Composition Of Cell Wall Polymers Research Articles

SEASONAL CHEMICAL STRUCTURE VARIABILITY IN BETULA TORTUOSA LEDEB. TREE RINGS IN ALPINE FOREST-TUNDRA OF KUZNETSK ALA TAU MOUNTAINS

Woody vegetation growth conditions have marked effects on hemicellulose, cellulose and lignin formation. In this study, we analyzed the climatic responses of these major cell wall polymers in Betula tortuosa. We studied 35 annual rings (1980–2015) of Betula Tortuosa Ledeb. trees growing in the alpine forest-tundra of Kuznetsk Ala Tau using and pyrolysis gas chromatography mass spectrometry (Py-GC/MS). Our analysis of the correlation of the resulting spectra and Py-GC/MS values with mean air temperature and precipitation showed that the polymeric composition of Betula Tortuosa Ledeb. was mainly determined by June-August climate. The major factor limiting the development of the “unique” cell wall polymer composition of Betula Tortuosa Ledeb. found in alpine forest-tundra of Kuznetsk Ala Tau was a deficit of heat. At the end of the growing season, precipitation had largely a negative impact on polymer formation in Betula Tortuosa Ledeb. cell walls. We believe that Py-GC/MS is an effective approach to quantifying the consequences of current climate trends for Siberian forest ecosystems.

Seasonal biochemical changes in Betula tortuosa Ledeb. annual rings in Alpine forest-tundra of Kuznetsk Ala Tau Mountains

Woody vegetation growth conditions have marked effects on hemicellulose, cellulose and lignin formation. In this study, the climatic responses of these major cell wall polymers in Betula tortuosa Ledeb. were analyzed. 35 annual rings (1980–2015) of Betula tortuosa Ledeb. trees growing in the alpine forest-tundra of Kuznetsk Ala Tau were studied using Fourier-transform infrared (FTIR) spectroscopy and pyrolysis–gas chromatography–mass spectrometry (Py–GC/MS). Analysis of the correlation of the resulting spectra and Py–GC/MS values with mean air temperature and precipitation showed that the polymeric composition of Betula tortuosa Ledeb. was mainly determined by June–August climate. The major factor limiting the development of the “unique” cell wall polymer composition of Betula tortuosa Ledeb. found in alpine forest-tundra of Kuznetsk Ala Tau was a deficit of heat. At the end of the growing season, precipitation had a largely negative impact on polymer formation in Betula tortuosa Ledeb. cell walls. The authors believe that combining FTIR spectroscopy and Py–GC/MS is an effective approach to quantifying the consequences of current climate trends for Siberian forest ecosystems.

The placenta of Physcomitrium patens: transfer cell wall polymers compared across the three bryophyte groups.

Following similar studies of cell wall constituents in the placenta of Phaeoceros and Marchantia, we conducted immunogold labeling TEM studies of Physcomitrium patens to determine the composition of cell wall polymers in transfer cells on both sides of the placenta. 16 monoclonal antibodies were used to localize cell wall epitopes in the basal walls and wall ingrowths in this moss. In general, placental transfer cell walls of P. patens contain fewer pectins and far fewer AGPs than those of the hornwort and liverwort. P. patens also lacks the differential labeling that is pronounced between generations in the other bryophytes. In contrast, transfer cell walls on either side of the placenta of P. patens are relatively similar in composition with slight variation in HG pectins. Compositional similarities between wall ingrowths and primary cell walls in P. patens suggest that wall ingrowths may simply be extensions of the primary cell wall. Considerable variability in occurrence, abundance, and types of polymers among the three bryophytes and between the two generations suggests that similarity in function and morphology of cell walls does not require a common cell wall composition. We propose that the specific developmental and life history traits of these plants may provide even more important clues in understanding the basis for these differences. This study significantly builds on our knowledge of cell wall composition in bryophytes in general and transfer cells across plants.

Cell Wall Polymer Composition and Spatial Distribution in Ripe Banana and Mango Fruit: Implications for Cell Adhesion and Texture Perception.

Banana (Musa acuminata) and mango (Mangifera indica) are two of the most popular fruits eaten worldwide. They both soften during ripening but their textural attributes are markedly different. This study aimed to elucidate the molecular mechanism underpinning textural differences between banana and mango. We used a novel combination of methods at different scales to analyse the surface properties of fruit cells and the potential contribution of cells and cell wall components to oral processing and texture perception. The results indicated that cell separation occurred easily in both organs under mild mechanical stress. Banana cells showed distinctively elongated shapes with distinct distribution of pectin and hemicellulose epitopes at the cell surface. In contrast, mango had relatively spherical cells that ruptured during cell separation. Atomic force microscopy detected soft surfaces indicative of middle lamella remnants on banana cells, while mango cells had cleaner, smoother surfaces, suggesting absence of middle lamellae and more advanced cell wall disassembly. Comparison of solubilized polymers by cell wall glycome analysis showed abundance of mannan and feruylated xylan in separation exudate from banana but not mango, but comparable levels of pectin and arabinogalactan proteins. Bulk rheology experiments showed that both fruits had similar apparent viscosity and hence might be extrapolated to have similar “oral thickness” perception. On the other hand, oral tribology experiments showed significant differences in their frictional behavior at orally relevant speeds. The instrumental lubrication behavior can be interpreted as “smooth” mouthfeel for mango as compared to “astringent” or “dry” for banana in the later stages of oral processing. The results suggest that cell wall surface properties contribute to lubricating behavior associated with textural perception in the oral phase.

Pyruvylated cell wall glycopolymers of Promicromonospora citrea VKM A≿-665T and Promicromonospora sp. VKM A≿-1028

The cell walls of two strains of the genus Promicromonospora (phylum Actinobacteria) were found to include non-phosphorylated anionic glycopolymers with pyruvic acid acetals of R-configuration. The cell wall of the type strain P. citrea 665T contains two glycopolymers of the sort, including the Kdn-teichulosonic acid with the repeating unit →6)-α-d-Gl≿p/→6)-α-d-Gl≿p3SO3−-(1 → 4)-α-[7,9Pyr]-Kdn-(2→, and the galactan with the repeating unit →3)-α-[4,6Pyr]-d-Galp-2OAc-(1 → . The cell wall of Promicromonospora sp.VKM Ac-1028 contains the teichuronic acid with the repeating unit →6)-α-d-Gl≿p-(1 → 4)-β-[2,3Pyr]-d-GlcpA-(1 → . The detected glycopolymer structures are reported for the first time. Presented results expand the notion on the diversity of the organic world and on the role of the structures and composition of cell wall polymers in bacterial taxonomy. The glycopolymer structures were established by using a combination of chemical methods, NMR- and IR-spectroscopy, and ESI MS.

High-throughput microarray mapping of cell wall polymers in roots and tubers during the viscosity-reducing process.

Viscosity reduction has a great impact on the efficiency of ethanol production when using roots and tubers as feedstock. Plant cell wall-degrading enzymes have been successfully applied to overcome the challenges posed by high viscosity. However, the changes in cell wall polymers during the viscosity-reducing process are poorly characterized. Comprehensive microarray polymer profiling, which is a high-throughput microarray, was used for the first time to map changes in the cell wall polymers of sweet potato (Ipomoea batatas), cassava (Manihot esculenta), and Canna edulis Ker. over the entire viscosity-reducing process. The results indicated that the composition of cell wall polymers among these three roots and tubers was markedly different. The gel-like matrix and glycoprotein network in the C. edulis Ker. cell wall caused difficulty in viscosity reduction. The obvious viscosity reduction of the sweet potato and the cassava was attributed to the degradation of homogalacturonan and the released 1,4-β-d-galactan and 1,5-α-l-arabinan.

Cell wall traits as potential resources to improve resistance of durum wheat against Fusarium graminearum.

BackgroundFusarium graminearum, one of the causal agents of Fusarium Head Blight (FHB, scab), leads to severe losses in grain yield and quality due to the production of mycotoxins which are harmful to human and livestock. Different traits for FHB resistance in wheat were identified for common wheat (Triticum aestivum L.) while the sources of FHB resistance in durum wheat (Triticum turgidum ssp. Durum), one of the cereals most susceptible to F. graminearum infection, have not been found. New lines of evidence indicate that content and composition of cell wall polymers affect the susceptibility of the wall to degrading enzymes produced by pathogens during infection and can play a role in the outcome of host-pathogen interactions. The objective of our research is to identify potential cell wall biochemical traits linked to Fusariosis resistance to be transferred from a resistant common wheat to a susceptible durum wheat line.ResultsA detailed analysis of cell wall composition in spikes isolated from a highly resistant common wheat accession “02-5B-318”, a breeding line derived from the FHB-resistant Chinese cv. Sumai-3 and a high susceptible durum wheat cv. Saragolla was performed. Significant differences in lignin monolignols composition, arabinoxylan (AX) substitutions and pectin methylesterification were found between resistant and susceptible plants. We isolated and characterized a pectin methylesterase gene WheatPME1, which we found being down regulated in the FHB-resistant line and induced by fungal infection in the susceptible wheat.ConclusionsOur results indicate cell wall traits differing between the FHB sensitive and resistant wheat genotypes, possibly related to FHB-resistance, and identify the line 02-5B-318R as a potential resource of such traits. Evidence suggests that WheatPME1 is involved in wheat response to F. graminearum.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-014-0369-1) contains supplementary material, which is available to authorized users.

Effect of cell wall integrity stress and RlmA transcription factor on asexual development and autolysis in Aspergillus nidulans

The cell wall integrity (CWI) signaling pathway is responsible for cell wall remodeling and reinforcement upon cell wall stress, which is proposed to be universal in fungal cultures. In Aspergillus nidulans, both the deletion of rlmA encoding the RlmA transcription factor in CWI signaling and low concentrations of the cell wall polymer intercalating agent Congo Red caused significant physiological changes. The gene deletion mutant ΔrlmA strain showed decreased CWI and oxidative stress resistances, which indicated the connection between the CWI pathway and the oxidative stress response system. The Congo Red stress resulted in alterations in the cell wall polymer composition in submerged cultures due to the induction of the biosynthesis of the alkali soluble fraction as well as the hydrolysis of cell wall biopolymers. Both RlmA and RlmA-independent factors induced by Congo Red stress regulated the expression of glucanase (ANID_00245, engA) and chitinase (chiB, chiA) genes, which promoted the autolysis of the cultures and also modulated the pellet sizes. CWI stress and rlmA deletion affected the expression of brlA encoding the early conidiophore development regulator transcription factor BrlA and, as a consequence, the formation of conidiophores was significantly changed in submerged cultures. Interestingly, the number of conidiospores increased in surface cultures of the ΔrlmA strain. The in silico analysis of genes putatively regulated by RlmA and the CWI transcription factors AnSwi4/AnSwi6 in the SBF complex revealed only a few jointly regulated genes, including ugmA and srrA coding for UgmA UDP-galactopyranose mutase and SrrA stress response regulator, respectively.

PhEXPA1, a Petunia hybrida expansin, is involved in cell wall metabolism and in plant architecture specification

Expansins are wall-loosening proteins that induce wall stress relaxation and irreversible wall extension in a pH-dependent manner. Despite a substantial body of work has been performed on the characterization of many expansins genes in different plant species, the knowledge about their precise biological roles during plant development remains scarce. To yield insights into the expansion process in Petunia hybrida, PhEXPA1, an expansin gene preferentially expressed in petal limb, has been characterized. The constitutive overexpression of PhEXPA1 significantly increased expansin activity, cells size and organ dimensions. Moreover, 35S::PhEXPA1 transgenic plants exhibited an altered cell wall polymer composition and a precocious timing of axillary meristem development compared with wild-type plants. These findings supported a previous hypothesis that expansins are not merely structural proteins involved in plant cell wall metabolism but they also take part in many plant development processes. Here, to support this expansins dual role, we discuss about differential cell wall-related genes expressed in PhEXPA1 expression mutants and gradients of altered petunia branching pattern.

Dissecting the Role of CHITINASE-LIKE1 in Nitrate-Dependent Changes in Root Architecture

The root phenotype of an Arabidopsis (Arabidopsis thaliana) mutant of CHITINASE-LIKE1 (CTL1), called arm (for anion-related root morphology), was previously shown to be conditional on growth on high nitrate, chloride, or sucrose. Mutants grown under restrictive conditions displayed inhibition of primary root growth, radial swelling, proliferation of lateral roots, and increased root hair density. We found here that the spatial pattern of CTL1 expression was mainly in the root and root tips during seedling development and that the protein localized to the cell wall. Fourier-transform infrared microspectroscopy of mutant root tissues indicated differences in spectra assigned to linkages in cellulose and pectin. Indeed, root cell wall polymer composition analysis revealed that the arm mutant contained less crystalline cellulose and reduced methylesterification of pectins. We also explored the implication of growth regulators on the phenotype of the mutant response to the nitrate supply. Exogenous abscisic acid application inhibited more drastically primary root growth in the arm mutant but failed to repress lateral branching compared with the wild type. Cytokinin levels were higher in the arm root, but there were no changes in mitotic activity, suggesting that cytokinin is not directly involved in the mutant phenotype. Ethylene production was higher in arm but inversely proportional to the nitrate concentration in the medium. Interestingly, eto2 and eto3 ethylene overproduction mutants mimicked some of the conditional root characteristics of the arm mutant on high nitrate. Our data suggest that ethylene may be involved in the arm mutant phenotype, albeit indirectly, rather than functioning as a primary signal.

Phosphate-containing cell wall polymers of bacilli

Anionic phosphate-containing cell wall polymers of bacilli are represented by teichoic acids and poly(glycosyl 1-phosphates). Different locations of phosphodiester bonds in the main chain of teichoic acids as well as the nature and combination of the constituent structural elements underlie their structural diversity. Currently, the structures of teichoic acids of bacilli can be classified into three types, viz. poly(polyol phosphates) with glycerol or ribitol as the polyol; poly(glycosylpolyol phosphates), mainly glycerol-containing polymers; and poly(acylglycosylglycerol phosphate), in which the components are covalently linked through glycosidic, phosphodiester, and amide bonds. In addition to teichoic acids, poly(glycosyl 1-phosphates) with mono- and disaccharide residues in the repeating units have been detected in cell walls of several Bacillus subtilis and Bacillus pumilus strains. The known structures of teichoic acids and poly(glycosyl 1-phosphates) of B. subtilis, B. atrophaeus, B. licheniformis, B. pumilus, B. stearothermophilus, B. coagulans, B. cereus as well as oligomers that link the polymers to peptidoglycan are surveyed. The reported data on the structures of phosphate-containing polymers of different strains of B. subtilis suggest heterogeneity of the species and may be of interest for the taxonomy of bacilli to allow differentiation of closely related organisms according to the "structures and composition of cell wall polymers" criterion.

Overexpression of PhEXPA1 increases cell size, modifies cell wall polymer composition and affects the timing of axillary meristem development in Petunia hybrida

• Expansins are cell wall proteins required for cell enlargement and cell wall loosening during many developmental processes. The involvement of the Petunia hybrida expansin A1 (PhEXPA1) gene in cell expansion, the control of organ size and cell wall polysaccharide composition was investigated by overexpressing PhEXPA1 in petunia plants. • PhEXPA1 promoter activity was evaluated using a promoter-GUS assay and the protein's subcellular localization was established by expressing a PhEXPA1-GFP fusion protein. PhEXPA1 was overexpressed in transgenic plants using the cauliflower mosaic virus (CaMV) 35S promoter. Fourier transform infrared (FTIR) and chemical analysis were used for the quantitative analysis of cell wall polymers. • The GUS and GFP assays demonstrated that PhEXPA1 is present in the cell walls of expanding tissues. The constitutive overexpression of PhEXPA1 significantly affected expansin activity and organ size, leading to changes in the architecture of petunia plants by initiating premature axillary meristem outgrowth. Moreover, a significant change in cell wall polymer composition in the petal limbs of transgenic plants was observed. • These results support a role for expansins in the determination of organ shape, in lateral branching, and in the variation of cell wall polymer composition, probably reflecting a complex role in cell wall metabolism.

Actuation systems in plants as prototypes for bioinspired devices

Plants have evolved a multitude of mechanisms to actuate organ movement. The osmotic influx and efflux of water in living cells can cause a rapid movement of organs in a predetermined direction. Even dead tissue can be actuated by a swelling or drying of the plant cell walls. The deformation of the organ is controlled at different levels of tissue hierarchy by geometrical constraints at the micrometre level (e.g. cell shape and size) and cell wall polymer composition at the nanoscale (e.g. cellulose fibril orientation). This paper reviews different mechanisms of organ movement in plants and highlights recent research in the field. Particular attention is paid to systems that are activated without any metabolism. The design principles of such systems may be particularly useful for a biomimetic translation into active technical composites and moving devices.

SKG1, a suppressor gene of synthetic lethality of kex2Δgas1Δ mutations, encodes a novel membrane protein that affects cell wall composition

The fungal GAS1-related genes encode GPI-anchored beta-1,3-glucanosyltransferase, and their loss causes a defect in the assembly of the cell wall. The KEX2 gene encodes a processing protease in the late Golgi compartment and its loss also results in defects in the cell wall. Simultaneous mutations of these genes are lethal in Saccharomyces cerevisiae. To understand the basis of this synthetic lethality, we screened for multicopy suppressors and identified 13 SKG (suppressor of kex2 gas1 synthetic lethality) genes. SKG1 encodes a transmembrane protein that localizes on the inner surface of the plasma membrane at the bud and in the daughter cell. The multicopy SKG1 increases the sensitivity of cells to zymolyase, and the skg1Delta null mutation increases resistance to it. This zymolyase susceptibility corresponds to an increase of alkali-soluble beta-1,3-glucan and a decrease of chitin in the cell wall. Thus SKG1 encodes a novel protein that affects the cell wall polymer composition in the growing region of the cell.