School of Agriculture and Food Sciences, The University of Queensland, Brisbane 4072, Australia.
School of Agriculture and Food Sciences, The University of Queensland, Brisbane 4072, Australia; School of Plant Biology, The University of Western Australia, Perth 6009, Australia.
Bioresour Technol. 2017 Nov;244(Pt 2):1281-1293. doi: 10.1016/j.biortech.2017.06.003. Epub 2017 Jun 6.
To map out key lipid-related pathways that lead to rapid triacylglyceride accumulation in oleaginous microalgae, RNA-Seq was performed with Tetraselmis sp. M8 at 24h after exhaustion of exogenous nitrogen to reveal molecular changes during early stationary phase. Further gene expression profiling by quantitative real-time PCR at 16-72h revealed a distinct shift in expression of the fatty acid/triacylglyceride biosynthesis and β-oxidation pathways, when cells transitioned from log-phase into early-stationary and stationary phase. Metabolic reconstruction modeling combined with real-time PCR and RNA-Seq gene expression data indicates that the increased lipid accumulation is a result of a decrease in lipid catabolism during the early-stationary phase combined with increased metabolic fluxes in lipid biosynthesis during the stationary phase. During these two stages, Tetraselmis shifts from reduced lipid consumption to active lipid production. This process appears to be independent from DGAT expression, a key gene for lipid accumulation in microalgae.
为了绘制导致产油微藻中三酰基甘油迅速积累的关键脂质相关途径，在耗尽外源氮 24 小时后，对三角褐指藻 M8 进行了 RNA-Seq，以揭示早期静止期的分子变化。在 16-72 小时通过定量实时 PCR 进行进一步的基因表达谱分析显示，当细胞从对数期进入早期静止期和静止期时，脂肪酸/三酰基甘油生物合成和β-氧化途径的表达发生明显变化。代谢重建模型结合实时 PCR 和 RNA-Seq 基因表达数据表明，脂质积累的增加是由于早期静止期脂质分解代谢减少，同时静止期脂质生物合成的代谢通量增加所致。在这两个阶段，三角褐指藻从减少脂质消耗转变为积极的脂质生产。这个过程似乎与 DGAT 表达无关，DGAT 是微藻中脂质积累的关键基因。
