• The Plant Pathology Journal
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• v.27 no.4
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• pp.354-359
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• 2011

Chemotype composition of Fusarium graminearum strains, isolated from durum wheat kernels from naturally FHB infected fields in Northern and Central Italy, was investigated by multiplex PCR. The different climatic and environmental conditions of the two examined areas separated by the Apennines affected the composition of chemotypes. 15Ac-DON chemotype was predominant in both the sub areas. Nivalneol chemotype was more frequent in the warmer sub area.

• The Plant Pathology Journal
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• v.27 no.4
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• pp.301-309
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• 2011

The filamentous fungus Fusarium graminearum is an important cereal pathogen. Although quantitative realtime PCR (qRT-PCR) is commonly used to analyze the expression of important fungal genes, no detailed validation of reference genes for the normalization of qRT-PCR data has been performed in this fungus. Here, we evaluated 15 candidate genes as references, including those previously described as housekeeping genes and those selected from the whole transcriptome sequencing data. By a combination of three statistical algorithms (BestKeeper, geNorm, and NormFinder), the variation in the expression of these genes was assessed under different culture conditions that favored mycelial growth, sexual development, and trichothecene mycotoxin production. When favoring mycelial growth, GzFLO and GzUBH expression were most stable in complete medium. Both EF1A and GzRPS16 expression were relatively stable under all conditions on carrot agar, including mycelial growth and the subsequent perithecial induction stage. These two genes were also most stable during trichothecene production. For the combined data set, GzUBH and EF1A were selected as the most stable. Thus, these genes are suitable reference genes for accurate normalization of qRT-PCR data for gene expression analyses of F. graminearum and other related fungi.

• The Plant Pathology Journal
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• v.27 no.3
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• pp.285-290
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• 2011

Fusarium graminearum virus 2 (FgV2) infects Fusarium graminearum strain 98-8-60 and has at least five segments of double-stranded RNAs (dsRNAs), denoted as dsRNA-1 to dsRNA-5. In this study, the genome of FgV2 was sequenced and its phylogenetic relationship with other mycoviruses was analyzed. The lengths of FgV2 dsRNAs 1-5 ranged from 2414 to 3580 base pairs (bp). The 5' and 3' untranslated regions (UTRs) are highly conserved, and each dsRNA segment had 78-105 and 84-306 bp of 5' and 3' UTRs, respectively. Each dsRNA segment contained a single open reading frame (ORF). Computer analysis of dsRNA-1 revealed a putative open reading frame (ORF) that shows high sequence identity with an RNA-dependent RNA polymerase (RdRp) containing eight conserved motifs. dsRNAs 2-5 also each contain one putative ORF coding for products of unknown function. The sequences of FgV2 dsRNA-2 and dsRNA-3 have significant sequence identity with Magnaporthe oryzae chrysovirus 1 (MoCV1) dsRNA-3 and -4, respectively. When compared to other dsRNA mycoviruses in a phylogenetic analysis of the putative RdRp protein, FgV2 was found to form a distinct virus clade with Aspergillus mycovirus 1816 and MoCV1 in the family Chrysoviridae.

• The Plant Pathology Journal
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• v.27 no.4
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• pp.349-353
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• 2011

The ascomycete fungus Fusarium graminearum is an important plant pathogen responsible for Fusarium head blight in small grains and ear rot on maize. This fungus also produces the estrogenic metabolite, zearalenone (ZEA) that causes estrogenic disorders in humans and animals. Previously, we developed a conditional gene expression system for this fungus using a ZEA-inducible promoter (Pzear). In the present study, four other estrogenic compounds, including ${\beta}$-estradiol, estriol, estrone, and secoisolariciresinol, were screened as possible substitutes for ZEA in this system. Among them, ${\beta}$-estradiol was able to successfully induce the expression of a gene controlled by Pzear, while estrone was only able to partially induce its expression but the other two compounds were not effective. In combination, these results demonstrate that ${\beta}$-estradiol can replace ZEA in this conditional gene expression system, thereby eliminating the need to use the more expensive reagent, ZEA, and facilitating high-throughput functional analyses of F. graminearum in future studies.

• 한국균학회소식:학술대회논문집
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• 2016.05a
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• pp.27-27
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• 2016

The ascomycete fungus Fusarium graminearum is the most common pathogen of Fusarium head blight (FHB), a devastating disease for major cereal crops worldwide. FHB causes significant crop losses by reducing grain yield and quality as well as contaminating cereals with trichothecenes and zearalenone (ZEA) that pose a serious threat to animal health and food safety. ZEA is a causative agent of hyperestrogenic syndrome in mammals and can result in reproductive disorders in farm animals. In F. graminearum, the ZEA biosynthetic cluster is composed of four genes, PKS4, PKS13, ZEB1, and ZEB2, which encode a reducing polyketide synthase, a nonreducing polyketide synthase, an isoamyl alcohol oxidase, and a transcription factor, respectively. Although it is known that ZEB2 primarily acts as a regulator of ZEA biosynthetic cluster genes, the mechanism underlying this regulation remains undetermined. In this study, two isoforms (ZEB2L and ZEB2S) from the ZEB2 gene in F. graminearum were characterized. It was revealed that ZEB2L contains a basic leucine zipper (bZIP) DNA-binding domain at the N-terminus, whereas ZEB2S is an N-terminally truncated form of ZEB2L that lacks the bZIP domain. Interestingly, ZEA triggered the induction of both ZEB2L and ZEB2S transcription. In ZEA producing condition, the expression of ZEB2S transcripts via alternative promoter usage was directly or indirectly initiated by ZEA. Physical interaction between ZEB2L and ZEB2L as well as between ZEB2L and ZEB2S was observed in the nucleus. The ZEB2S-ZEB2S interaction was detected in both the cytosol and the nucleus. ZEB2L-ZEB2L oligomers activated ZEA biosynthetic cluster genes, including ZEB2L. ZEB2S inhibited ZEB2L transcription by forming ZEB2L-ZEB2S heterodimers, which reduced the DNA-binding activity of ZEB2L. This study provides insight into the autoregulation of ZEB2 expression by alternative promoter usage and a feedback loop during ZEA production.

• Korean Journal of Microbiology
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• v.2 no.1
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• pp.25-27
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• 1964

Lee, Bae Ham, Rha, Min Keun and Choi, Tae joo (Dept. of Biology, Kon Kuk University). Identification of the causal organism of cereal scab in Korea. Kor. J. Microbiol. Vol. 2, No. 1, p. 25-27 (1964) Head blight or scab occurred in barley, wheat, rye and some other cereals widely in this country during the spring of 1963. The causal organisms were collected from 34local areas and isolated purely. All isolates identified as Gibberella zeae (Schw.) Petch. and Fusarium graminearum Schw. as conidial stage.

• The Plant Pathology Journal
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• v.27 no.1
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• pp.20-25
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• 2011

Gibberella zeae (anamorph: Fusarium graminearum), a homothallic (self-ferile) ascomycete with ubiquitous geographic distribution, causes serious diseases in several cereal crops. Ascospores (sexual spores) produced by this fungal pathogen have been suggested as the main source of primary inoculum in disease development. Here, we report the function of a gene designated GzRUM1, which is essential for ascospore formation in G. zeae. The deduced product of GzRUM1 showed significant similarities to the human retinoblastoma (tumor suppressor) binding protein 2 and a transcriptional repressor, Rum1 in the corn smut fungus (Ustilago maydis). The transcript of GzRUM1 was detected during the both vegetative and sexual stages, but was more highly accumulated during the latter stage. In addition, no GzRUM1 transcript was detected in a G. zeae strain lacking a mating-type gene (MAT1-2), a master regulator for sexual development in G. zeae. Targeted deletion of GzRUM1 caused no dramatic changes in several traits except ascospore formation. The ${\Delta}$GzRUM1 strain produced perithecia (sexual fruit bodies) but not asci nor ascospores within them. This specific defect leading to an arrest in ascospore development suggests that GzRUM1, as Rum1 in U. maydis, functions as a transcriptional regulator during sexual reproduction in G. zeae.

• Research in Plant Disease
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• v.25 no.4
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• pp.157-163
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• 2019

This study aimed to assess the incidence and distribution of toxigenic fungi in Korean oat. Toxigenic fungi were isolated from oat samples collected from 12 oat fields from heading to harvest in 2017 and 2018. A total of 745 fungal colonies were isolated based on morphology and identified using marker genes. About 92% of the fungal isolates were Fusarium spp. and others were Penicillium (5.9%) and Aspergillus (2.1%). Fusarium isolates comprised mostly of F. asiaticum (83.1%), followed by F. incarnatum (5.4%), F. proliferatum (3.5%), F. fujikuroi (2.8%), F. tricinctum species complex (FTSC) 11 (1.5%) and F. graminearum (1.0%). About 97% of F. asiaticum was nivalenol type, and 3-acetyl deoxynivalenol (3.2%) and 15-acetyl deoxynivalenol (0.4%) types also were found. Pathogenicity test of the selected Fusarium isolates revealed that F. asiaticum isolates have a wide range of virulence depending on the tested plants. F. graminearum and FTSC 11 isolates from blighted spikelets were the most virulent in naked oat. All Fusarium isolates (n=18) except one (FTSC 11) produced nivalenol (0.2-7.6 ㎍/g), deoxynivalenol (0.03-6.1 ㎍/g), and zearalenone (0.1-27.0 ㎍/g) on rice medium. This study is first report that F. asiaticum causes Fusarium head blight disease of oat in Korea. These findings demonstrate the dominance of F. asiaticum in oat agroecosystems as in rice, wheat and barley in Korea.

• The Plant Pathology Journal
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• v.35 no.6
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• pp.553-563
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• 2019

Investigations related with factors influencing root and crown rot are rare and mainly related to farming practice and soil management. The main objective of this study was to examine broader range of factors influencing stem-base infestation of winter wheat in the field conditions. The effect of spatial distribution of infected plants on disease index (DIs) assessments was also investigated. Analysis of factors influencing DIs of crown rot of wheat demonstrated significant influence of the growing seasons (P < 0.001) and extreme fluctuations in winter temperatures (P < 0.001). In addition to that, localities together with their interaction with the growing season also significantly influenced DIs (P < 0.001). Aggregation of infected plants influenced variability of DI estimations, and it was pointed out that more extensive investigation should be conducted on broad range of DI in order to establish sampling method giving uniform sampling precision. Fusarium graminearum was shown to be predominant Fusarium species in Serbia (72.6%) using sequence-characterized amplified region analysis. Interestingly F. oxysporum was isolated in higher frequencies (27.4%) than it was reported in the literature. Given that there were no reports on the diversity of Fusarium species causing crown rot of wheat in Serbia, this study presents first report on this important subject. It also indicated that more attention should be focused on combined effects of abiotic and biotic factors influencing stem-base infestation of winter wheat. This knowledge will contribute to better understanding of factors influencing root and crown rot of wheat which would ensure sustainable disease management in the future.

• Korean Journal of Microbiology
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• v.27 no.4
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• pp.342-347
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• 1989

by use of HCl-Giemsa technique and light microscope, dividing vegetative nuclei in hyphae of Fusarium species were observed and the results are summerized. The chromosome number of these fungi was ranged 4 to 8. Of the 20 strains, the highest haploid chromosome number is 8 in F. solani S Hongchun K4, F. moniliforme (from banana) and F. raphani (from radish). The lowest is 4 in F. sporotrichioides NRRL 3510 and F. equiseti KFCC 11843 IFO 30198. F. solani 7468 (from Sydney), F. solani 7475 (from Sydney), F. oxysporum(from tomato). F. roseum (from rice), F. sporotrichioides C Jngsun 1, F. equiseti C Kosung 1 and F. avenaceum 46039 are n=7. F. moniliforme (from rice) F. graminearum, F. proliferatum 6787 (from Syndey), F. proliferatum 7459 (from Synder) and F. anguioides ATCC 20351 are n=6. F. moniliforme NRRL 2284, F. poae NRRL 3287 and F. trincinctum NRRL 3299 are n=5. From these results, it may be concluded that the basic haploid chromosome number of the genus Fusarium is 4 and mat have been evolutionary variation of chromosome number through aneuploidy and polyploidy.