Environmental Pollution, 2009, 157(8-9):2452-2458
Abstract:
Organochlorine pollutants in the m... more Environmental Pollution, 2009, 157(8-9):2452-2458
Abstract:
Organochlorine pollutants in the major fish species (pike Esox lucius, perch Perca fluviatilis, and roach Rutilus rutilus) of Lake Årungen, Norway, were investigated after an extensive removal of large pike in 2004. The organochlorine pollutants detected in fish liver samples in 2005 were dichlorodiphenyltrichloroethane (DDTs), polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and heptachlor epoxide (HCE). DDTs were the dominant among all analyzed OCs. ΣPCB and HCB, detected in fish from two clearly distinct trophic levels (prey and predators), give an indication of biomagnification. All OC concentrations in female pike were significantly lower compared to males, which might be due to the removal of high concentrations of pollutants in roe during spawning. Organochlorine pollutants in fish tissues tend to magnify up the food chain
Phosphorus (P) is an important element for crop productivity and is widely applied in fertilizers... more Phosphorus (P) is an important element for crop productivity and is widely applied in fertilizers. Most P fertilizers applied to land are sorbed onto soil particles, so research on improving plant uptake of less easily available P is important. In the current study, we investigated the responses in root morphology and root-exuded organic acids to low available P (1 µM P) and sufficient P (50 µM P) in barley, canola and micropropagated seedlings of potato - three important food crops with divergent root traits, using a hydroponic plant growth system. We hypothesized that the dicots canola and tuber-producing potato and the monocot barley would respond differently under various P availabilities. WinRHIZO and liquid chromatography triple quadrupole mass spectrometry results suggested that under low P availability, canola developed longer roots and exhibited the fastest root exudation rate for citric acid. Barley showed a reduction in root length and root surface area, and an increase i...
Rhodiola rosea is a well-known herbal medicinal plant. It is growing wild in large parts of Norwa... more Rhodiola rosea is a well-known herbal medicinal plant. It is growing wild in large parts of Norway and many other countries in the world. R. rosea has been used by the Sami people for centuries. Some of the most important metabolites are believed to be salidroside, cinnamyl alcohol, glycosides (rosine, rosavine, rosarine), flavonoids (rhodionin, rhodiosin, rhodiolin) and terpenes (Galambosi 1999). In Norway, germplasm collections of R. rosea are maintained by Bioforsk; at Svanhovd in northern Norway and at Bioforsk Apelsvoll in southern Norway. The germplasm collection of R. rosea at Bioforsk Apelsvoll consists of 97 different clones. The ranges in content of secondary metabolites in the collection are for rosavin 2.90-85.95 mg g-1, salidroside 0.03-12.85 mg g-1, rosin 0.08-4.75 mg g-1, tyrosol 0.04-2.15 mg g-1 and cinnamyl alcohol 0.02-1.18 mg g-1. Analysis performed to estimate genetic diversity within this collection using AFLP markers showed that each of the 97 R. rosea clones c...
ABSTRACT Streptomyces scabies causes yield losses in potato by inducing common scab (CS) symptoms... more ABSTRACT Streptomyces scabies causes yield losses in potato by inducing common scab (CS) symptoms on tubers. Little information is available on global gene expression responses in CS‐causing streptomycetes upon interaction with host plants. In this study, expression of 8746 genes was analysed in the type strain of S. scabies (ATCC49173) using a custom‐designed, gene‐specific oligonucleotide microarray. Bacteria were grown in liquid yeast malt extract (YME) medium and 480 genes were found to be up‐regulated 24 h after supplementing the cultures with potato microtubers. Quantitative PCR analysis of eight putative or known virulence genes was consistent with the microarray data. Elevated expression of the thaxtomin synthesis gene txtA and txtR genes regulating synthesis of thaxomin A, the main pathogenicity factor of S. scabies, and production of thaxtomin A were detected in cultures containing microtubers. Unexpectedly, thaxtomin was also detected in cultures lacking microtubers, which indicated that growth in YME induces thaxtomin production in S. scabies. Many but not all microtubers incubated in the cultures of S. scabies for 48 h displayed symptoms, indicating that the microtubers were not equally susceptible even though they were produced under uniform in vitro growth conditions. These factors may have limited the differences in gene expression observed between S. scabies exposed to microtubers compared to controls. This study provides some of the first results on the transcriptome of S. scabies, a widely distributed and important potato pathogen, upon exposure to young developing potato tubers. The findings will inform future studies on interactions of CS‐inducing streptomycetes with potato and means to control the disease.
International Journal of Environmental Analytical Chemistry, 2002
Degradation and dissipation studies in laboratory and field were performed with isoproturon (IPU)... more Degradation and dissipation studies in laboratory and field were performed with isoproturon (IPU) to produce data for modelling the fate of an autumn applied pesticide in a Gleyic Podzoluvisol in Norway. Transformation rate studies of IPU in the laboratory during 8 weeks displayed a DT 50 of 13 days in topsoil (0-20 cm) and 21 days in subsoil (20-40 cm)
Organochlorine pollutants in the major fish species (pike Esox lucius, perch Perca fluviatilis, a... more Organochlorine pollutants in the major fish species (pike Esox lucius, perch Perca fluviatilis, and roach Rutilus rutilus) of Lake Årungen, Norway, were investigated after an extensive removal of large pike in 2004. The organochlorine pollutants detected in fish liver samples in 2005 were dichlorodiphenyltrichloroethane (DDTs), polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and heptachlor epoxide (HCE). DDTs were the dominant among all analyzed OCs. SPCB and HCB, detected in fish from two clearly distinct trophic levels (prey and predators), give an indication of biomagnification. All OC concentrations in female pike were significantly lower compared to males, which might be due to the removal of high concentrations of pollutants in roe during spawning.
Little research has been done on pesticide dissipation under cold climates, and there is a need t... more Little research has been done on pesticide dissipation under cold climates, and there is a need to focus on the influence of climate on pesticide degradation in soil and the risk of leaching to surface and ground waters. The objective of the work reported here was to increase the knowledge on the fate and risk of leaching of the mobile herbicide metribuzin under cold climatic conditions. Small-scale laboratory investigations of the metribuzin transformation process in soil at temperatures above and below 0°C have been performed parallel to and for comparison with, metribuzin dissipation studies under field conditions at a field site on silt loam soil (Fluvic Cambisol) in the South East of Norway. As expected, field results indicated faster degradation of metribuzin with increasing temperature, as summer temperatures differed significantly between years. Estimated dissipation rates appeared to be further affected by precipitation patterns, with high precipitation causing faster pesticide transport through the soil profile and possibly bypassing layers of high biological activity. Estimated half-lives close to 1 month during summer were in accordance with other reports, and in good agreement with laboratory scale studies under optimum conditions at 20°C (t 1/2 = 22 days). Sorption experiments showed weak sorption of metribuzin in this silt loam soil (K d -values below 0.5), only poorly correlated to soil organic carbon content (r 2 = 0.76). Laboratory studies of metribuzin degradation and bioavailability at low and below zero temperatures, indicated that frost will increase the mobility of metribuzin in soil by increasing the pore water concentrations upon release of frost; the longer the frost period, the larger the increase in leachable metribuzin concentrations. Further, metribuzin degradation at temperatures below 5°C was found to be so slow that we would not expect the soil microorganisms to be able to exploit this increased availability of metribuzin. Leaching during cold climatic periods (autumn, winter and spring) in this temporarily frozen soil, will bring metribuzin to deeper soil layers of low biological activity and a generally lower sorption capacity for pesticides, due to lower contents of soil organic carbon. Hence, residues of metribuzin might be recovered in the soil, down to deeper soil layers, one year after spraying. Risk assessment methods for pesticide leaching in cold climatic conditions should consider winter/spring processes, and knowledge about winter processes will be particularly important for forecasting effects of climatic change on leaching.
Environmental Pollution, 2009, 157(8-9):2452-2458
Abstract:
Organochlorine pollutants in the m... more Environmental Pollution, 2009, 157(8-9):2452-2458
Abstract:
Organochlorine pollutants in the major fish species (pike Esox lucius, perch Perca fluviatilis, and roach Rutilus rutilus) of Lake Årungen, Norway, were investigated after an extensive removal of large pike in 2004. The organochlorine pollutants detected in fish liver samples in 2005 were dichlorodiphenyltrichloroethane (DDTs), polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and heptachlor epoxide (HCE). DDTs were the dominant among all analyzed OCs. ΣPCB and HCB, detected in fish from two clearly distinct trophic levels (prey and predators), give an indication of biomagnification. All OC concentrations in female pike were significantly lower compared to males, which might be due to the removal of high concentrations of pollutants in roe during spawning. Organochlorine pollutants in fish tissues tend to magnify up the food chain
Phosphorus (P) is an important element for crop productivity and is widely applied in fertilizers... more Phosphorus (P) is an important element for crop productivity and is widely applied in fertilizers. Most P fertilizers applied to land are sorbed onto soil particles, so research on improving plant uptake of less easily available P is important. In the current study, we investigated the responses in root morphology and root-exuded organic acids to low available P (1 µM P) and sufficient P (50 µM P) in barley, canola and micropropagated seedlings of potato - three important food crops with divergent root traits, using a hydroponic plant growth system. We hypothesized that the dicots canola and tuber-producing potato and the monocot barley would respond differently under various P availabilities. WinRHIZO and liquid chromatography triple quadrupole mass spectrometry results suggested that under low P availability, canola developed longer roots and exhibited the fastest root exudation rate for citric acid. Barley showed a reduction in root length and root surface area, and an increase i...
Rhodiola rosea is a well-known herbal medicinal plant. It is growing wild in large parts of Norwa... more Rhodiola rosea is a well-known herbal medicinal plant. It is growing wild in large parts of Norway and many other countries in the world. R. rosea has been used by the Sami people for centuries. Some of the most important metabolites are believed to be salidroside, cinnamyl alcohol, glycosides (rosine, rosavine, rosarine), flavonoids (rhodionin, rhodiosin, rhodiolin) and terpenes (Galambosi 1999). In Norway, germplasm collections of R. rosea are maintained by Bioforsk; at Svanhovd in northern Norway and at Bioforsk Apelsvoll in southern Norway. The germplasm collection of R. rosea at Bioforsk Apelsvoll consists of 97 different clones. The ranges in content of secondary metabolites in the collection are for rosavin 2.90-85.95 mg g-1, salidroside 0.03-12.85 mg g-1, rosin 0.08-4.75 mg g-1, tyrosol 0.04-2.15 mg g-1 and cinnamyl alcohol 0.02-1.18 mg g-1. Analysis performed to estimate genetic diversity within this collection using AFLP markers showed that each of the 97 R. rosea clones c...
ABSTRACT Streptomyces scabies causes yield losses in potato by inducing common scab (CS) symptoms... more ABSTRACT Streptomyces scabies causes yield losses in potato by inducing common scab (CS) symptoms on tubers. Little information is available on global gene expression responses in CS‐causing streptomycetes upon interaction with host plants. In this study, expression of 8746 genes was analysed in the type strain of S. scabies (ATCC49173) using a custom‐designed, gene‐specific oligonucleotide microarray. Bacteria were grown in liquid yeast malt extract (YME) medium and 480 genes were found to be up‐regulated 24 h after supplementing the cultures with potato microtubers. Quantitative PCR analysis of eight putative or known virulence genes was consistent with the microarray data. Elevated expression of the thaxtomin synthesis gene txtA and txtR genes regulating synthesis of thaxomin A, the main pathogenicity factor of S. scabies, and production of thaxtomin A were detected in cultures containing microtubers. Unexpectedly, thaxtomin was also detected in cultures lacking microtubers, which indicated that growth in YME induces thaxtomin production in S. scabies. Many but not all microtubers incubated in the cultures of S. scabies for 48 h displayed symptoms, indicating that the microtubers were not equally susceptible even though they were produced under uniform in vitro growth conditions. These factors may have limited the differences in gene expression observed between S. scabies exposed to microtubers compared to controls. This study provides some of the first results on the transcriptome of S. scabies, a widely distributed and important potato pathogen, upon exposure to young developing potato tubers. The findings will inform future studies on interactions of CS‐inducing streptomycetes with potato and means to control the disease.
International Journal of Environmental Analytical Chemistry, 2002
Degradation and dissipation studies in laboratory and field were performed with isoproturon (IPU)... more Degradation and dissipation studies in laboratory and field were performed with isoproturon (IPU) to produce data for modelling the fate of an autumn applied pesticide in a Gleyic Podzoluvisol in Norway. Transformation rate studies of IPU in the laboratory during 8 weeks displayed a DT 50 of 13 days in topsoil (0-20 cm) and 21 days in subsoil (20-40 cm)
Organochlorine pollutants in the major fish species (pike Esox lucius, perch Perca fluviatilis, a... more Organochlorine pollutants in the major fish species (pike Esox lucius, perch Perca fluviatilis, and roach Rutilus rutilus) of Lake Årungen, Norway, were investigated after an extensive removal of large pike in 2004. The organochlorine pollutants detected in fish liver samples in 2005 were dichlorodiphenyltrichloroethane (DDTs), polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and heptachlor epoxide (HCE). DDTs were the dominant among all analyzed OCs. SPCB and HCB, detected in fish from two clearly distinct trophic levels (prey and predators), give an indication of biomagnification. All OC concentrations in female pike were significantly lower compared to males, which might be due to the removal of high concentrations of pollutants in roe during spawning.
Little research has been done on pesticide dissipation under cold climates, and there is a need t... more Little research has been done on pesticide dissipation under cold climates, and there is a need to focus on the influence of climate on pesticide degradation in soil and the risk of leaching to surface and ground waters. The objective of the work reported here was to increase the knowledge on the fate and risk of leaching of the mobile herbicide metribuzin under cold climatic conditions. Small-scale laboratory investigations of the metribuzin transformation process in soil at temperatures above and below 0°C have been performed parallel to and for comparison with, metribuzin dissipation studies under field conditions at a field site on silt loam soil (Fluvic Cambisol) in the South East of Norway. As expected, field results indicated faster degradation of metribuzin with increasing temperature, as summer temperatures differed significantly between years. Estimated dissipation rates appeared to be further affected by precipitation patterns, with high precipitation causing faster pesticide transport through the soil profile and possibly bypassing layers of high biological activity. Estimated half-lives close to 1 month during summer were in accordance with other reports, and in good agreement with laboratory scale studies under optimum conditions at 20°C (t 1/2 = 22 days). Sorption experiments showed weak sorption of metribuzin in this silt loam soil (K d -values below 0.5), only poorly correlated to soil organic carbon content (r 2 = 0.76). Laboratory studies of metribuzin degradation and bioavailability at low and below zero temperatures, indicated that frost will increase the mobility of metribuzin in soil by increasing the pore water concentrations upon release of frost; the longer the frost period, the larger the increase in leachable metribuzin concentrations. Further, metribuzin degradation at temperatures below 5°C was found to be so slow that we would not expect the soil microorganisms to be able to exploit this increased availability of metribuzin. Leaching during cold climatic periods (autumn, winter and spring) in this temporarily frozen soil, will bring metribuzin to deeper soil layers of low biological activity and a generally lower sorption capacity for pesticides, due to lower contents of soil organic carbon. Hence, residues of metribuzin might be recovered in the soil, down to deeper soil layers, one year after spraying. Risk assessment methods for pesticide leaching in cold climatic conditions should consider winter/spring processes, and knowledge about winter processes will be particularly important for forecasting effects of climatic change on leaching.
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Papers by Marit Almvik
Abstract:
Organochlorine pollutants in the major fish species (pike Esox lucius, perch Perca fluviatilis, and roach Rutilus rutilus) of Lake Årungen, Norway, were investigated after an extensive removal of large pike in 2004. The organochlorine pollutants detected in fish liver samples in 2005 were dichlorodiphenyltrichloroethane (DDTs), polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and heptachlor epoxide (HCE). DDTs were the dominant among all analyzed OCs. ΣPCB and HCB, detected in fish from two clearly distinct trophic levels (prey and predators), give an indication of biomagnification. All OC concentrations in female pike were significantly lower compared to males, which might be due to the removal of high concentrations of pollutants in roe during spawning. Organochlorine pollutants in fish tissues tend to magnify up the food chain
Keywords: Organochlorine compounds; Bioaccumulation; Pike
Abstract:
Organochlorine pollutants in the major fish species (pike Esox lucius, perch Perca fluviatilis, and roach Rutilus rutilus) of Lake Årungen, Norway, were investigated after an extensive removal of large pike in 2004. The organochlorine pollutants detected in fish liver samples in 2005 were dichlorodiphenyltrichloroethane (DDTs), polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and heptachlor epoxide (HCE). DDTs were the dominant among all analyzed OCs. ΣPCB and HCB, detected in fish from two clearly distinct trophic levels (prey and predators), give an indication of biomagnification. All OC concentrations in female pike were significantly lower compared to males, which might be due to the removal of high concentrations of pollutants in roe during spawning. Organochlorine pollutants in fish tissues tend to magnify up the food chain
Keywords: Organochlorine compounds; Bioaccumulation; Pike