Publikasjoner
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2004
Forfattere
K. RobertsenSammendrag
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Forfattere
K.R. RobertsenSammendrag
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Sammendrag
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Forfattere
Jens Køhler A. ArntzenSammendrag
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Forfattere
Knut Langeland Åsmund AsdalSammendrag
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Forfattere
Maria Herrero Jadwiga Treder Brita Toppe Hans Ragnar GislerødSammendrag
En mild varmebehandling ble tested for å bekjempe agurkmjøldogg.I dette forsøket var de to sikre behandligene for å drepe soppen 37 C i 10 timer og 40 C i 3 timer. Disse kominasjonene av temperatur og varighet gjør det i praksis vanskelig å implementere varmebehandling som bekjempelse mot mjøldogg.
Sammendrag
Introduction: The objectives of the present study were to monitor H. annosum colonization rate (Hietala et al., 2003) and expression of host chitinases in clonal Norway spruce material with differing resistances. Transcript levels of three chitinases, representing classes I, II and IV, were monitored with real-time PCR.Material and MethodsInoculation experiment: Ramets of two 32 -year-old clones differing in resistance were employed as host material. Inoculation and wounding was performed. A rectangular strip containing phloem and cambium, with the inoculation site in the middle, was removed 3, 7 and 14 days after inoculation.Quantification of fungal colonizationMultiplex real-time PCR detection of host and pathogen DNA was performed (Hietala et al., 2003). Quantification of gene expression: Chitinase levels were monitored with Singleplex real-time PCR.Results and ConclusionsThe colonization profiles provided by the quantitative multiplex real-time PCR procedure (Hietala et al., 2003), when combined with spatial and temporal transcript profiling of 3 chitinases, provide a useful basis for identifying defense related genes, and for assessing their impact on pathogen colonization rates.Three days after inoculation, comparable colonization levels were observed in both clones in the area immediately adjacent to inoculation. Fourteen days after infection, pathogen colonization was restricted to the area immediately adjacent to the site of inoculation for the strong clone (589), but had progressed further into the host tissue in the weak (409) clone.Transcript levels of the class II and IV chitinases increased following wounding or inoculation, while the transcript level of the class I chitinase declined following these treatments. Transcript levels of the class II and class IV chitinases were higher in areas immediately adjacent to the inoculation site in 589 than in similar sites in 409 three days after inoculation, suggesting that the clones differ in the rate of chitinase-related signalperception.
Sammendrag
We have monitored the H. annosum colonization rate and expression of host chitinases in Norway spruce material with differing resistances. Transcript levels of three chitinases, representing classes I, II and IV, were monitored with real-time PCR. Ramets of two 32 -year-old clones differing in resistance were employed as host material and inoculation and wounding was performed. Quantification of fungal colonization: Multiplex real-time PCR detection of host and pathogen DNA was performed. Chitinase transcript levels were also monitored with real-time PCR. Three days after inoculation, comparable colonization levels were observed in both clones in the area immediately adjacent to inoculation. Fourteen days after infection, pathogen colonization was restricted to the area immediately adjacent to the site of inoculation for the strong clone (589), but had progressed further into the host tissue in the weak clone (409). Transcript levels of the class II and IV chitinases increased following wounding or inoculation, while the transcript level of the class I chitinase declined following these treatments. Transcript levels of the class II and class IV chitinases were higher in areas immediately adjacent to the inoculation site in 589 than in similar sites in 409 three days after inoculation, suggesting that the clones differ in the rate of chitinase-related signal perception. The spatiotemporal accumulation patterns obtained for the two clones used are consistent with their resistance classifications, these warranting further and more detailed studies on these chitinases.
Sammendrag
Pathogen colonization and transcript levels of three host chitinases,putatively representing classes I, II, and IV, were monitored with real-time PCR after wounding and bark infection by Heterobasidion annosum in 32-year-old trees of Norway spruce (Picea abies) with low (clone 409) or high (clone 589) resistance to this pathogen. Three days after inoculation, comparable colonization levels were observed in both clones in the area immediately adjacent to inoculation. At 14 days after infection, pathogen colonization was restricted to the area immediately adjacent to the site of inoculation for clone 589 but had progressed further into the host tissue in clone 409. Transcript levels of the class II and IV chitinases increased after wounding or inoculation, but the transcript level of the class I chitinase declined after these treatments. Transcript levels of the class II and class IV chitinases were higher in areas immediately adjacent to the inoculation site in clone 589 than in similar sites in clone 409 3 days after inoculation. This difference was even more pronounced 2 to 6 mm away from the inoculation point, where no infection was yet established, and suggests that the clones differ in the rate of chitinase-related signal perception or transduction. At 14 days after inoculation, these transcript levels were higher in clone 409 than in clone 589, suggesting that the massive upregulation of class II and IV chitinases after the establishment of infection comes too late to reduce or prevent pathogen colonization.
Sammendrag
Det er ikke registrert sammendrag