scholarly journals Genomic Identification of the TOR Signaling Pathway as a Target of the Plant Alkaloid Antofine in the Phytopathogen Fusarium graminearum

mBio ◽  
2019 ◽  
Vol 10 (3) ◽  
Author(s):  
Christopher Mogg ◽  
Christopher Bonner ◽  
Li Wang ◽  
Johann Schernthaner ◽  
Myron Smith ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Fusarium Graminearum ◽  
Mode Of Action ◽  
Biological Activities ◽  
Extensive Study ◽  
Economic Losses ◽  
Head Blight ◽  
Tor Signaling ◽  
Content Type ◽  
Chemical Genomic

ABSTRACT Antofine, a phenanthroindolizidine alkaloid, is a bioactive natural product isolated from milkweeds that exhibits numerous biological activities, including anticancer, antimicrobial, antiviral, and anti-inflammatory properties. However, the direct targets and mode of action of antofine have not been determined. In this report, we show that antofine displays antifungal properties against the phytopathogen Fusarium graminearum, the cause of Fusarium head blight disease (FHB). FHB does devastating damage to agriculture, causing billions of dollars in economic losses annually. We therefore sought to understand the mode of action of antofine in F. graminearum using insights from yeast chemical genomic screens. We used haploinsufficiency profiling (HIP) to identify putative targets of antofine in yeast and identified three candidate targets, two of which had homologs in F. graminearum. The Fusarium homologues of two targets, glutamate dehydrogenase (FgGDH) and resistance to rapamycin deletion 2 (FgRRD2), can bind antofine. Of the two genes, only the Fgrrd2 knockout displayed a loss of virulence in wheat, indicating that RRD2 is an antivirulence target of antofine in F. graminearum. Mechanistically, we demonstrate that antofine disrupts the interaction between FgRRD2 and FgTap42, which is part of the Tap42-phosphatase complex in the target of rapamycin (TOR) signaling pathway, a central regulator of cell growth in eukaryotes and a pathway of extensive study for controlling numerous pathologies. IMPORTANCE Fusarium head blight caused by the fungal pathogen Fusarium graminearum is a devastating disease of cereal crops worldwide, with limited effective chemical treatments available. Here we show that the natural alkaloid compound antofine can inhibit fusarium head blight in wheat. Using yeast genomic screening, we identified the TOR pathway component RRD2 as a target of antofine that is also required for F. graminearum pathogenicity.

scholarly journals The Dynamin-Like GTPase FgSey1 Plays a Critical Role in Fungal Development and Virulence in Fusarium graminearum

2020 ◽  
Vol 86 (11) ◽  
Author(s):  
Xuefa Chong ◽  
Chenyu Wang ◽  
Yao Wang ◽  
Yixiao Wang ◽  
Liyuan Zhang ◽  
...  
Keyword(s):  
Fusarium Graminearum ◽  
Vegetative Growth ◽  
Animal Feed ◽  
Pathogenic Fungus ◽  
Critical Role ◽  
Effective Control ◽  
Economic Losses ◽  
Head Blight ◽  
Fungal Development ◽  
Content Type

ABSTRACT Fusarium graminearum, the main pathogenic fungus causing Fusarium head blight (FHB), produces deoxynivalenol (DON), a key virulence factor, which is synthesized in the endoplasmic reticulum (ER). Sey1/atlastin, a dynamin-like GTPase protein, is known to be required for homotypic fusion of ER membranes, but the functions of this protein are unknown in pathogenic fungi. Here, we characterized Sey1/atlastin homologue FgSey1 in F. graminearum. Like Sey1/atlastin, FgSey1 is located in the ER. The FgSEY1 deletion mutant exhibited significantly reduced vegetative growth, asexual development, DON biosynthesis, and virulence. Moreover, the ΔFgsey1 mutant was impaired in the formation of normal lipid droplets (LDs) and toxisomes, both of which participate in DON biosynthesis. The GTPase, helix bundle (HB), transmembrane segment (TM), and cytosolic tail (CT) domains of FgSey1 are essential for its function, but only the TM domain is responsible for its localization. Furthermore, the mutants FgSey1K63A and FgSey1T87A lacked GTPase activity and failed to rescue the defects of the ΔFgsey1 mutant. Collectively, our data suggest that the dynamin-like GTPase protein FgSey1 affects the generation of LDs and toxisomes and is required for DON biosynthesis and pathogenesis in F. graminearum. IMPORTANCE Fusarium graminearum is a major plant pathogen that causes Fusarium head blight (FHB) of wheats worldwide. In addition to reducing the plant yield, F. graminearum infection of wheats also results in the production of deoxynivalenol (DON) mycotoxins, which are harmful to humans and animals and therefore cause great economic losses through pollution of food products and animal feed. At present, effective strategies for controlling FHB are not available. Therefore, understanding the regulation mechanisms of fungal development, pathogenesis, and DON biosynthesis is important for the development of effective control strategies of this disease. In this study, we demonstrated that a dynamin-like GTPase protein Sey1/atlastin homologue, FgSey1, is required for vegetative growth, DON production, and pathogenicity in F. graminearum. Our results provide novel information on critical roles of FgSey1 in fungal pathogenicity; therefore, FgSey1 could be a potential target for effective control of the disease caused by F. graminearum.

scholarly journals Genome Sequence of Fusarium graminearum ITEM 124 (ATCC 56091), a Mycotoxigenic Plant Pathogen

2017 ◽  
Vol 5 (45) ◽  
Author(s):  
Antonio Zapparata ◽  
Daniele Da Lio ◽  
Stefania Somma ◽  
Isabel Vicente Muñoz ◽  
Luca Malfatti ◽  
...  
Keyword(s):  
Comparative Genomics ◽  
Fusarium Graminearum ◽  
Crop Yield ◽  
Genome Sequence ◽  
Whole Genome Sequence ◽  
Economic Losses ◽  
Whole Genome ◽  
Head Blight ◽  
Content Type ◽  
Yield And Quality

ABSTRACT Fusarium graminearum is among the main causal agents of Fusarium head blight (FHB), or scab, of wheat and other cereals, caused by a complex of Fusarium species, worldwide. Besides causing economic losses in terms of crop yield and quality, F. graminearum poses a severe threat to animal and human health. Here, we present the first draft whole-genome sequence of the mycotoxigenic Fusarium graminearum strain ITEM 124, also providing useful information for comparative genomics studies.

scholarly journals Chemical Activation of the Ethylene Signaling Pathway Promotes Fusarium graminearum Resistance in Detached Wheat Heads

2019 ◽  
Vol 109 (5) ◽  
pp. 796-803 ◽  
Author(s):  
Nora A. Foroud ◽  
Reyhaneh Pordel ◽  
Ravinder K. Goyal ◽  
Daria Ryabova ◽  
Anas Eranthodi ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Fusarium Graminearum ◽  
Host Response ◽  
Chemical Activation ◽  
Disease Spread ◽  
Plant Signaling ◽  
Head Blight ◽  
Wheat Genotypes ◽  
Ethylene Signaling Pathway

Plant signaling hormones such as ethylene have been shown to affect the host response to various pathogens. Often, the resistance responses to necrotrophic fungi are mediated through synergistic interactions of ethylene (ET) with the jasmonate signaling pathway. On the other hand, ET is also an inducer of senescence and cell death, which could be beneficial for some invading necrotrophic pathogens. Fusarium graminearum, a causative agent in Fusarium head blight of wheat, is a hemibiotrophic pathogen, meaning it has both biotrophic and necrotrophic phases during the course of infection. However, the role of ET signaling in the host response to Fusarium spp. is unclear; some studies indicate that ET mediates resistance, while others have shown that it is associated with susceptibility. These discrepancies could be related to various aspects of different experimental designs, and suggest that the role of ET signaling in the host response to FHB is potentially dependent on interactions with some undetermined factors. To investigate whether wheat genotype can influence the ET-mediated response to FHB, the effect of chemical treatments affecting the ET pathway was studied in six wheat genotypes in detached-head assays. ET-inhibitor treatments broke down resistance to both initial infection and disease spread in three resistant wheat genotypes, whereas ET-enhancer treatments resulted in reduced susceptibility in three susceptible genotypes. The results presented here show that the ET signaling can mediate FHB resistance to F. graminearum in different wheat backgrounds.

Incidence of Deoxynivalenol in Wheat Flour in Argentina and GC–ECD Method Validation

2019 ◽  
Vol 102 (6) ◽  
pp. 1721-1724 ◽  
Author(s):  
Mercedes Cirio ◽  
Marcela Villarreal ◽  
Tomás M López Seal ◽  
Mariano E Simón ◽  
Camila S Santana Smersu ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Wheat Flour ◽  
Fusarium Graminearum ◽  
Health Risks ◽  
Human Population ◽  
Economic Losses ◽  
Head Blight ◽  
Tolerance Limits ◽  
Intermediate Precision ◽  
Median Level

Abstract Background: Deoxynivalenol (DON) is a mycotoxin produced mainly by Fusarium graminearum. This fungus is the main plant pathogen associated with Fusarium Head Blight (FHB) wheat disease, causing significant economic losses and exposing human population to severe health risks. DON production changes widely among different years and areas and its effects are larger in years with abundant rainfall and high relative humidity. To date, Argentina has not established DON tolerance limits. Objective: To validate a method using GC with electron capture detector (GC-ECD) and to provide evidence of DON contamination in Argentinean commercial wheat flour. Results: A total of 34 different flour samples were analyzed obtaining 91.2% of incidence with a mean level of 243 µg/kg and a median level of 165 µg/kg. The method showed acceptable LOD (24 µg/kg) and LOQ (79 µg/kg), relative SD (RSD) of the intermediate precision (RSD = 5.98%), recovery (89.3%) and uncertainty (14%). Conclusions: The method was successfully validated according to the studied parameters. Incidence results for DON contamination are low and in accordance with previous studies for years with low FHB incidence in wheat.

scholarly journals Effects of Temperature and Moisture on Development of Fusarium graminearum Perithecia in Maize Stalk Residues

2015 ◽  
Vol 82 (1) ◽  
pp. 184-191 ◽  
Author(s):  
Valentina Manstretta ◽  
Vittorio Rossi
Keyword(s):  
Fusarium Graminearum ◽  
Crop Residues ◽  
Head Blight ◽  
Dispersal Patterns ◽  
Content Type ◽  
Predominant Component ◽  
Effects Of Temperature ◽  
Ascospore Production ◽  
Maize Stalks ◽  
Over Time

ABSTRACTFusarium graminearumis the predominant component of the Fusarium head blight complex of wheat.F. graminearumascospores, which initiate head infection, mature in perithecia on crop residues and become airborne. The effects of temperature (T) and moisture on perithecium production and maturation and on ascospore production on maize stalk residues were determined. In the laboratory, perithecia were produced at temperatures between 5 and 30°C (the optimum was 21.7°C) but matured only at 20 and 25°C. Perithecia were produced when relative humidity (RH) was ≥75% but matured only when RH was ≥85%; perithecium production and maturation increased with RH. Equations describing perithecium production and maturation over time as a function ofTand RH (R2> 0.96) were developed. Maize stalks were also placed outdoors on three substrates: a grass lawn exposed to rain; a constantly wet, spongelike foam exposed to rain; and a grass lawn protected from rain. No perithecia were produced on stalks protected from rain. Perithecium production and maturation were significantly higher on the constantly wet foam than on the intermittently wet lawn (both exposed to rain). Ascospore numbers but not their dispersal patterns were also affected by the substrate.

scholarly journals Genome-Wide Characterization of PX Domain-Containing Proteins Involved in Membrane Trafficking-Dependent Growth and Pathogenicity of Fusarium graminearum

mBio ◽  
2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Yi Lou ◽  
Jing Zhang ◽  
Guanghui Wang ◽  
Wenqin Fang ◽  
Shumin Wang ◽  
...  
Keyword(s):  
Fusarium Graminearum ◽  
Membrane Trafficking ◽  
Cereal Crops ◽  
Head Blight ◽  
Content Type ◽  
Px Domain ◽  
Genome Wide ◽  
Wide Range ◽  
Dependent Growth

Fusarium head blight (FHB), caused predominantly by Fusarium graminearum , is an economically devastating disease of a wide range of cereal crops. Our previous study identified F. graminearum Vps17, Vps5, Snx41, and Snx4 as PX domain-containing proteins that were involved in membrane trafficking mediating the fungal development and pathogenicity, but the identity and biological roles of the remaining members of this protein family remain unknown in this model phytopathogen.

scholarly journals Rhb1 Regulates the Expression of Secreted Aspartic Protease 2 through the TOR Signaling Pathway in Candida albicans

2011 ◽  
Vol 11 (2) ◽  
pp. 168-182 ◽  
Author(s):  
Yu-Ting Chen ◽  
Chia-Ying Lin ◽  
Pei-Wen Tsai ◽  
Cheng-Yao Yang ◽  
Wen-Ping Hsieh ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Signaling Pathway ◽  
Virulence Factor ◽  
Nitrogen Availability ◽  
Target Genes ◽  
Small Gtpase ◽  
Aspartic Protease ◽  
Tor Signaling ◽  
Content Type

ABSTRACTCandida albicansis a major fungal pathogen in humans. InC. albicans, secreted aspartyl protease 2 (Sap2) is the most highly expressed secreted aspartic proteasein vitroand is a virulence factor. Recent research links the small GTPase Rhb1 toC. albicanstarget of rapamycin (TOR) signaling in response to nitrogen availability. The results of this study show that Rhb1 is related to cell growth through the control ofSAP2expression when protein is the major nitrogen source. This process involves various components of the TOR signaling pathway, including Tor1 kinase and its downstream effectors. TOR signaling not only controlsSAP2transcription but also affects Sap2 protein levels, possibly through general amino acid control. DNA microarray analysis identifies other target genes downstream of Rhb1 in addition toSAP2. These findings provide new insight into nutrients, Rhb1-TOR signaling, and expression ofC. albicansvirulence factor.

Incidence of Deoxynivalenol in Wheat Flour in Argentina and GC–ECD Method Validation

2019 ◽  
Vol 102 (6) ◽  
pp. 1721-1724
Author(s):  
Mercedes Cirio ◽  
Marcela Villarreal ◽  
Tomás M. López Seal ◽  
Mariano E. Simón ◽  
Camila S. Santana Smersu ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Wheat Flour ◽  
Fusarium Graminearum ◽  
Health Risks ◽  
Human Population ◽  
Economic Losses ◽  
Head Blight ◽  
Tolerance Limits ◽  
Intermediate Precision ◽  
Median Level

Background: Deoxynivalenol (DON) is a mycotoxin produced mainly by Fusarium graminearum. This fungus is the main plant pathogen associated with Fusarium Head Blight (FHB) wheat disease, causing significant economic losses and exposing human population to severe health risks. DON production changes widely among different years and areas and its effects are larger in years with abundant rainfall and high relative humidity. To date, Argentina has not established DON tolerance limits. Objective: To validate a method using GC with electron capture detector (GC-ECD) and to provide evidence of DON contamination in Argentinean commercial wheat flour. Results: A total of 34 different flour samples were analyzed obtaining 91.2% of incidence with a mean level of 243 µg/kg and a median level of 165 µg/kg. The method showed acceptable LOD (24 µg/kg) and LOQ (79 µg/kg), relative SD (RSD) of the intermediate precision (RSD = 5.98%), recovery (89.3%) and uncertainty (14%). Conclusions: The method was successfully validated according to the studied parameters. Incidence results for DON contamination are low and in accordance with previous studies for years with low FHB incidence in wheat.

scholarly journals Fungal Development and Induction of Defense Response Genes During Early Infection of Wheat Spikes by Fusarium graminearum

2000 ◽  
Vol 13 (2) ◽  
pp. 159-169 ◽  
Author(s):  
Clara Pritsch ◽  
Gary J. Muehlbauer ◽  
William R. Bushnell ◽  
David A. Somers ◽  
Carroll P. Vance
Keyword(s):  
Fusarium Graminearum ◽  
Defense Response ◽  
Expression Patterns ◽  
Economic Losses ◽  
Temporal Expression ◽  
Head Blight ◽  
Transcript Accumulation ◽  
Genes Encoding ◽  
Defense Response Genes ◽  
Sumai 3

Fusarium head blight (FHB) of wheat is a crippling disease that causes severe economic losses in many of the wheat-growing regions of the world. Temporal patterns of fungus development and transcript accumulation of defense response genes were studied in Fusarium graminearum-inoculated wheat spikes within the first 48 to 76 h after inoculation (hai). Microscopy of inoculated glumes revealed that the fungus appeared to penetrate through stomata, exhibited subcuticular growth along stomatal rows, colonized glume parenchyma cells, and sporulated within 48 to 76 hai. No major differences in the timing of these events were found between Sumai 3 (resistant) and Wheaton (susceptible) genotypes. In complementary experiments, RNA was extracted from spikes at several time intervals up to 48 hai and temporal expression patterns were determined for defense response genes encoding peroxidase, PR-1, PR-2 (β-1,3-glucanase), PR-3 (chitinase), PR-4, and PR-5 (thaumatin-like protein). In both genotypes, transcripts for the six defense response genes accumulated as early as 6 to 12 hai during F. graminearum infection and peaked at 36 to 48 hai. Greater and earlier PR-4 and PR-5 transcript accumulation was observed in Sumai 3, compared with Wheaton. Our results show that the timing of defense response gene induction is correlated with F. graminearum infection.

scholarly journals Genome Sequence of Fusarium graminearum Strain MDC_Fg1, Isolated from Bread Wheat Grown in France

2018 ◽  
Vol 7 (19) ◽  
Author(s):  
Tarek Alouane ◽  
Hélène Rimbert ◽  
Francis Fabre ◽  
Florence Cambon ◽  
Thierry Langin ◽  
...  
Keyword(s):  
Bread Wheat ◽  
Fusarium Graminearum ◽  
Genome Sequence ◽  
Fungal Pathogen ◽  
Whole Genome Sequence ◽  
Whole Genome ◽  
Head Blight ◽  
Content Type ◽  
French Isolate ◽  
Highly Virulent

Fusarium graminearum is a major fungal pathogen that induces Fusarium head blight (FHB), a devastating disease of small-grain cereals worldwide. This announcement provides the whole-genome sequence of a highly virulent and toxin-producing French isolate, MDC_Fg1.

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