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.
2016
Sammendrag
There is limited knowledge on the toxicological, physiological, and molecular effects attributed to organophosphate (OP) compounds currently used as flame retardants or additives in consumer products. This study investigated the effects on oxidative stress and lipid peroxidation in juvenile Atlantic salmon liver and brain samples after exposure to two OP compounds, tris(2-butoxyethyl) phosphate (TBOEP) and tris(2-chloroethyl) phosphate (TCEP). In this study, groups of juvenile Atlantic salmon were exposed using a semistatic experimental protocol over a 7-d period to 3 different concentrations (0.04, 0.2, or 1 mg/L) of TBOEP and TCEP. When toxicological factors such as bioaccumulation and bioconcentration, and chemical structural characteristics and behavior, including absorption to solid materials, are considered, these concentrations represent environmentally relevant concentrations. The concentrations of the contaminants were derived from levels of their environmental occurrence. The expression of genes related to oxidative stress—glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST)—and to lipid peroxidation—peroxisome proliferator-activated receptors (PPAR)—were determined using quantitative (real-time) polymerase chain reaction (PCR). The presence of PPAR proteins was also investigated using immunochemical methods. Levels of thiobarbituric acid-reactive substances (TBARS) in liver were used as a measure of lipid peroxidation. Overall, our data show an increase in lipid peroxidation, and this was associated with an augmented expression of genes from the glutathione family of responses. Interestingly, PPAR expression in liver after exposure to TBOEP and TCEP was consistently decreased compared to controls, while expression in brain did not show a similar trend. The results suggest that OP contaminants may induce oxidative stress and thus production of reactive oxygen substances (ROS), and modulate lipid peroxidation processes in organisms.
Forfattere
Augustine Arukwe Camilla Catarci Carteney Monica Möder Alberto Bonini Morten Andre Maubach Trine EggenSammendrag
Following the ban of polybrominated diphenyl ether (PBDEs) flame retardants under well-documented toxicity issues, organophosphate such as tris(2-butoxyethyl) phosphate (TBOEP) and tris(2-cloroethyl) phosphate (TCEP) were considered as potential substitutes. Although TBOEP and TCEP are consistently detected in the aquatic environment, there are few data about the possible toxicological effects of these compounds on aquatic organisms, including fish. In the present study, we have investigated the influence of TBOEP and TCEP on neuro- and interrenal steroidogenesis of juvenile Atlantic salmon (Salmo salar), after a seven-day exposure to four different concentrations (0 (control), 0.04, 0.2 and 1 mg/L) of each compound. TBOEP and TCEP were diluted in Milli-Q water. The expression of genes involved in ster- oidogenesis (StAR, cyp19a, cyp19b, cholesterol side-chain cleavage enzyme (P450scc), 3β-hydroxysteroid dehydrogenase (3β-hsd), and 11β-hydroxylase (cyp11β)), were analyzed in the brain and head kidney using real-time PCR. Plasma 11-ketotestosterone (11-KT) analysis was performed using enzyme im- munoassay (EIA). Our results showed that TBOEP accumulated more rapidly than TCEP in fish muscle tissue. Surprisingly, TBOEP produced less pronounced effects than TCEP on neural and interrenal ster- oidogenic responses, despite the observed rapid uptake and bioaccumulation pattern. Specifically, TBOEP produced significant and consistent concentration-specific alterations on neural- and interrenal ster- oidogenesis. Plasma levels of 11-KT were not significantly altered by any of the exposures. The increased expression of steroidogenic genes demonstrated in the present study could produce time-specific al- terations in the production of glucocorticoids and steroid hormones that play integral roles in fish me- tabolism, stress responses and adaptation, sexual maturation, reproduction and migration with overt consequences on reproductive success and survival.
Forfattere
Eva Brod Anne K. Falk Øgaard Tore Krogstad Trond Haraldsen Emmanuel Frossard Astrid ObersonSammendrag
Det er ikke registrert sammendrag
Forfattere
Yanliang Wang Tore Krogstad Jihong Liu Clarke Moritz Hallama Anne K. Falk Øgaard Susanne Eich-Greatorex Ellen Kandeler Nicholas ClarkeSammendrag
Det er ikke registrert sammendrag
Forfattere
Jing Liu Huang Peng Jiangkuan Cui Wenkun Huang Lingan Kong Jihong Liu Clarke Heng Jian Guo Liang Wang Deliang PengSammendrag
Cereal cyst nematodes are sedentary biotrophic endoparasites that maintain a complex interaction with their host plants. Nematode effector proteins are synthesized in the oesophageal glands and are secreted into plant tissues through the stylet. To understand the function of nematode effectors in parasitic plants, we cloned predicted effectors genes from Heterodera avenae and transiently expressed them in Nicotiana benthamiana. Infiltration assays showed that HaEXPB2, a predicted expansin-like protein, caused cell death in N. benthamiana. In situ hybridization showed that HaEXPB2 transcripts were localised within the subventral gland cells of the pre-parasitic second-stage nematode. HaEXPB2 had the highest expression levels in parasitic second-stage juveniles. Subcellular localization assays revealed that HaEXPB2 could be localized in the plant cell wall after H. avenae infection.This The cell wall localization was likely affected by its N-terminal and C-terminal regions. In addition, we found that HaEXPB2 bound to cellulose and its carbohydrate-binding domain was required for this binding. The infectivity of H. avenae was significantly reduced when HaEXPB2 was knocked down by RNA interference in vitro. This study indicates that HaEXPB2 may play an important role in the parasitism of H. avenae through targeting the host cell wall.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Nonylphenols (NP) are a group of alkylphenols, formed upon degradation of nonylphenol ethoxylates such as nonylphenol monoethoxylate (NP1EO) or nonylphenol diethoxylate (NP2EO), which have been broadly used as non-ionic surfactants. Both NP and their ethoxylates are often present in the sewage, despite being banned and substituted by less toxic alcohol ethoxylates in many countries. There is a number of degradation studies of nonylphenol in the soil environment, but there is a lack of understanding on how plants and soil organisms such as earthworms can affect the degradation. In our study, we investigated the degradation of 4-nonylphenol (4-NP) in a mineral field soil in the presence of barley (Hordeum vulgare) and earthworms (Aporrectodea caliginosa). Soil was spiked with 4-NP at a concentration of 12.5 mg kg-1 d.w. soil. Results showed that the degradation of 4-NP in soil was rapid during the 28 days after spiking, with remaining concentration of 0.397 mg kg-1 d.w. soil on day 28. Degradation was much slower between days 28 and 120, with a remaining concentration of 0.214 mg kg-1 d.w. soil on day 120. No significant difference in the degradation of 4-NP in the presence of either plants or worms was observed, but sampling after 28 days of exposure revealed transfer of 4-NP to worms (worm tissue concentration = 0.79 μg g-1), which increased with time (1.66 μg g-1 after 120 d). The calculated transfer factor after 28 (TF28) and 120 days (TF120) was 0.07 and 0.13 respectively. No toxicity or accumulation in plants was observed at the concentration tested herein. Concentration of 4-NP in the rhizosphere was not statistically different from that in the bulk soil.
Forfattere
Priit Tammeorg Ana Catarina Bastos Simon Jeffery Frédéric Rees Jürgen Kern Ellen R. Graber Maurizio Ventura Mark Kibblewhite António Amaro Alice Budai Cláudia M.d.S. Cordovil Xavier Domene Ciro Gardi Gabriel Gascó Jan Horak Claudia Kammann Elena Kondrlova David Laird Susana Loureiro Martinho A.S. Martins Pietro Panzacchi Munoo Prasad Marija Prodana Aline Peregrina Puga Greet Ruysschaert Lidia Sas-Paszt Flávio C. Silva Wenceslau Geraldes Teixeira Giustino Tonon Gemini Delle Vedove Costanza Zavalloni Bruno Glaser Frank G. A. VerheijenSammendrag
Key priorities in biochar research for future guidance of sustainable policy development have been identified by expert assessment within the COST Action TD1107. The current level of scientific understanding (LOSU) regarding the consequences of biochar application to soil were explored. Five broad thematic areas of biochar research were addressed: soil biodiversity and ecotoxicology, soil organic matter and greenhouse gas (GHG) emissions, soil physical properties, nutrient cycles and crop production, and soil remediation. The highest future research priorities regarding biochar’s effects in soils were: functional redundancy within soil microbial communities, bioavailability of biochar’s contaminants to soil biota, soil organic matter stability, GHG emissions, soil formation, soil hydrology, nutrient cycling due to microbial priming as well as altered rhizosphere ecology, and soil pH buffering capacity. Methodological and other constraints to achieve the required LOSU are discussed and options for efficient progress of biochar research and sustainable application to soil are presented.
Forfattere
Eva SkarbøvikSammendrag
Artikkelen presenterer resultater fra analyser av fosforinnhold i sediment i elvekanter, samt ut testing av fem ulike metoder for å kvanti sere kanterosjon i to leirelver på Østlandet. Gjennom snittlig innhold av totalfosfor i kantsedimentet var om lag 700 mg/kg. Fosforinnholdet i kant sedimentet var noe lavere enn i åkerjorda, men denne forskjellen kunne forklares med en lavere andel leirfraksjoner og organisk materiale i kant sedimentet. Metodene som ble testet ut for å kvanti sere kanterosjon, omfattet gjentatte befaringer og fotografering av elvekantene, erosjonspinner, fotogrammetri (3Dfotografering), sammenlig ning av elveløpsform med historiske yfoto, samt kjemisk sporing av sedimentet. Konklusjonen var at ingen av de utprøvde metodene er optimale, men at erosjonspinner kombinert med fotogra fering under befaringer kan gi et grovt estimat av erosjonen. Av 13 lokaliteter var det re hvor det ikke ble påvist erosjon, og ni lokaliteter hvor beregnede erosjonsrater utgjorde fra 100 til mer enn 1500 kg sediment pr. lengdemeter elvebredde og år. Den mest omfattende erosjonen ble funnet ved en lokalitet hvor trær langs elvekanten var kuttet ned.