Degradation of plant pathogenic fungi by Trichoderma harzianum

1982 ◽  
Vol 28 (7) ◽  
pp. 719-725 ◽  
Author(s):  
Y. Elad ◽  
I. Chet ◽  
Y. Henis
Keyword(s):  
Trichoderma Harzianum ◽  
Cell Walls ◽  
Sole Carbon Source ◽  
Hydrolytic Enzymes ◽  
Sclerotium Rolfsii ◽  
Pathogenic Fungi ◽  
Plant Pathogenic Fungi ◽  
Soilborne Pathogens ◽  
Glucanase Activity ◽  
Trichoderma Isolates

Trichoderma harzianum excreted β-1, 3-glucanase and chitinase into the medium when grown on laminarin and chitin, respectively, or on cell walls of the pathogen Sclerotium rolfsii, as sole carbon source. Trichoderma harzianum also showed high activity of both enzymes when grown on homogenized S. rolfsii sclerotia. Glucanase activity increased by 67% when the fungus was grown on a mixture of laminarin and glucose (3:1, v/v). Similarly, high lytic activity was detected in wheat bran culture of the fungus and in soil inoculated with this culture. Protease and lipase activity were detected in the medium when the antagonist attacked mycelium of S. rolfsii.Isolates of T. harzianum were found to differ in the levels of hydrolytic enzymes produced when mycelium of S. rolfsii, Rhizoctonia solani, and Pythium aphanidermatum in soil was attacked. This phenomenon was correlated with the ability of each of the Trichoderma isolates to control the respective soilborne pathogens.

scholarly journals Beta-1,3-Glucanase Activities in Wheat and Relative Species

2016 ◽  
Vol 15 (2) ◽  
pp. 122-132
Author(s):  
Jana Moravčíková ◽  
Denisa Margetínyová ◽  
Zdenka Gálová ◽  
Iwona Žur ◽  
Zuzana Gregorová ◽  
...  
Keyword(s):  
Ploidy Level ◽  
Cell Walls ◽  
Higher Plants ◽  
Hydrolytic Enzymes ◽  
Callose Synthase ◽  
Glucanase Activity ◽  
Callose Deposition ◽  
Qualitative And Quantitative ◽  
Physiological Processes ◽  
Main Component

Abstract The (1,3)-β-D-glucan also referred to as callose is a main component of cell walls of higher plants. Many physiological processes are associated with the changes in callose deposition. Callose is synthesised by the callose synthase complex while its degradation is regulated by the hydrolytic enzymes β-1,3-glucanases. The latter one specifically degrade (1,3)-β-D-glucans. This work is aimed to study β-1,3-glucanase activities in the leaves of plants at two leaf stage in two diploids (Agilops tauschii, Triticum monococcum L.), four tetraploids (Ae. cylindrica, Ae. triuncialis, T. araraticum, T. dicoccum) and two hexaploids (T. aestivum L, T. spelta L.). The leaves were subjected to qualitative and quantitative β-1,3-glucanase activity assays. Our results showed that the total β-1,3-glucanase activities were variable and genotype dependent. No significant correlation between β-1,3-glucanase activities and ploidy level was observed. The gel activity assays revealed a single fraction of ~52 kDa Glu1 that was found in all genotypes. The Glu1 fraction corresponds to a single or two acidic Glu isoforms in dependence on genotype. However, none of the acidic Glu fractions can be assigned as a specific for di-, tetra- or hexaploid genotypes. A single basic GluF isoform was detected and found as present in all genotypes.

The Biocontrol Mechanism of Trichoderma asperellum Resistance Plant Pathogenic Fungi

2013 ◽  
Vol 726-731 ◽  
pp. 4525-4528
Author(s):  
Ping Yang ◽  
Qian Xu
Keyword(s):  
Cell Wall ◽  
Plant Pathogens ◽  
Control Plant ◽  
Hydrolytic Enzymes ◽  
Pathogenic Fungi ◽  
Dry Weight ◽  
Plant Pathogenic Fungi ◽  
Cell Wall Degrading Enzymes ◽  
Antifungal Metabolites ◽  
Degrading Enzymes

T. asperellum is an important biocontrol fungus owing to their ability to antagonize plant pathogenic fungi. The biocontrol effects of T. asperellum were played by secreting many kinds of hydrolytic enzymes and antibiotics. T. asperellum producing more cell wall degrading enzymes when meeting plant pathogens. Moreover, the growth of the plant pathogens was inhibited by T. asperellum secondary metabolites. The yield of antibiotic 6-PP was 1.32 mg 6-PP/g mycelial dry weight. T. asperellum control plant pathogens through secreting cell wall degrading enzymes and producing antifungal metabolites.

Comparative degradation of oomycete, ascomycete, and basidiomycete cell walls by mycoparasitic and biocontrol fungi

2002 ◽  
Vol 48 (1) ◽  
pp. 60-70 ◽  
Author(s):  
G D Inglis ◽  
L M Kawchuk
Keyword(s):  
Multivariate Analysis ◽  
Trichoderma Harzianum ◽  
Cell Walls ◽  
Trichoderma Viride ◽  
Hydrolytic Enzymes ◽  
Pythium Ultimum ◽  
Coniothyrium Minitans ◽  
Talaromyces Flavus ◽  
Highly Correlated ◽  
Biocontrol Fungi

Fourteen fungi (primarily representing mycoparasitic and biocontrol fungi) were tested for their ability to grow on and degrade cell walls (CWs) of an oomycete (Pythium ultimum), ascomycete (Fusarium equisetii), and basidiomycete (Rhizoctonia solani), and their hydrolytic enzymes were characterized. Protein was detected in the cultural medium of eleven of the test isolates, and these fungi significantly degraded CWs over the 14-day duration of the experiment. In general, a greater level of CW degradation occurred for F. equisetii and P. ultimum than for R. solani. Fungi that degraded F. equisetii CWs were Coniothyrium minitans, Gliocladium roseum, Myrothecium verrucaria, Talaromyces flavus, and Trichoderma harzianum. Taxa degrading P. ultimum CWs included Chaetomium globosum, Coniothyrium minitans, M. verrucaria, Seimatosporium sp., Talaromyces flavus, Trichoderma hamatum, Trichoderma harzianum, and Trichoderma viride. Production of extracellular protein was highly correlated with CW degradation. Considerable variation in the molecular weights of CW-degrading enzymes were detected among the test fungi and the CW substrates in zymogram electrophoresis. Multivariate analysis between CW degradation and hydrolysis of barley β-glucan (β1,3- and β1,4-glucanases), laminarin (β1,3- and β1,6-glucanases), carboxymethyl cellulose (endo-β1,4-glucanases), colloidal chitin (chitinases), and chitosan (chitosanases) was conducted. For F. equisetii CWs, the regression model accounted for 80% of the variability, and carboxymethyl cellulases acting together with β-glucanases contributed an R2of 0.52, whereas chitinases and β-glucanases alone contributed an R2of 0.11 and 0.12, respectively. Only 61% of the variability observed in the degradation of P. ultimum CWs was explained by the enzyme classes tested, and primarily β-glucanases (R2of 0.53) and carboxymethyl cellulases (R2of 0.08) alone contributed to CW break down. Too few of the test fungi degraded R. solani CWs to perform multivariate analysis effectively. This study identified several fungi that degraded ascomyceteous and oomyceteous, and to a lesser extent, basidiomycetous CWs. An array of enzymes were implicated in CW degradation.Key words: enzymes, phytopathogens, hydrolysis, cell wall, CW.

Release of peroxidase from soybean hypocotyl cell walls by Sclerotium rolfsii culture filtrates

1974 ◽  
Vol 52 (1) ◽  
pp. 265-271 ◽  
Author(s):  
Neal M. Barnett
Keyword(s):  
Culture Filtrate ◽  
Peroxidase Activity ◽  
Cell Walls ◽  
Hydrolytic Enzymes ◽  
Sclerotium Rolfsii ◽  
Release Reaction ◽  
Culture Filtrates ◽  
Ph Range

Up to 24% of the peroxidase of purified cell walls of soybean hypocotyls was released by incubation of cell walls with hydrolytic enzymes secreted by the fungus Sclerotium rolfsii. This estimate is based on comparison of peroxidase activity recovered in the medium with peroxidase activity in unincubated cell walls, estimated by a new assay. The peroxidase-release reaction occurs at 0 °C at half the rate at 30 °C. The peroxidase-release reaction occurs almost equally fast in the pH range of 3.5 to 8.0. The release of peroxidase from cell walls cannot be attributed solely to arabanase, polygalacturonase, or cellulase in the culture filtrate, although on Sephadex G-75 chromatography these activities overlap the peroxidase-releasing activity. Culture filtrate released less than 5% of the hydroxyproline protein of the cell walls.

Trichoderma protoplast fusion: a tool for improving biocontrol agents

1990 ◽  
Vol 36 (1) ◽  
pp. 6-9 ◽  
Author(s):  
S. Pe'er ◽  
I. Chet
Keyword(s):  
Cell Wall ◽  
Key Words ◽  
Protoplast Fusion ◽  
Trichoderma Harzianum ◽  
Pathogenic Fungus ◽  
Sclerotium Rolfsii ◽  
Pathogenic Fungi ◽  
Damping Off ◽  
Dual Cultures ◽  
Young Thalli

Protoplasts from two auxotrophic mutants of Trichoderma harzianum Rifai (ATCC 32173), obtained from young thalli following cell wall digestion by NovoZym 234, were fused in 33% PEG suspended in 10 mM Tris-HCl and 10 mM CaCl2, pH 7.5. The frequency of fusion between lysine- and arginine-requiring auxotrophs resulting in prototrophic strains was about 5%. These prototrophic strains were classified into parental and nonparental types. Colonies developed from single conidia of the nonparental phenotype exhibited prototrophic parental or recombinant phenotypes. The ability of both prototrophic and parental strains to overgrow the soil-borne pathogenic fungi Rhizoctonia solani, Sclerotium rolfsii, and Pythium aphanidermatum in dual cultures was used to evaluate their antagonistic capability. The antagonistic abilities of the prototrophic strains were found to vary with each pathogenic fungus. The prototrophic strain A2 overgrew all the pathogenic fungi more rapidly than the parental strains. Strain A2 effectively controlled Rhizoctonia damping-off of cotton seedlings, in the greenhouse, when compared with the parental strains. Protoplast fusion appears to be a useful tool for combining desirable traits from parental strains to produce improved biocontrol strains. Key words: Trichoderma harzianum, biocontrol, protoplast fusion.

scholarly journals The toxicity of jack bean [Canavalia ensiformis (L.) DC.] canatoxin to plant pathogenic fungi

1999 ◽  
Vol 59 (1) ◽  
pp. 59-62 ◽  
Author(s):  
A. E. A. OLIVEIRA ◽  
V. M. GOMES ◽  
M. P. SALES ◽  
K. V. S. FERNANDES ◽  
C. R. CARLINI ◽  
...  
Keyword(s):  
Amino Acid ◽  
Sclerotium Rolfsii ◽  
Pathogenic Fungi ◽  
Macrophomina Phaseolina ◽  
Phytopathogenic Fungi ◽  
The Other ◽  
Plant Pathogenic Fungi ◽  
Jack Bean ◽  
Toxic Protein ◽  
Canavalia Ensiformis

Protein fractions obtained from seeds of the jack bean (Canavalia ensiformis) as well as the amino acid canavanine, present in these seeds, were tested for their capacity to inhibit the growth of the phytopathogenic fungi Macrophomina phaseolina, Colletotrichum gloesporioides, Sclerotium rolfsii and Fusarium oxysporum. We found that most of the proteins examined and also canavanine did not have any effect on the growth of these fungi. On the other hand the toxic protein canatoxin was found to be effective, at a concentration of 2%, in the inhibition of the growth of M. phaseolina, C. gloesporioides and S. rolfsii.

scholarly journals Role of the Trichoderma harzianumEndochitinase Gene, ech42, in Mycoparasitism

1999 ◽  
Vol 65 (3) ◽  
pp. 929-935 ◽  
Author(s):  
Carolina Carsolio ◽  
Nicole Benhamou ◽  
Shoshan Haran ◽  
Carlos Cortés ◽  
Ana Gutiérrez ◽  
...  
Keyword(s):  
Rhizoctonia Solani ◽  
Trichoderma Harzianum ◽  
Cell Walls ◽  
Sclerotium Rolfsii ◽  
Biocontrol Agents ◽  
Wild Type ◽  
Greenhouse Experiments ◽  
Multiple Copies

ABSTRACT The role of the Trichoderma harzianum endochitinase (Ech42) in mycoparasitism was studied by genetically manipulating the gene that encodes Ech42, ech42. We constructed several transgenic T. harzianum strains carrying multiple copies of ech42 and the corresponding gene disruptants. The level of extracellular endochitinase activity when T. harzianum was grown under inducing conditions increased up to 42-fold in multicopy strains as compared with the wild type, whereas gene disruptants exhibited practically no activity. The densities of chitin labeling of Rhizoctonia solani cell walls, after interactions with gene disruptants were not statistically significantly different than the density of chitin labeling after interactions with the wild type. Finally, no major differences in the efficacies of the strains generated as biocontrol agents against R. solani or Sclerotium rolfsii were observed in greenhouse experiments.

scholarly journals Developmentally regulated conversion of surface-exposed chitin to chitosan in cell walls of plant pathogenic fungi

2002 ◽  
Vol 156 (1) ◽  
pp. 103-112 ◽  
Author(s):  
Nour Eddine El Gueddari ◽  
Una Rauchhaus ◽  
Bruno M. Moerschbacher ◽  
Holger B. Deising
Keyword(s):  
Cell Walls ◽  
Pathogenic Fungi ◽  
Plant Pathogenic Fungi ◽  
Developmentally Regulated

scholarly journals Diversity and biological activity of culturable endophytic bacteria associated with marigold (Calendula officinalis L.)

2021 ◽  
Vol 7 (3) ◽  
pp. 336-353
Author(s):  
Vyacheslav Shurigin ◽  
◽  
Burak Alaylar ◽  
Kakhramon Davranov ◽  
Stephan Wirth ◽  
...  
Keyword(s):  
Plant Growth ◽  
Endophytic Bacteria ◽  
Plant Pathogens ◽  
Hydrolytic Enzymes ◽  
Pathogenic Fungi ◽  
Rrna Gene ◽  
Plant Pathogenic Fungi ◽  
Bacterial Isolates ◽  
Calendula Officinalis ◽  
Fungal Plant Pathogens

<abstract> <p>Endophytes colonizing plant tissue play an essential role in plant growth, development, stress tolerance and plant protection from soil-borne diseases. In this study, we report the diversity of cultivable endophytic bacteria associated with marigold (<italic>Calendula officinalis</italic> L.) by using 16S rRNA gene analysis and their plant beneficial properties. A total of 42 bacterial isolates were obtained from plant tissues of marigold. They belonged to the genera <italic>Pantoea, Enterobacter, Pseudomonas, Achromobacter, Xanthomonas, Rathayibacter, Agrobacterium, Pseudoxanthomonas</italic>, and <italic>Beijerinckia</italic>. Among the bacterial strains, <italic>P. kilonensis</italic> FRT12, and <italic>P. rhizosphaerae</italic> FST5 showed moderate or vigorous inhibition against three tested plant pathogenic fungi, <italic>F. culmorum, F. solani</italic> and <italic>R. solani</italic>. They also demonstrated the capability to produce hydrolytic enzymes and indole-3-acetic acid (IAA). Five out of 16 isolates significantly stimulated shoot and root growth of marigold in a pot experiment. The present study reveals that more than half of the bacterial isolates associated with marigold (<italic>C. officinalis</italic> L.) provided antifungal activity against one or more plant pathogenic fungi. Our findings suggest that medicinal plants with antimicrobial activity could be a source for selecting microbes with antagonistic activity against fungal plant pathogens or with plant growth stimulating potential. These isolates might be considered as promising candidates for the improvement of plant health.</p> </abstract>

scholarly journals Analysis of the β-1,3-Glucanolytic System of the Biocontrol Agent Trichoderma harzianum

1998 ◽  
Vol 64 (4) ◽  
pp. 1442-1446 ◽  
Author(s):  
Soledad Vázquez-Garcidueñas ◽  
Carlos A. Leal-Morales ◽  
Alfredo Herrera-Estrella
Keyword(s):  
Trichoderma Harzianum ◽  
Cell Walls ◽  
Biocontrol Agent ◽  
Glucanase Activity ◽  
Fungal Cell ◽  
Molecular Weights ◽  
Cell Wall Lysis ◽  
Host Cell Wall ◽  
35 Kda Protein ◽  
Fungal Cell Walls

ABSTRACT The biocontrol agent Trichoderma harzianum IMI206040 secretes β-1,3-glucanases in the presence of different glucose polymers and fungal cell walls. The level of β-1,3-glucanase activity secreted was found to be proportional to the amount of glucan present in the inducer. The fungus produces at least seven extracellular β-1,3-glucanases upon induction with laminarin, a soluble β-1,3-glucan. The molecular weights of five of these enzymes fall in the range from 60,000 to 80,000, and their pIs are 5.0 to 6.8. In addition, a 35-kDa protein with a pI of 5.5 and a 39-kDa protein are also secreted. Glucose appears to inhibit the formation of all of the inducible β-1,3-glucanases detected. A 77-kDa glucanase was partially purified from the laminarin culture filtrate. This enzyme is glycosylated and belongs to the exo-β-1,3-glucanase group. The properties of this complex group of enzymes suggest that the enzymes might play different roles in host cell wall lysis during mycoparasitism.

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