Distribution of pectins in cell walls of maize coleoptiles and evidence against their involvement in auxin-induced extension growth

Schindler, Thomas M.; Bergfeld, R.; Cutsem, Pierre Van; Sengbusch, Dominik Von; Schöpfer, Peter

doi:10.1007/bf01280373

Cited by 22 publications

(13 citation statements)

References 35 publications

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“…The physiological role of such ubiquitous isoforms is unknown. However, un-methylesterified pectin epitopes within the middle lamella surrounding intercellular spaces have been observed by immunocytochemistry in all higher plant cell types so far studied (Knox et al, 1990;Knox, 1992;Liners and Van Cutsem, 1992;Schindler et al, 1995). These data support the hypothesis that housekeeping PME isoforms may be involved in the formation, the maintenance, or the function of the intercellular spaces throughout the plant.…”

Section: Discussionsupporting

confidence: 75%

Radial Distribution Pattern of Pectin Methylesterases across the Cambial Region of Hybrid Aspen at Activity and Dormancy

et al. 2000

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Biochemical microanalysis combined with tangential cryosectioning was used to visualize the distribution of pectin methylesterases (PMEs) across the cambial region in active and dormant hybrid aspen (Populus tremula L. × Populus tremuloides Michx). These novel techniques allowed us to relate activity and isoforms of PMEs to specific tissues and developmental stages of the stem to get more information on the physiological function of PMEs in cambial growth. Isoelectrofocusing analysis revealed numerous isoforms that were differentially distributed according to the tissue-type and to the cambial stage. A neutral isoform was found to be distributed ubiquitously across the stem of both active and dormant trees, which suggests that it is a housekeeping isoform involved in the maintenance of the cell wall integrity throughout the stem. In addition, two distinct isoforms having different isoelectric points were found to be related to the differentiation of cambial derivatives. A basic isoform appears to be a physiological marker of the dormant stage involved in the cessation of meristematic radial growth, whereas an acidic isoform is functionally related to the immediate expansion of the cambial daughter cells that occurs bilaterally on each side of the cambium at the active stage.

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Section: Discussionsupporting

confidence: 75%

Radial Distribution Pattern of Pectin Methylesterases across the Cambial Region of Hybrid Aspen at Activity and Dormancy

et al. 2000

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“…The localization of pectic polysaccharides in different plant tissues has been well documented , Schindler et al 1995. However, none of these studies has considered both calcium and esterified/unesterified pectins within the same wall.…”

Section: Discussionmentioning

confidence: 98%

“…In addition, an increase in Ca2+-pectins binding has been shown to correlate with the increase of unesterified pectins during cessation of elongation (Jarvis 1984, Goldberg et al 1996. Conversely, Schindler et al (1995), in the epidermal wall of maize coleoptile, observed no change in the distribution of unesterified, Ca 2+ bound and esterified pectins after induction of extension growth by IAA. However, the authors do not exclude that the rupture of a limited number of bonds in the pectic polymers by pectinases affects the ability of the wall to expand.…”

Section: Introductionmentioning

confidence: 91%

Micro-heterogeneity of pectins and calcium distribution in the epidermal and cortical parenchyma cell walls of flax hypocotyl

1997

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Summary. Pectic polysaccharides are major components of the plant cell wall matrix and are known to perform many important functions for the plant. In the course of our studies on the putative role of pectic polysaccharides in the control of cell elongation, we have examined the distribution of polygalacturonans in the epidermal and cortical parenchyma cell walls of flax seedling hypocotyls. Pectic components have been detected with (1) the nickel (Ni 2+) staining method to visualize polygalacturonates, (2) monoclonal antibodies specific to low (JIM5) and highly methylesterified (JIM7) pectins and (3) a combination of subtractive treatment and PATAg (periodic acid-thiocarbohydrazide-silver proteinate) staining. In parallel, calcium (Ca 2+) distribution has been imaged using SIMS microscopy (secondary ion mass spectrometry) on cryo-prepared samples and TEM (transmission electron microscopy) after precipitation of calcium with potassium pyroantimonate. Our results show that, at the tissular level, polygalacturonans are mainly located in the epidermal cell walls, as revealed by the Ni 2+ staining and immunofluorescence microscopy with JIM5 and JIM7 antibodies. In parallel, Ca 2 § distribution points to a higher content of this cation in the epidermal walls compared to cortical parenchyma walls. At the ultrastructural level, immunogold labeling with JIM5 and JIM7 antibodies shows a differential distribution of pectic polysaccharides within cell walls of both tissues. The acidic polygalacturonans (recognized by JIM5) held through calcium bridges are mainly found in the outer part of the external wall of epidermal cells. In contrast, the labeling of methylesterified pectins with JIM7 is slightly higher in the inner part than in the outer part of the wall. In the cortical parenchyma cells, acidic pectins are restricted to the cell junctions and the wall areas in contact with the air-spaces, whereas methylesterified pectins are evenly distributed all over the wall. In addition, the pyroantimonate precipitation method reveals a clear difference in the Ca 2+ distribution in the epidermal wall, suggesting that this cation is more tightly bound to acidic pectins in the outer part than in the inner part of that wall. Our findings show that the distribution of pectic polysaccharides and the nature of their linkages differ not only between tissues, but also within a single wall of a given cell in flax hypocotyls. The differential distribution of pectins and Ca 2+ in the external epidermal wall suggests a specific control of the demethylation of pectins and a central role for Ca 2+ in this regulation.

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“…This is in agreement with other models of the distribution of pectin epitopes, one of which is presented in Figure 2.10. In these models, unesterified pectins are restricted to the corner junctions and esterified pectins are present in the middle lamella far away from the corner junction and in the primary walls 61,66 . In the growing regions of hypocotyl mung bean seedlings, a high content of methylesterified pectins are observed, whereas non-growing regions are characterised by unesterified pectins 63 .…”

Section: Pectic Polysaccharidesmentioning

confidence: 99%

“…Thus the distribution of the calcium cross-linked epitope at the intercellular space is particularly important for resisting the separation stresses that are concentrated at this location. 66 ).…”

Section: Pectic Polysaccharidesmentioning

confidence: 99%

Bio-tribology of plant cell walls: measuring the interactive forces between cell wall components

Dolan¹

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Plants have naturally evolved complex cell wall structures to give mechanical and friction properties that facilitate plant growth and development. A biomimetic approach is employed to gain insight into how plants are able to lubricate moving surfaces at multiple length scales. The outcomes of this study advance the fundamental scientific understanding of plant cell wall biology.New insights provided here may have significant implications for optimising the value of plant material as a food source, biofuel precursor, and as a model for functional biomaterial design, particularly for medical applications. A review of the plant cell wall structure, mechanics, and extension processes is used to identify the forces and tribological contacts that are relevant for plant growth. Plant cell walls are essentially hydrogel composites of cellulose fibres within a matrix of biopolymers (e.g. hemicelluloses, pectin) and water. Plant tissue is comprised of a cluster of plant cells where adjacent cell walls are mediated by a pectin rich middle lamella layer. Plant growth is initiated by expansins which are proteins that disrupt cellulose fibre contact points, leading to the extension of the cell wall matrix. As cells expand within the tissue structure, a sliding contact forms between adjacent walls that are extending at different rates. The two critical length scales that are considered here to influence plant growth are the contact between cellulose nano-fibres in the cell wall matrix, and the sliding interface between adjacent cell walls.A large component of this thesis is the development of techniques to mimic the two tribological contacts; that is, fibre-fibre and cell-cell interactions. The sliding interface between two surfaces is achieved using a rotational rheometer, which also allows in situ material characterisation of the surfaces with pre-compression, relaxation, and oscillatory shear mechanical testing steps. The interactive forces between nano-fibres are measured directly using an Atomic Force Microscope (AFM) tip to laterally pull fibres out of a network. Bacterial cellulose networks are used as a model system that is compatible with the developed techniques. Bacterial cellulose is a good model because of the structural similarity to plant cellulose, and its ability to grow as a self-assembled random fibre network with the shape and dimensions controlled by the vessel within which it is grown. The lubricating role of individual cell wall components at the two tribological contacts is examined; including arabinoxylan (AX), xyloglucan (XG), pectin, and expansins. This is achieved ii by growing composite bacterial cellulose networks with AX and XG, and by adding pectin or expansin solutions to the liquid medium surrounding the pre-formed cellulose networks during testing.The unique aspect of this mechanical study is that the experimental results are analysed using computation modelling. Appropriate models are used to simulate the behaviour of fibrous assemblies at multiple length scales, and under condition...

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Distribution of pectins in cell walls of maize coleoptiles and evidence against their involvement in auxin-induced extension growth

Cited by 22 publications

References 35 publications

Radial Distribution Pattern of Pectin Methylesterases across the Cambial Region of Hybrid Aspen at Activity and Dormancy

Radial Distribution Pattern of Pectin Methylesterases across the Cambial Region of Hybrid Aspen at Activity and Dormancy

Micro-heterogeneity of pectins and calcium distribution in the epidermal and cortical parenchyma cell walls of flax hypocotyl

Bio-tribology of plant cell walls: measuring the interactive forces between cell wall components

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