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.
2021
Forfattere
Abdelhameed Elameen Svein Stueland Ralf Kristensen Rosa Ferreira Fristad Trude Vrålstad Ida SkaarSammendrag
Saprolegnia parasitica is recognized as one of the most important oomycetes pests of salmon and trout species. The amplified fragment length polymorphism (AFLP) and method sequence data of the internal transcribed spacer (ITS) were used to study the genetic diversity and relationships of Saprolegnia spp. collected from Canada, Chile, Japan, Norway and Scotland. AFLP analysis of 37 Saprolegnia spp. isolates using six primer combinations gave a total of 163 clear polymorphic bands. Bayesian cluster analysis using genetic similarity divided the isolates into three main groups, suggesting that there are genetic relationships among the isolates. The unweighted pair group method with arithmetic mean (UPGMA) and principal coordinate analysis (PCO) confirmed the pattern of the cluster analyses. ITS analyses of 48 Saprolegnia sequences resulted in five well-defined clades. Analysis of molecular variance (AMOVA) revealed greater variation within countries (91.01%) than among countries (8.99%). We were able to distinguish the Saprolegnia isolates according to their species, ability to produce oogonia with and without long spines on the cysts and their ability to or not to cause mortality in salmonids. AFLP markers and ITS sequencing data obtained in the study, were found to be an efficient tool to characterize the genetic diversity and relationships of Saprolegnia spp. The comparison of AFLP analysis and ITS sequence data using the Mantel test showed a very high and significant correlation (r2 = 0.8317).
Forfattere
Johanna Eva Bodin Tage Thorstensen Muath K Alsheikh Dean Basic Rolf Brudvik Edvardsen Knut Tomas Dalen Nur Duale Ole Martin Eklo Åshild Gunilla Ergon Anne-Marthe Ganes Jevnaker Kjetil Hindar Leiv Sigve Håvarstein Martin Malmstrøm Kaare Magne Nielsen Siri Lie Olsen Eli Knispel Rueness Monica Sanden Ville Erling Sipinen Kristine von Krogh Dag Inge Våge Anna Wargelius Per Hans Micael Wendell Siamak Pour Yazdankhah Jan Alexander Ellen Merete Bruzell Gro Ingunn Hemre Vigdis Vandvik Angelika Agdestein Edel O. Elvevoll Dag Olav Hessen Merete Hofshagen Trine Husøy Helle Katrine Knutsen Åshild Krogdahl Asbjørn Magne Nilsen Trond Rafoss Olaug Taran Skjerdal Inger-Lise Karin Steffensen Tor Arne Strand Gaute Velle Yngvild WastesonSammendrag
The Norwegian Scientific Committee for Food and Environment (VKM) initiated this work to examine the extent to which organisms developed by genome-editing technologies pose new challenges in terms of risk assessment. This report considers whether the risk assessment guidance on genetically modified organisms, developed by the European Food Safety Authority (EFSA), can be applied to evaluate potential risks of organisms developed by genome editing. Background Gene technology has allowed for the transfer of genes between organisms and species, and thereby to design altered genotypes with novel traits, i.e. GMOs. A new paradigm started in the early 2000s with the development of genome-editing techniques. Unlike traditional genetic modification techniques resulting in insertion of foreign DNA fragments at random locations in the genome, the new genome-editing techniques additionally open for a few single nucleotide edits or short insertions/deletions at a targeted site in an organism’s genome. These new techniques can be applied to most types of organisms, including plants, animals and microorganisms of commercial interest. An important question is how the novel, genome-edited organisms should be evaluated with respect to risks to health and the environment. The European Court of Justice decided in 2018 to include genome-edited organisms in the GMO definition and hence in the regulatory system already in place. This implies that all products developed by genome-editing techniques must be risk-assessed within the existing regulatory framework for GMOs. The European and Norwegian regulatory frameworks regulate the production, import and placing on the market of food and feed containing, consisting of or produced from GMOs, as well as the release of GMOs into the environment. The assessment draws on guidance documents originally developed by EFSA for risk assessment of GMOs, which were drawn up mainly to address risks regarding insertion of transgenes. The new genome-editing techniques, however, provide a new continuum of organisms ranging from those only containing a minor genetic alteration to organisms containing insertion or deletion of larger genomic regions. Risk assessment of organisms developed by genome editing The present discourse on how new genome-editing techniques should be regulated lacks an analysis of whether risk assessment methodologies for GMOs are adequate for risk assessment of organisms developed through the use of the new genome-editing techniques. Therefore, this report describes the use of genome-editing techniques in food and feed production and discusses challenges in risk assessment with the regulatory framework. Specifically, this report poses the question as to whether the EFSA guidance documents are sufficient for evaluating risks to health and environment posed by genome-edited plants, animals and microorganisms. To address these questions, the report makes use of case examples relevant for Norway. These examples, intended for food and feed, include oilseed rape with a modified fatty acid profile, herbicide-tolerant and pest-resistant crops, sterile salmon, virus-resistant pigs and hornless cattle. The report considers all aspects of the stepwise approach as described in the EFSA guidance documents. Conclusions The inherent flexibility of the EFSA guidance makes it suitable to cover health and environmental risk assessments of a wide range of organisms with various traits and intended uses. Combined with the embedded case-by-case approach the guidance is applicable to genome-edited organisms. The evaluation of the guidance demonstrates that the parts of the health and environmental risk assessment concerned with novel traits (i.e. the phenotype of the organism) may be fully applied to all categories of genome-edited organisms. ............
Forfattere
Kirill Ovchinnikov Christian Kranjec Amar A. Telke Morten Kjos Tage Thorstensen Dzung B. DiepSammendrag
Det er ikke registrert sammendrag
Forfattere
Klaus. R Westphal Simone Bachleitner Manja M. Severinsen Mathias L. Brundtø Frederik T. Hansen Trine Sørensen Rasmus D. Wollenberg Erik Lysøe Lena Studt Jens L. Sørensen Teis E. Sondergaard Reinhard WimmerSammendrag
The plant pathogenic fungus Fusarium graminearum is known to produce a wide array of secondary metabolites during plant infection. This includes several nonribosomal peptides. Recently, the fusaoctaxin (NRPS5/9) and gramilin (NRPS8) gene clusters were shown to be induced by host interactions. To widen our understanding of this important pathogen, we investigated the involvement of the NRPS4 gene cluster during infection and oxidative and osmotic stress. Overexpression of NRPS4 led to the discovery of a new cyclic hexapeptide, fusahexin (1), with the amino acid sequence cyclo-(d-Ala-l-Leu-d-allo-Thr-l-Pro-d-Leu-l-Leu). The structural analyses revealed an unusual ether bond between a proline Cδ to Cβ of the preceding threonine resulting in an oxazine ring system. The comparative genomic analyses showed that the small gene cluster only encodes an ABC transporter in addition to the five-module nonribosomal peptide synthetase (NRPS). Based on the structure of fusahexin and the domain architecture of NRPS4, we propose a biosynthetic model in which the terminal module is used to incorporate two leucine units. So far, iterative use of NRPS modules has primarily been described for siderophore synthetases, which makes NRPS4 a rare example of a fungal nonsiderophore NRPS with distinct iterative module usage.
Forfattere
Paal Krokene Bjørn Arild Hatteland Christer Magnusson Daniel Flø Iben Margrete Thomsen Johan A. Stenberg May Bente Brurberg Per Hans Micael Wendell Mogens Nicolaisen Simeon Rossmann Venche Talgø Beatrix Alsanius Sandra A.I. Wright Trond RafossSammendrag
Det er ikke registrert sammendrag
Forfattere
Daniel Powell Ewald Groβe-Wilde Paal Krokene Amit Roy Amrita Chakraborty Christer Löfstedt Heiko Vogel Martin N. Andersson Fredrik SchlyterSammendrag
Conifer-feeding bark beetles are important herbivores and decomposers in forest ecosystems. These species complete their life cycle in nutritionally poor substrates and some can kill enormous numbers of trees during population outbreaks. The Eurasian spruce bark beetle (Ips typographus) can destroy >100 million m3 of spruce in a single year. We report a 236.8 Mb I. typographus genome assembly using PacBio long-read sequencing. The final phased assembly has a contig N50 of 6.65 Mb in 272 contigs and is predicted to contain 23,923 protein-coding genes. We reveal expanded gene families associated with plant cell wall degradation, including pectinases, aspartyl proteases, and glycosyl hydrolases. This genome sequence from the genus Ips provides timely resources to address questions about the evolutionary biology of the true weevils (Curculionidae), one of the most species-rich animal families. In forests of today, increasingly stressed by global warming, this draft genome may assist in developing pest control strategies to mitigate outbreaks.
Forfattere
Tomáš Hlásny Louis König Paal Krokene Marcus Lindner Claire Montagné-Huck Jörg Müller Hua Qin Kenneth F. Raffa Mart-Jan Schelhaas Miroslav Svoboda Heli Viiri Rupert SeidlSammendrag
Purpose of Review Outbreaks of tree-killing bark beetles have reached unprecedented levels in conifer forests in the northern hemisphere and are expected to further intensify due to climate change. In parts of Europe, bark beetle outbreaks and efforts to manage them have even triggered social unrests and political instability. These events have increasingly challenged traditional responses to outbreaks, and highlight the need for a more comprehensive management framework. Recent Findings Several synthesis papers on different aspects of bark beetle ecology and management exist. However, our understanding of outbreak drivers and impacts, principles of ecosystem management, governance, and the role of climate change in the dynamics of ecological and social systems has rapidly advanced in recent years. These advances are suggesting a reconsideration of previous management strategies. Summary We synthesize the state of knowledge on drivers and impacts of bark beetle outbreaks in Europe and propose a comprehensive context-dependent framework for their management. We illustrate our ideas for two contrasting societal objectives that represent the end-members of a continuum of forest management goals: wood and biomass production and the conservation of biodiversity and natural processes. For production forests, we propose a management approach addressing economic, social, ecological, infrastructural, and legislative aspects of bark beetle disturbances. In conservation forests, where non-intervention is the default option, we elaborate under which circumstances an active intervention is necessary, and whether such an intervention is in conflict with the objective to conserve biodiversity. Our approach revises the current management response to bark beetles in Europe and promotes an interdisciplinary social-ecological approach to dealing with disturbances.
Forfattere
Paal KrokeneSammendrag
Det er ikke registrert sammendrag
Sammendrag
The spruce bark beetle Ips typographus is the most damaging pest in European spruce forests and has caused great ecological and economic disturbances in recent years. Although native to Eurasia, I. typographus has been intercepted more than 200 times in North America and could establish there as an exotic pest if it can find suitable host trees. Using in vitro bioassays, we compared the preference of I. typographus for its coevolved historical host Norway spruce (Picea abies) and two non-coevolved (naïve) North American hosts: black spruce (Picea mariana) and white spruce (Picea glauca). Additionally, we tested how I. typographus responded to its own fungal associates (conspecific fungi) and to fungi vectored by the North American spruce beetle Dendroctonus rufipennis (allospecific fungi). All tested fungi were grown on both historical and naïve host bark media. In a four-choice Petri dish bioassay, I. typographus readily tunneled into bark medium from each of the three spruce species and showed no preference for the historical host over the naïve hosts. Additionally, the beetles showed a clear preference for bark media colonized by fungi and made longer tunnels in fungus-colonized media compared to fungus-free media. The preference for fungus-colonized media did not depend on whether the medium was colonized by conspecific or allospecific fungi. Furthermore, olfactometer bioassays demonstrated that beetles were strongly attracted toward volatiles emitted by both con- and allospecific fungi. Collectively, these results suggest that I. typographus could thrive in evolutionary naïve spruce hosts if it becomes established in North America. Also, I. typographus could probably form and maintain new associations with local allospecific fungi that might increase beetle fitness in naïve host trees.
Forfattere
Paal KrokeneSammendrag
Det er ikke registrert sammendrag