Graduation Term

2018

Degree Name

Doctor of Philosophy (PhD)

Department

School of Biological Sciences

Committee Chair

John C. Sedbrook

Abstract

Thlapsi arvense L. (pennycress) is currently being developed as a profitable oilseed-producing winter annual cover crop with extreme cold tolerance and a rapid life cycle that can be grown on fallow farmland throughout the U.S. Midwest Corn Belt, controlling soil erosion and nutrient runoff while serving as an additional source of income for the American farmer without displacing food crops. The research comprising this dissertation demonstrates that pennycress can serve as a user-friendly model system highly similar to Arabidopsis thaliana, and is well-suited for both laboratory and field experimentation, being readily employable in existing growth facilities. After 10 generations of single seed descent, the sequenced diploid genome of a spring-type cultivar which does not require vernalization to flower has been made public, along with a paired homogenous seed lot (Spring32-10) available for research. Plant growth conditions and selectable marker systems for pennycress have been elucidated, and a simple pressurized Agrobacterium-mediated floral dip transformation method has been developed. Proof of concept work shows that pennycress has been stably transformed with the diacylglycerol acetyltransferase (EaDAcT) gene from Euonymus alatus, producing low-viscosity acetyl-triacylglycerol-containing seed oil suitable as a diesel-engine drop-in fuel. CRISPR-Cas9 constructs were utilized to induce targeted mutations in the pennycress FATTY ACID ELONGATION1 (FAE1) gene, thereby abolishing erucic acid production and generating a seed oil fatty acid profile that is non-toxic and comparable to canola. CRISPR was also employed to alter putative pennycress glucosinolate target sequences in an attempt to develop pennycress cultivars with reduced sinigrin glucosinolate.

Access Type

Dissertation-Open Access

DOI

http://doi.org/10.30707/ETD2018.McGinn.M

Download

Share

COinS