scholarly journals Interaction of Ammonium, Glucose, and Chitin Regulates the Expression of Cell Wall-Degrading Enzymes inTrichoderma atroviride Strain P1

2001 ◽  
Vol 67 (12) ◽  
pp. 5643-5647 ◽  
Author(s):  
Bruno Giuliano Garisto Donzelli ◽  
Gary E. Harman
Keyword(s):  
Cell Wall ◽  
Nitrogen Starvation ◽  
Nitrogen Nutrition ◽  
Fungal Cell Wall ◽  
Cell Wall Degrading Enzymes ◽  
Fungal Cell ◽  
Carbon And Nitrogen ◽  
Degrading Enzymes ◽  
Early Expression ◽  
Low Levels

ABSTRACT Chitinolytic and glucanolytic fungal cell wall-degrading enzymes have been suggested to be primary determinants of biocontrol byTrichoderma spp. We examined the effects of ammonium, glucose, chitin, and chito-oligomers on transcription of specific genes and secretion of fungal cell wall-degrading enzymes. The genesech42, nag1, andgluc78 were examined, as were the enzymes they encode (endochitinase CHIT42, N-acetylhexosaminidase CHIT73, and glucan exo-1,3-β-glucanase GLUC78, respectively).gluc78 could be induced by nitrogen starvation alone, while both ech42 and nag1 required nitrogen starvation and the presence of chitin for induction. Starvation for both ammonium and glucose resulted in very early expression and secretion of all cell wall-degrading enzymes examined. In the presence of low levels of ammonium (10 mM), both chito-oligomers and chitin triggered CHIT42 and CHIT40 (chitobiosidase) production. CHIT73 secretion occurred in the presence ofN-acetylglucosamine and chito-oligomers, while chitin was less effective. The presence of different chito-oligomers resulted in secretion of specific N-acetylhexosaminidases, of which CHIT73 is one. Our results indicate that the expression and secretion of cell wall-degrading enzymes is nitrogen repressed, that effects of carbon and nitrogen nutrition are interactive, and that especially for chitinolytic enzymes, the inductive effect of chitin is altered by the level of ammonium or glucose in the medium.

Sugars and pH: A clue to the regulation of fungal cell wall-degrading enzymes in plants

2004 ◽  
Vol 65 (6) ◽  
pp. 271-275 ◽  
Author(s):  
K. Akimitsu ◽  
A. Isshiki ◽  
K. Ohtani ◽  
H. Yamamoto ◽  
D. Eshel ◽  
...  
Keyword(s):  
Cell Wall ◽  
Fungal Cell Wall ◽  
Cell Wall Degrading Enzymes ◽  
Fungal Cell ◽  
Degrading Enzymes

scholarly journals Possible Role of Colonization and Cell Wall-Degrading Enzymes in the Differential Ability of Three Ulocladium atrum Strains to Control Botrytis cinerea on Necrotic Strawberry Leaves

2001 ◽  
Vol 91 (11) ◽  
pp. 1030-1036 ◽  
Author(s):  
Philippe Berto ◽  
M. Haïssam Jijakli ◽  
Philippe Lepoivre
Keyword(s):  
Cell Wall ◽  
Botrytis Cinerea ◽  
Pectate Lyase ◽  
Fungal Cell Wall ◽  
Cell Wall Degrading Enzymes ◽  
Glucanase Activity ◽  
Fungal Cell ◽  
Degrading Enzymes ◽  
Complementary Role ◽  
Immunological Assays

Ulocladium atrum (strain 385) consistently reduced Botrytis cinerea sporulation on necrotic fragments of strawberry leaves. On these tissues, two strains of U. atrum (isolates 18558 and 18559) showed lower antagonistic activities than the reference strain 385. Colonization of strawberry leaflets by the three U. atrum strains appeared similar in the absence of B. cinerea, whether quantified by chitin or immunological assays. The second method (based on anti-U. atrum antibodies) revealed that strawberry leaflet colonization by U. atrum 385 was better than by the other U. atrum strains in the presence of B. cinerea. An immunoassay using anti-B. cinerea antibodies revealed that the colonization of B. cinerea in tissues was lower in the presence of U. atrum 385 than with the two other U. atrum strains. The enzymatic activities produced by U. atrum 385 during the colonization phases of necrotic tissues were compared to B. cinerea and U. atrum strains 18558 and 18559. U. atrum 385 had the highest lipase, pectate lyase, and cellobiase activities while B. cinerea had the highest endo-β-1,4-glucanase activity. The study of lytic activities hydrolyzing the fungal cell wall revealed higher β-1,3-glucanase activity with U. atrum 385, which was stimulated by B. cinerea on necrotic strawberry leaflets. These results suggest that plant and fungal cell wall-degrading enzymes produced by U. atrum 385 may play a complementary role in the competitive colonization of dead strawberry leaves against B. cinerea.

Regulation of three genes encoding cell-wall-degrading enzymes of Trichoderma aggressivum during interaction with Agaricus bisporus

2013 ◽  
Vol 59 (6) ◽  
pp. 417-424 ◽  
Author(s):  
Kamal S. Abubaker ◽  
Calvin Sjaarda ◽  
Alan J. Castle
Keyword(s):  
Cell Wall ◽  
Agaricus Bisporus ◽  
Mixed Cultures ◽  
Cell Wall Degrading Enzymes ◽  
Carbon And Nitrogen ◽  
Nitrogen Levels ◽  
Degrading Enzymes ◽  
Genes Encoding ◽  
Green Mould ◽  
Catabolite Regulation

Members of the genus Trichoderma are very effective competitors of a variety of fungi. Cell-wall-degrading enzymes, including proteinases, glucanases, and chitinases, are commonly secreted as part of the competitive process. Trichoderma aggressivum is the causative agent of green mould disease of the button mushroom, Agaricus bisporus. The structures of 3 T. aggressivum genes, prb1 encoding a proteinase, ech42 encoding an endochitinase, and a β-glucanase gene, were determined. Promoter elements in the prb1 and ech42 genes suggested that transcription is regulated by carbon and nitrogen levels and by stress. Both genes had mycoparasitism-related elements indicating potential roles for the protein products in competition. The promoter of the β-glucanase gene contained CreA and AreA binding sites indicative of catabolite regulation but contained no mycoparasitism elements. Transcription of the 3 genes was measured in mixed cultures of T. aggressivum and A. bisporus. Two A. bisporus strains, U1, which is sensitive to green mould disease, and SB65, which shows some resistance, were used in co-cultivation tests to assess possible roles of the genes in disease production and severity. prb1 and ech42 were coordinately upregulated after 5 days, whereas β-glucanase transcription was upregulated from day 0 with both Agaricus strains. Upregulation was much less pronounced in mixed cultures of T. aggressivum with the resistant strain, SB65, than with the sensitive strain, U1. These observations suggested that the proteins encoded by these genes have roles in both nutrition and in severity of green mould disease.

scholarly journals The origin of fungi-culture in termites was associated with a shift to a mycolytic gut bacteria community

2018 ◽  
Author(s):  
Haofu Hu ◽  
Rafael Rodrigues da Costa ◽  
Bo Pilgaard ◽  
Morten Schiøtt ◽  
Lene Lange ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plant Cell Wall ◽  
Proteolytic Enzymes ◽  
Gut Bacteria ◽  
Cell Wall Degrading Enzymes ◽  
Fungal Cell ◽  
Degrading Enzymes ◽  
Termite Gut ◽  
Decaying Wood ◽  
And Function

AbstractTermites forage on a range of substrates, and it has been suggested that diet shapes the composition and function of termite gut bacterial communities. Through comparative analyses of gut metagenomes in nine termite species with distinct diets, we characterise bacterial community compositions and identify biomass-degrading enzymes and the bacterial taxa that encode them. We find that fungus-growing termite guts are enriched in fungal cell wall-degrading and proteolytic enzymes, while wood-feeding termite gut communities are enriched for plant cell wall-degrading enzymes. Interestingly, wood-feeding termite gut bacteria code for abundant chitinolytic enzymes, suggesting that fungal biomass within the decaying wood likely contributes to gut bacteria or termite host nutrition. Across diets, the dominant biomass-degrading enzymes are predominantly coded for by the most abundant bacterial taxa, suggesting tight links between diet and gut community composition, with the most marked shift being the communities coding for the mycolytic capacity of the fungus-growing termite gut.

scholarly journals Analysis and application of a suite of recombinant endo-β(1,3)-d-glucanases for studying fungal cell walls

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Vanessa S. D. Carvalho ◽  
Laura Gómez-Delgado ◽  
M. Ángeles Curto ◽  
M. Belén Moreno ◽  
Pilar Pérez ◽  
...  
Keyword(s):  
Cell Wall ◽  
Environmental Changes ◽  
Antifungal Drugs ◽  
Fungal Cell Wall ◽  
Chemical Degradation ◽  
Cell Integrity ◽  
Cell Wall Degrading Enzymes ◽  
Cell Wall Polysaccharides ◽  
Fungal Cell ◽  
Commercial Applications

Abstract Background The fungal cell wall is an essential and robust external structure that protects the cell from the environment. It is mainly composed of polysaccharides with different functions, some of which are necessary for cell integrity. Thus, the process of fractionation and analysis of cell wall polysaccharides is useful for studying the function and relevance of each polysaccharide, as well as for developing a variety of practical and commercial applications. This method can be used to study the mechanisms that regulate cell morphogenesis and integrity, giving rise to information that could be applied in the design of new antifungal drugs. Nonetheless, for this method to be reliable, the availability of trustworthy commercial recombinant cell wall degrading enzymes with non-contaminating activities is vital. Results Here we examined the efficiency and reproducibility of 12 recombinant endo-β(1,3)-d-glucanases for specifically degrading the cell wall β(1,3)-d-glucan by using a fast and reliable protocol of fractionation and analysis of the fission yeast cell wall. This protocol combines enzymatic and chemical degradation to fractionate the cell wall into the four main polymers: galactomannoproteins, α-glucan, β(1,3)-d-glucan and β(1,6)-d-glucan. We found that the GH16 endo-β(1,3)-d-glucanase PfLam16A from Pyrococcus furiosus was able to completely and reproducibly degrade β(1,3)-d-glucan without causing the release of other polymers. The cell wall degradation caused by PfLam16A was similar to that of Quantazyme, a recombinant endo-β(1,3)-d-glucanase no longer commercially available. Moreover, other recombinant β(1,3)-d-glucanases caused either incomplete or excessive degradation, suggesting deficient access to the substrate or release of other polysaccharides. Conclusions The discovery of a reliable and efficient recombinant endo-β(1,3)-d-glucanase, capable of replacing the previously mentioned enzyme, will be useful for carrying out studies requiring the digestion of the fungal cell wall β(1,3)-d-glucan. This new commercial endo-β(1,3)-d-glucanase will allow the study of the cell wall composition under different conditions, along the cell cycle, in response to environmental changes or in cell wall mutants. Furthermore, this enzyme will also be greatly valuable for other practical and commercial applications such as genome research, chromosomes extraction, cell transformation, protoplast formation, cell fusion, cell disruption, industrial processes and studies of new antifungals that specifically target cell wall synthesis.

scholarly journals Pseudomonas Lipodepsipeptides and Fungal Cell Wall-Degrading Enzymes Act Synergistically in Biological Control

2002 ◽  
Vol 15 (4) ◽  
pp. 323-333 ◽  
Author(s):  
Vincenzo Fogliano ◽  
Alessandro Ballio ◽  
Monica Gallo ◽  
Sheridan Woo ◽  
Felice Scala ◽  
...  
Keyword(s):  
Cell Wall ◽  
Pseudomonas Syringae ◽  
Enzyme Inhibitor ◽  
Fungal Species ◽  
Cell Wall Degrading Enzymes ◽  
Fungal Cell ◽  
Knock Out ◽  
Degrading Enzymes ◽  
Combined Action

Pseudomonas syringae pv. syringae strain B359 secreted two main lipodepsipeptides (LDPs), syringomycin E (SRE) and syringopeptin 25A (SP25A), together with at least four types of cell wall—degrading enzymes (CWDEs). In antifungal bioassays, the purified toxins SRE and SP25A interacted synergistically with chitinolytic and glucanolytic enzymes purified from the same bacterial strain or from the biocontrol fungus Trichoderma atroviride strain P1. The synergism between LDPs and CWDEs occurred against all seven different fungal species tested and P. syringae itself, with a level dependent on the enzyme used to permeabilize the microbial cell wall. The antifungal activity of SP25A was much more increased by the CWDE action than was that of the smaller SRE, suggesting a stronger antifungal role for SP25A. In vivo biocontrol assays were performed by using P. syringae alone or in combination with T. atroviride, including a Trichoderma endochitinase knock-out mutant in place of the wild type and a chitinase-specific enzyme inhibitor. These experiments clearly indicate that the synergistic interaction LDPs—CWDEs is involved in the antagonistic mechanism of P. syringae, and they support the concept that a more effective disease control is given by the combined action of the two agents.

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