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 ◽  
...  

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.

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 976
Author(s):  
Lakshmipriya Perincherry ◽  
Chaima Ajmi ◽  
Souheib Oueslati ◽  
Agnieszka Waśkiewicz ◽  
Łukasz Stępień

Being pathogenic fungi, Fusarium produce various extracellular cell wall-degrading enzymes (CWDEs) that degrade the polysaccharides in the plant cell wall. They also produce mycotoxins that contaminate grains, thereby posing a serious threat to animals and human beings. Exposure to mycotoxins occurs through ingestion of contaminated grains, inhalation and through skin absorption, thereby causing mycotoxicoses. The toxins weaken the host plant, allowing the pathogen to invade successfully, with the efficiency varying from strain to strain and depending on the plant infected. Fusariumoxysporum predominantly produces moniliformin and cyclodepsipeptides, whereas F. proliferatum produces fumonisins. The aim of the study was to understand the role of various substrates and pea plant extracts in inducing the production of CWDEs and mycotoxins. Additionally, to monitor the differences in their levels when susceptible and resistant pea plant extracts were supplemented. The cultures of F. proliferatum and F. oxysporum strains were supplemented with various potential inducers of CWDEs. During the initial days after the addition of substrates, the fungus cocultivated with pea extracts and other carbon substrates showed increased activities of β-glucosidase, xylanase, exo-1,4-glucanase and lipase. The highest inhibition of mycelium growth (57%) was found in the cultures of F. proliferatum strain PEA1 upon the addition of cv. Sokolik extract. The lowest fumonisin content was exhibited by the cultures with the pea extracts and oat bran added, and this can be related to the secondary metabolites and antioxidants present in these substrates.


2019 ◽  
Vol 85 (13) ◽  
Author(s):  
Hongming Zhang ◽  
Bettina A. Buttaro ◽  
Derrick E. Fouts ◽  
Salar Sanjari ◽  
Bradley S. Evans ◽  
...  

ABSTRACTϕEf11 is a temperateSiphoviridaebacteriophage that infects strains ofEnterococcus faecalis. The ϕEf11 genome, encompassing 65 open reading frames (ORFs), is contained within 42,822 bp of DNA. Within this genome, a module of six lysis-related genes was identified. Based upon sequence homology, one of these six genes, ORF28, was predicted to code for anN-acetylmuramoyl-l-alanine amidase endolysin of 46.133 kDa, composed of 421 amino acids. The PCR-amplified ORF28 was cloned and expressed, and the resulting gene product was affinity purified to homogeneity. The purified protein was obtained from a fusion protein that exhibited a molecular mass of 72.5 kDa, consistent with a 46.1-kDa protein combined with a fused 26.5-kDa glutathioneS-transferase tag. It produced rapid, profound lysis inE. faecalispopulations and was active against 73 of 103 (71%)E. faecalisstrains tested. In addition, it caused substantial destruction ofE. faecalisbiofilms. The lysin was quite stable, retaining its activity for three years in refrigerated storage, was stable over a wide range of pHs, and was unaffected by the presence of a reducing agent; however, it was inhibited by increasing concentrations of Ca2+. Liquid chromatography-mass spectrometry analysis ofE. faecaliscell wall digestion products produced by the ORF28 endolysin indicated that the lysin acted as anN-acetylmuramidase, an endo-β-N-acetylglucosaminidase, and an endopeptidase, rather than anN-acetylmuramoyl-l-alanine amidase. The ϕEf11 ORF28 lysin shared 10% to 37% amino acid identity with the lytic enzymes of all other characterizedE. faecalisbacteriophages.IMPORTANCEThe emergence of multidrug-resistant pathogenic microorganisms has brought increasing attention to the urgent need for the development of alternative antimicrobial strategies. One such alternative to conventional antibiotics employs lytic enzymes (endolysins) that are produced by bacteriophages in the course of lytic infection. During lytic infection by a bacteriophage, these enzymes hydrolyze the cell wall peptidoglycan, resulting in the lysis of the host cell. However, external endolysin application can result in lysis from without. In this study, we have cloned, expressed, purified, and characterized an endolysin produced by a bacteriophage infecting strains ofEnterococcus faecalis. The lysin is broadly active against most of the testedE. faecalisstrains and exhibits multifunctional enzymatic specificities that differ from all other characterized endolysins produced byE. faecalisbacteriophages.


2013 ◽  
Vol 726-731 ◽  
pp. 4525-4528
Author(s):  
Ping Yang ◽  
Qian Xu

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.


Biomolecules ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 781 ◽  
Author(s):  
Marcela Suriani Ribeiro ◽  
Renato Graciano de Paula ◽  
Aline Raquel Voltan ◽  
Raphaela Georg de Castro ◽  
Cláudia Batista Carraro ◽  
...  

Trichoderma species are known for their ability to produce lytic enzymes, such as exoglucanases, endoglucanases, chitinases, and proteases, which play important roles in cell wall degradation of phytopathogens. β-glucanases play crucial roles in the morphogenetic-morphological process during the development and differentiation processes in Trichoderma species, which have β-glucans as the primary components of their cell walls. Despite the importance of glucanases in the mycoparasitism of Trichoderma spp., only a few functional analysis studies have been conducted on glucanases. In the present study, we used a functional genomics approach to investigate the functional role of the gluc31 gene, which encodes an endo-β-1,3-glucanase belonging to the GH16 family in Trichoderma harzianum ALL42. We demonstrated that the absence of the gluc31 gene did not affect the in vivo mycoparasitism ability of mutant T. harzianum ALL42; however, gluc31 evidently influenced cell wall organization. Polymer measurements and fluorescence microscopy analyses indicated that the lack of the gluc31 gene induced a compensatory response by increasing the production of chitin and glucan polymers on the cell walls of the mutant hyphae. The mutant strain became more resistant to the fungicide benomyl compared to the parental strain. Furthermore, qRT-PCR analysis showed that the absence of gluc31 in T. harzianum resulted in the differential expression of other glycosyl hydrolases belonging to the GH16 family, because of functional redundancy among the glucanases.


2010 ◽  
Vol 100 (12) ◽  
pp. 1364-1372 ◽  
Author(s):  
Marina Nadal ◽  
Maria D. Garcia-Pedrajas ◽  
Scott E. Gold

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.


2020 ◽  
Vol 117 (6) ◽  
pp. 3281-3290 ◽  
Author(s):  
Lina Gallego-Giraldo ◽  
Chang Liu ◽  
Sara Pose-Albacete ◽  
Sivakumar Pattathil ◽  
Angelo Gabriel Peralta ◽  
...  

There is considerable interest in engineering plant cell wall components, particularly lignin, to improve forage quality and biomass properties for processing to fuels and bioproducts. However, modifying lignin content and/or composition in transgenic plants through down-regulation of lignin biosynthetic enzymes can induce expression of defense response genes in the absence of biotic or abiotic stress. Arabidopsis thaliana lines with altered lignin through down-regulation of hydroxycinnamoyl CoA:shikimate/quinate hydroxycinnamoyl transferase (HCT) or loss of function of cinnamoyl CoA reductase 1 (CCR1) express a suite of pathogenesis-related (PR) protein genes. The plants also exhibit extensive cell wall remodeling associated with induction of multiple cell wall-degrading enzymes, a process which renders the corresponding biomass a substrate for growth of the cellulolytic thermophile Caldicellulosiruptor bescii lacking a functional pectinase gene cluster. The cell wall remodeling also results in the release of size- and charge-heterogeneous pectic oligosaccharide elicitors of PR gene expression. Genetic analysis shows that both in planta PR gene expression and release of elicitors are the result of ectopic expression in xylem of the gene ARABIDOPSIS DEHISCENCE ZONE POLYGALACTURONASE 1 (ADPG1), which is normally expressed during anther and silique dehiscence. These data highlight the importance of pectin in cell wall integrity and the value of lignin modification as a tool to interrogate the informational content of plant cell walls.


2021 ◽  
Vol 7 (12) ◽  
pp. 1004
Author(s):  
Lakshmipriya Perincherry ◽  
Natalia Witaszak ◽  
Monika Urbaniak ◽  
Agnieszka Waśkiewicz ◽  
Łukasz Stępień

Fusarium species present ubiquitously in the environment are capable of infecting a wide range of plant species. They produce several mycotoxins targeted to weaken the host plant. While infecting some resistant plants, the host can alter the expression of toxin-related genes and accumulate no/very low amounts of mycotoxins. The ability of the host plant to modulate the biosynthesis of these toxins is entirely depending on the secondary metabolites produced by the plant, often as a part of systemic acquired resistance (SAR). A major role plays in the family of metabolites called phenyl propanoids, consisting of thousands of natural products, synthesized from the phenylalanine or tyrosine amino acids through a cascade of enzymatic reactions. They are also famous for inhibiting or limiting infection through their antioxidant characteristics. The current study was aimed at identifying the differentially expressed secondary metabolites in resistant (Sokolik) and susceptible (Santana) cultivars of pea (Pisum sativum L.) and understanding their roles in the growth and mycotoxin biosynthesis of two different Fusarium species. Although metabolites such as coumarin, spermidine, p-coumaric acid, isoorientin, and quercetin reduced the growth of the pathogen, a higher level of p-coumaric acid was found to enhance the growth of F. proliferatum strain PEA1. It was also noticeable that the growth of the pathogen did not depend on their ability to produce mycotoxins, as all the metabolites were able to highly inhibit the biosynthesis of fumonisin B1 and beauvericin.


2021 ◽  
Author(s):  
Mina Ohtsu ◽  
Joanna Jennings ◽  
Matthew Johnston ◽  
Xiaokun Liu ◽  
Nathan Hughes ◽  
...  

SummaryMulticellular organisms exchange information and resources between cells to co-ordinate growth and responses. In plants, plasmodesmata establish cytoplasmic continuity between cells to allow for communication and resource exchange across the cell wall. Some plant pathogens use plasmodesmata as a pathway for both molecular and physical invasion. However, the benefits of molecular invasion (cell-to-cell movement of pathogen effectors) are poorly understood. To begin to investigate this and identify which effectors are cell-to-cell mobile, we performed a live imaging-based screen and identified 15 cell-to-cell mobile effectors of the fungal pathogen Colletotrichum higginsianum. Of these, 6 are “hypermobile”, showing cell-to-cell mobility greater than expected for a protein of its size. We further identified 3 effectors that can indirectly modify plasmodesmal aperture. Transcriptional profiling of plants expressing hypermobile effectors implicate them in a variety of processes including senescence, glucosinolate production, cell wall integrity, growth and iron metabolism. However, not all effectors had an independent effect on virulence. This suggests a wide range of benefits to infection gained by the mobility of C. higginsianum effectors that likely interact in a complex way during infection.


mBio ◽  
2021 ◽  
Author(s):  
Jasper R. L. Depotter ◽  
Fabian van Beveren ◽  
Luis Rodriguez-Moreno ◽  
H. Martin Kramer ◽  
Edgar A. Chavarro Carrero ◽  
...  

Verticillium is a genus of plant-associated fungi that includes a few plant pathogens that collectively affect a wide range of hosts. On several occasions, haploid Verticillium species hybridized into the stable allodiploid species Verticillium longisporum , which is, in contrast to haploid Verticillium species, a Brassicaceae specialist.


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