Vollheyde Katharina, Hornung Ellen, Herrfurth Cornelia, Ischebeck Till, Feussner Ivo
Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Justus-von-Liebig-Weg 11, 37077, Goettingen, Germany.
Service Unit for Metabolomics and Lipidomics, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, 37077, Goettingen, Germany.
Biotechnol Biofuels. 2021 Dec 15;14(1):238. doi: 10.1186/s13068-021-02062-1.
Wax esters (WE) are neutral lipids that consist of a fatty alcohol esterified to a fatty acid. WE are valuable feedstocks in industry for producing lubricants, coatings, and cosmetics. They can be produced chemically from fossil fuel or plant-derived triacylglycerol. As fossil fuel resources are finite, the synthesis of WE in transgenic plants may serve as an alternative source. As chain length and desaturation of the alcohol and acyl moieties determine the physicochemical properties of WE and their field of application, tightly controlled and tailor-made WE synthesis in plants would be a sustainable, beneficial, and valuable commodity. Here, we report the expression of ten combinations of WE producing transgenes in Arabidopsis thaliana. In order to study their suitability for WE production in planta, we analyzed WE amount and composition in the transgenic plants.
The transgenes consisted of different combinations of a FATTY ACYL-COA/ACP REDUCTASE (FAR) and two WAX SYNTHASES/ACYL-COA:DIACYLGLYCEROL O-ACYLTRANSFERASES (WSD), namely WSD2 and WSD5 from the bacterium Marinobacter aquaeoleoi. We generated constructs with and without plastidial transit peptides to access distinct alcohol and acyl substrate pools within A. thaliana cells. We observed WE formation with plastid and cytosol-localized FAR and WSD in seeds. A comparative WE analysis revealed the production of shorter and more saturated WE by plastid-localized WE biosynthesis compared to cytosolic WE synthesis.
A shift of WE formation into seed plastids is a suitable approach for tailor-made WE production and can be used to synthesize WE that are mainly derived from mid- and long-chain saturated and monounsaturated substrates.
蜡酯（WE）是由脂肪酸酯化的脂肪醇组成的中性脂质。蜡酯是工业上生产润滑剂、涂料和化妆品的宝贵原料。它们可以由化石燃料或植物衍生的三酰甘油化学合成。由于化石燃料资源有限，在转基因植物中合成蜡酯可能成为一种替代来源。由于醇和酰基部分的链长和去饱和度决定了蜡酯的物理化学性质及其应用领域，在植物中严格控制并定制蜡酯合成将是一种可持续、有益且有价值的商品。在此，我们报道了在拟南芥中表达十种产生蜡酯的转基因组合。为了研究它们在植物中生产蜡酯的适用性，我们分析了转基因植物中蜡酯的含量和组成。
转基因由脂肪酰辅酶A/酰基载体蛋白还原酶（FAR）以及两种蜡合成酶/酰基辅酶A：二酰甘油O-酰基转移酶（WSD）（即来自水生海洋杆菌的WSD2和WSD5）的不同组合组成。我们构建了带有和不带有质体转运肽的构建体，以利用拟南芥细胞内不同的醇和酰基底物库。我们观察到在种子中，质体和细胞质定位的FAR和WSD会形成蜡酯。蜡酯的比较分析表明，与细胞质蜡酯合成相比，质体定位的蜡酯生物合成产生的蜡酯更短且饱和度更高。
将蜡酯形成转移到种子质体中是定制蜡酯生产的合适方法，可用于合成主要源自中链和长链饱和及单不饱和底物的蜡酯。
