Evaluating Arabidopsis thaliana roots as a model system to study catecholamine action in plants
Plant scientists have long puzzled over the presence of catecholamines in plants; compounds including dopamine, norepinephrine, and epinephrine that in animals function as neurotransmitters. In mammals, epinephrine and norepinephrine are key neurotransmitters in the sympathetic nervous system and excess dopamine action has been linked to schizophrenia, while a lack of dopamine can lead to Parkinson’s disease, a finding that earned the 2000 Nobel Prize for Physiology or Medicine. The receptors and pathways surrounding these activities in mammals are well characterized.
Surprisingly, catecholamines have also been identified in a variety of plants, but little is known about their roles, modes of action, mechanisms of detection, or the associated biosynthetic and regulatory pathways. Some studies with plants have demonstrated that catecholamines have an antioxidative capacity, and others have found catecholamine levels to increase in response to abiotic stress, but their functions remain mysterious.
The main focus of my project was to determine whether Arabidopsis thaliana could be used as a model system to address these questions. Concentrating on A. thaliana roots as an easily observed and experimentally manipulated organ, I identified several developmental responses to the presence of dopamine and norepinephrine. I then investigated how these changes in root development corresponded to changes in expression of a selection of target genes using qRT-PCR. My findings indicate that exogenous treatment of Arabidopsis seedlings with catecholamines has the potential to provide molecular insights into catecholamine action.
This internship has been wonderfully educational for me. Coming from a small liberal arts college, I was exposed for the first time, to the research environment of a large university. Combined with this exposure, the weekly seminars by BTI faculty and special symposia on graduate school provided me with greater insight into how to succeed as a graduate student researcher and beyond. My favorite aspect of this research experience has been the development of our experimental plan. Working through primary research literature to come up with an entire summer’s research plan, in conjunction with my mentor, was thoroughly rewarding. Certainly, this internship has had a positive impact on my competence and future aptitude as a research scientist.