scholarly journals Apoplastic CBM1-interacting proteins bind conserved carbohydrate binding module 1 motifs in fungal hydrolases to counter pathogen invasion

2022 ◽  
Author(s):  
Takumi Takeda ◽  
Machiko Takahashi ◽  
Motoki Shimizu ◽  
Yu Sugihara ◽  
Hiromasa Saitoh ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Fungal Pathogens ◽  
Carbohydrate Binding ◽  
Carbohydrate Binding Module ◽  
Cell Wall Degrading Enzymes ◽  
Fungal Enzymes ◽  
General Role ◽  
Pathogen Invasion ◽  
Wide Range

When infecting plants, fungal pathogens secrete cell wall degrading enzymes (CWDEs) that break down cellulose and hemicellulose, the primary components of plant cell walls. Some fungal CWDEs contain a unique domain, named the carbohydrate binding module (CBM), that facilitates their access to polysaccharides. However, little is known about how plants counteract pathogen degradation of their cell walls. Here, we show that the rice cysteine-rich repeat secretion protein OsCBMIP binds to and inhibits xylanase MoCel10A of the blast fungus pathogen Magnaporthe oryzae, interfering with its access to the rice cell wall and degradation of rice xylan. We found binding of OsCBMIP to various CBM1-containing enzymes, suggesting it has a general role in inhibiting the catalytic activities of fungal enzymes. OsCBMIP is localized to the apoplast, and its expression is strongly induced in leaves infected with M. oryzae. Remarkably, knockdown of OsCBMIP reduced rice defense against M. oryzae, demonstrating that inhibition of CBM1-containing fungal enzymes by OsCBMIP is crucial for rice defense. We also identified additional CBMIP-related proteins from Arabidopsis thaliana and Setaria italica, indicating that a wide range of plants counteract pathogens through this mechanism.

scholarly journals Dynamics of Fusarium Mycotoxins and Lytic Enzymes during Pea Plants’ Infection

2021 ◽  
Vol 22 (18) ◽  
pp. 9888
Author(s):  
Lakshmipriya Perincherry ◽  
Monika Urbaniak ◽  
Izabela Pawłowicz ◽  
Karolina Kotowska ◽  
Agnieszka Waśkiewicz ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Wall ◽  
Host Plant ◽  
Plant Pathogens ◽  
Fusarium Species ◽  
Sudden Increase ◽  
Cell Wall Degrading Enzymes ◽  
Lytic Enzymes ◽  
Susceptible Host ◽  
Wide Range

Fusarium species are common plant pathogens that cause several important diseases. They produce a wide range of secondary metabolites, among which mycotoxins and extracellular cell wall-degrading enzymes (CWDEs) contribute to weakening and invading the host plant successfully. Two species of Fusarium isolated from peas were monitored for their expression profile of three cell wall-degrading enzyme coding genes upon culturing with extracts from resistant (Sokolik) and susceptible (Santana) pea cultivars. The extracts from Santana induced a sudden increase in the gene expression, whereas Sokolik elicited a reduced expression. The coherent observation was that the biochemical profile of the host plant plays a major role in regulating the fungal gene expression. In order to uncover the fungal characteristics in planta, both pea cultivars were infected with two strains each of F. proliferatum and F. oxysporum on the 30th day of growth. The enzyme activity assays from both roots and rhizosphere indicated that more enzymes were used for degrading the cell wall of the resistant host compared to the susceptible host. The most commonly produced enzymes were cellulase, β-glucosidase, xylanase, pectinase and lipase, where the pathogen selectively degraded the components of both the primary and secondary cell walls. The levels of beauvericin accumulated in the infected roots of both cultivars were also monitored. There was a difference between the levels of beauvericin accumulated in both the cultivars, where the susceptible cultivar had more beauvericin than the resistant one, showing that the plants susceptible to the pathogen were also susceptible to the toxin accumulation.

scholarly journals Comparative Analysis of Herbaceous and Woody Cell Wall Digestibility by Pathogenic Fungi

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7220
Author(s):  
Yanhua Dou ◽  
Yan Yang ◽  
Nitesh Kumar Mund ◽  
Yanping Wei ◽  
Yisong Liu ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Fungal Pathogens ◽  
Plant Cell Wall ◽  
Apple Tree ◽  
Plant Biomass ◽  
Genomic Analysis ◽  
Pathogenic Fungi ◽  
Cell Wall Degrading Enzymes ◽  
Enzyme Activity Assay

Fungal pathogens have evolved combinations of plant cell-wall-degrading enzymes (PCWDEs) to deconstruct host plant cell walls (PCWs). An understanding of this process is hoped to create a basis for improving plant biomass conversion efficiency into sustainable biofuels and bioproducts. Here, an approach integrating enzyme activity assay, biomass pretreatment, field emission scanning electron microscopy (FESEM), and genomic analysis of PCWDEs were applied to examine digestibility or degradability of selected woody and herbaceous biomass by pathogenic fungi. Preferred hydrolysis of apple tree branch, rapeseed straw, or wheat straw were observed by the apple-tree-specific pathogen Valsa mali, the rapeseed pathogen Sclerotinia sclerotiorum, and the wheat pathogen Rhizoctonia cerealis, respectively. Delignification by peracetic acid (PAA) pretreatment increased PCW digestibility, and the increase was generally more profound with non-host than host PCW substrates. Hemicellulase pretreatment slightly reduced or had no effect on hemicellulose content in the PCW substrates tested; however, the pretreatment significantly changed hydrolytic preferences of the selected pathogens, indicating a role of hemicellulose branching in PCW digestibility. Cellulose organization appears to also impact digestibility of host PCWs, as reflected by differences in cellulose microfibril organization in woody and herbaceous PCWs and variation in cellulose-binding domain organization in cellulases of pathogenic fungi, which is known to influence enzyme access to cellulose. Taken together, this study highlighted the importance of chemical structure of both hemicelluloses and cellulose in host PCW digestibility by fungal pathogens.

Surface charge and morphogenesis of regular arrays of macromolecules on bacterial cell walls

1978 ◽  
Vol 36 (2) ◽  
pp. 346-347 ◽  
Author(s):  
U. B. Sleytr ◽  
G. P. Friers
Keyword(s):  
Cell Wall ◽  
Surface Charge ◽  
Bacterial Cell ◽  
Cell Walls ◽  
Surface Layers ◽  
Regular Surface ◽  
Wide Range ◽  
Freeze Etching ◽  
Regular Arrays ◽  
Peptidoglycan Layer

Regular arrays of macromolecules can be demonstrated on the surface of a wide range of bacteria by negative staining and freeze-etching techniques. The isolated subunits of the regular surface layers (S-layers) examined in this study have shown to consist of protein or glycoprotein and to possess the ability to assemble spontaneously under certain conditions to form regular arrays with the same dimensions as those seen on intact bacteria. In appropriate conditions the isolated subunits reattach to the cell wall from which they have been removed. Analysis of the orientation of the reconstituted S-layers have shown that the pattern of the regular arrays seem to be determined only by the directional bonds between the subunits and not by any order in the underlying (peptidoglycan) layer.

Mannan specific family 35 carbohydrate-binding module (CtCBM35) of Clostridium thermocellum: structure analysis and ligand binding

Biologia ◽  
2014 ◽  
Vol 69 (10) ◽  
Author(s):  
Arabinda Ghosh ◽  
Anil Verma ◽  
Ana Luis ◽  
Joana Bras ◽  
Carlos Fontes ◽  
...  
Keyword(s):  
Cell Wall ◽  
Ligand Binding ◽  
Binding Affinity ◽  
Plant Cell ◽  
Clostridium Thermocellum ◽  
Plant Cell Wall ◽  
Konjac Glucomannan ◽  
Carbohydrate Binding ◽  
Carbohydrate Binding Module ◽  
Affinity Electrophoresis

AbstractThe three-dimensional model of the CtCBM35 (Cthe 2811), i.e. the family 35 carbohydrate binding module (CBM) from the Clostridium thermocellum family 26 glycoside hydrolase (GH) β-mannanase, generated by Modeller9v8 displayed predominance of β-sheets arranged as β-sandwich fold. Multiple sequence alignment of CtCBM35 with other CBM35s showed a conserved signature sequence motif Trp-Gly-Tyr, which is probably a specific determinant for mannan binding. Cloned CtCBM35 from Clostridium thermocellum ATCC 27405 was a homogenous, soluble 16 kDa protein. Ligand binding analysis of CtCBM35 by affinity electrophoresis displayed higher binding affinity against konjac glucomannan (K a = 2.5 × 105 M−1) than carob galactomannan (K a = 1.4 × 105 M−1). The presence of Ca2+ ions imparted slightly higher binding affinity of CtCBM35 against carob galactomannan and konjac glucomannan than without Ca2+ ion additive. However, CtCBM35 exhibited a low ligand-binding affinity K a = 2.5 × 10−5 M−1 with insoluble ivory nut mannan. Ligand binding study by fluorescence spectroscopy showed K a against konjac glucomannan and carob galactomannan, 2.4 × 105 M−1 and 1.44 × 105 M−1, and ΔG of binding −27.0 and −25.0 kJ/mol, respectively, substantiating the findings of affinity electrophoresis. Ca2+ ions escalated the thermostability of CtCBM35 and its melting temperature was shifted to 70°C from initial 55°C. Therefore thermostable CtCBM35 targets more β-(1,4)-manno-configured ligands from plant cell wall hemicellulosic reservoir. Thus a non-catalytic CtCBM35 of multienzyme cellulosomal enzymes may gain interest in the biofuel and food industry in the form of released sugars by targeting plant cell wall polysaccharides.

scholarly journals In situ detection of cell wall polysaccharides in sitka spruce (Picea sitchensis (Bong.) Carrière) wood tissue

BioResources ◽  
2007 ◽  
Vol 2 (2) ◽  
pp. 284-295
Author(s):  
Clemens Altaner ◽  
J. Paul Knox ◽  
Michael C. Jarvis
Keyword(s):  
Cell Wall ◽  
Monoclonal Antibodies ◽  
Cell Walls ◽  
Sitka Spruce ◽  
Picea Sitchensis ◽  
Crystalline Cellulose ◽  
Carbohydrate Binding ◽  
Cell Wall Polysaccharides ◽  
Amorphous Cellulose ◽  
Carbohydrate Binding Modules

Wood cell wall polysaccharides can be probed with monoclonal antibodies and carbohydrate-binding modules (CBMs). Binding of monoclonal antibodies to β-1-4-xylan, β-1-4-mannan, β-1-3-glucan, and α-1-5-arabinan structures were observed in native Sitka spruce (Picea sitchensis (Bong.) Carrière) wood cell walls. Furthermore CBMs of different families, differing in their affinities for crystalline cellulose (3a) and amorphous cellulose (17 and 28), were shown to bind to the native wood cell walls with varying intensities. Resin channel forming cells exhibited an increased β-1-4-xylan and a decreased β-1-4-mannan content. Focusing on severe compression wood (CW) tracheids, β-1-3-glucan was found towards the cell lumen. In contrast, α-1-5-arabinan structures were present in the intercellular spaces between the round tracheids in severe CW, highlighting the importance of this polymer in cell adhesion.

scholarly journals Xylan Decomposition in Plant Cell Walls as an Inducer of Surfactin Synthesis by Bacillus subtilis

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 239
Author(s):  
Ida Szmigiel ◽  
Dorota Kwiatkowska ◽  
Marcin Łukaszewicz ◽  
Anna Krasowska
Keyword(s):  
Cell Wall ◽  
Bacillus Subtilis ◽  
Cell Walls ◽  
Cell Wall Composition ◽  
Subtilis Strain ◽  
Efficient Production ◽  
Plant Cell Walls ◽  
Rapeseed Cake ◽  
Wide Range ◽  
Agro Residues

Hemicellulose is the second most abundant plant heterogenous biopolymer. Among products obtained from a wide range of agro-residues, biosurfactants, e.g., surfactin (SU), are gaining increasing interest. Our previous studies have shown that a Bacillus subtilis strain can successfully produce a significant amount of SU using a rapeseed cake. This work aimed to investigate plant hemicellulose components as substrates promoting SU’s efficient production by B. subtilis 87Y. Analyses of SU production, enzymatic activity and cell wall composition of hulled oat caryopses suggest that the main ingredients of plant hemicellulose, in particular xylan and its derivatives, may be responsible for an increased biosurfactant yield.

scholarly journals Mannan detecting C-type lectin receptor probes recognise immune epitopes with diverse chemical, spatial and phylogenetic heterogeneity in fungal cell walls

2019 ◽  
Author(s):  
Ingrida Vendele ◽  
Janet A. Willment ◽  
Lisete M. Silva ◽  
Angelina S. Palma ◽  
Wengang Chai ◽  
...  
Keyword(s):  
Cell Wall ◽  
Immune Responses ◽  
Cell Walls ◽  
Fungal Pathogens ◽  
Fungal Species ◽  
Fungal Cell Wall ◽  
Immune Recognition ◽  
Cell Surfaces ◽  
Fungal Cell ◽  
Wall Components

AbstractDuring the course of fungal infection, pathogen recognition by the innate immune system is critical to initiate efficient protective immune responses. The primary event that triggers immune responses is the binding of Pattern Recognition Receptors (PRRs), which are expressed at the surface of host immune cells, to Pathogen-Associated Molecular Patterns (PAMPs) located predominantly in the fungal cell wall. Most fungi have mannosylated PAMPs in their cell walls and these are recognized by a range of C-type lectin receptors (CTLs). However, the precise spatial distribution of the ligands that induce immune responses within the cell walls of fungi are not well defined. We used recombinant IgG Fc-CTLs fusions of three murine mannan detecting CTLs, including dectin-2, the mannose receptor (MR) carbohydrate recognition domains (CRDs) 4-7 (CRD4-7), and human DC-SIGN (hDC-SIGN) and the β-1,3 glucan-binding lectin dectin-1 to map PRR ligands in the fungal cell wall. We show that epitopes of mannan-specific CTL receptors can be clustered or diffuse, superficial or buried in the inner cell wall. We demonstrate that PRR ligands do not correlate well with phylogenetic relationships between fungi, and that Fc-lectin binding discriminated between mannosides expressed on different cell morphologies of the same fungus. We also demonstrate CTL epitope differentiation during different phases of the growth cycle ofCandida albicansand that MR and DC-SIGN labelled outer chainN-mannans whilst dectin-2 labelled coreN-mannans displayed deeper in the cell wall. These immune receptor maps of fungal walls therefore reveal remarkable spatial, temporal and chemical diversity, indicating that the triggering of immune recognition events originates from multiple physical origins at the fungal cell surface.Author SummaryInvasive fungal infections remain an important health problem in immunocompromised patients. Immune recognition of fungal pathogens involves binding of specific cell wall components by pathogen recognition receptors (PRRs) and subsequent activation of immune defences. Some cell wall components are conserved among fungal species while other components are species-specific and phenotypically diverse. The fungal cell wall is dynamic and capable of changing its composition and organization when adapting to different growth niches and environmental stresses. Differences in the composition of the cell wall lead to differential immune recognition by the host. Understanding how changes in the cell wall composition affect recognition by PRRs is likely to be of major diagnostic and clinical relevance. Here we address this fundamental question using four soluble immune receptor-probes which recognize mannans and β-glucan in the cell wall. We use this novel methodology to demonstrate that mannan epitopes are differentially distributed in the inner and outer layers of fungal cell wall in a clustered or diffuse manner. Immune reactivity of fungal cell surfaces did not correlate with relatedness of different fungal species, and mannan-detecting receptor-probes discriminated between cell surface mannans generated by the same fungus growing under different conditions. These studies demonstrate that mannan-epitopes on fungal cell surfaces are differentially distributed within and between the cell walls of fungal pathogens.

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