scholarly journals Intraspecies Interaction of Fusarium graminearum Contributes to Reduced Toxin Production and Virulence

2015 ◽  
Vol 28 (11) ◽  
pp. 1256-1267 ◽  
Author(s):  
Sean Walkowiak ◽  
Christopher T. Bonner ◽  
Li Wang ◽  
Barbara Blackwell ◽  
Owen Rowland ◽  
...  
Keyword(s):  
Fusarium Graminearum ◽  
Pathogenic Fungus ◽  
Pathogenic Fungi ◽  
Toxin Production ◽  
In Planta ◽  
Head Blight ◽  
Trichothecene Mycotoxin ◽  
Yield And Quality ◽  
Potential Interactions

Fusarium graminearum is a pathogenic fungus that causes Fusarium head blight in wheat and lowers the yield and quality of grains by contamination with the trichothecene mycotoxin deoxynivalenol. The fungi coexist and interact with several different fusaria as well as other plant pathogenic fungi and bacteria in the field. In Canada, F. graminearum exists as two main trichothecene chemotypes: 3-acetyldeoxynivalenol and 15-acetyldeoxynivalenol. To understand the potential interactions between two isolates of these chemotypes, we conducted coinoculation studies both in culture and in planta. The studies showed that intraspecies interaction reduces trichothecene yield in culture and disease symptoms in wheat. To elucidate the genes involved in the intraspecies interaction, expression profiling was performed on RNA samples isolated from coinoculated cultures, and potential genes were identified by using the genome sequences of the respective isolates.

scholarly journals Intrapopulation Antagonism Can Reduce the Growth and Aggressiveness of the Wheat Head Blight Pathogen Fusarium graminearum

2020 ◽  
Vol 110 (4) ◽  
pp. 916-926
Author(s):  
Martha M. Vaughan ◽  
Todd J. Ward ◽  
Susan P. McCormick ◽  
Nathane Orwig ◽  
William T. Hay ◽  
...  
Keyword(s):  
Fusarium Graminearum ◽  
Management Practices ◽  
Toxin Production ◽  
Antagonistic Effect ◽  
Head Blight ◽  
Yield And Quality ◽  
Pathogen Populations ◽  
Moderately Resistant

Fusarium graminearum is a causal agent of Fusarium head blight (FHB), a disease that reduces yield and quality of cereal crops and contaminates grain with mycotoxins that pose health risks to humans and livestock. Interpopulation antagonistic interactions between isolates that produce different trichothecene mycotoxins can reduce FHB in wheat, but it is not known if interactions between isolates with a shared population identity that produce the same trichothecenes have a similar effect. Using isolates from the predominant F. graminearum populations in North America (NA1 and NA2), we examined intrapopulation interactions by comparing growth, disease progression, and toxin production of individual isolates with multi-isolate mixes. In vitro, mycelial growth was significantly greater when most NA1 and NA2 isolates were cultured individually versus when cultured as a mixture of isolates from the same population. In susceptible wheat Norm, FHB generally progressed faster in heads inoculated with an individual isolate versus a multi-isolate mixture, but the antagonistic effect of intrapopulation interactions was more pronounced for NA1 than NA2 isolates. By contrast, in moderately resistant wheat Alsen, mixtures of isolates from either population caused obvious reductions in FHB development. Mycotoxin contamination was not consistently affected by intrapopulation interactions and varied depending on the interacting isolates from either population. Our results indicate that antagonistic intrapopulation interactions can influence FHB in controlled environmental conditions. Understanding if the regional composition of pathogen populations similarly influences FHB in the field could improve disease forecasting and management practices.

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

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.

scholarly journals Fengycin Produced by Bacillus amyloliquefaciens FZB42 Inhibits Fusarium graminearum Growth and Mycotoxins Biosynthesis

Toxins ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 295 ◽  
Author(s):  
Alvina Hanif ◽  
Feng Zhang ◽  
Pingping Li ◽  
Chuchu Li ◽  
Yujiao Xu ◽  
...  
Keyword(s):  
Fusarium Graminearum ◽  
Bacillus Amyloliquefaciens ◽  
Disease Incidence ◽  
Pathogenic Fungus ◽  
Plant Diseases ◽  
Cereal Crops ◽  
In Planta ◽  
Head Blight ◽  
Structural Deformations ◽  
Chemical Pesticides

Fusarium graminearum is a notorious pathogen that causes Fusarium head blight (FHB) in cereal crops. It produces secondary metabolites, such as deoxynivalenol, diminishing grain quality and leading to lesser crop yield. Many strategies have been developed to combat this pathogenic fungus; however, considering the lack of resistant cultivars and likelihood of environmental hazards upon using chemical pesticides, efforts have shifted toward the biocontrol of plant diseases, which is a sustainable and eco-friendly approach. Fengycin, derived from Bacillus amyloliquefaciens FZB42, was purified from the crude extract by HPLC and further analyzed by MALDI-TOF-MS. Its application resulted in structural deformations in fungal hyphae, as observed via scanning electron microscopy. In planta experiment revealed the ability of fengycin to suppress F. graminearum growth and highlighted its capacity to combat disease incidence. Fengycin significantly suppressed F. graminearum, and also reduced the deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-ADON), 15-acetyldeoxynivalenol (15-ADON), and zearalenone (ZEN) production in infected grains. To conclude, we report that fengycin produced by B. amyloliquefaciens FZB42 has potential as a biocontrol agent against F. graminearum and can also inhibit the mycotoxins produced by this fungus.

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

2019 ◽  
Vol 7 (10) ◽  
pp. 425 ◽  
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.

scholarly journals Investigating Useful Properties of Four Streptomyces Strains Active against Fusarium graminearum Growth and Deoxynivalenol Production on Wheat Grains by qPCR

Toxins ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 560
Author(s):  
Elena Maria Colombo ◽  
Andrea Kunova ◽  
Claudio Gardana ◽  
Cristina Pizzatti ◽  
Paolo Simonetti ◽  
...  
Keyword(s):  
Fusarium Graminearum ◽  
Plant Pathogens ◽  
Fungal Growth ◽  
Toxin Production ◽  
Fungal Mycelium ◽  
Head Blight ◽  
Wheat Grains ◽  
Streptomyces Spp ◽  
Dual Plate

Streptomyces spp. can be exploited as biocontrol agents (BCAs) against plant pathogens such as Fusarium graminearum, the main causal agent of Fusarium head blight (FHB) and against the contamination of grains with deoxynivalenol (DON). In the present research, four Streptomyces strains active against F. graminearum in dual plate assays were characterized for their ability to colonize detached wheat grains in the presence of F. graminearum and to limit DON production. The pathogen and BCA abundance were assessed by a quantitative real-time PCR, while DON production was assessed by HPLC quantification and compared to ergosterol to correlate the toxin production to the amount of fungal mycelium. Fungal growth and mycotoxin production were assessed with both co-inoculation and late inoculation of the BCAs in vitro (three days post-Fusarium inoculation) to test the interaction between the fungus and the bacteria. The level of inhibition of the pathogen and the toxin production were strain-specific. Overall, a higher level of DON inhibition (up to 99%) and a strong reduction in fungal biomass (up to 71%) were achieved when streptomycetes were co-inoculated with the fungus. This research enabled studying the antifungal efficacy of the four Streptomyces strains and monitoring their development in DON-inducing conditions.

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

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.

Endophytic fungi as a promising biocontrol agent to protect wheat from Fusarium graminearum head blight

Plant Disease ◽  
2021 ◽  
Author(s):  
Zachary Albert Noel ◽  
Ludmilla Roze ◽  
Mikaela Breunig ◽  
Frances Trail
Keyword(s):  
Microbial Community ◽  
Fusarium Graminearum ◽  
Endophytic Fungi ◽  
Seed Weight ◽  
Biocontrol Agent ◽  
Fungal Endophytes ◽  
In Planta ◽  
Head Blight ◽  
Species Definitions

The search for beneficial endophytes that can be part of a constructed microbial community has increased in recent years. We characterized three endophytic fungi previously isolated from wheat for their in vitro and in planta antagonism toward the Fusarium head blight pathogen, Fusarium graminearum. The endophytes were phylogenetically characterized and shown to be Alternaria destruens, Fusarium commune, and Fusarium oxysporum. Individual fungal endophytes significantly increased seed weight and lowered the accumulation of the mycotoxin deoxynivalenol compared to F. graminearum infected wheat heads without endophyte pretreatment. Investigation into the mechanism of competition in vitro showed that endophytes competitively excluded F. graminearum by pre-emptive colonization and possible inhibition over a distance. Investigations on the use of these endophytes in the field are in progress. Identification of these three endophytes highlights a common quandary in searching for beneficial microbes to use in agriculture: species definitions often do not separate individual isolates’ lifestyles. A greater understanding of the risks in using intraspecies variants for biocontrol is needed and should be examined in the context of the ecology of the individuals being investigated.

scholarly journals Toxigenic Capacity and Trichothecene Production by Fusarium graminearum Isolates from Argentina and Their Relationship with Aggressiveness and Fungal Expansion in the Wheat Spike

2014 ◽  
Vol 104 (4) ◽  
pp. 357-364 ◽  
Author(s):  
I. Malbrán ◽  
C. A. Mourelos ◽  
J. R. Girotti ◽  
P. A. Balatti ◽  
G. A. Lori
Keyword(s):  
Fusarium Graminearum ◽  
Vascular Tissue ◽  
Close Correlation ◽  
Field Trials ◽  
In Planta ◽  
Head Blight ◽  
Variable Intensity ◽  
Polymerase Chain

At least 20 epidemics of Fusarium head blight (FHB) of wheat have been registered in the last 50 years in Argentina, with variable intensity. Damage induced by the disease is further aggravated by the presence of mycotoxins in affected grains that may cause health problems to humans and animals. The trichothecene chemotype was analyzed for 112 isolates of Fusarium graminearum from Argentina by polymerase chain reaction and two field trials were conducted to study the aggressiveness of a subsample of 14 representative isolates and to analyze deoxynivalenol (DON) production in planta and in vitro. All isolates belonged to the 15-acetyl-DON chemotype. Significant differences were observed in both the symptom severity induced in wheat spikes and the in vivo DON production, and a close correlation was found between these two variables. However, in vitro toxigenic potential was not correlated with the capacity of F. graminearum isolates to produce DON under natural conditions. The progress of infection in the rachis of inoculated wheat spikes was analyzed and the pathogen presence verified in both symptomatic and symptomless spikes. Even isolates with a limited capacity to induce symptoms were able to colonize the vascular tissue and to produce considerable amounts of DON in planta.

scholarly journals Nivalenol-Type Populations of Fusarium graminearum and F. asiaticum Are Prevalent on Wheat in Southern Louisiana

2011 ◽  
Vol 101 (1) ◽  
pp. 124-134 ◽  
Author(s):  
Liane Rosewich Gale ◽  
Stephen A. Harrison ◽  
Todd J. Ward ◽  
Kerry O'Donnell ◽  
Eugene A. Milus ◽  
...  
Keyword(s):  
United States ◽  
North Carolina ◽  
Fusarium Graminearum ◽  
Gulf Coast ◽  
Pcr Primers ◽  
The United States ◽  
Sensu Stricto ◽  
Head Blight ◽  
Trichothecene Mycotoxin ◽  
Southern Louisiana

U.S. populations of the Fusarium graminearum clade cause head blight on wheat and barley and usually contaminate grain with the trichothecene mycotoxin deoxynivalenol (DON). Recently, however, individual nivalenol (NIV)-type isolates from the United States were described that belonged to either the newly described species F. gerlachii or the genetically distinct Gulf Coast population of F. graminearum sensu stricto (s.s.). Here, we describe the discovery of NIV-type F. graminearum s.s. populations that were found in high proportion (79%) among isolates from small-grain-growing regions of Louisiana. We genotyped 237 isolates from Louisiana with newly developed polymerase chain reaction (PCR) restriction fragment length polymorphism markers and multiplex PCR primers that distinguish among the three trichothecene types: the two DON types (15ADON and 3ADON) and NIV. These isolates were compared with 297 isolates from 11 other U.S. states, predominantly from the Midwest. Using Bayesian-model-based clustering, we discovered a southern Louisiana population of F. graminearum s.s. that was genetically distinct from the previously recognized pathogen population in the Midwest (MW15ADON population). Population membership was correlated with trichothecene type. Most isolates from the southern Louisiana population were of the NIV type, while the majority of the isolates from the Midwest were of the 15ADON type. A smaller proportion of isolates from Louisiana belonged to the previously described Gulf Coast population that was mostly of the 3ADON type. The NIV type was also identified in collections from Arkansas (12%), North Carolina (40%), and Missouri (2%), with the collections from Arkansas and North Carolina being small and unrepresentative. F. asiaticum was detected from the two southern Louisiana parishes Acadia and Alexandria. All identified 41 F. asiaticum isolates were of the NIV type. Greenhouse tests indicated that U.S. NIV types accumulated four times less trichothecene toxin than DON types on inoculated wheat. This is the first report of NIV-type populations of F. graminearum s. s. and F. asiaticum in the United States.

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