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Frances Trail - One of the best experts on this subject based on the ideXlab platform.
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Comparative Genomics and Transcriptomics During Sexual Development Gives Insight Into the Life History of the Cosmopolitan Fungus Fusarium neocosmosporiellum.
Frontiers in microbiology, 2019Co-Authors: Wonyong Kim, Brad Cavinder, Robert H. Proctor, Kerry O'donnell, Jeffrey P. Townsend, Frances TrailAbstract:Fusarium neocosmosporiellum (formerly Neocosmospora vasinfecta) is a cosmopolitan fungus that has been reported from soil, herbivore dung, and as a fruit- and root-rot pathogen of numerous field crops, although it is not known to cause significant losses on any crop. Taking advantage of the fact that this species produces prolific numbers of perithecia in culture, the genome of F. neocosmosporiellum was sequenced and transcriptomic analysis across five stages of Perithecium development was performed to better understand the metabolic potential for sexual development and gain insight into its life history. Perithecium morphology together with the genome and transcriptome were compared with those of the plant pathogen F. graminearum, a model for studying Perithecium development. Larger ascospores of F. neocosmosporiellum and their tendency to discharge as a cluster demonstrated a duality of dispersal: the majority are passively dispersed through the formation of cirrhi, while a minority of spores are shot longer distances than those of F. graminearum. The predicted gene number in the F. neocosmosporiellum genome was similar to that in F. graminearum, but F. neocosmosporiellum had more carbohydrate metabolism-related and transmembrane transport genes. Many transporter genes were differentially expressed during Perithecium development in F. neocosmosporiellum, which may account for its larger perithecia. Comparative analysis of the secondary metabolite gene clusters identified several polyketide synthase genes that were induced during later stages of Perithecium development. Deletion of a polyketide synthase gene in F. neocosmosporiellum resulted in a defective Perithecium phenotype, suggesting an important role of the corresponding metabolite, which has yet to be identified, in Perithecium development. Results of this study have provided novel insights into the genomic underpinning of development in F. neocosmosporiellum, which may help elucidate its ability to occupy diverse ecological niches.
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Perithecial development by Gibberella zeae: a light microscopy study
Mycologia, 2019Co-Authors: Frances Trail, Ralph S. CommonAbstract:Gibberella zeae (anamorph Fusarium gra- minearum) is the causal agent of head blight, and foot and crown rots of wheat, corn, oats and barley. The developmental sequence of perithecia from ho- mothallic Group II isolates of G. zeae was traced by light microscopy. Cultures induced to form perithe- cia produced wide hyphae with two or more nuclei per cell that gave rise to perithecial initials composed of undifferentiated, uninucleate cells. Neither asco- gonia nor antheridia were observed. The ascogenous system arose from cells in the inner wall of the young Perithecium and as the Perithecium matured, formed a hymenium at the base of the centrum. Api- cal paraphyses, differentiated from cells in the upper periderm, grew downward and became attached to the hymenium. In the central axis of the peritheci- um, the ostiole formed from small, darkly-staining, uninucleate cells that differentiated into the peri- physes. Once the apical paraphyses were completely developed, typical croziers formed in the hymenium. As the asci elongated, the apical paraphyses col- lapsed, although their walls remained intact between the asci. Mature asci contained eight, four-celled as- cospores in a biseriate arrangement. The ascus walls were simple with a slight thickening at the tip.
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Compression tests of Fusarium graminearum ascocarps provide insights into the strength of the perithecial wall and the quantity of ascospores.
Fungal genetics and biology : FG & B, 2016Co-Authors: Ray F. David, Frances Trail, Michael Reinisch, Linsey C. Marr, David G. SchmaleAbstract:The plant pathogenic ascomycete Fusarium graminearum produces perithecia on corn and small grain residues. These perithecia forcibly discharge ascospores into the atmosphere. Little is known about the relationship among the strength of the perithecial wall, the age of the Perithecium, and the quantity of ascospores produced. We used a mechanical compression testing instrument to examine the structural failure rate of perithecial walls from three different strains of F. graminearum (two wild type strains, and a mutant strain unable to produce asci). The force required to compress a Perithecium by one micrometer (the mean Perithecium compression constant, MPCC) was used to determine the strength of the perithecial wall. Over the course of perithecial maturation (5-12days after the initiation of perithecial development), the MPCC was compared to the number of ascospores contained inside the perithecia. The MPCC increased as perithecia matured, from 0.06Nμm-1 at 5d to 0.12Nμm-1 at 12d. The highest number of ascospores was found in older perithecia (12d). The results indicated that for every additional day of perithecial aging, the perithecia become more resilient to compression forces. Every additional day of perithecial aging resulted in ∼900 more ascospores. Knowledge of how perithecia respond to external forces may provide insight into the development of ascospores and the accumulation of turgor pressure. In the future, compression testing may provide a unique method of determining perithecial age in the field, which could extend to management practices that are informed by knowledge of ascospore release and dispersal.
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Video Article Sexual Development and Ascospore Discharge in Fusarium graminearum
2016Co-Authors: Brad Cavinder, Usha Sikhakolli, Kayla M. Fellows, Frances TrailAbstract:(61), e3895, doi:10.3791/3895 (2012). Fusarium graminearum has become a model system for studies in development and pathogenicity of filamentous fungi. F. graminearum most easily produces fruiting bodies, called perithecia, on carrot agar. Perithecia contain numerous tissue types, produced at specific stages of Perithecium development. These include (in order of appearance) formation of the Perithecium initials (which give rise to the ascogenous hyphae), the outer wall, paraphyses (sterile mycelia which occupy the center of the Perithecium until the asci develop), the asci, and the ascospores within the asci14. The development of each of these tissues is separated by approximately 24 hours and has been the basis of transcriptomic studies during sexual development12,8. Refer to Hallen et al. (2007) for a more thorough description of development, including photographs of each stage. Here, we present the methods for generating and harvesting synchronously developing lawns of perithecia for temporal studies of gene regulation, development, and physiological processes. Although these methods are written specifically to be used with F. graminearum, the techniques can be used for a variety of other fungi, provided that fruiting can be induced in culture and there is some synchrony to development. We have recently adapted this protocol to study the sexual development of F. verticillioides. Although individua
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Phenotypes of perithecia from crosses in N. crassa.
2014Co-Authors: Nina A. Lehr, Frances Trail, Zheng Wang, David A. Hewitt, Francesc López-giráldez, Jeffrey P. TownsendAbstract:(A) WT control, (B) ΔNCU06316: Perithecium development was arrested at early stage equally to 48–72 h, (C) ΔNCU07508: Perithecium development was arrested at 48–72 h, (D) ΔNCU06874: no perithecia formed, only protoperithecia, though melanin was released into the medium (white arrow heads), (E) ΔNCU05609: no perithecia formed, only protoperithecia, (F) ΔNCU00175: no perithecia formed, only protoperithecia, (G) ΔNCU00427: no perithecia formed, only protoperithecia. (H) ΔNCU02089: protoperithecia failed to develop into perithecia, and (I) ΔNCU09525: protoperithecia only. Perithecia (large, black) and protoperithecia (small, yellowish-gray to gray) are indicated with black arrow heads.
Yin-won Lee - One of the best experts on this subject based on the ideXlab platform.
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The novel bZIP transcription factor Fpo1 negatively regulates perithecial development by modulating carbon metabolism in the ascomycete fungus Fusarium graminearum
Environmental microbiology, 2020Co-Authors: Ji-young Shin, Duc-cuong Bui, Si Eun Kim, So Yun Jung, Hye Jin Nam, Jae Yun Lim, Gyung Ja Choi, Yin-won Lee, Jung-eun Kim, Hokyoung SonAbstract:Fungal sexual reproduction requires complex cellular differentiation processes of hyphal cells. The plant pathogenic fungus Fusarium graminearum produces fruiting bodies called perithecia via sexual reproduction, and perithecia forcibly discharge ascospores into the air for disease initiation and propagation. Lipid metabolism and accumulation are closely related to Perithecium formation, yet the molecular mechanisms that regulate these processes are largely unknown. Here, we report that a novel fungal specific bZIP transcription factor, F. graminearum Perithecium overproducing 1 (Fpo1), plays a role as a global transcriptional repressor during Perithecium production and maturation in F. graminearum. Deletion of FPO1 resulted in reduced vegetative growth, asexual sporulation and virulence and overproduced Perithecium, which reached maturity earlier, compared with the wild type. Intriguingly, the hyphae of the fpo1 mutant accumulated excess lipids during Perithecium production. Using a combination of molecular biological, transcriptomic and biochemical approaches, we demonstrate that repression of FPO1 after sexual induction leads to reprogramming of carbon metabolism, particularly fatty acid production, which affects sexual reproduction of this fungus. This is the first report of a Perithecium-overproducing F. graminearum mutant, and the findings provide comprehensive insight into the role of modulation of carbon metabolism in the sexual reproduction of fungi.
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A novel gene, GEA1, is required for ascus cell-wall development in the ascomycete fungus Fusarium graminearum.
Microbiology, 2013Co-Authors: Hokyoung Son, Jungkwan Lee, Yin-won LeeAbstract:The ascomycete fungus Fusarium graminearum is a devastating plant pathogen for major cereal crops. Ascospores are produced via sexual reproduction and forcibly discharged from mature perithecia, which function as the primary inocula. Perithecium development involves complex cellular processes and is under polygenic control. In this study, a novel gene, GEA1, was found to be required for ascus wall development in F. graminearum. GEA1 deletion mutants produced normal-shaped perithecia and ascospores, yet ascospores were observed to precociously germinate inside the Perithecium. Moreover, GEA1 deletions resulted in abnormal ascus walls that collapsed prior to ascospore discharge. Based on localization of GEA1 to plasma membrane, GEA1 may be directly involved in ascus wall biogenesis. This is the first report to identify a unique gene required for ascus wall development in F. graminearum.
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A Putative Transcription Factor MYT2 Regulates Perithecium Size in the Ascomycete Gibberella zeae
PloS one, 2012Co-Authors: Yang Lin, Gyung Ja Choi, Hokyoung Son, Kyunghun Min, Jungkwan Lee, Jin-cheol Kim, Yin-won LeeAbstract:The homothallic ascomycete fungus Gibberella zeae is a plant pathogen that is found worldwide, causing Fusarium head blight (FHB) in cereal crops and ear rot of maize. Ascospores formed in fruiting bodies (i.e., perithecia) are hypothesized to be the primary inocula for FHB disease. Perithecium development is a complex cellular differentiation process controlled by many developmentally regulated genes. In this study, we selected a previously reported putative transcription factor containing the Myb DNA-binding domain MYT2 for an in-depth study on sexual development. The deletion of MYT2 resulted in a larger Perithecium, while its overexpression resulted in a smaller Perithecium when compared to the wild-type strain. These data suggest that MYT2 regulates Perithecium size differentiation. MYT2 overexpression affected pleiotropic phenotypes including vegetative growth, conidia production, virulence, and mycotoxin production. Nuclear localization of the MYT2 protein supports its role as a transcriptional regulator. Transcriptional analyses of trichothecene synthetic genes suggest that MYT2 additionally functions as a suppressor for trichothecene production. This is the first study characterizing a transcription factor required for Perithecium size differentiation in G. zeae, and it provides a novel angle for understanding sexual development in filamentous fungi.
Hokyoung Son - One of the best experts on this subject based on the ideXlab platform.
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The novel bZIP transcription factor Fpo1 negatively regulates perithecial development by modulating carbon metabolism in the ascomycete fungus Fusarium graminearum
Environmental microbiology, 2020Co-Authors: Ji-young Shin, Duc-cuong Bui, Si Eun Kim, So Yun Jung, Hye Jin Nam, Jae Yun Lim, Gyung Ja Choi, Yin-won Lee, Jung-eun Kim, Hokyoung SonAbstract:Fungal sexual reproduction requires complex cellular differentiation processes of hyphal cells. The plant pathogenic fungus Fusarium graminearum produces fruiting bodies called perithecia via sexual reproduction, and perithecia forcibly discharge ascospores into the air for disease initiation and propagation. Lipid metabolism and accumulation are closely related to Perithecium formation, yet the molecular mechanisms that regulate these processes are largely unknown. Here, we report that a novel fungal specific bZIP transcription factor, F. graminearum Perithecium overproducing 1 (Fpo1), plays a role as a global transcriptional repressor during Perithecium production and maturation in F. graminearum. Deletion of FPO1 resulted in reduced vegetative growth, asexual sporulation and virulence and overproduced Perithecium, which reached maturity earlier, compared with the wild type. Intriguingly, the hyphae of the fpo1 mutant accumulated excess lipids during Perithecium production. Using a combination of molecular biological, transcriptomic and biochemical approaches, we demonstrate that repression of FPO1 after sexual induction leads to reprogramming of carbon metabolism, particularly fatty acid production, which affects sexual reproduction of this fungus. This is the first report of a Perithecium-overproducing F. graminearum mutant, and the findings provide comprehensive insight into the role of modulation of carbon metabolism in the sexual reproduction of fungi.
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A novel gene, GEA1, is required for ascus cell-wall development in the ascomycete fungus Fusarium graminearum.
Microbiology, 2013Co-Authors: Hokyoung Son, Jungkwan Lee, Yin-won LeeAbstract:The ascomycete fungus Fusarium graminearum is a devastating plant pathogen for major cereal crops. Ascospores are produced via sexual reproduction and forcibly discharged from mature perithecia, which function as the primary inocula. Perithecium development involves complex cellular processes and is under polygenic control. In this study, a novel gene, GEA1, was found to be required for ascus wall development in F. graminearum. GEA1 deletion mutants produced normal-shaped perithecia and ascospores, yet ascospores were observed to precociously germinate inside the Perithecium. Moreover, GEA1 deletions resulted in abnormal ascus walls that collapsed prior to ascospore discharge. Based on localization of GEA1 to plasma membrane, GEA1 may be directly involved in ascus wall biogenesis. This is the first report to identify a unique gene required for ascus wall development in F. graminearum.
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A Putative Transcription Factor MYT2 Regulates Perithecium Size in the Ascomycete Gibberella zeae
PloS one, 2012Co-Authors: Yang Lin, Gyung Ja Choi, Hokyoung Son, Kyunghun Min, Jungkwan Lee, Jin-cheol Kim, Yin-won LeeAbstract:The homothallic ascomycete fungus Gibberella zeae is a plant pathogen that is found worldwide, causing Fusarium head blight (FHB) in cereal crops and ear rot of maize. Ascospores formed in fruiting bodies (i.e., perithecia) are hypothesized to be the primary inocula for FHB disease. Perithecium development is a complex cellular differentiation process controlled by many developmentally regulated genes. In this study, we selected a previously reported putative transcription factor containing the Myb DNA-binding domain MYT2 for an in-depth study on sexual development. The deletion of MYT2 resulted in a larger Perithecium, while its overexpression resulted in a smaller Perithecium when compared to the wild-type strain. These data suggest that MYT2 regulates Perithecium size differentiation. MYT2 overexpression affected pleiotropic phenotypes including vegetative growth, conidia production, virulence, and mycotoxin production. Nuclear localization of the MYT2 protein supports its role as a transcriptional regulator. Transcriptional analyses of trichothecene synthetic genes suggest that MYT2 additionally functions as a suppressor for trichothecene production. This is the first study characterizing a transcription factor required for Perithecium size differentiation in G. zeae, and it provides a novel angle for understanding sexual development in filamentous fungi.
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A Putative Transcription Factor MYT2 Regulates Perithecium Size in the Ascomycete Gibberella zeae
2012Co-Authors: Yang Lin, Gyung Ja Choi, Hokyoung Son, Kyunghun Min, Jungkwan Lee, Jin-cheol Kim, Won LeeAbstract:The homothallic ascomycete fungus Gibberella zeae is a plant pathogen that is found worldwide, causing Fusarium head blight (FHB) in cereal crops and ear rot of maize. Ascospores formed in fruiting bodies (i.e., perithecia) are hypothesized to be the primary inocula for FHB disease. Perithecium development is a complex cellular differentiation process controlled by many developmentally regulated genes. In this study, we selected a previously reported putative transcription factor containing the Myb DNA-binding domain MYT2 for an in-depth study on sexual development. The deletion of MYT2 resulted in a larger Perithecium, while its overexpression resulted in a smaller Perithecium when compared to the wild-type strain. These data suggest that MYT2 regulates Perithecium size differentiation. MYT2 overexpression affected pleiotropic phenotypes including vegetative growth, conidia production, virulence, and mycotoxin production. Nuclear localization of the MYT2 protein supports its role as a transcriptional regulator. Transcriptional analyses of trichothecene synthetic genes suggest that MYT2 additionally functions as a suppressor for trichothecene production. This is the first study characterizing a transcription factor required for Perithecium size differentiation in G. zeae, and it provides a novel angle for understandin
Jiasen Cheng - One of the best experts on this subject based on the ideXlab platform.
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Dicer-Like Proteins Regulate Sexual Development via the Biogenesis of Perithecium-Specific MicroRNAs in a Plant Pathogenic Fungus Fusarium graminearum.
Frontiers in microbiology, 2018Co-Authors: Wenping Zeng, Jie Wang, Ying Wang, Jing Lin, Jiatao Xie, Daohong Jiang, Tao Chen, Huiquan Liu, Jiasen ChengAbstract:Ascospores act as the primary inoculum of Fusarium graminearum, which causes the destructive disease Fusarium head blight (FHB), or scab. MicroRNAs (miRNAs) have been reported in the F. graminearum vegetative stage, and Fgdcl2 is involved in microRNA-like RNA (milRNA) biogenesis but has no major impact on vegetative growth, abiotic stress or pathogenesis. In the present study, we found that ascospore discharge was decreased in the Fgdcl1 deletion mutant, and completely blocked in the double-deletion mutant of Fgdcl1 and Fgdcl2. Besides, more immature asci were observed in the double-deletion mutant. Interestingly, the up-regulated differentially expressed genes (DEGs) common to ΔFgdcl1 and ΔFgdcl1/2 were related to ion transmembrane transporter and membrane components. The combination of small RNA and transcriptome sequencing with bioinformatics analysis predicted 143 novel milRNAs in wild-type perithecia, and 138 of these milRNAs partly or absolutely depended on Fgdcl1, while only 5 novel milRNAs were still obtained in the Fgdcl1 and Fgdcl2 double-deletion mutant. Furthermore, 117 potential target genes were predicted. Overall, Fgdcl1 and Fgdcl2 genes were partly functionally redundant in ascospore discharge and Perithecium-specific milRNA generation in F. graminearum, and these Perithecium-specific milRNAs play potential roles in sexual development.
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Table_6_Dicer-Like Proteins Regulate Sexual Development via the Biogenesis of Perithecium-Specific MicroRNAs in a Plant Pathogenic Fungus Fusarium graminearum.XLSX
2018Co-Authors: Wenping Zeng, Jie Wang, Ying Wang, Jing Lin, Jiatao Xie, Daohong Jiang, Tao Chen, Huiquan Liu, Jiasen ChengAbstract:Ascospores act as the primary inoculum of Fusarium graminearum, which causes the destructive disease Fusarium head blight (FHB), or scab. MicroRNAs (miRNAs) have been reported in the F. graminearum vegetative stage, and Fgdcl2 is involved in microRNA-like RNA (milRNA) biogenesis but has no major impact on vegetative growth, abiotic stress or pathogenesis. In the present study, we found that ascospore discharge was decreased in the Fgdcl1 deletion mutant, and completely blocked in the double-deletion mutant of Fgdcl1 and Fgdcl2. Besides, more immature asci were observed in the double-deletion mutant. Interestingly, the up-regulated differentially expressed genes (DEGs) common to ΔFgdcl1 and ΔFgdcl1/2 were related to ion transmembrane transporter and membrane components. The combination of small RNA and transcriptome sequencing with bioinformatics analysis predicted 143 novel milRNAs in wild-type perithecia, and 138 of these milRNAs partly or absolutely depended on Fgdcl1, while only 5 novel milRNAs were still obtained in the Fgdcl1 and Fgdcl2 double-deletion mutant. Furthermore, 117 potential target genes were predicted. Overall, Fgdcl1 and Fgdcl2 genes were partly functionally redundant in ascospore discharge and Perithecium-specific milRNA generation in F. graminearum, and these Perithecium-specific milRNAs play potential roles in sexual development.
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Data_Sheet_1_Dicer-Like Proteins Regulate Sexual Development via the Biogenesis of Perithecium-Specific MicroRNAs in a Plant Pathogenic Fungus Fusarium graminearum.pdf
2018Co-Authors: Wenping Zeng, Jie Wang, Ying Wang, Jing Lin, Jiatao Xie, Daohong Jiang, Tao Chen, Huiquan Liu, Jiasen ChengAbstract:Ascospores act as the primary inoculum of Fusarium graminearum, which causes the destructive disease Fusarium head blight (FHB), or scab. MicroRNAs (miRNAs) have been reported in the F. graminearum vegetative stage, and Fgdcl2 is involved in microRNA-like RNA (milRNA) biogenesis but has no major impact on vegetative growth, abiotic stress or pathogenesis. In the present study, we found that ascospore discharge was decreased in the Fgdcl1 deletion mutant, and completely blocked in the double-deletion mutant of Fgdcl1 and Fgdcl2. Besides, more immature asci were observed in the double-deletion mutant. Interestingly, the up-regulated differentially expressed genes (DEGs) common to ΔFgdcl1 and ΔFgdcl1/2 were related to ion transmembrane transporter and membrane components. The combination of small RNA and transcriptome sequencing with bioinformatics analysis predicted 143 novel milRNAs in wild-type perithecia, and 138 of these milRNAs partly or absolutely depended on Fgdcl1, while only 5 novel milRNAs were still obtained in the Fgdcl1 and Fgdcl2 double-deletion mutant. Furthermore, 117 potential target genes were predicted. Overall, Fgdcl1 and Fgdcl2 genes were partly functionally redundant in ascospore discharge and Perithecium-specific milRNA generation in F. graminearum, and these Perithecium-specific milRNAs play potential roles in sexual development.
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Image_1_Dicer-Like Proteins Regulate Sexual Development via the Biogenesis of Perithecium-Specific MicroRNAs in a Plant Pathogenic Fungus Fusarium graminearum.tif
2018Co-Authors: Wenping Zeng, Jie Wang, Ying Wang, Jing Lin, Jiatao Xie, Daohong Jiang, Tao Chen, Huiquan Liu, Jiasen ChengAbstract:Ascospores act as the primary inoculum of Fusarium graminearum, which causes the destructive disease Fusarium head blight (FHB), or scab. MicroRNAs (miRNAs) have been reported in the F. graminearum vegetative stage, and Fgdcl2 is involved in microRNA-like RNA (milRNA) biogenesis but has no major impact on vegetative growth, abiotic stress or pathogenesis. In the present study, we found that ascospore discharge was decreased in the Fgdcl1 deletion mutant, and completely blocked in the double-deletion mutant of Fgdcl1 and Fgdcl2. Besides, more immature asci were observed in the double-deletion mutant. Interestingly, the up-regulated differentially expressed genes (DEGs) common to ΔFgdcl1 and ΔFgdcl1/2 were related to ion transmembrane transporter and membrane components. The combination of small RNA and transcriptome sequencing with bioinformatics analysis predicted 143 novel milRNAs in wild-type perithecia, and 138 of these milRNAs partly or absolutely depended on Fgdcl1, while only 5 novel milRNAs were still obtained in the Fgdcl1 and Fgdcl2 double-deletion mutant. Furthermore, 117 potential target genes were predicted. Overall, Fgdcl1 and Fgdcl2 genes were partly functionally redundant in ascospore discharge and Perithecium-specific milRNA generation in F. graminearum, and these Perithecium-specific milRNAs play potential roles in sexual development.
John C. Guenther - One of the best experts on this subject based on the ideXlab platform.
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Triacylglyceride Metabolism by Fusarium graminearum During Colonization and Sexual Development on Wheat
Molecular plant-microbe interactions : MPMI, 2009Co-Authors: John C. Guenther, Heather E. Hallen-adams, Heike Bücking, Yair Shachar-hill, Frances TrailAbstract:Fusarium graminearum, a devastating pathogen of small grains, overwinters on crop residues and produces ephemeral perithecia. Accumulation of lipids in overwintering hyphae would provide reserves for overwinter survival and Perithecium development. Fatty acid composition of cultures during Perithecium development indicated a drop in neutral lipid levels during development but little change in fatty acid composition across stages. Microscopic examination of cultures early in sexual development revealed hyphal cells engorged with lipid bodies. In comparison, vegetative hyphae contained few lipid bodies. Microarray analysis was performed on wheat stems at stages of colonization through Perithecium development. Gene expression analysis during stages of Perithecium development both in planta and in vitro (previously published) supports the view that lipid biosynthesis occurs during early stages of wheat colonization leading to sexual development and that lipid oxidation occurs as perithecia are developing. Analysis of gene expression during the stages of wheat stem colonization also revealed sets of genes unique to these stages. These results support the view that lipids accumulate in hyphae colonizing wheat stalks and are subsequently used in Perithecium formation on stalk tissue. These results indicate that extensive colonization of plant tissue prior to harvest is essential for subsequent sporulation on crop residues and, thus, has important implications for inoculum reduction.
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The development and differentiation of Gibberella zeae (anamorph Fusarium graminearum) during colonization of wheat
Mycologia, 2005Co-Authors: John C. Guenther, Frances TrailAbstract:Worldwide, one of the most devastating pathogens of small grains is the head blight fungus, Gibberella zeae. Ascospore-laden perithecia of this fungus develop on mature cereal crops and crop debris and provide the primary inoculum of the disease. We characterize the process of colonization of wheat tissue that leads to Perithecium production. Stems were colonized systemically and extensively following inoculation of the wheat head. Haploid mycelia moved down the vascular system and pith and then colonized the stem tissue radially. Dikaryotic hyphae developed at two distinct stages: in the xylem, in support of radial hyphal growth and in the chloremchyma, in support of Perithecium development. Perithecium formation was initiated in association with stomatesand silica cells. Vascular occlusions prevented mycelia from colonizing the stem in 25% of inoculated plants. Implications of these findings are discussed for developing resistant cultivars and improving chemical control of the disease.