Journal of Chemical Ecology

, Volume 38, Issue 5, pp 486–495 | Cite as

Seasonal Changes in Undifilum Colonization and Swainsonine Content of Locoweeds

  • Jorge Achata Böttger
  • Rebecca CreamerEmail author
  • Dale Gardner


Locoweeds (Astragalus and Oxytropis) are leguminous plants that are toxic due to a symbiotic association with the endophytic fungus Undifilum oxytropis. The fungus produces the alkaloid swainsonine, an α-mannosidase-inhibitor that causes serious damage to mammals when consumed. A real-time PCR technique was developed to quantify the colonization extent of Undifilum in locoweeds and to compare it to the swainsonine concentration in the plants. Amplification of the endophyte nuclear ITS region allowed reliable quantification of Undifilum DNA from field plants and in vitro cultures. Swainsonine concentration was highly correlated (ρ = 0.972, P < 0.001) with the proportion of Undifilum DNA during the first 4 weeks of in vitro culture growth. Species of Astragalus and Oxytropis were sampled seasonally in New Mexico and Colorado for two years. High swainsonine concentration in plant samples was associated with high levels of endophyte DNA, except in plant reproductive tissues.


Undifilum Quantitative PCR Swainsonine 



We thank Dr Jose Valdez-Barillas and David Graham for their guidance during field seasons, and Dr Steve Hanson, Dr Champa Sengupta-Gopalan, and Dr Tracy Sterling for allowing the use of their lab facilities and equipment. We acknowledge USDA Special Grant # 59-5428-1-327 and the New Mexico State University Agricultural Experiment Station for supporting this work.


  1. Andersen, B., Smedsgaard, J., Jørring, I., Skouboe, P., and Hagsholm Pederson, L. 2006. Real-time PCR quantification of the AM-toxin gene and HPLC qualification of toxigenic metabolites from Alternaria species from apples. International J of Food Microbiology 111:105–111.Google Scholar
  2. Braun, K., Romero, J., Liddell, C., and Creamer, R. 2003. Production of swainsonine by fungal endophytes of locoweed. Mycol. Res. 107:980–988.PubMedCrossRefGoogle Scholar
  3. Cook, D., Gardner, D. R., Welch, K. D., Roper, J. M., Ralphs, M. H., and GREEN, B. T. 2009. Quantitative PCR method to measure the fungal endophyte in locoweeds. J. Agric. Food Chem. 57:6050–6054.PubMedCrossRefGoogle Scholar
  4. Davis, D., Schwarz, P., Hernandez, T., Mitchell, M., Warnock, B., and ELBEIN, A. D. 1984. Isolation and characterization of swainsonine from Texas locoweed (Astragalus emoryanus). Plant Physiol. 76:972–975.PubMedCrossRefGoogle Scholar
  5. FOX, W.E., ALLRED, K.W., and ROALSON, E.H. 1998. A guide to the common locoweeds and milkvetches of New Mexico. NM Agric. Exp. Sta. Circ. 557.Google Scholar
  6. Gachon, C. and Saindrenan, P. 2004. Real-time PCR monitoring of fungal development in Arabidopsis thaliana infected by Alternaria brassicola and Botrytis cinerea. Plant Physiol. Biochem. 42:367–371.PubMedCrossRefGoogle Scholar
  7. Gardner, D. R., Molyneux, R. J., and Ralphs, M. H. 2001. Analysis of swainsonine: Extraction methods, detection, and measurement in populations of locoweeds (Oxytropis spp.). J. Agric Food Chem 49:4573–4580.PubMedCrossRefGoogle Scholar
  8. Glynn, N. C., Ray, R., Edwards, S. G., Hare, M. C., Parry, D. W., Barnett, C. J., and Beck, J. J. 2007. Quantitative Fusarium spp. and Microdochium spp. PCR assays to evaluate seed treatment for the control of Fusarium seedling blight of wheat. J. Appl. Microbiol. 102:1645–1653.PubMedCrossRefGoogle Scholar
  9. James, L. F. and Panter, K. E. 1989. Locoweed poisoning in livestock. pp 23-28 in: Swainsonine and related glycosidase inhibitors. Edited by L. F. James, A. D. Elbein, R. J. Molyneux and C. D. Warren, Iowa State University Press, Ames.Google Scholar
  10. James, L. F., Gardner, D. R., Lee, S. T., Panter, K. E., Pfister, J. A., Ralphs, M. H., and Stegelmeier, B. L. 2005. Important poisonous plants on rangelands. Management strategies based on toxin level in the plant, animal susceptibility, and grazing behavior can reduce the risk of poisoning. Rangelands 27:3–9.CrossRefGoogle Scholar
  11. Kobayashi, T. 2011. Regulation of ribosomal RNA gene copy number and its role in modulating genome integrity and evolutionary adaptability. Cell. Mol. Life Sci. 68:1395–1403.PubMedCrossRefGoogle Scholar
  12. Li, Y. Z. and Nan, Z. B. 2007a. Symptomology and etiology of a new disease, yellow stunt, and root rot of standing milkvetch caused by Embellisia sp. in Northern China. Mycopathologia 163:327–334.PubMedCrossRefGoogle Scholar
  13. Li, Y. Z. and Nan, Z. B. 2007b. A new species, Embellisia astragali sp. nov., causing standing milk-vetch disease in China. Mycologia 99:406–411.PubMedCrossRefGoogle Scholar
  14. Marsh, C.D. 1909. The locoweed disease of the plains. USDA Bureau of Animal Industries Bull. 112.Google Scholar
  15. McLain-Romero, J., Creamer, R., Zepeda, H., Strickland, J., and Bell, G. 2004. The toxicosis of Embellisia fungi from locoweed (Oxytropis lambertii) is similar to locoweed toxicosis in rats. J. Anim. Sci. 82:2169–2174.PubMedGoogle Scholar
  16. Molyneux, R. J. and James, L. F. 1982. Loco intoxication: Indolizidine alkaloids of spotted locoweed (Astragalus lentiginosus). Science 216:190–191.PubMedCrossRefGoogle Scholar
  17. NOAA 2006a. Climatological Data. Annual Summary. Colorado 2006. 111(13)Google Scholar
  18. NOAA 2006b. Climatological Data. Annual Summary. New Mexico 2006. 110(13)Google Scholar
  19. NOAA 2007a. Climatological Data. Annual Summary. Colorado 2006. 112(13)Google Scholar
  20. NOAA 2007b. Climatological Data. Annual Summary. New Mexico 2007. 111(13)Google Scholar
  21. NOAA 2008a. Climatological Data. Colorado. February 2008. 113(02)Google Scholar
  22. NOAA 2008b. Climatological Data. Colorado. May 2008. 113(05)Google Scholar
  23. NOAA 2008c. Climatological Data. New Mexico. February 2008. 112(02)Google Scholar
  24. NOAA 2008d. Climatological Data. New Mexico. May 2008. 112(05)Google Scholar
  25. Oldrup, E., McLain-Romero, J., Padilla, A., Moya, A., Gardner, D., and Creamer, R. 2010. Localization of endophytic fungi in locoweed seed and influence of environmental parameters on a locoweed in vitro culture system. Botany 88:512–521.CrossRefGoogle Scholar
  26. PARKER, J. 2008. Effects of insect herbivory by the four-lined locoweed weevil Cleonidius trivitattatus (Say) (Coleoptera: Curculionidae), on the alkaloid swainsonine in locoweeds Astagalus mollissimus and Oxytropis sericea. MS thesis. New Mexico State University, Las Cruces.Google Scholar
  27. Patterson, P. E. 1982. Loco, la yerba mala. Rangelands 4:147–148.Google Scholar
  28. Pfister, J. A., Stegelmeier, B. L., Gardner, D. R., and James, L. F. 2003. Grazing of spotted locoweed (Astragalus lentiginosus) by cattle and horses in Arizona. J. Anim. Sci. 2003:2285–2293.Google Scholar
  29. Pryor, B. M., Creamer, R., Shoemaker, R. A., McLain-Romero, J., and Hambleton, S. 2009. Undifilum, a new genus for endophytic Embellisia oxytropis and parasitic Helminthosporium bornmuelleri on legumes. Botany 87:178–194.CrossRefGoogle Scholar
  30. Ralphs, M. H., James, L. F., Nielsen, D. B., and Panter, K. E. 1984. Management practices reduce cattle loss due to locoweed on high mountain range. Rangelands 6:175–177.Google Scholar
  31. Ralphs, M. H., Graham, D., Molyneux, R. J., and James, L. F. 1993. Seasonal grazing of locoweeds by cattle in northeastern New Mexico. J. Rangeland Manage. 46:416–420.CrossRefGoogle Scholar
  32. Ralphs, M. H., Pfister, J. A., Welsh, S. L., Graham, J. D., Purvines, J., Jensen, D. T., and James, L. F. 2003. Locoweed population cycles. Rangelands 25:14–18.Google Scholar
  33. Ralphs, M. H., Creamer, R., Baucom, D., Gardner, D. R., Welsh, S. L., Graham, J. D., Hart, C., Cook, D., and Stegelmeier, B. L. 2008. Relationship between the endophyte Embellisia spp. and the toxic alkaloid swainsonine in major locoweed species (Astragalus and Oxytropis). J. Chem. Ecol. 34:32–38.PubMedCrossRefGoogle Scholar
  34. Rasmussen, S., Parsons, A. J., Bassett, S., Christensen, M. J., Hume, D. E., Johnson, L. J., Johnson, R. D., Simpson, W. R., Stacke, C., Voisey, C. R., Xue, H., and Newman, J. A. 2007. High nitrogen supply and carbohydrate content reduce fungal endophyte and alkaloid concentration in Lolium perenne. New Phytol. 173:787–797.PubMedCrossRefGoogle Scholar
  35. Stegelmeier, B. L., James, L. F., Gardner, D. R., Panter, K. E., Lee, S. T., Ralphs, M. H., Pfister, J. A., and Spraker, T. R. 2005. Locoweed (Oxytropis sericea)-induced lesions in mule deer (Odocoileius hemionus). Vet. Pathol. 42:566–578.PubMedCrossRefGoogle Scholar
  36. Vallotton, A. D. and Sterling, T. M. Sterling. 2007. Physiology, growth and swainsonine content response to water deficit stress in Astragalus mollissimus and Oxytropis sericea. Paper presented at the 47th Annual Meeting of the Weed Science Society of America in Houston, TX.Google Scholar
  37. White, T.J., Bruns, T., Lee, S., and Taylor, J. 1990. Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. pp. 315–352 in: PCR protocols: a guide to methods and applications. Edited by M.A. Innis, D.H. Gelfand, J. Sninsky and T.J. White, Academic Press, San Diego, CA.Google Scholar
  38. Williams, M. C., James, L. F., and Bond, B. O. 1979. Emory milkvetch (Astragalus emoryanus var emoryanus) poisoning in chicks, sheep, and cattle. Amer. J. Vet. Res. 40:403–406.PubMedGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2012

Authors and Affiliations

  • Jorge Achata Böttger
    • 1
  • Rebecca Creamer
    • 1
    Email author
  • Dale Gardner
    • 2
  1. 1.Department of Entomology, Plant Pathology and Weed ScienceNew Mexico State UniversityLas CrucesUSA
  2. 2.Poisonous Plant Research LabUSDA ARSLoganUSA

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