Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2008
Forfattere
Karl ThunesSammendrag
Det er ikke registrert sammendrag
Sammendrag
Kronevurdering av trærne på observasjonsflatene i 2007 viste at tilstanden fortsatt var god og som forventet ut fra vekstforholdene, og bekrefter de foregående års undersøkelser. Vi kan ikke tilskrive variasjon og forskjeller fra år til år i kronetilstanden til utslippene fra Kårstø gassprosesseringsanlegg. På lang sikt kan man likevel ikke se bort fra at enkelte av økosystemene kan være følsomme med hensyn på tilførsel av nitrogen, på grunn av områdets langvarige mottak av stort nedfall av langtransporterte luftforurensninger. Det er derfor fornuftig å følge med i økosystemenes skoglige tilstand.
Sammendrag
Potetcystenematodene (PCN) forekommer i to arter, gul (Globodera rostochiensis) og hvit (G. pallida). Begge har fl ere raser, hvor det i Norge er påvist fi re av den gule arten. Cystene ligger i jorda og er døde hunner, mens smitten er eggene som fi nnes inne i disse. Potet er den viktigste vertsplanten. Angrepne områder får dårlig vekst og vises ofte som fl ekker i åkeren. Gul PCN er påvist på 6400 eiendommer fra Lindesnes i sør til Ørland kommune i nord. Forebyggende tiltak er viktigst for å unngå smitte. Gul PCN er en karanteneskadegjører som reguleres av Matloven. Det er meldeplikt til Mattilsynet på mistanke om infeksjon av PCN. Bioforsk Plantehelse utfører analyser av forekomst, smittenivå og rasetesting.
Sammendrag
Potetcystenematodene (PCN) forekommer i to arter, hvit PCN (Globodera pallida) og gul (Globodera rostochiensis). Begge har fl ere raser. Cystene ligger i jorda og er døde hunner, mens smitten er eggene som fi nnes inne i disse. Potet er den viktigste vertsplanten. Angrepne områder får dårlig vekst og vises ofte som fl ekker i åkeren. Kjent utbredelse av hvit PCN er fra Grimstad i Aust-Agder i sør til Stjørdal i Trøndelag i nord. God hygiene er det viktigste tiltaket for å unngå smitte. Hvit PCN omfattes av Matloven og infi serte bruksenheter kan legges i karantene i 40 år. Det er meldeplikt til Mattilsynet ved mistanke og funn av PCN. Bioforsk Plantehelse utfører analyser og rasetesting av PCN.
Forfattere
Matias Pasquali Erik Lysøe Kye-yong Seong Sonja Klemsdal J.R. Xu Li-Jun Ma H. Corby KistlerSammendrag
To understand trichothecene accumulation and the infection cycle of the head light pathogen Fusarium gramineaum sesu stricto, fungal gene expression profiles were monitored during plant infection using the F. graminearum Affymetrix GeneChip. Strains containing mutations in genes for three transcription factors were found to control trichothecene accumulations in planta and pathogenicity. Expression profiles were compared between wildtype and these mutants during infection of wheat. Mutants deleted for the StuA gene were greatly decreased in sporulation and produced no perithecia in culture. Unlike stuA mutants in F. oxysporum, F. graminearum stuA mutants were greatly reduced in pathogenicity. Reducd pathogenicity may be due to decreased trichothecene levels in planta, which in the mutant were two-fold in either tri6 or tri10 deleted strains. A model for global regulation and cross pathway control of sporulation, mycotoxin biosynthesis and pathogenicity will be presented.
Sammendrag
The Fusarium genus includes devastating plant pathogenic fungi that cause diseases in cereals around the world. They produce several mycotoxins, including the estrogenic compound zearalenone. To better understand the molecular mechanisms determining zearalenone production, we performed differential display RT-PCR under conditions where Fusarium graminearum and F. culmorum produced high amounts of zearalenone. We found 133 expressed sequence tags (ESTs) and 54 of these were considered to be up-regulated during high zearalenone production. Several of the ESTs were confirmed to be up-regulated by real-time qPCR, but none showed any significant down-regulation in the zearalenone negative mutant Delta PKS4-T9, or were similar to typical gene expression patterns of previously described zearalenone-related genes. Some of the up-regulated ESTs were similar to genes involved in secondary metabolite production, lipid metabolism, transcriptional activation, provision of precursors, signal transduction, transport or detoxification. Several of the ESTs were also located adjacent to one another in the genome and therefore might represent genes involved in the same biosynthetic pathway. Members of six such putative pathways could be found. All sequences were compared to the MIPS F. graminearum Genome Database to verify autocalled gene predictions experimentally and to introduce new exons and gene structures.
Sammendrag
We deleted the FgStuA gene in Fusarium graminearum and demonstrate its involvement in spore development, pathogenicity and secondary metabolism. The FgStuA protein is a member of the APSES family which regulate morphogenesis and virulence in ascomycetes. FgStuA is closely related to FoStuA in F. oxysporum and stuA in Aspergillus, but unlike FoStuA mutants, the FgStuA mutants were greatly reduced in pathogenicity on wheat and colonization of apple slices. The mutant produces no detectable trichothecenes on the wheat cultivar Bobwhite, and
Sammendrag
We deleted the FgStuA gene in Fusarium graminearum and demonstrate its involvement in spore development, pathogenicity and secondary metabolism. The FgStuA protein is a member of the APSES family which regulate morphogenesis and virulence in ascomycetes. FgStuA is closely related to FoStuA in F. oxysporum and stuA in Aspergillus, but unlike FoStuA mutants, the FgStuA mutants were greatly reduced in pathogenicity on wheat and colonization of apple slices. The mutant produces no detectable trichothecenes on the wheat cultivar Bobwhite, and
Sammendrag
The filamentous fungus Fusarium graminearum causes extensive losses on cereals world-wide and contaminates harvested grain with mycotoxins, whose levels in the food supply are strictly regulated. We deleted the FgStuA gene in Fusarium graminearum and demonstrate its involvement in several different processes, such as spore development, pathogenicity and secondary metabolism. The FgStuA protein is a members of the APSES family which regulate morphogenesis and virulence in ascomycetes. FgStuA is closely related to FoStuA in F. oxysporum and StuA in Aspergillus, but unlike FoStuA mutants, the FgStuA mutants were greatly reduced in pathogenicity both on wheat and apple slices. Reduced pathogenicity may be due to decreased levels of trichothecene mycotoxins (
Forfattere
Matias Pasquali Erik Lysøe Andrew Breakspear Kyeyong Seong Jon Menke Jin-Rong Xu H. Corby KistlerSammendrag
To understand mycotoxin accumulation and the infection cycle of the wheat head blight pathogen Fusarium graminearum sensu stricto,fungal gene expression profiles were monitored during plant infection. Strains containing mutations in genes for three transcription factors were found to control deoxynivalenol (DON) accumulation in planta and pathogenicity. Expression profiles were compared between wildtype and these mutants during infection of wheat. Mutants deleted for the StuA gene were greatly decreased in sporulation and produced no perithecia in culture. Unlike "stuA mutants in F. oxysporum, F. graminearum "stuA mutants were greatly reduced in pathogenicity. Reduced pathogenicity may be due to decreased DON levels in planta, which in the mutant were