Date of Award
2023
Document Type
Thesis
Degree Name
Bachelors
Department
Natural Sciences
First Advisor
Clore, Amy
Area of Concentration
Botany
Abstract
Drosera is a genus of carnivorous plants commonly known as the sundews. Sundews capture insects to supplement nutrient intake in nutrient-poor environments by entrapping prey in sticky mucus secreted by specialized trichomes referred to as tentacles. They exhibit thigmonasty, non-directional movement in response to physical stimuli, in their tentacles and leaves during their prey capture process. There is evidence that carnivory in the Droseraceae evolved from existing plant defense signaling pathways. The goal of this study was to explore the potential of reactive oxygen species (ROS) being involved as signals in prey capture response; of particular interest was singlet oxygen. Sundew plants were stimulated by applying mechanical and/or chemical stimuli to the leaf blades and tentacles of a trap. For the majority of experiments, samples treated with the singlet oxygen sensor, Singlet Oxygen Sensor Green® (SOSG), and control samples were observed under a fluorescent microscope and examined for singlet oxygen fluorescence or background autofluorescence, respectively. Additionally, DPI (diphenyleneiodonium, an NADPH oxidase inhibitor) was used in further experiments to inhibit the latter enzyme, which is a potential source of ROS. It was found that leaves that were mechanically or chemically stimulated and treated with SOSG exhibited more visible fluorescence than control samples. Notable circumferential banding patterns occurred on stimulated tentacle stalks stained with SOSG. The visualization of singlet oxygen following chemical stimulation with the plant hormone jasmonic acid (JA) implies that singlet oxygen is downstream of JA signaling in the prey capture response. The DPI results were inconclusive and require further testing. Nonetheless, overall, there is evidence that ROS are involved in post-stimulation signaling of the Drosera prey capture response.
Recommended Citation
Setterberg, Cas, "ELUCIDATION OF CELL SIGNALING PATHWAYS IN THE DROSERA CAPENSIS PREY CAPTURE RESPONSE" (2023). Theses & ETDs. 6423.
https://digitalcommons.ncf.edu/theses_etds/6423