title: Reduced Triacylglycerol Mobilization during Seed Germination and Early Seedling Growth in Arabidopsis Containing Nutritionally Important Polyunsaturated Fatty Acids.
abstract: There are now several examples of plant species engineered to synthesize and accumulate nutritionally important polyunsaturated fatty acids in their seed triacylglycerols (TAG). The utilization of TAG in germinating seeds of such transgenic plants was unknown. In this study, we examined the TAG utilization efficiency during seed germination in transgenic Arabidopsis seeds containing several examples of these fatty acids. Seed TAG species with native fatty acids had higher utilization rate than the TAG species containing transgenically produced polyunsaturated fatty acids. Conversely, quantification of the fatty acid components remaining in the total TAG after early stages of seed germination revealed that the undigested TAGs tended to contain elevated levels of the engineered polyunsaturated fatty acids (PUFA). LC-MS analysis further revealed asymmetrical mobilization rates for the individual TAG species. TAGs which contained multiple PUFA fatty acids were mobilized slower than the species containing single PUFA. The mobilized engineered fatty acids were used inde novomembrane lipid synthesis during seedling development.
authors.affiliation: CSIRO Agriculture and Food Canberra, ACT, Australia.
authors.forename: Pushkar
authors.initials: P
authors.lastname: Shrestha
authors.affiliation: Metabolomics Australia, School of Biosciences, University of MelbourneMelbourne, VIC, Australia; Centre for Chemistry and Biotechnology, School of Life and Environmental Science, Deakin UniversityMelbourne, VIC, Australia.
authors.forename: Damien L
authors.initials: DL
authors.lastname: Callahan
authors.affiliation: CSIRO Agriculture and Food Canberra, ACT, Australia.
authors.forename: Surinder P
authors.initials: SP
authors.lastname: Singh
authors.affiliation: CSIRO Agriculture and Food Canberra, ACT, Australia.
authors.forename: James R
authors.initials: JR
authors.lastname: Petrie
authors.affiliation: CSIRO Agriculture and Food Canberra, ACT, Australia.
authors.forename: Xue-Rong
authors.initials: XR
authors.lastname: Zhou
keywords: ARA; Arabidopsis; DHA; SDA; lipidomics; seed germination; triacylglycerol utilization; ω3 LC-PUFA