Date of Award
5-2-2019
Document Type
Dissertation
Degree Name
Molecular Biosciences, Ph.D.
First Advisor
Argelia Lorence
Committee Members
Carole Cramer; Fiona Goggin; Maureen Dolan; Steven Green
Call Number
LD 251 .A566d 2019 A26
Abstract
L-Ascorbic acid (AsA, vitamin C) is an essential molecule that humans cannot synthesize; therefore, it must be acquired through dietary sources. Vitamin C has an important role in protecting organelles and cells against the damage caused by reactive oxygen species (ROS). In plants, AsA is synthesized by a complex metabolic network. Although progress has been made in the characterization of genes involved in some of these pathways, there is a gap in understanding which pathway(s) is/are activated in response to different stresses. The long term goal of this project is to assess the contribution of multiple ascorbate pathways to abiotic stress tolerance using phenomic approaches. The hypothesis of this study is that Arabidopsis lines over-expressing an enzyme in the myo-inositol pathway will restore AsA content of mutant lines in the D-mannose / L-galactose biosynthetic route. Transcriptional profiling suggests that the AsA pathways may differ in their responsiveness to various stresses, but their relative contributions to stress adaptation are not yet understood. While many past studies have presumed that the D-mannose/L-galactose pathway is the predominant route for AsA synthesis in plants, new evidence indicates that the other routes may also play a particularly important role in abiotic stress tolerance. Unfortunately, current methods are inadequate to assess the relative contributions of these pathways to the AsA pool in plants. Therefore, high-throughput plant phenotyping protocols were implemented to assess the contribution of this intriguing metabolic network to tolerance of model plant Arabidopsis to salinity, heat, and water stress. This work is generating new tools and approaches to study antioxidant metabolism and its effect on stress tolerance. By exploring plant responses to abiotic stresses, the project identified similarities and important differences among diverse abiotic stress responses. These differences can be manipulated in the future to enhance stress resistance and crop productivity. Furthermore, the project will establish robust protocols for high-throughput phenotyping of the model plant Arabidopsis.
Rights Management
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Acosta Gamboa, Lucia Margarita, "Assessing The Contribution of Multiple Ascorbate Pathways to Abiotic Stress Tolerance Using Phenomic Approaches" (2019). Student Theses and Dissertations. 448.
https://arch.astate.edu/all-etd/448
