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.

The Antibiosis of Trichoderma asperellum Resistance Plant Pathogenic Fungi

2014 ◽  
Vol 1073-1076 ◽  
pp. 1067-1070
Author(s):  
Ping Yang
Keyword(s):  
Plant Pathogens ◽  
Polyketide Synthase ◽  
Control Plant ◽  
Pathogenic Fungi ◽  
Dry Weight ◽  
Plant Pathogenic Fungi ◽  
Trichoderma Asperellum ◽  
Biosynthetic Gene ◽  
Antifungal Metabolites ◽  
Polyketide Synthase Gene

T. asperellumhas been turned out was an important biocontrol fungus and can antagonize many plant pathogenic fungi through a variety of biocontrol mechanisms. The antibiosis was considered one of important mechanisms. The antibiosis ofT.asperellumresistance plant pathogenic fungi was examined in this paper. The antibiotic biosynthetic gene polyketide synthase genepksT1can be induced by pathogens. Moreover, the growth of the plant pathogens was inhibited byT. asperellumsecondary metabolites. The yield of antibiotic 6-PP was 1.32 mg 6-PP/g mycelial dry weight.T. asperellumcontrol plant pathogens through producing antifungal metabolites.

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

Pathogenic Fungi Induce the Expression of Trichoderma asperellum Cell Wall Degrading Enzymes in the Process of Mycoparasitism

2014 ◽  
Vol 937 ◽  
pp. 282-285 ◽  
Author(s):  
Ping Yang
Keyword(s):  
Cell Wall ◽  
Control Plant ◽  
Pathogenic Fungi ◽  
Pythium Ultimum ◽  
Chitinase Gene ◽  
Trichoderma Asperellum ◽  
Cell Wall Degrading Enzymes ◽  
Degrading Enzymes ◽  
Plant Soil ◽  
Cytospora Chrysosperma

Trichoderma asperellum is an important biocontrol fungus which has been shown to control plant soil-borne pathogens, such as: Pythium ultimum, Fusariumoxysporum, Cytospora chrysosperma and Sclerotinia sclerotiorum. The goal of this research is to study whether the cell wall degrading enzymes genes were induced by pathogens or not in the process of T. asperellum mycoparasitism. The results suggest that chitinase gene ech42, β-1,3 glucanase gene bgn13.1, and β-1,6 glucanase gene bgn16.1 can be induced by pathogens. However, two N-acetyl-amino glycosidase nag1 and nag2 can not be induced by pathogens.

scholarly journals Discovery and Use of Genes and Gene Combinations Coding for Proteins Useful in Biological Control

1994 ◽  
Author(s):  
Gary E. Harman ◽  
Ilan Chet
Keyword(s):  
Cell Wall ◽  
Pathogenic Fungi ◽  
Plant Pathogenic Fungi ◽  
Cell Wall Degrading Enzymes ◽  
Fungal Cell ◽  
Degrading Enzymes ◽  
Transgenic Organisms ◽  
Genetic Sequences ◽  
High Level ◽  
First Time

The objectives of the research in this proposal were to (A) identify synergy among proteins that provide enhanced activity over single proteins for control of plant pathogenic fungi, (B) clone and characterize genetic sequences coding for proteins with ability to control pathogenic fungi, (C) produce transgenic organisms with enhanced biocontrol ability using genes and gene combinations and determine their efficiency in protecting plants against plant pathogenic fungi. A related objective was to produce disease-resistant plants. Fungal cell wall degrading enzymes from any source are strongly synergistic with any membrane active compound and, further, different classes of cell wall degrading enzymes are also strongly synergistic. We have cloned and sequenced a number of genes from bacterial and fungal sources including five that are structurally unrelated. We have prepared transgenic fungi that are deficient in production of enzymes and useful in mechanistic studies. Others are hyperproducers of specific enzymes that permit us, for the first time, to produce enzymes from T. harzianum in sufficient quantity to conduct tests of their potential use in commercial agriculture. Finally, genes from these studies have been inserted into several species of crop plants were they produce a high level of resistance to several plant pathogenic fungi.

scholarly journals The snf1 Gene of Ustilago maydis Acts as a Dual Regulator of Cell Wall Degrading Enzymes

2010 ◽  
Vol 100 (12) ◽  
pp. 1364-1372 ◽  
Author(s):  
Marina Nadal ◽  
Maria D. Garcia-Pedrajas ◽  
Scott E. Gold
Keyword(s):  
Cell Wall ◽  
Growth Medium ◽  
Plant Pathogens ◽  
Ustilago Maydis ◽  
Fungal Genome ◽  
Wild Type ◽  
Cell Wall Degrading Enzymes ◽  
Relative Expression ◽  
Degrading Enzymes ◽  
In The Wild

Many fungal plant pathogens are known to produce extracellular enzymes that degrade cell wall elements required for host penetration and infection. Due to gene redundancy, single gene deletions generally do not address the importance of these enzymes in pathogenicity. Cell wall degrading enzymes (CWDEs) in fungi are often subject to carbon catabolite repression at the transcriptional level such that, when glucose is available, CWDE-encoding genes, along with many other genes, are repressed. In Saccharomyces cerevisiae, one of the main players controlling this process is SNF1, which encodes a protein kinase. In this yeast, Snf1p is required to release glucose repression when this sugar is depleted from the growth medium. We have employed a reverse genetic approach to explore the role of the SNF1 ortholog as a potential regulator of CWDE gene expression in Ustilago maydis. We identified U. maydis snf1 and deleted it from the fungal genome. Consistent with our hypothesis, the relative expression of an endoglucanase and a pectinase was higher in the wild type than in the Δsnf1 mutant strain when glucose was depleted from the growth medium. However, when cells were grown in derepressive conditions, the relative expression of two xylanase genes was unexpectedly higher in the Δsnf1 strain than in the wild type, indicating that, in this case, snf1 negatively regulated the expression of these genes. Additionally, we found that, contrary to several other fungal species, U. maydis Snf1 was not required for utilization of alternative carbon sources. Also, unlike in ascomycete plant pathogens, deletion of snf1 did not profoundly affect virulence in U. maydis.

scholarly journals How the Necrotrophic Fungus Alternaria brassicicola Kills Plant Cells Remains an Enigma

2015 ◽  
Vol 14 (4) ◽  
pp. 335-344 ◽  
Author(s):  
Yangrae Cho
Keyword(s):  
Cell Wall ◽  
Plant Pathogens ◽  
Host Cells ◽  
Alternaria Brassicicola ◽  
Full Genome Sequencing ◽  
Cell Wall Degrading Enzymes ◽  
Content Type ◽  
Pathogenicity Factors ◽  
Degrading Enzymes ◽  
Host Specific Toxins

ABSTRACTAlternariaspecies are mainly saprophytic fungi, but some are plant pathogens. Seven pathotypes ofAlternaria alternatause secondary metabolites of host-specific toxins as pathogenicity factors. These toxins kill host cells prior to colonization. Genes associated with toxin synthesis reside on conditionally dispensable chromosomes, supporting the notion that pathogenicity might have been acquired several times byA. alternata.Alternaria brassicicola, however, seems to employ a different mechanism. Evidence on the use of host-specific toxins as pathogenicity factors remains tenuous, even after a diligent search aided by full-genome sequencing and efficient reverse-genetics approaches. Similarly, no individual genes encoding lipases or cell wall-degrading enzymes have been identified as strong virulence factors, although these enzymes have been considered important for fungal pathogenesis. This review describes our current understanding of toxins, lipases, and cell wall-degrading enzymes and their roles in the pathogenesis ofA. brassicicolacompared to those of other pathogenic fungi. It also describes a set of genes that affect pathogenesis inA. brassicicola. They are involved in various cellular functions that are likely important in most organisms and probably indirectly associated with pathogenesis. Deletion or disruption of these genes results in weakly virulent strains that appear to be sensitive to the defense mechanisms of host plants. Finally, this review discusses the implications of a recent discovery of three important transcription factors associated with pathogenesis and the putative downstream genes that they regulate.

The Contribution of Cell Wall Degrading Enzymes to Pathogenesis of Fungal Plant Pathogens

2002 ◽  
pp. 341-358 ◽  
Author(s):  
Arjen ten Have ◽  
Klaus B. Tenberge ◽  
Jacques A. E. Benen ◽  
Paul Tudzynski ◽  
Jaap Visser ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plant Pathogens ◽  
Cell Wall Degrading Enzymes ◽  
Degrading Enzymes ◽  
Fungal Plant Pathogens

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>

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