Skip to main content
ARS Home » Pacific West Area » Logan, Utah » Poisonous Plant Research » Research » Publications at this Location » Publication #334900
Title: Effects of elevated CO2 on the swainsonine chemotypes of Astragalus lentiginosus and Astragalus mollissimus

Author
item Cook, Daniel
item Gardner, Dale
item Pfister, James
item Stonecipher, Clinton - Clint
item Robins, Joseph
item Morgan, Jack

Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/30/2017
Publication Date: 2/11/2017
Citation: Cook, D., Gardner, D.R., Pfister, J.A., Stonecipher, C.A., Robins, J.G., Morgan, J.A. 2017. Effects of elevated CO2 on the swainsonine chemotypes of Astragalus lentiginosus and Astragalus mollissimus. Journal of Chemical Ecology. 43(3):307-316.

Interpretive Summary: Rapid changes in the Earth’s atmosphere and climate associated with human activity can have significant impacts on agricultural and livestock production. CO2 concentrations, representing one of many atmospheric changes, have risen from the industrial revolution to the current time, and are expected to continue to rise. Climatic changes have been shown to alter physiological processes, and growth and development in numerous plant species, thus 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 potential 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 the two respective chemotypes (i.e., positive and negative for swainsonine) of each species at near present-day ambient and elevated CO2. Biomass and water soluble carbohydrate concentrations responded positively while crude protein concentrations responded negatively to elevated CO2 in the two species. Swainsonine concentrations were variable in response to 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. Changes in CO2 and endophyte status will likely alter multiple physiological responses in toxic plants such as locoweed, however it is difficult to predict how these changes will impact plant herbivore interactions.

Technical Abstract: Rapid changes in the Earth’s atmosphere and climate associated with human activity can have significant impacts on agricultural and livestock production. CO2 concentrations, representing one of many atmospheric changes, have risen from the industrial revolution to the current time, and are expected to continue to rise. Climatic changes have been shown to alter physiological processes, and growth and development in numerous plant species, thus 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 potential 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 the two respective chemotypes (i.e., positive and negative for swainsonine) of each species at near present-day ambient and elevated CO2. Biomass and water soluble carbohydrate concentrations responded positively while crude protein concentrations responded negatively to elevated CO2 in the two species. Swainsonine concentrations were variable in response to 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, however it is difficult to predict how these changes will impact plant herbivore interactions.