Document Type

Open Access Thesis

Embargo Period

5-31-2015

Degree Program

Molecular & Cellular Biology

Degree Type

Master of Science (M.S.)

Year Degree Awarded

2014

Month Degree Awarded

September

Advisor Name

Om Parkash

Advisor Last Name

Dhankher

Abstract

In an effort to engineer Camelina sativa for enhanced oil yield and tolerance to abiotic stresses, we have cloned and overexpressed Camelina γ-Glutamyl Cyclotransferase (GGCT2;1); a gene involved in oxidative stress tolerance via glutathione homeostasis and Wrinkled 1; a transcription factor that regulates genes involved in fatty acid biosynthesis to increase triacylglycerol (TAG) accumulation in seeds. The GGCT gene family in Camelina consists of three genes-GGCT1, GGCT2;1 and GGCT2;2. Camelina GGCT genes showed differential expression under oxidative stress caused as a result of exposure to various abiotic stresses. The GGCT2;1 gene, which showed strong up-regulation, was selected as a candidate gene for further characterization. RT-PCR analysis of overexpressed GGCT2;1 in leaf tissues from individual T1 seedlings shows increased transcript levels compared to wildtype. T1 plants overexpressing GGCT2;1 are maturing in the greenhouse and T2 seeds from T1 plants will be used for further analysis for oxidative stress tolerance. The Camelina WRl1 gene showed expression in the early stages of seed development. WRl1 was overexpressed under a seed-specific promoter and 10 independent T1 lines showing DsRed fluorescence were selected. These T1 plants are growing in the greenhouse. In future studies, after characterization of T3 lines of each gene, homozygous T3 lines will be cross pollinated to combine the expression of both genes in single line. These lines will be subject to further analyses for their tolerance to various abiotic stresses and enhanced oil yield. We will compare individual transgenic lines’ total seed weight, total biomass and total oil accumulation per plant with that of wildtype under normal and oxidative stress conditions.

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