scholarly journals A Novel Transcriptional Factor Important for Pathogenesis and Ascosporogenesis in Fusarium graminearum

2011 ◽  
Vol 24 (1) ◽  
pp. 118-128 ◽  
Author(s):  
Yang Wang ◽  
Wende Liu ◽  
Zhanming Hou ◽  
Chenfang Wang ◽  
Xiaoying Zhou ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Sexual Reproduction ◽  
Fusarium Graminearum ◽  
Fungal Pathogens ◽  
Insertional Mutagenesis ◽  
Gene Replacement ◽  
Normal Male ◽  
Head Blight ◽  
Function Expression ◽  
Female Specific

Fusarium head blight or scab caused by Fusarium graminearum is an important disease of wheat and barley. The pathogen not only causes severe yield losses but also contaminates infested grains with mycotoxins. In a previous study, we identified several pathogenicity mutants by random insertional mutagenesis. One of these mutants was disrupted in the ZIF1 gene, which encodes a b-ZIP transcription factor unique to filamentous ascomycetes. The Δzif1 mutant generated by gene replacement was significantly reduced in deoxynivalenol (DON) production and virulence on flowering wheat heads. It was defective in spreading from inoculated florets to the rachis and other spikelets. Deletion of the ZIF1 ortholog MoZIF1 in the rice blast fungus also caused reductions in virulence and in invasive growth. In addition, the Δzif1 mutant is defective in sexual reproduction. Although it had normal male fertility, when selfed or mated as the female in outcrosess, the Δzif1 mutant produced small, pigmented perithecia that were sterile (lack of asci and ascospores), suggesting a female-specific role for ZIF1 during fertilization or ascus development. Similar female-specific defects in sexual reproduction were observed in the ΔMozif1 mutant. When mated as the female, the ΔMozif1 perithecia failed to develop long necks and asci or ascospores. The ZIF1 gene is well conserved in filamentous ascomycetes, particularly in the b-ZIP domain, which is essential for its function. Expression of ZIF1 in Magnaporthe oryzae complemented the defects of the ΔMozif1 mutant. These results indicate that this b-ZIP transcription factor is functionally conserved in these two fungal pathogens for plant infection and sexual reproduction.

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

2009 ◽  
Vol 8 (6) ◽  
pp. 867-876 ◽  
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.

scholarly journals The HDF1 Histone Deacetylase Gene Is Important for Conidiation, Sexual Reproduction, and Pathogenesis in Fusarium graminearum

2011 ◽  
Vol 24 (4) ◽  
pp. 487-496 ◽  
Author(s):  
Yimin Li ◽  
Chenfang Wang ◽  
Wende Liu ◽  
Guanghui Wang ◽  
Zhensheng Kang ◽  
...  
Keyword(s):  
Sexual Reproduction ◽  
Histone Deacetylase ◽  
Fusarium Graminearum ◽  
Chromatin Modification ◽  
Class Ii ◽  
In Planta ◽  
Head Blight ◽  
Obvious Effect ◽  
A Minor ◽  
And Function

Head blight caused by Fusarium graminearum is an important disease of wheat and barley. Its genome contains chromosomal regions with higher genetic variation and enriched for genes expressed in planta, suggesting a role of chromatin modification in the regulation of infection-related genes. In a previous study, the FTL1 gene was characterized as a novel virulence factor in the head blight fungus. FTL1 is homologous to yeast SIF2, which is a component of the Set3 complex. Many members of the yeast Set3 complex, including Hos2 histone deacetylase (HDAC), are conserved in F. graminearum. In this study, we characterized the HDF1 gene that is orthologous to HOS2. HDF1 physically interacted with FTL1 in yeast two-hybrid assays. Deletion of HDF1 resulted in a significant reduction in virulence and deoxynivalenol (DON) production. The Δhdf1 mutant failed to spread from the inoculation site to other parts of wheat heads or corn stalks. It was defective in sexual reproduction and significantly reduced in conidiation. Expression of HDF1 was highest in conidia in comparison with germlings and hyphae. Deletion of HDF1 also resulted in a 60% reduction in HDAC activity. Microarray analysis revealed that 149 and 253 genes were down- and upregulated, respectively, over fivefold in the Δhdf1 mutant. Consistent with upregulation of putative catalase and peroxidase genes, the Δhdf1 mutant was more tolerant to H2O2 than the wild type. Deletion of the other two class II HDAC genes had no obvious effect on vegetative growth and resulted in only a minor reduction in conidiation and virulence in the Δhdf2 mutant. Overall, our results indicate that HDF1 is the major class II HDAC gene in F. graminearum. It may interact with FTL1 and function as a component in a well-conserved HDAC complex in the regulation of conidiation, DON production, and pathogenesis.

scholarly journals Random Insertional Mutagenesis Identifies Genes Associated with Virulence in the Wheat Scab Fungus Fusarium graminearum

2005 ◽  
Vol 95 (7) ◽  
pp. 744-750 ◽  
Author(s):  
Kyeyong Seong ◽  
Zhanming Hou ◽  
Miles Tracy ◽  
H. Corby Kistler ◽  
Jin-Rong Xu
Keyword(s):  
Fusarium Graminearum ◽  
Insertional Mutagenesis ◽  
Molecular Mechanisms ◽  
Gene Replacement ◽  
Start Codon ◽  
Fungal Virulence ◽  
Ubiquinone Oxidoreductase ◽  
Plant Infection ◽  
Nadh Ubiquinone Oxidoreductase ◽  
Small Grains

Fusarium graminearum is an important pathogen of small grains and maize in many areas of the world. To better understand the molecular mechanisms of F. graminearum pathogenesis, we used the restriction enzyme-mediated integration (REMI) approach to generate random insertional mutants. Eleven pathogenicity mutants were identified by screening 6,500 hygromycin-resistant transformants. Genetic analyses indicated that the defects in plant infection were tagged by the transforming vector in six of these mutants. In mutant M8, the transforming plasmid was integrated 110-bp upstream from the start codon of the cystathionine betalyase gene (CBL1). Gene replacement mutants deleted for CBL1 and the methionine synthase gene MSY1 were also obtained. Both the cbl1 and msy1 deletion mutants were methionine auxotrophic and significantly reduced in virulence on corn silks and wheat heads. We also identified genes disrupted by the transforming DNA in three other REMI mutants exhibiting reduced virulence. In mutants M68, the transforming vectors were inserted in the NADH: ubiquinone oxidoreductase. The putative b-ZIP transcription factor gene and the transducin beta-subunit-like gene disrupted in mutants M7 and M75, respectively, had no known homologs in filamentous fungi and were likely to be novel fungal virulence factors.

scholarly journals Genomic analysis of host–pathogen interaction between Fusarium graminearum and wheat during early stages of disease development

Microbiology ◽  
2006 ◽  
Vol 152 (6) ◽  
pp. 1877-1890 ◽  
Author(s):  
Rubella S. Goswami ◽  
Jin-Rong Xu ◽  
Frances Trail ◽  
Karen Hilburn ◽  
H. Corby Kistler
Keyword(s):  
Fusarium Graminearum ◽  
Response Regulator ◽  
Gene Prediction ◽  
Genomic Analysis ◽  
Bioinformatic Analysis ◽  
Gene Replacement ◽  
Cdna Libraries ◽  
Disease Development ◽  
Head Blight ◽  
Fungal Genes

Fusarium graminearum strains responsible for causing the plant disease Fusarium head blight vary greatly in their ability to cause disease and produce mycotoxins on wheat. With the goal of understanding fungal gene expression related to pathogenicity, three cDNA libraries were created by suppression subtractive hybridization using wheat heads inoculated with a highly aggressive strain and either water or a less aggressive strain of this pathogen. Eighty-four fungal genes expressed during initial disease development were identified. The probable functions of 49 of these genes could be inferred by bioinformatic analysis. Thirty-five ESTs had no known homologues in current databases and were not identified by ab initio gene prediction methods. These ESTs from infected wheat heads probably represent F. graminearum genes that previously were not annotated. Four genes represented in one of these libraries were selected for targeted gene replacement, leading to the characterization of a two-component response regulator homologue involved in pathogenicity of the fungus. The mutants for this gene showed reduced sporulation and delayed spread of Fusarium head blight on wheat.

scholarly journals The Transcription Factor FgStuAp Influences Spore Development, Pathogenicity, and Secondary Metabolism in Fusarium graminearum

2011 ◽  
Vol 24 (1) ◽  
pp. 54-67 ◽  
Author(s):  
Erik Lysøe ◽  
Matias Pasquali ◽  
Andrew Breakspear ◽  
H. Corby Kistler
Keyword(s):  
Cell Cycle ◽  
Transcription Factor ◽  
Secondary Metabolites ◽  
Fusarium Graminearum ◽  
Deletion Mutant ◽  
Pathogenic Fungus ◽  
Cell Cycle Control ◽  
Head Blight ◽  
Helix Loop Helix ◽  
Mutant Phenotypes

Fusarium graminearum is an important plant-pathogenic fungus and the major cause of cereal head blight. Here, we report the functional analysis of FgStuA, the gene for a transcription factor with homology to key developmental regulators in fungi. The deletion mutant was greatly reduced in pathogenicity on wheat heads and in production of secondary metabolites. Spore production was significantly impaired in ΔFgStuA, which did not develop perithecia and sexual ascospores, and lacked conidiophores and phialides, leading to delayed production of aberrant macroconidia. FgStuAp appears to act as a global regulator that may affect many diverse aspects of the life cycle of F. graminearum. Transcriptome analysis shows that thousands of genes are differentially expressed in the mutant during asexual sporulation and infection of wheat heads and under conditions that induce secondary metabolites, including many that could account for the mutant phenotypes observed. The primary regulatory targets of FgStuAp are likely genes involved in cell-cycle control, and the predicted FgStuAp sequence has an APSES domain, with homology to helix-loop-helix proteins involved in cell-cycle regulation. The Aspergillus StuAp response element (A/TCGCGT/ANA/C) was found highly enriched in the promoter sequences of cell-cycle genes, which was upregulated in the ΔFgStuA deletion mutant.

A Simple Culture Method Inducing Sexual Reproduction by Fusarium graminearum, the Primary Causal Agent of Fusarium Head Blight

2018 ◽  
Vol 19 (2) ◽  
pp. 129-130
Author(s):  
Shunwen Lu ◽  
Michael C. Edwards
Keyword(s):  
Sexual Reproduction ◽  
Fusarium Head Blight ◽  
Fusarium Graminearum ◽  
Culture Method ◽  
Potato Dextrose Agar ◽  
Sexual Stage ◽  
Head Blight ◽  
Primary Inoculum ◽  
Traditional Procedure ◽  
Sexual Stages

Fusarium graminearum, the primary pathogen of Fusarium head blight (FHB), undergoes both asexual and sexual stages, and the ascospore is an important primary inoculum of FHB. Induction of the sexual stage under laboratory conditions is important for the study of FHB. Here we report a simple culture method that uses potato dextrose agar plates. This method works as well as the traditional procedure, which depends on carrot extracts and involves multiple steps in preparation.

scholarly journals Insights Into Triticum aestivum Seedling Root Rot Caused by Fusarium graminearum

2015 ◽  
Vol 28 (12) ◽  
pp. 1288-1303 ◽  
Author(s):  
Qing Wang ◽  
Stefanie Vera Buxa ◽  
Alexandra Furch ◽  
Wolfgang Friedt ◽  
Sven Gottwald
Keyword(s):  
Triticum Aestivum ◽  
Life Cycle ◽  
Fusarium Graminearum ◽  
Root Rot ◽  
Fungal Pathogens ◽  
Resistance Breeding ◽  
Root Infection ◽  
Head Blight ◽  
Root Rot Disease ◽  
Rot Disease

Fusarium graminearum is one of the most common and potent fungal pathogens of wheat (Triticum aestivum), known for causing devastating spike infections and grain yield damage. F. graminearum is a typical soil-borne pathogen that builds up during consecutive cereal cropping. Speculation on systemic colonization of cereals by F. graminearum root infection have long existed but have not been proven. We have assessed the Fusarium root rot disease macroscopically in a diverse set of 12 wheat genotypes and microscopically in a comparative study of two genotypes with diverging responses. Here, we show a ‘new’ aspect of the F. graminearum life cycle, i.e., the head blight fungus uses a unique root-infection strategy with an initial stage typical for root pathogens and a later stage typical for spike infection. Root colonization negatively affects seedling development and leads to systemic plant invasion by tissue-adapted fungal strategies. Another major outcome is the identification of partial resistance to root rot. Disease severity assessments and histological examinations both demonstrated three distinct disease phases that, however, proceeded differently in resistant and susceptible genotypes. Soil-borne inoculum and root infection are considered significant components of the F. graminearum life cycle with important implications for the development of new strategies of resistance breeding and disease control.

scholarly journals Translational control of fungal gene expression during the wheat-Fusarium graminearum interaction

2021 ◽  
Author(s):  
UDAYKUMAR KAGE ◽  
Donald Gardiner ◽  
Jiri S Stiller ◽  
Kemal Kazan
Keyword(s):  
Gene Expression ◽  
Fusarium Graminearum ◽  
Translational Control ◽  
Fungal Pathogen ◽  
Translational Regulation ◽  
Fungal Pathogens ◽  
Ribosome Profiling ◽  
Open Reading Frames ◽  
Head Blight ◽  
Fungal Virulence

To date, translational regulation of key genes controlling infection-related processes in fungal pathogens during their interactions with plants has not been studied. Here, we employed ribosome profiling (ribo-seq) to study translational responses and how such responses are coordinated with transcriptional changes in the fungal pathogen Fusarium graminearum (Fg), which causes Fusarium head blight (FHB), a destructive disease of cereal crops worldwide. Transcription and translation were not always coordinated with approximately 22% of Fg genes showing a discordant relationship during wheat infection. Nitrite reductase, which we show here as an important component of fungal virulence, is only regulated at the translational level in Fg. In addition, more than 1000 new open reading frames (ORFs), many of which are short and highly conserved, were identified in the Fg genome. Like in higher eukaryotes, translation is controlled by upstream ORFs (uORFs) in Fg during infection. Similarly, miRNAs control both transcription and translation in Fg during wheat infection. However, Fgdicer2-dependent miRNAs do not have a significant effect on transcriptional gene expression at the global outset. The ribo-seq study undertaken here for the first time in any fungal pathogen discovered novel insights about the biology of an important plant pathogen.

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