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Estelle Rathahao - One of the best experts on this subject based on the ideXlab platform.
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distribution of 14c imidacloprid in sunflowers helianthus annuus l following Seed Treatment
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Francois Laurent, Estelle RathahaoAbstract:Imidacloprid, a neonicotinic insecticide, has been used as a Seed dressing (Gaucho) to protect crops against soil and aerial insects. However, French beekeepers observed abnormal behavior of bees foraging on sunflowers and suspected a link between the imidacloprid Seed Treatment and the observed bee syndrome. This work studies the distribution of [(14)C-imidazolidin]imidacloprid (1 mg/Seed) in three stages of Gaucho-treated sunflowers grown in an outdoor lysimeter. Plants absorbed <10% of [(14)C]imidacloprid spiked on Seeds, and 75% of that absorbed radioactivity was found in cotyledons. Concentrations in the upper leaves were 20 times lower than in the first leaves. From the extracted radioactivity, imidacloprid accounted for 50% and metabolites for the other 50%. Four major metabolites can be detected, in variable concentrations, among which the hydroxy- and olefin-imidacloprid have toxicities equivalent to that of imidacloprid. In pollen, concentrations of imidacloprid were 13 ng x g(-1). Thus, imidacloprid residues from Gaucho Seed Treatment contaminated sunflower pollen, involving the translocation of imidacloprid within the plant.
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distribution of 14c imidacloprid in sunflowers helianthus annuus l following Seed Treatment
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Francois Laurent, Estelle RathahaoAbstract:Imidacloprid, a neonicotinic insecticide, has been used as a Seed dressing (Gaucho) to protect crops against soil and aerial insects. However, French beekeepers observed abnormal behavior of bees foraging on sunflowers and suspected a link between the imidacloprid Seed Treatment and the observed bee syndrome. This work studies the distribution of [14C-imidazolidin]imidacloprid (1 mg/Seed) in three stages of Gaucho-treated sunflowers grown in an outdoor lysimeter. Plants absorbed <10% of [14C]imidacloprid spiked on Seeds, and 75% of that absorbed radioactivity was found in cotyledons. Concentrations in the upper leaves were 20 times lower than in the first leaves. From the extracted radioactivity, imidacloprid accounted for 50% and metabolites for the other 50%. Four major metabolites can be detected, in variable concentrations, among which the hydroxy- and olefin-imidacloprid have toxicities equivalent to that of imidacloprid. In pollen, concentrations of imidacloprid were 13 ng·g-1. Thus, imidacloprid re...
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Distribution of [(14)C]imidacloprid in sunflowers (Helianthus annuus L.) following Seed Treatment
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Francois Laurent, Estelle RathahaoAbstract:Imidacloprid, a neonicotinic insecticide, has been used as a Seed dressing (Gaucho) to protect crops against soil and aerial insects. However, French beekeepers observed abnormal behavior of bees foraging on sunflowers and suspected a link between the imidacloprid Seed Treatment and the observed bee syndrome. This work studies the distribution of [(14)C-imidazolidin]imidacloprid (1 mg/Seed) in three stages of Gaucho-treated sunflowers grown in an outdoor lysimeter. Plants absorbed
Francois Laurent - One of the best experts on this subject based on the ideXlab platform.
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distribution of 14c imidacloprid in sunflowers helianthus annuus l following Seed Treatment
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Francois Laurent, Estelle RathahaoAbstract:Imidacloprid, a neonicotinic insecticide, has been used as a Seed dressing (Gaucho) to protect crops against soil and aerial insects. However, French beekeepers observed abnormal behavior of bees foraging on sunflowers and suspected a link between the imidacloprid Seed Treatment and the observed bee syndrome. This work studies the distribution of [(14)C-imidazolidin]imidacloprid (1 mg/Seed) in three stages of Gaucho-treated sunflowers grown in an outdoor lysimeter. Plants absorbed <10% of [(14)C]imidacloprid spiked on Seeds, and 75% of that absorbed radioactivity was found in cotyledons. Concentrations in the upper leaves were 20 times lower than in the first leaves. From the extracted radioactivity, imidacloprid accounted for 50% and metabolites for the other 50%. Four major metabolites can be detected, in variable concentrations, among which the hydroxy- and olefin-imidacloprid have toxicities equivalent to that of imidacloprid. In pollen, concentrations of imidacloprid were 13 ng x g(-1). Thus, imidacloprid residues from Gaucho Seed Treatment contaminated sunflower pollen, involving the translocation of imidacloprid within the plant.
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distribution of 14c imidacloprid in sunflowers helianthus annuus l following Seed Treatment
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Francois Laurent, Estelle RathahaoAbstract:Imidacloprid, a neonicotinic insecticide, has been used as a Seed dressing (Gaucho) to protect crops against soil and aerial insects. However, French beekeepers observed abnormal behavior of bees foraging on sunflowers and suspected a link between the imidacloprid Seed Treatment and the observed bee syndrome. This work studies the distribution of [14C-imidazolidin]imidacloprid (1 mg/Seed) in three stages of Gaucho-treated sunflowers grown in an outdoor lysimeter. Plants absorbed <10% of [14C]imidacloprid spiked on Seeds, and 75% of that absorbed radioactivity was found in cotyledons. Concentrations in the upper leaves were 20 times lower than in the first leaves. From the extracted radioactivity, imidacloprid accounted for 50% and metabolites for the other 50%. Four major metabolites can be detected, in variable concentrations, among which the hydroxy- and olefin-imidacloprid have toxicities equivalent to that of imidacloprid. In pollen, concentrations of imidacloprid were 13 ng·g-1. Thus, imidacloprid re...
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Distribution of [(14)C]imidacloprid in sunflowers (Helianthus annuus L.) following Seed Treatment
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Francois Laurent, Estelle RathahaoAbstract:Imidacloprid, a neonicotinic insecticide, has been used as a Seed dressing (Gaucho) to protect crops against soil and aerial insects. However, French beekeepers observed abnormal behavior of bees foraging on sunflowers and suspected a link between the imidacloprid Seed Treatment and the observed bee syndrome. This work studies the distribution of [(14)C-imidazolidin]imidacloprid (1 mg/Seed) in three stages of Gaucho-treated sunflowers grown in an outdoor lysimeter. Plants absorbed
Tiffany M. Heng-moss - One of the best experts on this subject based on the ideXlab platform.
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Transcriptional response of soybean to thiamethoxam Seed Treatment in the presence and absence of drought stress
BMC Genomics, 2014Co-Authors: Mitchell D Stamm, Teresa J Donze-reiner, Frederick P. Baxendale, Laramy S Enders, Blair D Siegfried, Tiffany M. Heng-mossAbstract:BackgroundNeonicotinoid insecticides are widely known for their broad-spectrum control of arthropod pests. Recently, their effects on plant physiological mechanisms have been characterized as producing a stress shield, which is predicted to enhance tolerance to adverse conditions. Here we investigate the molecular underpinnings of the stress shield concept using the neonicotinoid thiamethoxam in two separate experiments that compare gene expression. We hypothesized that the application of a thiamethoxam Seed Treatment to soybean would alter the expression of genes involved in plant defensive pathways and general stress response in later vegetative growth. First, we used next-generation sequencing to examine the broad scale transcriptional effects of the thiamethoxam Seed Treatment at three vegetative stages in soybean. Second, we selected ten target genes associated with plant defense pathways in soybean and examined the interactive effects of thiamethoxam Seed Treatment and drought stress on expression using qRT-PCR.ResultsDirect comparison of thiamethoxam-treated and untreated soybeans revealed minor transcriptional differences. However, when examined across vegetative stages, the thiamethoxam Seed Treatment induced substantial transcriptional changes that were not observed in untreated plants. Genes associated with photosynthesis, carbohydrate and lipid metabolism, development of the cell wall and membrane organization were uniquely upregulated between vegetative stages in thiamethoxam-treated plants. In addition, several genes associated with phytohormone and oxidative stress responses were downregulated between vegetative stages. When we examined the expression of a subset of ten genes associated with plant defense and stress response, the application of thiamethoxam was found to interact with drought stress by enhancing or repressing expression. In drought stressed plants, thiamethoxam induced (upregulated) expression of a thiamine biosynthetic enzyme (THIZ2) and gibberellin regulated protein (GRP), but repressed (downregulated) the expression of an apetala 2 (GmDREB2A;2), lipoxygenase (LIP), and SAM dependent carboxyl methyltransferase (SAM).ConclusionsWe found evidence that a thiamethoxam Seed Treatment alters the expression soybean genes related to plant defense and stress response both in the presence and absence of drought stress. Consistent with the thiamethoxam stress shield concept, several genes associated with phytohormones showed enhanced expression in drought stressed plants.
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Transcriptional response of soybean to thiamethoxam Seed Treatment in the presence and absence of drought stress
BMC Genomics, 2014Co-Authors: Mitchell D Stamm, Teresa J Donze-reiner, Frederick P. Baxendale, Laramy S Enders, Blair D Siegfried, Tiffany M. Heng-mossAbstract:Neonicotinoid insecticides are widely known for their broad-spectrum control of arthropod pests. Recently, their effects on plant physiological mechanisms have been characterized as producing a stress shield, which is predicted to enhance tolerance to adverse conditions. Here we investigate the molecular underpinnings of the stress shield concept using the neonicotinoid thiamethoxam in two separate experiments that compare gene expression. We hypothesized that the application of a thiamethoxam Seed Treatment to soybean would alter the expression of genes involved in plant defensive pathways and general stress response in later vegetative growth. First, we used next-generation sequencing to examine the broad scale transcriptional effects of the thiamethoxam Seed Treatment at three vegetative stages in soybean. Second, we selected ten target genes associated with plant defense pathways in soybean and examined the interactive effects of thiamethoxam Seed Treatment and drought stress on expression using qRT-PCR. Direct comparison of thiamethoxam-treated and untreated soybeans revealed minor transcriptional differences. However, when examined across vegetative stages, the thiamethoxam Seed Treatment induced substantial transcriptional changes that were not observed in untreated plants. Genes associated with photosynthesis, carbohydrate and lipid metabolism, development of the cell wall and membrane organization were uniquely upregulated between vegetative stages in thiamethoxam-treated plants. In addition, several genes associated with phytohormone and oxidative stress responses were downregulated between vegetative stages. When we examined the expression of a subset of ten genes associated with plant defense and stress response, the application of thiamethoxam was found to interact with drought stress by enhancing or repressing expression. In drought stressed plants, thiamethoxam induced (upregulated) expression of a thiamine biosynthetic enzyme (THIZ2) and gibberellin regulated protein (GRP), but repressed (downregulated) the expression of an apetala 2 (GmDREB2A;2), lipoxygenase (LIP), and SAM dependent carboxyl methyltransferase (SAM). We found evidence that a thiamethoxam Seed Treatment alters the expression soybean genes related to plant defense and stress response both in the presence and absence of drought stress. Consistent with the thiamethoxam stress shield concept, several genes associated with phytohormones showed enhanced expression in drought stressed plants.
Michael Oostendorp - One of the best experts on this subject based on the ideXlab platform.
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biological activity of sedaxane a novel broad spectrum fungicide for Seed Treatment
Pest Management Science, 2013Co-Authors: Ronald Zeun, Gabriel Scalliet, Michael OostendorpAbstract:BACKGROUND: Sedaxane is a new broad-spectrum Seed Treatment fungicide developed by Syngenta Crop Protection for control of Seed- and soil-borne diseases in a broad range of crops. Its physicochemical properties and activity spectrum have been optimised for use as a Seed Treatment providing both local and systemic protection of the Seed and roots of target crops. RESULTS: Sedaxane inhibits respiration by binding to the succinate dehydrogenase complex in the fungal mitochondrium. Its activity spectrum covers Seed-borne fungi such as Ustilago nuda, Tilletia caries, Monographella nivalis and Pyrenophora graminea, as well as the soil-borne fungi Rhizoctonia solani, R. cerealis and Typhula incarnata. Under greenhouse conditions, sedaxane showed high levels and consistent protection against U. nuda, P. graminea and Rhizoctonia spp. Under field conditions, efficacy against Rhizoctonia spp. resulted in increased yield compared with the untreated check. Efficacy against snow mould has been shown under very high disease pressure conditions. The combination of sedaxane plus fludioxonil against snow mould can provide resistance management for sustainable use. CONCLUSIONS: The broad spectrum and high level of activity in combination with excellent crop tolerance allow the use of sedaxane as a Seed Treatment in a wide variety of crops. It is a potential tool for precautionary resistance management when combined with other fungicides, especially against pathogens showing a potential for resistance development, such as M. nivalis.
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biological activity of sedaxane a novel broad spectrum fungicide for Seed Treatment
Pest Management Science, 2013Co-Authors: Ronald Zeun, Gabriel Scalliet, Michael OostendorpAbstract:Background Sedaxane is a new broad-spectrum Seed Treatment fungicide developed by Syngenta Crop Protection for control of Seed- and soil-borne diseases in a broad range of crops. Its physicochemical properties and activity spectrum have been optimised for use as a Seed Treatment providing both local and systemic protection of the Seed and roots of target crops. Results Sedaxane inhibits respiration by binding to the succinate dehydrogenase complex in the fungal mitochondrium. Its activity spectrum covers Seed-borne fungi such as Ustilago nuda, Tilletia caries, Monographella nivalis and Pyrenophora graminea, as well as the soil-borne fungi Rhizoctonia solani, R. cerealis and Typhula incarnata. Under greenhouse conditions, sedaxane showed high levels and consistent protection against U. nuda, P. graminea and Rhizoctonia spp. Under field conditions, efficacy against Rhizoctonia spp. resulted in increased yield compared with the untreated check. Efficacy against snow mould has been shown under very high disease pressure conditions. The combination of sedaxane plus fludioxonil against snow mould can provide resistance management for sustainable use. Conclusions The broad spectrum and high level of activity in combination with excellent crop tolerance allow the use of sedaxane as a Seed Treatment in a wide variety of crops. It is a potential tool for precautionary resistance management when combined with other fungicides, especially against pathogens showing a potential for resistance development, such as M. nivalis. © 2012 Syngenta Crop Protection, AG. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Mitchell D Stamm - One of the best experts on this subject based on the ideXlab platform.
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Transcriptional response of soybean to thiamethoxam Seed Treatment in the presence and absence of drought stress
BMC Genomics, 2014Co-Authors: Mitchell D Stamm, Teresa J Donze-reiner, Frederick P. Baxendale, Laramy S Enders, Blair D Siegfried, Tiffany M. Heng-mossAbstract:BackgroundNeonicotinoid insecticides are widely known for their broad-spectrum control of arthropod pests. Recently, their effects on plant physiological mechanisms have been characterized as producing a stress shield, which is predicted to enhance tolerance to adverse conditions. Here we investigate the molecular underpinnings of the stress shield concept using the neonicotinoid thiamethoxam in two separate experiments that compare gene expression. We hypothesized that the application of a thiamethoxam Seed Treatment to soybean would alter the expression of genes involved in plant defensive pathways and general stress response in later vegetative growth. First, we used next-generation sequencing to examine the broad scale transcriptional effects of the thiamethoxam Seed Treatment at three vegetative stages in soybean. Second, we selected ten target genes associated with plant defense pathways in soybean and examined the interactive effects of thiamethoxam Seed Treatment and drought stress on expression using qRT-PCR.ResultsDirect comparison of thiamethoxam-treated and untreated soybeans revealed minor transcriptional differences. However, when examined across vegetative stages, the thiamethoxam Seed Treatment induced substantial transcriptional changes that were not observed in untreated plants. Genes associated with photosynthesis, carbohydrate and lipid metabolism, development of the cell wall and membrane organization were uniquely upregulated between vegetative stages in thiamethoxam-treated plants. In addition, several genes associated with phytohormone and oxidative stress responses were downregulated between vegetative stages. When we examined the expression of a subset of ten genes associated with plant defense and stress response, the application of thiamethoxam was found to interact with drought stress by enhancing or repressing expression. In drought stressed plants, thiamethoxam induced (upregulated) expression of a thiamine biosynthetic enzyme (THIZ2) and gibberellin regulated protein (GRP), but repressed (downregulated) the expression of an apetala 2 (GmDREB2A;2), lipoxygenase (LIP), and SAM dependent carboxyl methyltransferase (SAM).ConclusionsWe found evidence that a thiamethoxam Seed Treatment alters the expression soybean genes related to plant defense and stress response both in the presence and absence of drought stress. Consistent with the thiamethoxam stress shield concept, several genes associated with phytohormones showed enhanced expression in drought stressed plants.
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Transcriptional response of soybean to thiamethoxam Seed Treatment in the presence and absence of drought stress
BMC Genomics, 2014Co-Authors: Mitchell D Stamm, Teresa J Donze-reiner, Frederick P. Baxendale, Laramy S Enders, Blair D Siegfried, Tiffany M. Heng-mossAbstract:Neonicotinoid insecticides are widely known for their broad-spectrum control of arthropod pests. Recently, their effects on plant physiological mechanisms have been characterized as producing a stress shield, which is predicted to enhance tolerance to adverse conditions. Here we investigate the molecular underpinnings of the stress shield concept using the neonicotinoid thiamethoxam in two separate experiments that compare gene expression. We hypothesized that the application of a thiamethoxam Seed Treatment to soybean would alter the expression of genes involved in plant defensive pathways and general stress response in later vegetative growth. First, we used next-generation sequencing to examine the broad scale transcriptional effects of the thiamethoxam Seed Treatment at three vegetative stages in soybean. Second, we selected ten target genes associated with plant defense pathways in soybean and examined the interactive effects of thiamethoxam Seed Treatment and drought stress on expression using qRT-PCR. Direct comparison of thiamethoxam-treated and untreated soybeans revealed minor transcriptional differences. However, when examined across vegetative stages, the thiamethoxam Seed Treatment induced substantial transcriptional changes that were not observed in untreated plants. Genes associated with photosynthesis, carbohydrate and lipid metabolism, development of the cell wall and membrane organization were uniquely upregulated between vegetative stages in thiamethoxam-treated plants. In addition, several genes associated with phytohormone and oxidative stress responses were downregulated between vegetative stages. When we examined the expression of a subset of ten genes associated with plant defense and stress response, the application of thiamethoxam was found to interact with drought stress by enhancing or repressing expression. In drought stressed plants, thiamethoxam induced (upregulated) expression of a thiamine biosynthetic enzyme (THIZ2) and gibberellin regulated protein (GRP), but repressed (downregulated) the expression of an apetala 2 (GmDREB2A;2), lipoxygenase (LIP), and SAM dependent carboxyl methyltransferase (SAM). We found evidence that a thiamethoxam Seed Treatment alters the expression soybean genes related to plant defense and stress response both in the presence and absence of drought stress. Consistent with the thiamethoxam stress shield concept, several genes associated with phytohormones showed enhanced expression in drought stressed plants.
