Discipline: Biological Sciences
Subcategory: Plant Research
Jordan Iverson - University of Arkansas at Pine Bluff
Co-Author(s): Jessica P. Yactayo-Chang, Nirman Nepal, Natalie Turner, Zachary Campbell, and Argelia Lorence all from Arkansas State University, Jonesboro, AR
Vitamin C (L-ascorbic acid, ascorbate, AsA) is the most abundant water-soluble antioxidant found in plants. Ascorbate has a wide variety of physiological roles. It functions as an enzyme cofactor, as a radical scavenger, and protects tissues against damage caused by reactive oxygen species produced from stresses such as water deficit, soil salinity, cold, and heat. One of the great challenges we currently face in agriculture is the need to increase the productivity of crops capable of thriving under challenging environmental conditions to feed the growing population. One of the potential solutions to this challenge is the development of genetically modified plants with enhanced nutritional value, improved tolerance to stresses, and superior yields. The Lorence Laboratory has studied four enzymes involved in AsA biosynthesis via the myo-inositol pathway: myo-inositol oxygenase (MIOX), glucuronate reductase (GlcUR), gulonolactonase (GNL), and L-gulono-1,4-lactone oxidase (GuILO). In this work, we studied the effect of water limitation stress on the growth and health of Arabidopsis thaliana lines over-expressing AtMIOX, AtGNL, AtGuILO, and rGuILO enzymes. Based on conclusions I drew from reading prior publications related to the enzymes, I predicted that AtGNL would out perform the other enzymes. To measure plant growth and health we used a high throughput phenotyping platform equipped with visible, fluorescence, and near infrared cameras. We complemented that data with photosynthetic parameters measured using a hand-held fluorometer. Ascorbate measurements were done via an enzyme-based spectrophotometric assay. Our findings show that the over-expressers had higher foliar AsA content, grew faster, accumulated more biomass, and displayed healthier profiles than the wild type controls. It was concluded that 50% soil saturation was not a condition that allow detection of major differences in the performance of the high AsA lines. In the future the experiment will be repeated with more severe water limitation to tease out greater phenotypic differences. The seeds will be collected and counted to assess the effect of water limitation on seed yield.Not Submitted
Funder Acknowledgement(s): Plant Imaging Consortium (PIC) funded by the NSF Award Numbers IIA-1430427 and IIA-1430428; NSF grant #1348389 to Srivatsan; Arkansas Biosciences Institute; Office of Diversity at A-State
Faculty Advisor: Argelia Lorence, email@example.com
Role: I was responsible for cleaning the seeds, making media for the petri dishes, dispensing the seeds in petri dishes, monitoring seed growth within the growth chamber, transferring the seedlings to soil, watering and weighing the plants daily, measuring the plants for photosynthetic efficiency, phenotyping the plants using the scanalyzer, conducting an ascorbate assay, analyzing images, calculating data, converting the data into table form using Excel, and constructing a powerpoint about the entire thing.