中文摘要：

丝氨酸棕榈酰转移酶（Serine Palmitoyltransferase, SPT）是鞘脂合成途径中的关键酶,其表达水平的高低影响生物体内鞘脂的含量。该实验利用荧光定量 PCR 和液相色谱―质谱技术分析了营养盐对假微型海链藻中SPT表达及鞘脂合成的影响。结果表明： SPT在微藻细胞中的表达水平直接影响其鞘脂的合成,且P饥饿促进SPT的表达和细胞内神经酰胺的合成,进而影响假微型海链藻的生长；而N饥饿抑制SPT的表达和细胞内神经酰胺的合成及假微型海链藻的生长。

英文摘要：

Serine palmitoyltransferase （SPT） is the key enzyme in the de novo synthesis of sphingolipid, and its expression level can affect the content of sphingolipid in cells. In this experiment, the effect of nutrient on the expression of SPT and the synthesis of sphingolipid inThalassiosira pseudonana is investigated using real-time PCR and ultra performance liquid chromatography mass spectrometry. Results indicate that the expression level of SPT affects sphingolipid content in microalgae cells. Moreover, phosphorus starvation makes both the expression level of SPT and the synthesis of ceramides in cell increase, which affects the growth ofT. pseudonana. In contrast, the nitrogen deprivation inhibites both the expression of SPT and the synthesis of ceramides in cell, and significantly restrains the growth ofT. pseudonana. The results are expected to provide theory foundation for some studies of the growth, decay and metabolism ofT. pseudonana.