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

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.

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The Golgin Protein RUD3 Regulates Fusarium graminearum Growth and Virulence

Applied and Environmental Microbiology ◽

10.1128/aem.02522-20 ◽

2021 ◽

Vol 87 (6) ◽

Author(s):

Chenyu Wang ◽

Yao Wang ◽

Liyuan Zhang ◽

Ziyi Yin ◽

Yuancun Liang ◽

...

Keyword(s):

Fusarium Graminearum ◽

Vegetative Growth ◽

Mammalian Cells ◽

Cellular Localization ◽

Pathogenic Fungus ◽

Coiled Coil ◽

Effective Control ◽

Content Type ◽

Ascospore Discharge ◽

And Function

ABSTRACT Golgins are coiled-coil proteins that play prominent roles in maintaining the structure and function of the Golgi complex. However, the role of golgin proteins in phytopathogenic fungi remains poorly understood. In this study, we functionally characterized the Fusarium graminearum golgin protein RUD3, a homolog of ScRUD3/GMAP-210 in Saccharomyces cerevisiae and mammalian cells. Cellular localization observation revealed that RUD3 is located in the cis-Golgi. Deletion of RUD3 caused defects in vegetative growth, ascospore discharge, deoxynivalenol (DON) production, and virulence. Moreover, the Δrud3 mutant showed reduced expression of tri genes and impairment of the formation of toxisomes, both of which play essential roles in DON biosynthesis. We further used green fluorescent protein (GFP)-tagged SNARE protein SEC22 (SEC22-GFP) as a tool to study the transport between the endoplasmic reticulum (ER) and Golgi and observed that SEC22-GFP was retained in the cis-Golgi in the Δrud3 mutant. RUD3 contains the coiled coil (CC), GRAB-associated 2 (GA2), GRIP-related Arf binding (GRAB), and GRAB-associated 1 (GA1) domains, which except for GA1, are indispensable for normal localization and function of RUD3, whereas only CC is essential for normal RUD3-RUD3 interaction. Together, these results demonstrate how the golgin protein RUD3 mediates retrograde trafficking in the ER-to-Golgi pathway and is necessary for growth, ascospore discharge, DON biosynthesis, and pathogenicity in F. graminearum. IMPORTANCE Fusarium head blight (FHB) caused by the fungal pathogen Fusarium graminearum is an economically important disease of wheat and other small grain cereal crops worldwide, and limited effective control strategies are available. A better understanding of the regulation mechanisms of F. graminearum development, deoxynivalenol (DON) biosynthesis, and pathogenicity is therefore important for the development of effective control management of this disease. Golgins are attached via their extreme carboxy terminus to the Golgi membrane and are involved in vesicle trafficking and organelle maintenance in eukaryotic cells. In this study, we systematically characterized a highly conserved Golgin protein, RUD3, and found that it is required for vegetative growth, ascospore discharge, DON production, and pathogenicity in F. graminearum. Our findings provide a comprehensive characterization of the golgin family protein RUD3 in plant-pathogenic fungus, which could help to identify a new potential target for effective control of this devastating disease.

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

mBio ◽

10.1128/mbio.00792-19 ◽

2019 ◽

Vol 10 (3) ◽

Cited By ~ 1

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.

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

Genome Announcements ◽

10.1128/genomea.01209-17 ◽

2017 ◽

Vol 5 (45) ◽

Cited By ~ 5

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.

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

Journal of AOAC International ◽

10.1093/jaoac/102.6.1721 ◽

2019 ◽

Vol 102 (6) ◽

pp. 1721-1724 ◽

Cited By ~ 2

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.

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One Small RNA of Fusarium graminearum Targets and Silences CEBiP Gene in Common Wheat

Microorganisms ◽

10.3390/microorganisms7100425 ◽

2019 ◽

Vol 7 (10) ◽

pp. 425 ◽

Cited By ~ 6

Author(s):

Jiao Jian ◽

Xu Liang

Keyword(s):

Fusarium Graminearum ◽

Small Rna ◽

Pathogenic Fungus ◽

Effective Means ◽

Transcriptional Level ◽

Head Blight ◽

Protein Coding ◽

Pathogen Invasion

The pathogenic fungus Fusarium graminearum (F. graminearum), causing Fusarium head blight (FHB) or scab, is one of the most important cereal killers worldwide, exerting great economic and agronomic losses on global grain production. To repress pathogen invasion, plants have evolved a sophisticated innate immunity system for pathogen recognition and defense activation. Simultaneously, pathogens continue to evolve more effective means of invasion to conquer plant resistance systems. In the process of co-evolution of plants and pathogens, several small RNAs (sRNAs) have been proved in regulating plant immune response and plant-microbial interaction. In this study, we report that a F. graminearum sRNA (Fg-sRNA1) can suppress wheat defense response by targeting and silencing a resistance-related gene, which codes a Chitin Elicitor Binding Protein (TaCEBiP). Transcriptional level evidence indicates that Fg-sRNA1 can target TaCEBiP mRNA and trigger silencing of TaCEBiP in vivo, and in Nicotiana benthamiana (N. benthamiana) plants, Western blotting experiments and YFP Fluorescence observation proofs show that Fg-sRNA1 can suppress the accumulation of protein coding by TaCEBiP gene in vitro. F. graminearum PH-1 strain displays a weakening ability to invasion when Barley stripe mosaic virus (BSMV) vector induces effective silencing Fg-sRNA1 in PH-1 infected wheat plants. Taken together, our results suggest that a small RNA from F. graminearum can target and silence the wheat TaCEBiP gene to enhance invasion of F. graminearum.

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Transducin Beta-Like Gene FTL1 Is Essential for Pathogenesis in Fusarium graminearum

Eukaryotic Cell ◽

10.1128/ec.00048-09 ◽

2009 ◽

Vol 8 (6) ◽

pp. 867-876 ◽

Cited By ~ 63

Author(s):

Shengli Ding ◽

Rahim Mehrabi ◽

Cornelia Koten ◽

Zhensheng Kang ◽

Yangdou Wei ◽

...

Keyword(s):

Fusarium Graminearum ◽

Insertional Mutagenesis ◽

Critical Role ◽

Histone Deacetylation ◽

Head Blight ◽

Plant Infection ◽

Expression Of Genes ◽

Plant Defensins ◽

Mitogen Activated Protein ◽

Late Stages

ABSTRACT Fusarium head blight caused by Fusarium graminearum is an important disease of wheat and barley. In a previous study, we identified several mutants with reduced virulence by insertional mutagenesis. A transducin beta-like gene named FTL1 was disrupted in one of these nonpathogenic mutants. FTL1 is homologous to Saccharomyces cerevisiae SIF2, which is a component of the Set3 complex involved in late stages of ascospore formation. The Δftl1 mutant was significantly reduced in conidiation and failed to cause typical disease symptoms. It failed to colonize the vascular tissues of rachis or cause necrosis on the rachis of inoculated wheat heads. The Δftl1 mutant also was defective in spreading from infected anthers to ovaries and more sensitive than the wild type to plant defensins MsDef1 and osmotin. However, the activation of two mitogen-activated protein kinases, Mgv1 and Gpmk1, production of deoxynivalenol, and expression of genes known to be important for plant infection in F. graminearum were not affected, indicating that the defect of the Δftl1 mutant in plant infection is unrelated to known virulence factors in this pathogen and may involve novel mechanisms. The Δftl1 deletion mutant was significantly reduced in histone deacetylation, and many members of the yeast Set3 complex are conserved in F. graminearum. FTL1 appears to be a component of this well-conserved protein complex that plays a critical role in the penetration and colonization of wheat tissues.

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

Applied and Environmental Microbiology ◽

10.1128/aem.02436-15 ◽

2015 ◽

Vol 82 (1) ◽

pp. 184-191 ◽

Cited By ~ 16

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.

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The Fusarium graminearum transporters Abc1 and Abc6 are important for xenobiotic resistance, trichothecene accumulation, and virulence to wheat.

10.1101/2021.06.15.448535 ◽

2021 ◽

Author(s):

Sean O'Mara ◽

Karen Broz ◽

Yanhong Dong ◽

Harold Kistler

Keyword(s):

Heterologous Expression ◽

Fusarium Graminearum ◽

Abc Transporter ◽

Pathogenic Fungus ◽

Resistance Mechanism ◽

Plant Diseases ◽

Head Blight ◽

Severe Reduction ◽

Membrane Bound ◽

Management Techniques

The plant pathogenic fungus Fusarium graminearum is the causal agent of Fusarium Head Blight (FHB) disease on small grain cereals. F. graminearum produces trichothecene mycotoxins such as deoxynivalenol (DON) that are required for full virulence. DON must be exported outside the cell to cause FHB disease, a process that may require the involvement of membrane-bound transporters. In this study we how the deletion of membrane-bound transporters results in reduced DON accumulation as well as reduced FHB symptoms on wheat. Deletion of the ATP-Binding Cassette (ABC) transporter Abc1 results in the most severe reduction in DON accumulation and virulence. Deletion of another ABC transporter, Abc6, also reduces FHB symptoms to a lesser degree. Combining deletions fails to reduce DON accumulation or virulence in an additive fashion, even when including an ∆abc1 deletion. Heterologous expression of F. graminearum transporters in a DON-sensitive strain of yeast confirms Abc1 as a major DON resistance mechanism. Yeast expression further indicates that multiple transporters, including Abc1 play an important role in resistance to the wheat phytoalexin 2-benzoxazolinone (BOA) and other xenobiotics. Thus, Abc1 may contribute to wheat virulence both by allowing export of DON and by providing resistance to the wheat phytoalexin BOA. This research provides useful information which may aid in designing novel management techniques of FHB or other destructive plant diseases.

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

mBio ◽

10.1128/mbio.02324-21 ◽

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.

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The Fusarium graminearum t-SNARE Sso2 Is Involved in Growth, Defense, and DON Accumulation and Virulence

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-01-20-0012-r ◽

2020 ◽

Vol 33 (7) ◽

pp. 888-901

Author(s):

Sean P. O’Mara ◽

Karen Broz ◽

Marike Boenisch ◽

Zixuan Zhong ◽

Yanhong Dong ◽

...

Keyword(s):

Fusarium Graminearum ◽

Deletion Mutant ◽

Expression Profiles ◽

Pathogenic Fungus ◽

Gene Expression Profiles ◽

Plant Diseases ◽

In Planta ◽

Head Blight ◽

Double Deletion

The plant-pathogenic fungus Fusarium graminearum, causal agent of Fusarium head blight (FHB) disease on small grain cereals, produces toxic trichothecenes that require facilitated export for full virulence. Two potential modes of mycotoxin transport are membrane-bound transporters, which move toxins across cellular membranes, and N-ethylmaleimide-sensitive factor attachment receptor (SNARE)-mediated vesicular transport, by which toxins may be packaged as cargo in vesicles bound for organelles or the plasma membrane. In this study, we show that deletion of a gene (Sso2) for a subapically localized t-SNARE protein results in growth alteration, increased sensitivity to xenobiotics, altered gene expression profiles, and reduced deoxynivalenol (DON) accumulation in vitro and in planta as well as reduced FHB symptoms on wheat. A double deletion mutant generated by crossing the ∆sso2 deletion mutant with an ATP-binding cassette transporter deletion mutant (∆abc1) resulted in an additive reduction in DON accumulation and almost complete loss of FHB symptoms in planta. These results suggest an important role of Sso2-mediated subapical exocytosis in FHB progression and xenobiotic defense and are the first report of an additive reduction in F. graminearum DON accumulation upon deletion of two distinct modes of cellular export. This research provides useful information which may aid in formulating novel management plans of FHB or other destructive plant diseases.

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