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.
2019
Forfattere
Inger Skrede Monica Hongrø Solbakken Jaqueline Hess Carl Gunnar Fossdal Olav Aaseth Hegnar Gry AlfredsenSammendrag
The aim of this study was to investigate differential expression profiles of the brown rot fungus Rhodonia placenta (previously Postia placenta) harvested at several time points when grown on radiata pine (Pinus radiata) and radiata pine with three different levels of modification by furfuryl alcohol, an environmentally benign commercial wood protection system. The entire gene expression pattern of a decay fungus was followed in untreated and modified wood from initial to advanced stages of decay. The results support the current model of a two-step decay mechanism, with the expression of genes related to initial oxidative depolymerization, followed by an accumulation of transcripts of genes related to the hydrolysis of cell wall polysaccharides. When the wood decay process is finished, the fungus goes into starvation mode after five weeks when grown on unmodified radiata pine wood. The pattern of repression of oxidative processes and oxalic acid synthesis found in radiata pine at later stages of decay is not mirrored for the high-furfurylation treatment. The high treatment level provided a more unpredictable expression pattern throughout the incubation period. Furfurylation does not seem to directly influence the expression of core plant cell wall-hydrolyzing enzymes, as a delayed and prolonged, but similar, pattern was observed in the radiata pine and the modified experiments. This indicates that the fungus starts a common decay process in the modified wood but proceeds at a slower pace as access to the plant cell wall polysaccharides is restricted. This is further supported by the downregulation of hydrolytic enzymes for the high treatment level at the last harvest point (mass loss, 14%). Moreover, the mass loss does not increase during the last weeks. Collectively, this indicates a potential threshold for lower mass loss for the high-furfurylation treatment. IMPORTANCE Fungi are important decomposers of woody biomass in natural habitats. Investigation of the mechanisms employed by decay fungi in their attempt to degrade wood is important for both the basic scientific understanding of ecology and carbon cycling in nature and for applied uses of woody materials. For wooden building materials, long service life and carbon storage are essential, but decay fungi are responsible for massive losses of wood in service. Thus, the optimization of durable wood products for the future is of major importance. In this study, we have investigated the fungal genetic response to furfurylated wood, a commercial environmentally benign wood modification approach that improves the service life of wood in outdoor applications. Our results show that there is a delayed wood decay by the fungus as a response to furfurylated wood, and new knowledge about the mechanisms behind the delay is provided.
Forfattere
Dajana Blagojevic YeonKyeong Lee Dag Anders Brede Ole Christian Lind Igor A. Yakovlev Knut Asbjørn Solhaug Carl Gunnar Fossdal Brit Salbu Jorunn Elisabeth OlsenSammendrag
Main conclusion Persistent DNA damage in gamma-exposed Norway spruce, Scots pine and Arabidopsis thaliana, but persistent adverse effects at the organismal and cellular level in the conifers only. Gamma radiation emitted from natural and anthropogenic sources may have strong negative impact on plants, especially at high dose rates. Although previous studies implied different sensitivity among species, information from comparative studies under standardized conditions is scarce. In this study, sensitivity to gamma radiation was compared in young seedlings of the conifers Scots pine and Norway spruce and the herbaceous Arabidopsis thaliana by exposure to 60Co gamma dose rates of 1–540 mGy h−1 for 144 h, as well as 360 h for A. thaliana. Consistent with slightly less prominent shoot apical meristem, in the conifers growth was significantly inhibited with increasing dose rate ≥ 40 mGy h−1. Post-irradiation, the conifers showed dose-rate-dependent inhibition of needle and root development consistent with increasingly disorganized apical meristems with increasing dose rate, visible damage and mortality after exposure to ≥ 40 mGy h−1. Regardless of gamma duration, A. thaliana showed no visible or histological damage or mortality, only delayed lateral root development after ≥ 100 mGy h−1 and slightly, but transiently delayed post-irradiation reproductive development after ≥ 400 mGy h−1. In all species dose-rate-dependent DNA damage occurred following ≥ 1–10 mGy h−1 and was still at a similar level at day 44 post-irradiation. In conclusion, the persistent DNA damage (possible genomic instability) following gamma exposure in all species may suggest that DNA repair is not necessarily mobilized more extensively in A. thaliana than in Norway spruce and Scots pine, and the far higher sensitivity at the organismal and cellular level in the conifers indicates lower tolerance to DNA damage than in A. thaliana.
Forfattere
Hanno Sandvik Olga Hilmo Anders Gravbrøt Finstad Hanne Hegre Toril Loennechen Moen Trond Rafoss Olav Skarpaas Reidar Elven Helge Sandmark Lisbeth GederaasSammendrag
© The Author(s) 2019. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/)
Forfattere
Sissel Hansen Randi Berland Frøseth Maria Stenberg Jarosław Stalenga Jørgen E. Olesen Maike Krauss Paweł Radzikowski Jordi Doltra Shahid Nadeem Torfinn Torp Valentini Pappa Christine A. WatsonSammendrag
Det er ikke registrert sammendrag
Forfattere
N. Feau Dario Isidro Ojeda Alayon S. Beauseigle G. J. Bilodeau A. Brar S. Cervantes-Arango A. L. Dale B. Dhillon C. Hammett P. Herath S. F. Shamoun C. K. M. Tsui P. Tanguay R. C. HamelinSammendrag
Det er ikke registrert sammendrag
Forfattere
Dilli Prasad Rijal Kelsey Lorberau Peter D. Heintzman Youri Lammers Jutta Kapfer Einar Støvern Nigel Gilles Yoccoz Dorothee Ehrich Antony Brown Inger Greve Alsos Kari Anne BråthenSammendrag
Det er ikke registrert sammendrag
Forfattere
Jørgen Eilenberg Stephanie Saussure Ibtissem Ben Fekih Annette Bruun Jensen Ingeborg KlingenSammendrag
Pandora neoaphidis and Entomophthora planchoniana are widespread and important specialist fungal pathogens of aphids in cereals (Sitobion avenae and Rhopalosiphum padi). The two aphid species share these pathogens and we compare factors influencing susceptibility and resistance. Among factors that may influence susceptibility and resistance are aphid behavior, conspecific versus heterospecific host, aphid morph, life cycle, and presence of protective endosymbionts. It seems that the conspecific host is more susceptible (less resistant) than the heterospecific host, and alates are more susceptible than apterae. We conceptualize the findings in a diagram showing possible transmission in field situations and we pinpoint where there are knowledge gaps.
Forfattere
Günter Blöschl Marc F.P. Bierkens Antonio Chambel Christophe Cudennec Georgia Destouni Aldo Fiori James W. Kirchner Jeffrey J. McDonnell Hubert H.G. Savenije Murugesu Sivapalan Christine Stumpp Elena Toth Elena Volpi Gemma Carr Claire Lupton Josè Salinas Borbála Széles Alberto Viglione Hafzullah Aksoy Scott T. Allen Anam Amin Vazken Andréassian Berit Arheimer Santosh Aryal Victor Baker Earl Bardsley Marlies H. Barendrecht Alena Bartosova Okke Batelaan Wouter R. Berghuijs Keith Beven Theresa Blume Thom Bogaard Pablo de Amorim Borges Michael E. Böttcher Gilles Boulet Korbinian Breinl Mitja Brilly Luca Brocca Wouter Buytaert Attilio Castellarin Andrea Castelletti Xiaohong Chen Yangbo Chen Yuanfang Chen Peter Chifflard Annette Dathe Holger Lange Jacob Sebastian Haugaard Mernild Thomas Skaugen Ingelin SteinslandSammendrag
© 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Forfattere
Kristin Sørheim Johan Barstad Ildri Kristine Bergslid Annik Magerholm Fet Bjørn Egil Flø Unni Støbet Lande Liv Solemdal Håvard Steinshamn Liv Guri VelleSammendrag
Lokal verdiskaping basert på utmarka i verdsarvområda Vestlandsk fjordlandskap kan ikkje sjåast isolert, men er tett knytt til heile samfunnsutviklinga på desse stadene. Det tradisjonelle landbruket i desse områda har skapt verdfulle naturgode som biologisk mangfald, opne turområde med høg rekreasjonsverdi, turstiar og anna. Fleire av desse naturgoda er viktige for reiselivsnæringa. Kulturlandskapet er også viktig for verdsarvstatusen i seg sjølv, ettersom dette er ein viktig del av kjerneverdiane til området (OUV). Utviklinga i landbruket gjer at tungdrivne areal også i verdsarvområda går ut av bruk. Opphøyr eller låg bruksintensitet går spesielt ut over utmarksressursane og dei seminaturlege naturtypane. Utmarka i Geirangerfjordområdet er særleg trua, da tradisjonell bruk med beiting, slått og hausting no i stor grad har teke slutt, og naturtypane gror att med buskar og kratt. Gjengroing fører til tap avvariasjon, artar og økologiske funksjonar. Intensivering av landbruket vil også forringe naturverdiane og landskapskvalitetane. For at landbruket ikkje berre skal vere eit «kulisselandbruk», men vere del av eit berekraftig driftssystem, må tilgjengelege arealressursar på innmark og utmark nyttast til matproduksjon og andre livsviktige økosystemtenester. Gjeldande landbrukspolitikk, med mål om stordrift og effektivisering av matproduksjonen, er ei sterkare drivkraft enn dei tiltaka som er sett inn for å bremse og motverke at tungdrivne areal går ut av bruk i verdsarvområda. Den lokale turist- og reiselivsnæringa kan også hamne i noko av same marginaliserte situasjonen som landbruksnæringa fordi dei ikkje lenger er dei mest sentrale aktørane. Eksterne aktørar representert ved cruiseindustri, turbussar og storskala reisearrangørar er ofte i enda større grad premissleverandørar. Det trengs ei heilskapleg tilnærming for å løyse utfordringane. Ein prosess som forskyv maktbalansen frå eksterne aktørar innan masseturisme og i retning lokalt næringsliv og verdiskaping og som inkluderer innbyggjarane, krev nytenking, utvikling av nye forretningsmodellar og evne til gjennomføring gjennom demokratiske planprosessar. Av ulike konkrete verkemiddel som kan prøvast ut, men da helst som element i ein større endringsprosess, vil vi peike på særskilde landbrukspolitiske verkemiddel i retning sveitsisk modell, turistskatt, anna betaling for fellesgode og bygdeutviklingsprosjekt som kan gi auka tilflytting og ny næringsaktivitet. Dialog og partnarskapsbygging kan fremme ansvarleg medverknad.Forskingsbehova for verdsarvområda og tilsvarande område med store og unytta ressursar i utmarka er mange, og arbeidsgruppa si vurdering er summert og konkretisert i denne rapporten
Forfattere
Hege Divon Lise Bøe Martha Tveit Sonja KlemsdalSammendrag
Fusarium langsethiae is one of the common Fusarium species infecting small grain cereals in the Nordic region and the UK. It is usually described as a weak pathogen, and with a strong preference for oats, although no studies have yet addressed the explanations for this at the microscopic level. Using microscope techniques we have studied the early steps of colonization of oat and wheat grain by F. langsethiae particularly addressing the role of pollen in the infection process and the fungal ability to penetrate plant cell wall. The aim was to better understand its non-aggressive colonization picture and why oat is preferred over wheat as a host. Spray inoculated oat and wheat plants were scored for fungal progression at 3, 6, 10 and 14 days post inoculation (dpi) using light microscopy and scanning electron microscopy (SEM). Fungal hyphae entered the grain at the apex, or along the sides in the overlapping zone between palea wings and lemma, then spread basipetally and laterally, with a clear directional growth towards the caryopsis. Hyphal growth was clearly aided by the presence of pollen. On oat proliferating hyphae developed a variety of penetration structures on all internal surfaces. F. langsethiae infection on wheat progressed along the same routes, however slower and overall with less hyphal mass. Interestingly, hyphae closely associated to the wheat caryopsis seemed to undergo degradation, and profuse conidiation was observed at 14 dpi. Explanations for the differences in F. langsethiae colonization of oat versus wheat are suggested in light of the results.