scholarly journals Fusarium graminearum DICER-like-dependent sRNAs are required for the suppression of host immune genes and full virulence

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0252365
Author(s):  
Bernhard Timo Werner ◽  
Aline Koch ◽  
Ena Šečić ◽  
Jonas Engelhardt ◽  
Lukas Jelonek ◽  
...  
Keyword(s):  
Gene Silencing ◽  
Fusarium Graminearum ◽  
Degradation Products ◽  
Brachypodium Distachyon ◽  
Fungal Virulence ◽  
Knock Out ◽  
Immune Genes ◽  
Gene Transcripts ◽  
Rapid Amplification ◽  
Specific Degradation

In filamentous fungi, gene silencing by RNA interference (RNAi) shapes many biological processes, including pathogenicity. Recently, fungal small RNAs (sRNAs) have been shown to act as effectors that disrupt gene activity in interacting plant hosts, thereby undermining their defence responses. We show here that the devastating mycotoxin-producing ascomycete Fusarium graminearum (Fg) utilizes DICER-like (DCL)-dependent sRNAs to target defence genes in two Poaceae hosts, barley (Hordeum vulgare, Hv) and Brachypodium distachyon (Bd). We identified 104 Fg-sRNAs with sequence homology to host genes that were repressed during interactions of Fg and Hv, while they accumulated in plants infected by the DCL double knock-out (dKO) mutant PH1-dcl1/2. The strength of target gene expression correlated with the abundance of the corresponding Fg-sRNA. Specifically, the abundance of three tRNA-derived fragments (tRFs) targeting immunity-related Ethylene overproducer 1-like 1 (HvEOL1) and three Poaceae orthologues of Arabidopsis thaliana BRI1-associated receptor kinase 1 (HvBAK1, HvSERK2 and BdSERK2) was dependent on fungal DCL. Additionally, RNA-ligase-mediated Rapid Amplification of cDNA Ends (RLM-RACE) identified infection-specific degradation products for the three barley gene transcripts, consistent with the possibility that tRFs contribute to fungal virulence via targeted gene silencing.

scholarly journals Fusarium graminearum DICER-like-dependent sRNAs are required for the suppression of host immune genes and full virulence

2021 ◽  
Author(s):  
Bernhard Timo Werner ◽  
Aline Koch ◽  
Ena Secic ◽  
Jonas Engelhardt ◽  
Lukas Jelonek ◽  
...  
Keyword(s):  
Gene Silencing ◽  
Fusarium Graminearum ◽  
Degradation Products ◽  
Brachypodium Distachyon ◽  
Fungal Virulence ◽  
Knock Out ◽  
Immune Genes ◽  
Gene Transcripts ◽  
Rapid Amplification ◽  
Specific Degradation

In filamentous fungi, gene silencing by RNA interference (RNAi) shapes many biological processes, including pathogenicity. Recently, fungal small RNAs (sRNAs) have been shown to act as effectors that disrupt gene activity in interacting plant hosts, thereby undermining their defence responses. We show here that the devastating mycotoxin-producing ascomycete Fusarium graminearum ( Fg ) utilizes DICER-like (DCL)-dependent sRNAs to target defence genes in two Poaceae hosts, barley ( Hordeum vulgare Hv ) and Brachypodium distachyon ( Bd ). We identified 104 Fg -sRNAs with sequence homology to host genes that were repressed during interactions of Fg and Hv , while they accumulated in plants infected by the DCL double knock-out (dKO) mutant PH1- dcl1/2 . The strength of target gene expression correlated with the abundance of the corresponding Fg -sRNA. Specifically, the abundance of three tRNA-derived fragments (tRFs) targeting immunity-related Ethylene overproducer 1-like 1 ( HvEOL1) and three Poaceae orthologues of Arabidopsis thaliana BRI1-associated receptor kinase 1 ( HvBAK1, HvSERK2 and BdSERK2 ) was dependent on fungal DCL. Additionally, RNA-ligase-mediated Rapid Amplification of cDNA Ends (RLM-RACE) identified infection-specific degradation products for the three barley gene transcripts, consistent with the possibility that tRFs contribute to fungal virulence via targeted gene silencing.

scholarly journals Molecular Characterization of a Novel Strain of Fusarium graminearum Virus 1 Infecting Fusarium graminearum

Viruses ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 357 ◽  
Author(s):  
Lihang Zhang ◽  
Xiaoguang Chen ◽  
Pallab Bhattacharjee ◽  
Yue Shi ◽  
Lihua Guo ◽  
...  
Keyword(s):  
Fusarium Graminearum ◽  
Pathogenic Fungi ◽  
Open Reading Frames ◽  
Chinese Isolate ◽  
The Novel ◽  
Fungal Virulence ◽  
Host Interaction ◽  
Short Orfs ◽  
Rapid Amplification ◽  
Fungal Viruses

Fungal viruses (mycoviruses) have attracted more attention for their possible hypovirulence (attenuation of fungal virulence) trait, which may be developed as a biocontrol agent of plant pathogenic fungi. However, most discovered mycoviruses are asymptomatic in their hosts. In most cases, mycovirus hypovirulent factors have not been explored clearly. In this study, we characterized a ssRNA mycovirus in Fusarium graminearum strain HB56-9. The complete nucleotide genome was obtained by combining random sequencing and rapid amplification of cDNA ends (RACE). The full genome was 6621-nucleotides long, excluding the poly(A) tail. The mycovirus was quite interesting because it shared 95.91% nucleotide identities with previously reported Fusarium graminearum virus 1 strain DK21 (FgV1-DK21), while the colony morphology of their fungal hosts on PDA plates were very different. The novel virus was named Fusarium graminearum virus 1 Chinese isolate (FgV1-ch). Like FgV1-DK21, FgV1-ch also contains four putative open reading frames (ORFs), including one long and three short ORFs. A phylogenetic analysis indicated that FgV1-ch is clustered into a proposed family Fusariviridae. FgV1-ch, unlike FgV1-DK21, had mild or no effects on host mycelial growth, spore production and virulence. The nucleotide differences between FgV1-ch and FgV1-DK21 will help to elucidate the hypovirulence determinants during mycovirus–host interaction.

scholarly journals Identification of Putative Virulence Genes by DNA Methylation Studies in the Cereal Pathogen Fusarium graminearum

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1192
Author(s):  
Francesco Tini ◽  
Giovanni Beccari ◽  
Gianpiero Marconi ◽  
Andrea Porceddu ◽  
Micheal Sulyok ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Fusarium Graminearum ◽  
Environmental Changes ◽  
Virulent Strain ◽  
Fungal Virulence ◽  
Wheat Seedlings ◽  
Wide Range ◽  
Conidia Production ◽  
Natural Hosts

DNA methylation mediates organisms’ adaptations to environmental changes in a wide range of species. We investigated if a such a strategy is also adopted by Fusarium graminearum in regulating virulence toward its natural hosts. A virulent strain of this fungus was consecutively sub-cultured for 50 times (once a week) on potato dextrose agar. To assess the effect of subculturing on virulence, wheat seedlings and heads (cv. A416) were inoculated with subcultures (SC) 1, 23, and 50. SC50 was also used to re-infect (three times) wheat heads (SC50×3) to restore virulence. In vitro conidia production, colonies growth and secondary metabolites production were also determined for SC1, SC23, SC50, and SC50×3. Seedling stem base and head assays revealed a virulence decline of all subcultures, whereas virulence was restored in SC50×3. The same trend was observed in conidia production. The DNA isolated from SC50 and SC50×3 was subject to a methylation content-sensitive enzyme and double-digest, restriction-site-associated DNA technique (ddRAD-MCSeEd). DNA methylation analysis indicated 1024 genes, whose methylation levels changed in response to the inoculation on a healthy host after subculturing. Several of these genes are already known to be involved in virulence by functional analysis. These results demonstrate that the physiological shifts following sub-culturing have an impact on genomic DNA methylation levels and suggest that the ddRAD-MCSeEd approach can be an important tool for detecting genes potentially related to fungal virulence.

scholarly journals Molecular Characterization and Functional Analysis of PR-1-Like Proteins Identified from the Wheat Head Blight Fungus Fusarium graminearum

2018 ◽  
Vol 108 (4) ◽  
pp. 510-520 ◽  
Author(s):  
Shunwen Lu ◽  
Michael C. Edwards
Keyword(s):  
Functional Analysis ◽  
Fusarium Graminearum ◽  
Expression Patterns ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Transcriptional Analysis ◽  
Fungal Genome ◽  
Dimensional Structure ◽  
Head Blight ◽  
Fungal Virulence

The group 1 pathogenesis-related (PR-1) proteins originally identified from plants and their homologs are also found in other eukaryotic kingdoms. Studies on nonplant PR-1-like (PR-1L) proteins have been pursued widely in humans and animals but rarely in filamentous ascomycetes. Here, we report the characterization of four PR-1L proteins identified from the ascomycete fungus Fusarium graminearum, the primary cause of Fusarium head blight of wheat and barley (designated FgPR-1L). Molecular cloning revealed that the four FgPR-1L proteins are all encoded by small open reading frames (612 to 909 bp) that are often interrupted by introns, in contrast to plant PR-1 genes that lack introns. Sequence analysis indicated that all FgPR-1L proteins contain the PR-1-specific three-dimensional structure, and one of them features a C-terminal transmembrane (TM) domain that has not been reported for any stand-alone PR-1 proteins. Transcriptional analysis revealed that the four FgPR-1L genes are expressed in axenic cultures and in planta with different spatial or temporal expression patterns. Phylogenetic analysis indicated that fungal PR-1L proteins fall into three major groups, one of which harbors FgPR-1L-2-related TM-containing proteins from both phytopathogenic and human-pathogenic ascomycetes. Low-temperature sodium dodecyl sulfate polyacrylamide gel electrophoresis and proteolytic assays indicated that the recombinant FgPR-1L-4 protein exists as a monomer and is resistant to subtilisin of the serine protease family. Functional analysis confirmed that deletion of the FgPR-1L-4 gene from the fungal genome results in significantly reduced virulence on susceptible wheat. This study provides the first example that the F. graminearum–wheat interaction involves a pathogen-derived PR-1L protein that affects fungal virulence on the host.

THE ROLE OF VARIOUS HAEMOSTASIS PARAMETERS IN MONITORING FIBRINOLYSIS WITH PRO-UROKINASE/STREPTOKINASE IN TREATMENT OF MYOCARDIAL INFARCTION

1987 ◽  
Author(s):  
F Keller ◽  
P Schanzenbächer ◽  
F Dati ◽  
J Huber ◽  
K kochsiek
Keyword(s):  
Myocardial Infarction ◽  
Degradation Products ◽  
Therapy Monitoring ◽  
Latex Agglutination ◽  
Systemic Activity ◽  
Thromboplastic Activity ◽  
Specific Degradation ◽  
D Dimer

The new drug pro-urokinase, a proenzyme of urokinase (scu-PA), seems to have advantages in comparison with other fibrinolytic agents. Properties like higher fibrin specifity, non-systemic activity and lower antigenity may lead to a lower rate of complications. In a pilot study 10 patients with acute myocardial infarction have been treated under angiographical control with pro-urokinase (3-9 millions IU) by i.v. application. In case of no perfusion a further administration of streptokinase was carried on. The blood samples were obtained at therapy begin and after 5, 10, 30, 60 and 120 minutes. The therapy monitoring was performed by determination of established haemostasis parameters, like fibrinogen, fibrin(ogen)-split products (FSP), a2-antiplasmin. Plasminogen and batroxobin-time. Furthermore, the diagnostic relevance of new laboratory tests for fibrinolysis, D-Dimer and thrombin-anti thrombin Ill-complex (TAT) has been investigated considering some typical follow-ups. D-Dimer were determined by latex agglutination test and TAT by enzyme immunoassay.Generally the application of pro-urokinase in contrast to streptokinase results in minimal changes of the classic fibrinolysis parameters like fibrinogen, FSP, batroxobin-time etc. demonstrating no systemic lysis. The appearance of plasmic degradation products of cross-linked fibrin (D-Dimer) is a specific indi-cater of the release of thrombotic material. Other non-specific degradation products (fibrinogenolysis) were detected by the measurement of FSP. In some cases in which perfusion ocurred an increase of TAT followed by a rapid decrease was observed. This indicates a higher thromboplastic activity which may originate from the infarcted area producing TAT complex formation.

scholarly journals Cytokinin-Regulated Expression of Arabidopsis thaliana PAP Genes and Its Implication for the Expression of Chloroplast-Encoded Genes

Biomolecules ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1658
Author(s):  
Aleksandra A. Andreeva ◽  
Radomira Vankova ◽  
Ivan A. Bychkov ◽  
Natalia V. Kudryakova ◽  
Maria N. Danilova ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Nuclear Genes ◽  
Promoter Regions ◽  
Knock Out ◽  
Regulatory Circuit ◽  
Associated Proteins ◽  
Gene Transcripts ◽  
Plastid Rna Polymerase ◽  
Underlying Mechanisms

Cytokinins (CKs) are known to regulate the biogenesis of chloroplasts under changing environmental conditions and at different stages of plant ontogenesis. However, the underlying mechanisms are still poorly understood. Apparently, the mechanisms can be duplicated in several ways, including the influence of nuclear genes that determine the expression of plastome through the two-component CK regulatory circuit. In this study, we evaluated the role of cytokinins and CK signaling pathway on the expression of nuclear genes for plastid RNA polymerase-associated proteins (PAPs). Cytokinin induced the expression of all twelve Arabidopsis thalianaPAP genes irrespective of their functions via canonical CK signaling pathway but this regulation might be indirect taking into consideration their different functions and versatile structure of promoter regions. The disruption of PAP genes contributed to the abolishment of positive CK effect on the accumulation of the chloroplast gene transcripts and transcripts of the nuclear genes for plastid transcription machinery as can be judged from the analysis of pap1 and pap6 mutants. However, the CK regulatory circuit in the mutants remained practically unperturbed. Knock-out of PAP genes resulted in cytokinin overproduction as a consequence of the strong up-regulation of the genes for CK synthesis.

scholarly journals Novel Genes of Fusarium graminearum That Negatively Regulate Deoxynivalenol Production and Virulence

2009 ◽  
Vol 22 (12) ◽  
pp. 1588-1600 ◽  
Author(s):  
Donald M. Gardiner ◽  
Kemal Kazan ◽  
John M. Manners
Keyword(s):  
Gene Expression ◽  
Fusarium Graminearum ◽  
Global Analysis ◽  
Gene Clusters ◽  
Head Blight ◽  
Knock Out ◽  
Serious Disease ◽  
Amine Compounds ◽  
Fungal Genes ◽  
Fungal Gene Expression

Fusarium head blight of wheat, caused by Fusarium graminearum, is a serious disease resulting in both reduced yields and contamination of grain with trichothecene toxins, with severe consequences for mammalian health. Recently, we have identified several related amine compounds such as agmatine and putrescine that promote the production of high levels of trichothecene toxins, such as deoxynivalenol (DON), in culture by F. graminearum and F. sporotrichioides. Here, a global analysis of fungal gene expression using the Affymetrix Fusarium GeneChip during culture under DON-inducing conditions compared with noninducing conditions is reported. Agmatine differentially regulated a large number of fungal genes, including both known and previously uncharacterized putative secondary metabolite biosynthetic gene clusters. In silico prediction of binding sites for the transcriptional regulator (TRI6) controlling TRI gene expression and gene expression analysis in a TRI6 mutant of F. graminearum showed that three of the differentially regulated genes were under the control of TRI6. Gene knock-out mutations of two of these genes resulted in mutants with massively increased production of DON and increased aggressiveness toward wheat. Our results not only identify a novel mechanism of negative regulation of DON production and virulence in F. graminearum but also point out the potential of this pathogen to evolve with an ability to produce massively increased amounts of toxins and increased virulence.

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