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Metabolic engineering of Crambe abyssinica for producing high erucic acid oil

Guan, Rui (2014). Metabolic engineering of Crambe abyssinica for producing high erucic acid oil. Diss. (sammanfattning/summary) Alnarp : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2014:81
ISBN 978-91-576-8110-2
eISBN 978-91-576-8111-9
[Doctoral thesis]

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Vegetable oils are renewable and more environmentally friendly than fossil oils, and thus are good alternatives to fossil oils for industrial applications. Erucic acid (C22:1Δ13) is a valuable feedstock in the chemical industry. The current plant sources for erucic acid production are high erucic acid rapeseed (HEAR) and mustard. However, these crops readily outcross with food quality rapeseed, causing food oil safety concerns. Crambe abyssinica (crambe) is a dedicated non-food industrial oil crop, accumulating 22:1 to up to 60% of its seed oil, mainly in triacylglycerol (TAG). Further increasing the 22:1 content in crambe oil would reduce its downstream processing costs for purification or, if levels above 90% can be achieved, enable its direct application in the chemical industry.

This thesis focused on producing ultra-high erucic acid in crambe through genetic engineering. By modifying three genes (BnFAE1, CaFAD2-RNAi and LdLPAAT) involved in the biosynthesis of 22:1, genetically modified (GM) crambe lines that accumulate up to 73% of erucic acid in seed oil were developed. For re-transformation of the best erucic line to further increase the 22:1 level, a hygromycin based selection marker system was established. To study the phosphatidylcholine (PC) involvement in the accumulation of 22:1 in crambe, candidate genes encoding three enzymes (LPCAT, PDCT and PDAT) were cloned from wild type (WT) crambe. Several RNAi expression vectors with these genes were transformed into WT crambe. Significant changes in fatty acid composition were observed in the transgenic lines but not an increase in 22:1 level. The functions of these three enzymes in the 22:1 accumulation were discussed. By in vitro and in vivo investigation of enzymatic activities in GM and WT crambe, a bottleneck to higher 22:1 accumulating at early stages of seed development in GM crambe was pointed out. Comparative transcriptomic analysis of GM and WT crambe was carried out to identify key genes and to further elucidate the molecular mechanisms involved in 22:1 biosynthesis and TAG accumulation.

Authors/Creators:Guan, Rui
Title:Metabolic engineering of Crambe abyssinica for producing high erucic acid oil
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :October 2014
Number of Pages:49
I.Li, X., van Loo, E.N., Gruber, J., Fan, J., Guan, R., Frentzen, M., Stymne, S. and Zhu, L.H. (2012). Development of ultra-high erucic acid oil in the industrial oil crop Crambe abyssinica. Plant Biotechnology Journal, 10(7), 862-870.
II.Li, X., Fan, J., Gruber, J., Guan, R., Frentzen, M. and Zhu, L.H. (2013). Efficient selection and evaluation of transgenic lines of Crambe abyssinica. Frontiers in Plant Science, 4:162. DOI: 10.3389/fpls.2013.00162
III.Guan, R., Li, X., Hofvander P., Zhou X.R., Wang, D.N., Stymne, S. and Zhu, L.H. RNAi targeting putative genes in phosphatidylcholine turnover results in significant change in fatty acid composition in Crambe abyssinica seed oil. Lipids (under revision).
IV.Guan, R., Lager, I., Li, X., Stymne, S. and Zhu, L.H. (2014). Bottlenecks in erucic acid accumulation in genetically engineered ultrahigh erucic acid Crambe abyssinica. Plant Biotechnology Journal, 12(2), 193-203.
V.Guan, R., Kushwaha S.K., Li, X., Almeida B., Hofvander P., Stymne, S. and Zhu, L.H. Comparative transcriptome analysis of Crambe abyssinica during the seed development focusing on lipid metabolism and erucic acid accumulation. (Manuscript).
Place of Publication:Alnarp
Publisher:Department of Plant Breeding, Swedish University of Agricultural Sciences
ISBN for printed version:978-91-576-8110-2
ISBN for electronic version:978-91-576-8111-9
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:F Plant production > F30 Plant genetics and breeding
Subjects:(A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Biochemistry and Molecular Biology
(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 404 Agricultural Biotechnology > Plant Biotechnology
Agrovoc terms:crambe abyssinica, erucic acid, genetic engineering, fatty acids, biosynthesis, lipids, biochemistry, triglycerides, lecithins, rna, gene expression
Keywords:Crambe abyssinica, erucic acid, genetic engineering, fatty acid biosynthesis, lipid biochemistry, triacylglycerol, phosphatidylcholine, RNAi, transcriptomics
Permanent URL:
ID Code:11611
Faculty:LTV - Fakulteten för landskapsarkitektur, trädgårds- och växtproduktionsvetenskap
Department:(LTJ, LTV) > Department of Plant Breeding (from 130101)
External funders:Kungliga Fysiografiska Sällskapet i Lund
Deposited By: Rui Guan
Deposited On:30 Oct 2014 14:32
Metadata Last Modified:02 Dec 2014 11:09

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