ARS | Publication request: Quantitative PCR Method to Measure the Fungal Endopyte in Locoweeds

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 11, 2009
Publication Date: June 22, 2009
Repository URL: http://www.pprl.ars.usda.gov
Citation: Cook, D., Gardner, D.R., Welch, K.D., Roper, J.M., Ralphs, M.H., Green, B.T. 2009. Quantitative PCR Method to Measure the Fungal Endopyte in Locoweeds. Journal of Agricultural and Food Chemistry. 57:6050-6054

Interpretive Summary: A fungal endophyte (Undifilum oxytropis) is responsible for the synthesis of swainsonine in Oxytropis and Astragalus species, commonly known as locoweeds. Here we describe a quantitative PCR method developed to measure the amount of endophyte in Oxytropis and Astragalus species. This method will serve as a valuable tool to further describe the plant endophyte toxin relationship.

Technical Abstract: A fungal endophyte (Undifilum oxytropis) has been implicated in the synthesis of swainsonine in Oxytropis and Astragalus species, commonly known as locoweeds. Described is a quantitative PCR method developed to measure the amount of endophyte in Oxytropis and Astragalus species. The limit of quantitation was estimated to be 0.2 pg endophyte per ng total DNA. This method of analysis was used to quantify the amount of endophyte in 10 plants each of Oxytropis sericea (White locoweed), Astragalus mollissimus (Wooly Locoweed), and Astragalus lentiginosus (Spotted Locoweed). A significant amount of individual plant variability was observed in endophyte content among individuals in all three species. In one O. sericea and one A. lentiginosus plant swainsonine concentrations were near or below the limit of detection. Interestingly, these plants also had lowest amounts of the endophyte when compared to the other specimens.