scholarly journals Adaptation of Fusarium graminearum to Tebuconazole Yielded Descendants Diverging for Levels of Fitness, Fungicide Resistance, Virulence, and Mycotoxin Production

2010 ◽  
Vol 100 (5) ◽  
pp. 444-453 ◽  
Author(s):  
Rayko Becher ◽  
Ursula Hettwer ◽  
Petr Karlovsky ◽  
Holger B. Deising ◽  
Stefan G. R. Wirsel
Keyword(s):  
Fusarium Graminearum ◽  
Fungicide Resistance ◽  
Quantitative Polymerase Chain Reaction ◽  
Sublethal Dose ◽  
Cross Resistance ◽  
Azole Resistance ◽  
Head Blight ◽  
Widespread Application ◽  
Mycotoxin Production ◽  
Azole Fungicides

Azole fungicides play a prominent role for reliable plant disease management. However, quantitative azole resistance has been shown to develop in fungal pathogens, including Fusarium graminearum, the causal agent of Fusarium head blight (FHB). Due to widespread application of azole fungicides, resistance may accumulate to higher degrees in fungal field populations over time. Although azole fungicides are prominent components in FHB control, little effort has been made to investigate azole resistance in F. graminearum. We allowed F. graminearum strain NRRL 13383 to adapt to an azole fungicide in vitro, applying a strongly growth-reducing but sublethal dose of tebuconazole. Two morphologically distinguishable azole-resistant phenotypes were recovered that differed with regard to levels of fitness, fungicide resistance, virulence, and mycotoxin production. Isolates of the adapted “phenotype 1” exhibited azole-specific cross-resistance, whereas “phenotype 2” isolates displayed the phenomenon of multidrug resistance because the sensitivity to amine fungicides was also affected. Assessment of individual infected spikelets for mycotoxin contents by high-performance liquid chromatography mass spectrometry and for Fusarium DNA by quantitative polymerase chain reaction indicated that some of the adapted isolates produced significantly higher levels of nivalenol per fungal biomass than the NRRL 13383 strain.

scholarly journals Fusarium graminearum Isolates from Wheat and Maize in New York Show Similar Range of Aggressiveness and Toxigenicity in Cross-Species Pathogenicity Tests

2015 ◽  
Vol 105 (4) ◽  
pp. 441-448 ◽  
Author(s):  
Paulo R. Kuhnem ◽  
Emerson M. Del Ponte ◽  
Yanhong Dong ◽  
Gary C. Bergstrom
Keyword(s):  
New York ◽  
Fusarium Graminearum ◽  
Rank Order ◽  
Ear Rot ◽  
Head Blight ◽  
Mycotoxin Production ◽  
Pathogenicity Tests ◽  
Similar Range ◽  
Maize Kernels ◽  
Wheat Kernels

This study aimed to assess whether pathogenic Fusarium graminearum isolates from wheat and maize were more aggressive on their host of origin and whether aggressiveness was influenced further by B-trichothecene chemotype. Fifteen isolates were selected from a contemporary collection of isolates surveyed in New York in 2011 to 2012 to represent diversity of host of origin and chemotype. Three pathogenicity assays were used to evaluate and compare these isolates. Fusarium head blight (FHB) severity and trichothecene production in wheat, and maize seedling blight were evaluated in greenhouse inoculation experiments, and Gibberella ear rot (GER) severity and trichothecene production were evaluated in maize ears inoculated in the field. Our results showed among F. graminearum isolates a wide variation in aggressiveness and mycotoxin production toward wheat and maize and these isolates could not be structured by their host of origin or by chemotype. Moreover, aggressiveness rank order changed according to the host/organ evaluated. This indicates that relative susceptibility at the seedling stage may not predict susceptibility of ears. Significant correlations were observed of total trichothecenes (deoxynivalenol [DON] and its acetylated derivatives) produced with FHB and GER severity on wheat and maize, respectively. One isolate did not produce DON or ADON in wheat or maize kernels, yet was aggressive on both hosts. Nine of the fifteen isolates produced small amounts of zearalenone (ZON) in maize kernels, but not in wheat kernels, and ZON level was not correlated with GER severity. F. graminearum isolates from New York showed wide variation in aggressiveness and mycotoxin production toward susceptible wheat and maize. Neither host of origin nor trichothecene chemotype appeared to structure the populations we sampled.

scholarly journals Phases of Infection and Gene Expression of Fusarium graminearum During Crown Rot Disease of Wheat

2008 ◽  
Vol 21 (12) ◽  
pp. 1571-1581 ◽  
Author(s):  
Amber E. Stephens ◽  
Donald M. Gardiner ◽  
Rosemary G. White ◽  
Alan L. Munn ◽  
John M. Manners
Keyword(s):  
Gene Expression ◽  
Fusarium Graminearum ◽  
Quantitative Polymerase Chain Reaction ◽  
Crown Rot ◽  
Fungal Colonization ◽  
Published Data ◽  
In Planta ◽  
Head Blight ◽  
Fungal Gene Expression ◽  
Fungal Gene

Fusarium graminearum causes head blight (FHB) and crown rot (CR) diseases in wheat. Compared with FHB, CR symptom development occurs slowly, usually taking 4 to 8 weeks to become visible. To characterize CR development, we used histological and real-time quantitative polymerase chain reaction analyses to assess fungal colonization during a timecourse of infection. Three distinct phases of infection were identified: i) initial spore germination with formation of a superficial hyphal mat at the inoculation point, ii) colonization of the adaxial epidermis of the outer leaf sheath and mycelial growth from the inoculation point to the crown, concomitant with a drop in fungal biomass, and iii) extensive colonization of the internal crown tissue. Fungal gene expression was examined during each phase using Affymetrix GeneChips. In total, 1,839 F. graminearum genes were significantly upregulated, including some known FHB virulence genes (e.g., TRI5 and TRI14), and 2,649 genes were significantly downregulated in planta compared with axenically cultured mycelia. Global comparisons of fungal gene expression with published data for FHB showed significant similarities between early stages of FHB and CR. These results indicate that CR disease development involves distinct phases of colonization, each of which is associated with a different fungal gene expression program.

scholarly journals Biological Characteristics and Molecular Mechanisms of Fludioxonil Resistance in Fusarium graminearum in China

Plant Disease ◽  
2020 ◽  
Vol 104 (9) ◽  
pp. 2426-2433
Author(s):  
F. Zhou ◽  
D. X. Li ◽  
H. Y. Hu ◽  
Y. L. Song ◽  
Y. C. Fan ◽  
...  
Keyword(s):  
Fusarium Graminearum ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Stop Codon ◽  
Point Mutations ◽  
Premature Stop Codon ◽  
Cross Resistance ◽  
Alternative Mechanism ◽  
Head Blight ◽  
Resistant Mutants

Fusarium graminearum is the primary causal agent of Fusarium head blight (FHB) of wheat. The phenylpyrrole fungicide fludioxonil is not currently registered for the management of FHB in China. The current study assessed the fludioxonil sensitivity of a total of 53 F. graminearum isolates collected from the six most important wheat-growing provinces of China during 2018 and 2019. The baseline fludioxonil sensitivity distribution indicated that all of the isolates were sensitive, exhibiting a unimodal cure with a mean effective concentration for 50% inhibition value of 0.13 ± 0.12 μg/ml (standard deviation). Five fludioxonil-resistant mutants were subsequently induced by exposure to fludioxonil under laboratory conditions. Ten successive rounds of subculture in the absence of the selection pressure indicated that the mutation was stably inherited. However, the fludioxonil-resistant mutants were found to have reduced pathogenicity, higher glycerol accumulation, and higher osmotic sensitivity than the parental wild-type isolates, indicating that there was a fitness cost associated with fludioxonil resistance. In addition, the study also found a positive cross resistance between fludioxonil, procymidone, and iprodione, but not with other fungicides such as boscalid, carbendazim, tebuconazole, and fluazinam. Sequence analysis of four candidate target genes (FgOs1, FgOs2, FgOs4, and FgOs5) revealed that the HBXT2R mutant contained two point mutations that resulted in amino acid changes at K223T and K415R in its FgOs1 protein, and one point mutation at residue 520 of its FgOs5 protein that resulted in a premature stop codon. Similarly, the three other mutants contained point mutations that resulted in changes at the K192R, K293R, and K411R residues of the FgOs5 protein but none in the FgOs2 and FgOs4 genes. However, it is important to point out that the FgOs2 and FgOs4 expression of all the fludioxonil-resistant mutants was significantly (P < 0.05) downregulated compared with the sensitive isolates (except for the SQ1-2 isolate). It was also found that one of the resistant mutants did not have changes in any of the sequenced target genes, indicating that an alternative mechanism could also lead to fludioxonil resistance.

Temperature-responded biological fitness of carbendazim-resistance Fusarium graminearum mutants conferring the F167Y, E198K and E198L substitutions

Plant Disease ◽  
2021 ◽  
Author(s):  
Yingfan Wang ◽  
Yi-ping Hou ◽  
XueWei Mao ◽  
fuyu Liu ◽  
Mingguo Zhou
Keyword(s):  
Low Temperature ◽  
Fusarium Graminearum ◽  
Hyphal Growth ◽  
Atmospheric Temperature ◽  
Cross Resistance ◽  
Wild Type ◽  
Head Blight ◽  
Flower Stage ◽  
Effects Of Temperature ◽  
Resistance Mutants

Understanding the effects of temperature on Fusarium graminearum infection can provide the theoretical guidance for chemical control of Fusarium head blight (FHB)．Here, we evaluated the effects of various temperatures on biological fitness development of wild-type sensitive strain 2021 and carbendazim-resistance mutants conferring β2-tubulin substitutions F167Y, E198K and E198L. The results showed that mycelial growth and conidiation of four strains increased with the increase of the temperature between 10°C and 25°C. Conidia of F167Y displayed strong adaptability to low temperature. The virulence of the four strains was largely similar at the same temperature, showing an upward trend between 10°C and 25°C. At 10°C, the hyphal growth of all strains was significantly inhibited, and metabolism slowed down and the accumulation of secondary metabolites decreased. Subsequently, the production of deoxynivalenol (DON) and its intermediate, pyruvate and aurofusarin decreased at low temperature, and the expression of DON biosynthesis-related genes Tri5, FgPK and AUR decreased accordingly. At the same temperature, the aurofusarin production of the strains F167Y and E198K was higher than that of strains 2021 and E198L. The contents of DON and pyruvic acid in carbendazim-resistance mutants were higher than that of the wild-type strain 2021. The sensitivity of four strains to different fungicides changed at various temperatures. The sensitivity to most fungicides increased with the temperature decreasing. The carbendazim-resistance mutants appeared positive cross-resistance with other benzimidazoles. But there was no cross-resistance to pyraclostrobin and azoles. These results would direct us to use fungicide preventing the infection of F. graminearum with changeable atmospheric temperature at wheat flower stage.

Composition of Fusarium species causing natural spike infection in wheat

2011 ◽  
Vol 59 (3) ◽  
pp. 255-260 ◽  
Author(s):  
E. László ◽  
B. Varga ◽  
O. Veisz
Keyword(s):  
Winter Wheat ◽  
Fusarium Graminearum ◽  
Species Complex ◽  
Crop Yields ◽  
Fusarium Species ◽  
Cereal Crop ◽  
Head Blight ◽  
Mycotoxin Production ◽  
Cereal Grain

Numerous Fusarium species have been associated with the Fusarium head blight (FHB) disease of wheat, barley and other small-grain cereals, reducing worldwide cereal crop yields and, as a consequence of their mycotoxin production in the cereal grain, having an impact on both human and animal health.The year 2010 was extremely favourable for Fusarium head blight pathogens. Over a hundred symptomatic wheat heads were collected from various locations in Hungary. The aim was to determine the diversity of the Fusarium species infecting winter wheat ears. A total of 86 Fusarium spp. were morphologically identified from diseased kernels. F. sambucinum was found to be present in two of the Martonvásár samples. This pathogen had only previously been detected extremely sporadically. The species F. culmorum and F. verticillioides were found at a much lower rate than expected, while none of the isolates were identified as F. poae. On the basis of the results, 95% of the isolates belonged to the Fusarium graminearum species complex.

scholarly journals Screening of Durum Wheat (Triticum turgidum L. subsp. durum (Desf.) Husn.) Italian Cultivars for Susceptibility to Fusarium Head Blight Incited by Fusarium graminearum

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 68
Author(s):  
Gaetano Bentivenga ◽  
Alfio Spina ◽  
Karim Ammar ◽  
Maria Allegra ◽  
Santa Olga Cacciola
Keyword(s):  
Durum Wheat ◽  
Fusarium Head Blight ◽  
Fusarium Graminearum ◽  
Triticum Turgidum ◽  
Disease Incidence ◽  
Morphological Characteristics ◽  
Pcr Amplification ◽  
Conidial Suspension ◽  
Head Blight ◽  
Italian Origin

In 2009, a set of 35 cultivars of durum wheat (Triticum turgidum L. subsp. durum (Desf.) Husn.) of Italian origin was screened for fusarium head blight (FHB) susceptibility at CIMMYT (Mexico) and in the 2019–20 cropping season, 16 of these cultivars, which had been included in the Italian National Plant Variety Register, were tested again in southern and northern Italy. Wheat cultivars were artificially inoculated during anthesis with a conidial suspension of Fusarium graminearum sensu lato using a standard spray inoculation method. Inoculum was a mixture of mono-conidial isolates sourced in the same areas where the trials were performed. Isolates had been characterized on the basis of morphological characteristics and by DNA PCR amplification using a specific primer set and then selected for their virulence and ability to produce mycotoxins. The susceptibility to FHB was rated on the basis of the disease severity, disease incidence and FHB index. Almost all of the tested cultivars were susceptible or very susceptible to FHB with the only exception of “Duprì”, “Tiziana” and “Dylan” which proved to be moderately susceptible. The susceptibility to FHB was inversely correlated with the plant height and flowering biology, the tall and the late heading cultivars being less susceptible.

Near-infrared versus visual sorting of Fusarium-damaged kernels in winter wheat

2008 ◽  
Vol 88 (6) ◽  
pp. 1087-1089 ◽  
Author(s):  
Stephen N Wegulo ◽  
Floyd E Dowell
Keyword(s):  
Quality Assurance ◽  
Winter Wheat ◽  
Fusarium Head Blight ◽  
Key Words ◽  
Fusarium Graminearum ◽  
Near Infrared ◽  
Strongly Correlated ◽  
Head Blight ◽  
Rater Reliability ◽  
Key Words Wheat

Fusarium head blight (scab) of wheat, caused by Fusarium graminearum, often results in shriveled and/or discolored kernels, which are referred to as Fusarium-damaged kernels (FDK). FDK is a major grain grading factor and therefore is routinely determined for purposes of quality assurance. Measurement of FDK is usually done visually. Visual sorting can be laborious and is subject to inconsistencies resulting from variability in intra-rater repeatability and/or inter-rater reliability. The ability of a single-kernel near-infrared (SKNIR) system to detect FDK was evaluated by comparing FDK sorted by the system to FDK sorted visually. Visual sorting was strongly correlated with sorting by the SKNIR system (0.89 ≤ r ≤ 0.91); however, the SKNIR system had a wider range of FDK detection and was more consistent. Compared with the SKNIR system, visual raters overestimated FDK in samples with a low percentage of Fusarium-damaged grain and underestimated FDK in samples with a high percentage of Fusarium-damaged grain. Key words: Wheat, Fusarium head blight, Fusarium-damaged kernels, single-kernel near-infrared

Effects of insecticides chlorpyrifos, emamectin benzoate and fipronil on Spodoptera litura might be mediated by OBPs and CSPs

2017 ◽  
Vol 108 (5) ◽  
pp. 658-666 ◽  
Author(s):  
X. Lin ◽  
Y. Jiang ◽  
L. Zhang ◽  
Y. Cai
Keyword(s):  
Spodoptera Litura ◽  
Quantitative Polymerase Chain Reaction ◽  
Insect Pest ◽  
Survival Rates ◽  
Gene Families ◽  
Cross Resistance ◽  
Emamectin Benzoate ◽  
Insecticide Exposure ◽  
Polyphagous Insect ◽  
Related Proteins

AbstractSpodoptera litura is a widespread polyphagous insect pest that can develop resistance and cross-resistance to insecticides, making it difficult to control. Insecticide exposure has previously been linked with induction of specific olfactory-related proteins, including some chemosensory proteins (CSPs) and odorant-binding proteins (OPBs), which may disrupt detection of environmental factors and reduce fitness. However, functional evidence supporting insecticide and OBPs/CSPs mediation remains unknown. Here we fed male S. litura moths with sucrose water containing one of three insecticides, chlorpyrifos, emamectin benzoate or fipronil, and used real-time quantitative polymerase chain reaction and RNAi to investigate OBPs and CSPs expression and their correlations with survival. Chlorpyrifos and emamectin benzoate increased expression of 78% of OBPs, plus 63 and 56% of CSP genes, respectively, indicating a major impact on these gene families. RNAi knockdown of SlituCSP18, followed by feeding with chlorpyrifos or fipronil, decreased survival rates of male moths significantly compared with controls. Survival rate also decreased significantly with the downregulation of SlituOBP9 followed by feeding with chlorpyrifos. Thus, although these three insecticides had different effects on OBP and CSP gene expression, we hypothesize that SlituOBPs and SlituCSPs might mediate their effects by increasing their expression levels to improve survival. Moreover, the differential response of S. litura male moths to the three insecticides indicated the potential specificity of chlorpyrifos affect SlituCSP18 and SlituOBP9 expression.

scholarly journals Survival of Fusarium graminearum, the causal agent of Fusarium head blight. A review

2012 ◽  
Vol 33 (1) ◽  
pp. 97-111 ◽  
Author(s):  
Johann Leplat ◽  
Hanna Friberg ◽  
Muhammad Abid ◽  
Christian Steinberg
Keyword(s):  
Fusarium Head Blight ◽  
Fusarium Graminearum ◽  
Causal Agent ◽  
Head Blight

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.

Sign in / Sign up

Export Citation Format

Share Document