Shrestha Pushkar, Callahan Damien L, Singh Surinder P, Petrie James R, Zhou Xue-Rong
CSIRO Agriculture and Food Canberra, ACT, Australia.
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.
Front Plant Sci. 2016 Sep 26;7:1402. doi: 10.3389/fpls.2016.01402. eCollection 2016.
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 in membrane lipid synthesis during seedling development.
现在有几个植物物种的例子，它们经过基因工程改造，能在种子三酰甘油（TAG）中合成并积累具有重要营养意义的多不饱和脂肪酸。此前尚不清楚此类转基因植物种子萌发过程中TAG的利用情况。在本研究中，我们检测了含有这些脂肪酸实例的转基因拟南芥种子在萌发过程中TAG的利用效率。含有天然脂肪酸的种子TAG种类比含有转基因生产的多不饱和脂肪酸的TAG种类具有更高的利用率。相反，对种子萌发早期后总TAG中剩余脂肪酸成分的定量分析表明，未消化的TAG往往含有较高水平的工程多不饱和脂肪酸（PUFA）。液相色谱-质谱分析进一步揭示了各个TAG种类的不对称动员率。含有多种PUFA脂肪酸的TAG比含有单一PUFA的TAG动员得更慢。动员的工程脂肪酸在幼苗发育过程中用于膜脂合成。
