Fe3+胁迫对假微型海链藻中性脂累积及DGAT 表达的影响

二酰甘油酰基转移酶(DGAT)是脂类合成途径中的关键酶,其表达水平的高低影响着脂类含量的高低。微量元素Fe3+对于微藻的生长不可或缺,且影响着微藻中油脂的累积。本实验以假微型海链藻(Thalassiosira pseudonana)为研究对象,分析了铁限制(0.000 03mmol/L)和高铁胁迫(0.3 mmol/L)2种Fe3+胁迫条件下,不同种群生长期中性脂累积及二酰甘油酰基转移酶(DGAT)的基因表达受到的影响。结果显示:铁限制条件下,微藻种群生长及其中性脂的合成受到抑制,DGAT的表达量下降;高铁胁迫条件下,高浓度Fe3+可促进中性脂合成与DGAT的表达,但抑制微藻种群生长。因此,富铁条件下更利于总脂的收集。

Influence of iron stress on neural lipid accumulation and DGAT expression in Thalassiosira pseudonana

The iron is essential for the growth of microalgae and effects the accumulation of neural lipid in microalgae. Meanwhile, it is well known that during the lipid synthesis in microalgae, diacylgycerol acyltransferase (DGAT) is the crucial enzyme. Expression level of DGAT was related to the content of lipid to some extent. However, there is no report about this issue in Thalassiosira pseudonana so far. Herein, we tracked the accumulation of neutral lipid in T. pseudonana and detected the expression of DGAT under iron stress. The results showed that the growth, accumulation of neutral lipid and expression of DGAT were all restrained under iron-deficiency stress. Under iron-redundancy stress, the accumulation of neutral lipid was facilitated responding to the increasing expression of DGAT, but the growth of T. pseudonana was restricted.