scholarly journals Transcriptome Analysis of the Barley-Fusarium graminearum Interaction

2006 ◽  
Vol 19 (4) ◽  
pp. 407-417 ◽  
Author(s):  
Jayanand Boddu ◽  
Seungho Cho ◽  
Warren M. Kruger ◽  
Gary J. Muehlbauer
Keyword(s):  
Fusarium Graminearum ◽  
Early Stage ◽  
Intermediate Stage ◽  
Infection Process ◽  
Head Blight ◽  
Water Control ◽  
Transcript Accumulation ◽  
Hordeum Vulgare L ◽  
Fungal Development ◽  
Gene Transcripts

Fusarium head blight (FHB) of barley (Hordeum vulgare L.) is caused by Fusarium graminearum. FHB causes yield losses and reduction in grain quality primarily due to the accumulation of trichothecene mycotoxins such as deoxynivalenol (DON). To develop an understanding of the barley-F. graminearum interaction, we examined the relationship among the infection process, DON concentration, and host transcript accumulation for 22,439 genes in spikes from the susceptible cv. Morex from 0 to 144 h after F. graminearum and water control inoculation. We detected 467 differentially accumulating barley gene transcripts in the F. graminearum-treated plants compared with the water control-treated plants. Functional annotation of the transcripts revealed a variety of infection-induced host genes encoding defense response proteins, oxidative burst-associated enzymes, and phenylpropanoid pathway enzymes. Of particular interest was the induction of transcripts encoding potential trichothecene catabolic enzymes and transporters, and the induction of the tryptophan biosynthetic and catabolic pathway enzymes. Our results define three stages of F. graminearum infection. An early stage, between 0 and 48 h after inoculation (hai), exhibited limited fungal development, low DON accumulation, and little change in the transcript accumulation status. An intermediate stage, between 48 and 96 hai, showed increased fungal development and active infection, higher DON accumulation, and increased transcript accumulation. A majority of the host gene transcripts were detected by 72 hai, suggesting that this is an important timepoint for the barley-F. graminearum interaction. A late stage also identified between 96 and 144 hai, exhibiting development of hyphal mats, high DON accumulation, and a reduction in the number of transcripts observed. Our study provides a baseline and hypothesis-generating dataset in barley during F. graminearum infection and in other grasses during pathogen infection.

scholarly journals Fusarium graminearum Possesses Virulence Factors Common to Fusarium Head Blight of Wheat and Seedling Rot of Soybean but Differing in Their Impact on Disease Severity

2014 ◽  
Vol 104 (11) ◽  
pp. 1201-1207 ◽  
Author(s):  
Luca Sella ◽  
Katia Gazzetti ◽  
Carla Castiglioni ◽  
Wilhelm Schäfer ◽  
Francesco Favaron
Keyword(s):  
Fusarium Head Blight ◽  
Disease Severity ◽  
Fusarium Graminearum ◽  
Map Kinases ◽  
Early Stage ◽  
Single Gene ◽  
Crown Rot ◽  
Head Blight ◽  
Soybean Seedlings ◽  
Seedling Rot

Fusarium graminearum is a toxigenic fungal pathogen that causes Fusarium head blight (FHB) and crown rot on cereal crops worldwide. This fungus also causes damping-off and crown and root rots at the early stage of crop development in soybean cultivated in North and South America. Several F. graminearum genes were investigated for their contribution to FHB in cereals but no inherent study is reported for the dicotyledonous soybean host. In this study we determined the disease severity on soybean seedlings of five single gene disrupted mutants of F. graminearum, previously characterized in wheat spike infection. Three of these mutants are impaired on a specific function as the production of deoxynivalenol (DON, Δtri5), lipase (ΔFgl1), and xylanase (Δxyl03624), while the remaining two are MAP kinase mutants (ΔFgOS-2, Δgpmk1), which are altered in signaling pathways. The mutants that were reduced in virulence (Δtri5, ΔFgl1, and ΔFgOS-2) or are avirulent (Δgpmk1) on wheat were correspondently less virulent or avirulent in soybean seedlings, as shown by the extension of lesions and seedling lengths. The Δxyl03624 mutant was as virulent as the wild type mirroring the behavior observed in wheat. However, a different ranking of symptom severity occurred in the two hosts: the ΔFgOS-2 mutant, that infects wheat spikelets similarly to Δtri5 and ΔFgl1 mutants, provided much reduced symptoms in soybean. Differently from the other mutants, we observed that the ΔFgOS-2 mutant was several fold more sensitive to the glyceollin phytoalexin suggesting that its reduced virulence may be due to its hypersensitivity to this phytoalexin. In conclusion, lipase and DON seem important for full disease symptom development in soybean seedlings, OS-2 and Gpmk1 MAP kinases are essential for virulence, and OS-2 is involved in conferring resistance to the soybean phytoalexin.

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 Wheat transcriptome profiling reveals abscisic and gibberellic acid treatments regulate early-stage phytohormone defense signaling, cell wall fortification, and metabolic switches following Fusarium graminearum-challenge

2020 ◽  
Author(s):  
Leann M. Buhrow ◽  
Ziying Liu ◽  
Dustin Cram ◽  
Tanya Sharma ◽  
Nora A. Foroud ◽  
...  
Keyword(s):  
Cell Wall ◽  
Gibberellic Acid ◽  
Secondary Metabolism ◽  
Fusarium Graminearum ◽  
Stress Responses ◽  
Early Stage ◽  
Molecular Transport ◽  
Defense Responses ◽  
Head Blight ◽  
Primary And Secondary Metabolism

ABSTRACTBackgroundApplication of the wheat phytohormones abscisic acid (ABA) or gibberellic acid (GA) affect Fusarium head blight (FHB) disease severity; however, the molecular underpinnings of the elicited phenotypes remain unclear. Herein, the transcriptomic responses of an FHB-susceptible wheat cultivar ‘Fielder’ were characterized upon treatment with ABA, an ABA receptor antagonist (AS6), or GA in the presence or absence of Fusarium graminearum (Fg) challenge.ResultsA total of 30,876 differentially expressed genes (DEGs) where identified in ‘Fielder’ (26,004) and Fg (4,872). Fg challenge alone resulted in the most substantial wheat DEGs contributing to 57.2% of the total transcriptomic variation. Using a combination of topology overlap and correlation analyses, 9,689 Fg-related wheat DEGs were defined. Further enrichment analysis of the top 1% networked wheat DEGs identified critical expression changes within defense responses, cell structural metabolism, molecular transport, and membrane/lipid metabolism. Fg-challenged conditions also included the expression of a putative Fg ABA-biosynthetic cytochrome P450 and repression of wheat FUS3 for dysregulating ABA and GA crosstalk. ABA treatment alone elicited 4536 (32%) wheat DEGs common to those of the Fg-challenge, and Fg+ABA further enhanced 888 (12.5%) of them. These ABA elicited DEGs are involved in defense through both classical and non-classical phytohormone signaling and regulating cell wall structures including polyphenolic metabolism. Conversely, Fg+GA opposed 2239 (33%) Fg-elicited wheat DEGs, including modulating primary and secondary metabolism, defense responses, and flowering genes. ABA and jointly ABA⍰Fg⍰[Fg+ABA] treatments repressed, while Fg+GA induced an over-representation of wheat DEGs mapping to chromosome 6BL. Finally, compared to Fg+ABA, co-application of Fg+AS6 did not antagonize ABA biosynthesis or signal but rather elicited antagonistic Fg (557) and wheat (11) DEGs responses directly tied to stress responses, phytohormone transport, and FHB.ConclusionsComparative transcriptomics highlight the effects of wheat phytohormones on individual pathway and global metabolism simultaneously. Application of ABA may reduce FHB severity through misregulating defense mechanisms and cell wall fortification pathways. GA application may alter primary and secondary metabolism, creating a metabolic shift to ultimately reduce FHB severity. By comparing these findings to those previously reported for four additional plant genotypes, an additive model of the wheat-Fg interaction is proposed.

scholarly journals Characterization of Three Fusarium graminearum Effectors and Their Roles During Fusarium Head Blight

2020 ◽  
Vol 11 ◽  
Author(s):  
Guixia Hao ◽  
Susan McCormick ◽  
Thomas Usgaard ◽  
Helene Tiley ◽  
Martha M. Vaughan
Keyword(s):  
Fusarium Head Blight ◽  
Fusarium Graminearum ◽  
Early Stage ◽  
Expression Profiles ◽  
Plant Immunity ◽  
Resistant Variety ◽  
Deletion Mutants ◽  
Head Blight ◽  
Initial Infection ◽  
Significant Difference

Fusarium graminearum causes Fusarium head blight (FHB) on wheat, barley, and other grains. During infection, F. graminearum produces deoxynivalenol (DON), which contaminates grain and functions as a virulence factor to promote FHB spread throughout the wheat head. F. graminearum secretes hundreds of putative effectors, which can interfere with plant immunity to promote disease development. However, the function of most of these putative effectors remains unknown. In this study, we investigated the expression profiles of 23 F. graminearum effector-coding genes during the early stage of wheat head infection. Gene expression analyses revealed that three effectors, FGSG_01831, FGSG_03599, and FGSG_12160, respectively, were highly induced in both a FHB susceptible and a moderately resistant variety. We generated deletion mutants for these effector genes and performed FHB virulence assays on wheat head using point and dip inoculations to evaluate FHB spread and initial infection. No statistically significant difference in FHB spread was observed in the deletion mutants. However, deletion mutants Δ01831 displayed a significant reduction in initial infection, and thus resulted in less DON contamination. To investigate the potential mechanisms involved, these three effectors were transiently expressed in Nicotiana benthamiana leaves. N. benthamiana leaves expressing these individual effectors had significantly reduced production of reactive oxygen species induced by chitin, but not by flg22. Furthermore, FGSG_01831 and FGSG_03599 markedly suppressed Bax-induced cell death when co-expressed with Bax in N. benthamiana leaves. Our study provides new insights into the functions of these effectors and suggests they play collective or redundant roles that likely ensure the successful plant infection.

scholarly journals The Transcriptome of Fusarium graminearum During the Infection of Wheat

2011 ◽  
Vol 24 (9) ◽  
pp. 995-1000 ◽  
Author(s):  
Erik Lysøe ◽  
Kye-Yong Seong ◽  
H. Corby Kistler
Keyword(s):  
Fusarium Graminearum ◽  
Global Gene Expression ◽  
Infection Process ◽  
Complete Medium ◽  
Post Inoculation ◽  
Head Blight ◽  
Single Nucleotide ◽  
Evolutionary Selection ◽  
Blight Disease ◽  
Fungal Genes

Fusarium graminearum causes head blight disease in wheat and barley. To help understand the infection process on wheat, we studied global gene expression of F. graminearum in a time series from 24 to 196 h after inoculation, compared with a noninoculated control. The infection was rapid and, after 48 h, over 4,000 fungal genes were expressed. The number of genes expressed increased over time up to 96 h (>8,000 genes), and then declined at the 144- and 192-h post-inoculation time points. After subtraction of genes found expressed on complete medium, during carbon or nitrogen starvation, and on barley, only 355 were found exclusively expressed in wheat, mostly genes with unknown function (72.6%). These genes were mainly found in single-nucleotide polymorphism-enriched islands on the chromosomes, suggesting a higher evolutionary selection pressure. The annotated genes were enriched in functional groups predicted to be involved in allantoin and allantoate transport, detoxification, nitrogen, sulfur and selenium metabolism, secondary metabolism, carbohydrate metabolism, and degradation of polysaccharides and ester compounds. Several putative secreted virulence factors were also found expressed in wheat.

Effect of fungicide seed treatments on root pathogens of cereal crops under field conditions

2010 ◽  
Vol 90 (6) ◽  
pp. 905-917 ◽  
Author(s):  
M.R. Fernandez ◽  
W.E. May ◽  
G.P. Lafond
Keyword(s):  
Fusarium Graminearum ◽  
Triticum Aestivum L ◽  
Field Trials ◽  
Wheat Seed ◽  
Seed Treatments ◽  
Head Blight ◽  
Hordeum Vulgare L ◽  
Canadian Prairies ◽  
Infected Seed ◽  
Growing Conditions

It is of importance to reduce the spread of Fusarium graminearum to western regions of the Canadian prairies where Fusarium head blight has so far occurred to a limited extent. Determining the effectiveness of fungicides against F. graminearum in infected seed under various growing conditions will help design a comprehensive strategy for preventing the spread of this pathogen. Field trials at various locations in eastern Saskatchewan were conducted (2003-2005) to examine the performance of registered and experimental fungicides on Fusarium colonization of subcrown internodes (SIs) of plants derived from Fusarium-infected barley (Hordeum vulgare L.), common (Triticum aestivum L.) and durum [T. turgidum L. ssp. durum (Desf.) Husn.] wheat seed, and on SI discoloration. Among the fungi isolated from discolored SIs were Fusarium spp., including F. graminearum, and Cochliobolus sativus. Fusarium graminearum infections were mostly seed-borne whereas infection by other fungi appeared to be mostly soil-borne. Compared with the untreated infected control, the combined seed treatments reduced discoloration of SIs, but no single fungicide reduced discoloration consistently across site-years or crops. Similarly, no product consistently reduced the isolation of F. graminearum or other Fusarium pathogens, although some fungicides appeared to be more effective than others in reducing isolation of F. graminearum or C. sativus. Our observations agree with results from a controlled-environment study of effects of seed treatments on F. graminearum colonization of plants derived from infected common and durum wheat seed, thus confirming that treatment of F. graminearum-infected seed with fungicides will not likely prevent the spread of this pathogen.

scholarly journals Fungal Development and Induction of Defense Response Genes During Early Infection of Wheat Spikes by Fusarium graminearum

2000 ◽  
Vol 13 (2) ◽  
pp. 159-169 ◽  
Author(s):  
Clara Pritsch ◽  
Gary J. Muehlbauer ◽  
William R. Bushnell ◽  
David A. Somers ◽  
Carroll P. Vance
Keyword(s):  
Fusarium Graminearum ◽  
Defense Response ◽  
Expression Patterns ◽  
Economic Losses ◽  
Temporal Expression ◽  
Head Blight ◽  
Transcript Accumulation ◽  
Genes Encoding ◽  
Defense Response Genes ◽  
Sumai 3

Fusarium head blight (FHB) of wheat is a crippling disease that causes severe economic losses in many of the wheat-growing regions of the world. Temporal patterns of fungus development and transcript accumulation of defense response genes were studied in Fusarium graminearum-inoculated wheat spikes within the first 48 to 76 h after inoculation (hai). Microscopy of inoculated glumes revealed that the fungus appeared to penetrate through stomata, exhibited subcuticular growth along stomatal rows, colonized glume parenchyma cells, and sporulated within 48 to 76 hai. No major differences in the timing of these events were found between Sumai 3 (resistant) and Wheaton (susceptible) genotypes. In complementary experiments, RNA was extracted from spikes at several time intervals up to 48 hai and temporal expression patterns were determined for defense response genes encoding peroxidase, PR-1, PR-2 (β-1,3-glucanase), PR-3 (chitinase), PR-4, and PR-5 (thaumatin-like protein). In both genotypes, transcripts for the six defense response genes accumulated as early as 6 to 12 hai during F. graminearum infection and peaked at 36 to 48 hai. Greater and earlier PR-4 and PR-5 transcript accumulation was observed in Sumai 3, compared with Wheaton. Our results show that the timing of defense response gene induction is correlated with F. graminearum infection.

scholarly journals Degenerated Virulence and Irregular Development of Fusarium oxysporum f. sp. niveum Induced by Successive Subculture

2020 ◽  
Vol 6 (4) ◽  
pp. 382
Author(s):  
Tao-Ho Chang ◽  
Ying-Hong Lin ◽  
Yu-Ling Wan ◽  
Kan-Shu Chen ◽  
Jenn-Wen Huang ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Early Stage ◽  
Infection Process ◽  
Infested Soil ◽  
Cell Wall Degrading Enzymes ◽  
Related Factors ◽  
Pathogen Virulence ◽  
Chlamydospore Formation ◽  
Gene Transcripts ◽  
Successive Subculture

Successive cultivation of fungi on artificial media has been reported to cause the sectorization, which leads to degeneration of developmental phenotype, and virulence. Fusarium oxysporum f. sp. niveum (Fon), the causal agent of watermelon Fusarium wilt, forms degenerated sectors after successive cultivation. In the present research, we demonstrated that subculture with aged mycelia increased the incidence of degenerations. To further investigate the differences between the Fon wild type (sporodochial type, ST) and variants (MT: mycelial type and PT: pionnotal type), developmental phenotypes and pathogenicity to watermelon were examined. Results in variants (PT2, PT3, PT11, and MT6) were different from ST with mycelia growth, conidia production and chlamydospore formation. Virulence of degenerated variants on susceptible watermelon Grand Baby (GB) cultivar was determined after inoculation with Fon variants and Fon ST. In root dipping methods, Fon variants showed no significant differences in disease progress compared with ST. Fon variants showed a significant decrease in disease progression compared with ST through infested soil inoculation. The contrasting results of two inoculation methods suggest that the degenerative changes due to repeated successive cultivation may lead to the loss of pathogen virulence-related factors of the early stage of Fon infection process. Therefore, cell wall-degrading enzymes (CWDEs; cellulase, pectinase, and xylanase) activities of different variants were analyzed. All Fon degenerated variants demonstrated significant decreases of CWDEs activities compared with ST. Additionally, transcript levels of 9 virulence-related genes (fmk1, fgb1, pacC, xlnR, pl1, rho1, gas1, wc1, and fow1) were assessed in normal state. The degenerated variants demonstrated a significantly low level of tested virulence-related gene transcripts except for fmk1, xlnR, and fow1. In summary, the degeneration of Fon is triggered with successive subculture through aged mycelia. The degeneration showed significant impacts on virulence to watermelon, which was correlated with the reduction of CWDEs activities and declining expression of a set of virulence-related genes.

scholarly journals Wheat transcriptome profiling reveals abscisic and gibberellic acid treatments regulate early-stage phytohormone defense signaling, cell wall fortification, and metabolic switches following Fusarium graminearum-challenge

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Leann M. Buhrow ◽  
Ziying Liu ◽  
Dustin Cram ◽  
Tanya Sharma ◽  
Nora A. Foroud ◽  
...  
Keyword(s):  
Cell Wall ◽  
Gibberellic Acid ◽  
Secondary Metabolism ◽  
Fusarium Graminearum ◽  
Molecular Mechanisms ◽  
Early Stage ◽  
Molecular Transport ◽  
Defense Responses ◽  
Head Blight ◽  
Primary And Secondary Metabolism

Abstract Background Treatment of wheat with the phytohormones abscisic acid (ABA) and gibberellic acid (GA) has been shown to affect Fusarium head blight (FHB) disease severity. However, the molecular mechanisms underlying the elicited phenotypes remain unclear. Toward addressing this gap in our knowledge, global transcriptomic profiling was applied to the FHB-susceptible wheat cultivar ‘Fielder’ to map the regulatory responses effected upon treatment with ABA, an ABA receptor antagonist (AS6), or GA in the presence or absence of Fusarium graminearum (Fg) challenge. Results Spike treatments resulted in a total of 30,876 differentially expressed genes (DEGs) identified in ‘Fielder’ (26,004) and the Fg (4872) pathogen. Topology overlap and correlation analyses defined 9689 wheat DEGs as Fg-related across the treatments. Further enrichment analyses demonstrated that these included expression changes within ‘Fielder’ defense responses, cell structural metabolism, molecular transport, and membrane/lipid metabolism. Dysregulation of ABA and GA crosstalk arising from repression of ‘Fielder’ FUS3 was noted. As well, expression of a putative Fg ABA-biosynthetic cytochrome P450 was detected. The co-applied condition of Fg + ABA elicited further up-regulation of phytohormone biosynthesis, as well as SA and ET signaling pathways and cell wall/polyphenolic metabolism. In contrast, co-applied Fg + GA mainly suppressed phytohormone biosynthesis and signaling, while modulating primary and secondary metabolism and flowering. Unexpectedly, co-applied Fg + AS6 did not affect ABA biosynthesis or signaling, but rather elicited antagonistic responses tied to stress, phytohormone transport, and FHB disease-related genes. Conclusions Observed exacerbation (misregulation) of classical defense mechanisms and cell wall fortifications upon ABA treatment are consistent with its ability to promote FHB severity and its proposed role as a fungal effector. In contrast, GA was found to modulate primary and secondary metabolism, suggesting a general metabolic shift underlying its reduction in FHB severity. While AS6 did not antagonize traditional ABA pathways, its impact on host defense and Fg responses imply potential for future investigation. Overall, by comparing these findings to those previously reported for four additional plant genotypes, an additive model of the wheat-Fg interaction is proposed in the context of phytohormone responses.

Sign in / Sign up

Export Citation Format

Share Document