Yang Tianquan, Wang Xiaojuan, Dong Tingnan, Xu Wei, Liu Aizhong
Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China.
Department of Resources and Environmental Engineering, Henan University of Engineering, Zhengzhou, Henan, China.
PeerJ. 2020 May 26;8:e9169. doi: 10.7717/peerj.9169. eCollection 2020.
The development of -3 fatty acid-rich vegetable oils is essential to enrich the production of functional foods. Sacha Inchi ( L.) is a unique oilseed crop with much potential. Its seeds contain rich polyunsaturated fatty acids (PUFAs), especially linoleic acid (LA, C18:2) and -linolenic acid (ALA, C18:3). Endoplasmic reticulum -located -6 and -3 fatty acid desaturases (FAD) are responsible for the biosynthesis of LA and ALA, respectively, in plant seeds. Here, we isolated two full-length genes from Sacha Inchi, named and , which encoded predicted amino acid residues of 384 and 379 in protein, respectively. Protein sequence and subcellular localization analysis revealed that they were located in the endoplasmic reticulum (ER). Heterologous expression in confirmed that PvFAD2 and PvFAD3 could catalyze LA and ALA synthesis, respectively. The stability and catalytic efficiency of the PvFAD3 protein may be closely related to temperature. In transgenic tobacco, using seed-specific expression promoters, PvFAD2 and PvFAD3 significantly promotes the production of LA (from 68% to 70.5%) and ALA (from 0.7% to 3.1%) in seed oil. These results show that PvFAD2 and PvFAD3 do, indeed, function as crucial enzymes for PUFAs biosynthesis, and provide a key gene source for the sustainable production of lipids with tailored fatty acid compositions via genetic engineering in other oil crops.
富含ω-3脂肪酸的植物油的开发对于丰富功能性食品的生产至关重要。美藤果（Plukenetia volubilis L.）是一种具有很大潜力的独特油料作物。其种子含有丰富的多不饱和脂肪酸（PUFAs），尤其是亚油酸（LA，C18:2）和α-亚麻酸（ALA，C18:3）。内质网定位的ω-6和ω-3脂肪酸去饱和酶（FAD）分别负责植物种子中LA和ALA的生物合成。在此，我们从美藤果中分离出两个全长基因，命名为PvFAD2和PvFAD3，它们分别编码预测的384和379个氨基酸残基的蛋白质。蛋白质序列和亚细胞定位分析表明它们位于内质网（ER）中。在酵母中的异源表达证实PvFAD2和PvFAD3分别可以催化LA和ALA的合成。PvFAD3蛋白的稳定性和催化效率可能与温度密切相关。在转基因烟草中，使用种子特异性表达启动子，PvFAD2和PvFAD3显著促进了种子油中LA（从68%提高到70.5%）和ALA（从0.7%提高到3.1%）的产生。这些结果表明PvFAD2和PvFAD3确实是PUFAs生物合成的关键酶，并为通过基因工程在其他油料作物中可持续生产具有定制脂肪酸组成的脂质提供了关键基因来源。
