用脱落酸(ABA)和氮饥饿加高光诱导雨生红球藻,研究在胁迫条件下虾青素在细胞内积累的变化以及虾青素合成基因的表达模式。结果表明,在诱导条件下雨生红球藻细胞内虾青素积累明显。半定量RT-PCR结果表明,在虾青素合成酶系基因中八氢番茄红素合成酶基因(psy)、八氢番茄红素脱氢酶基因(pds)在诱导一段时间内mRNA水平一直在升高,在诱导后期mRNA依然具较高水平,胡萝卜素羟化酶基因(crtR-B)、胡萝卜素酮化酶基因(bkt)在诱导一段一段时间后mRNA水平升高后又略有下降,而番茄红素环化酶基因(lcy)则不受这些诱导条件的调控,一直处于较高水平的表达。虾青素合成基因表达模式的差异表明这些基因分子调控机制的差异。
Abscisic acid (ABA) and N starvation plus high light were used to induce Haematococcus pluvialis for harvesting this compound. Results revealed Haematococcus pluvlialis accumulated astaxanthin under these conditions. Semiquantitive PCR was used to evaluate expressions of the genes involved in the biosynthetic pathway of astax- anthin when astaxanthin accumulating. The result of semi-quantitive RT-PCR revealed that during the stress induction, the expressions of both phytoene synthase gene (psy) and phytoene desaturase gene (pds) gradually increased and mRNA of pds and psy maintained at a high level even at late stage, but the expressions of β-carotene hydroase (crtR-B) and beta-carotene ketolase gene (bkt) increased significantly after a short period and then decreased somewhat in the end of the experiment. However, lycopene cyclase gene (lcy) maintained a steady high level under these stress conditions. The results implied the difference of molecular regulatory mechanisms among genes involved in the biosynthesis of astaxanthin made them have different expression models under the same stress condition.