. Cellulose, hemicellulose, pectic polysaccharide, structural protein, and lignin have been identified as the major components of the plant cell wall. These components have been discussed in several recent reviews (4,9,26,35,47,52,63,64,68). Lignin is a characteristic component of secondary walls and is therefore not further discussed.Crystalline cellulose fibers make up an important part of the framework of the cell walls of all higher plants. Electron microscopy and x-ray diffraction have led to a rather detailed description of the structure of this wall component (35,57,69

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Ultrastructure of the Wall in Growing Cells and its Relation to the Direction of the Growth

Cited by 97 publications

References 138 publications

Extensibility and rheology of collenchyma I. Creep relaxation and viscoelasticity of young and senescent cells

Extensibility and rheology of collenchyma I. Creep relaxation and viscoelasticity of young and senescent cells

Light Regulation of β-Tubulin Gene Expression during Internode Development in Soybean (Glycine max [L.] Merr.)

The Structure of Plant Cell Walls

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