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.

Impact of the biofungicide tetramycin on the development of Fusarium head blight, grain yield and deoxynivalenol accumulation in wheat

2020 ◽  
Vol 13 (2) ◽  
pp. 235-246
Author(s):  
W.Q. Shi ◽  
L.B. Xiang ◽  
D.Z. Yu ◽  
S.J. Gong ◽  
L.J. Yang
Keyword(s):  
Fusarium Head Blight ◽  
Fusarium Graminearum ◽  
Spore Germination ◽  
Field Experiments ◽  
Synergistic Effects ◽  
Field Trials ◽  
Head Blight ◽  
Mycelium Growth ◽  
Key Aspects

Fusarium graminearum causes Fusarium head blight (FHB), a devastating disease that leads to extensive yield and quality loss in wheat and barley production. Integrated pest management (IPM) is required to control this disease and biofungicides, such as tetramycin, could be a novel addition to IPM strategies. The current study investigated in vitro tetramycin toxicity in Fusarium graminearum and evaluated its effectiveness for the control of Fusarium head blight FHB. Tetramycin was shown to affect three key aspects of Fusarium pathogenicity: spore germination, mycelium growth and deoxynivalenol (DON) production. The in vitro results indicated that tetramycin had strong inhibitory activity on the mycelial growth and spore germination. Field trials indicated that tetramycin treatment resulted in a significant reduction in both the FHB disease index and the level of DON accumulation. The reduced DON content in harvested grain was correlated with the amount of Tri5 mRNA determined by qRT-PCR. Synergistic effects between tetramycin and metconazole, in both the in vitro and field experiments were found. Tetramycin could provide an alternative option to control FHB.

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 Variation Among Isolates of Fusarium graminearum Associated with Fusarium Head Blight in North Carolina

Plant Disease ◽  
2001 ◽  
Vol 85 (4) ◽  
pp. 404-410 ◽  
Author(s):  
Scott L. Walker ◽  
Steven Leath ◽  
Winston M. Hagler ◽  
J. Paul Murphy
Keyword(s):  
North Carolina ◽  
Fusarium Head Blight ◽  
Fusarium Graminearum ◽  
Phenotypic Diversity ◽  
In Vitro Growth ◽  
Head Blight ◽  
Potential Threat ◽  
Previous Crop

Fusarium head blight (FHB) can reduce yield of wheat and decrease the value of harvested grain by accumulation of detrimental toxins. Understanding the variability of the fungal population associated with infection could improve disease control strategies. Sixty-six isolates of Fusarium graminearum associated with FHB were collected in North Carolina and tested for in vitro growth rate, in vitro production of deoxynivalenol (DON) and zearalenone, and pathogenicity on three cultivars of soft red winter wheat. Significant differences among isolates were found for all three traits. Randomly Amplified Polymorphic DNA (RAPD) analysis revealed high levels of genotypic diversity among isolates. Isolates of F. graminearum, F. culmorum, and F. avenaceum acquired from the Pennsylvania State University Fusarium Center were included for comparison in all tests. In vivo levels of DON were measured for the five isolates associated with the highest levels of disease and the five isolates associated with the lowest levels of disease, and no significant differences were found. However, all ten isolates produced detectable levels of DON in vivo. Mean disease ratings ranged from 3.4 to 96.4%, in vitro (DON) levels ranged from 0 to 7176.2 ppm, and zearalenone ranged from 0 to 354.7 ppm, among isolates. A multiple regression model using in vitro growth, in vitro DON, and zearalenone production, collection location, wheat cultivar of isolate origin, plot, tillage conditions, and previous crop as independent variables and percent blighted tissue as the dependent variable was developed. The cumulative R2 value for the model equaled 0.27 with in vitro rate of growth making the largest contribution. Analysis of phenotype and genotype among isolates demonstrated diversity in a single plot, in a single location, and in North Carolina. Genotypic and phenotypic diversity were significant under both conventional and reduced tillage conditions, and diversity was high regardless of whether the previous crop had been a host or non-host for F. graminearum. These data indicate a variable pathogen population of F. graminearum exists in North Carolina, and members of this population can be both highly pathogenic on wheat and produce high levels of detrimental toxins, indicating a potential threat for problems with FHB within the state.

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 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 The Stress-Activated Protein Kinase FgOS-2 Is a Key Regulator in the Life Cycle of the Cereal Pathogen Fusarium graminearum

2012 ◽  
Vol 25 (9) ◽  
pp. 1142-1156 ◽  
Author(s):  
Thuat Van Nguyen ◽  
Wilhelm Schäfer ◽  
Jörg Bormann
Keyword(s):  
Protein Kinase ◽  
Fusarium Graminearum ◽  
Fluorescent Protein ◽  
Microscopic Analysis ◽  
Deletion Mutants ◽  
Wild Type ◽  
In Planta ◽  
Head Blight ◽  
Food And Feed

Fusarium graminearum is one of the most destructive pathogens of cereals and a threat to food and feed production worldwide. It is an ascomycetous plant pathogen and the causal agent of Fusarium head blight disease in small grain cereals and of cob rot disease in maize. Infection with F. graminearum leads to yield losses and mycotoxin contamination. Zearalenone (ZEA) and deoxynivalenol (DON) are hazardous mycotoxins; the latter is necessary for virulence toward wheat. Deletion mutants of the F. graminearum orthologue of the Saccharomyces cerevisiae Hog1 stress-activated protein kinase, FgOS-2 (ΔFgOS-2), showed drastically reduced in planta DON and ZEA production. However, ΔFgOS-2 produced even more DON than the wild type under in vitro conditions, whereas ZEA production was similar to that of the wild type. These deletion strains are dramatically reduced in pathogenicity toward maize and wheat. We constitutively expressed the fluorescent protein dsRed in the deletion strains and the wild type. Microscopic analysis revealed that ΔFgOS-2 is unable to reach the rachis node at the base of wheat spikelets. During vegetative growth, ΔFgOS-2 strains exhibit increased resistance against the phenylpyrrole fludioxonil. Growth of mutant colonies on agar plates supplemented with NaCl is reduced but conidia formation remained unchanged. However, germination of mutant conidia on osmotic media is severely impaired. Germ tubes are swollen and contain multiple nuclei. The deletion mutants completely fail to produce perithecia and ascospores. Furthermore, FgOS-2 also plays a role in reactive oxygen species (ROS)-related signaling. The transcription and activity of fungal catalases is modulated by FgOS-2. Among the genes regulated by FgOS-2, we found a putative calcium-dependent NADPH-oxidase (noxC) and the transcriptional regulator of ROS metabolism, atf1. The present study describes new aspects of stress-activated protein kinase signaling in F. graminearum.

scholarly journals Hydrogen peroxide induced by the fungicide prothioconazole triggers deoxynivalenol (DON) production by Fusarium graminearum

2011 ◽  
Vol 63 (1) ◽  
pp. 3-21 ◽  
Author(s):  
Kris Audenaert ◽  
Elien Callewaert ◽  
Monica Höfte ◽  
Sarah De Saeger ◽  
Geert Haesaert
Keyword(s):  
Hydrogen Peroxide ◽  
Fusarium Graminearum ◽  
Point Of View ◽  
Head Blight ◽  
Fungal Genomics ◽  
Yield And Quality ◽  
Lethal Doses ◽  
Important Disease

Hydrogen peroxide induced by the fungicide prothioconazole triggers deoxynivalenol (DON) production by Fusarium graminearum Fusarium head blight is a very important disease of small grain cereals with F. graminearum as one of the most important causal agents. It not only causes reduction in yield and quality but from a human and animal healthcare point of view, it produces mycotoxins such as deoxynivalenol (DON) which can accumulate to toxic levels. Little is known about external triggers influencing DON production. In the present work, a combined in vivo/in vitro approach was used to test the effect of sub lethal fungicide treatments on DON production. Using a dilution series of prothioconazole, azoxystrobin and prothioconazole + fluoxastrobin, we demonstrated that sub lethal doses of prothioconazole coincide with an increase in DON production 48 h after fungicide treatment. In an artificial infection trial using wheat plants, the in vitro results of increased DON levels upon sub lethal prothioconazole application were confirmed illustrating the significance of these results from a practical point of view. In addition, further in vitro experiments revealed a timely hyperinduction of H2O2 production as fast as 4h after amending cultures with prothioconazole. When applying H2O2 directly to germinating conidia, a similar induction of DON-production by F. graminearum was observed. The effect of sub lethal prothioconazole concentrations on DON production completely disappeared when applying catalase together with the fungicide. These cumulative results suggest that H2O2 induced by sub lethal doses of the triazole fungicide prothioconazole acts as a trigger of DON biosynthesis. In a broader framework, this work clearly shows that DON production by the plant pathogen F. graminearum is the result of the interaction of fungal genomics and external environmental triggers.

scholarly journals Germination of Fusarium graminearum Ascospores and Wheat Infection are Affected by Dry Periods and by Temperature and Humidity During Dry Periods

2016 ◽  
Vol 106 (3) ◽  
pp. 262-269 ◽  
Author(s):  
V. Manstretta ◽  
C. Morcia ◽  
V. Terzi ◽  
V. Rossi
Keyword(s):  
Fusarium Graminearum ◽  
Fungal Biomass ◽  
Quantitative Polymerase Chain Reaction ◽  
In Planta ◽  
Chain Reaction ◽  
Ascospore Germination ◽  
Saturated Atmosphere ◽  
Polymerase Chain ◽  
Effects Of Temperature

The effects of temperature and relative humidity (RH) on germination of Fusarium graminearum ascospores, and of dry periods (DP) of different lengths and of temperature and RH during DP on ascospore survival were studied both in vitro and in planta. Optimal temperatures for ascospore germination at 100% RH were 20 and 25°C; germination was ≤5% when ascospores were incubated at 20°C and RH ≤ 93.5%. Viable ascospores were found at all tested combinations of DP duration (0 to 48 h) × temperature (5 to 40°C) or RH (32.5 to 100% RH). Germination declined as DP duration and temperature increased. Germination was lower for ascospores kept at 65.5% RH during the DP than at 76.0, 32.5, or 93.5% RH. Equations were developed describing the relationships between ascospore germination, DP duration and temperature or RH during DP. Durum wheat spikes were inoculated with ascospores and kept dry for 0 to 48 h at approximately 15°C and 65% RH; plants were then kept in saturated atmosphere for 48 h to favor infection. Fungal biomass, measured as F. graminearum DNA by quantitative polymerase chain reaction, declined as DP increased to 24 and 48 h at 3 and 9 days postinfection but not in spikes at maturity.

Surface Modification by Nanobiomaterials for Vascular Tissue Engineering Applications

2020 ◽  
Vol 27 (10) ◽  
pp. 1634-1646 ◽  
Author(s):  
Huey-Shan Hung ◽  
Shan-hui Hsu
Keyword(s):  
Tissue Engineering ◽  
Vascular Tissue ◽  
Thrombus Formation ◽  
Vascular Grafts ◽  
Vascular Tissue Engineering ◽  
Great Success ◽  
Natural Polymers ◽  
Vascular Biomaterials

Treatment of cardiovascular disease has achieved great success using artificial implants, particularly synthetic-polymer made grafts. However, thrombus formation and restenosis are the current clinical problems need to be conquered. New biomaterials, modifying the surface of synthetic vascular grafts, have been created to improve long-term patency for the better hemocompatibility. The vascular biomaterials can be fabricated from synthetic or natural polymers for vascular tissue engineering. Stem cells can be seeded by different techniques into tissue-engineered vascular grafts in vitro and implanted in vivo to repair the vascular tissues. To overcome the thrombogenesis and promote the endothelialization effect, vascular biomaterials employing nanotopography are more bio-mimic to the native tissue made and have been engineered by various approaches such as prepared as a simple surface coating on the vascular biomaterials. It has now become an important and interesting field to find novel approaches to better endothelization of vascular biomaterials. In this article, we focus to review the techniques with better potential improving endothelization and summarize for vascular biomaterial application. This review article will enable the development of biomaterials with a high degree of originality, innovative research on novel techniques for surface fabrication for vascular biomaterials application.

scholarly journals Effective decellularisation of human saphenous veins for biocompatible arterial tissue engineering applications: Bench optimisation and feasibility in vivo testing

2021 ◽  
Vol 12 ◽  
pp. 204173142098752
Author(s):  
Nadiah S Sulaiman ◽  
Andrew R Bond ◽  
Vito D Bruno ◽  
John Joseph ◽  
Jason L Johnson ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Mechanical Strength ◽  
Vascular Tissue ◽  
Sodium Dodecyl ◽  
Host Cells ◽  
Replacement Model ◽  
In Vivo Testing ◽  
Vascular Scaffolds

Human saphenous vein (hSV) and synthetic grafts are commonly used conduits in vascular grafting, despite high failure rates. Decellularising hSVs (D-hSVs) to produce vascular scaffolds might be an effective alternative. We assessed the effectiveness of a detergent-based method using 0% to 1% sodium dodecyl sulphate (SDS) to decellularise hSV. Decellularisation effectiveness was measured in vitro by nuclear counting, DNA content, residual cell viability, extracellular matrix integrity and mechanical strength. Cytotoxicity was assessed on human and porcine cells. The most effective SDS concentration was used to prepare D-hSV grafts that underwent preliminary in vivo testing using a porcine carotid artery replacement model. Effective decellularisation was achieved with 0.01% SDS, and D-hSVs were biocompatible after seeding. In vivo xeno-transplantation confirmed excellent mechanical strength and biocompatibility with recruitment of host cells without mechanical failure, and a 50% patency rate at 4-weeks. We have developed a simple biocompatible methodology to effectively decellularise hSVs. This could enhance vascular tissue engineering toward future clinical applications.

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