Journal article
Tri-Hydroxy-Triacylglycerol Is Efficiently Produced by Position-Specific Castor Acyltransferases
Plant physiology (Bethesda), Vol.179(3), pp.1050-1063
03/2019
Handle:
https://hdl.handle.net/2376/108745
PMID: 30610110
Abstract
Understanding the biochemistry of triacylglycerol (TAG) assembly is critical in tailoring seed oils to produce high-value products. Hydroxy-fatty acid (HFA) is one such valuable modified fatty acid, which can be produced at low levels in Arabidopsis (
) seed through transgenic expression of the castor (
) hydroxylase. The resulting plants have low seed oil content and poor seedling establishment, indicating that Arabidopsis lacks efficient metabolic networks for biosynthesis and catabolism of hydroxy-containing TAG. To improve utilization of such substrates, we expressed three castor acyltransferase enzymes that incorporate HFA at each stereochemical position during TAG synthesis. This produced abundant tri-HFA TAG and concentrated 44% of seed HFA moieties into this one TAG species. Ricinoleic acid was more abundant than any other fatty acid in these seeds, which had 3-fold more HFA by weight than that in seeds following simple hydroxylase expression, the highest yet measured in a nonnative plant. Efficient utilization of hydroxy-containing lipid substrates increased the rate of TAG synthesis 2-fold, leading to complete relief of the low-oil phenotype. Partition of HFA into specific TAG molecules increased the storage lipid available for mobilization during seedling development, resulting in a 1.9-fold increase in seedling establishment. Expression of a complete acyltransferase pathway to efficiently process HFA establishes a benchmark in the quest to successfully produce modified oils in plants.
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Details
- Title
- Tri-Hydroxy-Triacylglycerol Is Efficiently Produced by Position-Specific Castor Acyltransferases
- Creators
- Daniel Lunn - Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340James G Wallis - Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340John Browse - Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340 jab@wsu.edu
- Publication Details
- Plant physiology (Bethesda), Vol.179(3), pp.1050-1063
- Academic Unit
- Biological Chemistry, Institute of
- Publisher
- United States
- Identifiers
- 99900547484201842
- Language
- English
- Resource Type
- Journal article