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.

scholarly journals The regulatory and transcriptional landscape associated with carbon utilization in a filamentous fungus

2020 ◽  
Vol 117 (11) ◽  
pp. 6003-6013 ◽  
Author(s):  
Vincent W. Wu ◽  
Nils Thieme ◽  
Lori B. Huberman ◽  
Axel Dietschmann ◽  
David J. Kowbel ◽  
...  
Keyword(s):  
Cell Wall ◽  
Transcription Factors ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Plant Biomass ◽  
Carbon Sources ◽  
Cell Wall Degrading Enzymes ◽  
Degrading Enzymes ◽  
Genes Encoding

Filamentous fungi, such asNeurospora crassa, are very efficient in deconstructing plant biomass by the secretion of an arsenal of plant cell wall-degrading enzymes, by remodeling metabolism to accommodate production of secreted enzymes, and by enabling transport and intracellular utilization of plant biomass components. Although a number of enzymes and transcriptional regulators involved in plant biomass utilization have been identified, how filamentous fungi sense and integrate nutritional information encoded in the plant cell wall into a regulatory hierarchy for optimal utilization of complex carbon sources is not understood. Here, we performed transcriptional profiling ofN. crassaon 40 different carbon sources, including plant biomass, to provide data on how fungi sense simple to complex carbohydrates. From these data, we identified regulatory factors inN. crassaand characterized one (PDR-2) associated with pectin utilization and one with pectin/hemicellulose utilization (ARA-1). Using in vitro DNA affinity purification sequencing (DAP-seq), we identified direct targets of transcription factors involved in regulating genes encoding plant cell wall-degrading enzymes. In particular, our data clarified the role of the transcription factor VIB-1 in the regulation of genes encoding plant cell wall-degrading enzymes and nutrient scavenging and revealed a major role of the carbon catabolite repressor CRE-1 in regulating the expression of major facilitator transporter genes. These data contribute to a more complete understanding of cross talk between transcription factors and their target genes, which are involved in regulating nutrient sensing and plant biomass utilization on a global level.

scholarly journals Arsenal of plant cell wall degrading enzymes reflects host preference among plant pathogenic fungi

2011 ◽  
Vol 4 (1) ◽  
pp. 4 ◽  
Author(s):  
Brian C King ◽  
Katrina D Waxman ◽  
Nicholas V Nenni ◽  
Larry P Walker ◽  
Gary C Bergstrom ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Host Preference ◽  
Plant Cell Wall ◽  
Pathogenic Fungi ◽  
Plant Pathogenic Fungi ◽  
Cell Wall Degrading Enzymes ◽  
Degrading Enzymes

scholarly journals Mannose and mannobiose specific responses of insect associated cellulolytic Streptomyces.

2021 ◽  
Author(s):  
Keisuke Ohashi ◽  
Shogo Hataya ◽  
Akane Nakata ◽  
Kazuki Matsumoto ◽  
Natsumi Kato ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Carbon Sources ◽  
Genomic Analysis ◽  
Transcriptional Regulator ◽  
Sequence Motif ◽  
Cell Wall Degrading Enzymes ◽  
Degrading Enzymes ◽  
Available Carbon

The cellulolytic insect symbiont bacterium, Streptomyces sp. SirexAA-E (SirexAA-E) secretes a suite of Carbohydrate Active enZymes (CAZymes), which are involved in the degradation of various polysaccharides in the plant cell wall, in response to the available carbon sources. Here, we examined a poorly understood response of this bacterium to mannan, one of the major plant cell wall components. SirexAA-E grew well on mannose, carboxymethyl cellulose (CMC), and locust bean gum (LBG) as sole carbon sources in the culture medium. The secreted proteins from each culture supernatant were tested for their polysaccharide-degrading ability, and the composition of secreted CAZymes in each sample was determined by LC-MS/MS. The results indicated that mannose, LBG, and CMC induced the secretion of mannan and cellulose-degrading enzymes. Interestingly, two α-1,2-mannosidases were abundantly secreted during growth on mannose and LBG. By genomic analysis, we found a unique 12 bp palindromic sequence motif at 4 locations in the SirexAA-E genome, two of which were found upstream of the above-mentioned α-1,2-mannosidase genes, along with a newly identified mannose and mannobiose-responsive transcriptional regulator, SsManR. Furthermore, the previously reported cellobiose-responsive repressor, SsCebR, was determined to also use mannobiose as an effector ligand. To test whether mannobiose induces the sets of genes under the control of the two regulators, SirexAA-E was grown on mannobiose, and the secretome composition was analyzed. As hypothesized, the composition of the mannobiose secretome combined sets of CAZymes found in both LBG and CMC secretomes, and so are likely under the regulation of both SsManR and SsCebR. Importance Streptomyces sp. SirexAA-E, a microbial symbiont of biomass harvesting insects, secretes a suite of polysaccharide-degrading enzymes dependent on the available carbon sources. However, the response of this bacterium to mannan has not been documented. In this study, we investigated the response of this bacterium to mannose, mannobiose, and galactomannan (LBG). By combining biochemical, proteomic, and genomic approaches, we discovered a novel mannose and mannobiose responsive transcriptional regulator, SsManR, which selectively regulates three α-1,2-mannosidase-coding genes. We also demonstrated that the previously described cellobiose responsive regulator, SsCebR, could use mannobiose as an effector ligand. Overall, our findings suggest that the Streptomyces sp. SirexAA-E responds to mannose and mannooligosaccharides through two different transcriptional repressors that regulate the secretion of the plant cell wall-degrading enzymes to extract carbon sources in the host environment.

scholarly journals Heterologous Expression of Plant Cell Wall Degrading Enzymes for Effective Production of Cellulosic Biofuels

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Sang-Kyu Jung ◽  
Vinuselvi Parisutham ◽  
Seong Hun Jeong ◽  
Sung Kuk Lee
Keyword(s):  
Cell Wall ◽  
Heterologous Expression ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Plant Biomass ◽  
Consolidated Bioprocessing ◽  
Host Organism ◽  
Cell Wall Degrading Enzymes ◽  
Degrading Enzymes ◽  
The Cost

A major technical challenge in the cost-effective production of cellulosic biofuel is the need to lower the cost of plant cell wall degrading enzymes (PCDE), which is required for the production of sugars from biomass. Several competitive, low-cost technologies have been developed to produce PCDE in different host organisms such asEscherichia coli, Zymomonas mobilis, and plant. Selection of an ideal host organism is very important, because each host organism has its own unique features. Synthetic biology-aided tools enable heterologous expression of PCDE in recombinantE. coliorZ. mobilisand allow successful consolidated bioprocessing (CBP) in these microorganisms.In-plantaexpression provides an opportunity to simplify the process of enzyme production and plant biomass processing and leads to self-deconstruction of plant cell walls. Although the future of currently available technologies is difficult to predict, a complete and viable platform will most likely be available through the integration of the existing approaches with the development of breakthrough technologies.

scholarly journals Synergistic Effect of Different Plant Cell Wall–Degrading Enzymes Is Important for Virulence of Fusarium graminearum

2017 ◽  
Vol 30 (11) ◽  
pp. 886-895 ◽  
Author(s):  
Maria Chiara Paccanaro ◽  
Luca Sella ◽  
Carla Castiglioni ◽  
Francesca Giacomello ◽  
Ana Lilia Martínez-Rocha ◽  
...  
Keyword(s):  
Cell Wall ◽  
Fusarium Graminearum ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Xylanase Activity ◽  
Cellulase Activity ◽  
Wild Type ◽  
Cell Wall Degrading Enzymes ◽  
Xylanase Production ◽  
Significant Difference

Endo-polygalacturonases (PGs) and xylanases have been shown to play an important role during pathogenesis of some fungal pathogens of dicot plants, while their role in monocot pathogens is less defined. Pg1 and xyr1 genes of the wheat pathogen Fusarium graminearum encode the main PG and the major regulator of xylanase production, respectively. Single- and double-disrupted mutants for these genes were obtained to assess their contribution to fungal infection. Compared with wild-type strain, the ∆pg mutant showed a nearly abolished PG activity, slight reduced virulence on soybean seedlings, but no significant difference in disease symptoms on wheat spikes; the ∆xyr mutant was strongly reduced in xylanase activity and moderately reduced in cellulase activity but was as virulent as wild type on both soybean and wheat plants. Consequently, the ΔpgΔxyr double mutant was impaired in xylanase, PG, and cellulase activities but, differently from single mutants, was significantly reduced in virulence on both plants. These findings demonstrate that the concurrent presence of PG, xylanase, and cellulase activities is necessary for full virulence. The observation that the uronides released from wheat cell wall after a F. graminearum PG treatment were largely increased by the fungal xylanases suggests that these enzymes act synergistically in deconstructing the plant cell wall.

scholarly journals The Role of Arabinogalactan Type II Degradation in Plant-Microbe Interactions

2021 ◽  
Vol 12 ◽  
Author(s):  
Maria Guadalupe Villa-Rivera ◽  
Horacio Cano-Camacho ◽  
Everardo López-Romero ◽  
María Guadalupe Zavala-Páramo
Keyword(s):  
Cell Wall ◽  
Plant Defense ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Degradation Products ◽  
Hydrolytic Enzymes ◽  
Pathogenic Fungi ◽  
Plant Interactions ◽  
Root Tips ◽  
Microbe Interactions

Arabinogalactans (AGs) are structural polysaccharides of the plant cell wall. A small proportion of the AGs are associated with hemicellulose and pectin. Furthermore, AGs are associated with proteins forming the so-called arabinogalactan proteins (AGPs), which can be found in the plant cell wall or attached through a glycosylphosphatidylinositol (GPI) anchor to the plasma membrane. AGPs are a family of highly glycosylated proteins grouped with cell wall proteins rich in hydroxyproline. These glycoproteins have important and diverse functions in plants, such as growth, cellular differentiation, signaling, and microbe-plant interactions, and several reports suggest that carbohydrate components are crucial for AGP functions. In beneficial plant-microbe interactions, AGPs attract symbiotic species of fungi or bacteria, promote the development of infectious structures and the colonization of root tips, and furthermore, these interactions can activate plant defense mechanisms. On the other hand, plants secrete and accumulate AGPs at infection sites, creating cross-links with pectin. As part of the plant cell wall degradation machinery, beneficial and pathogenic fungi and bacteria can produce the enzymes necessary for the complete depolymerization of AGs including endo-β-(1,3), β-(1,4) and β-(1,6)-galactanases, β-(1,3/1,6) galactanases, α-L-arabinofuranosidases, β-L-arabinopyranosidases, and β-D-glucuronidases. These hydrolytic enzymes are secreted during plant-pathogen interactions and could have implications for the function of AGPs. It has been proposed that AGPs could prevent infection by pathogenic microorganisms because their degradation products generated by hydrolytic enzymes of pathogens function as damage-associated molecular patterns (DAMPs) eliciting the plant defense response. In this review, we describe the structure and function of AGs and AGPs as components of the plant cell wall. Additionally, we describe the set of enzymes secreted by microorganisms to degrade AGs from AGPs and its possible implication for plant-microbe interactions.

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