单细胞淡水绿藻-雨生红球藻能够在一定条件积累一种次生类胡萝卜素-虾青素,因而在生长后期藻体变为深红色。其中,IPP异构酶在雨生红球藻中的虾青素合成过程中发挥了重要作用。在本研究中,我们首次通过基因组上游步移克隆到了雨生红球藻中IPP异构酶基因的两个不同5’上游侧翼序列,大小分别是1.8kb和2.5kb。利用生物信息学方法分别对这两个不同5’上游侧翼序列进行了序列分析,结果发现,二者具有某些相同的顺式作用元件,如可能的脱落酸反应元件(ABRE)、干燥或低温反应元件(DRE/C-repeat)、几种光反应元件(G-box,GAG-motif,I-boxand ATC-motif)、热激反应元件(HSE)、机械伤害反应元件(WUN-motif)、水杨酸反应元件(TCA-element)、生长素反应元件(TGA-element)、茉莉酸甲酯反应元件(TGACG-element)、缺氧特异反应中的增强子类似元件(GC-motif)和反式作用因子MYB蛋白的结合位点(MBS and MRE),但是二者并不具有典型的TATA框和CCAAT框。上述研究预示了雨生红球藻虾青素合成中IPP异构酶基因转录调控方式的多样化。
The unicellular green alga Haematococcus pluvia/is uniquely accumulates carotenoids in the cytoplasm and in late developmental stages turns deep-red in color because of accumulation of astaxanthin in the cytosol. The enzyme, isopentenyl pyrophosphate (IPP) isomerase, plays a key role in astaxanthin biosynthesis of H. pluvialis. In this paper, two separate 5'-flanking regions (1.8 kb and 2.5 kb) of IPP isomerase gene was cloned through walking upstream firstly. Results of sequence analysis =showed that two separate 5'-flanking regions of IPP isomerase gene might have similar putative cis-acting elements such as ABA (abscisic acid)-responsive element (ABRE), drought-responsive element (DRE/C-repeat), light-responsive element (G-box, GAG-motif, I-box and ATC-motif), heat-shock element (HSE), wound-responsive element (WUN-motif), SA (salicylic acid)-responsive element (TCA-element), auxin-responsive element (TGA-element), MeJA (methyl jasmonate)-responsive element (TGACG-element), enhancer-like element involved in anoxic specific inducibility (GC-motif) and MYB binding sites (MBS and MRE), except for typical TATA box or CCAAT box, which exhibit diversiform transcriptional patterns of IPP isomerase gene in astaxanthin biosynthesis of Haematococcus pluvialis.