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.
2009
Forfattere
Jorunn Elisabeth Olsen Anna Holefors Lars Morten Opseth Daniel Asante Olavi Junttila Jørgen Aleksander Mølmann Igor A. Yakovlev Carl Fossdal Øystein JohnsenSammendrag
Det er ikke registrert sammendrag
Sammendrag
The estrogenic mycotoxin zearalenone (ZON) produced by some Fusarium spp. causes reproductive problems and hyperestrogenic syndromes in mammals. In an effort to elucidate the molecular pathways of ZON production, we present a comparative real-time quantitative polymerase chain reaction expression study of seven contiguous genes in the ZON biosynthetic cluster on sterile rice and during wheat and oat infection. Under ZON production on rice, the polyketide synthase (PKS) genes PKS4 and PKS13, alcohol oxidase FG12056 gene, and transcriptional regulator FG02398 gene showed similarly upregulated patterns, whereas the nonribosomal peptide synthetase (NPS) FG02394, the K+ channel beta subunit FG12015, and the protein kinase FG02399 displayed a variant pattern. During the same time period under wheat infection when no ZON was produced, the PKS genes and the NPS were downregulated relative to rice whereas the K+ channel beta subunit gene FG12015 was markedly upregulated, suggesting that it may play a role in the infection process. This is the first expression study of ZON biosynthetic genes in planta. The results give insight into the regulation and activities of the ZON gene cluster under different experimental systems and suggest a connection between ZON and a K+ channel that could reveal a novel function for ZON in Fusarium spp.
Sammendrag
Members of the APSES family of fungal proteins have been identified as key regulators of fungal development, controlling processes such as mating, sporulation and dimorphic growth. We deleted the FgStuA gene in Fusarium graminearum and show that the mutant is greatly impaired in spore development, pathogenicity and secondary metabolism. FgStuA is closely related to FoStuA in F. oxysporum, but unlike FoStuA mutants the FgStuA mutants were greatly reduced in pathogenicity both on wheat and apple slices. The lack of ability to cause disease on wheat heads may be due to lack of trichothecene accumulation in planta. The FgStuA mutant also had a white/yellow mycelial phenotype compared to the red pigmented (aurofusarin) wild-type, had reduced aerial mycelium, susceptibility to oxidative stress, and had a less hydrophobic surface. Microarray analysis showed that most phenotypes could be inferred from gene expression data, such as down-regulation of the trichothecene gene cluster in the mutant. In an attempt to separate primary and secondary effects of FgStuA deletion, we carefully examined gene expression data together with promoter analysis and comparative genomics. The genes flanking FgStuA are conserved and syntenous in other fungal genomes and contain a gene encoding a putative clock controlled protein. FgStuAp and other APSES proteins share significant homology with DNA-binding domains of transcription factors controlling the critical G1/S phase cell cycle transition in both S. cerevisiae and S. pombe. Genes within MIPS Functional Category (FunCat) 10 "Cell cycle and DNA processing" are enriched among those more highly expressed in the FgStuA mutant than wild-type. Aspergillus StuAp response elements (A/TCGCGT/ANA/C) also were found highly enriched in promoter sequences for FunCat 10 genes, compared to the genome as a whole. Our results suggests that FgStuAp may act primarily as a repressor involved in cell cycle regulation, and may act only secondarily on sporulation, pathogenicity, and secondary metabolism.
Sammendrag
Members of the APSES family of fungal proteins have been identified as key regulators of fungal development, controlling processes such as mating, sporulation and dimorphic growth. We deleted the FgStuA gene in Fusarium graminearum and show that the mutant is greatly impaired in spore development, pathogenicity and secondary metabolism. FgStuA is closely related to FoStuA in F. oxysporum, but unlike FoStuA mutants the FgStuA mutants were greatly reduced in pathogenicity both on wheat and apple slices. The lack of ability to cause disease on wheat heads may be due to lack of trichothecene accumulation in planta. The FgStuA mutant also had a white/yellow mycelial phenotype compared to the red pigmented (aurofusarin) wild-type, had reduced aerial mycelium, susceptibility to oxidative stress, and had a less hydrophobic surface. Microarray analysis showed that most phenotypes could be inferred from gene expression data, such as down-regulation of the trichothecene gene cluster in the mutant. In an attempt to separate primary and secondary effects of FgStuA deletion, we carefully examined gene expression data together with promoter analysis and comparative genomics. The genes flanking FgStuA are conserved and syntenous in other fungal genomes and contain a gene encoding a putative clock controlled protein. FgStuAp and other APSES proteins share significant homology with DNA-binding domains of transcription factors controlling the critical G1/S phase cell cycle transition in both S. cerevisiae and S. pombe. Genes within MIPS Functional Category (FunCat) 10 "Cell cycle and DNA processing" are enriched among those more highly expressed in the FgStuA mutant than wild-type. Aspergillus StuAp response elements (A/TCGCGT/ANA/C) also were found highly enriched in promoter sequences for FunCat 10 genes, compared to the genome as a whole. Our results suggests that FgStuAp may act primarily as a repressor involved in cell cycle regulation, and may act only secondarily on sporulation, pathogenicity, and secondary metabolism.
Sammendrag
Regulation of flowering time in Arabidopsis thaliana is controlled by a network of pathways integrating environmental and internal signals. Two of these pathways, the vernalization and photoperiodic pathways, mediate responses to prolonged cold period and photoperiod, respectively. A number of A. thaliana populations from high-latitude and high-altitude locations in Norway were collected and phenotyped for flowering time in response to 5 photoperiods and 5 vernalization treatments. Vernalization and photoperiodic sensitivity were not correlated with latitude but rather with climatic factors such as winter temperature and precipitation that do not vary with latitude, especially in coastal environments. Coastal populations, both from subarctic and intermediate latitudes, were rather insensitive towards the length of the vernalization treatment but very sensitive towards differences in photoperiods. Stronger photoperiod sensitivity in coastal populations might be a necessary adaptation for sensing the onset of spring in regions with relatively mild and unpredictable winter climates as opposed to continental climates with more stable winters. FLC sequence variation was only partly associated with vernalization response, whereas variation in transcript levels of CRY2, TOC1 and GI was correlated with photoperiodic responses. This suggests that local adaptation of populations may be partly mediated by photoreceptors and circadian clock pathways.
Forfattere
Anna Lewandowska-Sabat Siri Fjellheim Per Winge Atle M. Bones Torfinn Sparstad Carl Gunnar Fossdal Jorunn Elisabeth Olsen Odd Arne RognliSammendrag
Det er ikke registrert sammendrag
Forfattere
Anna Marie Holefors Lars Morten Opseth Anne Katrine Ree Rosnes Linda Ripel Lars Snipen Carl Gunnar Fossdal Jorunn Elisabeth OlsenSammendrag
In woody plants of the temperate zone short photoperiod (SD) leads to growth cessation. In angiosperms CONSTANS (CO) or CO-like genes play an important role in the photoperiodic control of flowering, tuberisation and shoot growth. To investigate the role of CO-like genes in photoperiodic control of shoot elongation in gymnosperms, PaCOL1 and PaCOL2 were isolated from Norway spruce. PaCOL1 encodes a 3.9 kb gene with a predicted protein of 444 amino acids. PaCOL2 encodes a 1.2 kb gene with a predicted protein of 385 amino acids. Both genes consist of two exons and have conserved domains found in other CO-like genes; two zinc finger domains, a CCT and a COOH domain. PaCOL1 and PaCOL2 fall into the group 1c clade of the CO-like genes, and are thus distinct from Arabidopsis CO that belongs to group la. Transcript levels of both PaCOL-genes appear to be light regulated, an increasing trend was observed upon transition from darkness to light, and a decreasing trend during darkness. The increasing trend at dawn was observed both in needles and shoot tips, whereas the decreasing trend in darkness was most prominent in shoot tips, and limited to the late part of the dark period in needles. The transcript levels of both genes decreased significantly in both tissues under SD prior to growth cessation and bud formation. This might suggest an involvement in photoperiodic control of shoot elongation or might be a consequence of regulation by light. (C) 2008 Elsevier Masson SAS. All rights reserved.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Paal KrokeneSammendrag
Mange insekter vil utvide sitt utbredelsesområde mot nord dersom klimaet blir varmere. Det kan føre til at norske skoger får nærkontakt med nye og ødeleggende skadegjørere. En av artene vi har størst grunn til å frykte er en vakker sommerfugl med et uskyldig navn.
Forfattere
Paal KrokeneSammendrag
Insektene er blant de organismene som reagerer raskest på klimaendringer. De har kort generasjonstid, er svært mobile og utviklingshastigheten deres er direkte påvirket av temperaturen. Dette betyr at utviklingen fra egg til voksent insekt går raskere når temperaturen øker, noe som kan få store praktiske konsekvenser for skogbruket.