A kalászfuzáriózis kórokozóinak PCR-dianosztikán alapuló azonosítása és a meteorológiai adatgyűjt... more A kalászfuzáriózis kórokozóinak PCR-dianosztikán alapuló azonosítása és a meteorológiai adatgyűjtésen alapuló elemzés igazolta, hogy a klasszikus Fusarium járványmodell magyarországi viszonyok között nem érvényesül. Nálunk másodlagos gombafertőzés okozza a betegséget, és ez vezethet mikotoxin szennyeződéshez. A komposztlakó Trichoderma nemzetség tagjait összetett lignocellulózbontó enzimrendszer jellemzi; a szinergista kölcsönhatásban együttműködő enzimek biztosítják a mezőgazdasági hulladékok különösen hatékony reciklizációját. Homológia modellezéssel három CMV-izolátum (Trk7,R,M) köpenyfehérje -szerkezetét készítettük el, majd ezeknek a modelleknek a felhasználásával értelmeztük azt, hogy a köpenyfehérje egy-egy aminosavának változása miért okozhat jelentős változásokat a tünetek fenotípusában, illetve a gazdanövénykörben. A CP-térszerkezet és a tünetek összefüggéseit vizsgálva elmondhatjuk, hogy a 129-es aminosavval kezdődő βE-αEF hurok mozgékonyságának döntő szerepe van a tünete...
Acta microbiologica et immunologica Hungarica, 1995
Forty-six strains representing 15 species of Drechslera, five of Bipolaris and four of Exserohilu... more Forty-six strains representing 15 species of Drechslera, five of Bipolaris and four of Exserohilum, as well as two formae of Drechslera teres were compared by RAPD analysis. Drechslera formed a large, heterologous group, while species of Bipolaris and Exserohilum were more closely related. Strong pair-wise affinities were observed between D. graminea and D. teres, D. tritici-repentis and D. bromi, D. siccans and D. biseptata, D. fugax and D. poae, B. sorghicola and B. zeicola, as well as between E. rostratum and E. turcicum.
For two fungal strains to be vegetatively compatible and capable of forming a stable vegetative h... more For two fungal strains to be vegetatively compatible and capable of forming a stable vegetative heterokaryon they must carry matching alleles at a series of loci variously termed het or vic genes. Cloned het/vic genes from Neurospora crassa and Podospora anserina have no obvious functional similarity and have various cellular functions. Our objective was to identify the homologue of the Neurospora het-c gene in Fusarium proliferatum and to determine if this gene has a vegetative compatibility function in this economically important and widely dispersed fungal pathogen. In F. proliferatum and five other closely related Fusarium species we found a few differences in the DNA sequence, but the changes were silent and did not alter the amino acid sequence of the resulting protein. Deleting the gene altered sexual fertility as the female parent, but it did not alter male fertility or existing vegetative compatibility interactions. Replacement of the allele-specific portion of the coding s...
During sclerotial infection of Sclerotinia sclerotiorum the mycoparasite Coniothyrium minitans pe... more During sclerotial infection of Sclerotinia sclerotiorum the mycoparasite Coniothyrium minitans penetrates through the host cell wall, which contains β-1,3-glucan as its major component. A PCR-based strategy was used to clone a β-1,3-glucanase-encoding gene, designated cmg1 , from a cDNA library of the fungus. The nucleotide and deduced amino acid sequences of this gene showed high levels of similarity to the sequences of other fungal exo-β-1,3-glucanase genes. The calculated molecular mass of the deduced protein (without the predicted 24-amino-acid N-terminal secretion signal peptide) was 83,346 Da, and the estimated pI was 4.73. Saccharomyces cerevisiae INVSc1 expressing the cmg1 gene secreted a ∼100-kDa β-1,3-glucanase enzyme (as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis) into the culture medium. N-terminal sequence analysis of the purified recombinant enzyme revealed that the secreted enzyme starts at Ala-32, seven amino acids downstream from the pre...
Acta Microbiologica et Immunologica Hungarica, 2014
Stress sensitivity of three related phytopathogenic Fusarium species (Fusarium graminearum, Fusar... more Stress sensitivity of three related phytopathogenic Fusarium species (Fusarium graminearum, Fusarium oxysporum and Fusarium verticillioides) to different oxidative, osmotic, cell wall, membrane, fungicide stressors and an antifungal protein (PAF) were studied in vitro. The most prominent and significant differences were found in oxidative stress tolerance: all the three F. graminearum strains showed much higher sensitivity to hydrogen peroxide and, to a lesser extent, to menadione than the other two species. High sensitivity of F. verticillioides strains was also detectable to an azole drug, Ketoconazole. Surprisingly, no or limited differences were observed in response to other oxidative, osmotic and cell wall stressors. These results indicate that fungal oxidative stress response and especially the response to hydrogen peroxide (this compound is involved in a wide range of plant-fungus interactions) might be modified on niche-specific manner in these phylogenetically related Fusar...
There is a urgent need to develop a rational strategy for managing Fusarium ear blight in order t... more There is a urgent need to develop a rational strategy for managing Fusarium ear blight in order to reduce current reliance on routine fungicide applications, based on an objective assessment of disease risks. One of important components for such a management strategy is a fast, easy, accurate and reliable method for disease assessment. The relationship between incidence of Fusarium ear
A trichodiene synthase gene (Tri5) was amplified from F. poae by polymerase chain reaction using ... more A trichodiene synthase gene (Tri5) was amplified from F. poae by polymerase chain reaction using synthetic primers constructed on the basis of the coding portion of the same gene from F. sporotrichioides. Sequence analysis showed a high degree of similarity with other trichodiene synthase genes. A 378 bp HindIII fragment of the gene that contains the genetic information for the putative active site of the trichodiene synthase enzyme was radiolabelled and used for dot blot analysis. This probe could detect Tri5 hybridization in 1-10 ng DNA of fusaria that have the genetic potentiality to synthesize toxic trichothecene compounds, but gave no reaction with trichothecene nonproducing members of the genus. When other fungi reported to produce trichothecenes (Myrothecium, Stachybotrys, Trichoderma, Trichothecium spp.) were tested, only strains of Myrothecium and Stachybotrys gave strong positive reaction. Faint but consistent hybridization signals were obtained in four species (F. semitec...
The similar sized double-stranded RNA (dsRNA) elements present in vegetatively compatible strains... more The similar sized double-stranded RNA (dsRNA) elements present in vegetatively compatible strains of Fusarium poae were always genetically related, while vegetatively incompatible strains of the fungus contained either homologous or non-homologous dsRNAs of the same size. Electron microscopic observations revealed the co-existence of encapsidated and naked dsRNA elements in the same host. A mycovirus, named FUPO-1 was purified from strain A-11 and was found to contain two kinds of dsRNA segments, dsRNA 1 and dsRNA 2. The dsRNA genome of these segments was converted to cDNA clones by reverse transcription and the clones were subjected to sequence analysis. The single long open reading frame deduced from the sequence of dsRNA 1 showed similarities to the putative coat protein genes known from other mycoviruses, while conserved motifs of an RNA-dependent RNA polymerase were identified in the predicted amino acid sequence of dsRNA 2. The genome organization and certain sequence motifs o...
Fusarium acuminatum subsp. acuminatum and F. acuminatum subsp. armeniacum were subjected to compa... more Fusarium acuminatum subsp. acuminatum and F. acuminatum subsp. armeniacum were subjected to comparative karyotype analysis. DifFerences in chro? mosome numbers and sizes were observed between the two taxa. When the karyotypes were probed with the trichodiene synthase gene Tox5, hybridization sig- nals occurred only in strains of F. acuminatum subsp. armeniacum, indicating that this subspecies has the ge? netic potential to produce trichothecene type myco? toxins, while F. acuminatum subsp. acuminatum is ge? netically incapable of synthesizing these compounds. Molecular karyotypes of F. acuminatum subsp. ar? meniacum strains were very similar to those of F. spo- rotrichioides isolates suggesting a strong phylogenetic relationship between the two fungi.
A kalászfuzáriózis kórokozóinak PCR-dianosztikán alapuló azonosítása és a meteorológiai adatgyűjt... more A kalászfuzáriózis kórokozóinak PCR-dianosztikán alapuló azonosítása és a meteorológiai adatgyűjtésen alapuló elemzés igazolta, hogy a klasszikus Fusarium járványmodell magyarországi viszonyok között nem érvényesül. Nálunk másodlagos gombafertőzés okozza a betegséget, és ez vezethet mikotoxin szennyeződéshez. A komposztlakó Trichoderma nemzetség tagjait összetett lignocellulózbontó enzimrendszer jellemzi; a szinergista kölcsönhatásban együttműködő enzimek biztosítják a mezőgazdasági hulladékok különösen hatékony reciklizációját. Homológia modellezéssel három CMV-izolátum (Trk7,R,M) köpenyfehérje -szerkezetét készítettük el, majd ezeknek a modelleknek a felhasználásával értelmeztük azt, hogy a köpenyfehérje egy-egy aminosavának változása miért okozhat jelentős változásokat a tünetek fenotípusában, illetve a gazdanövénykörben. A CP-térszerkezet és a tünetek összefüggéseit vizsgálva elmondhatjuk, hogy a 129-es aminosavval kezdődő βE-αEF hurok mozgékonyságának döntő szerepe van a tünete...
Acta microbiologica et immunologica Hungarica, 1995
Forty-six strains representing 15 species of Drechslera, five of Bipolaris and four of Exserohilu... more Forty-six strains representing 15 species of Drechslera, five of Bipolaris and four of Exserohilum, as well as two formae of Drechslera teres were compared by RAPD analysis. Drechslera formed a large, heterologous group, while species of Bipolaris and Exserohilum were more closely related. Strong pair-wise affinities were observed between D. graminea and D. teres, D. tritici-repentis and D. bromi, D. siccans and D. biseptata, D. fugax and D. poae, B. sorghicola and B. zeicola, as well as between E. rostratum and E. turcicum.
For two fungal strains to be vegetatively compatible and capable of forming a stable vegetative h... more For two fungal strains to be vegetatively compatible and capable of forming a stable vegetative heterokaryon they must carry matching alleles at a series of loci variously termed het or vic genes. Cloned het/vic genes from Neurospora crassa and Podospora anserina have no obvious functional similarity and have various cellular functions. Our objective was to identify the homologue of the Neurospora het-c gene in Fusarium proliferatum and to determine if this gene has a vegetative compatibility function in this economically important and widely dispersed fungal pathogen. In F. proliferatum and five other closely related Fusarium species we found a few differences in the DNA sequence, but the changes were silent and did not alter the amino acid sequence of the resulting protein. Deleting the gene altered sexual fertility as the female parent, but it did not alter male fertility or existing vegetative compatibility interactions. Replacement of the allele-specific portion of the coding s...
During sclerotial infection of Sclerotinia sclerotiorum the mycoparasite Coniothyrium minitans pe... more During sclerotial infection of Sclerotinia sclerotiorum the mycoparasite Coniothyrium minitans penetrates through the host cell wall, which contains β-1,3-glucan as its major component. A PCR-based strategy was used to clone a β-1,3-glucanase-encoding gene, designated cmg1 , from a cDNA library of the fungus. The nucleotide and deduced amino acid sequences of this gene showed high levels of similarity to the sequences of other fungal exo-β-1,3-glucanase genes. The calculated molecular mass of the deduced protein (without the predicted 24-amino-acid N-terminal secretion signal peptide) was 83,346 Da, and the estimated pI was 4.73. Saccharomyces cerevisiae INVSc1 expressing the cmg1 gene secreted a ∼100-kDa β-1,3-glucanase enzyme (as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis) into the culture medium. N-terminal sequence analysis of the purified recombinant enzyme revealed that the secreted enzyme starts at Ala-32, seven amino acids downstream from the pre...
Acta Microbiologica et Immunologica Hungarica, 2014
Stress sensitivity of three related phytopathogenic Fusarium species (Fusarium graminearum, Fusar... more Stress sensitivity of three related phytopathogenic Fusarium species (Fusarium graminearum, Fusarium oxysporum and Fusarium verticillioides) to different oxidative, osmotic, cell wall, membrane, fungicide stressors and an antifungal protein (PAF) were studied in vitro. The most prominent and significant differences were found in oxidative stress tolerance: all the three F. graminearum strains showed much higher sensitivity to hydrogen peroxide and, to a lesser extent, to menadione than the other two species. High sensitivity of F. verticillioides strains was also detectable to an azole drug, Ketoconazole. Surprisingly, no or limited differences were observed in response to other oxidative, osmotic and cell wall stressors. These results indicate that fungal oxidative stress response and especially the response to hydrogen peroxide (this compound is involved in a wide range of plant-fungus interactions) might be modified on niche-specific manner in these phylogenetically related Fusar...
There is a urgent need to develop a rational strategy for managing Fusarium ear blight in order t... more There is a urgent need to develop a rational strategy for managing Fusarium ear blight in order to reduce current reliance on routine fungicide applications, based on an objective assessment of disease risks. One of important components for such a management strategy is a fast, easy, accurate and reliable method for disease assessment. The relationship between incidence of Fusarium ear
A trichodiene synthase gene (Tri5) was amplified from F. poae by polymerase chain reaction using ... more A trichodiene synthase gene (Tri5) was amplified from F. poae by polymerase chain reaction using synthetic primers constructed on the basis of the coding portion of the same gene from F. sporotrichioides. Sequence analysis showed a high degree of similarity with other trichodiene synthase genes. A 378 bp HindIII fragment of the gene that contains the genetic information for the putative active site of the trichodiene synthase enzyme was radiolabelled and used for dot blot analysis. This probe could detect Tri5 hybridization in 1-10 ng DNA of fusaria that have the genetic potentiality to synthesize toxic trichothecene compounds, but gave no reaction with trichothecene nonproducing members of the genus. When other fungi reported to produce trichothecenes (Myrothecium, Stachybotrys, Trichoderma, Trichothecium spp.) were tested, only strains of Myrothecium and Stachybotrys gave strong positive reaction. Faint but consistent hybridization signals were obtained in four species (F. semitec...
The similar sized double-stranded RNA (dsRNA) elements present in vegetatively compatible strains... more The similar sized double-stranded RNA (dsRNA) elements present in vegetatively compatible strains of Fusarium poae were always genetically related, while vegetatively incompatible strains of the fungus contained either homologous or non-homologous dsRNAs of the same size. Electron microscopic observations revealed the co-existence of encapsidated and naked dsRNA elements in the same host. A mycovirus, named FUPO-1 was purified from strain A-11 and was found to contain two kinds of dsRNA segments, dsRNA 1 and dsRNA 2. The dsRNA genome of these segments was converted to cDNA clones by reverse transcription and the clones were subjected to sequence analysis. The single long open reading frame deduced from the sequence of dsRNA 1 showed similarities to the putative coat protein genes known from other mycoviruses, while conserved motifs of an RNA-dependent RNA polymerase were identified in the predicted amino acid sequence of dsRNA 2. The genome organization and certain sequence motifs o...
Fusarium acuminatum subsp. acuminatum and F. acuminatum subsp. armeniacum were subjected to compa... more Fusarium acuminatum subsp. acuminatum and F. acuminatum subsp. armeniacum were subjected to comparative karyotype analysis. DifFerences in chro? mosome numbers and sizes were observed between the two taxa. When the karyotypes were probed with the trichodiene synthase gene Tox5, hybridization sig- nals occurred only in strains of F. acuminatum subsp. armeniacum, indicating that this subspecies has the ge? netic potential to produce trichothecene type myco? toxins, while F. acuminatum subsp. acuminatum is ge? netically incapable of synthesizing these compounds. Molecular karyotypes of F. acuminatum subsp. ar? meniacum strains were very similar to those of F. spo- rotrichioides isolates suggesting a strong phylogenetic relationship between the two fungi.
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