Author ORCID Identifier
Date of Award
Doctor of Philosophy (PhD)
Bernard WM Wone
Abiotic stresses negatively affect plant growth and development across the globe, which also affect the production of food, feed, biofuel, and fiber to meet the demands of a growing population. Thus, developing novel strategies to increase abiotic stress tolerance in crops is necessary. One of these strategies is exploring transcription factors (TFs) in Crassulacean Acid Metabolism (CAM) plants to improve plant abiotic stress tolerances. Therefore, the first objective of this dissertation determine the abiotic stress tolerance function of a CAM TF, McHB7opt in Arabidopsis. This study found that McHB7opt increased stress-responsive pathways related to seed germination and early seedling development. To fully understand the function of this gene in the native plant, a knock-out mutant is needed, but CAM plants are recalcitrant to conventional transformation approaches. Thus, the second objective focused on nanoparticleenabled gene delivery and transformation in a CAM plant and different plants. The success of plant transformation heavily relies upon biomolecule delivery into the target plant, and nanoparticles can penetrate the cell wall and deliver the gene into the plant cell. Nanohydroxyapatite rods were synthesized which efficiently conjugated to plasmids encoded with reporter gene and partially protects the DNA from degradation. We demonstrated the uptake of a nano-biocompatible carrier of plasmid DNA and transient expression of a reporter gene in leaves of Arabidopsis, ice plant, and Nicotiana benthamiana, and in developing seed tissues of barley, wheat, and field mustard. Lastly, the third objective determine if the nanoparticle is phytotoxic in plants. We found that concentration-dependent treatment of arginine functionalized nanohydroxyapatite (R-nHA) accelerated germination in Arabidopsis and increased root and leaf length in wheat. With transcriptomic profiling, the pathways and genes involved in the stress responses were revealed, showing priming of the plant to withstand stresses induced by solution infiltration. Interestingly, these pathways observed were similar between water and R-nHA solution infiltration. The low-stress responses observed confirmed the concentration of R-nHA used for gene delivery in the second objective was not harmful in plants. Our study highlights the effects of nanoparticle concentration on their biocompatibility with plants and will facilitate the use of R-nHA for further biotechnological applications.
Biology | Molecular Biology | Plant Sciences
CAM Plants, McHB7, Nanohydroxyapatite, Nanotechnology, Transcription Factors, Transformation
Number of Pages
University of South Dakota
Izuegbunam, Chinenye Lilian, "OF TRANSCRIPTION FACTOR AND TRANSFORMATION: ELUCIDATING GENE FUNCTION IN THE COMMON ICE PLANT, Mesembryanthemum Crystallinum" (2023). Dissertations and Theses. 182.