School of Life Science, Shanxi University, Taiyuan 030006, China.
Int J Mol Sci. 2021 Jan 28;22(3):1304. doi: 10.3390/ijms22031304.
The oleaginous microalgae species GD is a promising feedstock for biodiesel production from soil. However, its metabolic mechanism of lipid production remains unclear. In this study, the lipid accumulation and metabolism mechanisms of GD were analyzed under salt stress based on transcriptome sequencing. The biomass and lipid content of the alga strain were determined under different NaCl concentrations, and total RNA from fresh cells were isolated and sequenced by HiSeq 2000 high throughput sequencing technology. As the salt concentration increased in culture medium, the algal lipid content increased but the biomass decreased. Following transcriptome sequencing by assembly and splicing, 24,128 unigenes were annotated, with read lengths mostly distributed in the 200-300 bp interval. Statistically significant differentially expressed unigenes were observed in different experimental groups, with 2051 up-regulated genes and 1835 down-regulated genes. The lipid metabolism pathway analysis showed that, under salt stress, gene-related fatty acid biosynthesis (ACCase, KASII, KAR, HAD, FATA) was significantly up-regulated, but some gene-related fatty acid degradation was significantly down-regulated. The comprehensive results showed that salt concentration can affect the lipid accumulation and metabolism of GD, and the lipid accumulation is closely related to the fatty acid synthesis pathway.
产油微藻 GD 是一种很有前途的生物柴油生产原料，可以从土壤中获得。然而，其产油的代谢机制尚不清楚。本研究基于转录组测序，分析了盐胁迫下 GD 的油脂积累和代谢机制。在不同 NaCl 浓度下测定藻株的生物量和油脂含量，采用 HiSeq 2000 高通量测序技术从新鲜细胞中提取总 RNA 并进行测序。随着培养基中盐浓度的增加，藻类的油脂含量增加，但生物量减少。通过组装和剪接进行转录组测序后，共注释了 24128 个 unigenes，读长主要分布在 200-300bp 区间。在不同实验组中观察到统计上显著差异表达的 unigenes，其中 2051 个上调基因和 1835 个下调基因。脂质代谢途径分析表明，在盐胁迫下，与脂肪酸生物合成（ACCase、KASII、KAR、HAD、FATA）相关的基因显著上调，但与脂肪酸降解相关的一些基因显著下调。综合结果表明，盐浓度可以影响 GD 的油脂积累和代谢，油脂积累与脂肪酸合成途径密切相关。
