Molecular strategies for increasing seed oil content in canola

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Wiehler, William B.
University of Lethbridge. Faculty of Arts and Science
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Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 2001
Previous research has shown that microsomal DGAT activity from cultures of Brassica napus was stimulated by human acylation stimulating protein (ASP) and bovine serum albumin (BSA). Genetic constructs were engineered to facilitate the expression of ASP or BSA in developing seeds to test the stimulatory effect of these proteins at the site of TAG formation. As well, genetic constructs were designed to produce a truncation of the BSA polypeptide in an attempt to localize the portion fo the macromolecule responsible for stimulation of DGAT activity. An oleosin promoter was used for seed specific expression and to express the polypeptides at a precisely cooridnated time when oil was accumulating in the developing seeds. Lipid analysis coordinated time when oil was accumlating in the developing seeds. Lipid analysis was performed on the seeds of transgenic plants designed to cytosolically express these mammalian proteins and the seeds of control plants. The first generation data revealed that the total lipid within the mature seeds of ASP and BSA plants was not significantly different from the total lipid of negative control plants using both gravimetric and low resolution-nuclear magnetic resonance methods of analysis. The seeds from ASP 8 and ASP 10 plants, however, did produce significantly more lipid on a per seed basis as compared to negative control plants. The levels of the fatty acid composition for total acyl lipids were measured in these first generation transgenic plants. ASP 3 had significantly lower levels of linoleic acid, ASP 14 had significantly lower levels of a-linolenic acid and BSA 11 had significantly higher levels of both of these fatty acids in comparison to negative control plants.
xix, 245 leaves : ill. ; 28 cm.
Canola oil , Oilseeds , Oilseed plants -- Composition , Canola oil -- Quality , Dissertations, Academic