School of Life Sciences, Shandong University of Technology, Zibo, China, 255049.
Biol Res. 2013;46(2):201-6. doi: 10.4067/S0716-97602013000200012.
The fresh-water green unicellular alga Haematococcus pluvialis is known to accumulate astaxanthin under stress conditions. In the present study, transcriptional expression of eight genes involved in astaxanthin biosynthesis exposed to EBR (25 and 50 mg/L) was analyzed using qRT-PCR. The results demonstrated that both 25 and 50 mg/L EBR could increase astaxanthin productivity and the eight carotenogenic genes were up-regulated by EBR with different expression profiles. Moreover, EBR25 induction had a greater influence on the transcriptional expression of ipi-1, ipi-2, crtR-B, lyc and crtO (> 5- fold up-regulation) than on psy, pds, bkt; EBR50 treatment had a greater effect on the transcriptional expression of ipi-2, pds, lyc, crtR-B, bkt and crtO than on ipi-1 and psy. Furthermore, astaxanthin biosynthesis under EBR was up-regulated mainly by ipi1־ and psy at the post-transcriptional level, pds, lyc, crtR-B, bkt and crtO at the transcriptional level and ipi-2 at both levels.
淡水绿藻雨生红球藻在应激条件下积累虾青素。本研究采用 qRT-PCR 分析了暴露于 EBR（25 和 50mg/L）时参与虾青素生物合成的 8 个基因的转录表达。结果表明，25 和 50mg/L EBR 均可提高虾青素产量，8 个类胡萝卜素生物合成基因受 EBR 诱导，表达谱不同。此外，EBR25 诱导对 ipi-1、ipi-2、crtR-B、lyc 和 crtO 的转录表达影响更大（上调超过 5 倍），而对 psy、pds、bkt 的影响较小；EBR50 处理对 ipi-2、pds、lyc、crtR-B、bkt 和 crtO 的转录表达影响更大，而对 ipi-1 和 psy 的影响较小。此外，EBR 下的虾青素生物合成主要通过转录后水平的 ipi1 和 psy、转录水平的 pds、lyc、crtR-B、bkt 和 crtO 以及两个水平的 ipi-2 上调。
