The Experts below are selected from a list of 105 Experts worldwide ranked by ideXlab platform
Dale R Gardner - One of the best experts on this subject based on the ideXlab platform.
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clinical and pathological comparison of Astragalus Lentiginosus and ipomoea carnea poisoning in goats
Toxicon, 2019Co-Authors: Louisiane De Carvalho Nunes, Dale R Gardner, James A Pfister, Franklin Rietcorrea, Daniel Cook, Bryan L. Stegelmeier, Kevin D WelchAbstract:Abstract The indolizidine alkaloid swainsonine, found in some Astragalus and Oxytropis (i.e., locoweed) species, is a potent cellular glycosidase inhibitor that often poisons livestock. Other toxic genera such as some Ipomoea species also contain swainsonine as well as calystegines which are similar polyhydroxy alkaloids. The toxicity of calystegines is poorly characterized; however, they are also potent glycoside inhibitors capable of intestinal and cellular glycoside dysfunction. The objective of this study was to directly compare A. Lentiginosus and I. carnea poisoning in goats to better characterize the role of the calystegines. Three groups of four goats each were treated with ground alfalfa (control), I. carnea or A. Lentiginosus to obtain daily doses of 0.0, 1.5, and 1.5 mg swainsonine/kg bw per day, respectively, for 45 days. Animals were observed daily and weekly body weights, serum enzyme activities, and serum swainsonine concentrations were determined. At day 45 all animals were euthanized and necropsied. Goats treated with A. Lentiginosus and I. carnea developed clinical disease characterized by mild intention tremors and proprioceptive deficits. Goats treated with A. Lentiginosus developed clinical disease sooner and with greater consistency. No differences in body weight, serum swainsonine concentrations and serum enzyme activity were observed between goats treated with A. Lentiginosus and I. carnea. Additionally, there were no differences in the microscopic and histochemical studies of the visceral and neurologic lesions observed between goats treated with A. Lentiginosus and I. carnea. These findings suggest that I. carnea-induced clinical signs and lesions are due to swainsonine and that calystegines contribute little or nothing to toxicity in goats in the presence of swainsonine.
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Effects of Elevated CO2 on the Swainsonine Chemotypes of Astragalus Lentiginosus and Astragalus mollissimus.
Journal of Chemical Ecology, 2017Co-Authors: Daniel Cook, Dale R Gardner, James A Pfister, Clinton A. Stonecipher, Joseph G. Robins, Jack A. MorganAbstract:Rapid changes in the Earth’s atmosphere and climate associated with human activity can have significant impacts on agriculture including livestock production. CO2 concentration has risen from the industrial revolution to the current time, and is expected to continue to rise. Climatic changes alter physiological processes, growth, and development in numerous plant species, potentially changing concentrations of plant secondary compounds. These physiological changes may influence plant population density, growth, fitness, and toxin concentrations and thus influence the risk of toxic plants to grazing livestock. Locoweeds, swainsonine-containing Astragalus species, are one group of plants that may be influenced by climate change. We evaluated how two different swainsonine-containing Astragalus species responded to elevated CO2 concentrations. Measurements of biomass, crude protein, water soluble carbohydrates and swainsonine concentrations were measured in two chemotypes (positive and negative for swainsonine) of each species after growth at CO2 levels near present day and at projected future concentrations. Biomass and water soluble carbohydrate concentrations responded positively while crude protein concentrations responded negatively to elevated CO2 in the two species. Swainsonine concentrations were not strongly affected by elevated CO2 in the two species. In the different chemotypes, biomass responded negatively and crude protein concentrations responded positively in the swainsonine-positive plants compared to the swainsonine-negative plants. Ultimately, changes in CO2 and endophyte status will likely alter multiple physiological responses in toxic plants such as locoweed, but it is difficult to predict how these changes will impact plant herbivore interactions.
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Influence of seed endophyte amounts on swainsonine concentrations in Astragalus and Oxytropis locoweeds.
Journal of agricultural and food chemistry, 2012Co-Authors: Daniel Grum, Dale R Gardner, James A Pfister, Daniel Cook, Jessie M. Roper, Michael H RalphsAbstract:Locoism is a toxic syndrome of livestock caused by the ingestion of a subset of legumes known as locoweeds endemic to arid and semiarid regions of the western United States. Locoweeds contain the toxic alkaloid swainsonine, which is produced by the endophytic fungi Undifilum species. Two chemotypes of plants can coexist within toxic populations of locoweeds: chemotype 1 plants are defined as individuals containing swainsonine concentrations greater than 0.01% and quantitatively greater amounts of Undifilum, while chemotype 2 plants are defined as individuals containing less than 0.01% swainsonine and quantitatively smaller amounts of Undifilum. To elucidate the mechanisms that govern chemotypes, the amount of Undifilum in seeds/embryos was manipulated, thus altering subsequent swainsonine concentrations in three locoweed species: Astragalus mollissimus, Astragalus Lentiginosus, and Oxytropis sericea. Chemotype 1 seeds that were fungicide-treated or had the seed coat removed resulted in plants with swainsonine concentrations comparable to those in chemotype 2 plants. Conversely, embryos from seeds of chemotypes 1 and 2 that were inoculated with the endophyte resulted in plants with swainsonine concentrations comparable to those of chemotype 1 plants. This reproducible interconversion between the two swainsonine chemotypes suggests that the quantity of endophyte present in the seed at the time of germination is a key determinant of the eventual chemotype. Additionally, this is the first report of the inoculation of locoweeds with the endophyte Undifilum species.
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influence of seed endophyte amounts on swainsonine concentrations in Astragalus and oxytropis locoweeds
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Daniel Grum, Dale R Gardner, James A Pfister, Daniel Cook, Jessie M. Roper, Michael H RalphsAbstract:Locoism is a toxic syndrome of livestock caused by the ingestion of a subset of legumes known as locoweeds endemic to arid and semiarid regions of the western United States. Locoweeds contain the toxic alkaloid swainsonine, which is produced by the endophytic fungi Undifilum species. Two chemotypes of plants can coexist within toxic populations of locoweeds: chemotype 1 plants are defined as individuals containing swainsonine concentrations greater than 0.01% and quantitatively greater amounts of Undifilum, while chemotype 2 plants are defined as individuals containing less than 0.01% swainsonine and quantitatively smaller amounts of Undifilum. To elucidate the mechanisms that govern chemotypes, the amount of Undifilum in seeds/embryos was manipulated, thus altering subsequent swainsonine concentrations in three locoweed species: Astragalus mollissimus, Astragalus Lentiginosus, and Oxytropis sericea. Chemotype 1 seeds that were fungicide-treated or had the seed coat removed resulted in plants with swainso...
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increased antitumor efficacy by the combined administration of swainsonine and cisplatin in vivo
Phytomedicine, 2011Co-Authors: Felipe Martins Dos Santos, Dale R Gardner, Andreia Oliveira Latorre, I M Hueza, Daniel Soares Sanches, Luciana Lucinio Lippi, Helenice De Souza SpinosaAbstract:Swainsonine is a natural α-mannosidase inhibitor found in numerous poisonous plants, such as Astragalus Lentiginosus. Its mechanism of action is through the inhibition of Golgi α-mannosidase II activity in the N-glycan biosynthesis pathway. As a result, swainsonine inhibits the production of complex β1,6-branched N-linked glycans, which are related to the malignant phenotype of tumor cells. In this study, we investigated whether treatment with swainsonine affects the sensitivity of Ehrlich ascites carcinoma (EAC) cells to cisplatin. To this end, male C57BL/6 mice were treated with swainsonine (SW--0.5 mg/kg, i.p., twice-daily for ten days) and/or cisplatin (Cis--0.25 mg/kg, i.p., every other day for a total of five applications) two days after transplantation with EAC cells. The results showed a greater reduction in the ascites volume in mice from the CisSW group (63.5%) than in mice from the Cis group (45.7%), an elevated induction of apoptosis by CisSW treatment when compared to Cis alone, as demonstrated by higher percentage of cells in the subG1 phase in that group (p<0.0001 Kruskal-Wallis, p<0.0001 control vs. CisSW, p<0.001 Co vs. Cis post-test Dunn), and an increase in the median survival from 12.5 days observed in the control group to 27 days in the CisSW group, which corresponds to a 116% survival increase (p=0.0022 Co vs. CisSW Log-rank test). In addition, the mice from the Cis group had a median survival of only 15 days, an increase of just 20% compared to controls. Our results indicate that swainsonine increases the sensitivity of EAC cells to cisplatin.
James A Pfister - One of the best experts on this subject based on the ideXlab platform.
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clinical and pathological comparison of Astragalus Lentiginosus and ipomoea carnea poisoning in goats
Toxicon, 2019Co-Authors: Louisiane De Carvalho Nunes, Dale R Gardner, James A Pfister, Franklin Rietcorrea, Daniel Cook, Bryan L. Stegelmeier, Kevin D WelchAbstract:Abstract The indolizidine alkaloid swainsonine, found in some Astragalus and Oxytropis (i.e., locoweed) species, is a potent cellular glycosidase inhibitor that often poisons livestock. Other toxic genera such as some Ipomoea species also contain swainsonine as well as calystegines which are similar polyhydroxy alkaloids. The toxicity of calystegines is poorly characterized; however, they are also potent glycoside inhibitors capable of intestinal and cellular glycoside dysfunction. The objective of this study was to directly compare A. Lentiginosus and I. carnea poisoning in goats to better characterize the role of the calystegines. Three groups of four goats each were treated with ground alfalfa (control), I. carnea or A. Lentiginosus to obtain daily doses of 0.0, 1.5, and 1.5 mg swainsonine/kg bw per day, respectively, for 45 days. Animals were observed daily and weekly body weights, serum enzyme activities, and serum swainsonine concentrations were determined. At day 45 all animals were euthanized and necropsied. Goats treated with A. Lentiginosus and I. carnea developed clinical disease characterized by mild intention tremors and proprioceptive deficits. Goats treated with A. Lentiginosus developed clinical disease sooner and with greater consistency. No differences in body weight, serum swainsonine concentrations and serum enzyme activity were observed between goats treated with A. Lentiginosus and I. carnea. Additionally, there were no differences in the microscopic and histochemical studies of the visceral and neurologic lesions observed between goats treated with A. Lentiginosus and I. carnea. These findings suggest that I. carnea-induced clinical signs and lesions are due to swainsonine and that calystegines contribute little or nothing to toxicity in goats in the presence of swainsonine.
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Effects of Elevated CO2 on the Swainsonine Chemotypes of Astragalus Lentiginosus and Astragalus mollissimus.
Journal of Chemical Ecology, 2017Co-Authors: Daniel Cook, Dale R Gardner, James A Pfister, Clinton A. Stonecipher, Joseph G. Robins, Jack A. MorganAbstract:Rapid changes in the Earth’s atmosphere and climate associated with human activity can have significant impacts on agriculture including livestock production. CO2 concentration has risen from the industrial revolution to the current time, and is expected to continue to rise. Climatic changes alter physiological processes, growth, and development in numerous plant species, potentially changing concentrations of plant secondary compounds. These physiological changes may influence plant population density, growth, fitness, and toxin concentrations and thus influence the risk of toxic plants to grazing livestock. Locoweeds, swainsonine-containing Astragalus species, are one group of plants that may be influenced by climate change. We evaluated how two different swainsonine-containing Astragalus species responded to elevated CO2 concentrations. Measurements of biomass, crude protein, water soluble carbohydrates and swainsonine concentrations were measured in two chemotypes (positive and negative for swainsonine) of each species after growth at CO2 levels near present day and at projected future concentrations. Biomass and water soluble carbohydrate concentrations responded positively while crude protein concentrations responded negatively to elevated CO2 in the two species. Swainsonine concentrations were not strongly affected by elevated CO2 in the two species. In the different chemotypes, biomass responded negatively and crude protein concentrations responded positively in the swainsonine-positive plants compared to the swainsonine-negative plants. Ultimately, changes in CO2 and endophyte status will likely alter multiple physiological responses in toxic plants such as locoweed, but it is difficult to predict how these changes will impact plant herbivore interactions.
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Influence of seed endophyte amounts on swainsonine concentrations in Astragalus and Oxytropis locoweeds.
Journal of agricultural and food chemistry, 2012Co-Authors: Daniel Grum, Dale R Gardner, James A Pfister, Daniel Cook, Jessie M. Roper, Michael H RalphsAbstract:Locoism is a toxic syndrome of livestock caused by the ingestion of a subset of legumes known as locoweeds endemic to arid and semiarid regions of the western United States. Locoweeds contain the toxic alkaloid swainsonine, which is produced by the endophytic fungi Undifilum species. Two chemotypes of plants can coexist within toxic populations of locoweeds: chemotype 1 plants are defined as individuals containing swainsonine concentrations greater than 0.01% and quantitatively greater amounts of Undifilum, while chemotype 2 plants are defined as individuals containing less than 0.01% swainsonine and quantitatively smaller amounts of Undifilum. To elucidate the mechanisms that govern chemotypes, the amount of Undifilum in seeds/embryos was manipulated, thus altering subsequent swainsonine concentrations in three locoweed species: Astragalus mollissimus, Astragalus Lentiginosus, and Oxytropis sericea. Chemotype 1 seeds that were fungicide-treated or had the seed coat removed resulted in plants with swainsonine concentrations comparable to those in chemotype 2 plants. Conversely, embryos from seeds of chemotypes 1 and 2 that were inoculated with the endophyte resulted in plants with swainsonine concentrations comparable to those of chemotype 1 plants. This reproducible interconversion between the two swainsonine chemotypes suggests that the quantity of endophyte present in the seed at the time of germination is a key determinant of the eventual chemotype. Additionally, this is the first report of the inoculation of locoweeds with the endophyte Undifilum species.
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influence of seed endophyte amounts on swainsonine concentrations in Astragalus and oxytropis locoweeds
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Daniel Grum, Dale R Gardner, James A Pfister, Daniel Cook, Jessie M. Roper, Michael H RalphsAbstract:Locoism is a toxic syndrome of livestock caused by the ingestion of a subset of legumes known as locoweeds endemic to arid and semiarid regions of the western United States. Locoweeds contain the toxic alkaloid swainsonine, which is produced by the endophytic fungi Undifilum species. Two chemotypes of plants can coexist within toxic populations of locoweeds: chemotype 1 plants are defined as individuals containing swainsonine concentrations greater than 0.01% and quantitatively greater amounts of Undifilum, while chemotype 2 plants are defined as individuals containing less than 0.01% swainsonine and quantitatively smaller amounts of Undifilum. To elucidate the mechanisms that govern chemotypes, the amount of Undifilum in seeds/embryos was manipulated, thus altering subsequent swainsonine concentrations in three locoweed species: Astragalus mollissimus, Astragalus Lentiginosus, and Oxytropis sericea. Chemotype 1 seeds that were fungicide-treated or had the seed coat removed resulted in plants with swainso...
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swainsonine and endophyte relationships in Astragalus mollissimus and Astragalus Lentiginosus
Journal of Agricultural and Food Chemistry, 2011Co-Authors: Daniel Cook, Daniel Grum, Dale R Gardner, Kevin D Welch, James A Pfister, Benedict T. GreenAbstract:Locoweeds are defined as Astragalus and Oxytropis species that induce locoism due to the toxic alkaloid swainsonine. Swainsonine was detected in all parts of Astragalus Lentiginosus and Astragalus mollissimus , with greater concentrations found in the aboveground parts. Undifilum oxytropis , a fungal endophyte responsible for the synthesis of swainsonine, was detected in all plant parts of A. Lentiginosus and A. mollissimus. The amount of endophyte within a plant part does not always correspond to the concentration of swainsonine in the same part. Plants of A. mollissimus and A. Lentiginosus can be divided into two chemotypes: those that contain swainsonine (>0.1%; chemotype 1) and those that contain little or no detectable swainsonine (<0.01%; chemotype 2). Chemotype 1 plants in both species had quantitatively higher amounts of endophyte compared to chemotype 2 plants. Swainsonine and endophyte amounts were not uniformly distributed within stalks of the same plant. For that reason, repeated sampling of stalks from the same plant during one growing season may provide misleading results. Sequence variants of U. oxytropis exist within populations of A. mollissimus, A. Lentiginosus, and Oxytropis sericea and do not correlate with chemotype. These findings suggest several possible reasons for differential concentrations of swainsonine that will be tested in future work.
Daniel Cook - One of the best experts on this subject based on the ideXlab platform.
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clinical and pathological comparison of Astragalus Lentiginosus and ipomoea carnea poisoning in goats
Toxicon, 2019Co-Authors: Louisiane De Carvalho Nunes, Dale R Gardner, James A Pfister, Franklin Rietcorrea, Daniel Cook, Bryan L. Stegelmeier, Kevin D WelchAbstract:Abstract The indolizidine alkaloid swainsonine, found in some Astragalus and Oxytropis (i.e., locoweed) species, is a potent cellular glycosidase inhibitor that often poisons livestock. Other toxic genera such as some Ipomoea species also contain swainsonine as well as calystegines which are similar polyhydroxy alkaloids. The toxicity of calystegines is poorly characterized; however, they are also potent glycoside inhibitors capable of intestinal and cellular glycoside dysfunction. The objective of this study was to directly compare A. Lentiginosus and I. carnea poisoning in goats to better characterize the role of the calystegines. Three groups of four goats each were treated with ground alfalfa (control), I. carnea or A. Lentiginosus to obtain daily doses of 0.0, 1.5, and 1.5 mg swainsonine/kg bw per day, respectively, for 45 days. Animals were observed daily and weekly body weights, serum enzyme activities, and serum swainsonine concentrations were determined. At day 45 all animals were euthanized and necropsied. Goats treated with A. Lentiginosus and I. carnea developed clinical disease characterized by mild intention tremors and proprioceptive deficits. Goats treated with A. Lentiginosus developed clinical disease sooner and with greater consistency. No differences in body weight, serum swainsonine concentrations and serum enzyme activity were observed between goats treated with A. Lentiginosus and I. carnea. Additionally, there were no differences in the microscopic and histochemical studies of the visceral and neurologic lesions observed between goats treated with A. Lentiginosus and I. carnea. These findings suggest that I. carnea-induced clinical signs and lesions are due to swainsonine and that calystegines contribute little or nothing to toxicity in goats in the presence of swainsonine.
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Effects of Elevated CO2 on the Swainsonine Chemotypes of Astragalus Lentiginosus and Astragalus mollissimus.
Journal of Chemical Ecology, 2017Co-Authors: Daniel Cook, Dale R Gardner, James A Pfister, Clinton A. Stonecipher, Joseph G. Robins, Jack A. MorganAbstract:Rapid changes in the Earth’s atmosphere and climate associated with human activity can have significant impacts on agriculture including livestock production. CO2 concentration has risen from the industrial revolution to the current time, and is expected to continue to rise. Climatic changes alter physiological processes, growth, and development in numerous plant species, potentially changing concentrations of plant secondary compounds. These physiological changes may influence plant population density, growth, fitness, and toxin concentrations and thus influence the risk of toxic plants to grazing livestock. Locoweeds, swainsonine-containing Astragalus species, are one group of plants that may be influenced by climate change. We evaluated how two different swainsonine-containing Astragalus species responded to elevated CO2 concentrations. Measurements of biomass, crude protein, water soluble carbohydrates and swainsonine concentrations were measured in two chemotypes (positive and negative for swainsonine) of each species after growth at CO2 levels near present day and at projected future concentrations. Biomass and water soluble carbohydrate concentrations responded positively while crude protein concentrations responded negatively to elevated CO2 in the two species. Swainsonine concentrations were not strongly affected by elevated CO2 in the two species. In the different chemotypes, biomass responded negatively and crude protein concentrations responded positively in the swainsonine-positive plants compared to the swainsonine-negative plants. Ultimately, changes in CO2 and endophyte status will likely alter multiple physiological responses in toxic plants such as locoweed, but it is difficult to predict how these changes will impact plant herbivore interactions.
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Influence of seed endophyte amounts on swainsonine concentrations in Astragalus and Oxytropis locoweeds.
Journal of agricultural and food chemistry, 2012Co-Authors: Daniel Grum, Dale R Gardner, James A Pfister, Daniel Cook, Jessie M. Roper, Michael H RalphsAbstract:Locoism is a toxic syndrome of livestock caused by the ingestion of a subset of legumes known as locoweeds endemic to arid and semiarid regions of the western United States. Locoweeds contain the toxic alkaloid swainsonine, which is produced by the endophytic fungi Undifilum species. Two chemotypes of plants can coexist within toxic populations of locoweeds: chemotype 1 plants are defined as individuals containing swainsonine concentrations greater than 0.01% and quantitatively greater amounts of Undifilum, while chemotype 2 plants are defined as individuals containing less than 0.01% swainsonine and quantitatively smaller amounts of Undifilum. To elucidate the mechanisms that govern chemotypes, the amount of Undifilum in seeds/embryos was manipulated, thus altering subsequent swainsonine concentrations in three locoweed species: Astragalus mollissimus, Astragalus Lentiginosus, and Oxytropis sericea. Chemotype 1 seeds that were fungicide-treated or had the seed coat removed resulted in plants with swainsonine concentrations comparable to those in chemotype 2 plants. Conversely, embryos from seeds of chemotypes 1 and 2 that were inoculated with the endophyte resulted in plants with swainsonine concentrations comparable to those of chemotype 1 plants. This reproducible interconversion between the two swainsonine chemotypes suggests that the quantity of endophyte present in the seed at the time of germination is a key determinant of the eventual chemotype. Additionally, this is the first report of the inoculation of locoweeds with the endophyte Undifilum species.
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influence of seed endophyte amounts on swainsonine concentrations in Astragalus and oxytropis locoweeds
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Daniel Grum, Dale R Gardner, James A Pfister, Daniel Cook, Jessie M. Roper, Michael H RalphsAbstract:Locoism is a toxic syndrome of livestock caused by the ingestion of a subset of legumes known as locoweeds endemic to arid and semiarid regions of the western United States. Locoweeds contain the toxic alkaloid swainsonine, which is produced by the endophytic fungi Undifilum species. Two chemotypes of plants can coexist within toxic populations of locoweeds: chemotype 1 plants are defined as individuals containing swainsonine concentrations greater than 0.01% and quantitatively greater amounts of Undifilum, while chemotype 2 plants are defined as individuals containing less than 0.01% swainsonine and quantitatively smaller amounts of Undifilum. To elucidate the mechanisms that govern chemotypes, the amount of Undifilum in seeds/embryos was manipulated, thus altering subsequent swainsonine concentrations in three locoweed species: Astragalus mollissimus, Astragalus Lentiginosus, and Oxytropis sericea. Chemotype 1 seeds that were fungicide-treated or had the seed coat removed resulted in plants with swainso...
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swainsonine and endophyte relationships in Astragalus mollissimus and Astragalus Lentiginosus
Journal of Agricultural and Food Chemistry, 2011Co-Authors: Daniel Cook, Daniel Grum, Dale R Gardner, Kevin D Welch, James A Pfister, Benedict T. GreenAbstract:Locoweeds are defined as Astragalus and Oxytropis species that induce locoism due to the toxic alkaloid swainsonine. Swainsonine was detected in all parts of Astragalus Lentiginosus and Astragalus mollissimus , with greater concentrations found in the aboveground parts. Undifilum oxytropis , a fungal endophyte responsible for the synthesis of swainsonine, was detected in all plant parts of A. Lentiginosus and A. mollissimus. The amount of endophyte within a plant part does not always correspond to the concentration of swainsonine in the same part. Plants of A. mollissimus and A. Lentiginosus can be divided into two chemotypes: those that contain swainsonine (>0.1%; chemotype 1) and those that contain little or no detectable swainsonine (<0.01%; chemotype 2). Chemotype 1 plants in both species had quantitatively higher amounts of endophyte compared to chemotype 2 plants. Swainsonine and endophyte amounts were not uniformly distributed within stalks of the same plant. For that reason, repeated sampling of stalks from the same plant during one growing season may provide misleading results. Sequence variants of U. oxytropis exist within populations of A. mollissimus, A. Lentiginosus, and Oxytropis sericea and do not correlate with chemotype. These findings suggest several possible reasons for differential concentrations of swainsonine that will be tested in future work.
Daniel Grum - One of the best experts on this subject based on the ideXlab platform.
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influence of seed endophyte amounts on swainsonine concentrations in Astragalus and oxytropis locoweeds
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Daniel Grum, Dale R Gardner, James A Pfister, Daniel Cook, Jessie M. Roper, Michael H RalphsAbstract:Locoism is a toxic syndrome of livestock caused by the ingestion of a subset of legumes known as locoweeds endemic to arid and semiarid regions of the western United States. Locoweeds contain the toxic alkaloid swainsonine, which is produced by the endophytic fungi Undifilum species. Two chemotypes of plants can coexist within toxic populations of locoweeds: chemotype 1 plants are defined as individuals containing swainsonine concentrations greater than 0.01% and quantitatively greater amounts of Undifilum, while chemotype 2 plants are defined as individuals containing less than 0.01% swainsonine and quantitatively smaller amounts of Undifilum. To elucidate the mechanisms that govern chemotypes, the amount of Undifilum in seeds/embryos was manipulated, thus altering subsequent swainsonine concentrations in three locoweed species: Astragalus mollissimus, Astragalus Lentiginosus, and Oxytropis sericea. Chemotype 1 seeds that were fungicide-treated or had the seed coat removed resulted in plants with swainso...
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Influence of seed endophyte amounts on swainsonine concentrations in Astragalus and Oxytropis locoweeds.
Journal of agricultural and food chemistry, 2012Co-Authors: Daniel Grum, Dale R Gardner, James A Pfister, Daniel Cook, Jessie M. Roper, Michael H RalphsAbstract:Locoism is a toxic syndrome of livestock caused by the ingestion of a subset of legumes known as locoweeds endemic to arid and semiarid regions of the western United States. Locoweeds contain the toxic alkaloid swainsonine, which is produced by the endophytic fungi Undifilum species. Two chemotypes of plants can coexist within toxic populations of locoweeds: chemotype 1 plants are defined as individuals containing swainsonine concentrations greater than 0.01% and quantitatively greater amounts of Undifilum, while chemotype 2 plants are defined as individuals containing less than 0.01% swainsonine and quantitatively smaller amounts of Undifilum. To elucidate the mechanisms that govern chemotypes, the amount of Undifilum in seeds/embryos was manipulated, thus altering subsequent swainsonine concentrations in three locoweed species: Astragalus mollissimus, Astragalus Lentiginosus, and Oxytropis sericea. Chemotype 1 seeds that were fungicide-treated or had the seed coat removed resulted in plants with swainsonine concentrations comparable to those in chemotype 2 plants. Conversely, embryos from seeds of chemotypes 1 and 2 that were inoculated with the endophyte resulted in plants with swainsonine concentrations comparable to those of chemotype 1 plants. This reproducible interconversion between the two swainsonine chemotypes suggests that the quantity of endophyte present in the seed at the time of germination is a key determinant of the eventual chemotype. Additionally, this is the first report of the inoculation of locoweeds with the endophyte Undifilum species.
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swainsonine and endophyte relationships in Astragalus mollissimus and Astragalus Lentiginosus
Journal of Agricultural and Food Chemistry, 2011Co-Authors: Daniel Cook, Daniel Grum, Dale R Gardner, Kevin D Welch, James A Pfister, Benedict T. GreenAbstract:Locoweeds are defined as Astragalus and Oxytropis species that induce locoism due to the toxic alkaloid swainsonine. Swainsonine was detected in all parts of Astragalus Lentiginosus and Astragalus mollissimus , with greater concentrations found in the aboveground parts. Undifilum oxytropis , a fungal endophyte responsible for the synthesis of swainsonine, was detected in all plant parts of A. Lentiginosus and A. mollissimus. The amount of endophyte within a plant part does not always correspond to the concentration of swainsonine in the same part. Plants of A. mollissimus and A. Lentiginosus can be divided into two chemotypes: those that contain swainsonine (>0.1%; chemotype 1) and those that contain little or no detectable swainsonine (<0.01%; chemotype 2). Chemotype 1 plants in both species had quantitatively higher amounts of endophyte compared to chemotype 2 plants. Swainsonine and endophyte amounts were not uniformly distributed within stalks of the same plant. For that reason, repeated sampling of stalks from the same plant during one growing season may provide misleading results. Sequence variants of U. oxytropis exist within populations of A. mollissimus, A. Lentiginosus, and Oxytropis sericea and do not correlate with chemotype. These findings suggest several possible reasons for differential concentrations of swainsonine that will be tested in future work.
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swainsonine and endophyte relationships in Astragalus mollissimus and Astragalus Lentiginosus
Journal of Agricultural and Food Chemistry, 2011Co-Authors: Daniel Cook, Daniel Grum, Dale R Gardner, Kevin D Welch, James A Pfister, Michael H Ralphs, Benedict T. GreenAbstract:Locoweeds are defined as Astragalus and Oxytropis species that induce locoism due to the toxic alkaloid swainsonine. Swainsonine was detected in all parts of Astragalus Lentiginosus and Astragalus ...
Michael H Ralphs - One of the best experts on this subject based on the ideXlab platform.
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Influence of seed endophyte amounts on swainsonine concentrations in Astragalus and Oxytropis locoweeds.
Journal of agricultural and food chemistry, 2012Co-Authors: Daniel Grum, Dale R Gardner, James A Pfister, Daniel Cook, Jessie M. Roper, Michael H RalphsAbstract:Locoism is a toxic syndrome of livestock caused by the ingestion of a subset of legumes known as locoweeds endemic to arid and semiarid regions of the western United States. Locoweeds contain the toxic alkaloid swainsonine, which is produced by the endophytic fungi Undifilum species. Two chemotypes of plants can coexist within toxic populations of locoweeds: chemotype 1 plants are defined as individuals containing swainsonine concentrations greater than 0.01% and quantitatively greater amounts of Undifilum, while chemotype 2 plants are defined as individuals containing less than 0.01% swainsonine and quantitatively smaller amounts of Undifilum. To elucidate the mechanisms that govern chemotypes, the amount of Undifilum in seeds/embryos was manipulated, thus altering subsequent swainsonine concentrations in three locoweed species: Astragalus mollissimus, Astragalus Lentiginosus, and Oxytropis sericea. Chemotype 1 seeds that were fungicide-treated or had the seed coat removed resulted in plants with swainsonine concentrations comparable to those in chemotype 2 plants. Conversely, embryos from seeds of chemotypes 1 and 2 that were inoculated with the endophyte resulted in plants with swainsonine concentrations comparable to those of chemotype 1 plants. This reproducible interconversion between the two swainsonine chemotypes suggests that the quantity of endophyte present in the seed at the time of germination is a key determinant of the eventual chemotype. Additionally, this is the first report of the inoculation of locoweeds with the endophyte Undifilum species.
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influence of seed endophyte amounts on swainsonine concentrations in Astragalus and oxytropis locoweeds
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Daniel Grum, Dale R Gardner, James A Pfister, Daniel Cook, Jessie M. Roper, Michael H RalphsAbstract:Locoism is a toxic syndrome of livestock caused by the ingestion of a subset of legumes known as locoweeds endemic to arid and semiarid regions of the western United States. Locoweeds contain the toxic alkaloid swainsonine, which is produced by the endophytic fungi Undifilum species. Two chemotypes of plants can coexist within toxic populations of locoweeds: chemotype 1 plants are defined as individuals containing swainsonine concentrations greater than 0.01% and quantitatively greater amounts of Undifilum, while chemotype 2 plants are defined as individuals containing less than 0.01% swainsonine and quantitatively smaller amounts of Undifilum. To elucidate the mechanisms that govern chemotypes, the amount of Undifilum in seeds/embryos was manipulated, thus altering subsequent swainsonine concentrations in three locoweed species: Astragalus mollissimus, Astragalus Lentiginosus, and Oxytropis sericea. Chemotype 1 seeds that were fungicide-treated or had the seed coat removed resulted in plants with swainso...
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swainsonine and endophyte relationships in Astragalus mollissimus and Astragalus Lentiginosus
Journal of Agricultural and Food Chemistry, 2011Co-Authors: Daniel Cook, Daniel Grum, Dale R Gardner, Kevin D Welch, James A Pfister, Michael H Ralphs, Benedict T. GreenAbstract:Locoweeds are defined as Astragalus and Oxytropis species that induce locoism due to the toxic alkaloid swainsonine. Swainsonine was detected in all parts of Astragalus Lentiginosus and Astragalus ...
