Post-Synthetic Reduction of Pectin Methylesterification Causes Morphological Abnormalities and Alterations to Stress Response in Arabidopsis thaliana

Pectin is a critical component of the plant cell wall, supporting wall biomechanics and contributing to cell wall signaling in response to stress. The plant cell carefully regulates pectin methylesterification with endogenous pectin methylesterases (PMEs) and their inhibitors (PMEIs) to promote growth and protect against pathogens. We expressed Aspergillus nidulans pectin methylesterase (AnPME) in Arabidopsis thaliana plants to determine the impacts of methylesterification status on pectin function. Plants expressing AnPME had a roughly 50% reduction in methylester content compared with control plants. AnPME plants displayed a severe dwarf phenotype, including small, bushy rosettes and shorter roots. This phenotype was caused by a reduction in cell elongation. Cell wall composition was altered in AnPME plants, with significantly more arabinose and significantly less galacturonic acid, suggesting that plants actively monitor and compensate for altered pectin content. Cell walls of AnPME plants were more readily degraded by polygalacturonase (PG) alone but were less susceptible to treatment with a mixture of PG and PME. AnPME plants were insensitive to osmotic stress, and their susceptibility to Botrytis cinerea was comparable to wild type plants despite their compromised cell walls. This is likely due to upregulated expression of defense response genes observed in AnPME plants. These results demonstrate the importance of pectin in both normal growth and development, and in response to biotic and abiotic stresses.

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The Multifaceted Role of Pectin Methylesterase Inhibitors (PMEIs)

International Journal of Molecular Sciences ◽

10.3390/ijms19102878 ◽

2018 ◽

Vol 19 (10) ◽

pp. 2878 ◽

Cited By ~ 32

Author(s):

Alexandra Wormit ◽

Björn Usadel

Keyword(s):

Cell Wall ◽

Plant Cell ◽

Cell Walls ◽

Galacturonic Acid ◽

Wall Stress ◽

Pectin Methylesterase ◽

Biomechanical Properties ◽

Plant Cell Walls ◽

Response To Stress ◽

Dynamic Structures

Plant cell walls are complex and dynamic structures that play important roles in growth and development, as well as in response to stresses. Pectin is a major polysaccharide of cell walls rich in galacturonic acid (GalA). Homogalacturonan (HG) is considered the most abundant pectic polymer in plant cell walls and is partially methylesterified at the C6 atom of galacturonic acid. Its degree (and pattern) of methylation (DM) has been shown to affect biomechanical properties of the cell wall by making pectin susceptible for enzymatic de-polymerization and enabling gel formation. Pectin methylesterases (PMEs) catalyze the removal of methyl-groups from the HG backbone and their activity is modulated by a family of proteinaceous inhibitors known as pectin methylesterase inhibitors (PMEIs). As such, the interplay between PME and PMEI can be considered as a determinant of cell adhesion, cell wall porosity and elasticity, as well as a source of signaling molecules released upon cell wall stress. This review aims to highlight recent updates in our understanding of the PMEI gene family, their regulation and structure, interaction with PMEs, as well as their function in response to stress and during development.

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Plant cell wall integrity maintenance and pattern-triggered immunity modulate jointly plant stress responses in Arabidopsis thaliana

10.1101/130013 ◽

2017 ◽

Author(s):

Timo Engelsdorf ◽

Nora Gigli-Bisceglia ◽

Manikandan Veerabagu ◽

Joseph F. McKenna ◽

Frauke Augstein ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Cell Wall ◽

Plant Growth ◽

Plant Cell ◽

Stress Responses ◽

Cell Walls ◽

Plant Cell Wall ◽

Cell Wall Integrity ◽

Maintenance Mechanism ◽

Signaling Components

AbstractPlant cells are surrounded by walls, which must often meet opposing functional requirements during plant growth and defense. The cells meet them by modifying wall structure and composition in a tightly controlled and adaptive manner. The modifications seem to be mediated by a dedicated cell wall integrity (CWI) maintenance mechanism. Currently the mode of action of the mechanism is not understood and it is unclear how its activity is coordinated with established plant defense signaling. We investigated responses to induced cell wall damage (CWD) impairing CWI and the underlying mechanism in Arabidopsis thaliana. Interestingly inhibitor- and enzyme-derived CWD induced similar, turgor-sensitive stress responses. Genetic analysis showed that the receptor-like kinase (RLK) FEI2 and the mechano-sensitive, plasma membrane-localized Ca2+- channel MCA1 function downstream of the THE1 RLK in CWD perception. Phenotypic clustering with 27 genotypes identified a core group of RLKs and ion channels, required for activation of CWD responses. By contrast, the responses were repressed by pattern-triggered immune (PTI) signaling components including PEPR1 and 2, the receptors for the immune signaling peptide AtPep1. Interestingly AtPep1 application repressed CWD-induced phytohormone accumulation in a PEPR1/2-dependent manner. These results suggest that PTI suppresses CWD-induced defense responses through elicitor peptide-mediated signaling during defense response activation. If PTI is impaired, the suppression of CWD-induced responses is alleviated, thus compensating for defective PTI.Significance statementStress resistance and plant growth determine food crop yield and efficiency of bioenergy production from ligno-cellulosic biomass. Plant cell walls are essential elements of the biological processes, therefore functional integrity of the cell walls must be maintained throughout. Here we investigate the plant cell wall integrity maintenance mechanism. We characterize its mode of action, identify essential signaling components and show that the AtPep1 signaling peptide apparently coordinates pattern triggered immunity (PTI) and cell wall integrity maintenance in plants. These results suggest how PTI and cell wall modification coordinately regulate biotic stress responses with plants possibly compensating for PTI impairment through enhanced activation of stress responses regulated by the CWI maintenance mechanism.

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Plant Cell Wall Hydration and Plant Physiology: An Exploration of the Consequences of Direct Effects of Water Deficit on the Plant Cell Wall

Plants ◽

10.3390/plants10071263 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1263

Author(s):

David Stuart Thompson ◽

Azharul Islam

Keyword(s):

Cell Wall ◽

Water Content ◽

Bacterial Cellulose ◽

Plant Cell ◽

Cell Walls ◽

Plant Cell Wall ◽

Plant Cell Walls ◽

Cell Wall Polysaccharides ◽

Degree Of Hydration ◽

Cellulose Composites

The extensibility of synthetic polymers is routinely modulated by the addition of lower molecular weight spacing molecules known as plasticizers, and there is some evidence that water may have similar effects on plant cell walls. Furthermore, it appears that changes in wall hydration could affect wall behavior to a degree that seems likely to have physiological consequences at water potentials that many plants would experience under field conditions. Osmotica large enough to be excluded from plant cell walls and bacterial cellulose composites with other cell wall polysaccharides were used to alter their water content and to demonstrate that the relationship between water potential and degree of hydration of these materials is affected by their composition. Additionally, it was found that expansins facilitate rehydration of bacterial cellulose and cellulose composites and cause swelling of plant cell wall fragments in suspension and that these responses are also affected by polysaccharide composition. Given these observations, it seems probable that plant environmental responses include measures to regulate cell wall water content or mitigate the consequences of changes in wall hydration and that it may be possible to exploit such mechanisms to improve crop resilience.

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Pectin methylesterase, metal ions and plant cell-wall extension. Hydrolysis of pectin by plant cell-wall pectin methylesterase

Biochemical Journal ◽

10.1042/bj2790343 ◽

1991 ◽

Vol 279 (2) ◽

pp. 343-350 ◽

Cited By ~ 81

Author(s):

J Nari ◽

G Noat ◽

J Ricard

Keyword(s):

Cell Wall ◽

Metal Ions ◽

Plant Cell ◽

Plant Cell Wall ◽

Direct Interaction ◽

Enzyme Reaction ◽

Pectin Methylesterase ◽

High Concentrations ◽

Enzyme Molecules ◽

Hydrolysis Of

The hydrolysis of p-nitrophenyl acetate catalysed by pectin methylesterase is competitively inhibited by pectin and does not require metal ions to occur. The results suggest that the activastion by metal ions may be explained by assuming that they interact with the substrate rather than with the enzyme. With pectin used as substrate, metal ions are required in order to allow the hydrolysis to occur in the presence of pectin methylesterase. This is explained by the existence of ‘blocks’ of carboxy groups on pectin that may trap enzyme molecules and thus prevent the enzyme reaction occurring. Metal ions may interact with these negatively charged groups, thus allowing the enzyme to interact with the ester bonds to be cleaved. At high concentrations, however, metal ions inhibit the enzyme reaction. This is again understandable on the basis of the view that some carboxy groups must be adjacent to the ester bond to be cleaved in order to allow the reaction to proceed. Indeed, if these groups are blocked by metal ions, the enzyme reaction cannot occur, and this is the reason for the apparent inhibition of the reaction by high concentrations of metal ions. Methylene Blue, which may be bound to pectin, may replace metal ions in the ‘activation’ and ‘inhibition’ of the enzyme reaction. A kinetic model based on these results has been proposed and fits the kinetic data very well. All the available results favour the view that metal ions do not affect the reaction through a direct interaction with enzyme, but rather with pectin.

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A Label-free, Fast and High-specificity Technique for Plant Cell Wall Imaging and Composition Analysis

10.21203/rs.3.rs-107437/v1 ◽

2020 ◽

Author(s):

Huimin Xu ◽

Yuanyuan Zhao ◽

Yuanzhen Suo ◽

Yayu Guo ◽

Yi Man ◽

...

Keyword(s):

Cell Wall ◽

Chemical Composition ◽

Raman Scattering ◽

Plant Cell ◽

Cell Walls ◽

Plant Cell Wall ◽

Composition Analysis ◽

Plant Cell Walls ◽

Label Free ◽

Wall Imaging

Abstract Background: Cell wall imaging can considerably permit direct visualization of the molecular architecture of cell walls and provide the detailed chemical information on wall polymers, which is imperative to better exploit and use the biomass polymers; however, detailed imaging and quantifying of the native composition and architecture in the cell wall remains challenging.Results: Here, we describe a label-free imaging technology, coherent Raman scattering microscopy (CRS), including coherent anti-Stokes Raman scattering (CARS) microscopy and stimulated Raman scattering (SRS) microscopy, which images the major structures and chemical composition of plant cell walls. The major steps of the procedure are demonstrated, including sample preparation, setting the mapping parameters, analysis of spectral data, and image generation. Applying this rapid approach, which will help researchers understand the highly heterogeneous structures and organization of plant cell walls.Conclusions: This method can potentially be incorporated into label-free microanalyses of plant cell wall chemical composition based on the in situ vibrations of molecules.

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Plasmodesmata-Related Structural and Functional Proteins: The Long Sought-After Secrets of a Cytoplasmic Channel in Plant Cell Walls

International Journal of Molecular Sciences ◽

10.3390/ijms20122946 ◽

2019 ◽

Vol 20 (12) ◽

pp. 2946 ◽

Cited By ~ 7

Author(s):

Xiao Han ◽

Li-Jun Huang ◽

Dan Feng ◽

Wenhan Jiang ◽

Wenzhuo Miu ◽

...

Keyword(s):

Cell Wall ◽

Plant Cell ◽

Cell Walls ◽

Plasma Membranes ◽

Plant Cell Wall ◽

Plant Cells ◽

Protein Composition ◽

Cell Contact ◽

Plant Cell Walls ◽

Cell Organelles

Plant cells are separated by cellulose cell walls that impede direct cell-to-cell contact. In order to facilitate intercellular communication, plant cells develop unique cell-wall-spanning structures termed plasmodesmata (PD). PD are membranous channels that link the cytoplasm, plasma membranes, and endoplasmic reticulum of adjacent cells to provide cytoplasmic and membrane continuity for molecular trafficking. PD play important roles for the development and physiology of all plants. The structure and function of PD in the plant cell walls are highly dynamic and tightly regulated. Despite their importance, plasmodesmata are among the few plant cell organelles that remain poorly understood. The molecular properties of PD seem largely elusive or speculative. In this review, we firstly describe the general PD structure and its protein composition. We then discuss the recent progress in identification and characterization of PD-associated plant cell-wall proteins that regulate PD function, with particular emphasis on callose metabolizing and binding proteins, and protein kinases targeted to and around PD.

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A putative Arabidopsis thaliana glycosyltransferase, At4g01220, which is closely related to three plant cell wall-specific xylosyltransferases, is differentially expressed spatially and temporally

Plant Science ◽

10.1016/j.plantsci.2010.11.002 ◽

2011 ◽

Vol 180 (3) ◽

pp. 470-479 ◽

Cited By ~ 6

Author(s):

Jonatan U. Fangel ◽

Bent L. Petersen ◽

Niels B. Jensen ◽

William G.T. Willats ◽

Antony Bacic ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Cell Wall ◽

Plant Cell ◽

Plant Cell Wall ◽

Differentially Expressed

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Feeding the Walls: How Does Nutrient Availability Regulate Cell Wall Composition?

International Journal of Molecular Sciences ◽

10.3390/ijms19092691 ◽

2018 ◽

Vol 19 (9) ◽

pp. 2691 ◽

Cited By ~ 11

Author(s):

Michael Ogden ◽

Rainer Hoefgen ◽

Ute Roessner ◽

Staffan Persson ◽

Ghazanfar Khan

Keyword(s):

Cell Wall ◽

Plant Cell ◽

Nutrient Availability ◽

Cell Walls ◽

Plant Cell Wall ◽

Nutrient Status ◽

Cell Wall Composition ◽

Nutrient Sensing ◽

Tissue Type ◽

Wall Components

Nutrients are critical for plants to grow and develop, and nutrient depletion severely affects crop yield. In order to optimize nutrient acquisition, plants adapt their growth and root architecture. Changes in growth are determined by modifications in the cell walls surrounding every plant cell. The plant cell wall, which is largely composed of complex polysaccharides, is essential for plants to attain their shape and to protect cells against the environment. Within the cell wall, cellulose strands form microfibrils that act as a framework for other wall components, including hemicelluloses, pectins, proteins, and, in some cases, callose, lignin, and suberin. Cell wall composition varies, depending on cell and tissue type. It is governed by synthesis, deposition and remodeling of wall components, and determines the physical and structural properties of the cell wall. How nutrient status affects cell wall synthesis and organization, and thus plant growth and morphology, remains poorly understood. In this review, we aim to summarize and synthesize research on the adaptation of root cell walls in response to nutrient availability and the potential role of cell walls in nutrient sensing.

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The Spatio-Temporal Distribution of Cell Wall-Associated Glycoproteins During Wood Formation in Populus

Frontiers in Plant Science ◽

10.3389/fpls.2020.611607 ◽

2020 ◽

Vol 11 ◽

Author(s):

Tayebeh Abedi ◽

Romain Castilleux ◽

Pieter Nibbering ◽

Totte Niittylä

Keyword(s):

Gene Expression ◽

Cell Wall ◽

Plant Cell ◽

Cell Walls ◽

Plant Cell Wall ◽

Expression Patterns ◽

Wood Formation ◽

Cell Type Specificity ◽

Spatio Temporal ◽

Ray Cell

Plant cell wall associated hydroxyproline-rich glycoproteins (HRGPs) are involved in several aspects of plant growth and development, including wood formation in trees. HRGPs such as arabinogalactan-proteins (AGPs), extensins (EXTs), and proline rich proteins (PRPs) are important for the development and architecture of plant cell walls. Analysis of publicly available gene expression data revealed that many HRGP encoding genes show tight spatio-temporal expression patterns in the developing wood of Populus that are indicative of specific functions during wood formation. Similar results were obtained for the expression of glycosyl transferases putatively involved in HRGP glycosylation. In situ immunolabelling of transverse wood sections using AGP and EXT antibodies revealed the cell type specificity of different epitopes. In mature wood AGP epitopes were located in xylem ray cell walls, whereas EXT epitopes were specifically observed between neighboring xylem vessels, and on the ray cell side of the vessel walls, likely in association with pits. Molecular mass and glycan analysis of AGPs and EXTs in phloem/cambium, developing xylem, and mature xylem revealed clear differences in glycan structures and size between the tissues. Separation of AGPs by agarose gel electrophoresis and staining with β-D-glucosyl Yariv confirmed the presence of different AGP populations in phloem/cambium and xylem. These results reveal the diverse changes in HRGP-related processes that occur during wood formation at the gene expression and HRGP glycan biosynthesis levels, and relate HRGPs and glycosylation processes to the developmental processes of wood formation.

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