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Daniel Cook - One of the best experts on this subject based on the ideXlab platform.
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Molecular Characterization of a Fungal Ketide Synthase Gene Among Swainsonine-Producing Alternaria Species in the USA
Current Microbiology, 2020Co-Authors: Aziza I. Noor, Daniel Cook, Marwa Neyaz, Rebecca CreamerAbstract:Locoweeds are toxic leguminous plants in Astragalus and Oxytropis genera that contain fungal endophytes of Alternaria section Undifilum species. These fungi produce Swainsonine, an alkaloid α-mannosidase inhibitor that causes a neurological syndrome, locoism in grazing animals. A SWN gene cluster has been identified in many Swainsonine-producing fungi. The swnK gene, which is an essential component of the Swainsonine biosynthetic pathway, encodes a polyketide synthase-nonribosomal peptide synthase (PKS-NRPS). To determine if swnK was conserved among Alternaria section Undifilum endophytes of locoweed, the sequence of the KS region of swnK was compared between various Swainsonine-producing fungi. The internal transcribed spacer (ITS), and glyceraldehyde-3-phosphate dehydrogenase (GPD) regions from the same fungi were also assessed. Sequences were examined at the nucleotide and protein levels. Alternaria oxytropis , A. fulva , A. cinerea, and Alternaria sp. from Swainsona species produced distinct clades for all multigene data sets. swnK –KS sequence did not differ among fungi isolated from Astragalus mollissimus varieties or A. lentiginosus varieties. The swnK-KS amino acid sequence was essentially identical among all Swainsonine-producing Alternaria sp. Two low Swainsonine-producing fungi, Alternaria bornmuelleri and A. gansuense , clustered together, as did non-pathogen Alternaria endophytes. The swnK -KS sequence comparisons were effective in identifying Swainsonine production capability and differentiating among Swainsonine-producing fungal species.
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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, B 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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Detection of Swainsonine-producing endophytes in Patagonian Astragalus species.
Toxicon, 2019Co-Authors: Agustin Martinez, Dale R Gardner, Jessie M. Roper, Carlos Alejandro Robles, Marwah S. Neyaz, Natalia Z. Joelson, Daniel CookAbstract:Abstract Swainsonine has been identified as the toxin in legumes belonging to the genera Astragalus and Oxytropis throughout the world including China, North America, and South America. Several South American Astragalus species have been reported to contain Swainsonine; however, data is lacking to support the presence of a fungal symbiont in South American Astragalus species as has been shown for North American and Chinese Astragalus and Oxytropis species. The objective of this study was to investigate several South American species that have been reported to contain Swainsonine for the presence of the fungal symbiont using culturing and PCR. Swainsonine was detected in field collections of A. pehuenches, A. illinii and A. chamissonis but not A. moyanoi, which is consistent with reports of toxicity regarding these species. The symbiont Alternaria section Undifilum was detected by PCR in all three species that contained Swainsonine but not in A. moyanoi. A fungal symbiont was isolated from seeds of Astragalus pehuenches and A. illinii. The isolated symbiont from both respective species produced Swainsonine in vitro, and was demonstrated to belong to the genus Alternaria section Undifilum by analysis of the nuclear ribosomal DNA. It is highly likely that Alternaria section Undifilum isolates will be associated with other South American Astragalus species that are reported to contain Swainsonine.
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Screening for Swainsonine among South American Astragalus species.
Toxicon, 2017Co-Authors: Daniel Cook, Dale R Gardner, Agustin Martinez, Carlos Alejandro Robles, James A PfisterAbstract:Swainsonine is a toxic alkaloid found in several plant genera worldwide. The objective of this study was to screen several South American Astragalus species for the toxin Swainsonine. Swainsonine was detected in 16 of 30 Astragalus species using liquid and gas chromatography coupled with mass spectrometry. Information in regard to the Swainsonine content of these species may provide important information on the risk of grazing these toxic species.
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Swainsonine Biosynthesis Genes in Diverse Symbiotic and Pathogenic Fungi
G3: Genes Genomes Genetics, 2017Co-Authors: Daniel Cook, Rebecca Creamer, Dale R Gardner, Deana L Baucom, Bruno G. G. Donzelli, Juan Pan, Neil Moore, Stuart B. Krasnoff, Jerzy W. Jaromczyk, Christopher L. SchardlAbstract:Swainsonine-a cytotoxic fungal alkaloid and a potential cancer therapy drug-is produced by the insect pathogen and plant symbiont Metarhizium robertsii, the clover pathogen Slafractonia leguminicola, locoweed symbionts belonging to Alternaria sect. Undifilum, and a recently discovered morning glory symbiont belonging to order Chaetothyriales. Genome sequence analyses revealed that these fungi share orthologous gene clusters, designated "SWN," which included a multifunctional swnK gene comprising predicted adenylylation and acyltransferase domains with their associated thiolation domains, a β-ketoacyl synthase domain, and two reductase domains. The role of swnK was demonstrated by inactivating it in M. robertsii through homologous gene replacement to give a ∆swnK mutant that produced no detectable Swainsonine, then complementing the mutant with the wild-type gene to restore Swainsonine biosynthesis. Other SWN cluster genes were predicted to encode two putative hydroxylases and two reductases, as expected to complete biosynthesis of Swainsonine from the predicted SwnK product. SWN gene clusters were identified in six out of seven sequenced genomes of Metarhzium species, and in all 15 sequenced genomes of Arthrodermataceae, a family of fungi that cause athlete's foot and ringworm diseases in humans and other mammals. Representative isolates of all of these species were cultured, and all Metarhizium spp. with SWN clusters, as well as all but one of the Arthrodermataceae, produced Swainsonine. These results suggest a new biosynthetic hypothesis for this alkaloid, extending the known taxonomic breadth of Swainsonine producers to at least four orders of Ascomycota, and suggest that Swainsonine has roles in mutualistic symbioses and diseases of plants and animals.
P A Obrien - One of the best experts on this subject based on the ideXlab platform.
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growth and Swainsonine production of swainsona galegifolia andr r br untransformed and transformed root cultures
Journal of Experimental Botany, 1994Co-Authors: T M Ermayanti, Jennifer A Mccomb, P A ObrienAbstract:Untransformed and transformed root cultures of Swainsona galegifolla were established for Swainsonine production. Transformed roots grew faster and produced higher Swainsonine levels (62.3 μg g−1 DW) than untransformed roots (23.6 ,μg g−1 DW) or roots of intact plants (8.7 μg g−1 DW). Transformation of a number of plant genotypes using A. rhizogenes strain LBA 9402 showed that plant genotype Influences Swainsonine level in transformed roots but that a wide range of Swainsonine levels can be induced by separate transformation events in the same genotype. Enhancement of Swainsonine production was attempted by treatment with sugars and induction of polyploid roots.
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stimulation of synthesis and release of swainosonine from transformed roots of swainsona galegifolia
Phytochemistry, 1994Co-Authors: T M Ermayanti, Jennifer A Mccomb, P A ObrienAbstract:Transformed root cultures of Swainsona galegifolia were established for Swainsonine production. Stimulation of production of Swainsonine and its release into the culture medium was achieved using copper sulphate, reduction of medium pH and supply of Swainsonine precursors. The yield of control cultures (0.3 g of roots grown in 15 ml medium for 30 days) was 79 μg Swainsonine with only a trace of Swainsonine in the medium. After treatment with 1 mM copper sulphate for two days before harvest on day 30, 155 μg of Swainsonine was produced, of which 14.3 μg was in the medium. Reduction of medium pH from 5.7 to 2.7 for one day before harvest resulted in 159 μg of Swainsonine (47 μg in the medium). Supplementation with 2 mM malonic acid for 12 days before harvest resulted in 187 μg total Swainsonine (34 μg in the medium), while 2 mM pipecolic acid for six days before harvest gave the highest Swainsonine yield (220 μg total, 43 μg in the medium). The increased yields were achieved through small increases in biomass, as well as increases in the level of Swainsonine synthesis.
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, B 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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Detection of Swainsonine-producing endophytes in Patagonian Astragalus species.
Toxicon, 2019Co-Authors: Agustin Martinez, Dale R Gardner, Jessie M. Roper, Carlos Alejandro Robles, Marwah S. Neyaz, Natalia Z. Joelson, Daniel CookAbstract:Abstract Swainsonine has been identified as the toxin in legumes belonging to the genera Astragalus and Oxytropis throughout the world including China, North America, and South America. Several South American Astragalus species have been reported to contain Swainsonine; however, data is lacking to support the presence of a fungal symbiont in South American Astragalus species as has been shown for North American and Chinese Astragalus and Oxytropis species. The objective of this study was to investigate several South American species that have been reported to contain Swainsonine for the presence of the fungal symbiont using culturing and PCR. Swainsonine was detected in field collections of A. pehuenches, A. illinii and A. chamissonis but not A. moyanoi, which is consistent with reports of toxicity regarding these species. The symbiont Alternaria section Undifilum was detected by PCR in all three species that contained Swainsonine but not in A. moyanoi. A fungal symbiont was isolated from seeds of Astragalus pehuenches and A. illinii. The isolated symbiont from both respective species produced Swainsonine in vitro, and was demonstrated to belong to the genus Alternaria section Undifilum by analysis of the nuclear ribosomal DNA. It is highly likely that Alternaria section Undifilum isolates will be associated with other South American Astragalus species that are reported to contain Swainsonine.
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Screening for Swainsonine among South American Astragalus species.
Toxicon, 2017Co-Authors: Daniel Cook, Dale R Gardner, Agustin Martinez, Carlos Alejandro Robles, James A PfisterAbstract:Swainsonine is a toxic alkaloid found in several plant genera worldwide. The objective of this study was to screen several South American Astragalus species for the toxin Swainsonine. Swainsonine was detected in 16 of 30 Astragalus species using liquid and gas chromatography coupled with mass spectrometry. Information in regard to the Swainsonine content of these species may provide important information on the risk of grazing these toxic species.
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Swainsonine Biosynthesis Genes in Diverse Symbiotic and Pathogenic Fungi
G3: Genes Genomes Genetics, 2017Co-Authors: Daniel Cook, Rebecca Creamer, Dale R Gardner, Deana L Baucom, Bruno G. G. Donzelli, Juan Pan, Neil Moore, Stuart B. Krasnoff, Jerzy W. Jaromczyk, Christopher L. SchardlAbstract:Swainsonine-a cytotoxic fungal alkaloid and a potential cancer therapy drug-is produced by the insect pathogen and plant symbiont Metarhizium robertsii, the clover pathogen Slafractonia leguminicola, locoweed symbionts belonging to Alternaria sect. Undifilum, and a recently discovered morning glory symbiont belonging to order Chaetothyriales. Genome sequence analyses revealed that these fungi share orthologous gene clusters, designated "SWN," which included a multifunctional swnK gene comprising predicted adenylylation and acyltransferase domains with their associated thiolation domains, a β-ketoacyl synthase domain, and two reductase domains. The role of swnK was demonstrated by inactivating it in M. robertsii through homologous gene replacement to give a ∆swnK mutant that produced no detectable Swainsonine, then complementing the mutant with the wild-type gene to restore Swainsonine biosynthesis. Other SWN cluster genes were predicted to encode two putative hydroxylases and two reductases, as expected to complete biosynthesis of Swainsonine from the predicted SwnK product. SWN gene clusters were identified in six out of seven sequenced genomes of Metarhzium species, and in all 15 sequenced genomes of Arthrodermataceae, a family of fungi that cause athlete's foot and ringworm diseases in humans and other mammals. Representative isolates of all of these species were cultured, and all Metarhizium spp. with SWN clusters, as well as all but one of the Arthrodermataceae, produced Swainsonine. These results suggest a new biosynthetic hypothesis for this alkaloid, extending the known taxonomic breadth of Swainsonine producers to at least four orders of Ascomycota, and suggest that Swainsonine has roles in mutualistic symbioses and diseases of plants and animals.
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a survey of Swainsonine content in swainsona species
Rangeland Journal, 2017Co-Authors: Daniel Cook, Kevin D Welch, Dale R Gardner, Jeremy G AllenAbstract:The indolizidine alkaloid Swainsonine is an inhibitor of α-mannosidase and mannosidase II that causes lysosomal storage disease and alters glycoprotein processing. Several plant species worldwide contain Swainsonine, grazing these plants may cause severe toxicosis in livestock, leading to a chronic disease characterised by altered behaviour, depression, weight loss, decreased libido, infertility and death. Swainsona is a large genus of the Fabaceae family with all species but one being endemic to Australia. Swainsonine has previously been reported to be, or expected to be, present in 26 Swainsona species in Australia. Methods of detection in these 26 species were a jack bean α-mannosidase inhibition assay, gas chromatography, or gas or liquid chromatography coupled with mass spectrometry. Seven of these 26 Swainsona species are reported to be toxic, and for three of these no chemical assay for Swainsonine has been undertaken. Only 1 of the 26 species has been analysed for Swainsonine using modern instrumentation such as gas or liquid chromatography coupled with mass spectrometry. Using both liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry, 248 specimens representing 41 Swainsona species were screened in the present study for Swainsonine. Swainsonine was detected in 9 of the 41 Swainsona species, eight of which had not been determined to contain Swainsonine previously using modern instrumentation. The list of Swainsonine-containing taxa reported here will serve as a reference for diagnostic purposes and risk assessment.
T M Ermayanti - One of the best experts on this subject based on the ideXlab platform.
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growth and Swainsonine production of swainsona galegifolia andr r br untransformed and transformed root cultures
Journal of Experimental Botany, 1994Co-Authors: T M Ermayanti, Jennifer A Mccomb, P A ObrienAbstract:Untransformed and transformed root cultures of Swainsona galegifolla were established for Swainsonine production. Transformed roots grew faster and produced higher Swainsonine levels (62.3 μg g−1 DW) than untransformed roots (23.6 ,μg g−1 DW) or roots of intact plants (8.7 μg g−1 DW). Transformation of a number of plant genotypes using A. rhizogenes strain LBA 9402 showed that plant genotype Influences Swainsonine level in transformed roots but that a wide range of Swainsonine levels can be induced by separate transformation events in the same genotype. Enhancement of Swainsonine production was attempted by treatment with sugars and induction of polyploid roots.
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stimulation of synthesis and release of swainosonine from transformed roots of swainsona galegifolia
Phytochemistry, 1994Co-Authors: T M Ermayanti, Jennifer A Mccomb, P A ObrienAbstract:Transformed root cultures of Swainsona galegifolia were established for Swainsonine production. Stimulation of production of Swainsonine and its release into the culture medium was achieved using copper sulphate, reduction of medium pH and supply of Swainsonine precursors. The yield of control cultures (0.3 g of roots grown in 15 ml medium for 30 days) was 79 μg Swainsonine with only a trace of Swainsonine in the medium. After treatment with 1 mM copper sulphate for two days before harvest on day 30, 155 μg of Swainsonine was produced, of which 14.3 μg was in the medium. Reduction of medium pH from 5.7 to 2.7 for one day before harvest resulted in 159 μg of Swainsonine (47 μg in the medium). Supplementation with 2 mM malonic acid for 12 days before harvest resulted in 187 μg total Swainsonine (34 μg in the medium), while 2 mM pipecolic acid for six days before harvest gave the highest Swainsonine yield (220 μg total, 43 μg in the medium). The increased yields were achieved through small increases in biomass, as well as increases in the level of Swainsonine synthesis.
Jennifer A Mccomb - One of the best experts on this subject based on the ideXlab platform.
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growth and Swainsonine production of swainsona galegifolia andr r br untransformed and transformed root cultures
Journal of Experimental Botany, 1994Co-Authors: T M Ermayanti, Jennifer A Mccomb, P A ObrienAbstract:Untransformed and transformed root cultures of Swainsona galegifolla were established for Swainsonine production. Transformed roots grew faster and produced higher Swainsonine levels (62.3 μg g−1 DW) than untransformed roots (23.6 ,μg g−1 DW) or roots of intact plants (8.7 μg g−1 DW). Transformation of a number of plant genotypes using A. rhizogenes strain LBA 9402 showed that plant genotype Influences Swainsonine level in transformed roots but that a wide range of Swainsonine levels can be induced by separate transformation events in the same genotype. Enhancement of Swainsonine production was attempted by treatment with sugars and induction of polyploid roots.
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stimulation of synthesis and release of swainosonine from transformed roots of swainsona galegifolia
Phytochemistry, 1994Co-Authors: T M Ermayanti, Jennifer A Mccomb, P A ObrienAbstract:Transformed root cultures of Swainsona galegifolia were established for Swainsonine production. Stimulation of production of Swainsonine and its release into the culture medium was achieved using copper sulphate, reduction of medium pH and supply of Swainsonine precursors. The yield of control cultures (0.3 g of roots grown in 15 ml medium for 30 days) was 79 μg Swainsonine with only a trace of Swainsonine in the medium. After treatment with 1 mM copper sulphate for two days before harvest on day 30, 155 μg of Swainsonine was produced, of which 14.3 μg was in the medium. Reduction of medium pH from 5.7 to 2.7 for one day before harvest resulted in 159 μg of Swainsonine (47 μg in the medium). Supplementation with 2 mM malonic acid for 12 days before harvest resulted in 187 μg total Swainsonine (34 μg in the medium), while 2 mM pipecolic acid for six days before harvest gave the highest Swainsonine yield (220 μg total, 43 μg in the medium). The increased yields were achieved through small increases in biomass, as well as increases in the level of Swainsonine synthesis.
