Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2016
Abstract
No abstract has been registered
Authors
Gunn StrømengAbstract
No abstract has been registered
Authors
Gunn StrømengAbstract
No abstract has been registered
Abstract
In order to determine the relation between the structural properties and fungistatic activity of quinolizidine and bisquinolizidine alkaloids, the bioactive derivatives of cytisine, sparteine and lupanine were tested for the inhibitory activity against the microfungus causing mould growth phenomenon (Aspergillus niger van Tieghem ATCC 6275). The compounds tested were screened for antifungal properties using the bioautography-TLC. According to the results, the following cytisines showed an inhibiting effect on mould; spirocytisine, 3,5-dibromocytisine, bromo-N-boccytisine, N-Boccytisine, 3-bromobenzylocytisine, 4-bromo-benzylcytisine, 3-iodobenzylcytisine, 4-iodobenzylcytisine.
Abstract
Modified wood can provide protection against a range of wood deteriorating organisms. Several hypotheses have been put forward regarding the protection mechanisms against wood decaying fungi including fungal enzyme inefficiency due to non-recognition, lower micropore size, and insufficient wood moisture content. The aim of this study was to obtain new insight into the protection manner of furfuryl alcohol (FA) modified Scots pine sapwood (WFA), and to examine biochemical mechanisms and adaptive changes in gene expression utilised by Postia placenta during early colonisation of WFA. Samples were harvested after 2, 4, and 8 weeks of incubation. After 8 weeks, the mass loss (0.1%) and wood moisture content (21.0%) was lower inWFA, than in non-modified Scots pine sapwood samples (W), 26.1% and 46.1%, respectively. Microscopy revealed needle-shaped calcium oxalate crystals, at all harvesting points, most prominently present after 4 and 8 weeks, and only in the WFA samples. Among the findings based on gene profiles were indications of a possible shift toward increased expression, or at least no down regulation, of genes related to oxidative metabolism and concomitant reduction of several genes related to the breakdown of polysaccharides in WFA compared to W.
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No abstract has been registered
Authors
Martina Jonsson Marika Jestoi Minna Anthoni Annikki Welling Iida Loivamaa Ville Hallikainen Matti Kankainen Erik Lysøe Pertti Koivisto Kimmo PeltonenAbstract
The mycotoxin enniatin B, a cyclic hexadepsipeptide produced by the plant pathogen Fusarium, is prevalent in grains and grain-based products in different geographical areas. Although enniatins have not been associated with toxic outbreaks, they have caused toxicity in vitro in several cell lines. In this study, the cytotoxic effects of enniatin B were assessed in relation to cellular energy metabolism, cell proliferation, and the induction of apoptosis in Balb 3T3 and HepG2 cells. The mechanism of toxicity was examined by means of whole genome expression profiling of exposed rat primary hepatocytes. Enniatin B altered cellular energy metabolism and reduced cell proliferation in Balb 3T3 and HepG2 cell lines. Furthermore, the proportion of apoptotic cell populations of Balb 3T3 cells slightly increased. On the other hand, enniatin B caused necrotic cell death in primary hepatocytes. Gene expression studies revealed the alteration of energy metabolism due to effects on mitochondrial organization and function and the assembly of complex I of the electron transport chain.
Authors
Pia Heltoft Thomsen May Bente Brurberg Monica Skogen Vinh Hong Le Jafar Razzaghian Arne HermansenAbstract
The prevalence of Fusarium dry rot in potatoes produced in Norway was investigated in a survey for three consecutive years in the period 2010 to 2012. A total of 238 samples (comprising 23,800 tubers) were collected, representing different cultivars and production regions in Norway. Fusarium spp. were detected in 47% of the samples, with one to three species per sample. In total, 718 isolates of Fusarium spp. were recovered and identified to seven species. The most commonly isolated species was Fusarium coeruleum, comprising 59.6% of the total Fusarium isolates and found in 17.2% of the collected samples, followed by Fusarium avenaceum (27.2% of the isolates and found in 27.7% of the samples). Fusarium sambucinum was the third most prevalent species (6.4% in 8.8% of the samples) and Fusarium culmorum the fourth (5.2% in 6.3% of the samples). Less prevalent species included Fusarium cerealis, Fusarium graminearum, and Fusarium equiseti (<1% in 0.4 to 1.3% of the samples). F. coeruleum was the most prevalent species in northern and southwestern Norway, whereas F. avenaceum was dominating in eastern Norway. The potato cultivars Berber and Rutt were susceptible to all Fusarium spp. A new TaqMan real-time PCR assay specific for F. coeruleum was developed, which successfully identified Norwegian isolates. This and other previously developed real-time PCR assays targeting different Fusarium species were evaluated for their ability to detect latent infections in potatoes at harvest. This study provides new information on the current occurrence of different Fusarium species causing Fusarium dry rot in potatoes in Europe including areas far into the arctic in the north of Norway.
Abstract
No abstract has been registered
Abstract
Stem elongation and flower bud emergence in response to photoperiod (16 and 20 h) and temperature (10, 14 and 18 °C) were characterized in three Norwegian (Lea, Nordi, Reipo) and one Swiss (Fregata) red clover variety. The Norwegian varieties were slower in generative development than Fregata, and were, unlike Fregata, responsive to an increase in photoperiod from 16 to 20 h. Lea was later than Reipo, while Nordi was intermediate. Across all varieties, the earliness of stem elongation in response to temperature was saturated at 14 °C, whereas earliness of flower bud emergence also responded to an increase from 14 to 18 °C. Photoperiod and temperature had additive effects on timing of development prior to stem elongation and complementary effects on timing of development prior to flower bud emergence. Developmental rates calculated on a thermal time basis varied between temperature treatments.