Assessing the Role of UV-B Radiation and Litter Position on UV-Absorbing, Bulk-Soluble Phenylpropanoid Concentrations in Typha angustifolia
Location
CSU Ballroom
Start Date
10-4-2018 10:00 AM
End Date
10-4-2018 11:30 AM
Student's Major
Biological Sciences
Student's College
Science, Engineering and Technology
Mentor's Name
Christopher Ruhland,
Mentor's Department
Biological Sciences
Mentor's College
Science, Engineering and Technology
Second Mentor's Name
Erin Moseman
Second Mentor's Department
Biological Sciences
Second Mentor's College
Science, Engineering and Technology
Description
Plant phenylpropanoids are secondary metabolites produced via the Shikimate Pathway and act as a protective sunscreen for terrestrial and aquatic plants. These phenolics are essential in deterring herbivory, pathogen-attacks and inhibiting decomposition. Narrow-leaf cattail (Typha angustifolia) is an emergent, invasive hydrophyte prominent in Minnesota's wetlands. Decomposition of cattail is a major contributor to biogeochemical cycling in these systems. Therefore, understanding how this material breaks down is important for quantifying carbon fluxes in wetlands. Senescent litter persists throughout the winter months when microbial decomposition is presumably low and limited by temperature. Litter is exposed to sunlight throughout the season and how visible and ultraviolet (UV) radiation influences the breakdown of this material is unknown. We examined how concentrations of bulk-soluble UV-absorbing phenylpropanoids in cattails changed over time when exposed to near-ambient and reduced UV irradiance. We compared litter placement (standing vs. fallen), as much of this material is lodged during winter months. Litter was placed in bags that either transmitted 85 (“Aclar”) or 2.8% (“Mylar”) of ambient ultraviolet-B radiation (UV-B) for 225 d. Concentrations of phenylpropanoids were measured spectrophotometrically at 300 and 375 nm. Over the course of the experiment, litter lost significant amounts of soluble phenolics and on average, standing litter lost 19% more of these compounds than fallen litter. Standing litter placed in Aclar bags lost 53% of their initial phenolics, which was higher than all other treatments. Exposure to UV-B, especially during the winter months, may prime litter for leaching of bulk-soluble compounds.
Assessing the Role of UV-B Radiation and Litter Position on UV-Absorbing, Bulk-Soluble Phenylpropanoid Concentrations in Typha angustifolia
CSU Ballroom
Plant phenylpropanoids are secondary metabolites produced via the Shikimate Pathway and act as a protective sunscreen for terrestrial and aquatic plants. These phenolics are essential in deterring herbivory, pathogen-attacks and inhibiting decomposition. Narrow-leaf cattail (Typha angustifolia) is an emergent, invasive hydrophyte prominent in Minnesota's wetlands. Decomposition of cattail is a major contributor to biogeochemical cycling in these systems. Therefore, understanding how this material breaks down is important for quantifying carbon fluxes in wetlands. Senescent litter persists throughout the winter months when microbial decomposition is presumably low and limited by temperature. Litter is exposed to sunlight throughout the season and how visible and ultraviolet (UV) radiation influences the breakdown of this material is unknown. We examined how concentrations of bulk-soluble UV-absorbing phenylpropanoids in cattails changed over time when exposed to near-ambient and reduced UV irradiance. We compared litter placement (standing vs. fallen), as much of this material is lodged during winter months. Litter was placed in bags that either transmitted 85 (“Aclar”) or 2.8% (“Mylar”) of ambient ultraviolet-B radiation (UV-B) for 225 d. Concentrations of phenylpropanoids were measured spectrophotometrically at 300 and 375 nm. Over the course of the experiment, litter lost significant amounts of soluble phenolics and on average, standing litter lost 19% more of these compounds than fallen litter. Standing litter placed in Aclar bags lost 53% of their initial phenolics, which was higher than all other treatments. Exposure to UV-B, especially during the winter months, may prime litter for leaching of bulk-soluble compounds.
Recommended Citation
Schmid, Samuel. "Assessing the Role of UV-B Radiation and Litter Position on UV-Absorbing, Bulk-Soluble Phenylpropanoid Concentrations in Typha angustifolia." Undergraduate Research Symposium, Mankato, MN, April 10, 2018.
https://cornerstone.lib.mnsu.edu/urs/2018/poster-session-A/20
