Chen Ru, Yamaoka Yasuyo, Feng Yanbin, Chi Zhanyou, Xue Song, Kong Fantao
School of Bioengineering, Dalian University of Technology, Dalian 116024, China.
Division of Biotechnology, Catholic University of Korea, Bucheon 420-743, Republic of Korea.
Metabolites. 2023 Jan 10;13(1):115. doi: 10.3390/metabo13010115.
Lipid transporters synergistically contribute to oil accumulation under normal conditions in microalgae; however, their effects on lipid metabolism under stress conditions are unknown. Here, we examined the effect of the co-expression of lipid transporters, fatty acid transporters, (FAX1 and FAX2) and ABC transporter (ABCA2) on lipid metabolism and physiological changes in the green microalga under nitrogen (N) starvation. The results showed that the TAG content in over-expressor (OE) was 2.4-fold greater than in the parental line. Notably, in , the major membrane lipids and the starch and cellular biomass content also significantly increased compared with the control lines. Moreover, the expression levels of genes directly involved in TAG, fatty acid, and starch biosynthesis were upregulated. showed altered photosynthesis activity and increased ROS levels during nitrogen (N) deprivation. Our results indicated that overexpression not only enhanced cellular lipids but also improved starch and biomass contents under N starvation through modulation of lipid and starch metabolism and changes in photosynthesis activity. The strategy developed here could also be applied to other microalgae to produce FA-derived energy-rich and value-added compounds.
脂质转运蛋白在正常条件下协同促进微藻中的油脂积累；然而，它们在胁迫条件下对脂质代谢的影响尚不清楚。在此，我们研究了脂质转运蛋白、脂肪酸转运蛋白（FAX1和FAX2）和ABC转运蛋白（ABCA2）共表达对绿色微藻在氮（N）饥饿条件下脂质代谢和生理变化的影响。结果表明，过表达株系（OE）中的三酰甘油（TAG）含量比亲本株系高2.4倍。值得注意的是，与对照株系相比，[具体微藻名称]中的主要膜脂以及淀粉和细胞生物量含量也显著增加。此外，直接参与TAG、脂肪酸和淀粉生物合成的基因表达水平上调。[具体微藻名称]在氮（N）缺乏期间显示出光合作用活性改变和活性氧水平增加。我们的结果表明，[具体微藻名称]过表达不仅通过调节脂质和淀粉代谢以及光合作用活性的变化增强了细胞脂质，而且还提高了氮饥饿条件下的淀粉和生物量含量。这里开发的策略也可以应用于其他微藻，以生产源自脂肪酸的富含能量和高附加值的化合物。
