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Down-Regulation of CELLULOSE SYNTHASE Expression in Arabidopsis Seeds as a Possible Means of Increasing Seed Oil and Protein Content, and Reducing Fibre Content
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- Author / Creator
- Jayawardhane Rathnayaka,Kethmi N
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Oleaginous seeds, with higher oil and protein content, have higher economic value in the seed oil industry. Meal resulting from the seed oil extraction process is a widely used protein source in animal feed. The reduction of the complex fibre component of seed tissues may direct more carbon into oil and/or protein biosynthesis, thus resulting in seed with higher oil and/or protein content. Since cellulose makes up a large fraction of fibre within seed meal, reducing the levels of this complex carbohydrate may lead to the improved digestibility of the meal. Partial down-regulation of genes catalyzing cellulose synthesis (i.e., AtCESA1 and AtCESA9) using seed-specific intron-spliced hairpin RNA (RNAi) constructs in Arabidopsis (Arabidopsis thaliana) resulted in reductions in the cellulose content of seeds compared to the empty vector control line. Constitutive down-regulation of the AtCESA9 gene also resulted in reduced cellulose content without impacting the vegetative growth of the plant. These results suggest that down-regulation of cellulose synthesis could be a promising strategy for increasing the digestibility of meal derived from oilseed crops such as canola-type Brassica napus. The observed reduction in cellulose content in Arabidopsis, however, did not result in an increase in seed oil content. In contrast, cellulose reduction in AtCESA1 seed-specific RNAi lines resulted in a slight increase in seed protein content. Based on the results presented, it can be concluded that down-regulation of AtCESA genes combined with other metabolic engineering interventions has the potential to result in significantly increased seed oil and/or protein content.
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- Subjects / Keywords
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- Graduation date
- Spring 2017
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- Type of Item
- Thesis
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- Degree
- Master of Science
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- License
- This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.